@article{li_yuan_wang_tan_zhang_rouskas_2024, title={Fast and scalable all-optical network architecture for distributed deep learning}, volume={16}, ISSN={["1943-0639"]}, url={https://doi.org/10.1364/JOCN.511696}, DOI={10.1364/JOCN.511696}, abstractNote={With the ever-increasing size of training models and datasets, network communication has emerged as a major bottleneck in distributed deep learning training. To address this challenge, we propose an optical distributed deep learning (ODDL) architecture. ODDL utilizes a fast yet scalable all-optical network architecture to accelerate distributed training. One of the key features of the architecture is its flow-based transmit scheduling with fast reconfiguration. This allows ODDL to allocate dedicated optical paths for each traffic stream dynamically, resulting in low network latency and high network utilization. Additionally, ODDL provides physically isolated and tailored network resources for training tasks by reconfiguring the optical switch using LCoS-WSS technology. The ODDL topology also uses tunable transceivers to adapt to time-varying traffic patterns. To achieve accurate and fine-grained scheduling of optical circuits, we propose an efficient distributed control scheme that incurs minimal delay overhead. Our evaluation on real-world traces showcases ODDL’s remarkable performance. When implemented with 1024 nodes and 100 Gbps bandwidth, ODDL accelerates VGG19 training by 1.6× and 1.7× compared to conventional fat-tree electrical networks and photonic SiP-Ring architectures, respectively. We further build a four-node testbed, and our experiments show that ODDL can achieve comparable training time compared to that of an ideal electrical switching network.}, number={3}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Li, Wenzhe and Yuan, Guojun and Wang, Zhan and Tan, Guangming and Zhang, Peiheng and Rouskas, George N.}, year={2024}, month={Mar}, pages={342–357} }
 @article{rouskas_2023, title={A symmetry-free spectrum allocation heuristic for elastic optical networks}, volume={49}, ISSN={["1872-9770"]}, url={https://doi.org/10.1016/j.osn.2023.100742}, DOI={10.1016/j.osn.2023.100742}, abstractNote={We revisit spectrum allocation (SA), a fundamental problem in optical network design, and we explain that it can be modeled as a permutation problem. This new model eliminates spectrum symmetry, a property that presents a significant challenge to conventional spectrum allocation solutions. Accordingly, we develop parameterized first-fit (PFF), a new symmetry-free heuristic for the SA problem that has several desirable features: it explores a pre-defined subset of the solution space whose size is tailored to the available computational budget; it constructs this subset by sampling from diverse areas of the solution space rather than from the neighborhood of an initial solution; it finds solutions by applying the well-known first-fit (FF) algorithm and thus it can be deployed readily; its execution can be easily parallelized; and it is effective and efficient in finding good quality solutions.}, journal={OPTICAL SWITCHING AND NETWORKING}, author={Rouskas, George N.}, year={2023}, month={May} }
 @article{rouskas_gupta_sharma_2023, title={Symmetry-Free Algorithm for Spectrum Allocation: Parallel Implementations and Evaluation [Invited]}, volume={15}, ISSN={1943-0620 1943-0639}, url={http://dx.doi.org/10.1364/jocn.487181}, DOI={10.1364/jocn.487181}, abstractNote={Our symmetry-free model for spectrum allocation (SA) in networks of
					general topology leverages two properties: (1) SA is equivalent
					to a connection permutation problem, and (2) in assigning
					spectrum, it is sufficient to consider the allocation made by the
					first-fit (FF) algorithm. This model opens up algorithmic approaches
					that altogether sidestep spectrum symmetry, i.e., eliminate
					from consideration the exponential number of equivalent solutions
					resulting from spectrum slot permutations. Recursive FF (RFF) is such
					an algorithm; it applies FF recursively to search the connection
					permutation space and solve the SA problem optimally. Moreover,
					parallelism is inherent in the spectrum symmetry-free model, as the
					connection permutation space may be naturally decomposed into
					non-overlapping subsets that can be searched independently.
					Accordingly, RFF admits multi-threaded implementations that may be
					tailored to the computing environment at hand. In this work, we
					present two strategies for parallelizing the execution of RFF, and we
					evaluate them experimentally using a comprehensive set of metrics. Our
					experiments indicate that RFF explores a vast number of symmetry-free
					solutions, and for moderate-sized networks, it takes mere seconds to
					yield solutions that are either optimal or very close to the lower
					bound.}, number={10}, journal={Journal of Optical Communications and Networking}, publisher={Optica Publishing Group}, author={Rouskas, George and Gupta, Shubham and Sharma, Priya}, year={2023}, month={Jun}, pages={E40–E50} }
 @article{rouskas_bandikatla_2022, title={Recursive first fit: a highly parallel optimal solution to spectrum allocation}, volume={14}, ISSN={["1943-0639"]}, url={https://doi.org/10.1364/JOCN.445492}, DOI={10.1364/JOCN.445492}, abstractNote={We revisit the classical spectrum allocation (SA) problem, a fundamental subproblem in optical network design, and make three contributions. First, we show how some SA problem instances may be decomposed into smaller instances that may be solved independently without loss of optimality. Second, we prove an optimality property of the well-known first-fit (FF) heuristic. Finally, we leverage this property to develop a recursive and parallel algorithm that applies the FF heuristic to find an optimal solution efficiently. This recursive FF algorithm is highly scalable because of two unique properties: (1) it completely sidesteps the symmetry inherent in SA and hence drastically reduces the solution space compared to typical integer linear programming formulations, and (2) the solution space can be naturally decomposed in non-overlapping subtrees that may be explored in parallel almost independently of each other, resulting in faster than linear speedup.}, number={3}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Rouskas, George N. and Bandikatla, Chaitanya}, year={2022}, month={Mar}, pages={165–176} }
 @article{tang_shen_rouskas_2021, title={Crosstalk-Aware Shared Backup Path Protection in Multi-Core Fiber Elastic Optical Networks}, volume={39}, ISSN={["1558-2213"]}, url={https://doi.org/10.1109/JLT.2021.3064935}, DOI={10.1109/JLT.2021.3064935}, abstractNote={Elastic optical networks employing multi-core fibers (MCF-EON) have the potential to expand significantly the transmission capacity of optical transport. However, wide deployment of such networks depends on addressing effectively two critical challenges: inter-core crosstalk, which may cause serious signal performance degradation in an MCF link, and survivability against network failures that may cause enormous data loss. In this article, we consider the design of MCF-EONs with shared-backup path protection (SBPP), one of the most efficient techniques for protecting network traffic. Specifically, we tackle the crosstalk-aware routing, core, and spectrum assignment (CA-RCSA) problem with the objective of jointly minimizing the network spectrum resources used and the total inter-core crosstalk. We formulate the problem as an integer linear programming (ILP) model subject to strict inter-core crosstalk limits for each provisioned lightpath, and we also propose an auxiliary graph (AG) based heuristic algorithm for lightpath provisioning. Simulation studies show that our algorithm is effective in terms of the objectives, and it is efficient to perform close to the ILP model in small networks, for which solving the ILP is feasible.}, number={10}, journal={JOURNAL OF LIGHTWAVE TECHNOLOGY}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Tang, Fengxian and Shen, Gangxiang and Rouskas, George N.}, year={2021}, month={May}, pages={3025–3036} }
 @article{rouskas_bandikatla_2021, title={Parameterized Exhaustive Routing with First Fit for RSA Problem Variants}, ISSN={["2576-6813"]}, DOI={10.1109/GLOBECOM46510.2021.9685126}, abstractNote={We present a new single-step solution approach for the routing and spectrum allocation (RSA) problem that integrates the first-fit (FF) heuristic with a new routing strategy that we refer to as “parameterized exhaustive routing.” Our approach is to explore the whole routing space for a subset of the traffic requests, e.g., those with the largest demands or those of higher priority or importance. For each of the remaining requests we employ a greedy heuristic to select one of the candidate paths jointly with spectrum allocation. Our solution represents a two-parameter family of algorithms that bridges the gap between an exhaustive search of the routing space and current two-step methodologies for the RSA problem that select paths for each traffic request in isolation. The parameter values may be used to trade off the quality of the final solution and the computational requirements. Our results indicate that exploring the joint routing space of even a few large requests leads to better solutions than purely greedy approaches.}, journal={2021 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM)}, author={Rouskas, George N. and Bandikatla, Chaitanya}, year={2021} }
 @article{fayez_katib_rouskas_gharib_ahmed_faheem_2020, title={A Scalable Solution to Network Design Problems: Decomposition with Exhaustive Routing Search}, ISSN={["2576-6813"]}, DOI={10.1109/GLOBECOM42002.2020.9322439}, abstractNote={Many network design problems encompass two tasks, routing and resource allocation, that are so intricately intertwined as to contribute significantly to the intractability of such problems. In this paper, we make two contributions to addressing general network design problems of this nature. First, we present a new decomposition method that optimally decouples resource allocation from routing, making it possible to tackle each of these aspects separately. Second, we develop a recursive branch-and-bound algorithm to search the routing space exhaustively, yet in a scalable manner. We apply our method to a well-known intractable problem in optical networks, routing and spectrum assignment (RSA). Our results indicate that the recursive algorithm is able to search efficiently the entire routing space of topologies representative of large-scale wide area networks.}, journal={2020 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM)}, author={Fayez, Mahmoud and Katib, Iyad and Rouskas, George N. and Gharib, Tarek F. and Ahmed, H. K. and Faheem, H. M.}, year={2020} }
 @article{gao_rouskas_2020, title={Congestion Minimization for Service Chain Routing Problems With Path Length Considerations}, volume={28}, ISSN={["1558-2566"]}, url={https://doi.org/10.1109/TNET.2020.3017792}, DOI={10.1109/TNET.2020.3017792}, abstractNote={Network function virtualization (NFV), with its perceived potential to accelerate service deployment and to introduce flexibility in service provisioning, has drawn a growing interest from industry and academia alike over the past few years. One of the key challenges in realizing NFV is the service chain routing problem, whereby traffic must be routed so as to traverse the various components of a network service that have been mapped onto the underlying network. In this work, we consider the online service chain routing problem. We route the service chain with the goal of jointly minimizing the maximum network congestion and the number of hops from the source to the destination. To this end, we present a simple yet effective online algorithm in which the routing decision is irrevocably made without prior knowledge of future requests. We prove that our algorithm is <inline-formula> <tex-math notation="LaTeX">$O(\log m)$ </tex-math></inline-formula>-competitive in terms of congestion minimization, where <inline-formula> <tex-math notation="LaTeX">$m$ </tex-math></inline-formula> is the number of edges of the underlying network topology, and we show that this ratio is asymptotically optimal.}, number={6}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Gao, Lingnan and Rouskas, George N.}, year={2020}, month={Dec}, pages={2643–2656} }
 @article{tang_li_shen_rouskas_2020, title={Minimizing Inter-Core Crosstalk Jointly in Spatial, Frequency, and Time Domains for Scheduled Lightpath Demands in Multi-Core Fiber-based Elastic Optical Network}, volume={38}, ISSN={["1558-2213"]}, url={https://doi.org/10.1109/JLT.2020.3004138}, DOI={10.1109/JLT.2020.3004138}, abstractNote={Elastic optical networks (EON) technology in combination with space division multiplexing (SDM) is considered as having the potential to expand the transmission capacity of optical transport networks. However, inter-core crosstalk may cause serious signal impairment in a multi-core fiber (MCF) links. At the same time, scheduled lightpath demands, for which the expected setup and teardown times are known in advance, are considered as an important type of traffic demand for future networks. In this article, we develop approaches to schedule simultaneous lightpaths onto non-adjacent MCF cores so as to reduce inter-core crosstalk between these lightpaths. To this end, we first define a new metric to estimate the inter-core crosstalk jointly considering the spatial, frequency, and time domains. We then tackle the routing, spectrum, core, and time assignment (RSCTA) problem for the MCF-based EON by developing an integer linear programming (ILP) model, as well as an auxiliary graph (AG) based heuristic algorithm, which jointly optimize spectrum resource utilization and reduce the lightpath inter-core crosstalk. Simulation studies show the effectiveness of the proposed approach in terms of both performance aspects. In addition, the performance of the proposed heuristic algorithm is shown to be close to that of the ILP model in small networks.}, number={20}, journal={JOURNAL OF LIGHTWAVE TECHNOLOGY}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Tang, Fengxian and Li, Yongcheng and Shen, Gangxiang and Rouskas, George N.}, year={2020}, month={Oct}, pages={5595–5607} }
 @article{fayez_katib_rouskas_gharib_khaleed_faheem_2020, title={Recursive algorithm for selecting optimum routing tables to solve offline routing and spectrum assignment problem}, volume={11}, ISSN={["2090-4495"]}, DOI={10.1016/j.asej.2019.10.008}, abstractNote={The Routing and Spectrum Assignment (RSA) problem is NP-Hard so searching the entire problem space is not applicable. Many decomposition algorithms rely on reducing the search space in the routing space and applying heuristics algorithm in the spectrum assignment sub-problem. This is not necessarily a right solution as the ignored routing tables may lead to a better solution when they are used later as input to the Spectrum Assignment sub-problem. In this paper, we develop a new recursive decomposition approach for the RSA problem in optical networks. At the core of our approach is a new recursive branch and-bound procedure for carrying out an exhaustive search of the routing space in a scalable manner. This recursion effectively decouples the routing from the spectrum assignment part of the problem. Sequential generation of the full set of routing tables requires huge memory and very large processing time. Alternatively, our approach deploys multi-core architectures to generate the routing tables in parallel using OpenMP. Experimental results indicate that our recursive algorithm is quite efficient in searching the entire routing space for topologies representing large-scale wide area networks. Importantly, the decomposition may be more generally applied to any network design problem whose solution involves a search over both a routing and a resource allocation space. The main contributions for this paper are that we are able to generate all the search space in parallel in less than 1 min for 32-nodes network. Secondly, we are able to investigate all the routing tables, eliminate most of the search space, and select the promising routing tables that are proven to lead to a better solution in the Spectrum Assignment Sub-Problem}, number={2}, journal={AIN SHAMS ENGINEERING JOURNAL}, author={Fayez, Mahmoud and Katib, Iyad and Rouskas, George N. and Gharib, Tarek F. and Khaleed, Heba and Faheem, Hossam M.}, year={2020}, month={Jun}, pages={273–280} }
 @inbook{simmons_rouskas_2020, title={Routing and Wavelength (Spectrum) Assignment}, ISBN={9783030162498 9783030162504}, ISSN={2522-8692 2522-8706}, url={http://dx.doi.org/10.1007/978-3-030-16250-4_12}, DOI={10.1007/978-3-030-16250-4_12}, abstractNote={ZusammenfassungRouting a connection from its source to its destination is a fundamental component of network design. The choice of route affects numerous properties of a connection, most notably cost, latency, and availability, as well as the resulting level of congestion in the network. This chapter addresses various algorithms, strategies, and tradeoffs related to routing.At the physical optical layer, connections are assigned a unique wavelength on a particular optical fiber, a process known as wavelength assignment (). Together with routing, the combination of these two processes is commonly referred to as . In networks based on all-optical technology, WA can be challenging. It becomes more so when the physical properties of the optical signal need to be considered. This chapter covers several WA algorithms and strategies that have produced efficient designs in practical networks.A recent development in the evolution of optical networks is flexible networking, where the amount of spectrum allocated to a connection can be variable. Spectrum assignment is analogous to, though more complex than, wavelength assignment; various heuristics have been proposed as covered in this chapter. Flexible (or elastic) networks are prone to more contention issues as compared to traditional optical networks. To maintain a high degree of capacity efficiency, it is likely that spectral defragmentation will be needed in these networks; several design choices are discussed.}, booktitle={Springer Handbook of Optical Networks}, publisher={Springer International Publishing}, author={Simmons, Jane M. and Rouskas, George N.}, editor={Mukherjee, Biswanath and Tomkos, Ioannis and Tornatore, Massimo and Winzer, Peter and Zhao, YongliEditors}, year={2020}, pages={447–484} }
 @article{gao_rouskas_2020, title={Service Chain Rerouting for NFV Load Balancing}, ISSN={["2576-6813"]}, DOI={10.1109/GLOBECOM42002.2020.9322265}, abstractNote={Network function virtualization (NFV), with its potential to facilitate network service provisioning, has drawn growing interest from both academia and industry. One essential challenge is to allocate efficiently the bandwidth and computational resources to the service requests. In an online context, service chain requests may arrive, depart or evolve in an arbitrary fashion, adding more difficulty to the problem. Service chain reconfiguration may help improve the performance by individually rerouting a subset of the service chain requests. In this paper, we propose a new service chain reconfiguration framework to achieve load balancing in an NFV environment under varying levels of support from the underlying infrastructure. We show that our framework can achieve an approximation ratio of O(lnm/ln lnm) with high probability for the service chain request rerouting problem.}, journal={2020 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM)}, author={Gao, Lingnan and Rouskas, George N.}, year={2020} }
 @article{li_guo_li_zhou_huang_rouskas_2019, title={A large-scale nesting ring multi-chip architecture for manycore processor systems}, volume={31}, ISSN={["1872-9770"]}, url={https://doi.org/10.1016/j.osn.2018.10.004}, DOI={10.1016/j.osn.2018.10.004}, abstractNote={The optical network on chip (ONoC) paradigm has emerged as a promising solution to multi-core/many-core processor systems for offering enormous bandwidth and low power consumption. As chip multiprocessors (CMPs) scale to unprecedented numbers of cores, the performance of next-generation CMPs will be bounded by the process yield and power density of single chip. In earlier work we proposed a multi-chip ONoC architecture that scales to large numbers of CMPs and delivers high performance in terms of delay and throughout. Building on that work, in this paper we propose an optimized architecture for integrating a large number of cores into chips with a novel control strategy, including a contention resolution scheme and a resource reservation scheme. The proposed control strategy is crucial to large scale ONoCs, because the resource reservation scheme ensures efficient wavelength allocation for the traffic while the contention management scheme is effective in reducing the impact of contentions. To sustain good performance and energy efficiency of large-scale ONoC, the topology is optimized to reduce the average transmission distance with minimum increase of power consumption. We evaluate the proposed architecture within a 1000-core processor system and compare it with CMesh and several previously proposed topologies with different control strategies. The simulation results show that, our new large-scale architecture can achieve better performance on throughput and delay.}, journal={OPTICAL SWITCHING AND NETWORKING}, publisher={Elsevier BV}, author={Li, Wenzhe and Guo, Bingli and Li, Xin and Zhou, Yu and Huang, Shanguo and Rouskas, George N.}, year={2019}, month={Jan}, pages={183–192} }
 @article{xiong_yang_ye_rouskas_2019, title={A machine learning approach to mitigating fragmentation and crosstalk in space division multiplexing elastic optical networks}, volume={50}, ISSN={["1095-9912"]}, DOI={10.1016/j.yofte.2019.03.001}, abstractNote={As network traffic is expected to continue to grow at high rates for the foreseeable future, it becomes imperative to introduce space division multiplexing elastic optical networks (SDM-EONs) into the optical transport network. However, spectrum fragmentation and crosstalk present significant challenges that may negatively impact the performance of SDM-EONs. In this paper, we leverage machine learning techniques to enhance the transmission performance of SDM-EONs, and make two contributions. Specifically, we use an Elman neural network to forecast traffic demands, and use a two-dimensional rectangular packing model to allocate spectrum so as to decrease unnecessary spectrum fragmentation (and, in turn, increase resource utilization). We also present a novel spectrum partition scheme to reduce crosstalk. Our evaluation study confirms that the proposed strategy is effective in improving spectrum utilization while reducing blocking probability and crosstalk.}, journal={OPTICAL FIBER TECHNOLOGY}, author={Xiong, Yu and Yang, Yaya and Ye, Yulong and Rouskas, George N.}, year={2019}, month={Jul}, pages={99–107} }
 @article{rouskas_verikoukis_2019, title={Editorial}, volume={1}, url={https://doi.org/10.1109/LNET.2019.2897895}, DOI={10.1109/LNET.2019.2897895}, abstractNote={We are proud to present this inaugural issue of the IEEE Networking Letters. This issue is the culmination of an effort that started two years ago and introduces a new publication that rounds out the IEEE portfolio of journals in the broad field of communications and networking. Specifically, IEEE Networking Letters is intended to complement its sister publications, IEEE Communications Letters and IEEE Wireless Communications Letters, by providing a forum for letter-style journal papers reporting on research advances in all layers of the networking stack <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">above</i> the physical layer.}, number={1}, journal={IEEE Networking Letters}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Rouskas, George and Verikoukis, Christos}, year={2019}, month={Mar}, pages={1–1} }
 @article{gao_rouskas_2018, title={A spectral clustering approach to network-aware virtual request partitioning}, volume={139}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2018.04.005}, abstractNote={Virtual request partitioning is an essential subproblem of two common problems in virtual networks, namely, virtual network embedding (VNE) and virtual machine placement (VMP). In this study, we consider a network-aware variant of the problem where the objective is to partition a virtual request so as to minimize the total amount of inter-cluster traffic. This problem is equivalent to the (k, v)-balanced partitioning problem, an NP-complete problem. To handle the inherent complexity of this problem, we develop a spectral clustering-based partitioning scheme that produces good solutions in a reasonable amount of time. Our solution consists of several components: (a) spectral clustering, (b) a Constrained k-means partitioning algorithm that ensures that capacity limits for clusters are met, and for which we present a polynomial-time greedy algorithm, and (c) a greedy refinement algorithm using simulated annealing to further improve the clustering solution. Simulation results indicate that our algorithm outperforms existing partitioning schemes in terms of inter-cluster traffic minimization.}, journal={COMPUTER NETWORKS}, author={Gao, Lingnan and Rouskas, George N.}, year={2018}, month={Jul}, pages={70–80} }
