SRSP-308.2 — Technical Requirements for Fixed Line-of-Sight Radio Systems Operating in the Band 8275-8500 MHz

Issue 4
May 2012

Spectrum Management and Telecommunications
Standard Radio System Plan

January 2013 — Table 2 has been corrected by adding an entry for 20 degrees so that it corresponds with Figure 2.

Preface

Issue 4 of SRSP-308.2 has been released to reflect editorial updates. This SRSP replaces SRSP-308.2, Issue 3.

The following are the main changes:

  1. A paragraph describing the preferred growth pattern has been added under Section 4.5, Assignment of Frequencies.
  2. Numerous other editorial updates and improvements have been made.

Issued under the authority of
the Minister of Industry

space to insert signature
Marc Dupuis
Director General
Engineering, Planning and Standards Branch

Contents

1. Intent

1.1 This Standard Radio System Plan (SRSP) states the minimum technical requirements for the efficient use of the frequency band 8275-8500 MHz by line-of-sight radio systems in the fixed service using analog or digital modulation and conveying video signals requiring a radio frequency bandwidth of up to 18.75 MHz. On a case-by-case basis, wideband radar video information may be carried on systems having a bandwidth of up to 37.5 MHz.

1.2 This SRSP is intended to be employed in the design and specification of radio systems and equipment, as well as in the technical evaluation of applications for new radio facilities or modification to radio systems submitted in accordance with the current issue of Radio Standards Procedure RSP-113, Application Procedures for Planned Radio Stations Above 960 MHz in the Fixed Service.

1.3 This SRSP specifies equipment characteristics related to efficient spectrum usage only, and is not to be regarded as a comprehensive specification for equipment design and/or selection.

2. General

2.1 This standard replaces SRSP-308.2, Issue 3. Further revision of this SRSP will be made as required.

2.2 Existing radio systems operating in the band 8275-8500 MHz that were licensed as standard prior to the issuance of this SRSP may continue to operate as standard. Extension or expansion of these systems will be considered by Industry Canada on a case-by-case basis. New systems deployed in the bands 8275-8500 MHz must conform to the requirements of this SRSP to be licensed as standard.

2.3 Radio systems conforming to the requirements of this SRSP will be given priority in licensing over non-standard radio systems operating in this band.

2.4 The arrangements for non-standard systems are outlined in SP GEN, General Information Related to Spectrum Utilization and Radio Systems Policies.

2.5 The Geographical Differences Policy (GDP) guideline applies in this frequency band. Further information on the GDP can be found in SP 1-20 GHz.1

2.6 Even if a radio system complies with the requirements of this SRSP, modifications may be required to the system if it causes harmful interference.2

2.7 When potential conflict between radio systems cannot be resolved by the parties concerned, Industry Canada should be advised. After consultation with these parties, the Department will determine the necessary modifications and schedule of modifications to resolve the conflict.

2.8 Industry Canada may require licensees and/or applicants to use a receiver with improved selectivity characteristics, in case of a potential interference conflict.

2.9 The use of a two-frequency plan is required. Where reasonable technical justification is provided (e.g. where siting prevents adequate antenna discrimination), additional frequencies may be used to resolve the problem on a case-by-case basis, at the discretion of the Department. These additional frequencies will be subject to the provisions of the GDP as referenced in Section 2.5.

2.10 It should be noted that the fixed terrestrial service shares this band with other services in accordance with the Canadian Table of Frequency Allocations 9 kHz to 275 GHz.

3. Related Documents

3.1 The current issues of the following documents are applicable and available on Industry Canada’s Spectrum Management and Telecommunications website at http://www.ic.gc.ca/spectrum.

