A method for a user equipment (UE) to synchronize with a first transmit-receive point (TRP) is disclosed. The method includes receiving, by the UE, beam information of the first TRP from a second TRP; detecting, by the UE, a synchronization signal in a beam from the first TRP based on the beam information; transmitting, by the UE, a physical random access channel (PRACH) preamble to the first TRP to synchronize with the first TRP; where the first TRP operates in a first frequency, and the second TRP operates in a second frequency lower than the first frequency.