[GUIDE] Enable Carrier Aggregation [LTE+] - Xiaomi Redmi Note 7 Pro Guides, News, & Discussion

Hello !
Here is an easy guide to enable CA ( Carrier Aggregation ) in your violet. I won't be writing a long-ass guide, lets be on point.
There are two seperate files, one for Jio & Airtel and another for VI (vodafone-idea). This seperation is made because:
> The Jio-Airtel file has all combos for Jio, Airtel and VI. Few users arent getting CA on VI using this file.
> Hence, a new file optimised for VI only is being uploaded too. Theoritically this file should be fine for Airtel and Jio too but isnt tested.
tldr; If u have internet only on VI, use the VI optimised file. Else, use the other file.
Pre-requisites :
1. Brain and Patience
2. Windows 7 and higher ( I tested on 10 and 7 ) and 32-bit should work fine.
3. A rooted Q/R ROM
4. Network Signal Guru ( needs Permissive SELinux btw )
5. QPST Tool ( latest )
6. QDLoader HS-USB Driver [link] [64-bit] (look for 32-bit on internet)
7. Fully functional ADB
Telegram : [ For more support ]
Azure Kernel for Redmi N7p
Attached 00028874 File [ updated 1-1-2021]
Google Drive [ Optimised for Jio / Airtel users ]
Google Drive [ Optimised for only Vi users ]
Steps are Simple AF. Lets Start.
1. Install QDLoader HS-USB Driver. Alongside / beforehand keep your EFS backed up via Ofox/Pbrp or EFS Explorer ( u should be introduced to EFS soon along way ).
2. Connect your phone to PC, make sure ADB is working and USB Debugging is enabled !!
The next steps should be followed with your device properly connected to PC
3. Enable Diag mode for USB. Install Terminal on your Android and execute this command
Bash:
su -c "setprop sys.usb.config diag,adb"
4. Launch Device Manager on PC. Under Ports (COM & LPT) , you will find Marshall London or Qualcomm HS-USB listed. I would suggest you to uninstall Qualcomm HS-USB and install the one I provided.
5. On your PC, launch QPST Configuration. You will see your device enlisted as SM6150 under Active Phones tab.
6. Head over to Start Clients > EFS Explorer section. A Phone Selection will pop-up. U will find your device there connected. Click OK button. Wait for a few seconds / minutes until your storage gets read. You will see a bouncing bar while the storage is being read.
NOTE - If you get errors like "The phone you have chosen does not support an embedded file system" , then probably you are damned. Either you are on R or you have missed drivers.
7. Now you got yourself landed in EFS Explorer. Head over to nv > item_files > rfnv .
You will see a lot of files named 0002xxxx . Don't worry xD you need to deal with only one file.
Locate 00028874 and back it up to a safe place by clicking on it and selecting "Copy Data File to PC".
8. Now comes the real deal to be dealt with You need to replace the file 00028874 .
I will be providing you a modified file of 00028874 and you need to replace this with the original one, assuming you already backed up the original file as per Step 7 .
> Download the attached "modified" file.
> Delete the original file by clicking on it and then Delete
> After successful deletion of 00028874, right-click on empty space and "Copy Data File from PC" and select the downloaded "modified 00028874" , Upload it by selecting OK and keeping settings untouched. The downloaded file should not have any extensions !!
> Look in the folder if the file is successfully uploaded or not. It should have same atttributes as others.
9. After successful "operation" xD , disconnect your phone. REBOOT!!!
|| Look for the next post for verifying CA ||

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So, you need to verify whether you really have enabled CA or not !
Listen Buddy, first of all , CA is regional / region-dependent. It isnt like you are gonna get CA from wherever the f you live. Cities / Towns have a higher probability of aggregation.
Here are few checks I am mentioning.
1. Open Phone Dialer and dial "*#*#4636#*#*" to enter in Testing menu.
2. Tap on Phone Information and check "LTE physical channel configuration".
If CA is working, It will show you two connections PrimaryServing and SecondaryServing along with their bandwidth, otherwise nothing .
{
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"lightbox_full_screen": "Full screen",
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"lightbox_new_window": "New window",
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}
( Screenshot from @M_3L_W1_N [telegram] )
Another proof is from Network Signal Guru. You can see P in first cloumn and S ( S1, S2...) next . You can see LTE 2xCA at the top header . This means two carriers are aggregating.
Also, you can see 20Mhz Bandwidth in action
( Screenshot from my device )
|| Look for FAQ and Solutions on next post and also if u have a different QCOM device ||

