When compared with legacy Power Save mode, how does VHT TXOP power save improve battery life for devices on a WLAN?

VHT TXOP (Very High Throughput Transmit Opportunity) power save is a feature introduced with the

802.11ac amendment, which is designed to improve the power efficiency of devices connected to a

WLAN. This feature enhances battery life in several ways, compared to the legacy Power Save mode:

Enhanced Power Saving: VHT TXOP power save allows devices to disable more components of the

WLAN transceiver when they are in a low power state. This reduces the power consumption during

periods when the device is not actively transmitting or receiving data.

Intelligent Wake-Up Mechanisms: It employs more sophisticated mechanisms for devices to

determine when they need to wake up and listen to the channel, further reducing unnecessary

power usage.

Optimized Operation: This power save mode is optimized for the high-throughput environment of

802.11ac networks, allowing devices to efficiently manage power while maintaining high

performance.

Legacy Power Save mode, introduced in earlier versions of the 802.11 standards, does not provide

the same level of component disablement or the intelligent wake-up mechanisms found in VHT TXOP

power save, making option B the correct answer.

Reference:

IEEE 802.11ac-2013 Amendment: Enhancements for Very High Throughput for Operation in Bands

below 6 GHz.

CWNA Certified Wireless Network Administrator Official Study Guide: Exam CWNA-109, by David D.

Coleman and David A. Westcott.