Abstract: A simplex optical fiber cable of this invention includes an optical fiber, a buffer preferably of nylon, surrounding and in contact with the optical fiber, a yarn layer with strength fibers, preferably aramid fibers, disposed about the buffer and a sheath preferably formed of polyvinyl chloride (PVC) surrounding and in contact with the yarn layer. In cross-section, the simplex optical fiber cable has a diameter less than 2.0 millimeters (mm), and thus is much smaller in diameter than optical fiber cables presently available. Preferably, if the buffer is relatively tin providing limited protection to the optical fiber, a slick substance such as talc is applied to an outer surface of the buffer before the yam layer is disposed thereon. The slick substance allows the buffer of the optical fiber to slide to a degree in contact with the yarn layer and thus reduces fatigue caused by axial movement of a ferrule of the connector terminating the optical fiber cable.

Abstract: A Code-Division Multiple Access (CDMA) receiver removes the pilot signal from the received signal. The pilot signal is defined by its multipath parameters (amplitudes, phase shift and delays) and its signature sequence. Since this information is known at the user's receiver terminal (i.e., handset), the pilot signals of the interfering multipath components of the baseband received signal are detected and removed prior to demodulation of the desired multipath component. The pilot signal may be cancelled prior to or following the data accumulation stage. The pilot signal cancellation can be switched on and off depending on the detected path signal level.

Abstract: A router uses the destination address of its incoming packets to decide the proper outgoing interfaces by searching among all of the stored prefixes for the prefix which has the longest match when compared to the destination address in the packet. Prefix trees are employed to represent the set of prefixes to be searched and high-speed, longest prefix matches are performed. An efficient data structure compresses any prefix tree structure so that the number of memory accesses needed to find the longest prefix for any address depends only on the length of the prefix rather than on the number of stored prefixes. Illustratively, only four, 64-bit memory accesses are required to find the longest prefix match for each IPv4 address in the worst case, while only 3 Mbytes are required to store a 128K-entry routing table.

Abstract: A current driver circuit for a vertical cavity surface emitting laser (VCSEL), flip-chip bonded to a CMOS device. In a preferred embodiment, the circuit includes only two transistors. Specifically, a P-channel metal-oxide semiconductor (PMOS) source supplies a current under the control of a tuning voltage (Vtune) while an N-channel metal-oxide semiconductor (NMOS) transistor acts as a high-speed current shunt that modulates the current flowing through the VCSEL, and hence its emitted power.

Abstract: An optical assembly for detecting an optical signal from a signal source in systems where the intensity of the optical signal may surpass the operational range of the optical detector being used. The optical assembly includes an optical detector for converting the optical input signal into a corresponding electrical output signal. The optical detector has a set operational range of input signal intensities. An attenuator is disposed between the optical detector and the signal source. The attenuator is capable of reducing the signal intensity of the optical signal if required so that the optical signal falls within the operational range of the optical detector. A controller is electronically coupled to both the optical detector and the attenuator. The controller controls the attenuator as a function of the output signal of the optical detector, wherein the attenuator attenuates the optical signal to fall within the operational range of the optical detector.

Abstract: A resource port that provides a host processor the facility to request, share and access the resources of data communication equipment (DCE), including the memory and I/O registers of the DCE controller. In one embodiment the resource port has a controller request line to provide the host with a facility to request access to the controller resources, and an interface circuit to provide the facility to index all the resources of the DCE. The interface circuit compensates for any disparity between the widths of the controller address bus and the host processor address bus, and between the widths of the host processor data bus and the controller data bus.

Abstract: Apparatus for measuring the dispersion and dispersion parameter of an optical fiber as a function of distance (the dispersion map) by the optical-time-domain reflection technique uses a multi-frequency laser with an extra cavity semiconductor optical amplifier switch to generate the short pulses of two wavelengths to displace the four-wave mixing oscillations away from the origin of the complex plane. Additionally laser power is supplied at both ends of the fiber under test to provide pump power to Raman amplify the backscattered signal being measured. Finally a novel Fast Fourier Transform based algorithm is used to calculate the dispersion map fast and accurately.

Abstract: A method and system of operating a wireless local area network station adapted to transmit and receive a signal within a communication cell. The method includes the steps of establishing a carrier detect threshold level, establishing a defer threshold level, and transmitting a signal when the signal level detected by the network station is above the defer threshold level. Additionally, the method further includes the step of receiving a signal transmission intended for the network station when the power of the received signal transmission is above the carrier detect threshold level.

Abstract: A display rerouting apparatus reroutes a displayed image from an image source in a display module for providing a redirected angular visibility for the displayed image. In an illustrative embodiment, the display rerouting apparatus includes a base panel having a rectangular opening or widow for positioning atop of a display module in communication equipment, a rear panel having a one-way reflective mirror positioned in a rectangular opening in this rear panel, and a front panel having a two-way reflective mirror positioned in a rectangular opening in this front panel. Both the rear and front panels are respectively hingeably attached at their lower edges to the rear and front edges of the base panel for facilitating the use of the rerouting apparatus on different types of communication. In operation, the image from the display module is projected through the base of the apparatus onto the two-way reflective mirror.

Abstract: An electrical connector (e.g., a plug or receptacle for a plug) has multiple conductors that carry two or more transmission paths, where each transmission path uses (at least) two conductors to carry a balanced signal. A portion of the like conductors of one type are grouped together and separated from a portion of like conductors of another type. For example, in one embodiment, the electrical connector is a plug having contacts used to terminate a multi-wire cable carrying up to four voice or data signal transmission paths and having four pairs of TIP-RING contacts, where a portion of the four TIP contacts are grouped together and a portion of the four RING contacts are grouped together and separated from the group of TIP contacts. In this way, electromagnetic (e.g., capacitive and/or inductive) coupling between like conductors (e.g., from TIP contact to TIP contact) will be generated that opposes electromagnetic coupling between unlike conductors (e.g.

