Abstract: The present invention relates to a radio communications system which transmits same downlink information to a plurality of cells by using downlink common channels. The radio communications system includes a radio network controller and a base station. The radio communications system is configured to measure delays between the time when the radio network controller transmits the downlink information and the time when the base station transmits the downlink information to each of the plurality of cells; and to control timing for transmitting the downlink information to each of the plurality of cells by the base station in accordance with measured delays.

Abstract: A packet data transmission method of the HSDPA system includes collecting information on the quality of physical channels, a status of the MAC buffer, the priority level of data, the delay of data, and the like, determining the transmission order of data and the size of a data block to be transmitted based on the collected information, and transmitting the data block through the physical layer according to the order of transmissions. Since the HSDPA scheduler takes into account the delay of data, the quality of real-time services can be improved.

Abstract: A method and apparatus for staggercasting includes encoding a set of signals representing content. The set of encoded signals is capable of being decoded to produce a corresponding set of decoded signals, each having a quality which is different from the qualities of the decoded signals corresponding to the other encoded signals. A composite signal is generated which includes the set of encoded signals, staggered in time. The set of encoded signals extracting from the composite signal. Errors in the set of extracted encoded signals are detected to produce a subset of available extracted encoded signals which are not erroneous. A content representative signal at a selectable desired quality is then decoded.

Abstract: A method and apparatus for processing member containers of a virtual concatenation group at a source side of a member container transmission network to compensate for differential delay between the member containers.

Abstract: A remote control transmitting and receiving system for operating electric equipment with little operational misjudgment or malfunction. By setting a plurality of transmission codes of remote control signals of a plurality of remote control transmitters to different periods and by providing transmission order data in these transmission codes, even if transmission is carried out from a plurality of remote control transmitters completely simultaneously or with a slight time difference, it is possible to judge the transmission operation order accurately.

Abstract: A communication system includes a plurality of mobile nodes forming a mobile ad-hoc network (MANET) and having a network clock time. A plurality of wireless communications links connects the mobile nodes together. Each mobile node includes a communications device and controller for transmitting and routing data packets wirelessly to other mobile nodes via the wireless communications link using a Time Division Multiple Access (TDMA) data transmission. Each mobile node includes a clock circuit having a digital clock time. A clock circuit is operative for processing a second order internal clock compensation factor as a learned and accumulated value for establishing a virtual clock time to correct any clock timing errors of the physical clock time from the network clock time.

Abstract: A packet data transmission method of the HSDPA system includes collecting information on the quality of physical channels, a status of the MAC buffer, the priority level of data, the delay of data, and the like, determining the transmission order of data and the size of a data block to be transmitted based on the collected information, and transmitting the data block through the physical layer according to the order of transmissions. Since the HSDPA scheduler takes into account the delay of data, the quality of real-time services can be improved.

Abstract: In a buffer (10) to compensate for runtime fluctuations of data packets (1) transmitted over a transmission line (40), in order to be able to set optimally an additional retransmission delay by the buffer (10) it is proposed to calculate the probable hold time of a data packet (1) immediately after arrival of a data packet (1) in the buffer (10). The additional retransmission delay by the buffer (10) is set based on the probable hold time of the data packets (1) in the buffer (10). To guarantee optimum setting of the retransmission delay, both the maximum detected probable hold time and the minimum detected probable hold time of the data packets (1) are used. This is achieved preferably by means of a minimum value detector and a maximum value detector which detect extreme values of the probable hold time occurring at specific time intervals.

Abstract: A method and apparatus that use dynamic latency to estimate traffic flows in a communication network are disclosed. For example, the method obtains a demand matrix having at least one point pair demand, and satisfies each of the at least one point pair demand in the demand matrix by selecting a shortest path that minimizes a dynamic latency and a number of hops.

Abstract: Described are the architecture of such a system, algorithms for time synchronization during a multiway conferencing session, methods to fight with network imperfections such as jitter to improve synchronization, methods of introducing buffering delays to create handicaps for players with faster connections, methods which help players with synchronization (such as a synchronized metronome during a music conferencing session), methods for synchronized recording and live delivery of synchronized data to the audience watching the distributed interaction live over the Internet.

Abstract: A communications system for controlling equipment associated with a vehicle, includes a micro-controller (604) and a digital serial communication link (621, 622, 662, 663) using a multiplexed timing signal and first data signal. A camera or image sensor (650) located in the vehicular component communicates with the micro-controller (604) via the digital serial communication link.

Abstract: The present invention relates to a method for creating a correspondence between the local time of a first machine (B), having a first clock (HB), and that of a second machine (A), having a second clock (HA). The invention also relates to a method of synchronization between data recorded and date stamped by said first machine (B) with respect to the local time of said second machine (A). In order to make it more flexible and robust, this method does not comprise a synchronization of said clocks (HA, HB), but is based on the establishment of a correspondence ‘by intervals’ between the times that they indicate. In order to establish correspondence, a non-monotonic temporal reference may be formed by the clock of a synchronous bus connecting, at least temporarily, the two machines (and possibly other devices).

Abstract: In various exemplary embodiments, the present invention provides transport systems and methods incorporating absolute time references, such as global positioning system (GPS) time references and/or the like, and selective buildout delays, such as first-in, first-out (FIFO) buildout delays and/or the like. In one exemplary embodiment, the transport systems and methods of the present invention are used in conjunction with the International Business Machine Corporation (IBM) Geographically-Dispersed Parallel Sysplex (GDPS) integrated, automated application and data availability solution to meet and/or exceed the associated 10 microseconds transmit/receive path differential delay requirement. Other comparable uses are also contemplated herein, as will be obvious to those of ordinary skill in the art.

Abstract: Gaming systems to manage the secure download of data to a very large number of network connected client gaming machines distributed within large geographic areas. The gaming systems utilize adaptive data throttling and make optimal use of network data bandwidth. The gaming systems may advantageously manage simultaneous data downloading to millions of network connected gaming machines via private networks, public networks and/or the Internet. A close-loop download regulation algorithm achieves the highest download capacity for the files without exceeding the maximum network capacity and without degrading the operational traffic performance between the server and the connected client gaming machine.

Abstract: A method and mechanism for monitoring performance in a network computing system. A user application on a source system is configured to communication with a destination system. The application is configured to load a dynamic linked library upon execution. The dynamic linked library is configured to store packet identifiers and time stamp information for communication packets received from the application prior to the packets being conveyed to the destination system. Upon receipt of an acknowledgement packet from the destination system, the library code is configured to retrieve the previously stored time stamp information, determine transit latency information corresponding to the communication packet, and log the determined transit latency information. Acknowledgement packets may further include time stamp information which may be utilized to determine additional latency information corresponding to the communication packet and/or acknowledgement packet.

Abstract: Disclosed are a method and system to estimate the maximum error in the clock offset and skew estimation between two clocks in a computer system. The method comprises the steps of obtaining a first set of data values representing a forward delay between the first and second clocks, and obtaining a second set of data values representing a negative backward delay between the first and second clocks. The method comprises the further step of forming a lower convex hull for said first set of data values, and forming an upper convex hull for said second set of data values. First and second parallel lines are formed between the upper and lower convex hulls, and these parallel lines are used to estimate the worst case error for the offset, skew rate and dispersion of said first and second clocks.

Abstract: Output clock adjustment for a digital I/O between physical layer devices and media access controller. A method is disclosed for transferring data received on the input of a physical layer device from a transmission medium to an output associated with the physical layer device and to a media independent layer, the transferred data associated with transferred timing information from the physical layer device to the media independent layer. A receive clock is generated and then the data transitions in the received data are synchronized to at least one edge of the receive clock to provide synchronized receive data. The synchronized received data is then transmitted to the media independent layer. The generated receive clock is delayed by a predetermined clock delay to provide a delayed receive clock, and wherein the data transitions in the synchronized receive data is positioned relative to the rising edge of the delayed receive clock at a predetermined position therein following the rising edge thereof.

Abstract: Systems and methods for adapting IEEE 802.11 wireless communications for environments involving long propagation delays. Improved system throughput and stability are provided. Propagation delays are measured systematically and used to adjust contention timing boundaries and a common time slot duration. This reduces the probability of collision in the CSMA/CA mode of the IEEE 802.11 standard. One particular application is a point-to-multipoint campus bridge network.

