A mapping table holds correspondence relation between quality of service information of wired sections and quality of service information of wireless sections. A quality of service information converter, upon receiving encapsulated packets directed from a mobile communication network to a wireless local area network terminal, acquires quality of service information of wired sections that has been conferred to the packets, and finds quality of service information of wireless sections that corresponds to the quality of service information of wired sections in the mapping table. The quality of service information converter then uses this quality of service information of wireless sections to wirelessly transmit the encapsulated packets to a wireless local area network terminal.