 proper MAC Service Flow Identifiers (SFID) and Connection Identifiers (CID). The convergence sub-layer also includes payload header suppression function to compress the higher-layer protocol headers. Multiple CS specifications are provided for interfacing with various network-layer protocols such as Asynchronous Transfer Mode (ATM) and packet-switched protocols such as IP or Ethernet. The internal format of the CS payload is unique to the CS, and the MAC CPS is not required to understand the format of or parse any information from the CS payload. The MAC CPS provides the core MAC functionality of system access, bandwidth allocation, connection establishment, and connection maintenance. It can receive data from the various conver- gence sub-layers, through the MAC SAP classified into particular MAC connections. An example of MAC CPS service definition is given in reference [3]. The Quality of Service (QoS) is further applied to the transmission and scheduling of data over the physical layer. The MAC also contains a separate security sub-layer providing authentication, secure key exchange, and encryption. The user data, physical layer control, and statistics are transferred between the MAC CPS and the Physical Layer (PHY) via the PHY SAP which is implementation-specific. The IEEE 802.16 physical layer protocols include multiple specifications, defined through several amendments and revisions, each appropriate for a particular frequency range and application. The IEEE 802.16 compliant devices include mobile stations or base stations. Given that the IEEE 802.16 devices may be part of a larger network, and therefore would require interfacing with entities for management and control purposes, a Network Control and Management System (NCMS) abstraction has been introduced in the IEEE 802.16 standard as a "black box" containing these entities [3]. The NCMS abstraction allows the physical and MAC layers specified in the IEEE 802.16 standard to be independent of the network architecture, the transport network, and the prot