Abstract: A method of synchronizing a network includes transmitting a tone signal to convey time information and setting a local time according to the conveyed time information. The method may also include detecting an occurrence of a predefined aspect of the tone signal, and setting a local time based on the occurrence of the predefined aspect of the signal.

Abstract: Virtual concatenation circuitry is disclosed for implementation in a network element of a data communication network. The virtual concatenation circuitry in a preferred embodiment is operative: (i) to maintain, for each of the individual member streams of a virtual concatenation stream, a corresponding counter which tracks pointer adjustments for that member stream; and (ii) to generate pointers based on values of the counters so as to substantially equalize incoming and outgoing pointer adjustments for the member streams at the network element.

Abstract: One embodiment of the present invention includes a method for synchronizing packet production and receipt from a digital signal processor (DSP) with polled transmission opportunities in an IEEE 802.11e network. The method comprises producing a packet via the DSP and transmitting the packet from the DSP to a transmission device at a time that is substantially synchronized with a next polled transmission opportunity granted by an access point in an IEEE 802.11(e) network. The method also comprises time stamping the arrival of the packet at the transmission device and transmitting the packet from the transmission device.

Abstract: A method and apparatus for data multiplexing is capable of high-speed operation with acceptable timing margins and has reduced sensitivity to supply voltage, temperature, manufacturing and other variations. One implementation relates to a data multiplexer that has no significant speed limitation associated with the clock-to-data delay of data latches, flip-flops, etc. In one implementation, clock-to-data delay is compensated for by introducing a delay-compensator in the clock line that drives a selector stage of the multiplexer. In one such implementation, a timing relationship is established between clock and data waveforms by timing the data waveforms with a first in-phase clock and operating the delay-compensated selector clock line with a second clock, which is delayed with respect to the first clock. The second clock can have a quadrature-phase delay with respect to the in-phase clock.

Abstract: A transmitting side relay device comprises additional information generation means for generating additional information about the characteristics of a data stream, packet generation means for generating a packet by attaching additional information to each transfer unit and transmitting means for transmitting the packet to the third network according to prescribed procedures. A receiving side relay device comprises separation means for breaking down the received packet into additional information and a transfer unit, analysis means for analyzing the additional information, reproduction means for locating information included in a corresponding transfer unit in an appropriate position and reproducing the data stream and output means for outputting the data stream reproduced by the reproduction means to the second network.

Abstract: An inband signaling modem communicates digital data over a voice channel of a wireless telecommunications network. An input receives digital data. An encoder converts the digital data into audio tones that synthesize frequency characteristics of human speech. The digital data is also encoded to prevent voice encoding circuitry in the telecommunications network from corrupting the synthesized audio tones representing the digital data. An output then outputs the synthesized audio tones to a voice channel of a digital wireless telecommunications network.

Abstract: A determination of latency in IP networks is performed by sensing packets, determining a status of the sensed packets and comparing original packets with acknowledgements (ACKs). A packet header on a physical layer interface (e.g., int 0) is sensed. A determination is made of a sensed packet status. If the packet is sensed, a hashed record of the packet header is created, including a local clock time of when the packet was sensed. A determination is made as to whether the packet represents an ACK to a previously sensed TCP packet. If the packet represents an ACK to a previously sensed packet, a time delay between the previous sensing of the packet and the ACK is calculated. The time delay is the TCP ACK Round Trip Time (TCP RTT).

Abstract: A multiple stream cyclic-shifted delay transmitter including a baseband processing module and a plurality of RF transmit sections. The baseband processing module is operably coupled to convert outbound data into a plurality of transmit baseband signal streams and cyclic-shift delay at least one of the plurality of transmit baseband signal streams to produce at least one cyclic shift delayed transmit baseband signal stream. The plurality of RF) transmit sections is operably coupled to convert the plurality of transmit baseband signal streams and the at least one cyclic-shift delayed transmit baseband signal stream into a plurality of RF signals.

Abstract: A host computer running a TCP connection transfers the connection to a TCP offload network interface device (NID) which performs certain network processes, thereby reducing the load on the host CPU. The NID later transfers the connection back to the host. The host and the NID maintain separate timestamp clocks which provide timestamp values for connections using the TCP Timestamp option. Synchronization of the host and NID timestamp clocks can be realized by transfer of a clock value. The NID or host receives the transferred TCP connection and the transferred clock value, and decides whether to update its own clock to equal the transferred clock value, the decision being guided by the requirement to never allow the timestamp clock to run backward. Acceleration of the timestamp clocks is prevented so that RTT measurements are accurate. Synchronization of the host and NID timestamp clocks improves performance and reduces erroneous connection drops.

