RFID Technology Overview

Transcription

1 Psion Teklogix RFID Technology Overview RFID provides a powerful technology, enabling fast and accurate identification, tracking and management, allowing you to quickly process, retrieve or transfer data for a variety of mobile computing applications

2 CONTENT 1.0 RFID Overview Benefits of RFID RFID tags VS Barcodes RFID Technology Wireless communication and the air interface Carrier frequencies Data transfer rate and bandwidth Range and Power Levels Transponders/Tags Basic features of an RFID transponder Powering tags Data carrying options Data read rate Data programming options Physical Form Costs The Reader/Interrogator RF Transponder Programmers RFID System Categories Areas of Application for RFID Standardisation Decision Making Why RFID? What Must It Do? RF Tag Types RF Tags generally fall into three broad categories Inductive Back Scatter Two Way What are the Issues? Radio Frequencies Used Lack of Standards Cost Integration No one technology works for all applications RFID Tag capabilities vary greatly Infrastructure cost is a major concern Is the technology viable? Can RFID tags replace barcodes cost-effectively? RF Tag System Criteria Amount of Data Stored in Tag 34 2

3 3.8.2 Read/Write Capability Read and/or Write Distance Frequency of Operation Low vs. High-Frequency RFID Scan Module Low Frequency (125kHz) tags Low Frequency (134kHz) tags High (Intermediate) Frequency (13.56kHz) tags Support included for Standards & Issues Radio Frequency Issues relating to Tags Standards relating to Tags Magnetic based tags for labelling animals Electric field based tags for rail/toll roads ISO ad-hoc Working Group of SC31 - Current Situation Current Applications Areas Electronic Article Surveillance (EAS) Shipping Container and Rail Car Tracking Animal Tracking Vehicle Access and Control Personnel Access Production Control Document Authentication Tool Identification Logistics Automatic Transport Systems Product Classification Supplier Identification Waste Management Application Trends Issues Driving the Industry Manufacturing Methods Technological Design Tag Prices Spectrum Allocation Applications Driving RFID Technologies EAS Security Applications Electronic Car Security Toll Roads Petrol and Chemical Dispensing Postal Systems Efficiency Postage Stamp Replacement Gaming Chips Criminal Penal Monitoring Smart Appliances Example in the Supply Chain - Consolidation of Information 50 3

4 6.7.1 Consumer Units Boxes and Containers Pallets Transport Vehicles Possible Focus Areas Healthcare Field Data Processing & Management Systems Providers Process Control System Providers 52 Glossary of Radio Frequency Identification (RFID)Terms 53 4

5 1.0 RFID Overview Battery (if attive tag) Silicon Chip RF TAG Input Signal Antenna Output Signal Antenna Packaging Decoder Diagram 1 A basic RFID system consist of three components: An antenna or coil A transceiver (with decoder) A transponder (commonly called an RF tag) The antenna emits radio signals to activate the tag and read and write data to it. Antennas are the conduits between the tag and the transceiver, which controls the system s data acquisition and communication. Antennas are available in a variety of shapes and sizes; they can be built into a door frame to receive tag data from persons or things passing through the door, or mounted on an interstate toll booth to monitor traffic passing by on a freeway. The electromagnetic field produced by an antenna can be constantly present when multiple tags are expected continually. If constant interrogation is not required, the field can be activated by a sensor device. Often the antenna is packaged with the transceiver and decoder to become a reader (see diagram 1 above), which can be configured either as a handheld or a fixed-mount device. The reader emits radio waves in ranges of anywhere from one inch to 100 feet or more, depending upon its power output and the radio frequency used. When an RFID tag passes 5

6 through the electromagnetic zone, it detects the reader s activation signal. The reader decodes the data encoded in the tag s integrated circuit (silicon chip) and the data is passed to the host computer for processing. RFID tags come in a wide variety of shapes and sizes. Animal tracking tags, inserted beneath the skin, can be as small as a pencil lead in diameter and one-half inch in length. Tags can be screw-shaped to identify trees or wooden items, or credit-card shaped for use in access applications. The anti-theft hard plastic tags attached to merchandise in stores are RFID tags. In addition, heavy-duty 5- by 4- by 2-inch rectangular transponders used to track intermodal containers or heavy machinery, trucks, and railroad cars for maintenance and tracking applications are RFID tags. RFID tags are categorised as either active or passive. Active RFID tags are powered by an internal battery and are typically read/write, i.e. tag data can be rewritten and/or modified. An active tag s memory size varies according to application requirements; some systems operate with up to 1MB of memory. In a typical read/write RFID work-in-process system, a tag might give a machine a set of instructions, and the machine would then report its performance to the tag. This encoded data would then become part of the tagged part s history. The battery-supplied power of an active tag generally gives it a longer read range. The trade off is greater size, greater cost, and a limited operational life (which may yield a maximum of 10 years, depending upon operating temperatures and battery type). Passive RFID tags operate without a separate external power source and obtain operating power generated from the reader. Passive tags are consequently much lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime. The trade off is that they have shorter read ranges than active tags and require a higher-powered reader. Readonly tags are typically passive and are programmed with a unique set of data (usually 32 to 128 bits) that cannot be modified. Read-only tags most often operate as a license plate into a database, in the same way as linear barcodes reference a database containing modifiable product-specific information. RFID systems are also distinguished by their frequency ranges. Low-frequency (30 khz to 500 khz) systems have short reading ranges and lower system costs. They are most commonly used in security access, asset tracking, and animal identification applications. High-frequency (850 MHz to 950 MHz and 2.4 GHz to 2.5 GHz) systems, offering long read ranges (greater than 90 feet) and high reading speeds, are used for such applications as railroad car tracking and automated toll collection. However, the higher performance of highfrequency RFID systems incurs higher system costs. The significant advantage of all types of RFID systems is the non-contact, non-line-of-sight 6

7 nature of the technology. Tags can be read through a variety of substances such as snow, fog, ice, paint, crusted grime, and other visually and environmentally challenging conditions, where barcodes or other optically read technologies would be useless. RFID tags can also be read in challenging circumstances at remarkable speeds, in most cases responding in less than 100 milliseconds. The read/write capability of an active RFID system is also a significant advantage in interactive applications such as work-in-process or maintenance tracking. Though it is a costlier technology (compared with barcode), RFID has become indispensable for a wide range of automated data collection and identification applications that would not be possible otherwise. RFID, its application, standardisation, and innovation are constantly changing. Its adoption is still relatively new and hence there are many features of the technology that are not well understood. Developments in RFID technology continue to yield larger memory capacities, wider reading ranges, and faster processing. It s highly unlikely that the technology will ultimately replace bar code - even with the inevitable reduction in raw materials coupled with economies of scale, the integrated circuit in an RF tag will never be as cost-effective as a bar code label. However, RFID will continue to grow rapidly where bar code or other optical technologies aren t effective. 1.1 Benefits of RFID Radio Frequency Identification (RFID) provides an extremely powerful and cost effective method for identifying and tracking a wide range of objects, in an extraordinarily diverse range of applications and environments. It is based on the use of a small tag (transponder), which stores a unique code, together with additional information that may be specified by the user. A 'reader' (i.e. handheld reader) is used both to transmit information to a tag and retrieve stored information from it; no contact or line-of-sight is required, and long operating ranges are possible. RFID provides a number of significant and powerful advantages over bar codes, including: RFID tags VS Barcodes 1. RFID tags can store information dynamically Unlike barcodes, RFID systems not only allow the user to read information stored in a tag, but also to change or add information. 2. RFID tags can be read from, and written to, through a variety of materials RFID tags can be read from, and written to, through a variety of non-metallic materials, including dirt, wood, steam, plastic, paint, water. 3. RFID does not require contact or line-of-sight for operation 7

