From: Michael Lorrey (retroman@tpk.net)
Date: Mon Nov 18 1996 - 13:00:33 MST
Ira Brodsky wrote:
>
> Michael Lorrey wrote:
>
> >The problem with Hughes satellites is their geosynch orbit. Being 23K
> >miles up, there is a significant lag time in transmission, slowing baud
> >rates considerably. THis is why Teledesic is going for LEO (200-400
> >mi.) with 840 sats to specifically offer ISDN rates by satellite.
> >
> >Motorola's Iridium will be a good interim solution, if they open service
> >in the next year or so, with 14Kbaud rates. Teledesic will be up by
> >2001.
>
> Actually, Iridium and Teledesic (or Hughes Spaceway) serve very different
> purposes.
>
> Iridium is part of the mobile satellite service (MSS) and is primarily
> intended to provide voice communications for mobile and remote users.
>
> Teledesic and Spaceway are part of the fixed satellite service (FSS) and
> are intended to provide advanced telecomm services (ISDN - T1/E1) to fixed
> users in rural and remote areas. In fact, Motorola has recently proposed
> its own FSS, distinct from Iridium.
>
> Ira Brodsky
> Datacomm Research Company
> Wilmette, Illinois
I had read that Motorola was planning on using the Iridium constellation
to provide the online access service. I also had read, or thought I
read, that the Teledesic system was going to be accessible via small 18
inch dishes (which from my own experience, would be very easy to have on
a camper, boat, even a phased array antennae on the roof of a car or as
a fold up pack with a solar panel). It does not seem like FSS to me.
The main distinction I was getting at was the difference in bandwidth
one can have depending on a satellite constellations altitude.
Mike
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