Technical Training Seminar on “Egress & Ingress Testing and Troubleshooting” for CCTA Member Companies August 25, 26 and 27, 2009 San Juan, Puerto.

Technical Training Seminar on “Egress & Ingress Testing and Troubleshooting” for CCTA Member Companies August 25, 26 and 27, 2009 San Juan, Puerto Rico Mario Sebastiani Tony Holmes

Seminar Summary How the Egress and Ingress of unwanted signals in the forward and reverse plant behave How they effect picture, data and voice quality What to look for and how to fix it

Technical Training Outline
Egress terminology What is egress Why do we test for egress What causes egress Egress characteristics Locating source of egress Signal Egress/Leakage Automation The specific chapters of this seminar are Leakage terminology - I will go over various terms commonly used with regard to signal leakage What is leakage - I will define leakage and try to create a mental picture of signal leakage Why do we monitor for leakage - I will discuss the 4 basic reasons for monitoring leakage What causes leakage - I will mention some of the common and unusual causes of leakage Leakage characteristics - I will explain why leakage acts the way it does

Egress Terminology Leakage Radiation (Never Say!!!) µV/M Squelch
Calibration Tagging (CT-2 or CT-3) Egress - Older term used among RF engineers - Term still used in other industries Radiation - Original CATV term - Not advisable term around customers Leakage - Fairly recent term which best describes the nature of the problem Ingress - Opposite of leakage - Signal leaking “into” the cable system uV/M - Microvolts per meter -.Preferred unit of measure by the FCC - Leakage measurements are in the same units of measure as radio transmission Squelch - Adjustment to leakage detector determining the leakage amplitude necessary to set off audible alarm of a leakage detector Calibration - Adjustment to leakage detector to assure accurate level reading of leakage

What is Egress/Leakage?
Definition: Undesired emission of signals out of HFC networks Egress is generally referred to as signal leakage What is signal leakage? The undesired emission of signal out of an HFC network. We monitor a specific frequency for signal leakage However: 1.) If you leak one you are leaking all frequencies 2.) All frequencies do not leak at the same amplitude. 3.) Leaks become worse over time. 4.) Leakage is evasive, measurements taken at the same location at different times do not always produce the same readings. We will discuss how leakage can be: Dangerous - to aero-navigational users Disruptive - to off-air broadcasters Destructive - to the physical condition of the plant if left unrepaired

Egress & Ingress Egress Ingress
RF signal leaking out of the coaxial environment Ingress RF or electrical energy that enters the coaxial environment

Why do we test for leakage?
Why do we monitor for leakage? 4 Primary reasons

Reason #1 to Test for Leakage
Meet FCC Compliance

Spectrum Chart 108MHz 137MHz Aircraft Radio & Navigation CH 98 CH 99
Off-air Cable Broadband communication networks are designed to be closed system networks. Since Signals in these networks are theoretically “contained” and not exposed to the “off-air” environment, all frequencies then become available for the network operators’ use. The problem arises when signals leak out of these networks and interfere with off-air users of the same frequencies. TV Aircraft Land mobile Government communications

Cumulative Leakage Index (CLI)
CLI is the net effect of the combination of all the leaks in the system added together These cumulative leaks form an invisible cloud of unwanted RF energy over the cable system Compliance = 64 or less

CLI Quarterly Rules Ride out 100% of system and log all leaks
Log should include Date found and Date fixed Documenting leakage levels isn’t required for this drive out Actual practice for your system may vary!

CLI Annual Rules Ride out 75% of the oldest part of the system and log all leaks location and measured level Must be performed within a reasonable period of time Usually within 2 wks of due date

Required Actions All leaks 20µV/m must be logged and fixed
Only leaks above 50 μV/m are used in CLI calculation All measurements taken outside MHz must be converted as if they were taken within the band

μV/M Standard unit of measure for CLI 50 Ohm off air measurement
Voltage developed in 1 meter of infinitely thin section of wire submerged in a leakage field produces 1µV of energy

Acceptable Procedures for Leakage Measurement
Use a calibrated halfwave dipole antenna Antenna must be elevated 3 meters off the ground and positioned 3 meters from the leakage source Antenna must be rotated 360º in the horizontal plane for maximum reading CLI Fly-over

Prevent Off-Air Interference

Off-Air Interference Aeronautical & Aircraft Communications
Amateur Communications Broadcast TV signals (Analog & Digital) Public and Emergency Communications Radio Mobile Communications

Off-Air Spectrum (forward path)
300 400 500 900 700 800 Frequency in MHz Source: NTIA

Improves System Performance Reduces Repeat Service Calls Locate Physical problems

Common Causes 70% of all leakage is caused by problems between the tap and entry to the house Aging and environmental stress Physical trauma to cables or connectors Loose drop connectors Inferior quality coaxial cable, passives, or connectors Loose hard line connectors Common causes: - cracks in cable - corroded or loose connectors - loose device enclosures

Other Causes of Leakage
Improperly installed connectors Cracks in the trunk and feeder cables Animal chews Poorly-shielded drop cables Bad connectors at the taps Bad/loose port terminators Corroded connectors Unusual causes: - squirrel chewing on hardline coax - dog chewing RG coax - puncture in coax at midspan locations clamps without the use of spacers tree branch rubbing or falling on cable projectiles - gunshots, arrows, pellets, etc. vandalism - customer caused leakage use of antenna on A/B switch illegal outlets using inferior materials tampering with settop box

Other Causes Continued
Customer installed equipment Damaged amplifier housings Loose amplifier housing lids Broken tap ports Poor installation of splices and connectors Poorly-shielded customer premise equipment

Polarization Angle Dipole
Monopole Dipole Leakage signals are normally at their highest amplitude in the horizontal plane. This is probably due to the fact that most of the cable plant is in a horizontal position. The FCC requires the use of a horizontal dipole antenna to make CLI compliance measurements. This would be to optimize the leakage signal reading by matching the polarization plane. However, it is required to rotate the dipole antenna to match the polarization angle for peak amplitude readings. For “Find and Fix” maintenance purposes, a vertical whip antenna is preferred because of its omni-directional properties vs. the directional properties of a dipole. Peaking a dipole antenna on a moving vehicle would be impractical. With a handheld leakage detector, you would be rotating the “rubber duck” antenna from a vertical to horizontal plane, looking to maximize the peak amplitude reading and determine the direction and ultimately the location of a leak.

Leakage Antennas-Whip

Leakage Antennas-Dipole

Signal phasing Radiated signals can: 1.) Reflect off surfaces
` 2.) Travel on conductive surfaces 3.) Occur from more than one nearby location These “Multipath” signals arrive at the leakage receiver at different times but at the same frequency. These multipath signals can combine inside the leakage receiver and cause a time relationship problem which may add to or cancel from the signal amplitude reading, depending on the phase relationship. Being aware of potential multipath conditions is the only thing a technician can do. Awareness of such condition would encourage the technician make extra effort in properly peaking the antenna.

Standing Waves As stated before, leakage signals can travel down a conductive path to ground. In most cases this conductive path will be the strand wire or the coaxial sheath. The technician should continue monitoring a leak until a peak reading is made.

Electrical Noise Electrical noise is an interesting annoyance to the leakage technician. In most cases, electrical noise is caused by “spark gap energy” at power line insulators. This energy can manifest itself as RF! This spark gap energy (RF) may reach the leakage frequency range and cause a buzzing noise on the audio circuit of a leakage detector. Channel tagging usually eliminates this problem.

Leakage Field Strength
Amp Lowest Potential Consider an amplifier the transmitter.... Consider leakage points along the cable as antennas.... Result: The antennas closest to the transmitter have the highest potential for power. Leakage amplitude is determined by: - the available signal level in the coax at the point of leakage. - the severity of the physical condition causing the leak. Highest Potential

Distance Correction Reading x Distance (meters)
= Corrected Reading 3 Why would you want to know the leakage level from a 10 foot distance? The FCC states: Leaks greater than 20uV/m at 10 feet shall be logged and then repaired within a reasonable period of time. Note the measurement reference is at a 10 foot distance from the plant. This distance correction formula will aid in determining the repair priority of a leak. At this point it would be well to note that many operating companies commonly have more stringent requirements than the FCC.

