Abstract: An echo canceller system includes first and second echo cancellers. Each echo canceller includes a foreground filter and an adaptive background filter, with the foreground filter providing the actual echo cancellation and the background filter updating the foreground filter. The echo canceller system also includes send and receive paths, a shared coefficient memory, and a controller for switching the shared coefficient memory between background filters in response to signals along the send and receive paths. The switching includes resetting the shared coefficient memory to prevent any transfer of filter coefficients between the background filters. The background filters operate one at a time, depending on which background filter has access to the shared coefficient memory, while the foreground filters operate simultaneously.

Abstract: A multi-ring network structured by connecting a plurality of rings having different speeds. The multi-ring network includes a first ring structured by connecting a plurality of first nodes by a pair of ring-formed first transmission lines, a second ring structured by connecting a plurality of second nodes by a pair of ring-formed second transmission lines, and a third node for connecting the first ring and the second ring. The first transmission line has a first transmission speed and the second transmission line has a second transmission speed lower than the first transmission speed.

Abstract: A method and apparatus for concurrent communication of analog information and digital information. In general terms, when the communication channel is viewed as a multi-dimensional space, the digital information signal is divided into symbols, and the symbols are mapped onto the signal space with a preset distance between them. The analog signal, generally limited in magnitude to less than the distance separating the symbols, is converted to component signals and added (i.e., vector addition) to the symbols. The sum signal is then transmitted to the receiver where the symbols are detected and subtracted from the received signal to yield the analog signal components. The transmitted analog signal is recreated from those components. Both half-duplex and full-duplex operation is available in accordance with the disclosure.

Abstract: A wideband frequency signal digitizer and method for digitizing multiple bands of a wideband frequency signal. The digitizer and method providing for optimally positioning a segment (402) of the wideband frequency signal within a Nyquist band of an analog-to-digital converter. Remaining segments (402) of the wideband frequency signal are closely positioned relative to the first segment such that the entire wideband frequency signal (400) is easily digitized using a single or multiple analog-to-digital converters (36) while reducing or eliminating undesirable spurious signals.

Abstract: The present invention provides to a distributed restoration scheme a set of timers so that multiple senders and choosers can more fairly contend for the spare capacity of a telecommunications network. In particular, a preactivation timer would force a sender that had reserved excess spare capacity of the network for restoring its own failed links to release any unused spare capacity prior to the time that it terminates its operation, provided that it has found an alt-route or alt-routes for its failed link. An alarm validation timer and a hold off timer in the invention scheme further provide for respective validation and detection that a detected fault is not transient or intermittent in nature and that a restoration process is needed to find the alt-routes.

Abstract: A looped bus system includes several nodes connected by unidirectional buses having opposite directions of signal transmission. The head of bus function for each bus is located at a node different from the head of bus function for the other bus. The head of bus function for each bus is located at the same node as the termination of bus function for the other bus. As a result, the buses can be reconfigured and nodes can be added freely by the use of a bus portion that is unused in the looped bus under normal condition.

Abstract: Method and apparatus are provided for segmenting a multiple program multimedia digital data stream for transmission over a distribution communications network. Each program multimedia digital data stream includes sequential transport system (TS) packets with program clock references (PCRs) at a set time interval and a program identification (PID) associated with the PCRs. The multiple program multimedia digital data stream is received. The TS packets are decoded to identify the program clock references (PCRs). A selected number N of TS packets are identified. The multimedia digital data stream into frames responsive to both the identified number N of TS packets and the identified PCRs. A program identification (PID) associated with one of the PCRs is selected for timing the transmission of segmented multiple program multimedia digital data stream.

Abstract: A system for full duplex real time two-way voice and data communication between a pair of computer terminal locations is disclosed. Analog voice signals are converted to digital form at one terminal location and those digital signals are interleaved with other digital information for transmission to the other terminal location. A value for the number of bytes, in a data packet is first established, and then values for the number of bytes and the location dedicated to the transmission of voice information, control information, and data transmission within such fixed size data packets is established. Thereafter, a sequence of data packets with synchronization bytes in the voice byte locations is transmitted from each computer terminal location and received by the other of the terminal location. Upon receipt thereof, an acknowledgement of the receipt is transmitted back to the originating location to indicate the establishment of synchronization between the two locations.

Abstract: The present invention, in an ATM (Asynchronous Transfer Mode) which houses data in fixed length packets known as cells and transmits them to a receiving end, has as its object to provide a technology which can relay and transmit, within an ATM exchange, overhead section control information and can effectively perform maintenance and management of a communication network. Also, the order wire apparatus of the present invention comprises a network end device between a subscriber terminal and an exchange, this network end device comprising a frame data preparing means for simultaneously mapping communication data transmitted from a subscriber terminal into the payload section of frame data and mapping control information input by a maintenance worker into the overhead section of the frame data.

Abstract: A communication system comprising an Asynchronous Transmission Mode ("ATM") network and at least one demultiplexing device. The demultiplexing device receives information cells which include a header, containing the destination to which the cells are to be transmitted, and data. The demultiplexing device comprises at least one input access for receiving the cells, a plurality of output accesses, at least one network circuit, a plurality of service circuits and a common data line. The network circuit has an input access, a header analyzing element, a routing table and a combining element. At least one of the output accesses are assigned to each of the service circuits. The routing table produces a routing information signal which determines the destination to which the cells are to be transmitted. The combining element combines the information signal and the data and transmits the same on the common data line.

