Freeview Chain Delay

Black Hole

May contain traces of nut
With the coming of digital radio and TV, the Greenwich pips (and other time signals) have lost their relevance - digital transmission takes time to encode at the source end, has buffers at various places in the chain, and takes time to decode at the reception end. The signals could be launched at a predicted time ahead, but the broadcaster has no control over the decoding in the receiver, and different receivers have different decoding delays (I have thought they missed a trick by not including a time base in the transmitted data).

So why have I raised this? The 30th Anniversary celebration edition of Breakfast this morning had an interview with a live TV in the background. The delay from the outside broadcast, through the transmission chain, to the screen on the TV (with the decoder in that particular TV) was about 5 seconds. With analogue it would have been almost instant.

This calls to mind a minor storm going on (it may have been resolved now) in the theatrical world about radio microphones. The regulatory authorities wanted to change the licensing on radio mics to a digital standard, but the delays (although slight in this case) would be intolerable for musical performances.
 

4291

Well-Known Member
So why have I raised this? The 30th Anniversary celebration edition of Breakfast this morning had an interview with a live TV in the background. The delay from the outside broadcast, through the transmission chain, to the screen on the TV (with the decoder in that particular TV) was about 5 seconds. With analogue it would have been almost instant.
I commented on this to the OH whilst watching in bed this morning, taking the timing from Russell Grant's hand gestures.
 

dandnsmith

Forum Supporter
There are some time delays which appear a little odd in the freesat stuff as well - I found, a week or so back, that I could, consistently, switch from BBC News to BBC1 and receive the last couple of seconds again. These are both on the same transponder of the same satellite, suggesting delays introduced between studio and satellite.
 
Top