Abstract: Method and apparatus are provided for data communication control within the communication controllers of stations within a local area network. In general, the method and apparatus involves maintaining within the command and status control interface unit of the communication controller, receive and transmit command queues as well as receive and transmit status queues. Pluralities of receive and transmit data packet storage locations are provided for storing data packets to be received as well as transmitted. Each receive command is uniquely associated with a data packet storage location. Receive and transmit commands are buffered in a pipeline manner in the receive and transmit command queues, respectively, whereas receive and transmit status bits are buffered in a pipeline manner in the receive and transmit status queues, respectively.

Abstract: In this system STM (Synchronous Transfer Mode) and ATM (Asynchronous Transfer Mode) cell streams are supplied to corresponding STM and ATM switching exchanges STME and ATME via the cascade connection of a multiplexer (MUX), a transmission link (LI) and a demultiplexer (DMUX). The MUX and DMUX are each constituted by a switching element with a plurality of inputs (II/2; I3) and outputs (03, 04/5) coupled to a common switching means (SB1, TM1; SB2, TM2) via respective receiver (RC1/3) and transmitter (TC1/3) circuits. The common switching means samples the input cell streams at a frequency at least equal to the sum of the time slot frequencies of the time frames of the input cell streams. The time frames of the input and output cell streams are phase synchronous and the sampling of the input cell streams is performed in a predetermined order. The cells of the resultant (STM/ATM) cell stream are supplied to the transmitter circuits in function of their destination.

Abstract: To be able to load an ATM switching network as efficiently as possible, the successive cells of one and the same connection are routed to the output by as many different paths as possible; however, mutual overtaking of successive cells must be avoided or corrected. Each cell is held at the output until it is certain that no older cell can be buffered in the switching network. Before the cell is passed on, a check is made to determine whether the cells received from the switching network later include an older cell which must be passed on before that cell. At the input end, consecutive numbers ("Sequence Numbers") are allocated to the cells. A buffer (1) at the output end is operated, at least in part (1 . . . d), in the manner of a shift register, thereby introducing a predetermined delay. Prior to the output of a cell, at least the shift-register-like portion of the buffer is examined as to whether a cell written in later is to be put out earlier: if so, the two cells are interchanged.

Abstract: A portable self-contained T-carrier network simulating device including multiple modules which are removably mounted and connected and include a first customer premise simulation which includes an actual network smart jack and a repeater, a first T-carrier link simulation which provides conductive isolation between the ends thereof, bipolar violation removal and signal level change control to simulate a fiber link, a switching office simulation including an actual network digital signal cross-connect frame (DSX) and repeater, a second T-carrier link simulation which comprises wire T-carrier link simulation including an actual manhole repeater and line reversal device and also includes a simulation of bridge tap which is accessible from the front panel to simulate variation in the effect of positioning of the bridge tap, and a second customer premise simulation which includes an actual network smart jack and CPE jack.

Abstract: A multiple access satellite communication system in which a plurality of mini-earth stations each transmit data packets to hub earth station via a satellite over an inbound channel, while the hub station transmits to the mini-earth stations in a broadcast mode over outbound channels. Each mini-earth station selectively uses a fixed assignement access method, random access method, and demand assignment access method, depending on the frequency of the transmission from a terminal connected thereto, the amount of transmitted data, and whether or not the transmission from the terminal is periodic. The hub station outputs a reception response signal to the outbound channels by determining whether or not a conflict of data packets or a transmission error has occurred on the inbound channels. Packets for re-transmission are sent out to the inbound channels by the demand assignment access method at all times, with no regard to the access method used at the time of transmission.

Abstract: An internetwork communication system provides communication from a first local area network to a second, ring-type, local area network via a bridge. The bridge receives a frame from the first local area network and transmits a dummy frame followed by a transfer frame to the second local area network. The transfer frame defines a node of the second local area network as a distant apparatus (receiver) and a node of the first local area network as a self apparatus (sender). The bridge later receives the dummy frame from the second local area network, after transmission of the dummy frame around the ring, and deletes the dummy frame and the transfer frame received following the dummy frame so that the communication in the second local area network does not circulate indefinitely around the ring.

