Abstract: Provided is a method of controlling the flow of downstream traffic in a cable network headend. The method includes the steps of: establishing a session with the modulator; transferring traffic to the modulator over the session; and receiving a buffer-status reporting message reporting the status of a receive buffer from the modulator while transferring the traffic. The method reports buffer-status information of an Edge-Quadrature Amplitude Modulator (E-QAM) to a traffic source, thereby enabling control of the transfer rate of traffic transferred from the traffic source to the E-QAM and preventing overflow/underflow of a receive buffer, packet loss and deterioration of channel use.

Abstract: A programmable error correcting device is disclosed. The programmable error correcting device includes a controller for receiving information about a length of a codeword, an error correcting capacity, whether of not a shortened codeword mode is supported and a total byte number of burst data and outputting a control signal; a preprocessor for dividing input information data by a length of information byte in a codeword and outputting the divided input information data with a valid data indicating signal in response to the control signal input from the controller for an error correcting coding; and a coder for deciding a structure for an error correcting encoding according to the control signal inputted from the controller and performing an error correcting encoding on information data inputted from the preprocessor according to the decided structure.

Abstract: A packet processing apparatus of a cable modem in hybrid fiber coaxial networks for processing a packet received from a cable modem termination system through a plurality of downstream channels is provided. A specific channel number is assigned to each channel and the cable modem termination system transmits downstream service identifier encoding information to the cable modem during an initializing process therebetween. The apparatus includes a plurality of channel receivers, each for generating an interface packet by inserting the channel number of a corresponding channel into the packet received through the corresponding channel; and an input controller that classifies the interface packet into a resequencing packet, which needs to be resequenced, and an ordinary packet, for which resequencing is not necessary, using the downstream service identifier encoding information and stores the resequencing packet and the ordinary packet.

Abstract: A downstream external PHY interface (DEPI) interface apparatus for a modular-cable modem termination system (M-CMTS) cable system complying with a data over cable service interface specifications (DOCSIS) standard is provided.

Abstract: An apparatus for receiving an upstream data packet in a channel bonding mode is provided. The apparatus includes: an upstream demodulator for receiving a data packet transmitted from a cable modem and converting the received packet; an upstream processor for adding packet re-combination information to the data packet received from the upstream demodulator; an upstream segment processor for re-combining the data packet received from the upstream processor in response to the packet re-combination information; and an upstream channel band allocation unit for transmitting information comprising a data allocation band and an allocation interval to the cable modem and providing the packet re-combination information to the upstream processor. Also, a method of receiving an upstream data packet in a channel bonding mode is provided.

Abstract: Provided is a method for classifying packets in a cable modem termination system (CMTS) supporting a channel bonding mode.

Abstract: Provided is a method by which a cable modem reports a downstream packet resequencing status to a cable modem termination system, and more particularly, a method of effectively reporting detailed information on a packet resequencing status by further defining a packet resequencing-related event and event-related information in a message reporting the packet resequencing status. The method by which a cable modem reports a resequencing status of the resequenced packets includes the steps of: when a packet resequencing-related event occurs, generating a resequencing status message (CM-STATUS) including packet sequence numbers of packets causing the event; transmitting a band allocation request message for requesting a cable modem termination system to allocate an upstream band for transmission of the resequencing status message; and transmitting the resequencing status message to the cable modem termination system over the upstream band allocated by the band allocation request message.

Abstract: A restricted reception device enabling a subscriber receiver to selectively receive broadcasting data transferred via a digital cable broadcasting network, includes: a demultiplexer for receiving broadcasting data and an ECM including a CW from the subscriber receiver, and demultiplexing them, the broadcasting data and the ECM being transferred through an in-band channel; an out-of-band channel signal processor for receiving an EMM from the subscriber receiver, and processing the EMM, the EMM being transferred through an out-of-band channel; a restricted reception processor for descrambling the scrambled broadcasting data using the ECM and the EMM received from the out-of-band channel signal processor; and a remultiplexer for multiplexing the descrambled broadcasting data received from the restricted reception processor, and sending the multiplexed broadcasting data to the subscriber receiver.

Abstract: Provided are an apparatus and method for upstream transmission of variable bit rate traffic in a Hybrid Fiber Coaxial (HFC) network. The apparatus includes: a VoIP signal processing unit for digitizing a voice of a speaker to create a voice packet, detecting a mute section to suppress packet generation, and generating an Service identification (SID) packet in the mute section; a storage unit for storing the voice packet and the SID packet created by the VoIP signal processing unit and notifying information on the stored packets; a VoIP activity determining unit for determining a voice activity based on the information on the stored packets notified from the storage unit; and a packet processing unit for including the voice activity transferred from the VoIP activity determining unit in the packets from the storage unit to encapsulate them and transmit it to a network device.

Abstract: An apparatus for determining a downstream topology in a hybrid-fiber-coaxial network includes: a signal branching unit for branching a signal received from a cable modem termination system into a plurality of branched signals; a plurality of signal selecting units for selectively receiving a frequency band signal corresponding to a specific downstream channel among the plurality of branched signals; a downstream topology determining unit for analyzing a downstream ambiguity resolution frequency list contained in a channel information message of a downstream primary channel received from the cable modem termination system, collecting in parallel channel information messages with respect to a plurality of downstream channels, and determining a downstream topology at a high speed using the collected channel information messages; and a plurality of packet generating units for setting downstream channel frequency bands of the signal selecting units under control of the downstream topology determining unit, and sen

Abstract: Provided is an outdoor optical node unit (ONU) and method for converting/combining frequencies, and an apparatus and method for converting/combining frequencies in a cable television headend system.