 @article{xiong_shi_yang_lv_rouskas_2018, title={Lightpath Management in SDN-Based Elastic Optical Networks With Power Consumption Considerations}, volume={36}, url={https://doi.org/10.1109/JLT.2017.2785410}, DOI={10.1109/JLT.2017.2785410}, abstractNote={Elastic optical networks (EONs) are increasingly used to interconnect data centers. As interdatacenter traffic is expected to continue to grow at high rates for the foreseeable future, it becomes imperative to address the respective growth in power consumption within EONs. In this paper, we take the first steps toward enhancing the energy efficiency of interdatacenter EONs. Specifically, we use traffic prediction techniques for centralized lightpath management that leverages the capabilities of software defined networking (SDN) technology. Our objective is to eliminate unnecessary lightpath termination and re-establishment operations, and in turn decrease switching power consumption within the network. Our evaluation study confirms that the proposed algorithm is effective in achieving substantial savings in power consumption while maintaining a bandwidth blocking ratio at levels comparable to those of earlier algorithms.}, number={9}, journal={Journal of Lightwave Technology}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Xiong, Yu and Shi, Jin and Yang, Yaya and Lv, Yi and Rouskas, George N.}, year={2018}, month={May}, pages={1650–1660} }
 @article{bhat_rouskas_katib_2018, title={On time dependent routing algorithms for open marketplaces of path services with support for in-advance path reservation}, volume={138}, ISSN={["1872-7069"]}, url={https://doi.org/10.1016/j.comnet.2018.04.006}, DOI={10.1016/j.comnet.2018.04.006}, abstractNote={Open marketplaces of path services are the next step towards realizing "routing-as-a-service." Such marketplaces will enable users to select from a set of path services offered by multiple competing network providers so as to construct customized end-to-end paths for their applications. This is analogous to online travel marketplaces that allow users to explore travel options and book their travel. We review the requirements for path planners to assist users in stitching together available path services which are time sensitive. We define the problem of finding multi-criteria time-constrained paths in this context, and present algorithms to construct these paths and also provide support for in-advance path reservation.}, journal={COMPUTER NETWORKS}, publisher={Elsevier BV}, author={Bhat, Shireesh and Rouskas, George N. and Katib, Iyad}, year={2018}, month={Jun}, pages={201–212} }
 @article{xiong_li_zhou_wang_rouskas_2018, title={SDN Enabled Restoration With Triggered Precomputation in Elastic Optical Inter- Datacenter Networks}, volume={10}, ISSN={["1943-0639"]}, DOI={10.1364/jocn.10.000024}, abstractNote={Flexi-grid elastic optical networks (EONs) provide a promising infrastructure for meeting the high-bandwidth and low-latency requirements of interconnecting datacenters. Since failures of high-capacity fiber links prevent users from accessing cloud services and lead to large amounts of data loss, much recent research has focused on inter-datacenter network failure recovery. In this paper, we build upon software-defined networking (SDN) technology and develop a fast restoration strategy with triggered precomputation (FR-TP) that achieves fast failure recovery with minimal resource overhead. Our work makes several contributions. We extend the controller functionality and OpenFlow protocol for software-defined elastic optical inter-datacenter network architectures, so as to obtain the global network state information quickly and accurately. We then present the FR-TP strategy and an associated trigger mechanism to compute backup paths before a link failure occurs. Furthermore, to improve the efficiency of path computation and bandwidth resource assignment, we construct a layered auxiliary graph of spectrum window planes (SWP-LAG) using a residual capacity matrix to change dynamically the width of the spectrum window planes (SWPs) to satisfy different service requests. Simulation results demonstrate that, compared with existing restoration strategies, the proposed FR-TP strategy combined with SWP-LAG reduces the recovery time by up to 30.4% in the network topologies studied without increasing the blocking probability.}, number={1}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Xiong, Yu and Li, Yuanyuan and Zhou, Bin and Wang, Ruyan and Rouskas, George N.}, year={2018}, month={Jan}, pages={24–34} }
 @article{bhat_udechukwu_dutta_rouskas_2017, title={Network service orchestration in heterogeneous 5G networks using an open marketplace}, volume={6}, ISSN={2047-4954 2047-4962}, url={http://dx.doi.org/10.1049/IET-NET.2017.0058}, DOI={10.1049/IET-NET.2017.0058}, abstractNote={Network service orchestration across heterogeneous networks needs an open marketplace where the services advertised by the providers in different domains can be purchased for short-term or long-term time scales. The authors present two design paradigms and evaluate two corresponding prototypes which provide a framework for network services to be purchased. They compare the two prototypes from the point of view of how effective they are in addressing some of the challenges posed by heterogeneous 5G networks namely programmability, scalability and innovation. They present a network service orchestration algorithm which is advertised as a network service in the marketplace.}, number={6}, journal={IET Networks}, publisher={Institution of Engineering and Technology (IET)}, author={Bhat, Shireesh and Udechukwu, Robinson and Dutta, Rudra and Rouskas, George N.}, year={2017}, month={Nov}, pages={149–156} }
 @article{talebi_rouskas_2017, title={On Distance-Adaptive Routing and Spectrum Assignment in Mesh Elastic Optical Networks}, volume={9}, ISSN={["1943-0639"]}, DOI={10.1364/jocn.9.000456}, abstractNote={The routing and spectrum assignment (RSA) problem has emerged as the key design and control problem in elastic optical networks. Distance-adaptive spectrum allocation exploits the tradeoff between spectrum width and reach to improve resource utilization by tailoring the modulation format to the level of impairments along the path. In this paper, we consider the distance-adaptive RSA (DA-RSA) problem with fixed alternate routing. We first show that the DA-RSA problem in networks of general topology is a special case of a well-studied multiprocessor scheduling problem. We then leverage insights from the scheduling theory to 1) present new results regarding the complexity of the DA-RSA problem and 2) build upon the list of scheduling concepts to develop a computationally efficient solution approach that is effective in utilizing the available spectrum resources.}, number={5}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Talebi, Sahar and Rouskas, George N.}, year={2017}, month={May}, pages={456–465} }
 @inproceedings{bhat_udechukwu_dutta_rouskas_2017, title={On service composition algorithm for open marketplaces of network services}, DOI={10.1109/eucnc.2017.7980657}, abstractNote={Network service composition provided as a service in an Open Marketplace enables users to obtain customized end-to-end composed service(s) using the services advertised by the providers in the marketplace. By providing a semantic language for advertising services and offering choice for the composed service(s) we provide a level playing field for the providers and alternatives for the users to choose from based on their requirement. This is similar to the services offered in the cloud, but without the provider monopoly or the limitation of having to select from limited options.}, booktitle={2017 european conference on networks and communications (eucnc)}, author={Bhat, S. and Udechukwu, R. and Dutta, Rudra and Rouskas, George}, year={2017} }
 @article{talebi_katib_rouskas_2016, title={Distance-adaptive routing and spectrum assignment in rings}, volume={5}, ISSN={2047-4954 2047-4962}, url={http://dx.doi.org/10.1049/IET-NET.2015.0085}, DOI={10.1049/IET-NET.2015.0085}, abstractNote={Distance adaptive spectrum allocation exploits the tradeoff between spectrum width and reach to improve resource utilisation by tailoring the modulation format to the level of impairments along the path. The authors first show that the distance-adaptive routing and spectrum assignment (DA-RSA) problem is a special case of a multiprocessor scheduling problem. The authors then develop a suite of efficient and effective DA-RSA algorithms for ring networks, that build upon list scheduling concepts. This work explores the tradeoffs involved in DA-RSA algorithm design, and opens up new research directions that may leverage the vast literature in scheduling theory.}, number={3}, journal={IET Networks}, publisher={Institution of Engineering and Technology (IET)}, author={Talebi, Sahar and Katib, Iyad and Rouskas, George N.}, year={2016}, month={May}, pages={64–70} }
 @inproceedings{xiong_li_dong_gao_rouskas_2016, title={Exploiting SDN principles for extremely fast restoration in elastic optical datacenter Networks}, DOI={10.1109/glocom.2016.7841831}, abstractNote={In order to find out the tradeoff between recovery time and resource overhead when a link failure occurs, we propose a software-defined based fast restoration scheme for elastic optical datacenter networks, called precomputation based restoration path (P-RP). By extending the controller functionality and OpenFlow protocol in software defined networking (SDN) technology, we establish a novel elastic optical inter-datacenter network architecture which can quickly and accurately converge the network state information with a global view for failure recovery. Based on this architecture, the P-RP performs path computation and bandwidth resource selection for restoration before a failure occurs. The experimental results demonstrate that the proposed scheme can achieve fast recovery with low blocking probability while maintaining high spectrum efficiency. Compared with existing restoration schemes, average recovery time is improved by up to 28%.}, booktitle={2016 ieee global communications conference (globecom)}, author={Xiong, Y. and Li, Y. Y. and Dong, X. C. and Gao, Y. P. and Rouskas, George}, year={2016} }
 @article{yayah_coulibaly_ismail_rouskas_2016, title={Hybrid offset-time and burst assembly algorithm (H-OTBA) for delay sensitive applications over optical burst switching networks}, volume={29}, ISSN={["1099-1131"]}, DOI={10.1002/dac.2821}, abstractNote={Summary}, number={2}, journal={INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS}, author={Yayah, Abdulsalam A. and Coulibaly, Yahaya and Ismail, Abdul Samad and Rouskas, George}, year={2016}, month={Jan}, pages={251–261} }
 @inproceedings{bhat_udechukwu_dutta_rouskas_2016, title={Inception to application: A GENI based prototype of an Open Marketplace for Network Services}, DOI={10.1109/infcomw.2016.7562244}, abstractNote={Choice-based network architecture enables users the power to choose services from a set of network service offerings from multiple providers within a marketplace. To facilitate marketplace alternatives and enable fine-grain service composition, a common service specification should represent a general-extensible design for describing a service. This allows users to discover, negotiate, and purchase network services from service providers using service advertisements in the marketplace. We have successfully developed a ChoiceNet prototype which rectifies some of the shortcomings of the earlier prototypes and demonstrates a contractual agreement between multiple network service providers to realize multiple end-to-end application scenarios using the common service specification within the GENI environment. Our implementation showcases the integration of two contrasting payment models for the procurement of contractual agreements for network services. Successful agreements results in the provisioning of the advertised network services. This demo helps in visualizing the network service life cycle as seen by the Marketplace.}, booktitle={2016 ieee conference on computer communications workshops (infocom wkshps)}, author={Bhat, S. and Udechukwu, R. and Dutta, Rudra and Rouskas, George}, year={2016} }
 @inproceedings{udechukwu_bhat_dutta_rouskas_2016, title={Language of choice: On embedding choice-related semantics in a realizable protocol}, DOI={10.1109/sarnof.2016.7846760}, abstractNote={Choice-based future Internet architectures, in which choice is offered for fine-grained network services to different traffic flows, have been proposed in the literature. Such choice-based architectures have been envisioned in literature as realizing an economy of networking services that can give rise to a beneficial ecosystem of providers and consumers over time. Such an architecture would use an economy plane to allow service providers and customers to exchange information about available service alternatives, complete purchase and payment interactions, and use purchased services. While samples of such semantics have been proposed in these previous works, embedding them in specific realizations by defining messages to be exchanged and their syntax is a separate challenge, in which the needs for efficiency, ease of implementation, and extensibility, all need to be balanced. In this paper, we present the design of a possible embedding of the entities, and a functionally complete set of interactions, comprising a choice-based architecture. Further, to show the practical realizability of this embedding, we report on a prototype built on the GENI environment, and our experience in confronting real-world design issues. The prototype showcases new service models for value-added transport in such an architecture.}, booktitle={2016 ieee 37th sarnoff symposium}, author={Udechukwu, R. and Bhat, S. and Dutta, Rudra and Rouskas, George}, year={2016}, pages={31–36} }
 @inproceedings{gao_rouskas_2016, title={Network-aware virtual request partitioning based on spectral clustering}, DOI={10.1109/icccn.2016.7568548}, abstractNote={Virtual request partitioning is an essential subproblem of two common problems in virtual networks, namely, virtual network embedding (VNE) and virtual machine placement (VMP). In this study, we consider a network-aware variant of the problem where the objective is to partition a virtual request so as to minimize the total amount of inter-cluster traffic. This problem is equivalent to the (k,v)-balanced partitioning problem, an NP-complete problem. To handle the inherent complexity of this problem, we develop a spectral clustering-based partitioning scheme that produces good solutions in a reasonable amount of time. Our solution consists of several components: (a) spectral clustering, (b) a constrained k-means partitioning algorithm that ensures that capacity limits for clusters are met, and for which we present a polynomial-time greedy algorithm, and (c) a greedy refinement algorithm using simulated annealing to further improve the clustering solution. Simulation results indicate that our algorithm outperforms existing partitioning schemes in terms of inter-cluster traffic minimization.}, booktitle={2016 25th international conference on computer communications and networks (icccn)}, author={Gao, L. N. and Rouskas, George}, year={2016} }
 @inproceedings{talebi_rouskas_katib_2016, title={Offline distance-adaptive routing and spectrum assignment in mesh elastic optical networks}, DOI={10.1109/glocom.2016.7842036}, abstractNote={The routing and spectrum assignment (RSA) problem has emerged as the key design and control problem in elastic optical networks. Distance adaptive spectrum allocation exploits the tradeoff between spectrum width and reach to improve resource utilization by tailoring the modulation format to the level of impairments along the path. In this paper, we consider the distance-adaptive RSA (DA-RSA) problem with fixed alternate routing. We first show that the DA-RSA problem in networks of general topology is a special case of a well-studied multiprocessor scheduling problem. We then leverage insights from scheduling theory to (1) present new results regarding the complexity of the DA-RSA problem, and (2) build upon list scheduling concepts to develop a computationally efficient solution approach that is effective in utilizing the available spectrum resources.}, booktitle={2016 ieee global communications conference (globecom)}, author={Talebi, S. and Rouskas, George and Katib, I.}, year={2016} }
 @article{bhat_rouskas_2016, title={On Routing Algorithms for Open Marketplaces of Path Services}, ISSN={["1550-3607"]}, DOI={10.1109/icc.2016.7511582}, abstractNote={Open marketplaces of path services are the next step towards realizing “routing-as-a-service.” Such marketplaces will enable users to select from a set of path services offered by multiple competing network providers so as to construct customized end-to-end paths for their applications. This is analogous to online travel marketplaces that allow users to explore travel options and book their travel. We review the requirements for path planners to assist users in stitching together available path services. We define the problem of finding multi-criteria time-constrained paths in this context, and present a dynamic programming algorithm that constructs Pareto-optimal paths.}, journal={2016 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC)}, author={Bhat, Shireesh and Rouskas, George N.}, year={2016} }
 @article{krishnamurthy_rouskas_2016, title={Performance Evaluation of Multi-Core, Multi-Threaded SIP Proxy Servers (SPS)}, ISSN={["1550-3607"]}, DOI={10.1109/icc.2016.7511427}, abstractNote={Process schedulers are part of the core functionality of an operating system (OS), and have been enhanced over the years to account for multiple cores in the processors and to support multi-threaded applications. In this study, we investigate the impact of the Linux scheduler's load-balancing algorithm on the performance of multi-threaded OpenSIPS (an open source SIP proxy server, SPS) running on a multi-core processor system. Linux uses the “completely fair scheduler” (CFS) scheduling policy and provides parameters specifically tunable in a multi-core environment. We conducted extensive experiments and analyzed the collected data to characterize the performance of SPS as a function of the number of CPU cores, the number of server threads and the call arrival rate. Based on our analysis, we show how to configure the various scheduler parameters as a function of the number of CPU cores to achieve a significant improvement in SPS performance. We further present a capacity planning model as a tool that service providers may use to obtain a first-order approximation of the capacity of their system that yields a good match to experimental results.}, journal={2016 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS (ICC)}, author={Krishnamurthy, Ramesh and Rouskas, George N.}, year={2016} }
 @article{rouskas_ho_tapolcai_cinkler_2016, title={Special issue on advances in availability and survivability in optical networks}, volume={19}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/J.OSN.2015.09.002}, DOI={10.1016/J.OSN.2015.09.002}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Rouskas, George and Ho, Pin-Han and Tapolcai, Janos and Cinkler, Tibor}, year={2016}, month={Jan}, pages={41} }
 @inproceedings{chen_wolf_griffioen_ascigil_dutta_rouskas_bhat_baldin_calvert_2015, title={Design of a protocol to enable economic transactions for network services}, DOI={10.1109/icc.2015.7249175}, abstractNote={Deployment of innovative new networking services requires support by network providers. Since economic motivation plays an important role for network providers, it is critical that a network architecture intrinsically considers economic relationships. We present the design of a protocol that associates access to network services with economic contracts. We show how this protocol can be realized in fundamentally different ways, using out-of-band signaling and in-band signaling, based on two different prototype implementations. We present results that show the effectiveness of the proposed protocol and thus demonstrate a first step toward realizing an economy plane for the Internet.}, booktitle={2015 ieee international conference on communications (icc)}, author={Chen, X. M. and Wolf, T. and Griffioen, J. and Ascigil, O. and Dutta, Rudra and Rouskas, George and Bhat, S. and Baldin, I. and Calvert, K.}, year={2015}, pages={5354–5359} }
 @article{talebi_katib_rouskas_2015, title={Offline Distance-Adaptive Routing and Spectrum Assignment (DA-RSA) in Rings}, ISSN={["2334-0983"]}, DOI={10.1109/glocom.2015.7417037}, abstractNote={Distance adaptive spectrum allocation exploits the tradeoff between spectrum width and reach to improve resource utilization by tailoring the modulation format to the level of impairments along the path. We first show that the distance-adaptive routing and spectrum assignment (DA-RSA) problem in mesh networks is a special case of a multiprocessor scheduling problem. We then develop a suite of efficient and effective DA-RSA algorithms that build upon list scheduling concepts. Our work explores the tradeoffs involved in DA-RSA algorithm design, and opens up new research directions that may leverage the vast literature in scheduling theory.}, journal={2015 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM)}, author={Talebi, Sahar and Katib, Iyad and Rouskas, George N.}, year={2015} }
 @article{talebi_bampis_lucarelli_katib_rouskas_2015, title={On Routing and Spectrum Assignment in Rings}, volume={33}, ISSN={["1558-2213"]}, DOI={10.1109/jlt.2014.2376871}, abstractNote={We present a theoretical study of the routing and spectrum assignment (RSA) problem in ring networks. We first show that the RSA problem with fixed-alternate routing in general-topology (mesh) networks (and, hence, in rings as well) is a special case of a multiprocessor scheduling problem. We then consider bidirectional ring networks and investigate two problems: 1) the spectrum assignment problem under the assumption that each demand is routed along a single fixed path (e.g., the shortest path), and 2) the general case of the RSA problem whereby a routing decision along the clockwise and counter-clockwise directions must be made jointly with spectrum allocation. Based on insights from multiprocessor scheduling theory, we derive the complexity of the two problems and develop new constant-ratio approximation algorithms with a ratio that is strictly smaller than the best known ratio to date.}, number={1}, journal={JOURNAL OF LIGHTWAVE TECHNOLOGY}, author={Talebi, Sahar and Bampis, Evripidis and Lucarelli, Giorgio and Katib, Iyad and Rouskas, George N.}, year={2015}, month={Jan}, pages={151–160} }
 @inproceedings{krishnamurthy_rouskas_2015, title={On the impact of scheduler settings on the performance of multi-threaded SIP servers}, DOI={10.1109/icc.2015.7249307}, abstractNote={Multi-threading is a widely used program execution model, where each thread executes independently while sharing some of the process resources. Multi-threaded processes are used for a range of network application servers including web servers, mail servers and SIP proxy servers (SPS) for Voice over IP (VoIP). The process scheduler is a core part of any Operating System and the policy it uses may have a significant impact on the various applications executing on the system. In this work, we investigate the impact of the Linux scheduler on the performance of OpenSIPS, an open source SIP proxy server. The version of Linux used in our study uses a scheduling policy known as “Completely Fair Scheduler” (CFS), and the Linux kernel provides several parameters that may be used to tune the CFS policy. We have collected a large set of experimental data, in a methodical fashion, to characterize the performance of SPS as a function of the number of server threads and the call arrival rate under (1) default CFS setting and (2) with CFS parameters tuned for improved performance. By fine tuning the scheduler parameters, SPS performance is improved in all scenarios, in some cases significantly. To the best of our knowledge, this is the first study that takes into account the scheduler parameters in improving the performance of the SPS. Our results indicate that network operators may increase server capacity without additional capital expenditures, by applying insightful configuration changes to scheduler policy.}, booktitle={2015 ieee international conference on communications (icc)}, author={Krishnamurthy, R. and Rouskas, George}, year={2015}, pages={6175–6180} }
