Abstract: Under the situation in a network including a transmitter and a receiver in which a transmitter converts a non-compressed packet to be transmitted into a full-header packet including a full header or a header-compressed packet including a compressed header, and sends the converted packet to the receiver, the transmitter sends at least important packet in the non-compressed packet to be transmitted as a full-header packet. The important packet means for example, a packet containing the data serving an important role when the data terminal eventually receiving each packet reproduces the audio and/or image in accordance with the data in each of the packet.

Abstract: A network interface device includes receive logic, which is coupled to receive from a network a sequence of data packets, each packet including respective header data. A protocol processor is coupled to read and process the header data so as to identify a group of the received packets that contain respective fragments of a data frame, the fragments having a fragment order within the data frame. Host interface logic is coupled to a host memory accessible by a host processor, and is controlled by the protocol processor so as to allocate space for the data frame in the host memory, and to reassemble the fragments of the data frame in the fragment order in the space allocated in the host memory.

Abstract: Data transmission system for transmitting packets of data from a source workstation (10) to a destination workstation (40) wherein the packets of data are transmitted over at least a first IP network (14) and a second IP network (30) between an ingress node (20) connected to the source workstation in the first network and an egress node (38) connected to the destination workstation in the second network. The system comprises a local reservation server (26) in the first network accessible by the source workstation and a remote reservation server (42) in the second network accessible by the local reservation server. The local reservation server includes connection setup means for setting up a virtual connection meeting a predefined requirement of Quality of Service from the ingress node to the egress node in response to a request from the source workstation and bandwidth request means for requesting additional bandwidth in the second network to the remote reservation server.

Abstract: A method an a system for providing transparent Quality of Service (QoS) and reducing bandwidth usage in an ATM access network uses VC-merge and delivery of content directly through the access network. Root-initiated join proxy messages sent from a service gateway include a merge-eligibility indicator that prompts an access module to merge content delivered through the access networks into a virtual circuit link (VCL) provisioned for the subscriber. TCP splicing is also supported to further improve overall QoS.

Abstract: In one direction of transmission, an ATM switch establishes a virtual connection from any of its input ports to any of outgoing transmission links. Multiplexers receive and multiplexes user cells from the ATM switch into outbound cells having any one of all virtual channel identifiers assigned to the multiplexers and return the outbound cells to the input ports of the ATM switch, where they are routed through the virtual connections to the outgoing transmission links. In the opposite direction, the ATM switch establishes a virtual connection from any of incoming transmission links to any of its output ports. Inbound cells from the incoming links are first routed through the virtual connections in the ATM switch to demultiplexers, where they are decomposed into user cells for application to the ATM switch. Similar to the outbound cells, the inbound cells have any of the virtual channel identifiers assigned to the demultiplexers.

Abstract: A system and method for providing multimedia service using a mobile communication terminal comprising the steps of accessing a web server of an IP address in response to a request for multimedia information from a user via an Internet, receiving the requested multimedia information from the web server and displaying the multimedia information on a display as a moving image.

Abstract: An IPv6 mobile packet communication network in which mobile VPN service can be provided without having to use a mobile tunnel. A control signal for enabling packet data transmission and reception is sent from a mobile terminal to a gateway node. Using destination-of-connection information contained in the control signal, the gateway node checks whether mobile VPN service is requested or not. Upon detection of a mobile VPN service request, the gateway node returns IP address information of the gateway node to the mobile terminal via a subscriber node. The mobile terminal then assembles an IPv6 header (210) and an IPv6 routing header (220) so that packet data will be unexceptionally transferred through the gateway node.

Abstract: A ring network for transporting data packets between network devices is provided. The ring network includes a number of ring switches. Each ring switch has at least one ring port, at least one local port and at least one table that self learns which network devices are associated with each port of the ring switch based on a selected source identifier from the packets processed by the ring switch. The source and destination identifiers may, for example, be a media access control (MAC) address from an Ethernet packet, an Internet Protocol (IP) address, at least a portion of a hierarchical address, a combination of two or more identifiers at different protocol levels for the data packet, a port number of a universal datagram protocol, or other appropriate identifier. The at least one ring port of each ring switch is coupled to a ring port of another ring switch in the ring network.

