Abstract: A method for providing reliable multicasting is described. A transmitted multicast packet is received at second devices, each of which in response transmits a first acknowledgement. If a second acknowledgement, which acknowledges the first acknowledgement, is not received within a predetermined time period, the first acknowledgement is retransmitted. If all first acknowledgements are not received within a preset time period, the multicast packet is retransmitted. If the retransmitted multicast packet has been received, at each of the second devices, if the second acknowledgement has not been received the first acknowledgement is retransmitted, while if the second acknowledgement has been received, the retransmitted multicast packet is ignored and no additional first acknowledgement is transmitted.

Abstract: A system and method are provided which add, via an add-on module, synchronization functionality to an instrument that does not otherwise support such synchronization functionality. Various synchronization techniques may be supported by the synchronization module. For instance, in certain embodiments the synchronization module supports message-based synchronization techniques and/or time-based synchronization techniques. Accordingly, in certain embodiments, the add-on module supports synchronization with another device (e.g., another instrument or another add-on module coupled to an instrument) via synchronized local clocks (e.g., IEEE 1588) and messaging over a communication network. In certain embodiments, the add-on module additionally or alternatively supports the use of “time bombs” to trigger scheduled actions on the instrument with which the synchronization module is interfaced.

Abstract: Disclosed is a time-synchronization algorithm for use among disparate systems, such as between a controller system and a system having one or more application workstations. In an embodiment of the invention, the workstation system acts as a master timekeeper, ensuring that the time stored in the controller system is in synchrony with the time kept by the workstation system. In a further embodiment of the invention, the time-synchronization system provides staggered time-synchronization signals from each of two or more workstations for receipt by the controller system. The controller system sets its local time by resetting the time for each such incoming synchronization signal. In a further embodiment of the invention, each of two or more workstations employs a technique for evaluating the error accumulated in the controller's time clock and transmits a time-synchronization message in response to finding that the accumulated error has exceeded a predetermined acceptable error threshold.

Abstract: OFDM signals each including a plurality of subcarriers (including data carriers and pilot carriers) orthogonal to each other are received by a plurality of receiver antennas. The received OFDM signals are each OFDM-demodulated into a plurality of receive subcarriers. Based on the plurality of receive subcarriers, the propagation coefficients of a plurality of space paths are estimated. An inverse matrix of a propagation matrix whose elements are the estimated propagation coefficients is calculated. Interference cancellation is performed for the plurality of receive subcarriers by using the inverse matrix, and transmit subcarriers multiplexed in space are estimated. A reliability of the inverse matrix is calculated. A pilot carrier is extracted from the estimated transmit subcarriers, and the extracted pilot carrier is weighted according to the reliability. An error included in the plurality of receive subcarriers is corrected based on the weighted pilot carrier.

Abstract: To synchronize time between network devices equally capable of accurately maintaining an indication of current time, one of the network devices is deemed to be a reference for time and the other network devices synchronize their indications of current time to the reference. To synchronize copies of data at multiple network devices, each network device maintains a counter representative of the passage of time but not necessarily of current time. The counter at each device is periodically synchronized with the counters of other network devices. When data is changed at a network device, the value of the counter at the time of changing is stored in association with the changed data. Stored counter values are used to determine whether a local copy or a remote copy of the data is likely more recent and therefore preferable. A further test may be applied if a counter value comparison is inconclusive.

Abstract: A method and system to synchronize a first device and a second device includes generating a first tone by the first device, the first tone one of including an identity of the second device and generated at a predefined time, receiving the first tone by the second device, setting a clock of the second device based on the received first time, and sending an acknowledgment by the second device to the first device.

Abstract: A two-way time transfer protocol includes: sending a signal from a first node including a first clock and a first time interval counter coupled to the first clock over a transport physical layer coupled to the first node to a second node coupled to the transport physical layer, the second node including a second clock and a second time interval counter coupled to the second clock; then sending a last second node time interval counter value from the second time interval counter of the second node over the transport physical layer to the first node; and then comparing at the first node a last first node time interval counter value to the last second node time interval counter value. A first-way path latency from the first node to the second node is substantially equal to a second-way path latency from the second node to the first node, and all of a first node transmit delay, a first node receive delay, a second node transmit delay and a second node receive delay are substantially constant.