8 Tags can be read at distances of up to 1 metre, and unlike barcodes, do not require line-ofsight for effective operation. 4. RFID tags have greater flexibility in their placement The fact that RFID tags do not require line-of-sight (coupled with their ability to be read through different materials) provides for greater flexibility in their placement. A wide variety of package styles even allows tags to be embedded within an object! 5. RFID tags can be used in harsher environments Many tags operate effectively at extreme levels of temperature and humidity. 6. RFID is extremely accurate RFID has the lowest error rate of all automatic identification technologies, with accuracy levels approaching 100%. 7. RFID tags are secure The integrity of information stored in a tag may be protected using a range of comprehensive security options, specified by the user. 8. RFID tags can carry large amounts of data The storage capacity of read/write RFID tags can range from around eight characters of user defined data to more than 1000 characters. 9. RFID tags can be used repeatedly As data stored in a read/write tag can be over-written, it can be used repeatedly. 10. Multiple RFID tags can be read simultaneously Some RFID tags support the reading of multiple tags simultaneously. In contrast barcodes must be read individually. 8

9 2.0 RFID Technology The object of any RFID system is to carry data in suitable transponders, generally known as tags, and to retrieve data, by machine-readable means, at a suitable time and place to satisfy particular application needs. Data within a tag may provide identification for an item in manufacture, goods in transit, a location, the identity of a vehicle, an animal or individual. By including additional data the prospect is provided for supporting applications through item specific information or instructions immediately available on reading the tag. For example, the colour of paint for a car body entering a paint spray area on the production line, the setup instructions for a flexible manufacturing cell or the manifest to accompany a shipment of goods. A system requires, in addition to tags, a means of reading or interrogating the tags and some means of communicating the data to a host computer or information management system. A system will also include a facility for entering or programming data into the tags. Quite often an antenna is distinguished as if it were a separate part of an RFID system. While its importance justifies the attention it must be seen as a feature that is present in both readers and tags, essential for the communication between the two. To understand and appreciate the capabilities of RFID systems it is necessary to consider their constituent parts. It is also necessary to consider the data flow requirements that influence the choice of systems and the practicalities of communicating across the air interface. By considering the system components and their function within the data flow chain it is possible to grasp most of the important issues that influence the effective application of RFID. However, it is useful to begin by briefly considering the manner in which wireless communication is achieved, as the techniques involved have an important bearing upon the design of the system components. 2.1 Wireless communication and the air interface Communication of data between tags and a reader is by wireless communication. Two methods distinguish and categorise RFID systems, one based upon close proximity electromagnetic or inductive coupling and one based upon propagating electromagnetic waves (See diagram 2). Coupling is via antenna structures forming an integral feature in both tags and readers. While the term antenna is generally considered more appropriate for propagating systems it is also loosely applied to inductive systems. 9

10 Diagram 2 Inductive Coupling Propagation Coupling Transmitting data is subject to the vagaries and influences of the media or channels through which the data has to pass, including the air interface. Noise, interference and distortion are the sources of data corruption that arise in practical communication channels that must be guarded against in seeking to achieve error free data recovery. Moreover, the nature of the data communication processes, being asynchronous or unsynchronised in nature, requires attention to the form in which the data is communicated. Structuring the bit stream to accommodate these needs is often referred to as channel encoding and although transparent to the user of an RFID system the coding scheme applied appears in system specifications. Various encoding schemes can be distinguished, each exhibiting different performance features. To transfer data efficiently via the air interface or space that separates the two communicating components requires the data to be superimposed upon a rhythmically varying (sinusoidal) field or carrier wave. This process of superimposition is referred to as modulation, and various schemes are available for this purposes, each having particular attributes that favour their use. They are essentially based upon changing the value of one of the primary features of an alternating sinusoidal source, its amplitude, frequency or phase in accordance with the data carrying bit stream. On this basis one can distinguish amplitude shift keying (ASK), frequency shift keying (FSK) and phase shift keying (PSK). In addition to non-contact data transfer, wireless communication can also allow non-line-ofsight communication. However, with very high frequency systems more directionality is evident and can be tailored to needs through appropriate antenna design. 2.2 Carrier frequencies In wired communication systems the physical wiring constraints allow communication links and networks to be effectively isolated from each other. The approach that is generally adopted for radio frequency communication channels is to separate on the basis of frequency allocation. This requires, and is generally covered by government legislation, with different parts of the electromagnetic spectrum being assigned to different purposes. Allocations may differ depending on the governments concerned, requiring care in considering RFID 10

11 applications in different countries. Standardisation efforts are seeking to obviate problems in this respect. Three frequency ranges are generally distinguished for RFID systems, low, intermediate (medium) and high. The following table summarises these three frequency ranges, along with the typical system characteristics and examples of major areas of application. Table 1. Frequency Bands and Applications Error! No bookmark name given.frequency Band Low khz Intermediate MHz High GHz CharacteristicsTypical Applications Short to medium read range Access control Inexpensive Animal identification low reading speed Inventory control Short to medium read range Access control potentially inexpensive Smart cards medium reading speed Long read range Railroad car monitoring High reading speed Toll collection systems Line of sight required Expensive A degree of uniformity is being sought for carrier frequency usage, through three regulatory areas, Europe and Africa (Region 1), North and South America (Region 2) and Far East and Australasia (Region 3). Each country manages their frequency allocations within the guidelines set out by the three regions. Unfortunately, there has been little or no consistency over time with the allocation of frequency, and so there are very few frequencies that are available on a global basis for the technology. This will change with time, as countries are required to try to achieve some uniformity by the year Three carrier frequencies receiving attention as representative of the low, intermediate and high ranges are 125kHz, MHz and 2.45 GHz. However, there are eight frequency bands in use around the world, for RFID applications. The applications using these frequency bands are listed in Table 2. Not all of the countries in the world have access to all of the frequency bands listed above, as some countries have assigned these bands to other users. Within each country and within each frequency range there are specific regulations that govern the use of the frequency. 11

