REPORT ON RFID

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RFID  Report Transcript

1. INTRODUCTION TO RFID 1.1 Brief description RFID stands for Radio Frequency Identification and is a term that describes a system of identification. RFID is based on storing and remotely retrieving information or data as it consists of RFID tag, RFID reader and back-end Database. RFID tags store unique identification information of objects and communicate the tags so as to allow remote retrieval of their ID. RFID technology depends on the communication between the RFID tags and RFID readers.

The range of the reader is dependent upon its operational frequency. Usually the readers have their own software running on their ROM and also, communicate with other software to manipulate these unique identified tags. Basically, the application which manipulates tag deduction information for the end user, communicates with the RFID reader to get the tag information through antennas. Many researchers have addressed issues that are related to RFID reliability and capability. RFID is continuing to become popular because it increases efficiency and provides better service to stakeholders. RFID technology has been realized as a performance differentiator for a variety of commercial applications, but its capability is yet to be fully utilized. 1.2 RFID Evolution RFID technology has passed through many phases over the last few decades. The technology has been used in tracking delivery of goods, in courier services and in baggage handling. Other applications includes automatic toll payments, departmental access control in large buildings, personal and vehicle control in a particular area, security of items which shouldn’t leave the area,

equipment tracking in engineering firms, hospital filing systems, etc. • 1940-1950: RFID investigated in 1948. Radar defined and used. Major World War II development efforts were made. • 1950-1960: Exposure to the laboratory experiments was given. Early exploration of the technology was done. • 1960-1970: Early field trails. Development of the theory of RFID. • 1970-1980: Early adopter implementation of RFID. Explosion of RFID development. Tests of RFID accelerated. • 1980-1990: Main stream of RFID communication application was defined. • 1990-2000: Widely deployed and standardized. • 2000-2010: Innovative application. Involvement in personal services and became the part of a daily life. 2. COMPONENTS OF RFID The RFID system consists of various components which are intergraded in a manner defined in the above section. This allows the RFID system to deduct the objects (tag) and perform various operations on it. The integration of RFID components enables the implementation of an RFID solution. The RFID system consists of following five components. 2.1 Tags Tags contain microchips that store the unique identification (ID) of each object. The ID is a serial number stored in the RFID memory. The chip is made up of intergraded circuit and embedded in a silicon chip. RFID memory chip can be permanent or changeable depending on the read/write characteristics. Read-only and rewrite circuits are different as read-only tag contains fixed data and cannot be changed without re-program electronically. On the other hand, re-write tags can be programmed through the reader at any time without any limit. RFID tags can be different sizes and shapes depending on the application and the environment at which it will be used. A variety of materials are intergraded on these tags. For example, in the case of the credit cards, small plastic pieces are stuck on various objects,

and the labels. Labels are also embedded in a variety of objects such as documents, cloths, manufacturing materials etc. There are mainly three types of Tags which are as follows: 2.1.1 Active tags Active RFID tags have their own internal power source which is used to power any ICs that generate the outgoing signal. Active tags are typically much more reliable (e.g. fewer errors) than passive tags due to the ability for active tags to conduct a

"session" with a reader. Active tags, due to their onboard power supply, also transmit at higher power levels than passive tags, allowing them to be more effective in "RF challenged" environments like water (including humans/cattle, which are mostly water), metal (shipping containers, vehicles), or at longer distances. Many active tags have practical ranges of hundreds of meters, and a battery life of up to 10 years. Some active RFID tags include sensors such as temperature logging which have been used in concrete maturity monitoring or to monitor the temperature of perishable goods. Other sensors that have been married with active RFID include humidity, shock/vibration, light, radiation, temperature and atmospherics like ethylene. Active tags typically have much longer range (approximately 300 feet) and larger memories than passive tags,

as well as the ability to store additional information sent by the transceiver. The United States Department of Defense has successfully used active tags to reduce logistics costs and improve supply chain visibility for more than 15 years. At present, the smallest active tags are about the size of a coin and sell for a few dollars. Fig 2.1.1 Active RFID Tag 2.1.2 Passive Tags Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming radio frequency signal provides just enough power for the CMOS integrated circuit in the tag to power up and transmit a response.

