@article{tezcan_wang_2008, title={Self-orienting wireless multimedia sensor networks for maximizing multimedia coverage}, ISBN={["978-1-4244-2074-2"]}, ISSN={["1550-3607"]}, DOI={10.1109/icc.2008.421}, abstractNote={The performance of a wireless multimedia sensor network (WMSN) is tightly coupled with the pose of individual multimedia sensors. In particular, orientation of an individual multimedia sensor (direction of its sensing unit) is of great importance for the sensor network applications in order to capture the entire image of the field. In this paper, we study the problem of self-orientation in a wireless multimedia sensor network, that is finding the most beneficial pose of multimedia sensors to maximize multimedia coverage with occlusion-free viewpoints. We first propose a distributed algorithm to detect a node's multimedia coverage and then determine its orientation, while minimizing the effect of occlusions and total overlapping regions in the sensing field. Our approach enables multimedia sensor nodes to compute their directional coverage, provisioning self-configurable sensor orientations in an efficient way. Simulations show that using distributed messaging and self-orientation having occlusion-free viewpoints significantly increase the multimedia coverage.}, journal={2008 IEEE INTERNATIONAL CONFERENCE ON COMMUNICATIONS, PROCEEDINGS, VOLS 1-13}, author={Tezcan, Nurcan and Wang, Wenye}, year={2008}, pages={2206–2210} }
 @article{tezcan_wang_2008, title={Self-orienting wireless multimedia sensor networks for occlusion-free viewpoints}, volume={52}, ISSN={["1872-7069"]}, DOI={10.1016/j.comnet.2008.05.014}, abstractNote={Wireless multimedia sensor networks (WMSN) are formations of a large number of compact form-factor computing devices that can capture multimedia content, such as video and audio, and communicate them over wireless channels. The efficiency of a WMSN heavily depends on the correct orientation (i.e., view) of its individual sensory units in the field. In this paper, we study the problem of self-orientation in WMSN, that is finding the most beneficial orientation for all multimedia sensors to maximize multimedia coverage. We propose a new algorithm to determine a node’s multimedia coverage and find the sensor orientation that minimizes the negative effect of occlusions and overlapping regions in the sensing field. Our approach enables multimedia sensor nodes to compute their directional coverage leading to an efficient and self-configurable sensor orientation calculation. By using simulations, we show that the occlusion-free viewpoint approach increases the multimedia coverage significantly. The self-orientation methodology is designed in the form of a distributed algorithm, making it a suitable candidate for deployment in practical systems.}, number={13}, journal={COMPUTER NETWORKS}, author={Tezcan, Nurcan and Wang, Wenye}, year={2008}, month={Sep}, pages={2558–2567} }
 @inproceedings{tezcan_wang_2006, title={effective energy conservation in wireless sensor networks}, DOI={10.1109/icc.2006.255235}, abstractNote={In this paper, we present a two-tiered scheduling scheme that provides effective energy conservation in wireless sensor networks. The effectiveness of this scheme relies on dynamically updated two-tiered scheduling architecture. We aim to prolong network lifetime, while preserving the major requirements of wireless sensor networks: coverage and connectivity. In this approach, sensors are periodically scheduled to sleep in two phases using weighted greedy algorithms. First, we establish a coverage-tier by selecting a set of sensors that covers the sensing field in order to provide fully monitoring of entire field. Sensors that are not selected for the coverage-tier, are put into sleep immediately. Then, a second tier, called connectivity-tier, is formed on top of the coverage-tier to forward the data traffic to sink node. Thus sensors, essential to coverage-tier but not in connectivity-tier may periodically sleep and become active only for sending new sensing measurement and receiving query from the sink to preserve coverage. By this way, we may allow more nodes to sleep with different sleeping behaviors, i.e., continuous sleep or periodic sleep/active. Moreover, fair energy consumption among sensors is achieved by periodically rotating the coverage and connectivity tiers. Through extensive simulations in ns2, we demonstrate that the two-tier scheduling can reduce average energy consumption up to 40% while balancing the residual energy of sensors.}, booktitle={2006 ieee international conference on communications, vols 1-12}, author={Tezcan, N. and Wang, Wenye}, year={2006}, pages={3359–3364} }