Homework 5 – GIS Encyclopedia Article – E5
Student: Antony Philip (Group 7)
1. Radio Frequency Identification (RFID)
Radio Frequency Identification (RFID) is an electronic identification technology that
allows an object, place, or person to be automatically identified at a distance without it
being in direct line-of-sight. The main beneficiary of this technology is the global supply
chain management industry. Traditionally product identification was done using bar
codes and scanners. These bar-codes met the needs of the industry provided constraints in
using them were met, namely operator scans the bar code or by carefully moving the
products in an automated system so that bar codes are visible below the scanner. This is
not efficient and subject to errors. RFID system is much more than a bar-code reading
system. But to give an idea, products which use RFID tags for identification can be read
even if they are obscured by other products.
Figure 1 Retail Supply Chain
Above shows a typical supply chain maintained by retail stores such as Walmart to
support end customers who buy goods from them. The retailer may buy things from
distributors and the distributors get the goods from the manufacturers and stock them in
their storage. The goods are manufactured using parts from the suppliers. As materials
move from the initial supplier in the chain to the end-customer, value and costs are added
at each node. Businesses strive to make their supply chains more efficient by improving
the information sharing throughout the supply chain in order to optimize profit based on
supply and demand. Introducing RFID tags and readers in the supply chain can greatly
increase the productivity, reduce chances for mistakes and improve the overall efficiency
of this supply chain system.
Much of the literature focuses on the activity performed in the last five years especially in
the supply chain industry and after the formation of EPCGlobal. However, radio
frequency identification has been used since World War II to solve identification and
asset tracking problems. The first known use of RF Identification was during World War
II. The British Royal Air Force used the technology as an identification tool in its Identify
Friend/Foe (IFF) systems. Allied planes with an IFF transponder would respond to
queries from ground-based radars with a specific response. By the late 1970s, RFID was
used for the tracking of livestock. Individual cattle were tagged with their own
identification beacon. RF readers were placed at points of entry into barns, feeding stalls
and other locations. The ability to identify individual cows without human interaction
allowed better tracking of feeding and health irregularities. In the early 1980s, railroad
companies were using RFID to tag rail cars. This was among the first uses of RFID for
asset tracking over a large geographic area. An earlier initiative to do this with bar codes
failed due to poor read reliability in adverse weather conditions, high travel speeds and
direct sunlight. In 1990s, RFID arrived in the suburban malls throughout the United
States as an enabling technology for Electronic Article Surveillance (EAS). RFID readers
positioned by store exits would trigger an alarm if an EAS tag passed through the field.
2. RFID System
In many ways, the physical processes involved in RFID systems are the same across all
types of wireless communications systems, cordless telephones, or even baby monitors.
There is a transmission of an interrogator signal from an antenna to a transponder, and a
separate transmission of a reply from the transponder to a receiving antenna. Most
interrogator designs allow for a single antenna to be used for transmission and reception.
Figure 2 RFID Tags
Figure 3 RFID Reader
Tags come in variety of shapes as shown above. Tags are the computer chips which are
tagged with the products so that they can be identified. Depending on how the chips are
powered they can be active or passive tags. Passive tags have no internal power supply.
But, Active tags have their own internal power source to power the chip. Majority of
RFID tags in existence are of the passive variety because they don’t need a battery to
operate. Tag readers generate a signal creating an electromagnetic field. This causes
RFID tag’s antenna to function as a voltage generator. Current generated in the tag
powers the chip which modulates the radar cross-section of the tag and therefore its
reflected power. The modulation applied is usually specific to the tag, and so information
on that tag can be sent to the receiver. The simplest command results in the tag sending
back a signal containing a unique digital ID (e.g., the EPC-96 standard uses 96 bits).
Once the id for the tag is read the reader can send the data to the application software for
further processing. The application software then queries the information about the id
from its known data bases. This will give the history of the tag/product and enables
updating the database with the current spatial and temporal information about the
product. Sometimes, the tag may have an additional EEPROM memory which allows the
reader to write back instance specific information to the tag.
A typical RFID system may have the following:
• Hardware components
o Tags, which are programmed with binary data and respond to commands
propagated through the electromagnetic field
o Fixtures which attach the tag to the object being tracked
o Readers or integrators, which may have an integrated antenna to transmit
commands to tags and interpret the modulated results
o Network infrastructure, to allow communication between integrators and
the enterprise systems which evaluate the data read from the tags – This
could be RS-232, Ethernet or 802.11b wireless cards or proprietary
o Power infrastructure, to provide AC or DC power to the readers.
