Abstract: A second set of telecommunication devices is arranged to substantially mirror a first set of telecommunication devices in order to provide redundancy. First and second computer modules are included, respectively, in the first and second sets of devices wherein each module is capable of providing operating system control of the system and both modules initially operating with the same operating system. Only one of the computer modules controls the system at a given time. One of the devices of each pair of devices in the first and second sets of devices is isolated from the corresponding other device. The isolated computer module is loaded with a new operating system and tested by allowing the new operating system to control the isolated devices. This permits testing of the new operating system while maintaining uninterrupted control which is provided by the other devices operating under the same operating system.

Abstract: A spread spectrum code pulse position modulated communication system is disclosed. The communication system includes a spread spectrum code pulse position modulated receiver that compensates for the delay spread of a transmission medium, such as a wireless radio channel of a local area network. Delay spread may cause signal components of one transmitted spread spectrum codeword to spill over into chip positions of adjacent symbols, causing intersymbol interference, or into chip positions on quadrature channels of a given symbol interval, such as in a QPSK implementation, causing interchip interference. The disclosed receiver decodes a transmitted spread spectrum code pulse position modulated signal in the presence of such delay spread, utilizing a tentative symbol estimator to sample the matched filter data.

Abstract: A user transparent telephone fraud detection and prevention system employs speech analysis techniques to determine whether at least one participant in a telephone conversation is an authorized user of the telephone line. A multi-party conversation on a phone line (e.g., a PBX line) is analyzed to separate speech information from noise and then the speech information is separated according to each participant in the conversation. Speech data for each participant is then compared to a library of speech data of authorized users of the system. If a match is found the system determines that the call is authorized. If no match is found the call is determined to be unauthorized and appropriate line control functions are carried out. Examples of the line control functions are: terminating the call; recording the call; disabling the line; intruding into the call and playing noise or a warning message; and intruding into the call to demand identification data from the call participants.

Abstract: An Operations Support System, comprised of a computer and workstation, stores digit analysis specifications for telecommunications call processing. A graphical user interface displays digit analysis specifications visually as subtrees made up of nodes representing the digits of the dialed number. Two subtrees can be displayed contemporaneously for evaluation and manipulation independently and from one to another. Operations performed on the nodes also operate on the embedded digit analysis specifications permitting manipulation of the specifications without the need to view or deal with the specifications themselves directly. Related information such as Routing Table Indexes and local exchange numbers called NXX numbers are displayed contemporaneous with display of a subtree of interest and are manipulated with regard to that subtree.

Abstract: The disclosed method of fusion splicing silica-based optical fiber comprises removing of the polymer coating from the end portions of the respective fibers by contacting the end portions with a chemical polymer remover (e.q., hot sulfuric acid with 5% nitric acid) such that a film of material that comprises the remover remains on the stripped fiber. Typically this is accomplished by refraining from the conventional rinsing of the stripped fiber portions. The film-covered stripped fibers are then fusion spliced in conventional fashion. Splices of strength close to the strength of as-drawn fiber were obtained by this method.

Abstract: Improved bit rate reduction techniques are disclosed. When incorporated into an existing video processing system having a DCT coefficients processor, the motion vector processor disclosed herein provides enhanced computational and memory storage efficiencies over prior art designs. The motion vector processor includes a microprocessor and associated motion vector memory. The motion vector memory is adapted to store a plurality of motion vectors corresponding to at least one image frame containing a plurality of macro blocks. Each motion vector is represented by an X value and a Y value, the X value and the Y value signifying image changes within a given macro block from a given frame to the immediately preceding frame.

Abstract: A mechanically stable self-aligned optical switch having a low insertion loss is achieved by employing two silica optical structures containing a plurality of waveguides. The waveguides within each structure are arranged in a common plane. It is possible to achieve such silica optical structures by cleaving a monolithic silica optical structure. In one embodiment, the structures are disposed on respective flat surfaces of moveable and fixed bases that are aligned in a common plane. The structures are further positioned with their cleaved edges adjacent to and facing one another. In this manner, the waveguides of the cleaved structures are effectively self aligned in the direction normal to the flat surface of the bases. In operation, the moveable base moves in the direction along the cleaved edges to selectively provide connections between the waveguides in each structure.

