Methods for performing various operations via unlicensed mobile access (UMA) radio link control (URLC) messages in an unlicensed mobile access network (UMAN). The UMAN comprises a first radio access network that may be employed for accessing data services provided by a core network comprising a second radio access network. URLC messages are exchanged between mobile stations (MSs) and UMA network controllers (UNCs) to perform various operations associated with the UMAN. An MS may access the UMAN via a wireless access point (AP) that is communicatively coupled to a UNC via an IP network. The URLC messages are sent between MSs and UNCs using an Up interface comprising a set of layered protocols over an underlying IP transport.