Policy routing architecture for IP flow mobility in 3GPP´s Evolved Packet Core

The 3^rd Generation Partnership Project is specifying solutions for IP flow mobility, which enable IP data flows being routed between a mobile terminal and the infrastructure via a 3GPP and non-3GPP access systems, e.g. over LTE and WLAN. Connectivity via the different access systems is provided based on the concept of a shared single Packet Data Network connection. In order to enable IP flow mobility, the mobile terminal must be able to identify individual data flows and take routing decisions in the uplink. The mobile terminal´s mobility anchor, the PDN Gateway, in the Evolved Packet Core requires the equivalent functionality for the downlink. Synchronization and dynamic changes in these flow routing policies, either initiated by the mobile terminal or the mobile operator, entail technical challenges in particular for network-based mobility management according to the Proxy Mobile IPv6 protocol, which does not consider mobility-related signaling between a mobile terminal and the network infrastructure. This paper proposes a solution for IP flow mobility, which re-uses the Policy and Charging Control system of the 3^rd Generation Partnership Project´s packet core. The flexibility and efficiency of the proposed Routing Policy Configuration Application Function, which represents an integral part of the Policy and Charging Control system, is analyzed and discussed based on existing and new use cases.