Application of Modified Bellman-Ford Algorithm for Cooperative Communication

Abstract

Network lifetime of mobile ad hoc networks is limited by the battery power of the mobile nodes. Energy saving can be achieved by operating the nodes in power save mode (PSM). Cooperative communication provides the cooperative diversity and the performance of the network can be improved by using cooperative relays. A new cooperative modified Bellman ford algorithm (CMBFA) using PSM is proposed to improve the performance of the network. Distributed Bellman ford algorithm (DBFA) is considered as a basic routing protocol. A modified Bellman-ford algorithm (MBFA) also called as Non-cooperative MBFA (NCMBFA) is developed by modifying the DBFA. In NCMBFA, residual energy of a node is considered to select the optimal path for routing the packets. NCMBFA is energy efficient and suitable for Grid topology using PSM. In the proposed CMBFA, the nodes in the Grid topology are categorized into amplify-and-forward and decode-and-forward nodes using the received signal-to-noise ratio at the relay. All the DF nodes are considered for routing and the optimum route is calculated using the NCMBFA. For CMBFA and NCMBFA, the bit error rate performance of the network for BPSK, QPSK, and 64-QAM modulation schemes are analyzed. The performance metrics of the packet received, delay and the average jitter of CMBFA and NCMBFA are compared. Simulation results show clearly that CMBFA gives better performance over NCMBFA and CMBFA consumes less energy compared to NCMBFA using PSM.