Voice over lte is a HD voice technology which is work on 4G LTE network. By using this technology clearity of the voice is high.

2. Contents
• Introduction
• LTE
• The New Conservation Experience
• History
• Requirements for Voice over LTE
• Architecture
• QoS & bearers
• Voice for the 4G LTE subscriber
• Circuit Switched Fallback (CSFB)
• Network Architecture End-to-End

3. Continue……
• Call Handling
• Applications
• Advantages
• Conclusion
• References

4. Introduction
• Voice over Long-Term Evolution (VoLTE) is a standard for high-speed
wireless communication for mobile phones and data terminals.
• VoLTE has up to three times more voice and data capacity than 3G UMTS
and up to six times more than 2G GSM.
• Designed to carry both voice and data.
• Supports voice as well as data transmission.
• Voice quality remains excellent even if the data connection is on.

5. LTE
• LTE stands for Long Term Evolution.
• Primarily designed to be a data-only technology.
• Does not natively support voice transmission.
• Quality of voice reduces if data connection is left on.

6. The New Conservation
Experience
• A better user experience: Gained by making video and messaging as easy as
voice.
• Connected communities: Users can easily contact friends and family over
social network.
Figure 1: Conservation Experience

7. History Of Mobile Communication
• 1G ~1980
• analog signal
• 2G ~1990 (Global system for mobile communication: GSM)
• SMS, circuit switched data transfer 9,6kbps
• 2.5 ~ 2000 (General packet radio service: GPRS, Enhanced data for GSM
evolution :EDGE)
• Packet switched data transfer 50-150 kbps
• 3G ~2000 ( Universal Mobile Telecommunication System: UMTS )
• 2 Mbps
• 4G ~2010 (LTE)
• ~100Mbps

9. Requirements for Voice over LTE
Subscriber Requirements
• Telephony
• Quality
• Battery
Carrier Requirements
• Cost
• Complexity
• Efficiency

10. • The 4G VoLTE network is composed of the evolved universal terrestrial
radio access network (e-UTRAN) and the Evolved Packet Core (EPC).
Figure 2 : VoLTE network architecture
Architecture

11. QoS & bearers
• Typically multiple bearers are running on a UE at the same time, for
example, covering the default bearer, streaming video and an in-
progress VoLTE call.
• Unlike 2G and 3G packet data services, which treat everything on a first-
come, first-served basis.
• A real-time voice session (such as VoLTE) can tolerate more missed bits
because the ear does not notice it as quickly as the eye.
• In this priority is set for all functions.

12. Voice for the 4G LTE subscriber
Voice Options
• Voice over LTE (VoLTE)
• Circuit switched fallback (CSFB)
• Simultaneous voice and LTE (SV-LTE)
• VoLGA, Voice over LTE via GAN

13. Circuit switched fallback (CSFB)
• The Circuit Switched Fallback technique is the widely accepted solution for
voice and messaging services within LTE.
• To prevent a VoLTE call from being dropped in such cases, a handover
mechanism allows the call to continue as a CS call.
• This process is enabled by the Single Radio Voice Call Continuity (SRVCC)
mechanism.
Figure 3 : Handover from packet-switched voice to circuit-switched voice

14. Simultaneous voice and LTE (SV-LTE)
• Simultaneous Voice and LTE (SV-LTE) is implemented by some device
manufacturers for CDMA operators.
• An SV-LTE smartphone actually has two simultaneously active radios.
• One radio provides CDMA 1xRTT(single-carrier radio transmission technology) for
circuit voice, and a second radio provides 4G LTE for IP data.
• In this way, an SV-LTE handset equips the CDMA operator with the clear
subscriber value of simultaneous legacy voice and 4G LTE data.
• However, such a handset might be larger or heavier due to the need for two
simultaneously used antennas plus a larger battery.

15. Voice over LTE via generic access
(VoLGA)
• Another fallback technique suitable for LTE is called the Voice over LTE via
Generic Access method (i.e. VoLGA) an industry based initiative
introduced in 2009.
• Voice over LTE via generic access (VoLGA) is a true voice-over-LTE
solution which enables LTE mobile devices to access legacy systems and
services without having to leave the LTE domain.
• Generic Access Network architecture (GAN) which was developed to
support circuit switched services such as SMS messaging in an IP-based
network it quickly gained attention and became one possible candidate for
LTE's voice and messaging requirements.

16. • VoLTE includes voice in full duplex, either in a one-to-one or one-to-many
communication format.
• For end-to-end Full-HD Voice calls to succeed however both the caller and
recipient's handsets as well as networks have to support the feature.
Figure 4 : VoLTE end-to-end (simplified view).
Network Architecture End-to-End

17. Call Handling
• The LTE radio network uses admission control to ensure that there are
sufficient resources and capacity for the network-requested voice bearer.
• End-to-end voice latency is on par with or even better than 2G/3G CS.
Figure 5 : Signaling bearer and a dedicated bearer for voice

18. APPLICATIONS
• Near/far noise cancellation.
• Call continuity across networks, push-to-talk over cellular, group calling.
• Video telephony.
• Enhanced address book features such as status, location, communication
capabilities and pictures.

19. ADVANTAGES
• HD Voice.
• More Capacity with good quality.
• Video Calling.
• Power saving of 30%.
• Provides rapid call establishment time.

20. CONCLUSION
• The increasing demand and increased number of users has forced the
communication industry to modify technology from 1G to 4G.
• Operators can use VoLTE to innovate and extend mobile voice beyond a
traditional call.
• Voice can become a feature of other services, such as navigation, e-
commerce, social networking, status updates and augmented reality
applications.
• VoLTE time is now.

21. REFERENCES
• Alcatel-Lucent, Service Consistency for Today’s VoLTE Subscribers,
2011,M201110952,www.alcatel-lucent.com/4g-consumer-communications.
• GSMA, April 2014, IR.92 IMS Profile for Voice and SMS v. 8.0, available
at:http://www.gsma.com/newsroom/wp content/uploads/2014/06/ IR92v8-
0.pdf.
• F.Alomary and I. Kostanic, “Evaluation of Quality of Service in 4th
Generation (4G) Long Term Evolution (LTE) Cellular Data Networks”,
Universal Journal of Communications and Network ,Vol. 1, pp. 110-117,
2013.