What Is RFID?

A Zebra employee speaks on what is RFID.

RFID stands for radio frequency identification. It is an automatic identification technology whereby digital data is encoded in an RFID tag or "smart label" and is captured by a reader using radio waves. Put simply, RFID is similar to barcode technology but uses radio waves to capture data from tags, rather than optically scanning the barcodes on a label. RFID does not require the tag or label to be seen to read its stored data—that's one of the key characteristics of an RFID system.

Tags can be read using handheld or mobile readers, shelf or tabletop readers, or readers that can be installed at doorways or in portal configurations. A line of sight is not required – tags can be read automatically, even through packaging materials and in transit, whenever moving items or people come within range of a reader. Learn more about RFID Tags in our dedicated What is an RFID Tag FAQ.

RFID systems greatly streamline inventory and asset tracking, virtually eliminating human error while providing instant, detailed records of the movement of assets.

Common references include: UHF  RFID, EPC UHF  Gen 2, G2V2, ISO  18000-63 and RAIN RFID. These RFID standards ensure hardware and data interoperability. If it complies with the standard, it will be interoperable.

How Does RFID Work?

RFID works by employing an RFID transponder (or tag) and a reader. The RFID transponder is comprised of a microchip that holds information to identify an object, product, or person and an antenna for transmitting this data to the reader.

The antenna transmits the data to a reader that converts the radio waves to usable information. Unlike bar code and magnetic stripe technology, RFID transponders can be read anywhere within the magnetic field sent out by the reader. Radio waves can travel and be read through many non-metallic objects. Depending on the power of the reader, an RFID antenna can be read from direct contact up to 20 feet.

In passive systems, which are the most common, an RFID reader transmits an energy field that "wakes up" the tag and provides the power for the tag to respond to the reader.

Passive tags do not have a battery and draw their power from the reader. The reader sends out electromagnetic waves that induce a current in the tags antenna. Since these tags obtain their power from the reader, they generally have shorter read ranges and are in a defined reader zone. Passive RFID is relatively inexpensive and found in many daily surroundings. They can be very small with size dependent on the type of tag antenna.

In active systems, a battery in the tag is used to boost the effective operating range of the tag and to support additional features over passive tags, such as temperature sensing. Data collected from tags is then passed through communication interfaces (cable or wireless) to host computer systems in the same manner that data scanned from barcode labels is captured and passed to computer systems for interpretation, storage, and action.

Active RFID tags work independently, so the tags themselves can transmit and receive data. As they generally transmit data over a longer distance they are physically larger and more expensive than passive tags and are operational as long as the battery is functional. Passive RFID is an optimum combination of benefit and costs and uses a frequency that fits most customer applications.

What Is the Frequency Range of RFID?

There are several radio frequencies in use.

  • Low Frequency (LF): 125kHz
  • High Frequency (HF): 13.56 MHz
  • Very High Frequency (VHF): 433 MHz
  • Ultra High Frequency (UHF): 860 - 960 MHz
  • Microwave Frequency: 2.4 GHz

Tags and readers must use the same frequency in order to work together. Readers work on a specific frequency and the frequency depends on several factors such as read range, speed of data transfer, type of material and environment. Government and industry regulations also affect which frequencies are used.

Where Is RFID Used?

RFID is used where there is a high volume of items moving quickly in and out of an area and where there is a high selectivity and multitude of sizes, colors and styles.

  1. High Volume and Quick Movement of Items: In environments with a high volume of items that are constantly being moved in and out, traditional manual tracking methods can quickly become cumbersome and error-prone. RFID offers a solution by enabling automated and non-contact identification and tracking of items. For instance, in a busy warehouse, retail store, or distribution center, RFID tags can be attached to items, and as these items pass through RFID-equipped checkpoints or portals, the technology can instantaneously read and record information without requiring physical handling. This capability greatly enhances the speed and accuracy of inventory management, shipping, and receiving processes.

  2. Diverse Items with Various Attributes: In situations where items come in a wide variety of sizes, colors, and styles, it can be challenging to use traditional barcode-based systems, especially if different products share similar physical appearances. RFID tags can store more detailed and unique information about each item, enabling differentiation even among items with similar outward appearances. This is particularly useful in industries like fashion retail, where clothing items can have multiple variants (sizes, colors, styles) that need to be tracked individually.

The ability of RFID technology to handle a multitude of attributes allows businesses to have better control over their inventory and supply chain. It can help prevent errors in order fulfillment, improve accuracy in stock management, and enhance customer experiences by ensuring the availability of the right products in the right sizes and colors.

