Abstract: Disclosed herein is a communications system in which a transponder having no radio wave generating source executes data transmission with a reader/writer. The transponder is incorporated in a memory card having a memory with which the reader/writer reads and writes information the memory card being used as loaded in a dedicated slot of a host device. The reader/writer transmits a beacon signal telling a service area at a predetermined time interval. The memory card waits for a beacon signal from the reader/writer within a preset period of time after the host device loaded with the memory card is powered on, executes a connection establishment procedure with the reader/writer upon reception of the signal within the preset period of time and, if the beacon signal has not been received within die preset period of time, enters a sleep state in which at least a wait state of the transponder is stopped.

Abstract: The present invention provides a communication system of a backscatter type, the communication system including: a reflector for transmitting data by a reflected wave formed by subjecting a non-modulated wave to a modulation process; and a reflected wave reader for reading the data from the modulated reflected wave signal from the reflector.

Abstract: Disclosed herein is a communication system including: at least one power line communication apparatus connected via a general power line for supplying a commercial alternate current power; a communication terminal having a modem for power line communication, and a plurality of first coils having different directivities; and a coupling apparatus, connected to a power line, having a filter for attenuating an alternate current component of the power line, and a second coil arranged after the filter; wherein the communication terminal executes mutual communication with any of the power line communication apparatus connected via the general power line through proximity communication based on an electromagnetic coupling action that is generated between the plurality of first coils and the second coil when the communication terminal is brought to the proximity of a coupling surface of the coupling apparatus.

Abstract: A transmitting apparatus includes a data dividing unit operable to divide data into pieces of transmittable data, a data outputting unit operable to add a distribution order to the divided pieces of transmittable data to form transmission data, and a transmitter operable to transmit the transmission data in different transmission paths simultaneously. As a result, the effects of using different transmission paths simultaneously and efficient transmission by a form of transmission corresponding to a state of communication are realized.

Abstract: A communication system is disclosed which includes: at least one power line communication device configured to be connected with another power line communication device via a common power line for providing a commercial alternate-current power supply; and a communication terminal configured to include a modem for power line communication and a coil for exchanging power line communication signals with an external entity through electromagnetic coupling, the communication terminal sending and receiving the signals to and from the external entity through electromagnetic coupling between the coil and the power line.

Abstract: An inexpensive metallic material for interconnects of solid-oxide fuel cells, a fuel cell using the metallic material, and a method for producing the metallic material having excellent oxidation resistance and spalling resistance of an oxide layer, high electrical conductivity, and a small difference in thermal expansion from an electrolyte. Specifically, 0.20 percent by mass or less of C, 0.02 to 1.0 percent by mass of Si, 2.0 percent by mass or less of Mn, 10 to 40 percent by mass of Cr, 0.03 to 5.0 percent by mass of Mo, 0.1 to 3.0 percent by mass of Nb, and at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Zr, and Hf in a total of 1.0 percent by mass or less are added so as to satisfy 0.1?Mo/Nb?30, for decreasing the growth rate of the oxide layer and improving the spalling resistance.

Abstract: This invention relates to an information processing apparatus, an information processing method, a recording medium, and a program for transmitting an RTS frame at full power and data at low power. If it is ascertained that data is to be transmitted, an RTS frame is transmitted at full power. If a CTS frame enabling data transmission is not received, a determination is made as to whether a CTS frame is received with its RA field carrying the address of another terminal. If the latter CTS is found to have been received, a transmission-prohibited interval is set and counted based on a duration field in the CTS frame. If the CTS frame enabling data transmission is found to have been received, a reception level of the frame is measured and stored. Data is transmitted by a PDA at lower power. An ACK frame is received. This invention applies illustratively to PDAs.

