Abstract: A communications device such as a mobile telephone (1) responds to the input of a dialed number for a call destination (2) by generating and outputting a request message transmitted to a control centre (7) via a telecommunications system (3). The device receives a response message from the control centre containing routing data and credit data representing remaining credit within an account limit of the subscriber. An outgoing communications session is then initiated using the routing data which may for example enable a dialed telephone number to be modified to achieve optimum routing to the call destination via one or more preferred networks. The device also includes a credit control application (83) for limiting the duration of the communication in accordance with the credit data. Mobile telephones may thereby be used with a prepayment subscription account even during roaming operation in which the mobile telephone registers with a network other than the subscriber's home network.

Abstract: Mobile terminals are operated in a mobile telecommunications system such as GSM routing data messages such as SMS messages to a destination address via a selected of plural routing centers. A terminal receives user generated data defining an outgoing message and generates a first data field containing a first routing center address, a second data field containing the destination address, and a third data field containing the user generated data. The terminal traps the outgoing message and compares the first routing center address and a second routing center address, determined by a system administrator, stored in a memory the user cannot write-access. If the addresses differ, the first routing center address is replaced by the second routing center address in the data field and the outgoing message is routed via a second routing center with the second routing center address. The administrator thereby controls message routing.

Abstract: A communications device such as a mobile telephone (1) responds to the input of a dialled number for a call destination (2) by generating and outputting a request message transmitted to a control centre (7) via a telecommunications system (3). The device receives a response message from the control centre containing routing data and credit data representing remaining credit within an account limit of the subscriber. An outgoing communications session is then initiated using the routing data which may for example enable a dialled telephone number to be modified to achieve optimum routing to the call destination via one or more preferred networks. The device also includes a credit control application (83) for limiting the duration of the communication in accordance with the credit data. Mobile telephones may thereby be used with a prepayment subscription account even during roaming operation in which the mobile telephone registers with a network other than the subscriber's home network.

Abstract: A method of operating a mobile telecommunications apparatus in a telecommunications system where the apparatus includes means for making outgoing telephone calls via the system, means for receiving a user generated input defining a call destination and routing means for selecting a preferred route to the call destination via the system for an outgoing telephone call by referring to routing information stored in the apparatus. The method includes registering with a network of the system which is local to the current location of the apparatus, receiving network identification information from the local network, determining from the network identification information whether the stored routing information requires updating, and outputting a request message for receiving updating information for updating the stored routing information if the stored routing information is determined to require updating.