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: An in-home-system master station of an in-home communication system detects a frequency band (a channel number corresponding to a data communication subchannel) or a time slot used by each station of an access communication system, using a coexistence signal subchannel. Based on the detected information, the in-home-system master station determines a frequency band or a time slot to be used in the in-home communication system to which the in-home-system master station belongs, so as not to avoid overlapping the frequency or time slot used in the access communication system, and informs each in-home-system slave station of the determined frequency band or time slot.

Abstract: This invention provides an image transmission method, image anti-duplication method, image anti-duplication device, and image recording medium in which the information for anti-duplication control is superimposed on the video signal without deterioration of the resultant video signal and the information is extracted accurately and quickly to perform anti-duplication control. The output device starts generation of PN code correspondingly to the PN code start timing signal T1 generated based on the video sync signal. One chip interval of the PN code is divided to a plurality of divided chips correspondingly to the PN code inversion timing signal HT, and the original value of the chip is inverted on alternate one divided interval to generate the PN inversion code. The anti-duplication control signal is subjected to spectral spreading using the PN inversion code and superimposed on the video signal.

Abstract: A communication apparatus which is in a wireless network is characterized by comprising a communication means transmitting information among the other communication devices, a means receiving priority order information representing stand-by times different in each communication device from the control station and setting communication devices as control station candidates in a memory, and a means performing communication control as a control station in the wireless network when the stand-by time elapses.

Abstract: The present invention relates to a radio transmission method and apparatus for a radio network using a plurality of communication stations. More specifically, the apparatus defines a radio transmission frame based on a signal sent from a control station. A management information transmission region and an information transmission region are set in the defined frame period. A station synchronous section for transmitting a signal for every communication station constituting the radio network is set in the management information transmission region. The length of the station synchronous section is variable in accordance with the number of communication stations in the network. Using this frame format, it is possible to efficiently conduct radio transmission.

Abstract: A communication apparatus which is in a wireless network is characterized by comprising a communication means transmitting information among the other communication devices, a means receiving priority order information representing stand-by times different in each communication device from the control station and setting communication devices as control station candidates in a memory, and a means performing communication control as a control station in the wireless network when the stand-by time elapses.

Abstract: A wireless communication system has transmission apparatus transmitting a wireless signal based on a transmission unit and reception apparatus. The reception apparatus includes plural reception devices receiving the wireless signal to obtain the informational signals and output-controlling device selecting any informational signal from the informational signals. The reception device has communication-quality-detecting device that detects communication quality of the wireless signal, a memory storing the informational signal, and synchronization-detection-storage-controlling device that detects the synchronization signal and controls the memory to store the informational signal based on a detected result of the synchronization signal.

Abstract: To provide a radio transmission method and a radio transmission apparatus capable of performing a highly-efficient radio transmission depending on the number of communicating stations, a predetermined frame period is prescribed, a management information transmitting field being provided within the frame period, a station sync transmit/receive interval being provided within the management information transmitting field and an arbitrary communicating station being designated to transmit a station sync at plural frame period intervals during the station sync transmit/receive interval. Thus even if only the station sync transmitting area corresponding to the number which is less than the number of communicating stations forming a network exists within one frame, the station sync can be transmitted and received.

Abstract: A communication apparatus which is in a wireless network is characterized by comprising a communication means transmitting information among the other communication devices, a means receiving priority order information representing stand-by times different in each communication device from the control station and setting communication devices as control station candidates in a memory, and a means performing communication control as a control station in the wireless network when the stand-by time elapses.

Abstract: A communication apparatus which is in a wireless network is characterized by comprising a communication means transmitting information among the other communication devices, a means receiving priority order information representing stand-by times different in each communication device from the control station and setting communication devices as control station candidates in a memory, and a means performing communication control as a control station in the wireless network when the stand-by time elapses.

Abstract: An offset value corresponding to the difference between counter values of cycle time counters in two buses is obtained and stored, so that the buses are connected, the value of a first cycle time counter is compensated for buy an offset value. The counter value of the first cycle time counter is compared with the counter value of a second cycle time counter, and a time stamp of data is changed corresponding to the offset value.

