Provided by: National Taiwan University
Date Added: Nov 2012
As future M2M (Machine-To-Machine) communications aim at supporting wireless networks which feature long range, long operating duration and large device number, the IEEE 802.11ah Task Group is going to specify a global WLAN standard that utilizes carrier frequencies below 1GHz. To power the M2M devices, harvesting energy from ambient environment has attracted attentions from researchers. Although applying the IEEE 802.11 PSM (Power-Saving Mode) scheme reduces energy consumption, devices go to sleep only when the traffic buffer is empty, staying awake unnecessarily, which wastes energy in overhearing the uplink traffic transmitted to the AP.