3G ME and SIM – Scenario M
ICC, BSS and VLR/SGSN are 2G, the ME is 3G. This applies when e.g. a 2G subscriber with a 3G ME roams in a 2G network.
2G AKA is performed just like in a plain 2G situation.
A 2G/3G dual mode ME is transparent for 2G AKA.
No service with a 3G single mode ME.