Hardcore Hustler
ISP Rep
even though i dont use sat bb i tend to agree with Micronet. It seems Eutelsat are really going on something good.
Gadget said:I believe Web Buddy has already mentioned that the fundamental difference here is that broadcasting TV requires a bandwidth per channel which all users then "tune" into.
So for 1000 TV channels (sort of max for a 3 digit channel number) there will only every be 1000 streams of data.
Broadband via satellite requires that different datastreams are made available to each different customer (and there are ways that statistical multiplexing can maximise this - its used already in the telephone via sat scenario), but even so it chews through bandwidth at a massive rate compared to simple broadcast. So if thats the case then at 50:1 contention and every user having 500Kbps service you are looing at 10kbps on average per customer, or 100 customers/Mb so you'd need 10Gb/s transponder space per million customers, assuming the logic is correct. And thats only for the downstream. Happy to be corrected if I've messed the logic.
Its not that satellite is "wrong" for Broadband, but rather IMHO that it is not scaleable to the extent that terrestrial systems are, and thats not to say it may not prove vaulable in some cases.
ukneilw said:Not saying all providers are the same, but if you look at the SkyDSL available bandwidth checker at http://service.skydsl.de/monitor/index.html it shows bandwidth as 16mb split between 6 priorities, so 96mbit for the SkyDSL transponder. The checker shows quite a shocking trend on the fair usage priority of less than 0.5mb free during peak hours! 96mbit is a rough guess as to be honest I also thought it was around 40mbit per transponder.
I get ADSL on Thursday and will be glad to be rid of the awful disappointing world of satellite broadband!
micronet said:So if you have satellite that is designed and optimised to distribute mainly Unicast(Internet) bandwidth at a very large scale, you can in effect turn the tables and start to offer Unicast bandwidth near the the same scale as the multicast bandwidth, this is why an internet dedicated satellite makes so much sense.
Eutelsat have not just launched an internet dedicated satellite at a massive cost (mostly in research), to have the same sorts of bandwidth available as any old satellite that bundles other TV, Tracking, broadcasting and a whole range of services, there is obviously an improved performance which they are serious about, otherwise why would they bother launching it?