Patent ID: 8140082

Claim:
A communication system for establishing a secured first connection between a mobile station and an access point located on a radio access system, comprising: a judgment unit configured to judge, in case of an identification of an identical first identifier that uniquely identifies a radio-access-system-controlling apparatus and a second identifier that uniquely identifies a switch-controlling apparatus, not to establish a secured second connection between the mobile station and a switch apparatus connected to the radio access system and to keep the secured first connection, and in case of an identification of a non-identical first identifier and second identifier, to establish the secured second connection between the mobile station and the switch apparatus; an address list storage unit configured to store an address list that indicates a range of an address assigned by the radio access system on which the switch apparatus is located; and an algorithm list storage unit configured to store, as an algorithm list, a secured algorithm used in the radio access system or a non-secured algorithm used in the radio access system on which the access point is located; wherein the judgment unit is configured to judge whether or not to establish the secured second connection by comparing the address list and an address of the mobile station transmitted from the mobile station, and by comparing the algorithm list and the algorithm used in the radio access system on which the access point is located.