Which one of the following power management modes populates a TIM in a BSS or ESS?

• A. Power Save Polling (PSP) mode.
• B. Always Awake mode.
• C. Continuous On mode.
• D. Idle mode.

Answer: (A)

The concept this tests is how a network tells sleeping stations that there’s data waiting for them. The TIM (Traffic Indication Map) is carried in the AP’s beacon frames within a BSS or ESS and is used to indicate which stations have buffered data at the AP. This signaling only becomes relevant when stations are in power-save mode, saving battery while they’re asleep. When a station is asleep, the AP marks its bit in the TIM if it has data queued. When that station wakes up, it sees its bit set and uses a PS-Poll to retrieve the buffered frames from the AP. This behavior is exactly what Power Save Polling enables: it allows a sleeping station to wake, poll for data, and receive what’s waiting, with the TIM guiding the process. The other modes describe continuous listening or non-power-saving operation, where the TIM signaling isn’t part of the data-retrieval flow.