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Glossary of RFID Terms

  • Accelerometer

    A device that measures acceleration (the rate of change of velocity). An accelerometer inherently measures its own motion (locomotion), as opposed to a device based on remote sensing….

  • Active

    When used to refer to an RFID transponder, the term “active” means a transponder has a power source. This is usually a battery, but energy can also be captured from light via photovoltaic cells or other sources. An active tag can, therefore, broadcast its own signal, like a cell phone. Because an active tag has its own source of power to broadcast a signal, it has a longer read range than most passive tags….

  • Active tag

    An RFID transponder that has its own power source, which enables it to broadcast a signal….

  • Addressability

    The ability to write data to different fields, or blocks of memory, in the microchip in an RFID transponder….

  • Advance shipping notice

    An electronic document that is sent to a trading partner, so the partner knows what goods have been shipped. These documents are typically sent via electronic data interchange (EDI)….

  • Agile reader

    A generic term that usually refers to an RFID reader that can read tags operating at different frequencies or using different methods of communication between the tags and readers….

  • Air Interface Protocol

    The rules that govern how tags and readers communicate….

  • Alignment

    See Orientation….

  • American National Standards Institute

    An American technical standards body and the representative of the United States to the International Organization for Standardization….

  • Amplitude

    The maximum absolute value of a periodic curve measured along its vertical axis (the height of a wave, in layman’s terms)….

  • Amplitude Modulation

    Changing the amplitude of a radio wave. A higher wave is interpreted as a 1 and a normal wave is interpreted as a zero. By changing the wave, the RFID tag can communicate a string of binary digits to the reader. Computers can interpret these digits as digital information. The method of changing the amplitude is known as amplitude shift keying, or ASK….

  • Amplitude shift keying

    Changing the amplitude of the wave to communicate data stored on a tag. …

  • ANSI

    See American National Standards Institute…

  • Antenna

    The tag antenna is the conductive element that enables the tag to send and receive data. Passive, low- (135 kHz) and high-frequency (13.56 MHz) tags usually have a coiled antenna that couples with the coiled antenna of the reader to form a magnetic field. UHF tag antennas can be a variety of shapes. Readers also have antennas which are used to emit radio waves. The RF energy from the reader antenna is “harvested” by the antenna and used to power up the microchip, which then changes the electrical load on the antenna to reflect back its own signals.

  • Antenna gain

    In technical terms, the gain is the ratio of the power required at the input of a loss-free reference antenna to the power supplied to the input of the given antenna to produce, in a given direction, the same field strength at the same distance. Antenna gain is usually expressed in decibels and the higher the gain the more powerful the energy output. Antennas with higher gain will be able to read tags from farther away….

  • Anti-collision

    A general term used to cover methods of preventing radio waves from one device from interfering with radio waves from another. Anti-collision algorithms are also used to read more than one tag in the same reader’s field….

  • API

    A source-code interface provided by a computer system or program library to support a computer program’s requests for services. Unlike an application binary interface, an API is specified in terms of a programming language that can be compiled when an application is built, rather than an explicit low-level description of how data is laid out in memory….

  • Applet

    A software component designed to run in the context of another program, such as a Web browser….

  • Application family identifier

    An International Organization for Standardization (ISO) method for
    classifying radio frequency identification by application, enabling a single air interface protocol to be used across several applications….

  • Application Level Events

    An EPCglobal standard that defines interfaces through which clients may
    interact with filtered, consolidated EPC data and related data from a variety
    of sources. The role of the ALE interface within the EPCglobal Architecture
    Framework is to provide independence between the infrastructure
    components that acquire the raw EPC data, the architectural component(s)
    that filter & count that data, and the applications that use the data….

  • Application Programming Interface

    A source-code interface provided by a computer system or program library to support a computer program’s requests for services. Unlike an application binary interface, an API is specified in terms of a programming language that can be compiled when an application is built, rather than an explicit low-level description of how data is laid out in memory….

  • Application-Specific Integrated Circuit (ASIC)

    An integrated circuit (IC) customized for a particular use (such as a chip designed solely to run a cell phone) rather than general use….

  • Applicator

    A label-printing device that automatically prints and applies pressure-sensitive labels to various products. Such labels can be used for shipping, content, graphic images or complying with specific standards, such as UPC or GS1. A pressure-sensitive label consists of a label substrate and an adhesive….

  • ASIC

    An integrated circuit (IC) customized for a particular use (such as a chip designed solely to run a cell phone) rather than general use….

  • Asset Tracking

    One of the most common applications for RFID. Placing RFID transponders on or in high-value assets and returnable transport containers enables companies to gather data on their location quickly and with little or no manual intervention. Tagging assets allows companies to increase asset utilization, identify the last known user of assets, automate maintenance routines and reduce lost items….

  • Association for Automatic Identification and Mobility

    A global trade association for companies that provide products and services related to automatic identification, data collection, networking and information management systems….

  • Attenuation

    The reduction of energy. See signal attenuation….

  • Attenuator

    A device that attaches to a transmission line (a coaxial cable) that reduces the power of the RF signal as the signal travels through the cable from the reader to the antenna. Attenuators usually work by dissipating the RF energy as heat. …

  • Authentication

    The verification of the identity of a person, object or process. In RFID, the term is used in two ways. For contactless smart cards and other payments systems, the reader must make sure the transponder is a valid device within the system. That is, someone is not using an unauthorized device to commit fraud. There is also some talk of using EPC technology to authenticate products as a way of reducing counterfeiting….

  • Auto-ID Center

    A non-profit collaboration between private companies and academia that pioneered the development of an Internet-like infrastructure for tracking goods globally through the use of RFID tags carrying Electronic Product Codes. The center closed its doors in September 2003. EPCglobal was set up to continue the work of commercializing EPC technology, and the center’s research work is carried on by Auto-ID Labs at universities around the world….

  • Auto-ID Labs

    Nonprofit research labs, headquartered at the Massachusetts Institute of Technology, which continue to do primary research into the development of EPC and related technologies. The Auto-ID Labs are the successors to the Auto-ID Center.

  • Automatic Identification

    A broad term that covers methods of collecting data and entering it directly into computer systems without human involvement. Technologies normally considered part of auto-ID include bar codes, biometrics, RFID and voice recognition….

  • Automatic identification and data capture

    A broad term that covers methods of identifying objects, capturing information about them and entering it directly into computer systems without human involvement. Technologies normally considered part of auto-ID include bar codes, biometrics, RFID and voice recognition….

  • Back channel

    See reverse channel….

  • Backscatter

    A method of communication between passive tags (ones that do not use batteries to broadcast a signal) and readers. RFID tags using backscatter technology reflect back to the reader radio waves from a reader, usually at the same carrier frequency. The reflected signal is modulated to transmit data….

  • Bar code

    A standard method of identifying the manufacturer and product category of a particular item. The bar code was adopted in the 1970s because the bars were easier for machines to read than optical characters. The main drawbacks of bar codes main are they don’t, in most cases, identify unique items and scanners have to have line of sight to read them….

  • Barrier

    See Shielding…

  • Base station

    An RFID reader that is connected to a host system. …

  • Battery-assisted tag

    These are RFID tags with batteries, but they communicate using the same backscatter technique as passive tags (tags with no battery). They use the battery to run the circuitry on the microchip and sometimes an onboard sensor. They have a longer read range than a regular passive tag because all of the energy gathered from the reader can be reflected back to the reader. They are sometimes called “semi-passive RFID tags.”…

  • Beacon

    An active or semi-active RFID tag that is programmed to wake up and broadcast its signal at a set intervals….

  • Biometrics

    The study of methods to uniquely recognize and authenticate the identity of humans based upon one or more intrinsic physical or behavioral traits (fingerprints, retinal patterns and so forth). Biometric technology offers several advantages over traditional systems. Unlike passwords, biometric traits cannot be lost or forgotten, and are very difficult to copy, share or distribute. Biometric systems can be used in tandem with passwords or tokens, improving existing security systems rather than replacing them….

  • Bistatic

    A bistatic RFID interrogator, or reader, uses one antenna to transmit RF energy to the RFID tag and a different antenna to receive energy reflected back from the tag….

  • Capacitor

    An electric circuit element used to store a charge temporarily. A capacitor usually consists of two metallic plates separated and insulated from each other by a dielectric substance….

  • Card operating system

    The software program stored in the smart card IC, which manages the basic functions of the card, such as communication with the terminal, security management and data management in the smart card file system….

