ZigBee-Assisted Power Saving for More Efficient and Sustainable Ad Hoc Networks

In emergency situations, infrastructure-based wireless access networks (e.g., WLANs, cellular networks) may collapse due to power outage or infrastructure damages. To enable responsive communication for rescue operations, wireless ad hoc networks may be set up. However, due to limited battery capacity, the networks may not sustain long enough, especially when stringent communication delay is demanded. Aimed at energy efficiency, the Power Saving Management (PSM) for IEEE 802.11 DCF has been standardized and can be applied in multi-hop ad hoc networks. With PSM, however, it is difficult to achieve high energy efficiency and low delay simultaneously when data traffic is unpredictable. Motivated by the trend that low-power ZigBee interface will be more and more commonly embedded in mobile devices together with WiFi interface in the near future, we propose a ZigBee-assisted PSM (called ZPSM) for DCF, which leverages ZigBee interfaces to wake up WiFi interfaces on demand to reduce WiFi interfaces´ energy consumption and thus prolong network lifetime, while satisfying delay requirements. The results of extensive simulation and prototype-based experiments have verified the performance advantages of ZPSM.