Broadcast time-of-departure (TOD) frame format

An access point (AP) comprising:

• a clock;
• a wireless communication subsystem;
• and
• a processing unit communicatively coupled with the clock and the wireless communication subsystem, the processing unit being configured to:
• synchronize the clock of the AP with clocks of one or more other APs;
• perform a synchronization session with one or more wireless stations (STAs);
• and
• broadcast, without receiving a request from the one or more STAs, one or more Broadcast time-of-departure (TOD) frames to the one or more STAs through the wireless communication subsystem, wherein each of the one or more Broadcast TOD frames includes a time of departure of a Broadcast TOD frame from the AP.

A method of range measurement between a wireless station (STA) and one or more synchronized access points (APs), the method comprising:

• performing, by the STA, a synchronization session with a first AP in a network of synchronized APs;
• receiving, by the STA without sending a request to a second AP in the network of synchronized APs, one or more Broadcast time-of-departure (TOD) frames broadcasted by the second AP in the network of synchronized APs, wherein each of the one or more Broadcast TOD frames includes a time of departure of a Broadcast TOD frame from the second AP;
• and
• determining, by the STA, a range between the STA and the second AP based on the time of departure of at least one Broadcast TOD frame from the second AP.

A wireless station (STA) comprising:

• a clock;
• a wireless communication subsystem;
• and
• a processing unit communicatively coupled with the clock and the wireless communication subsystem, the processing unit being configured to:
• perform a synchronization session with a first AP in a network of synchronized APs;
• receive, without sending a request to a second AP in the network of synchronized APs, one or more Broadcast time-of-departure (TOD) frames broadcasted by the second AP in the network of synchronized APs through the wireless communication subsystem, wherein each of the one or more Broadcast TOD frames includes a time of departure of a Broadcast TOD frame from the second AP;
• and
• determine a range between the STA and the second AP based on the time of departure of at least one Broadcast TOD frame from the second AP.