lysis under the ITU-R specified test environments. Report ITU-R M.2135-1 provided a methodology and common CHAPTER 12 Performance of IEEE 802. 16m and 3GPP LTE-Advanced TABLE 12-15 IEEE 802. 16m Handover Interruption Time Analysis [2] Procedure Estimated Latency (ms) The MS initiates handover by sending an AAI_HO-REQ 20 to 35 ms to the serving BS The serving-BS processes AAI_HO-REQ message and sends AAI_HO-REQ to one or more target base stations Target base stations reply to the serving BS with 10 ms AAI_HO-RSP, which may include handover optimization related MAC update information The serving BS responds to MS with AAI_HO-CMD containing target BS list and the disconnect time MS acknowledges to the serving BS with AAI_HO-IND containing selected target BS and confirmation/rejection of the disconnect time (unsolicited uplink grant) At or after the Disconnect Time, the serving BS transfers 0 to 10 ms (R8 interface latency) the unacknowledged and the new data, if any, to the target BS to allow MS data continuity at target BS MS switches to the target BS and acquires downlink broadcast overhead channels The MS waits for handover ranging opportunity to 5 to 20 ms perform uplink synchronization with dedicated ranging Note that 20 ms is the worst case code assigned by the target BS during handover when no dedicated ranging preparation opportunity is provided for this Note that initial ranging, uplink synchronization handover. In most cases, target BS procedures are not counted into handover interruption has prior knowledge of the MS time according to the definition capability and therefore target BS can prepare the ranging opportunity at the next frame, in that case the latency will be 5 ms MS detects the downlink control channels for unsolicited 10 ms uplink grant in order to send AAI_RNG-REQ message and data MS sends AAI_RNG-REQ to the target BS The target BS responds with AAI_RNG-RSP with the 10 ms necessary information for the MS to perform uplink synchronization MS processes AAI_RNG-RSP If necessary, repeat steps 8 