Abstract: A method of making core holes in cast cladding glass for fabricating optical fiber preforms to make single and multimode optical fibers. Liquid cladding glass is pored into a casting mold having a metallic wire that is translated through the liquid glass as it cools so that the wire essentially carves out a smooth cylindrical core hole along the cylindrical axis of the cooled cladding glass. The method substantially reduces surface contamination at the interface of the core hole and the cladding glass because any liquid glass that comes in contacts with the metallic wire is removed during the process, leaving behind a pristine glass surface.

Abstract: In a telecommunication switching system having a plurality of switch nodes with each of the switch nodes responsive to a failure of a communication link within a group of communication links to establish a flexible rate interface (FRI) link upon there being no spare channels within the group of communication links and to switch active calls from the channels of the failed communication link to the channels of the newly established FRI link. Advantageously, the group of communication links can be a non-facility access service (NFAS) group. Advantageously, this allows for additional B channels to be added to the NFAS group even though there are no remaining physical communication links between the two switch nodes being interconnected by the NFAS group. The establishment of the FRI link allows for the addition of B channels to the NFAS group with these B channels being routed through other switch nodes of the communication switching system.

Abstract: In order to provide reliable backup memory for the operational memory (RAM) of a control unit, two segments of a memory with write protect facility are used. Only one of these segments contains the backup memory at any one time, but the other segment may be updated with a new release. Write protect is removed from one of these segments only when an update is taking place. The software for controlling initialization of the operational memory from the backup memory is stored in the backup memory. Extensive checks are performed before accepting an update of the backup memory or an initialization of the operational memory.

Abstract: A self-tuning optical waveguide filter for attenuating a lower power light signal at .lambda..sub.1 more than a higher power signal at .lambda..sub.2 comprises a length of single core waveguide and a light injector for applying .lambda..sub.1, .lambda..sub.2 into the waveguide in two propagating modes subject to mode beating. The mode beating produces high intensity regions of .lambda..sub.1 physically displaced from high intensity regions of .lambda..sub.2. A portion of the waveguide is doped with a saturable absorber for disproportionately attenuating wavelengths at lower power levels. Advantageously the waveguide is a single-core fiber having its central core doped with rare-earth saturable absorber. In a preferred embodiment, the fiber is dimensioned to propagate .lambda..sub.1, .lambda..sub.2 in the LP.sub.01 and LP.sub.02 modes, and the saturable absorber is Erbium.

Abstract: A method for reducing frequency-related power losses in a telecommunication line interface circuit comprises operating a switching converter circuit at an optimum frequency. Determination of the optimum frequency is based upon a subscriber loop length. Particularly, the subscriber loop voltage is detected at a battery feed circuit of the line interface circuit, and used to access an optimum frequency stored in an initialized database. The optimum frequency information is received in the switching converter circuit, and determines its operating frequency.

Abstract: Radio frequency (RF) mobile telephone communications signals are converted to cable television (CATV) frequencies for transmission over existing CATV infrastructure. In the upstream path (i.e., from one or more mobile telephones to a base station), multiple receivers (called remote converters) receive and convert RF signals to cable signals. The cable signals from different receivers are combined by a remote cable node and transmitted over tie cable network to tie base station. In order to reduce noise in the combined cable signal, only those remote converters that receive RF signals of sufficient power level will contribute cable signals to the combined signal. This scheme enables the communications network to be configured with a greater number of relatively inexpensive, low-power remote converters for each remote cable node while still maintaining signal integrity.

Abstract: A method for re-configuring a pre-compiled discrete-event digital simulation program. The method comprises the steps of creating a template having a series of generic tasks and incorporating the template onto a computer to create a generic computer simulation. Next information associated with the steps of a process are input on the computer. The information includes the time duration of each step and the resources expended in accomplishing each step. Finally, the step information is applied to the generic computer simulation to create the discrete event simulation model of the process.

Abstract: A call-distribution function (150) of an ACD system (101) improves the equity of distribution of calls to agents (106-108) by basing the distribution on the agents' individual occupancies. Illustratively, determining an agent's occupancy involves either determining (304) how many calls the agent has handled within a predetermined time interval, or determining (305) how much time of a predetermined time interval the agent has spent on handling of calls. The occupancy is periodically re-determined, and a next call is allocated to the presently least-occupied one of agents who are available to take the call, or to an agent to whose occupancy the allocation will be most beneficial, such as an available agent to whom allocation of the call will maximize convergence of actual and target occupancies.

Abstract: A timing technique for a Quantization-Level-Sampling (QLS) modem puts timing information in a downstream pulsed signal transmitted from the public switched telephone network (PSTN) to the QLS modem. In response to this timing information, the QLS modem synchronizes to the network sampling clock in the PSTN. In particular, the pulsed signal includes data-bearing samples, which were provided by a far-end QLS modem, and at least one non-user-data-bearing (NUDB) sample in which the level of this NUDB sample periodically alternates. The QLS modem extracts timing information from this periodic alternating signal level to synchronize the QLS modem to the network sampling clock.

Abstract: A wide-band tuned photodiode input circuit comprising: a photodiode; an step up double tuned network having an input and an output. The double tuned network is responsive to the photodiode. The input is capacitively coupled to the photodiode.

