LogA: Concurrent Medium Access Control through Time Log Analysis in Sensor Networks

This paper focuses on the design of high-throughput MAC for data-intensive sensor networks with unpredictable traffic. We propose Log A, a reactive concurrent MAC protocol that increases transmission concurrency based on time log analysis. Each node reactively and passively learns the interference relationship by analyzing the start transmission time and the end transmission time of packet blocks. Then, the learned interference relationship is exploited to improve the probability of beneficial concurrent transmissions of nodes that are within the interference range of each other. Log A has two salient features. First, it is passive and does not need network downtime to build interference relationship. Second, it is reactive and works only when traffic are generated. Log A has been implemented in Tinyos-2.1 and extensively evaluated in TOSSIM, the simulator of sensor networks. Experimental result shows that Log A outperforms the traditional CSMA protocol and an existing reactive concurrent MAC in terms of throughput, delivery latency, and energy consumption.