SRSP-305.9 — Technical Requirements for Fixed Line-of-Sight Radio Systems Operating in the Band 5925-6425 MHz

This Standard Radio System Plan (SRSP) replaces SRSP-305.9, issue 5. Issue 6 of SRSP-305.9 has been released to reflect policy changes in Canada Gazette notice SMSE-022-14, Decisions on Spectrum Utilization Policies and Technical Requirements Related to Backhaul, released in December 2014.

The following are the main changes:

1. The radio frequency (RF) channel arrangement was updated to add RF channel bandwidths of 60 MHz and to remove RF channel bandwidths of less than 5 MHz. Consequential changes were made through the rest of this document.
2. References to low-, medium- and high-capacity systems were removed, based on policy decisions in SMSE-022-14.
3. Text was added in section 4.5 to reflect the case of systems using adaptive modulation or adaptive error-correction coding.
4. The antenna envelope B was modified in figure 1 and table 6 of section 6.
5. Section 9 on enhanced technical standards for moderately congested and highly congested areas was added.
6. Section 10 on international coordination was added.
7. Stylistic changes and improvements have been made throughout the document.

Issued under the authority of
the Minister of Innovation, Science and Industry

Martin Proulx
Director General
Engineering, Planning and Standards Branch

This Standard Radio System Plan (SRSP) states the minimum technical requirements for the efficient use of the frequency band 5925-6425 MHz by point-to-point radio systems in the fixed service using digital modulation.

This SRSP is intended to be employed in the design and specification of radio systems and equipment, and in the technical evaluation of applications for new radio facilities or modifications 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.

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

This standard replaces SRSP-305.9, issue 5. Further revision of this SRSP will be made as required.

2.1 Licensing process

Existing point-to-point radio systems operating in the frequency band 5925-6425 MHz, which 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 Innovation, Science and Economic Development Canada (ISED) on a case-by-case basis. New systems deployed in the frequency band 5925-6425 MHz shall conform to the requirements of this standard.

2.2 Compliance of radio systems

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

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

The Geographical Differences Policy (GDP) guideline applies to the frequency band 5925-6425 MHz. The GDP incorporates some technical requirements that are applied in areas having certain levels of congestion, which are also further described in part B, section 1.6, Geographical Differences Policy Guideline, of SP 1-20 GHz, Revisions to Microwave Spectrum Utilization Policies in the Range of 1-20 GHz.

Even though a radio system conforms to the requirements of this SRSP, modifications may be required to the system whenever harmful interference, as defined in the Radiocommunication Act, is caused.

Radio systems in this band are required to be designed using a two-frequency plan, whereby the same frequency pair is typically reused along a route of successive hops. Where reasonable justification is provided (e.g. where siting prevents adequate antenna discrimination), extra frequencies beyond the initial pair may be permitted to resolve the problem, at the discretion of ISED’s regional offices.

2.3 Resolution of interference conflicts between radio systems

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

In cases of a potential interference conflict, ISED may require licensees and/or applicants to use a receiver with improved selectivity characteristics.

2.4 Spectrum sharing

It should be noted that the fixed service shares this frequency band equally on a primary basis with the fixed-satellite service (FSS) (Earth-to-space) in accordance with the Canadian Table of Frequency Allocations.

Information on FSS earth stations transmitting in this band is available through ISED’s Spectrum Management and Telecommunications website. Licensees and applicants for the deployment of fixed service and FSS earth stations shall coordinate their installations on a first-come first-served basis.

The current issues of the following documents are applicable, and are available on ISED’s Spectrum Management and Telecommunications website.

Acronyms

RF channel arrangements described in this section apply to point-to-point digital radio systems.

4.1 RF channel arrangements for the frequency band 5925-6425 MHz

The channel plans defined in this standard provide for four different RF channel spacings. The allowable channel bandwidths are:

• greater than 30 MHz and less than or equal to 60 MHz
• greater than 10 MHz and less than or equal to 30 MHz
• greater than 5 MHz and less than or equal to 10 MHz
• less than or equal to 5 MHz

It should be noted that the channel spacing values are not exactly the same as the sizes given in the table headings. In addition, not all channels within a given RF channel bandwidth table are evenly spaced. The channel spacing for each bandwidth is shown in tables 1 to 4 of this document.

60 MHz channel spacing

The centre frequencies of the 4 paired channels that allow RF channel bandwidths greater than 30 MHz and less than or equal to 60 MHz are shown in table 1.

Channel F4/F4′ is set aside for narrow bandwidth systems and should be used only if all other channels are unavailable.

30 MHz channel spacing

The centre frequencies of the 8 paired channels that allow RF channel bandwidths greater than 10 MHz and less than or equal to 30 MHz are shown in table 2.

Channels A7/A7′ and A8/A8′ are set aside for narrow bandwidth systems and should be used only if all other channels are unavailable.

10 MHz channel spacing

Channels B19/B19′ to B24/B24′ are set aside for narrow bandwidth systems and should be used only if all other channels are unavailable.

5 MHz channel spacing

The centre frequencies of the 12 paired channels that allow RF channel bandwidths less than or equal to 5 MHz are shown in table 4.

4.2 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 to ensure sufficient antenna discrimination at the branch-off angle.

4.3 Closed loops

When point-to-point digital radio systems form a closed loop, such systems shall be designed to consist of an even number of hops to permit the use of two frequency plans.

4.4 Assignment of frequencies

New radio systems using 10 MHz, 30 MHz, or 60 MHz channel plans should normally use the lowest available frequency pair that can be successfully coordinated. New radio systems employing 5 MHz channel plans should use the highest available frequency pair that can be successfully coordinated. However, due to varying conditions and circumstances across Canada, ISED’s regional offices may assign frequencies using a procedure different from the one described above, at their own discretion.

