A wireless transmit/receive unit (WTRU) configured to perform wireless communications in higher frequency bands (e.g., above 6 GHz) using a fallback scheme is provided. The WTRU includes a receiver configured to receive, in a time transmission interval (TTI), at least one control signal and a first data signal using a first beam associated with a first beam identifier (ID) and a second data signal, subsequent to the first data signal, using a second beam associated with a second beam ID different from the first beam ID, such that one of the at least one control signal indicates the second beam ID; and a processor configured to switch a receive beam of the receiver from the first beam to the second beam based on the second beam ID to receive the second data signal.