BBC to reduce live TV streaming lag for online viewers

The simulcast delay – the one that left many World Cup viewers behind the action – could be a thing of the past


The BBC has said it has worked out how to reduce the streaming delay that leaves online viewers several seconds behind the live TV broadcast.


Although the BBC Research & Development department claims to be able to eliminate the delay with new technology, the upgrades won’t be rolled out to the public just yet.

Live TV watched online take longer to transmit than traditional broadcasts, often resulting in a delay of several seconds.

It’s this delay that meant football fans watching this year’s World Cup online for example experienced 30 seconds of hurt as neighbours’ cheers gave the game away.

Such delays also affected Amazon’s Prime recent coverage of the US Open, with online viewers lagging up to 44 seconds behind the live TV according to Broadcast.

Why does this delay occur? The BBC’s Research and Development department explains that says: “Because much of the Internet is built around moving files around (for example, as you browse the web), Internet video distribution today usually delivers portions of video and audio data in separate files”.

If these files are too long this might lead to a delay as they take longer to process by the recipient’s device. The BBC is now aiming to deliver smaller chunks of files that make this easier.

In a new prototype being demonstrated at the IBC in Amsterdam, the R&D team will show how the gap between an Internet-delivered live stream and live TV via broadcast can be eliminated.


It’s unclear when the new technology might be rolled out, but the broadcaster has suggested it could be in place by the time of the next World Cup in 2022.

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