RFID – Radio Frequency Identification
RFID is a flexible technology that allows businesses to close the gap between acquiring data, converting it to meaningful information, and automating all associated transactions. It can provide traceability and real-time control to meet customer and regulatory requirements while actually improving efficiency and profitability. RFID can be read-only or read/write, does not require contact or line-of-sight to operate, can function under a variety of environmental conditions, and provides a high level of data integrity. In addition, because the technology is difficult to counterfeit, RFID provides a high level of security.
Components of RFID Solution
- RFID technology uses frequencies within the range of 50 kHz to 2.5 GHz.
- An RFID system typically includes the following components
RFID device that actively transmits to a reader is termed an “active” tag; an RFID device that only reflects or backscatters transmission from a reader is termed “passive”. The tags are programmed with data that identifies the item to which the tag is attached. Tags can be either read-only, volatile read/write, or write-once /read many (WORM) and can be either active or passive. In general, active tags use batteries to power the tag transmitter (radio) and receiver. These tags usually contain a greater number of components than do passive tags. Therefore, active tags are usually larger in size and are more expensive than passive tags. In addition, the life of an active tag is directly related to battery life. Passive tags can be either battery or non-battery operated, as determined by the intended applications. Passive tags reflect the RF signal transmitted to them from a reader or transceiver and add information by modulating the reflected signal. A passive tag does not use a battery to boost the energy of the reflected signal. A passive tag may use a battery to maintain memory in the tag or power the electronics that enable the tag to modulate the reflected signal – Antenna
Each RFID system includes at least one antenna to transmit and receive the RF signals. In some systems, a single antenna transmits and receives the signals; in other systems, one antenna transmits and one antenna receives the signals. The quantity and type of antennas used to depend on the application.RF Transceiver
The RF transceiver is the source of the RF energy used to activate and power the passive RFID tags. The RF transceiver may be enclosed in the same cabinet as the reader or it may be a separate piece of equipment. When provided as a separate piece of equipment, the transceiver is commonly referred to as an RF module. The RF transceiver controls and modulates the radio frequencies that the antenna transmits and receives. The transceiver filters and amplifies the backscatter signal from a passive RFID tag. Reader: The RFID reader directs the RF transceiver to transmit RF signals, receives a coded signal from the tag through the RF transceiver, decodes the tag’s identification, and transmits the identification with any other data from the tag to the host computer. The reader may also provide other functions. For example, ETC applications include accepting data from other input devices such as a vehicle detector and controlling gate and lights. Firmware in the reader controls reader operations. The user can change or customize the reader’s operations to suit a specific requirement by issuing commands through the host computer or a local terminal.
There are basically four frequency bands in which RFID works namely; LFHFUHF Microwave
- LF or Low Frequency is in the 100-500 kHz frequency band and provides short to medium read range at low reading speed. Its advantages are its ability to penetrate obscuring materials and it’s inexpensive compared to other frequencies. Most suitable application areas are animal control, car immobilizer, access control and inventory control.
- HF or High Frequency ranges from 10 -15 MHz; typically 13.56 MHz and provides short to the medium reading range at medium reading speed. It’s potentially inexpensive and has moderate penetration in obscuring materials. Mainly finds use in the application areas like access control, pallet and carton identification and smart cards.
- UHF or Ultra High Frequency has a comparatively long read range and is available in the 860-950 MHz frequency band. It has high reading speed and is expensive compared to the other frequencies. It is ideal for applications like supply chain management, railroad car monitoring and toll collection systems.
Microwave Frequency is found in the 2.4 -5.8 GHz frequency band and has a medium read range with moderate penetration ability in obscuring materials. It’s relatively expensive compared to LF and HF. Microwave is most suitable for applications like carton and pallet identification.
Typical Applications for RFID
- Automatic Vehicle identification
- Inventory Management
- Work-in-Process Container
- Yard Management Document
- Jewellery tracking
- Patient Monitoring
Benefits of RFID Technology
- Increase visibility within the supply chain
- Lower operating costs
- Increase competitiveness
- Reduce human intervention
- Decrease working capital
- Reduce stock outages
- Real time information processing
- No line of sight required
RFID systems can offer a business many benefits ranging from better tracking of work in process to speeding up throughput in a warehouse. When a business has pain points, such as asset tracking and visibility issues, RFID technology can enable an organization to have automatic visualization of objects with no line of sight or human intervention. The use of RFID technology can benefit a business through reduced administrative errors, labour costs associated with scanning bar codes, internal theft, errors in shipping goods and more efficient inventory levels. RFID systems can be used just about anywhere, from clothing tags to missiles to pet tags to food – anywhere that a unique identification system is needed.
RFID – Air interface (frequency) standards
RFID frequencies are governed by the ISO 18000–RFID Air Interface family of standards and a complete set of standards was released in September 2004: ISO 18000-1 – Generic Parameters for the Air Interface for Globally Accepted FrequenciesISO 18000-2 – for frequencies below 135 kHzISO 18000-3 – for 13.56 MHzISO 18000-4 – for 2.45 GHzISO 18000-6 – for 860 to 960 MHzISO 18000-7 – for 433 MHz.
There are also earlier standards relating to, for example, cattle tracking systems (ISO11785), tag-based payment proximity” cards (ISO 14443) and electronic toll collection “vicinity” cards (ISO 15693). ISO 14443 and ISO 15693 both operate at 13.56MHz (HF), but the first standard has a read range of about 10cm whereas the later has a read range of 1 to 1.5 meters.
The situation regarding frequencies is somewhat confused by the introduction, by EPC Global, of a separate air interface standard for UHF frequencies (covered by ISO 18000-6) for their early class 0 and class 1 tags. These tags are not interoperable with each other, nor are they compatible with ISO’s air interface standards (RFID Journal, 2006).
EPC Global has subsequently developed a second generation of protocols(GEN 2) that merge the old Class 0 and Class 1 passive tags and should be more closely aligned with the ISO, although is agreements remain between the two organizations at the time of writing. Obviously, supply chain managers and equipment vendors would like to see an agreed, international standard.