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.