  • Carrier frequency

    A frequency used to transmit data….

  • Carrier wave

    A radio wave of a specific frequency that is modulated or changed in some way in order to transmit data. The amplitude of the carrier wave can be increased—for example, to indicate a one or zero of binary code. …

  • Central processing unit

    The brains of a computer, which controls all the other parts of the computer….

  • Checksum

    A code added to the contents of a block of data stored on an RFID microchip that can be checked before and after data is transmitted from the tag to the reader to determine whether the data has been corrupted or lost. The cyclic redundancy check is one form of checksum….

  • Chip

    A programmable digital electronic component (also called a microprocessor) designed to incorporate the functions of a central processing unit (CPU) onto a single semiconducting integrated circuit (IC). Multiple chips can serve as the CPU in a computer system, embedded system or handheld device….

  • Chipless RFID tag

    An RFID tag that doesn’t depend on a silicon microchip. Some chipless tags use plastic or conductive polymers instead of silicon-based microchips. Other chipless tags use materials that reflect back a portion of the radio waves beamed at them. A computer takes a snapshot of the waves beamed back and uses it like a fingerprint to identify the object with the tag. Companies are experimenting with embedding RF reflecting fibers in paper to prevent unauthorized photocopying of certain documents. Chipless tags that use embedded fibers have one drawback for supply chain uses—only one tag can be read at a time….

  • Circular-polarized antenna

    A UHF reader antenna that emits radio waves in a circular pattern. These antennas are used in situations where the orientation of the tag to the reader cannot be controlled. Since the waves are moving in a circular pattern, they have a better chance of hitting the antenna, but circular-polarized antennas have a shorter read range than linear-polarized antennas….

  • Closed-loop systems

    RFID tracking systems set up within a company. Since the tracked item never leaves the company’s control, it does not need to worry about using technology based on open standards. …

  • Cold Chain

    A temperature-controlled supply chain for perishable goods such as foods and pharmaceuticals, as well as for some chemical applications. In the cold chain, storage and distribution activities must maintain a given temperature range to prevent product spoilage. Specific temperature tolerances vary, depending on the actual items being shipped….

  • Collaborative planning, forecasting and replenishment

    A general term used to describe cooperation between manufacturers and retailers to better match supply of goods with demand for them….

  • Command set

    The set of commands a reader uses to communicate with a group of tags in the read field. …

  • Commissioning a tag

    This term is sometime used to refer to the process of writing a serial number to a tag (or programming a tag) and associating that number with the product it is put on in a database….

  • Compatibility

    Two RFID systems are considered compatible if they use the same protocols, frequencies and voltage levels and are able to operate together within the same overall application (see interoperability)….

  • Compliance Label

    A label that conforms with data content and format standards, usually established by an industry. …

  • Compliance Labeling

    Many industries, including the auto, technology and aerospace industries, have established label standards for products and goods moving through the supply chain. These standards specify the use of mandatory data fields, acceptable bar code symbologies, print quality minimums and environmental considerations. Compliance labeling standards ensure that everyone practices a similar labeling approach that clearly defines the label format, usage, and the information to include on the label. There are no compliance labeling standards yet for RFID, but some consider bar-code labels with embedded UHF EPC tags as compliance labels….

  • Compliance testing

    Testing done to confirm whether hardware or software product complies to a particular standard. …

  • Concentrator

    A device connected to several RFID readers to gather data from the readers. The concentrator usually performs some filtering and then passes only useful information from the readers on to a host computer. …

  • Conducted Power

    Conducted power is the RF power that is supplied by an RFID system to the antenna. Typically, it is calculated or measured at the cable to antenna connection. In the United States, Federal Communication Commission regulations require a maximum conducted power of 1 Watt….

  • Conductive Ink

    A type of ink able to conduct a signal, usually containing powdered silver and carbon. With conductive ink, companies can draw or print circuits on a variety of materials. Conductive ink provides a cheap method for printing circuit boards on paper, for instance….

  • Conductor

    A material, such as aluminum and copper, that readily conducts electricity. Conductors have a significant impact on the performance of RFID tags. Conductors near tags can reflect RF energy in a way that reduces tag performance, and they can also detune the tag….

  • Conformance testing

    Testing done to determine whether or not hardware or software products conform to a particular standard. See also compliance testing….

  • Contactless smart card

    An awkward name for a credit card or loyalty card that contains an RFID chip to transmit information to a reader without having to be swiped through a reader. Such cards can speed checkout, providing consumers with more convenience. …

  • COS

    See card operating system…

  • Coupling

    See inductive coupling….

  • CPFR

    See collaborative planning, forecasting and replenishment…

  • CPU

    See central processing unit …

  • CRC

    See cyclic redundancy check …

  • Cryptographic coprocessor

    Special circuitry that perform cryptographic calculations, such as modular arithmetic and large integer calculations. These circuits are added to a standard processor core and therefore are called coprocessors….

  • Cyclic redundancy check

    A method of checking data stored on an RFID tag to be sure that it hasn’t been corrupted or some of it lost. (See Checksum.)…

  • Data carrier

    A medium that holds machine-readable data. Bar codes and RFID tags are types of data carriers. The term is also applied to a carrier frequency used to transmit data….

  • Data field

    An area of memory in RFID microchips that is assigned to a particular type of information. Data fields may be protected (see below) or they may be written over, so a data field might contain information about where an item should be sent. When the destination changes, the new information is written to the data field….

  • Data field protection

    The ability to prevent data stored in a specific area of memory of an RFID microchip from being overwritten. Companies might want to protect the data field that stores an Electronic Product Code, which doesn’t change during the life of the product it’s associated with….

  • Data retention

    The ability of a microchip to maintain the information stored in EEPROM. RFID tags and other microchips can typically retain data for 10 years or more, but data retention depends on temperature, humidity and other factors….

  • Data synchronization

    The harmonisation of information between trading partners ensures that the master data is the same in all trading partners systems….

  • Data transfer rate

    The number of characters that can be transferred from an RFID tag to a reader within a given time. Baud rates are also used to quantify how fast readers can read the information on the RFID tag. This differs from read rate, which refers to how many tags can be read within a given period of time….

  • dB

    See decibel….

  • dBi

    The gain of an antenna compared to an isotropic antenna—that is, an antenna that radiates energy equally in every direction. A typical dipole antenna has a dBi of 2.2 when compared to an isotropic antenna….

  • dBm

    See decibel…

  • dBw

    Decibels (dB) referenced to 1.0 watt. Using the decibel formula: dB=10 log(P1/P2), P2 equals 1.0 watt and P1 is in units of watts….

  • De-tune

    UHF antennas are tuned to receive RFID waves of a certain length from a reader, just as the tuner on the radio in a car changes the antenna to receive signals of different frequencies. When UHF antenna is close to metal or metallic material, the antenna can be detuned, resulting in poor performance….

  • Deactivation

    Rendering an RFID transponder in operable or, in the case of anti-theft applications, indicating an item with a specific serial number has been sold, so it does not set off an alarm as the tagged item leaves the store….

  • Dead tag

    An RFID tag that cannot be read by an interrogator….

  • Decibel

    A unit used to express the ratio between two values, including antenna gain, cable losses and reader power output. The formula for decibel is: dB=10 log (P1/P2). In layman’s terms, dB represents the difference in the intensity of an emitted signal or power where 0 dB is the reference, 3 dB is twice the intensity of 0 dB, 10 dB is 10 times the intensity, and 20 dB is 100 times the intensity and so on. (See also dBi, dBm and dBw.)…

  • Die

    The silicon block onto which circuits have been etched to create a microchip….

  • Dielectric

    Unable to conduct direct electric current. Dielectric substances are used as insulators….

  • Dielectric constant

    The measure of a material’s ability to store a charge when an electric field is applied, or its “capacitance.” If a material has a high dielectric constant, it reflects more RF energy and detunes the antenna more, which makes it harder to tag. Examples of materials with a low dielectric constant are dry paper (2), plastics (most are between 2 and 4), and glass (between 5 and 10). Water’s dielectric constant changes: At room temperature it is 80; near boiling it is 55; and when frozen it is 3.2. …

  • Digital certificate

    A digital message that contains the identity of an company or organization, its public key combined and a signature of this data from a certificate authority (Trust Center) proving the correctness of this data….

  • Digital signal processor

    As special kind of microprocessor that converts changes in analog waves into digital information. DSPs are used in RFID readers….

