For around three months I am facing this problem. Most of the time my phone doesn't have any problems while on a call. It works perfectly fine no matter how long I am on call but at least once in a week my calls are getting frequently disconnected after say 20-30 secs or sometimes after 2-3 mins while on a call. It happens for both making a call as well as receiving a call.
I have tried uninstalling most of the third party apps which are taking a lot of my RAM usage. I even tried disabling suppress background noise option in call setting. I used this SIM card on another phone and found out that it's surely not a network related issue. Most of my friends in my area do not have any such call dropping issues for this network. I face this problem even in safe mode where all third party apps are disabled.
I am on Android KitKat.
Where do you think is the problem. Is it the software or hardware? I was planning to do a repair but before this I want to hear something from you. Whether anyone had or heard about such a problem.
Thanks in advance.