Abstract: A wireless communication network system (1) comprising a sensor device (10) transmitting detected data, one or a plurality of relay devices (100) relaying the data, and a gateway device (11) transferring the data to another network, wherein the sensor device, the relay device, and the gateway device being connected by a wireless communication network, wherein the relay device comprising: a receiver (101) receiving a received signal containing the data; a storage (104) storing heartbeat data; a transmitter (102) transmitting a transmission signal containing the data received by the receiver and periodically transmitting a transmission signal containing the heartbeat data; and a frequency setting unit (103) directing to set a frequency of the received signal received by the receiver and/or a frequency of the transmission signal transmitted from the transmitter based on a frequency setting command transmitted from the gateway device.

Abstract: A data transmission rate control method in which a transmission control scheme used for data transmission over each channel is switched depending on a subband to which a proper transmission rate of the channel belongs, the subband being prepared by dividing an entire band by one or more boundaries. This makes it possible to solve a problem in conventional systems of variations in accuracy due to the bandwidth, and an increase in the circuit scale, when the a cell rate to be controlled ranges over wide bandwidth.