Abstract: A scheduling system and method, which employ a token passing scheme, for scheduling transmission of multimedia information between information warehouses (IWHs) and CO clusters (CCs) interconnected by ATM switch(es). Each CO cluster employs a CC schedule processor, which has means for receiving and means for storing requests for multimedia information, means for sorting and prioritizing the requests, means for forwarding requests to appropriate IWHs, and means for accepting or rejecting tokens offered by IWHs in response to a request. The IWH employs an IWH schedule processor which includes means for receiving and means for storing requests from CO clusters, means for selecting a request and generating a token to be sent to the CO cluster originating the request, and means for storing a list of CO cluster rejecting tokens. Requests received from multiple subscribers are stored, sorted, and prioritized at CC schedule processors, which forward the requests to appropriate IWHs.

Abstract: The present invention is directed to a system for the wavelength division multiplexing/asynchronous transfer mode (WDM/ATM) operation of high-capacity optical communication networks. The optical components of the network can transport vast amounts of information, while the ATM-based electronics provides data processing, and information distribution. The capacity of the communications network to reconfigure and rearrange itself is maximized through wavelength translation of its data signals using a limited set of fixed-wavelength channels. The system incorporates an optical fiber communication network ring, or several optical fiber communication network rings that are connected to each other, through which data signals are transmitted and received. Optical WDM cross-connecting switch devices 4a-4e connect adjacent optical fiber rings 3a, 3b to each other, and control the routing of the data signals into and out of the optical fiber rings 3a, 3b.

Abstract: A method for designing a ring communication network is presented. A candidate ring defined by a candidate subset of nodes and a candidate routing is identified. A direction of communication is determined for each of a set of anticipated demands. The cost of operating the ring is calculated based upon the anticipated demands. Finally, the calculated cost is compared to a selected cost threshold to determine if a candidate ring is feasible, wherein the ring communication network comprises the candidate ring.

Abstract: A diode laser (2) including multiple quantum wells (26) of AlGaInAs in either compressive or tensile strain and barrier layers (28), wherein the conduction band confines the electron preferably to at least 150 meV, or at least 135 meV, such that the diode laser is efficient and can operate for extended periods at elevated temperatures up to 85.degree. C. and above.

Abstract: Apparatus and methods are provided for photonic contention resolution in a switch including a plurality of input modules and a plurality of output modules, wherein at least two of the plurality of input modules have cells to be transmitted to a destination output module. The photonic contention resolution device includes a plurality of coherent light sources for emitting a beam of coherent light and a plurality of tunable receivers. Each of the coherent light sources and tunable receivers are tunable by an associated input module to a plurality of distinct wavelengths. Each tunable laser preferably illuminates at least one of the plurality of tunable receivers at the particular wavelength associated with the destination output module such that one of the at least two input modules transmits its cell to the destination output module if none of the plurality of coherent light sources is illuminating its associated tunable receiver at the particular wavelength.

Abstract: A distributed service management system for providing communication services comprises a plurality of individual service management systems operated by a plurality of different service providers. Each service management system includes its own local database and an Interactive Distributed Transaction Monitor (IDTM) that allows locally running applications to access the local database as well as remote databases belonging to remotely located service management systems. The interfaces serve to integrate multiple individual service management systems into a single multidatabase transaction management system. The distributed service management system can be used to provide special personal communication services involving multiple service providers, such as call forwarding to a temporarily rented mobile telephone.

Abstract: A ring is routed through a subset of nodes of a communication network by first providing a branch-decomposition having a pattern relating to separations of the network. The branch-decomposition can be performed using internal two-separations, internal three-separations, eigenvector separations and pushing. If the branch-decomposition has a branch-width less than or equal to a predetermined constant value, then the branch-decomposition is used to determine costs associated with portions of the ring passing through separations of the network by examining matchings corresponding to edges of the branch-decomposition and selecting a lowest cost ring by examining the matchings and choosing a lowest cost set of matchings containing the subset of nodes. The branch-decomposition can be provided once for a fixed network and then costs can be determined and the ring route selected repeatedly for different subsets of ring nodes and different edge costs. The edge costs can be negative.

