Abstract: A system for transmitting digital data messages between a plurality of stations using a common communications channel is disclosed. The data messages are assembled into data packets which include address and control information. The data packets are then transmitted from the stations over the common channel using appropriate data representative waveforms or modulation. A composite waveform representative of the data packets including potentially time overlapping data packets are received and processed to decode at least one packet. The waveform representative of the at least one decoded packet is reconstructed and subtracted from the received composite waveform to obtain a residual waveform. The residual waveform is then further processed to attempt to decode at least one further packet.

Abstract: A wireless user terminal (10), such as a cellular telephone, is of a type that receives a forward digital control channel that is comprised of a plurality of continuously transmitted frames, comprised of time slots, which are logically organized into Superframes contained within Hyperframes. A method includes the steps of (a) receiving and storing a first SPACH slot from a first Hyperframe; (b) receiving and storing at least a F-BCCH slot from a second, next Hyperframe; (c) receiving a second SPACH slot from the second, next Hyperframe; (d) decoding the stored first SPACH slot and the second SPACH slot and calculating a CRC of each decoded SPACH slot using DVCC information contained within the received F-BCCH slot; and (e) comparing a state of a BCN flag in the first SPACH slot to the state of the BCN flag in the second SPACH slot and, if they are equal, declaring that the received and stored F-BCCH slot is valid.

Abstract: A personal communications system is described which includes components of software and hardware operating in conjunction with a personal computer. The user interface control software operates on a personal computer, preferably within the Microsoft Windows.RTM. environment. The software control system communicates with hardware components linked to the software through the personal computer serial communications port. The hardware components include telephone communication equipment, digital signal processors, and hardware to enable voice, fax and data communication with a remote site connected through a standard telephone line. The functions of the hardware components are controlled by control software operating within the hardware component and from the software components operating within the personal computer.

Abstract: An office point is connected to a central office using a plurality of basic rate interface (BRI) lines. A physical layer of the office point provides connection to the BRI lines. A second layer uses a first table for accessing terminal endpoint identifiers (TEIs) using port numbers and logical link numbers. A third layer uses a second table for accessing logical terminal number using the port numbers and the logical link numbers. The third layer also uses a third table for using logical terminal numbers to access service profile identifiers.

Abstract: A more efficient and less complex structure and method for combining multiple user channels onto a single carrier frequency in spread spectrum communication systems. A single transformation element, such as a fast Hadamard Transformation processor, is used to orthogonally encode and combine a series of subscriber digital data signals in parallel. Portions of the orthogonally encoded and combined data signals are then selected over preselected time intervals to generate a single encoded data signal which is subsequently PN spread, subjected to analog signal processing, and transmitted to system subscribers. This is typically effected by summing digital values in an array of data signal combiners. An exemplary data transformation device uses at least one of a preselected set of orthogonal functions as a controlling pattern for interconnection of the combining elements.

Abstract: For a call-associated bit rate monitoring, it is provided that a count value (d) corresponding to the relationship between the maximally allowed transmission bit rate and the transmission bit rate declared for the connection and a minimum counter reading (W.sub.min) (or, respectively, a maximum counter reading (W.sub.max)) are determined during the course of the setup of the respective connection. Over and above this, the plurality of message cells appearing during the course of established connections is acquired by a global counter that is incremented by a value "1" at every appearance of a message cell. In response to the appearance of a message cell, a sum value (or, respectively, difference value) is additionally individually formed for the respective connection from a momentary counter reading maintained for the respective connection and the global counter reading.

Abstract: A communication system, such as an ATM network, is disclosed having a multiplexing device formed by a plurality of access terminals for users who have cells to be transmitted at a certain rate, and at least one connecting terminal. An allocation circuit determines, at a current date, the supply of a cell (called chosen cell) to the connecting terminal. The allocation circuit includes a circuit for producing a first destination identifier (VP), a theoretical date determining circuit, a tree circuit, a sub-tree circuit, a root date determining circuit, and an extracting circuit. The theoretical date determining circuit is for determining a theoretical date for the transmission of the available cells of each service circuit as a function of the rate.

