Prototype implementation and performance evaluation of a QoS-conditionalized handoff scheme for Mobile IPv6 networks

Future internetworks will include large numbers of portable devices moving among small, wireless cells. In order to support real-time applications, users demand seamless mobility and quality-of-service (QoS) provisioning. One approach towards a more flexible, customizable and scalable mobility architecture that also reduces signaling load and handoff latency results from the introduction of micro-mobility. Furthermore, by coupling QoS signaling and mobility management, QoS requirements can be negotiated without incurring significant additional signaling latency. The paper presents the prototype implementation and performance evaluation of such a QoS-enabled micro-mobility scheme, which is called "QoS-conditionalized handoff". We extended the Mobile IPv6 for Linux implementation to support the basic mode of Hierarchical Mobile IPv6 as the underlying micro-mobility mechanism. One problem that appeared during the implementation was the rather complex event handling in the mobile node; to enable a simple and generic way of event handling, a priority-based execution structure has been developed that can be easily adapted to various policies. Our experimental results show that by this QoS-conditionalized handoff scheme, QoS-enabled handoffs can be achieved with a small amount of introduced latency compared to Hierarchical Mobile IPv6, which is much less than that of Mobile IPv6. It is further observed that fewer packets were lost and registration latency could be much more decreased when mobility management in the mobile node takes advantage of a movement detection mechanism to expedite the QoS-conditionalized handoff procedure.