IBOC is a method whereby both analog and digital signals are transmitted on the same frequency. Additional digital subcarriers are carried on the normal AM or FM analog signal. They extend beyond the normal channel bandwidth though so there is an increased chance of adjacent channel interference. I think the plan in the future is to eliminate the analog portion and have all stations strictly digital.
_____ From: digitalradio@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of "John Becker, WØJAB" Sent: Monday, November 12, 2007 5:25 PM To: digitalradio@yahoogroups.com Subject: Re: [digitalradio] Digital Radio - Well Broadcast This has been going on for over 25 years that I know of. But I don't think it was digital. AM and FM radio had a service for the blind that was a sub carrier. Sounds very close to it. At 06:29 PM 11/12/2007, you wrote: >In the U.S. the FCC has approved a system called IBOC (In-Band On Channel) to add digitial audio to existing AM and FM stations. In broadcast radio, there isn't the luxury of unused channels that allow every station to have one analog and one digital transmitter. I haven't seen any terrestrial digital radio receivers in stores yet.
