Abstract:
Call admission control (CAC) plays a very important role in Heterogeneous
Wireless Networks (HetNet), as it is one of the basic mechanisms for
ensuring the quality of service (QoS) offered to the user. Based on the
available network resources, it estimates the impact of accepting or blocking
a new session request.
The aim of this thesis it to evaluate the performance and functionality of
CAC algorithms with respect to the QoS parameters; this was done through
a system-level MATLAB simulation.
This thesis gives a design of three Call Admission Control CAC algorithms
suitable for future 4G HetNets: Fixed Independent CAC (FICAC), Fixed
Joint CAC FICAC and Adaptive Joint CAC (AJCAC).
Two bandwidth allocation policies; “On-demand Partitioning” and
“Complete Partitioning” are applied on the two JCACs (FJCAC and
AJCAC); their results are compared to the FICAC where no partitioning is
applied to evaluate the effeteness of bandwidth allocation policies.
Then the bandwidth adaptation of the AJCAC algorithm is simulated and
analyzed as a solution for congestion; where the AJCAC algorithm degrades
the bandwidth of some ongoing users to make room for new incoming ones.
A restoration process must take place when the network is underutilized;
where the algorithm restores the maximum bandwidth service to the
degraded users. These two concepts are analyzed and evaluated in this
thesis. The variation of QoS degradation -bandwidth degradation- during the
adaption process was also discussed and evaluated.
