TmoNews reports that T-Mobile USA has issued an internal memo announcing that it will release a new carrier update on April 5 that will add LTE support for unlocked iPhones running on its network. The update will also bring Visual Voicemail and other features to the devices.The T-Mobile Carrier Update is a minor iOS software update that enables official iPhone support by T-Mobile. When installed, the software update enables a handful of capabilities like Visual Voicemail, MMS Settings and Network/Device optimizations that customers do not have access to today. On April 5, the software update will begin being pushed via OTA to all iPhone devices on the T-Mobile network with iOS 6.1.x or higher.
