Once the minefield is employed, the individual mines begin to assemble into a completely ad-hoc network. By exploiting novel networking approaches and the close mine-to-mine distances, the minefield network is able to self-assemble in less than five minutes. In parallel to the assembly process, the minefield self-maps the location of all mines in the minefield. This local mapping can be achieved without access to the Global Positioning System (GPS). An absolute position of all mines within the minefield can be determined by onboard GPS, but this is not necessary for the standard functions of the minefield.
http://www.darpa.mil/ato/programs/SHM/shmdemo.swf