12 These regulations may apply to power levels and interference as well as frequency tolerances. Error! No bookmark Applications and comments name given.frequency range Less than 135kHzA wide range of products available to suit a range of applications, including animal tagging, access control and track and traceability. Transponder systems which operate in this band do not need to be licensed in many countries MHz, 3.25MHz, Electronic article surveillance (EAS) systems used in retail 4.75MHz, and 8.2MHz stores Approx. 13 MHz, EAS systems and ISM (Industrial, Scientific and Medical) 13.56MHz Approx. 27 MHzISM applications MHzISM applications specifically in Region MHzISM applications specifically in Region 2. In the USA this band is well organised with many different types of applications with different levels of priorities. This includes Railcar and Toll road applications. The band has been divided into narrow band sources and wide band (spread spectrum type) sources. In Region 1 the same frequencies are used by the GSM telephone network MHzRFID in Australia for transmitters with EIRP less than 1 watt MHzA recognised ISM band in most parts of the world. IEEE recognises this band as acceptable for RF communications and both spread spectrum and narrow band systems are in use MHzThis band is allocated for future use. The FCC have been requested to provide a spectrum allocation of 75 MHz in the GHz band for Intelligent Transportation Services use. In France the TIS system is based on the proposed European pre-standard (preenv) for vehicle to roadside communications communicating with the roadside via microwave beacons operating at 5.8 GHz. 2.3 Data transfer rate and bandwidth Choice of field or carrier wave frequency is of primary importance in determining data 12

13 transfer rates. In practical terms the rate of data transfer is influenced primarily by the frequency of the carrier wave or varying field used to carry the data between the tag and its reader. Generally speaking the higher the frequency the higher the data transfer or throughput rates that can be achieved. This is intimately linked to bandwidth or range available within the frequency spectrum for the communication process. The channel bandwidth needs to be at least twice the bit rate required for the application in mind. Where narrow band allocations are involved the limitation on data rate can be an important consideration. It is clearly less of an issue where wide bandwidths are involved. Using the GHz spread spectrum band, for example, 2 megabits per second data rates may be achieved, with added noise immunity provided by the spread spectrum modulation approach. Spread spectrum apart, increasing the bandwidth allows an increase noise level and a reduction in signal-to-noise ratio. Since it is generally necessary to ensure a signal is above the noise floor for a given application, bandwidth is an important consideration in this respect. 2.4 Range and Power Levels The range that can be achieved in an RFID system is essentially determined by: The power available at the reader/interrogator to communicate with the tag(s) The power available within the tag to respond The environmental conditions and structures, the former being more significant at higher frequencies including signal to noise ratio Although the level of available power is the primary determinant of range the manner and efficiency in which that power is deployed also influences the range. The field or wave delivered from an antenna extends into the space surrounding it and its strength diminishes with respect to distance. The antenna design will determine the shape of the field or propagation wave delivered, so that range will also be influenced by the angle subtended between the tag and antenna. In space free of any obstructions or absorption mechanisms the strength of the field reduces in inverse proportion to the square of the distance. For a wave propagating through a region in which reflections can arise from the ground and from obstacles, the reduction in strength can vary quite considerable, in some cases as an inverse fourth power of the distance. Where different paths arise in this way the phenomenon is known as "multi-path attenuation". At higher frequencies absorption due to the presence of moisture can further influence range. It is therefore important in many applications to determine how the environment, internal or external, can influence the range of communication. Where a number of reflective metal obstacles are to encountered within the application to be considered, and can vary in 13

14 number from time to time, it may also be necessary to establish the implications of such changes through an appropriate environmental evaluation. The power within the tag is generally speaking a lot less than from the reader, requiring sensitive detection capability within the reader to handle the return signals. In some systems the reader constitutes a receiver and is separate from the interrogation source or transmitter, particularly if the up-link (from transmitter-to-tag) carrier is different from the down-link (from tag-to-reader). Although it is possible to choose power levels to suit different application needs is not possible to exercise complete freedom of choice. Like the restrictions on carrier frequencies there are also legislative constraints on power levels. While mW are values often quoted for RFID systems actual values should be confirmed with the appropriate regulatory authorities, in the countries where the technology is to be applied. The authorities will also be able to indicate the form in which the power is delivered, pulsed or continuous, and the associated allowed values. Having gained some grasp of the data communication parameters and their associated values it is appropriate to consider, in a little more detail, the components of an RFID system. Diagram Transponders/Tags & Smart Labels The word transponder, derived from TRANSmitter/resPONDER, reveals the function of the device. The tag responds to a transmitted or communicated request for the data it carries, the mode of communication between the reader and the tag being by wireless means across 14

15 the space or air interface between the two. The term also suggests the essential components that form an RFID system tags and a reader or interrogator (See diagram 3). Where interrogator is often used as an alternative to that of reader, a difference is sometime drawn on the basis of a reader together with a decoder and interface forming the interrogator. The basic components of a transponder may be represented as shown above. Generally speaking they are fabricated as low power integrated circuits suitable for interfacing to external coils, or utilising "coil-on-chip" technology, for data transfer and power generation (passive mode). 2.6 Basic features of an RFID transponder The transponder memory may comprise read-only (ROM), random access (RAM) and nonvolatile programmable memory for data storage depending upon the type and sophistication of the device. The ROM-based memory is used to accommodate security data and the transponder operating system instructions which, in conjunction with the processor or processing logic deals with the internal "house-keeping" functions such as response delay timing, data flow control and power supply switching. The RAM-based memory is used to facilitate temporary data storage during transponder interrogation and response (See diagram 4 below). The non-volatile programmable memory may take various forms, electrically erasable programmable read only memory (EEPROM) being typical. It is used to store the transponder data and needs to be non-volatile to ensure that the data is retained when the device is in its quiescent or power-saving "sleep" state. Data buffers are further components of memory, used to temporarily hold incoming data following demodulation and outgoing data for modulation and interface with the transponder antenna. The interface circuitry provides the facility to direct and accommodate the interrogation field energy for powering purposes in passive transponders and triggering of the transponder response. Where programming is accommodated facilities must be provided to accept the data modulated signal and perform the necessary demodulation and data transfer processes 15

16 Diagram 4 The transponder antenna is the means by which the device senses the interrogating field and, where appropriate, the programming field and also serves as the means of transmitting the transponder response to interrogation. A number of features, in addition to carrier frequency, characterise RFID transponders and form the basis of device specifications, including: Means by which a transponder is powered Data carrying options Data read rates Programming options Physical form Costs 2.7 Powering tags For tags to work they require power, even though the levels are invariably very small (micro to milliwatts). Tags are either passive or active, the designation being determined entirely by the manner in which the device derives its power. Active tags are powered by an internal battery and are typically read/write devices. They usually contain a cell that exhibits a high power-to-weight ratio and are usually capable of operating over a temperature range of -50 C to +70 C. The use of a battery means that a sealed active transponder has a finite lifetime. However, a suitable cell coupled to suitable low power circuitry can ensure functionality for as long as ten or more years, depending upon the operating temperatures, read/write cycles and usage. The trade-off is greater size and greater cost compared with passive tags. 16

