An application service provider (ASP) subscribes to a slice of the network of the mobile operator to offer its users on mobile devices a better-quality transport service. For example, the ASP subscribes to and pays for, say, a premium network slice dedicated for the use of its premium users that are on mobile devices. When a premium user accesses the application (and gets authorized by it), the application sends identifiers of the application/user to the Slice Identifier Function (SIF) of the mobile operator, which in turn directs the configuration of the core network components as well as the RAN attached to said user's mobile device according to the application's slice policies. As another example, the ASP subscribes to and pays for the default network slice for a differentiated treatment. When SIF identifies the application, it gives its users a higher QoS/priority than other users within the same slice.