Abstract: Control of communication by a plurality of devices, such as computer programs and terminals, via a computer is controlled by an arrangement referred to as a connector. The connector receives a request for communication defining the devices to the communication and, in response to the request, establishes a mapping table defining the source devices and destination devices to the connection. A source device stores data in connector memory and the connector reads the mapping table to determine the destination devices for the stored data. The connector then creates a linked list coupling structure between the stored data and the determined destination devices. The destination devices issue read commands to which the connector responds by reading the stored data in accordance with the coupling structure and providing that data to the requesting device.

Abstract: This invention relates to apparatus and a method for controlling a Digital Access and Crossconnect System (DACS) from a connected toll switching system. All control messages from operations support systems (OSS) for making crossconnect changes in the DACS are first routed to the toll switch. The toll switch extracts information needed to update its database and sends a control message to the DACS. In addition, the toll switch responds to changes in traffic patterns, perhaps due to the loss of a transmission facility, to generate a crossconnect change message to the DACS to rearrange facilities for more optimum performance. Advantageously, the OSSs for DACS control and switch control is combined and the toll network is made more responsive to traffic pattern changes and to losses of transmission facilities.

Abstract: A multi-stage network which achieves the same overall connectivity as known networks but where individual switching nodes have no input selectivity and no output selectivity. Each node is enabled or disabled to control communication therethrough in response to a single control signal. The functionality of a switching network is achieved by controlling which nodes are enabled rather than specifying connections of particular node inputs and outputs to be effected by the nodes. In a photonic network embodiment, each network node is implemented using a single symmetric self electro-optic effect device (S-SEED).

Abstract: A call processing method for distributed switching which substantially increases the percentage of calls that are intra-module calls by distributing the members of trunk groups among a plurality of switching modules and biasing the processing of a call originating on one switching module such that an available trunk group member on that same switching module is assigned to the call if possible. The path hunt function for intra-module calls is separated from the corresponding function for inter-module calls and only the latter function is performed by the system central control. The separation is achieved by dividing the set of switch path resources, e.g., channels or time slots, associated with a switching module into two disjoint subsets--a first subset for intra-module call connections and a second subset for inter-module call connections.

Abstract: A distributed switching system where calls are processed in one of two call processing modes: 1) in a first call processing mode, available paths through a time-multiplexed switch (TMS) are selected without reference to whether the paths are presently established through the TMS, and 2) in a second call processing mode, the available path selections are made from only established paths through the TMS. Reliability is improved without an addition of hardware to the system because a transition may be advantageously effected to the second call processing mode in response to any system failure where it becomes impossible to select new TMS paths or to control their establishment, but where the established TMS paths at the time of the failure are still usable for new calls. Once such transition is completed, the system can continue to operate to complete calls between switching modules (SMs) in a reduced performance mode dependent on the number of TMS paths established between the SMs at the time of the failure.

Abstract: A broadband packet switch arrangement comprising a broadband packet unit connected to a plurality of customer lines and a video switch for selectively connecting packetized video signals from a plurality of video sources to the customer lines. The broadband packet switch unit selectively connects customer lines and transmits received control packets received from the customer lines to a control unit which responds to video request packets by controlling the video switch to connect selected video packets to the customers lines. Each customer line includes a selector circuit which receives video packets and inter-customer broadband ISDN packets and merges them onto the customer line. After the control unit has granted permission to connect a video source to a customer line, video source change requests for the line are sent directly to the video switch which responds thereto by connecting a requested video source to the customer line.

Abstract: A phase diffraction grating apparatus which is usable to generate an array of N spots, where n is an even integer, and the N spots are substantially equally spaced. The generation of an even number of spots is achieved using a translation symmetry in the grating design. Illustratively, the intensities of the N spots are substantially equal. Binary, multi-level, and continuous phase grating embodiments are disclosed. In the case of the multi-level and continuous embodiments, the uniform intensity is obtained using a reflection symmetry in the grating design.

Abstract: An optoelectronic apparatus where information is communicated to and from the apparatus in the optical domain, but where the apparatus includes a transmission gate advantageously interposed between successive optoelectronic gates to sequentially convey information internally in the form of electrical, rather than optical, signals. Illustratively, the transmission gate is optoelectronic and comprises two back to back p-i-n photodiodes each including a quantum well region. The first and second optoelectronic gates are S-SEEDs comprising p-i-n photodiodes also each including a quantum well region. The transmission gate is responsive to a first level of the optical control signal for substantially blocking current, and to a second level of the optical control signal for substantially passing current. Applications of the apparatus include its use in a shift register, 2.times.1 switch, 1.times.2 switch, and an exclusive OR gate.

Abstract: A method used by a digital computer in controlling execution of an object-oriented program to effect a defined action, e.g., stopping the program, when a specified virtual function is invoked on a specified object during execution of the program. A breakpoint address is determined at run time, advantageously after the specified object is created in accordance with execution of the program. The breakpoint address determination is not based solely on symbol table, pre-execution, information, but in addition on information generated in conjunction with the creation of the specified object. The breakpoint is inserted while program execution is stopped at an intermediate program point after the specified object is created. After program execution is resumed and the specified virtual function is invoked in accordance with the program, the breakpoint fires. However, the defined action is performed only in response to determining that the firing occurred on the specified object.

