Abstract: A home agent, attached to a home network, receives, adapts and forwards messages intended for a mobile node attached to one of a plurality foreign networks. The home agent, having received a message, passes the message on to a processing unit to assess whether the message should be adapted so as to be compatible with the destination foreign network and to adapt the message accordingly. The adapted message is returned to the home agent to be encapsulated and tunnelled to a foreign agent attached to the destination foreign network. The foreign agent decapsulates the message and passes it on to the mobile node. This method has the advantage that the mobile node is able to receive messages regardless of the type of network to which it is attached.

Abstract: A mobile telephone network stores a list of short dialling codes in association with each user's identity so as to define the short codes which each individual user is permitted to use for providing access to a data conversion device which gives access to a private network. When a short code is dialled on a mobile station, calling data comprising the short code together with caller identification data derived from the mobile station are transmitted over the radio link to the mobile switching center. Prior to routing the call, the identity of the dialling station is authenticated. The short code in the calling data is then compared with the permitted list of short codes to determine whether the user is permitted to make the call. If the caller is permitted to make the call, the call is routed to a destination corresponding to the data conversion device. Thus, only permitted users may access the data conversion device.