Voice and Emergency Services
In Chapter 5 we gave a brief overview of the various ways an operator can provide voice services in EPS. In this chapter we go a bit further into the realization of voice services in EPS, including MMTel/VoLTE, SRVCC, and CS Fallback. Finally, we touch briefly on the migration options from circuit-switched technology to VoLTE.
11.1 Voice Services Based on Circuit-Switched Technology
Circuit switching is the traditional technology used in a telephony network, where a continuous link is established between two end-users in a phone call. One vision for EPS is that IP technology will be used for all services, including voice, and effectively replacing circuit-switched services. In order to understand how voice ...