Abstract: A coin-validation arrangement in which a wavelet analysis is used to derive accurate information from signals related to coin sensors placed in the path of an input coin, this information being compared with corresponding information relating to sample coins, the result of the comparison giving rise to a “pass/fail” validation decision on the input coin. The information may be derived from a sampling of the sensor-related signal, a measurement of signal amplitudes for each point and a correlation of each amplitude with the corresponding amplitude of one or more preselected wavelets to provide a set of correlation coefficients. In an alternative embodiment the sampled sensor-related signal is subjected to a discrete wavelet transform operation using high-and low-pass filtering and subsequent subsampling stages, thereby producing a set of DWT coefficients. In either case the number of coefficients used in the comparison process may be reduced, thereby saving processing power.

Abstract: Microstructure materials which can be tuned to a particular range of r.f. frequencies to display particular magnetic permeabilities have been proposed. A typical material is made of an array of capacitive elements e.g. spirals or rolls of conducting material on a non-conducting substrate. These materials can be used as a guide which is effective for the particular band of frequencies to which it is tuned. In one example, the rolls (2a to 2c) guide magnetic flux along ducts (1, 2, 3) while rolls (4a, 5a) guide magnetic flux along ducts (4, 5). Flux can thus be guided upwardly along duct (2), along ducts (4 and 5), and down ducts (1, 3), or vice versa.

Abstract: A partially interconnected network has a plurality of Allocated Nodes, each allocated to one of a number of AREAs, and further has a plurality of Star Nodes (STARs), and also has point-to-point interconnections between the Allocated Nodes and the STARs. The number of AREAs with Allocated Nodes connected to an individual STAR forms the number of ROUTEs from an individual STAR. The Allocated Nodes of a first of the AREAs are connected to a set comprising some, but not all, of the STARs. Further of the AREAs are similarly interconnected to further sets each comprising STARs. There is at least one connection choice between any two Allocated Nodes in different AREAs and where a connection route is two point-to-point interconnections connected in series by a STAR.

Abstract: In a synchronous digital communications system a network of SDH (or SONET) equipments (SE) are arranged to exchange synchronisation signals via ports on the SEs, each port being allocated a source identifier (SID). These SIDs are used to identify the source of each synchronisation signal input at a particular SE. When the SE selects a synchronisation signal to transmit out of its ports, the SID associated with that selected signal is compared with SID of each port. If a match is found the synchronisation status message (SSM) associated with the synchronisation signal sent out at that port is set to “Do Not Use” (DNU) to warn the destination SE that the synchronisation signal has been looped back. Each SE is allocated a unique equipment identifier. The SID of each port is set to the unique SE identifier of SE to which it is directly connected.

Abstract: The invention provides an optical communication system (10) comprising a plurality of mutually interconnected bi-directional optical waveguide rings (20, 30, 40, 50, 60) in which radiation modulated with communication traffic propagates. The radiation is partitioned into 32 distinct wavebands. Interfaces (70, 80, 90, 100, 110, 120) are included in the system (10) where communication traffic propagating in the rings transfers from one ring to another. Each interface (70) is capable of providing an all-optical waveband reconfigurable communication link between the rings (20, 30, 40, 50, 60). At each interface (70), conversion of optical radiation to corresponding electrical signals is not required when transferring communication traffic from one ring to another, thereby providing the system (10) with a potentially larger communication bandwidth compared to conventional optical communication systems.

Abstract: Malicious code in a code-executing device is detected by generating test data, which is substantially unsusceptible to compression without reducing its information content, and storing it as image data in memory external to the device. The test data is stored into memory of the device. A checksum calculation is performed on the test data stored in the memory of the device to generate a first checksum value. A corresponding checksum calculation is performed on the image data to generate a second checksum value. The first value is compared with the second value to determine whether or not the test data in the memory of the device has been corrupted. These steps are repeated until sufficient test data in the memory of the device is checksum tested to determine whether or not malicious code is present in the device. The malicious code is difficult to conceal itself from the checksums. Hence, it is possible to determine whether or not the device has been compromised.

Abstract: A method of and system for memory access have address transformation circuitry for generating a single value of memory address from one or more corresponding values of an input quantity in which the number of values of the input quantity that correspond to a single value of the memory address varies across the range of values of the input quantity. The relationship between an input quantity and the corresponding memory address is a hyperbolic function.

