Technique prevents the stalling of videos streaming to mobiles

Researchers in Germany have found a way to prevent internet videos from stalling when streaming to mobile devices.

A team from the Fraunhofer Institute for Telecommunications in Berlin have developed a technique to counter the effects of poor mobile reception or network data overload by automatically switching the video file to a lower quality.

This prevents the video from stopping because it cannot download the file fast enough to keep the footage playing smoothly. When the connection improves, the video switches back to a higher-quality file.

To do this, the researchers optimised the radio resource manager technology used by mobile networks to allocate data transmission to different users depending on what they need.

‘To do so, we combined Long Term Evolution or LTE — the new cellular standard that is replacing UMTS — with a format for web streaming called Dynamic Adaptive Streaming over HTTP, or DASH for short,’ said researcher Dr Thomas Schierl.

The current problem with video files is that the resource managers don’t know how large they are and how much bandwidth to allocate a user who is downloading a video.

If the user’s reception is too weak to transfer enough data or the network becomes congested, the resource manager is unable to maintain a smooth stream as it usually can with defined file sizes.

The DASH standard makes videos and images available in various qualities that require different amounts of data streaming. It allows users to select different video qualities and choose how quickly they load.

When the user starts a video, the transmitting stations and the mobile device automatically check reception and the volume of traffic on the network and adjust the quality of the video so it displays without stalling. The quality then changes as the signal strength improves or worsens.

Network operators also benefit from the optimised radio resource managers as they can operate more efficiently. ‘With our mechanism, resources can be optimally distributed and hence saved,’ said group manager Thomas Wirth.

‘The saved resources can then be allocated to others. This means we can increase the number of users that can be serviced.’

Researchers have already completed a prototype of the optimised radio resource manager.