Abstract: A method and apparatus 200 for converting dual 4-wire digital data services (DDS-1 and DDS-2) for transmission over a single twisted pair telephone line 205. The present method includes use of a digital data service remote terminal 219 and a digital data service central office terminal 201. Each terminal converts more than one 4-wire digital data services into a 2B1Q signal for transmission over the single twisted pair telephone line 205. The present method provides an efficient and cost effective technique for increasing 4-wire digital data services to a customer premises without a corresponding increase in the number of telephone lines.

Abstract: A variable gain echo suppressor is provided that utilizes two variable attenuators (410) and (412) that are disposed in the receive and transmit paths, respectively, of a communication system. An echo suppressor (414) receives the input from the far end and transmits the output from the near end and controls the two attenuators to set a variable gain therein. The echo suppressor utilizes a normalized power level which is normalized with respect to the background noise at the respective end and then takes the ratio of this normalized power and the normalized power at the opposite end to define an associated power ratio. This power ratio value is utilized to determine the attenuation for the associated end. When the power ratio is high, this indicates that a stronger signal is being received from that end and a small amount of attenuation is associated in the transmit path from that end. When they aye equal, this will result in both systems having approximately the same attenuation, a mid-level attenuation.

Abstract: A speech signal has its characteristics extracted and encoded (16), transmitted over a limited-data-rate path (18) and is decoded (20) and synthesized (22) at the receiving end. The characteristics include line spectral frequencies (LSF), pitch and jitter. The LSF are extracted by autoregression, and splitvector quantized (SVQ) in a single frame, and, in parallel, in blocks of two, three and four frames. The SVQ codes have equal length and are evaluated for distortion in conjunction with a threshold. The threshold is varied in such a manner as tend to select for transmission those codewords which maintain a constant data rate into a transmit buffer. A single-bit jitter bit, and encoded pitch value, are product coded with the selected LSF codeword, and all are transmitted over the data path (18) to the receiver. The receiver decodes the characteristics, and controls a pitch generated (1226) in response to the pitch value and a random pitch jitter in response to the jitter bit.

Abstract: A multiplex broadcasting method and system which limits an object district for broadcasting of district information such as a commercial message relating closely to the district is disclosed. On the broadcasting station side, multiplex data such as animation are broadcast with a district code such as a postal code number added thereto. On the receiving set side, a district code of the location is registered as an identification number of the multiplex broadcast receiving set in a memory in advance, and the district code of received multiplex data separated by a data extraction circuit and the identification number stored in the memory are compared with each other. Only when they coincide with each other, an image corresponding to the received multiplex data is displayed on the receiving set.

Abstract: A high-speed data processor and data compression method includes an input module for receiving an input data stream from an input port. An encoder is coupled to the input module and performs arithmetic coding to encode the input data stream. An output module provides an encoded data stream from the encoder to an output port. During the encoding process, the encoder performs a combination of parallel and serial processing steps on data in the input data stream. As a result, the processing cycle time for the encoding process is significantly reduced.

Abstract: A method for signal transmission and reception by a bidirectional bus system in which plural devices performing the communication of a command and a request are interconnected over a bidirectional bus includes the steps of providing a frame of a transmission signal on the bidirectional bus the frame including an address field for designating addresses of communicating devices and a data field for designating the command or request to be transmitted, and inserting the discrimination information for discriminating between the command and the request at a pre-set position in the data field. The transmission signal including the discrimination information is transmitted over the bidirectional bus to other devices. A communication system employing such a bidirectional bus system is also provided.

Abstract: The time division multiple access (TDMA) frame time synchronization error for received mobile station burst communications transmitted on the reverse digital control channel is monitored by the receiving base station. A probability density function is then prepared by the base station reflecting the number of instances of each determined length of time synchronization error monitored over a predetermined time period. The probability density function is then processed to identify the percentage of burst communications during that predetermined time period that exceed a synchronization error threshold. If the determined percentage exceeds a given percentage, then abbreviated length burst communication operating mode is ordered by the base station for all mobile stations operating within the cell. Otherwise, conventional length burst communication operating mode is ordered by the base station.

Abstract: A method and apparatus of communicating information using Time Division Multiple Access and adaptive transmission and reception are disclosed. Signal bursts are transmitted from TDMA transmitters to a TDMA receiver wherein the transmitter codes the information and transmits coded information to the receiver using at least one of two timeslots of a plurality of timeslots in a repetitive TDMA frame period. Both of the two timeslots are received whether or not the transmitter has transmitted using one or two timeslots and the received signals are classified as intended and non-intended. Successively received signals classified as intended are then assembled into a block for decoding to reproduce the information.

Abstract: The frame timing control of TDMA signals in cellular systems is implemented in mobile stations and/or base stations according to the invention so that the functions are divided between the frame timing control unit (1) and the microcontroller (2). In this way, the frame timing can be controlled in a flexible manner, for instance when moving from one TDMA cell type to another, without breaking the speech or data communication.

Abstract: A system having a computer, test control logic, an electrostatic discharge unit and a high voltage probe unit is provided for performing multiple, random, asynchronous electrostatic discharge testing of machines. The test control logic includes multiple, asynchronous, random, firing logic for controlling the states of a plurality of output lines which send control signals from the computer to the electrostatic discharge unit and the high voltage probe unit. The test control logic allows a user a preference of testing modes through an interactive input graph. The user may specify either a run time experiment or a specific probability of test coverage test.

