Low Latency, 5G, and the Video Streaming Pipeline

By Stuart Newton, VP Strategy and Business Development at Telestream

From attending some of the recent video streaming seminars, it’s clear that sports content providers (as well as betting companies) are driving the industry to provide low latency and streaming and 5G as soon as possible.  For the content providers, this is to provide an end-to-end delivery chain from camera to screen in a comparable timescale to traditional broadband, satellite, and terrestrial channels.  Hearing others cheer 20-40 seconds before you see or hear the goal is a common issue that desperately needs to be solved, but synching live streaming with broadcast provides other opportunities to have companion screens with different camera angles in sync with the main broadcast, or simply to make sure what you see on the screen matches the timing of the sports alerts popping up on the screen from social media.

One of the big “themes” being pitched to address this is 5G, but it’s really important to understand that unless a single company controls the entire video delivery architecture from camera to mobile device (which is very rare today), then 5G is just one piece (albeit an exciting piece) of the end to end puzzle for video delivery.

There have been many successful trials of 5G for video streaming, from multiple cameras at a stadium back to spectators in the stadium, from golf course greens back to outside broadcast trucks, and many other permutations where 5G will revolutionize the need for providing high speed, low latency bridges between locations.  And 5G will be really exciting for all low latency applications where there needs to be rapid communications into and out of the 5G network for applications such as car telematics, IoT or augmented reality applications.  However, for end to end delivery of video from a live sports event to general sports consumers, it’s important to understand that low latency streaming across that entire workflow requires all elements in the chain to be tuned for low latency.  If that’s not the case, a super-fast 5G pipe on the end of the delivery chain will add some benefit for “last mile” speed and latency but will not resolve the end to end latency issue.

What do we regard as live in terms of latency?

In live sports streaming from events to mobile platforms (or smart TVs), the original video contribution from the camera feeds are typically routed to a video headend which encodes the streams into the various resolution formats, conditions for advertising adds digital rights management, and chunks the video up into the relevant adaptive streaming protocols (e.g. HLS or DASH) for storage on an origin server.  The content delivery networks (CDN) then typically pull the HLS and DASH manifests (instruction files for how to access the chunks) and video chunks from the origin server and distribute them across the content delivery network for caching (temporary storage) at the CDN edge locations so they are available to many people via distribution across the broadband, cellular (e.g. 5G), or Wi-Fi clouds as required by the consumer devices.  To achieve low latency streaming (say 3-10 seconds camera to screen), and especially Ultra Low Latency streaming (<3 seconds), every element in the chain needs to be in tune.  This is very different from the 30-50 second typical delay experienced today, which is mainly due to the inefficiency of the chunk delivery across the package-origin-CDN process coupled with a typical buffering storage of 3-4 chunks on the player before the video is actually delivered to the screen.  When these chunks are typically in the 6-10 seconds range, it’s easy to see why the current latencies exist.

The new low latency and ultra-low latency protocols being used in early trials are attempting to solve this issue by tuning the manifest and chunk delivery across the entire chain, where manifests are made available as early as possible and “partial” chunks of the video are made available from the packager and sent out as soon as they are ready.  This provides a mechanism for sending the video in near real-time rather than waiting for the larger video chunks to be completed before sending across the network.  Maintaining backward compatibility with existing protocols is an essential part of this, so devices or CDNs not upgraded to be capable of delivering the new low latency mechanism have a fallback to the existing manifest and chunk retrieval methods.

Quality trumps latency in live streaming apps
There are several promising competing low-latency protocols (each with pros and cons) and time will tell which one will become the adopted standard.  Early trials are happening now, and the protocols will gradually adapt over the next few years as the industry embraces them and identifies potential improvements.  Low latency protocols will have a huge impact on sports video streaming, and combining low latency protocols with super-fast last mile delivery mechanisms such as 5G will have an even greater impact on the live sports streaming experience, especially where 5G enables the viewing device to access higher resolutions and HDR formats than 4G allowed.  However, the complexity of these new protocols brings in another factor that will absolutely need to be addressed:  Quality.

Monitoring end-to-end delivery of adaptive protocols today is a specialized topic and has evolved over the last eight years to provide excellent visibility into issues around adaptive video delivery.  During times of architecture change, monitoring becomes even more critical, and the monitoring has to evolve as fast as possible to keep up with the new protocols and provide robust, actionable data to help isolate faults and tune the network for improvements. 

With three major industry shifts over the next few years to new low latency protocols, cloud-based video architectures, and the rollout of 5G-based streaming, video monitoring is going to be absolutely critical to making sure content brands are protected, the experience is good, and people perceive value for money.  The potential for these three major shifts coming together will transform video delivery and the viewer experience far beyond anything people are used to today, but only if the viewing quality experience matches that potential. 

Having seamless operational visibility of low-latency video delivery from camera ingest to cloud, CDN, ISP and ultimately the end-user will ensure that whatever wonders the next-generation services will bring, the viewing experience will be in tune. At Telestream, we have been focused on this challenge for a number of years. For more information on our breadth and depth of systems approach, visit the iQ Solutions section of our website http://www.telestream.net/iq/overview.htm

*This article was originally published by TVBEurope. To see the original please follow this link: http://bit.ly/2S5a8tE

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