SP — Spectrum Utilization Policy
RSP — Radio Standards Procedure
TRC — Telecommunications Regulation Circular
CTFA — Canadian Table of Frequency Allocations
CPC — Client Procedures Circular

4. Radio Frequency (RF) Channel Arrangement Description

4.1 RF Channel Arrangements

The channel plans defined in this standard provide for the development of radio systems transmitting up to 6 one-way video channels, or 6 go and 3 return video channels3 in the prescribed 225 MHz bandwidth as shown in Figure 1. The permissible types of video transmission systems are specified in SP 8275. Audio channels may be carried with the associated video channels. The carriage of wideband radar signals4 will be considered on a case-by-case basis. Channel pairs are provided with a transmit/receive separation of 112.5 MHz.

The maximum allowable channel bandwidth is 18.75 MHz.

4.2 RF Channel Centre Frequencies

  • (a) The centre frequencies of the 12 paired channels which allow RF channel bandwidths of 18.75 MHz and less are expressed by the following relationships:

    Lower half of the band An = 8265.625 + 18.75n where n = 1 to 6

    Upper half of the band A'n = 8265.625 + 18.75n where n = 7 to 12

    where n is the channel number and An and A'n are the centre frequencies (in megahertz) of the paired channels. For any hop, as shown in Figure 1, only channels N = 1-6 and 10-12 or channels N = 1-3 and 7-12 will be available.

  • (b) Users operating systems which use the two bands 7725-8275 MHz and 8275-8500 MHz on common structures should note that channel 1 mentioned in Table 1 of this SRSP and upper channels of SRSP-307.7 are very close. A possibility of adjacent channel interference exists if the same polarization is used on both channels.

4.3 Branching or Spur Route Channels

The frequencies assigned to a main route system should be reused on the branching or spur routes where possible. The siting of repeater stations should be planned with this requirement in mind, in order to obtain sufficient antenna discrimination at the branch-off angle.

4.4 Closed Loops

Systems must be designed so that any closed loop will consist of an even number of hops.

4.5 Assignment of Frequencies

The preferred growth pattern is to use vertical polarized channels first and then use horizontal polarized channels. For go channels, the preferred growth pattern is to start with vertical polarized channels 1, 3 and 5, then use horizontal polarized channels, starting with 2, 4 and 6. For return channels, the preferred growth pattern is to start with vertical polarized channels 10 and 12 and then use horizontal polarized channel 11. This preferred growth pattern is shown in Figure 1.

However, due to varying conditions and circumstances across Canada, regional offices may assign frequencies using a procedure different from the one described above, at their own discretion.

4.6 Spectral Efficiency

Systems shall have a minimum spectral efficiency of 1 standard definition video signal plus associated audio channel(s) per RF channel on a single polarization.

4.7 Protection Channels

The use of additional frequency channels as protection channels is not permitted, except in systems which affect the safety or protection of a person or persons.

4.8 Polarization Scheme

The recommended polarization scheme is shown in Figure 1.

5. Transmitter Characteristics

5.1 The transmitter power delivered to the antenna input per RF channel shall not exceed the following limit for the bandwidth:

Bandwidth (MHz) Power Limit
(Watts) (dBW)
18.75 5 7

5.2 An increase in transmitter power over the above specified limits may be permitted if technical justification is provided. In no event will the power delivered to the antenna be permitted to exceed 20 watts (13 dBW) per RF channel.

5.3 The centre frequency of the emission shall be maintained with ± 0.01% of the assigned frequency.

5.4 All significant emissions from the transmitter shall be contained within the licensed bandwidth.

6. International Coordination

Stations located in the band 8275-8400 MHz are subject to frequency coordination with systems deployed in the United States under the provisions of Arrangement D between Canada and the United States.

Canada does not currently have a formal arrangement with the U.S. government for the sharing of the 8400-8500 MHz frequency band along the border regions. Licensees will be subject to any future agreements between Canada and the United States regarding use of these systems in the border regions, which may include modifications of previously authorized stations.

7. Antenna Characteristics

7.1 The co-polarized radiation pattern envelope in the horizontal plane of the antenna must remain within envelope A shown in Figure 2 and Table 2 for both vertical and horizontal polarization.

