An adaptive transmit power scheme for wireless sensor networks

The MAC protocol for wireless sensor networks is different from traditional wireless MACs such as IEEE 802.11. Energy conservation is one of the most important goals, while per-node fairness and latency are less important. This paper proposes an adaptive transmit power scheme based on S-MAC named ATPM (Adaptive Transmit Power MAC). In S-MAC, all the nodes transmit data with a fixed power level, no matter how close the involved nodes are. The proposed ATPM can calculate the distance between the sender and the receiver by measuring the received power, and then adaptively decide the appropriate transmit power level according to the propagation model and distance. Simulations have been done to evaluate the performance of the proposed new protocol, by which we can find out that ATPM can really reduce energy consumption compared with S-MAC.