Consultation on SRSP-520, issue 3 and RSS-192, issue 5 - Annexes

Since late 2021, ISED has conducted laboratory and field studies to assess the potential interference between 5G systems operating in the 3500 MHz, 3800 MHz and 3900-3980 MHz (3900 MHz) bands and radio altimeters operating in the 4200-4400 MHz band. Moreover, ISED has performed a computational study, analyzing different parameters of 5G and aviation systems for fixed and rotary aircraft under various scenarios.

The results of these studies were taken into account when developing the 3500 MHz and 3800 MHz SRSP and RSS in annex B and annex C, respectively. In addition, pending the outcome of the Consultation on a Non-Competitive Local Licensing Framework, Including Spectrum in the 3900-3980 MHz Band and Portions of the 26, 28 and 38 GHz Bands, released in August 2022, the results of the mentioned studies will also be considered in the development of upcoming technical standards for the 3900 MHz band. These studies are further described below.

A.1 Laboratory study

The main objective of this study was to quantify the susceptibility thresholds of various radio altimeters when subjected to fundamental and spurious emissions from 5G systems operating in the 3500 MHz, 3800 MHz and 3900 MHz frequency bands. Measurements were performed on a total of eleven radio altimeters, ten frequency-modulated continuous wave (FMCW) and one pulse modulated, operating in a controlled laboratory environment. Moreover, band-pass filters, including a specific filter solution from one radio altimeter manufacturer, were assessed to determine their effectiveness in mitigating radio altimeter susceptibility to 5G fundamental emissions.

Laboratory test setup and measurement procedure

The laboratory test setup was designed to simulate the propagation environment of different radio altimeters (see table A.1) mounted on aircraft and operating at various fixed altitudes.

1. Category 1 represents radio altimeters on commercial aircraft, category 2 on regional/business aircraft and category 3 on helicopters. These categories are based on the RTCA report.

Fiber spools and a step attenuator were utilized to simulate different flight altitudes (i.e., 50, 200, 1000 and 2000 ft) with corresponding external loop loss (assuming an antenna gain of 10.8 dBi). The laboratory transmission loop loss was calculated by summing the external loop loss and the test setup cable losses of 2.3 dB. For these laboratory tests, a reflectivity coefficient for the transmission loop loss was set at 0.01, derived from the TSO-C87a standard, for all test cases. This coefficient was selected in order to compare ISED’s results with results published in international studies such as those produced by the RTCA. In addition to simulating the reflected radio altimeter signal from the ground, the test setup also simulated an isolation of 80 dB between the transmit and receive antennas.

Interfering signals consisted of Additive white Gaussian noise (AWGN) and 5G New Radio (NR) signals. AWGN served to simulate spurious emissions from 5G systems falling into the radio altimeter band. The 5G NR signal represented the fundamental emissions from 5G systems operating in the 3500 MHz, 3800 MHz and 3900 MHz frequency bands. The interfering 5G NR signal was generated using a vector signal generator (VSG) operating at various center frequencies, bandwidths and duplex modes:

• 5G NR frequency division duplexing (FDD) and time division duplexing (TDD) signals using 3GPP NR-FR1 Test Model 1.1;
• Bandwidths of 10 MHz and 100 MHz;
• Maximum producible power levels at the input of the radio altimeter were -7 dBm/ MHz for a bandwidth of 10 MHz and -17 dBm/ MHz for a bandwidth of 100 MHz;
• Operating upper frequency from 3550 to 4000 MHz, in 50 MHz steps.

To ensure spurious emissions did not affect 5G fundamental results, the VSG’s output signal was filtered with a 3450-4000 MHz band-pass filter to attenuate spurious emissions. The two interfering signal components were tested separately to determine the impact of each potential interference mechanism.

The measurement procedure was developed to assess the power levels at the receiver port of the radio altimeters under test, where impairment was reached by varying step attenuators. Impairment was defined by a 2% or 1.5-foot (whichever was greater) altitude accuracy criteria based on the ARINC 707 standard. Each test sequence started by first taking a reference altitude measurement with the interfering AWGN or 5G signal completely attenuated. The interfering signal level varied in steps of 0.5 dB, with the altitude readings captured at each step. The susceptibility thresholds (i.e. break points) were then determined for each radio altimeter. It is noted that all references to break points do not take into consideration any additional factors such as, but not limited to, varying environmental conditions, manufacturing tolerance and aviation safety margin.

Results of 5G spurious emissions on radio altimeters

Under study-specific test conditions, AUT.02, AUT.06, AUT.10 and AUT.12 were found to be most susceptible to spurious emissions at lower altitudes when compared to all other radio altimeters tested (see table A.2). AUT.10, a pulse modulated radio altimeter, was the radio altimeter most susceptible to spurious emissions at higher altitudes by a considerable margin when compared to other AUTs. Pulse modulated systems are subject to more loop loss at higher altitudes compared to FMCW radio altimeters.

Results of 5G fundamental emissions on radio altimeters

Radio altimeters AUT.01, AUT.06, AUT.08, AUT.09 AUT.10 and AUT.12 were found to be susceptible to 5G fundamental emissions at all altitudes tested (see figure A.1). Two of the most susceptible radio altimeters, AUT.06 and AUT.12, are the same model with different hardware and software modifications. Despite a few exceptions, results were similar between TDD and FDD signals.

Figure A.1 – Results of 5G fundamental emission levels for bandwidths of 10 MHz and 100 MHz for both TDD (top two figures) and FDD (bottom two figures) creating impairments (i.e., break points) at different simulated flight altitudes

Results of mitigation measures

Supplemental testing was conducted with a 4200-4400 MHz band-pass filter added at the receiver port of susceptible radio altimeters. Results demonstrated that the radio altimeters under test were no longer affected by 5G fundamental emissions when evaluated under the same study-specific test conditions. Additionally, a manufacturer-supplied 5G filtering solution was evaluated. This solution was also found to be effective in resolving 5G fundamental susceptibility during the testing performed by ISED.

Band-pass filters added at the receiver port of radio altimeters would not mitigate susceptibility to 5G spurious emissions. It should also be noted that adding a filter may require aviation system recalibration.

Conclusion

The laboratory study assessed the susceptibility of radio altimeters to 5G spurious and fundamental emissions.

Results from spurious emissions testing demonstrated a high disparity in interference susceptibility between radio altimeter models. When compared to other radio altimeters, four units were more susceptible to spurious emissions at lower altitudes, of which one was also significantly more susceptible to spurious emissions than other radio altimeters under test at higher altitudes. Under study-specific test conditions, six out of eleven radio altimeters tested were found to be susceptible to 5G fundamental emissions.

Adding band-pass filtering at the input of the radio altimeter receiver can mitigate 5G fundamental interference.

A.2 Over-the-air (OTA) study

The main objective of the OTA study was to perform qualitative and quantitative assessments of the susceptibility of different radio altimeters to 5G operations in the 3500 MHz, 3800 MHz and 3900 MHz bands in the field. The OTA study was limited to the performance of the radio altimeters configured in the aircraft. The impact on downstream avionics systems was outside the scope of this study.

The OTA test plan was developed in consultation with other government departments such as Transport Canada (TC), National Research Council (NRC), DND, and NAV CANADA. Moreover, the Radio Advisory Board of Canada’s working group on 5G and radio altimeters, comprised of telecommunication and aviation stakeholders, was also consulted during the development of the OTA test plan.

OTA test setup and measurement procedure

For the qualitative assessment, a total of ten aircraft representing nine different radio altimeter models were assessed by DND and TC pilots.

For the quantitative assessment, a fully instrumented research aircraft from NRC was used. The measurement instruments on the research aircraft captured the radio altimeter’s transmit and receive signal power levels, GPS altitude readings, barometric altitude readings, radio altimeter status flags, 5G signal power levels at the receiver of the radio altimeter and at the 5G monitor antenna port as well as aircraft flight telemetry information such as pitch, roll, velocity and heading. The research aircraft was equipped with seven different radio altimeters (see table A.3). These seven radio altimeters represented five different models.

¹ The identification number of the altimeter under test in the OTA study represents the same altimeter under test in the laboratory study (see section A.1).

² AUT.11 was the on-board radio altimeter of the research aircraft and could not be removed from the aircraft for laboratory testing purposes.

The DND, TC and NRC aircraft were flown on flight paths that would subject the radio altimeters to the main traffic beam of the 5G base station (see parameters in table A.4).

¹ The tilt angles were selected to create stringent test conditions, whereby the aircraft was flown through the base station’s main beam at each test altitude, as well as to evaluate whether laboratory findings could be observed in the field. When considering the telecommunication industry’s feedback regarding possible deployment scenarios in the 3500 and 3800 MHz bands, as well as existing deployments in other commercial mobile bands, ISED determined that the use of uptilt during the OTA study was an important consideration.

² 5G signal bandwidths were selected to ensure stringent test conditions while considering equipment limitations and environmental factors such as other licensees operating in the Carp area.

For the qualitative assessment, two test cases were used as follows:

1. Pilots flew on a 3-degree glide slope while using the 5G base station as a waypoint and assessing whether there were any visible anomalies observed on the aircraft instruments within the cockpit. All test scenarios were repeated with the 5G base station turned off and on.
2. Helicopters ascended and descended within the traffic beam or the vertical side lobes of the 5G base station while the flight crews were assessing whether there were any visible anomalies observed on the aircraft instruments within the cockpit. Assessments were repeated with the nose, tail and both sides of the helicopters facing the base station. All test scenarios were repeated with the 5G base station turned off and on.

For the quantitative assessment, testing was performed with the use of approximately 300 different test configurations. For all test scenarios, the 5G base station was first turned off and then turned on for subsequent flight runs to determine whether any erroneous altitude readings were caused by the 5G base station. Level-flight altitudes of 50, 200, 500 and 1000 feet were selected to provide a good coverage of the altitudes tested in international and ISED’s laboratory studies. Additionally, touch-and-go flights were performed over the runway to evaluate low-altitude flight conditions. For different flight altitudes, the effective tilt was selected to ensure the aircraft was flying directly in the main traffic beam of the 5G base station. In order to supplement study-specific findings, the actual transmission loop loss was evaluated and then artificially increased by introducing a tailored attenuator in the radio altimeter transmission path to simulate more stringent test conditions that more closely align with ISED’s laboratory study. The tailored attenuator value was validated with the 5G base station turned off to confirm that the radio altimeters under test performed adequately under such test conditions. Susceptibility events were determined based on multiple factors such as altitude deviations (radio altimeter reported altitude versus corrected DGPS altitude), 5G power levels at the radio altimeter receive port, 5G on versus 5G off flight comparisons, aircraft telemetry readings, loop loss measurements, high-resolution clutter/terrain data and ISED’s laboratory break points.

Results of qualitative assessment

The flight crews did not observe any anomalies on the aircraft instruments for all test cases performed during the qualitative assessment.

Results of quantitative assessment

The results of the quantitative assessment demonstrated that three radio altimeters (AUT.06, AUT.10 and AUT.12) were found to be susceptible to 5G for 29 unique test configurations (see table A.5). AUT.06 and AUT.12 are the same model, as mentioned in section A.1.

The susceptibility events ranged from approximately 0.5 to 9 seconds in duration, with an average of approximately 2.3 seconds, during which the radio altimeters under test reported erroneous altitudes. Test results showed that susceptibility events can be prolonged when the radio altimeter indicates warning/error status flags and recovery time can vary based on factors such as radio altimeter design and environmental conditions. Test results also demonstrated that erroneous altitude readings, some of which involved large deviations, did not always result in a warning status flag. Additionally, some errors in the reported altitude were found to have higher or lower values when compared to the corrected DGPS altitudes.

A strong correlation was observed between the 5G power at the receive port of the radio altimeter under test and the 5G fundamental emission break point found in ISED’s laboratory study for the susceptibility events listed in table A.5.

A review of the certification records of the 5G base station equipment used during ISED’s OTA study confirmed that the spurious emission levels in the 4200-4400 MHz band were well below the applicable regulatory limit of -13 dBm/MHz. This supports the conclusion reached by the NTIA during the US study (see section 3). ISED is of the view that the susceptibility events identified during OTA testing were due to 5G fundamental emissions.

Conclusion

No observable issues were reported by DND and TC flight crews during the qualitative assessment.

During the quantitative assessment, three radio altimeters, classified as category 2 and 3, were found to be susceptible to 5G fundamental emissions. Susceptibility events were identified across the 3500 MHz, 3800 MHz and 3900 MHz bands, at all fixed-flight altitudes and with both the actual and/or simulated loop loss test conditions. However, touch-and-go flights over the runway yielded no observable issues. When considering study-specific test conditions, a strong correlation was observed between the findings of ISED’s OTA and laboratory studies.