The lack of an onboard power supply means that the device can be quite small: commercially available products exist that can be embedded in a sticker, or under the skin. As of 2006, the smallest such devices measured 0.15 mm × 0.15 mm, and are thinner than a sheet of paper (7.5 micrometers). The lowest cost EPC RFID tags, which are the standard chosen by Wal-Mart, DOD, Target, Tesco in the UK and Metro AG in Germany, are available today at a price of 5 cents each. The addition of the antenna creates a tag that varies from the size of a postage stamp to the size of a post card. Passive tags have practical read distances ranging from about 10 cm (4 in.) (ISO 14443) up to a few meters (EPC and ISO 18000-6) depending on the chosen radio frequency and antenna design/size. Due to their simplicity in design they are also suitable for manufacture with a printing process for the antennas. Fig 2.1.2 Passive RFID Tags 2.1.3 Semi-passive tags Semi-passive tags, also called semi-active tags, are similar to active tags in that they have their own power source, but the battery only powers the microchip and does not power the broadcasting of a signal. Fig. 2.1.3.1 RFID active and passive tags comparison. Fig2.1.3.2 Tag classification The simplest RFID chips contain only a serial number—

say a 64- bit or 96-bit block of read-only storage. Although the serial number can be burned into the chip by the manufacturer, it is also common for the chips to be programmed in the ?eld by the end user. Some chips will accept only a single serial number, while other chips allow the serial number to be changed after it is burned in. More sophisticated RFID chips can contain read-write memory that can be programmed by a reader. Chips can also have sensors, an example of which is an air pressure sensor to monitor the in?ation of a tire. The chips might store the results of the sensor in a piece of read-write memory or simply report the sensor’s reading to the RFID reader. Chips can also have a self-destruct, or “kill” feature. This is a special code that, when received by the chip, causes the chip to no longer respond to commands. For ?nancial applications, the full capabilities of smart cards have been combined with the wireless protocols and passive powering used in RFID.

The result is a class of high-capability RFID tags also called contactless smart cards. 2.2 Readers The RFID reader sends a pulse of radio energy to the tag and listens for the tag’s response. The tag detects this energy and sends back a response that contains the tag’s serial number and possibly other information as well. In simple RFID systems, the reader’s pulse of energy functioned as an on-off switch; in more sophisticated systems, the reader’s RF signal can contain commands to the tag, instructions to read or write memory that the tag contains, and even passwords. Historically, RFID readers were designed to read only a particular kind of tag, but so-called multimode readers that can read many different kinds of tags are becoming increasingly popular. RFID readers are usually on,

continually transmitting radio energy and awaiting any tags that enter their ?eld of operation. However, for some applications, this is unnecessary and could be undesirable in battery-powered devices that need to conserve energy. Thus, it is possible to con?gure an RFID reader so that it sends the radio pulse only in response to an external event. For example, most electronic toll collection systems have the reader constantly powered up so that every passing car will be recorded. On the other hand, RFID scanners used in veterinarian’s offices are frequently equipped with triggers and power up the only when the trigger is pulled.

Like the tags themselves, RFID readers come in many sizes. The largest readers might consist of a desktop personal computer with a special card and multiple antennas connected to the card through shielded cable. Such a reader would typically have a network connection as well so that it could report tags that it reads to other computers. The smallest readers are the size of a postage stamp and are designed to be embedded in mobile telephones. Fig 2.2.1 RFID Readers 2.3 Antenna and frequency The RFID physical layer consists of the actual radios and antennas used to couple the reader to the tag so that information can be transferred between the two. Radio energy is measured by two fundamental characteristics: the frequencies at which it oscillates and the strength or power of those oscillations. Commercial FM broadcast stations in the United States transmit with energy at a frequency between 88MHz and 108MHz, or 1 million isolations per second. The AM spectrum, by contrast, transmits at 500,000 to 1,500,000 oscillations per second, or between 500 KHz and 1500KHz. Microwave ovens cook with RF energy that vibrates 2.4 billion times each second, which is 2.4GHz. The RFID physical layer consists of the actual radios and antennas used to couple the reader to the tag so that information can be transferred between the two. Radio energy is measured by two fundamental characteristics:

