Sports Broadcast Case
From Buffering To Unlimited Video Quality For Unlimited Live Streaming Audience
Would your customer wait to load the video or switch to another website?
53% would abandon a poor-quality stream in 90 seconds or less.
55% of interviewed professionals working in the online video industry today, from Broadcasters and Publishers to OTT streaming services and Online Video Platforms (OVPs) agreed that the most common problem experienced with video technology today was broadcast delay (also referred to as latencyBit) — stated in Bitmovin Video Developer Report 2018. Latency can be measured by the quantity and duration of buffering events during broadcasts.
Buffering (or “rebuffering”) causes the video to stall because a video player can’t download data fast enough to keep up with the rate of playback. When this happens, playback stops until enough video is downloaded to play again without stalling.
45% of live streaming sessions are affected by buffering resulting in the broadcast delay for the viewer — reported from "Impacts of video quality of experience on user management in a live event" by Orange Lab Networks.
39% decrease in the amount of video watched online according to MUX research, not surprisingly.
Moreover, viewers themselves say that they are not going to pay for subscriptions any more if the situation of a particular service does not change.
All of this makes buffering a real challenge for business as well as for viewers.
When CDN is not enough
If you do not take into account the issues on the user side, it is clear that CDN cannot cope with the load. This is expected because due to SLA it has to serve a maximum of viewers with acceptable quality. It works on a regular basis and predictable loads. However, when the growth of the audience is hardly predictable, no one will expect the exact level nor undertake it. In this case, a reserve resource is should be activated. And then two problems are faced at once: it is very expensive to keep a 10-fold resource reserve, and even if it is possible, it is not safe. As a result, the situation goes out of control and viewers experience a broadcast delay or a serious lack of quality.
FIFA 2018 case
We have made our research during the games of the World Cup 2018. The streaming was divided into segments of events so as to note the audience growth. We observed how the rate of content return from the CDN was changing during the game. We also measured the CDN capacity and Teleport above-CDN traffic allocation. The difference is shown on Chart 1 which reflects the situation better than any words.
And if you say: well ok this is the World Cup, it is obvious that there will be a high demand. Spoiler alert: this is one of the official national broadcasters with Akamai as a CDN provider.
Teleport Media Solution
Teleport Media’s distributed delivery solution ensured a 40% decrease in buffering and broadcast delays during a live sports event with an audience of more than 100K concurrent viewers. And no additional CDN or other resources were used.
How Did It Work
Quality
Conviva's "Understanding the Impact of Video Quality on User Engagement For the Live streaming content" claims that the average bitrate is as important as latency in defining user satisfaction and experience. We measured bitrate during the most popular matches of the FIFA World Cup 2018. We discovered that on the average a CDN provides almost minimal bitrate for most of the viewers when the audience grows 10x or more.
On the other hand, a CDN accelerated with Teleport distributed video delivery service provided a bitrate large enough to provide an HD quality experience for up to 40% of the users. See chart 2 of bitrate range with p2p off/on options.
Speed
On the other hand, decreasing bitrate on the fly to cope with buffering events leads to many switches. Users do not tolerate overly frequent bitrate switches as it impacts their perceptual experience, according to "A Quest for an Internet Video Quality-of-Experience Metric" by Athula Balachandran, Carnegie Mellon University.
When the audience grew exponentially, CDN delivery speed fell 4 times. And it did not grow above 1.5 Mbits. Apparently, this speed is enough for 480–720p, but not enough for full HD. At the same time, most of the audience is already go with smart tv with the appropriate screens and bitrate.
Meanwhile, streaming powered by Teleport ensured an almost perfect rate in delivering chunks of video, regardless of the number of users in the delivery network. See chart 3 of Average speed comparing Teleport technology with regular CDN infrastructure.
The results
By using the technology of direct content transfer between devices, we achieve 3 most important results:
- Offload CDN by 70%, making the whole platform more stable and reliable at high loads;
- Grow the share of higher bitrate consumption by 30–40%, improving the subjective quality;
- Reduce the current delivery price tag and the need for future investments in channels.
