[Samsung Galaxy A7 (2018) Guides, News, & Discussio] blazzer12:
PSA: I bought the phone from some other country & I want VoTLE to work in my country!

Given your Mobile Operator supports VoLTE, working of it depends on your phone's firmware. Especially two components of the firmware called "CSC" and "CP". CSC, depending on who you ask, is either Country Specific (Product) Code or Country Specific Content. CP or "Core Processor" is the firmware for your modem.

OBJECTIVE OF THE POST: Determine if your phone supports your mobile phone operators LTE bands. Check which firmware you need to change to. How to obtain that firmware.

WARNING: MESSING WITH FIRMWARE CAN TURN YOUR PHONE INTO A PAPER WEIGHT.​

PART A [CP] : Does my phone support VoTLE provided by my Mobile Operator to begin with?

1. First of all your modem should support the bands used by your mobile operator. You need to cross check bands supported by your Mobile Operator and your phone modem.

2. Search for the LTE bands supported by your mobile operator. Make a list.

3. To check the LTE Bands supported by your phone modem you need to know the Model Number of your phone. Goto Settings -> About Phone. You will see the Model Number there. Now goto Samsung website and check the phone specs using the model number. Specs - > Show all specs -> Network/Bearer-> 4G FDD/TDD TLE.

4. After cross checking bands from #2 and #3 if any of the bands match proceed to Part B. If not, unfortunately your phone cannot support VoTLE for your mobile operator; this post is no longer relevant to you. Maybe change the mobile operator and go through PART A again.

PART B [CSC] : Can I change the firmware on my phone to make VoLTE work?

1. Now you need to change the firmware of your phone. Change it to the current country you are in. The country in which you wish to utilize VoTLE. The country in which your mobile operator is.

2. To which firmware you can change to depends on your firmware's CSC. You cannot jump from any firmware to any other firmware. That stuff is locked down by Samsung.

3. You need to know your phone's firmware's CSC to know which firmwares you can change to.

4. Install the "Phone INFO Samsung" app. Open App, goto "CSC CODE" tap. You can see your Firmware's CSC code. But more importantly see "Available CSC Codes" section. Available CSC Codes tells you to which firmware you can change to.

5. Search each of those codes (Available CSC) in this page or the internet.

6. If any CSC corresponds to your Country/Mobile operator-- congratulations you can now change to that firmware and VoLTE will work for you. Note down that CSC code.

Eg: If you are in the country "India" and one of the Availabe CSC is "INS", you will find the entry "India= INU (unbranded), IND, INA, INS (unbranded), IMS, REL". [Success]

If you are in the country "Singapore" and one of the Availabe CSC is "XSP", you will find the entry "Singapore= MM1, XSP (unbranded), SIN (Singtel), STH (Starhub), BGD, XSO". [Success]

7. If none of the CSC codes correspond to your Country/Mobile operator then at present there is no way to make VoLTE work on your phone. Contact your mobile operator if there is work around for this, probably like an app.

Eg: If your avialabe CSC are : {BRI, CAM, LAO, ... , SIN, SMA, STH} and your country is "India" : India= {INU (unbranded), IND, INA, INS (unbranded), IMS, REL}; you can see those two sets have no common CSC [Failure]

PART C: How to get the correct firmware file according to the CSC?

If you have root, there used to be apps to just change the CSC to the required CSC Code. Used to be.

I am not really sure but you may try following that route and skip PART C.

Hint: Phone INFO Samsung app -> Hamburger menu -> other tools -> CSC Changer (ROOT)

PS:Rooting trips KNOX. No more Samsung Pay etc.

​

1. Goto https://updato.com

2. Enter your Model Number (PART A #3). You can ignore the part after the slash. Eg: If the model number is "SM-A750GN/DS" just enter "SM-A750GN".

3. Sort/click the "Region / Carrier" column. The CSC you noted down (PART B #6) should appear in one of the entries.

4. Observe the "Date" column and download the latest firmware.

PART D: How do I flash the downloaded firmware to my phone?

1. This part is out of the scope of this guide.

2. Find the latest guide/tutorial on how to flash a firmware to your Samsung phone using a program called Odin.

3. The latest one. The one that recommends at least Odin3 v3.13.1.