Physical Layer (PHY) FIGURE 3-9 The IEEE 802. 16m control-plane entity [12] confidentiality protection is utilized, the negotiated keying materials and cipher suites are used to encrypt the management messages. There are three levels of selective confidentiality protection applied to MAC management messages in the IEEE 802. 16m: (1) no protection where the MS and BS have no shared security context or protection is not required, then the management messages are neither encrypted nor authenticated. Management messages before the authorization phase also fall into this category; (2) cipher-based message authentication code (CMAC) integrity protection protects the integrity of the entire MAC management message; and (3) advanced encryption stan- dard-based viii (AES-CCM) authentication/encryption protects the integrity of payload and MAC header [3]. A cipher-based MAC (CMAC) is a block cipher-based message/code authentication algorithm. It may be used to provide assurance of the authenticity and integrity of user payloads. AES-CMAC provides stronger assurance of data integrity than a checksum or an error-detecting code. The verification of a checksum or an error-detecting code detects only accidental modifications of the data, while CMAC is designed to detect intentional, unauthorized modifications of the data, as well as accidental modifications. The counter with CBC-MAC (CCM), as defined in IETF RFC 3610, is a generic authenticated encryption block cipher mode. CCM is only defined for use with 128-bit block ciphers, such as AES. It is an authenticated encryption algorithm designed to provide both authentication and privacy. 3.1 The IEEE 802.16m reference model 3.1.5 Management-Plane A management-plane is also defined for external management and system configuration. Therefore, all management and protocol configuration entities, as well as management information base, fall into the management-plane category. Definition of management information bases are out of scope of the IEEE 802.16m standard. As shown in Figure 3