WORLD METEOROLOGICAL ORGANIZATION COMMISSION FOR BASIC SYSTEMS STEERING GROUP ON RADIO FREQUENCY COORDINATION (SG-RFC) Author : Philippe TRISTANT Chairman WMO SG-RFC (philippe.tristant@meteo.fr) Date issued: 22 June 2009 Subject: Comments to Industry Canada on the Radio Standard Specification on devices using Ultra-Wideband (UWB) Technology (RSS-220- Issue 1-March 2009) Note : This submission is also supported by the Group on earth Observation (GEO), as agreed within its Task Group AR-06-11dedicated to radio-frequency issues. 1 Introduction The World Meteorological Organisation (WMO) would like to thank Industry Canada for the opportunity to comment on the document RSS-220 issued March 2009 and related to devices using Ultra-Wideband (UWB) Technology. Radio-frequencies represent scarce and key resources for the meteorological community, organised within WMO, to either collect the observation data upon which its predictions are based or processed, or disseminate weather information and warnings to the public. It should also be understood that all related frequency applications are inter-related and represent a global meteorological system. More detailed information on these frequency uses can be found in the joint ITU-WMO Handbook on Use of radio Spectrum for Meteorology: Weather, Water and Climate monitoring that can be found at: http://www.itu.int/publications/publications.aspx?lang=en&media=electronic&parent=r-hdb-45-2008 The present document provides background information and expresses WMO comments and concerns about the conditions of use of UWB devices under regulations set in document RSS-220, with a particular emphasis on essential passive bands 10.6-10.7 GHz and 23.6-24 GHz as well as on the meteorological radar bands 5600-5650 MHz band ad 9300-9500 MHz. 2 ITU-R reference documents on UWB applications Ultra-Wide Band (UWB) technology devices and their potential impact on radio services were considered in length and high details in ITU-R within the framework of TG 1/8. After considerable amount of technical and regulatory work, at which WMO took a very active part, ITU-R issued 1 technical Report (ITU-R SM.2057) and 4 Recommendations namely ITU-R SM.1754 (Measurements), ITU-R SM.1755 (UWB Characteristics), ITU-R SM.1756 (Regulatory Framework) and ITU-R SM.1757 (Compatibility).
- 2 - WMO considers Report ITU-R SM.2057 and Recommendation ITU-R SM.1757 as reflecting relevant UWB maximum EIRP density levels to ensure protection of meteorological related radioservices and applications and would have and is still expected them becoming a worldwide reference. WMO stresses and can only regret that the United States issued their national regulations in 2002, prior to TG 1/8 work, hence not having benefited from the most up-to-date technical studies, but would be of the highest concerns if other countries, nowadays, would align their own regulation on the US one without considering ITU-R studies. In particular, recognising that TG 1/8 was chaired by an Industry Canada representative, such situation in Canada would represent a serious breach in ITU-R Reference document significance and would be a wrong message to be sent to other countries that are currently in the process of issuing their own regulation. Overall, on a general basis, WMO would like to urge and encourage Industry Canada to consider UWB maximum EIRP density levels set in Recommendation ITU-R SM.1757 in its national regulation, as was done in a number of countries or regional organisations (e.g. Europe, Japan, ). 2 Passive sensing Satellite passive sensing represents a very specific application on both technical (due to the interference susceptibility of the highly sensitive passive sensors) and regulatory basis (through proposed exceptions to the provisions of RR footnote 5.340), that is increasingly under threat from active radiocommunication applications. Space-borne passive sensing of the Earth s surface and atmosphere has an essential and increasing importance in operational and research meteorology, in particular for mitigation of weather and climate-related disasters, and in the scientific understanding, monitoring and prediction of climate change and its impacts. It is worldwide recognised that the impressive progress made in the recent years in weather and climate analysis and forecasts, including warnings for dangerous weather phenomena (heavy rain, storms, cyclones) that affect all populations and economies, is mainly attributable to spaceborne observations and their assimilation in numerical models. The utmost importance should be