Abstract: A digital optical switch in the shape of the letter "Y" at least an input optical waveguide and first and second output optical waveguides. Each output waveguide comprises at least a first part and a second part coupled by a transition in a transition region. An applied electrical control signal commands a refractive index difference between respective first parts of the output waveguides. At least one of the output optical waveguides has in a plane containing the output waveguides a guided propagation mode width that is lower in the second part than the mode width in the first part of the respective output waveguide. In a preferred implementation, the transition is an adiabatic transition. Applications include photonic routing and optical switching matrices.

Abstract: For subscriber access, via optical fibre, to communications networks that offer various types of service by means of an optical access node (AN), connections between the optical network terminating units (ONT) unit to which the subscribers are connected, and the access node (AN) can be made with point-to-point or point-to-multipoint fibre optic links. The links between the access node (AN) and the switching centre (CE) are made via optical fibres through which pass the lightwave signals corresponding to a number of subscribers, multiplexed together by means of wavelength division multiplexing. This network permits access to all types of communications services in which each type of service employs a reserved wavelength for its connection between the access node (AN) and the optical network terminating equipment (ONT) unit. This reserved wavelength is fixed and depends only on the type of service.

Abstract: The present invention concerns a monomode optical fiber comprising an optical core for guiding the majority of light waves, surrounded by an optical sheath, the difference between the maximum refraction coefficient of the core and that of the optical sheath being indicated as .DELTA.n and the radius of the core being indicated as a, characterized in that:a .epsilon.?0.6a.sub.c :1.1a.sub.c !, a.sub.c being provided, in .mu.m, by the formula: ##EQU1## where k=2.pi./.lambda., .lambda. being (in .mu.m) the wavelength of the transmission, and where n.sub.g is the coefficient of said optical sheath, equal within 10.sup.-3 to that of pure silica,.DELTA.n is greater than or equal to 0.01,and in that, .phi. being the diameter of said optical sheath, in .mu.m: .phi..epsilon.?.phi..sub.min :100!, .phi..sub.min being provided, in .mu.

Abstract: The present receiver includes a radiofrequency part (RF) coupled to a limiting amplifier (SL) which is in turn coupled to a demodulation means (DM) which recovers a digital signal from a received signal obtained by modulating a carrier signal with this digital signal. The limiting amplifier (SL) has an input-output characteristic which is substantially linear for smaller input signals and which strives with a decreasing gain towards a limit value for larger input signals. Due to this input-output characteristic smaller received signals are treated linearly up to the demodulation means (DM). The latter can therefore for these signals compensate for a specific spectrum shaping of the digital signal performed before the actual modulation. In this way the receiver will perform in a nearly optimal way resulting in low bit error rates. For larger received signals the limiting amplifier (SL) is non-linear and such compensation is consequently without effect resulting for these signals in a performance degradation.

Abstract: A housing (1) which gently holds at least one pressure sensitive connecting cable (4) and provides strain relief for the at least one pressure sensitive connecting cable has a housing wall portion (2) which has an opening (3) through which the at least one connecting cable (4) can be passed into the housing (1). The housing (1) has a holding comb (22) therein, which include an angle member (5) having tangs or projections (7). The tangs or projections (7) are loosely fitted into additional openings (8) formed in the housing wall portion (2). The holding comb (22) also has tines (10) for respectively securing one of the connecting cables (4) using a heat shrinkable tube (11) to a respective one of the tines (10).

Abstract: A network termination (NT) with a network interface (U.sub.KO), several subscriber interfaces (S.sub.O 1, S.sub.O 2), a control unit (CPU) and an internal bus (IBUS) is indicated for a telecommunications network. Information is transmitted on the network side in a frame structure by the time division multiplex method. The frame structure contains several useful information channels and one or more signaling channels. The control unit (CPU) assigns the useful information channels to the terminals in such a way, that each terminal has at least one channel available for the transmission of useful information. In addition, the network terminations (NT) of several subscribers are combined in the circuit of a network termination arrangement (NTE) outside of the subscribers' premises, and is jointly supplied by a voltage transformer (ACDC). A power supply that is independent of the telecommunications network supplies the voltage transformer (ACDC).

Abstract: An optical waveguide includes, in monolithic manner, a rear segment, a transition segment, and a front segment extending and succeeding one another along the length of the waveguide. A lateral confinement factor and a width the waveguide are respectively larger and smaller in the rear segment than in the front segment. According to the invention, the width increases in the transition segment until it reaches a value that is larger than that of the front segment. The invention is particularly applicable to integrating together a laser and an optical modulator for a telecommunications system.

Abstract: Logic operations are carried out on binary optical signals using a non-linear optical amplifier having a front port and a rear port respectively receiving a front wave and a modulated rear wave. The output wave via the rear port is separated from the rear wave by exploiting the fact that they have opposite propagation directions. Applications include optical data switching and transmission.

Abstract: An interconnection unit OB includes a flat member FM with connectors OC1, and flexible tongue-shaped elements T formed to be integral with the flat member FM. Conductors F each have a first end part fixed to one of the tongue-shaped elements T and a second end part fixed to the flat member. The tongue-shaped elements T and the flat member FM are formed of a layer of rigid material and each of the tongue-shaped elements T has a portion thereof that includes separated transverse strips S, which are kept together by the conductors F fixed to the tongue-shaped elements, thereby making the tongue-shape elements flexible. A stainless steel plate is fixed to the rigid layer. The interconnection unit is especially useful as an optical backpanel to interconnect optical connectors of printed boards mounted in a rack.

