d Management System AAA Services Security Services Mobility Management Services Radio Resource Service Flow Paging and Idle Mode Management Services Management Services Services Multicast Broadcast Location Based Services Media Independent Services Management Management Handover Functions Subscriber Station Management Network Management (Only MS Side) Services FIGURE 3-6 Decomposition of the network control and management system [3] IEEE 802.16 Entity CS SAP Radio Resource Service Specific Control and Convergence Management Sublayer Functional Group MAC SAP CS Management/Configuration Medium Access Control Functional Group MAC CPS MAC Management/Configuration Security Sublayer Management Information Base PHY SAP (MIB) Physical Layer (PHY) PHY Management/Configuration Control Plane Data Plane Management Plane FIGURE 3-7 The IEEE 802. 16m reference model [12] 3.1 The IEEE 802. .16m reference model such as 3GPP LTE/LTE-Advanced that have been designed based on similar structured protocol design methodology. Furthermore, the structured functional/protocol design in IEEE 802.16m would elimi- nate the inherent complexity and ambiguity of studying, understanding, and implementing the legacy standard. It must be noted that there are new, modified or extended functions and protocols that are classified under generic classes of PHY, MAC CPS, and CS in IEEE 802.16m, where there are no counterparts in the legacy standard. Therefore, similarity of the reference models should not be interpreted as func- tional compatibility at the service access points. The backward compatibility of the IEEE 802.16m with the legacy standard ensures that non-compatible functions/protocols are not utilized in the time intervals where legacy base stations and mobile stations are supported in the network. 3.1.3 Data-Plane The MAC and PHY functions of the IEEE 802. 16m can be classified into three categories namely data- plane, control-plane, and management-plane. The data-plane (alternatively known as user-plane) comprises functions in the user da