An Efficient Cross Layer Intra and Inter Domain Mobility Solution for IEEE 802.16e mobile WiMAX Imran Khan + , D. A. Karras † + Mohammad Ali Jinnah University, Islamabad Campus, Blue Area 44000, Islamabad, Pakistan, imrankhan1984@gmail.com † Chalkis Institute of Technology, Greece, Automation Dept., Psachna, Evoia, Hellas (Greece) P.C. 34400, dakarras@ieee.org, dakarras@teihal.gr Abstract- In this paper a novel cross layer mobility management scheme for IEEE 802.16e standard is proposed using Cellular IP (CIP) and Fast Mobile IPv6 (FMIPv6). The research focuses on the use of CIP for intra domain and FMIPv6 for inter domain mobility management. A cross layer design is considered to enable smooth integration of link layer triggers and their use for the benefit of network layer. The network model used is a hierarchical one, which allows integration of CIP and FMIPv6 into the IEEE 802.16e, mobile –WiMAX, network. Keywords- IEEE 802.16e, Cellular IP, Fast Mobile IPv6, handover, mobility management. 1. INTRODUCTION IEEE 802.16 standard commonly known as WiMAX is poised to become next generation wireless network standard providing broadband services to the end users that were left alone by the ADSL, and cable based wired broadband services around the globe. Initially the WiMAX standard was for fixed wireless users. In 2004, IEEE 802.16e or mobile WiMAX addressing the mobile users came on to the scene [1]. Its purpose was to provide broadband services to the users moving at vehicular speeds of up to60 mph [2]. WiMAX is known to have an effective range of 4 to 5 miles. A service provider will have to set up a network of towers or base stations, covering together a much larger area. But mobile users introduce a problem of handover or handoff that is associated with their movement. Initially a mobile station (MS) is registered to receive data services from a particular base station using its air interface. Once it starts moving away from the base station the signal strength starts decreasing and communication becomes difficult. Once this happens, the MS might arrive near another base station which is offering a strong signal as compared to the one currently in use. Then the MS or the network must decide which of the two base stations to choose from. The obvious choice would be to choose the one with strong signal. But what will happen to ongoing communication and how will the associated delays be reduced? The mobility of an MS can be classified into two categories, inter domain mobility and intra domain mobility. In inter domain mobility, the MS moves from one domain to another. Usually, in wireless networks a domain is under control of an entity normally called access router (AR). Whenever an MS moves into a domain, it uses the IP address of the AR as Care of address (CoA), and starts communication. But when an MS changes its location, its AR will change, hence the IP address. The IP address will need to be updated and notified to the corresponding party, who will be sending data to previous AR. When the change in IP address is notified, the communication can resume at new place. In intra domain mobility an MS moves inside a domain, so in order to restrict the movement of an MS inside a domain, a hierarchical structure of network is constructed so that most of the time, the movement of MS does not change its IP address. AR is made responsible to keep track of MS mobility inside its domain. The delay to update the current position inside a domain is shortened, and while the MS roams inside the domain, for the outside world there is no change in the position of the MS. In this paper a scheme, considering both intra and inter domain mobility, is presented. Cellular IP (CIP) is used for intra domain mobility management. It is known to be more effective in dealing with mobility inside a domain [3]. CIP maintains and tracks location of the MS with very little signaling overhead. FMIPv6 over IEEE 802.16e [4] is used to handle inter domain mobility. FMIPv6 provides a quick way to update address of the MS at new location by predicting and preparing an impending handover in advance. Link layer triggers are 978-1-4244-4530-1/09/$25.00 ©2009 IEEE