Abstract: A data transmission system including a telephone service subscriber loop utilized for transmission of data including telephone service signals; a splitter operable for splitting the subscriber loop into a first transmission path including a low pass filter which accommodates a continuation of telephone service signal transmissions along the subscriber loop and a second transmission path, said second transmission path including a capacitive element for attenuating the telephone service signals; and a digital subscriber loop transceiver coupled to the second transmission path for implementing high rate digital data transmission over the subscriber loop, the transceiver including a frontend processing circuit having a transmit path and a receive path, at least said receive path comprising a high pass filter for further attenuating said telephone service signals.

Abstract: A satellite communications system is provided for full mesh connectivity between a number of earth terminals via a satellite link. The earth terminals are connected to user access devices to receive and transmit voice, video and data and are operable to generate bursts to transmit user data via a satellite, and to process data received from the satellite and transmit it to the addressed user access devices. The terminals each comprise a programmable computing device which organizes bursts in at least one of a plurality of slots constituting a time division multiple access frame in accordance with a burst plan. Billing is based on usage and committed information rates. Data and voice can be billed on one invoice.

Abstract: A method of scheduling cell transmission over an asynchronous transfer mode communication channel. The channel has a characteristic transmission rate that is related to the system clock frequency .function. and an allowed cell rate ACR expressed as a floating point number having a mantissa m, and an exponent e, where 0.ltoreq.m.ltoreq.511, 0.ltoreq.e.ltoreq.31 and ACR=(1+m/512)*2.sup.e. If m.gtoreq.128 then the reciprocal of the mantissa portion (1+m/512) is evaluated by piece-wise linear approximation of the function: ##EQU1## Otherwise, if m<128 then the mantissa portion is evaluated by piece-wise linear approximation of the function: ##EQU2## A selected cell is then scheduled for transmission at a time T relative to the transmission time T.sub.0 of a cell transmitted immediately prior to the selected cell, where T=T.sub.0 +(ACR.sup.-1)*f.

Abstract: A system associates a time-stamp with data inputted at its input, specifying an instant with a predetermined delay after receiving the data. The system outputs said data at an output according to the time-stamp. Inputting and outputting is timed by different clocks, which are periodically synchronized. At certain times the source of synchronization may change, potentially causing a discontinuity in synchronized time. The system contains potential discontinuity signalling means, for signalling a potential discontinuity in a progression of the clocked time. The predetermined relation is corrected when such a potential discontinuity is signalled for an instant between inputting and outputting the data.

Abstract: When establishing a link (i-j) between two nodes i, j in a mobile radio communications network, transmission parameters are assigned such that conflicts and interference with nodes that neighbor the nodes i and j are avoided. A time-slot and a frequency-code value are assigned to the link (i-j) from a defined set of time-slots T, and from a defined set of frequency-code values FC. Set T contains time slots (t) during which links in the network can be activated, and set FC contains frequency-code values (f, c) each of which specifies a frequency or a frequency-code pair for association with the links. A time slot t.sub.k is first chosen from set T which slot is not in use for links between node i and nodes neighboring node i, or for links between node j and nodes neighboring node j. A frequency-code value (f, c).sub.1 is next chosen from set FC which value is not in use by any node that neighbors node i or by any node that neighbors node j, during the chosen time slot t.sub.k.

Abstract: The disclosed system is capable of allocating plural subchannels based on user data priority. In one embodiment, a subscriber determines the throughput it would like and fragments a data packet in that number of service data units, and requests that number of subchannel allocations from a serving base station. Upon receipt of the access request(s), including any priority indicators, the system determines from the access request(s) whether to allocate the subchannel(s) to the subscriber. Further access requests are received periodically and scheduled, and when a higher priority message is received, completion of a lower priority message is deferred and the higher priority request allocated. Thus, an improved access procedure is provided accommodating varying throughput rates with a more robust transfer because of the packet fragmentation and multiple-subchannel transfer.