 @article{coulibaly_rouskas_abd latiff_razzaque_mandala_2015, title={QoS-aware ant-based route, wavelength and timeslot assignment algorithm for optical burst switchednetworks}, volume={26}, ISSN={["2161-3915"]}, DOI={10.1002/ett.2919}, abstractNote={Abstract}, number={11}, journal={TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES}, author={Coulibaly, Yahaya and Rouskas, George and Abd Latiff, Muhammad Shafie and Razzaque, M. A. and Mandala, Satria}, year={2015}, month={Nov}, pages={1265–1277} }
 @inproceedings{fayez_katib_rouskas_faheem_2015, title={Spectrum assignment in mesh elastic optical networks}, DOI={10.1109/icccn.2015.7288470}, abstractNote={Spectrum assignment has emerged as the key design and control problem in elastic optical networks. We have shown that spectrum assignment in networks of general topology is a special case of scheduling multiprocessor tasks on dedicated processors. Based on this insight, we develop and evaluate efficient and effective algorithms for mesh and chain networks that build upon list scheduling concepts.}, booktitle={24th international conference on computer communications and networks icccn 2015}, author={Fayez, M. and Katib, I. and Rouskas, George and Faheem, H. M.}, year={2015} }
 @inproceedings{talebi_alam_katib_rouskas_2015, title={Spectrum assignment in rings with shortest-path routing: Complexity and approximation algorithms}, DOI={10.1109/iccnc.2015.7069420}, abstractNote={We study the spectrum assignment (SA) problem in ring networks with shortest path (or, more generally, fixed) routing. With fixed routing, each traffic demand follows a predetermined path to its destination. In earlier work, we have shown that the SA problem can be viewed as a multiprocessor problem. Based on this insight, we prove that, under the shortest path assumption, the SA problem can be solved in polynomial time in small rings, and we develop constant-ratio approximation algorithms for large rings. For rings of size up to 16 nodes (the maximum size of a SONET/SDH ring), the approximation ratios of our algorithms are strictly smaller than the best known ratio to date.}, booktitle={2015 International Conference on Computing, Networking and Communications (ICNC)}, author={Talebi, S. and Alam, F. and Katib, I. and Rouskas, George}, year={2015}, pages={642–647} }
 @article{wolf_griffioen_calvert_dutta_rouskas_baldin_nagurney_2014, title={ChoiceNet: Toward an Economy Plane for the Internet}, volume={44}, ISSN={["1943-5819"]}, DOI={10.1145/2656877.2656886}, abstractNote={The Internet has been a key enabling technology for many new distributed applications and services. However, the deployment of new protocols and services in the Internet infrastructure itself has been sluggish, especially where economic incentives for network providers are unclear. In our work, we seek to develop an "economy plane" for the Internet that enables network providers to offer new network-based services (QoS, storage, etc.) for sale to customers. The explicit connection between economic relationships and network services across various time scales enables users to select among service alternatives. The resulting competition among network service providers will lead to overall better technological solutions and more competitive prices. In this paper, we present the architectural aspects of our ChoiceNet economy plane as well as some of the technological problems that need to be addressed in a practical deployment.}, number={3}, journal={ACM SIGCOMM COMPUTER COMMUNICATION REVIEW}, author={Wolf, Tilman and Griffioen, James and Calvert, Ken and Dutta, Rudra and Rouskas, George and Baldin, Ilya and Nagurney, Anna}, year={2014}, month={Jul}, pages={58–65} }
 @article{wang_rouskas_2014, title={Hierarchical traffic grooming: A tutorial}, volume={69}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2014.04.019}, abstractNote={Traffic grooming is concerned with the design, operation, and control of networks with multigranular bandwidth demands. As the number of resources in a multigranular network increases rapidly with the network size, wavelength capacity, and load, a scalable framework for managing these entities becomes essential. Hierarchical traffic grooming facilitates the control and management of multigranular WDM networks. In this paper, we present a survey of traffic grooming schemes for optical networks that make use of architectures, algorithms and design techniques that impose a hierarchical structure on the network topology.}, journal={COMPUTER NETWORKS}, author={Wang, Hui and Rouskas, George N.}, year={2014}, month={Aug}, pages={147–156} }
 @article{liu_rouskas_he_xiong_2014, title={Multipoint Control Protocol With Look-Ahead for Wavelength Division Multiplexed Ethernet Passive Optical Network}, volume={6}, ISSN={["1943-0639"]}, DOI={10.1364/jocn.6.000104}, abstractNote={We presenta simple yet effective enhancement to the operation of the Ethernet passive optical network (EPON) multipoint control protocol (MPCP) for wavelength division multiplexing (WDM) EPON. The enhancement, inspired by our earlier work in a related but different context, allows the optical line terminal (OLT) to perform look-ahead scheduling on each of the upstream channels. The look-ahead operation is fully compatible with the existing standard and may be implemented via software updates to the OLT without affecting the operation of optical network units in EPON. The look-ahead enhanced MPCP achieves significant performance gains across a wide range of traffic loads and opens up new opportunities for the design of sophisticated dynamic bandwidth algorithms to support advanced quality of service capabilities.}, number={2}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Liu, Xiaomin and Rouskas, George N. and He, Feng and Xiong, Huagang}, year={2014}, month={Feb}, pages={104–113} }
 @article{talebi_bampis_lucarelli_katib_rouskas_2014, title={Spectrum Assignment in Optical Networks: A Multiprocessor Scheduling Perspective}, volume={6}, ISSN={1943-0620 1943-0639}, url={http://dx.doi.org/10.1364/jocn.6.000754}, DOI={10.1364/jocn.6.000754}, abstractNote={The routing and spectrum assignment problem has emerged as the key design and control problem in elastic optical networks. In this work, we show that the spectrum assignment (SA) problem in mesh networks transforms to the problem of scheduling multiprocessor tasks on dedicated processors. Based on this new perspective, we show that the SA problem in chain (linear) networks is NP-hard for four or more links, but is solvable in polynomial time for three links. We also develop new constant-ratio approximation algorithms for the SA problem in chains when the number of links is fixed. Finally, we present several list scheduling algorithms that are computationally efficient and simple to implement, yet produce solutions that, on average, are within 1%-5% of the lower bound.}, number={8}, journal={Journal of Optical Communications and Networking}, publisher={The Optical Society}, author={Talebi, Sahar and Bampis, Evripidis and Lucarelli, Giorgio and Katib, Iyad and Rouskas, George N.}, year={2014}, month={Jul}, pages={754} }
 @misc{talebi_alam_katib_khamis_salama_rouskas_2014, title={Spectrum management techniques for elastic optical networks: A survey}, volume={13}, ISSN={["1872-9770"]}, DOI={10.1016/j.osn.2014.02.003}, abstractNote={In recent years, OFDM has been the focus of extensive research efforts in optical transmission and networking, initially as a means to overcome physical impairments in optical communications. However, unlike, say, in wireless LANs or xDSL systems where OFDM is deployed as a transmission technology in a single link, in optical networks it is being considered as the technology underlying the novel elastic network paradigm. Consequently, network-wide spectrum management arises as the key challenge to be addressed in network design and control. In this work, we review and classify a range of spectrum management techniques for elastic optical networks, including offline and online routing and spectrum assignment (RSA), distance-adaptive RSA, fragmentation-aware RSA, traffic grooming, and survivability.}, journal={OPTICAL SWITCHING AND NETWORKING}, author={Talebi, Sahar and Alam, Furcian and Katib, Lyad and Khamis, Mohamed and Salama, Reda and Rouskas, George N.}, year={2014}, month={Jul}, pages={34–48} }
 @inproceedings{dutta_rouskas_baldiney_2013, title={Converging choice and service in future commodity optical networks using traffic grooming}, DOI={10.1109/icton.2013.6602954}, abstractNote={The problem of providing an agile, energy-aware, flexible optical network architecture is one of the challenges in optical networking in the coming decade. A key element in this challenge is the balancing of the benefits to customer and provider, and creating an agile system capable of reflecting both provider and customer interests on an ongoing basis as network conditions change. In this paper, we articulate how the traditional optical networking research area of traffic grooming may be combined with recent advances in Internet architecture, specifically a proposed Future Internet architecture called ChoiceNet, and empowered by the recently emerged concept of software defined networking, to make some key contributions to this problem.}, booktitle={2013 15th international conference on transparent optical networks (icton 2013)}, author={Dutta, Rudra and Rouskas, George and Baldiney, I.}, year={2013} }
 @article{cao_rouskas_wang_tang_2013, title={Hybrid FRR/p-cycle design for link and node protection in MPLS networks}, volume={67}, ISSN={["1618-0399"]}, DOI={10.1016/j.aeue.2012.11.005}, abstractNote={Survivable MPLS technologies are crucial in ensuring reliable communication services. The fast reroute (FRR) mechanism has been standardized to achieve fast local repair of label switched paths (LSPs) in the event of link or node failures. We present a suite of hybrid protection schemes for MPLS networks that combine the well-known p-cycle method with FRR technology. Whereas with pure FRR backup paths are planned by each node individually, the hybrid schemes employ a set of p-cycles that may be selected using techniques that take a holistic view of the network so as to share protection bandwidth effectively. The hybrid FRR/p-cycle methods are fully RFC 4090-compliant, yet allow network operators to leverage a large existing body of p-cycle design techniques. Numerical results on realistic network topologies indicate that the hybrid approach is successful in combining the advantages of p-cycle design and FRR.}, number={6}, journal={AEU-INTERNATIONAL JOURNAL OF ELECTRONICS AND COMMUNICATIONS}, author={Cao, Chang and Rouskas, George N. and Wang, Jianquan and Tang, Xiongyan}, year={2013}, pages={470–478} }
 @article{wang_iyer_dutta_rouskas_baldine_2013, title={Network Virtualization: Technologies, Perspectives, and Frontiers}, volume={31}, ISSN={["1558-2213"]}, DOI={10.1109/jlt.2012.2213796}, abstractNote={Network virtualization refers to a broad set of technologies. Commercial solutions have been offered by the industry for years, while more recently the academic community has emphasized virtualization as an enabler for network architecture research, deployment, and experimentation. We review the entire spectrum of relevant approaches with the goal of identifying the underlying commonalities. We offer a unifying definition of the term “network virtualization” and examine existing approaches to bring out this unifying perspective. We also discuss a set of challenges and research directions that we expect to come to the forefront as network virtualization technologies proliferate.}, number={4}, journal={JOURNAL OF LIGHTWAVE TECHNOLOGY}, author={Wang, Anjing and Iyer, Mohan and Dutta, Rudra and Rouskas, George N. and Baldine, Ilia}, year={2013}, month={Feb}, pages={523–537} }
 @article{wang_rouskas_2013, title={Traffic grooming in optical networks: Decomposition and partial linear programming (LP) relaxation}, volume={5}, DOI={10.1364/jocn.5.000825}, abstractNote={We consider the traffic grooming problem, a fundamental network design problem in optical networks. We review a typical integer linear program formulation considered in the literature, and we identify two challenges related to this formulation in terms of scalability and wavelength fragmentation. We then propose a new (to our knowledge) solution approach that decomposes the traffic grooming problem into two subproblems that are solved sequentially: 1) the virtual topology and traffic routing (VTTR) subproblem, which does not take into account physical topology constraints, and 2) the routing and wavelength assignment subproblem, which reconciles the virtual topology determined by VTTR with the physical topology. The decomposition is exact when the network is not wavelength limited. We also propose an algorithm that uses a partial linear programming relaxation technique driven by lightpath utilization information to solve the VTTR subproblem efficiently. Our approach delivers a desirable tradeoff between running time and quality of the final solution.}, number={8}, journal={Journal of Optical Communications and Networking}, author={Wang, H. and Rouskas, G. N.}, year={2013}, pages={825–835} }
 @inproceedings{liu_rouskas_2012, title={A fast path-based ILP formulation for offline RWA in mesh optical networks}, DOI={10.1109/glocom.2012.6503572}, abstractNote={RWA is a fundamental problem in the design and control of optical networks. We introduce the concept of symmetric RWA solutions and present a new ILP formulation to construct optimally such solutions. The formulation scales to mesh topologies representative of backbone and regional networks. Numerical results demonstrate that the new formulation achieves a decrease of up to two orders of magnitude in running time compared to existing formulations. In particular, optimal solutions for topologies up to 20 nodes can be obtained within minutes using commodity CPUs, and larger networks can be solved in reasonable time. Our approach significantly lowers the barrier to entry in fully exploring the solution space of optical network design and in investigating the sensitivity of design decisions to forecast demands via extensive “what-if” analysis. Such analysis cannot be carried out currently without large investments in computational resources and time.}, booktitle={2012 ieee global communications conference (globecom)}, author={Liu, Z. Y. and Rouskas, George}, year={2012}, pages={2990–2995} }
 @article{wolf_griffioen_calvert_dutta_rouskas_baldine_nagurney_2012, title={Choice as a Principle in Network Architecture}, volume={42}, ISSN={["1943-5819"]}, DOI={10.1145/2377677.2377703}, abstractNote={There has been a great interest in defining a new network architecture that can meet the needs of a future Internet. One of the main challenges in this context is how to realize the many different technical solutions that have developed in recent years in a single coherent architecture. In addition, it is necessary to consider how to ensure economic viability of architecture solutions. In this work, we discuss how to design a network architecture where choices at different layers of the protocol stack are explicitly exposed to users. This approach ensures that innovative technical solutions can be used and rewarded, which is essential to encourage wide deployment of this architecture.}, number={4}, journal={ACM SIGCOMM COMPUTER COMMUNICATION REVIEW}, author={Wolf, Tilman and Griffioen, Jim and Calvert, Ken and Dutta, Rudra and Rouskas, George and Baldine, Ilia and Nagurney, Anna}, year={2012}, month={Oct}, pages={105–106} }
 @article{el-bawab_esfandiari_rouskas_jayasumana_kincaid_effenberger_kazovsky_medard_frost_baniewicz_2012, title={TOWARD SPECIALIZED UNDERGRADUATE TELECOMMUNICATION ENGINEERING EDUCATION IN THE US}, volume={50}, ISSN={["0163-6804"]}, DOI={10.1109/mcom.2012.6295705}, abstractNote={In ancient times, unless somebody was prepared to travel, man could only communicate as far as he could shout. Methods were then developed to enable communications to extend over longer distances, using trumpets, beacon fire, flags, etc. It was not until the inauguration of telegraphy (by W. Cooke and C. Wheatstone in England in 1839, and by S. Morse in the US in 1844) and telephony (by A. G. Bell in 1876), that electricity was utilized to facilitate commercial telecommunication service [1]-[2]. Then, for nearly 100 years, telecommunications was mainly about telephony and telegraphy and was based almost entirely on electrical engineering methods. From audio to radio signals, electro-mechanic to electronic technologies, analog to digital systems, and electronic to photonic devices; telecommunications has witnessed tremendous progress on numerous fronts. In terms of services and applications, telecommunications evolved in recent years to embrace cyber space, entertainment, and electronic commerce and business.}, number={9}, journal={IEEE COMMUNICATIONS MAGAZINE}, author={El-Bawab, Tarek S. and Esfandiari, Mehran and Rouskas, George and Jayasumana, Anura and Kincaid, Michael and Effenberger, Frank and Kazovsky, Leonid and Medard, Muriel and Frost, Victor and Baniewicz, Paul}, year={2012}, month={Sep}, pages={14–16} }
 @article{el-bawab_esfandiari_rouskas_jayasumana_kincaid_effenberger_kazovsky_medard_frost_baniewicz_2012, title={TOWARD SPECIALIZED UNDERGRADUATE TELECOMMUNICATION ENGINEERING EDUCATION IN THE US}, volume={50}, number={9}, journal={Ieee Communications Magazine}, author={El-Bawab, Tarek S. and Esfandiari, Mehran and Rouskas, George and Jayasumana, Anura and Kincaid, Michael and Effenberger, Frank and Kazovsky, Leonid and Medard, Muriel and Frost, Victor and Baniewicz, Paul}, year={2012}, pages={14–16} }
 @article{touch_baldine_dutta_finn_ford_jordan_massey_matta_papadopoulos_reiher_et al._2011, title={A Dynamic Recursive Unified Internet Design (DRUID)}, volume={55}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2010.12.016}, abstractNote={The Dynamic Recursive Unified Internet Design (DRUID) is a future Internet design that unifies overlay networks with conventional layered network architectures. DRUID is based on the fundamental concept of recursion, enabling a simple and direct network architecture that unifies the data, control, management, and security aspects of the current Internet, leading to a more trustworthy network. DRUID’s architecture is based on a single recursive block that can adapt to support a variety of communication functions, including parameterized mechanisms for hard/soft state, flow and congestion control, sequence control, fragmentation and reassembly, compression, encryption, and error recovery. This recursion is guided by the structure of a graph of translation tables that help compartmentalize the scope of various functions and identifier spaces, while relating these spaces for resource discovery, resolution, and routing. The graph also organizes persistent state that coordinates behavior between individual data events (e.g., coordinating packets as a connection), among different associations (e.g., between connections), as well as helping optimize the recursive discovery process through caching, and supporting prefetching and distributed pre-coordination. This paper describes the DRUID architecture composed of these three parts (recursive block, translation tables, persistent state), and highlights its goals and benefits, including unifying the data, control, management, and security planes currently considered orthogonal aspects of network architecture.}, number={4}, journal={COMPUTER NETWORKS}, author={Touch, Joe and Baldine, Ilia and Dutta, Rudra and Finn, Gregory G. and Ford, Bryan and Jordan, Scott and Massey, Dan and Matta, Abraham and Papadopoulos, Christos and Reiher, Peter and et al.}, year={2011}, month={Mar}, pages={919–935} }
 @article{dwekat_rouskas_2011, title={A practical fair queuing scheduler: Simplification through quantization}, volume={55}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2011.04.004}, abstractNote={The design of fair packet schedulers involves a tradeoff between implementation complexity, on one hand, and delay and fairness guarantees, on the other. In this paper, we present tiered-service fair queuing (TSFQ), a new scheduler that exploits certain properties of Internet traffic to speed up the bottleneck operations related to virtual time computation and packet sorting. Specifically, TSFQ makes innovative use of quantization (along the two dimensions of flow weights and packet lengths) her with specialized yet simple queuing structures. TSFQ combines all three properties that are important to a fair queuing algorithm, namely, a tight delay bound, worst-case fairness, and low complexity and amenability to hardware implementation. Hence, we believe that, for network operators, deploying TSFQ scheduling has the potential to enhance their ability to offer and guarantee a wide range of services.}, number={10}, journal={COMPUTER NETWORKS}, author={Dwekat, Z. and Rouskas, G. N.}, year={2011}, month={Jul}, pages={2392–2406} }
 @article{vishwanath_sivaraman_rouskas_2011, title={Anomalous Loss Performance for Mixed Real-Time and TCP Traffic in Routers With Very Small Buffers}, volume={19}, ISSN={["1558-2566"]}, DOI={10.1109/tnet.2010.2091721}, abstractNote={In the past few years there has been vigorous debate regarding the size of buffers required at core Internet routers. Recent arguments supported by theory and experimentation show that under certain conditions, core router buffer sizes of a few tens of packets suffice for realizing acceptable end-to-end TCP throughputs. This is a significant step toward the realization of optical packet switched (OPS) networks, which are inherently limited in their ability to buffer optical signals. However, prior studies have largely ignored the presence of real-time traffic, which is increasing in importance as a source of revenue for Internet service providers. In this paper, we study the interaction that happens between real-time (open-loop) and TCP (closed-loop) traffic when they multiplex at buffers of very small size (few tens of packets) and make a significant discovery - namely that in a specific range of buffer size, real-time traffic losses increase as buffer size becomes larger. Our contributions pertaining to this anomalous behavior are threefold. First, we exhibit this anomalous loss performance for real-time traffic via extensive simulations using synthetic traffic and real video traces. Second, we develop quantitative models that reveal the dynamics of buffer sharing between real-time and TCP traffic that lead to this behavior. Third, we show how various factors such as the nature of real-time traffic, mixture of long-lived and short-lived TCP flows, and packet sizes impact the severity of the anomaly. Our study is the first to consider interactions between real-time and TCP traffic in very small (potentially all-optical) buffers and informs router manufacturers and network operators of the factors to consider when dimensioning such small buffer sizes for desired performance balance between real-time and TCP traffic.}, number={4}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, author={Vishwanath, Arun and Sivaraman, Vijay and Rouskas, George N.}, year={2011}, month={Aug}, pages={933–946} }
 @article{bristianou_panou_chatzidakis_tsiligrou_theodosopoulos_rouskas_liaskoni_lanaras_2011, title={CAUSES OF FOURTH AGED PATIENTS HOSPITALIZATION IN AN INTERNAL MEDICINE HOSPITAL CLINIC}, volume={22}, ISSN={0953-6205}, url={http://dx.doi.org/10.1016/S0953-6205(11)60442-1}, DOI={10.1016/S0953-6205(11)60442-1}, journal={European Journal of Internal Medicine}, publisher={Elsevier BV}, author={Bristianou, Magdalini and Panou, Charalambos and Chatzidakis, Ioannis and Tsiligrou, Vaina and Theodosopoulos, Ioannis and Rouskas, Georgios and Liaskoni, Constantina and Lanaras, Leonidas}, year={2011}, month={Oct}, pages={S108–S109} }
 @article{wang_wang_bathula_lai_baldine_chen_majumder_gurkan_rouskas_dutta_et al._2011, title={Demonstration of QoS-Aware Video Streaming over a Metro-Scale Optical Network Using a Cross-Layer Architectural Design}, journal={2011 Optical Fiber Communication Conference and Exposition (Ofc/nfoec) and the National Fiber Optic Engineers Conference}, author={Wang, Michael S. and Wang, Anjing and Bathula, Balagangadhar G. and Lai, Caroline P. and Baldine, Ilia and Chen, Cathy and Majumder, Debjyoti and Gurkan, Deniz and Rouskas, George N. and Dutta, Rudra and et al.}, year={2011} }