• Software / Middleware
o Reader can identify that one or more tags are in the presence of a field. It
is useful to identify information such as presence of new tag or tag which
has been there is currently missing. But repeatedly reading the same tag
data may not be useful. So the events of interest need to be defined by the
o A software middleware which adapts to the requirements of the upstream
applications and the varying reader protocols is necessary as explained in
o Software systems to update and get information from company’s
enterprise systems like MRP, ERP, CRM, etc.
o Spatio-Temporal databases which can capture spatial and time information
of the data collected.
In the last several years RFID technology got tremendous coverage from the main media
because of successful applications like ExxonMobil’s credit card linked Speed Pass,
north eastern states toll collection system using EZPass and DoD asset tracking during
the second gulf war. RFID also got more attention from privacy advocacy groups because
of its potential as a powerful data mining tool. In recent years this is increasingly more
pre-dominant than the positive applications of RFID. To be successful as a technology,
RFID applications should give clear, tangible value to the average consumer. This will
compensate for whatever privacy fears they may have. Consumers tend to accept the risk of
being tracked if they feel it’s worth the benefits the application provides. So the key to a
successful RFID application is how it considers the equation from the consumer’s point of
view . To alleviate this privacy concern EPCGlobal specifies a ‘kill’ function for the tag
allowing the end-user the opportunity to remove the tag-id from the product.
Some of the other popular applications of RFID are as follows:
• Electronic Product Code (EPC) tags for products stored in a store
• Embedded tag in Library books to track check-in, check-out of books
• Traffic toll collection (such as EZPass)
• Passports and other IDs
• Pet identification
• Semiconductor factory lot tracking
• Livestock tracking
• Measuring reach and network routing of water and sediment by tracking RFID’ed
One natural extension for RFID is RFID with sensing capability. Adding this facilitates
collecting sensor derived data on the product it is tagging along. Some of the applications
of RFID with sensor are
• Measuring physical parameters such as temperature, acceleration. This includes
some of the well-known applications like detecting the temperature changes for
frozen poultry, detecting the acceleration changes in packaging for sensitive
equipments such as computers, artwork, etc.
• Harmful agent such as biological, nuclear, chemical monitoring – This is an
application of interest especially after 9/11 events.
RFID data can be integrated into spatial databases to develop powerful applications. Tag
reader can be considered as one of the information provider node in a spatial database
application framework. Tag reader provides both spatial and temporal information for a
product it read. In a retail environment this facilitates spatio-temporal queries and
facilitates demand forecasting.
4. RFID Solution Architecture
Figure 4 RFID Solution Architecture 
Above shows the RFID solution architecture proposed in . In the lowest level is RFID
sensor networks. Data from these tags are read by the readers. These readers vary in the
way in the communication protocol with the software systems above. So, the challenge in
the data consumption layer is to add an abstraction layer for the readers so that impact of
changes in the hardware can be minimized. RFID Readers are generating data constantly
as they read the tags. In order to filter and read the generated data, an asynchronous data
consumption layer is necessary. This layer can act as a store and forward layer for tag
data ensuring reliable message delivery. In an enterprise scenario, various applications
may need access to these RFID data. Web services provide an easy mechanism to expose
these data in and interoperable XML format. These data are persisted in spatio-temporal
databases to cater business intelligence queries.
There are several challenges to widespread of adoption of RFID technology. Some of
them are technical and some of them non-technical.
The tag-reader cannot communicate effectively with a tag that is oriented
perpendicular to the reader antenna. As we can see this limits RFID usage to
applications such as ‘one scan identification’ of all products in a shopping basket.
This problem can be mitigated by using multiple readers oriented in many
directions. But, using multiple readers requires additional synchronization and
merging of results.
• Reader Coordination and Signal Processing
Most RFID readers are not designed to operate in the presence of another reader
that is also scanning for tags. Standards are needed to define a protocol to allow
these systems to share the available bandwidth. Further improvements can be
made when interpreting the tag signals received at the reader, intelligently
filtering out noise.
• Product Packaging Independence
RFID tag information can be disrupted by materials in the product it is
identifying. Since, tags use RF circuits it is possible to attenuate the signals if they
are placed next to products made of metals such as food cans.
• Multiple Standards
Because of cost trade-offs, national frequency use restrictions, and politics there
are several standards active. Consolidation or interoperability is required
• Data Formats
Although the data format returned by read-only tags is defined by standards, the
writable tags provide flash memory that customers can use in a proprietary way.
Standardizing this data format will facilitate inter-operability. An XML-based
format might be adopted for this purpose.
• Longer Range
In practice most of the lower-frequency RFID systems can read tags at a
maximum distance of about a meter. Reliable longer-range systems should
become possible and expand the usefulness of RFID in warehouses and other
• Lowering Manufacturing Costs
Lowering tag and system costs would likely further the adoption of RFID,
particularly for item-level tagging. Industry currently aims to bring down the cost
of tag to be 5 cents to enable large scale adoption for individual product tracking.
• RFID with sensor
RFID with sensor has several unique problems. First of all, packaging a sensing
material with tag chip is difficult. Also, the sensors need to operate in a condition
where it gets power only when the tag is being read.
• Privacy And Customer Pushback
Privacy groups claim that RFID embedded products could be used to provide
directed marketing to people. If early adopters of the technology do not address
these issues successfully, they may well face customer pushback and loss of sales.
6. Role Of EPCGlobal
RFID industry participants recognized these challenges and worked with MIT and other
universities to create the Auto-ID Center in the late 1990s. Founding members included
several hardware and software component manufacturers, system integrators and a
number of product manufacturers and distribution chain participants. Its overall goal was
to drive the adoption of RFID. In 2003, the administrative function of the center was spun
off into an organization called EPCGlobal, while the university research components
continued under Auto-ID Labs. EPCGlobal works towards its goal of driving RFID
adoption in several ways. Each targets one or more of the challenges presented by the
industry structure or specifics of the technology.
First and foremost, EPCGlobal establishes and promotes standards for the automatic
identification of items in the supply chain of any company, industry and country. EPC is
an acronym for “Electronic Product Code”. The EPC number is a compact numerical
naming convention to uniquely identify items in the supply chain. When an EPC-
compliant tag responds to an interrogator, it usually transmits its EPC number. Current
versions of the EPC contain either 64 or 96 bits, and store four pieces of information:
• A Header that identifies the format and version of this EPC
• A Manager Number to identify the company associated with the product
• An Object Class, identifying a product type unique to that company
• A Serial Number which uniquely identifies the item
The software standards serve to meet the supply chain coordination challenges. The
Physical Markup Language (PML) which is an XML standard offers a common
vocabulary for communicating information about items across the entire supply chain.
PML is extensible, meaning that additional attributes can be appended as needed. Object
Naming Service (ONS) provides for the translation of tag data into useable information
about the manufacturer and product. There are already many companies working with
RFID technologies and more are being added to this list every day. An important role of
the EPCGlobal consortium is to provide a single voice for the industry. The consortium
provides a forum for all the value chain actors to interact. EPCGlobal maintains a
relationship with the Auto-ID Labs at several universities worldwide. The labs conduct
research into various aspects of RFID systems, and continue to publish research. Through
this relationship, EPCGlobal™ can help shape the direction of research in order to
address obstacles adoption might face in the future.
RFID technology can provide considerable value to the industry and ultimately to the end
user. The technical challenges listed in section 5 may be overcome in the coming years
but the privacy concern is going to remain unless the industry makes a concerted effort to
alleviate that. One major challenge is integrating the vast amount of data generated in
these readers with existing databases. The data generated is about individual products
whose product life-cycle is kept in the database. Since the data generated is of spatio-
temporal nature, spatial database technologists can play a crucial role in mining that data
to give valuable information.
1. Eckfeldt, B., ., “What does RFID do for the consumer”, Communications of the
ACM, Vol 48 , No 9, pp 77-79, 2005
2. Landt, J., "The history of RFID", IEEE Potentials, Vol.24, no.4, pp. 8- 11, Oct-
3. Ohkubo, M., Suzuki, K., Kinoshita, S., “RFID privacy issues and technical
challenges”, Communications of the ACM, Vol 48 , No 9, pp 66-71, 2005
4. Sarma, S., “Integrating RFID”, ACM Queue, Vol 2, No 7, pp 50-57, 2004
5. Sikander, J., RFID Enabled Retail Supply Chain, MSDN April 2005
6. Want, R., “The magic of RFID”, ACM Queue, Vol 2, No 7, pp 40-48, 2004
7. Want, R., "Enabling ubiquitous sensing with RFID," Computer , vol.37, no.4, pp.
84- 86, 2004
8. EPCGlobal Website, http://www.epcglobalinc.org/