Technical and Regulatory Studies on HAPS 04 December 2008 Jong Min Park
Contents 1. Overview of HAPS 2. Frequency identifications for HAPS 3. Technical and regulatory conditions for HAPS 4. Conclusions 2
1. Overview of HAPS 2. Frequency identifications for HAPS 3. Technical and regulatory conditions for HAPS 4. Conclusions
Definition Radio Regulations, No.1.66A High altitude platform station: A station located on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the Earth. 36,000 km GEO Coverage (diameter) Terrestrial HAPS LEO GEO <1km Up to 200km >500km Up to global 800 km LEO Cell size (diameter) 0.1-1km 1-10km 50km 400km min. 322 km 20 km 16 km 8.8km Sea Level Space Shuttle HAPS Airplane Mt. Everest Total service coverage Max. Tx rate per user System deployment Spot service National/ regional 155Mbps 25-155Mbps Several base stations before use flexible global <2Mbps(up ) 64Mbps(do wn) Many satellites Before use Quasiglobal 155Mbps Flexible, but long lead time 4
Potential applications using HAPS HAPS Digital TV, news gathering Inter-HAPS link Broadcasting Gateway High Speed Mobile Multimedia 64k ~ 512kbps Leased Line 512k ~ 2Mbps, 2M ~ 45Mbps High Speed Internet 512k ~ 2Mbps Additional Services Meteorological Observation Air Pollution Monitoring Radio Monitoring Disaster Monitoring Plant Observation Surveillance PSTN PSDN WWW Service Provider, Private Company Handheld, Mobile SOHO router Major Communication Services 5
World map of HAPS development StratXX 6
Necessity of technical and regulatory studies Limited spectrum resources Evolution of various wireless services HAPS GSO sat. Terr. station GSO ES 7
1. Overview of HAPS 2. Frequency identifications for HAPS 3. Technical and regulatory conditions for HAPS 4. Conclusions
47/48 GHz Frequency Bands WRC-97 made provision for operation of HAPS so that the frequency allocation to the FS(Fixed Service) in the bands 47.2-47.5 47.5 GHz and 47.9-48.2 48.2 GHz would be designated for use by HAPS on the global basis. There is no specific identification for either HAPS-to-ground direction or ground-to-haps direction. Such use of the bands above is subject to the provisions of Resolution 122, which was revised at WRC-07. However, it should be noted that under the provision of RR footnote No. 5.552, administrations are urged to take all practicable steps to reserve fixed-satellite service(fss) ) use of the band 47.2-49.2 49.2 GHz for feeder links for the broadcasting- satellite service(bss) ) operating in the band 40.5-42.5 42.5 GHz. 9
27/31 GHz Frequency Bands At WRC-2000 2000, several countries expressed a need for a lower frequency band for HAPS on account of severe rain attenuation which occurs at 47/48 GHz bands. HAPS in the FS may use the band 27.5-28.35 28.35 GHz (down-link) and the band 31-31.3 31.3 GHz (up-link) in 12 countries located mainly at Asia-Pacific region under certain conditions. At WRC-03 03, some countries including Korea and North/South America also expressed an interest in use of the frequency bands. The additional countries may use the bands by HAPS under certain conditions. (The use of the band 27.5-28.35 GHz was changed to limit to a single 300 MHz sub-band band within the band.) At WRC-07 07, feasibility of identifying a common suitable and preferable a common 300 MHz segment of the band 27.5-28.35 28.35 GHz for use by HAPS was considered. Finally, the band 27.9-28.2 28.2 GHz was identified as the common segment. (Cameroon and India were included for the list of countries.) 10
Frequency Bands for IMT-2000 Service At WRC-2000 2000, the use of HAPS as base stations within terrestrial component of IMT-2000 was considered as optional for any countries. Under the Radio Regulations No.5.388A, HAPS may be used as base stations in the bands; 1,885-1,980 1,980 MHz, 2,010-2,025 2,025 MHz and 2,110-2,170 2,170 MHz* (in Regions 1 and 3) 1,885-1,980 1,980 MHz and 2,110-2,160 2,160 MHz * (in Region 2) (* : HAPS stations are intended to transmit.) 11
Others Since WRC-2000 2000, for the possible use of HAPS in the FS and MS in the frequency bands above 3 GHz allocated exclusively for terrestrial radiocommunication, feasibility study has been conducted under Resolution 734. There have been no frequency identifications for the purpose of the Resolution until WRC-07. WRC-07 revised the Resolution to study in order to identify two channels of 80 MHz each for gateway links for HAPS in the range from 5,850 to 7,075 MHz, in bands already allocated to the FS, while ensuring the protection of existing services, under WRC-11 agenda item 1.20. 12
1. Overview of HAPS 2. Frequency identifications for HAPS 3. Technical and regulatory conditions for HAPS 4. Conclusions
