ImsService.apk is a service to provide IMS functionalities like volte, vilte, SS over LTE, WFC. WHAT IT DOES? ============= ImsService.apk contains - ImsService handle IMS power on/off or registration event. - IMS OEM implementation files handle volte, vilte, ss over LTE or WFC functionalities. - IMSA make the connection with volte processes to dispatch messages to related modules. HOW IT WAS BUILT? ================== ImsService.apk is built from MTK internal build process if IMS feature is enable. HOW TO USE IT? ============== It's a persist APK. It will launch by AMS and create ImsService why application oncreat function is called. When ImsService is avaiable it will enable/disable IMS from volte setting to register/de-register to server and provide the IMS features.