Abstract: A mobile radio system enables exchange of bidirectional digital signals between at least one mobile station and at least one base transceiver station and provides at least two coding modes, each mode corresponding to a predetermined source code and a predetermined channel code for the transmission of a wanted signal for each transmission direction. Each source code corresponds to a given user bit rate and each channel code corresponds to a given coding efficiency and therefore to a given total bit rate for a given source code. For adaptation of the air interface of this system, at the time of a call between a mobile station and a base transceiver station, two separate analyses of transmission quality are carried out for each transmission direction, respectively, and, for each transmission direction, one of the coding modes is selected in accordance with the corresponding transmission quality analysis.

Abstract: A channel selector device for a multiple access system of direct transmission between mobile stations carries out measurements on various channels during calls in order to determine if there is a better channel than the traffic channel used for the call. This better channel constitutes the new traffic channel to be-used.

Abstract: A mobile radio system enables exchange of bidirectional digital signals between at least one mobile station and at least one base transceiver station and provides at least two coding modes, each mode corresponding to a predetermined source code and a predetermined channel code for the transmission of a wanted signal for each transmission direction. Each source code corresponds to a given user bit rate and each channel code corresponds to a given coding efficiency and therefore to a given total bit rate for a given source code. For adaptation of the air interface of this system, at the time of a call between a mobile station and a base transceiver station, two separate analyses of transmission quality are carried out for each transmission direction, respectively, and, for each transmission direction, one of the coding modes is selected in accordance with the corresponding transmission quality analysis.

Abstract: A leak detector including at least one analysis unit connected to the inlet of a first secondary pump, a pre-evacuation set connected to an inlet coupling, the inlet of said pre-evacuation set further being connected to the outlet of said first secondary pump via a pipe provided with a first valve, wherein said pre-evacuation set comprises a second secondary pump and a mechanical primary pump connected together in series, and wherein a pipe provided with a second valve connects an intermediate point of said first secondary pump to the inlet of said second secondary pump.

Abstract: An extract-and-insert optical wavelength division multiplexer includes a broadcaster (D1) for applying an incoming multiplex signal to N outputs, a combiner-diffuser (D2) for broadcasting the multiplex to be inserted (MI) on N outputs, a first set of N tunable filters (FIT, . . . , FNT) for selecting the carriers of the signals which are to be used for modulating the carriers of the outgoing multiplex (MS), a second set of N tunable filters (F1E, . . . , FNE) for selecting the carriers which are to constitute the extracted multiplex (MT), N wavelength converter devices (CL1, . . . , CLN) suitable for supplying N carriers of the outgoing multiplex (MS), and N two-input, two-output optical switches (SW1, . . .

Abstract: A system for transmitting digital information, especially on an optical link, comprises a send end unit and a receive end unit. It includes a device for evaluating the bit error rate at the receiving end and a device for controlling one or more characteristic parameters of the send end unit and/or the receive end unit according to the evaluated bit error rate and in such a way as continuously to optimize the parameter(s) in the light of the actual performance of the transmission system.

Abstract: A mobile radio system enables exchange of bidirectional digital signals between at least one mobile station and at least one base transceiver station and provides at least two coding modes, each mode corresponding to a predetermined source code and a predetermined channel code for the transmission of a wanted signal for each transmission direction. Each source code corresponds to a given user bit rate and each channel code corresponds to a given coding efficiency and therefore to a given total bit rate for a given source code. For adaptation of the air interface of this system, at the time of a call between a mobile station and a base transceiver station, two separate analyses of transmission quality are carried out for each transmission direction, respectively, and, for each transmission direction, one of the coding modes is selected in accordance with the corresponding transmission quality analysis.

Abstract: A telecommunication management system including management centers provides management services which communicate via management messages in both directions with telecommunication network elements of a telecommunication network and a management message transfer point which enables the management centers and the telecommunication network elements to communicate, each in its own specific way, carries out the necessary conversion in the transfer of management messages between management centers and telecommunication network elements and is responsible for routing messages and making multiple copies of them in the case of messages with more than one destination. The message transfer point includes a plurality of management message transfer devices each serving a set of management applications and each telecommunication network element associated with a set of management applications has an interface for communicating with the management message transfer device serving that set.

Abstract: A system for synchronizing base transceiver stations includes a reference base transceiver station and a subordinate base transceiver station. Each base transceiver station has a clocks with the same frequency but any relative phase, and a timing reference. The reference base transceiver station imposes its own timing reference on each subordinate base transceiver station to compensate the phase difference between the two stations. The timing reference is imposed by having a mobile station listen to the reference base transceiver station and the subordinate base transceiver station, deducing a time shift D1 between the two base transceiver stations from the perspective of the mobile, determining a propagation time difference D2 between the mobile and the reference base transceiver station and the subordinate base transceiver station upon the occurrence of a handover that involves the reference base transceiver station.

Abstract: In a TDMA type cellular mobile radio system frequencies are shared between cells of the same re-use pattern and frequency hopping is used so that the frequency used at any time in one of the cells of a re-use pattern is different from those used at the same time in the other cells of that pattern. A base transceiver station of this system commands the sending of one of the frequencies shared in this way during a part of the time division multiple access frame and commands the stopping of all sending during the other part of the frame.

