A UE may receive, from a base station/TRP, a configuration for a beam pair including an UL beam and a DL beam and transmit a RACH message via the UL beam while receiving DL information via the DL beam. The UE and/or the base station/TRP may be configured to operate in a FD mode. In aspects, the UE may transmit a RACH preamble based on a first mode of transmission. After a threshold time delay measured from the transmission of the RACH preamble, the UE may retransmit the RACH preamble based on a second mode of transmission. The second mode of transmission may be a same mode of transmission or a different mode of transmission from the first mode of transmission. Each mode of transmission may be based on one or more of TDM, FDM, or SDM.