17 In general terms, active transponders allow greater communication range than can be expected for passive devices, better noise immunity and higher data transmissions rates when used to power a higher frequency response mode. Passive tags operate without an internal battery source, deriving the power to operate from the field generated by the reader. Passive tags are consequently much lighter than active tags, less expensive, and offer a virtually unlimited operational lifetime. The trade-off is that they have shorter read ranges than active tags and require a higher-powered reader. Passive tags are also constrained in their capacity to store data and the ability to perform well in electromagnetically noisy environments. Sensitivity and orientation performance may also be constrained by the limitation on available power. Despite these limitations passive transponders offer advantages in terms of cost and longevity. They have an almost indefinite lifetime and are generally lower on price than active transponders. 2.8 Data carrying options Data stored in data carriers invariable require some organisation and additions, such as data identifiers and error detection bits, to satisfy recovery needs. This process is often referred to as source encoding. Standard numbering systems, such as UCC/EAN and associated data defining elements may also be applied to data stored in tags. The amount of data will of course depend on application and require an appropriate tag to meet the need. Basically, tags may be used to carry: Identifiers, in which a numeric or alphanumeric string is stored for identification purposes or as an access key to data stored elsewhere in a computer or information management system, or Portable data files, in which information can be organised, for communication or as a means of initiating actions without recourse to, or in combination with, data stored elsewhere. In terms of data capacity tags can be obtained that satisfy needs from single bit to kilobits. The single bit devices are essentially for surveillance purposes. Retail electronic article surveillance (EAS) is the typical application for such devices, being used to activate an alarm when detected in the interrogating field. They may also be used in counting applications. Devices characterised by data storage capacities up to 128 bits are sufficient to hold a serial or identification number together, possibly, with parity check bits. Such devices may be manufacturer or user programmable. Tags with data storage capacities up to 512 bits, are invariably user programmable, and suitable for accommodating identification and other specific data such as serial numbers, package content, key process instructions or possibly results of earlier interrogation/response transactions. 17

18 Tags characterised by data storage capacities of around 64 kilobits may be regarded as carriers for portable data files. With increased capacity the facility can also be provided for organising data into fields or pages that may be selectively interrogated during the reading process. 2.9 Data read rate It has been mentioned already that data transfer rate is essentially linked to carrier frequency. The higher the frequency, generally speaking the higher the transfer rates. It should also be appreciated that reading or transferring the data requires a finite period of time, even if rated in milliseconds, and can be an important consideration in applications where a tag is passing swiftly through an interrogation or read zone Data programming options Depending upon the type of memory a tag contains the data carried may be read-only, write once read many (WORM) or read/write. Read-only tags are invariably low capacity devices programmed at source, usually with an identification number. WORM devices are user programmable devices. Read/write devices are also user-programmable but allowing the user to change data stored in a tag. Portable programmers may be recognised that also allow in-field programming of the tag while attached to the item being identified or accompanied Physical Form RFID tags come in a wide variety of physical forms, shapes sizes and protective housings. Animal tracking tags, inserted beneath the skin, can be as small as a pencil lead in diameter and ten millimetres in length. Tags can be screw-shaped to identify trees or wooden items, or credit-card shaped for use in access applications. The anti-theft hard plastic tags attached to merchandise in stores are also RFID tags, as are heavy-duty 120 by 100 by 50 millimetre rectangular transponders used to track inter-modal containers, or heavy machinery, trucks, and railroad cars for maintenance and tracking applications Costs The cost of tags obviously depends upon the type and quantities that are purchased. For large quantities (tens of thousands) the price can range from less than a few tens of pence for extremely simple tags to tens of pounds for the larger and more sophisticated devices. Increasing complexity of circuit function, construction and memory capacity will influence cost of both transponders and reader/programmers. 18

19 The manner in which the transponder is packaged to form a unit will also have a bearing on cost. Some applications where harsh environments may be expected, such as steel mills, mines, and car body paint shops, will require mechanically robust, chemical and temperature tolerant packaging. Such packaging will undoubtedly represent a significant proportion of the total transponder cost. Generally, low frequency transponders are cheaper than high frequency devices, passive transponders are usually cheaper than active transponders The Reader/Interrogator The reader/interrogators can differ quite considerably in complexity, depending upon the type of tags being supported and the functions to be fulfilled. However, the overall function is to provide the means of communicating with the tags and facilitating data transfer. Functions performed by the reader may include quite sophisticated signal conditioning, parity error checking and correction. Once the signal from a transponder has been correctly received and decoded, algorithms may be applied to decide whether the signal is a repeat transmission, and may then instruct the transponder to cease transmitting. This is known as the "Command Response Protocol" and is used to circumvent the problem of reading multiple tags in a short space of time. Using interrogators in this way is sometimes referred to as "Hands Down Polling". An alternative, more secure, but slower tag polling technique is called "Hands Up Polling" which involves the interrogator looking for tags with specific identities, and interrogating them in turn. This is contention management, and a variety of techniques have been developed to improve the process of batch reading. A further approach may use multiple readers, multiplexed into one interrogator, but with attendant increases in costs RF Transponder Programmers Transponder programmers are the means by which data is delivered to write once, read many (WORM) and read/write tags. Programming is generally carried out off-line, at the beginning of a batch production run, for example; For some systems re-programming may be carried out on-line, particularly if it is being used as an interactive portable data file within a production environment, for example; Data may need to be recorded during each process. Removing the transponder at the end of each process to read the previous process data, and to programme the new data, would naturally increase process time and would detract substantially from the intended flexibility of the application. By combining the functions of a reader/interrogator and a programmer, data may be appended or altered in the transponder as required, without compromising the production line. 19

20 The range over which the programming can be achieved is generally less than the read range and in some systems near contact positioning is required. Programmers are also generally designed to handle a single tag at a time. However, developments are now satisfying the need for selective programming of a number of tags present within the range of the programmer RFID System Categories RFID systems may be roughly grouped into four categories: EAS (Electronic Article Surveillance) systems Portable Data Capture systems Networked systems Positioning systems 1. Electronic Article Surveillance systems are typically a one bit system used to sense the presence/absence of an item. The large use for this technology is in retail stores where each item is tagged and a large antenna readers are placed at each exit of the store to detect unauthorised removal of the item (theft). 2. Portable data capture systems are characterised by the use of portable data terminals with integral RFID readers and are used in applications where a high degree of variability in sourcing required data from tagged items may be exhibited. The hand-held readers/portable data terminals capture data which is then either transmitted directly to a host information management system via a radio frequency data communication (RFDC) link or held for delivery by line-linkage to the host on a batch processing basis. 3. Networked systems applications can generally be characterised by fixed position readers deployed within a given site and connected directly to a networked information management system. The transponders are positioned on moving or moveable items, or people, depending upon application. 4. Positioning systems use transponders to facilitate automated location and navigation support for guided vehicles. Readers are positioned on the vehicles and linked to an onboard computer and RFDC link to the host information management system. The transponders are embedded in the floor of the operating environment and programmed with appropriate identification and location data. The reader antenna is usually located beneath the vehicle to allow closer proximity to the embedded transponders Areas of Application for RFID Potential applications for RFID may be identified in virtually every sector of industry, commerce and services where data is to be collected. The attributes of RFID are 20

