Abstract: An monolithic version of optical multiplexer/demultiplexer with an improved spectral characteristic is provided by two diffraction gratings arranged optically in tandem and with a field stop in the coupling between them, the gratings also being arranged to provide free spectral ranges differing by a factor of at least two, and having a coupling between them that carries over into the second grating information concerning the dispersion afforded by the first grating. The field stop is constituted by a pair of etched troughs arranged in the pattern of an open chevron.

Abstract: A method and apparatus for scaling a wireless telecommunications network having an architecture based upon subscriber distribution includes providing a base station subsystem (BSS) and a pool of mobile switching centers (MSCs) interconnected with one another. The mobile switching centers include visitor location registers (VLRs). Lastly, a dispatcher mobile switching center (DMSC) is provided, the dispatcher mobile switching center being coupled between the base station subsystem (BSS) and the pool of mobile switching centers (MSCs) for establishing communication between the base station subsystem (BSS) and the pool of mobile switching centers (MSCs). The dispatcher mobile switching center (DMSC) further provides for distributing mobile station subscribers and call related work among the pool of mobile switching centers (MSCs).

Abstract: A system and method that uses an advanced positioning system in combination with a cellular communication network to improve the performance of the network is disclosed. The system is capable of receiving an identification number for a mobile unit as well as a location code. In order to determine if the mobile unit is a fraudulent user of the cellular communication network, the system compares the location code with a previously received location code. Since there are natural physical constraints on how quickly a mobile unit can move from one location to another, the system can thereby determine if there are two mobile units using the same identification number. If so, then one is likely a fraudulent user. In addition, the system is capable of assisting the mobile unit by providing the location code to a third party. This is especially beneficial for emergency dispatcher services since, due to the very nature of mobile units, the user of the mobile unit may not know his precise location.

Abstract: A system and method for initially locating and subsequently tracking the location of one or more mobile phones in a cellular communication network are disclosed. Software for implementing a scheduling and tracking system ("STS") is incorporated into the base station controller ("BSC") of a cellular communication network for performing scheduling and tracking functions with respect to mobile phone location. In one aspect of the invention, time difference of arrival ("TDOA") techniques are used to determine a location of each of a number of designated mobile phones active in the network. In another aspect of the invention, a scheduling portion of the STS originates and maintains a schedule of time measurement updates with reference to the previous location of the mobile phone. In yet another aspect of the invention, a tracking portion of the STS keeps track of the location of each of the designated mobile phones over time.

Abstract: A system and method is described herein which provides an originating telecommunications unit with the geographic location of a mobile telecommunications unit without actually placing a call to, or receiving a call from, the mobile unit. The originating unit provides a service platform with an authorization code and the telephone number, or other identification, of the mobile unit to be located. The service platform then initiates a location program which uses various geographic location methods to provide the originating unit with the location of the mobile unit, without the user of the mobile unit becoming aware that the location of the mobile unit is being determined.

Abstract: A cabinet for outdoor use for enclosing a rack of electronics equipment has a double skin protective outer casing comprising a lower air intake into a cavity between the skins of the double skin and an upper air output from the cavity to the outside, for unforced cooling air to flow, to extract heat from the equipment by convection. The inner of the skins is formed in part at least by a heat sink of the rack. This unites the thermal management of the rack and that of the enclosure to provide an improved thermal path from the cards in the rack to the cold wall. This means the temperature difference between the inner skin and the air in the cavity can be increased for a given card temperature, so more heat can be extracted. The heat sink may share the back wall of the rack with the motherboard.

Abstract: The present invention relates to environmental control apparatus for telecommunications equipment, and in particular, relates to a radio telecommunications electronics enclosure drain valve. A base station antenna electronics enclosure typically comprises antenna arrangements and associated control cabinets. Whilst ideally the internal space within an electronics enclosure is hermetically sealed, this is not generally possible due to, inter alia, the differential expansion of the different components within the enclosure, the need for access for maintenance purposes, the electrical performance characteristics and so on. The antennas are contained within an antenna enclosure--the enclosures on masts visible to the public. In order to provide a sufficient field of coverage, the antenna should be placed at a height above ground level, typically upon a building or a mast, extending 15 m or more. In such a position, an antenna enclosure is subject to extremes of temperature, windage and moisture.

Abstract: An encoding technique of the invention protects software programs and hardware designs from being copied, tampered with, and its functions from being exposed. The software programs and hardware designs (collectively called programs) thus encoded still remain executable. The encoding technique employs the concept of complexity of programs and produces proximity inversion in terms of functions contained in the programs, while preserving the behaviors. Various embodiments are possible to achieve this encoding which includes, for example, cascading and intertwining of blocks of the programs.

Abstract: The present invention is an improved method of pigtailing of high-density Wavelength Division Multiplex (WDM) components, achieved by etching silicon V-grooves for locating the fibres after completion of the PLC device fabrication processes. This avoids the need for etching or pre-patterning of the V-grooves on substrates before device fabrication, and hence avoids any of the waveguide to fibre alignment problems that have been found in the methods of the prior art.

