@book{perros_2021, title={An Introduction to IoT Analytics}, ISBN={9781003139041}, url={http://dx.doi.org/10.1201/9781003139041}, DOI={10.1201/9781003139041}, abstractNote={This book covers techniques that can be used to analyze data from IoT sensors and addresses questions regarding the performance of an IoT system. It strikes a balance between practice and theory so one can learn how to apply these tools in practice with a good understanding of their inner workings. This is an introductory book for readers who have no familiarity with these techniques. The techniques presented in An Introduction to IoT Analytics come from the areas of machine learning, statistics, and operations research. Machine learning techniques are described that can be used to analyze IoT data generated from sensors for clustering, classification, and regression. The statistical techniques described can be used to carry out regression and forecasting of IoT sensor data and dimensionality reduction of data sets. Operations research is concerned with the performance of an IoT system by constructing a model of the system under study and then carrying out a what-if analysis. The book also describes simulation techniques. Key Features IoT analytics is not just machine learning but also involves other tools, such as forecasting and simulation techniques. Many diagrams and examples are given throughout the book to fully explain the material presented. Each chapter concludes with a project designed to help readers better understand the techniques described. The material in this book has been class tested over several semesters. Practice exercises are included with solutions provided online at www.routledge.com/9780367686314 Harry G. Perros is a Professor of Computer Science at North Carolina State University, an Alumni Distinguished Graduate Professor, and an IEEE Fellow. He has published extensively in the area of performance modeling of computer and communication systems.}, publisher={Chapman and Hall/CRC}, author={Perros, Harry G.}, year={2021}, month={Mar} }
 @article{nayak_perros_2020, title={Automated real-time anomaly detection of temperature sensors through machine-learning}, volume={34}, ISSN={["1748-1287"]}, DOI={10.1504/IJSNET.2020.111233}, abstractNote={Fast identification of faulty sensors is necessary for guaranteeing their robust functions in diverse applications ranging from extreme weather prediction to energy saving to healthcare. We present an automated machine-learning based framework that can detect anomalies of temperature sensor data in real-time. We adopted a purely temporal approach that utilises a univariate time-series (UTS) generated by a single sensor. The framework divides the UTS into subsequences, models each subsequence stochastically as an autoregressive function, and finally mines the function parameters with a one-class support vector machines (OC-SVM) that classifies any outlier as an anomaly. Extensive experimentation showed that the framework identifies both normal and anomalous data correctly with high degrees of accuracy.}, number={3}, journal={INTERNATIONAL JOURNAL OF SENSOR NETWORKS}, author={Nayak, Debanjana and Perros, Harry}, year={2020}, pages={137–152} }
 @article{akbulut_perros_shahzad_2020, title={Bimodal affect recognition based on autoregressive hidden Markov models from physiological signals}, volume={195}, ISSN={["1872-7565"]}, DOI={10.1016/j.cmpb.2020.105571}, abstractNote={Background and objective: Affect provides contextual information about the emotional state of a person as he/she communicates in both verbal and/or non-verbal forms. While human’s are great at determining the emotional state of people while they communicate in person, it is challenging and still largely an unsolved problem to computationally determine the emotional state of a person. Methods: Emotional states of a person manifest in the physiological biosignals such as electrocardiogram (ECG) and electrodermal activity (EDA) because these signals are impacted by the peripheral nervous system of the body, and the peripheral nervous system is strongly coupled with the mental state of the person. In this paper, we present a method to accurately recognize six emotions using ECG and EDA signals and applying autoregressive hidden Markov models (AR-HMMs) and heart rate variability analysis on these signals. The six emotions include happiness, sadness, surprise, fear, anger, and disgust. Results: We evaluated our method on a comprehensive new dataset collected from 30 participants. Our results show that our proposed method achieves an average accuracy of 88.6% in distinguishing across the 6 emotions. Conclusions: The key technical depth of the paper is in the use of the AR-HMMs to model the EDA signal and the use of LDA to enable accurate emotion recognition without requiring a large number of training samples. Unlike other studies, we have taken a hierarchical approach to classify emotions, where we first categorize the emotion as either positive or negative and then identify the exact emotion.}, journal={COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE}, author={Akbulut, Fatma Patlar and Perros, Harry G. and Shahzad, Muhammad}, year={2020}, month={Oct} }
 @article{akbulut_perros_2019, title={Performance Analysis of Microservice Design Patterns}, volume={23}, ISSN={["1941-0131"]}, DOI={10.1109/MIC.2019.2951094}, abstractNote={Microservice-based solutions are currently gaining momentum because they do not have the disadvantages of traditional monolithic architectures. Business interest in microservices is increasing since the microservice architecture brings a lightweight, independent, reuse-oriented, and fast service deployment approach that minimizes infrastructural risks. This approach is at an early stage of its development, and in view of this, it is important to understand the performance of its design patterns. In this article, we obtained performance results related to query response time, efficient hardware usage, hosting costs, and packet-loss rate, for three microservice design patterns practiced in the software industry.}, number={6}, journal={IEEE INTERNET COMPUTING}, author={Akbulut, Akhan and Perros, Harry G.}, year={2019}, pages={19–27} }
 @article{bouterse_perros_2019, title={Performance analysis of the reserve capacity policy for dynamic VM allocation in a SaaS environment}, volume={93}, ISSN={["1878-1462"]}, DOI={10.1016/j.simpat.2018.07.002}, abstractNote={We consider a periodic-review provision scheme with constant inspection intervals for allocating dynamically virtual machines (VMs) in a Software-as-a Service (SaaS) environment. At each interval, we determine how many virtual machines (VMs) to provisioned or de-provision using a simple heuristic referred to as the reserve capacity policy, since it maintains a fixed reserve capacity of VMs. We analyze the performance of the reserve capacity policy within the context of a periodic-review provision scheme using a Markov Chain embedded at the inspection intervals. We assume a single stream of jobs with each job requiring a single VM. Jobs arrive in a Poisson fashion and the execution time of a job in a VM is exponentially distributed. We calculate the probability distribution of the number of customers in the system, the number of in-service VMs, the utilization, and the queue-length distribution of the waiting customers. The embedded Markov Chain is solved numerically. For cases where the underlying transition matrix is very large, we have proposed approximations and showed that they have a root mean square error (RMSE) of less than 2%.}, journal={SIMULATION MODELLING PRACTICE AND THEORY}, author={Bouterse, Brian and Perros, Harry}, year={2019}, month={May}, pages={293–304} }
