 Initiation: the handover process begins with a decision by an MS (or a BS) to handover from a serving BS to a target BS. The decision may originate either at the MS or at the serving BS. The handover decision is completed with a notification of MS intent to handover through a MOB_MSHO-REQ or MOB_BSHO-REQ message. 3. Downlink Synchronization: the MS synchronizes with the DL transmissions of the target BS and obtains DL and UL transmission parameters (system configuration information). If the MS had previously received a MOB_NBR-ADV message including target BS-ID, physical frequency, and other essential system parameters, this process may be simplified. If the target BS has previously received handover notification from the serving BS over the backhaul, then the target BS may allocate one or more non-contention-based initial ranging opportunities for the MS. 4. Ranging: the MS and target BS must perform initial ranging or handover ranging. If the MS RNG- REQ message includes the serving BS-ID, then the target BS may request the serving BS to provide the MS information over the backhaul. The normal network re-entry process may be shortened by target BS possession of MS information (see Chapter 4 for more information on fast network re- entry). This type of handover is referred to as optimized handover. The MS context may include static and dynamic information where static context consists of all configuration parameters that were acquired during initial network entry or via exchange of information between the BS and MS (e.g., the SBC-RSP and REG-RSP parameters, service flow encodings from DSA-REQ/RSP CHAPTER 6 The IEEE 802.16m MAC CPS (Part I) Initiate Cell Selection Select Alternative Target DL Synchronization and New DL Synchronization System Information and System Information Acquisition Acquisition (DL/UL Parameters) (New DL/UL Parameters) Cell Rejected Cell Rejected Ranging and UL Ranging and UL Synchronization Synchronization Cell Rejected Cell Rejected Basic Capability Negotiation MS Re-authorization Cell Re