Presentation on theme: "Texas Gulf Coast Chapter of SCTE presents…"— Presentation transcript:
1Texas Gulf Coast Chapter of SCTE presents… “Cumulative Leakage Index”What? Why? Who? Where? When? And How?
2Listen for answers to these questions… What is CLI?Why do I need to be concerned with CLI? FCC ---who are they and why are they involved? Why keep leakage logs?What’s a microvolt? What is noise and how can it impact customers? Is there a direct correlation between CLI and other distortions?Why is the customer's home a major contributor to system problems? Why is proper cable and connector craftsmanship so important?
3What is Leakage?*Cumulative Leakage Index (CLI)CLI is the net effect of the combination of all the leaks in the system added together =the amount of radio frequency (RF) signal that escapes or infects the cable systemThese cumulative leaks form an invisible cloud of unwanted RF energy over the cable systemLeakage results from:Improper cable installationcomponent corrosionpoor product designVandalismcable breakspoor connections
4Two types of leakage: Egress and Ingress Egress= RF signal leaking out of the cable systemDamaged cableImproperly installed cableSignal escapes and follows the path of least resistance including free space (air), strand, power and phone linesIngress= RF noise or interference that leaks into the cable system through a break or external leak (loose connectors)Hair dryers, microwaves, radios, etc.Feeds into the coax drop from bad TV’s, long center conductors, amplifiers, jumpers, customer equipment (VCR)
5Ingress/Egress Ingress: RF signal leaking into the coaxial plant RF signal leaking out of the coaxial plant
6Why Is It Important to Determine Leakage? Cable television systems and licensed over-the-air broadcasters use many of the same frequencies to transmit programming. Specifically, cable systems use TV, radio and aeronautical radio channels, among others, within their cable plant.Cable operators are considered the secondary users of these frequencies; therefore they must not interfere with the licensed over-the-air users who are the protected (primary) users of these frequencies.
7What Problems Can Signal Leakage Cause? Cable signal leakage can interfere with any of the over-the-air services that happen to be using the same frequencies as the cable operator and that are within the vicinity of the cable system.Such interference, especially on the emergency channels, can interfere with the communications of safety personnel or airplane pilots.When such interference occurs, it can endanger the lives or hamper the rescue efforts of safety personnel.
8What are the FCC Rules Governing Signal Leakage? The FCC (Federal Communication Commission)has set maximum individual signal leakage levels for cable systems.The FCC sets even more stringent limits for cable systems that may interfere with aeronautical and navigation communications.As a further measure, the FCC requires cable operators to have a periodic, on-going program to inspect, locate and repair leaks on their systems. –FCC files include:CLI quarterly ride outs (100% of system & log all leaks)Annual Flyovers (report on form 320)Daily Leakage Logs (date found/date repaired)
9Can the Cable Company be penalized if it fails to control CLI? 4/17/2012Pays to keep the system clean…In this Notice of Apparent Liability for Forfeiture (NAL), we find that Cebridge Acquisition, LP (Cebridge), operator of the cable television system in Honey Grove, Texas, apparently willfully violated Sections (a)(12) and (a)(1) of the Commission’s rules (Rules), by failing to prevent excessive signal leakage in the Honey Grove cable system. We conclude that Cebridge is apparently liable for a forfeiture in the amount of eight thousand dollars ($8,000).
10Quarterly CLI Drive Out Results Unauthorized Connection %Loose F Connector %Loose Terminator %Replace Connector %No Fault Found %
11Who’s Responsible? And What can I do? It is a shared responsibility across Operations and Engineering.
12Five Steps in Leakage Abatement DetectionLocationMeasurementCorrectionRe-measurement
13Detection (What do I need?) Carrier Generator- a unique frequency inserted by the headend that can be recognized by the leakage detector tuned to the carrier’s frequencyLeakage Detector- (Seekers’, Searchers’, Sleuths’)-provided and used by all technicians to detect leaks in the free space where RF energy is encountered
14Calibrating Leakage Equipment 1.Connect calibrated signal source set at 20 uV/m.2. Position the dipole antenna.3. Adjust to read 20 uV/m.
15Identify the precise Location of the leak with your Leakage Detector
16Hand Held DetectorsCheck the battery voltage, insure the unit is charged before you proceed to isolate the leakListen to the audible alarm indicator as you proceed to isolate the leak sourceIncreases in the tone pitch indicate you are closer to the sourceDecreases in the tone pitch indicate you are moving away from the leak sourceFollow the manufacturers recommended mode to identify the leak sourceOnce the leak is identified to a pole, cable, or a home, follow standard troubleshooting procedures until the leak is within compliance
17Measurement-rules of engagement Once a leak is located it must be measuredμV/M What is a microvolt per Meter?Standard unit of measure for CLI50 Ohm off air measurementVoltage developed in 1 meter of infinitely thin section of wire submerged in a leakage field produces 1μV of energyAll leaks greater than 20 microvolt's MUST be repaired per FCC rulesAny leak greater than 50 microvolt's MUST be repaired IMMEDIATELY per FCC rules
18Measurement-rules of engagement (cont.) Only leaks above 50 μV/m are used in CLI calculationAll measurements taken outside MHz must be converted as if they were taken within the bandLeakage Detector-measures the level of the leakTake the reading at about 10 feet (3 meters)Repair itRe-measure
19Measurement-rules of engagement (cont.) Use a calibrated halfwave dipole antennaAntenna must be elevated 3 meters off the ground and positioned 3 meters from the leakage sourceAntenna must be rotated 360º in the horizontal plane for maximum reading
20Let’s Practice finding a leak Turn on your Leakage Detector!
