The FCC this week has formally adopted a Notice of Proposed Rulemaking to introduce a number of possible
improvements to the AM broadcasting.
The Commission is seeking ways to revitalize the AM band by identifying ways
to enhance AM broadcast quality and
proposing changes to our technical rules that would enable AM stations to
improve service.
The Commission’s last comprehensive examination of the
technical, legal, and policy issues relating to AM broadcasting took place a generation
ago, in a proceeding that began with a 1987.
In the more than quarter-century since, the challenges facing the AM
band have increased dramatically.
In the mid-1980s, AM radio represented 30 percent of the
nation’s radio listening hours. By 2010, that number had dropped to 17
percent, with AM radio comprising only 4 percent of listening hours among younger Americans. The
causes of this decline are well-documented.
As the Commission has previously stated, a “combination of
higher fidelity alternatives to AM radio and increased interference to AM radio have caused
an erosion of the AM radio audience and the loss of young listeners to other programming outlets.”
The Commission says the sustainability of the AM broadcast
service has been threatened by the migration of AM listeners to newer media services, including
FM, satellite radio, personal media players, podcasts, and audio streams
provided over the Internet.
In its Notice, the FCC states the AM band is also subject to
interference concerns not faced by other broadcast sources.
- First, due to the nighttime propagation characteristics of AM signals, many AM stations are unable to operate at night, and many others must reduce operating power substantially and/or use a complex directional antenna system in order to avoid interference to co- and adjacent-channel AM stations at night.
- Second, reinforced structures, such as buildings with steel frames or aluminum siding, can block AM signals.
- Third, AM radio is particularly susceptible to interference from electronic devices of all types, including such ubiquitous items as TV sets, vehicle engines, fluorescent lighting, computers, and power lines. The noise on the AM band that is caused by those sources is only expected to increase as electronic devices continue to proliferate.
No comments:
Post a Comment