In an integrated access and backhaul (IAB) system, an access WTRU may receive a random access channel (RACH) occasion (RO) configuration comprising one or more RO resources from a first integrated access backhaul (IAB) node. The access WTRU may receive an indication that one or more of the configured RO resources have an overlap with one or more IAB node RO resources. The access WTRU may monitor and receive the ROI indicating the configured RO resources that overlap with the one or more IAB node RO resources. Based on the received ROI and the configured RO resources, the access WTRU may determine one or more RO resources available for PRACH transmission. The access WTRU may select an RO resource from the available RO resources for PRACH transmission. The access WTRU may send a first PRACH transmission to the first IAB node using the selected RO resource.