the frequencies at which it oscillates and the strength or power of those oscillations. Commercial FM broadcast stations in the United States transmit with energy at a frequency between 88MHz and 108MHz, or 1 million isolations per second. The AM spectrum, by contrast, transmits at 500,000 to 1,500,000 oscillations per second, or between 500 KHz and 1500KHz. Microwave ovens cook with RF energy that vibrates 2.4 billion times each second, which is 2.4GHz. Band Unlicensed frequency Wavelength Classical use LF 125-134.2 KHz 2,400 m Animal tagging, keyless entry HF 13.56 MHz 22 m Same as above UHF 865.5-867.6 MHz (Europe) 915 MHz (U.S) 950-956 MHz (Japan) 865-867 MHz (India) 32.8 cm Smart cards, logistics, item management ISM 2.4 GHz 12.5 cm Item management Table 2.3.1 Sizes of waves of each unlicensed band Building proximity cards, automobile immobilizer chips, and implantable RFID ampoules tend to operate in the LF band. The FDA has adopted the HF band for RFID systems used for prescription drugs. The EPC system operates in the HF and UHF bands,

although early deployments are favoring the UHF band. When analyzing the energy that is radiated from an antenna, electrical engineers divide the ?eld into two parts: the near ?eld, which is the part of radiation that is within a small number of wavelengths of the antenna, and the far ?eld, which is the energy that is radiated beyond the near ?eld. Because the wavelength of LF and HF devices tends to be much larger than the ranges at which RFID systems typically operate, these systems operate in the near ?eld, while UFH and ISM systems operate in the far ?eld. As with most radio systems, the larger the antenna on the reader and the tag, the better an RFID system will work because large antennas are generally more efficient at transmitting and receiving radio power than are small antennas. Thus, a large antenna on the reader means that more power can be sent to the RFID tag and more of the tag’s emitted energy can be collected and analyzed. A large antenna on the tag means that more of the power can be collected and used to power the chip. Likewise, a large antenna on the chip means that more power can be transmitted back to the reader. Fig 2.3.2 RFID Antennas Fig 2.3.3 System Overview 2.2 Network and Software Most RFID tags transmit a number and nothing more. So what does a typical reader do with a typical 96-bit number like 79,228,162,514,264,337,593, 543,950,335? 6 In most cases, the reader sends it to a computer.

What the computer does with the RFID code depends on the application. With an access control system, the computer might look to see if the RFID number is present on a list of numbers that’s allowed access to a particular door or location. If the number is present, the computer might energize a solenoid that would unlock the door. In the case of the Mobil Speed pass system, the tag’s serial number and its response to the random challenge that was generated by the reader are sent over Mobil’s payment network. If the challenge response matches the token, Mobil’s computers approve the user of the customer’s credit-card number to complete the transaction. With the EPC, the serial number will be sent to a network of computers that make up the Object Name Service (ONS), a large distributed database that will track a variety of pieces of information about objects that have been assigned EPC codes. The database consists of both central “root” servers and distributed servers at each company that creates products labeled with EPC tags.

Given any EPC code, the root servers would tell a computer which company’s servers to go to, and then the company’s servers would explain what the EPC code means. The overall design of the ONS is similar to that of another distributed database, the Domain Name System (DNS), which maps Internet hostnames to Internet Protocol (IP) addresses. In fact, VeriSign, the company that has the contract to run the global DNS, was also awarded the contract by EPC global to run the ONS. 3. SOME PARAMETERS OF RFID 3.1 Coupling range and Penetration Active and passive RFID systems have very different reading ranges. With batteries and high-gain antennas, active RFID systems have ranges roughly equivalent to those of any other system operating under the rules for unlicensed radio systems. In the United States, for example, an unlicensed system can transmit with up to 1 watt of power; under these conditions, a signal can be received over a mile if directional antennas are used and there are no obstructions.

Coupling While it is possible to build RFID systems such that both the tag and reader contain a radio transmitter and a radio receiver, this method of operation is ideal only for active systems attempting to communicate over the longest distances. Because placing and powering a transmitter on the tag is an expensive proposition, passive tag systems are usually chosen for applications that are extremely sensitive to the cost of the tag. The passive tag will have to have some form of energy storage, for example a capacitor, to provide power when the reader stops transmitting and starts receiving or the reader must always transmit, meaning the tag has to reply on a different frequency. Instead, passive RFID systems typically couple the transmitter to the receiver with either load modulation or backscatter, depending on whether the tags are operating in the near or far ?eld of the reader, respectively. In the near ?eld, a tag couples with a reader via electromagnetic inductance.

