New Bandwidth Upgradation and Degradation Algorithms for Next Generation of Wireless Network Systems

With the increase of the usage of multimedia applications, the next generation of wireless networks need to satisfy the quality of the transmitted application even if the network is characterized by limited radio resources such as bandwidth (that it is not less than that required by all the traffic sessions). Many call admission control (CAC) and bandwidth degradation algorithms for real time transmissions were proposed. However, CAC algorithms may consume intensive processing time that can provoke delay constraint violation for new calls and handover calls, in particular when it deals with real-time transmission. All this could cause the degradation of the quality of service (QoS) requirements. To overcome this problem, our proposed algorithm aims to minimize the risk of delay violation by facilitating the triggering of the CAC algorithms. The objective is to adapt the available bandwidth of the wireless resources to be ready to admit any new session without degrading the QoS of already existing sessions. A bandwidth level degradation algorithm is presented to reduce the bandwidth of some active sessions in the cell in order to accommodate the arrived calls. Moreover, an upgrading bandwidth algorithm is also presented when a call is finished or passed to another cell to increase the bandwidth of residual calls having a risk of QoS degradation. New call blocking probability, handover call dropping probability and bandwidth utilization were used to evaluate the performance of our algorithm. Simulation results show that the proposed algorithm is efficient and it is advantageous to use it for a better management of radio resources. The blocking probability for new calls is about 10% which is significantly lower than of others studied algorithms and about 15% is shown for handover dropping ratio. Those result respond to the QoS requirements although 100% of bandwidth utilization.