RE: Wi-Fi Power saving and Exit strategy

Susheel Nuguru — Wed, 25 Jun 2025 09:40:52 GMT

Woo-chan, I am not an expert in this but I have some interpretation of some standard power saving and exit modes described in the spec.

Listen Interval is simply “how many beacons I’ll sleep through before I wake up and check for traffic.” If you set it to 1, the chip wakes on every beacon (about every 100 ms). If you set it to 5, it sleeps through four beacons and only wakes on the fifth.

EVERY_TIM says “whenever I do wake up for a beacon, I’ll immediately send a single ‘I’m here , do you have data?’ frame and pull in everything the AP has buffered.”

In WMM-PS mode that frame is a QoS Null.
In Legacy PS mode it becomes a PS-Poll under the hood.

“Listen Interval” controls when you wake.
“EVERY_TIM” controls how you exit sleep on each wake and grab your data.

The exit strategy you pick just chooses which frame style you use on every wake. EVERY_TIM - one QoS-Null (WMM) or PS-Poll (Legacy) per wake, then go back to sleep or stay up as needed. CUSTOM_ALGO - Nordic’s tuned mix of PS-Poll calls and QoS-Nulls, optimized to reduce overhead during heavy traffic.