Communication system, relay element, and content server

A provider code is added to a request signal transmitted to a contents server CP1 from a mobile unit MS by a mobile communication network GSM. A border switching station CMMS adds a roaming flag to the request signal, and forwards the request signal to a gateway unit GW. The gateway unit GW converts the provider code contained in the request signal into the country code by referring to the code conversation table, and transmits a HTTP request to the contents server CP1 after adding the country code and roaming identification information to HTTP header. When the contents server CP1 receives the above-mentioned HTTP request, the contents server CP1 determines whether the requested contents are allowed to be transmitted abroad by referring to a transmission table. When the transmission of the requested contents is not permitted, the contents server CP1 transmits an error notification to the mobile unit MS to notify that transmission is not permitted.