Communicating Embedded Systems: Networks Applications

Chapter 4

RFID Technology ¹

4.1. Introduction

Radiofrequency identification (RFID) is now unavoidable. RFID systems allow us to automatically identify products or living things from a distance, without physical contact, and in a very simple way.

In order to be able to identify an item, we have to attach a transponder to it, containing some identification information. Afterwards, it is enough to read this from a distance with an RFID reader to obtain the identification information [FIN 03], with the possible requirement of a centralized database.

4.2. Automatic identification systems

4.2.1. Barcodes

Since the 1980s, barcode systems have been the most commonly used automatic identification systems. According to [VIR 92], at the start of the 1990s the total volume of barcode systems in Western Europe came to the equivalent of almost one and a half billion Euros.

A barcode is an image designed to be easily read by automated optical systems. This graphical representation is composed of alternating black and white vertical bars of varying widths. A barcode is composed of patterns associated with symbols. A sequence of patterns can be interpreted alphanumerically. Essentially, the alternating vertical bars are scanned by a laser reader and then interpreted into a number [IDE 96]. There are around a dozen different kinds of barcodes, all visually similar.

The European Article Number (EAN) system is very widely used. This was designed in 1976 to meet the specific needs of the food-processing ...