Agreement Between the Government of Canada and the Government of the United States of America Relating to the TV Broadcasting Service and the Associated Working Arrangement

Terrestrial Broadcasting Agreements and Arrangements

Note: Table  B has been updated since this document was originally signed.


All persons making use of this consolidation are reminded that the documents included herein are provided only for convenience of reference. This consolidation is for the guidance of those engaged in radiocommunications in Canada. The information contained in this document is subject to change without notice. While every reasonable effort has been made to ensure accuracy, no warranty is expressed or implied. For more details, please contact the Broadcast Applications Engineering Division.

The agreements and arrangements contained herein have been negotiated under the authority of the Government of Canada by the Department of Communications whose spectrum management and telecommunications programs have been transferred to Industry Canada.

Prepared by:

Industry Canada
Radiocommunications and Broadcasting Regulatory Branch
235 Queen Street
Ottawa, Ontario
K1A 0H5


All spectrum publications are now available on the Internet at:

Publication Date: June 1997


Washington, November 3, 1993

Note No. 192

Dear Secretary Christopher,

I have the honour to refer to the Agreement between Canada and the United States of America effected by the Exchange of Notes dated on Apri 23 and June 23, 1952 -- in force on June 23, 1952, as amended by the Exchange of Notes dated February 26 and April 7, 1982 on the allocation of channels for television broadcasting (the 1952 Agreement); and to the recent discussions between representatives of both governments concerning the use of the 54 to 72 MHz, 76 to 88 MHz, 174 to 216 MHz and 470 to 806 MHz frequency bands for television broadcasting. Furthermore, I have the honour to propose that the above-mentioned Agreement be replaced by the following.

In order to prevent undue interference between stations in the respective countries, the allotment and assignment of channels in areas adjacent to the border of Canada and the United States of America shall be in accordance with the conditions set forth herein and in the attached Working Arrangement.

For the purpose of this Agreement, the expression "Administrations" refers to the Department of Communications for Canada and the Federal Communications Commission for the United States of America. The Administrations shall exchange information and co-operate with each other for the purpose of minimizing interference and obtaining maximum efficiency in the use of television broadcast channels. To this end, the Administrations have accepted the attached Working Arrangement, including its Annexes. Tables A and B of Annex  VI of the Working Arrangement may be revised by direct correspondence between the Administrations. The Administrations shall, as necessary, review the Working Arrangement and its implementation in the light of domestic and international developments. Amendments to the Working Arrangement, other than revisions to Tables A and B of Annex  VI, shall be accomplished by Exchange of Notes between the two Governments.

The Honourable Warren M. Christopher
Secretary of State
Department of State
Washington, D.C.

Notification of proposed revisions to Tables A and B shall be made to the other Administration in accordance with the provisions of the Working Arrangement. Assignments made within 400 kilometres of the border shall be in accordance with these Tables, as revised, and shall be notified in accordance with the provisions of the Working Arrangement.

Assignments made at points which are more than 400 kilometres from the nearest point on the border of Canada and the United States of America will normally have no international significance and need not be notified except in cases of unusual operating parameters where the possibility exists that interference could be caused to stations of the other Administration.

This Agreement may be amended through Exchange of Notes between the two Governments.

Either Government may terminate this Agreement at any time by giving written notice to this effect at least one year prior to the date contemplated for such termination.

Upon entry into force the present Agreement shall supersede the 1952 Agreement as amended.

If the foregoing proposals are acceptable to the Government of the United States of America, I have the honour to propose that this Note and the Attached Working Arrangement, which are authentic in English and French, and your Note in reply shall constitute an Agreement between the Government of Canada and the Government of the United States of America, which shall enter into force on the date of your reply.

Accept, Mr. Secretary, the renewed assurances of my highest consideration.

John de Chastelain


Working Arrangement for Allotment and Assignment of VHF and UHF Television Broadcasting Channels under the Agreement Between the Government t United States Of America and the Government of Canada Relating to the TV Broadcasting Service

Effective Date: March 1, 1989

1. Preamble

Mutual undertakings concerning the allotment and assignment of television broadcast channels by Canada and the United States in the area lying within 400 km of their common border are set out in the Agreement between the Government of the United States of America and the Government of Canada relating to the TV broadcasting service (1989 TV Agreement). The Arrangement set out herein states the basis upon which the Canadian and U.S.A. Administrations shall consider responses to border area television channel allotments and assignments proposed by the other Administration pursuant to the Agreement.

