Network performance improvement of MIMO two-way relay with respect to CSMA/CA mesh networks

Backbone wireless mesh network has been attracted much of attention due to a wide range of its application such as smart utility network, sensor network, etc. The employment of CSMA/CA based MAC protocols to mesh network, however, reveals high latency and low resource utilization due to problems of hidden terminal, exposed terminal, information asymmetry etc. Several alternative protocols including directional MAC, multichannel MAC only provide marginal improvement. In recent publication, a cross-layer design employing multiple antenna techniques and network coding called MIMO two-way relay is proposed for one dimensional mesh network. Owing to interference cancellation ability of MIMO, bi-directional flow multiplexing capability of network coding in combination with an efficient channel access scheme of TDMA/TDD, MIMO two-way relay provides significantly high end-to-end capacity. In this paper, we propose MIMO two-way relay as an alternative PHY/MAC protocol of CSMA/CA. A network simulator employing MIMO two-way relay is developed and more details on packet relaying mechanism of the algorithm are presented. Simulation results show that MIMO two-way relay achieves an extremely large improvement in network throughput, and packet delay reduction in comparison with CSMA/CA mesh networks.