Methods and apparatus for enabling short message service (SMS) and supplementary services (SS) in a long term evolution (LTE) network via evolved packet system (EPS) mobility management (EMM) over the LTE control plane are described. In one embodiment, the radio resource control (RRC) connection signaling radio bearer (SRB) is used for SMS and SS transport over the LTE control plane between a wireless transmit/receive unit (WTRU) and a mobility management entity (MME). EMM interfaces and primitives are defined for actions towards SMS and SS entities for enabling SMS and SS services in LTE via the LTE control plane media. Message formats for SMS and SS message transport are also disclosed for sending SMS and SS messages within EMM uplink (UL) non-access stratum (NAS) transport and downlink (DL) NAS transport messages.