Dynamic wireless link adaptation

Abstract

A system that adapts wireless link parameters for a wireless communication link. A measure is determined of errors occurring in communication over a wireless link. In a case that the measure of errors corresponds to more errors than a first predetermined threshold, communication changes from a first set of wireless link parameters to a second set of wireless link parameters. The second set of wireless link parameters corresponds to higher error tolerance than the first set of wireless link parameters. In a case that the measure of errors corresponds to fewer errors than a second predetermined threshold, communication changes from the first set of wireless link parameters to a third set of wireless link parameters. The third set of wireless link parameters corresponds to lower error tolerance than the first set of wireless link parameters. Preferably, the measure of errors is determined by monitoring a number of NACK messages and a number of ACK messages that occur. It is determined that the measure of errors corresponds to more errors than the first predetermined threshold when more than a predetermined number of NACK messages occur in succession. It is determined that the measure of errors corresponds to fewer errors than the second predetermined threshold when more than a predetermined number of ACK messages occur in succession.

What is claimed is: 
     
       1. A method of dynamically adapting wireless link parameters for a wireless link, comprising:
 determining a plurality of states, each state corresponding to a plurality set of wireless link parameters; 
 determining a plurality of thresholds for transitioning from a current state to a next state of between said plurality of states, said thresholds comprising a number of being determined based on a measure of error rate; 
 monitoring the error rate using a count of NACK messages or a number of and ACK messages received using said set of wireless link parameters for said a current state; and 
 transitioning among said plurality of states from the current state to a next state based on said thresholds, thereby dynamically adapting said wireless link parameters for a wireless link. 
 
     
     
       2. A method as in according to  claim 1 , wherein said set of wireless link parameters comprise comprises a modulation scheme, a symbol rate, and an error correction scheme. 
     
     
       3. A method as in according to  claim 1 , wherein each of said plurality of states can only transition to and from one or two adjacent states. 
     
     
       4. A method as in according to  claim 1 , wherein said set of wireless link parameters corresponding to said plurality of states are stored in a memory. 
     
     
       5. An apparatus that dynamically adapts wireless link parameters for a wireless link, comprising:
 a wireless link interface to a the wireless link; 
 a processor; and 
 a memory storing instructions executable by the processor to control communication over the wireless link interface, the instructions including the steps of:
 determining a plurality of states, each state corresponding to a plurality set of wireless link parameters; 
 determining a plurality of thresholds for transitioning from a current state to a next state of between said plurality of states, said thresholds comprising a number being determined based on a measure of error rate; 
 monitoring the error rate using a count of NACK messages or a number of and ACK messages received using said set of wireless link parameters for said a current state; and 
 transitioning among said plurality of states from the current state to a next state based on said thresholds, thereby dynamically adapting said wireless link parameters for the wireless link. 
 
 
     
     
       6. A method of dynamically adapting wireless link parameters, comprising:
 determining a plurality of states, each state corresponding to a set of wireless link parameters;   determining a plurality of thresholds for transitioning between said plurality of states, said thresholds being determined based on a measure of error rate;   monitoring the error rate using a count of NACK messages received using said set of wireless link parameters for a current state; and   transitioning from the current state to a next state based on said thresholds.   
     
     
       7. A method according to claim 6, wherein a threshold is determined by measuring a throughput efficiency versus signal to interference and noise ratio (SINR) for a set of values for the corresponding wireless link parameters. 
     
     
       8. A method according to claim 6, wherein the current state is determined by the highest throughput efficiency for a current measure of error rate. 
     
     
       9. A method of dynamically adapting wireless link parameters, comprising:
 determining a plurality of states, each state corresponding to a set of wireless link parameters;   determining a plurality of thresholds for transitioning between said plurality of states, said thresholds being determined based on a measure of error rate;   monitoring the error rate using a count of ACK messages received using said set of wireless link parameters for a current state; and   transitioning from the current state to a next state based on said thresholds.   
     
     
       10. An apparatus that dynamically adapts wireless link parameters for a wireless link, comprising:
 a wireless link interface to the wireless link;   a processor; and   a memory storing instructions executable by the processor to control communication over the wireless link interface, the instructions including the steps of:
 determining a plurality of states, each state corresponding to a set of wireless link parameters, 
 determining a plurality of thresholds for transitioning between said plurality of states, said thresholds being determined based on a measure of error rate; 
 monitoring the error rate using a count of NACK messages received using said set of wireless link parameters for a current state, and 
 transitioning from the current state to a next state based on said thresholds. 
   
     
     
       11. An apparatus that dynamically adapts wireless link parameters for a wireless link, comprising:
 a wireless link interface to the wireless link;   a processor; and
 a memory storing instructions executable by the processor to control communication over the wireless link interface, the instructions including the steps of: 
 determining a plurality of states, each state corresponding to a set of wireless link parameters, 
 determining a plurality of thresholds for transitioning between said plurality of states, said thresholds being determined bases on a measure of error rate, 
 monitoring the error rate using a count of ACK messages received using said set of wireless link parameters for a current state, and 
 transitioning from the current state to a next state based on said thresholds. 
   
     
     
       12. A method of dynamically adapting wireless link parameters, comprising:
 obtaining a plurality of states, each state corresponding to one or more wireless link parameters;   obtaining one or more thresholds for transitioning between a current state and a next state in the plurality of states, the one or more thresholds comprising a measure of errors occurring over a wireless link using the one or more wireless link parameters for the current state; and   transitioning among the plurality of states based, at least in part, on the one or more thresholds.