Abstract: An optical switch includes an optical router portion for distributing multi-wavelength optical signals received at input ports of the switch, an optical combiner portion for supplying multi-wavelength signals at the output ports of the switch, and optical fibers for interconnecting the optical router portion and optical combiner portion. Selected ones of the interconnecting optical fibers include wavelength-selective elements, such as fiber gratings, which are capable of transmitting or reflecting individual channels within the multi-wavelength optical signal so that a selected channel of a particular wavelength can be routed from any of the input ports to any of the output ports of the switch. In one exemplary embodiment, the optical router portion includes a plurality of input optical couplers, wherein each input optical coupler is associated with a corresponding input port of the optical switch.

Abstract: A loop antenna includes a dielectric substrate, and an antenna conductor forming a loop that extends over a surface of the substrate. A matching circuit near the conductor is dimensioned and arranged for electromagnetically coupling a radio frequency circuit with the antenna conductor. In one embodiment, the antenna conductor forms a closed loop on a surface of a first substrate layer, and the matching network includes a strip transmission line on a surface of a second substrate layer overlying the antenna conductor on the first substrate layer. The substrate layers form part of an interface unit that provides a wireless data link with a residential electric utility meter.

Abstract: The specification describes Schottky barrier devices with distributed guard rings. In one embodiment the guard ring only partially overlaps the barrier. In another embodiment the guard ring is spaced from the barrier throughout, but separated by an MOS gate so that the guard ring and barrier are connected at low bias by an inversion layer.

Abstract: An efficient method and apparatus for reducing the effect of ghost signals during the recovery of information bits in wireless systems. The delay spread between each burst and its ghost are estimated so that an equalizer is only engaged to eliminate the effects of the ghost on data recovery when the delay spread increases beyond a given threshold. The estimation of the nonstationary delay spread is based on the estimation of the impulse response of the wireless channel. That is, the response of how the burst and its ghost will be reflected in the wireless channel. Since, the burst and its ghost arrive at the receiver .tau. symbol times apart and have different and random power with respect to each other, once the channel impulse is accurately estimated, the value of .tau. can be used to determine whether to engage or disengage an equalizer. That is, the equalizer is only turned on if .tau.

Abstract: A method and system for providing redundancy for security systems served by the public switched telephone network (PSTN) includes a cable modem interconnected to a security system controller. Upon detection of inoperability of a telecommunications line serving the system via the PSTN, the cable modem extends an alert message to a security monitoring service via a packet data network. Advantageously, the cable modem can also send video images and audio from the secured premises to the security monitoring system due to the bandwidth capabilities of the packet data network.

Abstract: A device for housing electronic components that produce heat and must be cooled. The device includes a housing having at least one vertical wall that has an interior surface and a corresponding exterior surface. Rows of vains are disposed on the interior surface of the wall. Each row of vains contains a plurality of parallel vains having the same general dimensions. Adjacent rows of vains are not aligned. As a result, the vains on one internal row do not lay in the same line as vains from adjacent internal rows. External vains are disposed on the exterior surface of the wall, opposite the internal vains. The external vains correspond in position and number with the internal vains. Heat absorbed by the internal vains is transferred to the external vains by conduction, wherein the external vains dissipate the absorbed heat to the surrounding environment with an efficiency that is made possible by the configuration of the vains.

Abstract: Various modem designs are described, along with systems that use the modem designs for communicating data between a large number of remote locations and one or more central locations preferably over CATV. One aspect features a modem having a transmitter which uses a state machine and digital waveform signals stored in a memory to create a modulated signal. Another aspect features a modem having a receiver which uses a digital correlator including an SRAM for detecting a bipolar phase shift keyed signal. Still another aspect features a modem comprising an oscillator circuit having a feedback loop, wherein the feedback loop utilizes a downlink signal, and a protection circuit which prevents a malfunction in the modem from causing system-wide shutdown.

Abstract: A telecommunications protection unit includes a voltage unit having an electrically insulating base configured to house a diode module assembly and a voltage limiting cell therein. The voltage limiting cell and diode module assembly are retained within the housing by a bus clip. The housing includes structure for preventing damage to the voltage limiting cell and diode module assembly during placement of the bus clip thereon. The diode module assembly is a one-piece article including a bus bar and several diodes and terminals which can be used by itself or in a voltage unit to provide desired electrical effects and facilitate assembly of an electrical system such as a telecommunications protection unit.

Abstract: A connector block 6 for selectively routing wiring connections contains a first terminal strip 12, a second terminal strip 14, and a third terminal strip 16, which are disposed on the connector block 6. The first terminal strip 12 has a first wire receiving terminal 42 which is electrically connected to a first output connector 52. The second terminal strip 14 has a second wire receiving terminal 44 which is electrically connected to a second output connector 54. Similarly, the third terminal strip 16 has a third wire receiving terminal 46 which is electrically connected to a third output connector 56. The connector block 6 also contains a bridging device 22 which can be used for selectively connecting either the first output connector 52 or the third output connector 56 to the second output connector 54 thereby establishing an electrical connection between the second wire receiving terminal 44 and the selected output connector.

Abstract: A method is disclosed for determining estimates of the perceived noise masking level of audio signals as a function of frequency. By developing a randomness metric related to the euclidian distance between (i) actual frequency components amplitude and phase for each block of sampled values of the signal and (ii) predicted values for these components based on values in prior blocks, it is possible to form a tonality index which provides more detailed information useful in forming the noise masking function. Application of these techniques is illustrated in a coding and decoding context for audio recording or transmission. The noise spectrum is shaped based on a noise threshold and a tonality measure for each critical frequency-band (bark).