Abstract

The usage of wireless channels is based on Media Access Control (MAC) protocols, which allocate wireless resources and control the way that sensors access a shared radio channel to communicate with their neighbors. Designing low energy consumption, high efficiency MAC protocols is one of the most important directions in Wireless Sensor Networks (WSN). So far, MAC protocols in WSN are usually divided into two categories: contention-based MAC protocols and schedule-based MAC protocols. However, both protocols have their own advantages and disadvantages that sometimes it is hard to decide which one is better than the other one. A hybrid protocol is concerned a lot now in WSN, which is IEEE 802.15.4. It integrates the advantages of both contention-based and schedule-based mechanisms. However, this protocol has some improving spaces as well, which motivated us to further study it and proposed a new contention reserve MAC protocol, named CRMAC, under the inspiration of IEEE 802.15.4's superframe structure. Through a series of theoretical and simulation analysis, we show that CRMAC performs better in energy consumption, system delay and network throughput than IEEE 802.15.4 and LEACH (Low Energy Adaptive Clustering Hierarchy). CRMAC is especially suitable for short packet transmission under logy traffic networks, which is the main situation in WSN, so this protocol is practical in WSN.