  The Next Generation Wireless Networks (NGWN) will be heterogeneous in nature
where the different Radio Access Technologies (RATs) operate together .The
mobile terminals operating in this heterogeneous environment will have
different QoS requirements to be handled by the system. These QoS requirements
are determined by a set of QoS parameters. The radio resource management is one
of the key challenges in NGWN. Call admission control is one of the radio
resource management technique plays instrumental role in ensure the desired QoS
to the users working on different applications which have diversified QoS
requirements from the wireless networks . The call blocking probability is one
such QoS parameter for the wireless network. For better QoS it is desirable to
reduce the call blocking probability. In this customary scenario it is highly
desirable to obtain analytic Performance model. In this paper we propose a
higher order Markov chain based performance model for call admission control in
a heterogeneous wireless network environment. In the proposed algorithm we have
considered three classes of traffic having different QoS requirements and we
have considered the heterogeneous network environment which includes the RATs
that can effectively handle applications like voice calls, Web browsing and
file transfer applications which are with varied QoS parameters. The paper
presents the call blocking probabilities for all the three types of traffic
both for fixed and varied traffic scenario.
