The pandemic has shone a light on CDNs as they are the backbone of much of what we do with video for streaming and broadcast. CDNs aim to scale up in a fast, sophisticated way so you don’t have to put in the research to achieve this yourself. This panel from the Content Delivery Summit sees Dom Robinson bringing together Jim Hall from Fastly with Akamai’s Peter Chave, Ted Middleton from Amazon and Paul Tweedy from BBC Design + Engineering.
The panel discusses the fact that although much video conferencing traffic being WebRTC isn’t supported, there are a lot of API calls that are handled by the CDN. In fact, over 300 trillion API calls were made to Amazon last year. Zoom and other solutions do have an HLS streaming option that has been used and can benefit from CDN scaling. Dom asks whether people’s expectations have changed during the pandemic and then we hear from Paul as he talks a little about the BBC’s response to Covid.
THE CTA’s Common Media Client Data standard, also known as CTA 5004, is a way for a video player to pass info back to the CDN. In fact, this is so powerful that it can provide highly granular real-time reports for customers but also enables hints to be handed back from the players so the CDNs can pre-fetch content that is likely to be needed. Furthermore, having a standard for logging will be great for customers who are multi-CDN and need a way to match logs and analyse their system in its entirety. This work is also being extended, under a separate specification to be able to look upstream in a CDN workflow to understand the status of other systems like edge servers.
The panel touches on custom-made analytics, low latency streaming such as Apples LL-HLS and why it’s not yet been adopted, current attempts in the wild to bring HLS latency down, Edge computing and piracy.
Wireless internet is here to stay and as it improves, it opens new opportunities for streaming and broadcasting. With SpaceX delivering between 20 and 40ms latency, we see that even satellite can be relevant for low-latency streaming. Indeed radio (RF) is the focus of this talk discussing how 5G, LTE, 4G, ATSC and satellite fit into delivering streaming media o everyone.
Matt explains that BT did a trial of LTE-B with BBC. The major breakthrough was they could ‘immediately’ deliver the output of an EVS direct to the fans in the stadium. For BT, the problem came with hitting critical mass. Matt makes the point that it’s not just sports, Love Island can get the same viewership. But with no support from Apple, the number of compatible devices isn’t high enough.
“Spectrum is final and you shouldn’t waste it sending unicast”
Turning the attention of the panel which includes Synamedia’s Mark Myslinski and Jack Arky from Verizon Wireless. Matt says that, in general, bandwidth capacity to edges in the UK is not a big issue since there is usually dark fibre, but hosting content at the edge doesn’t hit the spot due to the RAN. 5G has helped us move on beyond that.
Mark from Verizon explains that multi-edge access compute enabled by the low-latency of 5G. We need to move as much as is sensible to the edge to keep the delay down. Later in the video, we hear that XR (mixed reality) and AR (augmented reality) are two technologies which will likely depend on cloud computation to get the level of accurate graphics necessary. This will, therefore, require a low-latency connection.
From Verizon’s perspective, the most important technology being rolled out is actually ATSC 3.0. Much discussed at NAB 2015, stability has come to the standard and it’s now in use in South Korea and increasingly in the US. ATSC 3.0, as Mark explains, is a complimentary fully-IP technology to fit alongside 5G. He even talks about how 5G and ATSC could co-exist due to the open way the standards were created.
Will streaming really be any better with 5G? What problems won’t 5G solve? Just a couple of the questions in this panel from the Streaming Video Alliance. There are so many aspects of 5G which are improvements, it can be very hard to clearly articulate for a given use case which are the main ones that matter. In this webinar, the use case is clear: streaming to the consumer.
Moderating the session, Dom Robinson kicks off the conversation asking the panellists to dig below the hype and talk about what 5G means for streaming right now. Brian Stevenson is first up explaining that the low-bandwidth 5G option really useful as it allows operators to roll out 5G offerings with the spectrum they already have and, given its low frequency, get a good decent a propagation distance. In the low frequencies, 5G can still give a 20% improvement bandwidth. Whilst this is a good start, he continues, it’s really delivering in the mid-band – where bandwidth is 6x – that we can really start enabling the applications which are discussed in the rest of the talk.