Abstract: Methods and apparatus are disclosed for automatically establishing a conference call to a preselected list of prospective participants to the conference call. A subscriber to the conference calling service predefines one or more lists of participants, each list being associated with a different conference call. When the subscriber wishes to initiate a conference call, the subscriber accesses the network and requests that the call be set up. The network originates (e.g., dials) calls to each of the participants on a specified list. The network then bridges these individual calls to establish the conference call. The cost of the conference call can be billed to the subscriber or shared among the participants to the call.

Abstract: In a video conference between N parties, each video conferencing terminal produces a respective video signal comprising, in the case of the National Television Standard Committee (NTSC) standard, sixty fields per second. The input video signals are input to an analog multi-point control unit which selects every Nth field from each input video signal and derives therefrom a single output video signal also of sixty fields per second, in which consecutive fields are derived cyclically from each of the N input video signals in turn. The single output video signal is transmitted to each video conferencing terminal, which separates out the fields of the input video signals present in the single output video signal to provide N individual reduced field rate video signals each comprising 60/N fields per second and each having fields derived from a respective one of the input video signals.

Abstract: A DS3 level access, monitor and test system for a telephone network. The system provides selective, and hitless, bit overwrite in any of the embedded DS1, DS0 and substrate channels in a DS3 signal. Multiple DS0 and subrate channels can be tested via the asynchronous time slot interchange in conjunction with the recombiner of the present invention. The present invention further includes a lookahead reframer for framing to the DS3 signal. The present invention also includes a facilities data link (FDL) handler for capturing the FDL channel data in every DS1 channel in a DS3 signal. A high speed bit-for-bit compare is interfaced to a protect path to provide 1:1 fault protection in the system of the present invention. Full time performance monitoring on DS1 and DS3 signals is performed by a shared resource. The system of the present invention provides an integrated approach to synchronization measurement and relative synchronization.

Abstract: In a transmission system having a procedure to exchange control information at least one time between a first terminal and a second terminal to transfer data from the first terminal to the second terminal, a relay station receives control information transmitted from the first terminal and detects existence of the control information from the second terminal during a preset detection time interval from a time of reception of the control information. If the control information has not been detected, the relay station exchanges the control information with said first terminal instead of the second terminal, receives data from the first terminal and transfers the data to the second terminal.

Abstract: In this communications architecture, a receiver or a receiver control entity acting on behalf of the receiver or a group of receivers, controls the communication of voice, data, or video from individual senders. This is accomplished by placing a Registrar between the senders and receivers. Upon an authorized request from a sender to access a receiver, the Registrar issues a vector to the sender and stores the vector in a database. The vector uniquely identifies both the sender and the receiver. Each time the sender wishes to make a voice call or send a data packet or a video transmission to a particular receiver, the corresponding vector is sent to the switch as the receiver's address. The switch sends the vector to the Registrar for call treatment instruction.

Abstract: A DS3 level access, monitor and test system for a telephone network. The system provides selective, and hitless, bit overwrite in any of the embedded DS1, DS0 and subrate channels in a DS3 signal. Multiple DS0 and subrate channels can be tested via the asynchronous time slot interchange in conjunction with the recombiner of the present invention. A second embodiment of the invention partitions the system into a base subsystem, a communications link and a remote subsystem, collectively referred to as a distributed architecture system. The distributed architecture system provides all of the performance monitoring and testing capabilities of the existing access system. The distributed architecture system provides a mechanism to transport a plurality of asynchronous and rate independent signals across the link to permit remote testing of digital and voice DS0 frequency circuits. In the preferred embodiment, the link that connects the base to the remote system is a standard DS1 channel.

Abstract: In a CDMA communication network, each base station (BS) is made to establish synchronism between a downward transmission signal directed to a mobile station (MS) and an upward reception signal received from the mobile station by adjusting in the mobile station a mobile generated SS pattern into an adjusted SS pattern of producing an upward transmission signal for reception at the base station as the upward reception signal. In order to get the adjusted SS pattern, the base station inserts in the downward transmission signal an inserted signal representative of a propagation delay t(D) between the base and the mobile stations and a propagation delay increment t(d) while the mobile station is in a prelminary state of receiving the downward transmission signal as a downward reception signal first from the base station and is in a steady state, respectively. The signals may ba propagated through at least one communication satellite.

Abstract: In a digital half-duplex frequency division multiple access radio system a mobile station is either sending or receiving. For each call between a mobile station and a base station, a first frequency is allocated for the up link direction (from the mobile station to the base station) and a second frequency is allocated for the down link direction (from the base station to the mobile station). The signals exchanged by the stations are organized in frames of predetermined fixed duration grouped into multiframes comprising a predetermined number of frames including at least one control frame. At least some of the control frames are listening frames during which the sending mobile station interrupts sending, switches to receive mode and (if appropriate) reverts to send mode.

Abstract: In a telecommunication system, especially a telephone system having at least one electronic computer controlled telephone exchange, in its turn having time-space type switches, including a number of memory devices in the form of matrices, a method and an apparatus for transferring, via inputs and outputs of the memory devices, speech and data information in binary form between subscribers connected to the exchange. To considerably reduce the power consumption of the memory matrix as a whole, devices are provided to activate only those memories, which, for the moment, are intended to emit a corresponding output signal after that data has been written into same, and to cut off those portions of the memory matrix, which are not used for emitting output signals, in that no information is written into those, thus, not activated memories.

Abstract: A system provides for detection of enhanced capabilities of stations on a communications network. A specified pattern of link test pulses are detected and transmitted to provide for the indication of enhanced capabilities. This is particularly useful for determining whether a particular station is in full duplex or half duplex mode without affecting overall network performance.