Channels B19/B19′ to B24/B24′, A7/A7′ and A8/A8′ and F4/F4′ in the 10 MHz, 30 MHz and 60 MHz channel plans respectively, are set aside for narrow bandwidth systems and should be used only if all other channels are unavailable.

The use of co-channel dual polarization (CCDP) is both permitted and encouraged by ISED as a measure of increasing backhaul capacity while minimizing the need for additional spectrum. An applicant requesting paired channels using an RF channel of 60 MHz and not employing CCDP technology could be required to provide technical justification for not employing CCDP on a smaller RF channel spacing.

4.5 Spectral efficiency

1. Digital systems submitted for licensing shall meet a minimum spectral efficiency of 4.4 bits/s/Hz on a single polarization in a bandwidth corresponding to the channel spacing.
2. In the case of systems using adaptive modulation or adaptive error-correction coding to maintain link availability during deep fading conditions, the spectral efficiency level may be temporarily lowered for a short period of time, provided that the link is designed to meet the minimal spectral efficiency requirements specified in the provisions above.

4.6 Protection channels

1. One paired protection channel may be permitted for systems with more than one paired working channel in normal congestion and uncongested areas.
2. Protection channels for radio systems operating in moderately congested and highly congested areas are not permitted.
3. Quad-path diversity (the use of frequency diversity and space diversity on the same path) applications will be considered on a hop-by-hop basis to solve special propagation problems.

This section describes the transmitter characteristics for point-to-point digital radio systems.

5.1 Transmitter power limits

1. The transmitter power delivered to the antenna input per RF channel shall not exceed the limits for each authorized bandwidth shown in table 5.

   Table 5: Transmitter power limits

   Bandwidth (BW) (MHz)	Power limit (watts)	Power limit (dBW)
   30 < BW ≤ 60	10	+10
   10 < BW ≤ 30	10	+10
   5 < BW ≤ 10	7.5	+8.8
   BW ≤ 5	5	+7

2. An increase in transmitter power may be permitted if technical justification is provided. In no event will the power delivered to the antenna be permitted to exceed 20 W (+13 dBW) per RF channel.
3. In the case of systems using automatic transmit power control (ATPC) to maintain link availability during deep fading conditions, the maximum transmitter power at the antenna port may be temporarily increased by a value corresponding to the ATPC range, up to a maximum of the transmitter power limits indicated in table 5, above. In addition, the maximum equivalent isotropically radiated power (e.i.r.p.) limits indicated in section 7 of this document shall be met at all times.

5.2 Frequency stability

The centre frequency of the emission shall be maintained within ±0.005% of the assigned frequency.

5.3 Emission limits

1. In any 4 kHz band, the centre frequency of which is removed from the assigned frequency by more than 50% up to and including 250% of the authorized bandwidth, the mean power of emission shall be attenuated below the mean output power of the transmitter in accordance with the following equation:
   A = 35 + 0.8 (P - 50) + 10 log₁₀ B (dB)
    

   where:

   • A = attenuation (in dB) below the mean output power level
   • P = percent removed from the centre frequency of the assigned RF channel
   • B = authorized bandwidth (in MHz)
   Notes:

   1. In no case shall the attenuation be less than 50 dB.
   2. Attenuation greater than 80 dB or to an absolute power of less than -13 dBm/MHz is not necessary.
2. In any 1 MHz band, the centre frequency of which is removed from the assigned frequency by more than 250% of the authorized bandwidth, the mean power of emission shall be attenuated by 43 + 10 log₁₀ (mean output power in watts) dB, or 80 dB, whichever is the lesser attenuation.

This section describes the antenna characteristics for point-to-point digital radio systems.

1. The co-polarized radiation pattern envelope in the horizontal plane of the antenna must remain within envelope B defined in table 6 and shown in figure 1, for both vertical and horizontal polarizations.
2. The antenna shall have a minimum front-to-back ratio of 45 dB.
3. Requirements related to envelope A for moderately and highly congested areas are addressed in section 9 of this SRSP.

Figure 1: Minimum antenna characteristics for point-to-point digital radio systems operating in the band 5925-6425 MHz

The maximum equivalent isotropically radiated power (e.i.r.p.) from the antenna must not in any case exceed +55 dBW per RF channel.

As far as practicable, sites for transmitting terrestrial stations operating in the fixed service and employing maximum values of e.i.r.p. exceeding +35 dBW in the frequency band 5925-6425 MHz should be selected so that the direction of maximum radiation of the antenna will be pointed at least 2° away from the geostationary-satellite orbit, taking into account the effect of atmospheric refraction.

Where compliance with the above paragraph is impracticable, the e.i.r.p. of the station shall not exceed:

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

Note: 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.

1. The co-polarized radiation pattern envelope in the horizontal plane of the antenna must remain within envelope A shown in figure 1 and table 7 of section 6 for both vertical and horizontal polarizations.
2. The antenna shall have a minimum front-to-back ratio of 55 dB.
3. Radio systems employing bandwidth channels less than or equal to 60 MHz must have adequate filtering to allow for the operation of separate systems on adjacent channels using co-polarization when the undesired and the desired signals are of the same magnitude at the antenna input. Systems employing co-channel dual-polarization must also be in accordance with this requirement.
4. Protection channels for radio systems operating in congested areas are not permitted. For protection channel requirements in areas which are not moderately or highly congested, see section 4.6 of this document.

Stations operating in the band 5925-6425 MHz near the Canada-United States border are subject to the provisions of Arrangement A, Arrangement between the Department of Transport and the Federal Communications Commission for the Exchange of Frequency Assignment Information and Engineering Comments on Proposed Assignments along the Canada-United States borders in certain bands above 30 Mc/s.