Patent ID: 7047000

Claim:
A method of identifying errors in a data frame transmitted via a cellular network from a first mobile station to a second mobile station different from the first mobile station, comprising the first mobile station performing the steps of: generating an uplink error check code for a data frame for uplink transmission; and transmitting the data frame and its associated uplink error check code to the network; the network performing the steps of: determining the quality of the received data frame; generating a downlink error check code for the received data frame, if the received frame quality is good, on the basis of the received data frame, and if the received frame quality is bad, on the basis of a function of the received data and a parameter indicative of the quality of the received data frame; and transmitting the data frame and the associated downlink error check code to the second mobile station; the second mobile station performing the steps of: decoding the received data frame and the associated downlink error check code; and determining if the received data frame and the associated downlink error check code represent a good quality data frame.