How does VHT TXOP power save improve battery life compared to legacy Power Save mode?

The improvement in battery life provided by Very High Throughput (VHT) Transmission Opportunity (TXOP) power save mode compared to legacy power save mode is primarily due to the use of the partial AID (Association Identifier) in the MAC layer protocols. This mechanism allows a device to enter sleep mode while still being able to receive targeted frames addressed specifically to it.

In VHT TXOP power save, devices can manage their power consumption more effectively. The partial AID in the preamble enables the access point to identify which frames are intended for the sleeping device without the need for that device to remain active and constantly listen to the wireless medium. As a result, the device can wake up only when necessary to receive its specific frames, minimizing the time that the radio is powered on and reducing overall energy consumption. This targeted approach helps extend battery life by allowing devices to stay in a low-power state for longer periods and waking up less frequently than they would in legacy modes, where such specific targeting is not utilized.

The other options do not directly contribute to the significant advances in battery efficiency afforded by VHT TXOP power save. For instance, less frequent association requests, longer disassociation times, or changes to the beacon interval do not fundamentally change how power