Abstract: A system for eliminating the effects of transmission errors in a digital stream is characterized by the presence of a predictor. The output signal of this system is taken from a predicted signal during the presence of errors and from the received signal when the errors are not present.

Abstract: Of special application in cellular mobile networks that communicate this terminal, via radio, with a base station to provide services of voice and/or data communications to a number of subscribers and which, in addition to the basic communications service, also support an emergency call service performed through the terminal in question by dialling a certain number. This terminal comprises means (41) for generating user signalling tones and which also generate an emergency call dial tone, different from the other tones already present, when a call process is initiated by the subscriber (5) in the case where the fixed cellular terminal is only capable of making emergency calls.

Abstract: Creation of an all-digital answering set with voice control, which is able to perform a multitude of functions. The software for performing functions is subdivided into individual software modules which execute sub functions. These can be used in multiple ways and are integrated into a digital signal processor (DSP) of the answering set.

Abstract: Based on a phase locked loop (PC1, CP1, VCXO) which receives an incoming data signal (DS) and generates a recovered clock signal (RC), in the event that this incoming data signal (DS) includes low frequency cycling, false phase locking can occur, consequently leading to impaired operation; in order to avoid this, according to the invention, there is also included a false locking detector (FLD) to which is applied the incoming data signal (DS) and the recovered clock signal (RC) and the output of, which is added in an adder circuit (ADD) to that coming from the first loop, for producing voltage pulses when both signals are not at the same frequency, provoking a non-locked state. Only when the frequency is correct, does the false locking detector (FLD) not alter loop operation.

Abstract: A chaining arrangement between intermediate modules (14), particularly of the repeater type, servicing transceiver terminals (0) communicating via a common, digital, packet transmission link (LP), in a communications installation. Each module has an access monitoring signal input (acki) linked to the output of a first individual concentrator logical circuit (15), this circuit including "p" inputs each capable of being linked to an access monitoring signal output (acko) of "p" different modules. Each module has its access monitoring signal output linked to a scattering circuit (16) making it possible to simultaneously drive the access monitoring signal inputs of "p" different modules.

Abstract: A time-continuous tunable Gm-C integrator including a "super Gm" differential input stage (O1; MI1/O2, MI2) and using linear and constant degeneration resistors (R1/R2) for obtaining the most optimal linear input-voltage to output-current conversion is tunable in a time-continuous manner. The integrator is provided with three tuning CMOS transistors (MU1, MU2, MU3) controlling the integrating currents flowing between the input stages and from the input stages towards the outputs (OP/ON). By a suitable control of the tuning transistors and owing to the fact that the voltage swing across the latter is small, it is possible to obtain a perfectly linear transconductance (Gm) characteristic over the whole operating range of the integrator.

Abstract: The invention concerns a microwave transmit/receive (T/R) circuit for a polarization synthesizer array antenna, especially a radar antenna. According to the invention the required polarization is obtained by applying two signals to an array element on two orthogonal feed paths with a variable phase difference between the two paths, both of which function simultaneously. In a preferred embodiment both transmit channels are provided with two power amplifiers which each amplify a signal from an in-phase power divider or a hybrid coupler, with a one-bit or two-bit controllable phase-shifter adding a phase-shift of 0.degree., 90.degree. or 180.degree. to synthesize orthogonal linear or circular polarizations. In a preferred embodiment the circuit according to the invention is partly or entirely implemented in monolithic (MMIC) technology. The invention also concerns an antenna including a T/R circuit as specified hereinabove.

Abstract: A mobile radio network comprises a base transceiver station for transmitting and receiving radio signals to and from mobiles on different basic frequencies and a radio booster for receiving, amplifying and retransmitting radio signals to and from at least one shadow area. To cover the shadow areas a radio signal received by a radio booster from the base transceiver station on a basic frequency is retransmitted to a mobile station on a translated frequency different from the basic frequency and associated with the latter by a translation law. This law is such that, firstly, each of the basic frequencies is either associated with at least one translated frequency or is not associated with any translated frequency and, secondly, the difference between the value of a translated frequency and the value of the associated basic frequency is not the same for all the translated frequencies.

Abstract: The invention concerns an optical waveguide transition and its fabrication method, enabling coupling between a buried optical waveguide and a ridged optical waveguide. The transition structure is formed during etching of a layer containing the buried optical waveguide, the transition area being formed by adiabatically increasing the lateral dimensions of the buried waveguide. Top layers are deposited on the buried waveguide and its widened structure in the transition area, and the ridged optical waveguide is fabricated with one part on top of the transition area. Coupling of the respective propagation modes in the buried and ridged waveguides is effected by mode adaptation in the region between the two waveguide structures in the transition area. The transition of the invention is made in two conventional epitaxy steps.

Abstract: In networks with switched broad-brand communication, agreements exist between customer and network operator with regard to permissible data flows, which are maintained by a usage parameter control. To attempt to utilize the capacity of the network as much as possible, the network operator offers a service of utilizing the available bit rate frequency. This service requires a separate treatment of the respective data, to maintain the priorities and avoid overloading of the switching unit. The device for equalizing the data flow contains a switching network (22) which is located upstream of the switching unit (10), and reroutes the data flow that utilizes the available bit rate frequency service, to a server (23).

Abstract: The present invention concerns a signal processor module (SPU,AVF) which is adapted to check if a received vector (RV) representing a received signal in a QAM signal vector plane is located in the intersection zone of a first and second zone (ABCDEF,ab) of this signal vector plane. The intersection zone is well chosen so that the phase angle difference (Da) between the received vector (RV) and an expected vector (EV) which represents a signal which should have been received instead of the received signal and which is located in the intersection zone, is limited.