Shyam Sundar Panigrahi
Rapid identification technologies have led to a better handling of raw materials / inputs and finished products in the Supply Chain. In the past few years Radio Frequency Identification (RFID) has grown to be one of the most popular technologies in the area of identification systems and today it’s a disruptive technology in Asset Identification and Tracking. RFID is an alternative technology with a potential to replace traditional universal product code (UPC) barcodes. RFID enables identification of an object from a distance without requiring a line of sight. RFID use automatic data capture allowing contact less identification of objects using radio frequency. Differences in Principles, advantages and disadvantages of Bar Coding System and RFID are depicted below:
Applications of RFID
Typical applications of RFID technology include automatic payment of highway tolls, labeling of products for rapid checkout, tracking of warehouse inventories, retail merchandise / grocery stores, tracking vehicles, to identify cargo in shipyards, airline passengers, baggage handling, hotel locking systems, goods delivery tracking and courier services, tagging of animals, securing of automobile keys, automatic equipment tracking, inventory control and document management and so on. The technology is also used for security and attendance purpose in schools, colleges as well as office establishments. So in this context RFID is the very heart of Internet of Things (IoT) systems used in multiple ways and various applications.
Example of Usage
Imagine going to the grocery store, filling up your cart and walking right out the door. No longer will you have to wait as someone rings up each item in your cart one at a time. Instead, these RFID tags will communicate with an electronic reader (also known as an RFID reader) that will detect every item in the cart and will ring each up almost instantly and the information will be stored in the database by sending it to a large network that in turn sends information of your products to the retailer and product manufacturers. Your bank will then be notified and the amount of the bill will be deducted from your account. No lines, no waiting. Its fast and more accurate system of identification and tracking of objects.
How RFID system works?
A typical RFID system consists of
>a RFID Reader (The tag reader is a device that powers and communicates with a tag)
>an Antenna (is a conductive element that enables communication between the tag and an RFID reader) and
>a Tag (a small device that can be attached to an object so that the object could be identified and tracked)
The RFID tag is placed on any object or item which is to be tracked. The RFID reader continuously sends radio wave and when the object is in the range of the reader, the tag attached to the object sends a feedback signal to the reader. This might look very similar to the technology used in a bar code scanner but in that technology barcode and the scanner must be in the line of sight but in RFID technology the tag and reader need not be in the same line of sight (but it must be within the given range of the reader).
RFID system deducts Tags within antennas’ range and performs various operations onto each tag. RFID operational structure is shown below, which integrates various components logically to effectively function.
RFID reader is an external powered equipment used in RFID system for producing and accepting radio signals. Reader is the central part of the RFID system and communicates with tags and computer program, it supplies tags information to a computer program after reading each tags unique ID. It can also perform writing onto tag, if the tag is supported.
RFID antenna is the middle-ware technology or component, it works between Reader and Tag and provide energy to tags in some cases (passive tags). It performs function of data transmission between Reader and Tags.
The basic unit of RFID system is tags and tags have its own unique identification number system by which it recognizes uniquely. An RFID tag, also known as a transponder, is a small device that can be attached to an object so that the object could be identified and tracked. The tag is composed of a microchip, an antenna, and a substrate or encapsulation material. The microchip stores data whereas the antenna transmits and receives the data. The microchip and antenna attached to the substrate are referred to as the inlay. The inlay is encased in protective material such as paper, plastic, or a film. Tags are available in many different shapes, sizes, and protective housings.
Types of RFID Tags :
There are various types of RFID Tags and are broadly classified into Two Categories
1. Based on Power Source
2. Based on Read – Write Capabilities
Based on Power Source Tags can be classified a
1. Active Tags
2. Passive Tags
3. Semi-Passive Tags
Active Tag : Active tags require a battery to power up its microchip. Active tags have longer range of operation, greater processing power, and higher operating frequency because they have their own power source.
Passive Tag: Passive tags do not require any power source. They derive power from the signal received from the reader. Therefore, they require a strong signal from the reader and transmit a weak signal to the reader. They transmit only when they are in the field of the reader. These tags are less expensive
Semi-passive Tag: Semi-passive tags, also known as semi-active tags, use a battery only to run the circuit of its microchip. They transmit the signal using the same method as that of passive tags. These tags can be read at a higher speed as compared to passive tags.
The Classification also be done on Read / Write capabilities of Tags such as Read-only tags; Write-once read-many (WORM) tags; Electronically erasable programmable read-only memory (EEPROM) tags; Read–write tags.
