Abstract: In a ring-type network system including a plurality of nodes connected by an L-ring and a R-ring, each of the nodes is constructed by a branch unit for branching data to first and second directions, a first delay unit for delaying the data in the first direction by a first delay time period, a second delay unit for delaying the data in the second direction by a second delay time period, a first combiner for inserting the delayed data in the first direction into a first time slot of a data frame on the L-ring, and a second combiner for inserting the delayed data in the second direction into a first time slot of a data frame on the R-ring.

Abstract: A radio base station inter-station synchronizing circuit is disclosed that is provided in a radio base station device of a TDMA digital mobile communication system and that synchronizes the frame timing generated by each radio base station. The synchronizing circuit includes: data reception/comparison circuit 4 that outputs data match signal S9 when synchronizing signal data transmitted from a synchronized timing control station provided in a mobile communication system match with the same synchronizing signal data held by that radio base station; delay time correction counter 5 that, upon receiving the data match signal S9, subtracts from the timing of the received synchronizing signal data line delay time from the synchronized timing control station to that radio base station; timing holding circuit 8 that holds the corrected synchronized timing; and frame timing generation circuit 9 that generates and outputs frame timing from the output pulse of the timing holding circuit 8.

Abstract: An ATM interface apparatus for time-division multiplex highways includes registers, a counter, FIFO memories, coincidence detection circuits, and flip-flop circuits. The registers hold allocation information of time slots used to transmit cells in asynchronous transfer mode (ATM) communication through time-division multiplex highways. The counter detects the timings and numbers of respective time slots of the time-division multiplex highways. The FIFO memories store cells transmitted through ATM communication lines and exchange the cells between the ATM communication lines and the time-division multiplex highways. The coincidence detection circuits determine, on the basis of the detected time slot numbers and the allocation information, whether time slots are used for the transmission of cells.

Abstract: A star configured multiple access radio communication system wherein a hub station communicates, in time division multiplex mode, with a plurality of remote subscriber stations by a forward link signal path and the remote subscriber stations communicate with the hub on a return link signal path and wherein all received return link signals are time synchronous, and all signals possess the same time division multiplex structure in which a portion of the signal is dedicated to time synchronization. Each remote subscriber station has a synchronization burst sequence generator, each generated burst sequence is constructed such that the time tracking and synchronization process of each return link is relatively unaffected by all other remote stations. At the hub station there is a delay discrimi-nator for each remote subscriber, each delay discriminator includes a first and a second channel. The first channel has a one symbol delay device, a matched filter, and a squaring circuit.

Abstract: A novel and improved method and apparatus for signal acquisition in a wireless telecommunication system having large transmission delay uncertainty is described. A terminal first acquires the forward link signal from a hub and extracts timing information from that forward link signal. Using the timing information the terminal estimates the time at which a next search window takes place during an access slot, and the time and pseudorandom code state necessary to transmit an access probe so as to arrive at during the search window assuming the terminal is located a maximum distance from the hub. The terminal proceeds to transmit additional access probes at times occurring one access slot period plus a delta time interval after the previous transmission. The delta time interval has a duration less than that of a search window associated with each access slot.

Abstract: A method and apparatus for providing full duplex asynchronous communication between two transceivers in a communication system is disclosed. First each bit period is divided in half creating a transmit half bit period and a receive half bit period wherein each transceiver can transmit data during the transmit half bit periods and can receive data during the receive half bit periods. The bit periods of the two transceivers are synchronized so that the transmit half bit periods of each transceiver are aligned with the receive half bit periods of the other transceiver.

Abstract: A timing system (100) for coordinating the components of a distributed digital cross-connect system (10) is provided. The timing system (100) includes a master timing system (102) that receives a network timing reference (98, 99) and generates a master timing signal. A distributed services node timing system (104, 106) is connected to the master timing system (102) and receives the master timing signal. The distributed services node timing system (104, 106) then embeds a timing signal in a data transmission frame (150). Two or more digital cross-connect timing systems (108) are connected to the distributed services node timing system (104, 106) and receive the data transmission frame (150). The digital cross-connect timing systems (108) retrieve the embedded timing signal from the data transmission frame (150).

