LTE Security, Second Edition

Chapter 11

Interworking Security between EPS and Other Systems

In this chapter, we describe how the Evolved Packet Core (EPC) can interwork with the other 3rd Generation Partnership Project (3GPP) access technologies GSM/EDGE Radio Access Network (GERAN) and Universal Terrestrial Radio Access Network (UTRAN), and also how the EPC supports interworking with non-3GPP access technologies like cdma2000® High Rate Packet Data (HRPD), Worldwide Interoperability for Microwave Access (WiMAX) and Wireless Local Area Network (WLAN). Interworking is important as Long Term Evolution (LTE) allows different deployment options for the operators. Clients supporting multiple-access technologies, including LTE, need to have continuous access to the network for good user experience. For example, a client using the third-generation (3G) packet service may enter an LTE hotspot and thus be handed over to it for a higher data throughput.

We start by describing the interworking with Global System for Mobile communications (GSM) and 3G in Section 11.1 and move then to the non-3GPP interworking part in Section 11.2.

11.1 Interworking with GSM and 3G Networks

Here we describe intersystem idle state mobility and handovers between 3G or GSM and Evolved Packet System (EPS). This is particularly interesting as there are multiple cases for handling the security context depending on the originating system and mobility mode (handover or idle state mobility). Refer to Section 7.4 for detailed definitions relating ...