Abstract: Apparatus, and accompanying methods for use therein, for a large (e.g. approximately 1 Terabit/second), fault tolerant packet switch (200), particularly suited for asynchronous mode transfer (ATM) communication, which utilizes cell address look-ahead in conjunction with parallel planes of self-routing cross-points (550), staggered time phased contention resolution and shared memory based input and output modules (260 and 270, respectively). Each incoming packet cell has added thereto an additional header field containing information identifying a particular output module and a particular output port of that module. An input module associated with the switching crosspoints changes the additional header information to identify the particular output module of the next subsequent packet cell.

Abstract: In configurable intelligent primary multiplexers the individual 64 kbits/s channels of several incoming and outgoing PCM-links are to be re-arranged with the aid of a commercially available integrated circuit in such a manner that the desired channel configuration is achieved. The signalling information belonging to the individual channels is transmitted for all intelligence channels of a link in the time slots No. 16 of the superframe, each time slot containing the signalling information of two channels. In order to be able to perform the re-arrangement of the signalling information in parallel to that of the intelligence channels without the continuous help of a processor the signalling bit stream lined-up by an ancillary device is converted in such manner that the signalling information of the individual 64 kbit/s channels is in identically numbered time slots as they are allocated to the corresponding intelligence channels.

Abstract: In a digital messaging system (10), an apparatus (37) and method for determining whether a DTMF (Dual Tone Multi Frequency) digit is present on an input signal (11,12). A heuristics engine (37) performs a series of tests on the input signal (11,12) using a set of parameters that are stored in a RAM (38). There is one parameter for each of a set of input signal (11,12) characteristics and for each of a set of operating modes of the digital messaging system (10). All of the parameters are configurable. The configurability allows for the use of non-standard telephone equipment (13,14) and minimizes deleterious effects such as talkoff. The tests are from the set of sets comprising an absolute magnitude test, a frequency deviation test, a twist test, an echo test, a consistency test, and a temporal test.

Abstract: A broadcast facility is provided in a synchronous network comprising a number of nodes (b 20l ) coupled via a star coupler (b 21l ). Data is transmitted via the network in a sequence of frames. Each node with a public write to send transmits it to all system nodes (including itself) in the next available frame. Each node has its own identifying characteristic, e.g. a unique assigned frequency. These identifying characteristics determine the notional order in which data packets within a frame are received thus providing each frame with a timestamp.

Abstract: A multi-slot call relocation control method and system having a multi-slot call switching system and/or transmission equipment constituted by an address control memory, address controller and address location changing circuit whereby address write and read information for a channel memory is controlled. Where unoccupied circuits are 2.sup.N (N: natural number) times the basic switching unit, incoming calls with a maximum of 2.sup.N basic switching units in capacity may not be switched or transmitted by the unoccupied circuits depending on their status involving the presence of other calls. In that case, calls are relocated within a frame using the fewest steps possible. This is achieved by a neural network in the address control memory of multi-slot call switching system A, the neural network learning to output a call allocation pattern such that the number of times calls are relocated becomes minimal.

Abstract: In a packet communication method, a packet communication device, an input transmission frame of V (bytes/sec) consisting of a transmission overhead of V.sub.OH (bytes/sec) containing control information for transmission and a pay load of V.sub.p (bytes/sec) of c (=a+b) bytes, the outer cell consisting of an information field of a b-byte length containing transmission data and a header field of an a-byte length containing a first control information for transmitting the information field. The transmission overhead is removed from and a second control information is added to the input transmission frame. The input transmission frame with the second control information and without the transmission overhead is converted to a plurality of inner cell trains of f (=b+j) bytes length, the inner cell trains consisting of an information field of a b-byte containing the transmission data and a second header field of j (=a+d) bytes consisting of the first control information and the second control information (where f.