Abstract: Communicating nodes in a network exchange state variable signals indicating the timing of periodic operations performed at the nodes. Each node autonomously controls the timing of its periodic operation so as to distance the timing from the timing of the periodic operations performed at other nodes. If the periodic operations include data transmission, this arrangement enables the nodes to avoid data collisions. The nodes can also adapt autonomously to changing conditions such as changing priority levels and the addition and removal of nodes.

Abstract: A server apparatus receives packetized data and transmits the packetized data over a network. The apparatus includes an input for receiving the packetized data from a signal source. An AC clock counter receives an AC power signal and generates a count value in dependence upon a frequency of the AC power signal. An output is coupled to the network and transmits the packetized data and the count value to a client device. A clock associated with the client device is controlled in dependence upon the count value.

Abstract: A system for locating a client in a wireless network. The system includes at least three access points. Each access point is adapted to wirelessly communicate with a client having a location using packeted data, be placed in wired data communication within a selected data network; and to share a common precise time reference using the selected data network. The system further includes a switch adapted to translate the relative position of the access points based on a shared common precise time reference and to calculate the location of the client based on a transmission from the client.

Abstract: Virtual concatenation circuitry is disclosed which provides stall need detection and an associated stall mechanism in a network element of a data communication network. The virtual concatenation circuitry in a preferred embodiment is operative to provide differential delay compensation for one or more member streams of a virtual concatenation stream. The differential delay compensation involves introducing delay into at least one of the member streams. The stall need detection aspect of the invention relates to detecting a condition under which introduction of the delay is required for alignment of member streams, for example, upon addition of a member stream to the virtual concatenation stream. Such a condition may arise, for example, if a transmission delay of an added stream is larger than that of all other member streams of the virtual concatenation stream.

Abstract: A system and method for clock synchronization in a network having one or more asynchronous data links is provided. A clock signal is propagated through, at the physical layer, a sequence of network devices linking a source network device to a destination network device of the network. Each asynchronous data link between the source network device and the destination network device is adapted to receive an incoming clock signal from the previous network device and then provide a clock signal synchronized to the received clock signal to the next network device of the sequence. At the same time, each network device of an asynchronous segment of the network can continue to transmit packets of data asynchronously. By locking the link-based frequency on a per link bases, the receiver clocks located at the edge of a network can be tied directly to a primary source located in the core network.

Abstract: Systems and methods for implanting synchronous data transfer between clock domains are disclosed. An exemplary system may comprise an adaptable data path having an input for receiving a signal from a first clock domain and an output in a second clock domain. A controller is operatively associated with the adaptable data path. The controller is responsive to operating parameters to configure the adaptable data path to align a logical clock pulse on the signal received from the first clock domain with the same logical clock pulse in the second clock domain based on a measured delay between the first and second clock domains.

Abstract: A method for compensating for one or more transmission delays between a multiplexer, a first node and a second node.

Abstract: A digital information mapper and method for mapping sequences of information characters into a SONET (synchronous optical network) payload in such a manner that there can be an arbitrary mixture of control and/or data values in those sequences. Each information character comprises 9 bits consisting of an 8 bit information byte, being either a control byte or a data byte, and one octet type bit identifying the byte as control or data. A processor applies a mapping algorithm of a mapping module to the input information characters. The mapping algorithm is applied to sequences of eight input information characters, the algorithm being operable to map the information bytes of each sequence of eight information characters to eight of a sequence of nine contiguous SPE octets. The algorithm then maps the octet type bits for the eight mapped information bytes of the character sequence to the ninth octet of the contiguous SPE octets of the SPE octet sequence.

