A Traffic-Load Oriented Power Saving Mechanism for MAC Protocol in Ad Hoc Networks

In ad hoc networks, energy conservation is a critical issue because devices are battery powered. In order to save energy, nodes should turn their radios off when they have no packet to send or receive. To achieve this, IEEE 802.11 defined a power saving mechanism (PSM) based on periodical beacon transmitting. It allows devices to turn their radios off when no data has to be sent or received. However, the idle state is large because the device must remain awake during the entire beacon interval even to transmit only a small amount of data packets. Although other PSMs were proposed to solve this problem, they still suffer from a large idle state. In this paper, we propose a new power saving mechanism by dynamically adjusting the sleeping strategy of nodes based on traffic load. Simulation results show that the proposed PSM outperforms other PSMs in energy goodput and lifetime.