Other

Yvon Rouaud

Michel A Devault

Michel Servel

Pierre Boyer

Jean-Paul Quinquis

Bernard Gerard

Herve Le Bris

Denis Chomel

The invention is a method of controlling asynchronous time-division communications. Cells received from an in-coming time division multiplex system are delivered to an out-going asynchronous time division multiplex system. Each in-coming cell is stored in a buffer memory at an address that corresponds to its re-sending time. At the time when the next cell of a particular communication arrives, the number of previously stored cells for that particular communication, that are stored in the buffer memory, is compared with a maximal number assigned to the particular communication. If the first number exceeds the second number, the next in-coming cell is not re-sent. Besides the buffer memory, the system includes a status memory and an arithmetic and logic unit. The status memory is divided into zones, each zone having two sections. When the next cell is received, a first number of cells stored in the first section of the particular communication which were stored in the buffer memory and which have not yet been sent, is compared with the maximal number stored in the second zone. The arithmetic and logic unit makes the comparison and inhibits the re-sending of the next in-coming cell, if the first number exceeds the maximal number.

Method and a system of control of asynchronous time communication outputs

The invention smooths asynchronous time communication outputs which are formed by cells received from an incoming synchronous time multiplex(XE) in order to supply an outgoing asynchronous time multiplex(XS). Each incoming cell is stored in a buffer memory (MT) with an address (Add) corresponding to the actual time when that cell will be transmitted (t) on the outgoing time multiplex (XS). The address (Add) of the cell entering the buffer memory (MT) is determined by calculating a function of the theoretical minimum time period (pm) between outgoing cells. The searching in the buffer memory (MT) is for the first free address (Add) corresponding to an actual transmission time (t) which is chronologically beyond the next theoretical transmission time (tso). The actual time for outgoing transmission is determined as a function of a period (pm) allotted to the communication to which the incoming cell belongs. The period (pm) corresponds to the theoretical minimum time period between transmitted cells in the outgoing synchronous time multiplex (XS).

Method and system of smoothing and control of asynchronous time

The system comprises a first unidirectional packet bus having a bit rate D, each packet including an e-bit identifier and a b-bit package, sources having differing bit rates d.sub.i such that d.sub.m .ltoreq.d.sub.i .ltoreq.d.sub.M &lt;D, and access means for introducing packets from the sources into the first bus. An allocator located at the receiving end of the first bus builds up frames of identifiers identifying active sources. Each frame has a length T=b/d.sub.m and is shared into N=d.sub.M /d.sub.m time slots. Each time slot has a period .theta.=b/d.sub.M and includes a source identifier. The identifier for a same active source having a bit rate d.sub.i is repeated in the frame n.sub.i times such that n.sub.i =d.sub.i /d.sub.m when d.sub.i /d.sub.m is an integer, or such that n.sub.i =1+ integer part of (d.sub.i /d.sub.m) otherwise. The identifier frames are transmitted from the allocator into a second unidirectional bus distributed to all the access means. The access means of each source transmits a packet in the first bus whenever a b-bit package delivered from the source is received and an identifier of the source is detected in the second bus after package reception.

Asynchronous digital time-division multiplexing system with distributed

An asynchronous time division multiplex switching network for switching multi-service communication data performs point-to-point data switching, data switching between a single calling party and a plurality of called parties, and data switching between plural calling parties and a single called party. The network comprises plural incoming and outgoing time division multiplex highways including asynchronous channels each formed by a packet data and an address label (j, k). Incoming and outgoing terminal switching equipments are respectively connected to the incoming and outgoing highways. A bus interconnects the terminal switching equipments. The labels are converted into several sub-words according to the type of communication switching. In response to the values of these sub-words, the outgoing terminal switching equipments accept or do not accept the packets to be transmitted.

Time division multiplex switching network permitting communications

Asynchronous time division multiplex switching network for multi-service digital network. It comprises a plurality of time division multiplex bidirectional highways, a plurality of data transmit and receive stations connected to and associated with said bidirectional highways and a plurality of buses connecting these stations therebetween. The highways convey digital data arranged in a hybrid frame including a time slot part formed of a plurality of time slots containing sample words having a variable number of bits and a packet channel part formed of a plurality of channels for packets having a variable number of bits. Means are provided in each transmit station for converting the sample words in the time slot part and the packets in the packet channel part into a message including the sample word proper, its number of bits, the address of the terminating highway, the number of the time slot in the hybrid frame and a first indicator marking the sample words and, the packet proper, its number of bits, the address of the terminating highway, the number of the packet channel in the hybrid frame and a second indicator marking the packets. The messages are then transmitted and in the receive station, the items added to form the messages are deleted, leaving only the sample words and packets.

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Lannion, France

Yvon Rouaud