Power Saving with p-Persistent Sleep Decision for Ubiquitous Mobile Communications

Battery power is an important and limited resource in ubiquitous mobile communications. Energy consumption can be reduced by turning off the radio during idle times. In most power saving schemes, a node decides whether to put its wireless interfaces in the sleep state or in an awake state, based only on the presence of packets destined for the node. However, by considering other factors related to the node status such as the remaining energy, the node can achieve more power savings for the given delay constraints. In this paper, we propose a p-persistent power saving scheme for mobile devices (nodes) in ubiquitous mobile communications systems. The proposed scheme first computes the sleep probability, considering the node status-related factors, including the channel state between nodes, the number of packets queued, the constraint on packet delay, the intensity of load, and the remaining available battery energy. Then, using the probability, the proposed scheme decides the node state. By using simulation, we compare the proposed scheme with IEEE 802.11 power saving mode. The results show that the proposed scheme saves remarkably more energy for the given delay constraints