Abstract: The invention relates to a network comprising a plurality of network nodes. At least part of the network nodes are directly coupled to each other via at least one star node. The star node comprises a plurality of star interfaces which are assigned to at least one network node. In dependence on a respective pilot signal, a star interface conveys a message from the assigned network node to the other star interfaces, or from another star interface to at least one of the assigned network nodes. Also in the event of simultaneous arrival of at least two pilot signals at the respective star interfaces, a decision circuit releases one star interface for the transmission of data.

Abstract: A virtual reassembly system for use with a fast pattern processor and a method of operating the same. In one embodiment, the virtual reassembly system includes a first pass subsystem configured to convert a packet of a protocol data unit into at least one processing block, queue the at least one processing block based upon a header of the packet and determine if the packet is a last packet of the protocol data unit. The virtual reassembly system further includes a second pass subsystem configured to virtually reassemble the protocol data unit by retrieving the at least one processing block based upon the queue.

Abstract: Data switching systems for use in ATM and other packet and cell switching networks can more smoothly switch data if incoming data packets to be switched are re-ordered to avoid overwhelming an output port with too many consecutive packets to a particular destination. An apparatus and method for simply re-ordering data samples in a non-consecutive manner is computationally efficient and effective.

Abstract: This invention provides interference predictions, suitable for least interference dynamic channel assignment use or other frequency hopping uses by de-coupling the time slot assignment and the frequency hopping pattern assignment. In particular, a least interfered time slot is selected based on an aggregate interference measurement performed across an entire transmission band or a pre-specified range of frequencies in the transmission band. A user is assigned a least interfered time slot and provided an appropriate frequency hopping pattern.

Abstract: The invention relates to a method for medium access control by transmission units (2) for data transmission over a network (1), wherein data from a transmission unit (2) can be transmitted over the network within cyclical time slots. The method is particularly suited as a control protocol in a local powerline network within a building. It is proposed that access to a non-occupied time slot (8) by a plurality of transmission units (2) is controlled in that one of said transmission units (2) wins the corresponding time slot (9) of the next cycle based on comparing priority values. Each priority value is determined by the type, the amount and/or a time delay of the data to be transmitted, and the corresponding time slot of the following cycle is reserved for data transmission by said winning transmission unit (2).

Abstract: Methods for performing multi connections at point-to-point protocol are disclosed. One method for transmitting a datagram in an apparatus having point-to-point protocol sessions which transmits datagrams received from a physical layer of a communication network to a network layer, includes the steps of: a) establishing a least two PPP sessions; b) classifying the datagrams received from a physical layer based on the PPP session and transmitting the datagram to a corresponding PPP session; c) processing the datagram received by the PPP in the PPP session; and d) selecting one of the processed datagrams and transmitting the selected datagram to the network layer.

Abstract: A single physical channel carries “fast feedback” information in such a way that each type of data is on a physical sub-channel. The sub-channels are not “logical” channels in that they cannot be separated by logical functions alone because some knowledge of the modulation mechanisms is required. Each sub-channel is independently channel coded (this is outer channel coding if an inner code is applied). The resulting code symbols from all sub-channels are then merged into one set of symbols. These code symbols can then optionally be concatenation interleaved and inner channel coded, if the performance enhancement is desired and the complexity is acceptable. The result is then extended by code symbol repetition to provide a total number of symbols greater than or equal to one of the possible quantities of symbols per frame supported by the physical channel, and then decimated (symbols deleted) to provide a number of symbols equal to one of the allowable quantities of symbols per frame.

Abstract: A system and method for achieving high speed modulation of semi-conductor devices, such as VCSELs, utilizing field effect to confine a signal path is described. In semi-conductor devices operating at high data rates the configuration of connector rails and signal paths can become a limiting factor. Thc present invention provides an arrangement in which the signal return path is confined relative to the energizing signal path by a field effect in a common conductor extending under the signal path.

