METHOD AND APPARATUS FOR DYNAMIC SPECTRUM ACCESS

• US 20100135226A1
• Filed: 10/09/2009
• Published: 06/03/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: The Trustees of The Stevens Institute of Technology (Stevens Institute Of Technology)
• Original Assignee: The Trustees of The Stevens Institute of Technology (Stevens Institute Of Technology)
• Inventors: Hong, Kai, Chandramouli, Rajarathnam, Sengupta, Shamik
• Granted Patent: US 8,699,430 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04L 49/252 Store and forward routing
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off

Abstract

Methods and apparatus are provided for the efficient use of cognitive radios in the performance of dynamic spectrum access. This includes spectrum sensing algorithms, adaptive optimized sensing of parameters based on changing radio environments, and identifying vacant channels. Protocols for switching communication links to different channels, and synchronizing communicating nodes in order to maintain reliable connectively while maximizing spectrum usage are also provided.

Claims

1. A method for facilitating communication between first and second communication devices, comprising the steps of:

establishing a first communication link between the first and second communication devices through a first data channel;

monitoring a plurality of second channels to determine whether they are used by incumbent users;

sending a management frame from the first communication device to the second communication device through the first data channel, the management frame including a list of the second channels, the list indicating a set of the second channels available for switching communication thereto;

establishing a second communication link between the first and second communication devices through one of the set of the second channels.

2. The method of claim 1, wherein the management frame includes a bitmap, the list of the data channels being included in the bitmap.

3. The method of claim 2, wherein the channel bitmap includes a bitmap vector, the list of the second channels being included in the bitmap vector, the bitmap vector including an indication for each of the second channels whether it is available for switching communication thereto.

4. The method of claim 1, further comprising the step of receiving a response message at the first communication device from the second communication, said response message including a selection made by the second communication device on the set of the second channels.

5. The method of claim 4, further comprising the step of sending an acknowledgement message from the first communication device to the second communication device confirming the selection made by the second communication device.

6. A method for facilitating communication between first and second communication devices, comprising the steps of:

establishing a first communication link between the first and second communication devices through a first channel;

initiating a channel switching operation upon detecting a channel switching event associated with the first channel, said initiating step including the step of directing data transmitted from an upper layer of a communication protocol of the first communication device to a buffer for storage therein;

completing the channel switching operation by establishing a second communication link between the first and second communication devices through a second channel; and

transmitting the data stored in the buffer to the second communication device upon completing the completing step.

7. The method of claim 6, wherein said directing step is performed continuously from the initiation of said initiating step until the completion of said completion step.

8. The method of claim 7, wherein said directing step includes the step of creating the buffer in a MAC layer of the first communication device.

9. The method of claim 7, wherein the data stored in the buffer is transmitted to the second communication device through the second channel.

10. A method for facilitating communication between first and second communication devices, comprising the steps of:

establishing a first communication link between the first and second communication devices through a first channel;

determining an in-band threshold dynamically based on a first set of parameters detected in the first channel;

determining a channel quality of the first channel dynamically based on a second set of parameters detected in the first channel; and

establishing a second communication link between the first and second communication devices through a second channel if the channel quality of the first channel at a given time exceeds the threshold.

11. The method of claim 10, wherein said step of determining the in-band threshold includes detecting the first set of parameters;

and calculating the threshold based on the detected set of parameters, said detecting step and said calculating step are performed repeatedly on a predetermined time cycle.

12. The method of claim 10, further comprising the steps of:

determining an out-band threshold dynamically based on a third set of parameters detected in the second channel;

determining a channel quality of the second channel based a fourth of a set of parameters detected therein;

determining whether the second channel can be used for establishing the second communication link by comparing the out-band threshold of the second channel to the channel quality of the second channel.

13. The method of claim 10, wherein said determining step includes the steps of collecting experimental data relating to channel parameters and building a mathematical model based on the experimental data to optimize the threshold.