INSERTING TIME OF DEPARTURE INFORMATION IN FRAMES TO SUPPORT MULTI-CHANNEL LOCATION TECHNIQUES

摘要

A device whose location is to be determined (target device) generates a plurality of frames (messages) and time of departure (TOD) timestamp information indicating when the target device transmits the plurality of frames in a sequence or burst. The target device transmits the plurality of frames and the TOD information, wherein the plurality of frames are transmitted such that at least two of the frames are on different radio frequency (RF) channels. Within a sequence or burst (or across multiple sequences or bursts), multiple widely spaced transmissions on the same channel are included to allow for estimation of the crystal frequency offset of the transmitting device. The TOD information included in the transmitted packets allows devices that receive the packets not to change their channels of operation solely for the purpose of receiving packets from the device to be located.