Abstract: A digital audio broadcasting (DAB) system includes a radio-frequency (RF) transmitter and a corresponding RF receiver. The RF transmitter transmits an RF DAB signal that includes a pilot signal at 250 Khz. An RF section of the RF receiver includes a phase-lock-loop (PLL) to compensate for any carrier frequency differences in the received RF DAB signal. This PLL tracks the phase of the received RF DAB signal when an amplitude of a recovered IF signal is above a predetermined threshold and upon detection of the pilot signal.

Abstract: Test points (20, 24) placed at selected nodes (16) within a circuit (10) based on a cost function that accounts for (a) the global improvement in testability and (b) the penalty in circuit performance associated with propagation delays attributable to such test points. By accounting for both the global impact on testability and circuit performance degradation, the cost function maximizes fault coverage while achieving nearly minimal impairment of circuit performance.

Abstract: This invention relates to arrangements for interconnecting a plurality of stand-alone switches by data and communication channels (the latter typically used for communicating voice signals) in such a way as to make the plurality of switches act as if they were one switch. The invention further relates to arrangements for permitting groups of lines, the groups connected to different stand-alone switches, to be treated essentially as if they were connected to a single switch. Each switch of a symbiotic network (a group of stand-alone switches) or a virtual symbiotic network (the grouping of the groups of lines) accesses pertinent data in its own data base or the data base of one of the other switches of the symbiotic or virtual symbiotic network and treats the results of such data base accesses as if they were made internally in the switch.

Abstract: An integrated circuit includes a power-up detector circuit that includes a node that is held at a charged state by a capacitor during normal operation. The voltage on the node is sensed by a sensing circuit, typically an inverter that produces a power-up reset pulse when power is initially applied. However, the voltage on the node may not properly discharge in all cases during brief power interruptions. Therefore, to increase the reliability of the power-up detector, a discharge circuit is included to help ensure that the voltage sensed by the power supply voltage-sensing circuit is at the proper level when the power supply voltage drops below a given level. The discharge circuit comprises a first capacitor that turns on a node discharge transistor when the power supply voltage drops below the given level. To provide protection against false discharge, a second capacitor is optionally provided that prevents the discharge transistor from conducting during very brief power supply voltage interruptions.

Abstract: A method and apparatus for rendering statistical graphics which utilizes geometric constraints and bounding boxes to compute coordinate transformations at the time a graphical object is rendered. The invention transforms coordinates in an intrinsic coordinate system of a drawing element into coordinates in an absolute coordinate system of a computer display device. The geometric constraints tie the drawing elements together and define linear equality constraints between the initially unknown parameters while allowing computation of rotation and reflection parameters in advance and independently of the remaining initially unknown parameters. Rendering bounding boxes are used to define linear inequality constraints that require the rendering bounding boxes to be completely confined within a display bounding box of known size.

Abstract: A central strength member anchor for use, for example, in a splice closure, for anchoring the central strength member of a cable entrant into the closure has a planar member having at least one upstanding leg at one end thereof. The distal end of the leg has clamping a strength member receiving member having a bore into which the strength member is to be inserted. The receiving member has clamping arrangement, such as one or more set screws, for clamping the strength member in the bore. The height of the leg is such that the bore in the receiving member is substantially axially aligned with the cable strength member. The planar member has locating holes therein for locating the anchor in the closure, and side walls depending from the planar member have slots for mounting the anchor in the enclosure. The side walls also have at least one slit therein and the planar member is scored so that a portion of the anchor member may be broken off to shorten it.

Abstract: The test system of the invention uses suppressed ringing connections from a test unit to the customer premise equipment via the central office to establish connections for performing the loop-back test. The suppressed ringing connections are established over standard voice trunks between a switch in the central office and the test unit by a central office service unit (COSU) such that the number of lines that can be tested simultaneously is limited only by the number of trunks linking the COSU to a switch. Because these trunks are relatively inexpensive and simple to install and maintain, the test system of the invention can be readily installed and expanded in the existing network to provide virtually any level of monitoring capability.

Abstract: An SMA PC mount connector for attaching a test cable for test equipment to a printed circuit board. The connector includes a conductor element having a reduced diameter so as to substantially eliminate impedance discontinuity resulting from the contact between the conductor element and the ground planes of the board at the mounting junction between the connector and the board to enable a more accurate measurement of the impedance of the true impedance of the board.

Abstract: An apparatus for lifting, carrying, and positioning probemats or fixtures. The apparatus comprises movable opposing side arms having a mechanism for receipt of a fixture handle, as well as a stationary support member. An arrangement is provided to connect the side arms to the support member by the use of a first track positioned on the front of the support member and a second track positioned on the rear of the support member. First and second rollers for rolling engagement with the tracks are connected to each side arm to support the weight of the side arm and to permit each side arm to slidably move along the tracks. The fixture handler also includes jaws comprising a channel and stops at the ends of the channel to permit the handler to be used with a plurality of different fixtures handles. Finally, an insert is provided for use with the jaws to further enhance the ability of the fixture handler to support a myriad of fixture types.

Abstract: A method of determining Inter-Symbol Interference (ISI) in transmission systems first measures, for each of a plurality of received signal having different Signal-to-Noise (S/N) ratio, the minimum Bit-Error Rate (BER) as a function of the threshold level of a decision circuit at the system receiver. The measurements are then repeated on the system or on a simulated system where one or more segments of the transmission facility has been replaced with one or more non-ISI producing attenuators. The ISI levels for a given BER value is determined from the first and second sets of measurements. An alternate method measures minimum BER values of the system and the simulated system, as a function of the received signal power, for received signals having different S/N ratios. The ISI levels for a given BER value is then determined from these two sets of measurements.