Efficient synchronization for wakeup radio

An apparatus for wireless communication at an access point (AP) operating in a shared radio frequency spectrum band, comprising:

• a processor,
• memory in electronic communication with the processor;
• and
• instructions stored in the memory and executable by the processor to cause the apparatus to:
• determine a time resolution for values indicative of wakeup signal transmission times based at least in part on a wakeup schedule of a station (STA) and a clock drift value for the STA;
• transmit, to a primary radio of the STA, an indication of the time resolution;
• identify a transmission time of a wakeup signal for the STA;
• determine a value indicative of the transmission time of the wakeup signal based at least in part on the transmission time and the time resolution;
• and
• transmit, to a wakeup radio of the STA, the wakeup signal as a packet that comprises the value indicative of the transmission time of the wakeup signal.

A method for wireless communication at a station (STA) operating in a shared radio frequency spectrum band, comprising:

• receiving, using a primary radio, an indication of a time resolution for values indicative of wakeup signal transmission times;
• receiving, using a wakeup radio and based at least in part on a wakeup schedule of the STA, a wakeup signal as a packet that comprises a value indicative of a transmission time of the wakeup signal;
• determining the transmission time of the wakeup signal based at least in part on the wakeup schedule, the indication of the time resolution, and the value indicative of the transmission time;
• and
• updating a local clock timing based at least in part on the transmission time.