[comp.dcom.modems] Modems on cellular phones?

Mitchell_K_Hobish@cup.portal.com (03/01/88)

Is it possible to use a standard (e.g., Hayes-type) modem with a cellular
phone?  I can understand how problems could crop up during hand-offs
between cells, but how about if the vehicle were stationary?  Are the
bandwidth requirements such that cellular phones would preclude such
use?

Kenneth_R_Jongsma@cup.portal.com (03/02/88)

It certainly is possible. In fact Bell Atlantic was doing tests not too
long ago. The bandwidth is not the problem, but even standing still, you
can get switched from cell to cell for load balancing. You need modems that
will take a loss of carrier for a bit loner than normal.

Eric_D_Davis@cup.portal.com (03/03/88)

Ships are doing this now to communicate to buyers....
They have a basically a poratable pc ..modem ..and cell phone....
of course this is for local use only...shore or near...
There are device that tap you mic and speaker and create a balenced
network to fake the modem.....
I'll try and find moore on this...
Oliver@cup.portal.com

gary@percival.UUCP (Gary Wells) (03/04/88)

Per a recent article in the magazine "Celluar News", standard modems are useable
over cellular phones.  According to the article, some top of the line phones
include either a rs-232 connector, or D connector for the modem to connect to.

Their report was basically:

no problem at 300.
generally good at 1200, but occassional dropouts, etc.
best results when vehicle was stationary, and not near a cell boundary
no test at 2400

Sorry I can't be more specific about the magazine.  It was one of those "free
subscription if you qualify (and who doesn't?)" jobs, which has since stopped
coming.

-- 
--------------------------------------------------------------------------------
Still working on _natural_ intelligence.

gary@percival

Phil_CW_Sih@cup.portal.com (03/05/88)

I'd bet that Telebit trailblazers would work very well across a cellular
link as they are very tolarant of interruptions and all kinds of noise
when running in PEP mode.  When I tested the ones we use internally I
did several tests including whistling into the phone, playing music into
the phone and putting the modem on hold for a few seconds.  There were
no hangups or errors.

David_J_Buerger@cup.portal.com (03/06/88)

I haven't used a Telebit modem on a cellular phone connection, but
I have used a Hayes external on a 2400 bps connection through Telenet
to another host computer.  I'm not sure if it was a "bad" connection,
but there was considerable noise which led to the intrusion of
numerous strange characters on-screen.  This ade it annoying to
issue commands to the host.  But it worked.

David Buerger
dbuerger@scu.bitnet

wb8foz@netsys.UUCP (David Lesher) (03/11/88)

::
:::
Telebit had all their big guns at FOSE this week. I took the
opportunity to ask one of them the above question. The answer
I got was that it should work fine......if the vehicle is
standing still. The problem, you see, is the characteristics
of the path change greatly when the mobile moves. This is true
even within a cell. The Trailblazer then attempts to update
its knowledge of the path. But before it can.....
Just think how confused it could get if you put it on a
air-ground RF link...



-- 
Fetch the Holy hand grenade
decuac!netsys!wb8foz