Overview Frequency sharing scenarios considered Fixed satellite service(fss) space station FSS Earth station HAPS User terminal Radio astronomy service (RAS)(passive) station HAPS platform Earth-exploration satellite service(eess)(passive) Space station Wanted signal Interference Fixed wireless system (FWS) Mobile service(ms) systems Outputs of ITU-R R studies on HAPS Freq. Res. Rec. Service concerned with HAPS FS FSS PS MS SF.1481 F.1500 F.1501 U-band 122 F.1608 F.1819 F.1820 SF.1843 F.1569 F.1570 Ka-band 145 SF.1601 F.1607 F.1609 F.1612 S-band 221 M.1456 M.1641 > 3 GHz 734 F.1764 Note: Res. Resolution (WRC) Rec. Recommendation (ITU-R) PS Passive services 14
For 47/48 GHz Frequency Bands Technical matters Preferred characteristics of systems in the FS using HAPS (F.1500) Frequency sharing between HAPS and other FS systems Methodology for determining coordination distance (F.1501) Methodology for analysing the sharing possibilities (F.1608) Power flux density at international borders (F.1820) 141 db(w/(m2 MHz)) for 0 0 θ 3 141 + 2.0(θ 3) db(w/(m2 MHz)) for 3 3 < θ 13 121 db(w/(m2 MHz)) for 13 < θ 90 where θ is the angle of the arrival above the horizontal plane of the Earth Frequency sharing between HAPS and FSS systems Methodology for analysing the sharing possibilities (SF.1481) Methodology to determine power level to facilitate sharing with space station receivers (SF.1843) Protection of RAS from unwanted emissions from HAPS (F.1819) The separation distance between the radio astronomy station and the nadir of a HAPS platform should exceed 50 km. 15
For 47/48 GHz Frequency Bands (cont d) Regulatory matters Resolution 122 is a regulatory provision for the use of the bands by HAPS in the FS, which was adopted in 1997. Based on the progress of technical and regulatory studies, the Resolution has been reviewed and appropriately modified through next three WRCs. The Resolution provides several provisions as follows; For facilitating sharing with the FSS (Earth-to-space), the maximum transmit e.i.r.p. density of a ubiquitous HAPS ground terminal shall not exceed 6.4 db(w/mhz), 22.57 db(w/mhz) and 28 db(w/mhz) under clear-sky conditions, respectively for urban, sub-urban and rural area coverage and it could be increased by up to 5 db for the rainy conditions. The ground terminal antenna pattern of HAPS is provided to be met in the Resolution. For protecting FWS in neighbouring countries from co-channel interference, a HAPS system should not exceed power flux-density of 141 db(w/(m 2 MHz))at the Earth s surface at border, unless explicit agreement of the affected country is provided at the time of the notification of HAPS. For protecting RAS stations operating in the band 48.94-49.04 GHz from unwanted emissions of HAPS, the separation distance between the RAS station and the nadir of a HAPS platform should exceed 50 km. Any countries planning to implement a HAPS system should notify the frequency assignments by submitting all mandatory information specified in RR Appendix 4 to the ITU. 16
For 27/31 GHz Frequency Bands Technical matters Technical and operational characteristics of systems in the FS using HAPS (F.1569) Frequency sharing between HAPS and other FS systems Interference mitigation techniques for use by HAPS (F.1607) Interference evaluation from HAPS to conventional FS systems (F.1609) Frequency sharing between HAPS and FSS systems Methodology for interference evaluation from the downlink of HAPS to the uplink of GSO/FSS (SF.1601) Protection of Passive Service from HAPS Impact of uplink transmission in HAPS in EESS(passive) in the 31.3-31.8 GHz band (F.1570) the level of unwanted emissions : limited to 105 db(w/mhz) Interference evaluation of HAPS to protect RAS from uplink tx in HAPS (F.1612) 17
For 27/31 GHz Frequency Bands (cont d) Regulatory matters 22 countries listed in the RR footnotes No.5.537A and No.5.543A should not cause harmful interference to, nor claim protection from, other types of FS systems or other co-primary services Countries in Region 2 in accordance with Resolution 145 can use Ka-bands. should not cause harmful interference to, nor claim protection from, other stations of services operating in accordance with the Table of Frequency Allocations of Article 5 of RR. Resolution 145 provides several provisions as follows; Systems using HAPS should not cause harmful interference to the RAS having a primary allocation in the band 31.3-31.8 GHz In order to ensure the protection of satellite passive services, the level of unwanted power density into the HAPS ground station antenna in the band 31.3-31.8 GHz should be limited to 106 db(w/mhz) under clear-sky. The countries intending to implement systems using HAPS in the FS should get explicit agreement of concerned countries with regard to their stations of primary services or other services for Region 2 to ensure that the conditions specified in the provisions of RR are met and notify the frequency assignment(s) by submitting all mandatory elements of RR Appendix 4 to ITU. 18
