Incorporating QoS Awareness in Routing Metrics for Wireless Mesh Networks

摘要

Wireless mesh networks (WMNs) consist of mesh clients that can be either stationary or mobile, and static mesh routers through which the clients communicate with each other and with the Internet or other networks. Wireless mesh networks have established their presence with a promise of supporting variegated traffic ranging from real-time to best-effort while providing coverage to large metropolitan areas. Multihop communication, the existence of inherently errorprone wireless channel, the static nature of mesh nodes, the availability of sufficient bandwidth resources and the need to transport multimedia traffic with different QoS budgets necessitate the design of QoS-aware routing metrics to improve the performance of routing algorithms. We study the motivations for new and quality-aware routing metrics and provide a detailed comparative analysis supported by NS-2 simulations of some routing metrics that attempt to address these goals. The routing metrics we compare include the traditional shortest-hop, ETX (Expected Transmission Count), ML (Minimum Loss) and MD (Minimum Delay). We observe that ETX improves throughput while MD reduces delay for different packet rates, proving that the right metric should be chosen based on user requirements.