 @article{bianco_jukan_rouskas_2011, title={Elsevier OSN is Sad to Announce the Loss of Fabio Neri, co-Editor-in-Chief of the Journal, Distinguished Professor and Researcher}, volume={8}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/j.osn.2011.09.001}, DOI={10.1016/j.osn.2011.09.001}, number={4}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Bianco, Andrea and Jukan, Admela and Rouskas, George}, year={2011}, month={Dec}, pages={286–287} }
 @article{yetginer_liu_rouskas_2011, title={Fast Exact ILP Decompositions for Ring RWA}, volume={3}, ISSN={["1943-0639"]}, DOI={10.1364/jocn.3.000577}, abstractNote={Wavelength division multiplexing rings are now capable of supporting more than 100 wavelengths over a single fiber. Conventional link and path formulations for the routing and wavelength assignment problem are inefficient due to the inherent symmetry in wavelength assignment and the fact that the problem size increases fast with the number of wavelengths. Although a formulation based on maximal independent sets (MIS) does not have these drawbacks, it suffers from exponential growth in the number of variables with increasing network size. We develop a new ILP (integer linear program) formulation based on the key idea of partitioning the path set and representing the MIS in the original network using the independent sets calculated in each of these partitions. This exact decomposition trades off the number of variables with the number of constraints and, as a result, achieves a much better scalability in terms of network dimension. Numerical results on ring networks of various sizes demonstrate that this new ILP decomposition achieves a decrease of several orders of magnitude in running time compared to existing formulations. Our main contribution is a novel and extremely fast technique for obtaining, in a few seconds using commodity CPUs, optimal solutions to instances of maximum size SONET rings with any number of wavelengths; such instances cannot be tackled with classical formulations without vast investments in computational resources and time.}, number={7}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Yetginer, Emre and Liu, Zeyu and Rouskas, George N.}, year={2011}, month={Jul}, pages={577–586} }
 @article{wang_rouskas_ieee_2011, title={Flow Isolation in Optical Networks}, journal={2011 18th Ieee Workshop on Local and Metropolitan Area Networks (Lanman)}, author={Wang, Hui and Rouskas, George N. and IEEE}, year={2011} }
 @article{cao_rouskas_ieee_2011, title={Hybrid FRR/p-Cycle MPLS Link Protection Design}, journal={2011 Ieee Global Telecommunications Conference (Globecom 2011)}, author={Cao, Chang and Rouskas, George N. and IEEE}, year={2011} }
 @article{lv_rouskas_ieee_2011, title={On Optimal Tiered Structures for Network Service Bundles}, journal={2011 Ieee Global Telecommunications Conference (Globecom 2011)}, author={Lv, Qian and Rouskas, George N. and IEEE}, year={2011} }
 @inproceedings{lv_rouskas_2011, title={On optimal tiered structures for network service bundles}, DOI={10.1109/glocom.2011.6133598}, abstractNote={Network operators offer a variety of tiered services in which users may select only from a small set of tiers which offer progressively higher levels of service. Service bundling, whereby several services are combined together and sold as a single package, is also common in the telecommunications market. We consider the problem of determining optimal tiering structures for service bundles using tools from economics and utility theory. Our work provides insight into the selection and pricing of Internet tiered services.}, booktitle={2011 ieee global telecommunications conference (globecom 2011)}, author={Lv, Q. and Rouskas, G. N.}, year={2011} }
 @article{castillo_rouskas_harfoush_2011, title={Online algorithms for advance resource reservations}, volume={71}, ISSN={["1096-0848"]}, DOI={10.1016/j.jpdc.2011.01.003}, abstractNote={We consider the problem of providing QoS guarantees to Grid users through advance reservation of resources. Advance reservation mechanisms provide the ability to allocate resources to users based on agreed-upon QoS requirements and increase the predictability of a Grid system, yet incorporating such mechanisms into current Grid environments has proven to be a challenging task due to the resulting resource fragmentation. We use concepts from computational geometry to present a framework for tackling the resource fragmentation, and for formulating a suite of scheduling strategies. We also develop efficient implementations of the scheduling algorithms that scale to large Grids. We conduct a comprehensive performance evaluation study using simulation, and we present numerical results to demonstrate that our strategies perform well across several metrics that reflect both user- and system-specific goals. Our main contribution is a timely, practical, and efficient solution to the problem of scheduling resources in emerging on-demand computing environments.}, number={7}, journal={JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING}, author={Castillo, C. and Rouskas, G. N. and Harfoush, K.}, year={2011}, month={Jul}, pages={963–973} }
 @article{dwekat_rouskas_ieee_2011, title={Worst-Case Fair Bin Sort Queuing (WBSQ): An O(1) Worst-Case Fair Scheduler}, journal={2011 Ieee International Conference on Communications (Icc)}, author={Dwekat, Zyad A. and Rouskas, George N. and IEEE}, year={2011} }
 @article{karmous-edwards_polito_jukan_rouskas_2010, title={A new framework for GLIF Interdomain Resource Reservation Architecture (GIRRA)}, volume={65}, ISSN={["1958-9395"]}, DOI={10.1007/s12243-010-0186-y}, number={11-12}, journal={ANNALS OF TELECOMMUNICATIONS}, author={Karmous-Edwards, Gigi and Polito, Silvana Greco and Jukan, Admela and Rouskas, George}, year={2010}, pages={723–737} }
 @article{lv_rouskas_2010, title={An economic model for pricing tiered network services}, volume={65}, ISSN={["1958-9395"]}, DOI={10.1007/s12243-009-0149-3}, number={3-4}, journal={ANNALS OF TELECOMMUNICATIONS}, author={Lv, Qian and Rouskas, George N.}, year={2010}, month={Apr}, pages={147–161} }
 @article{chen_rouskas_dutta_2010, title={Clustering Methods for Hierarchical Traffic Grooming in Large-Scale Mesh WDM Networks}, volume={2}, ISSN={["1943-0639"]}, DOI={10.1364/jocn.2.000502}, abstractNote={We consider a hierarchical approach for traffic grooming in large multiwavelength networks of a general topology. Inspired by similar concepts in the airline industry, we decompose the network into clusters, and select a hub node in each cluster to groom traffic originating and terminating locally. At the second level of the hierarchy, the hub nodes form a virtual cluster for the purpose of grooming intra-cluster traffic. Clustering and hierarchical grooming enables us to cope with large network sizes and facilitates the control and management of traffic and network resources. Yet, determining the size and composition of clusters so as to yield good grooming solutions is a challenging task. We identify the grooming-specific factors affecting the selection of clusters, and we develop a parameterized clustering algorithm that can achieve a desired trade-off among various goals. We also obtain lower bounds on two important objectives in traffic grooming: the number of lightpaths and wavelengths needed to carry the subwavelength traffic. We demonstrate the effectiveness of clustering and hierarchical grooming by presenting the results of experiments on two network topologies that are substantially larger than those considered in previous traffic grooming studies.}, number={8}, journal={JOURNAL OF OPTICAL COMMUNICATIONS AND NETWORKING}, author={Chen, Bensong and Rouskas, George N. and Dutta, Rudra}, year={2010}, month={Aug}, pages={502–514} }
 @article{baldine_dutta_rouskas_ieee_2009, title={A Unified Architecture for Cross Layer Design in the Future Optical Internet}, journal={2009 35th European Conference on Optical Communication (Ecoc)}, author={Baldine, I. and Dutta, R. and Rouskas, G. and IEEE}, year={2009} }
 @article{lv_rouskas_ieee_2009, title={An Economic Model for Pricing Tiered Network Services}, journal={2009 Ieee International Conference on Communications, Vols 1-8}, author={Lv, Qian and Rouskas, George N. and IEEE}, year={2009}, pages={1470–1475} }
 @article{vishwanath_sivaraman_rouskas_ieee_2009, title={Considerations for Sizing Buffers in Optical Packet Switched Networks}, DOI={10.1109/INFCOM.2009.5062047}, abstractNote={Optical packet switches of the foreseeable future are expected to have severely limited buffering capability, since storage of optical signals remains a difficult and expensive operation. Our observations in simulation of TCP and real- time traffic in networks with such small buffers have revealed regions of anomalous performance in which losses for real-time traffic become higher as buffers get larger. The detrimental impact of larger optical buffers is studied in this paper and three new contributions are made. First, we develop a Markov chain model that allows analytical computation of loss. Our model validates observations from simulation, and opens the doors to an analytical understanding of how various factors affect the anomaly. Second, we study the anomaly under realistic traffic mixes containing persistent and non-persistent TCP flows, and show that the traffic mix does not significantly alter the anomaly. Third, we show that larger diversity in packet size between TCP and real-time traffic increases the severity of the anomaly, and is an important consideration when sizing optical switch buffers, particularly since real-time and TCP ACK packets are significantly smaller than the TCP data packets. Our study informs switch manufacturers and network operators of factors to consider when selecting optical buffer sizes in order to achieve desired performance balance between TCP and real-time traffic.}, journal={Ieee Infocom 2009 - Ieee Conference on Computer Communications, Vols 1-5}, author={Vishwanath, Arun and Sivaraman, Vijay and Rouskas, George N. and IEEE}, year={2009}, pages={1323–1331} }
 @article{karmous-edwards_vishwanath_reeves_battestilli_vegesna_rouskas_ieee_2009, title={ERONs: Dynamic Lightpath Networking via Overlay Control of Static Optical Connections}, journal={Ondm: 2009 International Conference on Optical Network Design and Modeling}, author={Karmous-Edwards, Gigi and Vishwanath, Arun and Reeves, Douglas and Battestilli, Lina and Vegesna, Priyanka and Rouskas, George N. and IEEE}, year={2009}, pages={1–6} }
 @article{karmous-edwards_vishwanath_reeves_battestilli_vegesna_rouskas_2009, title={Edge-Reconfigurable Optical Networks (ERONs): Rationale, Network Design, and Evaluation}, volume={27}, ISSN={0733-8724 1558-2213}, url={http://dx.doi.org/10.1109/jlt.2009.2021279}, DOI={10.1109/JLT.2009.2021279}, abstractNote={To bridge the gap between the current practice of setting up expensive, dedicated, lightpath connections (i.e., static topologies), and the distant future vision of inexpensive access to dynamically switched end-to-end lightpaths, we propose a medium term solution in the form of edge-reconfigurable optical networks (ERONs). An ERON is an overlay-control network created by installing readily available MEMS optical switches, and implementing a GMPLS control plane at sites interconnected by static lightpaths. The switches and control software are deployed at the edge of the network and operated by the organization-user (i.e., outside the network provider's control), hence the term ldquoedge-reconfigurablerdquo. By providing dynamic, automated control of end-to-end lightpaths, ERONs enable the sharing of expensive network resources among multiple users and applications that require sporadic access to these resources. We develop an algorithm for creating an ERON from an existing topology of static lightpaths. We also present simulation results that quantify the benefits of ERONs, in terms of the number of lightpaths that are needed when compared to a static configuration of independent and dedicated circuits.}, number={12}, journal={Journal of Lightwave Technology}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Karmous-Edwards, G. and Vishwanath, A. and Reeves, D.S. and Battestilli, L. and Vegesna, P.B. and Rouskas, G.N.}, year={2009}, month={Jun}, pages={1837–1845} }
 @book{ramamurthy_rouskas_sivalingam_2009, title={Next-Generation Internet Architectures and Protocols}, ISBN={9780511920950}, url={http://dx.doi.org/10.1017/cbo9780511920950}, DOI={10.1017/cbo9780511920950}, abstractNote={With ever-increasing demands on capacity, quality of service, speed, and reliability, current Internet systems are under strain and under review. Combining contributions from experts in the field, this book captures the most recent and innovative designs, architectures, protocols, and mechanisms that will enable researchers to successfully build the next-generation Internet. A broad perspective is provided, with topics including innovations at the physical/transmission layer in wired and wireless media, as well as the support for new switching and routing paradigms at the device and sub-system layer. The proposed alternatives to TCP and UDP at the data transport layer for emerging environments are also covered, as are the novel models and theoretical foundations proposed for understanding network complexity. Finally, new approaches for pricing and network economics are discussed, making this ideal for students, researchers, and practitioners who need to know about designing, constructing, and operating the next-generation Internet.}, publisher={Cambridge University Press}, year={2009} }
 @article{rouskas_baradwaj_2009, title={On Bandwidth Tiered Service}, volume={17}, ISSN={["1063-6692"]}, DOI={10.1109/TNET.2009.2017928}, abstractNote={Many network operators offer some type of tiered service, in which users may select only from a small set of service levels (tiers). Such a service has the potential to simplify a wide range of core network functions, allowing the providers to scale their operations efficiently. In this work, we study a number of problem variants related to service tier selection. Our contributions include: (1) a faster algorithm for obtaining optimal service tiers; (2) a new formulation and optimal algorithm to optimize jointly the number and magnitude of each service tier; and (3) the concept of ??TDM emulation?? in which all service tiers are multiples of the same (software-configurable) bandwidth unit, and a suite of algorithms to select jointly the basic unit and service tiers. Our work provides a systematic framework for reasoning about and tackling algorithmically the general problem of service tier selection, and has applications to a number of networking contexts, including access networks (e.g., determining the tiers for ADSL, cable modem networks or PONs) and core networks (e.g., LSP sizing for MPLS networks).}, number={6}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, author={Rouskas, George N. and Baradwaj, Nikhil}, year={2009}, month={Dec}, pages={1780–1793} }
 @article{yetginer_rouskas_ulema_2009, title={Power Efficient Traffic Grooming in Optical WDM Networks}, journal={Globecom 2009 - 2009 Ieee Global Telecommunications Conference, Vols 1-8}, author={Yetginer, Emre and Rouskas, George N. and Ulema, M}, year={2009}, pages={1838–1843} }
 @article{castillo_rouskas_harfoush_acm_2009, title={Resource Co-Allocation for Large-Scale Distributed Environments}, journal={Hpdc'09: 18th Acm International Symposium on High Performance Distributed Computing}, author={Castillo, Claris and Rouskas, George N. and Harfoush, Khaled and ACM}, year={2009}, pages={131–140} }
 @article{iyer_rouskas_dutta_ieee_2008, title={A Hierarchical Model for Multigranular Optical Networks}, DOI={10.1109/BROADNETS.2008.4769124}, abstractNote={We present a hierarchical algorithm for grooming lightpaths into wavebands, and routing wavebands over a network of multigranular switching nodes. This algorithm focuses on lowering the number of wavelengths W and ports over the network while being conceptually simple, scalable, and consistent with the way networks are operated and controlled in practice. Our experiments indicate that this algorithm easily scales across different waveband and network sizes.}, journal={2008 5th International Conference on Broadband Communications, Networks and Systems (Broadnets 2008)}, author={Iyer, Mohan and Rouskas, George N. and Dutta, Rudra and IEEE}, year={2008}, pages={444–451} }
 @article{rouskas_dutta_baldine_ieee_2008, title={A New Internet Architecture to Enable Software Defined Optics and Evolving Optical Switching Models}, DOI={10.1109/BROADNETS.2008.4769046}, abstractNote={The design of the SILO network architecture of fine-grain services was based on three fundamental principles. First, SILO generalizes the concept of layering and decouples layers from services, making it possible to introduce easily new functionality and innovations into the architecture. Second, cross-layer interactions are explicitly supported by extending the definition of a service to include control interfaces that can be tuned externally so as to modify the behavior of the service. The third principle is ldquodesign for change:ldquo the architecture does not dictate the services to be implemented, but provides mechanisms to introduce new services and compose them to perform specific communication tasks. In this paper, we provide an update on the current status of the architecture and the prototype software implementation. We also introduce the concept of ldquosoftware defined opticsrdquo (SDO) to refer to the emerging intelligent and programmable optical layer. We then explain how the SILO architecture may enable the rapid adoption of SDO functionality as well as evolving optical switching models, in particular, optical burst switching (OBS).}, journal={2008 5th International Conference on Broadband Communications, Networks and Systems (Broadnets 2008)}, author={Rouskas, George N. and Dutta, Rudra and Baldine, Ilia and IEEE}, year={2008}, pages={71–76} }
 @article{karmous-edwards_reeves_rouskas_battestilli_vegesna_vishwanath_ieee_2008, title={Edge Reconfigurable Optical Network (ERON): Enabling Dynamic Sharing of Static Lightpaths}, DOI={10.1109/BROADNETS.2008.4769097}, abstractNote={In this paper, we propose an edge reconfigurable optical network as an intermediate step toward fully dynamic optical core network. ERON is an overlay-control network created by installing GMPLS-enabled MEMs optical switches at the edge of a core optical network composed of static lightpaths. We propose a network design algorithm that takes as input the key resource locations dispersed globally and a realistic traffic matrix from end-users and outputs a virtual topology comprised of the minimum required static lightpaths interconnected via ERON switches. This paper describes the key concepts involved in the design of an efficient ERON network combined with routing and reservation algorithms to assure low blocking probabilities. We also describe the management and control architecture and protocols required to provide end-user/application control of the dynamic lightpaths.}, journal={2008 5th International Conference on Broadband Communications, Networks and Systems (Broadnets 2008)}, author={Karmous-Edwards, Gigi and Reeves, Douglas and Rouskas, George and Battestilli, Lina and Vegesna, Priyanka and Vishwanath, Arun and IEEE}, year={2008}, pages={332–334} }
 @article{castillo_rouskas_harfoush_ieee_2008, title={Efficient resource management using advance reservations for heterogeneous Grids}, journal={2008 Ieee International Symposium on Parallel & Distributed Processing, Vols 1-8}, author={Castillo, Claris and Rouskas, George N. and Harfoush, Khaled and IEEE}, year={2008}, pages={916–927} }
 @misc{dutta_kamal_rouskas_2008, title={Grooming Mechanisms in SONET/SDH and Next-Generation SONET/SDH}, ISBN={9780387745176 9780387745183}, ISSN={1935-3839}, url={http://dx.doi.org/10.1007/978-0-387-74518-3_4}, DOI={10.1007/978-0-387-74518-3_4}, abstractNote={Synchronous Optical Network (SONET) and Synchronous Digital Hierarchy (SDH) are very closely related standards, which came into being primarily as a means of transporting telephone traffic in large volumes utilizing optical fiber transmission systems. SONET was brought forth by Bellcore (Telcordia), with coordination from International Telecommunication Union (ITU) as well as other standards organizations, and is primarily in use in North America, whereas SDH was developed by ITU, came into use slightly later than SONET, and is in use in the rest of the world. The two standards so closely resemble each other in most significant concepts as well as details that they are often spoken of as a single entity, and denoted as SONET/SDH. In what follows in the rest of this chapter as well as elsewhere in the book, the distinctions between the two are not important, and we continue to mean “SONET/SDH”, even when we mention just one of them, for ease of reference. From the grooming point of view, SONET/SDH are very important entities. Transmission systems for telephony, originally analog, adopted digital systems starting with the introduction of the T-carrier system in 1961. From the very beginning, such systems adopted a “base rate” which was defined by the digitization of a single voice line, and successively higher rates formed by multiplexing larger number of lower rate channels, thanks to the hierarchical nature of the telephony architecture; this is the origin of the term digital hierarchy. The term Plesiochronous Digital Hierarchy (PDH) is used to describe all such digital standards before the advent of SONET/SDH. This indicates a system in which all parts operate on clock signals that have exactly the same rate (within a bounded error), but may have different phases. Such a characteristic is arguably not a design decision as much as it is an adjustment to the realistically inevitable. The move to optical transmission systems was accompanied by a move to a synchronous architecture, which means that SONET/SDH performs multiplexing in a strictly time division multiplexed}, journal={Optical Networks}, publisher={Springer US}, author={Dutta, Rudra and Kamal, Ahmed E. and Rouskas, George N.}, year={2008}, month={Aug}, pages={39–55} }
 @inbook{rouskas_dutta_2008, title={Hierarchical Traffic Grooming}, ISBN={9780387745176 9780387745183}, ISSN={1935-3839}, url={http://dx.doi.org/10.1007/978-0-387-74518-3_6}, DOI={10.1007/978-0-387-74518-3_6}, booktitle={Optical Networks}, publisher={Springer US}, author={Rouskas, George N. and Dutta, Rudra}, editor={Dutta, Rudra and Kamal, Ahmed E. and Rouskas, George N.Editors}, year={2008}, pages={73–88} }
 @misc{dutta_kamal_rouskas_2008, title={Introduction}, ISBN={9780387745176 9780387745183}, ISSN={1935-3839}, url={http://dx.doi.org/10.1007/978-0-387-74518-3_1}, DOI={10.1007/978-0-387-74518-3_1}, journal={Optical Networks}, publisher={Springer US}, author={Dutta, Rudra and Kamal, Ahmed E. and Rouskas, George N.}, year={2008}, pages={1–6} }
 @article{chen_rouskas_dutta_2008, title={On Hierarchical Traffic Grooming in WDM Networks}, volume={16}, ISSN={["1558-2566"]}, DOI={10.1109/TNET.2007.906655}, abstractNote={The traffic grooming problem is of high practical importance in emerging wide-area wavelength division multiplexing (WDM) optical networks, yet it is intractable for any but trivial network topologies. In this work, we present an effective and efficient hierarchical traffic grooming framework for WDM networks of general topology, with the objective of minimizing the total number of electronic ports. At the first level of hierarchy, we decompose the network into clusters and designate one node in each cluster as the hub for grooming traffic. At the second level, the hubs form another cluster for grooming intercluster traffic. We view each (first- or second-level) cluster as a virtual star, and we present an efficient near-optimal algorithm for determining the logical topology of lightpaths to carry the traffic within each cluster. Routing and wavelength assignment is then performed directly on the underlying physical topology. We demonstrate the effectiveness of our approach by applying it to two networks of realistic size, a 32-node, 53-link topology and a 47-node, 96-link network. Comparisons to lower bounds indicate that hierarchical grooming is efficient in its use of the network resources of interest, namely, electronic ports and wavelengths. In addition to scaling to large network sizes, our hierarchical approach also facilitates the control and management of multigranular networks.}, number={5}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, author={Chen, Bensong and Rouskas, George N. and Dutta, Rudra}, year={2008}, month={Oct}, pages={1226–1238} }
