Wednesday, December 05, 2007

Detail in Class 1 and Implement Gen2

Passive Tag Transmission in Class 1:
5.2. Reader-Tag Half-Duplex Communication
As specified in Section 6, the Reader-to-Tag and Tag-to-Reader communication occurs in a half-duplex manner. The Reader initiates communication by modulating a complete command. The Reader then transmits an unmodulated continuous wave (CW) signal. The Tag modulates its reflection of the CW signal (backscatter communication).
5.3. Reader-to-Tag Communication Signals
A Reader may emit no signals at any frequency, may emit a CW signal at a single frequency, or may emit a modulated signal at a single frequency.
5.3.1. Reader-to-Tag Signal Modulation Depth
The Reader communicates with tags using Amplitude Shift Keying (ASK) with a minimum modulation depth of 30% and a maximum modulation depth of 100%. Modulation shape, depth and rate of modulation are variable within the limits described below. Compliant Tags will adjust their timing over a range of modulation rates to lock to reader transmissions automatically during the [CLKSYNC] period of a Reader command.

Have read Class 1 Gen2 specification, draft the pesudo-code framework using Java. Thinking about a whether a discrete simulation is necessary, and the means of performance measurement.

In implement simulation of Gen2, a simplification is made in message transmission, like ACK and Session selection etc., which have no influence in the anti-collision measurement so far.

Session selection deals with Reader-to-Reader collision.
ACK is reliable transmission and for further processing in tag.

No comments: