BPR-8: Application Procedures and Rules for Broadcasting Receiving Undertakings (Cable Television)

5. Measurement Procedures

5.1 General Provisions

5.1.1 The measurement procedures described in this section are intended to serve as a guide to typical measurement procedures, and when necessary, to clarify technical standards specified in Section 4.

5.1.2 Measurement procedures based on the use of different equipment or techniques may be used to verify system compliance, provided that they are in accordance with good engineering practice.

5.2 Equivalent Leakage Density (ELD) Measurement Procedure

5.2.1 Equipment Required

1. a half-wave dipole antenna
2. a field strength meter (FSM), spectrum analyzer or receiver
3. a patrol vehicle

5.2.2 Measurement Procedure

5.2.2.1 Operate the cable television system under standard operating condition. As much as possible, this measurement should not be carried out when it rains.

5.2.2.2 Before the patrol begins, the antenna should be tuned to the visual carrier frequency of a mid-band channel, preferably channel A, B or C. If this is not feasible, channel 6 or 7 should be selected. The level of the selected carrier must be maintained at the level of the nearest video carrier.

5.2.2.3 The antenna must be installed on top of the patrol vehicle, at a height of at least one metre above the roof. The antenna elements must be oriented along the horizontal (front-to-back) axis of the vehicle to detect signals from either side of the street.

5.2.2.4 It is recommended that the field strength meter or another instrument used to detect leaks, has the following minimum characteristics:

In addition, the frequency stability of the receiver must be sufficient to make frequency readjustments during the patrol unnecessary.

5.2.2.5 The calibration and operation of the measuring equipment must be checked before each patrol.

5.2.2.6 The patrol vehicle must be driven slowly (i.e., at no more than 20 km/hour) so that low-intensity signals may be detected. When a leak is detected, the vehicle must be positioned and/or the antenna oriented in such a way as to obtain a maximum field strength reading. This value is recorded in μV/m. It must also be noted whether the leak is coming from a front- or rear-lot plant.

5.2.2.7 To take into account the distance between the antenna and the cable leak, a correction factor of 10 dB must be added to the field strength measurements of leaks originating from rear-lot cable plants.

5.2.2.8 No correction factor must be added to field measurements of leaks from front-lot cable plants. In such cases, drive the vehicle as close to the cable leak as possible, while attempting to maintain a distance of 3 metres between the antenna and the cable.

5.2.2.9 All factors influencing field strength readings, such as the antenna factor, losses in the cable linking the antenna to the field strength meter, mismatch losses and amplifier gain, if any, must be evaluated. All these corrections must be taken into account to obtain the final field strength readings and are in addition to the correction for distance discussed in Section 5.2.2.7.

5.2.2.10 For the purposes of ELD calculations, only leaks equal to or greater than 50 μV/m need to be taken into account.

5.2.2.11 The total distance in kilometres travelled by the patrol vehicle must be noted for the purposes of ELD measurements.

5.2.2.12 The ELD measurement patrol must cover at least 25% of the entire cable system. The following patrol strategy has been designed to ensure that the measurement procedure is reliable:

• Identify the various cable system sectors on a map of the cable system. These sectors may be identified as the oldest sectors in the system, newer sectors, underground distribution sectors, aerial distribution sectors, etc.
• Each sector identified in this way must then be subdivided into smaller zones, in accordance with the natural divisions of the city, such as main streets, residential areas, etc.
• Next, samples from a certain number of zones in each sector must be taken. The sample area must represent at least 25% of the total surface area of a given sector so as to provide an acceptable representative reading of the leakage in that sector.
• Each sample area selected must be patrolled completely (i.e. every street where single and/or multiple cables are installed must be covered).
• When the sample surface areas patrolled in each zone are added together, the total patrolled surface area must equal at least 25% of the total service area of the cable television system.

5.2.2.13 If the patrol strategy detailed in Section 5.2.2.12 is not used, at least 75% of the system's total surface area must be patrolled.

5.2.2.14 As much as possible, the time period for completion of the ELD measurement should not exceed four consecutive weeks to ensure accuracy.

