Systems, methods, and instrumentalities are disclosed to enable Machine Type Communication (MTC) group communication in 3 GPP. For example, a wireless transmit/receive unit may be used for MTC group communication. The WTRU may contain a processor configured to receive a trigger, such as an SMS trigger. The WTRU may contact a server, such as an Application Server or Proximity based Service function. The WTRU may request additional information from a server. The WTRU may receive information from a server. The WTRU may trigger one or more WTRUs, for example, based on the information received from the server.