Anycast Subnet Optimization for Efficient IPv6 Mobility Management

In this paper we propose a new IPv6 micromobility framework together with a subnet forming algorithm for providing more seamless handover, while being able to coexist with the standard IPv6 macromobility protocol (MIPv6). Our framework is based on the IPv6 anycasting paradigm called anycast-based micromobility, where a scoped-anycast care-of-address is assigned for the visiting mobile nodes while moving in a given subnet (i.e. micromobility domain). According to the anycast communication model defined in IPv6, packets sent to the anycast CoA will be always optimally routed to the actual position of the mobile node in a given subnet. A simulated annealing based anycast subnet forming algorithm (SABAS) is also elemental part of our work aiming to demonstrate how IPv6 anycasting can be utilized for efficient micromobility. SABAS uses the handover and incoming session metrics generated by our mobile environment simulator.

I. Introduction

Wireless cellular networks are evolving toward convergent, heterogeneous, all-IP mobile communication architedures. Handover performance is very important when considering mobility management protocols applied by the emerging IPv6 systems of the future. Although Mobile IPv6 is capable of handling global mobility of users (i.e. macromobility), it introduces significant signaling overhead, increased delay and packet loss when mobile terminals change their point of attachment very frequently with in geographically small areas (i.e. micromobility domains)[1]. In order to overcome these perfomance deficiencies, several approaches attempt to extend IP level global macromobility mechanisms: micromobility methods (e.g. [2], [4]) offer faster and more seamless handover management while the paging extensions (e.g. [5]) enable more scalable resource utilization. However these approaches suffer from lack of robustness, inefficient handling of intra-domain traffic and added complexity, while they often require employing of new new protocol stacks, and do not offer optimal performance in several scenarios.