ARLA/CLUSTER: Reino Unido propõem tornar o segmento dos 50 a 54 MHz (banda dos 6m) como alocação primária para o serviço de amador na WRC-2019

[João Costa > CT1FBF]

Proposed 50-54 MHz agenda item for WRC-19

The UK positions for WRC-15, taking place November 2-27 include a proposal
for an Agenda Item for WRC-19 regarding a Primary Amateur 50-54 MHz
allocation

Ofcom’s statement references the document containing the European Common
Proposals for agenda items for the next conference, WRC-19. One proposal is
EUR-A25-2 – *Primary allocation of the band 50-54 MHz to the Amateur
Service in Region 1*. The inclusion of this proposal is very welcome since
it would facilitate further worldwide harmonization.

Unfortunately the proposal only references the Amateur Service although
such an allocation would be of great benefit to the Amateur Satellite
Service.

A 50 MHz Amateur Satellite allocation would offer:
• low Doppler shift
• good link budget requirements
• relieve pressure on the only existing VHF amateur satellite allocation on
145 MHz.

*Doppler*
A 50 MHz signal from a satellite in an 800 km orbit would have a Doppler
shift of +/-1.1 kHz during a 15 minute pass compared with +/-3.27 kHz at
145 MHz greatly easing tuning requirements.

*Link Budget*
The free space path loss at 50 MHz would be 9.2 dB lower than on 145 MHz. A
low path loss is particularly important for small satellites with a limited
power budget such as CubeSats or PocketQubes. These satellites may be just
10x10x10 cm or smaller and the limited surface area restricts the amount of
solar power than can be generated.
Typical transmitter output powers range between 100 mW and 400 mW. This
power might be shared by a beacon and up to 5 SSB stations in the
transponder passband, giving maybe 50 mw per station. Because of their size
these satellites have to use simple omni-directional antennas such as a
dipole or monopole

Satellite antennas for this band will need to be kept to a manageable size,
this will help drive experimentation and innovation in antenna design for
these frequencies. Where the band is used as a satellite uplink there is no
need to utilize a full size antenna.

The low path loss of this band could facilitate the development of compact
rapid deployment satellite ground stations utilizing omni-directional
antennas for emergency communication scenarios.

*Relieve Congestion*
The existing satellite segment at 145.8-146.0 MHz is already congested with
satellite downlinks. Most frequencies are already in use by four or more
satellites. An additional VHF allocation would relieve the pressure.

*ITU Footnote 5.282*
This footnote currently covers the Amateur Satellite Service UHF and
Microwave allocations between 435 MHz and 6 GHz. It would be desirable if
the footnote could be expanded to include operation in 50-51 MHz.
http://life.itu.int/radioclub/rr/arsfoot.htm

Read the European Common Position on Agenda Item 10
<https://ukamsat.files.wordpress.com/2015/10/cpgpta2014010_future-wrc-ais-iaru-input.docx>

Ofcom statement
http://stakeholders.ofcom.org.uk/binaries/consultations/wrc15/
statement/UK_Positions_for_WRC-15.pdf
<http://stakeholders.ofcom.org.uk/binaries/consultations/wrc15/statement/UK_Positions_for_WRC-15.pdf>
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