Abstract: A communication apparatus which is in a wireless network is characterized by comprising a communication means transmitting information among the other communication devices, a means receiving priority order information representing stand-by times different in each communication device from the control station and setting communication devices as control station candidates in a memory, and a means performing communication control as a control station in the wireless network when the stand-by time elapses.

Abstract: In a wireless transmission control method for controlling wireless communication access among a plurality of communication stations via wireless transmission of a control signal from a central control station to a terminal station, a communication station selected as the central control station judges a station with which each terminal station in a wireless network is capable of directly making communication. When it is detected that each terminal station is capable of directly making communication with a communication station having many more stations than those directly making wireless communication with the central control station, processing for changing the detected terminal station to the central control station is performed. Thus, when the control station is set and the access management of wireless communication is carried out under the control of the control station, the control station can be selected easily and satisfactorily.

Abstract: A playback device 10 generates a PN code with a start timing based on a video sync signal, and generates a PN inverse code which has a reverse polarity to that of the PN code with a timing based on the video sync signal. An anti-duplication control signal is spectrally spread using this PN code, superimposed on the video signal and supplied to a recording device. A PN inverse code which is the same as the PN inverse code used in the playback device is also generated in the recording device based on the video sync signal, and reverse spectral spread is performed using this PN inverse code.

Abstract: A communication control method and a communication system, in which the transmission efficiency, in a network system is improved in the case where the communication in the network system is controlled by a control station. A management data transmission area is set in a frame period, and a plurality of slots are arranged in the management data transmission area. Data on the communication condition of each station are individually transmitted by each of a plurality of communication stations or the control station in each of the slots.

Abstract: The present invention is to provide communication apparatus capable of selecting a transmission scheme suitable for a type of transmission information, its communication method, and programs. A transmitter/receiver portion 2 is capable of communicating under plural transmission schemes of different transmission rates in accordance with combinations of coding rates of a convolutional encoder and modulation schemes. A transmission scheme selection portion 5 prioritizes the transmission schemes in a plurality of different evaluation schemes in response to signal Ds representing the type of transmission information based on measurement results S4 measured at a measurement portion 4 and selects the optimum transmission scheme to be used for communications from the plural transmission schemes according to the prioritized result. The selected transmission scheme is sent to the transmitter/receiver portion 2 for switching the transmitter/receiver portion 2.

Abstract: In a radio communication system, efficient information provision services obtained, where various information is provided to mobile communication terminal devices separately from call services, update information on information to be provided is transmitted from a base station unit, and a mobile communication terminal device receives the update information and then receives the desired information upon confirming that the desired information has been updated. Consequently, due to the ability to easily determine whether or not the information to be provided has been updated, the mobile communication terminal device need not receive all the information or connect to an information service center, but can efficiently use the information provision services.

Abstract: A wireless communicating method for a system having a plurality of communicating stations and a controlling station for controlling an accessing operation of the communicating stations in which the controlling station is disposed between the communicating stations, a communication signal is transmitted and received between each of the communicating stations and the controlling station, as the communication signal has a control area and a data area structured as a frame on a time division basis. The method includes the steps of causing a communicating station to transmit a communicating station state change request signal to the control station, causing the control station to transmit a communicating station state signal to the communicating station so as to enter the relevant communicating station into a sleep state, and causing a communicating station in the sleep state to receive a start command signal that causes the relevant communicating station to cancel the sleep state.

Abstract: A wireless communicating method of a system having a plurality of communicating stations and a controlling station for causing the communicating stations to be accessed. A communication signal is transmitted between each of the communicating stations and the controlling station, the communication signal being structured as a frame divided as time periods of a control area and a data area. The controlling station transmits a communicating station state signal to each of the communicating stations and each of the communicating stations transmits a communicating station state change request signal to the controlling station so as to cause the controlling station to control access right of the communicating station corresponding to a priority level assigned to the communicating station.

Abstract: A frame period is specified by means of a predetermined signal; a management data transmission region is set in this frame period; and when common information to be transmitted from the control station in the management data transmission region is received at a plurality of communication stations, any of these communication stations performs processing for repeatedly transmitting the received common information, whereby when communications in a network system are controlled by a control station, a station incapable of directly making communication with a control station can be controlled satisfactorily.