Timing and Power Management

In order to achieve the most functionality from 802.11 wireless connectivity,
you need to exercise control of both timing and power management.
Synchronization is maintained using wireless beacons, with all
station clocks within a given BSS communicating through time-stamped
transmissions.

When functioning in infrastructure mode, an access point functions
as the timing master to produce timing beacons. Under these conditions,
synchronization is supported inside 4 microseconds in addition to propagation delay. The timing is important to keep power usage as low as possible.

There are two primary types of power saving modes: awake and doze.
When working in “awake” mode, the wireless stations are powered on
100 percent and can receive or send packets constantly. Nodes must contact
the access point prior to “dozing” off. In “doze” mode, nodes must
actually come into an awake state to monitor the frequency every so often,
to see if the access point has queued messages waiting for it.