Tunnel-Free Scheme Using a Routing Table in a PMIPv6-Based Nested NEMO Environment

As new mobile devices such as cellular phones, PDAs, laptop computers, and touch screen computers become more and more popular, many people want to be able to access the internet without limitations. Rapid advances in various wireless access technologies such as wideband code division multiple access (WCDMA), mobile worldwide interoperability for microwave access (M-WiMAX), long term evolution (LTE), wireless local area networks (WLANs), and wireless sensor networks (WSNs) respond to consumers’ demands for mobile and ubiquitous computing environments. As the number of network devices supporting the IPv4 protocol has been rapidly increasing, a shortage of IPv4 addresses to assign to new devices has arisen. To address the shortage in the IP address pool, the Internet Engineering Task Force (IETF) has proposed an IPv6 protocol with 64 bit addresses [1]. However, because mobility management is not supported in IPv6, Mobile IPv6 (MIPv6) [2] has also been standardized by the IETF. MIPv6 does not define a foreign agent (FA) and supports an optimized routing path through which a mobile node (MN) can communicate directly with a correspondent node (CN). Careful consideration has been required, however, to avoid a heavy and complicated MIPv6 protocol, which could cause several critical problems in wireless mobile devices, such as poor CPU performance, a large power consumption, and a shortened battery life. To overcome these problems in wireless environments, a network-based mobility management solution called Proxy MIPv6 (PMIPv6) [3] is standardized by the IETF NetworkBased Localized Mobility Management (NETLMM) working group. In a PMIPv6 protocol, the mobility management