Abstract: An arrangement for determining transmission delay in a subscriber network which has a plurality of subscriber sets, a plurality of subscriber terminals (to one subscriber terminals to one subscriber terminal being connected at least one subscriber set by a transmission connection implemented in an electrical form), and a central unit, which is common to the several subscriber terminals and connects the subscriber sets to a public switched telephone network. In the subscriber network, time-division data transmission between the several subscriber terminals and the central unit occurs along a common transmission path. A value representing the transmission delay between the central unit and an individual subscriber terminal is determined, whereby a transmission of a subscriber terminal towards the central unit is synchronized in he subscriber terminal with the frame structure of a signal to be transmitted from the central unit towards the subscriber terminal.

Abstract: The invention provides a computer implemented system comprised of two computer terminals for effectuating bidirectional digital, time synchronized communications between networks operating asynchronously with respect to one another. The system repackages the data field of a message received from a network into a message that further includes time indicia corresponding to a time slot in which the repackaged message is to be transmitted so that it may be received by a second network. The repackaged message then is buffered until it is transmitted in the the appropriate time slot so that it may be detected by the second network. The invention overcomes the problem of effectuating communications between distant networks where the message propagation time and time slot period for receiving messages limits the range of communications.

Abstract: A computer network for high-speed data communication, has a data transmission cable with a root and at least one leaf node wherein the upstream transmission is synchronized by information received on a downstream channel. Each client station receives data on a first frequency band, and transmits data on a second frequency band according to synchronization signals received on the first frequency band. The client station's transmission packets may include requests for reserved slots on the second frequency band for subsequent transmissions, and the SCS has a scheduler operable to determine a start time for requested reserved slots, and transmits the start time for the requested reserved slots. The client stations are operable to wait to continue transmission after waiting for the start time.

Abstract: A method of transferring payload, control and messaging data in a communications system, in a serial data stream at a pre-set bit rate per second is disclosed. The method comprises, transferring a chosen integer number of frames of serial data per second. Each frame comprises a number of timeslots of data. Each timeslot comprises a predetermined number of first bits comprising payload related data or messaging bits and a calculated number of second bits comprising control bits. The calculated number is calculated so that the sum of the predetermined number and the calculated number multiplied by the number of timeslots and the chosen integer number equals the number of bits transferred in one second at the pre-set bit rate. Preferably, bits from the second bits at fixed intervals within the serial data stream comprise a out-of-band communications channel with the stream. Preferably, the pre-set bit rate is synchronized to the clock of a host communications system.

Abstract: A method for transmitting random access signals from a mobile unit to a satellite or other control station which requires the transmission of less information than in conventional terrestrial cellular or proposed mobile satellite systems. According to the method, the mobile unit acquires synchronization from the satellite and transmits reduced random access information to the satellite, and the satellite calculates time adjustment information for the mobile units based on the reduced random access information. The random access information is reduced by predetermining a slot number for each mobile unit, and by transmitting only the odd or even status of the frame number desired by the mobile unit.

Abstract: The method is used in an optical transmission network with a plurality of terminal stations (TS1-TSn) connected to a central station (CS) via a tree-like connection structure, to determine a signal transmission delay time between one terminal station (TSi) and the central station. The terminal stations are adapted to send cells containing information signals to the central station in dedicated time slots.

Abstract: A system for efficient time division duplex communication between a base station and a plurality of user stations over a single frequency band whereby guard time overhead is reduced through use of an interleaved frame structure and active adjustment of reverse link transmission timing as a function of round trip propagation time. A time frame is divided into a plurality of time slots. The base station transmits a forward link message to a first user station in a first time slot. The user station responds with a reverse link message in the following time slot. In the meantime, the base station receives a reverse link message from a second user station in the first time slot, and sends out another forward link message to a third base station in the first portion of the first time slot. The delay between transmitting the forward and reverse link messages to a particular user station allows for round trip propagation of the forward and reverse link messages.

