Abstract: The present invention relates to a data collection system and a data collection method in a sensor network, enabling sensor modules to consume lower amounts of power. The base station transmits data collection request signals to one or more sensor modules which are lower than the base station by 1 in a tree structure. Each sensor module which has received the data collection request signal transfers the signal to one or more sensor modules which are lower than the module by 1. The base station regards the transfer of the signal as ACK for the data collection request signal transmitted therefrom to the sensor module which is lower than the base station by 1. The transmission of a data collection acknowledgement signal starts from a sensor module at the low-order end. When a sensor module receives the data collection acknowledgement signal from a downstream sensor module which is lower than the module by 1, the module transmits the signal to an upstream sensor module which is higher than the module by 1.

Abstract: A packet processing circuit includes a plurality of macros and a clock supply unit. Each of the macros processes packet data on the basis of a clock and outputs the processed packet data from at least one route. The macros are cascade-connected. The clock supply unit supplies the clock to a macro to be controlled and, when no packet data is output for a predetermined time from all routes of a macro on the input side of the macro to be controlled, stops supplying the clock to the macro to be controlled.

Abstract: In a data multiplexing network system, a first wavelength multiplexing function unit sets a plurality of different wavelengths which correspond to a plurality of different service classes, respectively, and maps each packet into each correspondent-wavelength which corresponds to each service class, to which the each packet belongs, and multiplexes the correspondent-wavelengths for the plurality of different service classes for a data transmission at a multiplexed-wavelength through a wavelength division multiplexing network. A second wavelength multiplexing function unit receives the each correspondent-wavelength and fetches a packet from the each correspondent-wavelength.

Abstract: A data transmission path establishing method for establishing a data transmission path from each device to a base station independently to thereby form a network with small devices which are required to consume lower amounts of power such as sensors, a radio communication network system and a sensor network system. A base station transmits detection signals to a plurality of radio devices. Each of the radio devices which have received the detection signal transmits detection response signals each including an identifier that uniquely identifies the device and doubling as a response signal and a detection signal for another radio device. Having received the detection response signal from a radio device, the base station recognizes the radio device as a radio device belonging to the station based on the identifier included in the detection response signal.

Abstract: Disclosed is a telemetering system that comprises a wireless base station and a number of wireless sensor nodes. Each wireless sensor node includes a solar cell, a sensor for producing observation data indicating a quantity being measured, a wireless interface for receiving the observation data from the sensor when the node is activated, and a time-schedule memory for storing time-schedule data. Control circuitry briefly activates its own node by supplying power from the solar cell to the wireless interface at periodic intervals according to the time-schedule data of the memory and briefly establishes a wireless link to the base station. During the time the wireless link is briefly established, the control circuitry of each node transmits the observation data to the base station and updates its time-schedule memory if it receives time-schedule data from the base station.

Abstract: Disclosed is a telemetering system that comprises a wireless base station and a number of wireless sensor nodes. Each wireless sensor node includes a solar cell, a sensor for producing observation data indicating a quantity being measured, a wireless interface for receiving the observation data from the sensor when the node is activated, and a time-schedule memory for storing time-schedule data. Control circuitry briefly activates its own node by supplying power from the solar cell to the wireless interface at periodic intervals according to the time-schedule data of the memory and briefly establishes a wireless link to the base station. During the time the wireless link is briefly established, the control circuitry of each node transmits the observation data to the base station and updates its time-schedule memory if it receives time-schedule data from the base station.

Abstract: A data transmission path establishing method for establishing a data transmission path from each device to a base station independently to thereby form a network with small devices which are required to consume lower amounts of power such as sensors, a radio communication network system and a sensor network system. A base station transmits detection signals to a plurality of radio devices. Each of the radio devices which have received the detection signal transmits detection response signals each including an identifier that uniquely identifies the device and doubling as a response signal and a detection signal for another radio device. Having received the detection response signal from a radio device, the base station recognizes the radio device as a radio device belonging to the station based on the identifier included in the detection response signal.

Abstract: The present invention relates to a data collection system and a data collection method in a sensor network, enabling sensor modules to consume lower amounts of power. The base station transmits data collection request signals to one or more sensor modules which are lower than the base station by 1 in a tree structure. Each sensor module which has received the data collection request signal transfers the signal to one or more sensor modules which are lower than the module by 1. The base station regards the transfer of the signal as ACK for the data collection request signal transmitted therefrom to the sensor module which is lower than the base station by 1. The transmission of a data collection acknowledgement signal starts from a sensor module at the low-order end. When a sensor module receives the data collection acknowledgement signal from a downstream sensor module which is lower than the module by 1, the module transmits the signal to an upstream sensor module which is higher than the module by 1.

Abstract: A packet processing circuit includes a plurality of macros and a clock supply unit. Each of the macros processes packet data on the basis of a clock and outputs the processed packet data from at least one route. The macros are cascade-connected. The clock supply unit supplies the clock to a macro to be controlled and, when no packet data is output for a predetermined time from all routes of a macro on the input side of the macro to be controlled, stops supplying the clock to the macro to be controlled.

Abstract: To provide a content distribution system that can distribute contents without selecting a content distribution method according to the number of receivers. Programs are associated with VLAN (Virtual Local Area Network) numbers indicating VLANs respectively. A broadcasting station distributes the programs using a broadcast model based on Layer 2 switches and the VLANs An information device belongs to the VLAN based on the VLAN number specified by a user to receive the user-desired program. Therefore, contents can be distributed without depending on the number of receivers.

Abstract: In a data multiplexing network system, a first wavelength multiplexing function unit sets a plurality of different wavelengths which correspond to a plurality of different service classes, respectively, and maps each packet into each correspondent-wavelength which corresponds to each service class, to which the each packet belongs, and multiplexes the correspondent-wavelengths for the plurality of different service classes for a data transmission at a multiplexed-wavelength through a wavelength division multiplexing network. A second wavelength multiplexing function unit receives the each correspondent-wavelength and fetches a packet from the each correspondent-wavelength.