  • Digital signature

    A cryptographic protocol that ensures the authenticity as well as the integrity of digital data. A digital signature typically is realized by encrypting the hash value of the data to be protected with the private key….

  • Digital signature algorithm

    A cryptographic algorithm approved by the United States government for use in creating digital signatures….

  • Dipole

    An antenna made of two straight electrical conductors (poles). In an RFID transponder, these are connected to a microchip. The antenna is typically 1/2 wavelength from end to end….

  • Discovery services

    A component of the EPCglobal Architecture Framework consisting of
    a suite of services that enable users to find data held by individual
    companies related to a specific Electronic Product Code. Object Naming
    Service is one component of Discovery Services….

  • DSP

    See digital signal processor…

  • Dual dipole

    An antenna that has two dipoles. In an RFID transponder, these are attached to a chip. The dual dipole design greatly reduces the tag’s orientation sensitivity….

  • Dual interface smart card

    A card that contains a microchip that can be read either when in content with a reader or remotely using radio waves. …

  • Dumb reader

    A generic term for a reader with limited computing power. It generally converts radio waves from a tag into a binary number and passes it to a host computer with little or no filtering. …

  • Duplex

    A channel capable of transmitting data in both directions at the same time. (Half duplex is a channel capable of transmitting data in both directions, but not simultaneously.)…

  • Duty cycle

    The length of time the reader can be emitting energy. Regulations in the European Union say readers can be on only 10 percent of the time. …

  • E-seal

    A method of sealing a digital document in a manner similar to that used for electronic signatures. Electronic seals enable computers to authenticate that documents or electronic messages have not been altered, providing a level of security in digital communications….

  • EAN

    See European Article Number…

  • EAS

    See electronic article surveillance …

  • Edge server

    A computer for running middleware or applications that is close to the edge of the network, where the digital world meets the real world. Edge servers are put in warehouses, distribution centers and factories, as opposed to corporate headquarters. …

  • EDI

    See Electronic Data Interchange…

  • EEPROM

    See Electrically Erasable Programmable Read-Only Memory…

  • Effective isotropic radiated power

    A measurement of the output of RFID reader antennas used in the United States and elsewhere. EIRP is usually expressed in watts. …

  • Effective radiated power

    A measurement of the output of RFID reader antennas used in Europe and elsewhere. ERP is usually expressed in watts and is not the same as EIRP. …

  • EIRP

    See Effective isotropic radiated power …

  • Electrically Erasable Programmable Read-Only Memory

    A method of storing data on microchips. Usually bytes can be erased and reprogrammed individually. RFID tags that use EEPROM are more expensive than factory programmed tags, where the number is written into the silicon when the chip is made, but they offer more flexibility because the end user can write an ID number to the tag at the time the tag is going to be used….

  • Electromagnetic interference

    Interference caused when the radio waves of one device distort the waves of another. Cells phones, wireless computers and even robots in factories can produce radio waves that interfere with RFID tags….

  • Electronic article surveillance

    Simple electronic tags that can be turned on or off. When an item is purchased (or borrowed from a library), the tag is turned off. When someone passes a gate area holding an item with a tag that hasn’t been turned off, an alarm sounds. EAS tags are embedded in the packaging of most pharmaceuticals. They can be RF-based, or acousto-magnetic….

  • Electronic Data Interchange

    A method of transmitting trade documents in standardized formats….

  • Electronic pedigree

    A secure file that stores data about each move a product makes through the supply chain. Pedigrees can help to reduce counterfeiting of drugs and other products. EPCglobal has ratified an e-pedigree standard for the industry….

  • Electronic Product Code

    A serial, created by the Auto-ID Center, which will complement barcodes. The EPC has digits to identify the manufacturer, product category and the individual item. …

  • Electronic Seal

    A method of sealing a digital document in a manner similar to that used for electronic signatures. Electronic seals enable computers to authenticate that documents or electronic messages have not been altered, providing a level of security in digital communications….

  • Electroplating

    The process of using electrical current to coat an electrically conductive object with a thin layer of metal. The primary application of electroplating deposits a layer of a metal with a desired property onto a surface lacking such a trait. Electroplating can also be used to build up the thickness of undersized parts….

  • EMI

    See Electromagnetic interference …

  • Encryption

    The scrambling of data in such a way that it can be unscrambled and read only by those for whom it is intended. In RFID systems, encryption is used to protect information store on a transponder’s microchip or to prevent the interception of communications between the tag and reader….

  • End user company

    A company that has deployed or wants to deploy an RFID system to improve the way it does business….

  • Enterprise resource planning:

    Software that is designed to be the operating system for large companies. ERP systems manage data across applications and functional areas, such as finance, human resources and supply chain management. …

  • EPC

    Electronic Product Code…

  • EPC Discovery Service

    An EPCglobal Network service that allows companies to search for every reader that has read a particular EPC tag….

  • EPC Generation 2

    The standard ratified by EPCglobal for the air-interface protocol for the second generation of EPC technologies….

  • EPC Information Service

    Part of the EPC Network. The EPC Information Service is a network infrastructure that enables companies to store data associated with EPCs in secure databases on the Web. The EPC Information Service has been ratified and enables companies to provide different levels of access to data to different groups. Some information associated with an EPC might be available to everyone. Other information might be available only to a manufacturer’s retail customers. The service also includes a number of applications, such as the EPC Discovery Service….

  • EPC Network

    See EPCglobal Network…

  • EPC reader

    An RFID reader that complies with EPCglobal standards, including the air interface protocol and Low Level Reader Protocol….

  • EPC tag

    An RFID tag that complies with EPCglobal standards, including
    the tag data standard, the air interface protocol. …

  • EPCglobal

    A non-profit organization set up the Uniform Code Council and EAN International, the two organizations that maintain barcode standards, to commercialize EPC technology. EPCglobal is made up of chapters in different countries and regions. It is commercializing the technology originally developed by the Auto-ID Center….

  • EPCglobal Network

    The Internet-based technologies and services that enable companies to retrieve data associated with EPCs. The network infrastructure includes the Object Name Service, distributed middleware (sometimes called Savants), the EPC Information Service and Physical Markup Language….

  • EPCIS Accessing Application

    A software application that receives EPCIS data from EPCIS Capturing Applications, either directly or via the EPCIS Query Interface, and processes those data to carry out a business objective….

  • EPCIS Capture Interface

    Provides a path for communicating EPCIS events generated by EPCIS Capturing Applications to other roles that require them, including EPCIS Repositories, internal EPCIS Accessing Applications, and Partner
    EPCIS Accessing Applications….

  • EPCIS Query Interface

    A set of programming interfaces by which an EPCIS application can request
    EPCIS data from an EPCIS Repository or another EPCIS applications….

  • EPROM

    See erasable programmable read-only memory…

  • Erasable programmable read-only memory

    Non-volatile memory that can be erased by exposing it to intense ultraviolet light. After erasing, EPROM memory can be reprogrammed….

  • ERP

    See Effective radiated power and enterprise resource planning…

  • Error correcting code

    A code stored on an RFID tag to enable the reader to figure out the value of missing or garbled bits of data. It’s needed because a reader might misinterpret some data from the tag and think a Rolex watch is actually a pair of socks. …

  • Error correcting mode

    A mode of data transmission between the tag and reader in which errors or missing data is automatically corrected. …

  • Error correcting protocol

    A set of rules used by readers to interpret data correctly from the tag….

  • ETSI

    See European Telecommunications Standards Institute…

  • European Article Number

    A system for identifying products developed by EAN International, the bar code standards body in Europe. There are several types of bar codes that use EANs, including EAN-8, EAN-13 and EAN-14….

  • European Telecommunications Standards Institute

    An independent, non-profit organization, whose mission is to produce telecommunications standards for Europe. Based in Sophia Antipolis, France, ETSI is officially responsible for standardization of Information and Communication Technologies, include telecommunications, broadcasting and related areas, such as intelligent transportation, medical electronics and RFID. …

  • Event data

    Information related to a transaction or incident with significance to the business. If a tag on a pallet is read as the pallet leaves a dock door, an event is recorded (the pallet was shipped). If a reader reads a tag on a pallet in a storage bay 100 times per minute but the pallet never moves, data is generated, but there is no event….

  • Excite

    The reader is said to “excite” a passive tag when the reader transmits RF energy to wake up the tag and enable it to transmit back….

  • Exciter

    An electronic device (also called a transmitter) that, with the aid of an antenna, propagates an electromagnetic signal such as radio, television or other telecommunications. An exciter typically incorporates a power supply, an oscillator, a modulator and amplifiers for audio frequency (AF) and radio frequency (RF)….

