RFID Awakens

May 1, 2007 12:00 PM, By Michael Fickes

Radio Frequency Identification (RFID) technology isn't just for paying highway tolls anymore.

A new RFID world is emerging, and it may offer a host of benefits to chief security officers (CSOs) and security directors searching for technology that will contribute to business goals as well as security goals.

Today, RFID applications include supply chain security, asset tracking, evacuation and mustering, parking, traditional RFID applications such as access control proximity and smart card systems, and much more.

“Every day we get someone asking for a new application,” says Pete Martin, president of AAID Security Solutions, Inc., an RFID supplier based in Peachtree City, Ga. “We've been thinking that we've heard it all, but it appears that we haven't.

Critics have lambasted some of these RFID applications, saying that they don't come close to providing economic benefits sufficient enough to justify replacing less expensive technologies. According to a critical Wall Street Journal article, for example, the widely reported effort of Wal-Mart Stores Inc. to install an RFID supply chain management is “fizzling. Likewise, some critics say that RFID asset tracking technology will never attain the efficiency necessary to replace barcodes.

But these criticisms address applications using one form of RFID technology. The RFID world has grown large over the past 20 years. Today, RFID includes different solutions appropriate for different tasks.

Getting the technology right

RFID hardware consists of tags carrying electronic information and readers that grab that information and send it to a database.

Most RFID applications use passive RFID tags. Some applications employ active tags. What's the difference?

Passive tags operate without an onboard power source. When radio waves from a reader reach a passive tag's antenna, which is connected to a microchip, the chip uses some of the radio wave energy to turn on the microchip. Once it has been turned on, the chip communicates information stored in its circuits by adding it to the radio waves it is receiving and reflecting that energy back to the reader. Passive tags are inexpensive. They cost from 20 cents to several dollars, depending upon features.

Active tags run on battery power and include transmitters that send stored information out in a beacon. Readers can detect and read data from active tags at a read-range of 300 feet and more. They are expensive compared to passive tags, costing between $12 and $30. Often affixed to shipping containers, active tags play a roll in certain areas of supply chain management and can also work with other technologies to provide security.

Supply chain and supply chain security

Supply chain management employs both passive and active tags. Wal-Mart, for example, has been piloting a supply chain management concept in which vendors apply passive tags to cartons and pallets before shipping to the giant retailer's distribution centers.

Readers positioned at the doors and throughout distribution centers operated both by Wal-Mart and the vendors activate and read the passive tags as tagged cartons and pallets pass by the sensors. The data enables Wal-Mart to track products from factory floors, onto trucks and ships, into and out of seaports, back onto trucks, into and through distribution centers, and finally to the retailer's shelves.

By knowing where every item in the supply chain is at any given time, Wal-Mart believes it can ensure that its store shelves will never lack for products, thereby increasing sales and profits.

In a February 15, 2007, article critiquing Wal-Mart's progress, The Wall Street Journal claimed that the project was fizzling and showing no return on investment.

Wal-Mart replied in a letter to the Journal and cited an independent study finding that out-of-stock items in stores served by the RFID supply chain decline by 30 percent. The study further found that stores equipped with RFID reduced manual ordering by 10 percent and showed less excess inventory on their books than other stores.

If those benefits ultimately play out, Wal-Mart will build revenues by reducing out-of-stock shelves, enhance productivity by reducing manual ordering and increase profits through increased revenues and less excess inventory. Those are the business benefits sought by companies monitoring their supply chains with RFID.

Depending on what a company ships and where, a security director might be able to enhance those benefits.

Tracking cargo containers for security

Cargo containers make the supply chain work. The large, standard sized boxes hold pallets that hold cartons that hold items being shipped by manufacturers over sea, in the air and over land.

A number of private companies, including GE Security in Bradenton, Fla., and Savi Networks in Mountain View, Calif., provide hardware and software systems to track cargo containers. A typical corporate supply chain affixes active RFID tags to cargo containers. Active tags can store container manifests or unique numbers that refer to manifest files held in secure databases. The tag suppliers install readers in seaports, airports, train depots and truck terminals around the country, based on the routes taken by their customers' goods.

When the readers encounter a customer's cargo container, they tell the owner's database where the container is. A customer can access that database over the Internet or have the data delivered to its own servers.

