Cortana will also be able to communicate with bots, according to Microsoft, so they can perform tasks like hotel reservations and pizza reservations by calling the app itself. Iphone 5s Unlocked Phone New. GSM uses a SIM card that stores the phone number and information and Towers and requires multiple steps to connect a call, which results in poor call quality. For example, a single port can save between 22% and 48%, while two or more lines can save between 23% and 50%, depending on a variety of variables like existing planetary costs, new flat rates and local taxes. It is especially important if you buy a cheap phone from a lesser known manufacturer, as the specification may make it impossible to work properly on the network. And even if the phone is unlocked and uses the same CDMA technology and some of the same radio frequency channels as Sprint, an unlocked iPhone 5 will not work on Sprint.