Abstract: The invention relates to a local area network interconnection system through a wide area network, certain interconnection nodes of this network being formed by a plurality of redundant pieces of interconnection equipment. According to the invention, the redundant pieces of interconnection equipment have a false physical address and a logical address in common to form a unique entity with respect to the stations of the local area network, while only a single one of the pieces of interconnection equipment of this entity performs a function of bridge/router at a given instant and the others are intended to ensure support in the case of breakdown. The redundant pieces of interconnection equipment further comprise monitoring means for monitoring their respective states by exchanges of frames on the local area network.

Abstract: The invention relates to an asynchronous time-division multiplex transmission system comprising an interconnection element, which element transmits cells supplied by auxiliary lines (6) and destined for a trunk line (8) at a preset interconnection element transmission rate and which comprises cell filters (7) coupled to each of the auxiliary lines, which filters pass the cells for storage in intersection buffers (15) coupled to each cell filter when the path identification contained in the cells is allocated to the trunk line. An output buffer (17) supplying cells to the trunk line is connected to the outputs of the intersection buffers. The cells are transmitted between the intersection buffers and the output buffer at a temporary transmission rate which is increased relative to the element transmission rate.

Abstract: Reproduction accuracy of, for example a digital stereo audio signal, is improved by transmitting sample data as sub-signals such as frequency subband signals. In one or more subbands, corresponding components such as left and right stereo channels are combined so that only one composite signal is transmitted per subband. An indicator signal is transmitted, indicating which subbands are combined. Scale factor signals for all subbands, and for the relative intensity of the respective subband signals which were combined, may also be transmitted. In the receiver a subband signal is derived for each channel from the composite signal, before synthesis of the full channel signals which will be reproduced.

Abstract: A method is disclosed for recording picture information, in which pictures (2) on an image carrier (3) are scanned and converted into a picture information signal, the picture information signal being converted into a coded picture, which is recorded on a record carrier (184). For a plurality of scanned pictures the information signal is converted into n independently coded pictures (TV/16, TV/4, TV) for each picture scanned, n being greater than or equal to two. The resolutions of the picture representations defined by these n coded pictures are different. For each of said plurality of scanned pictures (2) the associated coded pictures (TV/16, TV/4 TV) are recorded on the record carrier (184). Moreover, a picture retrieval and reproduction device (11) for reading the record carrier (184) thus obtained is disclosed.

Abstract: A reversible tape cassette drive includes a support plate which is displaceable with respect to the magnetic tape and is also pivotable about a pivot axis. By pivoting the support plate, a selected one of two pressure rollers is driven against a corresponding capstan to control the direction of tape movement. The magnetic head is pivotally mounted on the support plate about the pivot axis. Straight guides guide the head to be perpendicular to the tape independent of the pivoting of the support plate.

Abstract: A communication system comprising a controller (1) arranged for service implementation. The controller (1) is arranged for extracting a service logical program from a data bank (3) after the controller has received parameters transmitted by a terminal unit (6), and for activating a service in response to a service logical program and second parameters and, in response to a service logical program and first parameters, for providing a service for a subscriber and for transmitting at least one service parameter to the terminal unit (6, 8) and/or, in response to a service logical program and fourth parameters, for deleting a subscriber's authorization to use a service.

Abstract: During recording or reading of data in an optical record carrier such as a disc, focus is optimized by adding a focus offset signal to the focus servo error signal. Each frame contains pre-formatted control marks in a servo field, and reference data marks recorded there at a time of data recording. The focus offset signal is optimized by spacing the reference data marks a distance as close as any data marks between which a zero or non-recorded position must be resolved, and taking samples of the optical readout signal as the optical scanning beam passes over or adjacent the reference marks. Four samples are used, taken between the peaks of the signal corresponding to the two reference data marks.

Abstract: A read device (320) for reading a record carrier (184) on which coded pictures (4TV, TV, TV/4) have been recorded. The recorded coded pictures represent pictures made up of a matrix of P rows of Q pixels (p). The dimension of the pixels in a horizontal direction is substantially equal to the dimension of the pixels in a vertical direction. A read unit (6) reads the recorded coded pictures (4TV, TV, TV/4) from the record carrier (184). The device comprises a picture converter, which preferably comprises a sample rate converter (290), for converting the read-out coded pictures into an adapted coded picture comprising P'.times.Q' coded pixels. The sample rate converter is arranged in a data path between the read unit (6) and a picture memory unit (321). The picture memory unit (321) supplies a coded picture representing a picture made up of pixels (p') whose ratio between the dimension in the horizontal direction and the dimension in the vertical direction is substantially equal to Q/P, P and Q being integers.

Abstract: Teletext page signals are transmitted in a format providing only basic characters and colors, along with extension signals enlarging the character set, colors, and other presentation information which is used by decoders and display systems having more extensive capabilities. Decoders ignore extension signals intended for a higher level display than the associated apparatus. A code is added identifying the level of display for which extension signals are intended, so that extension signals can be transmitted for use only by a display of a given capability, without undesired use by a higher level display.

Abstract: A subscriber premise local bus (SPLB) is connected to a cable drop from a wide-band 2-way network through a gateway device providing frequency conversion and blocking of certain frequencies used in the subscriber premises local bus (SPLB). Service channels to the consumer are provided in a first band such as 54 to 750 MHZ, carried unchanged over the SPLB. Return signals from the subscriber are generated at subscriber devices, such as TV, computers, etc. at, or are up-converted to, signals in a higher frequency band, such as 900 to 950 Mhz, for transmission on the SPLB to the gateway device where they are down-converted to frequencies below 54 Mhz for transmission over the network. A band-pass or other filter may block at least some of the lower frequencies from carrying over from the SPLB to the cable drop or 2-way network.

