Communication system, communication device, and method for reconnecting communication system

A communication system includes a plurality of communication devices constituting a network. Each of the communication devices includes a first wireless communication circuit and a second wireless communication circuit. The second wireless communication circuit of a lower-level communication device accesses the first wireless communication circuit of a higher-level communication device, whereby the higher-level communication device and the lower-level communication device are connected so as to constitute the network. Each of the plurality of communication devices stores system information. When any one of the communication devices is disconnected from the higher-level communication device, the disconnected communication device searches for another communication device using the system information and makes reconnection to the communication device detected by the search.