“Most of our customers want more than a message that a container is here or there,” says Steve Sewell, senior vice president with Savi Networks. They may want to know where shock damage or humidity damage is occurring in the supply chain. They may also want to know if the container has been opened or tampered with in some way. All of these things can be tracked.”

Companies that provide supply chain security make tamper detection devices that can be attached to the door of a cargo container. If the container is opened during transit, the device date stamps that information onto the active tag, which communicates that information to the central database when it passes a reader.

Information about damage to products shipped in cargo containers or unauthorized access to the containers has value for companies. It becomes possible to prevent environmental damage or reduce theft when the system reveals when and where such problems arise.

“You can also get fast track status from C-TPAT,” says Robert Hayes, executive director of the CSO Executive Council in Framingham, Mass.

The Customs and Border Protection (CBP) unit of the Department of Homeland Security (DHS) created C-TPAT or Customs-Trade Partnership Against Terrorism. In the program, which now includes more than 6,000 major U.S. importers, CBP pre-screens importers and their shipping processes. Those deemed secure receive fast track status and may move goods back and forth across borders without undue delay — often without waiting in line.

“The Safe Port Act contains provisions under which shippers may be able to use container security devices — which are not fully defined in the Act — to qualify for Tier 3 C-TPAT status, the highest designation the program offers,” Sewell adds.

RFID tracks assets and takes inventory

Fifteen years ago, RFID proponents developed systems designed to track assets such as computers, copiers, fax machines and other devices susceptible to theft. It did not work. A lot of companies bought systems that did not work as advertised.

“For tracking assets, I always recommend barcodes,” says Don Small, a former senior executive with major security vendors in the passive and active RFID world. Small has little good to say about RFID's asset tracking capabilities. “I'm a naysayer on anything that doesn't have a 100 percent practical solution.”

Pete Martin of AAID Security Solutions has been selling RFID-based asset tracking systems for years. He says that many asset tracking concepts fail because they employ the wrong technology.

Instead of the RFID readers and tags used in most supply chains, Martin favors active tags and passive readers.

“We added power to RFID tags, making them active, to make longer range reads possible,” Martin adds, pointing to the active tags on cargo containers and the 100 to 300 foot read ranges they provide. “But there is another way to read at greater distances.”

Readers are also classified as active and passive, Martin says. While active tags are called active because they have a battery, all readers need power, and the terms “active” and “passive” mean something different when applied to readers.

Active readers create and broadcast radio frequency fields that wake up any RFID tags within range. Passive readers respond to signals from active tags.

Active readers cannot track assets over distances. The Federal Communications Commission (FCC) regards active readers as radio stations. One of the Commission's roles is to prevent radio stations from interfering with other radio signals. As a result, the FCC limits the magnitude and the range of active reader signals. The limited range is inadequate for asset tracking. It might accommodate an office door, but not a loading dock door.

Worse yet, Martin says, two active readers set side-by-side interfere with each other just like two radio stations broadcasting side-by-side on the same frequency. As a result, only one active reader can be placed at a doorway to watch for tagged assets moving in and out. And one reader only knows one thing: that a tag entered and exited its field.

But did that tag (affixed to, say, a laptop computer) go all the way out the door? Did it approach the door from the inside or outside of the office? Did it impinge on the active reader's signal but remain inside the office? Or outside the office?

Active readers cannot track assets. But passive readers can. “Passive readers don't have transmitters and are not regulated by the FCC,” Martin says. “Depending on the antenna, our readers have ranges of 600 feet to 3,500 feet.”

Passive readers listen for 433 MHz signals sent out by active tags. When a reader hears a signal, it passes the data along to a database. Isn't a signal sent by an active tag regulated? At the request of Savi Networks, the FCC loosened regulations for active tags operating at 433 MHz in 2004, permitting longer-range operation.

“Two passive readers are placed at an office door,” says Martin. “One is just outside, and the other just inside. The system is programmed to understand that when both readers see a tag, it has moved in or out of the office. The direction is determined by which reader sees the tag first and which sees it second. If only one reader activates, then the tag approached the door from that direction but didn't pass through.”

Another problem with asset management systems with active readers arises when someone removes the passive tag from an asset and walks out — with the asset. If the passive tag doesn't pass through the beacon broadcast by the active reader, the system will not generate an alarm.

It is also possible to wrap a passive tag in foil or to hide the asset in a metal trashcan. Metal absorbs the signal from the active reader, and the passive tag never knows that someone called.

