Data transmission method and apparatus in RFID and remote sensor systems

A non-transitory computer-readable medium comprising logic that when executed is operable to perform operations comprising:

• receiving, within an electromagnetic field of a reader, a transmission from the reader;
• transmitting to the reader in response to receiving the transmission from the reader a return link comprising a return link header, the return link header containing transmission parameters comprising plurality of subsymbols each having an associated time duration;
• and
• modifying the associated time duration of a first subsymbol of the plurality of subsymbols to select a data transfer mode for transmitting data to the reader, the selected data transfer mode being determined based on a comparison of the associated time duration of the first symbol with an associated time duration of a second subsymbol of the plurality of subsymbols.

An apparatus comprising:

• a transponder comprising an antenna;
• and
• a non-transitory computer-readable medium comprising logic that when executed is operable to perform operations comprising:
• receiving, within an electromagnetic field of a reader, a transmission from the reader;
• transmitting to the reader in response to receiving the transmission from the reader a return link comprising a return link header, the return link header containing transmission parameters comprising plurality of subsymbols each having an associated time duration;
• and
• modifying the associated time duration of a first subsymbol of the plurality of subsymbols to select a data transfer mode for transmitting data to the reader, the selected data transfer mode being determined based on a comparison of the associated time duration of the first symbol with an associated time duration of a second subsymbol of the plurality of subsymbols.