Meteorological Service of Canada Service météorologique du Canada 4905 rue Dufferin Street Downsview, Ontario M3H 5T4 31 May 2004 Director of Spectrum and Radio Services Industry Canada Room 1611A, 300 Slater Street Ottawa, Ontario K1A 0C8 Re: Canada Gazette Notice DGTP-005-04: Consultation on Allocation Changes and Revisions to Spectrum Utilization Policy and Technical Rules in the 5 GHz Band (2004-02-01) The Meteorological Service of Canada (MSC) of Environment Canada commends Industry Canada for this very important public consultation. While MSC generally accepts the proposals listed in DGTP-005-04, the Service has significant concerns regarding the potential for harmful radio interference with its weather radars if allocation is made to unlicensed wireless access systems (WAS) including Licence-exempt Radio Local Area Networks (LE-RLANs) in the 5600-5650 MHz frequency band. This interference could result in the reduced ability of MSC to fulfil its public safety mandate to detect the development of dangerous weather and issue appropriate warnings to the public and weather-sensitive industry. A brief description of MSC s radar network is attached. The International Telecommunications Union - Radio (ITU-R) recognized the inability for weather radars and the inevitable high density of WAS to operate on a co-channel basis without the application of mitigation techniques. The ITU-R recommended several mitigation techniques to be undertaken by the WAS industry including channel exclusion, if required. MSC requests that any mitigation measures intended to protect its meteorological radars, or any alternatives proposed by the industry, be thoroughly demonstrated and validated before they are implemented in the Canadian Spectrum Utilization Policy and Technical Rules in the 5 GHz Band. If testing does not conclusively demonstrate full mitigation of harmful interference, MSC would strongly suggest consideration for the 5600-5650 MHz to be excluded from WAS use. Also, MSC is one of the prime users of RadarSat, which provides vital data on ice conditions in Canada s navigable waters. We are concerned that spectrum usage changes in the 5250-5350 MHz band will create harmful interference with the collection of data by RadarSat, which will negatively affect the ice reports and forecasts required for safety in Canadian waters. /2
- 2 - The attachment to this letter contains the Meteorological Service of Canada s response to the specific sections in the Gazette. An electronic response of this letter and the attachment has also been e-mailed to wireless@ic.gc.ca. Yours sincerely, Original signed by Marc Denis Everell Marc Denis Everell Assistant Deputy Minister Attachments cc: Mike Minuk, A/DG AMWSD, MSC, Environment Canada Norm Naylor, Communications, MSC, EC Denis Bourque, MSC, EC
Attachment 1 Environment Canada s Doppler Radar Network MSC has just completed a six year, $35 million project to add new Doppler radars and upgrade the existing conventional weather radars across the country. The meteorological radar network in Canada operates 24 hours per day, 7 days per week and covers all major cities and over 90% of the Canadian population. It enables meteorologists to detect the development, intensity and location of precipitation such as rain, snow or freezing rain. Most importantly for public safety, Doppler weather radars measure the dynamics within storms and detect conditions that could lead to a tornado or other dangerous severe weather (such as: hail, freezing rain, snow squalls, strong winds, heavy snow or rain). Using this network, accurate and timely warnings of severe weather can be issued allowing sufficient time for the public to take actions to avoid or minimize risk to life and property. Advances in radar science, data processing and assimilation, technology and meteorological theory and training are all leading towards further expansion of the MSC radar network and enhancements such as dual polarization and increasingly sensitive data detection and processing.
