Abstract: A frequency band is divided into N subchannels. Sub-channels are first allocated for a power line communication system having a higher priority, such as public communication or the like. Sub-channels for a power line communication system having a relatively low priority, such as in-home communication or the like, are allocated from free subchannels. In this case, the subchannels used by the power line communication system having the high priority are limited to a plurality of consecutive subchannels from an upper side or a lower side of the frequency band.

Abstract: A communication network system sets communication parameters which enable an operation under a maximum possible communication rate in a situation where a transmission path has cyclic noise/impedance fluctuations. A transmission/reception apparatus 100 transmits training packets for checking the state of the power line at two distinct points in time. A transmission/reception apparatus analyzes SNR at each carrier frequency, and stores an SNR evaluation result. The transmission/reception apparatus compares two SNR evaluation results which are obtained through two instances of a channel estimation algorithm, selects an SNR evaluation result which dictates a faster PHY rate, and transmits it to the transmission/reception apparatus. The transmission/reception apparatus changes modulation/demodulation rules based on the received SNR analytical result.

Abstract: A frequency band is divided into N subchannels. Sub-channels are first allocated for a power line communication system having a higher priority, such as public communication or the like. Sub-channels for a power line communication system having a relatively low priority, such as in-home communication or the like, are allocated from free subchannels. In this case, the subchannels used by the power line communication system having the high priority are limited to a plurality of consecutive subchannels from an upper side or a lower side of the frequency band.

Abstract: A multicarrier communication method selects carriers on the basis of an SN-ratio and the balancing of a transmission line. Available carriers are selected in accordance with the balancing of the balanced transmission line, in which the balancing is measured at either a sending terminal or a receiving terminal or alternatively at both, and the SN-ratio is measured between the sending terminal and the receiving terminal. Additionally, a modulation method having the greatest permissible multivalue is selected for each of the carriers, wherein the carriers are selected in light of the SN-ratio and balancing, or alternatively in a highest-to-lowest order of frequency. Transmission power is controlled for each of the carriers to suppress radiated emission, and the SN-ratio and balancing are measured at predetermined time intervals to renew the selection of the carriers and the selection of the modulation methods.

Abstract: A communications device 100, which performs data communication, includes an AC cycle sensor 30 which is connected to a power line 106 supplied with an a.c. voltage and generates a synchronous signal SS at timing of an a.c. voltage waveform AC of the power line 106; a data communicator 10 for performing data communication; and a communications controller 20 which performs communication of a control signal including information showing at least one of a communications device and a communications standard and controls the data communicator 101. When the a.c. voltage supplied to the power line 106 is an N-phase and when the cycle of the a.c. voltage waveform is T, data communication to be performed in a communication period subsequent to the period is controlled on the basis of the control signal included in the period of T/2M on condition that M is a natural multiple of N.

Abstract: A communication network system sets communication parameters which enable an operation under a maximum possible communication rate in a situation where a transmission path has cyclic noise/impedance fluctuations. A transmission/reception apparatus transmits training packets for checking the state of the power line at two distinct points in time. A transmission/reception apparatus analyzes SNR at each carrier frequency, and stores an SNR evaluation result. The transmission/reception apparatus compares two SNR evaluations results which are obtained through two instances of a channel estimation algorithm, selects an SNR evaluation result which dictates a faster PHY rate, and transmits it to the transmission/reception apparatus. The transmission/reception apparatus changes modulation/demodulation rules based on the received SNR analytical result.

Abstract: A communications device 100, which performs data communication, includes an AC cycle sensor 30 which is connected to a power line 106 supplied with an a.c. voltage and generates a synchronous signal SS at timing of an a.c. voltage waveform AC of the power line 106; a data communicator 10 for performing data communication; and a communications controller 20 which performs communication of a control signal including information showing at least one of a communications device and a communications standard and controls the data communicator 101. When the a.c. voltage supplied to the power line 106 is an N-phase and when the cycle of the a.c. voltage waveform is T, data communication to be performed in a communication period subsequent to the period is controlled on the basis of the control signal included in the period of T/2M on condition that M is a natural multiple of N.

Abstract: A communication network system sets communication parameters which enable an operation under a maximum possible communication rate in a situation where a transmission path has cyclic noise/impedance fluctuations. A transmission/reception apparatus 100 transmits training packets for checking the state of the power line at two distinct points in time. A transmission/reception apparatus analyzes SNR at each carrier frequency, and stores an SNR evaluation result. The transmission/reception apparatus compares two SNR evaluation results which are obtained through two instances of a channel estimation algorithm, selects an SNR evaluation result which dictates a faster PHY rate, and transmits it to the transmission/reception apparatus. The transmission/reception apparatus changes modulation/demodulation rules based on the received SNR analytical result.

Abstract: In-home communication systems 110 and 130 and an access communication system 120 that are capable of co-existing. The communication systems 110 and 130 and the access communication system 120 are able to co-exist by utilizing TDM that is in synchronization with a power cycle. Further, communication system that needs to secure AV-QoS assigns transmission timing to a slave station within itself by synchronizing a beacon cycle with a cycle of a power line.

