About RFID :
RFID is an auto identification technology which is used for tracking items with a tag on it which sends data to readers through radio waves. These tags makes the item to speak about its identity, activity, location and data stored inside through readers and finally to the application software to make the information useful.
Components of RFID System:
Tags:
The tag is made up of a microchip with the unique identification number and the antenna to be able to transmit this data to the reader wirelessly. RFID tags have high data capacity and can include manufacturer, batch no., ownership, destination, history etc. depending on the application needs. The amount of storage available on the tag ranges from 16 bits to as high as several thousand bits. There are three types of encoding available in tags i.e. Read only, write once, and re-writable tags.
Active and Passive tags
Passive tags are battery less and transmit data only when energized by the reader. Active tags are able to transmit data using their own battery power. Read ranges are more for active tags than for passive tags but are costlier for their extra capability. Therefore active tags are used for high value items and for longer reading distance.
Structure of EPC Complaint Tag
| Electronic Product Code Type I |
| 01 |
0000A89 |
00016F |
000169DC0 |
| Header
8 bits |
EPC Manager
28 – bits |
Object Class
24 – bits |
Serial Number
36 – bits |
Readers:
The RFID Reader, which is also widely known as interrogator, sends RF signal to request tag for transmitting information within the chip. The response received from the tag is then translated in to digital form and send to the application software. Different types of readers are fixed readers, handheld readers, network readers, readers embedded in other mobile devices etc.
RFID Antenna:
The antenna transmits an electromagnetic field, which activates the tag. The antenna also receives the data from the tag and sends it to the reader. RFID tag also has an antenna, which receives the required power from the electromagnetic field, and transmits the data. Tags also require an antenna to transmit the information to the reader and to receive information from the reader if it is a rewritable tag.
Application Software:
It is enterprise software which finally uses the data captured by the readers and uses the information to provide real-time visibility to the process. In some cases RFID middleware is developed which lies between the hardware infrastructure and the software application as a common interface which manages data flow between the two and manages the hardware infrastructure.
Standards:
| Standard |
Frequencies |
Subject of the Standard |
| EPC Class 0 |
860 – 930 MHz
|
Parameters for air interface communication |
| EPC Class 1 |
860 – 930 MHz
|
Parameters for air interface communication |
| EPCglobal Gen 2 |
860 – 930 MHz
|
Parameters for air interface communication to replace Class 0 and Class 1
|
| ISO 14443 |
13.56 MHz
|
Regulation for contacless / proximity ID cards |
| ISO 15693 |
13.56 MHz
|
Regulation of contactless / vicinity cards, reading distance up to 1 m.
|
| ISO 18000-2 |
125, 134.2 KHz |
Low Frequency RFID air interference protocol |
| ISO 18000-3 |
13.56 MHz
|
Reading distance max. 1.5 m, improvement on ISO 15693 |
| ISO 18000-4 |
2.45 GHz |
Microwave |
| ISO 18000-5 |
5,8 GHz |
|
| ISO 18000-6 |
860 – 960 MHz |
EPCglobal Generation 2 Tags (submitted by EPC to ISO, under development phase) |
Advantages:
No line of sight
Contacless
Improved read range
Ability to write data
High data storage capacity
Can read multiple item
Suitable for harsh environment
No human intervention
Frequency Chart:
| Frequency |
Characteristics |
Applications |
| 125 KHz – 135 KHz
Low Frequency |
- Good performance around metal and liquid
- Slow data transfer rate
- Few inches of read range
|
- Access control
- Animal identification
|
| 13.56 MHz
High Frequency |
- Worldwide standards
- Longer read ranges than LF
- Tag cost lower than LF
- Poor performance around metal and liquid
|
- Library
- Access control
- Asset tracking
- Smart shelf
- People identification
- Item level tracking
|
| 433MHz and 860MHz to 930 MHz
Ultra High Frequency |
- Longer read ranges than HF
- Used as Active RFID systems
- Most widely accepted frequency in supply chain mandates
- Volumes may bring the tag cost to lowest when compared to others
- Poor performance when near metal and liquid
|
- Supply chain management
- Inventory control
- Warehouse management
- Logistics
- Asset tracking
|
| 2.45 GHz and 5.8 GHz |
- Fast data transfer rates
- Used for active and semi active RFID systems
- Poor performance when brought near metal and liquid
|
- Toll collection
- Industrial automation
- Fast moving conveyor belts
|
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