Abstract: An apparatus and associated methodology are provided for determining a transmission time per unit cell of a flow of data packets. A packet comprises at least one unit cell and the data packets are received in bursts. An expiration time is determined, beyond which a received data packet does not belong to a burst currently being observed, from a transmission time per unit cell. If a received data packet belongs to the burst currently being observed, a transmission time per unit cell is re-estimated from the lengths of the data packets of the burst currently being observed, The determining and re-estimating are repeated as long as data packets belonging to the burst currently being observed are received.

Abstract: Bit rate reservation is effected with the aid of a reservation cell containing a requested bit rate transmitted from a calling terminal to a called terminal via switching nodes of an asynchronous network. At each node, a bit rate increase request is at least partially satisfied even if the difference between the requested bit rate and the current bit rate is greater than the bit rate available at the node. The node replaces the requested bit rate in the reservation cell by a new bit rate lower than the latter so that the called terminal receives the lower new adopted bit rate by the nodes. An acknowledgement cell retransmitted with this lower new bit rate by the called terminal renders uniform the adopted bit rate at all the nodes. If no acknowledgement cell has been received after a predetermined time-delay the nodes revert to their initial state, with the current bit rate preceding the bit rate reservation.

Abstract: A process is described for spacing over time the transmissions of cells that belong to messages. The value of the address of the first cell of the message is stored in relation to the clock-time of the sending. At each time given by a local clock-time, the address value is read in relation to said local time. The cell having said address is sent. Then, the sending clock-time of the next cell of said message is computed. The address of the next cell of the message is determined. The address value of the next cell is stored in relation to the clock-time of its computed transmission. The invention also relates to spacing devices which are used to execute this process.

Abstract: A queueing circuit serves an asynchronous switching circuit. A number of input circuits are connected to inputs of a switching network in a one-to-one relationship with the outputs of the switching matrix. During its own time slot, each of the input circuit has a series of availability signals which are assigned to time slots that are later than the input circuit's own time slot. These availability signals indicate the availability condition at the matrix output for enabling an emission of a data cell during the time slot identified by the availability signal. Based upon the availability signal, the cell is released from a memory storage during an available one of the later time slots.

Abstract: A data transmission system has a time interval allocation system with a time interval management unit (UGIT) and a plurality of counters (CSO.sub.1 to CSO.sub.n) connected to one another in a cascaded series. The input of a counter (CSO.sub.i) is connected to the output of the preceding counter (CSO.sub.i-1) in the series. The input of the first counter (CSO.sub.1) is connected to the output of the time intervals management unit. Each counter (CSO.sub.i) is associated with an input carrying a time interval allocation demand signal (dem.sub.i) and provided with a command input for receiving the allocation demand signal (dem.sub.i) and delivering either the time interval value (ITin) present on its input if the allocation demand signal (dem.sub.i) is inactive, or the time interval value present on its input increased by a unit (ITin+1) if the demand signal (dem.sub.i) is active. The output of each counter (CSO.sub.i) is connected to the input of a register (RegAd.sub.

Abstract: A device for initiating multiple timings has a supply of clock pulses. At each clock pulse, an entering cell is stored in a communication system with asynchronous time switching. The stored cell belongs to a virtual communication circuit that carries a number in the label of the cell. A random access, read-write timing memory (MT) has a plurality of addressable zones which normally store null or inactive bits. The memory (MT) is alternately addressed for writing and for reading. The memory (MT) comprises a data input (ED) to store, in a zone addressed for writing, a parameter bound to a characteristic of a virtual circuit. A data output (SD) delivers the content of the memory zone addressed during reading.

Abstract: There is assigned to each virtual circuit a period (pm) corresponding to the theoretical minimum period between two consecutive cells of the virtual circuit and a maximum time limit (dm). The imaginary time of emission on the output multiplex of the last cell belonging to each virtual circuit is stored, and, upon the arrival of a new cell of a virtual circuit, a threshold time calculated by adding its actual time of arrival and the maximum time limit is compared with the imaginary time of emission expected of the new call in the course of being processed, the time being calculated by adding the imaginary time of emission of the last cell emitted and the minimum period (pm).

Abstract: 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.

Abstract: 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.

Abstract: The invention provides a method of measuring the load of a communication system, and more particularly of a multiplex switching network for asynchronous cells or packets. Each cell transmitted on the multiplex has a registered value which is divided by a predetermined number (N). The value forms the first operand (E2) of a subtraction and the result of the division forms the second operand (E1). A predetermined value is added to the result of the subtraction when the heading of the transmitted cell contains a particular identifier. A zero value is added in the contrary case. The result of the subtraction followed by the addition constitutes the new value which is to be recorded, which likewise represents the measurement of the load. The identifier identifies, for example, an occupied cell or a cell belonging to a given virtual circuit. A circuit for implementing the method is likewise described.

Abstract: The method embodying the invention authorizes communication bit rate reservations in a packet switching network. According to the method, a new communication is only accepted by the network if the communication does not exceed a maximum bit rate flowable by the switches of the network. A packet switch in the network comprises a bit rate reservation device for memorizing bit rate informations that are representative of total bit rates flowed by the switch and for processing said information as a function of data carried by service packets. The bit rate reservation device mainly comprises registers respectively associated with multiplex ways of the switch for memorizing the bit rate informations, an adder for incrementing and decrementing the bit rate informations as a function of service packet data, and a comparator for detecting overstepping of the maximum flowable bit rate.

Abstract: A device embodying the invention for a packet time-division switcher comprises essentially a circuit for detecting beginnings and ends of load interruption periods in the switcher, and a period counter. The detecting circuit is connected to a plurality of input buffer quenes of the switcher and detects a load interruption when all queues signal a state of packet emptiness. A time base of the switcher is inhibited at the end of a period of predetermined duration established by the counter and following the detection of a load interruption. Said duration is predetermined so as to complete the switching of a packet that has been begun. Once the time base is inhibited, the operating of the switcher is interrupted and its power consumption becomes very low. The time base is freed as soon as a packet is received by the queues, and the switcher resumes operating.

Abstract: Tracer gases are contained in a capsule which is closed-off by a fusible seal and placed within the interior of each fuel-pin can. The capsule is formed of material having a melting point above the operating temperature of the fuel pins within a nuclear reactor. The fusible seal is formed of material having a melting point below said temperature, with the result that the tracer gases are released into the interior of each fuel pin at that temperature.