Data transmission method and data relay method

A data transmission method comprising:

• a step of fragmenting a data sequence obtained as encoded video or audio based on any of a time of the video or audio, a space in the video, quality of the video or audio, and information given by the creator of the video or audio, or a combination thereof;
• and
• a step of executing an error correction encoding process on only a portion of the fragmented data sequence.

A data relay method comprising:

• a step wherein data to which a maximum value for a propagation delay time, which is determined by requirement specifications of an application, has been added are received from a plurality of sending devices;
• and
• a step wherein, of the data from the plurality of sending devices, the data which have the smallest added maximum value for the propagation delay time value is relayed with priority.

A data transmission method in which data are fragmented into packets and transmitted by a sending device, the data transmission method comprising:

• a first step, wherein the sending device again fragments the packets and generates sub-fragmented packets;
• and
• a second step, wherein the sending device generates error correction packets from at least a single sub-fragmented packet and then transmits those packets.

A data transmission device having a sending device that fragments data into packets and transmits those packets, wherein the sending device comprises:

• a refragmenting means for refragmenting packets to generate sub-fragmented packets, and
• an error correction packet creation means for creating error correction packets from at least a single sub-fragmented packet.