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A study of mobility management using IEEE 802.21
Alexandru Vulpe, Şerban-Georgică Obreja, Octavian Fratu
Facultatea de Electronică, Telecomunicaţii şi Tehnologia Informaţiei Universitatea Politehnica din Bucureşti Bucureşti, România alex.vulpe@radio.pub.ro, serban@radio.pub.ro, ofratu@elcom.pub.ro
Abstract— The evolution of mobile technologies had a major impact over the mobile services. Therequests for multimedia services on portable devices are increasing continuously and they are becoming one of the main engines for the telecommunications industry. The heterogeneous wireless access technologies available on the mobile devices are an opportunity for the Mobile Network Operators to improve the quality for the services they provide. To take advantage of these opportunities IEEE 802.21Media Independent Handover (MIH) standard was introduced to optimize handover between heterogeneous IEEE 802 networks, and facilitate handover between IEEE 802 networks and cellular networks. In this paper an architecture built on the Media Independent Handover framework is presented, along with some aspects related to the implementation of the architecture modules in QualNet simulator. The paperfocuses on the system functionalities evaluation based on experiments performed on a simulated MIH-enabled platform implemented in QualNet. Keywords: IEEE 802.21, MIH, vertical handover, simulation;

(Reconfigurable Interoperability of Wireless Communications Systems) NATO Project, and aims to develop a mobility management system which integrates different wireless communications technologiesinto a common hybrid communication infrastructure. Besides the system architecture proposed by the project, the MIH implementation represents a novelty of our work since the QualNet does not have support for MIH framework. The paper is structured as follows. Section II summarizes the main features and functionalities described by the IEEE 802.21 standard, and the next one is a short overview on theRIWCoS system architecture. In sections IV and V a sample simulation scenario and its results are presented. Section VI contains some conclusions and future work. II. A. OVERVIEW OF IEEE 802.21

I.

INTRODUCTION

Wireless 4G communication systems, although not deployed yet, are characterized by larger bandwidths, higher data rates, and fast and seamless handovers. In order to achieve this,it is essential that 4G capabilities be integrated into existing mobile technologies. Operators must manage rationally their networks in terms of both intra-system (horizontal) handovers and inter-system (vertical) handovers and mobility, quality of service and security. In all these aspects, the architecture proposed by the IEEE 802.21-2008 standard is a key element in easing the implementationof these 4G systems. IEEE 802.21 provides a framework that allows higher levels to interact with lower layers to provide session continuity without dealing with the specifics of each technology. It provides the missing, technology-independent abstraction layer, thus hiding technology-specific primitives. This abstraction can be exploited by the IP stack (or any other upper layer) to better interactwith the underlying technologies, ultimately leading to improved handover performance.[1][2][3] This paper presents a QualNet implementation of a mobility management system for heterogeneous wireless networks, which is based on the Media Independent Handover (MIH) framework. This system was proposed by the RIWCoS

Key features of the standard The standard provides MIH functionality thatfacilitates both mobile-initiated and network-initiated handovers. It consists of the following three main elements: • A framework that enables service continuity while a mobile node (MN) transitions between heterogeneous networks. It relies on the presence of a mobility management protocol stack within the network elements that support the handover. The MIH function (MIHF), which is an entity...