Method and apparatus for random access in repetition mode in wireless mobile communication system

A method performed by a wireless device, the method comprising:

• receiving system information of a cell, wherein the system information comprises a plurality of configuration parameters associated with random access, and wherein the plurality of configuration parameters associated with random access comprises:
• a first configuration parameter of uplink;
• a second configuration parameter of the uplink;
• a first configuration parameter of supplementary uplink, wherein the first configuration parameter of the supplementary uplink comprises a first power offset;
• and
• a second configuration parameter of the supplementary uplink, wherein the second configuration parameter of the supplementary uplink comprises a second power offset;
• selecting, based on a first reference signal received power (RSRP) threshold, a supplemental uplink (SUL) carrier for performing random access;
• determining, based on a second RSRP threshold, an uplink transmission repetition for the random access;
• selecting, based on an RSRP threshold of the second configuration parameter of the supplementary uplink, a synchronization signal block (SSB);
• selecting, based on a preamble power parameter of the second configuration parameter of the supplementary uplink and based on the second power offset of the second configuration parameter of the supplementary uplink, a preamble group;
• transmitting, based on the preamble power parameter of the second configuration parameter of the supplementary uplink, a random access preamble;
• receiving, based on a search space, a random access response (RAR);
• and
• determining, based on an uplink grant of the RAR, a number of repetitions for an uplink transmission scheduled by the uplink grant of the RAR.