Cooperative or Non-Cooperative Transmission in Synchronous DC WSNs: A DTMC-based Approach

Cooperative transmission (CT) enables balanced energy consumption among sensor nodes and mitigates the energy hole problem in wireless sensor networks (WSNs). In typical CT enabled medium access control (MAC) protocols, a source node decides to trigger CT or not based on a residual energy comparison between itself and its relay node. In this paper, we propose a receiver initiated CT MAC protocol, in which the receiving node makes the decision on initiating CT or not based on a tradeoff between performing CT and non-CT. In this way, nodes can avoid idle listening and achieve an extended lifetime. A discrete-time Markov chain (DTMC) model is developed to analyze the performance of CT associated with synchronous CT MAC protocols. Using this DTMC model, the performance of the protocol is evaluated with respect to energy consumption, energy efficiency and network lifetime. Numerical results demonstrate the accuracy of the model and the effectiveness of CT, in contrast to non-CT, as it leads to balanced energy consumption and an optimal network lifetime.