The antennas of both the reader and the tag are formed as coils, using many turns of small gauge wire. The current in the reader’s coil creates a magnetic ?eld. This ?eld, in turn, induces a current in the coil of the tag. A transformer works by the same principle, and in essence the coils of the reader and tag together form a transformer. The reader communicates with the tag by modulating a carrier wave, which it does by varying the amplitude, phase, or frequency of the carrier, depending on the design of the RFID system in question. This modulation can be directly detected as current changes in the coil of the tag. The tag communicates with the reader by varying how much it loads its antenna. This in turn affects the voltage across the reader’s antenna. By switching the load on and off rapidly, the tag can establish its own carrier frequency (really a subcarrier) that the tag can in turn modulate to communicate its reply. Tags that operate in the far ?eld (UHF and ISM bands) couple with their readers using backscatter. Backscatter results when an electromagnetic wave hits a surface and some of energy of that wave is reflected back to the transmitter, and it is one of the fundamental physics behind RADAR. The amount of energy reflected depends on how well the surface resonates with the frequency of the electromagnetic wave. RFID tags that use backscatter to reply to their readers have antennas that are designed to resonate well with the carrier put out by the reader. The tag can throw a switch that changes the resonant properties of its antenna so that it reflects poorly instead, thus creating a pattern in its backscatter that is detected at the reader.

The return communication is encoded in the backscatter pattern. There is a third, less common type of coupling between reader and tag: electrostatic coupling. With electrostatic coupling, the reader and tag antennas are charged plates. Adding electrons to the plate on the reader will push electrons off the plate onto the tag, and vice versa. The plate area determines range with electrostatic coupling. An advantage to electrostatic coupled systems is that the antenna patches can be printed with conductive ink, making their design very flexible and inexpensive. 3.2 Penetration, Screening, and Shielding Most tags are read through the air, but sometimes there is intervening material, such as water, plastics, cans, or people. As with all radio signals, the range of an RFID system is dramatically affected by the environment through which the radio signals travel.

Two of the most potent barriers for radio signals in the HF and UHF regions of the spectrum are water and metal, and they can profound impacts on RFID in typical operations. The phenomenon to be considered is dielectric coupling. Dielectric coupling can take place between antennas and dielectric materials like cardboard or, in some cases, the human body. Using this coupling will result in detuning the antenna, which will make the antenna less efficient and, consequently, will decrease read range. This is why some proximity cards can be read if they are in a wallet but can’t be read if that wallet is in a person’s pocket. In other cases, two proximity cards placed next to each other can cause mutual interference because of this kind of coupling. If the intention is to shield an RFID tag against an RFID reader,

it is quite easy to do. A single layer of aluminum foil is sufficient to shield most low power RF devices. For RFID, aluminum needs to be only 27 microns thick, according to Matthew Reynolds at Thing Magic to effectively shield a tag. And just 1mm of dilute salt water (also a conductor) provides similar protection. 4. RFID APPLICATIONS RFID, Radio Frequency Identification is a technology, which includes wireless data capture and transaction processing. Proximity (short range) and Vicinity (long range) are two major application areas where RFID technology is used. Track and trace applications are long range or vicinity applications. This technology provides additional functionality and benefits for product authentication. Access control applications are Short range or proximity type of applications. Agile Sense Technologies is focused on delivering innovative, high value RFID solutions assisting companies track assets, people and documents. Agile Sense provides robust and complete RFID solutions built on top of its extensible middleware/framework for Government, Healthcare, Manufacturing and Aerospace industries. 4.1 Supply Chain Management This is the most widely and successfully used application of RFID. This application is nearly used in many marts and warehouses. It is one of the most efficient technique which reduces manual labour and time. RFID in the Retail Supply Chain Wal-Mart and DoD suppliers are moving forward with EPC RFID implementations to gain operational improvements, such as: • 100 percent inventory visibility • Major reduction in losses and shrinkage • Tracking lot and expiration dates • Work in process data management • Enabling tags to carry real-time databases of item information • Assigning unique serial numbers to items • Sharing EPC and other product data with partners in the supply chain Tracing Operational Improvements with RFID 1.

In the Manufacturing plant, pallets arrive at the dock door where stationery readers pick up EPC numbers and other data about the shipment. 2. Received goods are checked against the Shipping Manifest and will go to one of three areas Inventory, Production or Returns. 3. A new shipping smart label is created to ship Returns back to suppliers. 4. Inventory cases are read by a forklift reader that updates the system with product and location data where they will be stored in the Warehouse. 5. Production components are read at the case level, updating the system that these goods will be used immediately. Individual components needed to assemble new products are collected into bins at the start of the Production Line, allowing the manufacturer to link EPC data of raw materials with the finished products.

