A Call Admission Control Algorithm CACA for Providing Guaranteed QoS in Cellular Networks

Future broadband wireless access systems plan to inte grate various classes of MTs Mobile Terminals each class with a di erent type of quality of service QoS requirement When the load on a wireless network is high the guarantee of QoS for each class of MTs is a challenging task This study considers two classes of MT pro led MTs and non pro led or regular MTs It is assumed that pro led users require a guaranteed QoS The measure of QoS is the probability of forced termination of a call that was allowed to access the network Two previous hando prioritization schemes i pre request scheme and ii guard channel scheme decrease hando failure and hence forced termination In this work we compare and contrast both the schemes through exten sive simulation it is found that neither method can guar antee a desired level of QoS for the pro led MTs We then propose a novel Call Admission Control Algorithm CACA that can maintain any desired level of QoS while successful call completion rate is very high In the proposed algorithm the new call arrival rate is estimated continuously and when the estimated arrival rate is higher than a predetermined level some new calls are blocked irrespective of the avail ability of channels The objective of this pre blocking of calls is to maintain the wireless network system s observed new call arrival rate at no more than a predetermined rate We show that the proposed method can guarantee any desired level of QoS for pro led users