Abstract: In coordinated spectrum access, when the networks sharing the same spectrum have highly varying spectrum requirement, existing mechanisms cannot provide better performance of end-to-end time delay and fairness. To tackle this problem, a coordinated dynamic spectrum allocation mechanism based on combined priority scheduling was proposed. The mechanism models the spectrum allocation as proportional fairness and set dynamic priority to networks by combining the service grade of networks and the arrival time of spectrum requirement. After figuring out the results of the proportional fairness model, the mechanism allocates spectrum according to the results based on the criterion that the center frequency of allocated spectrum is close to the spectrum requirement The simulation results show that the proposed mechanism can provide better fairness of spectrum allocation than existing mechanisms as network(or terminal) static priority, network(or terminal) dynamic priority and request dynamic priority based coordinated dynamic spectrum allocation, and also brings improvement in terms of performance of end-to-end time delay of packet transmislion.

Key words: Dynamic spectrum allocation,Coordinated spectrum access,Scheduling,Dime d}lay,Fairness