COMMUNICATION SYSTEM AND COMMUNICATION DEVICE

PROBLEM TO BE SOLVED: To construct a communication route whose origin is an added gateway apparatus by a simple procedure when adding a gateway apparatus in a radio network. SOLUTION: When adding a gateway apparatus 2b in the situation that a communication route connecting a plurality of radio nodes 1 with a gateway apparatus 2a as the origin is constructed, the gateway apparatus 2b broadcasts and transmits a group construction message for constructing a new communication route. In each radio node 1, the number of relay stages with the gateway apparatus 2a is stored, and in the case that the number of the relay stages with the gateway apparatus 2b indicated in the group construction message is smaller than the number of the relay stages with the gateway apparatus 2a when receiving the group construction message, it joins the communication route of the gateway apparatus 2b, 1 is added to the number of the relay stages of the group construction message, the message is broadcasted and transmitted to another radio node 1, and the group construction message is successively propagated among the radio nodes 1. COPYRIGHT: (C)2010,JPO&INPIT