 @article{perros_papapanagiotou_pujolle_2018, title={Cloud communications and networking}, volume={73}, ISSN={0003-4347 1958-9395}, url={http://dx.doi.org/10.1007/S12243-018-0630-Y}, DOI={10.1007/S12243-018-0630-Y}, number={3-4}, journal={Annals of Telecommunications}, publisher={Springer Science and Business Media LLC}, author={Perros, Harry and Papapanagiotou, Ioannis and Pujolle, Guy}, year={2018}, month={Mar}, pages={165–167} }
 @article{bouterse_perros_2018, title={Dynamic VM allocation in a SaaS environment}, volume={73}, ISSN={["1958-9395"]}, DOI={10.1007/s12243-017-0589-0}, number={3-4}, journal={ANNALS OF TELECOMMUNICATIONS}, author={Bouterse, Brian and Perros, Harry}, year={2018}, month={Apr}, pages={205–218} }
 @article{perros_2018, title={QoS architectures for the IP network}, journal={Encyclopedia of Information Science and Technology, 4th edition}, author={Perros, H. G.}, year={2018}, pages={6609–6617} }
 @inproceedings{kayal_perros_2017, title={A comparison of IoT application layer protocols through a smart parking implementation}, DOI={10.1109/icin.2017.7899436}, abstractNote={Several IoT protocols have been introduced in order to provide an efficient communication for resource-ronstrained applications. However, their performance is not as yet well understood. To address this issue, we evaluated and compared four communication protocols, namely, CoAP, MQTT, XMPP, and WebSocket. For this, we implemented a smart parking application using open source software for these protocols and measured their response time by varying the traffic load.}, booktitle={Proceedings of the 2017 20th conference on innovations in clouds, internet and networks (icin)}, author={Kayal, P. and Perros, H.}, year={2017}, pages={331–336} }
 @inproceedings{tanwir_nayak_perros_2016, title={Modeling 3D video traffic using a Markov Modulated Gamma Process}, DOI={10.1109/iccnc.2016.7440638}, abstractNote={Three-dimensional (3D) television and video streaming has become very popular over the last few years. Multiview encoded video is used to support 3D video applications. The statistical characteristics of multiview video are significantly different from the traditional single-view video and therefore existing video traffic models are no more applicable for this type of video. In this paper, we propose and evaluate a new model for multiview video that is based on a Markov process. To the best of our knowledge, there is only one other model for multiview video that has been proposed in the literature by Rossi et al. We compared the two models using Q-Q plots and the autocorrelation function of the frame sizes along with QoS metrics of the resulting packet traces estimated by simulation. The comparison results show that our model has less complexity and better accuracy.}, booktitle={2016 International Conference on Computing, Networking and Communications (ICNC)}, author={Tanwir, S. and Nayak, D. and Perros, H.}, year={2016} }
 @article{tanwir_perros_2016, title={Modeling live adaptive streaming over HTTP}, volume={85}, ISSN={["1873-703X"]}, DOI={10.1016/j.comcom.2016.03.025}, abstractNote={Video streaming methods have evolved greatly over the years. Today, the most prevalent technique to stream live and video on-demand is the adaptive HTTP streaming and is used by several commercial vendors. In this paper, we present an approximate analytic model for live adaptive streaming over HTTP. Using this model, we propose a new rate control algorithm that makes the rate transitions less frequent and increases the quality of experience for the viewer. Also, the model can be used to characterize the departure packet process at the video server. To the best of our knowledge, this is the first video traffic model for adaptive HTTP streaming to be reported in the literature.}, journal={COMPUTER COMMUNICATIONS}, author={Tanwir, Savera and Perros, Harry}, year={2016}, month={Jul}, pages={74–88} }
 @article{fan_yang_perros_pei_2015, title={A multi-dimensional trust-aware cloud service selection mechanism based on evidential reasoning approach}, volume={12}, ISSN={1476-8186 1751-8520}, url={http://dx.doi.org/10.1007/S11633-014-0840-3}, DOI={10.1007/S11633-014-0840-3}, abstractNote={In the last few years, cloud computing as a new computing paradigm has gone through significant development, but it is also facing many problems. One of them is the cloud service selection problem. As increasingly boosting cloud services are offered through the internet and some of them may be not reliable or even malicious, how to select trustworthy cloud services for cloud users is a big challenge. In this paper, we propose a multi-dimensional trust-aware cloud service selection mechanism based on evidential reasoning (ER) approach that integrates both perception-based trust value and reputation based trust value, which are derived from direct and indirect trust evidence respectively, to identify trustworthy services. Here, multi-dimensional trust evidence, which reflects the trustworthiness of cloud services from different aspects, is elicited in the form of historical users' feedback ratings. Then, the ER approach is applied to aggregate the multi-dimensional trust ratings to obtain the real-time trust value and select the most trustworthy cloud service of certain type for the active users. Finally, the fresh feedback from the active users will update the trust evidence for other service users in the future.}, number={2}, journal={International Journal of Automation and Computing}, publisher={Springer Science and Business Media LLC}, author={Fan, Wen-Juan and Yang, Shan-Lin and Perros, Harry and Pei, Jun}, year={2015}, pages={208–219} }
 @article{anjum_perros_2015, title={Bandwidth estimation for video streaming under percentile delay, jitter, and packet loss rate constraints using traces}, volume={57}, ISSN={["1873-703X"]}, DOI={10.1016/j.comcom.2014.08.018}, abstractNote={We present and use a CPU-efficient activity-based simulation model to calculate the sojourn time of a packet and the packet loss rate in a tandem queueing network that depicts the path of a video flow. The video flow is characterized by a packet trace. Background traffic, also characterized by a trace, is allowed in the tandem queueing network. In our analysis we used real video traces (Telepresence, WebEx, Jabber) and also generalized our results using traces generated by a theoretical model of a video arrival process depicted by a Markovian Arrival Process. Using this simulation model we calculate the bandwidth required for a video flow, so that a given set of constraints for the percentile end-to-end delay, jitter, and packet loss rate are satisfied. We also show that the bandwidth required for n identical video streams that follow the same path through an IP network, so that the end-to-end percentile delay remains the same, is a linear function of n. Further, it is experimentally depicted that for infinite-capacity queues the bandwidth required to satisfy the percentile end-to-end delay constraint also satisfies the jitter constraint. And for finite-capacity queues, the bandwidth required to satisfy both the percentile end-to-end delay and the packet loss rate constraints also satisfies the pair of jitter and packet loss rate constraints.}, journal={COMPUTER COMMUNICATIONS}, author={Anjum, Bushra and Perros, Harry}, year={2015}, month={Feb}, pages={73–84} }
