| 摘要 |
<p>In a cellular telephone system, subscribers each have a token (such as a smartcard) by means of which they may respectively identify themselves to the network. Each subscriber logs into the network by using his smartcard which inputs a unique secure identification number (IMSI) into the network. The relationship between each IMSI and the corresponding subscriber's telephone number (MSISDN) is random and known only to the network operator, this arrangement facilitating simple and secure issue of initial and replacement smartcards. A home location register (HLR) in the network stores each subscriber's MSISDN and the associated IMSI. The network also includes an analysis table linking each IMSI with the identity of the corresponding HLR storage location. This analysis table is split into parts which are held at different entities, such as different mobile services switching centres (MSC), in the network. In response to an input IMSI, the relevant MSC controlling the cell receiving that IMSI derives from the IMSI a Global Title which it uses to locate the relevant part of the analysis table. It can now access the correct storage location in the HLR, extract the MSISDN (and other subscriber data) and store this temporarily in its associated visitor location register.</p> |