21 complimentary to other data capture technologies and thus able to satisfy particular application requirements that cannot be adequately accommodate by alternative technologies. Principal areas of application for RFID that can be currently identified include: Transportation and logistics Manufacturing and Processing Security A range of miscellaneous applications may also be distinguished, some of which are steadily growing in terms of application numbers. They include: Animal tagging Waste management Time and attendance Postal tracking Airline baggage reconciliation Road toll management As standards emerge, technology develops still further, and costs reduce considerable growth in terms of application numbers and new areas of application may be expected. Some of the more prominent specific applications include: Electronic article surveillance - clothing retail outlets being typical. Protection of valuable equipment against theft, unauthorised removal or asset management. Controlled access to vehicles, parking areas and fuel facilities - depot facilities being typical. Automated toll collection for roads and bridges - since the 1980s, electronic Road- Pricing (ERP) systems have been used in Hong Kong. Controlled access of personnel to secure or hazardous locations. Time and attendance - to replace conventional "slot card" time keeping systems. Animal husbandry - for identification in support of individualised feeding programmes. Automatic identification of tools in numerically controlled machines - to facilitate condition monitoring of tools, for use in managing tool usage and minimising waste due to excessive machine tool wear. 21

22 Identification of product variants and process control in flexible manufacture systems. Sport time recording Electronic monitoring of offenders at home Vehicle anti-theft systems and car immobiliser A number of factors influence the suitability of RFID for given applications. The application needs must be carefully determined and examined with respect to the attributes that RFID and other data collection technologies can offer. Where RFID is identified as a contender further considerations have to be made in respect of application environment, from an electromagnetic standpoint, standards, and legislation concerning use of frequencies and power levels Standardisation If the unique advantages and flexibility of RFID is the good news, then the proliferation of incompatible RFID standards is the corresponding bad news. All major RFID vendors offer proprietary systems, with the result that various applications and industries have standardised on different vendors competing frequencies and protocols. The current state of RFID standards is severe disarray - standards based on incompatible RFID systems exist for rail, truck, air traffic control, and tolling authority usage. The US Intelligent Transportation System and the US Department of Defense (DOD) Total Asset Visibility system are among other special-interest applications. The lack of open systems interchangeability has severely crippled RFID industry growth as a whole, and the resultant technology price reductions that come with broad-based interindustry use. However, a number of organizations have been working to address and bring about some commonality among competing RFID systems, both in the U.S. and in Europe where RFID has made greater market inroads. Meanwhile in the U.S.A., ANSI s X3T6 group, comprising major RFID manufacturers and users, is currently developing a draft document based systems operation at a carrier frequency of 2.45 GHz, which it is seeking to have adopted by ISO. ISO has already adopted international RFID standards for animal tracking, ISO and Just as standardisation enabled the tremendous growth and widespread use of bar code, cooperation among RFID manufacturers will be necessary for promoting the technology developments and refinements that will enable broad-based application growth Decision Making 22

23 Radio frequency tagging is a seductive technology. Its ability to identify objects without a clear line of sight between tag and reader brings a smile to the face of any materials handling professional. Its read/write capability spawns realistic dreams of field-distributed databases for the information systems manager. Its semiconductor underpinning allows cost reduction curves that would make a financial officer jump for joy. But the attraction of RFID tags is accompanied by a significant set of technology and business questions that must be answered when designing an application. Users and integrators must decide among available frequencies, memory configurations, and air interface protocols. The combination of the lure of RF tagging and the need for detailed decision making sometimes forces users to focus too soon on the technical aspects of an implementation, to the detriment of the underlying business aspects. As in most technology purchase decisions, the thought process should begin well before you contact technology vendors. First, know what you need and want RFID to accomplish for your business. Second, determine how the technology must perform to accomplish those goals. Only then are you ready to see what offerings fit your needs (See Table 2 overleaf for an outline of RFID's capabilities and benefits). Error! No bookmark name given. The technical capabilities of RFID translate into benefits that are impossible to achieve economically with any other automatic identification technique. Table 2. RFID Capabilities and Benefits CAPABILITYTHE TECHNOLOGYAPPLICATION BENEFIT Identification without visual contact The radio signal used to communicate between reader and tag passes easily through objects that an optical technology (such as bar codes) would find opaque. Signals at different frequencies available for RFID systems differ in how they penetrate, reflect from, and are absorbed by obstacles. You can identify people, items, and cartons even if an object comes between the reader and the identification tag. 23

24 Read/writeMost RFID product lines include some models whose contents can be updated at the same time the tag is being read. Passive tags (those without batteries) can usually be read from farther away than the distance to which they can be written. Cluster readingwith proper intelligence built into the tag, you can read many tags presented simultaneously to a reader. Many different techniques are used, but most rely on selectively silencing tags until only one at a time transmits. Because of the time required to isolate each tag, most implementations currently allow up to several dozen tags simultaneously in the field. As a carton moves down a conveyor line, you can automatically change the destination or routing code stored in a read/write RFID tag. Many applications can share a single read/write tag, increasing the economic benefit of the installation. You can design a system that purposely presents more than one item at a time for identification. For example, automated manufacturing applications can identify simultaneously several components presented for assembly Why RFID? RF tagging lets companies accomplish a variety of business goals. Clarify in your own mind what you want. Mobil Corporation, for example, turned to RFID technology in its Speedpass system to build customer loyalty. Mobil reasoned that automating payment at the gas pump would increase fuel sales. Sainsbury's groceries in the United Kingdom have tested RFID on pallets to track perishable commodities. The company's first goal is to immediately know the identification and sell-by date of every pallet every time workers move it. This process will increase freshness and decrease the amount of perishable food scrapped or sold at discount. HMT Technologies uses RFID to track production processes in the firm's disk manufacturing plants. Disk platters are virtually impossible to tell apart during assembly, and high yields are absolutely essential. In addition recent field trials run by BAA in two major airports in the United Kingdom have shown a major reduction in lost baggage at airport. Decide what accomplishing your goal is worth. You do not have to perform a complete economic analysis before proceeding, but you may save yourself a great deal of effort if you think in financial terms early. Consider the monetary ramifications of decreased product loss from theft and misplacement. Your installation may reduce inventory levels and handling costs. It may decrease the cycle time between customer demand and order fulfilment, 24