Abstract: A temperature compensation apparatus for controlling an output power of a laser diode according to a temperature variation of the laser diode, and a method therefor. An error voltage between a voltage corresponding to the output power of the laser diode and a reference voltage is generated. The error voltage is output as a control voltage corrected based on the output power and is applied to the laser diode. When the level of the error voltage overflows or underflows in a first up/down counter, the control voltage based on the luminous efficiency of the laser diode is output by applying the corrected control voltage to the laser diode while interlocking the first up/down counter with a second up/down counter. Accordingly, it is possible to stabilize the luminous efficiency and reduce control error of the laser diode.

Abstract: In a semiconductor laser device, when a light beam is emitted from a semiconductor laser element in a state in which temperatures of the semiconductor laser element and a light detecting element are adjusted, effects of temperature characteristics of the semiconductor laser element and the light detecting element can be avoided, and a wavelength of the laser beam is stable. An amount of light of the light beam is detected at the light detecting element. On the basis of results of detection, the light amount of the light beam emitted from the semiconductor laser element is accurately controlled (APC).

Abstract: Mounting substrate and heat sink for high-power diode laser bars, the mounting substrate permitting mounting of the high-power diode laser bars by hard-soldering on the basis of a matching expansion to the semiconductor material. The mounting substrate is difficult to bend and of extremely high thermal conductivity, and can be used universally for the various cooling elements of conductive and convective cooling mechanisms.

Abstract: In an optical pickup device, a first and a second short-cutting terminal 40 and 50 are interposed in parallel between terminals of a laser diode 1. The first short-cut terminal 40 is disposed on a side surface of a housing. The second short-cut terminal 50 is disposed on a rear surface of the housing.

Abstract: According to the invention, a laser drive control circuit in a multibeam scanner comprises a regulation unit that provides reference values for a plurality of beam emitting points, respectively. The reference values are adjusted so that the total sum of the reference values is a predetermined value. The laser drive control circuit controls the beam emitting points, successively, to emit laser beams except when scanning a photosensitive drum, and detects the respective beam amounts of laser beams. Then, the laser drive control circuit adjusts driving currents fed to the beam emitting points for scanning the photosensitive drum upon the comparison of the detected beam amounts and reference values, respectively.

Abstract: A laser processing apparatus comprises a laser generator for generating laser light, a laser controller for controlling the laser generator, a positioning unit for positioning the laser light, a control method memory for storing an optimum control method corresponding to the moving distance of the positioning unit, and a position controller for controlling the position of the positioning unit by the optimum control method. Controlling the position by the optimum control method corresponding to the moving distance increases a processing speed.

Abstract: A semiconductor laser device and module for use in a dense wavelength division multiplexed optical communications system are shown. The laser device preferably has cavity lengths greater than 1000 &mgr;m, and compressive strain multi-quantum well active layer, and front-facet reflectivity of less than about 4%. Higher optical outputs and longer cavity lengths are achieved. Preferred modules use these laser diodes with external wavelength-selective reflectors that have narrow bandwidths of 3 nm or less, and which include a plurality of longitudinal mode subpeaks within the bandwidth. Relationships between reflectivity value of the front facet and the peak reflectivity of the wavelength-selective reflector for long cavity length laser device are also disclosed, with the relationships providing higher output power along with a stabilized output spectrum.

Abstract: A laser diode is disclosed, in which a laser diode for emitting the beams of a long wavelength and another laser diode for emitting the beams of a short wavelength are sequentially stacked upon a submount, thereby minimizing the gap errors and the position errors for the light emitting points. That is, the distance between the light emitting points can be minimized, and therefore, unlike in the conventional techniques, a separate additional optical component is not required. Accordingly the adjustment of the optical axis is rendered easier, and therefore, the yield is increased, while the assembling cost can be curtailed.

Abstract: By setting a width of an active layer larger than a cut-off width of a higher-order transverse mode in a distributed feedback (DFB) laser diode, laser emission in the higher-order transverse mode is restrained as well as a unevenness in an emission wavelength caused by a unevenness in the active layer can be minimized.

