QoS based opportunistic channel scheduling in cognitive radio networks

Opportunistic channel scheduling in cognitive radio networks allocate resources to cognitive users by exploiting the spectral activities of primary users. In cognitive radio networks, secondary users are regulated to use channel when it is not used by primary users. Secondary users need co-ordination in order to utilize channel effectively, but there are not exists standard regulation how to co-ordinate the channel access among secondary users. In this paper, we consider an approach that co-ordinate channel access among secondary users along with primary users. We propose a channel access scheduling scheme that assigns priorities values to users based on their maximum tolerable delay. This paper focuses on the real-time message scheduling in cognitive radio networks that maximizes the packet transmissions before they exceed their deadline (delay tolerance). In order to guarantee that the transmitted messages will not exceed their deadlines, dynamic priority queue scheduling mechanism has been considered. Through experimental results we show that the packets those are not able to meet their deadline have been reduced by using proposed dynamic scheduling as compared to static priority queue scheduling.