del where major functional blocks (i.e., physical layer, security sub-layer, MAC common part sub-layer, and service specific convergence sub-layer) and their interfaces, the premises of IEEE 802.16 entity, and a general network control and management system are specified. The IEEE 802.16m has modified this reference model by further classifying the MAC common part sub-layer functions into two functional groups, resulting in a more structured approach to characterizing the data link layer functions and their interoperation. The earlier revisions and/or amendments of the IEEE 802.16 standard did not explicitly define any detailed protocol structure; rather, the functional elements in the specification were implicitly clas- sified as convergence sub-layer, MAC common part sub-layer, security sub-layer, and physical layer. While each of these layers and/or sub-layers comprises constituent functions and protocols, no perspective was provided on how various components were interconnected and interoperated from a system standpoint. In fact, the IEEE 802.16 standards have never been developed with a system engineering approach; rather, they specify components and building blocks that can be integrated (obviously various combinations are potentially possible) to build a working and performing system. An example is the mobile WiMAX system profiles [1], where a specific set of IEEE 802.16-2009 features were selected to form a mobile broadband wireless access system. In an attempt to improve the clarity of the previous IEEE 802.16 standards and to take a systematic approach in development of the advanced air interface, IEEE 302.16m has defined a protocol structure and the functional components are classified into different layers and sub-layers, as well as differentiated based on data- plane or control-plane categories. The protocols and functional elements defined by the IEEE 802.16 standard correspond to the physical and data link layers of the Open System Interconnection (OSI) seven-layer network reference model as shown 