USA - World Wide Threat 70 cm Amateur Radio.

Bedrohung des 70-cm-Bandes durch US-Satellitensystem ?
[...]
Darueber berichten Bernd Mischlewski DF2ZC, und Martin Weber DL5DS, vom
DARC-Referat Frequenzmanagement.

Translate into English version:

Threat to the 70 cm band from an US satellite system?

Various articles in the trade press about the use of the 70 cm band by an
US satellite system have recently caused concern, not only in the amateur
radio world. What kind of system is this, and in what way is amateur radio
threatened by the use of the band by the company AST SpaceMobile? The Fre-
quency Management Department has therefore provided an assessment of the
issue.

What is it about?
AST Spacemobile [1] is a company based in the US state of Texas
that aims to supplement or replace terrestrial mobile phone networks with
base stations in space. The satellites communicate directly with conven-
tional mobile phones. So far, so good. But if the "earth stations" are
normal cell phones operating in their assigned frequency range, why does
SpaceMobile need frequencies in the 430-440 MHz range ?

In addition to the user channels, every satellite system also requires
communication capabilities for monitoring and controlling the satellites.

For this purpose, AST Spacemobile intends to use frequencies in the 70 cm
band, among others. So far, the system has used six channels, each with a
bandwidth of 50 kHz. The center frequencies are 430.5 MHz, 432.5 MHz,
434.1 MHz, 435.9 MHz, 437.5 MHz, and 439.5 MHz. This communication will
take place with several earth stations distributed around the globe. In
Europe, the first station is currently in operation in Bulgaria. In com-
munication with the Bulgarian station, the entire European region will, of
course, be "radiated" from the satellite.

How the situation will develop when the currently relatively small con-
stellation of six satellites grows to the planned size of well over 200
satellites remains to be seen. The deadline for a hearing with the U.S.
Federal Communications Commission (FCC) has now expired. A total of ap-
proximately 2,500 comments were received, including from amateur radio
associations and radio amateurs.

However, the use of the 430-440 MHz band for this project does not comply
with the frequency allocations agreed upon between the ITU member states
in the "Radio Regulations." In granting approval, the U.S. Telecommunica-
tions Administration refers to a clause that allows deviations from the
allocations if this does not cause interference with the assigned radio
services.

What does this mean for amateur radio use ? The existing usage rights for
the 70 cm band will not be restricted in any way. The satellite system
must accept interference from amateur radio transmissions; it must elimi-
nate the causes of any interference to amateur radio. This requires do-
cumentation of the interference, i.e., a report of the interference to
the Federal Network Agency.

What does the DARC do ? Any use of the amateur radio bands by other radio
services, especially if this is not provided for by international agree-
ments, potentially restricts the use by radio amateurs. A position against
such uses is essential. Therefore, the RTA already informed the Federal-
Network Agency of the situation in writing on June 18, 2025, and asked for
its support.

The situation must continue to be monitored. Above all, it is necessary to
document any interference in amateur radio and report it immediately.

[1] <https:ast-science.com>

(Deutschland-Rundspruch #31 des Deutschen Amateur-Radio-Clubs fuer die
32. Kalenderwoche 2025, Aug 7, 2025)

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