Date Added: Feb 2013
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 delay-sensitive 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.