Voice has historically been the first application of mobile communication networks, and the success of Global System for Mobile communications (GSM) has been primarily based on voice. While it is true that data applications have considerably gained in importance over the years, voice is still a major source of revenue for mobile operators. It is expected that voice will remain an important application even in the era of Long Term Evolution (LTE), so there has been a lot of discussion about the best way to provide voice in an LTE environment. Owing to this importance, we include this chapter on security of Voice over Long Term Evolution (VoLTE) in this book although, as we will show in this chapter, the corresponding security mechanisms are largely orthogonal to the LTE security mechanisms discussed in the rest of the book.
The nature of this chapter is therefore somewhat different from the rest of the book in that it describes all the relevant mechanisms, but does not go to a similar level of detail. It includes the necessary references for readers who want to delve into this subject more deeply.
In Section 12.2 we briefly introduce the methods standardized by 3GPP for providing VoLTE. Then in Section 12.2 we discuss the security mechanisms used with these methods. Finally, we show in Section 12.3 how these security mechanisms have been taken up by the specifications for VoLTE and the Rich Communications Suite.