ericsson White paper
284 23-3163 Uen | February 2012
Voice and video calling over LTE
a step towards future telephony
The GSMA IR.92 voice-over-LTE and GSMA IR.94 IMS conversational video specifications are the preferred industry choices for mass-market voice and video calling services over LTE, satisfying user expectations and providing the most advantageous solutions for operators. The specifications profile existing 3GPP IMS services, enhanced packet core and radio, and leverage telecom characteristics such as quality of service and global reach.
VOICE services in MOBILE BROADBAND networks
Mobile broadband has created a world of opportunities and opened up new revenue streams ...view middle of the document...
Consequently, the adoption of OTT clients is directly dependent on mobile broadband coverage and the willingness of subscribers to use a service that lacks quality, security and flexibility. With the industry aligned telecom solution, operators can now start commercial deployments of a telecom-grade, globally interoperable voice and video calling solution over LTE – even before LTE is fully deployed.
VOICE AND VIDEO CALLING OVER LTE • VOICE SERVICES IN MOBILE BROADBAND NETWORKS
A GLOBALLY INTEROPERABLE SOLUTION
LTE and Evolved Packet Core (EPC) architectures do not include support for circuit switched voice and video calls. When starting to use LTE in phones, this limitation will have to be addressed. Over the past two years, two complementary tracks have emerged in the telecom industry: circuit-switched fallback (CSFB) and IMS/VoLTE. CSFB is suitable for use when the LTE coverage is spotty (typically in the early phases of LTE deployment), while IMS/VoLTE can be implemented when the coverage is better (typically in mature LTE networks). IMS-BASED VOICE OVER LTE The term voice-over-LTE (VoLTE) is used to describe the GSMA specification  for voice and Short Message Service (SMS) in LTE, which has its origins in the 3GPP IMS-based multimedia telephony (MMTel) solution. VoLTE has widespread backing in the telecoms industry – more than 40 key players declared their support for it at the 2010 GSMA Mobile World Congress in Barcelona and many more have done so since. Both GSM/WCDMA and CDMA operators are planning to deploy VoLTE based on IMS. With MMTel, operators can evolve their voice and multimedia services, such as video calling – described in the GSMA specification for IMS conversational video . MMTel can leverage the world’s largest mobile user community (MSISDN), as well as traditional telecommunication principles such as guaranteed end-to-end QoS, support for emergency and regulatory services, global interoperability and mobility, as well as support for a user experience that meets the needs of the modern consumer. With the Ericsson MMTel, users can – for example – start a voice session, add and drop media such as video, and add callers. VoLTE, together with video calling over LTE, will bring deployment of interoperable and high-quality voice and video services together, as well as facilitating the development of interconnect and international roaming agreements among LTE operators. Operators deploying VoLTE can evolve their voice services into rich multimedia offerings, including HD voice, video calling and other multimedia services such as Rich Communication Suite (RCS), available anywhere on any device, combining mobility with service continuity. Leading operators are expected to launch voice and video calling over LTE in 2012.
VOICE AND VIDEO CALLING OVER LTE • A GLOBALLY INTEROPERABLE SOLUTION
CIRCUIT-SWITCHED FALLBACK The standardized solution for providing voice services in early LTE deployment is CSFB –...