A.3 Computational analysis

The main objective of the computational analysis was to determine the impact of different 5G base station parameters operating in the 3450-3980 MHz range on radio altimeters installed on fixed wings and helicopters.

Compared to ISED’s laboratory and OTA studies where a limited number of parameters could be assessed, the computational analysis provided flexibility to vary various 5G and aviation parameters to determine their impact on co-existence between these services.

The results of spurious and fundamental emission break points of specific radio altimeters tested in ISED’s laboratory study, including the break points from international studies and testing performed by radio altimeter manufacturers, fed into the computational analysis to determine mitigation measures on 5G operations.

Baseline and deployment simulators

In-house simulators were developed to model the co-existence between 5G base stations operating in the 3450-3980 MHz range and radio altimeters in the 4200-4400 MHz band, for aircraft landing at airport runways and helicopters scenarios.

The tools were developed in Matlab using object-oriented programming, consisting of over 75 modules. Base stations, aircraft and interference path objects were defined using different modules (e.g., antenna pattern, path loss).

The “baseline” simulators assessed the effectiveness of exclusion and protection zones around airports, including the national antenna down-tilt requirement. The scenarios covered an aircraft landing at an airport runway and a helicopter hovering at different altitudes. Furthermore, the simulators assessed a helicopter landing and departing from an elevated H1 heliport at St. Michael’s Hospital in downtown Toronto. For the “baseline” simulators, 5G base stations were placed at a variety of locations along a flight path, with the base station’s main beam pointing in the azimuth of the aircraft. The simulators recorded a single interference entry from each base station at each defined flight path location using a free-space propagation model.

The “deployment” simulators assessed the impact of 5G deployments in areas where commercial mobile systems already operate using existing deployment data from Advanced Wireless Services (AWS) and Personal Communication Services (PCS) in ISED’s Spectrum Management System (SMS) database. These simulators provided greater understanding of potential interference from typical deployments compared to “baseline” simulators. Similar to the “baseline” simulators, the “deployment” simulators assessed an aircraft landing at a runway and a helicopter landing or departing from an elevated H1 heliport. A free-space propagation model was also used for both scenarios. Additionally, the “deployment” simulators were combined with additional Matlab toolboxes to assess the impact of building shadowing (i.e., signal blocking) when 5G base stations are serving multi-dwellings to determine the overall impact on a helicopter landing and departure at the St. Michael’s Hospital heliport in Toronto’s core center. For this multi-dwelling scenario, a two-Ray tracing propagation model was selected. Building information and terrain data were available via open street maps and US Geological Survey (USGS) Shuttle Radar Topography Mission (SRTM), respectively. These “deployment” simulators assessed the aggregate interference from all base stations.

These simulators were validated using Visualyse and results of the OTA study, where good correlation was observed.

5G and aviation parameters in simulators

Different parameters associated with 5G AAS antenna (see table A.6), non-AAS antenna (see table A.7), base station (see table A.8), aircraft and radio altimeters (see table A.9) were evaluated in the simulators. Information on base station modeling parameters such as number of antenna elements, multi-beam modeling information, range of beam pointing angles, antenna pattern models and spurious emission levels of base station equipment was received from base station vendors and mobile network operators. Further, information on aviation parameters such as aircraft locations at airport runways, flight path models for helicopter take-off and landing at heliports and radio altimeter susceptibility were received from TC, helicopter operators and radio altimeter manufacturers. In addition, the Radio Advisory Board of Canada’s working group on 5G and radio altimeters, comprised of telecommunication and aviation stakeholders, was also consulted on different parameter values to be evaluated in the computational analysis.

Batch simulations for hundreds of different permutations of 5G base station and aviation parameters were executed over a cloud server to determine the impact on co-existence.

In 2021, when ISED developed the current exclusion and protection zones around airport runways, the interference tolerance mask (ITM) values were based solely on the Radio Technical Commission for Aeronautics (RTCA) report (see annex C of Addendum to Consultation on Amendments to SRSP-520, Technical Requirement for Fixed and/or Mobile Systems, Including Flexible Use Broadband Systems, in the Band 3450-3650 MHz) for category 1 radio altimeters.  Since then, ISED has gained a larger body of evidence from ISED’s laboratory and OTA studies, data from radio altimeter manufacturers and data from AVSI latest report.  In order to develop an ITM from this new body of data, ISED applied a testing margin of 6 dB to radio altimeter models for which only a few data points were available.  For radio altimeter models for which ISED had numerous data points, the worst-performing unit of a particular model was selected instead.  For each altitude listed in table A.10, ISED selected the break point for the most susceptible unit (with testing margins included).   The ITM values for category 1 radio altimeters were revised accordingly.  These new values were used to define the exclusion and protection zones around specific airports where automated landing is authorized. 

Results for exclusion and protection zones around airports

Based on the results of the analysis, the proposed exclusion zones have been revised to be formed of two segments: a rectangle having the same length as the runway and a width of 640 metres centred on the centreline of the runway; and an isosceles trapezoid, with a starting base width of 640 metres centred around the runway centreline and extending 2100 metres from the runway threshold, with an ending base width of 1269 meters.

Similarly, the proposed protection zones are represented by isosceles trapezoids with a length of 1000 metres from each edge of the exclusion zones, with an ending base width of 1568 metres for 3500 MHz and a length of 2500 metres from each edge of the exclusion zones, with an ending base width of 2017 metres for 3800 MHz.

Figure A.2 provides existing and newly revised exclusion and protections zones for the Ottawa International Airport.

Figure A.2 – Existing and newly revised exclusion and protection zones for the Ottawa airport

The revised exclusion and protection zones described above are based on ILS surfaces while previously, it was assumed that an aircraft flew closer to the runway centreline. Moreover, based on the information received from TC, while important to protect aircraft at 1000 feet or less, the critical flight altitudes are at 350 feet or less, when an aircraft is in its final descent to a runway. Consequently, the proposed exclusion zone boundary was aligned with the location where the aircraft would be at 350 feet above the ground. Further, using ISED’s baseline simulators, the sizes of the exclusion and protection zones were derived based on ISED’s laboratory results of patch antennas, which are used for aircraft with category 1 radio altimeters. The exclusion and protection zone sizes were based on worst-case base station emissions, with an assumed total e.i.r.p. of 77.5 dBm in one single beam serving one user aligned in azimuth with an aircraft. This total e.i.r.p. is equivalent to a power spectral density of 61 dBm/MHz e.i.r.p. with a channel bandwidth of 45 MHz. The results of the baseline simulator provided an overestimation of 6.2 dB (median value) when compared with the results obtained in the OTA study. As such, no additional safety margin was added when determining the sizes of the exclusion and protection zones.

Based on the results of the computational analysis, new pfd values towards the sky, including equivalent e.i.r.p. values of a base station, were derived for the protection zones (see table A.11).

In order to protect an aircraft located between 1000 ft and 350 ft above ground, the limiting e.i.r.p. of a base station is the one to protect an aircraft at 1000 feet, 40.19 dBm/MHz towards the sky. Using this most limiting e.i.r.p., a new pfd value at 350 feet was derived, which is equalled to -21.31 dBW/m²/100 MHz or -34.21 dBW/m²/5 MHz.

Additionally, pfd values, including equivalent e.i.r.p. values of a base station, were derived to protect an aircraft at 325 feet or less by limiting the power of a base station towards runways (see table A.12).

In order to protect an aircraft located at 325 feet above ground and lower, the limiting e.i.r.p. of a base station is the one to protect an aircraft at 325 feet, 57.25 dBm/MHz towards the runway. A pfd value of -10.45 dBW/m²/100 MHz or -23.45 dBW/m²/5 MHz at 325 feet above ground at the boundary of the exclusion zone would protect an aircraft in the critical phase of its final descent.

Results for antenna down-tilt requirement to protect aeronautical search and rescue operations

Different combinations of mechanical and digital tilt angles of a base station antenna and vertical scanning were assessed to determine the impact on helicopters hovering between 50 feet to 1000 feet above ground.

The results of the simulations demonstrated that the emissions from base stations in an up-tilt configuration are far less attenuated in rural areas in comparison to urban centres. In urban centres, where base stations would be up-tilted to serve multi-dwellings, clutter and building shadowing will reduce the emissions towards aircraft significantly. In rural areas, where most search and rescue operations take place, base station emissions will travel at larger distances since the impact of clutter or building shadowing is minimal. Consequently, the antenna down-tilt requirement does provide additional protection to aircraft flying in rural locations. Finally, the results of the simulations demonstrated that limiting the vertical scanning below the horizon had little impact when the combined digital and mechanical tilts were already kept below the horizon.

Results for exclusion and protection zones around elevated H1 heliports

For a category A helicopter landing and departure at an elevated H1 heliport, the critical phase was defined as the area within 50 metres of the FATO centre. An ITM value of -45 dBm was used for helicopters. Based on ISED’s data on radio altimeters used on helicopter, this ITM value would sufficiently protect the vast majority of radio altimeter models at altitudes between 50 feet and 1000 feet above ground.

Simulation results for the St. Michael’s Hospital heliport showed that an exclusion zone of 80-metre radius around the FATO’s centre would be required to protect an aircraft from outdoor base station emissions. Moreover, the results showed that sufficient protection can be achieved by limiting the power of outdoor base stations within 500-1000 metres of the FATO’s centre (i.e., protection zone) towards these aerodromes through a pfd value of -41 dBW/m²/5 MHz at a heliport surface, within the 50-metre circular boundary measured from the FATO’s centre. Due to the potential impact of the surrounding structures, further study is necessary to determine the precise size of the proposed protection zones around elevated H1 heliports.

Results for spurious emission levels of base stations

Finally, three spurious emission levels, -13, -30 and -48 dBm/MHz, were assessed for an aircraft above a base station with specific clearances of 50 feet (15.2 metres) and 35 feet (10.7 metres). The latter distance represents the typical minimum distance for a category A helicopter flying above an obstacle per rules mandated by TC. A clearance distance of 50 feet was also selected to represent the clearance of an aircraft flying above a base station located on the obstacle clearance surface around airport runways.

An ITM threshold of -91 dBm/MHz was considered as part of this analysis. This value represents the minimum breakpoint for aircraft altitudes of 50 feet and 200 feet for all models for which ISED had data, without any additional margin for unit-to-unit variation. ISED used a single-element pattern for a sub-array composed of three vertical sub-array elements to model spurious emissions of a 5G base station. Further, for this analysis, ISED considered the emissions of a single base station sector with a mechanical tilt of 0-degrees from the horizon and an azimuth aligned with the aircraft. Based on these parameters, table A.13 provides the maximum spurious emissions at the receiver of a radio altimeter generated by ISED’s simulators.

Based on the assumptions described above, the values in table A.13 indicate that an additional 3 dB is required to meet an ITM of -91 dBm/MHz for the minimum clearance of 35 feet (10.67 m). As such, a spurious emission level of -33 dBm/MHz would be required to meet the ITM of -91 dBm/MHz for both clearance distances.

Conclusion

Based on the computational analysis, isosceles trapezoidal shaped exclusion zones of 320 metres from either side of the runway edge and extending 2100 metres from the runway thresholds, with an ending base width of 1269 metres would protect category 1 aircraft landing at ILS runways. Further, isosceles trapezoidal shaped protection zones with a length of 1000 metres from the edge of the exclusion zones, with an ending base width of 1568 metres for 3500 MHz and a length of 2500 metres from the edge of the exclusion zones, with an ending base width of 2017 metres for 3800 MHz would provide protection to category 1 aircraft landing at ILS runways.

In urban areas, where base stations are more likely to be up-tilted to serve multi-dwelling units, it was determined that the impact of building shadowing and clutter significantly reduces the emissions towards aircraft. In rural areas, where most search and rescue operations take place, the antenna down-tilt restriction does provide additional protection since the impact of clutter or building shadowing is minimal. Additionally, limiting the vertical scanning below the horizon had little impact when the combined digital and mechanical tilts were already kept below the horizon.

Exclusion zones of an 80-metre radius and protection zones with a radius between 500 and 1000-metres around H1classified heliports would protect helicopters landing or departing from these aerodromes from outdoor base stations. Within the protection zones, base station emissions towards these aerodromes would be required to meet a pfd limit of -41 dBW/m²/5 MHz.

Finally, a spurious emission level of -33 dBm/MHz would protect radio altimeters with an ITM threshold of -91 dBm/MHz (50 foot to 200-foot aircraft altitude).

