>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