Energy Efficient Traffic Aware MAC Protocols for Delay-Sensitive Wireless Sensor networks

Abstract

Wireless sensor network (WSN) consists of large number of distributed sensor nodes, which are generally battery-powered and may not recharge easily. Consequently, how to maximize the lifetime of the nodes is an important issue while designing a MAC protocol. However, lowering the energy consumption may result in higher latency. To address such a tradeoff, this paper proposes DDC-MAC and UDDC-MAC. For delaysensitive WSNs, DDC-MAC minimizes latency with energy consumption at a reasonable level. In DDC-MAC, each sensor node chooses a duty cycle according to traffic and average latency experienced by that node. Each node follows multiple listen and sleep schedules. Therefore, they switch into the listen state frequently and reduce the network lifetime. To minimize energy consumption due to multiple listen and sleep schedules, UDDC-MAC is proposed in which Schedule Unifying Algorithm (SUA) is integrated with DDC-MAC so that multiple listen and sleep schedules are unified into a single unified sub-optimal schedule. We study the proposed protocols by simulating these protocols using NS-2 and compare their performance with DS-MAC, S-MAC (Full), S-MAC (10%) in terms of average energy consumption of a node and average end to end latency experienced by the packet. The simulation results show that UDDC-MAC achieves improved latency performance and is more energy efficient than DDC-MAC, S-MAC and DS-MAC.