Achieving seamless mobility in IP-based radio access networks

A handover in any IP-based mobile network is a complex procedure. Typically, it takes quite a long time before the new access router gets the parameters describing the flow states associated with an incoming mobile node. It may even be that the new access router does not have enough resources to support the rerouted flows. Thus, it is crucial to select from several candidate access routers the one that best fits the mobile node's requirements. This article describes the candidate access router discovery protocol, which can be used to select a suitable new access router. We also address the context transfer architecture that makes use of the candidate access router discovery protocol and aims to reduce the time required to recover flow descriptor parameters. Finally, we discuss how the two protocols can interoperate to achieve seamless handovers.