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AI 1.14 High Altitude Platforms

Agenda item 1.14

1.14 to consider, on the basis of ITU-R studies in accordance with Resolution 160 (WRC-15), appropriate regulatory actions for high-altitude platform stations (HAPS), within existing fixed-service allocations;

Resolution 160 (WRC-15) – Facilitating access to broadband applications delivered by high-altitude platform stations


The technological innovations and the growing urgency to expand the availability of broadband led to a review of the current regulatory environment for delivery platforms such as high-altitude platform stations (HAPS). Such stations deliver broadband from approximately 20 km above ground. These high-altitude platform stations operating in the stratosphere are high enough to provide service to a large area. Recent test deployments have demonstrated their maturity to provide connectivity to underserved communities with minimal ground-level infrastructure.

More options for broadband delivery are needed, especially for countries with less-developed infrastructure. HAPS can drive broadband rollout by providing an additional service platform.  Such HAPS could augment the capacity of other providers using innovative and easily deployable platforms positioned in the upper atmosphere. WRC-15 adopted Resolution 160 to study how to facilitate access to global broadband applications delivered by HAPS in the Fixed Service (FS).

Broadband HAPS applications

Broadband HAPS applications (in the Fixed Service) will serve several use cases. It can provide Internet access to users on a medium (days to weeks) to long-term basis. It can be a direct-to-home fixed access, a link to an access point, or a backhaul connection for remote networks. Capacity may vary for connectivity and specific use cases (such as for disaster relief missions or commercial use, etc.). Regardless, HAPS provide fixed service connections between an airborne platform and temporary or permanent FS ground stations. The ground stations include Gateway (GW) and Customer Premises Equipment (CPE) installations.

HAPS and ground station descriptions

A high-altitude platform station is a station that operates in accordance with No. 1.66A in the Radio Regulations. It is considered that a HAPS station operates at a nominal fixed position. It may do this by circling in the sky at about 20km (over 60000ft). The different platform implementations for HAPS are assumed to be in accordance with the HAPS definition in RR No. 1.66A.

The gateway (GW) link connects HAPS with terrestrial based networks for voice, data and video communications. It connects the high-altitude platform station to public switched telephone network (PSTN) and cell-phone providers. It connects the HAPS to worldwide providers of broadband communications, and television and sound broadcasters.

The customer premises equipment (CPE) for HAPS applications is equipment (fixed terminals) for ground-based fixed links. The CPE communicates with the HAPS and distributes connectivity to end users by other wired or wireless means. In effect it provides a connection for last mile communications systems such as international mobile telecommunications (IMT), wireless access systems and radio local area networks (WAS/RLAN). In such cases the CPE is at an "access point". The HAPS is a backhaul link for the access point. But CPE could also provide direct to home access.

Existing HAPS identifications in FS bands

The existing HAPS designations have not been fully utilised in the past partly due to physical, technical and regulatory constraints.

Common worldwide identifications for HAPS are desirable in order to improve and harmonise their utilisation of the radiofrequency spectrum. Further modifications to the footnotes of existing identifications could be considered to revise technical conditions to facilitate the use of the existing identifications for services at worldwide level. 

There are calls for multi-gigabit broadband in the future. The spectrum needs for broadband HAPS applications may not be fully accommodated within current HAPS identifications. That is the case even if modified to make them global and co-primary, with technically favourable conditions. This is demonstrated by studies that have been carried out on spectrum needs to satisfy HAPS capacity demand.

Existing HAPS identifications may provide spectrum for some broadband HAPS system use cases. Nonetheless the majority of broadband HAPS systems could not be satisfied using the existing spectrum identifications. The existing identifications associated with current HAPS regulatory provisions are not sufficient to accommodate the largest cases with more demanding spectrum requirements. The current regulatory provisions for the existing HAPS identifications cause this problem. Consequently, sharing and compatibility studies on possible new HAPS identifications were conducted per Resolution 160 (WRC-15).

