Abstract: A telephone link comprises two network terminals to which two subscriber sets are respectively connected, two subscriber lines respectively linking the two network terminals to two line terminals respectively located at two local switching centers mutually linked by a switched telephone network, the network terminal and the line terminal of at least one of the subscriber lines being respectively equipped with one network encryption/decryption means and with one line encryption/decryption means wherein information exchanged between the two subscriber sets is encrypted, at least on one of the two subscriber lines which is connected to the respective network and line encryption/decryption means, on the basis of at least one encryption key generated by the network encryption/decryption means or by the line encryption/decryption means, and varying temporally in pseudo-random fashion by the network encryption/decryption means or by the line encryption/decryption means, the information exchanged between the two subs

Abstract: A system for locating sources of degradation of an optical path of an optical transmission system comprises means for transmitting (1) along the path a test pattern signal having a frequency spectrum predominately in a band below a data traffic rate means (4) for recovering the test pattern at a plurality of separate points in the path means (4) for determining an amount of pattern degradation from the shape of the recovered pattern, and means (5) for comparing the amounts of pattern degradation at the separate points to locate the source. A broad range of types of degradation can be detected efficiently, and the results used to take corrective action.

Abstract: A system and method for evaluating an inventory management strategy combines multiple management strategies in a single inventory management system. The system analyzes the inventory portfolio on an item-by-item basis to assign the most suitable management strategy for that item. The inventory management system provides a high level of flexibility for the users to define input parameters to ensure a desired level of customer satisfaction. Additionally, it determines whether the inventory items are forecastable before predicting future demands.

Abstract: A bracket assembly for fixedly mounting an RF antenna to a support structure while permitting azimuth adjustment comprising a first bracket member adapted for fixed securance to the support structure and having a forwardly extending plate defining a first bolt hole and a spaced away arcuate slot defined by a radius of curvature about the center of the first bolt hole. A second bracket member mounted to the first bracket member and adapted for mounting an antenna, the second bracket member providing second and third bolt holes; whereby when the first and second fasteners are loose, the second bolt may move along the length of the arcuate slot to adjust the angular relationship of the bracket members and when the fasteners are tightened, the angular relationship of the bracket members is fixed.

Abstract: During a telephone call to a call center, in a first portion of the call is placed in a call queue, and the call center apparatus generates a pre-answer signal which is interpreted by a central office apparatus to meter and bill a cost of the call to a receiving party operating the call center. When the call is connected to an interactive device, e.g. a call center agent's telephone handset, the call center generates a call answer signal which is transmitted to the central office apparatus, and interpreted as a signal to meter and bill a second portion of the call, containing interactive communication to a caller.

Abstract: A method of digital differential demodulation if which the signal to be demodulated is over sampled at a rate double the rate of the elements of the spread sequence, the products of a current sample and the preceding conjugated sample are calculated and these products are summed, possibly weighting them, in a window covering at least a part of the period of the information symbols, the real part of this sum is taken in order to obtain a decision sample used to reconstruct the information. The method is applicable to multiple access type transmissions with code division.

Abstract: An orthogonal frequency division multiplex (OFDM) transmission system, e.g. for tranmitting data traffic over a telephone subscriber twisted pair loop, includes a transmitter for generating sets of time division samples in respective channels corresponding to an input data sequence comprising a series of bits, and a receiver coupled to the transmitter via the transmission path. The receiver incorporates a time variant digital filter having a plurality of elements one for each said channel, and Fourier transform means for recovering the data stream from the outputs of said filter elements. The time variant digital filter comprises a set of wavelet filters one for each transmission channel and whose tap weights are determined so as to provide specific interference rejection.

Abstract: A system and method for displaying text and graphics is provided. A subset of character codes from a character set are reserved to be associated with remotely redefinable pixel matrix definitions. After a connection to a remote server is made, pixel definitions are downloaded either interactively or in a script. Several of the pixel matrix definitions may be combined so as to display a graphic image.

Abstract: A power converter forming part of a telephone subscriber line interface circuit selectively generates a ringing signal waveform, for supply to the line, or a supply voltage for a driver circuit for providing loop current on the line. First and second fixed frequency PWM signals are used to control the power converter, and hence the voltage which it generates, for the ringing signal waveform and the supply voltage respectively. The first PWM signal enables the power converter to provide a high power level needed for ringing signals. The second PWM signal has a lower frequency, and hence results in lower switching losses and power dissipation, and a lower duty cycle, suitable for the lower power level needed for the supply voltage, and is conveniently produced by masking pulses of the first PWM signal. The frequency of the second PWM signal is greater than 270 kHz, to avoid transmitting spectral energy to the line below this frequency.

Abstract: An enhanced cellular layout for cellular networks having six-sectored cells is disclosed. In one embodiment, the cellular layout is implemented by rotating directional antennas located at each cell site of a triangular cellular layout of a six-sectored CDMA network clockwise or counterclockwise by approximately 10.893.degree. or rotating directional antennas located at each cell site of a parallelogram cellular layout of a six-sectored CDMA network clockwise or counterclockwise by approximately 19.107.degree..