Abstract: A bandwidth management system manages a plurality of virtual data connections within a communications network. The system includes an input for receiving data cells, wherein each cell is associated with a particular one of the virtual connections. The system also includes a cell pool, coupled to the input for storing the cells, first and second queues for ordering the virtual connections, and an output for transmitting cells from the cell pool. The relative position of a virtual connection in the first queue is determined by an eligibility variable that varies according to an anticipated data rate associated with the particular virtual connection and according to an amount of time that the particular virtual connection has been in the first queue. The relative position of a virtual connection in the second queue varies according to a predetermined quality of service that is assigned to each of the virtual connections.

Abstract: A camera arrangement (100) comprises first and second sets of one or more cameras (102, 104, 202, 204, 204') and a half-silvered mirror (130). The one or more cameras of the first set look through the half-silvered mirror--i.e., receive light that passes through the half-silvered mirror. The one or more cameras of the second set look off the half-silvered mirror (130)--i.e., receive light reflected off the half-silvered mirror. The cameras of the first and second sets are positioned so that individual fields of view (103, 105, 203, 205, 205') of the cameras of the first and second sets alternate to form a wide angle aggregate field of view (110, 210). The field of view of each individual camera merges contiguously along a boundary with the field of view of a camera from the other set.

Abstract: A broadcast database system module (300) is disclosed having a processor (310) and a memory subsystem (320). The processor (310) and memory subsystem (320) of the broadcast database system module (300) can cooperate to provide all functions of a broadcast database system (200, 400) such as the pump function, data filter function, database mirror function, snapshot function, etc. The memory subsystem (320) can transfer attribute information of broadcasted tuples to the processor (310) and the processor (310) can execute queries against the attribute information of tuples. Alternatively or additionally, the memory subsystem (320) stores all or part of a database and broadcasts all or part of this database information stored therein. Likewise, the processor (310) can maintain a database stored in the memory subsystem (320) according to instructions to add information to, delete information from, or modify information in, the database.

Abstract: A new class of error detection codes has powerful error detection properties, as well as significant implementation advantages. The inventive error detection codes are used in communication protocols to protect transmitted data from corruption.

Abstract: A method and apparatus for detecting a dual tone alerting signal in the presence of speech for the purpose of initiating transfer of special service information on a telephone line is described. The apparatus includes two channels for separately detecting each tone. Each channel includes means for comparing the signaling energy around one of the tones with the energy in a selected weighted guard band portion of the voiceband. Based on this comparison, a determination is made whether a tone is or is not present. A pulse signal formed from the coincidences of tone detection in each channel is used by timing circuitry to determine whether the dual tone alerting signal is actually present or whether speech energy caused both tones to be erroneously detected (talkoff). Characteristics of this pulse signal are analyzed to determine whether an alerting signal is present.

Abstract: In a quaded cable, coupling between circuits (side circuit 1, side circuit 2, and phantom circuit) is compensated for at the receiving end of a transmission system. By transmitting known signals from the transmission end separately on each circuit, coupling between circuits is initially estimated by measuring the signals received at the opposite end on each of the circuits. Following startup, during data transmission the received data signals are modified in accordance with this initially determined coupling between circuits to produce estimated transmitted data signals. During data transmission the coupling between circuits is reestimated by storing (303) N data signals received on each circuit and the corresponding N estimated transmitted data signals on each circuit. The coupling between circuits is determined as a function of the covariance of these N received signals on each circuit and the covariance of these N estimated transmitted data signals on each circuit.

Abstract: A unique electronic cash system protects the privacy of users in legitimate transactions while at the same time enabling the detection of a double spender of the same electronic coin. The electronic cash system takes advantage of a unique property of El Gamal signatures to achieve these results.

