today, a t-mobile retail store rep said I had a 3G sim card in my MyTouch 4G. He proceeded to replace it with a "4G" sim card.
was he making this up? can the sim card limit connection speed or reliability if it's the wrong card for the device?
There are a few different sim cards at this point. The first sim cards or "Legacy" sim cards have authentication limits that result in sim card exhaustion, or the complete inability to connect on T-mobile's network. The sim card that came after that is called a "UICC" sim card which does not experience sim card exhaustion. The newest sim card is a "UICC-GBA" sim card and that is used for phones with Wi-Fi calling over UMA and IMS. There are no 3G/4G sim cards and the sim cards do not limit connection speed or reliability.
shhh...don't tell anyone at tmobile retail or tmobile phone support. they both think that there are 3G AND 4G sim cards, and that they effect you connection abilities.
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