Cost-effective Web-based Media Synchronization Schemes for Real-time Distributed Groupware

A multitude of application domains benefit from synchronized multimedia content presentation and playback across spatially scattered client stations. Online remote tutoring, telework and teleconferencing, and the nonco-located synchronous browsing through a digital photo album are merely some examples of potential use cases, which are referred to collectively as real-time distributed groupware. This paper presents five concrete schemes that realize media synchronization over the Web. The proposed techniques have been implemented and experimentally validated as part of the synchronous MediaSharing (sMS) service, a framework which grants geographically dispersed users the ability to share and synchronously consume digital pictures and video clips. All five schemes are completely Web-compliant, achieve relatively loose synchronization accuracy, and can be categorized as being non-distributed in the sense that they require centralized coordination. Besides being technically compared, the synchronization solutions are subjected to a high-level assessment in terms of their infrastructural requirements and the thereby associated necessary operational expenditure.