Data retransmission method, apparatus, and system

A data retransmission method, comprising:

• obtaining, by a first apparatus, data, wherein the data comprises data slices, the data slice comprises code blocks contained by at least one forward error correction (FEC) codeword, and each of the data slices corresponds to one serial number;
• sending, by the first apparatus, the data to a second apparatus, and storing each of the data slices and the corresponding serial number into a buffer;
• receiving, by the first apparatus, a data retransmission request, wherein the data retransmission request comprises a target serial number;
• and
• sending, by the first apparatus, retransmission data to the second apparatus based on the target serial number.

A communication apparatus, comprising:

• a receiving unit, a processing unit, and a sending unit, wherein
• the receiving unit is configured to receive data, wherein the data comprises data slices, the data slice comprises code blocks contained by at least one forward error correction (FEC) codeword, and each of the data slices corresponds to one serial number;
• the processing unit is configured to check the data;
• and
• the sending unit is configured to send a data retransmission request to a peer communication apparatus if an uncorrectable error occurs in the data, wherein the data retransmission request comprises a target serial number, and the data retransmission request is used to request the peer communication apparatus to send retransmission data to the communication apparatus based on the target serial number.

A communication apparatus, comprising:

• a receiving unit, a processing unit, and a sending unit, wherein
• the processing unit is configured to obtain data, wherein the data comprises data slices, the data slice comprises code blocks contained by at least one forward error correction (FEC) codeword, and each of the data slices corresponds to one serial number;
• the sending unit is configured to send the data to a peer communication apparatus;
• the processing unit is configured to store each of the data slices and the corresponding serial number into a buffer;
• the receiving unit is configured to receive a data retransmission request, wherein the data retransmission request comprises a target serial number;
• and
• the sending unit is configured to send retransmission data to the peer communication apparatus based on the target serial number.