Mpt-Mac: A Multiple Packets Transmission Mac Protocol For Wireless Sensor Networks

Event detection is a major application in wireless sensor networks (WSNs). Current Medium Access Control (MAC) protocols for WSNs are mainly optimized for the situation that an event generates only one data packet on a single node and the event occurrence rate is low. When an event generates multiple data packets or the event occurrence rate is relatively high, packet delivery latency and delivery ratio are degraded rapidly. In this paper, we present a new MAC protocol called Multiple Packets Transmission MAC (MPT-MAC) for event-based WSNs. MPT-MAC schedules multiple data packets generated by an event on a single node to be forwarded over multiple hops in an operational cycle. By this means, MPT-MAC can achieve low delivery latency and high delivery ratio under heavy traffic loads. We use event delivery latency (EDL) and event delivery ratio (EDR) to measure the event detection capability of MPT-MAC protocol. We show the performance of MPT-MAC through detailed ns-2 simulation. Compared to S-MAC-AL, R-MAC and DW-MAC, MPT-MAC can achieve lower EDL and higher EDR without more energy consumption. Furthermore, MPT-MAC can obtain lower duty cycle than DW-MAC when satisfying the latency requirement of the applications.