In IEEE 802.16-2009, IEEE 802.16j-2009 and IEEE 802.16m, air interfaces are identified for the different elements (BS SS, RS, and MS) by a unique and universal 48-bit MAC address. This address is not used for identifying the MAC data PDU as in other IEEE 802.x technologies; rather, it is used during the initial ranging and authentication process. The standard also defines logical identifiers to facilitate data and control operations in the different operational modes (PMP, MR).
A connection-oriented technology, IEEE 802.16 establishes a logical link between the BS and MS MAC layers that is identified by a 16-bit unidirectional Connection Identifier (CID). The CID is used in the MAC PDU header as a temporary address for the data transmission. Three types of management connections are defined: