A system of distributing video and/or audio information employs digital signal processing to achieve high rates of data compression. The compressed and encoded audio and/or video information is sent over standard telephone, cable or satellite broadcast channels to a receiver specified by a subscriber of the service, preferably in less than real time, for later playback and optional recording on standard audio and/or video tape.

Audio and video transmission and receiving system

An audio program and message distribution system in which a host system organizes and transmits program segments to client subscriber locations. The hose organizes the program segments by subject matter and creates scheduled programming in accordance with preferences associated with each subscriber. Program segments are associated with descriptive subject matter segments, and the subject matter segments may be used to generate both text and audio cataloging presentations to enable the user to more easily identify and select desirable programming. A playback unit at the subscriber location reproduces the program segments received from the host and includes mechanisms for interactively navigating among the program segments. A usage log is compiled to record the subscriber's use of the provided program materials, to return data to the host for billing, to adaptively modify the subscriber's preferences based on actual usage, and to send subscriber-generated comments and requests to the host for processing. Voice input and control mechanisms included in the player allow the user to perform hands-free navigation of the program materials and to dictate comments and messages which are returned to the host for retransmission to other subscribers.

Audio message exchange system

A scalable architecture is disclosed for delivery of real-time information over a communications network. Embedded into the architecture is a control mechanism that provides for the management and administration of users who are to receive the real-time information. In the preferred embodiment, the information being delivered is high-quality audio. However, it could also be video, graphics, text or any other type of information that can be transmitted over a digital network. Preferably, there are multiple channels of information available simultaneously to be delivered to users, each channel consisting of an independent stream of information. A user chooses to tune in or tune out a particular channel, but does not choose the time at which the channel distributes its information. Advantageously, interactive (two-way) information can be incorporated into the system, multiple streams of information can be integrated for delivery to a user, and certain portions of the information being delivered can be tailored to the individual user.

Multicasting method and apparatus

Method implemented by a computer-based electronic assistant (60) include receiving and managing incoming calls to a subscriber. Methods include receiving an incoming call to the subscriber, establishing a connection between assistant (60) and subscriber, linking the caller and subscriber in response to receiving a call accept command, and switching the assistant (60) to a background mode. The assistant (60) monitors the subscriber for a summoning command while in the background mode and in response to receiving a summoning command, switches the assistant into a foreground mode which enables the subscriber to initiate conferencing features. Other methods include providing an electronic reminder service to the subscriber via use of personal locator and multimedia communication type determination, identification of a third party caller to subscriber while in an established connection, and providing multiple media type interaction capabilities.

A network based knowledgeable assistant

An improved system and method for providing multimedia data in a networked system is disclosed. The present invention provides a platform for distributed client-server computing and access to data over asymmetric real-time networks. A service mechanism allows applications to be split such that client devices (set-top boxes, personal digital assistants, etc.) can focus on presentation, while backend services running in a distributed server complex, provide access to data via messaging across an abstracted interface.

Method and apparatus for scalable, high bandwidth storage retrieval and transportation of multimedia data on a network

A method for use in a multimedia conferencing arrangement to control multiple concurrent calls where each call comprises one or more channels. A first call among a first set of user stations and a second call among a second set of user stations are merged into a single call comprising a plurality of channels among at least three user stations from the first and second sets. The plurality of channels of the single, merged call corresponds to a combination of channels of the first and second calls and may include a signalling channel, a voice channel, and one data channel for each data channel of the first and second calls. The method is also applicable to calls including image or video channels.

Multiple call control method in a multimedia conferencing system

The software architecture of a multimedia workstation connected to an experimental packet switching network which is capable of switching voice, data, and video simultaneously is described. The user of a multimedia workstation may engage in several multimedia calls, each using multiple information streams consisting of voice, data, and images. The network interface software in the workstation maintains the temporal relationship among a given call's information streams. For each call, the network interface provides a multiple information channel interface to upper layer software supporting the notion of a multimedia virtual circuit. A connector mechanism is provided to control the information exchange among the network interface, the various voice, data, and image peripherals, and the computer programs used in a multimedia application. These information sources and sinks share a common abstraction called active devices. >

A software architecture for workstations supporting multimedia conferencing in packet switching networks

A method and apparatus for executing parts of a program process on two processors of a multiprocessor system. A home process resides in a home processor and is the destination process of all interprocess messages. The home process may call for the execution of a selected procedure on a remote processor. A call message is sent to the remote processor and a remote process is initiated. When the selected procedure has been executed in the remote processor, a return message is sent to the home process and execution of the home process is continued. Interprocess messages to the program process are received by the home processor and are forwarded to the remote processor. Interprocess messages generated by the selected procedure are transmitted by the remote processor, but are tagged with the identity of the home processor and home process.

Program process execution in a distributed multiprocessor system

A method of testing interfaces between computer program modules. The individual cause/effect charts of each of the modules are used to test the interfaces between the modules by executing the test cases in the charts in such manner that each test case need only be executed once. The variables passed between modules are monitored and compared with the input conditions in the charts.

Method of testing interfaces between computer program modules

A transformation method for network conference connections where the network operations are determined based on stored information defining the original connection and stored information defining the target connection thus affording the opportunity to advantageously reuse existing paths. The paths to be deleted and the paths to be added to effect the transformation are determined such that no path is both deleted from and added to any switch. The connection information may be stored either in a central control entity or an intra-switch path information in the individual switches of the network. In the latter case, the individual switches determine their own intra-switch path additions and deletions in a distributed fashion.

Wu-Hon F. Leung

Papers

Multiple call control method in a multimedia conferencing system

A software architecture for workstations supporting multimedia conferencing in packet switching networks

Program process execution in a distributed multiprocessor system

Method of testing interfaces between computer program modules

Transformation method for network conference connections