Method and apparatus for transmitting and receving random access channel

A communication device configured to transmit a random access channel (RACH) in a wireless communication system, the communication device comprising:

• a transceiver;
• at least one processor;
• and
• at least one computer memory operably connected to the at least one processor and storing instructions that, based on being executed by the at least one processor, perform operations comprising:
• receiving, through the transceiver, (i) first information related to transmission of at least one synchronization signal block (SSB) and (ii) second information related to a plurality of RACH resources, wherein the second information relates to a time period within which to transmit the RACH in the plurality of RACH resources;
• and
• transmitting, through the transceiver, the RACH in a RACH resource, among at least one first RACH resource that is mapped to the at least one SSB, based on the first information and the second information,
• wherein the at least one SSB is repeatedly mapped to the at least one first RACH resource within the time period related to the second information, and
• wherein the plurality of RACH resources comprise (i) the at least one first RACH resource that is mapped to the at least one SSB and (ii) at least one second RACH resource that remains unmapped to the at least one SSB after the repeated mapping of the at least one SSB to the at least one first RACH resource within the time period related to the second information.