FM radio in North America has long stopped being simply a slice of frequency spectrum devoted to analogue broadcast stations. The widespread iBiquity IBOC syste

FM radio in North America has long stopped being simply a slice of frequency spectrum devoted to analogue broadcast stations. The widespread iBiquity IBOC system (better known as ''HD Radio'', now owned by DTS) features multiplexing of 2 or 3 digital subchannels per station across the existing band. This means that a simple FM receiver in a smartphone will only get the analogue portion of the signal, unless/until the smartphone manufacturer licences an HD Radio demodulator and accompanying software. Unlike in modern automobiles, which have integrated HD Radio playback through the usual speaker system but with no digital output, smartphones might be feared by broadcasters and content providers to be potential piracy devices if any of those HD Radio digital signals were able to be captured or retransmitted. Is that fear real? Beats me, but it might cause integrated smartphone FM radio receivers to be analogue-only.