Abstract: Provides a terminal for performing multiple access transmission suitable to a transmission path having varied characteristics. The terminal (100) includes a transmission/reception section (201), a control unit (204), a transfer management section (206), and an external interface section (203). The terminal (100) refers to an IGMP (MLD) message received by the transmission/reception section (201) to classify a transmitter host and a relay device of this message based on the characteristic of the transmission path, and performs a multiple access transmission of a multicast packet in a form suitable to the characteristic of the respective transmission path.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: Transmitter 2 includes inverse multicarrier transformer 23 and D/A converter 24. Inverse multicarrier transformer 23 generates a notch by masking a carrier at a frequency location predetermined in accordance with a communication method of the transmitter. D/A converter 24 performs a D/A conversion on a transmission signal containing the notch and transmits the signal to a transmission line. Receiver 1 includes power measurement unit 171, comparator 172 and coexistence signal determination unit 173. Power measurement unit 171 measures a power value of a signal input from the transmission line. Comparator 172 determines whether or not the notch exits by comparing the measured power value with a threshold. Coexistence method determination unit 173 determines the type of coexistence method, based on the location of the detected notch.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: A cable connecting device for power line communication includes: a first wiring line 231 and a second wiring line 232 through which AC power is capable of being supplied; a power plug 120 which is electrically connected to the first wiring line 231 and the second wiring line 232 and whose wiring lines are capable of being supplied with AC power; an Ethernet port 110 through which a communication signal is capable of being input and output; a power line communication modem 220 that is connected to the Ethernet port 110 and that is connected to the second wiring line 232 through which a communication signal is transmitted by using AC power input to the power plug 120 through the first wiring line 231 between the power plug 120 and the Ethernet port 110; a filter 210 disposed on the first wiring line 231 and having high impedance in at least a frequency band used for power line communication rather than a frequency band used for AC power; and connectors 101 to 104 which axe electrically connected to the first wi

Abstract: A channel-estimating apparatus according to the present invention, including: an input unit (2) operable to receive several pieces of channel information (5) from a plurality of receivers (10), (11), in which the plurality of receivers (10), (11) are operable to perform MIMO communication through a plurality of channels; an estimating unit (3) operable to collectively estimate statuses of the plurality of channels in accordance with the several pieces of channel information (5) received by the input unit (2), whereby estimation results (6) are generated; and an output unit (4) operable to feed the estimation results (6) into the plurality of receivers (10), (11). As a result, interference from other pieces of MIMO communication-adapted communication equipment is suppressible, with consequential improvements in both of quality and capacity of communication.

Abstract: A first communication apparatus 100 transmits a pilot signal which was generated by a pilot signal generation section 14, at predetermined timing, and detects an unbalance component of a transmission line 300 at the time of pilot signal transmission in an unbalance component detection section 13, and controls a transmission signal in such a manner that an unbalance component is reduced by a transmission control section 12 on the basis of the detected unbalance component.

Abstract: A power line communication apparatus transmits a signal to a first power line communication apparatus through a power line connecting to a second power line communication apparatus. The power line communication apparatus includes an information retriever for retrieving transmission rate information indicating both a first transmission rate and second transmission rate. The first transmission rate correspond to a first path of the power line along which the signal is directly transmitted to the first power line communication apparatus, and the second transmission rate corresponds to a second path of the power line along which the signal is transmitted through the second power line communication apparatus to the first power line communication apparatus. A selector selects, based on the transmission rate information, a path corresponding to a higher transmission rate among the first and second paths. A transmitter transmits the signal through the selected path.

Abstract: A communication apparatus includes a transmission signal generation section 1, a transmission signal control section 2, a transmission section 3, a leakage electric power detection section 4, and an electric power control judgment section 5. The transmission signal generation section 1 generates a transmission signal for carrying out transmission using a plurality of sub-carriers, under control of the transmission signal control section 2, and has a transmission electric power control function with respect to each sub-carrier. The leakage electric power detection section 4 detects electric power which is leaked from a transmission line 9 among transmission electric power.

Abstract: A communication system includes a synchronizing signal generator that generates a synchronizing signal based on a timing of an alternating waveform in a power line, a data communicating circuit that performs the data communication, and a communication controller that controls to acquire a transmitting right utilizing a timing of the synchronizing signal and to control the communication circuit in accordance with whether or not the communication apparatus acquires the transmitting right.

Abstract: A cable connecting device for power line communication includes: a first wiring line 231 and a second wiring line 232 through which AC power is capable of being supplied; a power plug 120 which is electrically connected to the first wiring line 231 and the second wiring line 232 and whose wiring lines are capable of being supplied with AC power; an Ethernet port 110 through which a communication signal is capable of being input and output; a power line communication modem 220 that is connected to the Ethernet port 110 and that is connected to the second wiring line 232 through which a communication signal is transmitted by using AC power input to the power plug 120 through the first wiring line 231 between the power plug 120 and the Ethernet port 110; a filter 210 disposed on the first wiring line 231 and having high impedance in at least a frequency band used for power line communication rather than a frequency band used for AC power; and connectors 101 to 104 which axe electrically connected to the first wi