Abstract: In one embodiment, a software-based cross-connect routes packets in an asynchronous Ethernet packet network to emulate circuit-based switching in a conventional circuit-oriented synchronous TDM network. The cross-connect has Ethernet interfaces for receiving and storing incoming Ethernet packets transmitted over the packet network from various source nodes. A cross-connect processor manipulates the stored Ethernet packets based on a stored connection table that defines emulated circuit-based connections in order to generate and store outgoing Ethernet packets in appropriate interfaces that then transmit the outgoing Ethernet packets via the packet network towards their defined destination nodes.

Abstract: Disclosed are methods and associated devices for minimizing the undesirable affects of interference signals in the upstream spectrum of an multiuser interactive system. The method comprises receiving an initial upstream signal at a multiuser interactive processor in a multiuser interactive system. The frequency of the initial upstream signal is at a frequency within the upstream spectrum. Next, the multiuser interactive processor determines a measure of interference associated with at least a portion of the upstream spectrum. Based upon the measure of interference, an upstream channel, from within the upstream spectrum, is selected. The upstream channel is within the upstream spectrum. Finally, the multiuser interactive processor transmits a second signal representative of the upstream channel.

Abstract: A system for composing multimedia signals from various source signals, such as still-frame video signals, full motion video signals and audio signals includes a plurality of composing units, each of which is capable of composing a multimedia signal from selected source signals. One of such composing units is assigned for each multimedia signal to be composed. Each composing unit accepts parameters specifying various properties for each element of the multimedia signal, such as size, position and precedence for each video element and gain for each audio element. The composing units can include decompressors for decompressing source signals furnished in compressed form and a compressor to compress the multimedia signal to be transmitted to a user. The source signals can be received from a packet network and the resulting multimedia signals transmitted to the respective users via the same packet network.

Abstract: A system is disclosed for delivering audio and/or video signals to users in connection with the provision of interactive television services. Various sources of such signals are connected to a digital network, such as a packet network. Also connected to such network are control and application processors and interfaces to distribution arrangements such as cable television systems and telephone subscriber loops. Each user has a signal converter for receiving a digital signal from the distribution arrangement, converting such signal for viewing on a conventional television receiver and transmitting control packets to other elements of the system. The signal sources can include a data cache for storing recorded video and audio materials, a broadcast source for receiving broadcast signals, apparatus for composing multimedia signals from multiple sources and apparatus for running games.

Abstract: Described is a technique for an interactive television ("ITV") system wherein viewers are allowed to select a desired level of advertisements with which they are provided. The technique comprises transmitting to a interactive services subscriber location a program and a set of advertisements (collectively referred to as a "show"). The set of advertisements is selected based upon an input from a user associated with the interactive services subscriber location. The input comprises an indicator of an amount of advertisements in the set of advertisements. Another feature of the ITV system described is that it allows for adjusting an amount of a bill of a subscriber to interactive television services based upon the amount of advertisements viewed in a show.

Abstract: A method and apparatus for the coding and efficient display of overlapping windows with transparency. Each pixel within a window which is not to be displayed may be coded as a "transparent" pixel. The method identifies those pixels which have been coded as transparent and displays non-transparent pixels contained in windows of lower display priority in place of the transparent pixels contained in windows of higher display priority. A pixel coded as transparent may have associated with it an integer representative of the number of successive pixels in the window which are also transparent. A pixel may be coded as transparent by assigning to it a preselected data value which is distinct from values otherwise used to indicate, e.g., the color and/or intensity for each displayed pixel. The method and apparatus may include one or more windows which contain full motion video (i.e., television) images, each of which may also contain transparent pixels.

Abstract: Different components of television programs, such as the video and audio components or different time segments of the program, are assigned to different channels transmitted in the form of packetized digital information in at least one of the channels of a multi-channel cable television distribution system. A particular subscriber's converter is configured to receive a particular subset of program components by enabling the converter to receive the virtual channels carrying the components in such subset. An embodiment is disclosed in which different combinations of program segments are enabled for different subscribers. Another embodiment is disclosed in which the viewing of a program by multiple subscribers who begin viewing at different times is synchronized by using "filler" program segments having different lengths.

Abstract: The invention relates to a system for transmitting stored programs, such as movies and musical works, to customers via a distribution network, such as a cable television system. The programs are stored in compressed form in a program library, such as a tape cartridge library. On receipt of a request for a program, a request processor sends control messages causing a data block comprising the requested program to be read from the program library at high speed and stored in a large dynamic random access memory (DRAM) in a server. The server then sends the program from DRAM over the distribution system to a customer as a series of digital packets. Each instance of sending a program is managed by a separate command word. The customer can request such operations as "fast forward" by sending control messages that change pointers in the command word. Command words can be grouped to send multiple audio and/or video overlays simultaneously and linked to send program sequences.

Abstract: Window border generating circuitry in a bitmapped graphics workstation. The workstation includes a host processor, a raster scanned graphics display device and means for controlling the display of data in one or more windows on the screen of the display device. An individual bitmap is provided for each window. At any given time, display data is retrieved from one of the bitmaps associated with a window presently being refreshed. Circuitry detects when the screen raster is located at a position at which a border of a window is to be displayed. Other circuitry responds to this condition by substituting for the display data from the bitmaps predefined signals for generating the screen borders.