Dynamic Channel Allocation for Class-Based QoS Provisioning and Call Admission in Visible Light Communication

Provisioning of quality of service (QoS) is a key issue in wireless communication systems. Owing to the fact that QoS requirements are not very strict for all traffic types, more calls of higher priority traffic classes can be accommodated by blocking a slightly greater number of calls of lower priority traffic classes. Diverse types of high data rate traffic are supported by existing wireless communication systems, although resources are limited. Hence, priority-based resource allocation can ensure sufficient service quality for calls of important traffic classes. However, the use of fixed guard channels to prioritize any class of calls always reduces channel utilization. Hence, we propose a priority-based dynamic channel reservation scheme for higher priority calls that does not reduce channel utilization significantly. The number of reserved channels for each individual traffic class is calculated using real-time observation of call arrival rates for all traffic. The scheme reduces the call blocking probability for higher priority calls while simultaneously increasing channel utilization. The proposed channel reservation scheme can be efficiently applied for visible light communication (VLC) systems as well as for other wireless communication systems. The proposed Markov Chain model is expected to be very effective for queuing analysis and particularly for implementing a priority-based scheme for any number of traffic classes. We consider VLC as the system model for performance analysis. The numerical results show that the proposed scheme is able to attain a reasonable call blocking probability for higher priority calls, without sacrificing channel utilization.