Classification and Evaluation of Multicast-Based Mobility Support in All-IP Cellular Networks

Abstract. To solve the IP mobility problem the use of multicast has been proposed in a number of different approaches, applying multicast in different characteristic ways. In this paper we provide a framework to classify such approaches by analyzing requirements, options for using multicast protocols, and mobility functionalities augmenting the multicast. Within this framework we identify promising combinations of mechanisms and derive four classes of multicast protocols. These classes include both the standard any-source IP multicast model as well as nonstandard multicast models. In particular, the use of source-specific multicast is a new approach to support mobility and turns out to be especially beneficial. The paper describes a corresponding network architecture and a flexible software environment that allows to easily implement these and other classes of mobility-supporting multicast protocols. Based on this software environment, an implemented prototype and measurements quantify handover-specific metrics, namely handover and paging latency and packet loss and duplication rates, showing that a multicastbased mobility solution has comparable performance to standard Mobile IP/hierarchical Mobile IP. Moreover, it is shown that a non-standard multicast model has reduced implementation and deployment complexity and security risks than a standard multicast model. 1