Abstract: A communications network (100) has coordinator devices (10) each transmitting a beacon message in a cluster area (30). Neighboring coordinator devices (1, 2) define overlap areas (60) in which each beacon message of the neighboring coordinator devices is present. Neighboring coordinator devices (1, 2) may also define non-overlap areas (204) in which each beacon message is present. A method for distributing communication signals includes providing nodes (50), (51,52) within a transmission region (30) of the coordinator devices (1, 2). The node (50) or nodes (51, 52) detect at least one beacon message of the neighboring coordinator devices (1, 2), determine the existence of a condition (302), and warn neighboring coordinator devices of the condition. The condition (302) is corrected by making an adjustment to the communication signal (such as beacon timing) by a correction amount (304).

Abstract: A system for receiving and handling a scrambled input data signal that includes a preamble with a start of frame delimiter (SFD) initiates an SFD search on the scrambled input data, thereby attempting to save an initialization period. The initialization period may be of the order of 7 uS, and its saving results in improved timeline management enabling antenna diversity and the possible use of high performance algorithms. The system may use two parallel paths for signal processing, each having an SFD detector and a descrambler. If the detected SFD is short, then the second path is disabled, and if it is long, then the first parallel path is disabled. Alternatively, the first path can be used for a finite period of time (for e.g., 40 symbols) and if the SFD is still not detected, the first path is disabled, and the system uses only the second path.

Abstract: In the case of radio base stations of different kinds, a synchronization in a radio section cannot be established so that the efficiently effective use of electric waves cannot be retained. According to the invention, therefore, there is provided a TDMA type mobile communication system 100 comprising: a plurality of radio base stations of different system kinds (i.e., a general type radio base station 1, an IP connection type radio base station 10 and a main digital cordless phone 2); mobile phones 5A and 5B wirelessly connected with the plural radio base stations; and a private branch exchange 4 wired with the radio base stations. The radio base station receives, when a synchronized operation mode is decided, a frame signal containing a control CH signal, from a reference radio base station (i.e.

Abstract: A method of processing a call with reduced call set-up times using one or more telecommunication networks includes providing one or more preferences for a call associated with a first terminal and a second terminal. The one or more preferences are associated with an initial setup of one or more media channels for the call. The method also includes processing the one or more preferences as a preference message, processing the preference message by an FEA procedure to provide an FEA preference message, and transferring a first framing synchronization flag sequence, the FEA preference message, and a second framing synchronization flag sequence from the first terminal to the second terminal. The method further includes receiving one or more acknowledgement preference messages from the second terminal, completing the initial setup of the one or more media channels, and thereafter, exchanging information between the first and second terminals.

Abstract: A bidirectional communication system is provided. In one embodiment, a system comprises a host; and a plurality of remote units, wherein a plurality of tones is shared among the plurality of remote units in order to communicate with the host using orthogonal frequency division multiplexing, wherein the plurality of tones is shared in a manner that permits at least two of the remote units to transmit to the host at any one time using the plurality of tones. The host causes at least one remote unit to adjust a timing of symbols transmitted on at least one of the plurality of orthogonal tones in order to improve an alignment of multiframes received at the host.

Abstract: Interoperability between wireless communication systems, such as the IS2000-1x and IS856 systems, is facilitated by using supervision timers. A wireless communication device starts one or more supervision timers and performs an intersystem transition. When the wireless communication device returns from the transition, the supervision timers are used to estimate the duration of the transition. The wireless communication device then performs a sequence of tasks appropriate to the estimated duration.

Abstract: The invention relates to a method and a device for synchronizing one or more remote clocks (2) to a central clock (1) via a bi-directional satellite radio link (9.1, 9.2). Time and data signals are exchanged via suitable transmitting (8, 12) and receiving devices (5, 11) at both ends of the radio link. From time difference measurements (6, 14) at both ends a control signal (17) is derived in such a manner that the clock (2) installed directly in the remote ground station devices (11) synchronizes in state and rate to the central clock (1) with the aid of the two-way method (TWSTFT, Two-Way Satellite Time and Frequency Transfer). The user has access to time signals (18) which directly represent the state of the central clock (1). The signals used for the time measurement are also used for data transmission, resulting in a system operating in real time in which the control deviations (15, 16) of the remote clock are accessible at both ends of the system.

