Performance analysis of modified bellman ford algorithm using cooperative relays

Abstract

Cooperative communication plays a vital role in modern wireless communication. It improves the performance of the system and supports higher data rates. In this paper, the nodes in the network are classified into amplifyand- forward (AF) and decode-and-forward (DF) relays based on the Signal to Noise Ratio (SNR). The node who’s received signal SNR is greater than threshold SNR is considered as DF relay, otherwise it considered as an AF relay. Network lifetime can be increased by operating nodes in the power save mode (PSM). The energy efficient Modified Bellman Ford Algorithm (MBFA) using the power saving mechanism of 802.11g is employed for routing. All the nodes acting as a DF relay will be considered for routing. The performance of MBFA can be improved by cooperative relays. Residual Energy is considered as a routing metric and optimal path is selected using MBFA. In a grid network, nodes are placed in a uniform distance and grid topology gives better performance over random topology. Mobility of nodes cause packet loss and the performance of a mobile network degrades further with PSM. Performance of MBFA with PSM for a static network using grid topology is better compare with mobile networks and random topology. For various node densities, the residual battery capacity of static and mobile networks for grid and random topologies are investigated using MBFA. The bit-error-rate performance of the MBFA using cooperative relay for different modulation schemes BPSK, QPSK and 64-QAM were analyzed.