A lot of work has gone into making efficient use of the available RF spectrum -- check out the latest in that regard... Looming in the background of recent wireless microphone development lies the growth of high-bandwidth wireless broadband services, smart phones, digital television, and other spectrum-hungry applications. Driven by the repurposing of wide swaths of RF spectrum traditionally used for wireless mics , manufacturers are pursuing solutions so that the wireless mics and similar devices will remain viable in the future.