In both scenarios mentioned above, RFID offers several benefits:

  • Efficiency: RFID systems can quickly read multiple tags simultaneously, making them ideal for environments where items move rapidly. This efficiency contributes to reduced operational time and increased productivity.

  • Accuracy: Automation reduces the chances of human error, leading to more accurate tracking and inventory control. This accuracy can result in better decision-making and resource allocation.

  • Real-Time Tracking: RFID enables real-time visibility into inventory movement, allowing businesses to respond swiftly to changes in demand, stockouts, or delays.

  • Non-Intrusive: RFID operates wirelessly and doesn't require line-of-sight scanning, making it less labor-intensive and more suitable for fast-paced environments.

  • Scalability: RFID systems can be scaled up or down to accommodate changing business needs without significant disruptions.

Additional use cases include when items have a high value so anything that is important not to lose and when there is a need for traceability, such examples include food/cold chain and pharmaceuticals.

One of the first use cases of RFID was in retail but now its uses are expanding beyond retail to the supply chain. Technological advancements are driving new uses in manufacturing, transportation, logistics and healthcare.

The technology can be used to label people and products, however RFID chips can carry more information, making them useful for identifying assets like prescription pharmaceuticals, blood, livestock and high-ticket items. Because RFID tags can be customized and programmed, encrypted and password-protected, they are suited to secure applications like healthcare and military usage.

Different industries use RFID in different ways. For example, in retail, it can be used for inventory visibility, reduction of out-of-stock items, omnichannel enablement, customer experience and loss prevention. Each item in a store can have an RFID tag. This means store owners can easily see what items they have in stock, how many are left and where the items are located. It can even help prevent theft, as items can be tracked as they move around the store. RFID technology also enables omnichannel shopping experiences, meaning customers can have a seamless experience whether shopping online from a mobile device, a laptop or in a brick-and-mortar store.

In a warehouse environment, it can be used for receiving accuracy, outbound shipment accuracy, asset utilization/tracking and analysis and locationing. In a warehouse, RFID can be used to ensure that the correct items are received and sent out. It can also be used to track the usage of assets like machinery or tools. For example, if a forklift has an RFID tag, warehouse management can know when it's used, where it's used and how often it's used. This can help in making decisions about equipment maintenance, replacement or purchasing. RFID technology can also be used to locate items or equipment within the warehouse, saving time and increasing efficiency.

In healthcare, it can be used for asset tracking, inventory visibility, locationing, and billing & processing while in manufacturing, it can be used for parts inventory, work-in-process (WIP), returnable transit items (RTIs), employees, vehicles and product recalls.

In transportation and logistics, it can used for airline baggage, materials management, supply chain tracking/management, field mobility (service, fulfillment/replenishment), vehicle and yard management, asset utilization/tracking and analysis.

What Is the Electronic Product Code (EPC) and EPCglobal?

Designed to be stored on an RFID tag, the Electronic Product Code (EPC) is a unique number that identifies a specific item in the supply chain. The EPC can be associated with dynamic data such as the origination point of an item or the date of its production.

Much like a Global Trade Item Number (GTIN) or Vehicle Identification Number (VIN), the EPC is key to unlocking the power of the information systems that are part of the EPCglobal Network™. EPCglobal Inc™ has responsibility for oversight of the EPC and the standards, specifications, and guidelines for the Auto-ID infrastructure to support its use. EPCglobal is a not-for-profit joint venture between GS1 (formerly EAN International) and GS1 US (formerly the Uniform Code Council).

GS1 is a leading global organization dedicated to the design and implementation of global standards and solutions to improve efficiency and visibility in supply and demand chains. GS1 US is a not-for-profit member organization of GS1 and is dedicated to the development and implementation of standards-based, global supply chain solutions. For more information about EPCglobal, visit https://www.gs1.org/epcglobal.

What Are the Benefits of RFID Technology?

RFID Technology has a number of benefits to help every business and organization to improves its efficency, in an economy where productivity inefficiences can mean the difference between profit or loss, efficiency is key.

RFID improves efficiency by allowing businesses to automate their inventory and data capture tasks along with reducing shrinkage through the improved monitoring of inventory movement. It works in real time where information is transmitted in real time enabling companies to take immediate actions and also increase accuracy by reducing manual processes, and increasing process automation.

It is reliable, proven technology. Because of its documented business value, RFID is continuing to expand into a wide variety of vertical markets and applications. As a result of this growth, industries have developed and deployed technology and usage standards. These standards embrace a variety of form factors and protocols designed for specific applications. Additionally, along with the integration of other technologies, complete business solutions are being developed and standardized.

Learn More About Zebra’s RFID Technology