Apparatuses, systems, and methods to perform attachment of a wireless device to a next generation gateway via either a base station of a next generation radio access network (RAN) or a mobility management entity of a legacy RAN. An apparatus may be configured to receive an attachment request from a wireless device, determine authentication information via communication with a home subscriber server, determine, based at least in part on the authentication information, whether the wireless device is capable of communicating via the next generation RAT, and send, in response to determining the wireless device is capable, a connection request to a gateway of the next generation RAN. The authentication information may include subscription information associated with the wireless device.