Analysis of express forwarding schemes in wireless mesh networks

In wireless mesh networks that are built using IEEE 802.11 techniques, there are significant problems in maintaining fairness and low delay to provide QoS for long-hop flows. To address these issues, express forwarding has been proposed. However, existing studies of express forwarding are simulation based, and the main benefits that have been demonstrated are limited to shortened delay for long-hop flows. In contrast, we present an analytical model in this paper that considers the possible interruptions of the express forwarding mechanism. Based on this model, we evaluate the fairness and efficiency of express forwarding with different queue management schemes. The evaluation shows the benefits of express forwarding in terms of removing spatial bias, obtaining higher end-to-end throughput, and achieving more efficient use of resources.