 @inbook{lv_rouskas_ieee_2008, title={On optimal sizing of tiered network services}, booktitle={27th Ieee Conference on Computer Communications (Infocom), Vols 1-5}, author={Lv, Qian and Rouskas, George N. and IEEE}, year={2008}, pages={1–5} }
 @book{dutta_kamal_rouskas_2008, title={Traffic Grooming for Optical Networks}, ISBN={9780387745176 9780387745183}, ISSN={1935-3839}, url={http://dx.doi.org/10.1007/978-0-387-74518-3}, DOI={10.1007/978-0-387-74518-3}, abstractNote={The objective of this book is to provide timely and comprehensive coverage of the principles, technology, practice, and future of tra?c grooming in op- cal networks. Tra?c grooming considerations are}, publisher={Springer US}, year={2008} }
 @article{rouskas_dwekat_ieee_2007, title={A practical and efficient implementation of WF(2)Q+}, DOI={10.1109/ICC.2007.36}, abstractNote={The WF2Q+ scheduler combines all three properties that are important to a fair queueing algorithm: a tight delay bound, a small worst-case fair index value, and a relatively low worst-case complexity of O(log n) for a link with n flows. We present a new implementation of WF2Q+ in which both the number of packet sorting operations and the computation of the virtual time function are independent of the number n of flows. Our implementation exploits two widely observed characteristics of the Internet, namely that service providers offer some type of tiered service with a small number of service levels, and that a small number of packet sizes dominate. Our scheduler combines provably good performance with amenability to hardware implementation in high-speed routers.}, journal={2007 Ieee International Conference on Communications, Vols 1-14}, author={Rouskas, George N. and Dwekat, Zyad and IEEE}, year={2007}, pages={172–176} }
 @inbook{baldine_vellala_wang_rouskas_dutta_stevenson_ieee_2007, title={A unified software architecture to enable cross-layer design in the future Internet}, booktitle={Proceedings - 16th International Conference on Computer Communications and Networks, Vols 1-3}, author={Baldine, Ilia and Vellala, Manoj and Wang, Anjing and Rouskas, George and Dutta, Rudra and Stevenson, Daniel and IEEE}, year={2007}, pages={26–32} }
 @inbook{chen_dutta_rouskas_2007, title={Clustering for Hierarchical Traffic Grooming in Large Scale Mesh WDM Networks}, ISBN={9783540727293}, url={http://dx.doi.org/10.1007/978-3-540-72731-6_28}, DOI={10.1007/978-3-540-72731-6_28}, abstractNote={We present a clustering algorithm for hierarchical traffic grooming in large WDM networks. In hierarchical grooming, the network is decomposed into clusters, and one hub node in each cluster is responsible for grooming traffic from and to the cluster. Hierarchical grooming scales to large network sizes and facilitates the control and management of traffic and network resources. Yet determining the size and composition of clusters so as to yield good grooming solutions is a challenging task. We identify the grooming-specific factors affecting the selection of clusters, and we develop a parameterized clustering algorithm that can achieve a desired tradeoff among various goals.}, booktitle={Optical Network Design and Modeling}, publisher={Springer Berlin Heidelberg}, author={Chen, Bensong and Dutta, Rudra and Rouskas, George N.}, year={2007}, month={Jul}, pages={249–258} }
 @inbook{chen_dutta_rouskas_tomkos_neri_pareta_bruin_lopez_2007, title={Clustering for hierarchical traffic grooming in large scale mesh WDM networks}, volume={4534}, booktitle={Optical Network Design and Modeling, Proceedings}, author={Chen, Bensong and Dutta, Rudra and Rouskas, George N. and Tomkos, I and Neri, F and Pareta, JS and Bruin, XM and Lopez, SS}, year={2007}, pages={249–258} }
 @article{rouskas_baradwaj_ieee_2007, title={Framework for tiered service in MPLS networks}, DOI={10.1109/INFCOM.2007.185}, abstractNote={Many network operators offer some type of tiered service, in which users may select only from a small set of service levels (tiers). Such a service has the potential to simplify a wide range of core network functions, allowing the providers to scale their operations efficiently. In this work, we provide a theoretical framework for reasoning about and tackling algorithmically the general problem of service tier selection. Drawing upon results from discrete location theory, we formulate the problem as a p-median problem under a new directional distance measure, and we develop efficient algorithms for a number of important variants. Our main finding is that, by appropriately selecting the set of service levels, network providers may realize the benefits of tiered service with only a small sacrifice in network resources.}, journal={Infocom 2007, Vols 1-5}, author={Rouskas, George N. and Baradwaj, Nikhil and IEEE}, year={2007}, pages={1577–1585} }
 @article{yang_rouskas_2007, title={Generalized wavelength sharing policies for absolute QoS guarantees in OBS networks}, volume={25}, ISSN={["1558-0008"]}, DOI={10.1109/TWC.2007.026706}, abstractNote={We consider the problem of supporting absolute QoS guarantees in terms of the end-to-end burst loss in OBS networks. We present a parameterized model for wavelength sharing which provides for isolation among different traffic classes while also making efficient use of wavelength capacity through statistical multiplexing. We develop a heuristic to optimize the policy parameters for a single link of an OBS network. We also develop a methodology for translating the end-to-end QoS requirements into appropriate per-link parameters so as to provide network-wide guarantees. Our approach is easy to implement, it can support a wide variety of traffic classes, and is effective in meeting the QoS requirements and keeping the loss rate of best-effort and overall traffic low}, number={4}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Yang, Li and Rouskas, George N.}, year={2007}, month={Apr}, pages={93–104} }
 @article{iyer_rouskas_dutta_ieee_2007, title={Hierarchical Grooming in Multigranular Networks}, journal={2007 First International Symposium on Advanced Networks and Telecommunication Systems}, author={Iyer, Mohan and Rouskas, George N. and Dutta, Rudra and IEEE}, year={2007}, pages={35–36} }
 @article{stevenson_dutta_rouskas_reeves_baldine_ieee_2007, title={On the suitability of composable services for the assurable future Internet}, journal={2007 Ieee Military Communications Conference, Vols 1-8}, author={Stevenson, Daniel and Dutta, Rudra and Rouskas, George and Reeves, Douglas and Baldine, Ilia and IEEE}, year={2007}, pages={3695–3701} }
 @article{yang_rouskas_2007, title={Optimal wavelength sharing policies in OBS networks subject to QoS constraints}, volume={25}, ISSN={["1558-0008"]}, DOI={10.1109/JSAC-OCN.2007.029707}, abstractNote={We consider the general problem of optimizing the performance of OBS networks with multiple traffic classes subject to strict (absolute) QoS constraints in terms of the end-to-end burst loss rate of each guaranteed class of traffic. We employ Markov decision process (MDP) theory to obtain optimal wavelength sharing policies for two performance objectives, namely, maximization of weighted network throughput and minimization of the loss rate of best-effort traffic, while meeting the QoS guarantees. The randomized threshold policies we obtain are simple to implement and operate, and make effective use of statistical multiplexing. In particular, the threshold randomization feature enables the policies to allocate bandwidth at arbitrarily fine sub-wavelength granularity, hence making effective use of the available network capacity.}, number={9}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Yang, Li and Rouskas, George N.}, year={2007}, month={Dec}, pages={40–49} }
 @article{rouskas_baradwaj_ieee_2007, title={TDM emulation in packet-switched networks}, DOI={10.1109/ICC.2007.318}, abstractNote={Many network operators offer some type of tiered service, in which users may select only from a small set of service levels (tiers). In this work, we study the problem of designing a tiered-service network that allocates bandwidth in multiples of a basic bandwidth unit. Such a packet-switched network can enjoy many of the benefits, in terms of control and management, of a TDM network, but without the associated data plane rigidities.}, journal={2007 Ieee International Conference on Communications, Vols 1-14}, author={Rouskas, George N. and BaradwaJ, Nikhil and IEEE}, year={2007}, pages={1911–1916} }
 @article{dutta_rouskas_baldine_bragg_stevenson_ieee_2007, title={The SILO architecture for services integration, control, and optimization for the future Internet}, DOI={10.1109/ICC.2007.316}, abstractNote={We propose a new internetworking architecture that represents a departure from current philosophy and practice, as a contribution to the ongoing debate regarding the future Internet. Building upon our experience with the design and prototyping of the just-in-time protocol suite, we outline a framework consisting of (1) building blocks of fine-grain functionality, (2) explicit support for combining elemental blocks to accomplish highly configurable complex communication tasks, and (3) control elements to facilitate (what is currently referred to as) cross-layer interactions. In this position paper, we take a holistic view of network design, allowing applications to work synergistically with the network architecture and physical layers to select the most appropriate functional blocks and tune their behavior so as to meet the application's needs within resource availability constraints. The proposed architecture is flexible and extensible so as to foster innovation and accommodate change, it supports a unified Internet, it allows for the integration of security and management features at any point in (what is now referred to as) the networking stack, and it is positioned to take advantage of hardware-based performance-enhancing techniques.}, journal={2007 Ieee International Conference on Communications, Vols 1-14}, author={Dutta, Rudra and Rouskas, George N. and Baldine, Ilia and Bragg, Arnold and Stevenson, Dan and IEEE}, year={2007}, pages={1899–1904} }
 @article{jackson_rouskas_stallmann_2007, title={The directional p-median problem: Definition, complexity, and algorithms}, volume={179}, ISSN={["0377-2217"]}, DOI={10.1016/j.ejor.2005.06.080}, abstractNote={An instance of a p-median problem gives n demand points. The objective is to locate p supply points in order to minimize the total distance of the demand points to their nearest supply point. p-Median is polynomially solvable in one dimension but NP-hard in two or more dimensions, when either the Euclidean or the rectilinear distance measure is used. In this paper, we treat the p-median problem under a new distance measure, the directional rectilinear distance, which requires the assigned supply point for a given demand point to lie above and to the right of it. In a previous work, we showed that the directional p-median problem is polynomially solvable in one dimension; we give here an improved solution through reformulating the problem as a special case of the constrained shortest path problem. We have previously proven that the problem is NP-complete in two or more dimensions; we present here an efficient heuristic to solve it. Compared to the robust Teitz and Bart heuristic, our heuristic enjoys substantial speedup while sacrificing little in terms of solution quality, making it an ideal choice for real-world applications with thousands of demand points.}, number={3}, journal={EUROPEAN JOURNAL OF OPERATIONAL RESEARCH}, author={Jackson, Laura E. and Rouskas, George N. and Stallmann, Matthias F. M.}, year={2007}, month={Jun}, pages={1097–1108} }
 @article{yang_rouskas_ieee_2006, title={A framework for absolute QoS guarantees in optical burst switched networks}, journal={2006 3rd International Conference on Broadband Communications, Networks and Systems, Vols 1-3}, author={Yang, Li and Rouskas, George N. and IEEE}, year={2006}, pages={1–10} }
 @article{yang_rouskas_2006, title={Adaptive path selection in OBS networks}, volume={24}, DOI={10.1109/JLT.2006.878087}, abstractNote={In this paper, the authors investigate the concept of adaptive path selection in optical burst-switched networks and its potential to reducing the overall burst drop probability. Specifically, the authors assume that each source maintains a (short) list of alternate paths to each destination and uses information regarding the recent congestion status of the network links to rank the paths; it then transmits bursts along the least congested path. The authors present a suite of path selection strategies, each utilizing a different type of information regarding the link congestion status, and evaluate them using simulation. The results demonstrate that, in general, adaptive path selection outperforms shortest path routing, and, depending on the path strategy involved, the network topology, and the traffic pattern, this improvement can be significant. A new framework for the development of hybrid (or meta) path selection strategies, which make routing decisions based on a weighted combination of the decisions taken by several independent path selection strategies, has been presented. This paper presents two instances of such hybrid strategies, i.e., 1) one that assigns static weights and 2) one that dynamically adjusts the weights based on feedback from the network; it has been shown that these strategies can further improve the overall burst drop probability in the network}, number={8}, journal={Journal of Lightwave Technology}, author={Yang, Li and Rouskas, George N.}, year={2006}, pages={3002–3011} }
 @article{yang_rouskas_ieee_2006, title={Dynamic Wavelength Sharing Policies for Absolute QoS in OBS Networks}, journal={Globecom 2006 - 2006 Ieee Global Telecommunications Conference}, author={Yang, Li and Rouskas, George N. and IEEE}, year={2006} }
 @inproceedings{yang_rouskas_2006, title={Dynamic wavelength sharing policies for absolute QoS in OBS networks}, DOI={10.1109/glocom.2006.386}, abstractNote={We consider the problem of providing absolute QoS guarantees to multiple classes of users of an OBS network in terms of the end-to-end burst loss. We employ Markov decision process (MDP) theory to develop wavelength sharing policies that maximize throughput while meeting the QoS guarantees. The randomized threshold policies we obtain are simple to implement and operate, and make effective use of statistical multiplexing.}, booktitle={Globecom 2006 - 2006 ieee global telecommunications conference}, author={Yang, L. and Rouskas, G. N.}, year={2006} }
 @inbook{rouskas_xu_2006, title={Optical Packet Switching (OPS)}, ISBN={0387290559}, url={http://dx.doi.org/10.1007/0-387-29188-1_17}, DOI={10.1007/0-387-29188-1_17}, booktitle={Optical Networks}, publisher={Kluwer Academic Publishers}, author={Rouskas, G.N. and Xu, L.}, editor={Sivalingam, Krishna and Subramanian, SureshEditors}, year={2006}, month={Jun}, pages={797–843} }
 @article{chen_rouskas_dutta_2006, title={Traffic grooming in WDM ring networks to minimize the maximum electronic port cost.}, volume={2}, number={1}, journal={Optical Switching and Networking}, author={Chen, B. and Rouskas, G. and Dutta, R.}, year={2006}, pages={1–18} }
 @article{huang_dutta_rouskas_2006, title={Traffic grooming in path, star, and tree networks: Complexity, bounds, and algorithms}, volume={24}, ISSN={["1558-0008"]}, DOI={10.1109/jsac-ocn.2006.04006}, number={4}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Huang, Shu and Dutta, Rudra and Rouskas, George N.}, year={2006}, month={Apr}, pages={66–82} }
 @article{chen_rouskas_dutta_ieee_2005, title={A Framework for Hierarchical Traffic Grooming in WDM Networks of General Topology}, journal={2nd International Conference on Broadband Networks (Broadnets 2005)}, author={Chen, Bensong and Rouskas, George N. and Dutta, Rudra and IEEE}, year={2005}, pages={167-+} }
 @article{teng_rouskas_2005, title={A detailed analysis and performance comparison of wavelength reservation schemes for optical burst switched networks}, volume={9}, ISSN={["1572-8188"]}, DOI={10.1007/s11107-004-6435-0}, number={3}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Teng, J and Rouskas, G}, year={2005}, month={May}, pages={311–335} }
 @article{baldine_mehrotra_rouskas_bragg_stevenson_ieee_2005, title={An Intra- and Inter-Domain Routing Architecture for Optical Burst Switched (OBS) Networks}, DOI={10.1109/ICBN.2005.1589726}, abstractNote={We describe an intra- and inter-domain routing architecture for just-in-time (JIT) optical burst switched (OBS) networks. The architecture addresses the problem of routing optical signals of varying types across an all-optical burst-switched backbone network while maintaining the optical signal quality required by each application. The architecture distinguishes between routing for bursts and ancillary signaling messages ("data plane routing"), and routing for other management and control messages ("control plane routing")}, journal={2nd International Conference on Broadband Networks (Broadnets 2005)}, author={Baldine, Ilia and Mehrotra, Pronita and Rouskas, George and Bragg, Arnold and Stevenson, Dan and IEEE}, year={2005}, pages={150-+} }
 @inbook{chen_rouskas_dutta_2005, title={Applying clustering techniques to general topology traffic grooming}, ISBN={0780392779}, booktitle={Proceedings of IEEE / Create-net broadnets 2005}, publisher={Piscataway, N.J.: IEEE}, author={Chen, B. and Rouskas, G. and Dutta, R.}, year={2005}, pages={308–314} }
 @article{neri_rouskas_2005, title={Editorial}, volume={1}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/j.osn.2004.11.003}, DOI={10.1016/j.osn.2004.11.003}, number={1}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Neri, Fabio and Rouskas, George N.}, year={2005}, month={Jan}, pages={1–2} }
 @article{chen_dutta_rouskas_ieee_2005, title={On the Application of K-Center Algorithms to Hierarchical Traffic Grooming}, journal={2nd International Conference on Broadband Networks (Broadnets 2005)}, author={Chen, Bensong and Dutta, Rudra and Rouskas, George N. and IEEE}, year={2005}, pages={295-+} }
 @inbook{chen_dutta_rouskas_2005, title={On the application of k-center algorithms in heirarchical traffic grooming}, ISBN={0780392779}, booktitle={Proceedings of the Second International IEEE/Create-net workshop on traffic grooming}, publisher={Los Alamitos, CA: IEEE Computer Society}, author={Chen, B. and Dutta, R. and Rouskas, G.}, year={2005}, pages={167–176} }
 @inbook{yang_rouskas_2005, title={Path Switching in OBS Networks}, volume={3462}, ISBN={9783540258094 9783540320173}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/11422778_33}, DOI={10.1007/11422778_33}, abstractNote={We investigate the concept of path switching in optical burst switched (OBS) networks and its potential to reducing the overall burst drop probability.With path switching, each source maintains a list of alternate paths to each destination, and uses information regarding the recent congestion status of the network links to rank the paths; it then transmits bursts along the least congested path. We present a suite of path switching strategies, each utilizing a different type of information regarding the link congestion status, and evaluate them using simulation. Our results demonstrate that, in general, path switching outperforms shortest path routing, and, depending on the path strategy involved, the network topology, and the traffic pattern, this improvement can be significant. We also present a new framework for the development of hybrid path switching strategies, which make routing decisions based on a weighted combination of the decisions taken by several independent path switching strategies. We present two instances of such hybrid strategies, one that assigns static weights and one that dynamically adjusts the weights based on feedback from the network.}, booktitle={NETWORKING 2005. Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems}, publisher={Springer Berlin Heidelberg}, author={Yang, Li and Rouskas, George N.}, year={2005}, pages={406–418} }
 @inbook{yang_rouskas_boutaba_almeroth_puigjaner_shen_black_2005, title={Path switching in OBS networks}, volume={3462}, booktitle={Networking 2005: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems}, author={Yang, L and Rouskas, GN and Boutaba, R and Almeroth, K and Puigjaner, R and Shen, S and Black, JP}, year={2005}, pages={406–418} }
 @article{teng_rouskas_pattavina_2005, title={Routing path optimization in optical burst switched networks}, journal={2005 Conference on Optical Network Design and Modelling, Proceedings}, author={Teng, J and Rouskas, GN and Pattavina, A}, year={2005}, pages={1–10} }
 @inbook{rouskas_2005, title={Scheduling Algorithms for Unicast, Multicast, and Broadcast}, ISBN={0792378253}, url={http://dx.doi.org/10.1007/0-306-47021-7_8}, DOI={10.1007/0-306-47021-7_8}, abstractNote={In this chapter we present a survey of algorithms for scheduling packet traffic in broadcast optical WDM networks. We first describe the context and motivations of the scheduling problem. We then review the current literature in the field with an emphasis on scheduling techniques for providing best-effort service as well as guaranteed service for both unicast and multi-destination traffic. We provide alternative formulations of the problem, and we compare the formulations and theoretical results, as well as algorithms and heuristics.}, booktitle={The International Series in Engineering and Computer Science}, publisher={Kluwer Academic Publishers}, author={Rouskas, George N.}, editor={Sivalingam, Krishna and Subramanian, SureshEditors}, year={2005}, month={Dec}, pages={171–188} }
 @article{rouskas_neri_pattavina_bregni_maier_2005, title={Selected papers from Optical Network Design and Modeling (ONDM) 2005 conference}, volume={2}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/j.osn.2006.02.001}, DOI={10.1016/j.osn.2006.02.001}, number={4}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Rouskas, George N. and Neri, Fabio and Pattavina, Achille and Bregni, Stefano and Maier, Guido}, year={2005}, month={Dec}, pages={199–200} }
 @article{rouskas_neri_2005, title={Selected papers from the BROADNETS 2004 Optical Networking Symposium}, volume={2}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/j.osn.2005.06.002}, DOI={10.1016/j.osn.2005.06.002}, number={2}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Rouskas, George N. and Neri, Fabio}, year={2005}, month={Sep}, pages={71} }
 @article{teng_rouskas_2005, title={Traffic engineering approach to path selection in optical burst switching networks}, volume={4}, DOI={10.1364/JON.4.000759}, abstractNote={It is usually assumed that optical burst switching (OBS) networks use the
 shortest path routing along with next-hop burst forwarding. The shortest path
 routing minimizes delay and optimizes utilization of resources, however, it often
 causes certain links to become congested while others remain underutilized. In a
 bufferless OBS network in which burst drop probability is the primary metric of
 interest, the existence of a few highly congested links could lead to unacceptable
 performance for the entire network. We take a traffic engineering approach to path
 selection in OBS networks with the objective of balancing the traffic across the
 network links to reduce congestion and to improve overall performance. We present an
 approximate integer linear optimization problem as well as a simple integer
 relaxation heuristic to solve the problem efficiently for large networks. Numerical
 results demonstrate that our approach is effective in reducing the network-wide
 burst drop probability, in many cases significantly, over the shortest path
 routing.}, number={11}, journal={Journal of Optical Networking}, author={Teng, J and Rouskas, George}, year={2005}, pages={759–777} }
 @article{chen_rouskas_dutta_2005, title={Traffic grooming in WDM ring networks to minimize the maximum electronic port cost}, volume={2}, ISSN={1573-4277}, url={http://dx.doi.org/10.1016/j.osn.2005.01.002}, DOI={10.1016/j.osn.2005.01.002}, abstractNote={We consider the problem of traffic grooming in WDM ring networks. Traffic grooming is a variant of the well-known logical topology design problem, and is concerned with the development of techniques for combining low speed traffic components onto high speed channels in order to minimize network cost. Previous studies have focused on aggregate representations of the network cost. In this work, we consider a Min–Max objective, in which it is desirable to minimize the cost at the node where this cost is maximum. Such an objective is of high practical value when dimensioning a network for unknown future traffic demands and/or for dynamic traffic scenarios. We present new theoretical results which demonstrate that traffic grooming with the Min–Max objective is NP-complete even when wavelength assignment is not an issue. We also present new polynomial-time traffic grooming algorithms for minimizing the maximum electronic port cost in both unidirectional and bidirectional rings. We evaluate our algorithms through experiments with a wide range of problem instances, by varying the network size, number of wavelengths, traffic load, and traffic pattern. Our results indicate that our algorithms produce solutions which are always close to the optimal and/or the lower bound, and which scale well to large network sizes, large number of wavelengths, and high loads. We also demonstrate that, despite the focus on minimizing the maximum cost, our algorithms also perform well in terms of the aggregate electronic port cost over all ring nodes.}, number={1}, journal={Optical Switching and Networking}, publisher={Elsevier BV}, author={Chen, Bensong and Rouskas, George N. and Dutta, Rudra}, year={2005}, month={May}, pages={1–18} }
