Campus Cable TV Signal Leakage:

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Campus Cable TV Signal Leakage

• Whats The Story,
• and What Should We Be Doing About It?

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Disclaimer

• The opinions expressed by the presenter during
  this presentation do not necessarily reflect
  those of The Georgia Institute of Technology,
  Campus Televideo, The Association of Higher
  Education Campus Television Administrators, or
  the Peabody Hotel.
• (But they should.)

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Signal Leakage Types

• Dont use the R word. (Radiation)
• Ingress
• Unwanted RF signals getting INTO the Cable
  System.
• Egress
• Unwanted RF signals getting OUT of the Cable
  System.

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Signal Ingress

• RF signals outside the cable at or near the same
  frequency of the RF signals on the cable will
  cause problems with the RF signals on the cable
  if they can get in.

Analog
Digital
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Cable TV Shares the Spectrum With Off-Air
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Signal Egress
Channels 95 through 22 added in the 1970s
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Signal Egress Air Distress Frequency (121.5 MHz)
1984 FCC begins Signal Leakage Monitoring
Requirements for Franchised Cable TV Systems
Frequency offsets added in 1989.
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Signal Leakage (CLI) Cumulative Leakage Index

• FCC begins CLI in the 1990s.

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Signal Leakage Cumulative Leakage Index

• What does this have to do with Me?

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Signal Leakage Cumulative Leakage Index

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Signal Leakage Cumulative Leakage Index

• (MVPDMultichannel Video Programming Distributor)

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Signal Leakage Cumulative Leakage Index

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Signal Leakage Cumulative Leakage Index

• So what does this mean?

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Signal Leakage Cumulative Leakage Index

• CFR 47 Part 76, 76.605(a)(12), 76.610-76.614,
  76.616, 76.617, 76.1706, 76.1803, 76.1804
• Prior to the use of signals in the aeronautical
  radio bands, and at least once each calendar
  year,
• CATV systems, MVPDs, and Non-Cable MVPDs
• must comply with FCC requirements for
  signal egress.

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Aeronautical Frequencies
108 MHz
137 MHz
Channels 98, 99, 14, 15, 16
225 MHz
400 MHz
Channels 24 thru 53
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Aeronautical Frequencies

• CFR 47 76.616 (b)The transmission of digital
  signals in this range is limited to power levels
  measured using a root-means-square detector of
  less than 10-5 watts (34 dBmV) in any 30 kHz
  bandwidth over any 2.5 millisecond interval.

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Signal Leakage Cumulative Leakage Index

• What do I need to do?

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Signal Leakage Cumulative Leakage Index

• If you are going to use the aeronautical
  channels
• Consult with your Legal department.
• Get FCC forms 320 321 in order.
• (More on this later)

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Signal Leakage Cumulative Leakage Index

• If you are already using the aeronautical
  channels
• Consult with your Legal department.
• Get FCC forms 320 321 in order.
• (More on this later)

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Signal Leakage Cumulative Leakage Index

• Acquire Commercial Signal Leakage detection
  equipment.
• (Make a calibrated leak.)
• FM Radio
• Contracted Fly-Over
• or Ride-Out

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Signal Leakage Cumulative Leakage Index

• At least 75 of the oldest part of the cable
  system needs to be tested every year.
• All Signal Leaks measured at more than 20 micro/V
  per meter _at_ 3 meters (10 feet) must be repaired.
• All Signal leaks measured at greater than 50
  micro/V per meter _at_ 3 meters must be logged for
  CLI calculation.

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Calculating CLI
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Calculating CLI
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Egress

• Where does Egress come from?

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Signal Leakage EgressHow does it get out?

• A lack of proper System Maintenance.

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Signal Leakage EgressHow does it get out?

• Loose or improperly made connectors.

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Signal Leakage EgressHow does it get out?

• Cracks in the Cable Shield.
• How old is your mainline coax?
• (Coax older than 15 years is very prone to
  shield defects.)

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Signal Leakage EgressHow does it get out?

• Attempted signal theft.
• Roughly 75 of all cable signal leakage occurs
  between the Tap and the Television.

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In case youre Wondering..

• What if I dont comply?
• (aka Ill take my chances.)

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Reminder
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Q A
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Penalties
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The Bottom Line

• File it.
• (FCC Form 321)
• Find it.
• Fix it.
• Report it.
• (FCC Form 320)

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• Questions?