A power-saving protocol for ad hoc networks

To extend the usage scope of an 802.11DCF based wireless LAN power-saving protocol 802.11PS to a multi-hop mobile environment, a modified protocol called 802.11NPS is proposed. It uses a packet-driven dynamic switching-off mechanism on the wireless network interface card to save power. By delaying the switching-off operations for a certain period of time after nodes receiving unrelated control packets, 802.11NPS can support the upper layer routing protocol excellently and thus can be used in multi-hop ad hoc networks. It also can be used in fully connected networks. By using a more accurate power-consumption model, the performance of 802.11NPS is studied through simulation. Results show that in a WLAN environment, 802.11NPS can save power by more than 60% as compared with 802.11DCF; while in a multi-hop mobile environment, 802.11NPS can save power by 18%. At the meanwhile, its delay performance is better than that of 802.11DCF and the throughput is still similar.