Bluefish Technologies has developed a SIM card for mobile handsets that can support multiple network identities. The card will be of particular interest to network operators working to provide preferred networks where possible.
The Bluefish SIM card uses the same IMSI technology as a normal SIM, but instead of storing the usual pair of IMSI and Ki numbers, which identifies and authenticates the subscriber, the new SIM can hold multiple IMSIs and a Ki pair.
The supplier of SIM cards and SIM based technologies developed the technology to automatically configure the appropriate account whilst roaming in different areas of network operation. There is also a manual facility on the card.