Patrolling for Leakage
3 meters 20µVm 30 meters Pinpointing sources of leakage can at times seem to be more of an art than a science. Patrolling the system: The first indication of leakage will be very short tone pulses from the leakage receiver. These will be followed by longer pulses eventually changing to a continuous tone if the leakage is strong enough. Relying solely on the audio indication, drive the vehicle until the tone starts to decay. Mentally mark the peak tone indication and return to that area for further investigation. Note: best result at at patrolling speeds of under 25 MPH. Apply distance correction formula: This will help determine the priority of the leakage repair. 2 μVm

Walking Out a Leakage Area
Walking the area: Use the rubber duck antenna or near-field probe to find the exact source of the leakage. The near-field probe is especially useful in congested mechanical areas, such as multi-connector housings and MDU locations. If the leakage amplitude is greater than the threshold setting on the leakage detector, an audible tone will sound from the detector. Listen for the audible pitch of the leakage detector to rise from the increasing signal amplitude as you get closer to the leakage source. Optional: In areas where it is difficult to determine the direction of a leak, the technician can use a dipole antenna to triangulate the leakage source. If necessary, use the near-field probe to literally touch suspected points of leakage. When many connectors are within close proximity of each other, using the near-field probe will help determine which connector(s) is the cause of leakage. 5 – 10 meters

Leakage Detection Tools

Seeker Lite Frequency Agile Leakage Detector
Built-in directional Antenna

How to Automate the Signal Leakage Process

Seeker GPS System LAW Client Serial GPS Rx Bluetooth GPS Rx Seeker LAW
The Seeker GPS System expands the Seeker into full GPS and map-based leakage management system, covering all activities from leak discovery to resolution, from data collection to map graphics, reports and analysis. When the MCA is communicating to the GPS receiver the blue LED will blink approx twice per second if not it blinks once per second. Connecting MCA to Seeker Setup: 1. Load Seeker Setup software then install USB drivers 2. Connect the MCA via the mini- USB to USB cable to PC. First, get Setup from MCA then Search for Devices then Send Setup to MCA LAW Server MCA BB-2

Seeker GPS Data Storage GPS Equipped WiFi Upload Capable MapQuest Mapping Server Based

Driving Preparation GPS
This icon is shown when the Seeker is placed in the mobile mount and a GPS connection is established with the MCA. When the icon is not shown, the Seeker is not in the mobile mount or the GPS connection cannot be established with the MCA. If the icon blinks the MCA is connected to the GPS but the GPS does not have a good position fix

Records uploaded to client
Seeker Data Paths Leak Readings From GPS Records Other Applications WIFI Port 24007 Records uploaded to client Law Server Port 80 Third Party Software

Work Order Distribution
As leaks are uncovered, work orders will be assigned to technicians assigned to a specific leakage territory or to the supervisor responsible for the area Work order sent to designated person via Techs can act on a leak reported via , take the appropriate pre- and post-fix snapshots, upload the data in the usual manner and the work orders will then close themselves out as the leaks are repaired Even the assignment of work orders can be automated. In this mode of operation, as leaks are uncovered, work orders will be assigned either to technicians who are designated in the application as responsible for a specific leakage territory, or perhaps to the supervisor responsible for the area. The designated person will be sent the work order via . In this way, technicians can act on a leak reported via , take the appropriate pre- and post-fix snapshots, upload the data in the usual automated manner and the work orders will then close themselves out as the leaks are repaired. In the fully automated method of working, the only supervisor intervention required will be for the FCC filing requirement.

LAW Map Versatile Map Interface Sort-able Leak List
The LAW map works like most familiar Internet map web sites, in that the user can click and drag to move the map within the window, double click to center, mouse over pinpoints to bring up further data, and click the pinpoint to get complete details. The data list below the map can be sorted by any of the columns, and the supervisor can check mark specific leaks by clicking on the associated box, and then create a work order by clicking the “Create Work Order” button. (The plant manager can sort the detected/mapped leaks by field strength in an associated table on the map page, and assign work orders logistically. ) Simple Work Order Generation

Aerial Image The ability to switch to a hybrid aerial image and map gives some insight into the physical features of the location, helping the tech to be more prepared for the work, and possibly speeding the leak repair.

Work Order Distribution
Even the assignment of work orders can be automated. In this mode of operation, as leaks are uncovered, work orders will be assigned either to technicians who are designated in the application as responsible for a specific leakage territory, or perhaps to the supervisor responsible for the area. The designated person will be sent the work order via . In this way, technicians can act on a leak reported via , take the appropriate pre- and post-fix snapshots, upload the data in the usual automated manner and the work orders will then close themselves out as the leaks are repaired. In the fully automated method of working, the only supervisor intervention required will be for the FCC filing requirement.

