The present invention relates to a wireless communication system. When performing maintenance of a sample stage, refrigerant collected from a refrigerant flow path is temporarily stored in a flow path section extending from an expansion valve to the check valve, making it possible to perform the maintenance without changing the amount of refrigerant in the refrigerating cycle. A fuel cell is disposed in the downhole assembly and operatively coupled to the electrical device for providing electrical power thereto. The mobile device then initiates a second communication session with a second RAN that is likewise connected to the wired network.