A method for transmitting packet data with hybrid FEC/ARQ type II

摘要

1. The invention relates to a method for transmitting packet data in an air interface of digital cellular radio telephone system based on a hybrid forward error correction/automatic repeat request, i.e. FEC/ARQ type II. comprising the following steps for each packet: a) encoding the bits of the packet of user data, header and frame check sequence, using error correcting codes and storing the resulting bits for transmission at the sender side; b) transmitting of a predefined part of the encoded bits that is bigger than the original packet; c) collecting and storing all received data at the receiver side with a storage capacity big enough to store at least the encoded bits of one packet; d) deciding on transmission success at the receiver side, based on the stored data and sending a positive acknowledge (ACK) if the transmission has been decided to be successful and a negative acknowledgement (NAK) if not; e) checking at the sender side of the positive or negative acknowledgement (ACK or NAK) and going to step b) in case of negative acknowledge (NAK) otherwise in case of positive acknowledgement (ACK) the transmitting of the packet is being completed and the receiver storage is cleared. With this method optimum throughput in response to a fluctuation in the error rate on a packet radio channel is procided.