Not so with passive readers and active tags. When an active tag is removed from a device, the tag sends a tamper alarm to the monitoring system. Likewise when foil or a metal container cuts off communication between the active tag and the passive reader, the system sounds an alarm.

In each case, the system communicates with the security center, saying that something has happened to a computer or other device at a particular location.

Asset tracking costs

According to Martin, a rule of thumb for asset management costs associates five assets with each employee. Each asset requires an active tag costing $12 to $30. If the average is $20, then the cost per employee for five tags is $100. For companies with 500 employees, tags will cost $50,000.

Martin says that passive readers cost less than active readers. “Active readers have transmitters, and transmitters are the expensive component,” he says. “Passive readers have no transmitter.”

Passive readers cost between $300 and $500. By contrast, active readers run from $800 to $5,000.

Martin notes that even though two passive readers are required for every doorway, they usually cost less than one active reader.

“It is easy to pay for this kind of system,” Martin says. “Since the system tracks your assets, it maintains a constant inventory. So you no longer have to shut down operations to take inventory. Many companies do that four times a year. Now all you have to do is check the asset-tracking computer.”

Emergency evacuation and mustering

The Sept. 11th terrorist attacks made it important for companies to figure out a way to know who is in a building and when.

The attacks also pointed out the flaws in mustering strategies. Security directors often conduct emergency drills designed to teach employees where to muster outside of the building in case of emergency. At the mustering point, someone calls the roll and determines who is missing and whether or not those people might be trapped inside the building. After Sept. 11th, security directors realized that no one goes to mustering points during emergencies.

To know who got out and who didn't, you have to know who is in the building to begin with. Conventional access control systems provide some idea of who entered a building during the day, even though tailgating creates inconsistencies with that data. But access control systems probably cannot tell much about who got out. Just like people don't go to the muster point in an emergency, they don't card out. So a security director cannot tell who remains in the building.

Martin suggests letting the asset tracking passive RFID readers at the doors do double duty by hanging active tags around everyone's neck — visitors too. “We can embed smart chips in the cards to open the doors in the building with the regular readers,” he says. “And passive tag technology can monitor people going in and out, so you always know who is in the building.

Flexible, yes. Perfect, no

RFID is a flexible technology that can handle different business and security tasks. Even, naysayer Don Small, the former RFID industry executive favors RFID for a number of applications:

• vehicle tracking, which includes automatic toll-paying;

• parking applications, in which an onboard device communicates with sensors and raises and lowers gates. Since the process is hands-free, it doesn't require drivers to roll down windows, which could be a security risk;

• tracking dementia patients in hospitals to make sure they don't wander off;

• traditional proximity card and smart card access control.

But RFID integration requires RFID integration specialists. “Access control integrators have been trying to make asset tracking work with Wiegand infrastructure for 15 years,” Martin says. “After all, they are selling mostly Wiegand access control panels and readers. But if you are doing asset and personnel tracking, a reader has to be able to identify multiple tags simultaneously. Wiegand readers can't process more than one tag at a time. RFID systems use serial output readers, which can handle that kind of processing requirement.”

In other words, emerging RFID applications are arriving with new RFID experts who can tell you whether a particular application will work within your system and within your budget. If you decide to look into RFID, look into an expert in the field as well.

RFID Frequencies Govern Different Applications

Different radio frequencies have different characteristics and work better with one or another kind of RFID application, according to Douglas L. Cram, vice president and chief operating officer of Security Holding Corp.

In the United States, Cram says, there are four basic frequencies in use:

1. 125 kHz. Proximity access control cards employ a frequency of 125 kHz. These are passive cards — with no batteries — and their range is limited to 20 to 30 inches.

2. 13.56 MHz. This is the frequency most commonly used by contactless smart cards. Document and file tracking applications also use this frequency, along with electronic article surveillance systems (EAS), which are designed to reduce shoplifting in retail stores.

3. 433 MHz. At this frequency, battery powered RFID tags transmit data received by readers. These systems handle asset and people tracking.

4. 902 MHz to 928 MHz. These can be either active or passive tags. Passive tags work with active readers and emit RF fields. Applications include automated toll way collections, parking, and file and document management.

Want to use this article? Click here for options!
© 2009 Penton Media Inc.

This month in Access Control

• Targeting The Customer
• Electronic Pedigrees
• One Hero Among Many
• Who? What? When? Where? Why?
• More from September's issue