If you wanted to know what was happening in Moscow as fast as possible last night, your best bet was the radio.
I’ve mentioned before that when a big fixture goes to penalties, I always listen on the radio, because I get the news first. More regularly, if there’s a match that’s both being covered by Five Live and Sky TV, I might have the TV switched on in my lounge, but the radio on in my kitchen. If I hear a goal described on the radio, I know that I can take my time strolling into my lounge to see the goal scored.
This was beautifully illustrated in a Tweet that showed some Brazilian fans watching a game on a big screen, with one fan listening to the radio:
one guy with a radio vs everyone else with (lagged) tv screen… pic.twitter.com/uw2bu6grwc
— Arthur Charpentier 🌼 (@freakonometrics) July 3, 2018
During the England semi-final, at a point of tension, I decided to see what got me news from Russia fastest. Here are my non-scientific findings in order:
Fastest to Slowest
BBC Radio Five Live AM
— ~0.2 seconds ahead of —
BBC Radio Five Live DAB
— ~5 seconds ahead of —
ITV Freeview SD
ITV Freeview HD
ITV Sky HD
(All TV roughly the same)
I didn’t bother with streams because they introduce too many variables based on the technology I’m using, the internet speeds I have, and so on. But I do know that UHD is especially slower than other streaming options. I also noted earlier in the tournament that BBC’s VR experiment delivered video faster than regular iPlayer! (I was, however, completely underwhelmed by the VR experience)
Note that I can’t accurately measure the time because I comparing things I can see myself with things that are being described by a commentator. In other words, radio is perhaps even further ahead than I’m estimating here, since the radio commentator has had to see and describe something before I hear it. On TV, I can simply see the net bulge with a goal.
What’s more, I’m told that AM is deliberately delayed by about a second – perhaps to keep it closer in sync with DAB.
I suspect that the overall delay is closer to 10 seconds for events happening in a stadium and me seeing them on a television. There will be uplinks and downlinks from the venue to the broadcast centre, then more from the broadcast centre to the UK broadcaster’s playout systems. Then that signal too is probably propagated by satellite to many transmitters and direct-to-home satellites. Each satellite “hop” might take 250 milliseconds, and then there encoding and decoding delays to account for. Finally a broadcaster may deliberately introduce a delay to ensure that they can cut the picture in case something happens that they don’t want to show (the equivalent of the “dump” button in many radio studios).
All of this shows that if you want to know what’s happening fastest, radio gets there first.