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.