Abstract: A wireless repeater for receiving, amplifying and transmitting one or more wireless signals. The repeater comprises a signal processing device for determining one or more attributes of a wireless signal received from a mobile device and a memory for storing a reference list that includes one or more preferred frequency bandwidths to be repeated. The repeater also comprises a controller coupled with the signal processing device for comparing the one or more attributes of the wireless signal with the reference list, wherein the controller selects a first active set of one or more frequency bandwidths from the preferred frequency bandwidths based on the comparison. The repeater still further comprises a first reception filter coupled with the controller, where the first reception filter, responsive to control signal(s) from the controller, filters out signals, communicated to the first reception filter, having frequencies outside the first active set of frequency bandwidths.

Abstract: A bidirectional communication system is provided. In one embodiment, a system comprises a host unit and a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit using orthogonal frequency division multiplexing (OFDM). The host unit repeatedly performs an analysis of a transmission characteristic of at least one upstream signal from at least one remote unit. The at least one remote unit makes adjustments to the transmission characteristic based on the analyses performed by the host unit to assist the host unit in demodulating a plurality of upstream signals from the plurality of remote units.

Abstract: A method for generating an accurate adaptive clock is disclosed. The method includes accessing data at a first clock rate, generating an adaptive clock that has an adaptive clock rate that is based on the arrival rate of said data, accessing data related to the first clock rate and the adaptive clock rate. The adaptive clock rate is adjusted based on a determined relationship between the first clock rate and the, adaptive clock rate.

Abstract: A new algorithm for clock offset estimation for resources distributed across a network (such as the Internet). By exchanging a sequence of time-stamped messages between pairs of network nodes and separately estimating variable delays for each message direction, present inventive embodiments provide more accurate estimates for clock offset between node pairs. Present inventive algorithms operate in a variety of peer and server network configurations while providing significant improvement in convergence speed and accuracy.

Abstract: A Time Division Duplex (TDD), Code Division Multiple Access (CDMA) communication system includes a plurality of Customer Premises Equipment (CPE) and an Access Point (AP) that communicate through RF links. A CPE contains a receiver baseband subsystem and a transmitter baseband subsystem, and further contains receiver circuitry operable during a receive period for receiving an RF carrier from the AP and for deriving a receiver tracking signal that is indicative of a frequency and phase shift between the received RF carrier and a reference signal. The receiver circuitry further includes a frequency to phase accumulator (FPA) and a digital phase shifter (DPS) for correcting the frequency and phase of a receiver baseband signal by an amount and in a direction indicated by the receiver tracking signal.

Abstract: Methods and systems are provided for synchronizing various time-stamped data streams. The data streams can be synchronized to another data stream or to a point of reference such as a reference clock. In one embodiment, synchronization processing takes place in association with a filter graph comprising multiple filters. The filter graph is configured to process multiple timestamped data streams for rendering the data streams in accordance with data stream timestamps. A synchronization module is provided and is associated with the filter graph queries individual filters of the filter graph to ascertain input timestamp-to-output timestamp mappings. The module computes adjustments that are to be made to output time stamps in order to synchronize the data streams, and then instructs queried filters to adjust their output timestamps in accordance with its adjustment computations.

Abstract: An integrated services digital network private branch exchange, which is capable of automatically choosing a synchronization clock source. The integrated services digital network private branch exchange comprises a plurality of trunk chips, a plurality of subscribe chips, and a plurality of priority selection circuits. Wherein, the trunk chips connect to the network terminal via the trunk interface, and then connect to the central office via the network terminal to receive the frame synchronization clock output signal and the data clock output signal. Whereas, the subscribe chips connect to the terminal equipment via the subscribe interface. The priority selection circuits that are connected to each other in a daisy chain circuit manner are connected to the trunk chips to send out the frame synchronization clock output signal and the data clock output signal.