DRAFT

Technical Requirements for Fixed and/or Mobile Systems, Including Flexible Use Broadband Systems, in the Band 3450 - 3900 MHz

Preface

Standard Radio System Plan SRSP-520, Technical Requirements for Fixed and/or Mobile Systems, Including Flexible Use Broadband Systems, in the Band 3450-3650 MHz, dated July 2020 replaced SRSP-303.4, Technical Requirements for Fixed Wireless Access Systems Operating in the Band 3475-3650 MHz, issue 3. However, as indicated in section 5 of SRSP-520, specific provisions of SRSP-303.4, issue 3, continue to apply for fixed spectrum licences issued prior to June 2019, and for fixed spectrum licences issued after June 2019 as a result of the conversion of existing fixed spectrum licences from Tier 4 to Tier 5 licence areas.

SRSP-520, issue 2, imposed measures to address the protection of radio altimeters operating in the frequency band 4200-4400 MHz from harmful interference.

SRSP-520, issue 3, extends the band range of SRSP-520, to include 3650-3900 MHz and introduces new technical requirements for flexible use licensees to coexist with Fixed Satellite Services (FSS) and fixed service (FS) stations in the 3700-4200 MHz band to align with policy decisions in SLPB-002-021, Decision on the Technical and Policy Framework for the 3650-4200 MHz Band and Changes to the Frequency Allocation of the 3500-3650 MHz Band.

In addition, issue 3 includes updated technical requirements on flexible use systems to address the protection of radio altimeters operating in the frequency band 4200-4400 MHz from harmful interference.

Issued under the authority of

the Minister of Innovation, Science and Industry

____________________________________

Martin Proulx

Director General

Engineering, Planning and Standards Branch

Contents

• 1. Intent
• 2. General
• 3. Related documents
• 4. Definitions
• 5. Fixed use spectrum licences in the 3475-3650 MHz band
• 6. Band plan
• 7. Technical criteria
• 8. General guidelines for the coexistence of flexible use broadband systems operating in the same frequency blocks and in adjacent service areas
• 9. General guidelines for the coexistence of flexible use broadband systems operating in adjacent frequency block groups
• 10. Coexistence with other systems
• 11. International coordination
• Annex A: Coordination procedure near the Canada-United States border
• Annex B: Sample pfd calculation
• Annex C: List of FSS earth stations in the frequency band 3500-3650 MHz
• Annex D: Definition of exclusion zones
• Annex E: Provisions applicable to protection zones
• Annex F: Lists of satellite dependent tiers, consolidated gateways, and tiers impacted by Government of Canada’s FSS operations
• Annex G: Receiver filter parameters for FSS earth station licensed only in the 4000-4200 MHz band
• Annex H: Fixed service sites in the 3800 MHz band

1. Intent

1. This Standard Radio System Plan (SRSP-520) replaces SRSP-303.4, Technical Requirements for Fixed Wireless Access Systems Operating in the Band 3475-3650 MHz, issue 3. SRSP-520 sets out the minimum technical requirements for the efficient use of the band 3450-3900 MHz and applies to fixed and mobile systems, including flexible use broadband systems, operating in the band. (“Flexible use” refers to deployment of mobile and/or fixed services.) However, as indicated in section 5, below, specific provisions of SRSP-303.4, issue 3, continue to apply for fixed spectrum licences issued prior to June 2019, and for fixed spectrum licences issued after June 2019 as a result of the conversion of existing fixed spectrum licences from Tier 4 to Tier 5 licence areas.

2. SRSP-520 does not apply to fixed and/or mobile systems operating in the 3650-3700 MHz band and deployed under a Wireless Broadband Services (WBS) spectrum licence. These systems must comply with the provisions in SRSP-303.65, Technical Requirements for Wireless Broadband Services (WBS) in the Band 3650-3700 MHz.

3. SRSP-520 is intended to aid in the design of radio systems and specifies the technical characteristics relating only to efficient spectrum usage; it is not to be regarded as a comprehensive specification for equipment design and/or selection.

2. General

4. This SRSP is based on current and planned technologies being considered by service provider(s) for implementing flexible use broadband systems in Canada. Revisions to this SRSP will be made as required.

5. Notwithstanding the fact that a system satisfies the requirements of this SRSP, Innovation, Science and Economic Development Canada (ISED) may require adjustments to radio and auxiliary equipment in radio stations whenever harmful interference is caused to other radio stations or systems. “Harmful interference,” as defined in the Radiocommunication Act, means an adverse effect of electromagnetic energy from any emission, radiation or induction that (a) endangers the use or functioning of a safety-related radiocommunication system; or (b) significantly degrades or obstructs, or repeatedly interrupts, the use or functioning of radio apparatus or radio-sensitive equipment.

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

7. Airborne operations (e.g. drones) are not permitted in the 3450-3900 MHz band.

8. ISED should be advised when potential conflict between radio systems cannot be resolved by the parties concerned. After consultation with these parties, ISED will determine what modifications need to be made and establish a schedule for these modifications in order to resolve the conflict.

9. ISED may require licensees to use receiver selectivity characteristics that provide improved rejection of harmful interference.

10. Equipment operating under flexible use licences in the 3450-3900 MHz band must be certified in accordance with the latest issue of Radio Standards Specification RSS-192, Flexible Use Broadband Equipment Operating in the Band 3450-3900 MHz [link to be added when available]. Equipment operating under fixed use spectrum licences may continue to operate, provided that such equipment has been previously certified in accordance with RSS-192, issue 3. Operation under fixed use spectrum licences is subject to the operational conditions defined in section 5 of this SRSP.

11. Licensees are required to make information on certain technical parameters of their radio systems available to ISED upon request.

3. Related documents

12. The current issues of the following documents are applicable and are available on the Spectrum management and telecommunications website.

TRAA

Treaty Series 1962 No. 15 – Coordination and Use of Radio Frequencies – Exchange of Notes between Canada and the United States of America

Interim Statement of Intent Between the Federal Communications Commission of the United States of America and the Department of Innovation, Science and Economic Development Canada Related to the Sharing and Use of the Frequency Band 3550-3650 MHz by Fixed and Mobile Services Along the Canada-United States Border (forthcoming)

CTFA

Canadian Table of Frequency Allocations

SP Gen

General Information Related to Spectrum Utilization and Radio Systems Policies

DGSO-007-14

Decisions Regarding Policy Changes in the 3500 MHz Band (3475-3650 MHz) and a New Licensing Process

SLPB-001-19

Decision on Revisions to the 3500 MHz Band to Accommodate Flexible Use and Preliminary Decisions on Changes to the 3800 MHz Band

SLPB-001-20

Policy and Licensing Framework for Spectrum in the 3500 MHz Band

SLPB-002-21

Decision on the Technical and Policy Framework for the 3650-4200 MHz Band and Changes to the Frequency Allocation of the 3500-3650 MHz Band

 

3500 MHz Transition Manual

 

3800 MHz Transition Manual [Insert link when available]

SLPB-002-22

Policy and Licensing Framework for Spectrum in the 3800 MHz Band

SMSE-008-22

Decision on Updates to the Licensing and Fee Framework for Earth Stations and Space Stations in Canada

RSS-Gen

General Requirements for Compliance of Radio Apparatus

RSS-192

Flexible Use Broadband Equipment Operating in the Band 3450-3900 MHz [Insert link when available]

RSS-102

Radio Frequency (RF) Exposure Compliance of Radiocommunication Apparatus (All Frequency Bands)

RSP-100

Certification of Radio Apparatus and Broadcasting Equipment

CPC-2-0-03

Radiocommunication and Broadcasting Antenna Systems

CPC-2-1-23

Licensing Procedure for Spectrum Licences for Terrestrial Services

SAB-001-21

Radio Altimeters and Technical Rules in the 3450-3650 MHz Band (3500 MHz Band)

[TBD]

[Technical requirements for earth stations in the 4000-4200 MHz band]

______________________________

• CPC – Client Procedures Circulars
• CTFA – Canadian Table of Frequency Allocations
• DGSO – Canada Gazette Notice
• RSP – Radio Standards Procedures
• RSS – Radio Standards Specifications
• SAB – Spectrum Advisory Bulletin
• SLPB – Canada Gazette Notice
• SP – Spectrum Utilization Policies
• TRAA – Terrestrial Radiocom Agreements and Arrangements

4. Definitions

13. The following terms are used in this document.

Active antenna system (AAS)
An antenna system where the amplitude and/or phase between antenna elements is dynamically adjusted resulting in an antenna pattern that varies in response to short-term changes in the radio environment. AAS may be integrated in a point-to-multipoint (P-MP) hub station, base station and non-fixed subscriber equipment. Antenna systems used for long-term beam shaping such as fixed electrical down tilt are not considered an AAS.

AAS base station equipment
A base station with an AAS antenna system.

Non-active antenna system (Non-AAS)
An antenna system that does not meet the definition of AAS.

Non-AAS base station equipment
A base station with a non-AAS antenna system.

Adjacent frequency block group
In the context of this SRSP, adjacent frequency block group is defined as a continuous frequency range of multiple block(s) of 10 MHz that contains the equipment’s channel bandwidth. For equipment with channel bandwidth smaller than 10 MHz, the frequency block group is the frequency range of a 10 MHz block.

Antenna height above average terrain (HAAT)
The height of the centre of radiation of the antenna above the average elevation of the terrain between 3 and 16 km from the antenna, for an individual radial. The final antenna HAAT (also known as the effective height of the antenna above average terrain (EHAAT) is the average of the antenna HAATs for 8 radials spaced every 45 degrees of azimuth starting with true north.

5. Fixed use spectrum licences in the 3475-3650 MHz band

14. Fixed stations operating in the 3475-3650 MHz band under fixed spectrum licences issued prior to June 2019, and those which have since been converted from Tier 4 to Tier 5 area licences, may continue to operate under SRSP-303.4, issue 3. Modifications to these existing fixed stations are allowed as long as the modifications comply with SRSP-303.4, issue 3. Any modified station not in compliance with SRSP-303.4, issue 3, will be considered a new fixed station. New fixed stations in the 3475-3650 MHz band are permitted, provided that they comply with all requirements specified in this SRSP, with the exception of the band plan in paragraphs 18 and 19; instead, new fixed stations shall be required to comply with the band plan specified in SRSP-303.4, issue 3. Collectively, stations deployed under these fixed spectrum licences are hereafter referred to as “fixed spectrum licence deployments.”

15. Notwithstanding compliance with SRSP-303.4, issue 3, or SRSP-520, all fixed spectrum licence deployments are subject to the transition plan outlined in section 6.9 of SLPB-001-19, Decision on Revisions to the 3500 MHz Band to Accommodate Flexible Use and Preliminary Decisions on Changes to the 3800 MHz Band, the transition process general guidelines outlined in section 15 of SLPB-001-20, Policy and Licensing Framework for Spectrum in the 3500 MHz Band, and the 3500 MHz Transition Manual.

16. The guidelines for coordination to resolve possible interference conflicts between fixed spectrum licence deployments and stations operating under flexible use licences are outlined in the 3500 MHz Transition Manual.

17. The guidelines for coordination to resolve possible interference conflicts between fixed spectrum licence deployments are outlined in SRSP-303.4, issue 3.

6. Band plan

18. The block structure for flexible use broadband systems in the 3450-3650 MHz (3500 MHz) and 3650-3900 MHz (3800 MHz) bands are shown in figures 1 and 2.

Figure 1: 3500 MHz band plan

Description of figure 1

This figure shows the 3500 MHz band plan, which includes the frequency range of 3450 to 3650 MHz. The frequency range is divided into 20 unpaired blocks of 10 MHz each, labelled from “A” to “V” except “I” and “O”.

Figure 2: 3800 MHz band plan

Description of figure 2

This figure shows the 3800 MHz band plan, which includes the frequency range of 3650 to 3900 MHz. The frequency range is divided into 25 unpaired blocks of 10 MHz each, labelled from “W” to “Z” and from “AA” to “AW” (except “AI” and “AO”).

19. Frequency blocks available for licensing in the 3450-3900 MHz band are intended for use with time division duplexing (TDD) systems. The band is divided in 45 unpaired blocks of 10 MHz. Frequency blocks can be aggregated to form a frequency block group. A frequency block group is a continuous frequency range of multiple block(s) of 10 MHz.

20. Non-TDD flexible use broadband systems operating in the 3450-3900 MHz band may be deployed. Such systems shall not interfere with, nor claim protection from, TDD flexible use broadband systems. Furthermore, flexible use broadband system licensees using non-TDD technology are required to provide sufficient guard bands or other mitigation measures such as the use of external filters, to reduce equivalent isotropically radiated power (e.i.r.p.) or total radiated power (TRP) to levels that are consistent with the unwanted emission limits set out in RSS-192.

