Abstract: The present invention provides a QAM modulation scheme compatible with a single channel demodulator. The inphase (I) channel is provided with luminance information encoded on a series of sine wave symbols. The quadrature (Q) channel is used for color difference values with a sine or cosine symbol being used for each color difference value. Alternate ones of these color difference symbols are inverted so that, on the average, their effect on the I channel zero-crossings simply cancels out. Thus, when sent to a single channel demodulator which expects a black and white picture, the quadrature channel will be filtered out; leaving luminance information which will be decoded as a black and white picture. The color information does not disturb the zero crossings of the luminance signal on an averaged basis, allowing the carrier recovery phase lock loop to maintain synchronization for demodulation purposes.

Abstract: A method for making a dopant well in a semiconductor substrate, wherein a dopant is implanted directly into an exposed surface of a semiconductor substrate through an opening in a dopant-absorbing coating and the substrate is heated to drive the implanted dopant further into the substrate. The method requires fewer steps than the conventional method, and is particularly applicable in the fabrication of CMOS devices.

Abstract: An apparatus, for attachment to an equipment frame, organizes the cables associated with each interface circuit card of the equipment. The apparatus includes a sheet metal panel having an upper slotted flange and a lower cable channel each extending along its length, giving the panel a J-shaped cross-section, and a plurality of resilient wire cable retaining members. For each group of cables, a resilient wire member is provided having a U-shaped base, substantially parallel arms and an openable gap formed by fingers projecting from the arms. The U-shaped base of the wire member is inserted into the slot corresponding to the circuit card for which the cables are to be grouped. The wire member is retained in the slot by a plurality of resilient tabs fromed on the panel. The form of the fingers is selected to facilitate insertion and extraction of the cables between cable retaining arms and to ensure retention of the cables once inserted.

Abstract: The present invention provides a method of establishing Carrier Independent Network Services (CINS) wherein feature and voice information are decoupled such that feature information is transmitted on a signalling link established on private and/or public facilities, but voice information is transmitted over a public network when calls overflow, thereby permitting the terminating node to identify the incoming call and associate feature information provided by the originating node.

Abstract: Instructions in the processor idle loop are used to measure the percentage of time the processor is at idle. The processor idle loop instructions control the processor to alternate a processor data output between output states. The processor data output thus alternates between states whenever the processor is idle, and remains in the same state when the processor is performing useful tasks. A frequency counter or other indicating device responsive to the rate of processor data output state change directly indicates the amount of time the processor is idle relative to the total amount of processing time. Since the change of state, not the state itself, of the data output is detected, it does not matter what state the data output is left in when the processor is interrupted from performing the idle loop instructions.

Abstract: A telephone line interface circuit includes a transformer with tip and ring windings connected between tip and ring feed resistors and tip and ring leads of a telephone line for feeding energizing current from telephone facility to the telephone line. A secondary winding in combination with the tip and ring windings couples a.c. signals between the facility. A capacitance is connected in combination with the secondary winding to simulate a function of a capacitance as would normally be connected between the tip and ring windings in prior art circuits, but without the problem of feed resistor interference at lower voice band frequencies. Network and component values are inserted between the secondary winding and an electronic hybrid circuit whereby the line circuit is precisely tailored for anyone of several national telephone line standards.

Abstract: A telephone paystation theft inhibiting circuit for detecting the grounding of the handset circuit conductors. Protection is provided for the receiver circuit conductor by means of an isolation transformer and solid state switching devices are employed to disconnect the transmitter from its associated circuit conductors when the grounding condition occurs.

Abstract: The present invention provides a method and apparatus of making secure conference calls in which the bridging unit does not need to know any encryption keys and can function independently of the encryption process used by the communicating parties. This means that there is no security requirement for the conference unit, there are fewer restrictions on where it can be placed, and it does not introduce any additional weaknesses in the security system.

Abstract: The present invention assigns amplitudes of sine wave cycles in a data packet on I and Q channels of a QAM signal to color, gray or luminance values. Overlapping sine wave cycles on the I and Q channels in the data packet are assigned to the same or neighboring pixels. A synchronizing signal is sent at the beginning of each transmission of a packet. The synchronizing signal is a plurality of cycles at a maximum amplitude on the I and Q channels. The synchronizing signal serves two functions simultaneously. First, it is used to indicate the beginning of a new packet. Second, the phase of the synchronizing signal is used to initialize the demodulator phase detecting circuitry.

Abstract: A grating is positioned on a surface acoustic wave device on a first axis in-line with the delay line for substantially reducing the amount of energy reflected on that axis to the transmitter and receiver. The grating site on the first axis at a position between the delay line and one of the edges of the device. The grating is comprised of a parallel series of grating members each oriented so as to extend at a first angle relative to the first axis, the grating members being generally longitudinally bisected by that axis. An optimum value for the first angle is provided by a theoretical analysis, and experimental results are presented. On the experimental device, the grating is defined by a series of parallel grooves formed in the surface of the device; however, the grating may also be defined by a series of metallic strips mounted on the surface of the device.

Abstract: An improved electro-optic module able to sustain high voltage transients is disclosed. The module is able to eliminate unwanted signals by providing a discharge path for high voltage transients, away from the electronic and opto-devices. The module is comprised of an optical connector having a connecting end adapted to receive and secure an optical fiber cable, a circuit board attached to the optical connector and which is electrically isolated therefrom and means for isolating the circuit board from the connecting end of the optical connector.

Abstract: Optical communications fibers extend from a central office to subscribers' premises for carrying signals in both directions between optical transmitters and receivers. Each subscriber's optical receiver continuously reflects back to its fiber, and then to the central office, about 20 percent of the light which it receives. At the central office the reflected light is monitored in turn for each subscriber, and is correlated with the signal transmitted to that subscriber to provide a signal for optical time domain reflectometry of the respective subscriber's fiber connection.

Abstract: With the deployment of ISDN within a building, a resistor box is usually required, at each distribution frame, between the first and second set of cross-connect connectors in order to maintain a balanced loop. In the present invention, a quick connect terminating resistor for use with cross-connect type of connectors is disclosed. It is used for eliminating the use of the resistor box. The quick connect terminating resistor is comprised of a body having a connecting end, conductor portions on said body at said connecting end adapted to mate with a pair of terminals of said cross-connect type connector and resistor means connected to said conductor portions for providing a terminating resistance across said pair of terminals of said cross-connect type connector.

Abstract: Termination shelf for telecommunications cable with mounting positions for conductor connector devices. The mounting positions are accessible from one side of the shelf for insertion of the connector devices. Also a guide is provided to enable a flexible transmission element to be inserted into the tray from the same side as for shelf insertion, the guide being shaped to guide the transmission element towards a remote side of the frame and then to guide the tramsmission element in the opposite direction through the mounting position. Frontal loading of the connector devices and of incoming conductors is thereby a use feature with the termination shelf.