Method for contention free traffic detection

Abstract

The invention discloses a method for detecting priority of data frames comprising the steps of extracting (S 1 ) a bit pattern from a predetermined position in a frame, comparing (S 2, S 3 ) said extracted bit pattern with a search pattern, and identifying (S 4 ) said received frame as a priority frame in case said extracted bit pattern (BP) matches with said first search pattern (SP). By this method, the priority of a data frame can easily be detected. The invention also proposes a corresponding device for detecting priority of data frames.

The invention claimed is: 
     
       1. A method comprising
 extracting a bit pattern from a predetermined position in a frame,;  
 comparing said extracted bit pattern with a search pattern,;  
 identifying a received frame as a priority frame in case said extracted bit pattern matches with said search pattern,;  
 forwarding said received frame to a high priority queue in case said frame is detected to be a high priority frame during a special period for sending priority traffic,; and 
 adjusting the duration of the special period for sending priority traffic according statistic information regarding sent priority frames. 
 
     
     
       2. The method according to  claim 1 , further comprising
 counting the total number of priority frames; 
 counting the number of priority frames outside said special period; and 
 deciding whether said special period has to be increased or decreased on the basis of the count values obtained in said counting steps. 
 
     
     
       3. A device comprising
 a receiver configured to receive data frames; 
 an exracter extracter configured to extract a bit pattern from a predetermined position of a data frame; 
 a comparator configured to compare said extracted bit pattern with a predetermined search pattern; and 
 an identifier configured to identify said received frame as a priority frame in case said extracted bit pattern matches with said first search pattern, 
 wherein a controller is configured to forward said received frame to a high priority queue in case said frame is detected to be a high priority frame during a special period for sending priority traffic, and 
 said controller is configured to adjust the duration of the special period for sending priority traffic according to statistical information regarding sent priority frames. 
 
     
     
       4. The device according to  claim 3 , wherein said controller, in order to obtain said statistic information, is configured to access a priority frames counter for counting the total number of priority frames and a counter for counting priority frames outside said special period, said controller configured to decide whether said special period has to be increased or decreased on the basis of the count values obtained in said counting. 
     
     
       5. A device comprising
 means for extracting a bit pattern from a predetermined position in a frame,;  
 means for comparing said extracted bit pattern with a search pattern,;  
 means for identifying a received frame as a priority frame in case said extracted bit pattern matches with said search pattern, and;  
 means for forwarding said received frame to a high priority queue in case said frame is detected to be a high priority frame during a special period for sending priority traffic,; and 
 means for adjusting the duration of the special period for sending priority traffic according statistic information regarding sent priority frames. 
 
     
     
       6. A memory having a program stored thereon for execution in a device by carrying out the method of  claim 1 . 
     
     
       7. A method comprising:
 detecting a received frame is a priority frame based, at least in part, on information in the received frame, including extracting a bit pattern from a predetermined position in the received frame and comparing the extracted bit pattern with a search pattern, and wherein the detecting is based on a match between the extracted bit pattern and the search pattern;   transmitting the received frame in a transmit period reserved for priority frames in response to the detecting; and   adjusting a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames.    
     
     
       8. The method of claim 7, further comprising forwarding the received frame to a priority queue for transmission in the transmit period reserved for priority frames.  
     
     
       9. The method of claim 8, further comprising forwarding the received frame from the priority queue to a normal queue for transmission outside of the transmit period reserved for priority frames in response to an expiration of the transmit period reserved for priority frames.  
     
     
       10. A method comprising:
 detecting a received frame is a priority frame based, at least in part, on information in the received frame;   transmitting the received frame in a transmit period reserved for priority frames in response to the detecting;   adjusting a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames; and   forwarding the received frame to a normal queue for transmission outside of the transmit period reserved for priority frames when the transmit period reserved for priority frames is unavailable.    
     
     
       11. A method comprising:
 detecting a received frame is a priority frame based, at least in part, on information in the received frame;   transmitting the received frame in a transmit period reserved for priority frames in response to the detecting;   adjusting a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames; and   counting a total number of priority frames; and   counting a number of the priority frames transmitted outside of the transmit period reserved for priority frames, wherein the adjusting of the transmit period is based on a ratio of number of the priority frames transmitted outside of the transmit period reserved for priority frames and the total number of priority frames.    
     
     
       12. A method comprising:
 detecting a received frame is a priority frame based, at least in part, on information in the received frame;   transmitting the received frame in a transmit period reserved for priority frames in response to the detecting;   adjusting a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames,   wherein the statistic information regarding sent priority frames is based on a percentage of priority frames transmitted outside of the transmit period reserved for priority frames to a total number of priority frames transmitted.    
     
     
       13. A device comprising:
 a controller to detect a received frame is a priority frame based, at least in part, on information in the received frame; and   a priority queue configured to transmit the received frame in a transmit period reserved for priority frames, wherein the controller is configured to adjust a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames,   wherein the controller is configured to extract a bit pattern from a predetermined position in the received frame, to compare the extracted bit pattern with a search pattern, and to detect a received frame is a priority frame based, at least in part, on a match between the extracted bit pattern and the search pattern.    
     
     
       14. The device of claim 13, wherein the controller is configured to forward the received frame to the priority queue for transmission in the transmit period reserved for priority frames.  
     
     
       15. The device of claim 13, further comprising a normal queue configured to transmit the received frame outside of the transmit period reserved for priority frames.  
     
     
       16. The device of claim 15, wherein the controller is configured to transfer the received frame from the priority queue to the normal queue in response to an expiration of the transmit period reserved for priority frames.  
     
     
       17. A device comprising:
 a controller to detect a received frame is a priority frame based, at least in part, on information in the received frame; and   a priority queue configured to transmit the received frame in a transmit period reserved for priority frames, wherein the controller is configured to adjust a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames,   wherein the controller is configured to count a total number of priority frames, to count a number of the priority frames transmitted outside of the transmit period reserved for priority frames, and to adjust the transmit period reserved for priority frames based on a ratio of number of the priority frames transmitted outside of the transmit period reserved for priority frames and the total number of priority frames.    
     
     
       18. A device comprising:
 a controller to detect a received frame is a priority frame based, at least in part, on information in the received frame; and   a priority queue configured to transmit the received frame in a transmit period reserved for priority frames, wherein the controller is configured to adjust a duration of the transmit period reserved for priority frames based on statistic information regarding sent priority frames,   wherein the statistic information regarding sent priority frames is based on a percentage of priority frames transmitted outside of the transmit period reserved for priority frames to a total number of priority frames transmitted.