21. Operations of new flexible use broadband systems in the 3450-3650 MHz band according to the above band plan are subject to the transition plan outlined in SLPB-001-19, the transition process general guidelines outlined in section 15 of SLPB-001-20, and the 3500 MHz Transition Manual.

22. Operations of new flexible use broadband systems in the 3650-3900 MHz band according to the above band plan are subject to the transition plan outlined in section 10 of SLPB-002-21 and the 3800 MHz Transition Manual [insert link when available].

[Editor’s note: 3800 MHz transition manual is under development.]

7. Technical criteria

23. This section covers technical criteria in regards to power, antenna height and use of multiple-input-multiple-output (MIMO) antennas.

7.1 Fixed and base stations using non-active antenna systems

24. This section outlines the technical criteria for fixed and base stations using non-active antenna systems (non-AAS).

7.1.1 E.i.r.p. for non-AAS correlated transmission

25. In non-AAS correlated transmission, multiple non-AAS antennas are used at a station to transmit the same digital data in a given symbol period (even with different coding or phase shifts) for transmit diversity, or to steer signal energy towards a particular direction for enhanced directional gain (i.e. beamforming), or to devise any other transmission mode where signals from different antennas are correlated, the equivalent isotropically radiated power (e.i.r.p.) shall be calculated based on the aggregate power conducted across all antennas and resulting directional gain 10log₁₀(N)+G_max dBi. Here, N is the number of antennas and G_max is the highest gain in dBi among all antennas.

7.1.2 E.i.r.p. for non-AAS uncorrelated transmission

26. In non-AAS uncorrelated transmission, multiple non-AAS antennas are used at a station in which each antenna transmits different digital data during any given symbol period (i.e. space-time block codes) or independent parallel data stream over the same frequency bandwidth in order to increase data rates (i.e. spatial multiplexing), or from any other transmission mode where signals from different antennas are completely uncorrelated, the e.i.r.p. shall be calculated based on the aggregate power conducted across all antennas and maximum antenna gain G_max.

7.1.3 E.i.r.p. limits and antenna height limits for non-AAS systems

27. For fixed and base stations transmitting in accordance with section 6 of this SRSP within the 3450-3900 MHz band with a channel bandwidth equal to or greater than 5 MHz, the maximum permissible e.i.r.p. is 68 dBm/5 MHz (i.e. no more than 68 dBm e.i.r.p. in any 5 MHz band segment) for stations with an antenna height above average terrain (HAAT) of up to 305 metres. For stations with a channel bandwidth less than 5 MHz, the maximum permissible e.i.r.p. is 61 dBm/MHz.

28. Irrespective of the e.i.r.p. limits defined in paragraph 27 above, fixed and base stations operating in the frequency band 3450-3900 MHz shall not exceed the e.i.r.p. limits defined in section 10.5 below.

29. For all installations with an antenna HAAT of more than 305 metres, a corresponding reduction in e.i.r.p. according to the following formula shall be applied:

e.i.r.p._reduction = 20log₁₀(HAAT / 305) dB

30. The HAAT of a fixed P-P station or flexible use base station with multiple antennas shall be calculated with reference to the highest antenna.

31. In mountainous areas where a licensee can demonstrate that the installation will not cause interference to other licensees in adjacent geographical service areas, this e.i.r.p. reduction is not required. In the context of this SRSP, a “mountainous area” is defined as a location, at which the ground level of the site has a HAAT greater than 305 metres and there is a terrain feature within 50 km that rises to an elevation higher than the ground level of the site. However, if an interference case arises involving any stations with HAAT above 305 metres, then the station(s) with HAAT above 305 metres will be required to reduce e.i.r.p. according to the formula in paragraph 29, above.

7.2 Fixed and base stations using active antenna systems

32. This section outlines the technical criteria for fixed and base stations using active antenna systems (AAS).

7.2.1 E.i.r.p. limits and antenna height limits for AAS systems

33. Fixed and base stations transmitting in accordance with section 6 of this SRSP within the 3450-3900 MHz band using active antenna system (AAS), the following technical requirements in table 1 apply.

34. The following equation shall be used in determining the e.i.r.p. for fixed and base stations operating in the 3450-3900 MHz band to ensure compliance with the maximum permissible e.i.r.p. specified in table 1 above:

e.i.r.p. = TRP + G_e + 10 log₁₀ (min (N_TX, 8))

where:
TRP is the total radiated power
G_e is the gain of one antenna element in dBi
N_TX is the number of transmit antenna elements.
The maximum permissible TRP limits are specified in RSS-192.

35. Irrespective of the e.i.r.p. formula defined in paragraph 34 above, fixed and base stations operating in the frequency band 3450-3900 MHz shall not exceed the e.i.r.p. limits defined in section 10.5 below.

36. In mountainous areas where a licensee can demonstrate that the installation will not cause interference to other licensees in adjacent geographical service areas, e.i.r.p. reduction is not required. In the context of this SRSP, a “mountainous area” is defined as a location, at which the ground level of the site has a HAAT greater than 305 metres and there is a terrain feature within 50 km that rises to an elevation higher than the ground level of the site. However, if an interference case arises involving any stations with HAAT above 305 metres, then the station(s) with HAAT above 305 metres will be required to reduce e.i.r.p. according to the formula in table 1, above.

7.3 Power limits for subscriber equipment

37. A wide array of subscriber equipment (e.g. mobile, nomadic, portable and fixed subscriber equipment) is expected to be supported by flexible use broadband systems. Maximum power limits for subscriber equipment are specified in RSS-192. The equipment should employ automatic transmit power control such that stations operate on the minimum required power.

7.4 Transmitter unwanted emissions

38. Transmitter unwanted emissions are specified in RSS-192. [Add link when new issue available]

8. General guidelines for the coexistence of flexible use broadband systems operating in the same frequency blocks and in adjacent service areas

39. This section deals only with coexistence between flexible use broadband systems. See section 5 of this SRSP for coordination guidelines for resolving possible interference conflicts between fixed spectrum licence deployments, or between fixed spectrum licence deployments and flexible use broadband systems.

40. When several flexible use licensees are authorized to operate systems using the same frequency block in adjacent licensing areas, coordination of any transmitter installations that are close to the licence area boundary shall be required to eliminate any harmful interference that might otherwise exist and ensure continuance of equal access to the frequency block by the affected licensees.

41. Fixed or base stations must not generate a power flux density (pfd) outside the licensed service area that exceeds -114.5 dBW/m² in any 1 MHz, unless agreed otherwise by the affected licensee. The pfd of -114.5 dBW/m²/MHz corresponds to an approximate field strength of 31.3 dBuV/m/MHz and a receiver power of -116.9 dBm/MHz. An example of a calculation for pfd is given in Annex B.

42. A pfd of -114.5 dBW/m²/MHz may be exceeded at or beyond a flexible use licensee’s service area boundary on a provisional basis where, within 70 km of its service area boundary, there is no station deployment by the neighbouring licensee (70 km zone). Licensees are encouraged to consult ISED’s Spectrum Management System for the latest deployment data for stations within 70 km of their service area boundary, and shall notify the licensees operating in the adjacent area for which the pfd of -114.5 dBW/m²/MHz is exceeded. However, in the event that new stations are deployed by the neighbouring licensee within the 70 km zone, both licensees will be required to meet the pfd at their respective service area boundary, unless otherwise agreed by both licensees.

43. Any fixed or base station will require further coordination with relevant flexible use licensees where any proposed modifications:

• result in a pfd at or beyond the other service area boundary exceeding a pfd of 114.5 dBW/m²/MHz; or
• involve operation on frequencies not previously coordinated; or
• change the polarization.

44. Possible harmful interference conflicts resulting from the operation of two flexible use broadband systems in adjacent geographical service areas may occur. The resolution of these conflicts should be arrived at through mutual arrangements between the affected parties following consultation and coordination. When potential conflicts between systems cannot be resolved in a timely fashion, ISED shall be so advised, whereupon, following consultations with the parties concerned, ISED will determine the necessary course of action.

45. System expansion measures, such as addition of cells, cell splitting and sectorization, must not force major changes in the system of the flexible use licensee in the adjacent geographical service area, except by mutual agreement between the affected parties. Major changes include those that would have potential impacts on the other licensee, including cell site locations, cell sectorization and cell splitting, require consultation with the other licensee.

46. All results of the analyses concerning the pfd and the agreements made between the licensees must be retained by the licensees and made available to ISED upon request.

9. General guidelines for the coexistence of flexible use broadband systems operating in adjacent frequency block groups

47. This section deals only with coexistence between flexible use broadband systems. See section 5 of this SRSP for coordination guidelines for resolving possible interference conflicts between fixed spectrum licence deployments, or between fixed spectrum licence deployments and flexible use broadband systems.

48. For TDD unsynchronized operations of fixed or base stations by different licensees in adjacent frequency blocks in the same geographic area, licensees are required to coordinate with each other if their emissions exceed the following limits in a particular adjacent frequency block:

1. an e.i.r.p. limit of -34 dBm/5 MHz for non-AAS fixed P-P stations and flexible use base stations; or
2. a TRP limit of -43 dBm/5 MHz for AAS fixed P-P stations and flexible use base stations.

49. During coordination, licensees may consider techniques including, but are not limited to, one or a combination of the following: the use of guard bands, the use of external filters, reducing e.i.r.p. or TRP, and synchronization of TDD operations. “Synchronized TDD operations” means operation of two or more different TDD systems where timeframes of all systems are synchronized in regards to start of the frame and uplink and downlink transmission durations.

50. Possible interference conflicts resulting from the operation of two flexible use broadband systems operating in adjacent block groups may occur even though the technical specifications of both this SRSP and RSS-192 are being met. The resolution of those conflicts should be arrived at through mutual arrangements between the affected parties following consultation and coordination.

51. When potential conflicts between systems cannot be resolved, ISED shall be so advised, whereupon, following consultations with the parties concerned, ISED will determine the necessary modifications and schedule of modifications.

10. Coexistence with other systems

52. Coexistence with other radio service licensees, both in-band and adjacent-band, is required. In this context, specific requirements are provided below, and in some cases, coordination may also be required. Coordination involves consultation between licensees to ensure coexistence with other systems including wireless broadband services (WBS), and fixed-satellite services (FSS).

53. Where an interference conflict occurs, licensees are directed to resolve the conflict through mutual arrangements between the affected parties following consultation and coordination.

54. When potential conflicts between systems cannot be resolved in a timely fashion, ISED shall be so advised, whereupon, following consultations with the parties concerned, ISED will determine the necessary course of action.

10.1 Coexistence between flexible use systems in the 3450-3650 MHz band and Radiolocation systems in the 3400-3650 MHz band

55. As indicated in section 6 of SLPB-001-19, existing government users confirmed that removal of the radiolocation allocation in the 3450-3500 MHz band in Canada would not negatively impact the operation of government radiolocation users. However, there is still some maritime radar use in the United States in the 3400-3650 MHz band. As a result, fixed or mobile systems operating in the cities of Halifax, Dartmouth and Vancouver, and nearby coastal areas including those communities that are along the Straits of Georgia and Juan de Fuca, would not be protected from potential interference in the 3450-3650 MHz band due to occasional radar use, particularly in the lower portion of the frequency band.

56. Further, there is the potential for intermittent interference resulting from aeronautical radar use below 3450 MHz in Canada and in the 3400-3650 MHz band in the United States from which fixed or mobile systems would not be protected.

10.2 Coexistence between flexible use systems in the 3450-3900 MHz band and Wireless Broadband systems (WBS) in the 3650-3700 MHz band

57. The displacement plan for WBS in the 3650-3700 MHz band is specified in SLPB-002-21, Decision on the Technical and Policy Framework for the 3650-4200 MHz Band and Changes to the Frequency Allocation of the 3500-3650 MHz Band. Specifically, the following displacement deadlines apply:

1. March 31, 2025 – for WBS operations in all metropolitan and urban Tier 5 service areas as specified in SLPB-002-21; and
2. March 31, 2027 – for WBS operations in rural and remote Tier 5 service areas.

58. As per SLPB-002-21, prior to the applicable displacement deadlines, WBS (where permitted to operate) are protected from interference from flexible use operations in the 3650-3900 MHz band. As well, flexible use licensees in the 3450-3650 MHz band are required to coordinate with WBS licensees prior to deployment. The coexistence requirements are specified in the 3800 MHz Transition Manual [insert link when available].