Abstract: A wavelength-variable semiconductor laser includes: a submount; and a semiconductor laser chip being mounted onto the submount and having at least an active layer region and a distributed Bragg reflection region, wherein the semiconductor laser chip is mounted onto the submount in such a manner that an epitaxial growth surface thereof faces the submount and a heat transfer condition of the active layer region is different from a heat transfer condition of the distributed Bragg reflection region. Moreover, an optical integrated device includes at least a semiconductor laser and an optical waveguide device both mounted on a submount, wherein the semiconductor laser is the wavelength-variable semiconductor laser as set forth above.

Abstract: The invention relates to a saturable reflector and a saturable absorber which are each arranged as a layer sequence (3) on a substrate (1) and is characterized in that the layer sequence (3) contains a strained-layer single quantum well (6) and a cap layer (7), whereby the material composition of the single quantum well (6), its layer thickness and its strain in the layer structure within a wavelength range all serve to define an absorbing effect, moreover, a saturable effect is defined by the selection of the position within the standing wave of a laser resonant cavity.

Abstract: In a process for melting down sponge metal (11) in an electric-arc furnace (1) having at least one electrode (6), the sponge metal (11) is introduced into the electric-arc furnace (1) under formation of at least one sponge metal jet (15) which in the immediate vicinity of an electrode (6) hits the bath level (16) present in the electric-arc furnace (1), and for decarburization and/or intermixing the bath and/or charging energy oxygen is blown into the melt (7).

Abstract: The thermal resistance of an entire semiconductor package with a semiconductor chip and radiation fins is calculated based on thermal resistance of resin between the semiconductor chip and case, thermal resistance of the radiation fins, and thermal resistance of three heat radiation paths in the semiconductor package. One of said three heat radiation paths is passing through the bottom surface of the case. The other of said three radiation paths is passing through the leadframe. The other of three radiation paths is passing through sides of the case other than the leadframe.

Abstract: The present invention provides for making code rate adjustments and modulation type adjustments in a pseudonoise (PN) encoded CDMA system. Coding rate adjustments may be made by changing the number of information bits per symbol, or Forward Error Code (FEC) coding rate. A forward error correction (FEC) block size is maintained at a constant amount. Therefore, as the number of information bits per symbol are increased, an integer multiple of bits per epoch is always maintained. The scheme permits for a greater flexibility and selection of effective data rates providing information bit rates ranging from, for example, approximately 50 kilobits per second to over 5 mega bits per second (Mbps) in one preferred embodiment.

Abstract: A new additional information generating section generates new additional information FS1 based upon information from an additional information reading section. The spectrum of the new additional information FS1 is spread by an SS additional information generating section and supplied to a signal superimposing section as SS additional information SF1. The signal superimposing section generates a digital video signal S2 by superimposing the SS additional information SF1 on a digital video signal S1. A writing section records the digital video signal S2 on which the SS additional information SF1 is superimposed on a recording medium. Hereby, adding additional information to an information signal without deteriorating the quality of the read information signal so that the falsification and deletion are disabled, detecting the additional information added to the information signal if necessary and utilizing it are enabled.

Abstract: The invention discloses a pilot synchronization channel structure for mobile communication systems. The channel structure includes a pilot channel overlapping a synchronization channel (SCH), defined in the wideband code division multiple access (WCDMA) protocol. Each frame of the pilot channel consists of plural time slots. Each time slot is packed with pre-selected pilot symbols, after spread spectrum and scrambling. The overlap can be defined as search code of one symbol length with pilot signal of m−1 symbols length by intermittent overlap. The overlap can also be defined as search code of one symbol length with pilot signal of m symbols length by continuous overlap. The invention combines organically both CDMA 2000 and WCDMA standards to provide better pilot and synchronization functions.

Abstract: A spectrum spread receiver is provided which correlatively executes in synchronism with a timing determined by each of multiple paths and conducts RAKE synthesis of correlating signal of each path, and which comprises: a plurality of finger processing circuits 100 (101, 102); a memory circuit 81, which stores inverse spread data of a unit length; a timing adjustment circuit 71, which outputs a timing signal at the time when a predetermined amount of inverse spread data are stored in a memory circuit; and a RAKE synthesizer 10 for conducting RAKE synthesis by reading a predetermined length of inverse spread data from the memory circuit 81 based on the timing signal output from the timing adjustment circuit 71.

