As further shown in FIG. 7A, at 710, one or more UEs may detect one or more events that trigger a RACH procedure in the target cell. For example, a UE may be communicating with the source cell, and may receive a handover command from the source cell that triggers a handover to the target cell. In another example, a UE may be communicating with the target cell and may detect one or more conditions that trigger an RRC reestablishment procedure (e.g., RLF with the target cell, a cell handover failure, and/or an RRC reconfiguration failure). In additional examples, a UE may be camping on the target cell in an idle mode and may detect a registration update triggered by a tracking area update, a gateway switch, a PLMN update, and/or another change in parameters in the target cell, or the UE may detect that uplink data is available to transmit while the UE is operating in an idle mode.