59. After the applicable displacement deadlines, WBS operations will no longer be protected from other services, including flexible use systems.

10.3 Coexistence between flexible use systems in the 3450-3650 MHz band and site-approved FSS earth station operations in the 3500-3650 MHz band

60. As indicated in Annex C, a limited number of FSS earth stations operate in the 3500-3650 MHz band. Flexible use spectrum licensees in the 3450-3650 MHz band planning to establish fixed or mobile systems within 80 km of these FSS earth stations (80 km zone) are required to coordinate with earth station licensees. The 80 km zone excludes any area that overlaps with a large or medium population centre. According to Statistics Canada’s Census Dictionary, a large urban population centre (LPC) has a population of 100,000 or more and a population density of 400 persons or more per km², and a medium population centre (MPC) has a population between 30,000 and 99,999 and a population density of 400 persons or more per km². MapInfo files describing the boundaries of these centres are available online. To facilitate coordination, fixed spectrum licensees and flexible use spectrum licensees in the 3450-3650 MHz band shall notify the FSS operator no less than 30 calendar days prior to deployment. If no objection is raised within the 30 days, fixed spectrum licensees or flexible use spectrum licensees may proceed with their deployment.

10.4 Coexistence between flexible use systems in the 3450-3900 MHz range and FSS earth station operations in the 3700-4200 MHz range

61. Further to SMSE-008-22, Decision on Updates to the Licensing and Fee Framework for Earth Stations and Space Stations in Canada, for earth stations in the 3700-4200 MHz range:

• site-specific radio licences will be converted to site-approved earth station spectrum licences;
• interim authorizations will be converted to generic earth station spectrum licences.

62. Coexistence between flexible use and FSS systems differs depending on the frequency range in which either system operates and whether an FSS earth station is subject to transition. Specific provisions for each relevant band apply.

63. In addition, for the purposes of this SRSP, “non-transitioned” earth stations which may continue to operate in the 3700-4200 MHz band are defined as:

1. Site-approved earth stations in satellite-dependent areas that were licensed before the publication of SLPB-002-21 (May 21, 2021) or generic earth stations in satellite-dependent areas that were uploaded to ISED’s Spectrum Management System under an interim authorization before October 22, 2021 (see Table F1 of Annex F);
2. Site-approved earth stations operating at consolidated gateway sites as listed in Table F2; and
3. Site-approved earth stations operated by Government of Canada at various locations, including in the North Bay area and in certain satellite-dependent areas (see paragraph 65 below).

64. For locations of non-transitioned earth stations, licensees are required to consult the list of licensed FSS earth stations in the 3700-4200 MHz band using ISED’s Spectrum Management System search tool.

65. Further, station information for Government of Canada operations identified above are not available to the public. As such, licensees operating in tiers identified in Tables F3 and F4 in Annex F shall use ISED’s Protected Microwave Frequency Information Search to obtain operator contact information of these non-transitioned Government of Canada earth stations.

66. An earth station is not considered as non-transitioned if its corresponding satellite operates only in the 4000-4200 MHz band.

67. Technical and operational requirements for earth stations in the 4000-4200 MHz band will be addressed in a separate document [under development - add title and link when available].

10.4.1 Coexistence between flexible use systems in the 3450-3700 MHz band and site-approved non-transitioned FSS earth station operations in the 3700-4200 MHz band

68. Prior to March 31, 2025, the coexistence requirements between fixed or mobile systems and existing site-approved non-transitioned FSS earth stations operating in the 3700-4200 MHz band are specified in the 3800 Transition Manual.

69. After March 31, 2025, licensees planning to establish a fixed or base station in the 3450 3700 MHz band (this does not include fixed or base stations with an authorized bandwidth that extends into the frequency range 3700-3900 MHz for which section 10.4.3 would apply) must notify the FSS operator of site-approved non-transitioned earth station at least a year in advance, if the fixed or base station:

1. is within 25 km of a non-transitioned site-approved earth station; or
2. exceeds a pfd limit of -87.72 dBW/m²/MHz at a site-approved non-transitioned earth station antenna, regardless of proximity to such earth station. This pfd limit applies to all emissions within the fixed or base station’s authorized bandwidth.

70. Notwithstanding the above requirements in paragraph 69, for fixed and base stations whose licensed frequency blocks do not extend above 3700 MHz, the unwanted emissions from these fixed or base stations shall not exceed -13 dBm TRP /MHz (per cell) or conducted power (all antenna connectors), where applicable, above 3700 MHz.

10.4.2 Coexistence between flexible use systems in the 3700-3900 MHz band and non-transitioned FSS earth station operations in the 3700-4200 MHz band

71. Prior to March 31, 2025, the coexistence requirements between fixed or mobile systems with non-transitioned FSS earth stations operating in the 3700-4200 MHz band are specified in the 3800 MHz Transition Manual [insert link when available].

72. After March 31, 2025:

1. Licensees planning to establish fixed or mobile systems in the 3700-3900 MHz band are required to protect non-transitioned FSS earth station operations in the 3700-4200 MHz band.
2. Fixed or base stations must not exceed the applicable pfd limit set out in Table 2 at a non-transitioned earth station’s antenna, unless otherwise agreed by the affected operators. The pfd limit applies to all emissions within the earth station’s authorized band of operation, 3700 4200 MHz.

   Table 2: PFD limits at the earth stations’ antenna based on their elevation angle

   Earth station antenna elevation angle (Θ)	Pfd limit (dBW/MHz/m2) at the earth station’s antenna
   Θ ≤ 5°	-158
   5° < Θ ≤ 10°	-140
   10° < Θ ≤ 15°	-133
   15° < Θ ≤ 20°	-128
   20° < Θ ≤ 25°	-125
   25° < Θ ≤ 30°	-123
   30° ≤ Θ	-121

3. In the event of interference (irrespective of fixed or base station meeting the above technical rules), it is the responsibility of the flexible use licensee to mitigate the interference (e.g., reduce power, adjust antennas, etc.) to any non-transitioned FSS earth station.

10.4.3 Coexistence between flexible use systems in the 3700-3900 MHz band and site-approved or generic FSS earth stations licensed only in 4000-4200 MHz

73. Licensees planning to establish fixed or mobile systems in the 3700-3900 MHz band are required to protect existing site-approved or generic FSS earth stations licensed to only operate in the 4000-4200 MHz band in all areas, as long as these earth stations meet the receiver filter parameters provided in Annex G. Earth station operations in 4000-4200 MHz do not include non-transitioned earth stations (for which section 10.4.2 would apply).

74. In line with the above, licensees planning to establish a fixed or base station in the 3700-3900 MHz band must coordinate with existing site-approved or generic FSS earth station operators in the 4000-4200 MHz band, if the planned fixed or base station:

• is within 25 km of an existing site-approved or generic FSS earth station; or
• exceeds a pfd limit of -6.2 dBW/m²/MHz at an existing site-approved or generic FSS earth station antenna, regardless of proximity to such earth station. This pfd limit applies to all emissions within the fixed or base station’s authorized bandwidth.

75. Unless agreed to by the affected earth station operator, these above limits cannot be exceeded and planned fixed or base station cannot be deployed within 25 km of the earth station.

76. Station information for Government of Canada operations identified above are not available to the public. As such, licensees planning to establish fixed or mobile systems in the 3700-3900 MHz band must also consult table F4 of annex F to determine if the planned fixed or base station is located in one of the Tier 4 service areas which may potentially impact an aforementioned earth station and belongs to Government of Canada. Before deploying any planned fixed or base station, licensees must coordinate with the Government of Canada earth station operator to ensure the conditions in paragraph 74 are met.

77. Section 10.4.3 provides protection to site-approved or generic FSS earth stations that have already been authorized (i.e. existing stations) prior to the establishment of a fixed or base station. Thus, in the event of interference (irrespective of fixed or base station meeting the above technical rules), it is the responsibility of the flexible use licensee to mitigate the interference (e.g., reduce power, adjust antennas, etc.) to the existing licensed FSS earth stations if the FSS earth stations meet the receiver filter specifications in Annex G. Site-approved or generic FSS earth stations authorized after the establishment of fixed or base stations may not claim protection from such fixed or mobile stations.

10.5 Coexistence between flexible use systems in the 3450-3900 MHz band and radio altimeters in the radionavigation service

78. Radio altimeters operate in the radionavigation service in the 4200-4400 MHz band. For coexistence between licensees in the 3450-3900 MHz band and radio altimeters in the 4200-4400 MHz band, all outdoor stations shall meet the following requirements:

1. Irrespective of the technical limits described in paragraphs 27 and 34, all non-AAS and AAS fixed and/or base stations shall not exceed a maximum e.i.r.p. of 77.5 dBm per carrier, calculated as follows:
   (e.i.r.p.)_max = TRP + G_e + 10 log₁₀ (N_Tx)
   where G_e is the gain of one antenna element in dBi, N_Tx is the maximum number of transmit antenna elements used to dynamically direct energy to form a beam and TRP per carrier.
2. Outdoor non-AAS and AAS fixed point-to-point and point-to-multipoint stations operating outside of Low Population Centres (LPCs) and Medium Population Centres (MPCs) (as defined in section 10.3) with a positive elevation angle with reference to the horizon, which is defined as the combination of electrical and mechanical tilt, and a channel bandwidth equal to or greater than 5 MHz shall not exceed a maximum e.i.r.p. of 55 dBm/5 MHz (i.e. no more than 55 dBm e.i.r.p. in any 5 MHz band segment). For stations with a channel bandwidth less than 5 MHz, the maximum e.i.r.p. shall not exceed 48 dBm/MHz. The e.i.r.p. of AAS fixed point-to-point and point-to-multipoint stations shall be calculated as follows:
   (e.i.r.p.)_max = TRP + G_e + 10 log₁₀ (N_Tx)
   where G_e is the gain of one antenna element in dBi, N_Tx is the maximum number of transmit antenna elements used to dynamically direct energy to form a beam and TRP is measured in dBm/5 MHz for channel bandwidth equal to or greater than 5 MHz or in dBm/MHz for channel bandwidth less than 5 MHz.
3. Outdoor non-AAS and AAS base stations outside of LPCs and MPCs shall operate their antenna systems at a negative elevation angle with reference to the horizon, which is defined as the combination of electrical and mechanical tilt.

79. No licensee shall operate a station within an exclusion zone around a runway or H1-classified heliport as defined in Annex D.

80. Licensees of existing stations already in operation prior to the publication of SRSP-520, issue 3, and any licensee planning to operate a new station or modify an existing station within a protection zone around a runway or H1-classified heliport as defined in sections E.1 and E.2 of Annex E shall conduct analyses to ensure compliance with all of the technical and operational requirements defined in section E.3. Reports of the analyses shall be included in a Pre-Operation Report as described in section E.4 and kept on file by the licensee. Licensees shall submit an attestation to ISED as described in section E4.4 at least 15 days prior to operation of any new station or to implementing any modification to an existing station. Licensees of existing stations shall submit an attestation within 15 days of the publication of SRSP-520, issue 3.

81. The provisions described in this section do not apply to indoor stations.

10.6 Coexistence between flexible use systems in the 3700-3900 MHz band and fixed services in the 3700-3900 MHz band

82. There are currently two fixed systems in operation located in two different Tier-4 areas listed in annex H. Flexible use licensees may not claim protection from, nor cause interference to these existing fixed systems.

83. One of these fixed systems is operated by the Government of Canada - Department of National Defence (DND). Although flexible use licensees planning to deploy stations in such tier is required to protect DND’s system, due to the nature of its operation, only limited technical information may be available. Thus, DND will be responsible to contact the flexible use licensees that may impact its operations and disclose the necessary information to ensure its fixed system is protected.

84. In the event of interference, it is the responsibility of the flexible use licensee to mitigate the interference (e.g., reduce power, adjust antennas, etc.) to these fixed systems (at their grandfathered operating parameters).

11. International coordination

85. Through their conditions of licence, flexible use licensees will be required to abide by certain technical requirements and to coordinate with U.S. licensees in accordance with the conditions of any international arrangements or agreements into which Canada enters for the 3450-3550 MHz, 3550-3700 MHz and 3700-3900 MHz bands.

86. Specific coordination rules and procedures for the sharing of the band 3450-3550 MHz, 3550-3700 MHz and 3700-3900 MHz between Canadian and U.S. licensees are under negotiation between ISED and the Federal Communications Commission (FCC).