attached to ensuring absolute protection of the passive bands that are unique natural resources. These few passive bands have been fully recognized by a very special regulatory measure in the ITU Radio Regulations, footnote No 5.340, which states that all emissions are prohibited. WMO would in particular like to emphasise that this specific protection requirement related to passive bands was fully recognised within ITU-R TG 1/8, ITU-R Recommendation SM. 1756 Framework for the introduction of devices using ultra-wideband technology specifically addressing this issue in section 2.2. of its Annex 1, joining both safety services and passive services as requiring particular attention (abstract below). 2.2.3 Passive services The operations of the RAS, EESS (passive) and SRS (passive) necessarily involve the measurement of naturally-occurring radiations, of very low power levels, which contain essential information on the physical process under investigation. The relevant frequency bands are mainly determined by fixed physical properties (e.g. molecular resonance) that cannot be changed. Those properties support scientific activities including weather forecasting, as well as water and climate modeling. These frequency bands are, therefore,
- 3 - an important natural resource. Even low levels of interference received at the input of the passive sensors may have a degrading effect on passive service band usage. Additionally, in most cases the sensors are unable to discriminate between these natural radiations and man-made radiations. In this respect, RR No. 5.340 enables the passive services to deploy and operate their systems. As an example, the EESS (passive) monitors the Earth and its atmosphere worldwide. Corrupted measurements from one or more areas may affect the ability to make reliable weather forecasts for the entire world, which may have significant economic and public safety impact. Therefore, special attention should be given to the protection requirements of the passive services. WMO acknowledges that the relevant essential meteorological and related environmental activities are safeguarded by the compliance to RR N 5.340 that is part of an international treaty between States. WMO emphasizes that a breach of these regulatory measures would lead to damaging meteorological and related environmental activities with their societal and economic impacts, including safety of life and property. Any relaxation of footnote 5.340 would result in a detrimental impact to operational and research meteorology. It would hamper further developments of improved weather and climate prediction that are anxiously expected by all Governments in this period of increasing weather and climate-related disasters, that in particular led to the establishment of the inter-governmental Group on Earth Observation (GEO). WMO notes that the current Industry Canada RSS-220 sets, in some essential passive bands, UWB maximum EIRP levels that are obviously consistent with the -10 db bandwidth definition and therefore allow UWB to transmit intentional emissions in frequency bands covered by RR N 5.340. WMO is of the view that, as such, Industry Canada RSS-220 is in contradiction with Radio Regulations. WMO would also like to call Industry Canada attention to the fact that first EESS measurements are performed on a worldwide basis by number of instruments implemented on spacecraft operated by different countries and secondly that the data measured over Canada are not for the only interest of weather forecasts in Canada but are essential to all meteorological services. Due to the high sensitivity of EESS remote sensors and their global coverage, the aggregate effect of emissions from UWB deployed in Canada could have negative impact on EESS systems operated by other administrations and, as such, WMO is of the view that, as far as EESS frequency bands are concerned, UWB regulations should not therefore be considered as limited to national issues and regulations but consistently with international regulations. To this respect, WMO would like to call Industry Canada attention to Recommend 2) of ITU-R Recommendation SM.1756 that introduces the following note: NOTE 1 Administrations authorizing or licensing devices using UWB technology should ensure, pursuant to the provisions of the Radio Regulations, that these devices do not cause interference to and do not claim protection from, or place constraints on, the radiocommunication services of other administrations as defined in the Radio Regulations and operating in accordance with those Regulations.
