LTE Security, Second Edition

Chapter 5

3G–WLAN Interworking

This chapter has a close relationship with Section 11.1 on interworking with non-3GPP networks. It is also helpful when reading the authentication procedures for home base stations in Section 13.1.2, but is not required for an understanding of other parts of the book. Therefore, readers not interested in the topics dealt with in Chapter 5 and Sections 11.2 and 13.4 may safely skip this chapter.

This chapter is about security procedures for the case of a user accessing a 3GPP core network via a Wireless Local Area Network (WLAN) radio access network (AN). While the two preceding chapters on the security of second- and third-generation (2G and 3G) mobile systems were meant to lay the foundations for understanding the security mechanisms applied when a user accesses the Evolved Packet Core via an Long Term Evolution (LTE) AN, this chapter is intended to provide the foundations for the case when a user accesses the Evolved Packet Core via an AN not defined in 3GPP specifications, for example via a WLAN [IEEE 802.11] or a Worldwide Interoperability for Microwave Access (WiMAX) network [WiMAX], or a cdma2000® High Rate Packet Data (HRPD) network defined in 3GPP2 specifications [3GPP2].

5.1 Principles of 3G–WLAN Interworking

5.1.1 The General Idea

3GPP performed its work on interworking between WLANs and 3GPP networks (3G–WLAN interworking) as part of its Release 6, around the year 2004. LTE was not even on the horizon at that time, but it turned out that ...