In this section, we further examine the functional elements
of each protocol layer and their interactions. The 802.16m MAC common
part sub-layer functions are classified into radio resource control
and management functional group and medium access control functional group.
The control-plane functions and data-plane functions are also
separately classified. This would allow more organized, efficient, and
structured method for specifying the MAC services in the IEEE
802.16m standard specification. The radio resource control
and management functional group comprises several functional blocks
including:
• Radio resource management block adjusts radio network
parameters related to the traffic load, and also includes the functions of
load control (load balancing), admission control, and
interference control;
• Mobility management block scans neighbor BSs and
decides whether MS should perform handover operation;
• Network-entry management block controls initialization
and access procedures and generates management messages during
initialization and access procedures;
• Location management block supports location based
service (LBS), generates messages including the LBS information, and
manages location update operation during idle mode;
• Idle mode management block controls idle mode operation,
and generates the paging advertisement message based on paging message
from paging controller in the core network;
• Security management block performs key management
for secure communication. Using managed key, traffic encryption/decryption
and authentication are performed;
• System configuration management block manages system
configuration parameters, and generates broadcast control messages such as
superframe headers;
• Multicast and broadcast service (MBS) block controls
and generates management messages and data associated with MBS;
• Service flow and connection management block allocates
Station Identifier (STID) and Flow Identifiers (FIDs) during
access/handover service flow creation procedures.