Abstract: A multi-fiber optical delay line incorporates a plurality of optical fibers nestedly positioned and affixed to a planar substrate. The fibers include input portions that are linearly and proximately positioned on the substrate, and of equivalent length. The fibers also include output portions that are linearly and proximately positioned on the substrate, and of equivalent length. The input and output portions of each fiber are interconnected by a u-shaped connecting portion, and each connecting portion is positioned to have a unique and predetermined length. The predetermined lengths are selected such that differences in length between a shortest fiber and another fiber in the plurality of fibers are equivalent to a fiber length that would be traversed by the input signal during a time period required for the transmission of a predetermined number of bits in the digital signal.

Abstract: A circuit pack blank occupies an unequipped position in an electronic equipment shelf that is cooled by forced-air convection. The blank incorporates two diffuser blades that protrude into a cooling space in the shelf adjacent to the blank. When air is forced through the cooling space at a constant velocity, a backpressure is generated that is equivalent to backpressures generated at cooling spaces adjacent to equipped positions. In addition, the blank has a faceplate that incorporates one or more cable trays used to retain cables at the unequipped position for future use.

Abstract: A pack houses an electrical and/or electronic board. The pack includes positioning structures that support the board. At least one of the positioning structures provides an electrically conductive path to an element located on the board, and has elastic properties that assist the positioning structure to maintain mechanical and electrical contact with the element.

Abstract: A touch-tone receiver (TTR) simulator is disclosed to analyze DTMF signals and facilitate the investigation of call failure problems. The TTR simulator captures DTMF data received by a private branch exchange (PBX) switch and utilizes the instruction set of the TTR being simulated to process the received DTMF signals on the simulated TTR. Diagnostic tools allow step-by-step tracing and recording of the instructions performed by the simulator. The TTR simulator allows the underlying cause of a call failure problem due to DTMF signals to be identified. Results of digit interpretation can be compared to expected results.

Abstract: A coaxial cable [10, 50] includes an inner conductor [11] that is separated from an outer conductor [13] by a layer of insulating material [12]. The outer conductor includes a thin sheet of metallic foil that envelops the insulating material and has a seam [14] that extends in the longitudinal direction of the cable. In a first embodiment, the insulated conductor is axially rotated (twisted) with respect to its own longitudinal axis. In a second embodiment, the outer conductor is wrapped around the layer of insulating material. In both embodiments, there is relative rotation between the insulated conductor and the outer conductor. This practice is referred to as relative insulated conductor rotation, and it significantly improves the structural return loss characteristics of a coaxial cable when the outer conductor includes an asymmetry, such as a seam, that extends in the longitudinal direction of the cable.

Abstract: An unbundling demarcation device (UDD) is disclosed for disconnecting the equipment of a local exchange carrier (LEC) from a subscriber in order to permit a competing local exchange carrier (CLEC) to provide local service to the subscriber. The unbundling demarcation device (UDD) and related CLEC equipment may be positioned at any point in the subscriber loop, between the LEC switch and the subscriber equipment. The unbundling demarcation device (UDD) is an electro-mechanical or electro-optical coupling device, such as a sensitive relay, a latching relay, a switching mechanism or a solid state device that simulates a relay. The unbundling demarcation device (UDD) connects the LEC equipment to the CLEC equipment when a voltage or other trigger signal is applied to the subscriber loop by the LEC.

Abstract: A layer 3 forwarding method for layer 3 forwarding an individual packet from a station I to a station II wherein the packet's layer 2 destination includes a router within the network which is reachable from a network element A via which stations I and II are connected to the network, the router storing ARP information, the method including providing network element A with a capability to perform layer 3 forwarding of a packet from station I to station II, wherein the providing step includes learning, on the part of network element A, of forwarding information used by the router to forward packets from station I to station II, by reading the ARP information of the router and performing layer 3 forwarding on the individual packet, at network element A.

Abstract: Redundant alarm messages generated by a plurality of Network Elements (NEs) in a Synchronous Optical Network (SONET) or Synchronous Digital Hierarchy (SDH) subnetwork are suppressed by a filter incorporated within a Subnetwork Controller (SBNC). In an illustrative embodiment of the invention, the SBNC filter collects and logs all alarm messages reported by the subnetwork NEs during a correlation period. After the period is completed, the filter determines whether at least one alarm that was reported during the period directly indicates a failure within the subnetwork and, if so, suppresses all other alarms arriving during the period that indicate conditions symptomatic of this failure. The correlation period persists for no longer than a maximum specified time period, and only so long as alarm messages continue to be reported during the interval.