Pre and Post-Fix Measurements
Snapshot Mode Use the Seeker’s Snapshot button to access the snapshot mode In the less automated part of the process (that dictated by the FCC procedure) the leakage tech makes a peak measurement of the leak with a dipole antenna (10 feet from the leak and 10 feet from the ground). The meter’s “snapshot” button makes capturing the peak level simple. The pre-fix measurement snapshot is automatically logged and recorded in the database when the stored measurement data is uploaded. The post-fix measurement snapshot automatically closes out the work order and eliminates that leakage flag (push pin) from the map. Through this process the leakage map in LAW has become a virtual real-time representation of the leakage condition of the cable plant.

Demonstration Egress/Leakage

Reason #4 to improve system quality
Eliminates forward and return Ingress Prepares network for triple play deployments To increase plant performance and reliability

Ingress There is a direct relationship between Leakage and Ingress
If signals can leak out of your system, off-air signals can leak into your system. The degree of ingress is determined by Signal leakage amplitude vs Off-air signal amplitude.

Ingress on Analog Channels
Lines in picture Ghosting Pay-per-view problems High speed data problems Interference with two-way radio services using the same frequencies Repeat Service Calls Interference to a customer’s analog pictures can be identified as: Ghosting or black vertical bars in the TV picture. This occurs when the same program on the same channel is ingressing into the cable or TV set. “S” shaped or diagonal lines in the TV picture. This occurs when a different program on the same channel is ingressing into the cable or TV set. Intermittent lines in the picture and possibly audio buzz. Possible causes are: - CB radio effecting channel 5 - Local pager services effecting channels 19 & 20 - Ham radio effecting 5-40 MHz return band and MHz band

Ingress on Digital Channels
Macro Blocking (Tiling) Freeze Frame Picture and Sound go to black Robotic Voice Data Packet Loss or slower speeds Repeat Service Calls Interference to a customer’s digital pictures can be identified as: Mosaic - This happens when ingress has created marginal Bit Error causing the loss of a packet(s) of video compression data Freeze frame - This happens when ingress has created significant Bit Error causing the loss of an entire refresh frame Loss of picture and sound to black - This happens when ingress is severe enough to completely destroy a data stream into unusable garbage.

Increased implementation of services requiring return path activation
If a system has egress it will most likely have ingress Ingress brings the viability of two-way services into question VoIP demands higher network reliability 4 98 98

Forward and Return Ingress Troubleshooting Tools

QAM EVS Troubleshooting in-channel ingress is easy with the QAM EVS mode Typical ingress areas Loose connector Tap plate loose Home wiring Sometimes CSO/CTB from an over driven amplifier The Trilithic 860DSPi has a unique feature that allows the user to see ingress or other interference under a 64- or 256-QAM digitally modulated signal without turning the carrier off. The meter mathematically removes the haystack from the display, allowing the noise floor under the signal to be seen. In this example, the QAM analyzer’s ‘Peak’ marker is auto placed on a beat -30.1dB 0.251MHz above the digitally modulated signal’s center frequency. Troubleshooting in-channel ingress is easy with the QAM EVS mode Typical problems: Ingress from of air UHF channels caused by: Loose connectors, Tap plates loose, Home wiring Example: In-channel carrier-to-interference ratio of -30.1dB MHz above center frequency

Constellation Good MER Poor MER Constellation screen
The constellation screen gives a visual indication of how far the noise is moving the signal from its ideal locations on the constellation. Problems: Low signal level High noise floor Good MER Poor MER

BER Digital signals work well until very close to the point of failure
Measurement of digital carriers critical to determine the system margin Signal level MER BER The BER Mode helps to find problems Digital signals work well until very close to the point of failure Measurement of digital carriers critical to determine the system margin Signal level MER BER The BER Mode helps to find problems

Demonstration Interferences from VHF/UHF sources

Return Path Ingress Troubleshooting Techniques

Ingress Funnelling Effect
Bi-directional system return path funnelling effect

Radio Communications and Transient Noise
Impairments Radio Communications and Transient Noise

