The Verizon iPad 3 always had 4G LTE. It doesn't need 6.1 for that. In order for a device to get LTE, it must have th LTE hardware bulit in. And LTE is a cellular service so, yes, it has to be an iPad with WiF + Cellular. The iPad 2 and the iPhone 4S do not have an LTE chip. The cannot use the LTE network regardless of the version of the software they're running.