textfiles/phreak/cellular

 PHONE CELL SATELLITES

Current cellular phones use a network of thousands of ground-based
towers each projecting a radio "cell" a few miles across.  Service is 
largely limited to cities in developed countries.  

Phone cells can greatly expand this service, while developing the
critical technology of miniature spacecraft components for the 21st
century.  The biggest markets are travellers and wealthy third
worlders, who number tens of millions despite being a small % of the
total -- in Russia, India, China, Brazil, Mexico, Iran, Indonesia,
Thailand, Turkey, Eastern Europe, etc. that have no cellular service.
Cellsats can also usefully serve international air and ocean lines.
At least initially, it won't compete with existing cellular service.
The market is universally (well, globally :-) available cellular
service, at a higher cost.  How much higher depending on how many
people sign on ... the old chicken and egg story.  If everybody signed
on, it would actually be much cheaper than the current local cell
system, but these companies do not count on that to happen initially;
the systems can pay for themselves by opening new niches.

The cost of the most publicized system, Iridium, is projected at $3
billion.  If one out of every five thousand people on our planet make
$300 worth of phone calls a year for ten years, the system pays for
itself.  Initially this would be mostly business, not personal use (as
was the case for city cellular when it started out).  For this market
the price will be about twice as high as the current city cellular.
If the market expands well beyond 1/5,000 of the world population, the
price can go below that of current urban markets, supplanting the
thousands of towers with a more efficient set of radio cells projected
from space.  Concievably, with an expanded set of satellites the price
of cellular service could drop well below the price of current
international long distance, replacing GEO satcoms altogether for this
$10 billion/year market.  Initially, the technology will be quite
properly marketed at the 90% of the Earth's surface currently without
cellular service.

IRIDIUM

Here are the Iridium specs.  Note that the constellation has been
redesigned for larger satellite and cell size, reducing the number of
satellites from 77 to 66:

satellite: 386 kg    
user handset: 3 lbs
voice,data,fax
digital and encryptable
global digital switch network
markets:
- general aviation and business aircraft
- maritime communications
- rural, Eastern Europe & Third World locations
$3/minute
- 1/2 to local providers
- 1/2 to Iridium members
370 mi. dia. cell * 37 * 11 * 7 (100K mi.^2)
66*4 cross-link antenae, each 20 Ghz
adjacent planes move in opposite directions	

Some tasks the Iridium people are working on:

* Building the satellites.  Since the scale is small, new technology
can be incorporated and tested with small risk.  Thus, there is no
need to stick with old electronic technology used in the larger GEO
satcoms.  Lockheed will be in charge of developing the satellite bus
and choosing the launcher.  Motorola will develop the communications
payload and make and market the cellular phones.

* Choosing a launcher capable of boosting test and replacement
satellites into their unique orbits for less than $10 million, as well
as a launcher for the main satellites, from one to seven at a time,
for less than $8 million apiece.  Currently Pegasus costs $10 million
and fits the first bill, although with only one good launch under its
belt it needs to prove its reliability.  Delta or Atlas launching
Iridium in groups of six could fit the second bill, and a rumored
Russian competitor to Pegasus might be able to launch singlets for
less than $8 million.  OSC needs to finish the Pegasus' hydrazine
stage to improve the orbital insertion accuracy.  The development of
Pegasus' low entry-level-cost capability was a main driver behind the
inspiration and genesis of Iridium and several other emerging small
satellite industries.

* The Iridium Consortium must obtain a set of frequencies in all the
countries in which it wants to market its service.  Phone cell
satellites have obtained frequency from WARC and now each proposal
must compete at national government levels.

* New members must be added to the Iridium consortium; Motorola and
Lockheed probably won't pay all the $3 billion on their own.  The
finance folks are busy talking to people like AT&T, NTT, and dozens of
other deep pockets.  Whoever puts in the most money could very well
gain control over the world's cellular phone industry.

GLOBALSTAR 

This information is from Klein Gilhousen of Quallcomm, Inc., which is
teamed with Loral and several European companies on Globalstar:

There will be 24 satellites in LEO (750 nm) in the initial deployment
with coverage optimized for the U.S.  Later, when international
agreements are in place, the constellation will be expanded to 48
satellites, providing global coverage and improved coverage and
capacity over the U.S.

The system uses NO intersatellite relays.  (I believe that these
relays are a prime cost driver of the Motorola approach and that they
would solve a non-existent problem.  The problem is to connect mobile
users into the network.  Period.  Global routing of phone calls is
something that we already have.)  By virtue of have no crosslinks, the
satellite is significantly smaller and cheaper than the Iridium
system.

Total launch mass of one satellite is 262 kg.  Eight satellites would
be stacked and launched at once by a Delta, Ariane, or other standard
launch vehicle.

Airtime charges are projected to be in the same range as cellular
service.  According to the filing, initially, the airtime would be
$0.31/minute with a monthly access fee of about $24.  Later on,
charges would fall to about $0.22/minute.

The mobile phones will be based on CDMA digital cellular phones with
RF adaptors to make them work in the L and S bands of the satellite
system.  Thus, the cost would be that of a CDMA cellular phone, plus
maybe ten to twenty percent for the adaptor.

The system would offer call capacity comparable to that of the Iridium
system's satellite network with many fewer and less costly satellites
through the use of the CDMA technology.  Because a much smaller
investment is required, the service cost will be correspondingly
smaller.

CONCLUSION

Thinking small -- thinking at the optimum economical scale of
technology, instead of the idealistic scale of technology -- is one of
the major paradigm advances of phone cell satellites.  The Iridium and
Globalstar breakthrough is a good example of why industry is needed to
set the standards for space technology, instead of government
dictating to industry.  Private industry is far more in tune both with
the advance of technology and the needs of people.  Government
civilian programs have practically ignored -- spent less than 1% of
their budgets on -- the technology needed for this lucrative market.
Private industry is putting up its own money to fill this gap.


szabo@techbook.COM