RFID Introduction

What is RFID?

Radio Frequency Identification (RFID) is a wireless technology that allows identifying objects with RFID tags attached. RFID works in the UHF band, the exactly allowed band is country or region dependent.

• • EU (ETSI): from 865.5 MHz - 867.5 MHz

  • US (FCC): from 902 MHz - 928 MHz

Almost any RFID equipment in use supports EPCGen2v1.2. EPCGen2v2 is the forthcoming updated standard. Standards can be downloaded from here

http://www.gs1.org/epcrfid/epc-rfid-uhf-air-interface-protocol/2-0-1

RFID technology is similar to bar code technology, as both are mainly used for identification purposes.

While bar code technologies use a barcode printed on a label, in RFID the identifier or TagID is stored inside the tag, and this information can be read and re-written with the help of RFID readers.

RFID has many advantages:

• • RFID can work up to item level: every product can be uniquely identified by the information stored in the tags attached to the products.

  • RFID is a wireless technology: multiple tags can be read simultaneously, at different distances and without requiring line of sight to the antennas.

EPC

The EPC, sometimes referred as TagID, is the information written in the RFID tags. It has commonly 96 bits length but can grow up to 512 bits or more.

(The length of the TagID depends on the chip embedded in RFID tags)

The TagID data is usually presented in hexadecimal format

0x303640ed875b086868ad3f8a

or

303640ed875b086868ad3f8ah

The TagID is commonly referred as EPC (Electronic Product Code), although the contents of the TagID might be anything.

GS1 EPC is a universal identifier that gives a unique identity to a RFID tag. The EPC is divided into the following parts:

RFID Reader

RFID readers implement the EPCGen2 standard in order the inventory and act on tags.

RFID reader generates the UHF signal that is radiated by the connected antennas. Besides transmitting, a reader also listens for a response from the tag.

Keonn Readers (AdvanReader-150/160 and AdvanReader-60/70) have a Linux board computer inside which allows the reader to work autonomously without the need of a computer. It has a Web Interface that allows a user to configure and test the reader without any technical knowledge. Also, it can export the reads into CSV files or SQL databases automatically, or even to the cloud (AdvanCloud).

RFID Tags

RFID tags are usually passive components that use the received energy to wake up and backscatter energy back to RFID readers.

Also, battery-assisted RFID tags exist. A small battery provides additional power to the tag, thus increasing the read range.

A passive RFID tag is made up of a chip and antenna:

• • Chip: Is a tiny micro-controller that runs parts of the EPCGen2 standard. It contains a tiny flash memory which is broken down in memory banks:

    • RESERVED: stores the access and kill password

    • EPC: stores some control information plus the TagID data

    • USER: if exists, can be used to store whatever value

    • TID: read-only memory with manufacturer information

  • Antenna: Enables the chip to receive power and communicate from and to the reader.

EAN13

The International Article Number (EAN) (also known as European Article Number) is a 13-digit barcode symbology.

The EAN code is composed of the company prefix, the skuid, and the cyclic redundancy check (CRC) digit:

• • Company Prefix: A GS1 Company Prefix is the foundation for identifying products, locations, and more. It is a globally unique number licensed by GS1 US for your company's use only (GS1 prefix list).

  • skuid: A stock-keeping unit or SKU refers to a specific item stored to a specific location.

  • CRC: To compute this digit, go to the gs1 digit calculator: http://www.gs1.org/check-digit-calculator.

EAN to EPC - Using SGTIN

Go to the GS1 web site EPC tool and do as the following example:

Keonn Systems

There is a Plug&Play set of Keonn Systems developed for different shop processes:

• • Encoding Systems: systems that encode tags, write an EPC inside a tag.

  • Automatic Inventory: systems that are designed to make automatic inventories of tagged items in a warehouse or in a store.

  • Interactive Systems: systems that combine RFID technology with touch-screens to enhance customer shopping experience and increase sales of retailers.

  • Payment Systems: systems with a confined reading area that replace the traditional bar code based POS by combining tag detachment and EAN-13 code extraction.

  • Loss Prevention Systems: systems that replace traditional EAS systems. They can be overhead, pedestals or mat based.

Real-world limitations

RF waves can be interfered by materials and/or conditions:

• • Large metallic piece close to a Keonn System will certainly cause a nonpredictable deformation of the beam shape. A possible consequence will be to have read of tags out of the "normal" range.

  • Other RFID systems working very close between each other may produce uncontrolled effects: reduce system performance or in some cases increase the read range.

  • Material to be tagged may detune RFID tags and therefore decrease the overall system sensitivity. Some of the well-known RFID detuning products are:

    • Metal

    • Products containing water or liquids

  • The human body may block RFID beams/waves in a way that it can be difficult or not possible to read the RFID tag.