5.2.2.15 Field readings and the distance patrolled should then be used to calculate the equivalent leakage density according to the formula described in Section 4.3.

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5.3 CLI Ground-Based Criterion (CLI_g) Measurement Procedure

5.3.1 Equipment Required

1. a half-wave dipole antenna
2. a field strength meter (FSM), spectrum analyzer or receiver
3. a patrol vehicle

5.3.2 Measurement Procedure

5.3.2.1 Operate the cable television system under standard operating conditions. As much as possible, this measurement should not be carried out when it rains.

5.3.2.2 Before the patrol begins, the antenna should be tuned to the visual carrier frequency of a mid-band channel, preferably channel A, B or C. If this is not feasible, channel 6 or 7 should be selected. The level of the selected carrier must be maintained at the level of the nearest video carrier.

5.3.2.3 The antenna must be installed on top of the patrol vehicle, at a height of at least one metre from the roof. The antenna elements must be oriented along the horizontal (front-to-back) axis of the vehicle to detect signals from either side of the street.

5.3.2.4 It is recommended that the field strength meter or another instrument used to detect leaks, has the following minimum characteristics:

In addition, the frequency stability of the receiver must be sufficient to make frequency readjustments during the patrol unnecessary.

5.3.2.5 The calibration and operation of the measuring equipment must be checked before each patrol.

5.3.2.6 The patrol vehicle must be driven slowly (i.e. at no more than 20 km/hr) so that low-intensity signals may be detected. When a leak is detected, the vehicle must be positioned and/or the antenna oriented in such a way as to obtain a maximum field strength reading. This value is recorded in μV/m. It must also be noted whether the leak is coming from a front- or rear-lot plant.

5.3.2.7 To take into account the distance between the antenna and the cable leak, a correction factor of 10 dB must be added to the field strength measurements of leaks originating from rear-lot cable plants.

5.3.2.8 No correction factor must be added to the field measurements of leaks originating from front-lot cable plants. In such cases, drive the vehicle as close to the cable leak as possible, while attempting to maintain a distance of 3 metres between the antenna and the cable.

5.3.2.9 All factors influencing field strength readings, such as the antenna factor, losses in the cable linking the antenna to the field strength meter, mismatch losses and amplifier gain, if any, must be evaluated. All these corrections must be taken into account to obtain the final field strength readings and are in addition to the distance correction described in Section 5.3.2.7.

5.3.2.10 Very large leaks (>500 μV/m) must be measured carefully, since they can greatly influence the CLI_g. However, for the purposes of CLI_g calculations, only leaks equal to or greater than 50 μV/m need to be taken into account.

5.3.2.11 The dimensions of the cable television system, in square kilometres (km²), must be obtained in order to calculate the CLI_g. The system dimensions correspond to the geographical surface area covered by the system. This surface may be measured using a geographical map, drawn to scale, showing the boundaries of the cable system service area.

5.3.2.12 Non-served areas such as city parks and industrial parks (i.e. completely surrounded by the service area and representing only a small fraction of the overall cable system area) are usually included in the surface calculation and considered to be leak-free areas for patrol purposes.

5.3.2.13 Areas demarcated by long rural branches - for example, a cable serving a rural route - are usually included in the surface calculation. A standard width of one kilometre should be used when the width of the trunk or branch is too narrow to be measured on the map.

5.3.2.14 The CLI_g measurement patrol should cover at least 25% of the surface area of the cable system situated within the area covered by the broadcasting certificate. The following patrol strategy has been defined to ensure that the measurement procedure is reliable:

• Identify the various cable system sectors on a map of the cable system. These sectors may be identified as the oldest sectors in the system, newer sectors, underground distribution sectors, aerial distribution sectors, etc.
• Each sector identified in this way must then be subdivided into smaller zones, in accordance with the natural divisions of the city, such as main streets, residential areas, etc.
• Next, samples from a certain number of zones in each sector must be taken. The sample area must represent at least 25% of the total surface of a given sector so as to provide an acceptable representative reading of the leakage in that sector.
• Each sample area selected must be patrolled completely (i.e. every street where single and/or multiple cables are installed must be covered).
• When the sample areas patrolled in each zone are added together, the total surface patrolled must equal at least 25% of the total service area of the cable television system.

