An opportunistic cooperative relaying protocol for mobile ad hoc networks

Mobile ad hoc networks (MANETs) have been gaining a great attention for flexible information accessibility and availability over the past decade. MANETs have driven by the potential applications in civil and military environments and become a part of ubiquitous communication infrastructure. Due to nodes' mobility and unreliable wireless medium, however, changes of network topology and frequent link disconnections may significantly reduce the information accessibility and increase the communication latency. In this thesis, we propose an opportunistic cooperative relaying protocol to improve the communication performance in terms of communication latency. In the protocol, a set of neighbor nodes located around a communication pair opportunistically overhears the transmission and initiates the cooperative relay only if the transmission fails. This technique is seamlessly integrated with the IEEE 802.11 power saving mechanism (PSM) in medium access control (MAC) layer. We establish a customized NS-2 based simulation framework and conduct an extensive simulation for design trade-off and multi-dimensional analysis. Extensive simulation results indicate that the proposed technique can reduce the latency around 10% with minor communication overhead in terms of the number of control messages and thus, is a viable approach for adopting in MANETs.