 @article{battestilli_perros_chukova_2015, title={Performance evaluation of an OBS network as a IPP/M/W/W network}, volume={39}, ISSN={["1872-8480"]}, DOI={10.1016/j.apm.2014.07.016}, abstractNote={We develop an analytical method for calculating the burst loss probabilities in a tandem Optical Burst Switched (OBS) network with a bursty arrival process, depicted by an Interrupted Poison Process (IPP). The OBS network is modeled as a tandem network of loss nodes which is analyzed using single-node decomposition, whereby each node is studied in isolation as an IPP/M/W/W. For this, we need the departure process from an IPP/M/W/W which we obtain using binomial moment techniques. Performance evaluation of an OBS network shows that our method gives results which are closer to simulation results than a Poisson arrival process.}, number={3-4}, journal={APPLIED MATHEMATICAL MODELLING}, author={Battestilli, Lina and Perros, Harry and Chukova, Stefanka}, year={2015}, month={Feb}, pages={965–981} }
 @article{fan_perros_2014, title={A novel trust management framework for multi-cloud environments based on trust service providers}, volume={70}, ISSN={["1872-7409"]}, DOI={10.1016/j.knosys.2014.07.018}, abstractNote={In this paper, we address the problem of trust management in multi-cloud environments based on a set of distributed Trust Service Providers (TSPs). These are independent third-party providers/trust agents, trusted by Cloud Providers (CPs), Cloud Service Providers (CSPs) and Cloud Service Users (CSUs), that provide trust related services to cloud participants. TSPs are distributed over the clouds, and they elicit raw trust evidence from different sources and in different formats. This evidence is information regarding the adherence of a CSP to a Service Level Agreement (SLA) for a cloud-based service and the feedback sent by CSUs. Using this information, they evaluate an objective trust and a subjective trust of CSPs. TSPs communicate among themselves through a trust propagation network that permits a TSP to obtain trust information about a CSP from other TSPs. Experiments show that our proposed framework is effective and relatively stable in differentiating trustworthy and untrustworthy CSPs in a multi-cloud environment.}, journal={KNOWLEDGE-BASED SYSTEMS}, author={Fan, Wenjuan and Perros, Harry}, year={2014}, month={Nov}, pages={392–406} }
 @article{perros_2014, title={Comments on: Queueing models for the analysis of communication systems}, volume={22}, ISSN={1134-5764 1863-8279}, url={http://dx.doi.org/10.1007/S11750-014-0329-9}, DOI={10.1007/S11750-014-0329-9}, abstractNote={Over the last 30 years, Dr. Bruneel’s team has produced a continuous stream of high-quality papers, which focus on the use of generating functions in the analysis of complex queueing systems that arise in communication networks.}, number={2}, journal={TOP}, publisher={Springer Science and Business Media LLC}, author={Perros, Harry G.}, year={2014}, month={May}, pages={458–459} }
 @article{geleji_perros_2014, title={Jitter analysis of an IPP tagged traffic stream in an {IPP,M}/M/1 queue}, volume={69}, ISSN={["1958-9395"]}, DOI={10.1007/s12243-013-0362-y}, number={5-6}, journal={ANNALS OF TELECOMMUNICATIONS}, author={Geleji, Geza and Perros, Harry}, year={2014}, month={Jun}, pages={283–294} }
 @article{geleji_perros_2014, title={Jitter analysis of an MMPP-2 tagged stream in the presence of an MMPP-2 background stream}, volume={38}, ISSN={["1872-8480"]}, DOI={10.1016/j.apm.2013.11.055}, abstractNote={We first consider a single-server queue that serves a tagged MMPP-2 stream and a background MMPP-2 stream in a FIFO manner. The service time is exponentially distributed. For this queueing system, we obtain the CDF of the tagged inter-departure time, from which we can calculate the jitter, defined as a percentile of the inter-departure time. The formulation is exact, but the solution is obtained numerically, which introduces an error that has been found to be negligible. Subsequently, we consider a tandem queueing network consisting of N tandem queues, which is traversed by the MMPP-2 tagged stream, and where each queue also serves a local MMPP-2 background stream. For this queueing network, we obtain an upper bound on the CDF of the inter-departure time from the Nth queue using a heavy traffic approximation, and we verify it by simulation.}, number={14}, journal={APPLIED MATHEMATICAL MODELLING}, author={Geleji, G. and Perros, H.}, year={2014}, month={Jul}, pages={3380–3400} }
 @book{perros_2014, title={Networking services : QoS, signaling, processes}, ISBN={9781495437489}, publisher={CreateSpace Independent Publishing Platform}, author={Perros, H.}, year={2014} }
 @book{tanwir_perros_2014, title={VBR Video Traffic Models}, ISBN={["978-1-84821-636-5"]}, ISSN={["2051-249X"]}, DOI={10.1002/9781118931066}, journal={VBR VIDEO TRAFFIC MODELS}, author={Tanwir, S and Perros, H}, year={2014}, pages={1–148} }
 @article{tanwir_perros_2013, title={A Survey of VBR Video Traffic Models}, volume={15}, ISSN={["1553-877X"]}, DOI={10.1109/surv.2013.010413.00071}, abstractNote={We have seen a phenomenal growth in video applications in the past few years. An accurate traffic model of VBR video is necessary for performance evaluation of a network design and also for creating synthetic loads that can be used for benchmarking a network. In view of this, various models for VBR video traffic have been proposed in the literature. In this paper, we classify and survey these models. In addition, we implemented four representative video traffic models and compared them using the H.264 AVC video traces available at the Arizona State University video traces library. These models are: the Markov Modulated Gamma (MMG) model, the Discrete Autoregressive (DAR) model, the second order Autoregressive AR(2) model, and a wavelet-based model. The results show that the MMG and the wavelet-based models are suitable for both video conference and IPTV, while the DAR model is good for video conference traffic only. According to our results, the AR(2) model is not suitable for generating any type of H.264 video. A brief overview of SVC, HD, and 3D video is also provided.}, number={4}, journal={IEEE COMMUNICATIONS SURVEYS AND TUTORIALS}, author={Tanwir, Savera and Perros, Harry}, year={2013}, pages={1778–1802} }
