Abstract: To segregate functionality and to eliminate redundancy in service logic and associated hardware that together control the interconnection of narrowband trunk circuits (252-256) and broadband virtual channels (258-262) of a mixed node communication system (FIG. 5), a switch fabric (16) has an associated memory (280) that contains a pre-provisioned table of mappings between narrowband trunk circuits (DS-0s) and broadband virtual channel identities. Therefore, to establish an end-to-end connection, the switch fabric (16) searches the pre-provisioned table (280) for an available connection and then performs the necessary cross-connection between the narrowband trunk circuit is (252-256) and the broadband virtual channel (258-262). The mappings principally relate to the narrowband-to-switch fabric interface and, as such, avoid the requirement for UNI signalling translation and negotiation, although the mappings may also include the broadband-to-switch fabric interface.

Abstract: An underwater telecommunications system has a first underwater cable for carrying data traffic, one or more underwater repeaters, and an underwater power network for supplying power to the repeaters. By providing a separate cable for some or all of the power supply, the power route may be made shorter, thus more power can be delivered, therefore more repeaters can be used, which enables more fiber pairs to be laid, and thus the capacity to be increased.

Abstract: A crosspoint switch is provided that has N inputs, M outputs, and an array of (N+X)×(M+X) switching elements, where N, M, and X are all positive integers. By providing more than the standard N×M switching elements, it becomes possible to utilise the additional switching elements to provide one or more additional protection pathways to compensate for a failure in a switching element: in the event of failure of a switching element, an affected path between one of the M inputs and M outputs can be replaced by an alternate path utilising one or more of the additional switching elements.

Abstract: The invention concerns a hydraulic line coupling arrangement of a consumer, with a pump line, a tank line and a safety valve in the pump line, the valve element of the safety valve being acted upon in the opening direction by an opening pressure from the pump line and in the closing direction by a closing pressure of a closing pressure connection. In such an arrangement it is desired to prevent overloading of the consumer. For this purpose, a pilot valve is provided for controlling the closing pressure, the position of the pilot valve being controlled by the pressure in the tank line.

Abstract: A steering device with a steering angle transducer, a steering drive having a motor and a first gear, at least one wheel driven by the steering drive and a sensor arrangement for detecting the angle position of the wheel with a detection device, which produces a reference signal for at least one reference position of the steering device. In this connection, it is desired to improve the reliability of the steering device. For this purpose, the detection device is connected with the motor via a second gear.

Abstract: A system for determining the position of each of a plurality of objects in a specified environment by determining the transit times of slowly propagating measurement energy transmitted from a measurement energy transmitter on each object to a plurality of fixed measurement energy receivers in the specified environment, the transmission of the measurement energy being triggered by a burst of high speed propagating trigger energy into the specified environment from a trigger energy transmitter, the measurement energy transmitter on each object being triggered by an object-mounted trigger energy receiver, each burst of trigger energy being encoded so as to trigger one only of the measurement energy transmitters, wherein a coordinating control system determines the order in which the measurement energy transmitters are triggered, in response to updatable information relating to service demands of the trigger energy transmitter and/or objects.

Abstract: An asynchronous transfer mode adaptation layer switching network has independent call routing and connection control for setting up connections across the system. A plurality of adaptation layer switches (ALS) coupled to the ATM network comprise a group adapted to function as an adaptation layer switching network whose fabric and control are distributed over the group. The network having means for determining its current system status whereby to set up multimedia calls across the network based on that status determination.

Abstract: The fibre fuse effect, also termed self propelled self focusing (SPSF) is a catastrophic damage mechanism resulting from a runaway thermal affect which can melt optical fibres. A method and apparatus for limiting the damage caused by a fibre fuse is provided by utilising a detector external to the fibre for monitoring the condition of the fibre.

Abstract: In a cellular mobile telecommunications system the position of a mobile station can be estimated in terms of its bearing and range from a cell site. A multi-element direction finding antenna at the cell site receives signals from the mobile station and a receiver circuit estimates the bearing using the relative phase of signals received at different antenna elements and estimates the range by measuring round trip delay of signals to and from the mobile station. Motion of the mobile station can introduce errors into the bearing estimate due to frequency offset and frequency spread when element sampling is non-simultaneous. Compensation for these errors is introduced by using signal samples successively received at the same antenna element to estimate Doppler frequency offset and spread. It is necessary to ensure accurate calibration of the direction finding antenna and the receiver circuit.

