MAX: A Maximal Transmission Concurrency MAC for Wireless Networks with Regular Structure

Abstract

Multi-hop wireless networks facilitate applications in metropolitan area broadband, home multimedia, surveillance and industrial control networks. Many of these applications require high end-to- end throughput and/or bounded delay. Random access link-layer protocols such as carrier sense multiple access (CSMA) which are widely used in single-hop networks perform poorly in the multi-hop regime and provide no end-to-end QoS guarantees. The primary causes for their poor performance are uncoordinated interference and unfairness in exclusive access of the shared wireless medium. Furthermore, random access schemes do not leverage spatial reuse effectively and require routes to be link- aware. In this paper, we propose and study MAX, a time-division- multiplexed resource allocation framework for multi-hop networks with regular topologies. MAX tiling delivers optimal end-to-end throughput across arbitrarily large regularly structured networks while providing bounded delay. It outperforms CSMA-based random access protocols by a factor of 5 to 8. The MAX approach also supports network services including flexible uplink and downlink bandwidth management, deterministic route admission control, and optimal gateway placement. MAX has been implemented on IEEE 802.15.3 embedded nodes and a test-bed of 50 nodes has been deployed both indoors and outdoors.