Abstract: Disclosed herein is a demodulating device including, first high-frequency receiving means and second high-frequency receiving means for receiving a high-frequency signal of one of a first frequency and a second frequency, first signal strength detecting means and second signal strength detecting means for detecting strengths of signals received by the first high-frequency receiving means and the second high-frequency receiving means, respectively, and strength determining means for performing control so as to make the second high-frequency receiving means receive a high-frequency signal of the first frequency when the first high-frequency receiving means is made to receive the high-frequency signal of the first frequency and the second high-frequency receiving means is made to receive a high-frequency signal of the second frequency and when the second signal strength detecting means does not detect a predetermined signal strength within a predetermined time after the first signal strength detecting means dete

Abstract: Data stored in a memory unit can be transmitted to an external apparatus such as a PC, a television or a printer without relying on operations carried out on a host apparatus, onto which the memory unit has been mounted. The memory unit includes a memory card and an adapter into which the memory card is inserted. At a request made by the external apparatus through a radio transmission line as a request for data, the data can be read out from a memory device employed in the memory card in accordance with control executed by a communication control section employed in the adapter. Thus, it is not necessary to install driver software for controlling communications in a digital camera or the like serving as the host apparatus, on which the memory unit is mounted.

Abstract: It is possible to realize remote control in a reflection wave transmission system, and enhance operability for a mobile apparatus having a reflector. The mobile apparatus comprises a reflector and performs reflection wave transmission by carrying data on a reflection wave for unmodulated carrier. A reflection wave reader comprises an infrared light receiving section, receives and decodes a request signal sent as an infrared remote control command, transmits it to the mobile apparatus by an ASK modulated signal and then transmits the unmodulated carrier. The mobile apparatus transmits requested data by reflection wave. The mobile apparatus can be operated from an infrared remote controller and remote control distance can be extended.

Abstract: A data transmission device for sending back data on a reflected wave of an unmodulated carrier, the data transmission device includes: an antenna adapted to receive an unmodulated carrier Fo from a data reader with which data is to be exchanged and send a reflected wave of the unmodulated carrier Fo to the data reader; subcarrier oscillation means for generating a subcarrier frequency Fs; subcarrier modulation means for digitally modulating sending data on the subcarrier Fs; D/A conversion means for generating the analog modulated subcarrier wave Fs by converting a digital modulated signal, generated by the subcarrier modulation means, into analog form; and frequency mixing means for mixing the unmodulated carrier Fo and modulated subcarrier wave Fs to generate new modulated waves Fo+Fs and Fo?Fs.

Abstract: To realize a wireless communication system capable of keeping a beacon interval fixed, keeping transmission quality, and performing intermittence reception without fail. A wireless communication management device includes and transmits beacon time period information in a main beacon and a sub beacon. Then, a wireless terminal device divides transmission data based on the beacon time period information so that the transmission of the transmission data is finished before the transmission of a main beacon is started. Thereby, overlap of transmission timings of the beacon and the transmission data can be prevented and the beacon interval can be made fixed. This can keep transmission quality, makes the wireless terminal device to perform intermittence reception without fail, and improve the entire data transmission efficiency of the system.

Abstract: Disclosed herein a communication system in which communicating stations are interconnected via a first transmission path and a second transmission path, the communication system including: a data transmitting station for dividing one piece of transmission data to generate two data packets, assigning the data packets to the first transmission path and the second transmission path, and transmitting each data packet; and a data receiving station for receiving the data packets from the data transmitting station via the first transmission path and the second transmission path, obtaining the original transmission data by combining the data packets assigned to the respective transmission paths with each other, and transmitting a packet including a response to reception of the data packets from the first transmission path and the second transmission path simultaneously.

Abstract: A sleep length calculation unit 410 of a terminal calculates a sleep length based on what is contained in a PLCP header of a frame, and sets the calculated length on a timer 430. An address detection unit 420 of the terminal detects a destination address from inside a MAC header of the frame to see if this frame is destined for another terminal. If the frame is found destined for another terminal, then this terminal gives a power supply unit 180 an instruction to start sleeping while causing the timer 430 to start counting time. When the sleep length is found to have elapsed on the timer 430, the terminal gives the power supply unit 180 an instruction to stop sleeping. If what is contained in the PLCP header or MAC header is not deemed reliable, then a sleep inhibit determination unit 440 inhibits the power supply unit 180 from going to sleep.