87. Until the negotiation is finalized, the coordination process is outlined in annex A shall be used.

88. Canadian licensees are encouraged to enter into agreements with U.S. licensees (Agreements) to facilitate coordination, which should:

1. allow reasonable and timely development of the respective systems of the licensees;
2. allow for the provision of services by licensees within their service areas on either side of the border to the maximum extent possible;
3. utilize all available interference mitigation techniques, including antenna directivity, polarization, frequency offset, shielding, site selection and/or power control; and
4. continue to apply to any subordinate licensees or transferees.

89. Licensees must retain all data and calculations related to coordination of stations and/or Agreements and must provide ISED with such data and calculations, along with other supporting documentation, upon request.

90. If a licence is transferred, assigned or reissued, ISED requires any existing agreement forming the basis for coordination to continue to apply to the new licensee unless a new agreement is reached.

11.1 Flexible use to flexible use coordination

91. Until the international agreements are finalized, flexible use licensees planning to establish or modify a fixed or base station within 70 km of the Canada-U.S. border shall coordinate with the U.S. flexible use licensees if the ground level pfd exceeds -114.5 dBW/m²/MHz in other country’s territory.

92. The maximum pfd limit in paragraph 91 can only be exceeded upon successful coordination between licensees

93. These requirements are subject to change from time to time in accordance with international agreements.

11.2 Flexible use and FSS coordination

94. With respect to coordination with U.S. FSS registered earth stations operating in the 4000-4200 MHz band, the sharing zone is defined as an [x] km area from the border.

95. Pending the arrangements, coordination of a new fixed or base station within the sharing zone is required if:

1. The station exceeds a pfd limit of -124 dBW/m²/MHz as measured at the earth station antenna. This pfd limit applies to all emissions within the earth station’s authorized band of operation, 4000-4200 MHz.
2. the station exceeds a pfd limit of -16 dBW/m²/MHz applied across the 3700-3900 MHz band at the earth station antenna. The pfd limit applies to all emissions within the fixed or base station’s authorized bandwidth.

96. These maximum pfd limits in paragraph 95 can only be exceeded upon successful coordination between licensees.

97. These requirements are subject to change from time to time in accordance with international agreements.

Annex A: Coordination procedure near the Canada-United States border

When coordination with U.S. licensees is required, Canadian licensees must complete the process outlined below.

The licensee seeking coordination shall determine the maximum power flux density (pfd) at and beyond the border that could be produced by any single transmitting station. In making this determination (calculation), the licensee shall use sound engineering practices and generally accepted terrain-sensitive propagation models.

The licensee must communicate with any affected U.S. licensee and either enter into an Agreement as defined in this SRSP or provide the U.S. licensee with a Coordination Request.

A Coordination Request shall set out information and parameters including, but not limited to, the following:

• licensee information (corporate name/mailing address/telephone/email)
• licensed service areas
• point of contact
• location of transmitter (community/province/territory)
• geographic coordinates of transmitting antenna
• effective isotropically radiated power (e.i.r.p.) or total radiated power (TRP) (dBW)
• ground elevation and antenna height above ground (m)
• centre frequency (MHz)
• antenna polarization
• antenna pattern/tabulation of the pattern
• azimuth of the maximum antenna gain
• bandwidth and emission designation

The Coordination Request shall be sent by registered mail (or mutually acceptable method) and shall provide notification that the recipient may respond by registered mail (or mutually acceptable method) within 30 days of its receipt to state any objection to deployment of the proposed facilities. It should be noted that the date of postmark shall be taken as the date of response. If no objection is raised by the U.S. licensee within this time period, then the coordination process may be considered complete.

If a recipient of a Coordination Request raises an objection within 30 days of receipt of that request, licensees shall collaborate to develop a mutually acceptable solution to the potential interference problem (an Agreement).

In the event that the Canadian licensee and the U.S. licensee cannot reach an Agreement within 30 days of receipt of an objection, the Canadian licensee may request that ISED facilitate resolution of the case with the Federal Communications Commission (FCC) in the United States.

A station that requires coordination shall not be placed in operation until an Agreement has been reached between the relevant licensees or until ISED and the FCC have agreed on sharing terms.

Annex B: Sample pfd calculation

The following example illustrates how the pfd at the service area boundary may be determined. Note that the calculation in the example assumes line‑of‑sight conditions. Where line-of-sight does not exist, an appropriate propagation model that takes the non-line-of-sight situation into account should be used.

Example station parameters are provided in table B1.

An example deployment scenario is depicted in figure B1.

Figure B1: Example deployment scenario

[Description of figure B1: This figure shows the geometry for the sample pfd calculation. A transmitting flexible use base station is located within Service Area X. It is recommended that one find the pfd resulting from this transmitter at the boundary of a nearby Service Area Y. The distance, Dkm, to be used in this calculation is from the base station transmitter location to the boundary of Service Area Y, i.e. not from boundary to boundary. This base station transmitter has an associated power, P_T, and gain in the direction of the boundary of Service Area Y, G_T.]

The spectral power density in dB(W/MHz) at the boundary of service area Y (Pboundary) may be calculated using free‑space propagation, taking into account such factors as atmospheric losses, as follows:

P_boundary
= P_T' + G_T – Path Loss
= P_T' + G_T − 20 log F_MHz − 20 log D_km − 32.4
= (10 + 17 − 20 log (3515) − 20 log (50) − 32.4) dB(W/MHz)
= (10 + 17 – 70.92 – 33.98 − 32.4) dB(W/MHz)
= -110.3 dB(W/ MHz)

where: P_T'
= P_T − 10 log B_MHz
= 20 − 10 log (10)
= 10 dB(W/MHz)

Then, the power flux density in dB(W/m²) in 1 MHz (pfd) may be calculated as follows:

pfd
= P_boundary − 10 log A_r
= (-110.3 − 10 log (579.9 x 10^-6)) dB(W/m²) in 1 MHz
= (-110.3 − (-32.36)) dB(W/m²) in 1 MHz
= -77.94 dB(W/m²) in 1 MHz

where: A_r
= λ² / (4π)
= c² / ((4π) x (F_Hz )²)
= (3 x 10⁸)² / ((4π) x (3515 x 10⁶ )²)
= 579.9 x 10^-6 m²

Note that the above calculation is presented in this form to illustrate the ease by which an alternative Path Loss calculation method can be substituted for the free-space formulation used here. This example is provided for information only and the use of other generally accepted calculation methods is permitted.

Annex C: List of FSS earth stations in the frequency band 3500-3650 MHz

The licence and location information of the FSS earth stations operating in the frequency band 3500‑3650 MHz is provided in table C1.

Table C1: FSS earth stations in the frequency band 3500-3650 MHz

Annex D: Definition of exclusion zones

D.1 Definition of exclusion zones around airport runways

The exclusion zones are the same size for the 3500 MHz and 3800 MHz bands and are composed of two segments. The first segment is a rectangle having the same length as the runway and a width of 640 metres centred on the centreline of the runway. The second segment is an isosceles trapezoid centred on the centreline of the runway and extending 2100 metres from the runway thresholds. The width of the trapezoid at the runway threshold is 640 metres and the width of the trapezoid 2,100 metres from the runway threshold is 1269 meters.

Figure D1: Illustration of the exclusion zone geometry (red) with respect to runway thresholds for both the 3500 MHz and 3800 MHz bands

Description of figure D1: Figure D1 illustrates the exclusion zones around airport runways. The exclusion zones are red filled shapes composed of two segments. The first segment is a rectangle having the same length as the runway and a width of 640 metres centred on the centreline of the runway. The second segment is an isosceles trapezoid centred on the centreline of the runway that extends 2100 metres from the runway threshold. The width of the trapezoid at the runway threshold is 640 metres and the width of the trapezoid 2100 metres from the runway threshold is 1269 metres.

The list of exclusion zones and maps depicting these zones is available for download on the Map of Exclusion Zones and Protection Zones (SRSP-520) web page.

D.2 Definition of exclusion zones around elevated H1-classified heliports

The exclusion zones are circular areas of an 80 m radius measured from the final approach and take-off area’s (FATO) centre.

Figure D2: Illustration of 80 metre exclusion zone for H1-classified heliports

[Description of figure D2: Figure D2 illustrates the exclusion zones for H1-classified heliports. It illustrates an filled red circle of radius 80 metres centred on the centre of the FATO, which is indicated using a black dot in the centre of the circle.]

The list of exclusion zones and maps depicting these zones is available for download on the Map of Exclusion Zones and Protection Zones (SRSP-520) web page.

Annex E: Provisions applicable to protection zones

E.1 Definition of protection zones around airport runways

For fixed and base stations operating in the 3500 MHz frequency band, the protection zones are isosceles trapezoids centred on the centreline of the runway with a length of 1000 metres, extending from the edge of the exclusion zones (i.e. the exclusion zone boundary). The width of the 3500 MHz trapezoid at the exclusion zone boundary is 1269 metres, and the width of the 3500 MHz trapezoid is 1568 metres at a distance of 1,000 m from the exclusion zone boundary.  For fixed and base station operating in the 3800 MHz frequency band, the protection zones are isosceles trapezoids centred on the centreline of the runway with a length of 2500 metres, extending from the edge of the exclusion zones (i.e. the exclusion zone boundary). The width of the 3800 MHz trapezoid at the exclusion zone boundary is 1269 metres, and the width of the 3800 MHz trapezoid is 2017 metres at a distance of 2500 metres from the exclusion zone boundary.

In cases of overlap between the exclusion zone and the protection zone, the fixed or base station is considered to be within an exclusion zone.

In cases where a base station operates in both the 3500 MHz and 3800 MHz bands, the 3800 MHz protection zone shall apply.

Figure E1: Exclusion zone (red) and protection zone (blue) geometries with respect to runway thresholds for 3500 MHz (above) and 3800 MHz (below) bands.

[Description of figure E1: Figure E1 illustrates the protection zones around airport runways. It illustrates two figures: one for the 3500 MHz frequency band (above) and one for the 3800 MHz frequency band (below). Both figures illustrate a runway surrounded by an exclusion zone. The exclusion zones are red unfilled shapes composed of two segments. The first segment is a rectangle having the same length as the runway and a width of 640 metres centred on the centreline of the runway. The second segment is an isosceles trapezoid centred on the centreline of the runway that extends 2100 metres from the runway threshold. The width of the red trapezoid at the runway threshold is 640 metres and the width of the trapezoid 2100 metres from the runway threshold is 1269 metres. For the 3500 MHz frequency band figure, the protection zones are blue filled isosceles trapezoids centred on the centreline of the runway with a length of 1000 metres, extending from the edge of the exclusion zones (i.e. the exclusion zone boundary). The width of the blue trapezoid at the exclusion zone boundary is 1269 metres, and the width of the blue trapezoid is 1568 metres at a distance of 1000 m from the exclusion zone boundary.  For 3800 MHz frequency band figure, the protection zones are blue filled isosceles trapezoids centred on the centreline of the runway with a length of 2500 metres, extending from the edge of the exclusion zones (i.e. the exclusion zone boundary). The width of the blue trapezoid at the exclusion zone boundary is 1269 metres, and the width of the blue trapezoid is 2017 metres at a distance of 2500 m from the exclusion zone boundary. For both figures the exclusion zone boundary is demarcated in black text that is highlighted yellow.]

The list of protection zones and maps depicting these zones is available for download on the Map of Exclusion Zones and Protection Zones (SRSP-520) web page.

E.2 Definition of protection zones around H1-classified heliports

The protection zones are circular areas of  500 metres to 1000 metres radius measured from the FATO’s centre. The protection zones around H1-classified heliports are the same size for the 3500 MHz and 3800 MHz bands.

Figure E2: Exclusion zone (red) and protection zone (blue) circles for 3500 MHz and 3800 MHz bands for H1-classified heliports

[Description of figure E2: Figure E2 illustrates the protection zones for H1-classified heliports. It illustrates an unfilled red circle of radius 80 metres surrounded by a filled blue circle of size 500 metres to 1000 metres. The red circle represents the exclusion zone and the blue circle represents the protection zone. The two circles are centred on the centre of the FATO, which is indicated using a black dot in the centre of both circles.]

In cases of overlap between the exclusion zone and the protection zone, the exclusion zone takes precedence.

The list of protection zones and maps depicting these zones is available for download on the Map of the Exclusion Zones and Protection Zones (SRSP-520) web page.  [link to be inserted when available]

E.3 Technical and operational requirements in protection zones

All pfd limits described in this section shall be satisfied 100% of the time and be evaluated for all combinations of elevation and azimuth angles above the horizon relative to the location of the fixed or base station.

