Abstract: A data server for use in networks in which media signals are transmitted as digital signals in packet form comprises at least one shelf having at least one card whose purposes are to provide a shelf controller function and a media processor function, together with a plurality of backplane buses. The data server accesses media signals in packet form. Distributed software is distributed in the cards on the shelf, and consists of a modular software architecture having a transport layer, a media processing layer, a session control layer, and a management plane which spans across the other layers. A plurality of digital signal processors has a plurality of dynamically changeable discrete software objects so as to process packets of media data. The management plane provisions and monitors the operations of said data server, and gives alarms in keeping with predetermined criteria. There is at least one connection interface to a packet network from which media signals in media form are received.

Abstract: A data server for use in networks where media data are transmitted in packet form comprises at least one card shelf containing at least a bus controller card, a plurality of media processor cards, and a backplane. The backplane has a plurality of media buses, which carry data in packet form among the cards installed on the shelf. Each card has at least one bidirectional port with its own unique identity, and each bidirectional port outputs flow control information as to whether that port can or cannot accept packets of data that are intended to be sent to it, as well as transmit requests to transmit packets of data from that port. Each card outputs flow control information for each bus. A bus arbiter reviews each request to transmit and each flow control message, and grants requests to transmit media data packets only when the intended destination address is free to receive a media data packet over a free bus.

Abstract: In an object oriented video merging system for use in teleconferencing, at least an object from one discrete video stream is to be merged into a composite video output signal for return to a plurality of selected sources at each instant in time, and each object in each video frame is describable by a polynomial which defines a two-dimensional shape. Video processing units processing video data from a plurality of video sources on a frame-by-frame basis, and a backplane having at least a data bus, and a common video bus into which an object from one discrete video stream is merged at any instant in time from a respective video processing unit. Each video processing unit includes an object description generator, a video priority register, and a video selector for permitting an object from the video stream being processed by the respective video processor unit to be transmitted to the common video bus only if the priority of that video stream at any instant in time permits such transmission.

Abstract: A multimedia conferencing system has a plurality of remote user terminals, each of which may be different from any other, and each of which may communicate to a central processing hub using different communications protocols. The central processing hub receives, processes, and sends video and audio data from and to the plurality of remote users, and comprises a media bus for handling video and audio data signals, a packet bus for handling data and control signals, a shelf controller card which issues control messages in keeping with incoming management signals, a bus controller card which provides clock and bus arbitration signals, at least one media processor card for processing video and audio signals, and video encoding means for receiving video data from the one or more media processor cards and delivering video data signals to the packet bus. Video and audio data signals may be received by or delivered from any of the at least one media processor card and the at least one physical interface card.