The shift to multiscreen TV “broke” the social and interactive elements of television viewing. It was thought that through companion and messaging apps the social aspect of TV viewing could be revived. Unfortunately, the delay in delivering Over The Top (OTT) content to different devices and lack of synchronization between the primary screen and secondary screens quickly became an issue.

The second screen has become a frustration rather than an enhanced social experience. For example, second screen users being informed of who scored a touchdown in a football game and how before it happens on their screen means viewers of live OTT events are forced to log out of social media and messaging platforms.

They risk hearing about what is unfolding on someone else’s screen before it happens on theirs. This is only part of the problem. There is also little opportunity for real-time social messaging, viewer engagement and shared experiences when audiences are watching the same content on different screens and devices with a time delay ranging from tens of seconds to several minutes.

To bring the social element back to live TV viewing, OTT’s issue of synchronizing content delivery across all devices and harmonizing this with live linear broadcasts needs to be addressed.

This paper outlines the technical challenges in distributing true live OTT over today’s Content Delivery Network (CDN) platforms, and why their limitations in streaming live content breaks real-time social interactivity.

It further describes a software-based OTT distribution solution that is optimized for distribution of live content with low and synchronized OTT delivery, and further outlines the technical differences with today’s HTTP- based streaming solutions.

The last section of the paper provides examples of real-time social and audience engagement, and what this means for the entire media ecosystem.


CDNs and OTT video distribution platforms today use technologies such as HTTP Live Streaming (HLS) and MPEG-DASH, which use segmentation of the video streams and HTTP for delivery. This provides a reliable, personalized delivery of the video streams to consumers, optimized for on-demand content and catch-up TV. However, it also includes inherent caching and buffering of segments that in typical video OTT implementations result in a delay of around 30 to 40 seconds higher than linear TV broadcasts. Additionally, due to the use of TCP in HTTP and the way most players in the market are built, additional delays are accumulated during the playout of the video feeds. In long-tail content, such as live sports, this can result in a difference in delay of several minutes between devices, while HLS allows up to 15 minutes to be buffered.

This is not a major issue for video-on-demand (VoD) and catch-up TV, but for live content low delay and synchronized delivery is key to ensuring live TV experiences are not ruined, and social and interactive TV entertainment is maintained at the highest possible level.

Today, live and linear OTT is mainly used as a substitute when viewers are unable to watch live content on their largest screens and over standard broadcast TV. Contrary to this, research shows that a clear majority are willing to, and want to, watch major live events and sports content across OTT platforms, but ultimately actual live OTT viewing is still limited to a single-digit percentage compared with those watching live events on primary screens.

The OTT screen, with its strong computing power and graphics and its Internet connectivity, holds great promise in actually enriching and enhancing end-user experiences. However, because of the unsynchronized delay between TV screens, the OTT second screen promise has diminished to the second screen only holding data, and potentially graphics, but with no video content. This has, in general, resulted in a limited uptake for live OTT video distribution. An optimized true live OTT distribution in sync with regular broadcast television will change this by actually bringing a new, enhanced viewing experience that complements and harmonizes with the regular TV broadcasts, changing the way the second screen is used and how content is experienced.

In the coming sections we will look at the specific requirements for live OTT distribution and examine some use case examples in detail.