performing a first interference check on a first sub-band and a second sub-band, wherein the first sub-band is different from the second sub-band;

based on the first interference check, selecting the first sub-band for transmitting a first portion of a signaling message and in response to the selecting, transmitting the first portion of the signaling message in the first sub-band;

performing a second interference check on the second sub-band;

selecting the second sub-band for transmitting a second portion of the signaling message based on passing the second interference check on the second sub-band, the second portion including an indication to the first portion transmitted in the first sub-band,

wherein the first portion includes a preamble part of a random access procedure and the second portion further includes a data part of the random access procedure,

wherein the indication includes a mapping between the preamble part in the first portion in the first sub-band and a demodulation reference signal port for transmitting the second portion; and

monitoring for a response to the signaling message from an access network on multiple sub-bands including at least the first and second sub-bands.