 @inproceedings{anjum_perros_2012, title={End-to-end delay percentiles for video traces using a MAP2 approximation}, DOI={10.1109/netwks.2012.6381676}, abstractNote={Video traffic is widely expected to account for a large portion of the traffic in future wired and wireless networks. We propose an efficient and accurate approximation method for calculating a given percentile of the end-to-end delay of a video stream depicted by a trace. The queueing delay encountered in the network by the IP packets carrying the video is modeled by a tandem queueing network of infinite capacity queues. The video trace is approximated by a two-stage Markovian Arrival Process (MAP2), which is the arrival process to the tandem network. The proposed method uses only the first queue of the tandem queueing network to construct an upper and lower bound of a given percentile of the end-to-end delay. The percentile value is then approximated by interpolating between the two bounds. We used this method to estimate the 95th percentile of the end-to-end delay of two different types of video traces, Cisco's point-to-point presence and WebEx over a 10-node path. The results obtained were compared against simulation, and have an average relative error of 4.24%. Using this method, we then obtained the minimum amount of bandwidth required to be allocated on each link along the path of the video stream, so that a given 95th percentile of the end-to-end delay is satisfied.}, booktitle={2012 15th International Telecommunications Network Strategy and Planning Symposium (NETWORKS)}, author={Anjum, B. and Perros, H.}, year={2012} }
 @inproceedings{bouterse_perros_2012, title={Scheduling cloud capacity for time- varying customer demand}, DOI={10.1109/cloudnet.2012.6483668}, abstractNote={As utility computing resources become more ubiquitous, service providers increasingly look to the cloud for an in-full or in-part infrastructure to serve utility computing customers on demand. Given the costs associated with cloud infrastructure, dynamic scheduling of cloud resources can significantly lower costs while providing an acceptable service level. We investigated several methods for predicting the required cloud capacity in the presence of time-varying customer demand of application environments. We evaluated and compared their performance, using historical data of the Virtual Computing Laboratory (VCL) at North Carolina State University. We show that a simple heuristic, whereby we continuously maintain a fixed reserve capacity, performs better than the other methods.}, booktitle={2012 IEEE 1st International Conference on Cloud Networking (cloudnet)}, author={Bouterse, B. and Perros, H.}, year={2012} }
 @article{anjum_perros_2011, title={Adding Percentiles of Erlangian Distributions}, volume={15}, ISSN={["1089-7798"]}, DOI={10.1109/lcomm.2011.011011.102143}, abstractNote={In networking, enterprise computing and many other areas the issue of adding percentiles of a performance metric, such as the response time, arises regularly. Percentiles cannot be added using the arithmetic sum, and surprisingly there are no known formulae that permit us to do so correctly. In this paper, we obtain an exact analytical expression for adding percentiles of random variables which can be represented by a series of generalized exponential stages (e.g., Erlang, hypoexponential and two-stage Coxian). We demonstrate the applicability of our results by an example in which we use our expressions in the Dijkstra's algorithm to calculate the shortest 'percentile delay' path.}, number={3}, journal={IEEE COMMUNICATIONS LETTERS}, author={Anjum, Bushra and Perros, Harry}, year={2011}, month={Mar}, pages={346–348} }
 @article{anjum_perros_mountrouidou_kontovasilis_2011, title={Bandwidth allocation under end-to-end percentile delay bounds}, volume={21}, ISSN={["1099-1190"]}, DOI={10.1002/nem.783}, abstractNote={SUMMARY}, number={6}, journal={INTERNATIONAL JOURNAL OF NETWORK MANAGEMENT}, author={Anjum, Bushra and Perros, Harry and Mountrouidou, Xenia and Kontovasilis, Kimon}, year={2011}, pages={536–547} }
 @article{geleji_perros_2011, title={QoS routing across multiple autonomous systems using the path computation element architecture}, volume={66}, ISSN={["1958-9395"]}, DOI={10.1007/s12243-010-0206-y}, number={5-6}, journal={ANNALS OF TELECOMMUNICATIONS}, author={Geleji, Geza and Perros, Harry G.}, year={2011}, month={Jun}, pages={293–306} }
 @article{yiltas_perros_2011, title={Quality of service-based multi-domain routing under multiple quality of service metrics}, volume={5}, ISSN={1751-8628 1751-8636}, url={http://dx.doi.org/10.1049/iet-com.2010.0144}, DOI={10.1049/iet-com.2010.0144}, abstractNote={Applications such as voice and video require network paths that satisfy several different quality of service (QoS) metrics, such as delay, jitter, packet loss rate and availability. The calculation of paths under multiple QoS metrics, such as the above four metrics, is a difficult problem since these metrics are in general incompatible. The authors propose a simple method for combining the above four QoS metrics into a single composite QoS metric which can be used as a link cost in Dijkstra's algorithm in order to calculate a path. The authors evaluated the proposed method in a multi-domain routing environment where domain reachability information is available through a service oriented architecture paradigm, and they show that it outperforms two commonly used methods. The results are also applicable to routing within a single domain.}, number={3}, journal={IET Communications}, publisher={Institution of Engineering and Technology (IET)}, author={Yiltas, D. and Perros, H.}, year={2011}, month={Feb}, pages={327–336} }
 @article{fawaz_ouaiss_chen_perros_2010, title={Deadline-based connection setup in wavelength-routed WDM networks}, volume={54}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2010.02.008}, abstractNote={This article addresses the ubiquitous topic of quality of service (QoS) aware connection provisioning in wavelength-routed WDM optical networks. The impact of the connection setup time of an optical connection has not been adequately addressed in the open literature. As such, this paper presents a novel approach that uses the optical connection setup time as a service differentiator during connection provisioning. The proposed approach utilizes the Earliest Deadline First (EDF) queueing algorithm to achieve deadline-based connection setup management with the deadline being the setup time requirement of an optical connection. The proposed EDF-based approach would allow the network operator to improve the QoS perceived by the end clients. Performance of this novel scheme is analyzed by accurately calculating various parameters, such as the fraction of connections provisioned on-time (i.e. prior to deadline expiration) and the average time it takes to successfully setup a connection. In addition, the presented approach is validated by a simulation that analyzes the performance of the proposed connection setup scheme in the specific context of the National Science Foundation Network (NSFNET). The obtained results show that a deadline-based setup strategy can minimize blocking probability while achieving QoS differentiation.}, number={11}, journal={COMPUTER NETWORKS}, author={Fawaz, Wissam and Ouaiss, Iyad and Chen, Ken and Perros, Harry}, year={2010}, month={Aug}, pages={1792–1804} }
 @article{yun_perros_2010, title={QoS Control for NGN: A Survey of Techniques}, volume={18}, ISSN={["1064-7570"]}, DOI={10.1007/s10922-010-9157-x}, number={4}, journal={JOURNAL OF NETWORK AND SYSTEMS MANAGEMENT}, author={Yun, Changho and Perros, Harry}, year={2010}, month={Dec}, pages={447–461} }
 @article{mountrouidou_perros_2009, title={A discrete-time queueing network model of a hub-based OBS architecture}, volume={41}, ISSN={["1572-9451"]}, DOI={10.1007/s11235-009-9157-x}, number={3}, journal={TELECOMMUNICATION SYSTEMS}, author={Mountrouidou, Xenia and Perros, Harry}, year={2009}, month={Jul}, pages={173–184} }
 @article{xiong_perros_blake_2009, title={Bandwidth provisioning in ADSL access networks}, volume={19}, ISSN={1055-7148 1099-1190}, url={http://dx.doi.org/10.1002/nem.718}, DOI={10.1002/nem.718}, abstractNote={Abstract}, number={5}, journal={International Journal of Network Management}, publisher={Wiley}, author={Xiong, Kaiqi and Perros, Harry and Blake, Steven}, year={2009}, month={Sep}, pages={427–444} }
 @article{battestilli_perros_chukova_2009, title={Burst lost probabilities in a queuing network with simultaneous resource possession: a single-node decomposition approach}, volume={3}, ISSN={1751-8628}, url={http://dx.doi.org/10.1049/iet-com:20070426}, DOI={10.1049/iet-com:20070426}, abstractNote={An efficient analytical method is presented for the calculation of blocking probabilities in a tandem queuing network with simultaneous resource possession. This queuing network model is motivated from the need to model optical burst switching networks, where the size of the data bursts varies and the link distance between two adjacent network elements also varies depending on the network's topology. A fast single-node decomposition algorithm is developed to compute the blocking probabilities in the network. The algorithm extends the popular link-decomposition method from teletraffic theory by allowing dynamic simultaneous link possession. Simulation is used to validate the accuracy of the algorithm.}, number={3}, journal={IET Communications}, publisher={Institution of Engineering and Technology (IET)}, author={Battestilli, L. and Perros, H. and Chukova, S.}, year={2009}, pages={441–453} }
 @book{perros_2009, title={Computer simulation techniques: the definitive introduction!}, publisher={Raleigh, NC: Harry Perros.}, author={Perros, Harry G.}, year={2009} }
 @article{alnowibet_perros_2009, title={Nonstationary analysis of the loss queue and of queueing networks of loss queues}, volume={196}, ISSN={["1872-6860"]}, DOI={10.1016/j.ejor.2007.10.066}, abstractNote={We present an iterative scheme based on the fixed-point approximation method, for the numerical calculation of the time-dependent mean number of customers and blocking probability functions in a nonstationary queueing network with multi-rate loss queues. We first show how the proposed method can be used to analyze a single-class, multi-class, and multi-rate nonstationary loss queue. Subsequently, the proposed method is extended to the analysis of a nonstationary queueing network of multi-rate loss queues. Comparisons with exact and simulation results showed that the results are consistently close to the exact results and they are always within simulation confidence intervals.}, number={3}, journal={EUROPEAN JOURNAL OF OPERATIONAL RESEARCH}, author={Alnowibet, Khalid Abdulaziz and Perros, Harry}, year={2009}, month={Aug}, pages={1015–1030} }
 @article{mountrouidou_perros_2009, title={On the departure process of burst aggregation algorithms in optical burst switching}, volume={53}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2008.09.019}, abstractNote={We characterize analytically the departure process from the following three burst aggregation algorithms: the time based aggregation algorithm, the burst-length based aggregation algorithm and the time and burst-length based aggregation algorithm. The arrival process of packets is assumed to be Poisson or bursty modeled by an Interrupted Poisson Process (IPP). The analytic results are approximate and validation against simulation data showed that they have good accuracy.}, number={3}, journal={COMPUTER NETWORKS}, author={Mountrouidou, Xenia and Perros, Harry}, year={2009}, month={Feb}, pages={247–264} }
 @article{murphy_perros_2009, title={Optical burst switching}, volume={3}, number={3}, journal={IET Communications}, author={Murphy, J. and Perros, H.}, year={2009}, pages={331–333} }
 @article{tanwir_battestilli_perros_karmous-edwards_2008, title={Dynamic scheduling of network resources with advance reservations in optical grids}, volume={18}, ISSN={1055-7148 1099-1190}, url={http://dx.doi.org/10.1002/nem.680}, DOI={10.1002/nem.680}, abstractNote={Abstract}, number={2}, journal={International Journal of Network Management}, publisher={Wiley}, author={Tanwir, Savera and Battestilli, Lina and Perros, Harry and Karmous-Edwards, Gigi}, year={2008}, month={Mar}, pages={79–105} }
 @article{bouabdallah_pujolle_perros_2008, title={Multipoint-to-point lightpaths in all-optical networks: Dimensioning and cost analysis}, volume={65}, ISSN={["1872-745X"]}, DOI={10.1016/j.peva.2007.06.021}, abstractNote={One of the major concerns in optical networks is the bandwidth underutilization problem. In fact, as WDM technology keeps maturing, there is a bandwidth gap between the transmission speed of a wavelength channel (over a Gb/s) and the capacity requirement of customers’ connections. In this regard, building cost-efficient optical networks requires an efficient traffic grooming solution at the high speed optical access nodes. In this paper, we propose and evaluate a new concept of traffic aggregation in wavelength-division multiplexing (WDM) optical networks. Our objective is to reduce the network cost while preserving the benefits of all-optical wavelength-routed networks. In order to assess the efficiency of our proposal, all underlying network costs are compared. These costs include that of the transceivers required at node level as well as the number of wavelengths. Our results show that the proposed aggregation technique can significantly improve the network throughput while reducing its cost.}, number={3-4}, journal={PERFORMANCE EVALUATION}, author={Bouabdallah, Nizar and Pujolle, Guy and Perros, Haffy}, year={2008}, month={Mar}, pages={262–285} }
 @article{pujolle_perros_2008, title={Special issue: QoS, control, and security in next generation networks}, volume={39}, ISSN={1018-4864 1572-9451}, url={http://dx.doi.org/10.1007/S11235-008-9121-1}, DOI={10.1007/S11235-008-9121-1}, number={3-4}, journal={Telecommunication Systems}, publisher={Springer Science and Business Media LLC}, author={Pujolle, Guy and Perros, Harry}, year={2008}, month={Sep}, pages={169–169} }
 @article{xiong_perros_2008, title={Trustworthy Web services provisioning for differentiated customer services}, volume={39}, ISSN={["1572-9451"]}, DOI={10.1007/s11235-008-9126-9}, number={3-4}, journal={TELECOMMUNICATION SYSTEMS}, author={Xiong, Kaiqi and Perros, Harry}, year={2008}, month={Dec}, pages={171–185} }
 @inbook{tian_perros_2007, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={Analysis and Provisioning of a Circuit-Switched Link with Variable-Demand Customers}, ISBN={9783540729891}, url={http://dx.doi.org/10.1007/978-3-540-72990-7_77}, DOI={10.1007/978-3-540-72990-7_77}, abstractNote={We consider a single circuit-switched communication link, depicted by a Erlang multi-class loss queue, where a customer may vary its required bandwidth during its service. We obtain approximately the steady-state blocking probability of each class of customer. Comparisons with simulation results show that the approximation solution has a good accuracy. For the proposed model, we also provide an efficient capacity provisioning algorithm.}, booktitle={Managing Traffic Performance in Converged Networks. ITC 2007}, publisher={Springer}, author={Tian, Wenhong and Perros, Harry}, editor={Mason, L. and Drwirga, T. and Yan, J.Editors}, year={2007}, month={Sep}, pages={890–900}, collection={Lecture Notes in Computer Science} }