 @article{teng_rouskas_2005, title={Wavelength selection in OBS networks using traffic engineering and priority-based concepts}, volume={23}, ISSN={["1558-0008"]}, DOI={10.1109/JSAC.2005.851794}, abstractNote={A fundamental assumption underlying most studies of optical burst switched (OBS) networks is that full wavelength conversion is available throughout the network. In practice, however, economic and technical considerations are likely to dictate a more limited and sparse deployment of wavelength converters in the optical network. Therefore, we expect wavelength assignment policies to be an important component of OBS networks. In this paper, we explain why wavelength selection schemes developed for wavelength routed (circuit-switched) networks are not appropriate for OBS. We then develop a suite of adaptive and nonadaptive policies for OBS switches. We also apply traffic engineering techniques to reduce wavelength contention through traffic isolation. Our performance study indicates that, in the absence of full conversion capabilities, intelligent choices in assigning wavelengths to bursts at the source can have a profound effect on the burst drop probability in an OBS network.}, number={8}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Teng, J and Rouskas, GN}, year={2005}, month={Aug}, pages={1658–1669} }
 @article{xin_rouskas_2004, title={A study of path protection in large-scale optical networks}, volume={7}, ISSN={["1572-8188"]}, DOI={10.1023/B:PNET.0000026891.50610.48}, number={3}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Xin, YF and Rouskas, GN}, year={2004}, month={May}, pages={267–278} }
 @article{xin_teng_karmous-edwards_rouskas_stevenson_society_2004, title={Fault management with fast restoration for optical burst switched networks}, journal={First International Conference on Broadband Networks, Proceedings}, author={Xin, YF and Teng, J and Karmous-Edwards, G and Rouskas, GN and Stevenson, D and society}, year={2004}, pages={34–42} }
 @article{xin_rouskas_2004, title={Light-tree routing under optical power budget constraints [Invited]}, volume={3}, ISSN={1536-5379}, url={http://dx.doi.org/10.1364/jon.3.000282}, DOI={10.1364/jon.3.000282}, abstractNote={Feature Issue on Next-Generation WDM Network Design and Routing (WDMN). It has been widely recognized that physical-layer impairments, including power losses, must be taken into account when optical connections are routed in transparent networks. We study the problem of constructing light-trees under optical-layer power budget constraints, with a focus on algorithms that can guarantee a certain level of quality for the signals received by the destination nodes. We define a new constrained light-tree routing problem by introducing a set of constraints on the source-destination paths to account for the power losses at the optical layer. We investigate a number of variants of this problem, we characterize their complexity, and we develop a suite of corresponding routing algorithms; one of the algorithms is appropriate for networks with sparse light splitting and/or limited splitting fanout. We find that, to guarantee an adequate signal quality and to scale to large destination sets, light-trees must be as balanced as possible. Numerical results demonstrate that existing algorithms tend to construct highly unbalanced trees and are thus expected to perform poorly in an optical network setting. Our algorithms, on the other hand, are designed to construct balanced trees that, in addition to having good performance in terms of signal quality, also ensure a certain degree of fairness among destination nodes. Although we consider only power loss here, the algorithms that we develop could be appropriately modified to account for other physical-layer impairments, such as dispersion.}, number={5}, journal={Journal of Optical Networking}, publisher={The Optical Society}, author={Xin, Yufeng and Rouskas, George N.}, year={2004}, pages={282} }
 @inbook{xin_rouskas_ieee_2004, title={Multicast routing under optical layer constraints}, booktitle={Ieee Infocom 2004: the Conference on Computer Communications, Vols 1-4, Proceedings}, author={Xin, YF and Rouskas, GN and IEEE}, year={2004}, pages={2731–2742} }
 @article{teng_rouskas_society_2004, title={On wavelength assignment in optical burst switched networks}, journal={First International Conference on Broadband Networks, Proceedings}, author={Teng, J and Rouskas, GN and society}, year={2004}, pages={24–33} }
 @inbook{rouskas_2004, title={Optical Network Engineering}, url={http://dx.doi.org/10.1002/0471478342.ch10}, DOI={10.1002/0471478342.ch10}, abstractNote={This chapter discusses the application of traffic engineering and planning methodologies to the design and operation of optical networks employing WDM technology. The routing and wavelength assignment (RWA) problem is first introduced as the fundamental control problem in WDM networks. The RWA problem is then studied in two different but complementary contexts. The static RWA arises in the network design phase where the objective is capacity planning and the sizing of network resources. The dynamic RWA is encountered during the real-time network operation phase and involves the dynamic provisioning of optical connections. Both the static and dynamic variants of the problem are explored in depth with an emphasis on solution approaches and algorithms. The chapter concludes with a discussion of control plane issues and related standardization activities in support of traffic engineering functionality.}, booktitle={IP over WDM}, publisher={John Wiley & Sons, Inc.}, author={Rouskas, George N.}, editor={Dixit, SudhirEditor}, year={2004}, month={Jan}, pages={299–327} }
 @inbook{chen_rouskas_dutta_2004, title={Traffic Grooming in WDM Ring Networks with the Min-Max Objective}, volume={3042}, ISBN={9783540219590 9783540246930}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/978-3-540-24693-0_15}, DOI={10.1007/978-3-540-24693-0_15}, abstractNote={We consider the problem of traffic grooming in WDM ring networks. Previous studies have focused on minimizing aggregate representations of the network cost. In this work, we consider a Min-Max objective, in which it is desirable to minimize the cost at the node where this cost is maximum. Such an objective is of practical value when dimensioning a network for unknown future traffic demands and/or for dynamic traffic scenarios. We prove that traffic grooming with the Min-Max objective is NP-Complete even when wavelength assignment is not an issue. We also present a new polynomial-time algorithm for Min-Max traffic grooming. Experiments with a wide range of problem instances demonstrate that our algorithm produces solutions which are always close to the optimal and/or the lower bound, and which scale well to large network sizes, large number of wavelengths, and high loads.}, booktitle={Lecture Notes in Computer Science}, publisher={Springer Berlin Heidelberg}, author={Chen, Bensong and Rouskas, George N. and Dutta, Rudra}, year={2004}, pages={174–185} }
 @inbook{chen_rouskas_dutta_mitrou_kontovasilis_iliadis_merakos_2004, title={Traffic grooming in WDM ring networks with the min-max objective}, volume={3042}, booktitle={Networking 2004}, author={Chen, BS and Rouskas, GN and Dutta, R and Mitrou, N and Kontovasilis, K and Iliadis, I and Merakos, L}, year={2004}, pages={174–185} }
 @inbook{xu_perros_rouskas_ieee_2003, title={A queueing network model of an edge optical burst switching node}, booktitle={Ieee Infocom 2003: the Conference on Computer Communications, Vols 1-3, Proceedings}, author={Xu, LS and Perros, HG and Rouskas, GN and IEEE}, year={2003}, pages={2019–2029} }
 @article{xu_perros_rouskas_2003, title={A simulation study of optical burst switching and access protocols for WDM ring networks}, volume={41}, ISSN={["1389-1286"]}, DOI={10.1016/s1389-1286(02)00371-7}, abstractNote={We consider a wavelength division multiplexing metro ring architecture with optical burst switching. The ring consists of N nodes, and each node owns a home wavelength on which it transmits its bursts. The ring operates under the fixed transmitter tunable receiver scheme. Control information is transmitted on a separate control channel. Five different burst switching access protocols are proposed, and their performance and fairness is evaluated by simulation.}, number={2}, journal={COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING}, author={Xu, LS and Perros, HG and Rouskas, GN}, year={2003}, month={Feb}, pages={143–160} }
 @article{xu_perros_rouskas_2003, title={Access protocols for optical burst-switched ring networks}, volume={149}, ISSN={["0020-0255"]}, DOI={10.1016/S0020-0255(02)00247-5}, abstractNote={In this paper, we consider a WDM metro ring architecture with optical burst switching. Several access protocols are proposed and their performance is analyzed by simulation.}, number={1-3}, journal={INFORMATION SCIENCES}, author={Xu, LS and Perros, HG and Rouskas, GN}, year={2003}, month={Jan}, pages={75–81} }
 @article{zaim_perros_rouskas_2003, title={Computing call-blocking probabilities in leo satellite constellations}, volume={52}, ISSN={0018-9545}, url={http://dx.doi.org/10.1109/tvt.2003.811219}, DOI={10.1109/TVT.2003.811219}, abstractNote={We present an analytical model for computing call-blocking probabilities in a low Earth orbit (LEO) satellite network that carries voice calls. Both satellite-fixed and Earth-fixed constellations with interorbit links and handoffs are considered. We assume a single beam per satellite. Also, we assume that call arrivals are Poisson with a fixed arrival rate that is independent of the geographic area. The model is analyzed approximately by decomposing it into subsystems. Each subsystem is solved in isolation exactly using a Markov process and the individual results are combined together through an iterative method. Numerical results demonstrate that our method is accurate for a wide range of traffic patterns. We also derive an upper and lower bound for the link-blocking probabilities that can be computed efficiently. These bounds can be used for constellations of realistic size where each satellite has multiple beams.}, number={3}, journal={IEEE Transactions on Vehicular Technology}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Zaim, A.H. and Perros, H.G. and Rouskas, G.N.}, year={2003}, month={May}, pages={622–636} }
 @article{zaim_baldine_cassada_rouskas_perros_stevenson_2003, title={Jumpstart just-in-time signaling protocol: a formal description using extended finite state machines}, volume={42}, DOI={10.1117/1.1533795}, abstractNote={We present a formal protocol description for a just-in-time (JIT) signaling scheme running over a core dense wavelength division multiplexing (DWDM) network that utilizes optical burst switches (OBSs). We apply an eight-tuple extended finite state machine (EFSM) model to formally specify the protocol. Using the EFSM model, we define the communication between a source client node and a destination client node through an ingress and one or multiple intermediate switches. We work on on-the-fly and persistent unicast connections. The communication between the EFSMs is handled through messages.}, number={2}, journal={Optical Engineering}, author={Zaim, AH and Baldine, I and Cassada, M and Rouskas, George and Perros, HG and Stevenson, D}, year={2003}, pages={568–585} }
 @article{baldine_rouskas_perros_stevenson_2003, title={Multicast and QoS in the Jumpstart Architecture for WDM Burst-Switched Networks}, volume={4}, number={6}, journal={Optical Networks}, author={Baldine, I. and Rouskas, G.N. and Perros, H.G. and Stevenson, D.}, year={2003}, month={Nov}, pages={68–80} }
 @inbook{dutta_huang_rouskas_somani_zhang_2003, title={On optimal traffic grooming in elemental network topologies}, volume={5285}, DOI={10.1117/12.533162}, abstractNote={We consider the problem of traffic grooming in WDM path, star, and tree networks. Traffic grooming is a variant of the well-known logical topology design problem, and is concerned with the development of techniques for combining low speed traffic components onto high speed channels in order to minimize network cost. Our contribution is two-fold. In the first part of the paper we settle the complexity of traffic grooming in path and star networks by proving that a number of variants of the problem are computationally hard. Since routing and wavelength assignment in these two topologies is trivial, these results demonstrate that traffic grooming is itself an inherently difficult problem. Our results have implications for ring and other more general topologies, which we explore. In the second part, we design practical grooming algorithms with provable properties. Specifically, for all three topologies, we obtain a series of lower and upper bounds which are increasingly tighter but have considerably higher computational requirements; the series of upper bounds form an algorithm for the traffic grooming problem with strong performance guarantees. We also present corresponding heuristics with good performance. Our work is a first step towards a formal and systematic approach to the grooming problem in general topologies that builds upon results and algorithms for more elementary networks.}, booktitle={Opticomm 2003: Optical Networking and Communications}, author={Dutta, R and Huang, S and Rouskas, GN and Somani, AK and Zhang, Z}, year={2003}, pages={13–24} }
 @inproceedings{dutta_huang_rouskas_2003, title={On optimal traffic grooming in elemental network topologies.}, volume={5285}, booktitle={Proceedings of Opticomm 2003}, author={Dutta, R. and Huang, S. and Rouskas, G.}, year={2003} }
 @article{xin_rouskas_perros_2003, title={On the physical and logical topology design of large-scale optical networks}, volume={21}, DOI={10.1109/JLT.2002.810075}, number={4}, journal={Journal of Lightwave Technology}, author={Xin, YF and Rouskas, George and Perros, HG}, year={2003}, pages={904–915} }
 @article{rouskas_2003, title={Optical layer multicast: Rationale, building blocks, and challenges}, volume={17}, ISSN={["1558-156X"]}, DOI={10.1109/MNET.2003.1174179}, abstractNote={Optical layer multicast refers to the support of point-to-multipoint connections directly at the physical layer by employing passive devices capable of splitting the power of an input signal among several outputs. Optical multicast technology enables a broad set of applications and opens new directions to network design. We examine the underlying principles and essential components for a practical optical multicast service. We also present a set of key research challenges along with a survey of the literature.}, number={1}, journal={IEEE NETWORK}, author={Rouskas, GN}, year={2003}, pages={60–65} }
 @inbook{rouskas_jackson_charzinski_lehnert_trangia_2003, title={Optimal granularity of MPLS tunnels}, volume={5A-B}, booktitle={Providing Quality of Service in Heterogeneous Environments, Vols 5a and 5b}, author={Rouskas, GN and Jackson, LE and Charzinski, J and Lehnert, R and TranGia, P}, year={2003}, pages={1–10} }
 @article{jackson_rouskas_2003, title={Optimal quantization of periodic task requests on multiple identical processors}, volume={14}, ISSN={["1045-9219"]}, DOI={10.1109/TPDS.2003.1225058}, abstractNote={We simplify the periodic tasks scheduling problem by making a trade off between processor load and computational complexity. A set N of periodic tasks, each characterized by its density /spl rho//sub i/, contains n possibly unique values of /spl rho//sub i/. We transform N through a process called quantization, in which each /spl rho/i /spl isin/ N is mapped onto a service level s/sub j/ /spl isin/ L, where |L| = l /spl Lt/ n and /spl rho//sub i/ /spl les/ s/sub j/, (this second condition differentiates this problem from the p-median problem on the real line). We define the periodic task quantization problem with deterministic input (PTQ-D) and present an optimal polynomial time dynamic programming solution. We also introduce the problem PTQ-S (with stochastic input) and present an optimal solution. We examine, in a simulation study, the trade off penalty of excess processor load needed to service the set of quantized tasks over the original set, and find that, through quantization onto as few as 15 or 20 service levels, no more than 5 percent processor load is required above the amount requested. Finally, we demonstrate that the scheduling of a set of periodic tasks is greatly simplified through quantization and we present a fast online algorithm that schedules quantized periodic tasks.}, number={8}, journal={IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS}, author={Jackson, LE and Rouskas, GN}, year={2003}, month={Aug}, pages={795–806} }
 @inbook{xu_perios_rouskas_charzinski_lehnert_trangia_2003, title={Performance analysis of an edge optical burst switching node with a large number of wavelengths}, volume={5A-B}, booktitle={Providing Quality of Service in Heterogeneous Environments, Vols 5a and 5b}, author={Xu, LS and Perios, HG and Rouskas, GN and Charzinski, J and Lehnert, R and TranGia, P}, year={2003}, pages={891–900} }
 @article{xu_perros_rouskas_cicekli_cicekli_gelenbe_2003, title={Performance modeling of an edge optical burst switching node}, journal={Proceedings of the 17th International Symposium on Computer and Information Sciences}, author={Xu, LS and Perros, HG and Rouskas, GN and Cicekli, I and Cicekli, NK and Gelenbe, E}, year={2003}, pages={377–381} }
 @inbook{rouskas_2003, title={Routing and Wavelength Assignment in Optical WDM Networks}, url={http://dx.doi.org/10.1002/0471219282.eot205}, DOI={10.1002/0471219282.eot205}, abstractNote={Abstract}, booktitle={Wiley Encyclopedia of Telecommunications}, publisher={John Wiley & Sons, Inc.}, author={Rouskas, George N.}, editor={Proakis, J.Editor}, year={2003}, month={Apr} }
 @inproceedings{dutta_huang_rouskas_2003, title={Traffic grooming in path, star and tree networks: complexity, bounds, and algorithms}, ISBN={1581136641}, DOI={10.1145/781027.781066}, abstractNote={We consider the problem of traffic grooming in WDM path, star, and tree networks. Traffic grooming is a variant of the well-known logical topology design, and is concerned with the development of techniques for combining low speed traffic components onto high speed channels in order to minimize network cost. Our contribution is two-fold. In the first part of the paper we present a wealth of results which settle the complexity of traffic grooming in path and star networks, by proving that a number of variants of the problem are computationally intractable. Since routing and wavelength assignment in these two topologies is trivial, these results demonstrate that traffic grooming is itself an inherently difficult problem. Our results have implications for ring and other more general topologies, which we explore. In the second part we design practical grooming algorithms with provable properties. Specifically, for all three topologies, we obtain a series of lower and upper bounds which are increasingly tighter but have considerably higher computational requirements; the series of upper bounds forms an algorithm for the traffic grooming problem with strong performance guarantees. We also present corresponding heuristics with good performance. Our work is a first step towards a formal and systematic approach to the grooming problem in general topologies that builds upon results and algorithms for more elementary networks}, booktitle={Proceedings of the ACM Sigmetrics, International Conference on Measurement and Modeling of Computer Systems}, author={Dutta, Rudra and Huang, S and Rouskas, George}, year={2003}, pages={298–299} }
 @inbook{xu_perros_rouskas_2002, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={A Simulation Study of Access Protocols for Optical Burst-Switched Ring Networks}, ISBN={9783540437093 9783540479062}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/3-540-47906-6_70}, DOI={10.1007/3-540-47906-6_70}, abstractNote={In this paper, we consider a WDM metro ring architecture with optical burst switching. Several access protocols are proposed and their performance is analyzed by simulation.}, booktitle={NETWORKING 2002: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications}, publisher={Springer Berlin Heidelberg}, author={Xu, Lisong and Perros, Harry G. and Rouskas, George N.}, editor={Gregori, E. and Conti, M. and Campbell, A.T. and Omidyar, G. and Zukerman, M.Editors}, year={2002}, pages={863–874}, collection={Lecture Notes in Computer Science} }
 @inbook{rouskas_perros_2002, title={A tutorial on optical networks}, volume={2497}, ISBN={3540001654}, booktitle={Advanced lectures on networking: Networking 2002 tutorials}, publisher={Berlin; New York: Springer}, author={Rouskas, G. N. and Perros, H. G.}, editor={E. Gregori, G. Anastasi and Basagni, S.Editors}, year={2002}, pages={155–193} }
 @inbook{rouskas_perros_gregori_anastasi_basagni_2002, title={A tutorial on optical networks}, volume={2497}, booktitle={Advanced Lectures on Networking}, author={Rouskas, GN and Perros, HG and Gregori, E and Anastasi, G and Basagni, S}, year={2002}, pages={155–193} }
 @article{xu_perros_rouskas_caulfield_chen_duro_honavar_kerre_lu_romay_et al._2002, title={Access protocols for optical burst-switched ring networks}, journal={Proceedings of the 6th Joint Conference on Information Sciences}, author={Xu, LS and Perros, HG and Rouskas, GN and Caulfield, HJ and Chen, SH and Duro, R and Honavar, V and Kerre, EE and Lu, M and Romay, MG and et al.}, year={2002}, pages={1287–1290} }
 @article{ramesh_rouskas_perros_2002, title={Computing blocking probabilities in multiclass wavelength-routing networks with multicast calls}, volume={20}, ISSN={["1558-0008"]}, DOI={10.1109/49.974664}, abstractNote={We present an approximate analytical method to compute efficiently the call-blocking probabilities in wavelength-routing networks with multiple classes of both unicast and multicast calls. Our approach involves the following steps. We start with an approximate solution to a linear single-class unicast network which we developed earlier. Next, all classes of calls on a particular route are aggregated to give an equivalent single-class model. We then extend the path decomposition algorithms that we have developed for single-class networks to handle mesh networks with multiple classes of calls. We show how to use these path decomposition algorithms to decompose large networks with multicast paths into smaller subsystems with only linear paths, which, in turn, are solved by the product-form approximation algorithm. We also consider a state-dependent Poisson arrival process for multicast calls which is more accurate in capturing the behavior of these calls.}, number={1}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Ramesh, S and Rouskas, GN and Perros, HG}, year={2002}, month={Jan}, pages={89–96} }
 @article{zaim_rouskas_perros_2002, title={Computing call-blocking probabilities in LEO satellite networks: The single-orbit case}, volume={51}, ISSN={["1939-9359"]}, DOI={10.1109/25.994809}, abstractNote={We study the problem of carrying voice calls over a low-Earth-orbit satellite network and present an analytical model for computing call-blocking probabilities for a single orbit of a satellite constellation. We have devised a method to solve the corresponding Markov process efficiently for orbits of up to five satellites. For orbits consisting of a larger number of satellites, we have developed an approximate decomposition algorithm to compute the call-blocking probabilities by decomposing the system into smaller subsystems and iteratively solving each subsystem in isolation using the exact Markov process. Our approach can capture blocking due to handoffs for both satellite-fixed and Earth-fixed constellations. Numerical results demonstrate that our method is accurate for a wide range of traffic patterns and for orbits with a number of satellites that is representative of commercial satellite systems.}, number={2}, journal={IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY}, author={Zaim, AH and Rouskas, GN and Perros, HG}, year={2002}, month={Mar}, pages={332–347} }
