Method And Apparatus For Dynamic Spectrum Access

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.

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 - 13 . (canceled)