VoLTE technology in JIO; What is VoLTE?

In recent days JIO has generated lot of buzz which offers free calling for lifetime and free internet up to December. There is also new technology associated with JIO is VoLTE. Mobile phone manufacturers are selling phones with VoLTE enabled technology. Now there is curiosity what is VoLTE? and how it is different?

In this below article we will learn what is VoLTE technology all about?:-

VoLTE:-

There is new technology in field of data services. VoLTE is known as Voice over Long-Term Evolution. It is used for providing a uniform format of voice traffic on LTE and other systems including CSFB (Circuit Switched Fall Back) and SV-LTE(Simultaneous Voice Long term evolution). This technology is used for better voice call quality. VoLTE uses 4G technology and it is based on packet switching on the other hand 2G and 3G networks uses circuit based switch.

Now when we make a call using 2G and 3G then there is bandwidth assigned to that call this will not allow to terminate until call ends. On the other hand in VoLTE voice calls are divided into packets and are sent on whole data pipeline which will then get reconstructed at receiving end. As calling is done over whole data pipeline which means better calling using VoLTE technology.

VoLTE is designed for standardizing the system for transferring Voice traffic over Long term evolution.

LTE was basically an IP cellular system used for carrying data. Operators would be able to carry voice either by reverting to 2G / 3G Systems. Operators can use VoIP in one form or another.

LTE will lead disintegration and mismatch not allowing all phones to communicate with each other which will reduce the voice traffic. SMS services are still widely used, often proving a means of set-up for other applications.

Even though revenue from voice calls and SMS is falling, a format for voice over LTE and messaging, it was as necessary to have a viable and standardized scheme to provide the voice and SMS services to protect this revenue.

LTE Voice Options:-

There are following options for Long term Evolution voicing:-

(i)             CSFB known as Circuit switched Fall back

(ii)            SV-LTE Known as Simultaneous Voice LTE

(iii)           VoLGA known as Voice over LTE via GAN

(iv)          One Voice / later called Voice over LTE, VoLTE

Let’s discuss about these:-

(i)             CSFB:- This service has been standardized under 3GPP Specifications. CSFB uses different types of processes and network elements to enable the circuit to fall back to 2G/3G connection before a circuit switched call is initiated. The description also allows for SMS to be carried as this is important for very many set-up procedures for cellular telecommunications. To achieve this handset uses an interface known as SGs which allows messages to be sent over an LTE channel.

(ii)            SV-LTE:   This service allows packet switched LTE services to run concurrently with a circuit switched voice service. This facility provides the facilities of CSFB at the same time as running a packet switched data service. There is a disadvantage associated with this service is that, it requires two radios to run at the same time within the handset which has a serious impact on battery life.

(iii)           VoLGA:- This service was based on the current 3GPP Generic Access Network (GAN) standard, and the aim was to allow LTE users to obtain a steady set of voice, SMS services as they shift between GSM, UMTS and LTE access networks. For mobile operators, the aim of VoLGA was to provide a low-cost and low-risk approach for bringing their primary revenue generating services onto the new LTE network deployments.

(iv)          VoLTE:   This scheme for providing voice over an LTE system develops IMS The IP Multimedia Subsystem,  IMS is a framework for delivering Internet Protocol. It enables a variety of services to be run flawlessly rather than having several different applications operating simultaneously), which enables it to become part of a rich media solution. It was the option chosen by the GSMA for use on LTE and is the standardized method for providing SMS and voice over LTE.

Voice over LTE

When concept of SMS and voice System over LTE using IMS was introduced than it was opposed by many telecom operators as it was complex system involving IMS. It was observed that it is not only complex but also it is far too expensive and burdensome to introduce and maintain the same.

One Voice profile for Voice over LTE was developed by association between over 40 operators. In 2010 GSMA declared that they were supporting the One Voice solution to provide Voice over LTE. To achieve a workable system, a cut down variant of IMS was used. It was felt that this would be acceptable to operators while still providing the functionality required.

The VoLTE system is based on the IMS MMTel concepts that were previously in existence. It has been specified in the GSMA profile IR 92.

VoLTE IP versions

After update from IPv4 to IPv6 version ,VoLTE devices are needed to operate in dual mode which will cater both IPv4 and IPv6.

One of the issues with voice over IP type calls is the overhead resulting from the IP header. To overcome this issue VoLTE requires that IP header compression is used along with RoHC (Robust Header Compression) protocol for voice data packet headers.