For wireless devices, bandwidth (and size) directly translates to radio time and power. Alternatively, low bandwidth also allows the use of noisier links, sinc

For wireless devices, bandwidth (and size) directly translates to radio time and power. Alternatively, low bandwidth also allows the use of noisier links, since effective bandwidth is the product of the channel width and SNR margin. The military applications of either case are fairly obvious, but I could also imagine the utility for battery-powered devices (portable baby monitors?) if the processing itself is brought within tolerable power limits.