Siemens IEEE802.11 manual Timing Synchronization Function TSF, All stations maintain a local timer

Timing Synchronization Function (TSF)

νAll stations maintain a local timer.

–Used for Power Management

•All station timers in BSS are synchronized

–Used for Point Coordination Timing

•TSF Timer used to predict start of Contention Free burst

νTiming Synchronization Function (TSF)

–keeps timers from all stations in synch

–AP controls timing in infrastructure networks

–distributed function for Independent BSS

νTiming conveyed by periodic Beacon transmissions

–Beacons contain Timestamp for the entire BSS

–Timestamp from Beacons used to calibrate local clocks

–not required to hear every Beacon to stay in synch

–Beacons contain other management information

•also used for Power Management, Roaming

WLAN-IEEE802.11 Tutorial (Maximilian Riegel), 021018-wlan-tutorial.ppt Page 44 © Siemens, 2002