This is a common request, so I decided to open a post to allow you to check it by yourself.
The short answer is: Yes, if the carrier you're going to use does use one of the device LTE bands then you will get 4G LTE.
How to check the device LTE bands?
Those are all listed in this nice site, open it then input your phone model (e.g. SM-G920P) and open the result:https://www.frequencycheck.com
Once you have the supported LTE bands of your phone you just need to check if your carrier does use one of them, if you don't know which bands your carrier uses then you can find it here:https://en.wikipedia.org/wiki/List_of_LTE_networks
Or by calling your carrier.
If your carrier uses one of the phone LTE bands then you will be able to have LTE, (by setting the proper APN, we have the most used listed here: https://idoneapps.com/forum/index.php?topic=23.0
) in the other cases sadly there is now way yet to have 4G LTE because enabling them all using an external software doesn't seem to work as probably it's a modem lacks.
If you are not lucky with the above check you can use below methods to tweak the LTE settings, these methods will work because are supported by the phone modem:MSL/SPC
Using the MSL you may tweak the LTE settings, such as band priority, enabling/disabling certain bands etc...
Open our app, note down the MSL/SPC code shown in the main page and then:
1. Dial ##3282#
2. Select "EDIT"
3. Enter the phone MSL
4. Select LTE, then tweak the settings like you prefer.GCF Settings
Using the Service Menu you may enable/disable certain bands:
Open our app, tap on GCF Settings, then:
1. UE SETTING & INFO
4. NEXT PAGE
5. LTE BANDS ON/OFF
6. Manage the bands as you prefer.