Abstract: A method for synchronizing data utilized in a redundant, closed-loop feedback control system is disclosed. In an exemplary embodiment, the method includes configuring a plurality of control nodes within the control system, with each of the plurality of control nodes transmitting and receiving data through a common communication bus. At each of the plurality of control nodes during a given control loop time T=N, the receipt of externally generated data with respect to each control node is verified, the externally generated data having been generated during a preceding control loop time T=N?1. At each of the plurality of control nodes during the given control loop time T=N, output control data is calculated using the externally generated data. During the given control loop time T=N, the calculated output control data from each individual control node is further transmitted over the communication bus to be later utilized by other control nodes during a subsequent control loop time T=N+1.

Abstract: Methods and apparatuses for establishing time at a first basestation, and synchronizing the first basestation with other basestations in a cellular network. The method may be performed using a mobile (cellular communication) station that includes a satellite position system receiver. One method comprises determining a location of the mobile station, determining a time indicator that represents a time-of-day at the mobile station, wherein the time indicator is determined relative to a signal available at the first basestation, transmitting at least one of the position information and location, and transmitting the time indicator from the mobile station. The time indicator and at least one of the position information and the location are used to establish a time at the first basestation such that the first basestation is synchronized to other basestations in the cellular communication system. Other methods and apparatuses are also described for synchronizing basestations in a cellular network.

Abstract: A slave radio transceiver for use in a frequency hopping radio system synchronizes by receiving on a sequence of simultaneous combinations of radio channels until a paging message is received from a master transceiver, and may then revert to single channel frequency hopping operation. The slave's multi-channel receiver is sub-equipped to receive simultaneously on a only sub-set (PF12, PF13) of the channels within its bandwidth, the received channels being selected by independent programming within the bandwidth. The channels received simultaneously may be selected to correspond to different degrees of misalignment between the master and slave.

Abstract: In a synchronous digital communications system a network of SDH (or SONET) equipments (SE) are arranged to exchange synchronisation signals via ports on the SEs, each port being allocated a source identifier (SID). These SIDs are used to identify the source of each synchronisation signal input at a particular SE. When the SE selects a synchronisation signal to transmit out of its ports, the SID associated with that selected signal is compared with SID of each port. If a match is found the synchronisation status message (SSM) associated with the synchronisation signal sent out at that port is set to “Do Not Use” (DNU) to warn the destination SE that the synchronisation signal has been looped back. Each SE is allocated a unique equipment identifier. The SID of each port is set to the unique SE identifier of SE to which it is directly connected.

Abstract: A transceiver for a code division multiple access communication system comprises a receiver to receive coded information signals and a transmitter to transmit coded information signals. A local oscillator provides a time and frequency reference for the receiver and the transmitter. A timing controller provides timing signals for the receiver and the transmitter. A signal processor decodes received signals to determine a common error associated with the timing controller. A timing correction circuit smoothly adjusts the timing of the coded information signals transmitted by the transmitter responsive to the timing error to reduce the timing error over a desired time interval.

Abstract: A wireless local access network includes a hierarchy of access points and mobile devices capable of roaming among the access points. Communications in the network is based on a time division approach, such as a Time Division Multiple Access (TDMA) approach, or spread-spectrum wireless communications approach. An access point that is intermediary in the hierarchy is a slave to a higher level master access point in the hierarchy. The intermediary access point is also master to one or more lower level access points. The intermediary access point synchronizes its clock with its master, and then provides the same synchronization (e.g., clock offset) to any lower level slaves of the intermediary access point so that the lower level slaves can synchronize with the intermediary access point. Thus, the lower level slaves share synchronization with the intermediary access point and the higher level master access point.

