A system for wireless asset tracking is disclosed. The system includes a
plurality of mobile devices. Each mobile device performs two spreading
operations with two distinct PN codes, a first PN code and a second PN
code. Data is transmitted by each mobile device using a burst direct
sequence spread spectrum radio signal. The system also includes at least
three base stations. Each base station is configured to receive the burst
direct sequence spread spectrum radio signals from the mobile devices
which includes decoding the signals by first de-spreading with the second
PN code and second de-spreading with the first PN code. Each base station
is further configured to add a timestamp to each data packet received. A
system for calculating the location of the mobile devices creates
location information for each mobile device by calculating the time
difference of arrival of received bursts for each base station.