Abstract: A system and method for temporarily relocating a subscriber in a cellular communications network to a new location such as another telephone. The subscriber enables the service by contacting a user interface system, which then instructs a home location network associated with the subscriber's home network and accessible through an intelligent network to provide appropriate information to the switch that is serving the new location. As a result, the subscriber may receive services that are identical, equivalent, or a subset of those that he receives from his home network.

Abstract: An interactive subscriber telephone terminal, comprising: a display screen; a plurality of temporarily definable response/data entry keys; and local control means for selectively causing the display screen and/or the response/data entry keys to be controlled by one of: remote signals transmitted to the terminal from a telephone switching office, and the local control means.

Abstract: Modems using a telephone line for high speed communications between them are arranged to monitor crosstalk from other existing communications systems with which they may mutually interfere, and adjust the power spectral densities (PSDs) of their transmitted signals to reduce overlap between the PSDs of the different systems, thereby reducing near end crosstalk. Communications can thereby be optimized for whatever crosstalk conditions may exist. The modems can have a master-slave relationship for communicating buffered frames in a half-duplex manner using a collision avoidance protocol for computer network access. Analysis of monitored crosstalk PSD information can be performed by each modem, by the master modem, or by a separate computer on the network. A digital signal processor used in each modem for receiving signals can be configured to be used at other times for the monitoring of crosstalk.

Abstract: A data processing system implements a load balancing methodology which recognizes the effects that multiple, mobile subscribers have within a wireless communications network. During execution of this load balancing methodology, a rehoming operation is executed at a telephone central office to move some subscribers in a network to a new home mobile switching center with a minimum number of rehoming steps. To perform this rehoming operation, a mobile switching center in a network which has a highest load is selected first. Mobile switching centers which have a load lower than a network average load are considered to be candidates for a rehome destination. All subscriber groups homed to the highest loaded mobile switching center are evaluated to determine whether or not a rehoming operation using this subscriber group would provide a highest benefit and give a lowest standard deviation of loads among mobile switching centers after the rehome operation is selected.

Abstract: A system and method for causal ordering in a distributed network with a minimum amount of delay. In a distributed network having three interconnected nodes, each having synchronized clocks, the second node sends a message to the first node. Before it sends the message, however, the second node attaches a time stamp t2 to the message. To determine when the first node can provide a causally ordered response, the method first determines a minimum message latency f from the third node to the second node. The method then adds the value of the time stamp t2 to the message latency f to calculate a minimum response time t1. On or after the time t1, the first node can provide the causally ordered response.

Abstract: A noise suppression circuit for a two-wire communications channel comprises a hybrid device, for example a hybrid transformer or circuit, for providing a differential mode signal corresponding to a differential signal received from the two-wire channel. A summing device extracts from the two-wires of the channel a common mode signal and supplies it to a noise estimation unit which derives from the common mode signal an estimate of a noise level in at least one frequency band having a bandwidth considerably narrower than an operating bandwidth for the channel. The noise estimation unit adjusts the amplitude of the noise estimate to correspond to the residual noise in the differential mode signal and subtracts it from the differential mode signal to produce a noise-suppressed output signal. A noise detection and control unit scans the operating band, identifies a frequency band having an instant highest noise level, and sets the noise estimation unit to the detected noisy band.

Abstract: An information processing system 700 tests the RF coverage reliability of a signal transmitted by a base station in a radiotelephone system cell. Information processing system 700 includes processing circuitry for receiving information characterizing the cell and outputing in response test information, the processing system operable to: estimate a radius of the cell; estimate a bin size for each of a plurality of bins partitioning the cell; estimate a minimum drive distance for validating RF coverage of the cell from the estimated radius and the estimated bin size; and select a number or road segments having a combined length exceeding the estimated minimum distance.

Abstract: A state machine space for concurrent state machines is provided for use in a telecommunications system. Processing of the state machines (and their functions/actions) utilizes specialized data structures and processes to normalize and control data and events dynamically in the telecommunications system. A Universal Data Structure (UDS) provides data uniformity and represents an event in the telecommunications system. A typical UDS includes four fields which are defined by the UDS definition. Three of these fields include event, component types, and data, while an embedded fourth field includes enums. Each UDS represents an event occurring in the telecommunications system and activates one or more state machines contained within a sub-space.

Abstract: A method for formatting CDRs to reduce storage and processing requirements within a switch or telecommunications network which formats CDRs in accordance with the disclosed techniques. A switch includes a call condense agent for collecting raw call information for calls handled thereby and a formatting agent for selecting, based upon an examination of said raw call information, an optimal data structure for formatting the raw call information and for producing a CDR by formatting said raw call information in accordance with said optimal data structure. The optimal data structure is that which best fits the raw call information.

Abstract: In an optically amplified transmission system including a concatenation of optical amplifiers in the transmission path between an optical transmitter and a non-coherent receiver, the transmitter includes, in addition to a modulator for impressing data modulation, a polarisation state modulator for improving the signal-to-noise ratio at the detector.