Humberto la Roche from Cisco says that in his opinion, the focus needs to be on low-latency. Latency at the network level is reduced when working in the millimetre wavelengths, reducing around 10x. This is important even for video on demand. He points out, though that delay happens within the IP network fabric as well as in the 5G protocol itself and the wavelength it’s working on. Adding buffers into the network drives down the cost of that infrastructure so it’s important to look at ways of delivering the overall latency needed at a reasonable cost. We also hear from Sanjay Mishra who explains that some telcos are already deploying millimetre wavelengths and focussing on advancing edge compute in high-density areas as their differentiator.
The panel discusses the current technical challenges for operators. Thierry Fautier draws from his experience of watching sports in the US on his mobile devices. The US has a zero-rating policy, he explains, where a mobile operator waives all data charges when you use a certain service, but only delivers the video at SD resolution at 1.5 Mbps. Whilst the benefits to this are obvious, it means that as people buy new, often larger phones, with better screens, they expect to reap the benefits. At SD, Thierry says, you can’t see the ball in Tennis, so there 5G will offer the over-the-air network bandwidth needed to allow the telcos to offer HD as part of these deals.
The panel discusses the problems seen so far in delivering MBMS – multicast for mobile networks. MBMS has been deployed sporadically around the world in current LTE networks (using eMBMS) but has faced a typical chicken and egg problem. Given that both cell towers and mobile devices need to support the technology, it hasn’t been worth the upgrade cost for the telcos given that eMBMS is not yet supported by many chipsets including Apple’s. Thierry says there is hope for a 5G version of MBMS since Apple is now part of the 3GPP.
CMAF had a similar chicken and egg situation when it was finalised, there was hesitance in using it because Apple didn’t support it. Now with iOS 14 supporting HLS in CMAF, there is much more interest in deploying such services. This is just as well, cautions Thierry, as all the talk of reduced latency in 5G or in the network itself won’t solve the main problem with streaming latency which exists at the application layer. If services don’t abandon HLS/DASH and move to LL-HLS and LL-DASH/CMAF then the improvements in latency lower down the stack will only convey minimal benefits to the viewer.
Sanjay discusses the problem of coverage and penetration which will forever be a problem. “All cell towers are not created equal.” The challenge will remain as to how far and wide coverage will be there.
The panel finishes looking at what’s to come and suggests more ‘federations’ of companies working together, both commercially and technically, to deliver video to users in better ways. Thierry sums up the near future as providing higher quality experiences, making in-stadia experiences great and enabling immersive video.
As we saw yesterday, there’s an increasingly buoyant market for video codecs and whilst this is a breath of fresh air after AVC’s multi-decade dominance, we will likely never again see a market which isn’t fragmented with several dominant players, say AV1, AVC, VVC and VP9, each sharing 85% market share relatively equally and then ‘the rest’ bringing up the rear. So multi-codec distribution to home viewers is going to have to deal with delivering different codecs to different people.
fuboTV do this today and Nick Krzemienski is here to tell us how. Starting with an overview of fuboTV primarily streams both live and on VOD. Nick shows us the workflow they use and then explains how their AVC & HEVC combined workflow is set up. Starting with the ideal case where a single fmp4 is encoded into both AVD and HEVC, he proposes you would simply package both into an HLS and DASH manifest and let players work out the rest. Depending on your players, you may have to split out your manifests into single-codec files.
DRM’s very important for a sports broadcaster so Nick looks at how this might be achieved. CMAF allows you to deliver m3u8 and mpd files using CENC (Common ENCryption). This promises a single DRM process ahead of packaging, but the reality, we hear from Nick, is that you’ll need two sets of media for HLS and DASH if you’re going to use CENC.
When you’re delivering multiple manifest and, hence, multiple sources, how do you manage this? Nick outlines, and shows the code, of how he achieves this at the edge. Using Lamda, he’s able to look at the incoming requests and existing files at the CDN to deliver the right asset with the logic done close to the viewer. Nick closes by with his thoughts on the future for streaming and answering questions from the audience.
Host: Dom Robinson
Director and Creative Firestarter, id3as
Contributing Editor, StreamingMedia.com, UK
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