Migration to All IP UMTS networks: transport and mobility issues

This paper introduces the all IP UMTS based networks concept. The focus of the study is on the deployment of the VoIP technology only in the core network (CN). Initially, it is expected that the UMTS CN will be deployed based on the Release '99 and later in the All IP based (Release '00) specifications. This migration to the All IP UMTS CN and the technical challenges associated with it will be presented. Issues related to the transport of voice over the All IP UMTS CN and the handover of a voice call from an All TP to a GSM network are further analyzed. Alternative All IP UMTS CN architecture options are considered to overcome some of the disadvantages (particularly the ones related to the transport issues) of the existing All IP architecture. The comparisons among the proposals discussed take into consideration their efficiency, simplicity and the provided voice quality of service, where applicable