Abstract: A 3-stage switching system is provided for generating, i.e. finding, reserving and setting, path from one switch entrance port (1) to at least one switch exit port (transmit side) for asynchronously received and buffered data cells. While an Nth cell is being transferred, control means (36) generate a control word including the switch exit port address for cell (N+1)th to be subsequently transferred. Said control word is used to find and reserve a path through the switch on a stage-by-stage basis, and then set said path, if any, using a fed back acknowledgement. The (N+1)th cell path generation is performed during cell N transfer, on a cycle stealing basis.

Abstract: A method and apparatus for a time division multiplex transmission of data packets from a plurality of access units in a communications network having a pair of oppositely directed unidirectional buses between which the access units are coupled, each access unit transmitting its data packets in empty time slots on a first of such buses. A queue is formed in each access unit of the data packets therein, and each time a further data packet is added to such queue a request flag is transmitted on the second bus. A count is kept of the number of request flags passing the access unit on the second bus, and such further data packet is assigned a priority value corresponding to the number of request flags existing at the time the further data packet is added to the queue.

Abstract: A system for aligning framing bits from independent digital transmission facilities with framing of a higher transmission rate facility includes a RAM memory. Received framing bits from the independent digital transmission facilities are stored at RAM locations in accordance with multiframe addresses of the framing bits relative to the multiframe format of the independent facility. Multiframe indicator bytes indicative of the framing of the higher transmission rate facility are used as addresses to read framing bits from RAM. The multiframe address of the independent digital transmission facilities is established by a counter for each independent facility, said counter being synchronized to the framing of the independent facility and incremented to provide addresses identical to the multiframe indicator bytes of the higher transmission rate facility.

Abstract: The cross-point is intended for ATD multiplexing digital information in the form of packets of fixed lengths between two buses (A-B and C-D); it is constituted by: a first shift register (RAB), a first buffer register (RTE), a RAM (MRAM), a second buffer register (RTS), a second shift register (RCD), and logic circuits constituted by decision units for packet extraction (DE) and insertion (DI), associated with decision Tables (TEX and TIN), and a management unit of the RAM (GM). Packet extractions and insertions are effected in an asynchronous manner relative to each other.

Abstract: A communication control method for use in a communication system including a plurality of communication control apparatuses interconnected through an information transmission path, each of the communication control apparatuses including a packet transmission/reception unit, a timer unit and a controller unit. When a first communication control apparatus has become unable to perform communication due to accidental power-off or a power supply failure or the like in the course of communication with a second communication control apparatus (which has been brought into a locked state by the first communication control apparatus), the invention prevents the second communication control apparatus from being left permanently in the locked state.

Abstract: A data communication network subject to bursty traffic employs a bandwidth allocation scheme to avoid congestion. When a source node has a burst of traffic to send, it first sends a bandwidth request message through the network from source to destination. At each intermediate node, this bandwidth request is examined and the node determines how much of the requested traffic level it will be able to support at a time in the future of one round-trip interval hence, and this node either grants the request or marks down the request to a level that it can support, then passes it on. When the request reaches the destination, it is returned along the same path to the source, and the source then employs the marked-down allocation to select the rate used to send the burst of data. The allocation for this source node remains in effect for a limited time, depending upon the amount of data to be sent in the burst, then returns to a "residual" level.

Abstract: An automatic gain control for an inputted multiplex PCM data stream in a conferencing bridge in a telephone system. The inputted multiplexed data stream has a predetermined number of time slots wherein each time slot carries PCM speech data corresponding to an individual party in the conference call. The control of the present invention is capable of operating in .mu.-Law or A-Law companded format at a frequency of 192-256 kilobytes per second. The automatic gain control incorporates a digital root-mean-square meter, a COUNT sequence to change GAIN at predetermined intervals, and a set of GAIN rules to selectively increase or decrease GAIN based upon the output of the digital root-mean-square meter.