Abstract: An L-band EDFA may have three amplifier stages. In the first stage, a high power 980 nm laser is used to generate C-band ASE noise which is used to pump the erbium doped fiber of the second stage. The second stage fiber is arranged as a plug-in module which connects between a first stage isolator and a mid-stage loss between the second and third stages. The desired gain of the amplifier is obtained by selecting a plug-in module with a length of fiber that will give the desired amplifier output power for a given input power.

Abstract: A communications system comprising device (e.g. an ATM physical layer (PHY)) and higher layer devices (e.g. an ATM layer and an AAL2 layer) are connected via a bus for communication of traffic therebetween, the bus comprising lines for carrying data and control signals. The bus supports data in ATM and AAL2 form and the devices discriminate between the two forms of data traffic. The data in AAL2 form typically comprises AAL2 mini-cells associated with identification of the source of destination of the mini-cells.

Abstract: A method and apparatus for managing a length of optical fiber by housing the length of optical fiber in a duct, the length of optical fiber being so coiled as to extend along the duct and the length of optical fiber being connected to a plurality of fiber-joining devices positioned along the duct. The fiber-joining devices are contained in modules which are removably attached to the outer periphery of the duct.

Abstract: A method of, and apparatus for, setting an operating (control) voltage of a voltage controllable optical component, such as a Mach-Zehnder optical modulator, having a periodic voltage/optical parameter (optical power) characteristic include an up/down counter and a digital to analog converter operable to set the voltage applied to the component to a predetermined initial value, a device for measuring the optical parameter, and another device for sequentially progressively increasing and decreasing the voltage (incrementing/decrementing the counter) with respect to the predetermined value, and for determining respective voltage values which produce maximum and minimum values of the optical parameter. The voltage is set to a value intermediate the maximum and minimum voltage values. Further, the apparatus determines the sense of the slope of that portion of the periodic characteristic lying between the maximum and minimum values for use by a control loop during subsequent operation of the optical component.

Abstract: A telecommunications system comprising an intelligent network (IN) for providing IN and non-IN service creation environment function (SCEF) in which the SCEF is arranged to provide service logic and service data templates for supporting both IN and non-IN services. The service logic provided by the SCEF may either be distributed between the service control function (SCF), the service switching function (SSF) and the call control function (CCF) or located in the SCF with the SSF arranged to pass protocol input messages to the SCF and signaling messages from the SCF to the CCF.

Abstract: In a telecommunications network which comprises an Intelligent Network (IN), Call-Gapping is implemented in a call control function (CCF), so that calls are selectively discarded automatically in order to reduce the load on the IN. As the CCF is the point at which an incoming call is first recognized as an IN call, this arrangement reduces processing resources consumed by discarded calls and also provides for a faster IN call rejection response.

Abstract: A laser used in a DWDM optical-fiber application is controlled so that, before it is powered up or down, its output power is maximally attenuated, the result being minimal cross-channel interference due to out-of-spec. wavelength. Laser control is further characterized by the steps of: (a) with laser current at zero, establishing a desired temperature of operation of the laser; (b) with output attenuation at maximum, increasing the current and regulating it to a level at which the design operating wavelength is achieved, and (c) decreasing the attenuation until the desired output power to the optical-fiber link is attained. Maximum attenuation is preferably applied during step (a).

Abstract: A communications system comprising one or more servers and one or more clients. The servers are connected to the clients, for the provision of information to the clients. Each server is operative for sending control messages to the clients at or above a set rate. Each client is operative for detecting the control messages, and for determining a fault condition if the control messages are not received from each one of the servers at less than predetermined time intervals.

Abstract: The invention pertains to a communication system (300) including one or more communication channels (10), each channel comprising a transmitter unit (20) and a receiver unit (40). Each transmitter unit (20) is connected through an optical fiber link (30) to its associated receiver unit (40). In operation, each receiver unit (20) receives payload data from its associated sending client and adds overhead data to the payload data to generate corresponding aggregate data (600). The aggregate data of each transmitter unit (20) is conveyed through the fiber link (30) to its associated receiver unit (40) which receives the aggregate data, decodes it to separate the payload data from the overhead data and then outputs the payload data to its associated receiving client. The receiver unit (40) interprets the overhead data and uses it for controlling and managing the payload data in the system (300).

Abstract: A Synchronous Digital Hierarchy (SDH) signal cross connect architecture is realized by switching the signals as bits in the space switch. The bit signals between the space switch and the time switches are multiplexed. In this way it is possible to linearly expand the capacity of the space switch to a much larger size before its quadratic expansion begins. This invention is applicable for the cross-connection of SDH signals such as Synchronous Transport Module (STM)-1 through STM-16.