Frequency Bands for IMT-2000 Service Technical matters Minimum performance characteristics and operational conditions for HAPS providing IMT-2000 (M.1456) For the purpose of protecting stations operated by neighbouring countries from cochannel interference, specific antenna patterns applied to the countries using HAPS as base stations to provide IMT-2000 are provided. Co-channel power flux density(pfd) level on the Earth s surface outside a country s boundaries, out of band pfd level for protecting fixed stations and mobile earth stations(mes) are provided. Methodology for co-channel interference evaluation to determine separation distance from a system using HAPS to a cellular system to provide IMT-2000 (M.1641) The interference to a cellular mobile station from cellular base stations and a HAPS base station is estimated in terms of the C/I with the parameters of the HAPS system such as the number of users, and transmission power. For each estimated case, the optimum values are determined for the above parameters in the HAPS IMT-2000 system in order to be compatible with the cellular system. 19
Frequency Bands for IMT-2000 Service (cont d) Regulatory matters Resolution 221 is a regulatory provision for the use of S-bands by HAPS adapted in 2000. Based on the progress of technical and regulatory studies, the Resolution has been reviewed and appropriately modified through next two WRCs. Most of aforementioned operational conditions for HAPS were incorporated into the Resolution. In addition, the current version of the Resolution resolves that for facilitating consultations between countries, countries planning to implement a HAPS as an IMT base station should furnish to the concerned administrations the additional data elements listed in the Annex to this Resolution, if so requested and notify the frequency assignment(s) by submitting all mandatory elements of RR Appendix 4 to ITU. 20
Other Technical matters Methodology for interference evaluation that could be used for sharing studies between FS systems using HAPS and conventional fixed wireless systems in the frequency bands above 3 GHz. (F.1764) Regulatory matters Resolution 734 was adopted at WRC-2000 for the feasibility of HAPS in the FS and MS in the frequency bands above 3 GHz. It was revised at WRC-03 to extend the time frame of the feasibility study. And then there was another revision made at WRC-07 to invite ITU-R to extend the sharing studies, with a view to identifying two channels of 80 MHz each for gateway links for HAPS in the range from 5,850 to 7,075 MHz, in bands already allocated to the fixed service, while ensuring the protection of existing services. This issue is being studied under WRC-11 agenda item 1.20. 21
WRC-11 Agenda Item 1.20 Base Station Controller PSTN/PLMN/ PSDN/WWW PSTN/PLMN/ PSDN/WWW To consider the results of ITU-R studies and spectrum identification for gateway links for high altitude platform stations (HAPS) in the range 5 850-7 075MHz in order to support operations in the fixed and mobile services, in accordance with Resolution 734 (Rev.WRC-07) Core Network Terrestrial network A Gateway station HAPS network Gateway station HAPS platform with communications payload Gateway station Base Station Controller Core Network Terrestrial network B HAPS gateway links HAPS user links Gateway station Interface PSTN/PLMN/ PSDN/WWW PSTN/PLMN/ PSDN/WWW Region 1 Region 2 Region 3 5 850 5 925 FIXED FIXED- SATELLITE (Earth-tospace) MOBILE 5.150 5 850 5 925 FIXED FIXED- SATELLITE (Earth-tospace) MOBILE Amateur Radiolocation 5.150 5 850 5 925 FIXED FIXED- SATELLITE (Earth-tospace) MOBILE Radiolocation 5.150 5 925 6 700 FIXED FIXED-SATELLITE (Earth-to-space) 5.457A 5.457B MOBILE 5.149 5.440 5.458 6 700 7 075 FIXED FIXED-SATELLITE (Earth-to-space) (Space-to Earth) 5.441 MOBILE 5.458 5.458A 5.458B 5.458C 22
1. Overview of HAPS 2. Frequency identifications for HAPS 3. Technical and regulatory conditions for HAPS 4. Conclusions
Conclusions In this paper, we provide overall results obtained in the technical and regulatory studies conducted in ITU-R regarding HAPS. Several frequency bands are identified for the use of HAPS on a global, regional or national basis and for each frequency band, appropriate regulatory provisions are established based on the technical and operational studies. Additional spectrum identification for HAPS gateway link is being discussed under WRC-11 agenda item 1.20. When HAPS is implemented in the various applications, current regulatory provisions should be complied with for proper protection of other systems in the same or adjacent bands. Any problems related to interference between systems using HAPS and other systems could be resolved in a harmonized manner in accordance with the regulatory procedures. In the future, when we establish additional regulatory provisions and procedures, we need to bear in mind that the balance between facilitating implementation of HAPS and ensuring protection of other existing systems should be considered properly. 24