  • eXtensible markup language

    A widely accepted way of sharing information over the Internet in a way that computers can use, regardless of their operating system….

  • Factory programming

    Some read-only have to have their identification number written into the silicon microchip at the time the chip is made. The process of writing the number into the chip is called factory programming. This data can’t be written over or changed….

  • False read

    See phantom read….

  • Far-field communication

    RFID reader antennas emit electromagnetic radiation (radio waves). If an RFID tag is outside of one full wavelength of the reader, it is said to be in the “far field.” If it is within one full wavelength away, it is said to be in the “near field.” The far field signal decays as the square of the distance from the antenna, while the near field signal decays as the cube of distance from the antenna. So passive RFID systems that rely on far field communications (typically UHF and microwave systems) have a longer read range than those that use near field communications (typically low- and high-frequency systems)….

  • Faraday Cage

    Also called a Faraday shield. Named after physicist Michael Faraday, a Faraday Cage is an enclosure formed of conductive material, or by a mesh of conductive material, that blocks out external static electrical fields and external electromagnetic radiation, if the conductor is thick enough and any holes in the mesh are significantly smaller than the radiation’s wavelength. Faraday cages can provide effective electromagnetic shielding to prevent noise from interfering with the ability to read RFID tags, or to prevent RFID reader from interfering with other RFID devices….

  • Faraday Shield

    See Faraday Cage….

  • Federal Information Processing Standards Publication 201

    A United States federal government standard specifying Personal Identity Verification (PIV) requirements for federal employees and contractors. FIPS 201 was developed to satisfy the requirements of HSPD 12, approved by the Secretary of Commerce….

  • Field programming

    Tags that use EEPROM, or non-volatile memory, can be programmed after it is shipped from the factory. That is, users can write data to the tag when it is placed on a product. …

  • FIPS 201

    A United States federal government standard specifying Personal Identity Verification (PIV) requirements for federal employees and contractors. FIPS 201 was developed to satisfy the requirements of HSPD 12, approved by the Secretary of Commerce….

  • Firmware

    Coded instructions that are stored permanently in read-only memory. When upgrading a reader to read a new protocol, the firmware usually has to be changed. Some newer readers can be upgraded remotely over a network….

  • Fixed Reader

    An RFID interrogator mounted to a wall, doorway, gate, table, shelf or other permanent or non-mobile structure, enabling employees to read the unique ID numbers of RFID tags attached to items in a warehouse or other setting along the supply chain….

  • FLASH

    A special type of EEPROM that can be erased and reprogrammed in blocks instead of one byte at a time. It is usually written in capital letters, but it is not an acronym. …

  • Fluidic Self-Assembly

    A manufacturing process, patented by Alien Technology. It involves flowing tiny microchips in a special fluid over a base with holes shaped to catch the chips. The process is designed to mass assemble billions of RFID tags at very low cost….

  • Folded dipole

    A dipole antenna in which the two poles are connected to each other, as well as to the microchip….

  • Foreign tag

    A tag not associated with an item owned by a store or facility but which is nonetheless entering, leaving, or otherwise in the proximity of the store or
    facility and readable by RFID Readers located in the store or facility….

  • Form factor

    The packaging a transponder can be put in. These include thermal transfer labels, plastic cards, key fobs and so on….

  • Forward channel

    The path through which energy passes from the interrogator, or reader, to the RFID tag….

  • Free air

    A term used to describe the reading of an RFID tag that is not attached to anything….

  • Frequency

    The number of repetitions of a complete wave within one second. 1 Hz equals one complete waveform in one second. 1KHz equals 1,000 waves in a second. RFID tags use low, high, ultra-high and microwave frequencies. Each frequency has advantages and disadvantages that make them more suitable for some applications than for others….

  • Frequency hopping

    A technique used to prevent readers from interfering with one another. In the United States, UHF RFID readers actually operate between 902 and 928 MHz, even though it is said that they operate at 915 MHz. The readers may jump randomly or in a programmed sequence to any frequency between 902 MHz and 928 MHz. If the band is wide enough, the chances of two readers operating at exactly the same frequency is small. The UHF bands in Europe and Japan are much smaller so this technique is not effective for preventing reader interference….

  • Frequency shift keying

    A method of communicating data by switching between two slightly different frequencies. …

  • FSK

    See frequency shift keying…

  • GCI

    See Global Commerce Initiative…

  • GDS

    See global data synchronization…

  • Gen 2

    See EPC Generation 2…

  • General Pupose Input/Output

    Ports on a reader provided for interaction with hardware peripheral to
    the reader itself. For example, a device such as an electronic eye may
    be connected to a general purpose input (GPI) port so that when an
    object breaks the beam of the electronic eye the reader begins reading.
    As another example, an actuator device may be connected to a general
    purpose output port (GPO) so that when a tag is read, a conveyor is turned
    on or a dock door opened….

  • Geographical Information System Software

    A system for capturing, storing, analyzing and managing data and associated attributes that are spatially referenced to the earth. GIS software enables users to create interactive queries, analyze spatial information, edit data, create maps and present the results of these operations. GIS is often utilized in logistics applications; other common apps include scientific investigations, resource management, asset management, cartography, criminology, history, sales, marketing and emergency disaster relief….

  • Geospatial

    A term frequently used to describe the combination of spatial software and analytical methods with terrestrial or geographic datasets. The term is often employed in conjunction with geographical information systems (GIS) and geomatics….

  • GIS Software

    A system for capturing, storing, analyzing and managing data and associated attributes that are spatially referenced to the earth. GIS software enables users to create interactive queries, analyze spatial information, edit data, create maps and present the results of these operations. GIS is often utilized in logistics applications; other common apps include scientific investigations, resource management, asset management, cartography, criminology, history, sales, marketing and emergency disaster relief….

  • GLN

    See Global Location Number…

  • Global Commerce Initiative

    In user group founded in October 1999 by manufacturers, retailers and trade industry associations, to improve the performance of the international supply chain for consumer goods through the collaborative development and endorsement of recommended voluntary standards and best practices. Its charter is to drive the implementation of EAN•UCC standards and best practices, including use of EPC….

  • Global data synchronization

    A term that generally refers to the process of ensuring that a manufacturer’s master files with product information match those of retailers. GDS is an importan prerequisite to deploying RFID in open supply chains because companies need to ensure that RFID serial numbers refer to the right product information in a database….

  • Global Location Number

    A numbering scheme created by EAN International and the Uniform Code Council to as a means to identify virtually limitless numbers of legal entities, trading parties and locations to support the requirements of electronic commerce (B2B and B2C). Parties and locations that can be identified with GLNs include functional entities (e.g., a purchasing, accounting or returns department), physical entities (e.g., a particular room in a building, warehouse, loading dock, delivery point) and legal entities or trading partners (e.g. buyers, sellers, whole companies, subsidiaries or divisions such as suppliers, customers, financial services companies, or freight forwarders). …

  • Global Positioning System

    Developed for and managed by the United States military, GPS is a satellite navigation system. It consists of 24 satellites above the earth. They transmit radio signals to receivers placed on ships, trucks or other large assets that need to be tracked. The receivers compute longitude and latitude and velocity by calculating the difference in the time signals are received from four different satellites. Some companies are integrating RFID and GPS systems to track assets in transit. …

  • Global System for Mobiles

    The digital cellular telephone system, widely used in Europe, Asia and Australia. …

  • Global Trade Item Number

    A standardized system of identifying products and services created by the Uniform Code Council and EAN International. Product identification numbers, such as EAN/UCC-8, UCC-12, EAN/UCC-13, and EAN/UCC-14, are based on the GTIN….

  • GPS

    Global Positioning System…

  • GSM

    See Global System for Mobiles…

  • GTAG

    See Global Tag…

  • GTIN

    See Global Trade Item Number…

  • Harvesting

    A term sometimes used to describe the way passive tags gather energy from an RFID reader antenna. …

  • High-frequency

    This is generally considered to be from 3 MHz to 30 MHz. HF RFID tags typically operate at 13.56 MHz. They can be read from less than 3 feet away and transmit data faster than low-frequency tags. But they consume more power than low-frequency tags….

  • Host system

    A computer on a network, which provides services to users or other computers on that network….

