Tag-to-reader protocol

XRAG2

18/33

Figure 12.

FM0 answer preamble with pilot tone (TRext=1).

1.

V = violation.

6.1.3

Tag-to-reader FM0 end of signaling

As specified in the EPCglobal Class 1 generation 2 RFID UHF specification, revision 1.0.9,

the tag ends transmissions with a dummy ‘1’. Figure 13 shows the different possibilities

occurring during communications.

Figure 13.

Tag-to-reader FM0 end of signaling

6.1.4

Tag-to-reader FM0 data rate

The Tag provides all FM0 backscattering modulation data rate specified in the EPCglobal

Class 1 generation 2 RFID UHF specification, revision 1.0.9:

40 Kbps

≤ LF ≤ 640 Kbps

6.1.5

Tag-to-reader Miller-modulated subcarrier encoding

The tag provides tag-to-reader Miller subcarrier modulation as specified in EPCglobal Class

1 generation 2 RFID UHF specification, revision 1.0.9.

The tag-to-reader Miller subcarrier modulation is chosen by the reader by setting the

Subcarrier Number parameter (M) to 2, 4 or 8 during the Query command starting the

inventory round. Figure 14 shows Miller subcarrier modulation sequence examples for M=2,

M=4 and M=8.

1

ai12316

010

1

0

0

0

0

12 leading zeroes (pilot tone)

0

dummy 1

1

dummy 1

0

dummy 1

1

dummy 1

ai12317