Abstract: For data transfer between a host device and a communication apparatus via a radiocommunication network and for data transfer between an external communication network outside the radiocommunication network and the communication apparatus, a relation of connection between the communication apparatus and the host device according to a radiocommunication protocol held in the communication apparatus is used, communication setting information on the external communication network held in the communication apparatus is used to set a relation of connection between the communication apparatus and the external communication network according to an external communication protocol, and a relation of connection between the communication apparatus and the host device and between the communication apparatus and the external communication network are used to transfer data between the external communication network and the host device.

Abstract: A communication apparatus operating under a back scattering system involving processes of QPSK modulation is provided. The apparatus includes: a first signal channel for acquiring a first reflected wave by getting an incoming radio wave directly reflected without wave passage through any phase shifter; a second signal channel for acquiring a second reflected wave having a phase shifted by ?/2 relative to the phase of the first reflected wave through two-way wave passage through a first phase shifter alone; a third signal channel for acquiring a third reflected wave having a phase shifted by ? relative to the phase of the first reflected wave through two-way wave passage through the first and a second phase shifter; and a fourth signal channel for acquiring a fourth reflected wave having a phase shifted by 3?/2 relative to the phase of the first reflected wave through two-way wave passage through the first through a third phase shifter.

Abstract: In carrying out bidirectional communication with a base station device, one frame is prescribed for each predetermined time period Tf and a plurality of time slots are formed in one frame. In slots T1, T2, . . . , Tn of an uplink period Tu, communication of a down link from the base station device to a communication terminal device is carried out by using a multi-carrier signal having data dispersed to m units of subcarriers for transmission (where m is an integer not smaller than 2), and communication of an up link from the communication terminal device to the base station is carried out by using a multi-carrier signal having data dispersed to j units of subcarriers for transmission (where j is an integer smaller than m) or a multi-carrier signal having data dispersed to m units of subcarriers for transmission.

Abstract: A memory card, memory card communication control method, electronic device, and wireless communication system are provided. The memory card can be used when inserted into an electronic device on which driver software cannot be installed, and can be inserted into an electronic device in the same manner as an existing memory card. Data is read from a flash memory in compliance with a data transmission request from a data reader. Upon receipt of a bit string of the data read from the flash memory, a signal processing section exercises on/off control over an antenna switch in accordance with the bit string, changes a load impedance of an antenna, generates a reflected wave by modulating an unmodulated carrier, which is transmitted to the antenna from the outside and uses the reflected wave to transmit the data to the data reader.

Abstract: This invention relates to an information processing apparatus, an information processing method, a recording medium, and a program for transmitting an RTS frame at full power and data at low power. If it is found in step S1 that data is to be transmitted, then an RTS frame is transmitted at full power in step S2. If a CTS frame enabling data transmission is not found received in step S3, then a determination is made in step S4 to see if a CTS frame with its RA field carrying the address of another terminal is received. If the latter CTS is found received in step S4, a transmission-prohibited interval is set and counted in step S5 based on a duration field in the CTS frame. If the CTS frame enabling data transmission is found received, then a reception level of the frame is measured and stored in step S6. In step S7, data is transmitted by a PDA at lower power. In step S8, an ACK frame is received. This invention applies illustratively to PDAs.

Abstract: A low consumption power is realized in a communication type that a ratio of transmission between apparatus limited to a relatively short distance occupies most of communications. Upon reception of transmission data constituted of a bit series, a wireless transmission module unit performs an on/off operation of an antenna switch connected to an antenna, in accordance with a bit image of the transmission data, and transmits, by a back scattering scheme, the transmission data as reflected radio waves of radio waves from a transmission destination generated by a change in an antenna load impedance. The antenna switch is generally made of a gallium arsenide IC, its consumption power is several 10 ?W or less, and it becomes possible to realize ultra low consumption wireless image transmission.