  • Hybrid card

    A smart card that has both a contactless IC and a contact IC. Unlike a dual interface card, a hybrid card acts as two separate cards. …

  • Hysteresis

    A retardation of an effect when the forces acting upon a body are changed. When corrugated boxes and other materials absorb water and then dry, they are never as RF-friendly as they were before they became moist….

  • I/O

    See input/output…

  • I/O ports

    See input-output ports…

  • IC

    See integrated circuit …

  • Induction Loop

    A coil-wire transceiver used in a variety of applications, such as inductive loop detection, in which the coil detects metal objects. Other applications include vehicle detection at traffic lights and car parks, metal detectors and other functions involving RFID reads in the presence of metal….

  • Inductive coupling

    In technical terms, inductive coupling is the transfer of energy from one circuit to another by virtue of the mutual inductance between the circuits. In an RFID system that uses inductive coupling, the reader antenna and the tag antenna each have a coil, which together form a magnetic field. The tag draws energy from the field. The microchip uses this energy to change the electrical load on the tag antenna. These changes are picked up by the reader antenna and converted into a unique serial number….

  • Industrial, Scientific, and Medical bands

    A group of unlicensed frequencies of the electromagnetic spectrum….

  • Inlay

    An RFID microchip attached to an antenna and mounted on a substrate. Inlays are essentially unfinished RFID labels. They are usually sold to label converters who turn them into smart labels. They are also sometimes called inlets….

  • Inlet

    See inlay…

  • Input-output ports

    Ports on an RFID reader that can be connected to external devices. An input port might be connected to a photoelectric eye to turn on the reader when an object enters the reader field. An output device might be connected to a door that opens when a tag is read. …

  • Input/output

    Ports on a reader. Users can connect devices, such as an electronic eye to the input port so that when an object breaks the beam of the electronic eye the reader begins reading. Devices can also be connected to an output part, so that when a tag is read, a conveyor is turned on or a dock door opened. …

  • Integrated circuit

    A microelectronic semiconductor device comprising many interconnected transistors and other components. Most RFID tags have ICs….

  • Intelligent reader

    A generic term that is sometimes used to describe a reader that has the ability to filter data, execute commands and generally perform functions similar to a personal computer….

  • Intentional radiator

    A device that produces a RF signal for the purpose of data communications. Examples. Include garage door openers, cordless phones, RFID transmitter and so on….

  • International Organization for Standardization

    A non-governmental organization made up of the national standards institutes of 146 countries. Each member country has one representative and the organization maintains a Central Secretariat in Geneva, Switzerland, that coordinates the system….

  • Interoperability

    In computing, the term refers to the ability to exchange and use information among disparate software systems. In RFID, the term generally refers to the ability of tags and readers from different vendors to communicate….

  • Interoperability Testing

    Testing performed to assess the ability of two or more systems or components to exchange information, and to use the data that has been exchanged….

  • Interposer

    A device used to connect a microchip to an antenna to create an RFID transponder. Interposers make an electrical connection to the tiny pads on the chip and to create leads that can be bonded to an antenna….

  • Interrogation zone

    The area in which a passive interrogator can provide
    enough energy to power up a passive tag and receive back information. Also
    called the read field or reader field. Tags outside the interrogation zone
    do not receive enough energy from the interrogator to reflect back a signal….

  • Interrogator

    See reader…

  • ISM

    A group of unlicensed frequencies of the electromagnetic spectrum….

  • ISO

    See International Organization for Standardization…

  • ISO 10536

    The international standard for proximity cards…

  • ISO 11784

    The international standard defining frequencies, baud rate, bit coding and data structures of the transponders used for animal identification….

  • ISO 14443

    A set of international standards covering proximity smart cards….

  • ISO 15693

    The international standard for vicinity smart cards….

  • ISO 18000

    A series of international standards for the air interface protocol used in RFID systems for tagging goods within the supply chain….

  • ISO 7816

    A set of international standards covering the basic characteristics of smart cards, such as physical and electrical characteristics, communication protocols and others….

  • ISO/IEC 24730

    A standard defining two air interface protocols and a single application program interface (API) for real-time locating systems (RTLS) used in asset management. The standard is intended to allow for compatibility and encourage interoperability of products for the growing RTLS market….

  • Isotropic

    Identical in all direction. An isotropic antenna emits energy equally in every direction….

  • Item-level

    A term used to discribed the tagging of individual products, as opposed to case-level and pallet-level tagging….

  • Joint Requirements Group

    An EPCglobal Working Group created from participants of Industry Action Groups and Technical Action Groups to produce requirements for
    specifications….

  • Kill command

    A command sent to a tag to permanently deactivate it. …

  • KU-Tag

    An RFID tag developed by researchers at the University of Kansas’ Information and Telecommunication Technology Center to read objects containing metal or liquid. The tag’s thickness (about 1.5 millimeters, or 0.059 inch) qualifies it as one of the thinnest RFID tags designed to operate well in such conditions….

  • Label applicator

    A device that applies labels to cases or other items. Some label applicators can print bar codes on and encode RFID transponders in labels before applying the labels….

  • License plate

    This term generally applies to a simple RFID that has only a serial number that is associated with information in a database. The Auto-ID Center promoted the concept as a way to simplify the tag and reduce the cost….

  • License plate tag

    An RFID tag or other data carrier that contains
    a unique identifier for the physical object to which it is affixed, and no other
    business information. Other business information must be associated with
    the license plate identifier through an external database or other means….

  • Linear-polarized antenna

    An antenna that focuses the radio energy from the reader in one orientation or polarity. This increases the read distance possible and can provide greater penetration through dense materials. Tags designed to be used with a linear polarized reader antenna must be aligned with the reader antenna in order to be read. (See circular-polarized antenna.)…

  • LLRP Standard

    A standard produced by the EPCglobal Reader Operations Working Group to foster RFID reader interoperability and create the foundation for technology providers to extend basic capabilities in satisfaction of industry-specific requirements. The LLRP standard is the result of collaboration between more than 90 end users, RFID infrastructure vendors, middleware vendors, industry experts and networking professionals….

  • Lossy

    Characterized by or causing dissipation of energy. For instance, a cable is said to be a lossy cable if the signal attenuates as it travels through the cable….

  • Low-frequency

    From 30 kHz to 300 kHz. Low-frequency tags typical operate at 125 kHz or 134 kHz. The main disadvantages of low-frequency tags are they have to be read from within three feet and the rate of data transfer is slow. But they are less subject to interference than UHF tags….

  • Low-Level Reader Protocol Standard

    A standard produced by the EPCglobal Reader Operations Working Group to foster RFID reader interoperability and create the foundation for technology providers to extend basic capabilities in satisfaction of industry-specific requirements. The LLRP standard is the result of collaboration between more than 90 end users, RFID infrastructure vendors, middleware vendors, industry experts and networking professionals….

  • Manufacturing Execution System

    A system with which companies can measure and control critical production activities, offering improved traceability, productivity and quality. MES solutions serve numerous functions, such as equipment tracking, product genealogy, labor tracking, inventory management, costing, electronic signature capture, and defect and resolution monitoring…

  • Master data

    For the purpose of data synchronization, any data or constructs that are applicable across multiple business transactions. Master data can be divided into neutral and relationship dependent data. Typically master data is static – not transactional….

  • Memory

    The amount of data that can be stored on the microchip in an RFID tag. It can range from 64 bits to 32 kilobytes or more on passive tags….

  • Memory block

    The smallest unit of memory on an RFID tag that can be locked independently of other parts of memory….

  • MEMS

    Micro-electro-mechanical systems, smaller than microscopic dust mites and used in a variety of applications, from inkjet printers to accelerometers that deploy air bags in cars. A MEMS RFID tag contains micromechanical components that are expected to be rugged and easier to produce, and that can be attached directly to medical devices. Such a tag can withstand exposure to wide temperature ranges and gamma radiation….

  • Micro-electro-mechanical Systems

    Also known as MEMS, smaller than microscopic dust mites and used in a variety of applications, from inkjet printers to accelerometers that deploy air bags in cars. A MEMS RFID tag contains micromechanical components that are expected to be rugged and easier to produce, and that can be attached directly to medical devices. Such a tag can withstand exposure to wide temperature ranges and gamma radiation….

  • Microcontroller

    A complete microprocessor on a chip. A microcontroller includes a central processing unit, RAM or EPROM, clock and control circuits, and serial and parallel I/0 ports….

  • Microprocessor

    A programmable digital electronic component (also called a chip) designed to incorporate the functions of a central processing unit (CPU) onto a single semiconducting integrated circuit (IC). Multiple microprocessors can serve as the CPU in a computer system, embedded system or handheld device….

  • Microwave

    A high-frequency electromagnetic wave, one millimeter to one meter in wavelength….

  • Microwave tags

    A term that is sometimes used to refer to RFID tags that operate at 5.8 GHz. They have very high transfer rates and can be read from as far as 30 feet away, but they use a lot of power and are expensive. (Some people refer to any tag that operates above about 415 MHz as a microwave tag.)…

  • Middleware

    In the RFID world, this term is generally used to refer to software that resides on a server between readers and enterprise applications. The middleware is used to filter data and pass on only useful information to enterprise applications. Some middleware can also be used to manage readers on a network….

  • Milliwatt

    A unit of power equal to one thousandth of a watt….

  • MIPS

    Million instructions per second…

  • Mobile Reader

    An RFID interrogator that can be carried or transported on a person, vehicle or apparatus, enabling employees to read the unique ID numbers of RFID tags attached to items in a warehouse or other setting along the supply chain….

  • Modulation

    Changing the radio waves traveling between the reader and the transponder in ways that enable the transmission of information. Waves can be changed in a variety of ways that can be picked up by the reader and turned into the ones and zeroes of binary code. Waves can be made higher or lower (amplitude modulation) or shifted forward (phase modulation). The frequency can be varied (frequency modulation), or data can be contained in the duration of pulses (pulse-width modulation). …

  • Monostatic

    A monostatic RFID interrogator, or reader, uses the same antenna to transmit RF energy to and receive RF energy from the RFID tag….

  • Multimode

    Transponders are called “multimode” when they can be programmed to operate according to several different standards….

  • Multiple access schemes

    Methods of increasing the amount of data that can be transmitted wirelessly within the same frequency spectrum. Some RFID readers use Time Division Multiple Access, or TDMA, meaning they read tags at different times to avoid interfering with one another….

  • Multiplexer

    An electronic device that allows a reader to have more than one antenna. Each antenna scans the field in a preset order. This reduces the number of readers needed to cover a given area, such as a dock door, and prevents the antennas from interfering with one another….

  • NanoBlock

    The term Alien Technology uses to describe its tiny microchips, which are about the width of three human hairs….

  • National Institute for Standards and Technology

    An American standards body that establishes standards for information-processing technology, particularly IT used by the Federal government. …

  • Near-field communication

    RFID reader antennas emit electromagnetic radiation (radio waves). If an RFID tag is within full wavelength of the reader, it is sometimes said to be in the “near field” (as with many RFID terms, definitions are not precise). If it is more than the distance of one full wavelength away, it is said to be in the “far field.” The near field signal decays as the cube of distance from the antenna, while the far field signal decays as the square of the distance from the antenna. So passive RFID systems that rely on near-field communication (typically low- and high-frequency systems) have a shorter read range than those that use far field communication (UHF and microwave systems)…

  • NFC

    See near-field communication…

  • Noise

    Unwanted ambient electrical signals or electromagnetic energy found in the operating environment of RFID equipment. Other RF devices, robots, electric motors and other machines can cause noise….

  • Nominal range

    The read range at which the tag can be read reliably….

  • Non-volatile memory

    A generic term for the memory that holds its contents after power has been removed. EPROM, EEPROM and FLASH are examples of non-volatile memory….

  • Null spot

    Area in the reader field that doesn’t receive radio waves. This is essentially the reader’s blind spot. It is a phenomenon common to UHF systems….

  • Object Name Service

    An Auto-ID Center-designed system for looking up unique Electronic Product Codes and pointing computers to information about the item associated with the code. ONS is similar to the Domain Name Service, which points computers to sites on the Internet….

  • OEM

    See original equipment manufacturer…

  • One-time programmable

    Memory that can be written to, or programmed, only once and is afterwards write protected. After the memory is written to, it is like read-only memory….

  • One-time programmable tag

    Also called a field-programmable tag. An RFID tag that can be written to once and read many times (see WORM)….

  • ONS

    See Object Name Service …

  • Optical Character Recognition

    A type of computer software designed to translate images of handwritten or typewritten text (usually captured by a scanner) into machine-editable text, or to translate pictures of characters into a standard encoding scheme (such as ASCII or Unicode). OCR began as a field of research in pattern recognition, artificial intelligence and machine vision. …

  • Order Management System

    A software system used in a number of industries for order entry and processing. Such industries include e-commerce, cataloging and financial securities….

  • Orientation

    The position of a tag antenna vis-à-vis a reader antenna. With UHF systems, readers can be either circular-polarized or linear-polarized. When using a linear polarized antenna, the tag reader and antenna reader must be in alignment in order to achieve the longest reading distance. If that tag antenna is aligned vertically and the reader is sending out signals horizontally, only a small portion of the energy emitted by the reader will hit the tag antenna….

  • Original equipment manufacturer

    A company that builds its own products from components bought from other manufacturers. …

  • Passive

    When used to refer to an RFID transponder, the term “passive” means a transponder has no power source and cannot actively broadcast a signal. A passive tag harvests energy emitted by a reader antenna, uses it to run the circuitry on an RFID chip and then reflects back a signal to the reader. Because the signal to the reader is reflected by the passive tag, the signal is weak and the read range of passive tags is thus relatively short….

  • Passive tag

    An RFID tag without its own power source and transmitter. When radio waves from the reader reach the chip’s antenna, the energy is converted by the antenna into electricity that can power up the microchip in the tag. The tag is able to send back information stored on the chip. Today, simple passive tags cost from U.S. 20 cents to several dollars, depending on the amount of memory on the tag, packaging and other features….

  • Patch antenna

    A term used to describe a square reader antenna made from a solid piece of metal or foil….

  • Penetration

    The ability of a particular radio frequency to pass through non-metallic materials….

  • Permalock

    In the EPC Gen 2 standard, the ability to permanently lock a memory block. …

  • Persistent memory

    Memory that is not erased when a tag no longer is being powered by the reader or a battery….

  • Personal Identity Verification Format

    A format for improving the identification and authentication of federal employees and contractors for access to federal facilities and information systems….

  • Phantom read

    When a reader reports the presence of a tag that doesn’t exist. This phenomenon is also sometimes called a phantom transaction or false read….

  • Phase

    A part of a complete cycle of a waveform as measured from a specified reference point….

  • Phase Jitter Modulation

    A variant of phase-shift keying, created by Magellan Technology, which operates at 13.56 MHz and complies with the ISO/IEC 18000 3 Mode 2 standard. PJM technology enables a write data rate of up to 424 kilobits per second and a read data rate of 106 kbit/s. It is particularly suited to item-level tagging in the pharmaceutical industry….

  • Phase shift keying

    A method of communicating data by shifting the waveform’s period. Instead of being at the zero axis at a specific point in time, the wave might be shifted forward so that it is at its peak. The reader’s digital signal processor might interpret the out of phase signal as a one or zero….

  • Physical Markup Language

    An Auto-ID Center-designed method of describing products in a way computers can understand. PML is based on the widely accepted eXtensible Markup Language used to share data over the Internet in a format all computers can use. The idea is to create a computer language that companies can use to describe products so that computer can search for, say, all “soft drinks” in inventory….

  • PML

    See Physical Markup Language …

  • PML Server

    A server that responds to requests for Physical Markup Language (PML) files related to individual Electronic Product Codes. The manufacturer of the item will maintain the PML files and servers. The name PML server has been replaced by EPC Information Service….

  • Portal

    An RFID interrogator gateway used in manufacturing settings. Forklifts or other methods are used to transport tagged items through a portal reader to collect RFID tag data….

  • Power level

    The amount of RF energy radiated from a reader. The higher the power output, the longer the read range, but most governments regulate power levels to avoid interference with other devices….

  • Printer

    An RFID printer, or printer/encoder, is a device that prints a label with an embedded RFID transponder and encodes information in the chip within the transponder….

  • Printer/encoder

    See printer…

  • Private key

    A cryptographic key known only to the owner….

  • Programming a tag

    Writing data to an RFID tag. When a serial number is first written to a tag, this is sometimes called “commissioning a tag.”…

  • Protocol

    A set of rules that govern communications systems. (See Air-interface protocol.)…

  • proximity card

    A proximity card is a card with a passive RFID transponder that can be read when placed near an RFID reader. Proximity cards usually use the ISO 14443 passive HF RFID standard, which is designed to have a short read range, to ensure that the tag-to-reader communication cannot be intercepted by a third party….

