vice flows may be provisioned when an MS enters into the system. Following MS registration with the serving BS, transport connections are established and associated with the service flows (one connection per service flow) to provide a reference for requesting band- width. Furthermore, new transport connections may be established when a user's service needs to change. A transport connection defines both the mapping between peer convergence sub-layers that 6.1 Addressing utilize the MAC and a service flow. The service flow defines the QoS parameters for the PDUs that are exchanged on the connection. The concept of service flow mapping to a transport connection is essential to the operation of the MAC CPS protocols. Service flows provide a mechanism for UL and DL QoS management. In particular, they are an integral part of the bandwidth allocation process. An MS requests UL bandwidth per connection basis by implicitly identifying the service flow. The bandwidth is granted by the serving BS to an MS as an aggregate of grants in response to per-connection requests from the MS. Transport connections, once established, may require active maintenance with requirements which may vary depending on the type of service. In the following sections, the IEEE 802.16m MAC CPS functions are classified and described according to their location on the control-plane using a systematic approach. Some of the service control functions, such as E-MBS and location-based services, as well as some advanced features such as multi-carrier operation, relay, self-organizing networks, and security aspects will be described in separate chapters. 6.1 ADDRESSING A 48-bit universal MAC address, as defined in IEEE 802 standard [3], uniquely defines mobile terminals over the air interface. It is used during the legacy initial ranging process to establish the appropriate connections for an MS. It is also used as part of the legacy authentication process by which the BS and MS each verify the identity of each other. In IEEE 802.16-2009 standard, connecti