25 resulting in increased sales. It may decrease the number of times you and your trading partners must apply labels to cartons moving through your supply chain. With an estimate of the value of the entire project, try to translate this into a per-tag figure; the value per tag may include the effect of tag recycling, a common practice in industrial processes. Sainsbury's, for example, expects tags to last as long as the pallets to which they are affixed. The per-tag value need not be a precise estimate to provide good guidance. Any result over a dollar per tag warrants further pursuit. Under a dollar a tag may work if your volumes will be high enough and your environmental demands allow inexpensive tag packaging. If your analysis determines that you need a five-cent tag to justify the investment, you're on the wrong track. (Current tag prices start at about 50 cents.) If your instinct still tells you that RFID will be good for your business, look at your application design before you pursue any technology decisions and figure out how to increase the value it delivers. For example, an RFID application in a distribution centre may not be a good investment by itself, but if you expand the scope to include your manufacturing facilities, it might be a significant money maker (See Table 3 overleaf for an outline of relevant economic benchmarks when investigating RFID installation). Error! No bookmark name given. The demands of your application and the volume in which you buy tags determine the price you pay. When determining the value per installed tag, consider both the worth of the application and the economic effect of reusing tags, if possible. Table 3. Economic Benchmarks IF YOUR APPLICATION IS WORTH THIS MUCH PER INSTALLED TAG: YOUR APPLICATION PROBABLY MAKES ECONOMIC SENSE IF THE FOLLOWING CONDITIONS ARE TRUE: More than $10 Application probably makes sense unless the tag must survive extremely demanding environmental conditions or provide very large data capacity $5 to $10 Annual tag volume greater than 1000 $2 to $5 Moderate environmental challenges 25

26 Annual tag volume greater than 1000 $0.75 to $2 Moderate environmental challenges Annual tag volume greater than 100,000 $0.50 to $0.75 Moderate environmental challenges Annual tag volume greater than 250,000 Less than $0.50 Moderate environmental challenges Annual tag volume greater than 500,000 Keep this economic analysis in your head as you make technology inquiries. You don't have to share the information with potential suppliers, but you can use the knowledge to decide quickly whether a relationship is worth pursuing What Must It Do? If you know what you want RFID to accomplish and have some confidence that the technology makes economic sense for you, it is time to start characterising how the technology needs to operate. At this juncture, stick to general characteristics, not specific technologies. Now is the time to specify, for example, from how far away a tag must be readable, not the frequency to be used when reading it. Environmental conditions will be a critical determining factor in the ongoing costs of your RFID system. As production volume increases, the cost of RFID tags' semiconductor cores drops rapidly. Even the cost of antennas can be decreased for some technologies. In very demanding environments, though, packaging costs are sometimes less responsive to volume production. When characterising the environmental conditions for your RFID tags, consider temperature, humidity, vibration, shock, chemical attack, and the proximity of the installed tag to metallic surfaces. If the tag must endure temperatures above about 125 F or below freezing, know whether the tag needs to merely survive these extremes or to perform according to specification under those conditions. Now consider tag memory and how you need to manipulate it. Determining how much storage you need is deceptively complicated. Consider an application for identification and sorting of packing boxes. The data on the tag must tell you what the carton is and where it is going. Simple, right? Not if you look at the entire supply chain application for such a tag. For a freight consolidator, "what the carton is" means mostly how the carton should be handled. A few dozen codes for handling and storage instructions would suffice. That's 2 26

27 bytes, plus maybe another couple of bytes to point to material safety data sheets if appropriate. To a distribution centre manager, "what the carton is" probably means what order the carton is filling. If purchase order numbers run three letters and ten numbers long, you've got a decision to make. Encoding your purchase number will require at least 6 bytes, but it is doubtful that you really need to uniquely identify 175 times 1012 purchase orders. Using sequential tag numbers and mapping them to purchase orders in your WMS software saves tag space, and possibly expense. Such look-up techniques unfortunately also make it impossible to know the purchase order number associated with a carton without access to the mapping database. It is a trade-off you must resolve for yourself. A subtle aspect of specifying the tags' data capacity is determining whether you require unique identification numbers. Consider an application for tracking all the wooden pallets in the do-it-yourself supply chain. A properly designed RFID tag in each pallet would allow tracking of mixed pallet loads, the return of empty pallets to their proper owners for reuse, and even the tracking of pallets and deposits paid by contractors buying in volume. Such an application, however, hinges on the assumption that a pallet ID from Black and Decker could never be confused with one from Monrovia Nurseries. If you require unique identification along these lines, make sure you make this need clear when purchasing products or specifying development contracts. Your application environment determines how data gets written to your tags. For applications requiring unique identification, you'd typically purchase tags pre-programmed by the factory; the factory controls the numbers. On the other hand, identification card applications often use tags that arrive blank from the factory. An ID code can be written to the tag only once, when the badge is issued, preventing fraud later. Users may write to certain other tags many times. Some tags even combine different memory types, such as a permanent identification code and a separate read/write field. Finally, consider how the tags will be read and written. How far away must the reader be? How fast will the tag be moving? How much space will there be between tags? Do you know or can you control the orientation between tag and reader? If your application must write data to the tag, ask the same questions for the read operation. Knowing what your business wants and how the tags must perform puts you in a strong position when discussing specific technology with vendors. When the topic turns to frequency selection, you will be ready to relate the discussion to the read ranges your application requires. Memory capacity discussions can be guided by your needs analysis. Perhaps most 27

28 important, you will have established a realistic economic target for potential vendors to meet instead of starting with a cost estimate and trying to justify it. 28

29 3.0 RF Tag Types RF Tags are used to; Identify fish, livestock, pets, and products Provide inventory control and theft prevention Automation production systems Allow access to buildings and parking areas Collect tolls and automate traffic Access vehicles and provide theft prevention 3.1 RF Tags generally fall into three broad categories; Inductive RF Tags Interrogator Interrogator RF TAG Inductive tags are passage tags energised by passing through an energising field generated by the interrogator. The tag resonates at the frequency of the field causing a disruption of the field. These tags have minimal information storage capabilities. This type of RF tag is the lowest in cost ranging from less then $.01 to $8.00. Typical read ranges are less than 10 feet. Typical Applications for Inductive Tags are; Electronic Article Surveillance (EAS) Anti-theft systems Access control systems Personal identifications systems Wild life management Pet identification Product identification Vehicle Access & Security 29

30 3.1.2 Back Scatter RF TAG Interrogator Back Scatter tags may be either passive (no battery) or active (battery powered). They reflect a small portion of the RF energy of the interrogator. The reflected signal is modulated or encoded with information stored in the tag. Back scatter tags cost between $5 and $40 per tag. Passive back scatter tags convert a portion of the RF energy from the Tag reader/interrogator to power the transponder. The tag generates a data stream comprised of a clock signal and the data stored in the tag. Back scatter tags are capable of being programmed with varying amounts of information. Some tags may be re-programmed by a reader, others have the ability to store additional data from readers to their internal memory. Typical Applications for Back scatter Tags are - Toll Collection Traffic Management Systems Inter modal Container Management Asset Tracking Rail Car Identification Rail Control Systems 30

