Abstract: A telecommunications system includes a first (home) mobile telecommunications network A5 second (roamed) mobile telecommunications network B and a third (virtual) mobile telecommunications network C. The virtual network C does not have its own radio access network but uses the radio access network of network B in accordance with a commercial contract between networks B and C. Network C is a MVNO. When a mobile telecommunications device that has network A as its home network roams to network B, the mobile telecommunications device initially registers with network B as the roamed network. Conventionally, communications between network A and network B would be transmitted via a fixed communication link (25) (such as a leased line). However, in the embodiment described, the network A transmits a command to the mobile telecommunications device, instructing that device to de-register from network B and to re-register with virtual network C.

Abstract: Systems and methods of searching a plurality of data items which include selected data items with respective access tags defining access criteria for those data items. A search request token including search criteria and data identifying a user from an entity associated with the user is received. The user by verified by seeking confirmation that the user is a subscriber with a communications network. Data items from the plurality of data items which are potentially relevant to the search criteria are identified. For any identified data items having access tags, determining whether the verified user has permission to access the identified data items with reference to the data of the search request token. Search results including an indication of identified data items but excluding any such data items for which it is determined that the user does not have permission to access are generated.

Abstract: A telecommunications system includes a first (home) mobile telecommunications network A5 second (roamed) mobile telecommunications network B and a third (virtual) mobile telecommunications network C. The virtual network C does not have its own radio access network but uses the radio access network of network B in accordance with a commercial contract between networks B and C. Network C is a MVNO. When a mobile telecommunications device that has network A as its home network roams to network B, the mobile telecommunications device initially registers with network B as the roamed network. Conventionally, communications between network A and network B would be transmitted via a fixed communication link (25) (such as a leased line). However, in the embodiment described, the network A transmits a command to the mobile telecommunications device, instructing that device to de-register from network B and to re-register with virtual network C.

Abstract: A device or “dongle” (32) is provided for coupling to a Windows-based PC (23). The dongle (32) includes a subscriber identity module (SIM) (15), such as the type used in GSM or UMTS cellular or mobile telecommunications networks. A search engine (40) is accessed by the PC (23) by means of a client application (38) on the PC. The search engine (40) generates a list of search results in response to search criteria in a known manner. Further, the search engine is able to return search results relating to data for which there is restricted access (for example, encrypted data). Such data is identified with a tag which may, for example indicated which users or entities are able to access that data. A user's dongle (32) authenticates that user with the network (3) using a authentication arrangement similar to that employed for authenticating users of a GSM or UMTS mobile telecommunications network. The authenticated identity of the user is communicated to the search engine.