A self-organizing, location-aware media access control protocol for DS-CDMA sensor networks

This paper proposes CSMAC (CDMA Sensor MAC), a novel self-organizing, location-aware media-access control (MAC) protocol for DS-CDMA sensor networks to support applications that feature high bandwidth traffic and stringent latency requirements. Previously proposed MAC protocols for sensor networks such as SMAC (W. Ye et al, IEEE Proc. Infocom, pp. 1567-1576, 2002) primarily prioritize energy efficiency over latency. Our protocol design balances the considerations of energy efficiency, latency, accuracy, and fault-tolerance in sensor networks. CSMAC uses a combination of DS-CDMA and frequency diversity in channel allocation to reduce channel interference and consequently message latency in the network. It features two algorithms that exploit the location awareness of sensor nodes to enable intelligent and efficient network formation for collaborative sensing tasks: turn off redundant node (TORN) and select minimum neighbor (SMN).