Patent ID: 9125152
Filing Date: 2015-09-01
Classification: H04W,Y02D

Abstract:
1. A wireless device comprising: a transceiver for transmitting and receiving messages to and from an access point, the wireless device having a sleep mode from which a device application wakes up to perform actions and the transceiver may turn on to listen for beacons from the access point to transmit and receive packets; and a scheduling system which schedules each application wake up and transceiver turn-on time, the scheduling system comprising a clock drift estimator and wake up adjustment procedure which determines an expected clock drift from a history of synchronization errors calculated with each beacon reception, wherein each synchronization error is computed as the difference between a wireless device actual beacon arrival time and the wakeup time; wherein the scheduling system schedules the wakeup time such that: where t wherein the scheduling system schedules the wakeup time independent of timestamps associated with beacons.