- 4-3 Short-Range Radars in the 23.6-24 GHz band The exclusive passive band 23.6-24 GHz, covered by Footnote 5.340, is the only band that enables the accurate determination of the vertical vapour content of the atmosphere and is of crucial importance for weather, water and climate research and operations, nowadays assimilated in numerical models. The initial technical studies related to the compatibility between passive sensors and automotive 24 GHz Short-Range Radars (SRR) were performed prior to 2002 within the US Administration during its domestic process. These studies led to the authorisation of SRR in the 24 GHz, with already a number of technical limitations (i.e. 41.3 dbm/mhz maximum EIRP density and emissions with a time based progressively higher attenuation in elevation (above 30 ) towards the passive sensor receiver). It is however worth noting that these studies were not based on up-to-date assumptions, as stated by the US administration itself in Report ITU-R SM.2057. Note: It has to be noted that one Administration [namely US] has already established its domestic rules allowing vehicular anti-collision short range radars (SRR) to operate in the 23.6 to 24.0 GHz, based on a previous analysis using different parameters and assumptions. * * Scattering or reflection of SRR signals was not used in this analysis. Later studies, as described in Section A6.1.5.5.2, found that scattered energy added to the direct energy could substantially increase the total energy directed toward the sensor. The interference threshold used in this administration s analysis was based on Recommendation ITU-R SA.1029-1 which contains an interference threshold value for sensors in this band that is 6 db higher than the corresponding value in the current Recommendation ITU-R SA.1029. This analysis apportions 100% of this interference threshold to the UWB SRR devices. A 1% apportionment would decrease the margins by 20 db. It should also be stressed that, more recently, the US Administration has authorized an alternative 24 GHz SRR type, using frequency hopping technology allowing specific band avoidance, with the regulatory condition of not transmitting in the 23.6-24 GHz passive band. Following the US process, European countries within CEPT performed more detailed technical studies in the 2002/2004 timeframe that concluded on the non-compatibility between passive sensors and 24 GHz SRR recognising a negative margin higher than 10 db. After intensive discussions, with a very high involvement of the whole scientific and meteorological community, the European Regulation set is twofold : - temporary authorisation (up to 1 st July 2013) of 24 GHz SRR together with a maximum of 7% maximum car penetration. - clear incentive to develop and deploy SRR in the 79 GHz band. Finally, the latest technical studies were performed in ITU-R TG 1/8, in a 2 year process (2003/2005) during which a number of different contributions were submitted and discussed and led to an agreed set of up-to-date assumptions and mitigation techniques under which conclusions were drawn on a clear non-compatibility between 24 GHz SRR and passive sensors, confirming or even tightening conclusions reached within CEPT.
- 5 - These TG 1/8 conclusions, as given in the ITU-R Recommendation SM.1757, states that a 100% deployment of SRR operating at 24 GHz results in interference exceeding the EESS threshold up to 35 db with a 1% apportionment of the interference criteria and that data derived from measurements performed in the band 23.6-24 GHz, where vehicular radars are in operation, will be corrupted in corresponding EESS observations. Based on the calculated negative margins, TG 1/8 concludes that a maximum EIRP density of 70.6 dbm/mhz in rural areas and 76.2 dbm/mhz in urban areas would be necessary to protect passive sensors in the band 23.6-24 GHz. WMO was heavily involved in the TG 1/8 discussions and fully supports its conclusions, based on up-to-date technical analysis, that SRR 24 GHz are not compatible with passive sensing in the 23.6-24 GHz band. It is worth noting that these calculated negative margins means that a SRR deployment of only 0.1% (rural case) and 0.03% (urban case) of cars equipped with SRR operating at a 41.3 dbm/mhz maximum EIRP density would be enough to interfere with passive sensor operation in the 23.6-24 GHz band. One can probably agree that SRR 24 GHz will not represent the only available technology for providing the corresponding service, but it is obvious that any economically viable technology will represent a large penetration of several tens % (consistently with automotive industry expectations) that will definitively not allow for compatibility with EESS (passive). In any case, due to the specificities of EESS (passive) sensing and even exacerbated by the fact that, once on the market and should any adverse impact occur, it will be almost impossible for Radio Administrations to withdraw such equipments from use, any technical analysis that would not consider the maximum level of safe margin will put at highest risk this essential and unique natural resource passive band 23.6-24 GHz. WMO is highly concerns with the current level proposed by Industry Canada (-41.3 dbm/mhz) in the 23.6-24 GHz band and would therefore strongly urge Industry Canada to review its Radio Standard Specification (RSS-220) section 4.1 to consider a maximum EIRP density level of -76.2 dbm/mhz in the band 23.6-24 GHz consistent, first with the full protection of EESS (Passive) and secondly with the principle of not authorising intentional emissions in a frequency band covered by RR N 5.340. WMO would in particular emphasise that, even under these conditions, the automotive industry would still be able to develop SRR in the 22-29 GHz, either using a band avoidance technique for the 23.6-24 GHz (consistently with the more recent decision in the US) or to shift the SRR operational bandwidth within the 24-29 GHz band (as currently proposed by the car industry in Europe and Japan). 