GCRIS Repository Collection:
https://hdl.handle.net/20.500.11851/276
2024-03-29T14:37:53Z
2024-03-29T14:37:53Z
On the Tradeoff Between Network Lifetime and k-Connectivity-Based Reliability in UWSNs
Çobanlar, Muhammed
Yıldız, Huseyin Uğur
Akram, Vahid Khalilpour
Dağdeviren, Orhan
Tavlı, Bülent
https://hdl.handle.net/20.500.11851/10309
2023-04-16T10:27:29Z
2022-01-01T00:00:00Z
Title: On the Tradeoff Between Network Lifetime and k-Connectivity-Based Reliability in UWSNs
Authors: Çobanlar, Muhammed; Yıldız, Huseyin Uğur; Akram, Vahid Khalilpour; Dağdeviren, Orhan; Tavlı, Bülent
Abstract: Underwater wireless sensor networks (UWSNs) are utilized for a wide range of monitoring and surveillance applications. Lifetime maximization and maintenance of network reliability are among the most important considerations in the deployment of UWSNs. k-connectivity is a robust approach for reinforcing reliability. However, maintaining k disjoint paths from each sensor node to the BS, inevitably, results in extra energy dissipation, which reduces the network lifetime (NLT). Yet, there is no systematic exploration to determine the extent of lifetime reduction due to the increase in the k value, in the literature, to the best of our knowledge. In this study, we create an optimization framework to be able to explore the tradeoff between NLT and k-connectivity-based reliability in UWSNs. Through the optimal solutions of the proposed optimization model for a large set of salient parameters, we characterize the interplay between lifetime and k-connectivity. Our analysis reveals that the k value to be maintained in a UWSN can affect the NLT significantly.
2022-01-01T00:00:00Z
Long-Range Distributed Acoustic Sensor Based on 3×3 Coupler Assisted Passive Demodulation Scheme
Türker, V.
Uyar, F.
Kartaloglu, T.
Özbay,, E.
Özdür, I.
https://hdl.handle.net/20.500.11851/9267
2023-02-24T19:37:47Z
2022-01-01T00:00:00Z
Title: Long-Range Distributed Acoustic Sensor Based on 3×3 Coupler Assisted Passive Demodulation Scheme
Authors: Türker, V.; Uyar, F.; Kartaloglu, T.; Özbay,, E.; Özdür, I.
Abstract: A distributed acoustic sensor based on phase-sensitive optical time domain reflectometry (?-OTDR) and passive 3×3 coupler demodulation is demonstrated which is capable of quantifying strain perturbations at 40 km of a sensing fiber. © Optica Publishing Group 2022, © 2022 The Author(s)
Description: 2022 Conference on Lasers and Electro-Optics, CLEO 2022 -- 15 May 2022 through 20 May 2022 -- 182946
2022-01-01T00:00:00Z
Effect of End-to-end Delay on Lifetime and Average Bit Error Rate in Directional Antenna Based Wireless Sensor Networks
Yumusak, A.K.
Demirtas, A.M.
https://hdl.handle.net/20.500.11851/9247
2023-02-24T19:37:49Z
2022-01-01T00:00:00Z
Title: Effect of End-to-end Delay on Lifetime and Average Bit Error Rate in Directional Antenna Based Wireless Sensor Networks
Authors: Yumusak, A.K.; Demirtas, A.M.
Abstract: This paper evaluates the effect of end-to-end delay on lifetime and the average bit error rate for wireless sensor networks where each sensor node sends its data to sink via directional antennas. Using Mixed Integer Programming, lifetime is optimized for circular network topologies with different numbers of nodes. Using both directional and omnidirectional antennas, different end-to-end delay restrictions are applied to the same sensor network to examine the effect on lifetime and average bit error rate. When delay restriction is relaxed, an increase in lifetime and a decrease in average bit error rate are observed for both antennas. In this case, the directional antenna benefits more from relaxing the delay restriction. In the end, an optimal end-to-end delay was determined which provides sufficient lifetime and bit error rate while taking into account data freshness. © 2022 IEEE.
Description: 2022 International Balkan Conference on Communications and Networking, BalkanCom 2022 -- 22 August 2022 through 24 August 2022 -- 183326
2022-01-01T00:00:00Z
UAV-BS Trajectory Optimization under Coverage, Backhaul and QoS Constraints Using Q-Learning
Sazak, M.D.
Demirtas, A.M.
https://hdl.handle.net/20.500.11851/9246
2023-02-24T19:37:49Z
2022-01-01T00:00:00Z
Title: UAV-BS Trajectory Optimization under Coverage, Backhaul and QoS Constraints Using Q-Learning
Authors: Sazak, M.D.; Demirtas, A.M.
Abstract: In this study, three-dimensional optimal trajectory planning is performed for the Unmanned Aerial Vehicle (UAV) with the base station (BS) attached to it to increase the service provided to the users. The case that heterogeneous quality of service (QoS) requirements for different users are considered. While planning the trajectory, the coverage area of the UAV-BS and backhaul capacity between the UAV-BS and Ground Base Station (GBS) are limited. Under these constraints, the aim is to find a trajectory for the UAV-BS that maximizes the total data rate provided to the users during the flight using reinforcement learning. With the application of Q-learning in our problem, the UAV-BS learns to take action to achieve the desired goal. As a result of trial and error processes with different learning parameters, appropriate parameters are determined and a reinforcement learning model is trained. Different communication scenarios are compared for analyzing the effects of the constraints. According to the effects of the mentioned constraints and heterogeneous QoS demands, UAV-BS's trajectory preferences and total transmission rate changes are examined. Three prominent results shows the effects of coverage, backhaul, and heterogeneous QoS. The UAV-BS tends to increase its altitude as the coverage constraint increases. Moreover, the backhaul constraint forces the UAV-BS's trajectory closer to the GBS. Lastly, UAV-BS takes into account different QoS requirements of users as much as possible. UAV-BS maximizes the total transmission rate by determining the most suitable trajectory to meet these constraints. © 2022 IEEE.
Description: 2022 International Balkan Conference on Communications and Networking, BalkanCom 2022 -- 22 August 2022 through 24 August 2022 -- 183326
2022-01-01T00:00:00Z