Radio Frequency Identification (RFID)
RFID is all about the automation of tracking and identifying objects of interest to an organisation through the use of electronic tags, supported by hardware - readers and middleware - to collate the real-time information.
RFID technology can be viewed at 4 different levels:
- The Physical layer is on the "factory floor". It is where the events that need to be tracked and traced occur. So here is where the RFID tags reside. It is also where the other sensory devices such as barcodes, environmental sensors, photoelectric cells and biometric systems such as cameras are to be found. Tags can be active or passive in nature. The latter are like electronic barcodes and are only activated when a reader is used. The former send out a continual "I am here" message which readers can then locate.
- The Device layer is concerned with the devices that will record that an event has happened. The devices that collect the information include RFID readers and printers, barcode readers and PLCs (programmable logic controllers; specialised industrial computers used for automation of real-world processes).
- Interface and Edge Application layer - associated with the devices are computers, which host RFID middleware and edge applications. The middleware is used to apply rules that aggregate and filter the information gathered for an event and turn it into more business related terms. Edge applications exploit this "cleansed" information to provide support and business intelligence to people working at the edge of the enterprise.
- Business Application layer. These are the applications that currently run organisations such as ERP, HR, SCM and CRM. The data from the edge is passed to update these applications with more accurate data.
Physical layer - Tags
An active RFID tag has a transmitter to send out information, rather than reflecting back a signal from the reader, as a passive tag does. Most active tags use a battery to transmit a signal to a reader.
Passive RFID tags operate without a separate external power source and transmitter. They obtain operating power generated from the reader. When radio waves from the reader reach the chip's antenna, the energy is converted by the antenna into electricity that can power up the microchip in the tag.
When selecting tags, you need to know the following:
- what will they be attached to?
- what environment will they need to operate in?
- what distances do you want to be able to identify/track the object of interest?
- what operating frequency do you want to use?
- how many tags do you want and is this a one-off order or a repeat order?
Device layer - readers and printers
A reader is a transmitter/receiver that reads the contents of RFID tags in the vicinity. The reader is also sometimes called an interrogator because it "interrogates" the tag. An RFID reader typically contains a module (transmitter and receiver), a control unit and a coupling element (antenna). The reader has three main functions: energising, demodulating and decoding.
When selecting a reader, you need to know the following:
- what tags are you using?
- what is their frequency?
- what environment are the readers going to work in?
- what power output do you need?
- what is the size of the space you have to fit the reader into?
- how many ports do you need?
- do you need local or global compliance to standards?
An RFID printer, or printer/encoder, is a device that prints a label with an embedded RFID transponder and encodes information in the chip within the transponder. They are normally thermal printers that print RFID smart labels.
When selecting a printer, you need to consider the following:
- what is the width of the label you need to produce?
- what composition of label do you require? (this includes adhesive)
- how many labels to do you expect to print each day?
- what print resolution do you need? (typical support is for 200-300 dpi range)
Interface layer - RFID middleware
RFID middleware is the term used to refer to software that resides on a server between readers and enterprise applications. The middleware is used to filter data and pass on only useful information to enterprise applications. Some middleware can also be used to manage readers on a network. There are three primary motivations behind using RFID middleware:
- to encapsulate the applications from device interfaces
- to process the raw observations captured by the readers and sensors so that applications see only meaningful, high-level events, thereby lowering the volume of information that they need to process
- to provide an application-level interface for managing readers and querying RFID observations.
When selecting RFID middleware, you need to consider the following:
- support for technical standards that are relevant to the target application (for instance EPCGlobal for logistics)
- technical compatibility with the selected hardware to use the latter's capabilities in the best way
- the amount of development and integration effort required
- the usability of the RFID system to be implemented for all its primary and secondary end-users (such as employees, administrators, IT experts etc.)
- the effort required for expanding and/or scaling the RFID solution
- the ability of the target middleware solution to guarantee openness in order to avoid lock-ins to specific vendors and/or proprietary solutions
- support for functionality to support the following features:
- rules definition
- use and definition of adapters
- support for XML data format
- process modelling
- management of devices;
- report definition and generation.
Interface layer - edge applications
Edgeware applications are niche in nature and normally sit on top of RFID middleware to perform functionality on the data collected and processed by the latter to provide information at the edge without recourse to the main applications of the main servers of an organisation. Areas covered include:
- asset and people tracking
- animal tracking and identification
- logistics - real-time location
- event/journey ticketing
RFID technology helps, amongst many others:
- Hospitals, to locate expensive equipment more quickly, in order to improve patient care, as well as patient identification
- Pharmaceutical companies, to reduce counterfeiting; and logistics providers to improve the management of moveable assets
- Logistics organisations, to track and manage goods from the point of manufacture through to the retail point of sale (POS)
- Public transport authorities and public utilities, to improve customer service
- The automotive industry, which has used closed-loop RFID systems to track and control major assemblies within a production plant, for about 30 years
- Retailers, who mandate RFID tagging for pallets and cases shipped into their distribution centres, in order to provide better visibility
- Aerospace and automotive industries, who use RFID to ensure the authenticity of parts
- The farming sector, where RFID is being used to track the movement of farm animals, to assist with tracking issues when major animal diseases strike
- Countries that are using RFID chips in passports.
RFID technology is important to people responsible for the management of supply chains, fraud, health and safety, and assets.
There are two main groups forming RFID standards, ISO and EPCglobal. EPCglobal developed out of a joint venture between EAN/UCC and the AutoID Center at MIT that developed the EPC. This venture is charged with the commercialisation of the Electronic Product Code and its support network.
RFID tag standards are constantly evolving depending on the chosen frequency, the technology application, and geographic locations. Some standards, such as the ISO 15693 standard for 13.56 MHz, are global and can be used without modification across the world. Others, such as EPC, are not yet global due to intra-country regulations concerning radio frequency allocations for other technologies and applications.
EPC is also setting data standards for different industries in terms of the data collected by the devices and passed to business applications through middleware.
Big Data (and some!)
RFID generates an incredible amount of data. Even with rules, there is a vast amount. So one major emerging issue is what do you store and how long do you store it; both for immediate access and also for recovery from historical storage.
The market for RFID can be divided into 2 halves: those that supply tags and readers; and those that supply middleware and edgeware applications. Over the last 10 years the industry has gone through a major spate of mergers and acquisitions. This has resulted in the majority of RFID middleware vendors being swallowed by edge application or business application software companies. In addition, there has been acquisition of application and software companies by tag/reader hardware vendors. Examples are:
- ADT Tyco acquired Vue Technologies (reader/tag vendor acquiring middleware vendor)
- Checkpoint Systems Inc. acquired OATSystems (Application vendor acquiring middleware vendor)
- Odin Technologies acquired Reva Systems (SI acquiring tag/RTLS vendor)
- Zebra acquired Motorola which had previously acquired both Symbol and Psion Teklogix
- Honeywell acquired Intermec which had previously acquired Vocollect