4 General

24.3273GPPGeneral Packet Radio System (GPRS) and 3GPP I-WLAN aspectsMobility between 3GPP Wireless Local Area Network (WLAN) interworking (I-WLAN) and 3GPP systemsRelease 12Stage 3TS

4.1 Overview

This specification defines the solution to handle the mobility between 3GPP I-WLAN and GPRS systems. Such solution relies on DSMIPv6 protocol which is specified in IETF RFC 5555 [10] and IETF RFC 6275 [12] and is used to model the H1 reference point between the UE and the HA function. The H1 reference point enables the UE to handover from 3GPP I-WLAN towards GPRS systems, and vice-versa, and granting session continuity by means of a DSMIPv6 signalling and an IP tunnel between UE and HA functions. This specification specifies only the additional procedures which are specific to I-WLAN mobility scenarios and relies on 3GPP TS 24.303 [3] for DSMIPv6 procedures and 3GPP TS 24.234 [5] for I-WLAN network selection and tunnel establishment. In this specification, DSMIPv6 signalling is secured as specified in IETF RFC 4877 [8]: IKEv2 exchange is performed by the UE with the HA before tunnel establishment. The details of the security aspects are specified in 3GPP TS 33.402 [14]. The UE can interact with ANDSF, as described in 3GPP TS 24.302 [17], and receive information useful for performing access network discovery and selection. The information is described in 3GPP TS 24.312 [23].

4.2 Identities

As identification towards the HA, the UE shall use the same identities as described in 3GPP TS 24.303 [3]. To identify the desired HA, the UE shall use the HA-APN as specified in 3GPP TS 24.303 [3].

The UE shall use the same identities as specified in 3GPP TS 24.008 [4] to access GPRS systems.

The UE shall use the same identities as specified in 3GPP TS 24.234 [5] to access 3GPP I-WLAN.