Abstract: A Reed-Solomon (RS) decoding apparatus having high error correction capability and a method thereof are disclosed. The apparatus includes: error location and analysis polynomial generating units for performing a modified Euclid algorithm by receiving syndrome data upon receipt of an enable signal, and suspending input of the syndrome data and outputting error location polynomial data and error analysis polynomial data by executing the modified Euclid algorithm independently upon receipt of a disable signal; a controlling unit for controlling the error location and analysis polynomial generating unit and the input of the syndrome data; and switching units for providing the syndrome data to corresponding error location and analysis polynomial generating unit upon receipt of the enable signal and controlling the input of the syndrome data upon receipt of the disable signal. The number of the switching units is identical to that of the error location and analysis polynomial generating units.

Abstract: Provided is an automatic gain control (AGC) apparatus of a cable modem. The apparatus includes: a gain controller for measuring a power level of digital input signals transmitted from outside, accumulating the measured values of the digital input signals for a predetermined period, acquiring an average size of the signals, and calculating an error value between the average signal size and a predetermined signal size; an amplitude control unit for receiving error values adjusted by the gain controller and controlling an amplitude of the signal; a low pass filter for receiving the signal outputted from the amplitude control unit and performing low pass filtering on the signal; and a signal size control unit for receiving the signal obtained from filtering of the low pass filter and controlling the signal size.

Abstract: Provided is a scheduling apparatus and method in a channel bonding transmission system. The apparatus includes: a downstream service identifier storing unit for storing information related to a downstream service identifier (DSID); a packet transmitting unit for transmitting a packet inputted from outside; a packet classifying unit for analyzing the packet and distributing the downstream service identifier; a virtual storing unit for storing the packets by the packet classifying unit; a monitoring unit for checking downstream service identifier information of the packet stored in the virtual storing unit and requesting channel distributing and channel holding; a channel checking unit for checking the status of channels; a scheduling control unit for acquiring channel information from the downstream service identifier storing unit and controlling packet forwarding; a scheduling unit for forwarding the packets; and an output unit for outputting the forwarded packets.

Abstract: Provided are a multiplexing and demultiplexing apparatus and method for delivering an MPEG-2 TS packet error signal through a CableCARD interface. In the multiplexing apparatus, a TS packet reception unit receives TS packets, and a pre-header generation unit generates pre-headers corresponding to the received TS packets. A pre-header insertion unit inserts the pre-headers in front of the received TS packets to generate cable MPEG packets (CMPs), and an output FIFO unit stores the CMPs. A FIFO control unit transfers the CMPs without collision with CMPS of different channels, and an output signal generation unit generates output signals from the CMPs of the different channels.

Abstract: A timing lock detection apparatus and method for digital broadcasting receiver are provided. The apparatus includes: a discrete value generator for cyclically selecting a discrete signal value from a continuous timing error signal; a differential calculator for obtaining a difference between the currently selected timing error signal value and a previously selected timing error signal that is a timing jitter signal; a sign variation detector for detecting variation in a sign of the timing jitter signal; a lock control signal generator for discriminating a period based on the detected sign changing time, and controlling a lock step of the loop filter according to a convergence mode of the timing jitter signal at each period; and a lock detection signal generator for generating a lock signal or an unlock signal according to whether the timing jitter signal reaches a steady state and using the current lock step signal.

Abstract: A decision feedback equalizing apparatus selectively using a feedback filter and a method thereof are provided. The apparatus includes: an equalizing unit including a feed forward filter (FFF) for correcting a distorted transmission channel by receiving a match-filtered signal and a feedback filter (FBF) for reducing inter symbol interference ISI of the corrected transmission channel for driving only the FFF in a blind mode and driving the FFF and the FBF in a decision directed mode; a diverge/converge determining unit for determining whether the decision feedback equalizing apparatus is diverged or converged using a unit square error obtained through a least unit square algorithm; and a filter controlling unit for controlling the equalizing unit in a blind mode if the decision feedback equalizing apparatus is determined as divergence, and for controlling the equalizing unit in a decision directed mode if the decision feedback equalizing apparatus is determined as convergence.

Abstract: Provided is an IP data transmission apparatus using a legacy transmission system and a broadband downstream transmission system in a HFC network. The IP data transmission apparatus includes: an headend unit for receiving data from an application server system that is a service providing apparatus, splitting the received data into general user data and management message, determining whether the general user is transmitted using a broadband or an existing service band, and transmitting the general user data through the HFC network; and a user cable terminal unit for receiving the split data transmitted from the headend unit through the HFC network, transmitting the received data to an IP based user device, and transferring the management message to the IP based user device through the legacy transmission system.

Abstract: Provided is an apparatus and method for processing a Voice over Internet Protocol (VoIP) packet with multiple frames. The apparatus includes: a transmission packet processing unit for receiving a frame from a speech codec, forming a Real-time Transport Protocol (RTP) payload in a form of multiple frames and transmitting the RTP payload to an RTP stack; and a reception packet processing unit for receiving an RTP packet from the RTP stack, storing the RTP packet in a jitter buffer, performing dejittering, separating frames from the RTP payload one by one and transmitting the frames to the speech codec.

Abstract: A method for composing a lookup table and searching indexes thereof is provided. The method includes the steps of: a) composing a lookup table using a symmetry of a sine and a cosine function; b) changing and setting a gain of a DCO by reflecting a lookup table size in the DCO; c) transforming an absolute value of a DCO output to an integer value; d) determining a range of the integer value of the DCO output; e) searching indexes of a sine and an cosine function according to the range of the integer value of the DCO output; and f) correcting a sign of a lookup table value corresponding to the searched index of the sine function and a sign of a lookup table value corresponding to the searched index of the cosine function according to the range of integers of the DCO output.