2. Definitions

2.1 Channel Designation

TV broadcast channels are 6 MHz wide and are allotted in the frequency bands 54 to 72 MHz, 76 to 88 MHz, 174 to 216 MHz and 470 to 806 MHz. Refer to Annex I for channel designations. Frequency band 608 to 614 MHz, Channel 37, is allocated to the Radio Astronomy Service, and is therefore not available for broadcast use.

2.2 Primary Assignment

A primary assignment is a protected station assignment authorized or operating on an allotted channel.

2.3 Secondary Assignment

A secondary assignment is an unprotected station assignment authorized or operating on a channel in accordance with Section 2.14.

2.4 Unlimited Allotment

An unlimited allotment is one on which a station may operate with standard parameters.

2.5 Limited Allotment

A limited allotment is one on which a station for any reason is required to operate with less than the standard parameters.

2.6 Effective Height Above Average Terrain (EHAAT)

Effective height above average terrain is the height of the centre of radiation of the antenna above average elevation of the terrain between 3 and 16 km from the antenna for 8 radials spaced evenly each 45 degrees of azimuth starting with true north.

2.7 Effective Radiated Power (ERP)

Effective radiated power is the product of the antenna input power and the power gain of the antenna relative to a half-wave dipole.

2.8 Standard Parameters

Standard parameters are an EHAAT of 300 metres and a maximum ERP, in any horizontal or vertical direction, of 100 kw for Channels 2-6, 325 kW in Canada and 316 kW in the United StatesFootnote 1 for Channels 7-13, and 1,000 kW for Channels 14-69.

2.9 Maximum Parameters

For limited allotments, the maximum parameters are the maximum values of EHAAT and ERP determined from the distance between allotments and assignments in accordance with protection requirements of Section 3. For unlimited allotments, the maximum ERP for channels 2-13 shall not exceed the values in Section 2.8 and for channels 14-69 shall not exceed 5000 kW.

2.10 Operating Parameters

Operating parameters are the EHAAT and ERP actually used.

2.11 Directional Antennas

Directional antennas are those which are designed or altered to produce a non-circular radiation pattern in the horizontal plane.

2.12 Zones

For co-channel allotment purposes and optimum use of channels, both Canadian and the United States of America border areas are divided into two zones as described in Annex II.

2.13 Protected Contour

The protected contour is the Grade B contour, i.e. 47 dBu (dB above 1 uV/m) for channels 2-6, 56 dBu for channels 7-13 and 64 dBu for channels 14-69, but not exceeding distances as specified in Section 3.1.

2.14 Low Power Television Broadcasting Stations

Low power television broadcasting stations are secondary assignments which operate with a transmitter peak envelope power not exceeding 50 watts VHF and 500 watts UHF in Canada, and 100 watts VHF and 1,000 watts UHF in the United States. These stations operate on a non-interference non-protected basis with respect to existing or future primary assignments; however, they are assigned on a protected basis with respect to each other according to their date of notification. Refer to Section 5.4.

3. Basic Principles

3.1 Calculation of Protected Contour

3.1.1 For channels 2-6, 7-13 and 14-69, the distances to the protected contours shall be based on maximum allowable parameters and are calculated using the F(50,50) propagation curves in Figures  1, 3 and 5 of Annex V respectively, but shall not be considered to extend beyond 89 km for channels 2-6, 82 km for channels 7-13, or 70 km for channels 14-69. However, these limitations shall not apply when calculating interference from secondary assignments.

3.1.2 When the field strength corresponding to the protected contour extends beyond the boundary of the country in which the station is located, protection shall terminate at the border. That portion of the boundary lying within the protected contour shall be considered as the location of the said contour for purposes of protection.

3.1.3 For protection purposes, the boundary of a country shall be deemed to encompass only its land area including islands.

3.2 Co-channel Protection

3.2.1 VHF and UHF co-channel protection criteria are specified in Table  I of Annex IV.

3.2.2 If a proposed or existing allotment under consideration is located within either the Canadian or the United States Zone I, the Zone I minimum separations and maximum F(50,10) field strength values in Table I shall be used. If said allotments are in Zone II, the Zone II minimum separations and maximum F(50,10) field strength values shall be used.

3.2.3 Objectionable interference shall be considered to exist if the F(50,10) field strength value at the protected contour exceeds the appropriate maximum F(50,10) field strength value given in Table I.