Abstract: A method for synchronizing timing of signal transmissions in a telecommunication system (100) determines a "fixed portion" (222) of the propagation delay between the central unit (102) and subscribers (206, 208) in a particular node (202). Additionally, the method determines a `variable portion` (226) of the propagation delay that accounts for the variation of spacing of different subscribers (e.g., homes (206, 208)) on a particular node (202). The preferred method offsets the control unit's (102) receiving window (410) in accordance with the fixed portion, and directs the various subscriber units (206, 208) to offset the timing of signals (314, 322) (i.e., bursts of data) that they transmit by the variable portion (226).

Abstract: A method and apparatus for carrying out synchronous codivision multiple access (SCDMA) communication of multiple channels of digital data over a shared transmission media such as a cable television system coaxial cable, a fiber optic or copper conductor telephone link, terrestial microwave, satellite link, local or wide area network, wireless including cellur network or some combination of these media using suitable interface circuitry. The system includes modems at remote units and a central unit to receive time division multiplexed digital data arranged into timeslots or channels and uses orthogonal codes to encode each channel of multiple data and spread the energy of each channel data over a frame of data transmitted in the code domain. Spreading the data this way makes the system less susceptible to impulse noise.

Abstract: In a method of controlling the transmission of a downgoing control signal, a mobile terminal detects the presence of radio wave of a downgoing control signal in each time slot in response to an inquiry signal received from a base station. The mobile terminal generates an answer signal indicating the time positions of radio waves received within a predetermined interval, and transmits the answer signal to the base apparatus. The base apparatus, receiving the radio condition answer signal, detects time differences between the downgoing control signal sent by the base apparatus itself and other downgoing control signals sent by other base apparatuses. If at least one time difference becomes lower than a predetermined threshold, the base apparatus changes the transmission timing of the downgoing control signal such that the time difference becomes larger than the threshold.

Abstract: A networking protocol for wireless point (base station) to multipoint (user) networks where the users are stationary which utilized time-division multiplexing the in the direction of the base station to the user, heretofore called the downstream direction, and time-division multiple access in the direction of the user to the base station, heretofore called the upstream direction, where medium access control actively assigns time slots in the upstream direction to accommodate varying demands for bandwidth by multiple users, where upstream frame timing is synchronized to the downstream frame timing, where time slots carry individual ATM cells, where the first time slot of the downstream frame carries a frame start ATM cell, where upstream time slot synchronization is maintained to within .+-.

Abstract: A system for time division multiplexed communication over a single frequency band in which guard time overhead is reduced by active adjustment of reverse link transmission timing as a function of round trip propagation time. In one embodiment, during a first portion of a time frame, a base station issues a single burst segmented into time slots comprising data directed to each user station. After a single collective guard time, the user stations respond, one by one, in allocated time slots on the same frequency as the base station, with only minimal guard times between each reception. In order to prevent interference among the user transmissions, the base station measures the round trip propagation time for each user station and commands the user stations to advance or retard their transmission timing as necessary.

Abstract: A method of performing errorless switching in a ring network having one or more rings and a plurality of transmitting routes. The transmission delays or lengths of at least predetermined sections of the routes are compared, and the comparison is used to determine the value of a first delay added to one of the routes. Another delay is added to enable phase alignment of signals so that errorless switching can be achieved. The delays are then adjusted to reduce cumulative delays which could degrade the quality of data transmission.

Abstract: An improved SRTS clock recovery system of a network node that adjusts the range of a received source RTS sample and a locally generated destination RTS sample to compensate for inherent characteristics of a network system. In addition, the improved system extends the range of the RTS samples to properly interpret large phase differences between a source node clock and transmit clock generated by the network node. This novel technique for interpreting source and destination RTS samples enables the improved network node to accurately recover a source clock frequency from a network transmission in a highly stressed network system. Specifically, the SRTS clock recovery system includes an RTS sample interpreter having a slope determinator for determining the expected average change in source and destination RTS samples over time.