The reader of the RFID system is the heart of the entire RFID setup and it comes in various shapes and dimensions. In many shopping malls RFID readers are preinstalled at the exit doors and in many cases it is seen that these readers are as small as a handheld set.
Chip Less RFID Tags
If RFID were to perfectly substitute the traditional barcode scanner then it should be very cost effective, robust and adaptable (able to work in harsh environments). The best way to do so is to remove the electronic chip used in RFID systems. To address these issues, a new chip less approach has been proposed in recent years. The chip less transponder works on the concept similar to Radar, where the information is encoded in the EM response of the tag. This response, named EM Signature, is largely dependent on the tags passive physical architecture. As the communication principle for a chip less tag is dependent on the backscattered signal from the tag.
These chip less RFIDs make use of a very thin and cheap substrate analogous to the ones used in optical barcodes. These tags are basically Time domain reflectometers(TDR) which echoes the radio wave from the reader back to the sensors (present in the reader) in form of feedback signal which is then processed by the program used in RFID system.
Applications of RFID
1.Item Level Inventory Tracking
Tracking assets on the item level is beneficial for any industry, but the retail sector has one of the highest ceilings in terms of opportunity from the use of RFID. Tracking items through the supply chain is wonderful, but now think about tracking items through the supply chain all the way to the point of sale. With a well-designed inventory system sharing data across all business units has become lot easier. Tracking an item in an inventory is no longer a tedious task. Amazon and Walmart are already taking benefits of RFID to track their items.
2. IT Assert Tracking
IT assets such as server blades, laptops, tablets, peripherals and other gizmos are costly investments for any firm and not to mention that information stored on those items could prove detrimental in the wrong hands. RFID tags give the IT team the ability to quickly do an inventory count to ensure that everything is in its correct place.
3. Library Systems
An RFID library solution improves the efficiency of circulation operations. While barcodes require line of sight, RFID tags can be read from multiple angles which means the checkout and check-in process is significantly faster. Keeping a track of all the books that are being circulated becomes way too easy when RFID technology is deployed in libraries.
4. Contact Less Payment
Credit cards, Debit cards and smartphones make extensive use of RFIF and NFC (Near Field Communication) technology to enable Cashless payment. Samsung Pay, Apple Pay, Google Pay and Fitbit are a few applications that are compatible with RFID and NFC technologies to deliver a cashless mode of transaction.
5. Health Care – RFID Applications
RFID finds immense applications in health care system in blood collection, drugs management, sterilization management, operation theater equipment management, patients records management, bed & other assets management, clinical waste management etc.
6. Customs RFID : e-Sealing of Containers
Indian Customs have mandated that all containers sent to the port will require a one-time-use RFID seal. This is a significant measure towards paperless container movement using RFID technology to enable container trailers enter port without any manual intervention. This will enable self – sealing of container cargo to move expeditiously, fasten customs clearance process and prevent unnecessary hold ups at ports bringing down transaction costs of exporters and also chances of corruption.
This is major step to improve efficiency and reduce congestion. This is one of the measures towards the Government’s cherished goal of ease of doing business.
7. Vehicle Tracking Systems and FASTags :
Vehicle tracking systems and FASTags for electronic toll collection will be made mandatory for all commercial vehicles obtaining national permit as the Government’s proposed amend to the Central Motor Vehicles Rules. “Ministry of Road Transport and Highways (MoRTH) has notified draft amendments to the Central Motor Vehicles Rules, making FASTags and vehicle tracking system device mandatory for all commercial vehicles (CVs) obtaining national permit,”. This will decongest the traffic at toll and eliminate the waiting time.
Challenges in Implementation of RFID Technology
One of the main technical challenges in implementing RFID technology is its unreliability in a retail environment. It is very difficult to read ultrahigh frequency tags near a human body because of the interference from the high water content of humans. Tags on the products with large amount of liquid or metals cannot be read easily because liquids absorb signals while metals reflect them. Some of the other technical challenges in implementing RFID technology are read range, read accuracy (If a number of tagged objects are placed together randomly, some of them will be oriented in a direction that makes them invisible to the reader – like oriented perpendicular to the antenna of the reader); Non-uniform standards of devices and cost.
Despite all the challenges, RFID is a promising technology with the potential to be used for a variety of applications such as supply chain management, asset tracking monitoring, shipping and logistic industry and also ensuring safety in the industry. Use of RFID technology can improve the efficiency and productivity by providing better inventory management to reduce out-of-stock supplies and spoilage of perishable products.