Abstract: A thin film resistor for optoelectronic integrated circuits is described. A stable low resistance, thin film resistor comprising a bilayer of platinum on titanium is provided. Advantageously, the resistive layer is protected by a layer of dielectric, e.g. silicon dioxide or silicon nitride to reduce degradation from humidity an under high temperature operation at 300.degree. C. or more. The resistor may be formed on various substrates, including silicon dioxide, silicon nitride and semiconductor substrates. Applications for optoelectronic integrated circuits include integrated resistive heaters for wavelength fine tuning of a semiconductor laser array.

Abstract: A coaxial connector arrangement for transferring high frequency microwave signals between a coaxial cable and a further device is disclosed. In many present systems, the connector arrangement whereby microwave signals are passed from a coaxial cable to a device or the like at high frequencies has a tendency of radiating. Not only do the radiative emissions lose power, but this radiation can combine with the desired signals to form intermodulation products which further lose signal power and also distort the signal. The mating faces of the connector provide a malleable raised line portion which is disposed about the central conductor whereby a continuous line contact is defined on the mating components about the inner conductor, thereby preventing emission of high frequency signals which may interact with the intended signals.

Abstract: A selection diversity system and method for use in a TDMA (time division multiple access) radio system, particularly suited for DECT (Digital Enhanced Cordless Telephone) applications, in which a single receiver makes a performance measurement on each of two antennas in sequence during the beginning of a received data burst, the beginning of the burst being determined by a timing signal fed back from a previous burst. A slicing level used in the receiver to perform threshold detection is continuously improved during the measurements of the two antennas, but held while switching between the antennas. The previously unused antenna is measured first to minimize the likelihood of having to perform two antenna switches.

Abstract: An apparatus for interfacing a data processing system with a plurality of data communications networks comprises: M number of interfacing units, each for coordinating data exchange between the data processing system and the plurality of data communications networks, wherein each of the M number of interfacing units are identical to each other and operate alternately in an active and a stand-by modes so that one in the M number of interfacing units is in active mode while the others are in stand-by mode and M is a positive integer larger than one; and buses for exchanging data among the M number of interfacing units.

Abstract: An improved coin receiving mechanism having a foreign object release device. The invention includes first and second chute walls having spaced apart inner surfaces which are substantially parallel to each other when the mechanism is in an unactivated state. The inner surfaces define the walls of a coin chute path through which a coin travels. The first and second chute walls each further have an upper chute wall portion, disposed adjacent an entrance to the coin chute path, and a lower chute wall portion, disposed adjacent to and in communicating relationship with an exit of the coin chute path. The first and second coin chute walls are hingedly mounted to a frame. The invention also includes provisions for moving the coin chute walls from the unactivated state to an activated state wherein the coin chute walls are first pivoted together until the lower chute portions of each of the first and second chute walls are no longer disposed in communicating relationship with the exit of the coin chute path.

Abstract: A known form of electrically controlled optical attenuator is formed by a mach Zehnder waveguide configuration with a variable refractive index element in one arm to modify the undulatory spectral characteristic of the network to give a specific attenuation at a specific wavelength. The spectral characteristic of the network makes the attenuation that it provides wavelength dependent. An attenuator with a wavelength dependence of reduced magnitude is provided by the series combination of two Mach Zehnder networks, one having an electrically controllable optical path length adjuster in its longer interference arm, and the other with its adjuster in its shorter arm.

Abstract: A rake receiving apparatus used in communication systems using a DS/CDMA (direct sequence code division multiple access) system, wherein a single demodulating finger is used for a plurality of multipath signals, thereby being capable of not only greatly reducing the complexity of its demodulators, but also achieving an improvement in performance where a large number of multipaths are used.

Abstract: Exposure to UV light of a photosensitive optical fiber through a uniform pitch phase grating is employed to write a chirped Bragg reflection grating in that fiber by imparting tensile strain to the fiber while sections of the Bragg reflection grating are sequentially written, and by altering the magnitude of that strain during the writing process.

Abstract: In current voice telephony, CATV, and wireless networks, traffic is channelized for both access and transport, requiring a dedication of a fixed bandwidth end-to-end for the duration of a service connection. This channelization is wasteful of resources where multiple services have varying demands for bandwidth and holding times, or a service generates traffic that is bursty in nature. The invention addresses these problems by providing flexible and adaptable multiservice access to the networks. Customer requirements are checked by monitoring traffic on a local access at a connection request and/or during the established connection, and local access is configured according to transmission requirements. Customer traffic is segregated and routed to the appropriate network. One of the embodiments uses 2B1Q line coding and implements a novel protocol to perform the functions of the invention.

Abstract: A multiplex communication equipment which can switch circuits and which enables cost saving in circuit usage of a public network when the circuit is switched. Multiplex communication equipment 1 with circuit switching control, which is selectively connected to either an active circuit 5, having a large transmission line, or a spare circuit 6, having limited transmission line. A data terminal interface (I/F) 18 is connected to data terminal equipment 2, and a voice terminal I/F 17 is connected to voice terminal equipment 3. An active circuit I/F 13 is connected to circuit 5, and a spare circuit I/F 14 is connected to circuit 6. A multiplexing control section 16 multiplexes data and voice information, and a circuit switching section 15 switches circuits.