4 UWB devices in the 10.6-10.7 GHz band WMO is also highly concerned with the maximum EIRP level of -51 dbm/mhz set by Industry Canada in bands above 10.6 GHz for almost all UWB applications (Communications or Radar Imaging devices). Indeed, the band 10.6-10.7 GHz is also an essential passive band (within which, in particular, the band 10.68-10.7 GHz is covered by RR N 5.340) for which Recommendation ITU-R SM 1757 is giving 60 to 90 dbm/mhz EIRP level for 10 to 10 000 UWB devices/km 2 respectively and ITU-R Report SM.2057 specifically states in its section A6.1.4.3.2 that :
- 6 - This analysis concludes that UWB devices should avoid this exclusive and essential passive band using any adequate technique. Taking into account typical characteristics of EESS sensors, it is proposed to base the conclusions on scenario deployment consistent with rural/suburban (i.e. a density of 100 UWB transmitters per km²) and that hence a maximum UWB EIRP power density of 70 dbm/mhz would be adequate to ensure protection of EESS (passive) in the 10.6-10.7 GHz band. WMO would in particular like to stress that, in Europe, a maximum EIRP level of -85 dbm/mhz is regulated for UWB applications concerning bands above 10.6 GHz, building upon the fact that, in particular, UWB target bands are below 10.6 GHz and is therefore not constraining for UWB applications. Similarly with the 24 GHz band, WMO is highly concerned with the current level proposed by Industry Canada (mainly -51.3 dbm/mhz) in bands above 10.6 GHz and in particular the passive band 10.6-10.7 GHz and would therefore strongly urge Industry Canada to review its Radio Standard Specification (RSS-220) sections related to Communication devices (section 5), radar imaging devices (section 6) as well as to Short-Range radars (section 4) to consider a maximum EIRP density level of -70 dbm/mhz in the band 10.6-10.7 GHz consistent, first with the full protection of EESS (Passive) and secondly with the principle of not authorising intentional emissions in a frequency band covered by RR N 5.340. 5 Meteorological radars Meteorological radars perform an important and increasing part in the meteorological observation processes and mainly operate in the S-Band (2700-2900 MHz) and C-Band (5600-5650 MHz), whereas the X-Band (9300-9500 MHz) is currently mainly used for research or specific activities but is also being investigated as a means of complementing existing weather radar systems by detecting precursors to severe weather events. Radar data, mainly precipitation and wind measurements, are input to the Numerical Weather Prediction models for nowcasting, short-term and medium-term forecasting and play a crucial role in the immediate meteorological and hydrological alert processes. Meteorological radar networks represent the last line of defence against loss of life and property in flash flood or severe storm events, such as in several recent dramatic cases. As all radio services, meteorological radars were also considered in detail in TG 1/8 that concluded on the following maximum UWB EIRP levels that are given in both Recommendation ITU-R SM.1757 and Report ITU-R SM.2057 (section A1.7) Frequency band UWB application type Current US US power density limit Power density limit necessary to protect Meteorological radars 2.8 GHz Imaging (low density) 41.3 dbm/mhz 51 dbm/mhz Telecommunication (indoor) 51.3 dbm/mhz 61 dbm/mhz Telecommunication (outdoor) 61.3 dbm/mhz 71 dbm/mhz 5.6 GHz Imaging (low density) 41.3 dbm/mhz 51 dbm/mhz Telecommunication (indoor and 41.3 dbm/mhz 65 dbm/mhz outdoor) 9.4 GHz Imaging (low density) 41.3 dbm/mhz 54 dbm/mhz Telecommunication (indoor and outdoor) 41.3 dbm/mhz 60 dbm/mhz
- 7 - TG 1/8 also concluded that Hence, the power density limits as currently regulated in the United States are not adequate to ensure protection of meteorological radars in the 2.8 GHz, 5.6 GHz and 9.4 GHz bands deployed such as those in Europe, at the exception of the specific case of radars deployed in the United States in the 2.8 GHz with 30 m antenna height and 45.7 dbi antenna gain. WMO notes that, as far as meteorological radars bands are concerned, Industry Canada Standard specification RSS-220 has been aligned on the current US Regulations, hence, depending on the UWB applications, presenting EIRP increase in the range 10 to 24 db compared to ITU-R Recommendations. WMO was heavily involved in the TG 1/8 discussions and fully supports its conclusions, based on up-to-date technical