Abstract: A diversity scheme for allowing a transmitter/receiver, such as a mobile unit in a mobile telecommunications system, to exchange communication signals with more than one control station, such as a base station or satellite. According to an exemplary embodiment of the diversity scheme, the mobile unit scans for the control channel of a second satellite during idle time slots while communicating with a first satellite during active time slots. Once the mobile unit detects a control channel from a second satellite, the mobile unit stores synchronization information and establishes a communication link with the second satellite if shadowing or other severe fading causes signal quality over a communication link established with a first satellite to fall below a threshold level. The diversity scheme also allows the mobile unit to communicate simultaneously with two satellites, using alternate TDMA frames.

Abstract: A communication system for coupling a plurality of data terminals to a telephone network has a time division multiplexed telephone network access bus, providing a plurality of time division slots containing data, coupled to the telephone network, and a digital terminal access bus coupled to the plurality of communication devices, each communication device being configurable to access any of the time division slots. A controller for configures each communication device to access a time division slot.

Abstract: A signal transmitting apparatus using orthogonal frequency division multiplexing includes an inverse fast Fourier transform circuit for converting a digital information signal into a first multi-value QAM modulation signal. A guard interval setting circuit is operative for periodically generating a guard interval signal equal to a time segment of the first multi-value QAM modulation signal, and inserting the guard interval signal into the first multi-value QAM modulation signal to convert the first multi-value QAM modulation signal into a second multi-value QAM modulation signal. A clock signal generating circuit is operative for generating a first clock signal which drives the inverse fast Fourier transform circuit, and generating a second dock signal which drives the guard interval setting circuit. The inverse fast Fourier transform circuit includes a device for generating a pilot signal which corresponds to a given-order carrier, and adding the pilot signal to the first multi-value QAM modulation signal.

Abstract: For use with a frame-relay network capable of relaying frames having associated flags, a multiplexing circuit and method for providing end-to-end data management over a single frame-relay virtual circuit of the network.

Abstract: The packet communication system enables communication between a communication unit connected in a conventional telephone network and a communication unit in a packet mode network. A device for exclusively selecting the connection network is provided so that, at the time of transmission of a signal from one communication unit to another, the connection path is selected according to the kind of the network to which the other communication unit belongs. At the time of signal reception, the communication unit is connected to only one of the conventional telephone network and the packet mode network. The packet communication system includes a packet processor for converting an information signal, such as speech, inputted from an input unit (for example, a transmitter microphone of a handset) into the form of a packet.

Abstract: An architecture for a radio network having nodes that are subject to dynamically changing topology such as, e.g., a mobile radio network. The network is partitioned into a number of physical subnets wherein each physical subnet includes a certain number of network nodes in relatively close proximity to one another. Each node of each physical subnet is affiliated with a corresponding node of each of the other physical subnets, thus defining a certain number of virtual subnets. A desired communications path is routed from a source node of one physical subnet to a destination node of another physical subnet, by routing certain parts of the path within one or more physical subnets during a first transmission phase, and routing remaining parts of the path within one or more virtual subnets during a second transmission phase.

Abstract: A mobile station, and a method for making a handover in a CDMA cellular radio system, which includes in each cell at least one base station connected to the mobile stations in the cell. The connection includes both a traffic channel and one or more control channels. The transmissions of the base stations are not synchronized with each other. A mobile station, after having established a simultaneous connection with two or more of the base stations while making a handover, transmits to the base stations using the same spreading code. The signals received by the base stations are combined in a base station controller, or the like. The base stations with which the mobile station communicates simultaneously, transmit to the mobile station each using a different spreading code.

Abstract: A method and system provide efficient resolution of transmission collisions in a simultaneous channel access communication environment. At least a first Master device and a plurality of Slave devices utilize the steps of: (1) transmitting, by the plurality of Slave devices upon receiving a contention poll from the first Master device, information to the Master device, wherein transmissions of the Slave devices provide a collision; (2) selecting a subset of Slaves allowed to retransmit following the collision, by the first Master device using a collision resolution poll in accordance with a predetermined depth first tree search technique; and (3) retransmitting, by the subset of Slave devices, the information to the Master device, and, where another collision is obtained, recycling to step 2 and repeating steps 2 and 3 until all collisions are resolved.

Abstract: Methods and systems for determining the address of the nearest downstream reconfiguration unit in a dual ring communication system. In a dual ring communication system having a plurality of reconfiguration units one of the reconfiguration units determines if a Reconfiguration Unit Monitor is active on the system. If a Reconfiguration Unit Monitor is not active the reconfiguration unit requests and stores address information from the remaining reconfiguration units in the ring and assembles a ring sequence reconfiguration unit ring map. The reconfiguration unit transmits the reconfiguration unit ring map to the remaining reconfiguration units in the ring. Reconfiguration units receive the reconfiguration unit ring map from the Reconfiguration Unit Monitor and extracts the address of the nearest downstream reconfiguration unit from the reconfiguration unit ring map.

Abstract: A method for transmitting packets or cells (or both) in a communications network 10 is disclosed. The packets or cells are transmitted along a forward communications path in a network from a source node h1 via one or more intermediary nodes r1, x1, r5 and r2 to a destination node h4. At the intermediary nodes r1, x1, r5 or r2, the packets or cells are received in a buffer 38 or 42-1 to 42-4. The packets or cells are transmitted along the forward communications path according to a transmission schedule. In the presence of congestion at one of the intermediary nodes x1, an indication of the congestion is provided to the destination nodes h4 of the first packets to be transmitted according to the schedule. An indication of the congestion of the first packets or cells is provided by the destination nodes h4 of the first packets or cells to the source nodes h1 of the first packets or cells via a feedback communications path.