TIM broadcast

4.3.13.17 TIM broadcast

The TIM broadcast protocol defines a mechanism to enable a STA to receive an indication of buffered
individually addressed traffic, independent of the Beacon frame, reducing the wake time of the STA.
4.3.13.18 Timing measurement
Timing Measurement frames allow a recipient STA to accurately measure the offset of its clock relative to a
clock in the sending STA. With the regular transfer of Timing Measurement frames from one STA to
another, it is possible for the recipient STA to track changes in the offset of its clock with respect to the
sending STA over time and thus detect and compensate for any drift between the clocks.
4.3.13.19 Traffic filtering service
Traffic filtering is a service that may be provided by an AP to its associated STAs, where the AP examines
MSDUs and management frames destined for a STA. The AP determines if any of those frames match a
specific set of traffic filters that may be enabled at the AP per the request of the STA. Individually addressed
frames that do not match any of the traffic filters in the set are discarded. Individually addressed frames that
do match at least one of the set of the enabled traffic filters are delivered to the STA. The STA may also
negotiate to have a notification frame sent prior to the delivery of the frame matching the traffic filter.
4.3.13.20 U-APSD Coexistence
The U-APSD Coexistence capability enables the non-AP STA to indicate a requested transmission duration
to the AP for use of U-APSD service periods. Use of the transmission duration enables the AP to transmit
frames during the service period and improve the likelihood that the non-AP STA receives the frames when
the non-AP STA is experiencing interference. The U-APSD Coexistence capability reduces the likelihood
that the AP transmits frames during the service period that are not received successfully.
4.3.13.21 WNM-Notification
WNM-Notification provides a mechanism for a STA to notify another STA of a management event. One
event is defined: firmware update notification.
4.3.13.22 WNM-Sleep mode
WNM-Sleep mode is an extended power save mode for non-AP STAs in which a non-AP STA need not
listen for every DTIM Beacon frame, and need not perform GTK/IGTK updates. WNM-Sleep mode enables
a non-AP STA to signal to an AP that it will be sleeping for a specified length of time. This enables a non-
AP STA to reduce power consumption and remain associated while the non-AP STA has no traffic to send
to or receive from the AP.