In reply to a post by kwikbreaks:

Are Virgin actually supplying digital now or is it just analogue over their coax? Years back a house we bought had cable TV through coax (chan 1-4 and possibly 5 if it was around then). I cancelled it as I couldn't see the point in paying for what came free with an aerial.

They seem to be offering digital these days but still not very many channels. I also believe that they don't carry those channels that are available through DTT. I'm not sure how that works. It'd be a sensible idea to conserve bandwidth but if I was designing it I'd have the VM STB take a feed from the aerial and present those channels through the STB. Perhaps they do.

I think what I'd be most interested to know is what is the bandwidth available around the 'street loop' for IP traffic. ITSM that that's the area of concern moving forward. BT's FTTC can remove contention from the local loop quite easily. VM's, not so much. If a street/neighbourhood becomes congested you're pretty much stuffed.

I would imagine that a BB satellite would communicate directly with a ground-based router (one appropriate for it's position), so it would just be up - down - normal Internet route to server.

In reply to a post by AnotherExPipex:

I would imagine that a BB satellite would communicate directly with a ground-based router (one appropriate for it's position), so it would just be up - down - normal Internet route to server.

That would make more sense... but implies some semi-dedicated kit. Depends whether the money is there I suppose.

In reply to a post by billford:

I nearly replied to your pre-edit post

And it could be a lot worse than I said- if the server is too far around the planet you might have to go via two satellites... not sure if that would mean an extra ground station or if the satellites can talk to each other directly?

Heh, well that depends on the network itself. I'm assuming using satellite in-place of BB. If you're considering a full-on satellite network then I have no idea. It doesn't sound too clever though. I don't know if you can guarantee line-of sight between geo-sync satellites. Presumably there's also an issue of frequency allocation if you're going to start broadcasting between themselves?

I must admit that I've never really looked into satellite communications in-depth. In recent years I've learned a lot about how Sky/Freesat 'do their thing' but that's mostly about politics.

I don't know if you can guarantee line-of sight between geo-sync satellites.

Depends how many you've got, but if they can cover the whole planet then each will be able to see at least one other.

Incidentally, if you remove the square brackets from your sig, the youtube link will work

In reply to a post by AnotherExPipex:

I would imagine that a BB satellite would communicate directly with a ground-based router (one appropriate for it's position), so it would just be up - down - normal Internet route to server.

I don't quite understand what you're saying there.

Until recently I think all traffic for Europe went through Goonhilly in Cornwall (a brilliant name for such a high-tech site ).

Although not all that significant it implies an extra hop from ISP to Goonhilly to me.

http://en.wikipedia.org/wiki/Goonhilly_Satellite_Ear...

"On 12 September 2006, BT announced it would shut down satellite operations at Goonhilly in 2008, and move them to Madley Communications Centre in Herefordshire, which will become BT's only earth station and the biggest in the world."

Edit:I think I see what you're implying. Yeah, it could just go ISP->GS rather than ISP->ISP->GS.

Edited by Andrue (Tue 05-May-09 11:23:40)

In reply to a post by billford:

Incidentally, if you remove the square brackets from your sig, the youtube link will work

Hmmm.

What I was trying to say (not very clearly) is that the satellite doesn't talk directly to the end server, it communicates with a ground station.

I'm not sure what's happening at Goonhilly. Although it was announced that it was closing in 2008, it seems to be still going. In any case, "Arthur" is now a listed building!

In reply to a post by AnotherExPipex:

What I was trying to say (not very clearly) is that the satellite doesn't talk directly to the end server, it communicates with a ground station.

Analogy- the ground station acts as an industrial grade wireless router?

In reply to a post by billford:

In reply to a post by AnotherExPipex:

What I was trying to say (not very clearly) is that the satellite doesn't talk directly to the end server, it communicates with a ground station.

Analogy- the ground station acts as an industrial grade wireless router?

Heh, that didn't help me

I would have said that the satellite is a wireless router. It takes a stream sent up from the ground station and broadcasts it to all the End Users. I'll try and improve my routing diagram for a ping. I'll leave out the outward bound part because that is entirely ground-based for satellite BB as proposed for the UK:

Target->Target's ISP->EU's ISP->Ground station->Satellite->EU

The only improvement I can currently see is:

Target->Target's ISP->Ground station->Satellite->Client

..and I'm not entirely sure whether it would be practical to remove the EU's ISP on the return trip like that or whether it would have much of an impact if they did.

Edited by Andrue (Tue 05-May-09 11:46:42)