analysis, that UWB applications are not compatible with safe operation of meteorological radars in all bands. One could probably believe that some national-based assumptions slightly different from those used in TG 1/8 could be considered for specific radar deployment in Canada but WMO is doubtful that they could fill such 10 to 24 db gap. On the other hand, attention of Industry Canada is called to the fact that the US regulation and technical studies only considered NOAA Meteorological Radars in the S-Band (US FAA TDWR in the C-Band cannot at all compare to meteorological radars) and that, in this band, the US Administration recognised the non-compatibility between their radars and UWB (-61 dbm/mhz). Applying a similar approach in the C-band where Environment Canada has deployed its radar network, a rough consideration of only free-space attenuation would give only a 6 db difference (noting that this 6 db difference is also found between TG 1/8 conclusions in the 2 bands -71 and - 65 dbm/mhz) and would therefore consistently conclude on a non-compatibility between C-Band radars and UWB operating at -41.3 dbm/mhz. Finally, it should also be noted that levels for Imaging (low density) as specified by TG 1/8 represent the effect of one single UWB device on the ground, irrespective of the UWB density and radars location. As such, WMO is of the view that these levels (-51 dbm/mhz for S and C-Band and -54 dbm/mhz for X-Band) should be considered as the very maximum possible EIRP levels for any type of UWB application, and that, any regulated maximum EIRP density above these levels would put at high risk the availability of data of any meteorological network. WMO is therefore highly concerned with Industry Canada RSS-220, in particular in the 5.6 and 9.4 GHz bands in which a -41.3 dbm/mhz maximum EIRP is specified for all UWB types, respectively 24 db and 19 db above TG 1/8 conclusions, at first for the more than likely impact on Environment Canada radar network data availability and reliability and secondly, as expressed in section 2 above, for the precedence it will represent and the obvious negative message it will further on other countries. Although recognising that, unlike for passive bands, protection of meteorological radars is more of a national Canadian issue, WMO would however strongly encourage Industry Canada to review its Radio Standard Specification (RSS-220) to consider, for all UWB types (Communications and Radar Imaging) (sections 5 and 6), maximum EIRP density levels consistent with Recommendations ITU-R SM.1757 and Report ITU-R SM.2057, to provide the relevant and necessary protection to meteorological radars in Canada. 6 Conclusions
- 8 - The Fifteenth World Meteorological Congress (Geneva, May 2007), attended by 163 Member countries, including Canada, confirmed serious concern at the continuous threat to radio frequency bands allocated for meteorological and related environmental systems and adopted the related Resolution 4 (Cg-XV) Radio frequencies for meteorological and related environmental activities (see attachment). In particular, this Resolution Appeals to the International Telecommunication Union and its Member Administrations: (1) To ensure the availability and absolute protection of the radio-frequency bands which, due to their special physical characteristics, are a unique natural resource for spaceborne passive sensing of the atmosphere and the Earth surface; In this regard, the exclusive 23.6-24 GHz passive band that is associated with a water vapour absorption line is of crucial importance for weather, water and climate research and operations. (2) To give due consideration to the WMO requirements for radio frequency allocations and regulatory provisions for meteorological and related environmental operations and research. It is worth noting that the specific case of the 23.6-24 GHz is highlighted in this Resolution 4 (Cg- XV), hence stressing its essential and crucial importance for the whole meteorological community. Also, WMO would like to stress that at the recent Climate Change talks in Bonn (June 2009), preparing for an effective international climate change deal to be clinched in Copenhagen in December 2009, the UN Framework Convention on Climate Change Subsidiary Body on Scientific and Technical advice (UNFCCC-SBSTA) stressed the importance of long-term in-situ and satellitebased global climate observations for impact assessment and adaptation to climate change, and called for actions to further improve these observations. It also invited GCOS (Global Climate Observing System) to prepare an update of the GCOS Implementation Plan that lists and argues the Essential Climate Variables to be observed On this basis, WMO would like to urge and encourage Industry Canada to review its Radio Standard Specification RSS-220 (March 2009) and consider UWB maximum EIRP density levels as specified in Recommendation ITU-R SM.1757 as was done in a number of countries or regional organisations (e.g. Europe, Japan, ), stressing in particular passive bands 10.6-10.7 GHz and 23.6-24 GHz as well as meteorological radar bands 5600-5650 MHz band and 9300-9500 MHz that all support essential and increasingly reliable applications key to the meteorological processes.
