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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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)

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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)

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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)

Regulating Broadcasting

• 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

Regulating Broadcasting

• 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

Regulating Broadcasting

Regulating Broadcasting

Regulating Broadcasting

Regulating Broadcasting