UK SPF Cluster 1 HAPS workshop summary 08.06.17

1. Spectrum requirements for High Altitude
Platform Stations (HAPS)
8th June 2017 • Summary of SPF Cluster 1 workshop discussions
The UK Spectrum Policy Forum (SPF) held a workshop in London on 8th June 2017 to
highlight the latest technological developments in High Altitude Pseudo Satellites /
Platform Stations (HAPS), and to discuss the associated spectrum requirements for
the latest generation of HAPS. Presentations were delivered by Airbus, Access
Partnership, Ofcom and the CAA.
The Airbus presentation described the evolution of Zephyr as a platform, the latest
evolutions of the technology in terms of expanded payload and the range of
applications relevant to the markets that Zephyr addresses. The presentation
concluded with an overview of the broad impact of Zephyr to technology and
industry development, society and the environment.
Airbus described that the Zephyr platform can be used to deliver communication
services, observation and sensor services to commercial, military and government
users. In the commercial sector, applications are focussed on providing wireless
backhaul for communications and Internet of Things (IoT) data, whereas in the
military and government sectors here is the possibility of military surveillance,
remote sensing and tactical radio.
Contracting models for Zephyr HAPS services are broad ranging and flexible. They
include buying capacity as a service, using Zephyr as a platform to host a customer
payload, leasing or buying a Zephyr. Flexibility will be maximised around each
customers’ specific need.
Airbus described the positive economic and social impacts that can be derived
from the Zephyr developments including positive contribution to the UK economy
through the jobs created and sustained (ensuring the UK remains at the forefront
of HAPS manufacturing, and remains a centre of excellence in these technology
developments).
The presentation from Access Partnership explained the vision for HAPS platforms –
also referred to as High Altitude Pseudo Satellites – to complement terrestrial and
satellite networks with potential to provide wireless backhaul connectivity to
enable high speed broadband connectivity, especially to underserved areas.
Access Partnership described the eco-system for HAPS and the key players
involved in this eco-system including Airbus, Google, Boeing, Facebook, Thales
Space and others. Benefits of HAPS as a connectivity platform were summarised

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as the large footprint (larger than 100km in diameter per platform), low cost (limited
ground infrastructure needed), rapid deployment and flexibility (including ability to
reconfigure payloads), low environmental impact and quality of service.
Technology advancements enabling higher altitude solar aircraft and greater
throughput were described. The various HAPS platforms under development,
including Airbus Zephyr, Facebook Aquila and Thales StratoBus were contrasted in
terms of their type, dimensions, payload and other key characteristics – as shown
below.
Figure 1: HAPS platform comparison [Source: Access Partnership, 2017]
Zephyr Aquila StratoBus
Type Heavier than air Heavier than air Lighter than air
Dimensions 25m / 33m 43m 111m x 33m
Mass (total) 62kg / 140kg 450kg 5 000 kg
Payload mass 5kg / 20kg - 250kg
Autonomy - 90 days 5 years
Demo flight 2017, with 1/4-scale
model
2016 2018, with 1/3-scale
model
Full-size flight 2018 2016 2020
The typical geometry of platforms (20km altitude, service area of 50km and
elevation greater than 20 degrees) was described. Current work in ITU-R Working
Party 5C was described, indicating that the next generation HAPS platforms cannot
be supported within existing spectrum allocations identified for HAPS use.
Additional frequency requirements for HAPS will be discussed at WRC-19 with the
objectives of (a) providing spectrum certainty for the next generation of HAPS
platform (b) securing sufficient, globally identified, spectrum appropriate to new
HAPS links.
The latest status on the UK preparatory process for WRC-19 in relation to the
agenda item on HAPS (WRC-19 agenda item 1.14) was described in a presentation
by Ofcom. Ofcom described the purpose of the agenda item being to understand
spectrum requirements for broadband HAPS applications in the fixed service, assess
the feasibility of existing bands identified for HAPS to meet these requirements, and
consider selected new bands for HAPS identification (on a global level – 38-
39.5GHz, and, in Region 2, 21.4-22GHz and 24.25-27.5GHz) in accordance with
Resolution 160 (WRC-15). Work is underway within the European preparatory group
for WRC-19 to study spectrum needs for broadband HAPS. It was noted that key
issues to be addressed in this ongoing work are to build consensus on the potential
spectrum requirements, finalise technical characteristics for different use cases (as
input to sharing studies), develop the necessary sharing and compatibility
conditions between HAPS and existing services and assess feasibility of potential
options towards regional/global harmonisation of conditions for HAPS, based on

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the outcome of the sharing and compatibility assessments. It was further noted that
the band 24.25-27.5GHz is being promoted by Europe as a pioneer band for 5G
and for global harmonisation for IMT. Studies should be completed by August 2018.
The workshop concluded with a presentation from the Civil Aviation Authority
(CAA) in relation to the aviation perspective on the latest HAPS platform
developments. CAA’s responsibilities relating to regulation of air safety in the UK,
policy for the use of airspace, economic regulation of Heathrow, Gatwick and
Stansted airports, management the licensing and financial fitness of airlines, and
financial protection for airline users, were described. In relation to HAPS, the CAA’s
concerns were noted as airworthiness, airspace of operation, communication with
and within the platform, station keeping, surveillance and failure modes were
highlighted.
The SPF audience was appreciative of the presentations made during the
workshop. A discussion on relevant use cases in the UK market and spectrum needs
highlighted that UK market applications of HAPS seem limited at present. Hence,
there were no specific HAPS spectrum policy issues that the SPF identified as being
priorities for the UK market. However, it was noted that the development of HAPS
technologies within UK-based companies will have a positive impact in relation to
positioning the UK at the forefront of the latest HAPS developments, as well as
contributing to highly skilled jobs creation and the knowledge economy in the UK.