Research on Stop-Adjustable Control Mechanism for Classified Secondary User Packets

In cognitive radio network, considering that secondary user (SU) packets waiting in the cache will stop waiting and exit the system because of impatience, a dynamic stop-adjustable control mechanism is proposed in a single-channel network environment where impatient SU packets leave the system in advance. The SU packets in the cache are divided into retry SU packets and newly arrived SU packets, assuming that only the newly arrived SU packets can stop and leave the system because of impatience. A discrete-time queueing model is established, a three-dimensional Markov chain is constructed, and SU packets’ performance indicators are derived. Numerical experiments are carried out to verify the validity of the presented stop-adjustable control strategy. By comparing with the stopadjustable control mechanism for unclassified SU packets, it is found that the proposed stop-adjustable control mechanism for classified SU packets can effectively improve SU packets’ performance.