Optimal Relay Node Association for Two-Tiered Wireless Networks

Modern wireless networks use cooperative relaying to expand its coverage area. Wireless relaying allows mobile terminals toparticipate in transmission even when these terminals are not being the initial source or final destination. This can be achieved in differentways ranging from simple conventional relaying to more sophisticated coding at terminal and relay nodes to improve transmissionperformance. The proposed work here studied such system by simulating different coding techniques to be used in two way relay networkcoding (TWRC). Some of these techniques were previously proposed to improve transmission performance in conventional datacommunication systems. BER performance of different arrangements of coding and relaying schemes are evaluated using computersimulation tests. Ideal AWGN channel model and standard wireless channel models for wireless networks are considered in the simulationtests. The results have been shown that coding schemes such as Trellis Coded Modulation (TCM) and Repeat Accumulate (RA) codes aremore suitable in two way relaying networks. Over AWGN, TCM-8PSK improves BER performance by at least 2 dB at high SNR fordifferent relaying arrangements. For fading channels, this advantage is slightly reduced. Regenerative repeating at relay node seems to be apromising arrangement. It seems that there is no sense in using RA codes over fading channels due to its poor performance and relativelylower speed caused by repetitions.

Download Full-text

Genetic Algorithm for Effective Optimization of Delay Performance in Wireless Sensor Networks

Journal of University of Babylon for Pure and Applied Sciences ◽

10.29196/jubpas.v26i10.1886 ◽

2018 ◽

Vol 26 (10) ◽

pp. 281-308

Author(s):

Saif Khalid Musluh ◽

Alaa Abid Muslam ◽

Raid Abd Alreda Shekan

Keyword(s):

Genetic Algorithm ◽

Wireless Sensor Networks ◽

Wireless Networks ◽

Sensor Networks ◽

Network Performance ◽

Data Transfer ◽

Relay Node ◽

Network Capacity ◽

Wireless Sensor ◽

Delay Performance

Wireless sensor networks (WSNs) play an important role in many real-world applications like surveillance. Wireless networks are also used to have data transfer. In such cases, there are problems with resourcece-constraintnednetworks. The problems include a delay in communication and reduction in Quality of Service (QoS). Topology control can solve this problem to some extent. However, the delay performance and QoS need to be improved further to support intended operations in wireless networks. When relay node concept is considered, it is possible to optimize performance in such networks. In this paper, we proposed a Genetic Algorithm (GA) based relay configuration for optimizing delay performance in WSN. Relay nodes compute optimal positions using the proposed algorithm so as to improve QoS and reduce delay as much as possible. We implemented the algorithm using NS2 simulations. The results revealed that the proposed approach is able to improve QoS, reduce delay besides improving network performance in terms of throughput, network capacity, and energy efficiency.

Download Full-text