I am not sure that LEO are a good answer. Have you thought about how many
satellites you will need. I would guess around 5 or 6 in the orbit trace.
The second problem will be the handover of the data between the satellites.
This means either cross links or a single hub that all satellites can see
and the routing is on the ground. A third concern would be that
utilization. Most of the time they would not be over Australia.
A better idea would be a set of towers along the route like 3rd generation
mobile system. While the standards only give 2Mbps for fixed station unless
you are talking about a bullet train, I think they could be considered as
stationary. It will take a little thought.
Depending on the services offered, you might be able to use part of a GEO
transponder to feed the 3rd Gen Mobile from a single access point.
Harry Smith
Lockheed Martin Mission and Data Services
408 - 473 6491
> -----Original Message-----
> From: [email protected] [SMTP:[email protected]]
> Sent: Friday, September 29, 2000 10:51 PM
> To: [email protected]
> Subject: Moving Targets
>
> Hi,
>
> I'm doing a research project about providing Internet access to moving
> targets on the eastern seabord of Australia. In this case, the moving
> targets are trains.
>
> We really need to provide around 1MB or so downstream, maybe 56k or so
> uplink. I've been doing a lot of searching but facts seem to be hard
> to come by.
>
> By my reckoning something like a link to an LEO constellation is
> needed to make this work because:
> - GEO satellites can't easily provide this type of bandwidth
> - GEO satellites require reasonably large dishes and need to
> fairly precisely targetted at the sat
> - Line of sight is needed for GEO links to work
>
> Basically, I'm hoping that with LEO links a dish won't even be
> required, some sort of antenna? Do any of the currently existing LEO
> constellations provide this sort of service? Future ones?
>
> Am I completely barking up the wrong tree here? Is there a better way
> of providing reasonably high speed internet access to moving vehicles
> without cabling etc.
>
> Thanks in advance,
> Shaun
This archive was generated by hypermail 2b29 : Mon Oct 02 2000 - 15:14:27 EDT