Patent ID: 6598189
Filing Date: 2003-07-22
Classification: H04L

Abstract:
In a communication system having a transmitting system which transmits a frame to a receiving system, the frame being transmitted at an actual transmission rate which is one of a plurality of possible transmission rates, the receiving system generating an error check value for each possible transmission rate and an error rate value for each possible transmission rate, a method for determining at the receiving system the actual transmission rate comprising the steps of:determining whether exactly two error check values are positive, one error check value having a corresponding first error check rate and the other error check value having a corresponding second error check rate, and if so, the further steps of: determining whether the difference between the first error rate value and the second error rate value is less than a first predetermined threshold; and if the difference between the first error rate value and the second error rate value is less than the first predetermined threshold, generating a signal to indicate that the actual transmission rate is the possible transmission rate corresponding to the first error rate value, and otherwise, the further steps of: determining whether the difference between the first error rate value and the second error rate value is greater than a second predetermined threshold; and if the difference between the first error rate value and the second error rate value is greater than the second predetermined threshold, generating a signal to indicate that the actual transmission rate is the possible transmission rate corresponding to the second error rate value, and otherwise, the further step of: generating a signal to erase the frame; if other than exactly two of the error check values are positive, determining whether exactly one of the error check values is positive, and if so, the further steps of: for each of the error rate values corresponding to an error check value which is negative, determining whether the difference between the error rate value corresponding to the error rate value which is positive and the error rate value corresponding to the error check value which is negative is less than a predetermined threshold particular to the two possible transmission rates corresponding to the error check value which is positive and the error check value which is negative; and if each difference between the error rate value corresponding to the error check value which is positive and an error rate value corresponding to an error check value which is negative is less than the predetermined threshold particular to the two corresponding rates, generating a signal to indicate that the actual transmission rate was the possible transmission rate corresponding to the error check value which was positive, and otherwise, the further step of: â€ƒgenerating a signal to erase the frame; â€ƒif other than exactly two of the error check values are positive and other than exactly one of the error check values is positive, generating a signal to erase the frame.