 @article{jackson_rouskas_2002, title={Deterministic preemptive scheduling of real-time tasks}, volume={35}, ISSN={["1558-0814"]}, DOI={10.1109/MC.2002.999778}, abstractNote={Algorithms for the preemptive scheduling of deterministic, real-time tasks can have applications in providing quality-of-service guarantees to packet flows in multichannel optical networks.}, number={5}, journal={COMPUTER}, author={Jackson, LE and Rouskas, GN}, year={2002}, month={May}, pages={72-+} }
 @inbook{zaim_baldine_cassada_rouskas_perros_stevenson_ghani_sivalingam_2002, title={Formal description of the jumpstart just-in-time signaling protocol using EFSM}, volume={4874}, DOI={10.1117/12.475294}, abstractNote={We present a formal protocol description for a Just-In-Time (JIT) signaling scheme running over a core dWDM network which utilizes Optical Burst Switches (OBS). We apply an eight-tuple extended finite state machine (EFSM) model to formally specify the protocol. Using the EFSM model, we define the communication between a source client node and a destination client node through an ingress and one or multiple intermediate switches. We worked on single burst connections that means setting up the connection just before sending a single burst and then closing the connection as soon as the burst is sent. The communication between the EFSMs is handled through message transfer between protocol entities.}, booktitle={Opticomm 2002: Optical Networking and Communications}, author={Zaim, AH and Baldine, I and Cassada, M and Rouskas, GN and Perros, HG and Stevenson, D and Ghani, N and Sivalingam, KM}, year={2002}, pages={160–173} }
 @inbook{baldine_jackson_rouskas_2002, title={Helios: A Broadcast Optical Architecture}, ISBN={9783540437093 9783540479062}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/3-540-47906-6_72}, DOI={10.1007/3-540-47906-6_72}, abstractNote={In this article we present a new all-optical broadcast LAN architecture and an accompanying signaling protocol. The distinguishing characteristics of this architecture are its fault-tolerant design and its collision-free nature, which allows it to achieve high throughput in a broadcast environment. The flexibility of the design allows different schedulers to be used, which can introduce new features into the network (e.g. multicast and QoS) as well as optimize its behavior for the specific setting in which it is used.}, booktitle={NETWORKING 2002: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications}, publisher={Springer Berlin Heidelberg}, author={Baldine, Ilia and Jackson, Laura E. and Rouskas, George N.}, year={2002}, pages={887–898} }
 @inbook{baldine_perros_rouskas_stevenson_2002, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={JumpStart: A Just-in-Time Signaling Architecture for WDM Burst-Switched Networks}, ISBN={9783540437093 9783540479062}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/3-540-47906-6_88}, DOI={10.1007/3-540-47906-6_88}, abstractNote={We present an architecture for a core dWDM network which utilizes the concept of Optical Burst Switching (OBS) coupled with a Just-In-Time (JIT) signaling scheme. It is a reservation based architecture whose distinguishing characteristics are its relative simplicity, its amenability to hardware implementation, support for quality of service and multicast natively. Another important feature is data transparency - the network infrastructure is independent of the format of the data being transmitted on individual wavelengths. In this article we present a brief overview of the architecture and outline the most salient features.}, booktitle={NETWORKING 2002: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications}, publisher={Springer Berlin Heidelberg}, author={Baldine, Ilia and Perros, Harry G. and Rouskas, George N. and Stevenson, Dan}, editor={Gregori, E. and Conti, M. and Campbell, A.T. and Omidyar, G. and Zukerman, M.Editors}, year={2002}, pages={1081–1086}, collection={Lecture Notes in Computer Science} }
 @article{baldine_rouskas_perros_stevenson_2002, title={JumpStart: A just-in-time signaling architecture for WDM burst-switched networks}, volume={40}, ISSN={["0163-6804"]}, DOI={10.1109/35.983912}, abstractNote={We present an architecture for a core dWDM network which utilizes the concept of optical burst switching coupled with a just-in-time signaling scheme. It is a reservation-based architecture whose distinguishing characteristics are its relative simplicity, its amenability to hardware implementation, and the ability to support multicast natively. Another important feature is data transparency-the network infrastructure is independent of the format of the data being transmitted on individual wavelengths. We present the signaling protocol designed for this architecture, as well as an unified signaling message structure to be used in conjunction with the protocol. We also present the future directions of this research.}, number={2}, journal={IEEE COMMUNICATIONS MAGAZINE}, author={Baldine, I and Rouskas, GN and Perros, HG and Stevenson, D}, year={2002}, month={Feb}, pages={82–89} }
 @article{rhee_balaguru_rouskas_2002, title={MTCP: scalable TCP-like congestion control for reliable multicast}, volume={38}, ISSN={["1872-7069"]}, DOI={10.1016/s1389-1286(01)00268-7}, abstractNote={We present MTCP, a congestion control scheme for large-scale reliable multicast. Congestion control for reliable multicast is important, because of its wide applications in multimedia and collaborative computing, yet non-trivial, because of the potentially large number of receivers involved. Many schemes have been proposed to handle the recovery of lost packets in a scalable manner, but there is little work on the design and implementation of congestion control schemes for reliable multicast. We propose new techniques that can effectively handle instances of congestion occurring simultaneously at various parts of a multicast tree. Our protocol incorporates several novel features: (1) hierarchical congestion status reports that distribute the load of processing feedback from all receivers across the multicast group, (2) the relative time delay concept which overcomes the difficulty of estimating round-trip times in tree-based multicast environments, (3) window-based control that prevents the sender from transmitting faster than packets leave the bottleneck link on the multicast path through which the sender's traffic flows, (4) a retransmission window that regulates the flow of repair packets to prevent local recovery from causing congestion, and (5) a selective acknowledgment scheme that prevents independent (i.e., non-congestion-related) packet loss from reducing the sender's transmission rate. We have implemented MTCP both on UDP in SunOS 5.6 and on the simulator ns, and we have conducted extensive Internet experiments and simulation to test the scalability and inter-fairness properties of the protocol. The encouraging results we have obtained support our confidence that TCP-like congestion control for large-scale reliable multicast is within our grasp.}, number={5}, journal={COMPUTER NETWORKS}, author={Rhee, I and Balaguru, N and Rouskas, GN}, year={2002}, month={Apr}, pages={553–575} }
 @article{thaker_rouskas_2002, title={Multi-Destination Communication in Broadcast WDM Networks: A Survey}, volume={3}, number={1}, journal={Optical Networks}, author={Thaker, D. and Rouskas, G.N.}, year={2002}, month={Jan}, pages={34–44} }
 @article{dutta_rouskas_2002, title={On optimal traffic grooming in WDM rings}, volume={20}, ISSN={["1558-0008"]}, DOI={10.1109/49.974666}, abstractNote={We consider the problem of designing a virtual topology to minimize electronic routing, that is, grooming traffic, in wavelength routed optical rings. The full virtual topology design problem is NP-hard even in the restricted case where the physical topology is a ring, and various heuristics have been proposed in the literature for obtaining good solutions, usually for different classes of problem instances. We present a new framework which can be used to evaluate the performance of heuristics and which requires significantly less computation than evaluating the optimal solution. This framework is based on a general formulation of the virtual topology problem, and it consists of a sequence of bounds, both upper and lower, in which each successive bound is at least as strong as the previous one. The successive bounds take larger amounts of computation to evaluate, and the number of bounds to be evaluated for a given problem instance is only limited by the computational power available. The bounds are based on decomposing the ring into sets of nodes arranged in a path and adopting the locally optimal topology within each set. While we only consider the objective of minimizing electronic routing in this paper, our approach to obtaining the sequence of bounds can be applied to many virtual topology problems on rings. The upper bounds we obtain also provide a useful series of heuristic solutions.}, number={1}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Dutta, R and Rouskas, GN}, year={2002}, month={Jan}, pages={110–121} }
 @inbook{zaim_perros_rouskas_2002, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={Performance Analysis of LEO Satellite Networks}, ISBN={9783540437093 9783540479062}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/3-540-47906-6_64}, DOI={10.1007/3-540-47906-6_64}, abstractNote={We present an analytical model for computing call blocking probabilities in a LEO satellite network that carries voice calls. Both satellite-fixed and earth-fixed constellations with inter-orbit links and hand-offs are considered. The model is analyzed approximately by decomposing it into sub-systems. Each sub-system is solved in isolation exactly using a Markov process, and the individual results are combined together through an iterative method. Numerical results demonstrate that our method is accurate for a wide range of traffic patterns.}, booktitle={NETWORKING 2002: Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications}, publisher={Springer Berlin Heidelberg}, author={Zaim, A. Halim and Perros, Harry G. and Rouskas, George N.}, editor={Gregori, E. and Conti, M. and Campbell, A.T. and Omidyar, G. and Zukerman, M.Editors}, year={2002}, pages={790–801}, collection={Lecture Notes in Computer Science} }
 @article{bampis_rouskas_2002, title={The scheduling and wavelength assignment problem in optical WDM networks}, volume={20}, number={5}, journal={Journal of Lightwave Technology}, author={Bampis, E and Rouskas, GN}, year={2002}, pages={754–761} }
 @article{dutta_rouskas_2002, title={Traffic grooming in WDM networks: past and future}, volume={16}, ISSN={0890-8044}, url={http://dx.doi.org/10.1109/mnet.2002.1081765}, DOI={10.1109/MNET.2002.1081765}, abstractNote={Traffic grooming refers to techniques used to combine low-speed traffic streams onto high-speed wavelengths in order to minimize the networkwide cost in terms of line terminating equipment and/or electronic switching. Such techniques become increasingly important for emerging network technologies, including SONET/WDM rings and MPLS/MP/spl lambda/S backbones, for which traffic grooming is essential. In this article we formally define the traffic grooming problem, and we provide a general formulation that captures the features of a wide range of problem variants. We then present a comprehensive comparative survey of the literature that unveils the significant amount of research on this subject (the traffic grooming past). We also offer a broad set of ambitious research directions (the traffic grooming future) that are motivated by the exciting new challenges arising with the advent of MP/spl lambda/S technology.}, number={6}, journal={IEEE Network}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Dutta, R. and Rouskas, G.N.}, year={2002}, month={Nov}, pages={46–56} }
 @inproceedings{dutta_rouskas_2001, title={On optimal traffic grooming in WDM rings.}, ISBN={1581133340}, DOI={10.1145/384268.378779}, abstractNote={We consider the problem of designing a virtual topology to minimize electronic routing, that is, grooming traffic, in wavelength routed optical rings. We present a new framework consisting of a sequence of bounds, both upper and lower, in which each successive bound is at least as strong as the previous one. The successive bounds take larger amounts of computation to evaluate, and the number of bounds to be evaluated for a given problem instance is only limited by the computational power available. The bounds are based on decomposing the ring into sets of nodes arranged in a path, and adopting the locally optimal topology within each set. Our approach can be applied to many virtual topology problems on rings. The upper bounds we obtain also provide a useful series of heuristic solutions.}, booktitle={Proceedings of ACM sigmetrics/performance 2001}, author={Dutta, Rudra and Rouskas, George}, year={2001}, pages={164–174} }
 @inbook{bampis_rouskas_bannister_senior_touch_2001, title={On scheduling problems with applications to packet-switched optical WDM networks}, volume={4599}, DOI={10.1117/12.436056}, abstractNote={We consider a scheduling problem, which we call the Scheduling and Wavelength Assignment (SWA) problem, arising in optical networks that are based on the Wavelength Division Multiplexing (WDM) technology. We prove that the SWA problem is (Nu) (Rho) -hard for both the preemptive and the non- preemptive cases. Furthermore, we propose two efficient approximation algorithms. The first is for the preemptive case and it is based on a natural decomposition of the problem to the classical multiprocessor scheduling and open-shop problems. For the non-preemptive case, we prove that a naive implementation of list scheduling produces a schedule that can be m times far from the optimum, where m is the number of processors (equivalently, WDM channels). Finally, we give a more refined version of list scheduling and we prove it to be a 2-approximation algorithm for both the off-line and the on- line contexts.}, booktitle={Opticomm 2001: Optical Networking and Communications}, author={Bampis, E and Rouskas, GN and Bannister, JA and Senior, JM and Touch, JD}, year={2001}, pages={163–172} }
 @article{xu_perros_rouskas_2001, title={Techniques for optical packet switching and optical burst switching}, volume={39}, ISSN={["1558-1896"]}, DOI={10.1109/35.894388}, abstractNote={Wavelength-division multiplexing appears to be the solution of choice for providing a faster networking infrastructure that can meet the explosive growth of the Internet. Several different technologies have been developed so far for the transfer of data over WDM. We survey two new technologies which are still in the experimental stage-optical packet switching and optical burst switching-and comment on their suitability for transporting IP traffic.}, number={1}, journal={IEEE COMMUNICATIONS MAGAZINE}, author={Xu, LS and Perros, HG and Rouskas, G}, year={2001}, month={Jan}, pages={136–142} }
 @article{baldine_rouskas_2001, title={Traffic adaptive WDM networks: A study of reconfiguration issues}, volume={19}, ISSN={["1558-2213"]}, DOI={10.1109/50.920841}, abstractNote={This paper studies the issues arising in the reconfiguration phase of broadcast optical networks. Although the ability to dynamically optimize the network under changing traffic conditions has been recognized as one of the key features of multi-wavelength optical networks, this is the first in-depth study of the tradeoffs involved in carrying out the reconfiguration process. We develop and compare reconfiguration policies to determine when to reconfigure the network, and we present an approach to carry out the network transition by describing a class of strategies that determine how to retune the optical transceivers. We identify the degree of load balancing and the number of retunings as two important, albeit conflicting, objectives in the design of reconfiguration policies, naturally leading to a formulation of the problem as a Markovian decision process. Consequently, we develop a systematic and flexible framework in which to view and contrast reconfiguration policies. We show how an appropriate selection of reward and cost functions can be used to achieve the desired balance among various performance criteria of interest. We conduct a comprehensive evaluation of reconfiguration policies and retuning strategies and demonstrate the benefits of reconfiguration through both analytical and simulation results. The result of our work is a set of practical techniques for managing the network transition phase that can be directly applied to networks of large size. Although our work is in the context of broadcast networks, the results can be applied to any wavelength-division multiplexing network where it is necessary to multiplex traffic from a large user population into a number of wavelengths.}, number={4}, journal={JOURNAL OF LIGHTWAVE TECHNOLOGY}, author={Baldine, I and Rouskas, GN}, year={2001}, month={Apr}, pages={433–455} }
 @article{dutta_rouskas_2000, title={A Survey of virtual topology design algorithms for wavelength routed networks.}, volume={1}, number={1}, journal={Optical Networks Magazine}, author={Dutta, R. and Rouskas, G. N.}, year={2000}, pages={73–89} }
 @article{zhu_rouskas_perros_2000, title={A comparison of allocation policies in wavelength routing networks}, volume={2}, ISSN={["1572-8188"]}, DOI={10.1023/A:1010056408572}, number={3}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Zhu, YH and Rouskas, GN and Perros, HG}, year={2000}, month={Aug}, pages={267–295} }
 @article{zhu_rouskas_perros_2000, title={A path decomposition approach for computing blocking probabilities in wavelength-routing networks}, volume={8}, ISSN={["1558-2566"]}, DOI={10.1109/90.893871}, abstractNote={We study a class of circuit-switched wavelength-routing networks with fixed or alternate routing and with random wavelength allocation. We present an iterative path decomposition algorithm to evaluate accurately and efficiently the blocking performance of such networks with and without wavelength converters. Our iterative algorithm analyzes the original network by decomposing it into single-path subsystems. These subsystems are analyzed in isolation, and the individual results are appropriately combined to obtain a solution for the overall network. To analyze individual subsystems, we first construct an exact Markov process that captures the behavior of a path in terms of wavelength use. We also obtain an approximate Markov process which has a closed-form solution that can be computed efficiently for short paths. We then develop an iterative algorithm to analyze approximately arbitrarily long paths. The path decomposition approach naturally captures the correlation of both link loads and link blocking events. Our algorithm represents a simple and computationally efficient solution to the difficult problem of computing call-blocking probabilities in wavelength-routing networks. We also demonstrate how our analytical techniques can be applied to gain insight into the problem of converter placement in wavelength-routing networks.}, number={6}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, author={Zhu, YH and Rouskas, GN and Perros, HG}, year={2000}, month={Dec}, pages={747–762} }
 @article{zhu_rouskas_perros_2000, title={A path decomposition approach for computing blocking probabilities in wavelength-routing networks}, volume={8}, number={6}, journal={Ieee-Acm Transactions on Networking}, author={Zhu, YH and Rouskas, GN and Perros, HG}, year={2000}, pages={747–762} }
 @article{sivaraman_rouskas_2000, title={A reservation protocol for broadcast WDM networks and stability analysis}, volume={32}, ISSN={["1872-7069"]}, DOI={10.1016/s1389-1286(99)00137-1}, abstractNote={We consider the problem of coordinating access to the various channels of a single-hop wavelength division multiplexing (WDM) network. We present a high performance reservation (HiPeR-ℓ) protocol specifically designed to overcome the potential inefficiencies of operating in environments with non-negligible processing, tuning, and propagation delays. HiPeR-ℓ differs from previous reservation protocols in that each control packet makes reservations for all data packets waiting in a node's queues, thus significantly reducing control overhead. Packets are scheduled for transmission using algorithms that can effectively mask the tuning times. HiPeR-ℓ also uses pipelining to mask processing times and propagation delays; parameter ℓ of the protocol is used to control the degree of pipelining. We use Markov chain theory to obtain a sufficient condition for the stability of the protocol. The stability condition provides insight into the factors affecting the operation of the protocol, such as the degree of load balancing across the various channels, and the quality of the scheduling algorithms. The analysis is fairly general, as it holds for MMBP-like arrival processes with any number of states, and for non-uniform destinations.}, number={2}, journal={COMPUTER NETWORKS}, author={Sivaraman, V and Rouskas, GN}, year={2000}, month={Feb}, pages={211–227} }
 @inbook{ramesh_rouskas_perros_2000, title={Computing blocking probabilities in multi-class wavelength routing networks}, volume={1815}, ISBN={354067506X}, booktitle={Networking 2000: Broadband communications, high performance networking, and performance of communication networks / IFIP-TC6/European Commission International Conference, Paris, France, May 2000, proceedings}, publisher={Berlin; New York: Springer}, author={Ramesh, S. and Rouskas, G. N. and Perros, H. G.}, year={2000}, pages={176–188} }
 @inbook{ramesh_rouskas_perros_pujolle_perros_fdida_korner_stavrakakis_2000, title={Computing blocking probabilities in multi-class wavelength routing networks}, volume={1815}, booktitle={Networking 2000}, author={Ramesh, S and Rouskas, GN and Perros, HG and Pujolle, G and Perros, H and Fdida, S and Korner, U and Stavrakakis, I}, year={2000}, pages={176–188} }
 @article{ramesh_rouskas_perros_2000, title={Computing blocking probabilities in multiclass wavelength routing networks}, volume={10}, ISSN={1049-3301 1558-1195}, url={http://dx.doi.org/10.1145/364996.365001}, DOI={10.1145/364996.365001}, abstractNote={We present an approximate analytical method to evaluate efficiently and accurately the call blocking probabilities in wavelength routing networks with multiple classes of calls. The model is fairly general and allows each source-destination pair to service calls of different classes, with each call occupying one wavelength per link. Our approximate analytical approach involves two steps. The arrival process of calls on some routes is first modified slightly to obtain an approximate multiclass network model. Next, all classes of calls on a particular route are aggregated to give an equivalent single-class model. Thus, path decomposition algorithms for single-class wavelength routing networks may be readily extended to the multiclass case. This article is a first step towards  understanding the issues arising in wavelength routing networks that serve multiple classes of customers.}, number={2}, journal={ACM Transactions on Modeling and Computer Simulation}, publisher={Association for Computing Machinery (ACM)}, author={Ramesh, Sridhar and Rouskas, George N. and Perros, Harry G.}, year={2000}, month={Apr}, pages={87–103} }
 @inbook{dutta_rouskas_2000, title={Design of logical topologies for wavelength routed networks.}, ISBN={0792378253}, booktitle={Optical WDM networks: Principles and practice}, publisher={Boston: Kluwer Academic Publishers}, author={Dutta, R. and Rouskas, G. N.}, editor={K. M. Sivalingam and Subramaniam, S.Editors}, year={2000}, pages={79–102} }
 @article{gerstel_li_mcguire_rouskas_sivalingam_zhang_ramaswami_2000, title={Guest editorial - Protocols and architectures for next generation optical WDM networks}, volume={18}, ISSN={["0733-8716"]}, DOI={10.1109/JSAC.2000.887903}, number={10}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Gerstel, O and Li, B and McGuire, A and Rouskas, G and Sivalingam, KM and Zhang, ZS and Ramaswami, R}, year={2000}, month={Oct}, pages={1805–1809} }
 @article{ortiz_rouskas_perros_2000, title={Maximizing multicast throughput in WDM networks with tuning latencies using the virtual receiver concept}, volume={11}, ISSN={["1541-8251"]}, DOI={10.1002/ett.4460110109}, abstractNote={Abstract}, number={1}, journal={EUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS}, author={Ortiz, Z and Rouskas, GN and Perros, HG}, year={2000}, pages={63–72} }
