Published at LXer:
Playing around with radio-frequency transmission and reception used to be restricted to those of us with hardware skills. That has been changing for some years, though, as processors get faster and software techniques advance; now, many radio transmitters and receivers are built with simple (but flexible) hardware. The hard work of generating the signal to be transmitted is done in software. Some wireless network adapters work that way now, as do a number of other devices. There is a well-advanced project - GNU Radio - which enables experimenters to do amazing things with software defined radio (SDR) systems.