Abstract: A video system is disclosed in which a single generic MPEG standard encoder (107) is used to simultaneously code and compress plural different resolution video signals from a single input video signal; and in which a single generic MPEG standard decoder (402) is used to simultaneously decode plural coded and compressed video signals of different resolutions and form a single composite video signal. The coder converts each frame of pixel data of the input video signal into plural frames having different resolutions, which are then combined into a common frame (106) for input to the generic MPEG encoder. The MPEG encoder produces a single coded and compressed output bitstream in slices of microblocks of pixel data, which output bitstream is demultiplexed (108) into separate resolution bitstreams using Slice Start Code identifiers associated with each slice and Macroblock Address Increments associated with the first macroblock in each slice, to properly route each slice to the appropriate output.

Abstract: Techniques are disclosed for optimizing the prediction of RF propagation. A three-dimensional environment, such as a building, is modeled as a plurality of two-dimensional cross-sectional areas including a plurality of surfaces. Each surface is associated with a reflection coefficient and a transmission coefficient. A reference transmitter location and a plurality of reference receiver locations are selected. For each reference receiver location, RF propagation paths are determined with respect to the reference transmitter location. The reference transmitter location and the reference receiver locations represent propagation path endpoints. A plurality of parallel planes are used to partition the three-dimensional environment into a plurality of intervals. The RF reflective surfaces and propagation paths within each interval are projected into a cross-sectional area. A plurality of line segments are positioned in the cross-sectional area to form a plurality of triangular areas.

Abstract: A technique is provided for setting an error status bit in a first-in, first-out memory having data words with associated error bits. When a word having an associated error bit that is set to indicate an error is written into the FIFO, the write pointer is captured, and a flag is set, indicating that the FIFO has a word with an error. If a second word is written which has an error, that pointer value is captured, overwriting the current value. As the FIFO is read, the read pointers are compared with the captured write pointer. When the values are equal, and the FIFO is read, the flag is cleared, indicating that there are no more errors in the FIFO. In an exemplary case, each word in the FIFO has 8 data bits and 3 error bits. A FIFO used in implementing a UART in a modem typically includes 16 or 32 words.

Abstract: An optical switch provides improved high speed digital optical switching with a compact and fabrication tolerant configuration, and includes a first waveguide portion, a plurality of intermediate waveguide portions connected to the first portion, with each intermediate portion associated with a first angle .theta..sub.1 where the first angle .theta..sub.1 is less than about 2.0.degree.; and a plurality of branch waveguide portions, with each branch waveguide portion connected to a respective intermediate waveguide portion and associated with a second angle .theta..sub.2 where the second angle .theta..sub.2 is less than .theta..sub.1 and is less than about 0.3.degree..

Abstract: Initially storing multimedia messages from an originating communication terminal to a destination communication terminal on the destination communication terminal. If the destination communication terminal cannot store messages, then the message is stored on the originating communication terminal. The destination communication terminal may not be able to store messages because it no longer has present message storage facilities on an internal storage unit or it does not have any internal storage capability for messages. Similarly, the originating communication terminal also may have exceeded its capacity to store messages or may not have any internal storage devoted to the storing of messages. The destination communication terminal maintains a list of messages that are stored on other communication terminals. In addition, if the originating communication terminal cannot store messages, a message is stored on a third terminal which has the capacity to store messages.

Abstract: A unity gain or buffer amplifier having a low offset voltage. The amplifier uses two emitter followers of different conductivity types (PNP and NPN) in an up-down emitter or voltage follower configuration to provide high input impedance and low output impedance. By using both PNP and NPN transistors in a current mirror, the base-emitter voltages of the input and output transistors are forced to be substantially the same, reducing the offset voltage. N- and P-channel MOSFETs can be substituted for the NPN and PNP transistors. Single ended and push-pull arrangements are shown.