Compliance with the requirements defined in this SRSP, including the pfd limits specified below, is an ongoing obligation. At any time, ISED may require a licensee to demonstrate compliance with these limits by:

1. providing the Pre-Operation Report for any of its stations;
2. providing detailed calculations;
3. conducting site surveys; and/or
4. providing any additional compliance-related information. 

Despite compliance with the requirements specified above, ISED may require a licensee to implement additional measures to further enable coexistence.

Requirements for outdoor fixed and base stations operating with a channel bandwidth equal to or greater than 5 MHz

Outdoor fixed and base stations operating within the runway protection zones defined in section E.1 with a channel bandwidth equal to or greater than 5 MHz shall not exceed the following power flux density (pfd) limits:

• A “skyward pfd limit” of -34.21 dBW/m² in 5 MHz applied at a height of 106.68 metres (350 feet) above ground at all locations not contained by the boundaries of the exclusion zone; and
• An “exclusion zone boundary pfd limit” of -23.45 dBW/m² in 5 MHz at all locations along the boundary between exclusion and protection zones at 99.06 m (325 ft) above ground.

For outdoor fixed and base stations operating within the heliport protection zones defined in section E.2, they shall not exceed a -41 dBW/m²/5 MHz pfd limit at the surface defined by a circle with a radius of 50 metres at a height equal to the heliport’s height.

Requirements for outdoor fixed and base stations operating with a channel bandwidth less than 5 MHz

Outdoor fixed and base stations operating within the runway protection zones defined in section E.1 with a channel bandwidth less than 5 MHz shall not exceed the following pfd limits:

• A “skyward pfd limit” of -41.20 dBW/m² in 1 MHz applied at a height of 106.68 metres (350 feet) above ground at all locations not contained by the boundaries of the exclusion zone; and
• An “exclusion zone boundary pfd limit” of -30.44 dBW/m² in 1 MHz at all locations along the boundary between exclusion and protection zones at 99.06 m (325 ft) above ground.

For outdoor fixed and base stations operating within the heliport protection zones defined in section E.2 shall not exceed a -47.99 dBW/m²/1 MHz pfd limit at the surface defined by a circle with a radius of 50 metres at a height equal to the heliport’s height.

E.4 Pre-Operation Report requirements

This section provides a template of the information that must be included in each Pre-Operation Report.

A single Pre-Operation Report can be generated for all stations deployed with similar radio characteristics (e.g. same antenna, radio model, e.i.r.p., downtilt, vertical scanning angles, etc.). When multiple stations are included in a single Pre-Operation Report, the coordinates of all stations must be clearly stated. In addition, the pfd limit shall be calculated using the worst-case combination of technical parameters that would be used in operation of any of the stations. For each station, any variation in technical parameters described in E.4.2 (e.g. e.i.r.p. or height above ground) must be clearly identified in the Pre-Operation Report.

E.4.1 Title page

The title page should contain the assessment date, company name, site name where the station is located, name(s) of person(s) conducting the compliance study including title and signature, and date on which the Pre-Operation Report was signed.

E.4.2 Description of compliance with pfd limit

The Pre-Operation Report will describe the following elements for each station deployed in a protection zone:

• The coordinates (latitude and longitude) of the station
• Whether it is a fixed or base station
• Whether the fixed or base station is an active antenna system (AAS)
• Height of the antenna above the ground
• Mechanical (fixed) elevation, electrical (fixed) elevation, and azimuth angle of antenna
• For each non-AAS fixed or base station:
  • conducted power
  • radiation pattern of the antenna (including back lobes)
  • maximum e.i.r.p./MHz
• For each AAS fixed or base station:
  • conducted power or TRP, whichever is applicable
  • minimum and maximum vertical scanning angle values implemented
  • maximum envelope of the radiation pattern for all vertical scanning angles
  • maximum e.i.r.p./MHz (calculated using the sum of the TRP and maximum gain of the antenna)
• Maximum channel bandwidth used by the base station
• Maximum e.i.r.p. per carrier of the base station
• A technical description of the mitigation measures that will be implemented to ensure the pfd limits are respected. Technical measures may include, but are not limited to operating with a lower e.i.r.p., operating at a lower height above ground, limiting the vertical scan angle of an AAS fixed or base station, mechanical downtilt of the antenna, for AAS limiting the number of elements used to form a beam or adding additional shielding to limit emissions towards the sky.
• A demonstration, by computation or analysis, of how the mitigation measures implemented will result in the station meeting the pfd limits. The demonstration should include a description of any mathematical prediction models (e.g. propagation model) used. A sample calculation is provided in section E.5.
• A description of a plan to implement and monitor mitigation measures in practice, and the corrective actions that would be taken to remedy exceedance of the pfd limit, should it occur.

E.4.3 Compliance statement

A clear compliance statement should conclude the Pre-Operation Report. An example of a compliance statement is provided below.

E.4.4 Attestation requirements

At least 15 days prior to the operation of a station or the modification of an existing station within a protection zone, licensees are required to submit an attestation provided by a senior executive responsible for the installation of radio equipment (e.g. chief technical officer, VP engineering or equivalent). The attestation shall include the coordinates of the station, the protection zone number in which the station is located and the operational date of each station. The protection zone number is outlined in the first column of the table provided on the Map of Exclusion Zones and Protection Zones (SRSP-520) web page.

Each licensee is required to submit a single attestation for all stations located within any protection zones described in sections E.1 and E.2. The attestation shall include a list of all stations in the protection zone(s), the coordinates of each station, the corresponding protection zone number and the operational date of each station. When a new station or modifications to an existing station is planned, the licensee must conduct any necessary analyses to ensure technical compliance and update its Pre-Operation Report accordingly, and submit an updated attestation to ISED at least 15 days prior to the operation of the new or modified station(s). When updating the attestation to include new stations or to modify existing stations, the licensee shall indicate whether such entry is for a new station or a modification to an existing station.

The attestation must confirm that a Pre-Operation Report(s) has been completed and that the stations contained in the list of stations are in compliance with all the requirements defined in annex E of SRSP-520, issue 3.

An example of an attestation is provided below.

E.4.5 Submitting the Attestation

The attestation should be filed in an electronic format and sent to:

Spectrum Management Operations Branch
spectrumoperations-operationsduspectre@isde-isde.gc.ca

E.5 Sample pfd calculation

The following sections provide sample pfd calculations for protection zones around airport runways and heliports.

E.5.1 Sample pfd calculation for protection zones around airport runways

The following example illustrates how to calculate the skyward pfd limit at 106.68 metres (350 feet) above ground that applies outside of the exclusion zones and the exclusion zone boundary pfd limit that applies at the exclusion zone boundary at 99.06 m (325 ft) above ground for a station operating using the parameters defined in table E1. This example applies to both non-AAS and AAS base stations where the parameter PT is conducted power and TRP for non-AAS and AAS, respectively. These calculated pfd values are compared to the pfd limits defined in section E.3 for operation of a fixed or base station within a protection zone. Note that the calculation in the example assumes line-of-sight conditions. Where line-of-sight does not exist, an appropriate propagation model that takes the non-line-of-sight situation into account should be used.

The skyward pfd at 106.68 metres (350 feet) above the ground shall be evaluated for all combinations of elevation and azimuth angles above the horizon, as illustrated in figure E5. It is equivalent to finding the maximum skyward pfd value across all available elevation and azimuth angles. For simplicity, it was assumed that for the base station, the maximum skyward pfd at 106.68 metres (350 feet) above the ground occurred at α=50° elevation angle with an antenna gain of -2.5 dBi in that direction.

The exclusion zone boundary pfd at 99.06 metres (325 ft) above ground shall be evaluated for all combinations of elevation and azimuth angles above the horizon at all locations along the boundary of the exclusion and protection zone. For simplicity, it was assumed that for the base station, the maximum pfd at the boundary of exclusion and protection zones at 325 ft above ground occurs at β=30° elevation angle with a gain of 5 dBi.

Figure E3: Illustration of geometry for sample pfd calculation for runway protection zone

[Description of figure E3: This figure shows the geometry for the sample pfd calculations. A transmitting station has an antenna placed at HT metres above ground. The skyward pfd limit at 106.68 metres (350 feet) above the ground is -34.21 dBW/m² in 5 MHz.  For the sample skyward pfd calculation, the line represents an elevation angle of α degree for which the maximum skyward pfd occurs at 106.68 metres (350 feet) above the ground. At elevation angle α degree, an equation to determine the line-of-sight distance (C), C = (106.68 - H_T)/COS(90° - α), is shown.]

The maximum power spectral density (PSD) value could be used to calculate the skyward pfd to validate compliance with the skyward pfd limit defined in section E.3. The following formula may be used to calculate PSD for frequency expressed in MHz and distance expressed in metres:

PSD in dBm per 5 MHz =  P_T + G_T – (20 log ((106.68 – H_T) / cos (90° - α)) + 20 log (F_MHz)  – 27.55)

The following shows the calculation of skyward PSD and pfd for the base station:

PSD (skyward)

= 46.98 + (-2.5) - (20 log ((106.68 - 20) / (cos (90° – 50°))) + 20 log (3515) - 27.55)
= 44.48-84.44
= -39.96 dBm/5 MHz

Pfd in dBW/m² in 5 MHz may be calculated as follows:

Pfd
= Maximum PSD in dBm per 5MHz - 30 - 10 log A_r
= (-39.96 - 30 - 10 log (579.9 x 10^-6)) dBW/m² in 5 MHz
= (-69.96 - (-32.36)) dBW/m² in 5 MHz
= -37.60 dBW/m² in 5 MHz

where: A_r
= λ² / (4π)
= c² / {(4π) x (F_Hz )²}
= (3 x 10⁸)² / {(4π) x (3515 x 10⁶ )²}
= 579.9 x 10^-6 m²

The following shows the calculation of the exclusion zone boundary PSD and pfd for the base station at the boundary of exclusion zone. The angle β=30° represents the maximum PSD produced by the base station on the exclusion zone boundary.

PSD (exclusion zone boundary)

= 46.98 + (5) - (20 log ((99.06 -20) / (cos (90° – 30°))) + 20 log (3515) - 27.55)
= 51.98 - 87.35
= -35.37 dBm/5 MHz

Pfd in dBW/m² in 5 MHz may be calculated as follows:

Pfd
= Maximum PSD in dBm per MHz – 30 – 10 log A_r
= (-35.37 – 30 – 10 log (579.9 x 10^-6)) dBW/m² in 5 MHz
= (-65.37 − (-32.36)) dBW/m² in 5 MHz
= -33.01 dBW/m² in 5 MHz

Table E2 shows the maximum calculated skyward and border pfd values for the base station.

For this example, the base station is in compliance with both skyward and border pfd limits defined in section E.3.

E.5.2 Sample pfd calculation for protection zones around H1 heliports

The following example illustrates how to calculate the pfd of -41 dBW/m² in 5 MHz within the boundary of the circle that extends 50 m from the FATO centre of an H1 heliport at the height of the heliport. For this example, a small cell station is assumed to operate on street level using the parameters defined in table E3. This example applies to both non-AAS and AAS base stations where the parameter P_T is conducted power and TRP for non-AAS and AAS, respectively. Note that the calculation in the example assumes line-of-sight conditions. Where line of sight does not exist, an appropriate propagation model that takes the non-line-of-sight situation into account should be used.

The pfd limit of -41 dBW/m² in 5 MHz within the 50-metre circle, as measured from the FATO’s centre, at the heliport height above the ground shall be evaluated for all combinations of elevation and azimuth angles in the direction of the 50 m circle surrounding the heliport. For simplicity, it is assumed that  both base station A and B are located at the exclusion zone boundary (i.e. 80 metres horizontally from the heliport’s FATO centre). This means that the base station is horizontally separated by a distance of 30 metres from the 50 m radius around the helicopter’s FATO. The maximum PSD produced by these base stations towards the 50-metre circle around the heliport occurs at a 0-degree azimuth angle and an 53-degree elevation angle (α). Furthermore, the heliport of a 50-metre height above the ground is used in the subsequent calculations (i.e. d_FATO = 50 m).

Figure E4: Illustration of geometry for sample pfd calculation for heliport protection zone

[Description of Figure E4: This figure shows the geometry for the sample pfd calculations for a base station located in a heliport protection zone. A line is used to indicate ground level. A circle with a radius of 50 metres at the height of the FATO (H_FATO) above ground level is illustrated. The circle is drawn around a building with a FATO located on top of the building. A transmitting station is illustrated as having a height above ground of H_T metres and is placed at a separation distance of d_T from the circle boundary at the left position of the building. An elevation angle of α-degrees is indicated as an arrow drawn between the height of the station and the height of the FATO. A pfd limit of -41 dBW/m² in 5 MHz is indicated at the end of the aforementioned arrow.]

