As we All know 4G sim card available which having trouble in 3G smart phones because of VoLTE technology, so Use 4G on 3G Phone VoLTE Guide which easily explain to convert LTE device supportive system to VoLTE systems.3G phone user also get experience of 4G internet speed with it.here is the many different ways to make system properly supportive with 3G to 4G speed.it will be useful for 3G phone usersNote :this is not an official application of any company or product, this is made for the purpose of entertainment. If you have any issue regarding to the application , directly contact us to our e-mail address. we will respond u immediately.