METHOD OF INTER-SYSTEM COEXISTENCE AND SPECTRUM SHARING FOR DYNAMIC SPECTRUM ACCESS NETWORKS-ON-DEMAND SPECTRUM CONTENTION

• US 20080089279A1
• Filed: 10/16/2006
• Published: 04/17/2008
• Est. Priority Date: 10/16/2006
• Status: Active Grant

• Current Assignee: STMicroelectronics International N.V. (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Vlantis, George A., Hu, Wendong
• Granted Patent: US 7,869,400 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02

Abstract

This invention relates to cognitive radio based wireless communications of dynamic spectrum access networks, and more particularly to a method of addressing inter-systems (cells) coexistence and spectrum sharing. The described method of spectrum sharing mechanism, called On-Demand Spectrum Contention, integrates Dynamic Frequency Selection and Transmission Power Control with iterative on-demand spectrum contentions and provides fairness, adaptability, and efficiency of spectrum access for dynamic spectrum access systems using active inter-system coordination.

Claims

1. A spectrum sharing method for a DYSPAN system comprising:

performing channel evaluations and channel selections to detect and select spectrum holes;

verifying if non-exclusive sharing of selected channels is feasible;

if non-exclusive sharing of the selected channels is feasible, making a DFS decision and scheduling data transmissions on the selected channels with appropriate TPC settings;

if non-exclusive sharing is unfeasible, performing exclusive sharing of the selected channels;

if the selected spectrum hole is not occupied by a specific type of DYSPAN system, then performing data transmissions without using the selected channels if possible; and

if the selected spectrum hole is occupied by a specific type of DYSPAN system, initiating a spectrum contention process for ownership of the selected channels.

2. The method of claim 1 wherein non-exclusive sharing of a selected channel comprises sharing the selected channel through transmission power control (TPC) such that DYSPAN systems sharing the same channel do not cause harmful interference to one another.

3. The method of claim 1 wherein the spectrum contention process comprises a contention request function in which a requesting system generates and transmits contention requests containing contention tokens that are received by a responding system.

4. The method of claim 1 wherein the spectrum contention process comprises a contention resolution function in which spectrum contentions are resolved in a responding system by comparing the contention tokens generated by the contending systems.

5. The method of claim 1 wherein the spectrum contention process comprises a contention response function in which a responding system transmits the contention result to the requesting system.

6. The method of claim 1 wherein, if the contention process succeeds, making a DFS decision and scheduling data transmissions on the selected channels starting from a time agreed upon by both contending systems.

7. The method of claim 1 wherein DFS announcing and DFH/CA take place before data transmissions are performed on acquired channels.

8. The method of claim 1 wherein, if the contention fails, performing data transmissions without using the selected channels if possible.

9. The method of claim 1 wherein, if the contention fails, a DYSPAN system occupying the selected channel releases the channel after a defined grace period agreed upon by both contending systems.

10. The method of claim 1 wherein internal demands and external demands initiate iterations of the spectrum sharing process of a DYSPAN system that is operating in the data transmissions state.

11. The method of claim 1 further comprising an internal demand generated by the system itself.

12. The method of claim 1 wherein the internal demand is generated when the service workload exceeds the channel capacity.

13. The method of claim 1 wherein an internal demand is generated and initiates an iteration of the spectrum sharing process to acquire more channel resources in order to satisfying the Quality of Services requirements of the service workload of the systems.

14. The method of claim 1 further comprising an external demand received from another DYSPAN system.

15. The method of claim 14 wherein, when the external demand is received, the DYSPAN system initiates a spectrum contention iteration.

16. The method of claim 1 wherein channel evaluation and selection include RF sensing, measurement evaluations, measurement reporting, report processing and frequency selection.

17. The method of claim 1 wherein a non-exclusive spectrum sharing method is feasible as long as a maximum achievable signal-to-interference-ratio (SIR) on the selected channel is higher than a required SIR of the DYSPAN system.

18. The method of claim 1 wherein DFS announcing and DFH/CA take place before data transmissions are performed on the selected channels.

19. The method of claim 1 further comprising intersystem communications allowing the simultaneous coexistence communications and data transmissions.

20. The method of claim 1 wherein, for losing the spectrum contention, the DYSPAN system provides a contention response message including the time at which the occupied channel will be released.

21. The method of claim 20 wherein data transmissions are continued up to a maximum grace period before the channel is released.

22. The method of claim 1 wherein, after winning a channel from the coexisting systems, a DYSPAN system announces a DFS decision with respect to using the winning channel and schedules data transmission services on the winning channel starting from a time that is a summary of the channel release times received from the coexisting systems.

23. The method of claim 1 wherein, after losing a channel, a DYSPAN system performs another iteration of spectrum contention process initiated by internal demands in order to acquire sufficient bandwidth to maintain the quality of service of the on-going data transmission services.

24. The method of claim 1 wherein decision-making of contention resolutions for spectrum sharing are distributed and performed in individual coexisting systems.

25. The method of claim 1 wherein coexisting DYSPAN systems adapt to both internal demands and external demands for inter-system coexistence and radio resource management in real time.

26. The method of claim 1 further comprising an iterative process that is initiated by either internal or external demands adapting to workload and environment conditions.

27. A spectrum sharing method comprising integrating Dynamic Frequency Selection (DFS) and Transmission Power Control (TPC) with spectrum contentions that are initiated on-demand for spectrum access using active inter-system coordination.