7.2 In considering future growth, the user should note that:

  • (i) the use of the return channels for multi-hop systems requires the use of antennas at the repeater location(s) having a significantly better front-to-back ratio than shown in Figure 2.
  • (ii) the use of more than 3 go channels on a system requires dual polarized antennas.

8. Maximum Equivalent Isotropically Radiated Power (e.i.r.p.)

8.1 The e.i.r.p. from the antenna must not in any case exceed +55 dBW per RF channel.

9. Avoidance of the Geostationary Satellite Orbit

9.1 As far as practicable, sites for transmitting terrestrial stations operating in the fixed service employing a maximum e.i.r.p. value exceeding +35 dBW in the frequency band 8275-8500 MHz, should be selected so that the direction of maximum radiation of the antenna will be pointed at least 2o away from the geostationary satellite orbit, taking into account the effect of atmospheric refraction.5

9.2 Where compliance with the above paragraph is impracticable, the maximum equivalent isotropically radiated power (e.i.r.p.) of the station shall not exceed:

  • +47 dBW in any direction within 0.5o of the geostationary satellite orbit; or
  • +47 dBW to +55 dBW, on a linear decibel scale (8 dB per degree), in any direction between 0.5o and 1.5o of the geostationary-satellite orbit, taking into account the effect of atmospheric refraction.

Annex A: Channel Identification and Carrier Frequencies for Fixed Systems Operating in the Band 8275-8500 MHz

Table 1 — Channel Identification and Carrier Frequencies for Radio Systems Using 18.75 MHz Wide Channel Bandwidth
GO (RETURN) RETURN (GO)
Channel No. Centre Channel (MHz) Channel No. Centre Channel (MHz)
1 8284.375 7 8396.875
2 8303.125 8 8415.625
3 8321.875 9 8434.375
4 8340.625 10 8453.125
5 8359.375 11 8471.875
6 8378.125 12 8490.625

Figure 1: Radio Frequency Channel Arrangements for Video Systems in the Band 8275-8500 MHz
Photograph of [Description of Figure 1]

Annex B: Minimum Antenna Characteristics

Figure 2: Minimum Antenna Characteristics for the 8275-8500 MHz Frequency Band
Photograph of Figure 2: Minimum Antenna Characteristics for the 8275-8500 MHz Frequency 
 Band [Description of Figure 2]


Table 2 — Minimum Antenna Characteristics for the 8275-8500 MHz Frequency Band
Envelope A
Azimuth in Degrees from Main Lobe Antenna Directivity in dB down from Main Lobe
1 0
2 21
3 21
4 24
10 27
20 38
40 44
78 44
92 39
108 39
120 54
172 54
172 50
180 50

Footnotes

  1. 1 SP 1-20 GHz, Revisions to Microwave Spectrum Utilization Policies in the Range of 1-20 GHz, January 1995, contains new spectrum utilization principles, including the GDP guideline. This information will be incorporated into a revision of SP GEN.
  2. 2 For the purposes of this SRSP, “harmful interference” means interference that endangers the functioning of a radionavigation service or of other safety services or seriously degrades, obstructs, or repeatedly interrupts a radiocommunication service operating in accordance with regulations and technical requirements laid down by Industry Canada under the Radiocommunication Act.
  3. 3 While it is technically feasible to make a fourth channel two-way, it would impose severe requirements on the system design. Therefore, this arrangement is not proposed as the basic frequency plan. However, in high density cross-sections, some users may find it economically justifiable. For this reason, Industry Canada’s regional office may permit the use of a fourth channel, on a case-by-case basis.
  4. 4 Up to twice the channel bandwidth of 18.75 MHz (37.50 MHz) will be considered on a case-by-case basis for the conveyance of wideband radar information until suitable bandwidth reduction techniques and/or spectrum allocation solutions are finalized for this safety service. In such a case, two adjacent channels shall be utilized. The assigned and carrier frequencies will be exactly mid-way between the two adjacent “channel carrier” frequencies.
  5. 5 ITU-R Recommendation SF.765 provides guidance on calculating the intersection of radio-relay antenna beams with orbits used by space stations in the fixed-satellite service.