Abstract:
Un système d'allocation d'un intervalle de temps selon l'invention comporte une unité de gestion d'intervalles de temps (UGIT) et une pluralité de compteurs (CSO₁ à CSO n ) reliés entre eux en série de manière que l'entrée d'un compteur (CSO i ) soit reliée à la sortie du compteur précédent (CSO i - 1 ) dans la série, l'entrée du premier compteur (CSO₁) étant reliée à la sortie de l'unité de gestion d'intervalles de temps (UGIT), chaque compteur (CSO i ) étant associé à une entrée portant un signal de demande d'allocation d'intervalle de temps (dem i ) et étant pourvu d'une entrée de commande prévue pour recevoir ledit signal de demande d'allocation (dem i ) et délivrant, soit la valeur d'intervalle de temps (ITin) présente sur son entrée si ledit signal de demande d'allocation (dem i ) est inactif, soit la valeur d'intervalle de temps présente sur son entrée incrémentée d'une unité (ITin + 1) si ledit signal de demande (dem i ) est actif, la sortie de chaque compteur (CSO i ) étant reliée à l'entrée d'un registre (RegAd i ) dont l'entrée de commande est prévue pour recevoir ledit signal de demande (dem i ) correspondant, chaque registre (RegAd i ) délivrant alors, si ledit signal de demande correspondant (dem i ) est actif, un signal d'intervalle de temps alloué (ITa). L'invention concerne des variantes de réalisation d'un tel système d'allocation et des multiplexeurs qui sont pourvus d'un de ces systèmes.
Abstract:
A multiplexing arrangement for multiplexing data packets from different sources into a continuous flow, i.e. without gaps, of serially transmitted data packets. Each packet is constituted by several (13) sets of n(=4) digital words or bytes and by at least one set of r(=1) digital words, with r smaller than n. The arrangement includes several input memory units (RAM0-RAM3) each adapted to receive and to store at least one packet and comprising several memory portions each able to store up to n digital words of a packet, two input registers (RGR/RGN) adapted to read from the memory portions either one set of r digital words, one set of n digital words, or both simultaneously, a multiplexing means (MUX) adapted to combined the read sets and to transfer at least a portion of the combined sets to an output terminal (OUT) of the arrangement. The multiplexing means includes buffer means (BUFF),mixing means (MIX1) and transfer means (MIX2) for transferring, under the control of control means (CNTL), portions of n digital words from the combined sets and for re-combining the remaining part of these combined sets with other sets received from the input registers in order to obtain the above continuous flow data packets.
Abstract:
In a device for processing a time division multiplexed signal into asynchronous transfer mode cells, each comprising an information field, a single building unit (23) successively builds first through M-th cells (M: a plural and natural number) as the asynchronous transfer mode cells so that the information field of an m-th cell of the first through the M-th cells comprises first through N-th PCM signals (N: another plural and natural number) of an m-th frame of first through M-th frames of the time division multiplexed signal, where m consecutively varies from 1 to M. The first through the N-th PCM signals of the m-th frame are successively extracted from the time division multiplexed signal by an extracting unit (21). When the information field of each of the first through the M-th cells comprises first through N-th bytes and a prescribed number of remaining bytes, the building unit successively builds the first through the M-th cells so that the first through the N-th extracted signals of the m-th frame are placed in the first through the N-th bytes of the m-th cell, respectively, and that empty bytes are placed in the remaining bytes of the m-th cell.
Abstract:
An ATM switching system comprises a switch unit including a plurality of input ports and a plurality of output ports having the same cell transmission rate, and a multiplexer for multiplexing cell trains outputted from at least two output ports into a single cell train and outputting the cell train to a high-speed output line (and/or a demultiplexer for demultiplexing a cell train from an output port into a plurality of cell trains and outputting the cell trains to a plurality of low-speed output lines). The switch unit includes a buffer memory for temporarily storing cells inputted from the input ports while forming a queue chain for each output line to which each cell is to be outputted, a demultiplexer for distributing the cells read from the buffer memory among the output ports in circulation, and a buffer memory control circuit for controlling the write and read operation of cells with the shared buffer memory. The buffer memory control circuit has a control table device for outputting an identifier of an output line to which the cells read from the shared buffer memory are to be outputted, and cells are read from the chain designated by the output line identifier outputted from the control table device.