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|| Few important notes and QA ||
1. How to revert back / Will I lose my CA ?
Ans: You arent going to lose CA unless you flash EFS / QCN backup. Flashing modem / firmware won't take away your CA. Reportedly, locking bands might take away your CA if done via NSG and not all are affected with this mishap.
In case you want to revert, just load the backed up "00028874" and you are back again. Or you can just restore the EFS backup which you have safely kept aside on following the steps on previous post.
2. Is it a fake / facade ?
Ans: No, I conducted few tests , side-by-side with my A50 ( CA out-of-box ) and under same conditions, both devices managed to provide same speed.
I am attaching few comparative screenshots and kindly watch carefully to distinguish.
( left - A50 | right - violet )
( left - A50 | right - violet )
3. Will it fukcup my mobile phone ?
Ans: No, unless you are a careless brat and mis-followed a step. Other then, there are no such incidents yet reported by anyone.
4. I have a diff device. What shall I do ??
Ans: Same steps to follow, just the contents of the file is different.
Here is a Generator and Combolist and follow 3rd Step from the link.
Generator
Combolist
Link
So, its your time to decide.
--Signing-off

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|| My Opinions and Personals ||
[ for nerds ]
Since violet seems to support only 2CA, you can try selecting any two bands and prior selecting remember to find out which two bands is best-fitting throughputs.
2100 and higher bands are best-performers in my case.
[general case]
If I do not care about aggregation on Jio, I usually get 1MBps speed on upload on 1800Mhz.
850Mhz is the best-performer on downloads. But after aggregation, I usually get nicer speeds if I keep all bands untouched. Because, 850 and 1800 is needed for surfing.
[thanksgiving]
> Artem_sid [ 4pda guide ]
> @Roz_in [telegram]

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Nice work

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thanks pero sir

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Sir I request please make a youtube video for complete tutorial realy helpful for all of us

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paramparmatma said:
Sir I request please make a youtube video for complete tutorial realy helpful for all of us
Click to expand...
Click to collapse
I do not have enough resources sir. The guide is friendly enough.

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Last thing if I flash fastboot miui official rom will CA change or remain same

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paramparmatma said:
Last thing if I flash fastboot miui official rom will CA change or remain same
Click to expand...
Click to collapse
Might get re-written. I don't know yet.

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Working really well! Saw 2 MBps increase in speed(4->6). Finally, an LTE+ guide which worked. Well Done.
Technicals: 2CA on 2300(20Mhz) + 2300(10Mhz)

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Adding Proof. For context, it has never crossed 5 MB/s till today. After the changes, consistently got 6+ MB/s.
Many people in the Telegram are joking about this. Adding to support a fellow Dev @Panchajanya1999

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does it works with 2100 and 1800 mhz bands,bcz I really wish i was an Indian nd had access to jio..i need help

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Big thanks sir

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Great work sir..

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Does it works for vi/Idea as i see no LTE+ so im asking

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Rockstar_Rajat said:
Does it works for vi/Idea as i see no LTE+ so im asking
Click to expand...
Click to collapse
Well, if u are Vi user, we are trying to fix vi for some regions.
Can u please inbox me at telegram ??
Tg - @Panchajanya1999

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We all thankful to Mr. Panchajanya for awesome guide.
It will be more help for noobs like us if anyone post video tutorial.

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It's easy tutorial I have tried and it's really working thanks again

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Hello guys, Happy New Year !!
Also this post has been updated and few notables edits are committed to the post.
Spoiler: Notable changes
> Files has been updated on#1 post. Proper reasoning is done. Read the post carefully !
> Steps has been edited and added a note for users to take EFS backup.
> FAQ has been updated.
I request you to go through the post once again. I hope things are clear to you.