Media Independent Handovers: LAN, MAN and WAN Scenarios

A new plethora of wireless access technologies and services are emerging, driving the Internet access paradigm to a different stage. In order to provide seamless connectivity among the new wireless access technologies, such as Wi-Fi, WiMAX and UMTS, the IEEE 802.21 standard has defined the media independent handover framework. This paper presents a thorough description of a seamless handover procedure in a heterogeneous access network environment, by describing the different phases of the handover process to support the interactions with Wi-Fi, WiMAX and UMTS. Further, we present a meticulous evaluation of the depicted handover mechanisms, optimized by the 802.21 framework, demonstrating that seamless mobility is achieved with low latency and no packet loss. To perform the evaluation, significant add-ons, described in this paper, were implemented in the NS-2 simulator to support all the functionalities defined by the IEEE 802.21 standard.