Abstract: A parameter communication arrangement where a parameter that is transmitted over a channel using m-bit codewords or labels is quantized before transmission as one of only p levels, where, significantly, p<k=2.sup.m. Since only p labels are needed to transmit the p levels, the unused k-p labels are advantageously available to provide redundancy. The receiver decodes the redundant labels in accordance with an error routine. An encoding table mapping from the p levels to p labels and a decoding table inverse mapping from the p labels to p levels are obtained using an optimization procedure to minimize the effect of channels errors. The optimization is based on the probability distribution for the p levels such that a relatively high proportion of the error protection made available by having redundant labels inures to the benefit of parameter levels which are more likely to be transmitted.

Abstract: A reduced-blocking system where a perfect shuffle equivalent network having a plurality of node stages successively interconnected by link stages, is advantageously combined with expansion before the node stages and/or concentration after the node stages in a manner allowing the design of a system with arbitrarily low or zero blocking probability. An illustrative photonic system implementation uses free-space optical apparatus to effect a low loss, crossover interconnection of two-dimensional arrays of switching nodes comprising, for example, symmetric self electro-optic effect devices (S-SEEDs). Several low loss beam conbination techniques are used to direct multiple arrays of beams to an S-SEED array, and to redirect a reflected output beam array to a subsequent node stage.

Abstract: A network control arrangement where path hunts through a first network are performed with reference to a second network that is topologically equivalent to the first. Path hunts through a crossover network, well-suited for implementation in the photonics domain, are performed with reference to a topologically equivalent shuffle network using a very efficient, shuffle network path hunt algorithm.

Abstract: Optical apparatus for performing wavelength-dependent beam combination. The apparatus relies on a polarization beam splitter in combination with other optical elements to develop combined beams with the same polarization type and that are therefore suitable for polarization-dependent combination with other beam arrays. A dichroic mirror, which is used as the wavelength-dependent element of the apparatus, is oriented such that the incident beams are substantially perpendicular to the mirror. With this orientation, the dichroic mirror achieves near-ideal performance even with beam arrays having a substantial angular field. The apparatus also uses two plates which, although designed for operation as quarter-wave plates at one of the two wavelights being combined, are oriented with their respective fast axes substantially perpendicular to each other such that polarization conversions, effected by the plates on beams having the other of the two wavelengths, substantially cancel each other.

Abstract: A crossover network implemented using two-dimensional arrays of nodes. The network is a perfect shuffle equivalent network because it is topologically equivalent to a crossover network of one-dimensional arrays of nodes. The two-dimensional arrays are arranged in rows and columns and there are a plurality of link stages interconnecting successive arrays. The network is implemented efficiently in free space optics because the network topology requires optical crossovers in some link stages that interconnect only nodes in the same column of successive arrays and optical crossovers in the other link stages that interconnect only nodes in the same row of successive arrays.

Abstract: A harmonic speech coding arrangement where vector quantization is used to improve speech quality. Parameters are determined at the analyzer of an illustrative coding arrangement to model the magnitude and phase spectra of the input speech. A first codebook of vectors is searched for a vector that closely approximates the difference between the true and estimated magnitude spectra. A second codebook of vectors is searched for a vector that closely approximates the difference between the true and the estimated phase spectra. Indices and scaling factors for the vectors are communicated to the synthesizer such that scaled vectors can be added into the magnitude and phase spectra for use at the synthesizer in generating speech as a sum of sinusoids.

Abstract: Apparatus having a plurality of photodetectors interconnected to form an electrical circuit corresponding to any given logic function comprising at least two of the four basic AND, OR, NAND, and NOR logic operations. The apparatus performs optical logic without optical cascading since the electrical circuit controls the generation of an optical output beam based on the value that the given logic function assumes in response to a plurality of optical signal beams each incident on at least one of the photodetectors. A complementary optical output is obtained and time-sequential operation is effected when two, serially connected quantum well p-i-n diodes comprising an S-SEED are used to generate optical output beams in response to the voltage developed by the electrical circuit of interconnected photodetectors.

Abstract: A call processing method and apparatus in which a channel that was allocated to one terminal for processing a call is reallocated to allow another terminal to process the call. The channel is one of several channels of the digital subscriber line. In processing a call, the switching system allocates a channel for the exclusive use of a terminal sharing the digital subscriber line. While the channel is allocated to the terminal, only that terminal can use the channel. The switch enables another terminal sharing the digital subscriber line to process the call by reallocating the channel for the exclusive use of the other terminal.

Abstract: Apparatus having a first electrical circuit, comprising a plurality of photodetectors interconnected such that the first circuit corresponds to any given logic function, is connected in series with a second circuit comprising a plurality of photodetectors interconnected as the conduction complement of the connections of the first circuit. The apparatus performs optical logic without optical cascading since the first and second circuits control the generation of an optical output beam based on the value that the given logic function assumes in response to a plurality of optical signal beams incident on the photodetectors of the first circuit and a plurality of complementary beams incident on the photodetectors of the second circuit. A complementary optical output is obtained and time-sequential operation is effected when two, serially connected quantum well pin diodes comprising an S-SEED are used to generate optical output beams in response to the voltage developed by the first circuit.

Abstract: A call processing method and apparatus for maximizing the number of calls that are offered to terminals sharing a digital subscriber line while insuring that for every call offered, a channel of the digital subscriber line remains allocatable to at least one terminal addressed by the call for use in answering the call. The switching system reserves a channel of the digital subscriber line in response to an incoming call. This channel is reserved for a set of terminals that share the digital subscriber line and that are addressed by the incoming call. This reservation entitles one of the terminals to be allocated a channel to originate or answer calls.

Abstract: Apparatus comprising a monolithic structure having an array of substructures, e.g., mesas, each including first and second photodetectors electrically connected as components of different self electro-optic effect devices. The devices are optically interconnected due to the positioning of the component photodetectors within a single mesa.