A wireless transmit/receive unit (WTRU) may receive, from a base station, a synchronization signal/physical broadcast channel (SS/PBCH) block transmission. The WTRU may transmit using a physical random access channel (PRACH) resource. Further, the PRACH resource may be determined based on an SS/PBCH block index. Also, the SS/PBCH block index may be determined based on information associated with the SS/PBCH block transmission. In a further example, the information associated with the PBCH block may be derived from a demodulation reference signal (DMRS) sequence. In another example, the DMRS sequence may be a PBCH DMRS sequence. Also, the information associated with the PBCH block may be derived from PBCH payload bits. Further, the SS/PBCH block index may be associated with a beam. In addition, SS/PBCH transmissions of different beams may be transmitted at different times. Further, the PRACH resource may include a preamble resource, a time resource and a frequency resource.