  • Proximity sensor

    A device that detects the presence of an object and signals another device. Proximity sensors are often used on manufacturing lines to alert robots or routing devices on a conveyor to the presence of an object. They can be used in RFID systems to turn on readers….

  • Public key

    The publicly available and distributed key used in public key cryptography systems. …

  • Public key cryptography

    A generic term for all public key algorithms. PKC uses a pair of numeric “keys,” one public and one private key. The public key is published and can be used by anyone to either encrypt a message for the owner of the corresponding private key or to verify a signature generated by the owner of the secret key….

  • Public key infrastructure

    A system of storing and distributing public keys together with their current status….

  • Pulse interval encoding

    A method of sending data to an RFID tag by emitting pulses of energy with varying intervals, in order to indicate the ones and zeroes of binary code stored on the tag….

  • Q

    In the Gen 2 air interface protocol, Q is a parameter that a reader uses to regulate the probability of tag response. A reader commands tags in an
    inventory round to choose a random number between zero and 2^Q; a tag
    may be successfully singulated if no other tags choose the same random
    number (a “collision”). Larger Q values decrease the probability of collision,
    but require the reader to spend more time during singulation….

  • Quiet tag

    An RFID tag that can be read only occasionally with the interrogator output at full power, or which can only be read at very close range. …

  • Radio Frequency Identification

    Any method of identifying unique items using radio waves. Typically, a reader (also called an interrogator) communicates with a transponder, which holds digital information in a microchip. But there are chipless forms of RFID tags that use material to reflect back a portion of the radio waves beamed at them….

  • RAM

    See random access memory…

  • Random access memory

    Memory used for temporary storage of data. Information stored in RAM is lost when power is removed….

  • Read

    The process of retrieving data stored on an RFID tag by sending radio waves to the tag and converting the waves the tag sends back into data….

  • Read accuracy

    This term usually refers to percentage of tags read successfully. If there are 100 tags in the field and 95 are read, the read accuracy is 95 percent. …

  • Read field

    See reader field….

  • Read lock

    Locking one or more of a Tag’s memory areas so that a subsequent reader is required to exchange appropriate security safeguards with the Tag before being able to read these memory areas….

  • Read range

    The distance from which a reader can communicate with a tag. Active tags have a longer read range than passive tags because they use their own power source (usually a battery) to transmit signals to the reader. With passive tags, the read range is influenced by frequency, reader output power, antenna design, and method of powering up the tag. Low-frequency tags use inductive coupling, which requires the tag to be within a few feet of the reader….

  • Read rate

    A term usually used to describe the number of tags that can be read within a given period or the number of times a single tag can be read within a given period. The read rate can also mean the maximum rate at which data can be read from a tag expressed in bits or bytes per second. (See Data transfer rate.)…

  • Read-only

    A term used to describe RFID tags that contain data that cannot be changed unless the microchip is reprogrammed electronically….

  • Read-write

    A term used to describe an RFID tag that can store new information on its microchip. These tags are often used on reusable containers and other assets. When the contents of the container are changed, new information is written to the tag. …

  • Reader

    A device used to communicate with RFID tags. The reader has one or more antennas, which emit radio waves and receive signals back from the tag. The reader is also sometimes called an interrogator because it “interrogates” the tag. …

  • Reader field

    The area of coverage. Tags outside the reader field do not receive radio waves and can’t be read. This is also sometimes referred to as the read field….

  • Reader module

    The electronics of a reader, including a digital signal processor, on a circuit board. Modules can be put in an RFID label printer or other device, as opposed to a standalone reader….

  • Reader talks first

    A means by which a passive UHF reader communicates with tags in its read field. The reader sends energy to the tags but the tags sit idle until the reader requests them to respond. The reader is able to find tags with specific serial numbers by asking all tags with a serial number that starts with either 1 or 0 to respond. If more than one responds, the reader might ask for all tags with a serial number that starts with 01 to respond, and then 010. This is called “walking” a binary tree, or “tree walking.” (See singulation.)…

  • Real-time locating system

    A system of finding the position of assets, using active RFID tags. The tags broadcast a signal, which is received by three reader antennas. The time each signal is received is passed on to a software system that uses triangulation to calculate the location of the asset. RTLS is used to find containers in a distribution yard, and many automakers use it to track parts bins within a large factory. …

  • Received signal strength indication (RSSI)

    A measurement of the strength of a radio signal being received. In RFID, RSSI is used to determine a tag’s distance, as the signal is stronger from a tag that is closer to the reader antenna….

  • Return on Investment

    The ratio of money gained or lost on an investment relative to the amount invested. The amount gained or lost may be referred to as interest, profit/loss, gain/loss or net income/loss, while the money invested may be referred to as the asset, capital, principal or cost basis of the investment. ROI is sometimes also known as “rate of profit” or “rate of return.”…

  • Reverse channel

    The path through which energy travels from the RFID tag to the interrogator, or reader. It is also sometimes called the back channel….

  • RFID

    See radio frequency identification …

  • RFID Journal

    The leading independent publication focused on radio frequency identification and its many business applications….

  • RFID tag

    A microchip attached to an antenna that is packaged in a way that it can be applied to an object. The tag picks up signals from and sends signals to a reader. The tag contains a unique serial number, but may have other information, such as a customers’ account number. Tags come in many forms, such smart labels that can have a barcode printed on it, or the tag can simply be mounted inside a carton or embedded in plastic. RFID tags can be active, passive or semi-passive….

  • RTLS

    See real-time locating system…

  • RuBee

    A two-way, active wireless protocol designed for harsh-environment, high-security asset-visibility applications. The primary purpose of most RuBee deployments is to identify objects (often weapons), in order to better manage those objects….

  • Savants

    A term used to describe distributed middleware designed by the Auto-ID Center to filter data from EPC readers and pass it on to enterprise systems. It was envisioned that Savants would reside on servers across the EPC Network and pass data to one another and act as a kind of nervous system for the network. The term is being phase out by EPCglobal and many of the functions of Savants are being incorporated in commercial middleware products. …

  • SAW

    A technology used for automatic identification in which low power microwave radio frequency signals are converted to ultrasonic acoustic signals by a piezoelectric crystalline material in the transponder. Variations in the reflected signal can be used to provide a unique identity….

  • Scanner

    An electronic device that can send and receive radio waves. When combined with a digital signal processor that turns the waves into bits of information, the scanner is called a reader or interrogator….

  • Seismic Sensor

    A device combining a supersensitive piezoelectric accelerometer with an ultra-low-noise amplifier, used in such applications as earthquake detection, geophysics, geothermal development, structural analysis and mine safety….

  • Semi-passive tag

    Similar to active tags, but the battery is used to run the microchip’s circuitry but not to broadcast a signal to the reader. Some semi-passive tags sleep until they are woken up by a signal from the reader, which conserves battery life. Semi-passive tags can cost a dollar or more. These tags are sometimes called battery-assisted tags….

  • Sensor

    A device that responds to a physical stimulus and produces an electronic signal. Sensors are increasingly being combined with RFID tags to detect the presence of a stimulus at an identifiable location. …

  • Shielding

    Uses a Faraday cage, Mylar sheet or metal barrier to prevent RF noise from interfering with the ability to read RFID tags, or to prevent RFID readers from interfering with other RF devices….

  • Signal attenuation

    The weakening of RF energy from an RFID tag or reader. The energy emitted by the reader naturally decreases with distance. The rate of decrease is proportional to the inverse square of the distance. Passive UHF RFID tags reflect back a signal at very low power levels. A tag’s reflected signal decreases as the inverse fourth power of the distance between tag and reader. Attenuation can be increased by external factors as well. For instance, water absorbs UHF energy, causing signal attenuation….

  • Silent Commerce

    This term covers all business solutions enabled by tagging, tracking, sensing and other technologies, including RFID, which make everyday objects intelligent and interactive. When combined with continuous and pervasive Internet connectivity, they form a new infrastructure that enables companies to collect data and deliver services without human interaction….

  • SIM

    See subscriber identity module…

  • Singulation

    A means by which an RFID reader identifies a tag with a specific serial number from a number of tags in its field. There are different methods of singulation, but the most common is “tree walking”, which involves asking all tags with a serial number that starts with either a 1 or 0 to respond. If more than one responds, the reader might ask for all tags with a serial number that starts with 01 to respond, and then 010. It keeps doing this until it finds the tag it is looking for. (See Reader talks first.)…

  • Skimming

    Reading an RFID tag on a person without their knowledge or reading a tag surreptitiously….