5.3.2.15 If the patrol strategy detailed in Section 5.3.2.14 is not employed, at least 75% of the system's total surface must be patrolled.

5.3.2.16 To ensure accuracy, the time period for completion of the CLI, measurement should not exceed four consecutive weeks, whenever practicable.

5.3.2.17 The field readings and the surface of all the areas considered and patrolled are then used to calculate the CLI_g, according to the formula described in Section 4.4.

5.3.2.18 If the CLI_g is close to the limit of 64, it will be necessary to increase the surface patrolled until the definitive CLI_g can be positively confirmed (i.e. until it is established that the CLI_g is indeed above or below 64).

5.3.2.19 There may be cases where the CLI_g for a given system is extreme (i.e. either very high or very low). In such cases, it may not be necessary to complete a patrol of 25% of the cable system surface to determine that the CLI_g is definitely above or below the limit of 64.

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5.4 CLI Air-Based Criterion (CLI_a) Measurement Procedure

5.4.1 Equipment Required

Direct airborne measurement of the strength of the electromagnetic field present above a cable system requires the use of a measurement system especially designed for this purpose. The following list is generic and applies to any measurement system capable of direct field measurement from the air:

1. a signal generator
2. a receiver connected to a portable computer
3. an antenna system
4. a ground navigation system
5. an aircraft

5.4.2 Measurement Procedure

5.4.2.1 The purpose of airborne measurement is to obtain the 90^th percentile value of the field strength at 450 metres (1,500 feet) above a cable system. To take these readings, operators must install equipment designed and calibrated for this purpose, on board an aircraft equipped with a suitable antenna. The aircraft must fly a grid pattern over the cable system in question. The equipment on board the aircraft must be able to detect and measure the electromagnetic field produced by a carrier introduced into the system being tested.

5.4.2.2 Operate the cable television system under standard operating conditions.

5.4.2.3 Select a carrier to be introduced into the cable system for aerial detection purposes. It is recommended that a carrier in the 108-137 MHz band be used, since this range of frequencies belongs to the aeronautical band. The operator should be careful not to select a frequency that is negatively trapped anywhere in the system or that is used as a pilot in a microwave link.

5.4.2.4 The operator must obtain a special short-term licence issued by Industry Canada before being permitted to introduce a carrier within the 108-137 MHz band.

5.4.2.5 It should be noted that these frequencies, 108-137 MHz, are commonly utilized aeronautical frequencies. When they are used to measure the airborne field above cable systems, interference from signals transmitted by aircraft or control towers may occur occasionally. In such cases, it may be necessary to offset the carrier frequency introduced for airborne measurements. This offset is acceptable if it remains within the calibrated bandwidth of the airborne measurement equipment and antenna. It must be pointed out that when authorization to use a carrier frequency within the 108-137 MHz frequency band is requested, any offset that may be necessary to carry out the airborne measurements must be mentioned in the application to the Department.

5.4.2.6 The introduced carrier must remain unmodulated and be maintained at the RMS peak power level of the highest carrier transmitted over the system being tested.

5.4.2.7 The antenna should be tuned to the selected measurement frequency, and must be horizontally polarized, parallel to the body of the aircraft. In addition, the antenna's performance should not be hindered by its installation on the body of the aircraft or its connection to the measuring equipment. To accomplish this, the antenna must be mounted as far as possible from any large metallic sections of the aircraft and must have an unobstructed line of sight to the ground. The antenna must be able to resist mechanical stress caused by its being mounted on the outside of the aircraft, without its performance being compromised.

5.4.2.8 It should be noted that any structural modification to the exterior of an aircraft, such as the installation of an antenna, requires a certificate of airworthiness issued by Transport Canada. In addition, the installation must be carried out by a certified aeronautical engineer.

