Shu Du, Using Routine Information to Improve MAC Performance in Multi-Hop Wireless Networks

As wireless communication technology becomes more pervasive, multi-hop wireless networks, such as wireless sensor networks and wireless mesh networks, are receiving more attentions from both academic and industrial worlds. However, traditional MAC protocols for single-hop wireless networks, such as 802.11, do not perform well in multi-hop scenarios. In this talk, I will describe a new method to improve MAC performance in multi-hop wireless networks by using limited routing information. In this new mechanism, a setup control frame can travel across multiple hops and make bandwidth reservation along the route for upcoming data frame transmissions. By doing this, it introduces cooperation among multiple hops in MAC layer and greatly improves the efficiency of bandwidth reservation in media with contention.As an example, I will describe how we use this new mechanism in designing a duty-cycle based MAC protocol, called RMAC, for energy-constrained sensor networks. I will show the significant performance improvement in both packet delivery latency and and network throughput by comparing the new MAC protocol against a classic duty-cycle MAC protocol, the SMAC. I will then introduce the new mechanism to the general case of wireless multi-hop networks and conduct performance comparison of our new MAC protocol against 802.11. Our simulation results show promising potentials of the new MAC protocol in scenarios under heavy traffic.