yer protocols. There are two types of connections specified in IEEE 802.16m; control connections and transport connections. Control connections are used to carry MAC control messages. Transport connections are used to carry user data including upper layer signaling messages such as DHCP, etc., as well as data- plane signaling such as ARQ feedback. A MAC control message is never transferred over a transport connection, and user traffic (except short message service using ranging request and response messages) is never transferred over a control connection. One pair of bi-directional (DL/UL) unicast control connections are automatically established when an MS performs initial network entry where a unicast or broadcast control FID value is appropriately selected and assigned to the connection. Once the TSTID is allocated to the MS, the control connections are established automatically. The FIDs for the control connections are never changed during handover or network re-entry. 4.1.3 Connected State As shown in Figure 4-5, the mobile station in the Connected State operates in one of the three modes: Sleep; Active; or Scanning Mode. During the Connected State, the MS maintains two connections that were established during Access State (i.e., a control connection for management messages and a transport connection for data transmission). The MS and the BS may establish additional transport connections. The MS may remain in the Connected State during handover process (i.e., exchanging data/control with the serving BS while signaling with the target BS). The BS can ask the MS to transition from the Connected State to the Idle State after deregistration. The Idle State initiation may begin only after MS deregistration. Failure to maintain the connections at any time prompts the MS to transition to the Initialization State. The MS, RS, and BS are identified by a globally unique 48-bit IEEE Extended Unique Identifier (EUI-48TM) based on the 24-bit Organizationally Unique Identifier (OUI) value administered by the IEEE Registra