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 mobile telephone is provided with a look-up table enabling the mobile telephone to select preferred routes for connecting outgoing calls on the basis of predetermined codes which populate the look-up table. When operating in a cellular communications network a communications channel may thereby be selected from a plurality of available channels and ongoing transmission of an outgoing call may be routed via a further network selected in accordance with the route codes. The look-up table may be stored in a SIM card of the mobile telephone and may be updated via transmission of data from a remote control center via a cellular network or via a docking station to which the mobile telephone is releasably connectable. When the call is routed via a packet switching network, the routing code may include a string of network node addresses.

Abstract: A device for making telephone calls receives input data defining a call destination. The device generates a request message which is output to a control center, a response message then being received from the control center identifying a preferred route for routing the call to the call destination. The routing information is utilized by the device in initiating communication with the call destination. Typically the input data is a telephone number and the dialing means initiates communication using a modified telephone number which may include a prefix obtained from routing data contained in the response message. Response messages may be stored in a cache memory to reduce the need for request messages. The device may be a mobile telephone operating in a cellular telecommunications network or may be a landline device such as telephone or facsimile machine.

Abstract: A routing device is used to route telephone calls. The device prefixes user generated call numbers with a prefix code which determines the network connection route and provides billing and customer identification information. The device determines the preferred route by addressing a lookup table which is periodically updated with updating information transmitted by radio broadcast from a control center. The device may be a standalone device connected through a telephone in a local exchange connection or may be formed unitarily with a telephone facsimile machine or a mobile telephone. The broadcast updating information is transmitted by a message pager transmitting system during off peak message handling times. The device is provided with two memory areas for first and second lookup tables so that one of the tables remains addressable while the other table is being updated. The most recently updated table being subsequently used as the decision table.