[Technologist]

This is from lyngsat.com and shows a satellite mux with all of the BBC's TV and Radio channels, however it's on a satellite called Telstar 12 Vantage at 15.0°W. I am quite puzzled about why the BBC channels are located encrypted in this satellite, .......

The one give away is that the BBC one is "NE"
This is the Satelite back up of PSB 1 mux ..... www.digitalbitrate.com 

In simple terms each Main transmitter (now 100 or so) is fed by dual diversely routed Fibre
(expect in Scotland were there are some microwave links)
but they also have a satelite reciever to pick up this feed to provide coverage if the telco circuits fail.
and the (Slightly tweaked to select SD or HD ) Transport stream,
is fed directly from the Reciever to the Modulators at the transmitter without any decoding.
As there are lots of regional variations of BBC one the feed that is needed is selected in Coding and Mux
in this case NE - as when the Bilsdale mast caught fire a large number of smaller transmitters were set up taking this feed
to get BBC services including All HD back on air very quickly.
www.freeview.co.uk 

(this idea was proposed by one of the Tenderers for DSO as a way of getting round any issues with ReBroadcast Links failing during switch over .....and there a a very few permenant instalations to cover an RBL)

D3&4 now -after Bilsdale- can do something similar

Edit as Steve says the Back up mux used was Intelsat 901 www.lyngsat.com 
So this may be a BFBS feed