Closing the Gap: Human Factors in Cross-Device Media Synchronization

The continuing growth in the mobile phone arena, particularly in terms of device capabilities and ownership, is having a transformational impact on media consumption. It is now possible to consider orchestrated multistream experiences delivered across many devices, rather than the playback of content from a single device. However, there are significant challenges in realizing such a vision, particularly around the management of synchronicity between associated media streams. This is compounded by the heterogeneous nature of user devices, the networks upon which they operate, and the perceptions of users. This paper introduces IMSync, an open interstream synchronization framework that incorporates human factors to capture the quality of experience (QoE). IMSync adopts efficient monitoring and control mechanisms, alongside a QoE perception model that has been derived from a series of subjective user experiments. Based on an observation of lag, IMSync is able to use this model of impact to determine an appropriate strategy to catch-up with playback while minimizing the potential detrimental impacts on a users QoE. The impact model adopts a balanced approach: Trading off the potential impact on QoE of initiating a resynchronization process compared with retaining the current levels of nonsynchronicity, in order to maintain high levels of QoE. A series of experiments demonstrate the potential of the framework as a basis for enabling new immersive media experiences.