Attachment 2 Meteorological Service of Canada, Environment Canada Response to Canada Gazette Notice DGTP-005-04 (2004-02-01) Section 2.1 The Department proposes the following changes to the Canadian Table of Frequency Allocations in the band 5350-5650 MHz and as shown in Appendix 1: Upgrade the radiolocation service from secondary to primary status in the band 5350-5650 MHz. Adopt new international footnotes 5.448D, 5.450A, and 5.450B, relevant to the operation of the radiolocation service. MSC strongly supports upgrading the radiolocation service to co-primary status in the band 5350-5650 MHz and also supports adopting the international footnotes 5.448D, 5.450A, and 5.450B. Section 2.2 The Department proposes the following changes to the Canadian Table of Frequency Allocations in the band 5250-5570 MHz and as shown in Appendix 1: Enter a new allocation to the Earth exploration-satellite (active) service on a primary basis in the band 5460-5570 MHz. Enter a new allocation to the space research (active) service on a primary basis in the band 5350-5570 MHz. Adopt new and/or modified international footnotes 5.448A, 5.448B and 5.448C, relevant to the operation of Earth exploration-satellite (active) or space research (active) services. MSC supports entering new allocations for the EESS (active) and Space Research Service (active) into the bands 5460-5570 MHz and 5350-5570 MHz respectively and also supports adopting the current international footnotes (from WRC03) 5.448A, 5.448B and 5.448C, as well as the new or modified international footnotes 5.448A, 5.448B and 5.448C.
Section 2.3 The Department proposes the following changes to the Canadian Table of Frequency Allocations in the bands 5150-5350 MHz and 5470-5850 MHz, and as shown in Appendix 1: Enter a new allocation to the mobile service on a primary basis in the bands 5150-5350 MHz and 5470-5725 MHz. Adopt new international footnotes 5.446A, 5.446B, 5.447F and 5.450A, relevant to the operation of the mobile service. Modify Canadian footnote C39A and add a new footnote CXX to indicate that the operation of wireless local area network systems will be accommodated in the bands with the development of spectrum utilization policies and technical criteria. Subject to the demonstration that mitigation techniques proposed by Industry Canada will be efficient in preventing a degradation in the operation of its meteorological radars operating in the band 5600-5650 MHz, MSC supports new co-primary allocations for the mobile service in the bands 5150-5350 MHz and 5470-5725 MHz; the adoption of the new international footnotes 5.446A, 5.446B, 5.447F and 5.450A.; as well as the adoption of a new Canadian footnote (CXX). However, if recommended mitigation techniques are not conclusively demonstrated to prevent harmful interference with the weather radars, MSC would strongly recommend that the sub-band 5600-5650 MHz be excluded from use by services other than those licensed services currently in operation. 2 of 5
Section 3.2 Sub-Band 5250-5350 MHz In light of the above discussion, the Department is proposing to revise, where appropriate, a Radio Standard Specification, to incorporate the following technical rules on LE-LANs: (1) Stations are permitted to be used both indoors or outdoors; and (2) The maximum e.i.r.p. shall not exceed 1.0 watt or 17 + 10 log10 B, dbm, whichever power is less. B is the 99% power bandwidth in MHz; and (3) When operating above an e.i.r.p. of 200 mw, stations shall comply with the following e.i.r.p. elevation angle mask where θ is the angle above the local horizontal plane (of the Earth): -13 db(w/mhz) for 0 θ < 8-13-0.716 (θ-8) db(w/mhz) for 8 θ < 40-35.9-1.22 (θ-40) db(w/mhz) for 40 θ < 45-42 db(w/mhz) for 45 < θ (4) Systems in the mobile service shall either employ transmitter power control to provide, on average, a mitigation factor of at least 3 db on the maximum average output power of the systems, or, if transmitter power control is not in use, then the maximum e.i.r.p. shall be reduced by 3dB. (5) Stations shall implement dynamic frequency selection. The Department invites comments on these proposals. MSC strongly supports the protection of existing primary licensed services in the band 5250-5350 MHz, especially RADARSAT. It must be noted that the Canadian Ice Service (CIS) of Environment Canada is the main user of RADARSAT data. CIS is the leading authority for information about ice conditions in Canada's navigable waters and has developed extensive scientific knowledge about ice and icebergs. CIS delivers on a public safety mandate and provides support to the Canadian Coast Guard, the Department of National Defence and other public and private shipping interests, both domestic and international. 3 of 5