Abstract: A common clock shared by two or more nodes within a network used for time-synchronization. The nodes communicate via a packetized data transmission. Each data packet has a header with a value. The clock includes a first timing portion that includes at least two data packets where the value is constant for each data packet, and a second timing portion that includes at least two data packets where the value is constant for each data packet but different from the value of the data packets in the first timing portion. Alternatively, the clock includes a first timing portion that includes at least two data packets where the value changes with each data packet, and one or more subsequent timing portions each including at least two data packets where the value is constant for each data packet within a subsequent timing portion but changes with each of the subsequent timing portions.

Abstract: A timing network for a wireless communication network includes first and second Timing Unit Board (TUB) and processor boards for processing speech channels of the radio network, each processor board having a local timer that is slave to “PSTN time” from a Public Switch Telephone Network (PSTN). The first and second TUB each alternately transmits a timing cell containing time information to each processor board over a transport network. Each processor board realigns its local timer with the time information contained in a received timing cell whenever its local timer drifts from the time information contained in the received timing cell by a predetermined time offset. When one of the TUBs fails to transmit timing cells to the processor boards or transmits timing cells containing erroneous time information, the processor boards rely on the remaining TUB for timing cells to realign their local timers.

Abstract: The present invention is a system and method for enabling multicast synchronization of initially unicasted content. Multiple unicast streams are synchronized in order to convert the unicast streams into a multicast stream. Each unicast stream may be accelerated or slowed down in relation to a reference stream to a common point within each stream upon which the unicast streams are replaced by a multicast stream of the same content.

Abstract: The present invention relates to a method of synchronisation between communication networks exchanging information by frame of informations, each communication network having clock and the number of clock pulses is monitored by a counter. The synchronisation is made by reading information representing the counted clock pulses of the clock of the first network at the appearance of a reference event, inserting at least said information or calculated information on the basis of said information into the frame of information as the synchronisation information, transferring said frame of information from the first to the second network, reading information representing the number of counted clock pulse of the clock of the second network at the appearance of reference event, reading synchronisation information inserted in received frame of information from the first network, calculating a difference between information and synchronising the second network.

Abstract: A new algorithm for clock offset estimation for resources distributed across a network (such as the Internet). By exchanging a sequence of time-stamped messages between pairs of network nodes and separately estimating variable delays for each message direction, present inventive embodiments provide estimates for clock offset between node pairs and the bias of such estimates, thereby to permit more accurate correction. Present inventive algorithms operate in a variety of peer and server network configurations while providing significant improvement in convergence speed and accuracy.

Abstract: The invention relates to a method for synchronization of clock sources in a communications system, in particular a radio communications system, having a large number of devices (PSTN, MSC, RNM, BSi, MSi, OMC) which communicate directly or indirectly with one another and have reference clock sources (Cs) for their operation. In order to overcome aging effects or timing errors in the clock sources (C), the invention proposes the clock sources (C) of one or more communicating devices (MS, BS, RNM) be synchronized by means of asynchronous signaling from at least one reference clock source (Cs). This even allows devices with clock sources that are becoming old to be operated reliably. Furthermore, in particular, there is no need for every device to have its own high-precision clock source (CS). Use is particularly advantageous in communications systems in which no reference clock is transmitted via a landline network.

Abstract: Systems and methods are disclosed for time synchronization of operations in a control system. Synchronization networks and devices are provided for transferring synchronization information between controllers in a distributed or localized control system, which is employed in order to allow operation of such controllers to be synchronized with respect to time. Also disclosed are synchronization protocols and hardware apparatus employed in synchronizing control operations in a control system.

Abstract: Real-time communication of multimedia data over heterogeneous networks that may include constant delay networks, variable delay networks that have a common reckoning of time, and variable delay networks that do not have a common reckoning of time. If there are any variable delay networks in which there is no common reckoning of time in the heterogeneous networks, a common reckoning of time is established in each of those networks. Then, a constant delay network is emulated for each variable delay network using the specific common time reckoning present in each variable delay network.