Abstract:
Dans un système servant à transmettre des cellules de données à partir d'un émetteur (1) et vers un récepteur (2, 3), chaque cellule comporte une en-tête à format fixe contenant des informations d'adresse et une tranche de temps à format libre de durée prédéterminée. Les cellules peuvent être transmises par un réseau optique (4), et dans ce cas les cellules passent par un commutateur optique (5) qui lit l'en-tête et est transparent à la tranche de temps à format libre. Des cellules de deuxième niveau sont formés avec une en-tête de deuxième niveau et une tranche de temps remplie d'un certain nombre de cellules du premier niveau.
Abstract:
A congestion control method and apparatus for use with a communications link (111) comprising a plurality of N channels (106-110). A plurality of at most N-1 queues (101-104) are sequentially polled, and data is output therefrom to the communications link, thereby leaving at least one remaining channel (110). After the at most N-1 queues are polled, a determination is made as to at least one of the at most N-1 queues which is closest to a data overflow condition. The remaining at least one channel is then utilized to transmit data from the at least one queue which is closest to a data overflow condition.
Abstract:
Es soll erreicht werden, daß bei der Einführung von Breitband-Kommunikationsnetzen existierende Vermittlungsanlagen und Endgeräte des Dienste integrierenden Digitalnetzes ISDN unverändert beibehalten werden können und mit auf asynchroner Basis arbeitenden Breitband-Kommunikations-Vermittlungsanlagen zusammen arbeiten. Ein Anschlußorgan einer im asynchronen Zeitmultiplex arbeitenden ATM-Vermittlungsanlage ist jeweils mit einem zugeordneten Anschlußorgane an einer ISDN-Vermittlungsanlage verbunden. Dort werden ISDN-Schmalbanddaten den Breitbanddaten hinzugefügt und/oder von diesen getrennt, indem mit Verletzungen der Coderegel gearbeitet wird. Beide Arten von Daten werden gemeinsam über eine Teilnehmeranschlußleitung zu einer Netzabschlußeinrichtung übertragen woran Endgeräte verschiedener Kategorie angeschlossen sein können. Sowohl Breitbandvermittlungsanlagen nach dem asynchronen Zeitmultiplexverfahren als auch bestehende ISDN-Vermittlungsanlagen können zusammenarbeiten, ohne daß Vorleistungen größeren Umfangs erforderlich sind. Bei der Einführung von Breitband-Kommunikationsnetzen können bestehende Netzstrukturen des Dienste integrierenden Digitalnetzes beibehalten werden, wobei auch vorhandene Endgeräte benutzbar sind, welche mit Endgeräten des Breitband-Kommunikationsnetzes ohne weiteres kommunizieren können.
Abstract:
The present invention refers to a transmitter (1) comprising: - a serializer (3) comprising a plurality of inputs (3a) configured for receiving incoming data signals comprising successive data packets corresponding to a plurality of channels, the serializer being configured for serializing the said incoming data signals in an output signal, wherein the transmitter (1) also comprises: - a first oscillator (5a) configured for providing a first clock signal associated to a first frequency to the serializer (3), -a second oscillator (5b) configured for providing a second clock signal associated to a second frequency different from the first frequency to the serializer (3), - a first fast switching device (7) having a first input (7a) linked to the first oscillator (5a), a second input (7b) linked to the second oscillator (5b) and an output (7d) linked to the serializer (3), the first fast switching device (7) being configured for switching between a first switching state wherein the first input (7a) is linked to the output (7d) and a second switching state wherein the second input (7b) is linked to the output (7d), and wherein the transmitter (1) is configured, upon receipt of a clock signal change signal, for switching the first fast switching device (7) from the first to the second switching state.