Abstract: An end station of a both-way optical link comprises: a receiver (RX) preceded by a receive optical amplifier (RA); a transmitter (TX) followed by a transmit optical amplifier (TA); a pump laser diode (PX) for delivering the pumping waves required by said amplifiers; and a coupler (B) of the passive type having two groups of two branches. The two branches of one group (BL and BP) are connected respectively to a line fiber (L) for both-way light guidance and to the pump (PX), the two branches of the other group (BR and BT) being connected respectively to the receive optical amplifier (RA) and to the transmit optical amplifier (TA). An in-line optical amplifier apparatus can be constituted in similar manner. The invention is applicable to telecommunications.

Abstract: An electrical signal transmission device includes a core and an outer conductor separated by a dielectric. To eliminate external radiated interference, for which the device behaves like a receiving antenna, the core, the outer conductor and/or the dielectric feature discontinuities forming impedance discontinuities. The discontinuities are chosen to prevent propagation towards the core of external interference waves in a particular range of frequencies.

Abstract: A cellular mobile radio system selects the best cell to be accessed for a given position of a mobile station by determining the distance of the mobile station relative to the base transceiver station of a cell with which it is communicating by measuring the propagation time between the mobile station and the base transceiver station, resolving the indeterminacy associated with the direction in which said mobile station is located relative to said base transceiver station, and then determining which cell the mobile station is situated in the coverage area of, this cell constituting the best cell. The resolving of the indeterminacy is rendered independent of the synchronized or non-synchronized state of the system.

Abstract: An encryption device can be used to encrypt information units conveyed by cells that are broadcast from an optical broadcast node to network units by a passive optical network. Each cell conveys at least one information unit and each information unit is addressed to a respective subscriber terminal. The device includes an encryption system that receives in clear at least one key from at least one decryption device located in a network unit. Applications include ATM telecommunication networks.

Abstract: To optimize the amplification in a device for extracting channels from a wavelength division multiplex, the following steps are carried out in succession: a first amplification step with a first gain, a wavelength selection step, and a second amplification step with a second gain. The first and second gains respectively confer upon the output optical signal a fixed signal to noise ratio and a particular optical power. Applications include optical transmission networks.

Abstract: A molecular drag pump including a stator and a rotor supported in the stator using two ball bearings at least one of which presses against at least one bearing surface of the stator serving as an axial abutment for the rotor, wherein the contact between the ball bearing and the bearing surface operates in bending and not in shear.

Abstract: An optical transmission method and device consisting of coding a binary data pattern (SI) to be transmitted in the form of a second binary signal (SM), by differential coding; filtering the second binary signal (SM) to obtain a duobinary signal (SMF having three meaningful values (-1, 0.+-..epsilon., +a) and a narrower bandwidth; and modulating an optical carrier according to the values assumed by the filtered signal (SMF), the modulated carrier having a maximal amplitude to represent the maximal value (+a) and the minimal value (+a) of the duobinary signal (SMF), the phase of the modulated carrier being shifted by .theta..sub.1 and .theta..sub.2 =.theta..sub.1 +180.degree., respectively, and a minimal amplitude to represent values (0.+-..epsilon.) near 0 if the duobinary signal. The method of this invention is suitable for long distance fiber-optic transmissions.

Abstract: A method of assigning transaction identifiers assigns an identifier that is unique to each transaction, each transaction operating on data distributed across various stations. The method determines a first field of the identifier, having either a temporary value identifiable as such and unique to the station executing the application process that requested opening of the transaction if opening of the transaction is requested during an initialization phase or a value assigned by a first manager process specific to the station executing the requesting application process if opening of the transaction is requested after the initialization phase. The method also determines a second field having either a temporary value identifiable as such and unique to the set of stations if the opening of the transaction is requested during the initialization phase or a value assigned by a second manager process common to the set of stations if opening of the transaction is requested after the initialization phase.

Abstract: A mobile radio system conveys frames between at least one mobile station and at least one base station, each frame comprising N time slots, a burst of data being transmitted in each time slot, and each time slot being associated with a separate call between a mobile station and a base station. For each call over a transmission channel, the quality of the transmission channel is analyzed and, on the, basis thereof, a selection is made between first and second modes of transmission. In the first mode of transmission data to be transmitted is organized in first blocks obtained by a first encoding of source blocks, each of the first blocks has a size greater than the content of (P-1) bursts, where P is an even number at least equal to 2, and the data of the same first block is distributed between at least P bursts.

Abstract: A cell level change control device for cellular mobile radio networks with more than one level of cells includes means for comparing the value of a parameter representative of the speed of a mobile station with a threshold in order to decide if it is necessary to command a cell level change when the mobile station is served by a lower level cell contained in a higher level cell or when a mobile station is served by a higher level cell and it is determined that the lower level cell contained in that higher level cell constitutes the best cell. The device determines the load of the higher level cell and varies the threshold in accordance with the load.