3G, 4G and Beyond: Bringing Networks, Devices and the Web Together, 2nd Edition

Chapter 4

Voice over Wireless

Despite the growing number of Web 2.0 and mobile Web 2.0 applications being used in B3G networks (cf. Chapter 6), voice telephony continues to be one of the most important applications in a mobile network. As mobile operators have a long history of making voice telephony work over wireless networks, and as they control the mobile infrastructure, they are in a good position to secure a sizable market share of tomorrow's wireless telephony business. Up to and including UMTS, voice telephony was tightly integrated into the wireless network infrastructure. As a consequence, mobile operators enjoyed a voice telephony monopoly in their networks. From the user's point of view the situation changed slightly in many countries in recent years due to fierce competition. Mobile Virtual Network Operators (MVNOs) sprang up who bought buckets of voice minutes from mobile network operators for reselling to customers under their own brand. From a technical point of view, however, the network operator remained in charge, as MVNOs were mere resellers of voice minutes.

In Long Term Evolution (LTE) networks, the situation has changed. As already discussed in Chapters 2 and 3, LTE networks no longer have a separate core network for voice telephony and voice optimized protocol stacks in the radio network. As in fixed-line broadband networks, all services and applications are now delivered via the Internet Protocol and a packet-switched connection. This brings both opportunities ...