iPhone 6S and iPhone 6S Plus they are compatible with 4G+ 300 Mbps networks exactly as many rumors that have appeared on the Internet so far have said, stating that Apple will implement new telecommunications technologies in its products.
According to the Apple website, the iPhone 6S and iPhone 6S Plus are compatible with LTE Advanced networks, i.e. 4G+ networks that offer internet browsing speeds of up to 300 Mbps, this of course in the few countries around the world that have operators that support LTE technologies this kind.
Apart from support for better speeds, the iPhone 6S and iPhone 6S Plus are now compatible with 23 different 4G bands, being the only ones in the world capable of working on that many networks, or at least that's what Apple claims at the moment.
