BS ISO/IEC 15693-2:2006 pdf download.ldentification cards —-Contactless integrated circuit cards—- Vicinitycards— Part 2: Air interface and initialization.
7.2Data rate and data coding
Data coding shall be implemented using pulse position modulation.
Two data coding modes shall be supported by the ViICC. The selection shall be made by the VCD andindicated to the vICC within the start of frame (SOF),as defined in 7.3.
7.2.1Data coding mode: 1 out of 256
The value of one single byte shall be represented by the position of one pause.The position of the pause on 1of 256 successive time periods of 256/16e (~18,88 us),determines the value of the byte. In this case thetransmission of one byte takes ~4,833 ms and the resulting data rate is 1,66 kbits/s (6/8192).The last byte ofthe frame shall be completely transmitted before the EOF is sent by the vCD.
Figure 3 illustrates this pulse position modulation technique.
