When Apple introduces its newest iPhone today as expected, T-Mobile is looking to get its hands on the previous model. The company is the only major phone carrier that doesn’t carry the iPhone itself. But it does provide service for the devices, provided you BYOP – bring your own phone to hook up to their network. Now T-Mobile says it’s looking to buy up used iPhones from AT&T and put them on the network. Signing an iPhone up for T-Mobile service has been possible for years. The company says it has more than a million iPhones on its network. But they tend to run slower than on the AT&T network. T-Mobile plans to fix that this year, pumping up its service to let it match or even surpass AT&T data speeds on iPhones.