A method performed by a user equipment (UE) is provided. The method includes receiving, from a base station, configuration information on a random access configuration for a narrowband including: information on an initial power of a random access preamble for an enhanced coverage level, and information associated with a power ramping for the enhanced coverage level, and performing a first random access preamble transmission corresponding to a first transmit power, wherein the first transmit power is set based on the information on the initial power of the random access preamble and the information associated with the power ramping in case that the UE is in the enhanced coverage level, and wherein the UE is a narrow band internet of things (NB-IoT) UE.