Abstract: An apparatus for and method of estimating a one-way delay time between two hosts and an apparatus and method of clock synchronization using the same. The two hosts are connected to a network and communicate a predetermined packet; k-th, (k+1)-th, and (k+2)-th transmission times are measured at the first host, and k-th, and (k+1)-th transmission times are measured at the second host; a time difference of the m-th transmission time is measured at the first and second host, where m is k or k+1, and by using the measured transmission times, an m-th one-way delay time is calculated. If the time difference is identical to the calculated one-way delay time, a value equal to or less than the calculated one-way delay time is determined as the estimated one-way delay time. Accordingly, the estimation error of a one-way delay time is reduced for both symmetrically and asymmetrically connected hosts.

Abstract: The present invention prevents a receiving buffer from becoming empty by: storing received packets in the receiving buffer; detecting the largest arrival delay jitter of the packets and the buffer level of the receiving buffer by a state detecting part; obtaining an optimum buffer level for the largest delay jitter using a predetermined table by a control part; determining, based on the detected buffer level and the optimum buffer level, the level of urgency about the need to adjust the buffer level; expanding or reducing the waveform of a decoded audio data stream of the current frame decoded from a packet read out of the receiving buffer by a consumption adjusting part to adjust the consumption of reproduction frames on the basis of the urgency level, the detected buffer level, and the optimum buffer level.

Abstract: Aspects of the invention include a root node of a wireless communication infrastructure that buffers data packets for transmission by base stations over an air interface. The root node determines a time delay for transmission of a data packet from the root node to each base station, a maximum time delay of those time delays, and a timing latency based upon the maximum time delay. The root node transmits the timing latency to the base stations. In response, each base station initiates transmission of data packets received by the root node after expiration of the timing latency. Alternatively, the root node, instead of the base stations, may buffer the data packets, and transmit them so that they arrive at the base stations at substantially the same time.

Abstract: A method and apparatus for rate control adjusts or otherwise requests adjustment of a communication link data rate based on transmit queuing delays. For example, a mobile station may monitor expected transmit queuing delays relative to one or more delay targets or other Quality-of-Service constraints, and request reverse link rate increases or decreases accordingly. Similarly, the mobile station may be configured periodically to request reverse link rate changes based on determining the rate needed to meet targeted queuing delays for one or more service instances being supported by the mobile station in each of a succession of ongoing rate control intervals. Requested rates may be defined data rates or may be virtual rates that can be achieved by using combinations of defined data rates. Queuing-based rate control also can be applied to the base station's forward link, and, more broadly, to essentially any rate controlled communication link.

Abstract: In one aspect of the present invention, a network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, an Ethernet MAC, and a USB controller to provide high performance and robust operation.

Abstract: A method of operating a communication system comprises receiving a plurality of traffic, processing each traffic of the plurality of traffic to determine if a delay of the traffic exceeds a delay limit, discarding the traffic if the delay exceeds the delay limit, retaining the traffic if the delay does not exceed the delay limit, incrementing a late counter from a base amount of the late counter when the delay exceeds the delay limit, incrementing a retained counter from a base amount of the retained counter when the delay does not exceed the delay limit, returning the late counter to the base amount of the late counter when the delay does not exceed the delay limit and when the delay of a previous traffic exceeded the delay limit, clearing the retained counter to the base amount of the retained counter when the delay exceeds the delay limit and when the previous traffic did not exceed the delay limit, increasing the delay limit when the late counter exceeds a late limit, and decreasing the delay limit when t

Abstract: Transmitting messages to mobile telephones includes determining a time a standard requires or permits a standard compliant transmission to be received by a user, and scheduling a transmission by a base station to the user in the future based on a distance between the user and a base station such that the transmission will be received by the user at the determined time. The distance between the user and the base station is a distance such that a propagation delay between the user and the base station is larger than a propagation delay accommodated by the standard.

