Survey on multi-hop wireless networks

This paper analyzes the impact of different MAC (Medium Access Control) and transmission rate adaptation schemes on wireless mesh networks. The considered proto- cols include three different MAC protocols specified in IEEE 802.11 standards, i.e., 802.11, 802.11e, and 802.11n, and three rate adaptation schemes, i.e., ARF (Automatic Rate Fallback), RBAR (Receiver-Based Auto Rate), and 802.11n rate adaptation. We also study the interactions of these MAC strategies with the state-of-the-art routing metric ETT (Expected Transmission Tim e). Through comparative simulation evaluations, we investi- gate the effectiveness of these protocols when they coexist on both single-hop and multi-hop wireless mesh network environments. As these MAC strategies are designed for single-hop WLANs, we observed their limitations on multi-hop wireless mesh net- works. We analyze their performances and suggest solutions for improvements. Based on our simulation results, we also argue for the need of a new routing metric that takes advantage of the new emerging MAC features.