Patent ID: 8009596

Claim:
A data transmitting apparatus comprising: a first encoding unit that encodes a packet to be transmitted based on a first error-correcting method and generates an encoded packet in a media access control layer; an interleaving unit that interleaves the encoded packet; a dividing unit that divides the encoded packet output from the interleaving unit and generates a plurality of divided data; an identification-information generating unit that generates identification information unique to one of the divided data; a computing unit that computes data for error detection in the identification information; a second encoding unit that encodes, in a physical layer, the identification information and the data for error detection based on a second error-correcting method using a lower coding rate than a coding rate for the first error-correcting method, performed in the media access control layer, and generates an encoded block header; a block generating unit that adds the encoded block header to the one of the divided data and generates a block; a transmission-data storing unit that stores the block; a carrier sensing unit that performs a carrier sense on a plurality of frequency bands which are concurrently used; a transmitting unit that transmits the block using the frequency bands and, when the carrier sensing unit detects an interference wave in one of the frequency bands, stops transmission in the one of the frequency bands; a receiving unit that receives retransmission requesting information for requesting retransmission of the block from a data receiving apparatus, when an error is detected in the block based on the data for error detection; and a retransmission control unit that reads the block from the transmission-data storing unit and instructs the transmitting unit to transmit the block when the receiving unit receives the retransmission requesting information.