Patent ID: 8848622

Claim:
A method of increasing power efficiency and decreasing latency of communication of a mobile device operating in an unlicensed spectrum, the method comprising: receiving, at the mobile device, global timing data several times a second, said global timing data including an absolute time value received several times per second via said unlicensed spectrum from an external timing source, the mobile device communicating in the unlicensed spectrum; obtaining, at the mobile device at a rate of several times per second, a current time from the absolute time value included in the global timing data; determining, at the mobile device, a wake time to switch the mobile device from a sleep state to an active state based on a time determined from the global timing data; receiving, at the mobile device during the active state, signals from other devices communicating in the unlicensed spectrum; decoding the signals received during the active state from the other devices communicating in the unlicensed spectrum; determining, at the mobile device, a sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state based on the signals received during the active state from the other devices communicating in the unlicensed spectrum or the passage of a predetermined amount of time during the active state during which the mobile node does not receive any signals; wherein determining the sleep time occurring after the wake time to switch the mobile device from the active state to the sleep state includes: matching information in the decoded signals with a stored list of peer devices and determining that the sleep time is to begin when the mobile device determines that none of the transmitted peer discovery signals which were received are of interest to the mobile device or the mobile device does not receive any signals for said predetermined amount of time during the active state.