 @article{bouabdallah_perros_2007, title={Cost-effective single-hub WDM ring networks: A proposal and analysis}, volume={51}, DOI={10.1016/j.comnet.2007.04.014}, abstractNote={In this paper, we study a new concept of traffic grooming in wavelength-division multiplexing (WDM) ring networks that aims at eliminating both the bandwidth underutilization and the scalability concerns that are typical of all-optical wavelength routed ring networks. Our objective is to reduce the network cost while preserving the benefits of all-optical WDM ring networks. In order to assess the efficiency of our proposal, all underlying network costs are compared. These costs include that of the transceivers required at node level, as well as the number of wavelengths. Our results show that the proposed aggregation technique can significantly improve the resource utilization while reducing the network cost.}, number={13}, journal={Computer Networks (Amsterdam, Netherlands : 1999)}, author={Bouabdallah, N. and Perros, H.}, year={2007}, pages={3878–3901} }
 @inbook{neginhal_harfoush_perros_2007, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={Measuring Bandwidth Signatures of Network Paths}, ISBN={9783540726050 9783540726067}, ISSN={0302-9743 1611-3349}, url={http://dx.doi.org/10.1007/978-3-540-72606-7_92}, DOI={10.1007/978-3-540-72606-7_92}, abstractNote={In this paper, we propose a practical and efficient technique, Forecaster, to estimate (1) the end-to-end available bandwidth, and (2) the speed of the most congested (tight) link along an Internet path. Forecaster is practical since it does not assume any a priori knowledge about the measured path, does not make any simplifying assumptions about the nature of cross-traffic, does not assume the ability to capture accurate packet dispersions or packet queueing delays, and does not try to preserve inter-packet spacing along path segments. It merely relies on a simple binary test to estimate whether each probe packet has queued in the network or not. Forecaster is efficient as it only requires two streams of probe packets that are sent end-to-end at rates that are much lower than the available bandwidth of the investigated path, thus avoiding path saturation. Theoretical analysis and experimental results validate the efficacy of the proposed technique.}, booktitle={NETWORKING 2007. Ad Hoc and Sensor Networks, Wireless Networks, Next Generation Internet}, publisher={Springer}, author={Neginhal, Mradula and Harfoush, Khaled and Perros, Harry}, editor={Akyildiz, I.F. and Sivakumar, R. and Ekici, E. and Oliveira, J.C. and McNair, J.Editors}, year={2007}, pages={1072–1083}, collection={Lecture Notes in Computer Science} }
 @inbook{washington_perros_2007, place={Berlin Heidelberg}, series={Lecture Notes in Computer Science}, title={Performance Analysis of Traffic-Groomed Optical Networks Employing Alternate Routing Techniques}, ISBN={9783540729891}, url={http://dx.doi.org/10.1007/978-3-540-72990-7_90}, DOI={10.1007/978-3-540-72990-7_90}, booktitle={Managing Traffic Performance in Converged Networks. ITC 2007}, publisher={Springer}, author={Washington, Nicki and Perros, Harry}, editor={Mason, L. and Drwiega, T. and Yan, J.Editors}, year={2007}, month={Sep}, pages={1048–1059}, collection={Lecture Notes in Computer Science} }
 @article{xu_perros_2007, title={Performance analysis of an ingress switch in a JumpStart optical burst switching network}, volume={64}, ISSN={["1872-745X"]}, DOI={10.1016/j.peva.2006.05.012}, abstractNote={We consider an ingress optical burst switching (OBS) node employing the JumpStart signaling protocol. The switch serves a number of users, each connected to the switch with a fiber link that supports multiple wavelengths. Each wavelength is associated with a 3-state Markovian burst arrival process which permits short and long bursts to be modeled. We model the ingress switch as a closed multi-class non-product-form queueing network, which we analyze approximately by decomposition. Specifically, we develop new techniques to analyze the queueing network, first assuming a single class of customers, and subsequently multiple classes of customers. These analytical techniques have applications to general queueing networks beyond the one studied in this paper. We also develop computationally efficient approximate algorithms to analyze an ingress switch in the limiting case where the number of wavelengths is large. The algorithms have a good accuracy, and they provide insight into the effect of various system parameters on the performance of an ingress OBS switch.}, number={4}, journal={PERFORMANCE EVALUATION}, author={Xu, Lisong and Perros, Harry G.}, year={2007}, month={May}, pages={315–346} }
 @article{battestilli_perros_2006, title={A performance study of an optical burst switched network with dynamic simultaneous link possession}, volume={50}, ISSN={1389-1286}, url={http://dx.doi.org/10.1016/j.comnet.2005.05.021}, DOI={10.1016/j.comnet.2005.05.021}, abstractNote={In optical burst switched (OBS) networks a burst may occupy a wavelength on one or more links as it travels through the network. In the literature, OBS networks have been analyzed assuming that each burst occupies only a wavelength on a single link. In this paper, we study analytically the performance of an OBS network with a mixture of different size bursts. The short bursts occupy a wavelength on a single link while the long bursts occupy simultaneously wavelengths on multiple consecutive links. We develop a queueing network, which models simultaneous link possession, and we calculate analytically the end-to-end burst loss probabilities over a path in the OBS network. Our results indicate that having a mix of various size bursts can greatly effect the burst loss probabilities in the network.}, number={2}, journal={Computer Networks}, publisher={Elsevier BV}, author={Battestilli, Tzvetelina and Perros, Harry}, year={2006}, month={Feb}, pages={219–236} }
 @inbook{mountrouidou_perros_2006, title={Characterization of the burst aggregation process in optical burst switching}, volume={3976}, DOI={10.1007/11753810_63}, abstractNote={We describe an analytic approach for the calculation of the departure process from a burst ggregation algorithm that uses both a timer and maximum/minimum burst size. The arrival process of packets is assumed to be Poisson or bursty modelled by an Interrupted Poisson Process (IPP). The analytic results are approximate and validation against simulation data showed that they have good accuracy.}, booktitle={Networking 2006. Networking Technologies, Services, and Protocols; Performance of Computer and Communication Networks; Mobile and Wireless Communications Systems: 5th International IFIP-TC6 Networking Conference, Coimbra, Portugal, May 15-19, 2006. Proceedings (Lecture notes in computer science; 3976)}, publisher={Berlin; New York: Springer}, author={Mountrouidou, X. and Perros, H. G.}, year={2006}, pages={752–764} }