Abstract: An apparatus for establishing a flexible rate interface (FRI) link on a standard ISDN link. The FRI link has its own signaling channel that is distinct from the signaling channel of the standard ISDN link, and the signaling channel of the FRI link is transparent to intervening switching systems. There are no geographical restrictions on a FRI link. The signaling channel of a FRI link may be established by designating a B channel of a standard link, by using a logical link of a D channel of a standard ISDN link, or by using standard ISDN user information transport facilities to communicate the signaling channel. FRI transport channels are B channels of a standard ISDN link or subchannels of a B channel.

Abstract: A TDMA communication system (100) comprises a two-way subscriber unit (112') and at least two base stations (104b and 104c). The subscriber unit monitors the strengths of signals (114') received from the base stations. As the subscriber unit roams within the area serviced by the communication system, the received signal strength will vary as the subscriber unit moves nearer to or farther from the base station that is transmitting the call. When the subscriber unit moves out of the range of the base station, the subscriber unit determines, based on certain predetermined criteria, with which base station to communicate.

Abstract: A packet network in which the qualities of service can be maintained for different communications of different classes of requirement for quality of service, regardless of types of calls and data. In this packet network, a communication resource is subdivided into sub-resources which are to be allocated to communications classified into communication classes, where an amount of communications within each sub-resource is controlled independently to satisfy a required quality of service. Also, first type of calls for which a ratio of a maxium transfer speed of each call with respect to a transfer speed of multiplexed line of the packet network is greater than a predetermined threshold value, and second type of calls which are not the first type of calls are distinguished, and a priority control to favor the first type of calls over the second type of calls is performed.

Abstract: A network topography and associated protocol for exchanging data and control information between stations arranged in a daisy-chain wide-area-network (WAN) and a local-area-network (LAN). The protocol includes a circuit layer which routes messages between WAN stations, and a slot layer which routes slots between LAN channels and WAN devices. The protocol uses virtual circuits to route messages between devices. Broadcast messages distribute control information to all circuits. A circuit-specific control message allows passing control information to each circuit. Virtual circuits are established with a broadcast circuit-connect message and disconnected with a broadcast circuit-disconnect message. The maximum message size is regulated in accordance with the transmission speed of links over which a message must travel.

Abstract: A packet data communication network employs sequence numbers in message packets to identify the packets transmitted for a message, so that the order of packets can be checked, and so that the occurrence of lost or duplicated packets can be detected. A method of keeping track of these sequence numbers is provided. Any number below or above a bounded sequence number acceptance window is ignored (not accepted). Bit maps are established for the range of numbers within the bounded window, each bit representing a sequence number and the bit maps indexed by sequence number. One bit map is a received packet map, used to keep track of which sequence numbers have been received and thus to filter duplicate sequence numbers. An end-of-message bit map is used to record the positions of packets having end-of-message flags, and this is used with the received packet map to determine whether all packets of a message have been received, so that an end-of-message trigger can be generated.

Abstract: A terminal server architecture includes a central processing unit (CPU), a data movement module, local area network (LAN) interface and a plurality of connected terminals. The CPU manages pointers to data using command status registers to instruct the data movement module to actually perform data movement between the terminals and the LAN.

Abstract: A data packet switching network is formed by a number of transmitting/receiving stations which are interconnected by radio communication channels through which data packets can be transferred from one station to another according to a routing scheme. Each station is capable of altering its own access rate and of calculating and transmitting first, second and third parameters. The first parameter is indicative of the respective station's output flow (the number of packets successfully transferred per time unit). The second parameter is indicative of the respective station's input flow increase tendency (a measure based on the output flows of the neighboring stations which the station can relay). The third parameter is indicative of the load of the respective station. In each station, the first parameter is calculated and transmitted at regular time intervals to all neighboring stations in reach of the respective station.

Abstract: In a communications system, a base station has a memory for storing interval control values representative of time-varying traffic pattern of the communications system. A time-keeping circuit recalls a stored interval control value from the memory according to different time of day and a battery-saving command signal is sent from the base station at variable intervals as a function of the value recalled from the memory. Power supplies of a remote station are interrupted for a constant brief interval in response to the battery-saving signal, so that the remote station is powered for a shorter interval during a light traffic period and for a longer interval during a heavy traffic period. In a preferred embodiment, traffic data is automatically collected from the communications system and the stored interval control values are updated according to the collected traffic data.