Abstract: A computer is provided with the facility to display in map form spatially-time-varying data associated with respective nodes. Specifically, responsive to a user inputting a specific command, the computer displays a plurality of symbols representing respective ones of the nodes in which the symbols share a common characteristic, the size of which is varied commensurate with changes in the data associated with their respective nodes. In addition, the user is provided with a tool so that he/she may either manually or automatically play through the data. The user is also provided with a number of other tools to control the display of the symbols and/or data, such as, for example, a tool which changes the size of the symbols so that smaller symbols are not obscured by larger symbols.

Abstract: An insulation displacement connecting (IDC) terminal that accepts two insulated wires in a single slot for the making of an electrical connection. The IDC portion of the terminal, which cuts into the insulation of the wire to establish contact, is designed with large flat spring contacts about a centrally located slot, wherein the contacts displace torsionally when normal forces placed on the terminals exceed a fixed load. The torsional displacement is enabled by the inclusion of a widened slot proximate a base portion of the terminal. The widened slot in combination with an angular orientation of the terminal contained within an insulated connector module housing enables the contacts to twist to away from one another. This displacement effect allows for larger gauge and more than one conductor to be inserted into the terminal without permanently yielding the beam contacts of the terminal.

Abstract: A power system plant includes a backplane arrangement including a primary and secondary bus to which intermediate power processing modules are selectively connected to the input and output power control and monitors of the plant. The backplane connections are controlled by the plug-in power processing modules. the resulting connections are unique to the type of plug-in module placeed on an input shelf (i.e. rectifier or converter plug-in module) and determine how the plant is to operated. The connections of these plug-in modules to the backplane connector are such that the plug-in module is designed to have its connectors connect to either primary or secondary referenced control signals. The connectors of the backplane accept both type of plug-in modules so that any plug-in module inserted is automatically connected to respond to the appropriate primary or secondary referenced control signals.

Abstract: A combined wavelength router and switch apparatus for use in an optical communication system is disclosed. The apparatus includes arrays of optical signal demultiplexers, wavelength division switches, space division switches and multiplexers, arranged in a manner that can increase the connectivity of an optical system using wavelength division multiplexed (WDM) signals. In several embodiments, time-multiplexed wavelength division switches and time-multiplexed space division switches may be used to increase further the degree of connectivity of the system or to reduce the number of wavelength division switches and space division switches required. Additional arrays of wavelength division switches or time-multiplexed wavelength division switches may be included to allow carrier frequencies to be shifted to meet the channel ordering requirements of the optical system.

Abstract: A field programmable gate array includes programmable function units (PFUs) that may function as either a logic block or a random access memory (RAM). Each PFU has a write-port enable input when the PFUs are being used as user RAM units. In addition, each PFU includes a write-strobe input. The write operation is accomplished when both the write-port enable input and the write-strobe input are active. This technique allows a reduction of logic gates and control signal conductors. In many cases, these advantages allow for higher system operating frequencies and more gate capacity at a lower cost.

Abstract: 1.times.2 and more complex switching operations use routing corresponding with guides produced by heating with a laterally-homogeneous layer. Strip heaters, in contact with a silica-based sandwich structure, thermally increase refractive index to define laterally-constrained cores within the center layer.

Abstract: Thermal expansion mismatch between solder and substrate can result in substrate cracking, especially in the case of brittle substrates, e.g., Si or glass. This problem can be substantially eliminated through use of a novel bonding pad structure that comprises a sacrificial layer and a confinement layer disposed on the former, with a window through the latter. The confinement layer (e.g., Ti or Cr) is selected to be substantially inert with respect to the solder (e.g, AuSn) at the soldering temperature, and the sacrificial layer (e.g., Au) is selected to interact with the solder at that temperature, such that the molten solder consumes at least some of the sacrificial material, with the interface between the molten material moving laterally underneath the confinement layer. After re-solidification of the molten material the structure effectively has a distributed interface between the resolidified material and the substrate, with attendant decrease of stress in the substrate.