Abstract: A modular jack 200 includes a jack housing 220 with an opening 225 in its front end that is adapted to receive a modular plug 100. Within the opening there are a number of jack springs 215 for making electrical contact with metallic blades 120 that are installed in the plug. Variations in the actual position 211 where the plug blades make contact with the jack springs are reduced by the inclusion of a positioning member within the housing. This is extremely important in situations where the modular plug includes crosstalk compensation, since positional variations affect the amount of crosstalk compensation needed. In one embodiment, the positioning member comprises a cam 228 that engages a flexible latch 130 on the modular plug to create an axial force “F1” that pushes the plug toward a retaining surface 229 within the housing.

Abstract: A multi-wavelength optical cross-connect switch architecture incorporates a plurality of wavelength-selective optical cross-connect (WSXC) switch fabrics that receive multi-wavelength input signals distributed by one or more optical slicers and generate multi-wavelength output signals that are combined by a plurality of optical combiners. The WSXC fabrics employ fiber Bragg gratings (FBGs) as wavelength-selective elements. Using this architecture, the number of multi-wavelength channels carried by each WSXC is reduced from the number of channels present in each multi-wavelength input signal. In addition, the wavelength spacing between adjacent channels carried by each WSXC is increased over the spacing between adjacent channels in each multi-wavelength input signal.

Abstract: A cordless telephone provides for increased features available at a portable unit that have heretofore been available only at a base unit which combines a cordless telephone fixed station and telephone answering device. The cordless telephone includes a call screening feature which allows a user at the portable unit to monitor incoming messages received over telephone lines as they are being recorded at the telephone answering device without the user having to configure the portable unit in any way during actual receipt of the message. A built-in loudspeaker is incorporated into the portable unit so that the user may easily listen to the incoming messages. Once receipt of the incoming message is completed, amplifier circuitry driving the loudspeaker is turned off. The cordless telephone also includes a caller-ID feature which informs the user at the portable unit of the identity of a preidentified calling party before the call is answered.

Abstract: A cordless telephone arranged for operation in a frequency hopping system includes an arrangement which allows multiple cordless telephone portable units to operate in close reception proximity to each other and without interference while either responding to a service request from a cordless telephone base unit or in generating a service request to the base unit, also in the system. Contention between portable units in the system in responding to a service request from the telephone base is resolved through use of a polling process wherein the base unit polls each one of the portable units as part of this polling process. Each portable unit is assigned a number of acquisition channels distributed across the frequency hopping channels used for normal communications between the base unit and the portable units. These channels are different from and do not conflict with other acquisition channels respectively assigned to other portable units, also in the system.

Abstract: Synchronization among digital video and digital audio signals is maintained in a multimedia player with limited or highly varying processing power. In an exemplary embodiment of the invention, a processor with stored program memory controls the decoding and playback of audio blocks and video frames, each stream independently stored in an order of intended playback time. The processor gives priority to the decoding and playback of audio blocks, and periodically determines whether a backlog of encoded video frames exists. Under video backlog conditions, the processor reduces the backlog by decoding only those backlogged video frames that must be decoded in order to decode and play the frame in the sequence of backlogged video frames with the latest intended playback time. After decoding this latest backlogged frame, the processor directs it to be played. Normal video decoding and playback then resumes for video frames following this latest backlogged video frame in sequence and in intended playback time.

Abstract: A telecommunications system is arranged to efficiently route digital information from a mobile network to a Public Switched Telephone Network (PSTN) and vice versa by interposing a packet network between the mobile network and PSTN so that digital information originating from the wireless network at a first data rate may be forwarded over the packet network at that rate and then sent over a direct connection from the packet network to the PSTN at a second data rate expected by the PSTN. In this way the conversion of the digital information from the first to the second data rate is performed only when needed, i.e., at the ATM switch connected to the PSTN.

Abstract: Cross-over modulation between radio frequency circuits and audio circuits is minimized in a wireless portable transceiver by locating all audio circuitry in a first section of the portable transceiver and all radio frequency circuitry in a second, separate section of the portable transceiver. In view of modality considerations in small portable transceivers, an audio signal is either radiated or received in the vicinity of the radio frequency circuitry. Isolation of the audio signal is achieved by routing this signal while in its acoustic form. Since audio signals in an electrical form are not routed around or near the radio frequency circuitry, cross-over modulation does not occur between the radio frequency circuitry and the audio circuitry.