The following formula may be used to calculate PSD for frequency expressed in MHz and distance expressed in metres:

PSD in dBm per 5 MHz =  P_T + G_T – (20 log ((H_FATO – H_T) / cos (90°- α)) + 20 log (F_MHz)  – 27.55)

The PSD for the base station A is then:

PSD_A

= 35 – 6 – (20 log ((50 – 10) / (cos (90° – 53°)) + 20 log (3515) – 27.55)
= -48.36 dBm/5 MHz

Pfd in dBW/m² in 5 MHz may be calculated as follows:

Pfd_A
= Maximum PSD in dBm per 5 MHz – 30 − 10 log A_r
= (-48.36 – 30 − 10 log (579.9 x 10^-6)) dBW/m² in 5 MHz
= (-78.36 − (−32.36)) dBW/m² in 5 MHz
= -46 dBW/m² in 5 MHz

where: A_r
= λ² / (4π)
= c² / {(4π) x (F_Hz )²}
= (3 x 10⁸)² / {(4π) x (3515 x 10⁶ )²}
= 579.9 x 10^-6 m²

The PSD and pfd for base station B can be calculated in a similar manner.

Table E4 shows the maximum calculated pfd values for base stations A and B.

In this example, base station A is in compliance, whereas base station B is not in compliance with the pfd limit defined in section E.3.

Annex F: Lists of satellite dependent tiers, consolidated gateways, and tiers impacted by Government of Canada’s FSS operations

Annex G: Receiver filter parameters for FSS earth station licensed only in the 4000-4200 MHz band

The pfd limit in section 10.4.3 is based on the assumption that FSS earth station licensees operating in the 4000-4200 MHz band have installed filters on all earth station to reduce their susceptibility to blocking.
Flexible use licensees planning to establish fixed or mobile systems in the 3700-3900 MHz band are only required to protect existing site-approved or generic FSS earth stations licensed to only operate in the 4000-4200 MHz band and which meet the following receiver filter parameters:

Annex H: Fixed service sites in the 3800 MHz band

DRAFT

Preface

Radio Standards Specification RSS-192, Flexible Use Broadband Equipment Operating in the Band 3450-3900 MHz, issue 5, replaces of RSS-192, Flexible Use Broadband Equipment Operating in the Band 3450-3650 MHz, issue 4, dated May 2020.

Listed below are the main changes:

1. Extended the upper end of frequency range from 3650 to 3900 MHz to allow flexible use and the title of the standard is updated accordingly.
2. Added and revised definitions to clarify the terms used.
3. Modified the transmitter output power for indoor base station and subscriber equipment other than fixed subscriber equipment
4. Added out-of-frequency band unwanted emission requirements for equipment operating beyond 3900 MHz.
5. Removed the test report requirements as the requirement of identifying base station equipment as type 1 and type 2 classification has been removed.
6. Modernized to reflect the current RSS structure.
7. Made editorial changes and clarifications, as appropriate.

Inquiries may be submitted by one of the following methods:

1. Online using the General Inquiry form (in the form, select the Directorate of Regulatory Standards radio button and specify “RSS-192” in the General Inquiry field)
2. By mail to the following address:
   
   Innovation, Science and Economic Development Canada
   Engineering, Planning and Standards Branch
   Attention: Regulatory Standards Directorate
   235 Queen Street
   Ottawa ON  K1A 0H5
   Canada
3. By email to consultationradiostandards-consultationnormesradio@ised-isde.gc.ca

Comments and suggestions for improving this standard may be submitted online using the Standard Change Request form, or by mail or email to the above addresses.

All Innovation, Science and Economic Development Canada publications related to spectrum and telecommunications are available on the Spectrum Management and Telecommunications website.

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

________________________
Martin Proulx

Director General
Engineering, Planning and Standards Branch

Contents

1. Scope
2. Purpose and application
3. General requirements and references
4. Definitions
5. Transmitter standard specifications
6. Labelling requirement

1. Scope

This Radio Standard Specification (RSS) sets out the requirements for the certification of flexible use broadband equipment used in fixed and/or mobile services operating in the frequency band 3450-3900 MHz.

2. Purpose and application

This RSS applies to base station, point-to-point, point-to-multipoint,  and subscriber equipment operating in the frequency band 3450-3900 MHz.

3. General requirements and references

This section sets out the general requirements and references related to this RSS.

3.1 Coming into force and transition period

This document will be in force as of the date of its publication on Innovation, Science and Economic Development Canada’s (ISED) website. 

However, a transition period of six months from the publication date will be provided. During this transition period, applications for certification under either RSS-192 issue 5 or issue 4 will be accepted. After this period, only applications for the certification of equipment under RSS-192, issue 5, will be accepted, and equipment manufactured, imported, distributed, leased, offered for sale, or sold in Canada, shall comply with this present issue.

A copy of RSS-192, issue 4, is available upon request by emailing consultationradiostandards-consultationnormesradio@ised-isde.gc.ca

3.2 Certification requirements

Equipment covered by this standard is classified as Category I equipment and shall be certified. Either a technical acceptance certificate (TAC) issued by the Certification and Engineering Bureau (CEB) of ISED or a certificate issued by a recognized certification body (CB) is required.

3.3 Licensing requirements

Equipment covered by this standard is subject to licensing requirements pursuant to subsection 4(1) of the Radiocommunication Act.

3.4 RSS-Gen compliance

Equipment being certified under this standard shall comply with the general requirements set out in  RSS-Gen, General Requirement for Compliance of Radio Apparatus.

3.5 Related documents

All ISED publications related to spectrum management and telecommunications are available on the Spectrum Management and Telecommunications website. In addition to related documents specified in RSS-Gen, refer to the following documents as needed.

• SRSP-520, Technical Requirements for Fixed and/or Mobile Systems, including Flexible Use Broadband Systems in the Band 3450‑3900 MHz

Acronyms

• SRSP: Standard Radio System Plan

4. Definitions

The following terms are used in this document:

Active antenna system (AAS)
An antenna system where the amplitude and/or phase between antenna elements is dynamically adjusted, resulting in an antenna pattern that varies in response to short-term changes in the radio environment. An antenna systems used for long-term beam shaping such as fixed electrical down tilt are not considered an AAS. An AAS may be integrated in a point-to-multipoint (P-MP) hub station, base station and  subscriber equipment

Active antenna system (AAS) base station equipment
Base station equipment with an AAS.

Antenna
A radiating unit/component which contains all radiating elements forming a pattern.

Base station equipment
Equipment that provides network connectivity to, as well as management and control of, the subscriber equipment.

Channel bandwidth
The equipment’s operating bandwidth specified by the manufacturer that contains the information transmitted.

Channel frequency
The frequency at the center of the channel bandwidth.

Fixed subscriber equipment
Fixed equipment that provides connectivity between the user and the base station equipment. Fixed subscriber equipment is used at a fixed location. Fixed point-to-point , fixed point-to-multipoint, portable, mobile, and nomadic equipment are not considered fixed subscriber equipment.

Frequency block
In the bands covered by this RSS, 3450-3900 MHz, frequency blocks are portions of spectrum (see section 5.2).

Frequency block group
A continuous frequency range of multiple frequency blocks that contains the equipment’s channel bandwidth.

Frequency block range
The range of all frequency blocks that contains the equipment operating frequency range.

Indoor base station equipment
A base station, by the nature of its design, which operates in locations completely enclosed by walls and a ceiling (e.g. a transmitter that must be connected to the alternate current (AC) power lines, an enclosure that is not waterproof, etc.)

Maximum effective isotropic radiated power (e.i.r.p_max)
The maximum average channel power in dBm measured as e.i.r.p. across all antenna elements per channel.

Maximum total radiated power (TRP_max)
The maximum average channel power in dBm measured as TRP across all antenna elements per channel.

Non-active antenna system (non-AAS)
An antenna system that does not meet the definition of AAS.

Non-AAS base station equipment
A base station equipment with a non-AAS.

Point-to-point (P-P) equipment
Fixed equipment with directional antenna and is used between two fixed locations installed to provide service such as backhaul.

Point-to-multipoint (P-MP) hub equipment
Fixed equipment to provide communication with multiple user equipment installed at fixed locations.

Subscriber equipment
Equipment that provides connectivity between the user and the base station equipment. It includes but not limited to mobile, portable, nomadic, and fixed subscriber equipment.

Total radiated power (TRP)
The integral of the power transmitted by an antenna (all radiating elements), in different directions over the entire radiation sphere.

5. Transmitter standard specifications

This section sets out the requirements applicable to radio transmitters subject to this standard.

5.1 Measurement method

Unless otherwise specified, all measurements shall be performed in accordance with the requirements of RSS-Gen.

However, the alternate measurement procedure proposed in the Notice 2020-DRS0014 or alternate standards listed on ISED’s Certification and Engineering Bureau website can be used to demonstrate compliance with TRP limits.

The equipment measurement shall be performed for all operating channel bandwidths specified by the manufacturer.

AAS equipment with eight antenna elements or less can demonstrate compliance with the e.i.r.p. limits specified for non-AAS equipment in Table 1, using the standardized measurements procedures specified in RSS-Gen instead of the TRP limits.

All equipment with more than eight antenna connectors/elements shall demonstrate compliance with the TRP limits for the unwanted emission.

5.2 Band plan

The band 3450-3900 MHz is divided into 10 MHz blocks as per SRSP-520. Blocks can be aggregated to form a frequency block group larger than 10 MHz. For equipment with channel bandwidth smaller than 10 MHz, the frequency block group is 10 MHz.

5.3 Type of modulation

The modulation used shall be digital.

5.4 Frequency stability

The frequency stability shall be sufficient to ensure that the occupied bandwidth stays within the operating frequency block or frequency block group when tested at the temperature and supply voltage variations specified in RSS-Gen.

5.5 Transmitter output power

The maximum output power of the equipment measured in terms of average values shall comply with the limits specified in table 1.

In addition, the peak to average power ratio (PAPR) of the equipment shall not exceed 13 dB for more than 0.1% of the time, using a signal that corresponds to the highest PAPR during periods of continuous transmission.

5.6 Transmitter unwanted emissions

Unwanted emissions shall be measured in term of average value when the transmitter is operating at the manufacturer's rated power and modulated as specified in RSS-Gen.

Equipment shall meet the unwanted emission limits, specified below, outside each frequency block group. The unwanted emissions shall be measured and reported for two channels: one located at the bottom and one at the top of the operating frequency block range. In doing so, the equipment must be set such that the middle of the occupied bandwidth is as close to the bottom or the top edge of the frequency block range for each measurement respectively, as the equipment design permits. Set the channel frequency f_L to the lowest frequency of the frequency block range. Record f_L and the RF spectrum. Repeat the test using the highest channel frequency f_H of the frequency block range.

If the transmitter is designed for a multi-carrier operation, the tests shall be carried out using both the maximum and minimum number of carriers intended for the equipment.

5.6.1 Unwanted emission limits for outdoor base station, P-P and P-MP equipment

The unwanted emissions of base station, P-P and P-MP equipment shall comply with the following.

1. The limits in table 2 for all frequencies between 3450-3900 MHz
2. The limits in table 3 for all frequencies between 3400-3450 MHz
3. A limit of -13 dBm TRP /MHz  or conducted power (sum of conducted power across all antenna connectors), where applicable, for all frequencies below 3400 MHz
4. The limits in table 4 for all frequencies above 3900 MHz
5. A limit -33 dBm TRP /MHz or conducted power (sum of conducted power across all antenna connectors), where applicable, for all frequencies between 4200-4400 MHz

Note: e.i.r.p_max and TRP_max are expressed in dBm

Note: e.i.r.p_max and TRP_max are expressed in dBm

*OB is the occupied bandwidth

5.6.2 Unwanted emission limits for indoor base station equipment

Indoor base station equipment shall have the TRP or conducted power (per antenna), where applicable, of unwanted emission not exceeding:

1. The limits in table 5
2. A limit of -30 dBm/MHz for all frequencies below 3440 MHz and above 3910 MHz

5.6.3 Unwanted emission limits for subscriber equipment

Subscriber equipment shall have the TRP or conducted power (per antenna), where applicable, of unwanted emission not exceeding the following,

1. The limits in table 6
2. A limit of  -30 dBm/MHz in the frequency range greater than (B+5) MHz from the edge of the frequency band

6. Labelling requirement

Indoor base station equipment shall be labelled on the equipment or a statement shall be included in the user manual using the following text “For indoor use only”.