IP Mobility with High Speed Access and Network Intelligence Moshiur Rahman Fotios C. Harmantzis, Ph.D. AT&T Labs Stevens Institute of Technology 200 Laurel Ave., Middletown, NJ U.S.A. Hoboken 07030, NJ U.S.A. moshiurrahman@att.com fharmant@stevens.edu Abstract The original idea of Mobile IP (MIP) is to provide mobile users the ability to access the Internet anywhere, with an identical IP address. With rapid changes in both technology and the communication environment, wide bandwidth and low cost wireless LAN (WLAN) have emerged as a competitive choice not only for wireless high speed Internet access but also for wireless voice network access. To support mobility with Quality of Service (QoS), MIP has been found to be inefficient for both data and time sensitive services, such as Voice- over-IP (VoIP). In our paper, we first focus on the deficiencies of the MIP and other micro-mobility approaches found in the literature. We then propose an architecture for network layer mobility support, using always on high speed access and a network-based mobility manager, termed as network server or gateway. We believe that the proposed architecture obviates the need of MIP for IP mobility. 1 Introduction The original intent of IP addressing was that part of the IP address would uniquely identify exactly one physical network, i.e., an IP address contains location information. Any device (data or voice) should change its IP address whenever it connects to the Internet via different physical networks. In order to support a mobile Internet communication environment, the provision of a unique portable IP address is a crucial issue. To overcome this problem, the Internet Engineering Task Force (IETF) proposed the Mobile IP (MIP) [1, 2]. The MIP allows Internet access using an identical IP address, even when mobile users roam to a different physical network. The main drawback is that MIP communication behaviour introduces additional transferring cost and transmission delay. To deploy MIP, new network entities, such as Home Agent (HA) and Foreign Agent (FA), need to be introduced by upgrading both the network and every single Mobile Node (MN); this is costly and not feasible in practice. We believe that with the changing technologies, such as high speed access and backbone, the support of IP mobility could be simple and cost effective by leveraging the network control. If both the network and the mobile node have to be upgraded to support IP mobility with MIP which does not fit all service needs (such as handoff), why not take advantage of the evolving access and backbone networks (where appropriate) and upgrade both the network and mobile nodes with more future proof functionalities. In this paper, the proposed high speed data accessed network- assisted architecture, would reduce the signalling traffic, the functional complexities, and more importantly, the cost and delay. In the literature, an architecture that discusses network-assisted IP mobility for WLANs can be found in [4]. The authors propose an architecture based on a dynamic host configuration protocol (DHCP) and a transparent proxy mechanism. However, according to their approach, the MN cannot maintain the original IP address. Once the MN changes point of attachment, the DHCP assigns a new IP address to it. Therefore, real mobility support cannot be achieved through the DHCP- based WLANs, since a network connection can be maintained only within the WLAN boundary. A mobile user cannot move to another WLAN with its active network connection maintained, because the allocated IP address is only valid within the local network. In IP mobility though, we want a mobile node to move to another WLAN while maintaining the network connections. Our proposal differs form the one in [4], in the sense that a mobile node can keep the original IP address by using the central network server’s routing translation and mapping capabilities. In addition, our architecture is explicit in terms of high peed data access and backbone implementation, unlike [4]. WCNC 2004 / IEEE Communications Society 2159 0-7803-8344-3/04/$20.00 © 2004 IEEE