On Uplink Superposition Coding and Multi-user Diversity for Wireless Mesh Networks

In recent years wireless mesh networks (WMN) gained lots of attention in research and industry. Especially, the use of WMNs for community networks proved their ability to provide a high performance Internet access while demanding little deployment planning. However, one problem became apparent. Network congestion, especially around gateway nodes (GN), can dramatically decrease the overall performance of the entire network. We present a novel approach to efficiently decrease network congestion while maintaining fairness. To achieve that goal, we combine two modern techniques, namely uplink superposition-coding and multi-user diversity to create a MAC protocol that can dramatically improve the network throughput around GN, hence extending the capabilities of the entire WMN. We will present two distributed protocols, which are suitable for ad-hoc networks without any centralized infrastructure. Extensive analysis and simulations will be presented, that show a network throughput increase of up to 88% over the use of 802.11 with the OAR rate selection algorithm. In a fading environment an additional gain of 5-13% from multi-user diversity was observed.