31 3.1.3 Two-Way RF TAG Interrogator Two-Way tags are active tags which incorporate a miniature transmitter and/or receiver. The tag may be polled or transmit freely. Data may be read only or programmed by the interrogator. These are the most expensive type tag with typical costs between $75 to $190. Typical Applications for Two-Way Tags are; Toll Collection Traffic Management Systems Inter modal Container Management Mfg. Process Control Waste Management High Value Asset Control 3.2 What are the Issues? Radio Frequencies Used 78,000 Hz to 5,600,000,000 Hz. Affects range, reliability, and cost. US and International Regulations Lack of Standards Microchipping of companion animals in the US is an example of one of the industry failures due to the lack of an industry standard. Many proprietary protocols. Few international standards Cost RFID Tag costs vary greatly, from less than $.50 to $190 or more each. 31

32 3.2.4 Integration Interrogators cost between $1,000 to $12,000 ea. Data collected must be combined with existing data to be useful. 3.3 No one technology works for all applications Higher frequency tags can support higher read/write rates. Low frequency tags are more prevalent and less costly. Read only or license plate tags may be sufficient for identifying an object or customer but may not provide the capability to provide the status of a product or customer without numerous transactions with an information database. Transaction costs to an information database may be high enough to justify a more expensive RF tag capable of storing the new or changed status of the object tagged with out requiring a real time transaction with the information system. 3.4 RFID Tag capabilities vary greatly RFID tags can be read only, write once/read many (WORM), and read/write capable. The number of unique IDs, amount of read only memory, and the amount of write capable memory varies greatly. The ability to read and/or write to multiple RFID tags also varies between suppliers. 3.5 Infrastructure cost is a major concern Each reader or interrogator needs to read an average of 50 RF tags to be cost effective. Duplicate infrastructures for several RFID applications are cost prohibitive. 3.6 Is the technology viable? Read accuracy, reliability, compatibility with existing RF systems, and computability with local, national, and international regulations are all issues which must be examined carefully. 3.7 Can RFID tags replace barcodes cost-effectively? Recently two statements have been published suggesting that because the price of a barcode is so low, it is unlikely that RFID would be a viable replacement 32

33 In the one case the statement was: "I see RFID tags replacing bar codes in [more expensive] garments, for instance. But I don't see it happening in the supermarket. People have talked about replacing U.P.C. code with RFID, but I don't think it will ever happen. Because nothing's cheaper than zero. And it literally costs nothing to put a U.P.C. code on a package. You just integrate a bar code into your artwork and print it; it doesn't cost anything. And they're never going to bring an RFID tag down to a hundredth of a cent, or even less. Anything that it costs is going to cost more than zero." while the other read:: "Its highly unlikely that the technology will ultimately replace bar code- even with the inevitable reduction in raw material costs coupled with the economies of scale, the integrated circuit in the RF tag will never be as cheap as a barcode label." Both of these commentaries seem to be based on the premise that because a barcode label is integrated into the display packaging of the product, it is very cheap. Surely the real issue is what are the productivity benefits by using an RFID tag, versus a barcode, versus a numeric number? Barcodes have made their presence felt in society almost solely around potential productivity benefits they could offer. Surely at their inception, nobody would every believe that technology was advancing in a cost effective manner by adding some squiggly lines to a package that nobody could interpret without first purchasing some very expensive and then crude scanning equipment, compared to the then product identification methods in place. That barcodes have existed is in the belief that one day it would be such a widespread system and scanners would be so cheap that by providing machine readable tags productivity benefits over the manual systems would be realised. Barcodes are now widely accepted, particularly with the order that the UCC and EAN have brought to product labelling, as well as advances in computer systems allowing the data in the barcode label to act as a pointer to the appropriate description and pricing information. However barcodes do not cost only the cost of the ink on the packaging. The user needs to buy sophisticated scanning equipment, information systems, communication systems and manage databases just to be part of the user group for benefiting from machine readable labels. Simultaneous with the wide spread recent acceptance of barcode scanning by retailers and manufacturers, has been the growth of the EAS (Electronic Article Surveillance) industry. For some reason, maybe either for kicks or because of the chosen methods of selling goods, first world countries such as the USA and Europe suffer from a shoplifting disease that does not 33

34 seem to be as widespread in developing countries. This disease has led to the growth of an EAS industry, to combat the shoplifting shrinkage which has been reported as high as 12% of turnover in some industries. The solution to the problem has been to mark goods with a RF tag (one bit) which triggers an alarm if not deactivated before passing through a sensor's field at the exit to the shop. More than 6 billion such tags are reported as being sold in Europe alone, at prices as high as US$0-06 each. Recent documents from the US indicate that the estimated shoplifting per annum is in excess of $12billion and that the EAS industry in addition supply $10billion worth of equipment. The RFID tag to replace barcodes is about to arrive from a number of different suppliers who are all working towards this goal. At the end of the day, all the tags offered will comprise of a small integrated circuit and an antenna in some form. With the departure from the 125KHz frequency range by manufacturers targeting this market, the need for expensive 1000 turn coils is gone drastically reducing the delivered price of the new technologies. While features may vary from supplier to supplier (e.g. one claims it can read 1000 items at a time at 4 meter range with 3D orientation) almost all the new generation suppliers have included EAS features as standard, meaning that besides offering fast computer scanning, high accuracy, long range reading distances, and reading signals that penetrate packaging, besides other features, the EAS virtually comes for free. In addition the cost of an RFID scanner is generally very low, as it uses simple well established simple technology in simple packaging. RFID can also benefit not just the retailer, but all parties from the manufacturer, distributor, logistics operator, retailer and the user. For example, in a recent patent application a washing machine with an inbuilt RF scanner and RFID tags in the clothing, automatically senses the requirements of the clothes being loaded to be washed and adjusts its program accordingly. For productivity from Australia comes a trolley scanning design for a checkout aisle which by combining an RFID scanner, an EAS scanner and credit card processing features, an unmanned self service checkout with full EAS features can be offered. Of course the arrival of RFID is not going to remove the need for barcode labels on goods, as there are always going to be those users that have existing equipment, or purchase second hand equipment for low levels of machine readable tagging, or just want to operate a generation behind. The rollout of RFID as a viable replacement is not without its hurdles, particularly the size of the project that will require many players involvement and initially only allow leading/forwardlooking retailers to be involved. 34

