IC-MAC: A Dynamic Scheduling Supported MAC Protocol Optimized for Intra-cluster Communication

Cluster-based architecture is a widely and deeply studied network architecture used in wireless sensor networks. With enough available channels and proper channel assignment policy, clusters using the same channel can be separated distant enough to avoid interference from each other. In each such cluster, the traffic demand usually exists only between the cluster head and the end nodes. We refer to such kind of communication pattern as "independent intra-cluster communication (IICC)" pattern. In this paper we present IC-MAC, a MAC protocol specifically optimized for such a communication pattern. IC-MAC is a variant of IEEE 802.15.4 and it introduces a dynamic scheduling mechanism into the superframe structure of 802.15.4. With this mechanism, IC-MAC uses the slotted CSMA/CA algorithm under low network load, and can automatically switch to schedule-based transmission when the load becomes high. Simulation results show that the performance of IC-MAC exceeds IEEE 802.15.4 overwhelmingly under the IICC pattern, and the advantage is especially obvious under high network load