 @article{yang_nho_perros_mahalik_kim_ahn_2006, title={Dynamic bandwidth allocation by using efficient threshold reporting for quality of service in Ethernet passive optical networks}, volume={45}, number={3}, journal={Optical Engineering (Redondo Beach, Calif.)}, author={Yang, Y. M. and Nho, J. M. and Perros, H. and Mahalik, N. P. and Kim, K. and Ahn, B. H.}, year={2006} }
 @article{alnowibet_perros_2006, title={Nonstationary analysis of circuit-switched communication networks}, volume={63}, ISSN={["1872-745X"]}, DOI={10.1016/j.peva.2005.10.001}, abstractNote={Circuit-switched communication networks have been analyzed extensively in the stationary case, i.e. where the arrival and/or service rates are independent of time. In this paper, we study a circuit-switched network where the rates of external arrivals at the network are time-dependent functions. The circuit-switched network is modelled as a nonstationary queueing network with population constraints, which is analyzed approximately in order to obtain the blocking probability functions. Using this method we model two circuit-switched networks, namely, a traffic-groomed tandem optical network and a single-orbit LEO satellite network.}, number={9-10}, journal={PERFORMANCE EVALUATION}, author={Alnowibet, Khalid Abdulaziz and Perros, Harry}, year={2006}, month={Oct}, pages={892–909} }
 @article{perros_2006, title={Optical networks}, volume={50}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2005.05.020}, number={2}, journal={COMPUTER NETWORKS}, author={Perros, H}, year={2006}, month={Feb}, pages={145–148} }
 @article{puttasubbappa_perros_2006, title={Performance analysis of limited-range wavelength conversion in an OBS switch}, volume={31}, ISSN={["1572-9451"]}, DOI={10.1007/s11235-006-6522-x}, number={2-3}, journal={TELECOMMUNICATION SYSTEMS}, author={Puttasubbappa, VS and Perros, HG}, year={2006}, month={Mar}, pages={227–246} }
 @inbook{puttasubbappa_perros_2005, title={An  approximate queueing model for limited-range wavelength conversion in an OBS switch}, volume={3462}, ISBN={3540258094}, DOI={10.1007/11422778_56}, abstractNote={We develop an analytical model for modeling limited-range wavelength conversion employed in an OBS switch. The system is modeled as a simultaneous resource possession problem. We propose a product-form solution which calculates approximate blocking probabilities for degree of conversion d = 1,2 and for large number of wavelengths. We then propose an approximate model for large values of d. The output of our model was verified with simulation results.}, booktitle={Networking 2005: Networking technologies, services, and protocols: Performance of computer and communication networks: Mobile and wireless communication systems: 4th International IFIP-TC6 Networking Conference, Waterloo, Canada, May 2-6, 2005: Proceedings (Lecture notes in computer science; 3462)}, publisher={Berlin; New York: Springer}, author={Puttasubbappa, V. S. and Perros, H. G.}, year={2005}, pages={697–708} }
 @book{perros_2005, title={Connection-Oriented Networks: SONET/SDH, ATM, MPLS and Optical Networks}, DOI={10.1002/0470016361}, abstractNote={A thorough knowledge of modern connection-oriented networks is essential to understanding the current and near-future state of networking. This book provides a complete overview of connection-oriented networks, discussing both packet-switched and circuit-switched networks, which, though seemingly different, share common networking principles. It details the history and development of such networks, and defines their terminology and architecture, before progressing to aspects such as signaling and standards. There is inclusive coverage of SONET/SDH, ATM networks, Multi-Protocol Label Switching (MPLS), optical networks, access networks and voice over ATM and MPLS. Connection-oriented Networks: * Provides in-depth, systematic coverage of several connection-oriented networks in a single volume * Explains topics such as the Generic Framing Procedure, Label Distribution Protocols, Wavelength Routing Optical Networks, Optical Burst Switching, and Access Networks in detail * Illustrates all concepts with problems and simulation projects to test and deepen your understanding * Includes an accompanying website with solutions manual and complete set of PowerPoint presentations for each chapter Senior undergraduate and graduate students in telecommunication and networking courses, as well as networking engineers, will find this comprehensive guide to connection-oriented packet-switched and circuit-switched networks useful for their training. The book presents tried and tested material based on an existing, successful course.}, journal={CONNECTION-ORIENTED NETWORKS: SONET/SDH, ATM, MPLS AND OPTICAL NETWORKS}, author={Perros, HG}, year={2005}, pages={1–332} }
 @article{mountrouidou_perros_beshai_2005, title={Performance Evaluation of an Optical Burst Switching Scheme for Grid Networks}, DOI={10.1109/icbn.2005.1589775}, abstractNote={We propose and evaluate a novel scheme, referred to as bimodal burst switching (BBS) scheme, for optical burst switching (OBS) star networks, which can be used in grid networks. The main feature of this scheme is that it has zero burst loss and a large geographical coverage. Using simulation techniques we show that the proposed scheme provides high bandwidth and outperforms OBS}, journal={2ND INTERNATIONAL CONFERENCE ON BROADBAND NETWORKS (BROADNETS 2005)}, author={Mountrouidou, Xenia and Perros, Harry G. and Beshai, Maged}, year={2005}, pages={515-+} }
 @article{puttasubbappa_perros_2005, title={Quality of service in an optical burst switching ring}, volume={9}, ISSN={["1572-8188"]}, DOI={10.1007/s11107-004-6438-x}, number={3}, journal={PHOTONIC NETWORK COMMUNICATIONS}, author={Puttasubbappa, VS and Perros, HG}, year={2005}, month={May}, pages={357–371} }
 @inbook{puttasubbappa_perros_2004, title={Access protocols to support different service classes in an optical burst switching ring}, volume={3042}, ISBN={3540219595}, DOI={10.1007/978-3-540-24693-0_72}, abstractNote={Several access protocols are proposed to support different service classes in an optical burst switched ring. Their performance is evaluated through simulation. Various performance metrics such as throughput, utilization, burst loss rate, end-to-end delay and fairness are used to analyze the behaviour of each protocol.}, booktitle={Networking 2004: Networking technologies, services, and protocols: Performance of computer and communication networks, mobile and wireless commuication: Third International IFIP-TC6 Networking Conference, Athens, Greece, May 9-14, 2004 ; Proceedings}, publisher={Berlin; New York: Springer}, author={Puttasubbappa, V. S. and Perros, H. G.}, year={2004}, pages={878–889} }
 @article{washington_perros_2004, title={Call blocking probabilities in a traffic-groomed tandem optical network}, volume={45}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2004.03.008}, abstractNote={In this paper, we consider an optical network consisting of N nodes arranged in tandem. We assume traffic grooming, which permits multiple sub-rate traffic streams to be carried on the same wavelength. This optical network is modeled by a tandem queueing network of multi-rate Erlang loss nodes with simultaneous resource possession, with a view to calculating call blocking probabilities. The queueing network is analyzed by decomposition using a modified version of Courtois' algorithm. Numerical comparisons of the decomposition algorithm against simulation show that the algorithm has good accuracy. Also, it is shown that the proposed algorithm is an improvement over the well-known single-node decomposition algorithm based on the link-independence assumption.}, number={3}, journal={COMPUTER NETWORKS}, author={Washington, AN and Perros, H}, year={2004}, month={Jun}, pages={281–294} }