Abstract: A channel equalizer is formed using a self-learning neural network. During a training period, the neural network is taught the channel response function. The network is then used to equalize distortions introduced into signals by the channel. The neural network may be a Boltzmann Machine type of neural network comprising neurons arranged in an input layer, a hidden layer, and an output layer. The neurons are interconnected by bidirectional symmetric weighted synapses. Each neuron is preferably implemented by an analog integrated circuit. Direct communication between the input and output layers helps in faster channel acquisition. The scheme can very easily be extended to multilevel and multisymbol modulation schemes such as QAM and PSK.

Abstract: Communication among entities such as customer premises equipment (20, 22, 28) in a telecommunications network (10) is set up through the use of agents representing each entity (20, 22, 28). Agents representing corresponding entities in the telecommunications network (10) negotiate over the type of communication sessions in which the corresponding entities want to be involved. The negotiation process involves the exchange of proposals by agents. A proposal comprises one or more planned actions which can be taken in the network (10). One agent generates a proposal acceptable to it and transmits the proposal to another agent. The receiving agent determines if the received proposal is acceptable to it and if not generates a counterproposal. The process continues until a proposal acceptable to both agents is found or it is determined that there is no proposal for realizing the particular type of communication session which is acceptable to both agents.

Abstract: An asymmetric Fabry-Perot modulator (AFPM) is disclosed having an operating wavelength in the 1.5 .mu.m region used for long-haul optical transmission. The AFPM includes electro-absorption material consisting of an Al.sub.x In.sub.y Ga.sub.1-x-y As multiple quantum well structure. An amplitude modulated optical signal is produced by modulating the bias voltage across the electro-absorption material between zero bias and the matching voltage that gives zero reflectivity from the cavity formed by the electro-absorption material and top and bottom reflectors. An amplitude modulated optical signal having a negative chirp parameter is produced by coating the top of the modulator with a high-reflectivity coating to reduce the voltage required to achieve the matching condition and then modulating the electro-absorption material between the matching voltage and a higher voltage.

Abstract: Method and system for locating nomadic users in a personal communication services (PCS) system by utilizing two strategies for locating such users and a per-user criterion for determining which, if any, of the two strategies should be used. The method and system augment basic two-level strategies for locating users specified in IS-41 and GSM standards of PCS systems. One strategy utilizes forwarding pointers and the other strategy utilizes per-user location caching. One per-user criterion is a call-to-mobility ratio (CMR) which is the ratio of the average rate at which a user receives calls to the average rate at which the user moves. A variation of this criterion is the local CMR (LCMR) which is the ratio of the average rate at which a user receives calls from a given registration area, to the average rate at which the user moves. The method and system reduce the average time and overhead required to locate and deliver information to such nomadic users.

Abstract: The error performance of an ATM signaling link operating under the service specific connection oriented protocol (SSCOP) is monitored by determining the maximum retransmission count (i.e., the number of times a message has to be retransmitted from a transmitting to a receiving end) amongst those messages retransmitted within a polling interval. A quality of service (QOS) factor is the average maximum retransmission count at the end of N consecutive polling intervals. If the QOS factor is greater than a predetermined threshold, then the link is taken out of service.

Abstract: A compensator for thermal or other uncontrollable effects in a liquid-crystal etalon filter. The narrow pass band of the filter is controlled by adjusting the amplitude of an AC drive signal applied to the electrodes on either side of the liquid crystal in the filter. An optical detector detects the intensity of light from a narrow-bandwidth input beam passed by the detector. Electrical circuitry determines the bipolar amplitude of the component of the light intensity that is at twice the frequency of the AC drive signal (the doubled-frequency amplitude) and adjusts the amplitude of the AC drive signal in response to the doubled-frequency amplitude so as to reduce the doubled-frequency amplitude toward zero.