Section 3.3 Sub-band 5470-5725 MHz In light of the above discussion, the Department is proposing to revise, where appropriate, a Radio Standard Specification, to incorporate the following technical rules on LE-LANs: (1) Stations are permitted to be used both indoors or outdoors. (2) The maximum transmitter power shall not exceed 250 mw. (3) The maximum e.i.r.p. shall not exceed 1.0 watt or 17 + 10 log10 B, dbm, whichever power is less. B is the 99% power bandwidth in MHz. (4) Systems in the mobile service shall either employ transmitter power control to provide, on average, a mitigation factor of at least 3 db on the maximum average output power of the systems, or, if transmitter power control is not in use, then the maximum e.i.r.p. shall be reduced by 3 db. (5) Stations shall implement dynamic frequency selection, including the special provisions pertaining to the band 5600-5650 MHz. The special provisions pertaining to the band 5600-5650 MHz require that in the band 5600-5650 MHz, if a channel has been flagged as containing a radar, a 10-minute continuous monitoring of the flagged channel is required prior to use of that channel. Otherwise, other appropriate methods such as channel exclusion are required. The Department invites comments on these proposals. MSC supports all of (1), (2), (3), (4) and (5) above with the condition that these mitigation measures are clearly demonstrated to be effective in properly protecting the meteorological radars operating in the band 5600-5650 MHz. If the measures are not conclusively demonstrated to prevent harmful interference with the weather radars, MSC would strongly recommend the sub-band 5600-5650 MHz be excluded from use by services other than those licensed services currently in operation. In particular, MSC wants to stress the importance of (5) in protecting its radars against the accumulated impact of a moderate to high density of LE-RLANs. The requirement for the 10 minute continuous monitoring of a flagged channel results from the common scanning strategy that the meteorological radars use in order to detect the development of dynamic features that could result in life threatening severe weather events. During the 10 minute cycle, the radar antenna spins at varying rates of speed and regularly changing scan elevation angles. Due to the nature of this 10 minute cycle, it is possible that a device monitoring for less than 10 minutes would not detect the presence of a weather radar and begin to transmit on the frequency used by the radar. With the radar s high sensitivity it could see the interfering transmission. Because of the anticipated density of these devices (LE-RLANs) in the primary area of interest for weather 4 of 5
radar monitoring (populated areas), it is essential that they not use the 5600-5650 MHz where a weather radar is active. The Department also invites comments on the following: (1) Recognizing that mitigation techniques, such as DFS, are required to ensure compatibility with EESS (active) and the radiolocation service, what are the technical implications and the feasibility of implementing these techniques in the design of LE- LANs in this band? (2) The Department also seeks comments on appropriate test and certification procedures to ensure compliance by mobile devices and systems with dynamic frequency selection, and automatic power control. MSC requests that any mitigation measures aiming at protecting its meteorological radars, including those proposed in DGTP-005-04 be thoroughly demonstrated and validated before they are implemented in the Canadian Spectrum Utilization Policy and Technical Rules in the 5 GHz Band. Summary The Meteorological Service of Canada is generally supportive of all of the proposals in DGTP-005-04. However, significant concerns exist that regardless of mitigation measures established, there could be harmful radio interference with its meteorological radars if allocations are made to the mobile service for wireless access systems (WAS) including license exempt - radio local area networks (LE-RLAN) in the band 5600-5650 MHz. To address this, MSC requests that any mitigation measures intended to protect its meteorological radars, or any alternatives proposed by the industry, be thoroughly demonstrated and validated before they are implemented in the Canadian Spectrum Utilization Policy and Technical Rules in the 5 GHz Band. Additionally, that if the measures are not conclusively demonstrated to prevent harmful interference with the weather radars, MSC would strongly recommend that the sub-band 5600-5650 MHz be excluded from use by services other than those licensed services currently in operation (weather radars and radio navigation). 5 of 5