  • Slap and ship

    A generic term that refers to putting an RFID label on a case or pallet just before it is shipped from a supplier’s facility to a retailer’s facility. This approach to using RFID is strictly to meet the retailer’s requirements and delivers no internal benefits to the supplier….

  • Slotted antenna

    An antenna that consists only of a narrow slot cut into an electrical conductor connected to the transponder. Slotted antennas exhibit the same orientation sensitivity as dipoles….

  • Smart cards

    A credit card or other kind of card with an embedded microchip. When the card uses RFID technology to send and receive data it is called a contactless smart card….

  • Smart label

    A generic term that usually refers to a bar code label that contains an RFID transponder. It’s considered “smart” because it can store information, such as a unique serial number, and communicate with a reader….

  • Smart reader

    See intelligent reader…

  • Strap

    A type of interposer….

  • Subscriber identity module

    An essential component of a GSM mobile phone. It contains the identity of the subscriber and assures the authentication during the access into the network and provides data storage for other subscriber related information, such as a personal address books. …

  • Substrate

    An underlying layer….

  • Supply Chain Execution System

    The optimization of customer response by merging the storage and delivery of finished goods. The execution phase may involve the final assembly and packaging of products within a warehouse environment….

  • Supply Chain Management System

    The process of planning, implementing and controlling the operations of the supply chain to efficiently satisfy customer requirements. Supply-chain management spans all movement and storage of raw materials, work-in-process inventory and finished goods, from the point of origin to the point of consumption….

  • Surface acoustic wave

    A technology used for automatic identification in which low power microwave radio frequency signals are converted to ultrasonic acoustic signals by a piezoelectric crystalline material in the transponder. Variations in the reflected signal can be used to provide a unique identity. …

  • Synchronization

    In RFID, the term refers to timing readers or reader antennas near one another so that they don’t interfere with one another….

  • Tag

    See RFID tag…

  • Tag excitation device

    A term coined by the RFID Alliance Lab to refer to a device that sends signals to the tag regardless of the make or manufacturer. TED is used to measure the response of tags scientficially….

  • Tag talks first

    A means by which a reader in a passive UHF system identifies tags in the field. When tags enter the reader’s field, they immediately communicate their presence by reflecting back a signal. This is useful when you want to know everything that is passing a reader, such as when items are moving quickly on a conveyor. In other cases, the reader wants to simply find specific tags in a field, in which case it wants to broadcast a signal and have only certain tags respond. (See Reader talks first.)…

  • Tamper-evident tag

    An RFID tag that communicates to a reader when a package or container has been opened without authorization….

  • TDMA

    See time division multiple access …

  • TED

    See tag excitation device…

  • Time division multiple access

    A method of solving the problem of the signals of two readers colliding. Algorithms are used to make sure the readers attempt to read tags at different times….

  • Track and trace

    The process of retrieving information about the movement and location of goods. …

  • Transceiver

    A device that both transmits and receives radio waves….

  • Transponder

    A radio transmitter-receiver that is activated when it receives a predetermined signal. RFID transponders come in many forms, including smart labels, simple tags, smart cards and keychain fobs. RFID tags are sometimes referred to as transponders….

  • Type A Reference Interval (TARI)

    The duration of a pulse of energy sent to UHF EPC Gen 2 tags to indicate a 0 in binary code. EPC Gen 2-compliant readers use pulse interval encoding (PIE) to code binary data. A binary ‘0’ is indicated by a short, high-level pulse, followed by a low pulse of equal length. The length of a TARI can vary from 6.25 to 25 microseconds….

  • UCC

    See Uniform Code Council…

  • UHF

    See ultra-high frequency…

  • UID

    See Unique Identification…

  • Ultra-high frequency

    From 300 MHz to 3 GHz. Typically, RFID tags that operate between 866 MHz to 960 MHz. They can send information faster and farther than high- and low-frequency tags. But radio waves don’t pass through items with high water content, such as fruit, at these frequencies. …

  • Ultra-Wideband

    Any radio technology having a bandwidth exceeding the lesser of 500 MHz or 20 percent of the arithmetic center frequency, according to the Federal Communications Commission (FCC). Due to the extremely low emission levels currently allowed by regulatory agencies, UWB systems tend to be short-range and used indoors. High data-rate UWB can enable wireless monitors, the wireless printing of digital pictures from a camera without an intervening personal computer and the transfer of files among cell phone handsets and other handheld devices, such as personal digital audio and video players. UWB is used in location systems and real-time location systems….

  • Uniform Code Council

    The nonprofit organization that oversees the Universal Product Code, the bar code standard used in North America….

  • Unique Identification

    A numbering scheme used by the U.S. Department of Defense to track high-value items and items, such as chemical suits, that have an expiration date….

  • Unique identifier

    A unique serial number that identifies the transponder. …

  • Universal Product Code

    A generic term that refers to the 12 digit data structure encoded in a UCC bar codes….

  • Universal Serial Bus

    An external peripheral interface standard for communication between a computer and external peripherals over an inexpensive cable. Many newer RFID readers can connect to computers via a USB port….

  • UPC

    See Universal Product Code…

  • USB

    See Universal Serial Bus…

  • UWB

    Any radio technology having a bandwidth exceeding the lesser of 500 MHz or 20 percent of the arithmetic center frequency, according to the Federal Communications Commission (FCC). Due to the extremely low emission levels currently allowed by regulatory agencies, UWB systems tend to be short-range and used indoors. High data-rate UWB can enable wireless monitors, the wireless printing of digital pictures from a camera without an intervening personal computer and the transfer of files among cell phone handsets and other handheld devices, such as personal digital audio and video players. UWB is used in location systems and real-time location systems….

  • Voltage standing wave ratio

    A standing wave may be formed when a wave is transmitted into one end of a transmission line and is reflected from the other end by an impedance mismatch. The Voltage standing wave ratio is the ratio of maximum to minimum voltage in a standing wave pattern. It may be stated as a ratio (VSWR) or in dB (return loss)….

  • VSWR

    See voltage standing wave ratio…

  • Warehouse Management System

    A key component of the supply chain, intended to control the movement and storage of materials within a warehouse and process the associated transactions, including shipping, receiving, putaway and picking. Such systems also direct and optimize stock putaway based on real-time information about the status of bin utilization. WMSs utilize auto-ID data-capture technology, such as bar-code scanners, mobile computers, wireless LANs and RFID, to efficiently monitor the flow of products….

  • Wi-Fi

    The generic wireless interface of mobile computing devices, such as laptops used in local area networks (LANs). The term “Wi-Fi” (a play on the term “Hi-Fi”) is thought to be an abbreviation for “wireless fidelity.” Common uses include Internet and voice-over-IP phone access, gaming and network connectivity for such consumer electronics as televisions, DVD players and digital cameras. In spite of media reports about possible health risks from Wi-Fi, scientific studies have failed to show a causal effect….

  • WIP Tracking

    See Work-in-process tracking….

  • Wireless Markup Language

    WML is a markup language that is based on XML (eXtensible Markup Language). The official WML specification is developed and maintained by the WAP Forum, an industry-wide consortium founded by Nokia, Phone.com, Motorola, and Ericsson. This specification defines the syntax, variables, and elements used in a valid WML file….

  • WML

    See Wireless Markup Language…

  • Work-in-process Tracking

    Manufacturers often have to add parts to subassemblies or perform a series of processes on goods being manufactured. Using RFID to track work-in-process reduces manual data collection and can help ensure that the right processes are preformed at the proper time on the correct product….

  • WORM

    See write once, read many…

  • Write once, read many

    A tag that can be written to only once by the user. Thereafter, the tag can only be read….

  • Write range

    The distance from which data can be written to an RFID tag….

  • Write rate

    The rate at which information is transferred to a tag, written into the tag’s memory and verified as being correct….

  • X12 EDI

    An electronic data interchange schema developed for the American National Standards Institute for inter-industry electronic exchange of business transactions data….

  • XML

    See eXtensible Markup Language…

  • XML Query Language

    A method of searching a database based on the extensible markup language (XML). Files created using the Auto-ID Center’s Physical Markup Language can be searched using XQL….

  • XQL

    See XML Query Language…

  • ZigBee

    A specification for a suite of high-level communication protocols using small, low-power digital radios based on the IEEE 802.15.4 standard for wireless personal area networks (WPANs). ZigBee is targeted at RF applications requiring a low data rate, long battery life and secure networking….