High Altitude Platform System (HAPS): U.S. Proposal for frequency range 24.25-25.25 GHz

The following is a U.S. contribution to the World Radio-communication Conference (WRC-19) Sharm el-Sheikh, Egypt, 28 Oct – 22 Nov 2019:

ITU Radio Regulations defines a high-altitude platform station (HAPS) as “a station on an object at an altitude of 20 to 50 km and at a specified, nominal, fixed point relative to the Earth.”

Agenda item 1.14 was adopted by WRC-15 to consider, in accordance with Resolution 160 (WRC-15), regulatory actions that can facilitate deployment of HAPS for broadband applications. Resolution 160 resolves to invite the ITU-R to study additional spectrum needs of HAPS, examining the suitability of existing HAPS designations, and conducting sharing and compatibility studies for additional designations in existing fixed service allocations in the 38‑39.5 GHz band, on a global basis, and in bands already allocated to the fixed service in the 21.4‑22 GHz and 24.25-27.5 GHz bands in Region 2 exclusively.

Advances in aeronautics and transmission technologies have significantly improved the capabilities of HAPS to provide effective connectivity solutions and meet the growing demand for high capacity broadband networks, particularly in currently underserved areas. Recently conducted full-scale test flights have shown that solar-powered platforms in the upper-atmosphere can now be used to carry payloads that offer reliable and cost-effective connectivity, and a growing number of applications for the new generation of HAPS are being developed. The technology appears particularly well suited to complementing terrestrial networks by providing backhaul. A number of advantages of the new generation of HAPS are foreseen:

  • Reach: HAPS platforms may operate at around 20 km above ground, which reduces their vulnerability to weather conditions that may affect service, provides large coverage areas and helps mitigate interference caused by physical obstacles.
  • Geographical reach: HAPS that use the architecture of solar platforms can also provide connectivity where it is impossible to deploy terrestrial infrastructure: remote sites on land or sea.
  • Wide-area coverage: Depending on the operational scenario, a single platform is capable of providing footprints on the order of up to 100 km in diameter, and recent technological advances in the development of optical inter-HAPS links now support the deployment of multiple linked HAPS, in fleets that can provide greater coverage within a country as needed.
  • Low cost and environmental aspects: The cost of operating stratospheric platforms is projected to be lower than other connectivity solutions depending on geographical area, while mass production of the aircraft will significantly lower upfront capital expenditure for deployment. HAPS can run exclusively on solar power for long periods, connecting people with almost no environmental impact.
  • Rapid deployment and flexibility: It may be possible to deploy HAPS services without long lead times and it is relatively simple to return solar platforms to the ground for maintenance or payload reconfiguration.

The ITU-R conducted sharing and compatibility studies to assess coexistence between HAPS and incumbent and proposed systems and services (including issues of overlap with WRC-19 agenda items 1.6 and 1.13). Associated regulatory provisions are proposed below based on the results of sharing studies.

Proposal

For the frequency range 24.25-25.25 GHz in Region 2, the USA proposes “no change” (NOC) to the Radio Regulations, as Resolution 160 (WRC-15) calls for identifications for HAPS in frequency bands already allocated to the fixed service on a primary basis. In Region 2, the bands in this frequency range are not already allocated to the fixed service. No studies have been conducted in the ITU-R to assess the sharing and compatibility of adding a new fixed service allocation to the 24.25-25.25 GHz band in Region 2. As a frequency band cannot be designated for fixed service HAPS use without a fixed service allocation, no change is proposed under agenda item 1.14. This proposal is aligned with Method 4A of the CPM Report to WRC-19.

…………………………………………………………………………………………………………………………………………………………………………………………………….

