Low Latency in Video broadcasting

What is Low latency?

For live streaming, the time it takes for video from glass-to-glass (camera to playout on TV) is an important factor for news, sports and other live events. For news, to prevent that embarrassing delay between live questions, and for sports, well live means live! For example gambling and betting organizations who provide services on the outcome of sports results, such as horse racing, it is vital that there is no delays between the race and the results being announced ensuring that people cannot cheat.

But what is considered low latency in terms of time?

Video contribution solutions over satellites and 4G have always induced delay, typically 3-4 seconds but with latest generation of H.265 solutions, the Zao range can go as low as 240ms.  On the Zao solution the latency can be fixed but there is always a tradeoff between available bandwidth, latency and picture quality.  A longer delay at a lower bit rate will improve picture quality and stability. But typically the Zao will operate with under a second of latency with full 1080i/p HD at 2-3Mbps of bandwidth.

What about lower latency in the future?

Soliton has been working with the automotive industry to develop remote driving cars. Remote driving is achieved through the use of a remote driving console that includes a video display of cameras placed around the car. Even a delay of 240ms is too long in the event of an unexpected occurrence that depends on emergency barking or when trying to pull out of a junction.

Soliton has been active in developing low latency solution as low as 50ms to livestream video. This is unprecedented in video contribution solutions that rely on 4G. A typical delay of just the 4G infrastructure is 50ms even before the overhead of video and audio is added to the mix.

As 5G evolves this will also mean lower latencies, a typical latency is thought to be around 1ms within 5G.