Abstract: A data transmission method for transferring predetermined transmission data between a slave side and a master side to which the predetermined transmission data is transmitted and which are connected through a predetermined communications network, wherein the master side generates an independent synchronization clock signal and transmits synchronization data showing the frequency of the independent synchronization clock signal to the slave side, the slave side generates a slaved synchronization clock signal synchronized with the synchronization clock signal of the master side based on the synchronization data transmitted from the master side and generates the transmission data and transmits it to the master side in synchronization with the generated slaved synchronization clock signal, and the master side receives the transmission data transmitted from the slave side in synchronization with the independent synchronization clock signal.

Abstract: A signal generating apparatus generates four sets of signals whose rising timing and falling timing are controlled. One signal among the four signals is produced by employing a first sequence control unit, a first coincidence detecting unit, a second coincidence detecting unit, and a first output controlling unit. A timer increments a count value in response to a timer increment signal to produce a timer output value. The first sequence controlling unit produces two correction values obtained by correcting the timer output value inputted from the timer. The first coincidence detecting unit outputs a coincidence detection pulse when the correction value inputted from the first sequence control unit is coincident with the internally set set value. The second coincidence detecting unit outputs another coincidence detection pulse when the correction value inputted from the first sequence control unit is coincident with the internally set set value.

Abstract: In a time division multiple access point-to-multipoint transmission network, data is transmitted from a central station to local stations in multiframes containing a plurality of frames and a single free period allowing transmit time measurements and reflectometry measurements. Data is transmitted from the local stations to the central station in the form of multiframes containing a plurality of frames and a single free period allowing transmit time measurements and reflectometry measurements, each frame including subframes sent by the local stations, and each local station sending one or more of the subframes contained in a frame. The multiframes are constructed in a way that underuses the data sources, to obtain free periods between the frames, and by time-shifting the frames to construct a single free period per multiframe. Applications include telecommunication networks.

Abstract: A method for connecting a system utilizing message-based synchronization with an external system. The message-based system includes a plurality of nodes interchanging signals containing synchronization messages with information about the priority of the respective signal in the internal synchronization hierarchy of the system. For the external system to be able to utilize the message-based system as well as possible with respect to timing, synchronization status data in the internal format of the external system is transmitted from the interface node of the system utilizing message-based synchronization to the external system.

Abstract: To obtain service from a satellite communication system, a mobile subscriber unit must acquire a TDMA communication channel. Because the satellites move with respect to the surface of the earth, propagation delays and Doppler shift affect the timing and frequency of received signals. A mobile subscriber unit synchronizes to the frequency and timing windows of a satellite communication station by receiving frequency and timing corrections during channel acquisition. The satellite initially estimates correction factors during initial acquisition requests and further estimates correction factors from synchronization bursts from the subscriber unit.

Abstract: A system for use in a local switching center is provided for processing synchronization signals. A transmission sync signal is generated at the local switching center for transmission to a switching center of a higher hierarchy for looping back to the local switching center. The looped back sync signal has a propagation delay time with respect to the transmission sync signal. A time division switch produces clock pulses. A stored pattern is read out of a non-volatile memory according to an address value provided by an address counter which counts the clock pulses of the time division switch. A delay time is also read out of the non-volatile memory according to the same address value. A phase difference signal is produced by comparing the length of the propagation delay time with the delay time read out of the non-volatile memory.

Abstract: In a CDMA communication network, each base station (BS) is made to establish synchronism between a downward transmission signal directed to a mobile station (MS) and an upward reception signal received from the mobile station by adjusting in the mobile station a mobile generated SS pattern into an adjusted SS pattern of producing an upward transmission signal for reception at the base station as the upward reception signal. In order to get the adjusted SS pattern, the base station inserts in the downward transmission signal an inserted signal representative of a propagation delay t(D) between the base and the mobile stations and a propagation delay increment t(d) while the mobile station is in a prelminary state of receiving the downward transmission signal as a downward reception signal first from the base station and is in a steady state, respectively. The signals may ba propagated through at least one communication satellite.