PH-MAC: A Periodically Hybrid MAC Protocol for Wireless Sensor Networks

Abstract

This paper proposes a novel protocol termed periodically hybrid MAC protocol (PH-MAC) for wireless sensor networks. In order to save energy and maximize the throughput we introduce the channel access mechanism TDMA into the PH-MAC. PH-MAC divides the whole transmission process into various PH-MAC periods, and each PH-MAC period is further divided into synchronization period, allocation period and TDMA period. The synchronization period is used to synchronize the neighboring nodes to prevent long-time clock drift; the allocation period is used to allocate timeslots to every node for communication; and the TDMA period is used for data communication. We present the designing techniques of PH-MAC, and compare the performance of PH-MAC with the simplified 802.11 DCF (no duty cycle), S-MAC (fixed duty cycle) and T-MAC (dynamic duty cycle) through simulation. The simulation results show that, PH-MAC not only improve the throughput of the network, but also save nearly half of the energy that T-MAC usually consumes.