Off-Air Spectrum (return path)
3MHz 9MHz 10MHz 30MHz 40MHz Source: NTIA

Ingress Mitigation Test
This is a test where you can quickly check the drop and home wiring for ingress Set Ref level so as to not over-load the meter Detector set for averaging RBW at 300 KHz 10 db/div Spectrum MHz Use peak hold Set up the Analyzer so you see what you want to see, ingress. The reference level is set dependant on where the tech is located in the network (ground block, tap seizer screw, amp, etc…). What you don’t want is to set this ref level to low and over-load the front end of the meter which can cause spurious beats that don’t exist. Detector setting on averaging so you can control the amount of averages (“digital snap-shots”) during the sweep scan. Resolution Bandwidth setting at 300 KHz because this is what most spectrum analyzers have. If your fortunate to have a meter that you can adjust the RBW then try setting it lower like 100 KHz this will help with smoothing out the noise that you know is supposed to be there. 10 db/per division so you can see as much as possible at first. Spectrum bandwidth so you can see all of the return, plus the FM band. We (being the MSO) used to provide FM off-air signals across our network. There by a customer could connect his FM receiver up to the plant and receive quality FM signals to his stereo equipment. We long since abandoned this service (DMX is so much better!) but some customers still have their FM tuners still connected to the home wiring. So being able to “look” at the FM band we can quickly see unwanted signals. Use of the peak hold function will aid in seeing bursty and intermittent carriers that are there one second and gone the next.

What you should see is NOTHING! Just the noise floor

Look for ingress by using the “Peak Hold” function Identify the problem by working back towards the house Starting at the tap connect the drop to your meter and watch for ingress. If you see some work back towards the home and through the process of elimination you can dial in on the ingress and where it’s originating at.

Using the I-Stop Probe Press the button on the side of the probe
If the ingress decreases by 4-6 dB when the button is depressed, the source of the ingress is farther from the node than you are Ingress that doesn't decrease is entering the system nearer to the node than you are. The I-Stop Probe has little or no visible effect on forward path signals.

Preparing for Return Path Monitoring

Network Topology 9581 SST Return Path Analyzer Viewer II Clients
Viewer II Server SST 9581 R4s TCP 24007 Live Spectrum UDP 162 SNMP Traps TCP 80 and/or 443 Viewer II Services SST Data UDP 161 SNMP UDP 24008 Multicast on Network Topology 9581 SST Return Path Analyzer

Monitoring Thresholds
Alarm threshold information is stored in the 9581 SST Five degrees of severity For Ingress levels Critical to Warning For Outages No Signal Warning Persistence Settings Authenticate alarm conditions Traffic Curve Identifies the frequency and amplitude of carrier

Viewer II User Interface
Components Status Tree Incident Log Alarm History Node Reporting Spectrum Display ADIA Web View

Node Status Tree Geography Services Groups nodes by City Headend
Hubsite Services CMTS Blade

Incident Log Displays Current Node Alarm Events based on
SNMP Traps received by the Guardian II Server Traps Originate in the 9581 SST based on Alarm Threshold Violations Persistence Settings Displayed information is based on Status Tree Configuration, but typically includes Node ID Severity Elapsed Time Total Alarm Time

Alarm Management Prioritize Alarm Information Sorting Tools
Organize alarm information into logical groupings for managing service interruptions

Alarm Troubleshooting
To investigate alarm conditions NOC operators can click on alarm events in the incident log Brings up Spectrum view with Alarm threshold and ingress signature that caused the alarm event Allows operator to correlate alarm data from other monitoring sources Evaluate the effect of ingress on system services

Reporting Node Service Report
Returns Alarm Activity over user specified time periods and locations Provides correlation of service interruptions and return path ingress events Identifies and prioritizes nodes in need of maintenance Selection Criteria Alarm severity Number of nodes per location

Node Service Report Summary View Includes selection criteria
Lists nodes meeting selection criteria Grouped by location Number of nodes per location or top X nodes Number of alarm events per location

Spectrum Display View Max/Min/Avg ingress spectra over reporting period Pass/Fail Threshold Pass/Fail Tolerance Ratio (dB) between threshold & ingress spectra

ADIA Web View Real time access to headend ingress levels
Max/Min/Avg Traces Markers with Frequency Amplitude Delta

Demonstration Impairments from : Digital TV Transmitters
Return Path Ingress

Response to Your Question!!!! s
Now let me address the questions that were sent… 78

Thank you-Gracias-Merci-Masha danki…
Trilithic Applications Engineering Tel: Incospec Communications Inc. Your Value Adder Trilithic Re-Seller for the Caribbean Mario Sebastiani Bernard How

Technical Training Seminar on “Egress & Ingress Testing and Troubleshooting” for CCTA Member Companies August 25, 26 and 27, 2009 San Juan, Puerto.

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Technical Training Seminar on “Egress & Ingress Testing and Troubleshooting” for CCTA Member Companies August 25, 26 and 27, 2009 San Juan, Puerto.

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Presentation on theme: "Technical Training Seminar on “Egress & Ingress Testing and Troubleshooting” for CCTA Member Companies August 25, 26 and 27, 2009 San Juan, Puerto."— Presentation transcript:

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