Radio communication method and system

A radio communication system for transmitting and receiving data between at least two communication apparatuses capable of performing radio communication, comprising:

• a first communication apparatus, among the at least two communication apparatuses, that transmits existence confirmation request notices, separately using a first frequency band and a second frequency band that is a frequency band different from the first frequency band and that, after having received one or more of the existence confirmation response notices that respond to the existence confirmation request notices of the first frequency band and the second frequency band, transmits and receives data, using a frequency band corresponding to the higher frequency band of the first and second frequency bands;
• and,
• a second communication apparatus, among the at least two communication apparatuses, that, after having correctly received one or more of the existence request notices of the first frequency band and the second frequency band, returns existence confirmation response notices in response to the correctly received existence confirmation request notices, to the first communication apparatus, using the frequencies corresponding to the first frequency band and the second frequency band,
• wherein the first communication apparatus adjusts a transmitting power of a radio wave of the second frequency band such that a received power of the radio wave of the first frequency band and that of the radio wave of the second frequency band at the second communication apparatus will be equal to each other.