3.2.4 Although there is no limit on the maximum value for EHAAT, in cases where the EHAAT exceeds 600 m, the ERP for an unlimited allotment must be reduced so that the distance to the F(50,10) interfering contour is equivalent to that resulting from the maximum permitted ERP for the channel proposed and an EHAAT of 600 m. The F(50,10) interfering contour shall be determined using the appropriate maximum F(50,10) field strength value from Table I.

3.3 Other Channel ProtectionsFootnote 2

3.3.1 For VHF first adjacent channels, the minimum distance separation between Canadian and United States allotments shall be 95 km.

3.3.2 For UHF channels having restricted relationships known as the "taboos", the minimum distance separations between Canadian and United States allotments are as follows:

First Adjacent (n ± 1)
90 km
Intermodulation (n ± 2,3,4,5)
30 km
Local Oscillator Radiation (n ± 7)
95 km
Intermediate Frequency Beat (n ± 8)
30 km
Sound Image (n ± 14)
95 km
Picture Image (n ± 15)
120 km

Where "n" is the number of the reference channel.

3.3.3 The use of operating parameters greater than standard parameters shall be allowed for channels 14-69, provided the ERP does not exceed 5000 kW and the protection criteria in Table II of Annex IV are met.

3.4 Computation of Distance and Azimuth

Where transmitting antenna sites have been established the distance and azimuth shall be determined using the coordinates of the transmitter sites. If a transmitter site has not been established the community's reference coordinates (the post office or if not existant, the coordinates of the centre of the city) shall be used. Refer to Annex III for the method of calculating distance and azimuth.

3.5 Directional Antennas

Directional antennas may be used by stations on limited allotments to render protection to other stations or by stations on unlimited allotments to provide better service. The radiation from a directional antenna must not exceed the notified radiation pattern value in any direction where protection is being provided. In all other directions, the radiation may not exceed the notified pattern value by more than 2 dB. Moreover, the ratio of maximum to minimum fields of a directional antenna shall not be greater than 20 dB except where terrain will present a reception problem due to signal reflections. Where beam tilt is used, the effective radiated power shall be that calculated using the maximum radiation from the antenna in the plane of maximum radiation. Use of a directional antenna on an unlimited allotment shall not change the location of the protected contour (as defined in Section 3.1.1), which remains based on operation with an omnidirectional antenna.

3.6 Circular or Elliptical Polarization

All TV stations shall normally use horizontally polarized antennas; however, circular or elliptical polarization may be employed. The maximum ERP in any plane of polarization shall not exceed the maximum permissible ERP.

4. Tables and Figures 

4.1 Allotment Tables

Tables A and B of Annex VI contain all Canadian and U.S. allotments, respectively, on Channels 2 through 69 made to communities within 400 km of the common border.

4.2 Table I

Table I specifies the minimum separations and the maximum interfering F(50,10) field strength value permitted at the protected contour for VHF and UHF co-channel allotments and assignments, based on channel offset and non-offset operation.

4.3 Use of Table I

4.3.1 The minimum separations for each zone must be satisfied.

4.3.2 Determine the azimuth and distance to the most restrictive point(s) on the protected contour.

4.3.3 Using the EHAAT, and maximum ERP at the pertinent azimuth, the maximum co-channel field strength must not exceed the value in Table I, using appropriate F(50,10) curves.

4.4 Table II

Table II specifies the protection criteria for UHF assignments whose parameters exceed 1000 kW ERP and/or 300 metres EHAAT.

4.5 Use of Table II

4.5.1 The minimum separations specified in Section 3.3.2 must be satisfied.

4.5.2 If the separation is less than the value shown in the Table II column entitled "Maximum Separation Requiring Study", proceed to the following, more detailed calculations.Footnote 3

4.5.3 The values in the "Reference Distance"Footnote 4 column in Table II indicate the pointnearest to the protected station at which the field strength value specified in the column in Table II labeled "Maximum Field Strength At Reference Distance" may occur. Where the reference distance from the Table extends beyond the boundary of the country in which the station is located, the applicable field strength value may occur on that portion of the boundary lying within the reference distance. For this procedure, the boundary of a country is considered to encompass only its land area, including islands. Objectionable interference is considered to exist if these criteria are exceeded.

4.5.4 The field strength of the proposed station at the reference distance is determined, based on the maximum ERP at the pertinent azimuth and EHAAT, using the F(50,10) curves in Figure 6 if the study is co-channel, and using the F(50,50) curves in Figure 5 if the study is not co-channel.