Abstract: Embodiments of the present invention related generally to communication systems. One embodiment contemplates a method for operating a communication bus where the method includes detecting a start of frame symbol on the communication bus; determining a length of the start of frame symbol; detecting a start of a synchronization field on the communication bus; determining a length of an adjusted synchronization field; determining if the length of the adjusted synchronization field is less than the length of the start of frame symbol; and if the length of the adjusted synchronization field is less than the length of the start of frame symbol, concluding that the start of frame symbol is valid and concluding that the synchronization field is valid. Embodiments of the invention may be used, for example, with the Local Interconnect Network (LIN) protocol.

Abstract: Radio transmission of chronometric information. A device comprising an antenna (A1, A2) to which there are coupled on one hand a generator (G1, G2) generating a signal to be sent (e1, e2) and a reception processing circuit (C1, C2), capable of processing a received signal (r1, e2) where the signals exchanged have the same carrier frequency. Separate time segments are generated with successive random positions. Transmission is enabled only during these time segments, whilst reception is enabled only outside these segments, making it possible to use the time markers of the signals without any effect of recurrent masking of the reception signal by the transmission signal.

Abstract: The present invention provides a highly accurate synchronization method for a satellite communication system (100). The system maintains a downlink symbol counter at an earth terminal and determines a downlink symbol count representative of the time of arrival of a burst transmitted from the earth terminal to a satellite (106, 206). The earth terminal adjusts the downlink symbol counter to correspond to the downlink symbol count (136, 220) upon arrival of a predetermined reference point in a downlink frame. A timing error may initially be determined by launching an entry order wire from the earth terminal to the satellite (116). The timing error may be transmitted to the earth terminal using a correction code which indicates the transmission is early, late, absent, or no change is required (134, 218). The terminal may make additional periodic timing adjustments based on the length of the propagation path between the earth terminal and the satellite (108, 208).

Abstract: A system and method for effectuating the transfer of data blocks having intervals across a clock boundary between a first clock domain and a second clock domain. A first circuit portion provides the data blocks to a second circuit portion. A synchronizer controller disposed between the first and second clock domains provides at least one dead cycle control signal to the second circuit portion, which is indicative of the location of at least one dead cycle between the first and second clock signals. Control logic associated with the second circuit portion generates data transfer control signals responsive to the at least one dead cycle control signal in order to control the second circuit portion so that the data blocks may be transmitted as contiguous data blocks relative to the at least one dead cycle.

Abstract: Variation in delay in transmission of data from a transmitting station to a receiving station is measured by encapsulating a portion of the data and an outgoing time stamp in a packet, the outgoing time stamp substantially representing the degree of progression of a periodic process at the time of including the outgoing time stamp in the packet. The packet is transmitted from the transmitting station and is received at the receiving station. At the receiving station, an incoming time stamp is added to the packet. The incoming time stamp substantially represents the degree of progression of a periodic process at the time of adding the incoming time stamp to the packet. The incoming time stamp is compared to the outgoing time stamp.

Abstract: A device outputting a plurality of paths to a terminal after rearranging the plurality of paths when the paths are arranged in an order of free choice, the device having a counter which receives a path number of a path in response to first data about the path, and increments a count, starting from the path number, in response to additional data arriving and a storage unit, on a side of a communication line, shared by the plurality of paths, which stores real data of the path at positions indicated by the count, wherein the real data stored in the storage unit is output to the terminal.

Abstract: A pulse code modulation modem system is configured to transmit data from a first modem to a second modem over the public switched telephone network (PSTN). The PSTN employs robbed bit signaling (RBS) such that symbols affected by RBS arrive at the second modem in a periodic manner based on a period of six symbols. The modem system is configured such that signal segments are formatted and transmitted with six symbols per segment. After obtaining symbol synchronization, the second modem initializes a modulo-6 symbol counter such that the zero count corresponds to the first symbol of each received signal segment. Those symbols affected by RBS are identified and analyzed to determine optimized signal point constellations that may be used to compensate for the RBS on a symbol-by-symbol basis during subsequent encoding and decoding. Upon a loss of synchronization, the second modem resets its modulo-6 counter in response to the detection of the first symbol in a subsequent signal segment.