21Measurement-Why do we care? 1. Meet FCC Compliance2. Prevent Off-Air InterferenceAeronautical & Aircraft CommunicationsAmateur CommunicationsBroadcast TV signals (Analog & Digital)Public and Emergency CommunicationsRadio Mobile Communications
22Measurement-Why do we care? 3. Improves System PerformanceReduces Repeat Service CallsLocate Physical problems
23Correction of Leak80% of all leakage is caused by problems from the tap to customer equipmentCommon Causes of Leakage-Loose drop connectorsImproperly installed connectorsInferior quality coaxial cable, passives, or connectorsPoorly-shielded drop cablesBad connectors at the tapsBad/loose port terminatorsCorroded connectors
24Correction Common Causes of Leakage-cont. Cracks in the trunk and feeder cablesAnimal chewsPhysical trauma to cables or connectorsAging and environmental stressLoose hard line connectors
25Correction Common Causes of Leakage-cont. Customer installed equipment Damaged amplifier housingsLoose amplifier housing lidsBroken tap portsPoor installation of splices and connectorsPoorly-shielded customer premise equipment
26Ingress impacts on Digital Channels Macro Blocking (Tiling)Freeze FramePicture and Sound go to blackRobotic VoiceData Packet Loss or slower speedsRepeat Service Calls
27Ingress impacts on Analog Channels Lines in pictureGhostingPay-per-view problemsInterference with two-way radio services using the same frequenciesRepeat Service Calls
28CorrectionRepair the leak- determine the root cause and use TWC procedures to implement proper restorationTighten or replace connectorsReplace cracked or damaged cableTerminate open ports with 75 ohm terminatorsCorrect customer created issues (replace splitters, self-run inferior cable)Properly terminate unauthorized connections and report theft of service to Audit/Security operations
29Audit/Security Process Insert your local process and contact information
30Re-measurementTake a final reading using the same equipment and record the corrected CLI calculation (reportable to the FCC)If the leak is still above 20 microvolt's it is NOT repaired (incomplete diagnosis-reengage)Work the issue backtracking all the cable and connectionsCorrect issue until leak is under 20 microvolt's
31CLI tips Turn on your CLI equipment and use properly Record/Repair/Re-measure your leaksTighten all connectorsUse PPC Signal Tight Connectors indoorsProperly terminate open portsDisconnect unauthorized drops and properly terminate
32Signal Tight Connectors help prevent ingress/egress
33Benefits of CLI program Reduced ingress/noise in the plant (SNR)Increased plant performance (FEC)Better CPE performance thus improved Whole House CheckReduction in Trouble Calls (TC to RGU and rework)Customer Satisfaction!
34Customer FAQ’s Be careful using the word “radiate.” (Q & A’s from the FCC website)
35FAQ’s from the customer Does a Cable Operator Need to Come into My Home to Monitor for Signal Leakage?Usually, no. Cable operators can use equipment to locate the general area of a leak. To pinpoint a leakage source for subsequent repair, however, the cable operator may request access to your home.Am I Required to Let the Cable Operator into My Home to Monitor for and Repair Signal Leakage?Homeowners have the right to deny access to their premises. If a leak cannot be repaired without access to your home, however, a cable operator can disconnect your service for denied access.
36FAQ’s from the customer (cont.) Can My Cable Operator Terminate My Service Because of Signal Leakage?The FCC’s rules allow cable operators to disconnect service in order to repair signal leakage that exceeds FCC standards. The operator restores service when the signal leakage problem is remedied, and may not charge you for service while it is disconnected.Is the Cable Operator Responsible for Repairing Signal Leakage on Subscriber-owned Equipment?No.
37FAQ’s from the customer (cont.) Can I Hook Up a Second Set Myself?In terms of the signal leakage rules, yes, but because the cable operator is responsible for leakage from the wiring, the operator can either refuse to connect to it or terminate service if the hook up causes signal leakage problems.Is Signal Leakage Biologically Harmful?The power levels used in a cable system are low. Therefore, it is unlikely that cable signal leakage from a cable facility will exceed the FCC’s RF allowable limits for RF exposure.
38Thanks for your Participation Join the SCTE Texas Gulf Coast ChapterTODAY!!!