Patent ID: 8917640

Claim:
A method of processing data related to contention-based random access in a wireless communication system using a number of orthogonal frequency division multiplexing (OFDM) symbols, the method performed by a user equipment (UE) and comprising: receiving system information including preamble transmission number information via a system information block (SIB), wherein the preamble transmission number information is used to indicate a first maximum number of preamble transmission applicable to a first type UE performing normal access and a second maximum number of preamble transmission applicable to a second type UE performing delay tolerant access; performing random access by transmitting a preamble based on the preamble transmission number information; receiving, in response to the preamble, a random access response including back-off interval information, wherein the back-off interval information is used to indicate first type back-off interval information applicable to the first type UE and second type back-off interval information applicable to the second type UE; transmitting, in response to the random access response, a scheduled message; determining whether contention with respect to the scheduled message is resolved by receiving a contention resolution message; and if the contention is not resolved, performing a back-off operation based on the back-off interval information.