Methods and apparatuses are provided in which a base station transmits a synchronization signal (SS) physical broadcast channel (PBCH) block (SSB) associated with a master information block (MIB) including first configuration information for a first control resource set (CORESET) associated with a common search space (CSS). System information is transmitted. The terminal obtains MIB based on the SSB, monitors first control information for scheduling the system information on the CSS based on a first aggregation level, and receives the system information based on the first control information. A radio resource control (RRC) connection is established with the terminal based on the system information. An RRC message is transmitted to the terminal including second configuration information for a second CORESET associated with a UE specific search space (USS), based on the RRC connection. The terminal monitors second control information for the UE on the USS based on a second aggregation level.