B Sky B satellite broadband?

I've often wondered why Sky doesn't offer there broadband over there satellite network doing away with BT and getting coverage to most of the UK, can anyone tell me why?

I suspect that the Sky satellites can only transmit data to the consumer, not receive it.

Yes, you'd need some sort of modem to do the uploading, and the latency problems with satellite means that it would be no use for gaming, Skype and other voice calls, or any other time sensitive interactive applications.

Regards,
Steve

In reply to a post by AnotherExPipex:

I suspect that the Sky satellites can only transmit data to the consumer, not receive it.

Satellite BB is poor choice. It rarely supports uploading direct to the satellite so the consumer is still reliant on whatever ground-based BB they have for uploading. This can often cause bottlenecks downstream due to congestion in sending ACKs.

In addition there is lag. Geosync satellites orbit around 36,000km above us. The laws of physics mean that 240ms gets added to your pings (120ms from ground station to sat, then back again).

You are also in effect sharing your downstream connection with everyone else within the satellite footprint. Satellite broadcasting can offer a lot of bandwidth but it isn't unlimited. Sharing it with an entire country-or in the case of Eurobird the entire continent-is not sustainable. A couple of gigabits bandwidth sounds good but when you're sharing it with a couple of million other people it's not so hot.

But the real reason is likely cost. Sky don't own any satellites. They rent space off satellite providers. I doubt that the economics would make sense. In fact a lot of people don't realise that most of what they watch through Sky is not even broadcast by Sky

Personally I detest the idea of satellite BB as a general solution. I accept that it's good if you're stuck in the middle of a desert or a jungle but not for the UK. It's horribly innefficient to send a data stream to 30million homes and businesses when only one of them is actually going to be using it.

Edited by Andrue (Tue 05-May-09 09:58:53)

> It's horribly innefficient to send a data stream to 30million homes and businesses when only one of them is actually going to be using it.

As indeed is the opposite - sending multiple dedicated streams to umpteen different end users (eg iPlayer) when a single broadcast / multiple record system would work virtually as well or better in most instances because the video quality would be better.

In reply to a post by kwikbreaks:

> It's horribly innefficient to send a data stream to 30million homes and businesses when only one of them is actually going to be using it.

As indeed is the opposite - sending multiple dedicated streams to umpteen different end users (eg iPlayer) when a single broadcast / multiple record system would work virtually as well or better in most instances because the video quality would be better.

Agreed.

It'd be cool from a technical POV to have multicast servers in the street cabinets but something of an installation/maintenance headache

Edit:Of course VM don't have that issue but then their local loop doesn't have dedicated end-user feeds. It's surprising how the network topology in the last hundred metres can change things. It occurs to me that VM actually have a potential problem there if VoD takes over from broadcasting. Their network model is more like satellite at the front-door :-/

Edited by Andrue (Tue 05-May-09 10:42:58)

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.

In reply to a post by Andrue:

The laws of physics mean that 240ms gets added to your pings (120ms from ground station to sat, then back again).

Shouldn't that be doubled for round-trip time?

Ground to sat => sat to server being pinged => server back to sat => sat back to ground.

Unless you're pinging the satellite

In reply to a post by billford:

In reply to a post by Andrue:

The laws of physics mean that 240ms gets added to your pings (120ms from ground station to sat, then back again).

Shouldn't that be doubled for round-trip time?

Ground to sat => sat to server being pinged => server back to sat => sat back to ground.

Unless you're pinging the satellite

Hmmm.

Entirely ground based route:
EU-ISP->ISP->Target->ISP->ISP->EU

For satellite:
EU->ISP->ISP->Target->ISP->ISP->GS->Satellite->EU.

The final GS->Satellite->EU is 2 lots of 120ms.

You'll only get another 240ms if you are uploading to satellite which I think is unusual unless you're somewhere without access to any other form of telecommunications.

I could be wrong of course. I think that general advice is that satellite BB adds 300ms to ping times which suggests I might not be far of the mark

Edited by Andrue (Tue 05-May-09 11:03:52)

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?