Currently, Mobile IPv6 (MIPv6) working group of Internet Engineering Task Force (IETF) recommends to execute the Binding Update (BU) using Return Routability (RR) procedure. However, the RR procedure doesn't entirely satisfy the security requirements of MIPv6. The previous BU protocols are also likely to reduce the efficiency since they iterate entirely BU protocol courses in Pico/Micro cellular environment in which it occurs frequently handoff or handover and some protocols don't consider that the Correspondent Node (CN) is movable node and has the limited resources. In this paper we propose the ETBU protocol, which is based on Cryptographically Generated Address (CGA) to provide mutual authentication between nodes; it considers that the CN is a movable node. This protocol doesn't require a Mobile Node (MN) to create a signature each time it obtains a new Care-of Address (CoA) unlike the previous CGA-based BU protocol. An MN and its CN issue the ticket to minimize the computing costs that need to calculate CGA. Also, the ETBU protocol minimizes the loss of traffic using smooth handoff or handover. A performance analysis shows that the scheme provides the security as much as the previous BU protocols and more efficiency than them in case that each node obtains the ticket. Therefore, the proposed ETBU protocol can be applied easily to the mobile network environments.

The exciting goals of ubiquitous computing and communication services can only be achieved if we can increase the efficiency with which the location of mobile terminals can be managed; current mobile infrastructures are not efficient since they treat all mobile terminals uniformly despite that fact that many mobiles often move together (i.e. passengers on the same train or a group of cars on a road). This paper presents a hierarchical location management scheme that handles such grouped mobiles collectively and so reduces the overhead costs of location management. In our scheme, mobiles that move together for long enough form a mobile network and make a hierarchy in the wireless access network. The scheme also adjusts the number of mobile networks to keep communication overhead low. We apply the scheme to Mobile IPv6 and evaluate the resulting performance improvement. Simulation results confirm that our hierarchical approach can greatly reduce the overhead costs of location management, and that it is very practical since it can flexibly develop suitable mobile networks.