Table of Frequency Allocations

Allocation to services
Region 1 Region 2 Region 3
24.25-24.45

FIXED

24.25-24.45

RADIONAVIGATION

24.25-24.45

RADIONAVIGATION

FIXED

MOBILE

24.45-24.65

FIXED

INTER-SATELLITE

24.45-24.65

INTER-SATELLITE

RADIONAVIGATION

24.45-24.65

FIXED

INTER-SATELLITE

MOBILE

RADIONAVIGATION

5.533 5.533
24.65-24.75

FIXED

FIXED-SATELLITE
(Earth-to-space)  5.532B

INTER-SATELLITE

24.65-24.75

INTER-SATELLITE

RADIOLOCATION-
SATELLITE (Earth-to-space)

24.65-24.75

FIXED

FIXED-SATELLITE
(Earth-to-space)  5.532B

INTER-SATELLITE

MOBILE

5.533

Reasons:    Resolution 160 (WRC-15) calls for identifications for HAPS in frequency bands already allocated to the fixed service on a primary basis. In Region 2, for the frequency range 24.25-25.25 GHz, the bands in this frequency range are not allocated to the fixed service.

 

Allocation to services
Region 1 Region 2 Region 3
24.75-25.25

FIXED

FIXED-SATELLITE
(Earth-to-space)  5.532B

24.75-25.25

FIXED-SATELLITE
(Earth-to-space)  5.535

24.75-25.25

FIXED

FIXED-SATELLITE
(Earth-to-space)  5.535

MOBILE

Reasons:    Resolution 160 (WRC-15) calls for identifications for HAPS in frequency bands already allocated to the fixed service on a primary basis. In Region 2, for the frequency range 24.25-25.25 GHz, the bands in this frequency range are not allocated to the fixed service.

One thought on “High Altitude Platform System (HAPS): U.S. Proposal for frequency range 24.25-25.25 GHz

  1. Whether an airship or an airplane, a major challenge is the ability of the HAP to maintain station keeping in the face of winds. An operating altitude between 17 and 22 km is chosen because in most regions of the world this represents a layer of relatively mild wind and turbulence above the jet stream. Although the wind profile may vary considerably with latitude and with season, a form similar to that shown will usually obtain. This altitude (> 17 km) is also above commercial air-traffic heights, which would otherwise prove a potentially prohibitive constraint.

    Since HAPS operate at much lower altitudes than satellites, it is possible to cover a small region much more effectively. Lower altitude also means much lower telecommunications link budget (hence lower power consumption) and smaller round-trip delay compared to satellites. Furthermore, deploying a satellite requires significant time and monetary resources, in terms of development and launch. HAPS, on the other hand, are comparatively less expensive and are rapidly deployable. Another major difference is that a satellite, once launched, cannot be landed for maintenance, while HAPS can.

    Telecommunications:

    One of the latest uses of HAPS has been for radiocommunication service. Research on HAPS is being actively carried largely in Europe, where scientists are considering them as a platform to deliver high-speed connectivity to users, over areas of up to 400 km[clarify]. It has gained significant interest because HAPS will be able to deliver bandwidth and capacity similar to a broadband wireless access network (such as WiMAX) while providing a coverage area similar to that of a satellite. High-altitude airships can improve the military’s ability to communicate in remote areas such as those in Afghanistan, where mountainous terrain frequently interferes with communications signals.

    One of the best examples of a high-altitude platform used for surveillance and security is Northrop Grumman RQ-4 Global Hawk UAV used by the US Air Force. It has a service ceiling of 20 km and can stay in the air for continuous 36 hours. It carries a highly sophisticated sensor system including radar, optical, and infrared imagers. It is powered by a turbofan engine and is able to deliver digital sensor data in realtime to a ground station.

    Real-time monitoring of a region:

    Another future use that is currently being investigated is monitoring of a particular area or region for activities such as flood detection, seismic monitoring, remote sensing and disaster management.

    Weather and environmental monitoring:

    Perhaps the most common use of high-altitude platforms is for environment/weather monitoring. Numerous experiments are conducted through high-altitude balloons mounted with scientific equipment, which is used to measure environmental changes or to keep track of weather. Recently, NASA in partnership with The National Oceanic and Atmospheric Administration (NOAA), has started using Global Hawk UAV to study Earth’s atmosphere.

    https://en.wikipedia.org/wiki/High-altitude_platform_station#Altitude_selection_for_HAPS

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

*

 
 

 

Recent Posts