Abstract: An expansion bus is provided for use with bus systems of the type wherein only a single data signal or data packet may be transmitted over the bus at any one time, such as Ethernet bus systems. The expansion bus includes a set of repeater units each connected to a set of local transceivers respectively connected to remote bus masters, such as remote computers. The repeater units are interconnected by a single data bus. Collision detection and arbitration of usage of the single data line is achieved using a distributed symmetric arbitration system as follows. Each repeater unit has a dedicated activity line which is interconnected to each of the other repeater units. Each repeater unit also includes an identical arbitration unit connected to the respective activity lines. When a repeater unit receives data from a local transceiver for transmission onto the single data bus, the arbitration unit of the repeater unit asserts an activity signal onto the corresponding activity line.

Abstract: A connection method of a digital cordless telephone apparatus allows communication between a first calling side portable unit and a second called side portable unit of the plurality of portable units. The first portable unit transmits an access request signal for requesting a call to the second portable unit. A base unit receives an access request signal and determines whether or not there are any transmission slots and reception slots available for connecting the first portable unit to the second portable unit via the base unit. If there are the available transmission slots and reception slots, then the base unit uses usable slots to allow a call between the first portable unit and the second portable unit. If there are no available transmission slots and reception slots, then the base unit transmits a control signal including busy information.

Abstract: A method for automatically initializing a wireless, packet-hopping network, such as a building system control network which is used to control the operation of a building system, such as a lighting, security, and/or HVAC system. In accordance with this initialization method, each node in the network first determines its entire connectivity, i.e., its connectivity to every other node in the network within a prescribed range thereof, and then routes this connectivity information to the building computer. This connectivity information is transmitted in a packet or set of packets that are routed to the building computer, thus minimizing the volume of traffic that the building computer and the nodes nearest thereto must handle, and thus, significantly reducing the probability of collisions of the connectivity information packets. This connectivity information is transmitted using a "software handshaking" technique to ensure that all of the connectivity information is received by the building computer.

Abstract: An ATM switch capable of preventing the network resource from being wasted during the occurrence of an overcrowding condition. In the ATM switch, both a message type and a processing mode are stored in correspondence to the connections. When the discarding of a cell occurs, the connection to which the discarded cell belongs is set to a discard mode by a cell discard controlling circuit, and each cell constituting the same message as that of the discarded cell out of the subsequent cells is discarded, and when a demarkation of the message has been detected, the processing mode is returned to a transfer mode, whereby the subsequent received cells are transferred in a normal manner. Thus, the cell which has become useless for a reception terminal is discarded in the network.

Abstract: Efficient methods for rerouting failed channels on to spare channels in a multichannel transmission system are described. One method uses a minimal amount of rerouting to reroute all the channels if one or two line cards fail.Another set of methods reroute up to two failed channels on to spare channels in the event of channel failures. With this method only the failed channels are rerouted. However the failed channels may have to be routed through a slightly larger, but minimal, number of additional hops than with the first method.

Abstract: A multiplexer includes an n-th stage as a final output stage (n=integer, 2.ltoreq.n); j stages (j=integer, 1.ltoreq.j.ltoreq.n-1), the n-th stage including a D flip-flop having a clock input terminal for receiving a first clock signal, a data input terminal for receiving serial data, and a data output terminal, the D flip-flop synchronizing the clock signal with the serial data; and a j-th stage including m.sup.n-j-1 (m=integer, 2.ltoreq.m) multiplexer blocks, each multiplexer block including D flip-flops and having data input terminals for receiving m parallel data inputs and a clock input terminal for receiving a second clock signal produced by frequency division of the first clock signal, and converting the parallel data into serial data in response to the second clock signal. The multiplexer further includes a variable delay circuit connected to the data input terminal of each multiplexer block in one of the second to the n-th stages for delaying the data input by a variable delay time.

Abstract: A system and method which delivers data at very high data transmission speeds to many locations simultaneously. A SCANS system is supplied with a satellite uplink communication module which transmits data to an earth orbiting satellite. The satellite then retransmits the data over a wide geographical area. Each receiving location is equipped with a small satellite dish to receive data from the satellite. Advantageously, the satellite dish is connected to a work station in the switching office which then processes the received data and delivers all information in a form that is ready for use by the modules' switching office. Errors during data transmission are noted for further processing. After the data is broadcast from the beginning to the end, the SCANS system pauses for a brief interval during which time each receiving station performs error detection, error correction, and other recovery procedures on the data it just received.