5.4.2.9 The antenna and receiving system should be calibrated at regular intervals. The calibration procedure should be done by measuring, at an altitude of 450 metres, a 10 μV/m field transmitted by a ground-based antenna system.

5.4.2.10 It is recommended that the receiving system be able to detect signals of less than -100 dBm to ensure that the field readings are accurate.

5.4.2.11 Because of the specific nature of airborne measurements, the instruments used to carry them out often have their own special characteristics. Therefore, it may be necessary for applicants to prove to Industry Canada that their airborne measuring equipment is able to accurately detect and measure airborne field strength above cable systems. The Department will be able to make this type of assessment if it is provided with as much detail as possible on the characteristics of the equipment (i.e. input bandwidth, frequency tuning, selectivity, sensitivity, rejection, overload protection, input noise, gain, dynamic range, mechanical and temperature stability, and calibration method).

5.4.2.12 The aircraft flight speed and the sampling rate of the data collection instrument must be adjusted so that, on average, at least one valid reading is taken for every 100 metres or less of air travel.

5.4.2.13 Any suitable method may be used to record and present readings, provided that the data for each flight path are made available.

5.4.2.14 The aircraft must fly at an altitude of 450 or 900 metres. A correction factor of 1 dB must be added to data when readings are taken at 900 metres.

5.4.2.15 The aircraft must fly a grid pattern over the system being tested. The grid legs should be spaced approximately one kilometre apart and must not exceed 1.5 kilometres at an altitude of 450 or 900 metres.

5.4.2.16 The operator must be sure to clearly identify the cable system boundaries to avoid gathering data outside the service area.

5.4.2.17 All data gathered from outside the system boundaries must be eliminated before the 90th  percentile of the field strength is calculated.

5.4.2.18 For purposes of this measurement, the exterior boundaries of the service area are defined as being located at approximately 500 metres beyond the end of the trunk or distribution network at the periphery of the service area.

5.4.2.19 For long in-line trunk networks feeding outlying areas with little or no service along the path of the trunk, the system boundaries are set at no more than 500 metres on either side of the trunk in question.

5.4.2.20 The report must contain the following information:

• the 90th percentile value of the field strength measured at 450 metres (or corrected for that altitude) above average ground level of the cable system being tested;
• the date(s) on which the tests began and ended;
• the weather conditions during the tests;
• the test frequency used for the airborne measurements;
• the altitude at which the readings were taken;
• the grid spacing;
• a description of the measurement procedure;
• the date of the most recent calibration of the antenna and receiver system, a description of the calibration method employed, and the results obtained;
• the name, address and telephone number of the person(s)/company performing the airborne measurement and of those who had them taken.

5.4.2.21 If a new instrument or an existing instrument that has undergone significant modification is used for the airborne measurement, the report must also contain the following information:

• a description of the antenna system and the measurement equipment;
• the characteristics and technical specifications of the receiver, the measuring instrument and the antenna;
• a description of the data collection, correction and recording methods.

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5.5 Carrier-to-Noise Ratio Measurement Procedure

5.5.1 Equipment Required

The equipment required for the carrier-to-noise ratio measurement procedure is a spectrum analyzer.

5.5.2 Measurement Procedure

5.5.2.1 Operate the cable system under standard system operating conditions.

5.5.2.2 Tune the spectrum analyzer to the particular channel being tested and adjust the controls to set the carrier peak to the top graticule line.

5.5.2.3 Adequate sweep time, IF and video bandwidths must be chosen to ensure that the peak level has been obtained.

5.5.2.4 Measure and record the carrier level.

5.5.2.5 Choose a region of the spectrum located near the carrier and free from discrete signals, such as other carriers, intermodulation products and spurious and distortion products, and tune the spectrum analyzer to this area of the spectrum.

5.5.2.6 Measure the absolute noise level.

5.5.2.7 Make any necessary corrections to the reading obtained in Section 5.5.2.4, including the 4 MHz bandwidth correction, and calculate the carrier-to-noise ratio.