Abstract: A fast initial acquisition and search device for a spread spectrum communication system is disclosed herein. The search device includes a memory for storing the first code sequence, and a plurality of computation circuits coupled in parallel to the memory. The search device also includes a plurality of threshold detector circuits. Each of the plurality of threshold detector circuits is respectively coupled to one of the plurality of computation circuits. Each of the plurality of computation circuits implements a unique phase offset for a second code sequence with respect to the first code sequence. A correlation operation is performed in parallel at each of the plurality of computation circuits followed by a threshold evaluation that indicates whether the correlation result satisfied a threshold value.

Abstract: A method and apparatus for processing a secondary synchronization channel in a spread spectrum system is disclosed herein. The method includes several steps, the first of which is to receive a first input data at a correlator. Next, a first code sequence of a code group is received at the correlator. The first correlator then correlates the first input data with the first code sequence. Afterward, a second code sequence is received at the correlator. This time, the first input data is correlated with the second code sequence. Correlation of both the first code sequence and the second code sequence occurs prior to receiving a second input data. Lastly, correlation results from the first correlator are compared with a threshold value using a threshold detector.

Abstract: A single chip RF communication system and method is provided including a transmitter and a receiver. The RF communication system in accordance with the present invention includes an antenna for receiving transmitting RF signals, a PLL for generating multi-phase clock signals having a frequency different from a carrier frequency in response to the multi-phase clock signals and a reference signal having the carrier frequency, a demodulation-mixing unit for mixing the received RF signals with the multi-phase clock signals having the frequency different from the carrier frequency to output the RF signals having a frequency reduced by the carrier frequency and an A/D converting unit for converting the RF signals from the mixing unit into digital signals.

Abstract: An XDSL system comprising a hybrid circuit in operative communication with a transmission line and an XDSL modem associated with a subscriber premises. The hybrid circuit comprises a plurality of selectable impedance circuits having different impedance values. A controller selectively engages each of the impedance circuits in-line with the XDSL modem and the transmission line. The controller records the performance of the modem with each circuit engaged, and selects the desired impedance circuit as a function of the performance characteristics associated with each of the impedance circuits. The impedance circuit which provides the best performance characteristic is selected as the impedance circuit for normal modem operation.

Abstract: A training circuit for training a tap coefficient of an adaptive equalizer that performs error calculations in a training process and updating of the tap coefficient in a time area and thereby makes the tap coefficient converge stably in a short time.

Abstract: The concept of B-frames gives the MPEG video compression standard its high encoding efficiency. However, B-frame encoding roughly doubles the complexity of an MPEG encoder. In view thereof, MPEG encoders have been developed which produce I-frames and P-frames only. They are less complex but also less efficient. To improve the efficiency of such “IPP encoders”, selected P-frames are quantized more coarsely than other P-frames, for example, by multiplying the conventional quantization step size by 1.4. Although this results in isolated frames (“virtual B-frames”) being encoded with a lower quality, the overall perceptual quality is not affected. It has been found that the gain in bit rate obtained by the coarser quantization is not lost in subsequent P-frames, even though the subsequent frames are encoded with reference to the lower quality frames.

Abstract: A video signal layering-encoding system according to the present invention has at least either a frequency distribution unit to judge a frequency distribution in an input video signal or a motion judgment unit to judge the motion of an input video signal. With this, encoding quantity control according to the characteristics of the input video signal can be performed between layers. Also, with selection of encode modes and sharing of a motion vector, the encoded data of a bidirectionally predicted frame can be reduced and the encoding efficiency of a high resolution signal can be increased.

Abstract: Preprocessing for motion-compensated video encoding such as MPEG includes lowpass filtering, temporal (310) and/or spatial (312), locally per pixel in response to motion vector analysis and prediction error (304) and temporal change (306). This de-emphasizes image areas of rapid change which corresponds to human perception de-emphasis.

Abstract: A method and apparatus for recording moving picture data encoded using a prediction encoding system, in which the playback control information is recorded along with moving picture data encoded using the MPEG system. The playback control information includes the information specifying a program decoding starting picture and a display starting picture and the information specifying the program decoding terminating picture and a display terminating picture. During reproduction, the playback control information is first read out and moving picture data are decoded based on this information. This enables seamless reproduction from a pre-skipping picture to a post-skipping picture.