4.6 Use of Figures 1 to 6

4.6.1 Figures 1 to 6 are based on an effective power of 1 kW radiated from a half-wave dipole in free space which produces an unattenuated field strength at one kilometre of about 107 dB above 1 uV/m (221.8 mV/m). For an ERP other than 1 kW, the ordinate scale (field strength in dB above 1 uV/m for 1 kW ERP) should be changed by the appropriate dB value.

4.6.2 The F(50,50) curves in Figures 1, 3 and 5 give the estimated field strength in dB above 1 uV/m exceeded at 50% of the locations for at least 50% of the time for channels 2-6, 7-13 and 14-69, respectively.

4.6.3 The F(50,10) curves in Figures 2, 4 and 6 serve the same purpose as Figures 1, 3 and 5 except that they give the estimated field strength exceeded at 50% of the locations for at least 10% of the time for channels 2-6, 7-13 and 14-69, respectively.

5. Procedures For Notification

5.1 General

5.1.1 Proposed assignments, allotments and changes thereto, shall be notified by an exchange of correspondence between the Federal Communications Commission and the Department of Communications; such proposals may be presumed to be acceptable if they conform to the technical criteria set out in this Arrangement. Each Administration shall have forty-five (45) days, from the date of receipt of the notification, to reply thereto. If an objection is raised in this period, the letter shall state, with as much particularity as the circumstances permit, the basis for the objection. The proposing Administration may then have an opportunity to meet the stated objection by suitable amendments to its proposal. If no reply is sent within the 45 day period prescribed, a notified proposal shall be considered approved. In all cases, notification procedures shall be completed prior to domestic grant of authorization.

5.1.2 Each calendar quarter, the Administrations shall forward to each other a recapitulation of all notifications made during that three month period. Each year both Administrations shall exchange, verify and reconcile the complete database.

5.2 Notification of Changes to Allotments

5.2.1 Notification of changes to allotments shall contain community name, state or province, reference coordinates and pertinent channel changes.

5.2.2 Proposed allotments which do not conform to the protection criteria set out in the Arrangement may be established upon written acceptance by both Administrations.

5.2.3 The notifying Administration shall specify whether the notified allotment is unlimited or limited to protect allotments and assignments in the other country and it shall state the applicable limitations.

5.3 Notification of Station Assignments

Notification of station assignments or changes in operating parameters of existing stations shall set out the actual operating parameters which shall be employed (refer to Section 5.5). These may be less than the maximum allowable parameters for the allotment. The use of lesser operating parameters initially shall not preclude the later use of the parameters on which the allotment was accepted.

5.4 Assignment of Low Power Television Stations

5.4.1 Proposed low power television stations within 32 km of the common border which are not on allotted channels in accordance with the Agreement shall be referred to the other Administration for approval (refer to Section 5.5). A co-channel protection ratio of 45 dB shall be provided at the Grade B contour of the protected station using the appropriate F(50,10) curves.Footnote 5 Moreover, any proposal which is located more than 32 km from the border but whose F(50,10) interfering contour based on its specific parameters, would fall within the territory of the other country, shall be referred to the other Administration for approval. Proposals for low power stations not on allotted channels, at locations in excess of 32 km from the border, whose interfering F(50,10) contour would not fall within the territory of the other country, may be authorized without referral or notification.

5.4.2 Should any interference be caused by a low power television station to a primary or previously notified low power television assignment, the offending station must immediately change to a suitable channel or cease operation. The use of a channel by a low power television station as defined herein shall not prejudice in any manner the use of this channel for a primary assignment, and shall not constitute a basis for objection to a proposal by the other Administration for a new or modified allotment or primary assignment.

5.5 Assignment Data to be Notified

Notification of assignments or proposals needing referral shall contain the following information:

Name of Applicant (optional)
City, State or Province
Transmitter location (Latitude and Longitude)
Call Sign (where available)
Channel Number, including offset (if applicable)
Maximum visual effective radiated power and beam tilt angle (if applicable)
Transmitter Power (for low power television stations)

  1. effective height above average terrain (EHAAT)
  2. make and type
  3. horizontal pattern, if a directional antenna is proposed

5.6 Technical Coordination

Technical coordinations concerning allotments and assignments shall normally consist of an exchange of letters between the Department of Communications of Canada and the Federal Communications Commission of the United States of America. In the event that the matter cannot be resolved by correspondence, a meeting shall be arranged.