1. VoLTE Overview (Voice over LTE) - VoLTE Introduction - What is VoLTE - VoLTE Explained By TelecomTutorial info

The world have changed a lot in last 20 Years , But There are few things which didn’t changed at all … Just like TOM CRUISE Who is still in action is no change in Life of Voice Calls until VoLTE was Launched recently. It was same voice call on 2G Earlier which continued on 3G without any major change for so many years Do you know there is better way to Make or Receive Calls using your Normal Handset … Yes Now a days You can make Crystal clear HD calls on your phone with VoLTE. This is also called as Voice over LTE on 4G Network I am going to explain you Technical aspects of Voice over LTE Technology & Also Tell you How to enable this Technology on your handset VoLTE Stands for Voice over LTE or 4G Network For Easy understanding , Its Ordinary voice calls which is carried over Data Network , This Works like normal cellular call & Charged on same rate with No Extra Money required Since , This call is carried over IP Network provided by 4G , It also gives lot of Flexibility for Mobile Operator to Enhance Voice Calls here. For Example , If user is using High End Smartphone , Better Codecs will be provided which eventually give you HD Voice Quality & Faster call setup time. Let’s understand how VoLTE works For understanding VoLTE , We need to back into the history where VoLTE was not launched as there was only 4G network along with 2G / 3G Networks working on the Ground. As we discussed , 4G came prior to VoLTE , 4G started getting commercial launched in 2009 , while VoLTE came very late around 2014 Since , 4G is an all-IP technology and therefore cannot transport Circuit Switch services such as Voice Call.

You can see on the screen that so many data Packets which are moving between Internet & User using 4G Network. Let’s see how Voice works in this scenario Since 4G can’t carry voice traffic , This is big problem for everyone. Circuit Switch Fall Back which is also known as CSFB helped Operators here , While 4G or LTE Network is used for Internet and Data Connectivity , User is thrown to underlying 3G or 2G Networks for voice calls. Existing 2G/3G mobile systems use “Circuit Switching” to carry the voice traffic. Circuit Switching or CS is basically a dedicated, end-to-end, channel or a circuit is established to carry the voice traffic for the entire duration of the call While user is able to use Circuit Switch for voice services but there are so... many problems with this technology as user needs to Switch between 4G & 3G Network for every voice call This also requires lot of Battery in handset and also Generates lots of Signaling traffic for Mobile Operator.

This is really Bad for Network Now , Every one started working on Better solution & they come up with VoLTE as solution to all of these problems Now , Let's understand How VoLTE works... VoLTE uses your 4G Data Connectivity to send data packets for Voice calls. Basically it's like calling someone using internet just like Whatsapp call , Just like Skype Call VoLTE enables the Voice on LTE Network or 4G Network Let’s understand , How VoLTE Works.. As LTE have given us All IP to IP Based Network We need to have some technology to carry voice traffic using IP packets over data connection. For this , VoLTE solution is discovered.

We also call this as Packet Switched Network as all traffic goes in form of Stream of IP Packets & It doesn’t require dedicated or Reserved Path Lets understand what all benefits VoLTE brings to the Life of Users The 1st Benefit is Better User Experience : As user is not running pillar to post between 4G and 3G Radios , This improves overall experience of User and It also brings lot of relief for Mobile Operators The 2nd Benefit is HD Calling : As VoLTE is running on All IP to IP based Packet Network This provides opportunity for Mobile Operators to use Bigger Pipes and Better Codecs for carrying High Definition voice Calls. This gives us Crystal clear HD voice calls on VoLTE which was not possible in Old 3G or 2G Networks The 3rd Benefit is No drop in background data speeds Without VoLTE , User needs to switch from 4G Network to 2G / 3G Networks for voice call Which reduces speed of Data Connection running in Background. In few cases such as 2G Networks , Data stops working while you are on call. In case of VoLTE Call , Since user remains Always on 4G , Speed of Data Connection never degrades here … Even during voice calls Another Great benefit.. Faster calling A VoLTE network connects calls faster than the any legacy network.

