sometimes the military gets to have all the fun:
” The Darpa mobile-communications program, also know as the “situational awareness system,” would use high-capacity, low-power radios linked together by a “self-configuring” network to keep soldiers connected with each other at frequencies ranging from 20 MHz to 2.5 GHz. Kolodzy called the architecture a “mobile, ad-hoc, peer-to-peer network” that uses frequency-hopping technology to avoid communication intercepts and location-finding capability — in other words, situational awareness on the battlefield — but little power.”
“The planned technology demonstration next year would link 70 prototype radios over a network utilizing MontaVista’s Hard Hat version of the standard Linux kernel and other open-source components, as well as StrongARM processors, DSPs and FPGAs.”