Analysis of Low Latency MAC Protocols for Clustered Sensor Networks

In this paper, a low latency MAC protocol that can be used in sensor networks is proposed. To extend the lifetime of sensor nodes, it was used to synchronize active/sleep periods of all sensor nodes. However, due to these synchronized sensor nodes, packets in the intermediate nodes must wait until the next node wakes up before it can forward a packet. This induces a large delay in sensor nodes. To solve this latency problem, cluster-based sensor networks are used. The active/sleep periods of sensor nodes in each cluster are synchronized with a timing offset. Thus, the sensor nodes in each cluster have the same timing offsets and reduce the sleep delay. Using this concept, the latency problem can be solved. In addition, this method can also solve the collision problem in inter-cluster communication when a number of nodes try to send information to the same node in other clusters. Our numerical results show that the latency can be reduced when synchronized nodes with timing offsets are used.