Abstract: Current in a line is measured by passing it through a coil, having at least one turn, linking a small high permeability core; passing a measuring current through a bucking winding around the same core; and controlling the measuring current to buck the magnetomotive force of the line current so that the core flux stays below the saturation level. The measuring current may flow through a precision resistor so that a voltage across the resistor is an accurate measure of the line current. The measuring current is obtained from a high frequency switching circuit which senses the change of flux in the core. In normal operation the circuit switches when the core flux has risen to a predetermined value, such as 60% or 80% of the saturation value. If drift or extreme transients cause the flux to reach the saturation level, a sensing and correction circuit re-establishes operation between the desired points.

Abstract: Reproduction accuracy of, for example a digital stereo audio signal, is improved by transmitting sample data as sub-signals such as frequency subband signals. In one or more subbands, corresponding components such as left and right stereo channels are combined so that only one composite signal is transmitted per subband. An indicator signal is transmitted, indicating which subbands are combined. Scale factor signals for all subbands, and for the relative intensity of the respective subband signals which were combined, may also be transmitted. In the receiver a subband signal is derived for each channel from the composite signal, before synthesis of the full channel signals which will be reproduced.

Abstract: Monitoring of traffic on selected routes requires little communication time, through reporting only instances of abnormal speed. During a calibration phase calibrant vehicles are operated along the selected routes with sufficient frequency and for enough days to provide meaningful data. Each calibrant vehicle carries a differential GPS receiver for measuring location accurately. Average speeds for intervals of, for example, 15 seconds, are stored, with the time and place of observation. The data from all calibrant vehicles are then analyzed to determine patterns of mean speed and bandwidth. In the monitoring phase probe vehicles are deployed, each carrying similar GPS, a computer in which the patterns are stored, and a radio for automatically reporting speeds which are out of bandwidth for that time and place.

Abstract: An apparatus for reading picture data stored on a record carrier for first and second pictures, and providing an output video signal which changes smoothly from the first to the second picture. The apparatus has a single picture memory having storage locations for values representing individual pixels, and a converter for converting signal values fetched from the memory into a video signal. Data for a new picture are read into the memory without such adaptation as filtering or correcting color resolution. During intervals when the memory is not otherwise being accessed, newly recorded data are adapted and the adapted data are then stored. Priority are given to fetching data for the video generator, and loading data read from the record carrier.

Abstract: A transmission channel may be utilized for a combination of wide-band signals and auxiliary signals, while still providing improved reproduction accuracy. Digital sub-signals or subband signals representing at least first and second data-reduced components are combined with at least one auxiliary digital signal in defined frame portions before transmission. The auxiliary signal may be user-discernible information such as third and fourth audio channels, so that a four channel surround sound signal is transmitted; or teletext or video or picture information may be provided. Sampling reduction and filtering into subbands may be applied to the auxiliary signal as well as to the first and second signal components.

Abstract: A cordless telephone which includes a static RAM (50) for storing time management information and a real time clock (52). The time management information which includes telephone numbers and diary information is written into the static RAM (50) using a personal computer (PC) during recharging of the telephone's batteries. In operation, the telephone's microcontroller (40) compares the real time with entries stored in the static RAM (50) and when there is coincidence, an alert is given to the user. Alternatively data entered into the static RAM (50) by a user using a key pad (46) or derived from a received radio telephone link can be read-out to the PC when the batteries are being recharged.

Abstract: A device for coding still images has a device for segmenting the images into homogeneous regions whereto a specific label is attached, and a device for coding the contents of the contour. The contour coding device has a sub-assembly which detects contours for each regions, for each region successively considered, it detects points which are to form a series of control points and transforming the part of the contour joining two successive control points into a straight segment. Then the validity criterion is verified. If the criterion is not met, at least one supplementary control point is introduced between the two control points and so on until it is. The transformation is applied until the contour loop is completely closed.

Abstract: A rack of electronic equipment is convection cooled. Each unit in the rack has oblique cooling fins oriented in a same direction, to cause heated air to flow to a hot air pathway by a chimney effect, and to draw surrounding air along a cool air pathway to each of the units. A preferred unit has two housing sections thermally insulated from each other. Each housing section has its cooling fins on a side surface, some of the fins being aligned with fins on the other section, so that cooling air flows first over the cooler section and then over the hotter section. The cooler section is arranged for enhanced heat transfer from a heat sensitive element, and heat liberating units are heat sinked to the hotter section.

Abstract: A reading device (6) and an optical record carrier (5) having at least two information planes (1, 2, 3). The radiation from the record carrier is converted in a detection system (15) into a detection signal (16) which is applied to a detection circuit (17). In order that this circuit can derive the read information from the detection signal in a reliable manner, the interference signals generated by the information planes which are not to be read should comply with a requirement, referred to as the interference requirement, which is characteristic of the detection circuit. Values for the parameters of the record carrier, such as the thickness of the layers between the information planes and the reflection and transmission coefficients of the information planes then follow from this interference requirement.

Abstract: An apparatus having a frame (1) carrying a turntable (3) for supporting the information carrier, which turntable is rotatable about an axis of rotation (3A), a slide (9), which is movable between two end positions, with a scanning unit, guide spindles (5, 7) and a linear motor unit (17, 19) for the slide, and an electrically energizable clamping unit (21). In the non-energized condition the clamping unit clamps the slide in any arbitrary stationary position of the slide along its path and in the energized condition it does not clamp the slide. During operation of the device a control unit at least substantially simultaneously turns on a first energizing current to the motor drive unit and a second energizing current to the clamping unit at the beginning of a displacement of the slide and at least substantially simultaneously turns off the first energizing current and the second energizing current at the end of the displacement.