Abstract: Disclosed are a method and system for estimating the skew and offset between two clocks in a computer system. The method comprises the steps of obtaining a first set of data values representing a forward delay between the first and second clocks, and obtaining a second set of data values representing a negative backward delay between the first and second clocks. The method comprises the further steps of forming a lower convex hull for said first set of data values, and forming an upper convex hull, above the lower convex hull, for said second set of data values. The clock offset and the skew between said first and second clocks are estimated using those convex hulls. In a preferred embodiment, this estimation is made by identifying a best clock line between the first and second convex hulls.

Abstract: A method and apparatus for transmitting packets in a wireless communication system (100). The method and apparatus determining a delay period from among the various delay times at each of a plurality of access nodes (106-110) wherein the delay time is the time it takes for a node to receive a data packet from a source (102) through a network (104). During transmission of data from the source, the nodes receive data packets and from the data packets, the wall clock time is determined. The packets are transmitted from the nodes at a time equivalent to the wall clock time and the delay period so that the packets are synchronously transmitted from the multiple nodes.

Abstract: Program clock references in first and second MPEG data streams are re-stamped in accordance with delays introduced into the first and second MPEG data streams. Accordingly, the program clock references in the first MPEG data stream are re-stamped according to a variable delay in the first MPEG data stream, and the program clock references in the second MPEG data stream are re-stamped according to a variable delay in the second MPEG data stream. The re-stamped program clock references in the second MPEG data stream are corrected according to a fixed delay in the second MPEG data stream. The first and second MPEG data streams are multiplexed, and the multiplexed first and second MPEG data streams are transmitted and received.

Abstract: A CDMA apparatus including a propagation path variation estimator for estimating propagation path variations between respective prior transmit power control sections and a current transmit power control section to obtain propagation path variation estimation values, wherein each of the propagation path variation estimation values is obtained by estimating a propagation path variation between a different corresponding prior transmit power control section and the current transmit power control section; propagation path variation correction part for generating a plurality of corrected products, each corrected product obtained by multiplying at least one of vector, amplitude and/or power of a received signal of the different corresponding prior transmit power control section by said propagation path variation estimation value obtained by estimating the propagation path variation between the different corresponding prior transmit power control section and the current transmit power control section; and averaging p

Abstract: The propagation time (1605) of signals between a terminal (1304) and a base station (1302) is calculated from the round-trip time (1601) of signals between the terminal (1304) and the base station (1302) and the turn-around time (1603) from the reception by terminal (1304) of a signal from base station (1302) until the transmission of the signal to the base station (1302). The propagation time (1606) of signals between the terminal (1304) and another base station (1303) is similarly calculated. The difference between the propagation times (1605 and 1606) and the arrival time difference (1607) that is calculated in the terminal (1304) are then compared to calculate the transmission time difference (1608) between the base stations (1302 and 1303).

Abstract: Provided are an apparatus for estimating frequency offset from received signal and method for the same. The apparatus and method estimates frequency offset precisely without increment of autocorrelator by performing moving average filtering on a noised signal to thereby alleviate jitter. The frequency offset estimating apparatus includes: moving average filter for alleviating jitter of received signal; multiplier for multiplying a filtered signal by conjugate complex operanded pilot signal; phase-rotation value calculator for calculating a phase-rotation value from multiplicand operanded signal by using of symbol delay and an autocorrelation function; frequency offset estimator for estimating frequency offset from the phase-rotation value based on a smoothing function multiplication.

Abstract: A packetized data receiver establishes at the beginning of receiving each respective stream a buffer length for sending packets to higher levels of a protocol stack in the event that a packet is missed. This can be done by requesting retransmission of the first packet and measuring the actual time delay between request and receipt of the retransmitted packet.

Abstract: A method and computer-program product are provided for measuring the Round-Trip Time (RTT) of data flowing thorough a communications network using a single measurement point. The method includes timestamping a first packet traveling past the measurement point and timestamping a second packet traveling past said measurement point. These difference of these two values is the RTT. This RTT can be continuously updated during the life of the connection to provide an evermore accurate RTT measurement. Alternatively, two sub RTTs can be computed and then summed to arrive at the connection's RTT.

