A wireless transmit/receive unit (WTRU) may measure one or more of a first plurality of beam reference signals. Further, the WTRU may select a first beam reference signal from among the measured one or more of the first plurality of beam reference signals. Also, WTRU may determine a set of physical random access channel (PRACH) resources for the selected first beam reference signal. Moreover, the WTRU may measure one or more of a second plurality of beam reference signals. Further, the WTRU may select a second beam reference signal from among the measured one or more of the second plurality of beam reference signals. The WTRU may transmit an indication of the selected second beam reference signal in a physical uplink shared channel (PUSCH) transmission, and may transmit a PRACH signal using at least one PRACH resource of the determined set of PRACH resources.