uk bbc channels normally on 28.2 on intelsat 907 27.5w ?

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Analoguesat said:
Oh they are definitely using it - I know for certain Gibraltar Cable got their BBC back "by getting the signals off another satellite" after they lost 28E
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What I don't understand is why this feed is needed. Why don't Freeview just take their backup off 28.2E ?
 
Analoguesat said:
Redundancy. You dont put all your eggs in one satellite basket.
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So what is the principal method of distribution to DTT transmitters ? Is it 28.2E? Surely traditionally it was land lines or some form of micro-wave distribution?
 
Well at 28.2 there isn't an exact replica of the beeb DTT muxes.
But what I'd like to know,and it's not clear,is whether the satback tp is actually used as main source fot Freeview somewhere
 
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dvdfilm said:
Well at 28.2 there isn't an exact replica of the beeb DTT muxes.
But what I'd like to know,and it's not clear,is whether the satback tp is actually used as main source fot Freeview somewhere
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It is also odd that at 27.5W not all the BBC channels are there. Certainly either BBc4/Cbeebies HD is not there. Someone posted that it is because the channel is on a different DTT "MUX" (but I don't really understand what that means) and, in any case, why would it mean that no backup is required?
 
BLUEPLATINUM said:
It is also odd that at 27.5W not all the BBC channels are there. Certainly either BBc4/Cbeebies HD is not there. Someone posted that it is because the channel is on a different DTT "MUX" (but I don't really understand what that means) and, in any case, why would it mean that no backup is required?
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The ~80 main Freeview DVB-T/T2 transmitters in the UK are fed by fibre.

The many small transmitters around the country receive one of the main transmitters off-air via UHF antennas and rebroadcast Freeview that way.

A MUX (multiplex) can be thought of like a transponder on satellite where one frequency carries a number of digital channels.

The 27.5°W feeds are just a back-up; mainly for small transmitters where the UHF terrestrial feed from their main parent transmitter isn't 100% reliable (signal fading problems etc) and might fail sometimes.

The 27.5°W feed carries the contents of two MUXes; both operated by the BBC. All of the BBC SD TV services and radio services are on a MUX called BBC-A on terrestrial. The 27.5°W feed provides BBC One England (network), Scotland, Wales and Northern Ireland variations which are reassembled as appropriate by any transmitter using the feed. The HD channels on 11495 are a feed for the BBC-B MUX which carries BBC One HD, BBC Two HD, ITV HD, Channel 4 HD, and BBC Three/CBBC HD. The reason BBC Four HD and BBC News HD are not on there is because they are carried on a commercially-operated MUX which does not have satellite back-up.
 
Just to add, to go into more technical detail about why 28.2°E couldn't be used as a back-up; it's to do with MUX capacity and channel bitrates.

I've never analysed the 27.5°W feeds myself, but if you did you would find that BBC One England, BBC One Scotland, BBC One Wales or BBC One NI + the rest of the BBC SD channels and radio stations combined would never exceed a combined bitrate of 24.13Mbps (the capacity of the DVB-T BBC-A terrestrial multiplex). All of the HD channels combined would never exceed 40.2Mbps (the capacity of BBC-B's DVB-T2 multiplex).

The channels on 28.2°E are multiplexed together to be able to fit within their transponder capacity of around 34Mbps for DVB-S SD channels and around 45Mbps for DVB-S2 HD channels; if you were to start combining channels from different transponders you would not fit all the required channels within the 24.13Mbps/40.2Mbps configuration required without re-encoding them. Receiving multiple transponders and re-encoding channels would be a very expensive solution for relay transmitters that only require a back-up!
 
Just to add, to go into more technical detail about why 28.2°E couldn't be used as a back-up; it's to do with MUX capacity and channel bitrates.
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The satback mux at 27,5W has a rate of 77Mbps with about 5Mbps null packets. At the moment the highest SR at 28E is 29500Kbaud. This could yield with 8PSK, 5/6 a mux rate of 73Mbps. The satback mux could just fit :)
 
Inevitable ;):(
 
Next key should last until just before the World Cup.

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Only if the trend remains the same .......... !

Anyway, it only has to last until the end of the early stages :rolleyes::oops::D
 
If it disrupts anyone making money selling dodgy setups then it's only a good thing. So have some cable systems gone dark now?!:D
 
I have been doing a bit of Googling and have found a reference to Cbeebies being broadcast on Intelsat 905 11518 V 7000 24.5°W (in BISS). The information is dated 12/02/2014. No mention of any other UK channels. Could this be the start of something new? Anyone know anything about this? Flysat does not mention it on http://flysat.com/is905.php .
 
BLUEPLATINUM said:
I have been doing a bit of Googling and have found a reference to Cbeebies being broadcast on Intelsat 905 11518 V 7000 24.5°W (in BISS). The information is dated 12/02/2014. No mention of any other UK channels. Could this be the start of something new? Anyone know anything about this? Flysat does not mention it on http://flysat.com/is905.php .
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24.5°W's KU spots are aimed more at central Europe so not as ideal as 27.5°W. Maybe the feed was for Poland or something?
 
Historically has it taken the " internet " long to find the new keys ?
 
davidcmadrid said:
Historically has it taken the " internet " long to find the new keys ?
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Usually, around 2 weeks from what I have seen. It depends if people are prepared to release it when they find it.
 
About 9 days (apart from the time someone on the inside leaked it almost immediately).

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They haven't changed encryption yet but if keys will go again on public internet (hopefully not) they might do it
 
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