By Damien Lucas, CTO & co-founder
Earlier this week, I spoke in a panel at the OTT Executive Summit on how to enable and ensure broadcast-like video quality of experience in OTT. Is it possible yet? How? And what can we still improve? In this article I’ll give some of my key take-aways.
Let’s start by defining what we’re talking about. A broadcast-like video quality of experience means three things:
- high-quality video
- ultra-low latency
- high availability
And it means having all that at scale – regardless of how many people are watching.
So let’s look at each in turn.
OTT actually supports superior quality than broadcast. Why? Because it’s so much faster to get new technology to market in OTT than with broadcast. Think 4K and HDR. While a broadcast platform is built once to last for decades, an OTT platform is generally composed of many different software parts that are upgraded several times a year – and as agile methods are increasingly adopted, sometimes even every few weeks.
This is perhaps the aspect that has advanced the most over the last 2 years. Every year sees improvements. And today, it is possible to have latency below the typical 5 seconds of broadcast by using the right technology and the right standards (CMAF).
This is perhaps the biggest challenge nowadays. Rebuffering can occur – and that’s a big problem, because it may lead some viewers to stop and start again to see if the viewing is smoother. Others will just stop watching – leading some operators to increase the buffer size. This definitely reduces rebuffering, but it increases latency. And that is a real problem.
Unlike broadcast – where, once you’ve set up your system, it will work no matter how many people are watching – with OTT, you need to think ahead. How many people will be watching next month, or next year? Do you have enough capacity to meet that demand?
The solution? Obviously having a good CDN strategy is crucial. But what is a good CDN strategy?
Many different options were mentioned – peer-to-peer, multicast ABR, containerised CDN, private CDN, end CDN (a CDN inside a peering point), edge CDN, and more. Which one facilitates quality at scale?
Personally, I’m excited about edge CDNs. But it cannot solve everything. So the best solution, in my opinion, is to combine a large CDN with strategic edge cache nodes.
But whatever solution is chosen, it’s clear that no single CDN can solve everything. The solution will be a combination of different CDNs – meaning that standards such as OpenCaching become extremely important.
According to Akamai, simplicity wins. I agree. And multicast ABR – a technology that is more similar to broadcast than to unicast – is definitely not making things simpler in the OTT world. It delivers the same stream to everyone, so if you want to get the benefits of ABR (any screen, different bitrates, personalised ad insertion), you need to come up with some really convoluted fixes to make it work. Is it worth adding all that complexity?
Many other solutions exist to solve the problem simply and elegantly.
We recently issued a whitepaper on how to optimise traffic and other challenges posed by live video streaming services – exploring various CDN options and their pros and cons. You can download it here.
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