Regulating Broadcasting Overview of the technical specifications that make up the U. S. broadcast spectrum.

Regulating Broadcasting

Overview of the technical specifications that make up the U. S. broadcast spectrum


• FCC derives its power from – The Communications Act of 1934– The Telecommunications Act of 1996– Other amendments to these acts

• Satellite Communications Act

• Children’s Television Rules


• In order to license and regulate an industry some industrial policy needs to be developed that follows – The guidelines outlined in the legislative acts– Standard procedures that everyone can follow– A systems process so technology can be applied

as efficiently as possible


• Broadcasting uses a series of frequencies and we call those frequencies allocated to stations CHANNELS

• Channels are part of the spectrum allocation process

• Different parts of the spectrum are used for different purposes


• Broadcasting - to be useful to every potential user of the spectrum - needs to have standards applied to – The transmission of signals– The reception of signals– The use of the spectrum


• Terminology used– Frequency - the wavelength of the channel– Frequency (response) - the frequencies

broadcast that affect the quality of the programs– Amplitude - how the signal is modulated – Carrier wave - the frequency used to transmit– Hertz - the measure of frequency (1 HZ = 1

cycle per second)


• Modulation methods used– Amplitude modulation - the audio portion of

the program is superimposed upon the carrier– Frequency modulation - the carrier is made to

oscillate in proportion to the program audio– Pulse code modulation - the amplitude is turned

on and off to represent the digital words transmitted


• Standards– AM - Medium wave transmitting stations use amplitude

modulation– FM - VHF wave transmitting stations that use

frequency modulation– TV - VHF and UHF transmitting stations that use

NTSC standards (AM for the video picture and FM for the audio portion)

– DTV - VHF and UHF transmitting stations using 8 VSB (vestigal side band) modulation, MPEG 2 compression


• More Standards– DTV standards

• 480 Interlace - 480 lines X 640 pixels odd and even scan lines interlace

• 480 Progressive - 480 lines X 640 pixels with lines scanned progressively

• 720 - 720 lines X 1280 pixels either I or P

• 1080i - 1080 lines X 1920 pixels I (ATSC standard)


• The electromagnetic spectrum– 300,000 HZ to 3 MHZ (medium wave)

• 107 AM Channels

• Air and Marine, SOS and Ham radio

- 3 MHZ to 30 MHZ (shortwave)• International Shortwave, military, Ham


• The electromagnetic spectrum– VHF (Very High Frequency Band)

• 30 MHZ to 300 MHZ - – 100 FM channels, VHF TV 2 through 13, police

– UHF (Ultra High Frequency)• 300 MHZ to 3000 MHZ

– UHF TV 14-72, radar and weather satellites


• The electromagnetic spectrum– SHF (Super High Frequency Band)

• 3000 MHZ to 3 GHZ– Ku and C band communication satellites, Satellite radio,

microwave relay, air navagation, radar

– EHF (Extremely High Frequency Band)• 3 GHZ to 300 GHZ

– Military communications and future expansion


• Radio Classification– AM (Standard Broadcast Band)

• 107 Channels between 530KHZ and 1705 KHZ– 60 Clear Channels - Class A (high power)

– 41 Regional - Class B (medium power)

– 6 Local Channels - Class C (low power)

• Each station has a 10 KHZ bandwidth


• Radio Broadcasting– FM (authorized in 1945)

• 100 Channels between 88.0 MHZ and 108 MHZ– 80 Channels between 92 and 108 MHZ commercial

– 20 Channels between 88 and 92 MHZ educational

• Each channel is 200 KHZ wide and provides for the ability to multiplex transmission (FM Stereo)

– Power levels are classified A (lowest), B (medium) C (highest) and new D (low power FM)


• Television Broadcasting– VHF - Channels 2 - 13

• 54 MHZ to 216 MHZ spectrum– Each TV channel is 6 MHZ wide

– UHF - Channels 14 - 72• 470 MHZ to 890 Mhz spectrum

– DTV - Both VHF and UHF– Each channel is 6 MHZ and uses MPEG 2 compression

with 8 VSB modulation


• Other approved broadcasting services– DBS - Direct Broadcast Satellite

• TV service with satellite to home transmission– Using the DVB-2 modulation system capable of both

digital standard and HD signals in 12.75 to 14.5 GHZ band

– Satellite Radio• Audio service with satellite to car/home

transmission– Uses ACC coding in the S Band in the 2.332 to 2.345

GHZ band






Regulating Broadcasting Overview of the technical specifications that make up the U. S. broadcast spectrum.

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