An architecture of distributed media servers for supporting guaranteed QoS and media indexing

In a distributed multimedia system, multimedia sessions may get involved with multiple media servers for the retrieval of the media data or the creation of new multimedia documents. To provide the guaranteed Quality of Service (QoS) to real-time applications such as continuous media transfers, the system resources in the media servers must be reserved to avoid contention during execution time. Media indexing is also needed to support searching the media data in such a distributed environment and to provide the necessary information about the usage of system resources for delivering the media data. Due to the overhead, a centralized approach of scheduling all the requests and searching all the media data from only one agent is not efficient, and not scalable. In this study, we propose a new architecture, dividing the media servers into multiple groups of the right size. Within each group, there is a registration agent and an index agent, which take care of the resource reservation, membership management, media indexing searching, and load balancing. We demonstrate how to provide the guaranteed QoS by scheduling the requests among the multiple groups, and show the collaborations between the registration agents and the index agents inside and outside a group. The mobile media servers can fit in this architecture by the updates of membership status from the registration agents. The new IETF drafts such as SIP, RTSP and RTP are embedded into this architecture to support the general multiparty multimedia applications for real-time media streams.