Abstract: The variable latency associated with standard network forwarding devices is eliminated by forwarding timing packets through a network forwarding device with a constant delay. The network forwarding device of the invention time stamps timing packets that are received by the input ports with a predefined future time, and then outputs the timing packets from the output ports at the predefined time so that the transmission delay through the network forwarding device is the same from any port to any other port.

Abstract: An object of the present invention is to provide methods for properly correcting a frequency of a standard clock, receiving apparatuses, reproducing apparatuses, and programs in broadcasting data receiving systems comprising a receiving apparatus and a reproducing apparatus, in which the broadcasting data received at the receiving apparatus is transmitted to a reproducing apparatus via bus. In the broadcasting data receiving systems stated above, when the receiving apparatus detects the broadcasting-side time information that reflects the encoding standard clock, the extraction of the broadcasting-side time information is transmitted in a form of status change signal to the reproducing apparatus via the dedicated line, and the content of the broadcasting-side time information is transmitted to the reproducing apparatus via bus.

Abstract: An apparatus, method, and computer-readable medium encoded with executable instructions for Transmission Control Protocol (TCP) flow control in a communication system are provided. According to embodiments of the invention. TCP flow control includes determining delay in a transmit buffer of the system; and modifying TCP window size based on the determined delay and a target transmit buffer delay. An indication of a modified TCP window size is sent to a TCP server of the system in an acknowledge packet. Embodiments of the invention are particularly suitable for TCP flow control in wireless communication systems (e.g., UTRA) systems, and has the advantage that RTT (i.e., the latency of the system) can be substantially guaranteed, irrespective of the throughput that a user is allocated.

Abstract: A technique for scheduling transmissions for a plurality of transmitters in a TDMA network is described. The technique includes assigning guard time between each pair of successive transmitters, where the guard time is related to the propagation delay between the pair of successive transmitters. Total guard time is minimized by selecting an order of transmission for the plurality of transmitters to minimize the total guard time.

Abstract: Admission control is performed on a forward link shared packet data channel based on the measured delay per unit of data transmitted on the channel or the data throughput on the channel. In another embodiment, statistical analyses of channel quality metrics received at a base station are compared to the data rate used to serve mobile stations on the packet data channel to perform admission control. In any case, admission control may be performed for a new call setup request, hard handoff or virtual handoff. Admission control may be performed independently for a plurality of Quality of Service (QoS) flow categories, such as real time, best effort, rate sensitive, or QoS categories defined by cost. Users may be allocated among QoS flow categories as necessary to maintain performance.

Abstract: A system, method and apparatus for controlling a network post-demultiplexing function such as dejittering is described. The method includes accessing data relating to a multiplexing function of said network. The data is processed according to a hysteresis property relating to the multiplexing function. Based on this processing, a jitter value associated with said multiplexing function is estimated, which predicts a worst-case jitter associated with the multiplexing function. A signal processing function related to the post-demultiplexing function is adjusted according to the estimated worst-case jitter value. In response to such adjustment, the buffering function adapts to anticipate a change in the worst-case jitter.

Abstract: In a method for adaptive transmission timing control, the overlooking of a base path at the side of the base station that occurs when the transmission timing offset amount changes to the extent of falling outside the current delay-profile calculation range, and the side of the mobile station fails to demodulate the control information that contains the transmission timing offset amount, is prevented. A limit is put on the transmission timing offset amount applied in a single transmission timing control iteration. Together with setting the transmission timing offset value such that the main component of the delay profile calculated from the pilot signal transmitted with offset transmission timing falls within the time range of when the current delay profile was calculated, the time range for calculating the next delay profile is shifted such that a delay profile calculated from the pilot signal transmitted with offset transmission timing falls within the shifted range, starting at the earliest component.

Abstract: A resource allocation of multiple compressed AV streams delivered over the Internet is disclosed that achieves end-to-end optimal quality through a multimedia streaming TCP-friendly transport (MSTFP) protocol that adaptively estimates the network bandwidth while smoothing the sending rate. Resources allocated dynamically according to a media encoding distortion and network degradation algorithm. A scheme is also disclosed for dynamically estimating the available network bandwidth for streaming of objects, such as MPEG4 multiple video objects, in conjunction with the MSTFP protocol. The scheme can account for packet-loss rates to minimize end-to-end distortion for media delivery.