High Altitude Platform Stations (HAPS)
Agenda item 1.8 - to consider the results of ITU-R studies on technical sharing and regulatory provisions for the application of high altitude platform stations operating in the bands 27.5-28.35 GHz and 31-31.3 GHz in response to Resolution 145 (WRC-03), and for high altitude platform stations operating in the bands 47.2-47.5 GHz and 47.9-48.2 GHz in response to Resolution 122 (Rev.WRC-03);
Systems using new technologies based on the high altitude platform stations (HAPS) are stratospheric repeaters that will provide high capacity and competitive services to urban and rural areas. WRC-03 revised No. 5.543A of the RR to provide the signal levels that protect the stations that provide Earth exploration-satellite (passive), and space research (passive) services in the band 31.3-31.8 GHz. In addition, the procedures in Article 9 will provisionally be used for coordination between the satellite systems in the bands 47.2-47.5 GHz and 47.9-48.2 GHz and the systems using HAPS.
The issues of this agenda are as follows.
47- 48 GHz bands
- Power limitations applicable for HAPS ground stations to facilitate sharing with the space stations receivers.
- Technical sharing criteria between HAPS and radio astronomy, and between systems using HAPS and geostationary (GSO) fixed satellite service systems.
31/28 GHz bands
- Feasibility of specifying a common 300 MHz segment of the band 27.5-28.35 GHz paired with the 300 MHz band at 31-31.3 GHz, for use by HAPS in the countries listed in Nos. 5.537A and 5.543A of the RR or countries in Region 2 planning provisional operation.
- Technical sharing criteria or HAPS system design conditions that are necessary to ensure that HAPS applications in the fixed service operate successfully on a non-harmful interference, non-protected basis in bands 31/28 GHz.
- Interference criteria and methodology for evaluating interference from HAPS (HAPS-to-ground direction) to GSO satellite networks (Earth-to-space) of fixed satellite services in the band 28 GHz.
- Interference mitigation techniques between fixed services by HAPS and other fixed service conventional systems in the same area.
- Necessary regulations in case the implementation of fixed services by HAPS will affect other administrations.
Currently, the protection criteria from HAPS to GSO satellite networks of fixed satellite services and the interference assessment and interference mitigation techniques from HAPS to other fixed service systems are being studied at ITU-R WP4-9s and WP9B, respectively.
2 Japanese View
RR footnote 5.543A should be maintained as the conditions can appropriately protect the passive services of the stations by avoiding the harmful interference in out of band from HAPS to radio astronomy, Earth exploration-satellite (passive), and space research (passive) services.
ITU-R should study, the technical sharing criteria and interference mitigation techniques that are necessary to ensure that HAPS applications in the fixed service operate on a non-harmful interference in the bands 27.5-28.35 GHz and 31-31.3 GHz;
ITU-R should also complete studies on the interference criteria and methodology for evaluating interference from HAPS(HAPS-to-ground direction)to fixed satellite service GSO(Earth-to-space) in the band 28 GHz.
Agenda item 1.18 - to review pfd limits in the band 17.7-19.7 GHz for satellite systems using highly inclined orbits, in accordance with Resolution 141 (WRC-03);
This agenda item includes issues of considering appropriate pfd limits for non-GSO systems using HIO (highly-inclined orbit; an orbital inclination between 35° and 145° and an apogee altitude greater than 18,000 km) and method to mitigate interference to FS from FSS, which is carried over from WRC-03 considered about a review of pfd limits in non-GSO.
ITU-R WP 4-9S leads a study about frequency sharing between HIO satellite systems and FS and makes considerations of parameters of FS and FSS to be taken into account when calculating interference to review current pfd limits and sharing between these network systems from the various points of view. WP 9A, a Contributing WP of this item, is discussing interference criteria from HEO satellite system in 18 GHz band to FS. WP 4A which is also one of the Contributing WP is comprehensively considering validity of the current pfd limits, organizing parameters characterize HIO satellite systems used for performing simulations, and definition of HIO satellite systems including validity of using MEO parameters to calculate the pfd limits.
2 Japanese View
PFD limits should be appropriately defined in order to protect the fixed services and not to set the excessive limits to HIO systems, considering future practicable plans for HIO. Japan will contribute to the technical studies, ITU-R study groups are conducting.
This agenda item should not make an issue of MEO system as well as the former discussion about the HIO pfd limits, for it have never include the MEO systems into this work.
Agenda item 1.19 - to consider the results of the ITU-R studies regarding spectrum requirement for global broadband satellite systems in order to identify possible global harmonized fixed-satellite service frequency bands for the use of Internet applications, and consider the appropriate regulatory/technical provisions, taking also into account No. 5.516B;
WRC-03 discussed identifying the frequency bands for high-density applications in fixed satellite service (HDFSS) above 17.3 GHz and identified the frequency band for HDFSS, which is added to RR footnote No.5.516B. Regarding identification of globally collaborated frequency bands for using a high-speed Internet in the fixed satellite service, this agenda item is proposed to make a discussion of appropriate regulatory and technical provisions, based on a proposal that it should be discussed to identify frequency band below 17.3 GHz in order to bring a high-speed Internet into service, considering RR footnote No.5.516B.
ITU-R WP4A is discussing plans to realize the most effective satellite Internet service including the usage of the existing FSS Allotment Plan (AP30B) with a view to cost and economic effectiveness of satellite Internet service.
2 Japanese View
Japan finds that there is no need to review the present RR and to identify the frequencies as there is much possibility to implement broadband satellite systems in the bands allocated to the fixed satellite services in the present RR.