election Cell Selection Decision Decision Failed Operation Path To Access State To Access State Normal Operation Path Legacy Initialization State New Initialization State FIGURE 4-3 Initialization state procedures in the IEEE 802.16-2009 standard [1] and IEEE 802.16m [3] RF channel that was used, it begins to scan the available downlink RF channels, as specified in the band class specifications by the WiMAX Forum [8], until it finds a valid downlink signal. Once the downlink synchronization has been achieved and Cell_ID has been detected, the MS attempts to acquire the system configuration information in the second step. The legacy system configuration information consists of all essential parameters, such as RF carrier center frequency and bandwidth, DL/UL radio (in TDD systems), resource partitioning and multi-antenna parameters, etc., that a mobile station must acquire for successful initial network entry and cell selection, as well as handover. The system information can be classified into static and dynamic sets where the static parameters remain unchanged over a long period of time and dynamic parameters change over time. The system parameters also include information about native neighbor cells (or alternative radio access networks that might be accessible by the mobile station) to facilitate inter-RAT or intra-RAT handover operation. The initialization procedures in the legacy and IEEE 802.16m systems are different. In order to reduce the latency due to downlink scanning and initial network entry (or network re-entry), the 4.1 IEEE 802. 16m mobile station state diagrams initialization procedures have been simplified in IEEE 802.16m. As shown in Figure 4-3 for the legacy system, following successful non-hierarchical synchronization" using the preamble, the Cell_ID detected. The system configuration information is acquired through successful completion of the following steps [6,7,15]: 1. Detection and decoding of the frame control header, which follows the preamble symbol in every radio frame and contains i