35 The reality of the situation is that RFID is going to win its major position in these applications through real productivity enhancements and benefits for the users, which will completely outweigh that it might cost more than the price of the ink on the barcode label. In March 99 Motorola joined the list of companies developing RFID products to replace barcode systems with their Bistatix technology. They join Philips with their Icode product and Trolley Scan with the Trolleyponder range who are all focused on reducing the cost of RFID systems so that they become replacement technologies for the former barcode marking. 3.8 RF Tag System Criteria The following criteria must be fully considered and answered in order to design a successful RF Tag system Amount of Data Stored in Tag - (tag cost increases as storage increases) Minimal - Unique id only. This will require accessing an information system each time a tag is read to match the tag id with the data record for that tag. Some information storage - Tag could contain enough information for some decisions to be made without accessing an information system. Data could be batched and unlinked to the information system on an as needed basis. Other decisions may require a real time link to the information database record for that tag. Full data storage in tag - Tag could contain all the information necessary for decisions to be made at the read point without accessing an information database. Data collected could be batched and linked to an information system on an as needed basis Read/Write Capability - (tag and reader costs increase as capability is added) Read only tag - Data is encoded into the tag at the time of manufacture. No changes in the tad data can be made at a later date. Write once, read many tag - Data can be written into the tag when it is first used by a separate device. No changes in the tad data can be made at a later date. Read and Write - Data can be read from the tag and new or additional data can be written to the tag at some or all read locations Read and/or Write Distance 35

36 This requirement is application dependent. Write distance is typically less than read distance. (costs increase as distance increases) Minimum read distance - Typical is 2 to 5 inches. This may be desirable in some applications to prevent reading of other tags further away which could provide false information at the desired read point. Example: Secured area access. Read only the tag of the person directly in front of the access point. Average Read Distance - Typical is 2 to 10 feet. This may be a requirement for moving items or reading multiple items at the same time. Maximum Read Distance - Typical is 20 to 1000 feet. This may be a requirement for large items or reading many different items within the area Frequency of Operation This should be carefully considered in order to minimise potential frequency conflicts with other RF systems in the area. Some frequencies used in the US cannot be used in other countries. (costs increase with the higher frequency tags) Low frequency Tags - Typical is 66 to 125 Khz. This frequency range usually requires large antenna systems to increase range. Loop antennas are used extensively. Most frequencies in this range can be used world wide. Medium Frequency Tags - Tags operate on frequencies between 433 MHz to 928 MHz. The 902 to 928 MHz frequencies cannot be used in most countries outside the US. High Frequency Tags - Tags operate on frequencies between 2.4 to 5.6 GHz. These frequencies may be used in many countries outside the US Read and write ranges are typically less then lower frequency tags. More radio spectrum is available in these bands. 3.9 Low vs. High-Frequency The need for either the low-frequency or high-frequency tag is dependent on the application. A low-frequency device typically provides slower data transfer and must work at closer distances to an object. Relative speed of the tag moving on a production line past an interrogation unit is approximately 20 miles an hour. On the other hand, high-frequency devices can work at distances up to 250 feet and at relative speeds greater than 150 miles per hour. High-frequency passive systems are typically in the UHF range i.e. from 500 MHz and above, but usually in the 900 MHz band to 2.5 GHz. These systems are particularly well suited to the automotive, trucking and container shipping industries because they can read 36

37 distances in excess of 15 feet and can communicate large amounts of information at very high speeds. This high-frequency system works when a reader sends a signal to the transponder or ID tag via an antenna. The transponder's electronics return the ID code via a modulated signal being continuously reflected off the transponder's antenna, giving an impressively quick read. A fitting illustration of this speed is made by the Automatic Vehicle Identification (AVI) industry's endorsement of RFID technology. RFID systems are currently being integrated into AVI applications for the automatic collection of tolls. With a transponder placed on the dashboard, RFID technology is being used to deduct tolls from vehicles travelling at highway speeds. In this case these long-range high-frequency transponders are capable of transmitting at speeds of 100 miles per hour and at 300 kilobits per second. Low frequency systems on the other hand, are more suitable for tracking, monitoring or controlling the work flow of objects used for manufacturing, production, and processes. In a low frequency passive system (typically 30 khz to 500 khz), a reader sends a signal to the tag, charging the transponder and allowing it to return a signal carrying the unique identification code stored within it. Since most low-frequency systems are passive, the transponder can be built into devices or parts during the manufacturing process, and continue to electronically identify an object for its lifetime. In addition, low-frequency systems allow for accurate transmission through most non-metallic materials; making them an excellent solution when tracking almost any type of objects or containers. For example, in Victoria, Canada, RFID transponders installed on waste carts were an instrumental part of that city's innovative waste management program. Victoria officials installed RFID tags on household waste bins in order to promote recycling and reduce the amount of waste sent to landfills. Now, as fully-automatic trucks lift each high-tech plastic cart, the RFID-based system identifies the owner, weighs and empties the garbage, and later downloads the information in order to bill the resident according to the amount of trash they generate rather than recycle RFID Scan Module Low Frequency (125kHz) tags 37

38 Tags are available from a wide variety of manufacturers, in a diverse range of packaging styles, including; glass cylinders; pill; epoxy discs; credit card; kevlar nails and vehicle mounts cylinders. Tags with a wide range of operating characteristics are also available, including tags with high temperature and pressure capabilities. 125kHz Low Frequency RFID Scan Module provides support for approximately 90% of (low frequency) tags deployed worldwide; EM Marin silicon, including H4001/2/3/5, v4050, v4066, v some modes; this silicon is used by a wide variety of tag vendors Metget (all standard tags) Philips Semiconductors, PCF7930/31 and hitag 1 / 2 Sokymat (Unique, Nova, Titan, Zoodiac, Magic - some modes) Temic semiconductors (e5530 and e5550, standard configurations) Texas Instruments (4TIRIS) read only, read/write and MPT These tags are used in a wide variety of applications, including asset management (gas cylinders, beer barrels) and access control (people and vehicles) Low Frequency (134kHz) tags 134kHz Low Frequency RFID Scan Module; The 134kHz scan module will support ISO11784 and animal tags operating at 134.2kHz and FDK-B tags are supported from these standards, which are widely used for tagging livestock, particularly pigs, cows and sheep worldwide High (Intermediate) Frequency (13.56MHz) tags 38

39 The recent availability of high frequency tags has enabled the development of smart labels, which incorporate a paper thin tag sandwiched between paper or laminate. Such smart labels will co-exist with conventional bar code labels in a diverse range of applications. The infrastructure to support this - including printers enabled for programming smart labels - is evolving rapidly Smart labels are particularly suited to high volume, low cost applications, where flexible tags are required Support included for; Gemplus - AIRO and FOLIO ARIO10/40 tags are typically used for closed loop smart tracking applications the 2kbit size of the ARIO40 is particularly useful for local product databases. Omron -Icode Omron use Icode silicon for a variety of smart labels, with use primarily for airline luggage management and retail applications. Philips Semiconductors - Icode Icode silicon is being used by many label converters to provide a wide variety of smart labels, for applications in logistics, retail, airline luggage management, courier/parcel tracking, libraries and anti-counterfeit protection Texas Instruments - Tag-it Tag-it inlays are being used to provide a wide variety of smart labels, for applications in logistics, retail, airline luggage management, courier/parcel tracking and also in libraries Microchip - Series 300 In partnership with Checkpoint, Microchip silicon is being widely used in retail applications, and libraries. The longer operating distance and EAS facilities of this tag make it particularly suited for retail applications 39