 @article{ortiz_rouskas_perros_2000, title={Scheduling combined unicast and multicast traffic in broadcast WDM networks}, volume={2}, ISSN={["1387-974X"]}, DOI={10.1023/A:1010084306132}, number={2}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Ortiz, Z and Rouskas, GN and Perros, HG}, year={2000}, month={May}, pages={135–153} }
 @inbook{blocking in wavelength routing networks, part i: the single path case_1999, booktitle={Ieee Infocom '99 - the Conference on Computer Communications, Vols 1-3, Proceedings}, year={1999}, pages={321–328} }
 @inbook{zhu_rouskas_perros_key_smith_1999, title={Blocking in wavelength routing networks, part II: Mesh topologies}, volume={3}, booktitle={Teletraffic Engineering in a Competitive World}, author={Zhu, YH and Rouskas, GN and Perros, HG and Key, P and Smith, D}, year={1999}, pages={1321–1330} }
 @inbook{dynamic reconfiguration policies for wdm networks_1999, DOI={10.1109/INFCOM.1999.749297}, abstractNote={We study the issues arising when considering the problem of reconfiguring broadcast optical networks in response to changes in the traffic patterns. Although the ability to dynamically optimize the network under changing traffic conditions has been recognized as one of the key features of multiwavelength optical networks, this is the first in-depth study of the tradeoffs involved in carrying out the reconfiguration process. We first identify the degree of load balancing and the number of retunings as two important, albeit conflicting, objectives in the design of reconfiguration policies. We then formulate the problem as a Markovian decision process and we develop a systematic and flexible framework in which to study reconfiguration policies. We apply results from Markov decision process theory to obtain optimal reconfiguration policies for networks of large size. The advantages of optimal policies over a class of threshold-bused policies are illustrated through numerical results.}, booktitle={Ieee Infocom '99 - the Conference on Computer Communications, Vols 1-3, Proceedings}, year={1999}, pages={313–320} }
 @inbook{mtcp: scalable tcp-like congestion control for reliable multicast_1999, DOI={10.1109/INFCOM.1999.752144}, abstractNote={We present MTCT, a congestion control scheme for large-scale reliable multicast. Congestion control for reliable multicast is important because of its wide applications in multimedia and collaborative computing, yet nontrivial, because of the potentially large number of receivers involved. Many schemes have been proposed to handle the recovery of lost packets in a scalable manner; but there is little work on the design and implementation of congestion control schemes for reliable multicast. We propose new techniques that can effectively handle instances of congestion occurring simultaneously at various parts of a multicast tree. Our protocol incorporates several novel features: (1) hierarchical congestion status reports that distribute the load of processing feedback from all receivers across the multicast group, (2) the relative time delay (RTD) concept which overcomes the difficulty of estimating round-trip times in tree-based multicast environments, (3) window-based control that prevents the sender from transmitting faster than packets leave the bottleneck link an the multicast path through which the sender's traffic flows, (4) a retransmission window that regulates the flow of repair packets to prevent local recovery from causing congestion, and (5) a selective acknowledgment scheme that prevents independent (i.e., non-congestion-related) packet loss from reducing the sender's transmission rate. We have implemented MTCP both on UDP in SunOS 5.6 and on the simulator ns, and we have conducted extensive Internet experiments and simulation to test the scalability and inter-fairness properties of the protocol. The encouraging results we have obtained support our confidence that TCP-like congestion control for large-scale reliable multicast is within our grasp.}, booktitle={Ieee Infocom '99 - the Conference on Computer Communications, Vols 1-3, Proceedings}, year={1999}, pages={1265–1273} }
 @article{mckinnon_perros_rouskas_1999, title={Performance analysis of broadcast WDM networks under IP traffic}, volume={36-7}, ISSN={["1872-745X"]}, DOI={10.1016/S0166-5316(99)00031-0}, abstractNote={We consider the problem of carrying IP packet traffic over a broadcast WDM network. The network operates under a schedule that masks the transceiver tuning latency. Variable length IP packets are segmented at the transmitting end, the fixed-size segments are transmitted in slots specified by the schedule and are then reassembled into the original packet at the receiving end. We develop and analyze approximately a queueing model of the network in order to obtain the queue-length distribution and loss probabilities at the transmitting and receiving side of nodes. The analysis is carried out assuming finite buffer sizes, non-uniform destination probabilities, and an appropriate arrival process model. Our work makes it possible to study the interactions among the various system parameters (such as load balancing and scheduling algorithms, the number of channels, and the buffer capacity) and to predict, explain, and fine tune the performance of the network. To the best of our knowledge, this is the first comprehensive performance study of optical local area networks under variable length packets.}, journal={PERFORMANCE EVALUATION}, author={McKinnon, MW and Perros, HG and Rouskas, GN}, year={1999}, month={Aug}, pages={333–358} }
 @article{baldine_rouskas_1999, title={Reconfiguration and dynamic load balancing in broadcast WDM networks}, volume={1}, ISSN={["1387-974X"]}, DOI={10.1023/A:1010029100403}, number={1}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Baldine, I and Rouskas, GN}, year={1999}, month={Jun}, pages={49–64} }
 @inbook{baldine_rouskas_ieee_1998, title={Dynamic load balancing in broadcast WDM networks with tuning latencies}, booktitle={Ieee Infocom '98 - the Conference on Computer Communications, Vols. 1-3}, author={Baldine, I and Rouskas, GN and IEEE}, year={1998}, pages={78–85} }
 @inbook{baldine_rouskas_senoir_qiao_1998, title={On the design of dynamic reconfiguration policies for broadcast WDM networks}, volume={3531}, DOI={10.1117/12.327053}, abstractNote={We study the issues arising when considering the problem of reconfiguring broadcast optical networks in response to changes in the traffic patterns. Although the ability to dynamically optimize the network under changing traffic conditions has been recognized as one of the key features of multiwavelength optical networks, this is the first in-depth study of the tradeoffs involved in carrying out the reconfiguration process. We first identify the degree of local balancing and the number of retunings as two important, albeit conflicting, objectives in the design of reconfiguration policies. We then formulate the problem as a Markovian Decision Process and we develop a systematic and flexible framework in which to view and contrast reconfiguration policies. We also apply results from Markov Decision Process theory to obtain optimal reconfiguration policies even for networks of large size. The advantages of optimal policies over a class of threshold-based policies are also illustrated through numerical results.}, booktitle={All-Optical Networking: Architecture, Control, and Management Issues}, author={Baldine, I and Rouskas, GN and Senoir, JM and Qiao, C}, year={1998}, pages={146–157} }
 @article{mckinnon_rouskas_perros_1998, title={Performance analysis of a photonic single-hop ATM switch architecture, with tunable transmitters and fixed frequency receivers}, volume={33}, ISSN={["1872-745X"]}, DOI={10.1016/S0166-5316(98)00003-0}, abstractNote={We consider a photonic asynchronous transfer mode (ATM) switch based on the single-hop wavelength division multiplexing (WDM) architecture with tunable transmitters and fixed frequency receivers. The switch operates under a schedule that masks the transceiver tuning latency. We analyze approximately a queueing model of the switch in order to obtain the queue-length distribution and the cell-loss probability at the input and output ports. The analysis is carried out assuming two-state Markov modulated Bernoulli process (MMBP) sources that capture the notion of burstiness and correlation, two important characteristics of ATM traffic, and non-uniform destination probabilities. We present results which establish that the performance of the switch is a complex function of a number of system parameters, including the load balancing and scheduling algorithms, the number of available channels, and the buffer capacity. We also show that the behavior of the switch in terms of cell-loss probability as these parameters are varied cannot be predicted without an accurate analysis. Our work makes it possible to study the interactions among the system parameters, and to predict, explain, and fine tune the performance of the switch.}, number={2}, journal={PERFORMANCE EVALUATION}, author={McKinnon, MW and Rouskas, GN and Perros, HG}, year={1998}, month={Jul}, pages={113–136} }
 @inbook{sivaraman_rouskas_soc_1997, title={HiPeR-l: A high performance reservation protocol with look-ahead for broadcast WDM networks}, booktitle={Ieee Infocom '97 - the Conference on Computer Communications, Proceedings, Vols 1-3}, author={Sivaraman, V and Rouskas, GN and SOC, IEEE COMP}, year={1997}, pages={1270–1277} }
 @article{rouskas_baldine_1997, title={Multicast routing with end-to-end delay and delay variation constraints}, volume={15}, ISSN={["0733-8716"]}, DOI={10.1109/49.564133}, abstractNote={We study the problem or constructing multicast trees to meet the quality of service requirements of real-time interactive applications operating in high-speed packet-switched environments. In particular, we assume that multicast communication depends on: (1) bounded delay along the paths from the source to each destination and (2) bounded variation among the delays along these paths. We first establish that the problem of determining such a constrained tree is NP-complete. We then present a heuristic that demonstrates good average case behavior in terms of the maximum interdestination delay variation. The heuristic achieves its best performance under conditions typical of multicast scenarios in high speed networks. We also show that it is possible to dynamically reorganize the initial tree in response to changes in the destination set, in a way that is minimally disruptive to the multicast session.}, number={3}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Rouskas, GN and Baldine, I}, year={1997}, month={Apr}, pages={346–356} }
 @article{rouskas_ammar_1997, title={Multidestination communication over tunable-receiver single-hop WDM networks}, volume={15}, ISSN={["1558-0008"]}, DOI={10.1109/49.564145}, abstractNote={We address the issue of providing efficient mechanisms for multidestination communication over one class of lightwave wavelength division multiplexing (WDM) architectures, namely, single-hop networks with tunability provided only at the receiving side. We distinguish a number of multicast traffic types, we present a number of alternative broadcast/multicast time-division multiple-access (TDMA) schedules for each type, and we develop heuristics to obtain schedules that result in low average packet delay. One of our major contributions is the development of a suite of adaptive multicast protocols which are simple to implement, and have good performance under changing multicast traffic conditions.}, number={3}, journal={IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS}, author={Rouskas, GN and Ammar, MH}, year={1997}, month={Apr}, pages={501–511} }
 @article{rouskas_sivaraman_1997, title={Packet scheduling in broadcast WDM networks with arbitrary transceiver tuning latencies}, volume={5}, ISSN={["1558-2566"]}, DOI={10.1109/90.611101}, abstractNote={We consider the problem of scheduling packet transmissions in a broadcast, single-hop wavelength-division multiplexing (WDM) network, with tunability provided only at one end. Our objective is to design schedules of minimum length to satisfy a set of traffic requirements given in the form of a demand matrix. We address a fairly general version of the problem as we allow arbitrary traffic demands and arbitrary transmitter tuning latencies. The contribution of our work is twofold, First we define a special class of schedules which permit an intuitive formulation of the scheduling problem. Based on this formulation we present algorithms which construct schedules of length equal to the lower bound provided that the traffic requirements satisfy certain optimality conditions. We also develop heuristics which, in the general case, give schedules of length equal or very close to the lower bound. Secondly, we identify two distinct regions of network operation. The first region is such that the schedule length is determined by the tuning requirements of transmitters; when the network operates within the second region however, the length of the schedule is determined by the traffic demands, not the tuning latency. The point at which the network switches between the two regions is identified in terms of system parameters such as the number of nodes and channels and the tuning latency. Accordingly, we show that it is possible to appropriately dimension the network to minimize the effects of even large values of the tuning latency.}, number={3}, journal={IEEE-ACM TRANSACTIONS ON NETWORKING}, author={Rouskas, GN and Sivaraman, V}, year={1997}, month={Jun}, pages={359–370} }
 @article{rouskas_ammar_1996, title={Minimizing delay and packet loss in single-hop lightwave WDM networks using TDMA schedules}, volume={5}, number={4}, journal={Journal of High Speed Networks}, author={Rouskas, GN and Ammar, MH}, year={1996}, pages={309–327} }
 @inbook{rouskas_baldine_ieee_1996, title={Multicast routing with end-to-end delay and delay variation constraints}, booktitle={Ieee Infocom '96 - Fifteenth Annual Joint Conference of the Ieee Computer and Communications Societies: Networking the Next Generation, Proceedings Vols 1-3}, author={Rouskas, GN and Baldine, I and IEEE}, year={1996}, pages={353–360} }
 @inbook{rouskas_sivaraman_ieee_1996, title={On the design of optimal TDM schedules for broadcast WDM networks with arbitrary transceiver tuning latencies}, booktitle={Ieee Infocom '96 - Fifteenth Annual Joint Conference of the Ieee Computer and Communications Societies: Networking the Next Generation, Proceedings Vols 1-3}, author={Rouskas, GN and Sivaraman, V and IEEE}, year={1996}, pages={1217–1224} }
 @article{rouskas_ammar_1995, title={ANALYSIS AND OPTIMIZATION OF TRANSMISSION SCHEDULES FOR SINGLE-HOP WDM NETWORKS}, volume={3}, DOI={10.1109/90.374121}, abstractNote={Considers single-hop lightwave networks with stations interconnected using wave division multiplexing. The stations are equipped with tunable transmitters and/or receivers. A predefined, wavelength-time oriented schedule specifies the slots and the wavelengths on which communication between any two pairs of stations is allowed to take place. The authors define a wide variety of schedules and develop a general framework for analyzing their throughput performance for any number of available wavelengths, any tunability characteristics, and general (potentially nonuniform) traffic patterns. They then consider the optimization of schedules given the traffic requirements and present optimization heuristics that give near-optimal results. They also investigate how the number of available wavelengths (channels) affects the system throughput, and develop techniques to efficiently share the available channels among the network stations. As a result, they obtain systems that are easy to scale while having very good performance.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>}, number={2}, journal={Ieee-Acm Transactions on Networking}, author={ROUSKAS, GN and AMMAR, MH}, year={1995}, pages={211–221} }
 @article{rouskas_ammar_1995, title={Dynamic Reconfiguration in Multihop WDM Networks}, volume={4}, ISSN={0926-6801}, url={http://dx.doi.org/10.3233/jhs-1995-4301}, DOI={10.3233/jhs-1995-4301}, abstractNote={We consider multichannel multihop lightwave networks with stations equipped with a small number of transmitters and receivers. By assigning wavelengths to the receivers and transmitters at each station, one can define the logical connectivity of the network independently of the underlying physical topology. The advent of fast tunable optical transmitters and receivers makes it feasible to dynamically update the network connectivity to accommodate traffic demands that vary over time. Of major concern in such design is how the connectivity should react to changes in traffic patterns. The problem is formulated as a Markovian Decision Process and the properties of the optimal configuration policy are identified. These properties are then used to develop an algorithm for obtaining policies that make decisions similar to the decisions of the optimal policy. A procedure is also proposed to manage the large state space for systems with a large number of stations.}, number={3}, journal={Journal of High Speed Networks}, publisher={IOS Press}, author={Rouskas, George N. and Ammar, Mostafa H.}, year={1995}, pages={221–238} }
 @article{rouskas_ammar_ieee_1995, title={Minimizing delay and packet loss in single-hop lightwave WDM networks using TDM schedules}, journal={Icc '95 - 1995 Ieee International Conference on Communications, Conference Record, Vols 1-3}, author={ROUSKAS, GN and AMMAR, MH and IEEE}, year={1995}, pages={1267–1271} }
 @article{ammar_rouskas_1995, title={ON THE PERFORMANCE OF PROTOCOLS FOR COLLECTING RESPONSES OVER A MULTIPLE-ACCESS CHANNEL}, volume={43}, DOI={10.1109/26.380059}, abstractNote={We consider a generalization of the multiple access problem where it is necessary to identify a subset of the ready users, not all. The problem is motivated by several "response collection" applications that arise in distributed computing and database systems. In these applications, a collector is interested in gathering a set of responses from a number of potential respondents. The collector and respondents communicate over a shared channel. We define three collection objectives and investigate a suite of protocols that can be used to achieve these objectives. The protocols are based on the use of polling, TDMA, and group testing. Using a binomial respondent model we analyze and, where applicable, optimize the performance of the protocols. Our concern is with cost measures that reflect the computational load placed on the system, as well as the delay incurred for achieving a particular objective.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>}, number={2-4}, journal={Ieee Transactions on Communications}, author={AMMAR, MH and ROUSKAS, GN}, year={1995}, pages={412–420} }
 @inbook{rouskas_ammar_soc_1994, title={MULTI-DESTINATION COMMUNICATION OVER SINGLE-HOP LIGHTWAVE WDM NETWORKS}, booktitle={Ieee Infocom '94: the Conference on Computer Communications - Networking For Global Communications, Proceedings, Vols 1-3}, author={ROUSKAS, GN and AMMAR, MH and SOC, IEEE COMP}, year={1994}, pages={1520–1527} }
 @article{rouskas_ammar_ieee_1993, title={ANALYSIS AND OPTIMIZATION OF TRANSMISSION SCHEDULES FOR SINGLE-HOP WDM NETWORKS}, DOI={10.1109/INFCOM.1993.253398}, abstractNote={Single-hop lightwave networks with stations interconnected using wavelength-division multiplexing are considered. The stations are equipped with tunable transmitters and/or receivers. Coordination between the transmitting and receiving stations is achieved by assuming synchronous control and a predefined, frequency-time oriented schedule which specifies the slots and the wavelengths on which communication between any two pairs of stations is allowed to take place. The authors define and analyze, in terms of throughput, all possible types of schedules in the situation where the number of available wavelengths is equal to the number of stations. The results are valid for the general case, i.e., nonuniform traffic. The optimization of schedules, given the traffic requirements, is considered, and optimization heuristics that give near-optimal results are presented.<<ETX>>}, journal={Ieee Infocom 93 : the Conference on Computer Communications, Proceedings, Vols 1-3}, author={ROUSKAS, GN and AMMAR, MH and IEEE}, year={1993}, pages={1342–1349} }
 @article{ammar_rouskas_ieee_1991, title={ON THE PERFORMANCE OF PROTOCOLS FOR COLLECTING RESPONSES OVER A MULTIPLE-ACCESS CHANNEL}, DOI={10.1109/INFCOM.1991.147682}, abstractNote={A generalization of the multiple access problem is considered where it is necessary to identify a subset of the ready users, not all. The problem is motivated by several response collection applications that arise in distributed computing and database systems. In these applications, a collector is interested in gathering a set of responses from a number of potential respondents. The collector and respondents communicate over a shared channel. Three collection objectives are defined, and a suite of protocols that can be used to achieve these objectives is investigated. The protocols are based on the use of polling, time division multiple access (TDMA) and group testing. Using a binomial respondent model, the performance of the protocols is analyzed and, where possible, optimized. The main concern is with cost measures that reflect the computational load placed on the system, as well as the delay incurred for achieving a particular objective.<<ETX>>}, journal={Ieee Infocom 91, the Conference on Computer Communications, Proceedings Vols 1-3}, author={AMMAR, MH and ROUSKAS, GN and IEEE}, year={1991}, pages={1490–1499} }
 @inproceedings{chen_rouskas_dutta, title={A framework for hierarchical traffic grooming in WDM networks of general topology}, booktitle={2nd International Conference on Broadband Networks (Broadnets 2005)}, author={Chen, B. S. and Rouskas, G. N. and Dutta, R.}, pages={167-} }
 @inproceedings{rouskas_baldine_calvert_dutta_griffioen_nagurney_wolf, title={ChoiceNet: Network innovation through choice}, booktitle={2013 17th International Conference on Optical Networking Design and Modeling (ONDM)}, author={Rouskas, G. N. and Baldine, I. and Calvert, K. and Dutta, R. and Griffioen, J. and Nagurney, A. and Wolf, T.}, pages={1–6} }
 @book{rouskas, title={Internet tiered services: Theory, economics, and quality of service}, ISBN={9780387097374}, publisher={New York : Springer}, author={Rouskas, G. N.} }
 @article{xiong_shi_yang_lv_rouskas, title={Lightpath management in SDN-based elastic optical networks with power consumption considerations}, volume={36}, number={9}, journal={Journal of Lightwave Technology}, author={Xiong, Y. and Shi, J. and Yang, Y. Y. and Lv, Y. and Rouskas, G. N.}, pages={1650–1660} }
 @inproceedings{liu_rouskas, title={Link selection algorithms for link-based ilps and applications to RWA in mesh networks}, booktitle={2013 17th International Conference on Optical Networking Design and Modeling (ONDM)}, author={Liu, Z. Y. and Rouskas, G. N.}, pages={59–64} }
 @inproceedings{lv_rouskas, title={On optimal sizing of tiered network services}, booktitle={27th IEEE Conference on Computer Communications (Infocom), vols 1-5}, author={Lv, Q. and Rouskas, G. N.}, pages={1–5} }
 @inproceedings{chen_dutta_rouskas, title={On the application of k-center algorithms to hierarchical traffic grooming}, booktitle={2nd International Conference on Broadband Networks (Broadnets 2005)}, author={Chen, B. S. and Dutta, R. and Rouskas, G. N.}, pages={295-} }
 @article{fayez_katib_rouskas_faheem, title={Scheduling-inspired spectrum assignment algorithms for mesh elastic optical networks}, journal={Advances in computer communications and networks: from green, mobile, pervasive networking to big data computing}, author={Fayez, M. and Katib, I. and Rouskas, G. N. and Faheem, H. M.}, pages={225–244} }
 @inproceedings{coulibaly_al-kilany_abd latiff_rouskas_mandala_razzaque, title={Secure burst control packet scheme for optical burst switching networks}, booktitle={2015 IEEE International Broadband and Photonics Conference (IBP)}, author={Coulibaly, Y. and Al-Kilany, A. A. I. and Abd Latiff, M. S. and Rouskas, G. and Mandala, S. and Razzaque, M. A.}, pages={91–96} }
 @inproceedings{talebi_bampis_lucarelli_katib_rouskas, title={The spectrum assigment (SA) problem in optical networks: A multiprocesor scheduling perspective}, booktitle={2014 International Conference on Optical Network Design and Modeling}, author={Talebi, S. and Bampis, E. and Lucarelli, G. and Katib, I. and Rouskas, G. N.}, pages={55–60} }
 @inproceedings{dutta_rouskas, title={Topology design in WDM rings to minimize electronic routing: efficient comutation of tight bounds.}, booktitle={Proceedings of the 38th Allerton Conference on Communication, Control and Computing}, author={Dutta, R. and Rouskas, G. N.}, pages={1284–1293} }