A Normal 3G call takes 4-6 Seconds but VoLTE calls requires less than 1 Sec to connect Better battery life : Since your phone is not changing networks between 4G & 3G or 2G for voice calls. Users saves couple of Amps & battery life with the VoLTE Let’s Quickly understand the evolution of Mobile technology and the History of VoLTE Initially, IMS network , which is the core network providing VoLTE services was Opposed by various Operators due to multiple complexities involved in this. In the year 2009, Couple of Operators and Equipment Manufacturers such as AT&T, Verizon Wireless, Nokia and Alcatel-Lucent and so many of them gathered and proposed a solution for IMS based VoLTE Network. This initiative was called as “One Voice” and the proposed solution was supposed to provide seamless and common solution for voice over IP networks Further , GSMA (Global System for Mobile Communication) got attention on this Subject & they started to work towards standardizing this as an official solution for providing next generation voice Calls over LTE networks along with 3GPP , Finally we have seen initial working trial of VoLTE happening in Year 2012 Let’s Quickly run thru Evolution of Mobile Technology.. You must have seen all these symbols on your handset.

I have mapped them as per the Name of their Technical Specification & Year of Introduction. We can clearly see Evolution from 2G to 2.5G to 3G to 3.5G to 4G Networks Let's start with GPRS / Edge first : This is normal 2G Network with minimal support of Low Data Services This is very very old technology and It will be shutted across all Entire Globe in coming years There are so many Operators across the Globe who have already shut down their 2G Networks now 3G : This is 3G Network with Better Data Speeds and also provides voice support H / H+ : This is a Super fast 3G network which is still in use 4G or LTE Network : This is latest Technology which is having Bright future … This will play significant role for next 5-6 until 5G Launch Happens Now , Let’s come back to VoLTE again , Voice over LTE was available to End users in 2014 & SingTel Singapore became 1st Operator to Launch Commercial VoLTE Services. With VoLTE Networks , SingTel users were able to make or receive Voice calls on 4G Networks at that time Now , Let's understand , How to enable VoLTE on handset On Left hand side , We can see Android handset and Right handle side , There is Apple iPhone Here , We will cover simple steps which can be used to enable VoLTE in a handset. Now a days , Most of upcoming Smartphones are already supporting VoLTE , This also depends upon your Operator if a particular handset is allowed for VoLTE or Not I will run you thru , the basic simple steps on iPhone..1st of all , You need to Go to Settings > Here you will find Mobile Data Now , Go to Mobile Data Options Select Enable LTE & here and we can see 3 Options … Just Select 2nd Option which is Both voice and Data enabled.. This means , Both LTE & VoLTE are enabled , All Voice Calls will be now handled on 4G radio only Now , Let’s see similar settings on Android device.. Under Mobile Network Settings , First Select “LTE” in Preferred network type & Then Select “Enhanced 4G LTE Mode” which is nothing but a VoLTE Switch.

You will find this Option in various other Smartphone by the Name of Voice over Data or VoLTE or some basic On/OFF Switch for VoLTE In few smartphones , VoLTE can’t be enabled in Settings menu as Handset Manufacturer have not enabled same or You may Require a software Upgrade to get this Setiing in Settings menu However , In such devices , We can use the secret menu *#*#4636#*#* to go to Hidden Settings & Enable VoLTE. This Trick usually works in most of Android devices Now Let’s see what all is required for user in order to use VoLTE Services.. VoLTE is not supported in all the handset by default. Usually , Every Mobile Operator perform testing of a handset and then Handset Manufacturer such as Xiaomi , Apple , Samsung etc.. Enables VoLTE Support in Software Build shipped along with Handset.

This Software build & Operator will decide whether VoLTE will work for your handset or Not ?? Here , We are going to cover the mandatory things required for VoLTE to RUN. On Left hand side We can see stuff which needs to be done by Mobile Operator , On Right hand side , We can see what all to be done by the user in order to get the VoLTE Services Let’s start with Mobile Operator First.. The 1st Thing for Mobile Operator is Good 4G Coverage. A good 4G Coverage ensures , User can make or Receive calls fluently Good coverage will ensure that user will be getting required bandwidth or Radio Speeds for entire duration of a call The 2nd Thing is Provisioning of VoLTE Services Your Mobile Operator needs to Activate or Provision VoLTE Services in Profile of User which is stored in HSS. Few Operator Provision VoLTE by Default for all users , Other Operator provision VoLTE Services on basis of the Handset Make / Model used by User selectively On Right hand side , We can see Requirements for User in Order to use VoLTE Services First 2 are Most important things which belongs to a Handset.. The handset used should support VoLTE , Also The Software or Binary which is running on handset should also support VoLTE for corresponding Mobile Operator.

