A communication system configured to construct a communication network using a hopping pattern designated in a router advertisement between at least one wireless communication device configured to transmit the router advertisement designating the hopping pattern of channel hopping and timing to perform transmission/reception in the hopping pattern and an opposite party wireless communication device of a provisioning network configured to receive the router advertisement, wherein the at least one wireless communication device comprises: a receiver configured to, prior to transmitting the router advertisement, receive a router advertisement transmitted from another wireless communication device; determination means configured to determine whether or not the router advertisement is received by the receiver; a pattern analyzer configured to identify from the router advertisement the hopping pattern, offset and duration being used; a generator configured to generate, in case it is determined that the router advertisement is received by the receiver, a hopping pattern that does not use the same channel at the same time with respect to the hopping pattern that is designated by the router advertisement received by the receiver, and configured to select, in case it is determined that the router advertisement is not received by the receiver, a hopping pattern prescribed in advance; and a transmitter configured to transmit the router advertisement that designates the hopping pattern generated by the generator, in case it is determined that the router advertisement is received by the receiver, and configured to transmit the router advertisement that designates the prescribed hopping pattern selected by the generator, in case it is determined that the router advertisement is not received by the receiver, wherein the generator is further configured to generate in the case of receiving two or more router advertisements, channel hopping patterns that do not conflict with any one of the plurality of channel hopping patterns of the plurality of router advertisements, by adjusting the offsets of the hopping patterns received after limiting the hopping patterns and the durations used. a receiver configured to, prior to transmitting the router advertisement, receive a router advertisement transmitted from another wireless communication device; determination means configured to determine whether or not the router advertisement is received by the receiver; a pattern analyzer configured to identify from the router advertisement the hopping pattern, offset and duration being used; a generator configured to generate, in case it is determined that the router advertisement is received by the receiver, a hopping pattern that does not use the same channel at the same time with respect to the hopping pattern that is designated by the router advertisement received by the receiver, and configured to select, in case it is determined that the router advertisement is not received by the receiver, a hopping pattern prescribed in advance; and a transmitter configured to transmit the router advertisement that designates the hopping pattern generated by the generator, in case it is determined that the router advertisement is received by the receiver, and configured to transmit the router advertisement that designates the prescribed hopping pattern selected by the generator, in case it is determined that the router advertisement is not received by the receiver,