 @inbook{xin_baldine_cassada_stevenson_jackson_perros_2004, title={ORBIS: A reconfigurable hybrid optical metropolitan area network architecture}, volume={3042}, ISBN={3540219595}, DOI={10.1007/978-3-540-24693-0_142}, abstractNote={In this paper, we propose a novel metropolitan area network (MAN) ring architecture, ORBIS, a multiple-service WDM platform that supports multiple transport techniques. The WDM ring is horizontally divided into multiple subnetworks, each of which supports one type of the traffic with a subset of the total wavelengths. The system and subnetwork control mechanism and reconfiguration issues are addressed in this paper.}, booktitle={Networking 2004: Networking technologies, services, and protocols: Performance of computer and communication networks, mobile and wireless commuication: Third International IFIP-TC6 Networking Conference, Athens, Greece, May 9-14, 2004 ; Proceedings}, publisher={Berlin; New York: Springer}, author={Xin, Y. F. and Baldine, I. and Cassada, M. and Stevenson, D. and Jackson, L. E. and Perros, H.}, year={2004}, pages={1502–1507} }
 @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}, number={2}, journal={Optical Engineering (Redondo Beach, Calif.)}, author={Zaim, A. H. and Baldine, I. and Cassada, M. and Rouskas, G. N. and Perros, H. G. and Stevenson, D.}, year={2003}, pages={568–585} }
 @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} }
 @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}, 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} }
 @book{perros_2002, title={An introduction to ATM networks}, ISBN={0471498270}, publisher={New York: Wiley}, author={Perros, H. G.}, year={2002} }
 @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} }
 @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}, 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} }
 @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}, 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{ramesh_perros_2001, title={A multi-layer client-server queueing network model with non-hierarchical synchronous and asynchronous messages}, volume={45}, ISSN={["0166-5316"]}, DOI={10.1016/S0166-5316(01)00027-X}, abstractNote={Abstract We analyze a multi-layered queueing network that models a client–server system where clients and servers communicate via synchronous and asynchronous messages. The servers are organized in groups such that they form a multi-layered structure. The messaging pattern is non-hierarchical, i.e., a client can send a message to a server belonging to any layer, and a server from a layer-i may issue messages to a server belonging to any higher layer, j>i. The queueing network is analyzed approximately using a decomposition algorithm. Numerical tests show that the approximation algorithm has a good accuracy.}, number={4}, journal={PERFORMANCE EVALUATION}, author={Ramesh, S and Perros, HG}, year={2001}, month={Aug}, pages={223–256} }
 @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{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{ramesh_perros_2000, title={A multilayer client-server queueing network model with synchronous and asynchronous messages}, volume={26}, DOI={10.1109/32.881719}, abstractNote={We analyze a multilayered queueing network that models a client-server system where clients and servers communicate via synchronous and asynchronous messages. The servers are organized in groups such that they form a multilayered hierarchical structure. The queueing network is approximately analyzed using a decomposition algorithm. Numerical tests show that the approximation algorithm has a good accuracy.}, number={11}, journal={IEEE Transactions on Software Engineering}, author={Ramesh, S. and Perros, H. G.}, year={2000}, pages={1086–1100} }
 @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} }
 @inbook{ramesh_perros_2000, title={A two-level queueing network model with blocking and non- blocking messages}, volume={93}, booktitle={Performance evaluation and optimization of production lines  (Annals of operations research ; v. 93)}, publisher={Bussum, The Netherlands: Baltzer Science}, author={Ramesh, S. and Perros, H. G.}, editor={J. MacGregor Smith, S. B. Gershwin and Papadopoulos, C.T.Editors}, year={2000}, pages={357–372} }
 @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} }
 @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} }
 @article{elsayed_perros_2000, title={The superposition of discrete-time Markov renewal processes with an application to statistical multiplexing of bursty traffic sources}, volume={115}, DOI={10.1016/s0096-3003(99)00134-4}, abstractNote={The main contribution in this paper is the introduction of a methodology for approximately characterizing the superposition process of N⩾2 arbitrary (and possibly heterogeneous) discrete-time Markov Renewal Processes (MRP). In this model, the superposition process is characterized by a MRP with a state space that grows exponentially with N. We consider an on/off traffic source model, where the distribution of the on and off periods is arbitrary, as a special case of the general MRP. Subsequently, a queueing model for a FIFO finite-buffer multiplexer with arbitrary on/off input sources is analyzed. We provide numerical results for testing the algorithms introduced in the paper. We also study the effect of some of the statistical properties of on/off input sources on the multiplexer's performance.}, number={1}, journal={Applied Mathematics and Computation}, author={Elsayed, K. M. F. and Perros, H. G.}, year={2000}, pages={43–62} }
 @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{rhee_perros_1998, title={On the mean waiting time of a population constrained open tandem queueing network with constant service times}, volume={30}, DOI={10.1080/07408179808966550}, abstractNote={We obtain an approximate expression for the mean waiting time of an open tandem queueing network with population constraint, constant service times and an arbitrary arrival process.}, number={10}, journal={IIE Transactions}, author={Rhee, Y. and Perros, H. G.}, year={1998}, pages={973–979} }
 @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} }
 @article{rajala_vouk_nilsson_miller_schrag_burke_brawner_viniotis_perros_1997, title={Technology for support of network-based education workflows in North Carolina: NC State-Fujitsu education partnership final report for the period June 1, 1996-December 31, 1996}, number={3}, journal={TR (Center for Advanced Computing and Communication)}, author={Rajala, S. A. and Vouk, M. A. and Nilsson, A. A. and Miller, T. K. and Schrag, R. L. and Burke, J. R. and Brawner, C. E. and Viniotis, I. and Perros, H. G.}, year={1997} }
 @book{perros_1994, title={Queueing networks with blocking : exact and approximate solutions}, ISBN={0195085809}, publisher={New York, N.Y. : Oxford University Press}, author={Perros, H. G.}, year={1994} }