This Software / or Firmware Build is used to allow or Disallow VoLTE Service which is controlled by Handset manufacturer. It could be possible that the VoLTE Service on a particular handset is available on One of the Operator but is not available on Another Operator , So this is something which is Totally Totally controlled by handset manufacturer and on based of VoLTE testing which is done between handset manufacturer and the Mobile Operator , The VoLTE Service is enabled The 3rd one is ISIM or USIM which is used by the User , VoLTE will not work on traditional SIM used in 2G or 3G Era Last one but most critical is the VoLTE Switch in Handset where user can enable or Disable VoLTE Services himself Now , Let's see what all benefits , VoLTE brings to Mobile Operators The 1st one is the Increased Spectrum Efficiency : Operators have wasted lots of Spectrum of on Older technology such as 2G Radio which only is used for Voice now a days. If We can Re-Use this 2G Spectrum & Re-Farm it to LTE , By doing this , Operators will be able to use precious spectrum in a better way Operator can do this once majority of customers are moved to VoLTE Network which runs both Data & Voice Network. Ultimately, better use of spectrum makes for better quality, which in turn leads to higher subscriber satisfaction and retention. The same amount of spectrum if used in LTE as compared to 2G will give us 2x Numbers of Calls on LTE and 100% Incremental Data Capacity on LTE The 2nd one is Voice is still a Business driver Even in 2018 , Voice is still accounting for appx 50% of Total revenues coming for Mobile Operator.

Providing better Voice Experience is now mandatory for all Mobile Operators in order to Survive. VoLTE is best way to cater Voice call requirements 3rd One is Simplification : With VoLTE , Now Both Voice & data are riding on same LTE Network which means we don’t need separate network for Voice such as 3G / 2G.. This helps in reducing Operational Cost The Last One is New Service Integration : VoLTE Enables Faster , Quicker Integration of new services such as Chat / Multimedia services to compete with OTT Players in a better way Now , Let's go thru VoLTE Challenges. Although , VoLTE is booming technology , There are few challenges which are impacting VoLTE Penetration among the End Users The 1st One is.. Not all Operator Supports VoLTE Out of Total 850 Operators across the Globe , LTE is supported by 530 VoLTE out of this is only launched by 127 Operators as per GSMA Website I am expecting this to grow multi fold in coming Months The 2nd one is Not all Handset Supports VoLTE : This used to be a bottleneck some years ago , Now a days Handset Most of Smartphones which are shipped in the Market usually supports VoLTE Next one is Increased Complexity : VoLTE increases complexity multifold as there are many new Nodes which generates lot of Signaling traffic Next one is LTE Coverage is mandatory for VoLTE services , VoLTE Requires Good Strength 4G to be mandatory available which should provide both Outdoor and Indoor Coverage No Inter-Operator Connectivity : Even after VoLTE Launch , Operators are still connected to each other via traditional Non-SIP PSTN Networks The Last One is Every Operator needs to Test Every Device : Device is big mystery for VoLTE Support , There is lot of dependency on Device Validation prior to Launch by Every Operator How to handle Network Congestion Have you ever thought , What will happen to VoLTE Voice Calls if Radio is Congested ? As General principal , Data Internet can wait for some time , But Voice Can’t.

Voice has to be real-time VoLTE Technology uses Quality of Service concepts used in 4G Network.. This QOS or Quality of Service Provides Highest Priority to Voice Traffic and therefor Facilitates Super Highway for Voice Packets to Pass thru. In Order to give Highest priority to Voice , Internet traffic is De-Prioritized and is slowed down during Congestions in Network Now we have covered the VoLTE Basics almost completely here Guys , You can checkup my Another Video on VoLTE IMS Architecture Video on Youtube where I have covered Detailed Technical Architecture with More Granular details but keeping it Simple. If you want to download this PPT or Video , Please visit my Website. Its http://telecomtutorial.

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