Patent ID: 8743682

Claim:
A preamble transmission method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving, by the UE, a UE specific Radio Resource Control (RRC) message from a network, wherein the UE specific RRC message includes a plurality of dedicated preambles for reporting an occurrence of event, wherein the UE specific RRC message further includes maximum transmission number information indicating a maximum number of transmissions of the dedicated preamble by the UE, and wherein the UE specific RRC message is received by the UE only when the UE is in an RRC connected state; detecting, by the UE, an occurrence of an event, wherein the detecting of the occurrence of the event is performed by using a first threshold value, wherein the first threshold value is received from the network through system information; and transmitting a dedicated preamble corresponding to the detected event to a network through a random access channel (RACH), wherein the dedicated preamble is selected from among the plurality of dedicated preambles included in the UE specific RRC message, wherein the preamble is a dedicated preamble that is dedicated to the detected event, wherein the transmission of the dedicated preamble is performed when the UE is in an RRC idle state, wherein the transmission of the dedicated preamble is performed by selecting a PRACH resource capable of transmitting the dedicated preamble, and wherein the dedicated preamble is repetitively transmitted within a range of a maximum number of transmissions.