Random access point period optimization for viewport adaptive tile based streaming of 360° video

360° video streaming introduces stricter requirements to the established transmission chain than in traditional streaming services. Transmission of the complete 360° video in desirable quality can lead to multiple times UHD resolution which would waste a large fraction of network resources as the larger fraction of the video is not presented on the end device. Adaptivity to the user viewport promises substantial benefits and contrary to per-user or per-orientation encoding, tiled based streaming provides a scalable solution. We consider tiled streaming of 360° video using the cubic projection, where tiled content resides on the server at 2 different resolutions. User traces have been collected for a range of content and based on consumption patterns, tiles at the server have been optimized. More concretely, the paper optimizes the Random Access Point period that leads to the minimum transmitted bitrate, while ensuring that users watch most of the time high resolution content.