) based on the functionalities and features specified in the IEEE 802.16j-2009 standard [27]. The IEEE 802.16j-2009 standard does not define a system profile; therefore, many non-interoperable realizations of the relay stations can be considered. The WiMAX Forum technical working group started (and later abandoned) an initiative to define a relay system profile to facilitate certification and deployment of interoperable relay stations in mobile WiMAX systems. The non-transparent relay stations perform the same functions as a regular base station; however in some usage models, some functionalities of the regular base station may not be implemented in the relay station, resulting in less complexity and lower cost of implementation and deployment. The IEEE 802.1 16m RS MAC CPS is divided into two sub-layers: (1) Radio Resource Control and Management sub-layer; and (2) Medium Access Control sub-layer. The RS RRCM sub-layer includes the following functional blocks that are related to the RS radio resource management functions: Mobility management; Network-entry management; Location management; Security management; 3.2 The IEEE 802. 16m protocol structure Multicast and broadcast service; Relay functions; Self organization; Multi-carrier operation. In Figure 3-16, the mobility management block supports the MS handover operation in cooperation with the BS. The network-entry management block performs RS/MS initialization procedures, as well as the RS network entry/attachment procedure to the BS. The network-entry management block may generate management messages needed during RS/MS initialization procedures and performing the network entry. The location management block supports location-based services including positioning data at the RS and reporting location information to the BS. The security management block performs the key management functions for the RS. Since an IEEE 802.16m relay uses a distributed security model, there are two sets of security protocols on the access and the relay links. The enhanced multicast 