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6. Applications

6.1 General Provisions

This section contains information on departmental requirements and procedures that operators must follow when submitting applications for broadcasting certificates.

6.2 Provincial and Federal Laws and Regulations

6.2.1 It is the responsibility of the individual or firm in question to comply, insofar as engineering practices are concerned, with applicable legislation, as well as any other regulations and laws in force.

6.3 Licensing Requirements for Microwave Facilities

Applicants intending to use microwave facilities for signal reception must submit a radio licence application for these services to Industry Canada, in accordance with established procedures.

6.4 Applications for New Systems

6.4.1 To obtain a broadcasting certificate for a new broadcasting receiving undertaking, applicants must complete and submit the form IC-2363BE, Application for a Cable System (New or Modified). All forms can be found on the Spectrum Management and Telecommunications website at http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/h_sf01700.html.

6.4.2 Applicants for new systems must also comply with all applicable requirements and procedures described in Sections 6.7 to 6.9.

6.5 Application for a Change of Facilities or of Ownership

For change of facilities, the operator must complete and submit the form IC-2363BE to the Department for the introduction or addition of channels and signals in the 108-137 MHz and 328.6-335.4 MHz bands for distribution to existing or new service areas.

For change of ownership, the operator must send a letter to Industry Canada indicating that the ownership of the cable system has changed and give the name, address and telephone number of the new owner.

6.6 Submission of Applications

The operator must send the applications and supporting documentation to the appropriate regional office (see Appendix C).

6.7 Additional Information on the Introduction or Addition of Signals in the Aeronautical Bands

6.7.1 All Channels within the Aeronautical Bands

In addition to the requirements of Section 6.5 above, the application must include detailed information on the frequencies, maximum power levels and types of signals to be used. This will enable the Department to assign carrier offsets where necessary.

6.7.2 Aeronautical Channels A-1, A-2, EE and FF Only

6.7.2.1 In addition to the requirements of Section 6.7.1, the applicant must comply with a qualification procedure. To that end, the applicant must complete a leakage patrol and submit to the Department, along with the application, a detailed report as described in Section 3.10.1. The patrol must be executed according to the procedures set out in Section 5 of this document.

6.7.2.2 The Department will evaluate the applicant's detailed report and any relevant data already on file to determine if the qualification tests are required. If the evaluation suggests that the cable system leakage performance and maintenance practices are not satisfactory, the application processing will stop. The application processing will resume only after the applicant performs needed repairs, repeats the leakage patrol and submits the results to the Department, along with the necessary new information.

6.7.2.3 In addition to the requirements in Section 6.7.2.1 above, the qualification procedure includes the submission of a supplementary report every two years as described in Section 3.10.4. Also, if deemed necessary, Industry Canada may conduct a leakage patrol of its own. This patrol will be performed in accordance with Section 5 of this document. To facilitate the planning of the Department's leakage patrol, the applicant will include, in his application, urban maps of the cable system with clearly marked system boundaries, the aerial and underground cable sectors as well as the most accurate estimate of the cable plant in kilometres.

6.8 Antenna Structures

6.8.1 Structural Adequacy of Antenna Towers and Antenna Supporting Structures

To ensure structural adequacy, the Department recommends that all antenna towers and antenna-supporting structures be designed, manufactured and erected in accordance with accepted Canadian standards and that a qualified structural engineer be retained by the applicant.

6.8.2 Land-Use and Public Consultations, Environmental Assessment and Transport/NAV CANADA Safety-Related Issues

Refer to Section 3.1.1 above and to CPC-2-0-03 for the requirements regarding these issues.

6.9 Inspections and Investigations

If needed, Industry Canada may perform an inspection in which the Department will pay particular attention to leakage and the use of aeronautical frequencies. If the inspection reveals that the operating conditions are no longer met, the Department will require the system operator to take corrective action and submit a report, including measurements if required, to prove that the faults have been corrected.

In order to carry out its investigations and periodic inspections, the Department may require the system operator to supply an up-to-date map of the cable system service area.