A communications system comprising a radio access network for providing local wireless access for a mobile device and an authentication entity in a public land mobile network, wherein the authentication entity is arranged to authenticate the mobile device accessing the radio access network on the basis of authentication signalling between the authentication entity and the mobile device. The system includes a proxy entity via which transfer of the authentication signalling is arranged, and encapsulated transmission of the authentication signalling to and from the mobile device is arranged in messages of a cryptographic client-server transport layer encapsulation protocol between the mobile device and the proxy entity. The system provides encapsulated transfer of the authentication signalling to and from the authentication entity in messages of an AAA client-server protocol between the proxy entity and the authentication entity.