In radio communication, especially in a centralized network, a commonly faced problem is the issue of the coexistence between a plurality of networks and different networks use different network timing parameters with no synchronization to one another. Thus, a device of one network usually has a difficulty in communication with a device of another network whether or not both are in a radio communication range. This results in causing unwanted mutual interference because when two or more networks operate in the same operation space, a device belonging to a certain network has a difficulty in letting a device belonging to another network know about the existence of the device belonging to the certain network. A means for enabling the first device to communicate with the second device is presented and the operation in the current channel is stopped and the current channel in operation is opened with respect to the second device and the other devices in the network of the second device by the established communication means.