Satgen534  Sat MobilePhone Curbs   by GM4IHJ  (BID SGEN534) 1999-06-19

Since the official opening in September 98, the fleet of Iridium
Mobile Phone satellites has been having a difficult time. While there
seems to have been reluctant acceptance by American Radio Astronomers
that sat mobile phones will be a fact of life, European astronomers
have refused to accept this as inevitable. Rather than approach the
satellite operators singly, the Europeans have channelled their
complaints via the Committee on Radio Astronomy Frequencies (CRAF).
While they pressured European governments to withhold the all
important ground station licenses, stations which the sats must use to
connect to terrestrial non mobile phones.  Noting that overspill from
downlink signals is getting into the 1612 MHz radio astronomy hydroxyl
band. As a result of this joint action, agreement has been reached
which meets a minimal number of their requirements.

It has been agreed that :-
a.   As of now satellite operators will provide " quiet time" (
defined as pollution level below the level of detrimental
interference), at facilities in France, Germany, the Netherlands and
Britain for 7 hours every night, and 2 whole week end days each month.
This provision also to apply to Italy, Poland., Spain and Sweden , if
requested.
b.   As of now High Sensitivity Radio Astronomy Interferometry
facilities in Holland and Britain will have quiet time every weekend
c.   After 2006 satellite operators will be obliged to stop all
pollution of the 1612 MHz band.

Both Arecibo Puerto Rico and NRA Greenbank West Virginia USA , made
isolated agreements earlier, which fall well short of what the
combined Europeans have achieved. CRAF will be attending the next
World Radio Conference run by the ITU, to make sure that uncontrolled
spillover from forth coming satellite systems does not occur in either
the 1400 - 1427 MHz Hydrogen band, the 1612 MHz Hydroxyl band or the
the sub millimetre wave bands which are so useful to Radio
Astronomers.

>From the Radio Amateur point of view , threatened as we are by many of
these Low Earth Orbit developements. This particular European stand is
a useful tactical pointer. United we stand - Divided we fall. RSGB
please note, licensing by American authorities is not just something
for Americans. 

The weak point of all these commercial systems is that they usually
need to talk to other sat terminals and to terrestrial terminals via
ground stations. These problems will not go away but with foresight
and in combination with other radio amateurs around the world we can
exploit these weaknesses and make sure we do not lose out. If you have
equipment capable of receiving signal in the 1622 to 1626 MHz band
where these sats are presently heard. You will find them on channels
spaced roughly 166 kHz apart, dopplering widely inside these channels.
The Time division multiplex format used produces a series of wide band
clicks which have lots of harmonics. The resemblance to the late
unlamented Russian Woodpecker " Over the Horizon HF Radar", is quite
marked.