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: A radio transmitter/receiver and an intermittent transmission/reception control method thereof, capable of reducing the reception startup time as well as suppressing reception power consumption. A radio transmitter/receiver used for ad hoc communication is provided with a dedicated standby reception unit (10) having a simple combination of an RF demodulator (6) and a SAW oscillator (7) only to detect a carrier. For a time period of several bits, the activation system of the radio transmitter/receiver intermittently receives activation selection signals transmitted using ASK (or OOK) modulation prior to a preamble signal, and makes an activation selection based on the pattern of presence and absence of the carriers of the signals. As a result, the reception startup time can be shortened, and less reception power is required.

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.