Abstract: A method of establishing a digital time-division duplex radio communication link between one of a plurality of portable units and a base unit in a cordless telephone system, transmissions from the base unit are allowed only on a ping-pong basis with transmission bursts from all the active transmitters in the base unit being synchronized with one another. This prevents blocking of receiver sections due to co-sited transmitters transmitting at the same time on a different channel. The difficulty of synchronizing the transmission bursts of the active portable units with their respective transceivers within the base unit is overcome by allowing the portable unit to make an initial continuous call comprising multiple identical sequences of data containing units small enough to be completely received within the limited reception windows of the base unit.

Abstract: The invention concerns a network for communication between user equipments for the transfer of messages emitted by each user equipment to all the other user equipment. The network according to the invention has a tree-structured configuration (1-25) and operates with emission authorizations or tokens.

Abstract: Modular expandable digital switching network in ATM (Asynchronous Transfer Mode) technology for a fast packet-switched transmission of information. The switching network has a J.times.J array of pre-switching modules and a 1.times.J array of final switching modules. The inputs of the switching network are connected to primary inputs of the pre-switching modules, whose outputs are connected to expansion inputs of pre-switching modules in the same column of the subsequent row. The outputs of the pre-switching modules in the final row with index J are connected to the inputs of the final switching modules in the same column, whose outputs are connected to the outputs of the switching network. Thus, a modular expandable switching network in ATM technology can be realized with minimal wiring requirements.

Abstract: A synchronizing device synchronizes a pseudo-binary signal particularly affected by high jitter with a regenerated clock signal into a synchronized signal. The device can be included between an output of a bipolar-to-binary converter receiving a plesiochronous bipolar signal and an input of a HDB/binary transcoder in a synchronizing circuit of a time-division multiplexer. The clock signal has a period Tj substantially lower than the nominal period of the pseudo-binary signal and offers phase jumps, particularly included between Tj/2 and Tj, for the clock signal to have a mean period equal to the nominal period.

Abstract: A method provides reserved bandwidth in a system having dual unidirectional and oppositely oriented buses. The method is intended to enhance the proposed standard, DQDB Metropolitan Area Network. A portion of the bandwidth shared by the stations in accordance with the proposed standard is reserved for distribution to stations on an as required basis. Each station making a request for bandwidth is allocated a part of the reserved bandwidth. Empty isochronous cells are used to provide the reserved bandwidth on the buses.

Abstract: In asynchronous mode transmission for multiple-service networks with a wide range of throughput rates, it is stipulated that the digital data will be conveyed in standard cells having a header and a data field, with fixed lengths. For the low throughput rate services, which are penalized by this type of transmission as regards their transmission efficiency, the method disclosed provides for the transmission, while performing all the switching operations on the standardized cells, of microcells on those trunk lines where this type of transmission occupies a major place. These microcells result from the cutting up of the standardized cells, preventing the transmission of unnecessary data field lengths.

Abstract: An interface circuit which connects a Digital-Signal-Processor (DSP) to a serial controller. The interface circuit includes a bi-directional multiplexer which converts the separate address and data busses of the DSP to the multiplexed data and address bus of the serial controller. A timing generator is included for keeping track of the number of clock cycles in the present access. A decoder connected to the timing generator decodes the number of clock cycles and generates the appropriate control signals to both the serial controller and the DSP.

Abstract: A slotted CSMA contention technique and arrangement is disclosed for use in a radio data communications systems having a central base station/controller and a plurality of remote data terminals operating over inbound and outbound channels. The channels are divided into major frames, which are further divided into minor frames, which in turn are divided into microslots. An arrangement is devised whereby channel access may be prioritized as between periodic and aperiodic messages by advantageously utilizing the occurrence of these microslots so as to give priority to the former while completely eliminating collisions therebetween and, at the same time, optimally controlling the efficiency of the system as a whole.

Abstract: A sychronous frequency encoding technique (SFET) provides method and apparatus for recovering the timing of an isochronous source node input service signal at the destination node of a synchronous ATM telecommunication network despite cell jitter which arises from the broadband multiplexing and switching delays in the network. A source node control clock is employed which is of greater frequency than that of the service signal and as a result a data under-flow condition occurs in the cell assembly process at a rate that is a function of the difference between such clock frequencies. Regular cell transmission is inhibited for a period at each under-flow occurrence and this pseudo-"stuffed cell" gap is signaled by setting a flag bit carried by an ensuing transmitted cell.