Abstract: A data storage, storing input MPEG data for a period corresponding to three clocks, is formed of the data storage (A)1, the data storage (B)2 and the data storage (C)3. The synchronous byte detector 4 detects a synchronous byte (47h) at the time of inputting TS. The TS header processor 5 processes a TS header at the time of inputting TS. The PS header processor 6 processes a PS header at the time of inputting PS. The PES data processor 7 processes PES data containing TS and PS.

Abstract: A vestigial sideband/quadrature amplitude modulation (VSB/QAM) receiver, which receives both VSB and QAM signals and restores a carrier wave with a restored symbol clock after restoring a symbol timing in a front portion of a carrier wave restoration unit.

Abstract: A configurable all-digital coherent demodulator system for spread spectrum digital communications is disclosed herein. The demodulator system includes an extended and long code demodulator (ELCD) coupled to a traffic channel demodulator (TCD) and a parameter estimator (PE). The demodulator also includes a pilot assisted correction device (PACD) that is coupled to the PE and the TCD. The ELCD provides a code-demodulated signal to the TCD and the PE. In turn, the TCD provides a demodulated output data signal to the PE. The PACD corrects the phase error of the demodulated output data based on an error estimate that is fed forward from the PE. Accumulation operations in the ELCD, TCD, and PE are all programmable. Similarly, a phase delay in the PACD is also programmable to provide synchronization with the error estimate from the PE.

Abstract: According to the present invention, a method and system for array processing are disclosed. Signals transmitting a symbol set are received. A dominant signal set for each signal, which includes dominant signals that interfere with the signal, is determined. A trellis, which includes paths that represent possible symbol sets, is constructed from the dominant signal sets. An optimal path from the trellis is selected, and the symbol set represented by the optimal path is determined.

Abstract: In method and device for correlating digital signals, a correlation is determined a number of times between bit values of a pulse train input signal and bit values which define a number of leading and/or trailing edges of pulses of a reference pulse train. Each time the relative location of the two sets of bit values is effectively displaced by one bit. A correlator for this purpose (DC) has a number of parallel comparators, each for receiving and holding in a memory a different segment of the input pulse train. Each comparator is configured to calculate a correlation value at a bit location by varying a correlation value at the immediately preceding bit location which is held in a counter dependent on the bit values of the input pulse train corresponding to the ends and center of the associated defined pulse edge at the immediately preceding location.

Abstract: A method (150) of automatic gain control on a time slot by time slot basis in a base transceiver station (115) includes the steps of measuring (152) and storing (158) an amplitude of a signal on a given time slot for a predetermined number of prior time frames. Then, an appropriate gain adjustment factor for the given time slot is determined (166) and applied (168) to a received signal in a current time slot of the given time slot. Such application of the gain adjustment factor is applied on a time slot by time slot basis.

Abstract: Object stores are used as building blocks to construct a system with variable complexity on a network. Typically, an object store comprises information (e.g., data) stored in object format, or objects. The objects and object stores are managed by an object version management mechanism that adapts to different object store types and optimizes resource consumption by each object store. Various data fields are used to indicate an object's version within an object store. Version information is used to compare the states among matching object replicas in matching object stores. Utilizing both the object store based system and the object version management mechanism, a data synchronization protocol is developed. The data synchronization protocol is capable of adapting to different types of object stores and the characteristics of network connection media to optimize data synchronization.

Abstract: The present invention relates to a high speed sample and hold circuit which comprises a plurality of sample and hold subcircuits coupled in parallel between an input and an output. The circuit also comprises a calibration circuit coupled to the plurality of sample and hold subcircuits. The calibration circuit is operable to establish a timing relationship between a hold signal and a clock signal for each of the plurality of sample and hold subcircuits which is generally the same. The established timing relationship reduces a timing mismatch between the plurality of sample and hold subcircuits and distortion associated therewith. The present invention also comprises a method of reducing timing mismatch in a high speed, parallel coupled sample and hold circuit.