A UTRAN sends a Radio Bearer Setup message to a UE, which indicates that SRNS relocation is to be performed and that a new RB is to be established in a first domain. The UE receives the Radio Bearer Setup message and assigns a first START value to a START_VALUE_TO_TRANSMIT variable according to the HFNs of all established RBs in the first domain. The UE the generates a START list containing entries corresponding all domains, including the first domain. The UE fills the entries with corresponding START values, synchronizing the entry corresponding to the first domain to hold a value that is identical to the value of the START_VALUE_TO_TRANMIT variable. The UE then composes a reply message that includes the START list, and sends the reply message to the UTRAN. The UE utilizes the START_VALUE_TO_TRANSMIT variable to set an HFN of the new RB. In a second embodiment, the response message includes both the START list and the START_VALUE_TO_TRANMIT variable. The START list is applied to all RBs but the new RB. The START_VALUE_TO_TRANMIT variable is applied to the new RB.