Combined GSM and Mobile IP mobility handling in UMTS IP CN
The present document contains a feasibility study on using Mobile IP+ as a tunnelling and mobility management protocol in combination with GSM/UMTS mobility management in the packet domain of UMTS CN. A target architecture will be described and evaluated and the migration path from the current GPRS architecture towards the target architecture will be defined. It shall also describe the driving forces for moving from GTP towards Mobile IP+ as well as the benefits and disadvantages of the target architecture. A time schedule, i.e. UMTS releases, for the standardisation of such an architecture shall be proposed. Work on Mobile IP+ in the IETF should be taken into account.
This report will also contain a study on how to offer Mobile IP+ as an overlay to GPRS. This would allow an end user device, which is connected to the Internet (or intranet etc.) via LAN, to be reconnected during an active session via GPRS/UMTS or visa versa, without the need for any re-configuration or re-start of applications. The outcome of this part shall be part of UMTS release 99. Proposed solutions need to be balanced between the requirement to minimise the impact on the current GPRS standards and the requirements generated by further development of using Mobile IP+ within the CN in an efficient way. The output of this study is a description of the system and a set of CR's for those standards handled by 3GPP-TSG SA-WG2.