A method and apparatus for supporting routing area (RA) update in a long term evolution (LTE) general packet radio service (GPRS) tunneling protocol (GTP)-based system are disclosed. A wireless transmit/receive unit (WTRU) sends an RA update request to a new evolved Node-B (eNodeB) and a mobility management entity (MME). The MME sends an update packet data protocol (PDP) context request to an access gateway (AGW), whereby a new tunnel is established between the new eNodeB and the AGW. For an inter-MME routing area update, the WTRU sends an RA update request to a new eNodeB and a new MME. The new MME sends an MME context request to an AGW. The AGW sends an MME context response to the new MME. The new MME sends an update PDP context request to the AGW, whereby a new tunnel is established between the new eNodeB and the AGW.