A Model for Energy Usage in IEEE 802.11s Based Mesh Networks

Abstract

For wireless communications numbers of standards are there in market. Among these standards, IEEE 802.11s is specifically designed for Wireless Mesh Networks (WMN). Mesh nodes in IEEE 802.11s can maintain link specific power mode, independent of power saving mode (PSM) for other peers. In environment having scarce resource of energy, every joule can be precious. This work focuses on analysis of PSM of IEEE 802.11s in view of energy, delay and throughput. Energy consumption due to link-based PSM has been mathematically modelled and compared with existing work. Impact of number of peer links, beacon period, delivery traffic indication map period, bandwidth, traffic, awake window, etc., over energy efficiency have been analysed in light sleep and deep sleep mode. It is observed that, due to more number of peer links in denser network, light sleep mode is less effective in term of energy efficiency. WMN have scalability issue. Further, network nodes near to gateway have lesser lifetime compared to other nodes, but due to PSM significant increase in lifetime has been observed. With increasing traffic, a node devotes more in awake state, so network throughput does not degrade due to light sleep mode. But at lower Beacon Interval slight degradation in throughput has been observed. During low traffic period, ideal listening dominates. Hence, suitable configuration of parameters like awake window, beacon period and delivery traffic indication map period can play vital role in energy saving.