- 9 - ATTACHMENT RESOLUTION 4 (CG-XV) RADIO FREQUENCIES FOR METEOROLOGICAL AND RELATED ENVIRONMENTAL ACTIVITIES THE CONGRESS, Noting: (1) The WMO Strategic Plan and the Millennium Development Goals, (2) Resolution 3 (Cg-XIV) Radio-frequencies for meteorological and related environmental activities, (3) The current radio frequency allocations and regulatory provisions related to the meteorological aids, meteorological satellite, Earth exploration-satellite and radiolocation (weather and wind profiler radars) services in the Radio Regulations of ITU, (4) The outcome of the ITU World Radiocommunication Conferences (especially WRC-2000 and WRC-03), (5) The agenda of the forthcoming ITU World Radiocommunication Conference (WRC-07) and related WMO positions submitted during the ITU preparatory process, Considering: (1) The prime importance of the specific radiocommunication services for meteorological and related environmental activities required for the prevention, detection, early warning and mitigation of natural and technological (man-made) disasters, the safety of life and property, the protection of the environment, climate change studies and scientific research, (2) The importance of information provided by the Earth-exploration systems including meteorological systems for a wide range of economic activities such as agriculture, transportation, construction, tourism, etc, (3) The crucial importance of the allocation of suitable radio-frequency bands for the operation of surface-based meteorological observing systems, including in particular radiosondes, weather radars, wind profiler radars, (4) The crucial importance of the allocation of suitable radio-frequency bands for the operation of Meteorological and R&D satellites, including remote sensing, data collection and data distribution links, Stressing that some radio-frequency bands are a unique natural resource due to their special characteristics and natural radiation enabling spaceborne passive sensing of the atmosphere and
- 10 - the Earth surface, that deserve adequate allocation to the Earth exploration satellite service (passive) and absolute protection from interference, Expresses its serious concern at the continuing threat to several frequency bands allocated to the meteorological aids, meteorological satellite, Earth exploration-satellite and radiolocation (weather and wind profiler radars) services posed by the development of other radiocommunication services; Requests the Commission for Basic Systems to pursue the continuous review of regulatory and technical matters related to radio-frequencies for operational and research meteorological and related environmental activities, and preparation of guidance and information for NMHSs, in coordination with other technical commissions, especially CIMO, and in liaison with other relevant international bodies, in particular the Coordination Group for Meteorological Satellites; Urges all Members to do their utmost to ensure the availability and protection of suitable radio frequency bands required for meteorological and related environmental operations and research, and in particular: (1) To ensure that their national radiocommunication administrations are fully aware of the importance of and requirements for radio frequencies for meteorological and related activities, and to seek their support in the ITU World Radiocommunication Conferences and Radiocommunication Sector activities; (2) To participate actively in the national, regional and international activities on relevant radiocommunication regulatory issues and, in particular, to involve experts from their Services in the work of relevant regional radiocommunication organizations and of ITU-R, especially ITU-R Study Group 7 on Science Services; (3) To register adequately with their national radiocommunication administrations all radiocommunication stations and radio frequencies used for meteorological and related environmental operations and research; Appeals to ITU and its Member Administrations: (1) To ensure the availability and absolute protection of the radio-frequency bands which, due to their special physical characteristics, are a unique natural resource for spaceborne passive sensing of the atmosphere and the Earth surface; In this regard, the exclusive 23.6-24 GHz passive band that is associated with a water vapour absorption line is of crucial importance for weather, water and climate research and operations; (2) To give due consideration to the WMO requirements for radio frequency allocations and regulatory provisions for meteorological and related environmental operations and research; (3) To pay special attention to the WMO positions related to WRC-07 agenda, in the light of Appeals (1) and (2) above; Requests the Secretary-General: (1) To bring this resolution to the attention of all concerned, including the International Telecommunication Union;
- 11 - (2) To pursue as a matter of high priority the coordination role of the Secretariat in radio frequency matters, especially with ITU-R, including participation of WMO in ITU-R Radiocommunication Study Groups, conference preparatory meetings and World Radiocommunication Conferences; (3) To facilitate the coordination between National Meteorological and Hydrological Services and their national radiocommunication administrations, particularly in preparing the ITU World Radiocommunication conferences, by providing appropriate information and documentation; (4) To assist the Commission for Basic Systems in the implementation of this resolution.