 and BS. The SNMP is a protocol to access the managed objects in the BS and SS. The support of SNMP is optional for the SS: The wmanIfMib MIB module defines management objects relevant to the IEEE 802.16 broadband wireless interface as defined in the standard. The wmanDevMib MIB module defines management objects relevant to the device implementing the IEEE 802.16 interface. SS #1 Management agent Managed BS #1 Management proxy Managed Core IP Network SS #1 Management agent Managed Service Flow database Figure 8.28 WiMAX management reference model. Reproduced with permission from C 2005 IEEE [38] Core Networks and Operations Support Systems Network Network Control and Control and Management Management System (NCMS) System (NCMS) (SS/MS Side) (BS Side) M_SAP C_GAP C_SAP M_SAP 802.16 Entity 802.16 Entity (SS/MS) Figure 8.29 NCMS model. Reproduced with permission from © 2007 IEEE [39] 8.3.7.2 NCMS The NCMS (as shown in Figure 8.29) is a layer independent entity that may be viewed as a management entity or control entity. General system management entities can perform functions through NCMS and standard management protocols can be implemented in the NCMS. This standard includes a Control SAP (C-SAP) and Management SAP (M-SAP) that expose control plane and management plane functions to upper layers respectively. The NCMS uses the C-SAP and M-SAP to interface with the IEEE 802.16 entity.9 Mobile Station/CPE communicates to the Base Station over the U interface. In order to provide correct MAC operation, NCMS is present within each SS/MS: The NCMS can provide the following functions: AAA Services. Radio Resource Management Services. Multicast Broadcast Management Services. Device Management. Security Services. Service Flow Management Services. Location Based Management. Mobility Management Services. Paging and Idle Mode Services. A simplified NCMS model is shown in Figure 8.29 provides two key interfaces namely M-SAP and C-SAP. M-SAP is used for less sensitive management plane primitives related to system configuration, 