Methods to satisfy the agenda item

The following methods are considered under this agenda item and may be applied to potential candidate frequency bands. In the options below, changes to existing designations to HAPS are proposed on a global basis. They do not prejudge the consideration of these options on a regional basis or in country footnotes, where applicable.  Regional basis should be understood as in accordance with the Radio Regulations definition of Regions. In addition, proposals for candidate bands could include either partial or full band identifications for HAPS in respect of each candidate band.  Limitations on, or additional options for, directionality could also be included in order to ensure compatibility with existing services.

Method A – No change

The existing provisions in the Radio Regulation remain unchanged in the corresponding frequency band.

Method B – Identification of bands, in accordance with Resolution 160 (WRC-15) with options

This group of methods could be achieved by new or revised footnotes to the Table of Frequency Allocations, and new or revised associated Resolutions.


Method B1 – Revision of the regulatory provisions for HAPS in the FS with a primary status in bands already identified for HAPS

This may be by global or regional identification for HAPS with potential limitations regarding link directions. This also includes the technical conditions on the operation of HAPS systems for the protection of other services.

Method B2 – Add new identification(s) for HAPS in bands already allocated to the FS with a primary status

This may be by global or regional identification for HAPS with potential limitations regarding link directions. This also includes the technical conditions on the operation of HAPS systems for the protection of other services.

Method B3 – Add a primary allocation to the FS and a new identification for HAPS in the band 24.25-25.25 GHz (Region 2) not already allocated to the FS

This may include, primary allocation for FS in Region 2 and designation for HAPS in that Region, together with conditions. These conditions may include limitations regarding link directions, and inclusion of the technical conditions of operation of HAPS systems for the protection of other services.

Method C – Suppress the existing HAPS designation, pursuant to resolves 3 of Resolution 160 (WRC-15)

An overview of methods and relevant options currently under the agenda item is provided in the table below:

Bands                                       Methodsand   options 
                              Method A Method B Method C
6 440- 6 520 MHz B1  
6 560- 6 640 MHz Not proposed  
21.4-22 GHz (R2 only) B2 N/A  
24.25-25.25 GHz (R2 only) B3 N/A  
25.25-27.5 GHz (R2 only) B2 N/A  
27.9-28.2 GHz B1  
31-31.3 GHz B1  
38-39.5 GHz B2 N/A  
47.2-47.5 GHz / 47.9-48.2 GHz B1  




CEPT position

CEPT wishes to ensure the protection of existing services and their future development including other applications of the fixed service (in accordance with Resolution 160 (WRC-15)).

CEPT supports;

in the bands 6 440- 6 520 MHz, 27.9-28.2 GHz

–             Worldwide identifications for transmissions from high altitude platform stations (in the downlink direction). In the 28GHz band the HAPS ground stations should not claim protection from Fixed Satellite Service earth stations


in the bands 31-31.3 GHz and 38-39.5 GHz

–             Worldwide identifications for transmissions to and from high altitude platform stations (in the uplink and downlink directions)


     For the bands 6 440-6 520 MHz, 27.9-28.2 GHz, 31-31.3 GHz, 38-39.5 GHz, 47.2-47.5 GHz and 47.9-48.2 GHz;

CEPT is supporting new footnotes and associated resolutions and/or appropriate modifications to the existing footnotes and associated resolutions.


For the frequency bands 21.4-22 GHz and 24.25-27.5 GHz in Region 2;

       CEPT is of the view that any consideration under this Agenda item shall by accompanied by appropriate protection of:

                 ISS in the band 24.45-24.75 GHz and in the band 25.25-27.5 GHz,

                 EESS (passive) in the bands 21.2-21.4 GHz, 22.21-22.5 GHz and 23.6-24 GHz,

                 EESS and SRS (space-to-Earth) in the band 25.5-27 GHz and

                 FSS in the bands 24.75-25.25 GHz and 27-27.5 GHz.