An energy-efficient MAC protocol for delay-sensitive wireless sensor networks

In this paper, we propose a new medium access control protocol for wireless sensor networks, named LE-MAC (Latency and Energy aware MAC) that aims to minimize data delivery latency as well as energy consumption. To achieve both goals, we exploit a physical carrier sensing feature in CSMA/CA and combine it with a cross-layer technique. When nodes that are in routing path between source and sink become aware of the traffic based on the carrier signal, they wakeup once more during the sleep period for transmitting data over multiple hops. We evaluated the proposed scheme compared with S-MAC on the ns-2 simulator. The results show that our scheme outperforms S-MAC protocols in balancing the need of low latency and energy consumption.