A smart label is generated to identify the bin and its contents. 6. As the bins move toward the work-in-process line, they are read into the system by stationary conveyor-belt readers. 7. As workers assemble components into products, a smart label is attached to the product at the outset of Work in Process. Strategically positioned reader/encoders write data about each task that is completed to the read/write tag in the smart label. 8. At Quality Control, a reader picks up EPC numbers of products that have passed inspection.

EPC numbers and product data are recorded in the manufacturer’s database, providing QC documentation as goods move through the supply chain. 9. Finished goods go to Packaging and a smart label is created that contains specific new product data. 10. A fork-lift reader is used to update the system with information about the location where finished goods are stored. 11. Inventory is also stored in the warehouse. As cases are removed from shelves and used in manufacturing, a hand-held reader or forklift reader can be used to update the system. 12. In the Warehouse, finished goods destined for a particular Distribution Center are collected into pallets. 13. As pallets leave the dock door, stationary readers at Dispatch take a final reading of the goods and update the system that they have been loaded on to a truck for shipping out. 14.

Advance Shipping Manifests give Distribution Centers data about pallets of good that will arrive. Pallets are read by stationary readers that record the shipment and flag duplicate, unordered or suspect items. 15. Forklift readers/encoders update the system with the location of goods that are being stored. At any time, sensors can record conditions in the DC and add data to the smart label, allowing products to carry their own pedigree or history. 16. At the DC, goods from multiple suppliers are collected on pallets and targeted for a particular Retail destination. Pallets are shrink-wrapped to protect contents and keep them stable.

A smart label is created to identify the contents of the pallet and encode shipping instructions. Stationary readers at the dock doors update the system about outbound shipments. 17. Stationary readers at the dock doors update the system to reflect what types of goods have been received, from whom and when. Again, goods that are accepted will be stored in the Backroom or placed directly onto shelves in-store. 18. Stationary readers or forklift readers update the system as goods transition from the backroom into the Retail Store. 19. Shelf readers report back into the system when items are low and shelves need restocking. 20. EPC numbers become inactive at the end of the supply chain when containers are recycled in Compacting, unless assets, such as pallets or cartons, will be reused. Fig 4.1.1 Flow representation of Supply Chain Fig 4.1.2 Role of RFID in Supply Chain Management 4.2 Asset Identification Static or in-motion assets tracking or locating, like a healthcare facility, wheelchairs or IV pumps in, laptops in a corporation and servers in a data center, was not so easy task. User can instantly determine the general location of tagged assets anywhere within the facility with the help of active RFID technology. Control point detection zones at strategic locations throughout the facility allow the user to define logical zones and monitor high traffic areas. Tagged assets moving through these control points provide instant location data.

Asset tracking applications will see an almost vertical growth curve in the coming years and the growth rate in this area will be much higher than the growth rate of general RFID market. Fig 4.2.1 Role Of RFID in Asset Identification 4.3 People Identification People tracking system are used just as asset tracking system. Hospitals and jails are most general tracking required places. Hospital uses RFID tags for tracking their special patients. In emergency patient and other essential equipment can easily track. It will be mainly very useful in mental care hospitals where doctors can track each and every activity of the patient. Hospitals also use these RFID tags for locating and tracking all the activities of the newly born babies. The best use of the people tracking system will be in jails. It becomes an easy tracking system to track their inmates. Many jails of different US states like Michigan,

California, and Arizona are already using RFID-tracking systems to keep a close eye on jail inmates. 4.4 Document Identification This is most common problem. Availability of large amount of data and documents brings lots of problem in document management system. An RFID document-tracking system saves time and money by substantially reducing: • Time spent searching for lost document • The financial and legal impact associated with losing documents. 4.5 Library Many government libraries use barcode and electromagnetic strips to track various assets. RFID technology uses for reading these barcodes unlike the self-barcode reader RFID powered barcode reader can read multiple items simultaneously.

This reduces queues and increases the number of customers using self-check, which in turn will reduce the staff necessary at the circulation desks. Fig 4.5.1 Use of RFID Readers in Library Fig 4.5.2 Role of RFID in Library Management 4.6 Healthcare Patient safety is a big challenge of healthcare vertical. Reducing medication errors, meeting new standards, staff shortages, and reducing costs are the plus points of use of RFID solutions. RFID wristbands containing patient records and medication history address several of these concerns.