A soft-handoff transport protocol for media flows in heterogeneous mobile networks

In this paper we introduce a protocol for end-to-end handoff management in heterogeneous wireless IP-based networks. The protocol is based on the stream control transmission protocol (SCTP), and employs a soft-handoff mechanism that uses end-to-end semantics for signaling handoffs and for transmitting control messages. The objective of this protocol is first to reduce the home registration delay, and second, to eliminate the tunneling cost that exist in the current IP-based handoff management protocols. While the multihoming feature of SCTP has been suggested as way to realize soft-handoffs, our study is the first one the presents the relative merits of this handoff approach through an analytical methodology. After our theoretical analysis, we evaluate the performance the soft-handoff mobile-SCTP protocol, when media flows with stringent QoS requirements are employed. Our objective is to evaluate whether the soft-handoff mechanism employed by the protocol, can efficiently support media flows in terms of jitter and throughput. We present simulation results that show performance improvements for several vertical handoff scenarios in current and emerging mobile networks.