Abstract: A system for provisionally estimating the carrier-to-interference ratio of a terminal in a cellular mobile radio network which transmits sets of primary frequencies and sets of secondary frequencies and in which the rate of re-use of the sets of secondary frequencies is higher than that of the sets of primary frequencies. The system knows the level received by said terminal from a local cell (A1) to which it is connected. It also knows the levels (LB2, LC3, LD2, LE1, LG2, LF1) received by said terminal from adjoining cells (B2, C3, D2, E1, G2, F1). It selects a reference cell (B2) from said local cell and said adjoining cells, produces a potential noise by calculating the sum (N1) of the levels (LD2, LG2) received from the cells (D2, G2) using the same secondary frequencies as said reference cell (B2), and supplies said estimate in the reference cell (B2) by dividing the level received from said reference cell by the potential noise.

Abstract: Distortion compensation of an optical micro-electro-mechanical system (MEMS) device disposed on a substrate surface is effected by measuring degradation of an optical parameter of the device and applying a force to the substrate to reverse the degradation. The compensating force may be provided via a layer of piezo-electric material bonded to the opposite surface of the substrate and to which a control voltage is applied. The device distortion may arise from thermal mismatch effects in a package housing containing the device. Typically, the MEMS device comprises an optical crosspoint switch array.

Abstract: A hydraulic steering arrangement with a directional valve and a metering pump unit having two hydraulically parallel connected and mechanically parallel operable metering pumps, each having a toothed ring with inner toothing and a gear wheel with outer toothing being able to perform rotary and orbiting movements in the toothed ring. It is desired to extend the life of the metering pumps. For this purpose, a through-going driving part is provided for both gear wheels.

Abstract: A grinding machine has a wheelhead movable tinder computer control perpendicular to the axis of a composite workpiece, mounted between a headstock and a tailstock, and workrests slidable along front and rear rails. Between the workrests are sandwiched rigid cover-spacers to protect the rails and prevent lateral movement of the workrests. A spring-operated thrust bar may be supported against a fixed dressing wheelhead to clamp the stack of cover-spacers and workrests together, in order to accurately locate and space apart the workrests.

Abstract: The invention concerns a steering arrangement (1) with a steering handwheel (2), which is unrotatably connected with a steering sensor, and with a wheel (3) steered by a steering drive (4) without a mechanically active connection between steering handwheel (2) and steered wheel (3). In this steering arrangement a simple way of realizing a counter action of the steered wheel on the steering handwheel (2) is wanted. For this purpose the steering sensor is made as an electrical machine (6), which works as a generator, for the production of a steering signal and is connected with a switching device (9), whose load behavior is variable.

Abstract: A communication network with a set of nodes each arranged to extract signals received on orthogonal input paths when there is a predetermined correlation between them, and to retransmit the signals on orthogonal output paths when the predetermined correlation is absent. Each node is further arranged to launch signals intended for a particular destination node on orthogonal paths with a phase difference such that the signals arrive at the destination node with the predetermined correlation. Thus local processing of the signals is sufficient to extract a signal intended for a particular node. There is no need for centralized control or for the separate transmission of signaling data.

Abstract: The invention concerns a steering arrangement (1) for a vehicle, in particular for an automotive machine, with a steering drive (4) controlled by a steering unit (8). In a steering arrangement of this kind, it is endeavoured to make the steering less straining for the operator. For this purpose the steering unit (8) has a keyboard (9) instead of a steering handwheel.

Abstract: A variable gain optical amplifier, in which homogeneous gain broadening is dominant, has first and second fixed gain rare-earth doped optical waveguide amplifiers (21, 23) optically in series together with an intervening variable attenuation optical attenuator (22). This arrangement circumvents the problem of gain tilt encountered when operating such amplifiers under variable gain conditions. An alternative form of the module has variable gain waveguide amplifiers, but these are co-regulated so that the aggregate of their gain at a wavelength within the gain spectrum is maintained constant. A further alternative form of module is employed in a concatenation of such modules. In such a concatenation, the gain of individual modules is allowed to vary, but the aggregate of the gain, at wavelength within the gain spectrum, of all the waveguide amplifiers of all the modules of the concatenation is maintained constant.

Abstract: The power handling capabilities and operational lifetime of a MEMS device, e.g., a MEMS mirror, operating in a high intensity optical beam environment are enhanced by packaging the device in an packaging atmosphere having a suitably high thermal conductivity, preferably exceeding that of air. The packaging atmosphere can be selected to provide a desired level of heat loss from the MEMS device.

Abstract: A method of measuring the polarization mode dispersion (PMD) of an optical transmission path carrying clocked digital data traffic involves modulating the state of polarization (SOP) of the light launched into the transmission path, and detecting consequential frequency components in an electrical signal detected at the far end of the transmission path. The SOP modulation, when represented on a Poincaré sphere, has an oscillatory rotational component at a frequency f1 about a first axis of the sphere and an oscillatory rotational component at a frequency f2 about a second axis of the sphere that is orthogonal to said first axis, and where f1≠f2, f1≠2f2, and f2≠2f1.