CDN Offload: A Smarter Way to Stream
There is nothing more frustrating than tuning in to a streaming service watch the big game and finding the feed unwatchable due to poor picture quality, buffering or at worst a crashed feed. It’s not just sports. Anytime large audiences flock to watch a live event, the internet will struggle for capacity and audiences will suffer. Streaming brings interactivity and on demand programming, but to do so it delivers each individual its own copy of a video. This works well until you need to reach large amounts of people, and then the sheer numbers of people trying to get the content cause latency, quality issues, and crashes. Streaming’s strengths become its downfall when trying to reach a large audience.
This doesn’t just affect audiences. Streamers incur huge infrastructure costs to try to cope with the increased demand of highly watched live events, with Netflix alone spending an estimated $4 per user on CDNs and related technology to try and keep up. A single over-the-air broadcast signal, by contrast, can reach every user within a market area, with no quality loss, latency, or crashing.
ONE Media developed CDN Offload to deliver the high quality and reliability of live broadcast with the convenience and interactivity of streaming. The system leverages ATSC 3.0, the NextGen TV standard, to improve the reliability and quality of video for viewers, while reducing the cost for streamers.
The Problem with Streaming
When you watch a show on a streamer, the video is delivered in short segments, and your TV seamlessly plays them one after the other. This is useful, because it means that there can be multiple resolutions available for each segment. If you have a good internet connection, then the TV will retrieve the highest quality segment available, but if the network connection is poor it will deliver a lower quality segment. This is to make sure that you are receiving the best possible video content that your TV and internet can display.
You may have seen this when you stream a show, the opening few seconds appear blurry, then improve, and improve again, before reaching the best quality your TV can display. Your TV is playing the low quality file, checking your internet to see if you can get a better one, and then delivering the higher quality when it knows your network can handle it. This is called the ABR (Adaptive Bitrate) ladder, and it makes sure people can see their show, even if they have a poor connection. That is unless too many people are trying to access the content, like in the case of a large live sports event. With everyone trying to access the same program at the same time, everybody’s network suffers, and users struggle to get even the lowest quality feed.
CDN Offload with ATSC 3.0
CDN Offload adds another rung to the ABR ladder and takes pressure off the internet network. When a streamer is producing a live event, the over the air signal can be sent out simultaneously. Ultimately, offload carries the segments and serves them from a local server.
Like streaming, ATSC also uses the DASH protocol, so the signal integrates with the streamers systems perfectly. When a viewer starts to watch the live stream, the streaming process begins as normal. The player begins moving up the ABR ladder based on the network’s conditions.
However, if the player is ATSC 3.0 enabled and has good reception, it will switch to the broadcast signal. The switch happens seamlessly, so a user would be unaware they had made the switch to OTA. The quality improves, stability increases, the load on the network is decreased and streamer’s CDN costs go down.
CDN offload is a perfect example of what ATSC 3.0 can offer. It combines the reliability and scale of broadcast with the flexibility of internet delivery to provide a better service for audiences, and lower costs for streamers. NextGen TV is a smarter foundation for how video reaches you in the modern world. CDN Offload is a win for viewers, a win for streamers, and a giant leap forward for what broadcast can do in the digital age.