The basic features are 4 messages to handle binding updates, smooth hand-off, a new advertisement bit and the handling of mobility unaware IPv4 nodes. Introduced a binding warning extension to registration request with type number. The Home Agent MAY send binding updates whe na mobile node moves. Binding update should be used instead of registration messages in 3G Interoperability testing. The use of the MIER Generalized Key distribution extension is now used.
Elliptic curve is now a default.
Advertise digestified D-H computed value, and includes opaque date handover in algorithm. The 3G vision is to make use of Mobile IP, and the idea is to have cheap devices. 2G are incompatible, not integrated and not efficient. The existing IP solutions for user mobility have negative impacts, such as time delays, jitters, network efficiency, QOS and cost. UMIP has a simplified, low cost and long battery life solution.