RFID-(ar ef i dee) - Radio Frequency Identification (sometimes Identification Device). A small device which can be contained in a glass capsule to be placed in pets, carried in cards, worn in clothing or a multitude of other places. Used by the US postal service (USPS) to track mail bags, etc.

These devices respond to a low-frequency radio field from a transmitter(usually lower than the AM radio band) storing energy until they have enough to send an id back to the transmitter. Thus they need no batteries, and are small enough to be contained in cards just barely thicker than a credit card, or buttons, or inside glass capsules the size of a large hypodermic needle.

Ford uses them in Dearborn, Detroit on their employee ID cards. Many employees carry them in their planners (or wallets), and simple pass their planners (or shimmy their behind-which is very peculiar to observe) close to the reader. Most RFID devices have ranges of 10-20 inches (25-50 cm) but can be further depending on the antenna and transmitter configuration. Typically the RFID antenna is so small that it has to be within several inches of the transmitter to work well, so don't get all paranoid about it, eh?

I want to attach one to my watch for my home automation system so the system can be more intelligent.

Some of the advantages of RFID over the mag-swipe ID cards:

  • There are no moving parts, anywhere. This means dust, corrosion and wear and tear have a much smaller impact on RFID than mag-stripes, and mischief with chewing gum is ineffective.
  • It is contactless. The card doesn't even have to be on a line of sight from the reader in order to be detected. With enough range on an RFID lock, one just walks up to a door with the ID card still in a pocket, and it opens.
  • Greater security is possible on RFID systems. For example, code hopping can be implemented so a tag transmits a different ID code each time. Each card can still be distinguished from all others, but even if someone can get a copy of one transmission from a card, that one transmission, when reproduced, will be rejected by the interrogator later.
  • RFID is more transparent to the users than mag-stripes. A flexible tag on sticky paper could be attached to grocery items instead of a price tag, for example, then a checkout counter could read the contents of a shopping bag and total the prices without a clerk even having to open it.

RFID tags generally come in two types: FDX (Full duplex) and HDX (Half duplex). Either type can be made with or without a battery, though it's rare to find an FDX tag with a battery. FDX tags transmit their ID codes while the reader's activator signal is on - most of them actually get their energy from the activator signal, which is why they rarely have batteries. HDX tags transmit their ID codes after the signal turns off - sometimes the tag has a large capacitor, and gathers energy while the activator is on, sometimes it has a battery (in which case the activator merely is a signal for the HDX tag indicating when it should transmit its ID).

There are generally three types of modulation used in RFID - Amplitude modulation (ASK), Frequency modulation (FSK), and Phase modulation (PSK). There are several encoding schemes: NRZ, Manchester encoding, Differential bi-phase encoding, variants, and more exotic types. The bit rate may vary from one tag format to another, as may the length of the tag, and the logical arrangement of bits within the tag; all these variables make for a very wide variety of tag formats. On top of that, more sophisitcated tags implement query-response protocols for authentication, and anticollision routines so that multiple tags in a field don't interfere with each others transmissions.

Gillette's RFID Field Trial1

It's very likely that we are all going to be hearing a lot about RFID in the next few years.  RFID currently has that kind of wired buzz that technologies get when they are about to achieve critical mass.  RFID, or Radio Frequency IDentification is a location tracking technology that basically consists of tiny, inexpensive short-range radio transmitter tags, each with a unique ID number, that are applied to consumer products. The transmitters announce their presence to sensitive radio receivers in warehouses, shipping depots, and retail stores. This allows products to be tracked, "from cradle to grave."  Real-time tracking could revolutionize the supply chain by allowing retailers to automate the ordering and restocking of their shelves, shippers to automate their shipment handling and manufacturers to know exactly where their inventory is.

RFID technology has been around since the 1980's in one form or another2, but in the last few years it has advanced significantly in the areas of reductions in both size and cost of the transmitters.  Modern RFID transmitters are cheap (about $.05 U.S. each), and small (about the size of a grain of sand).  Modern RFID tags are powered inductively by the receiver, so they don't need a battery, and each one contains its own tiny antenna suitable for short range broadcasting.

At first glance one might be amused at the thought of a million tiny voices all mindlessly shouting the only word they know at the top of their little electronic lungs day and night. Consider this however; the waste and inefficiency inherent in the manufacturing and distribution process results in hundreds of millions of dollars of lost and waste every year due to products that are lost, stolen, or out of stock.  According to the Auto-ID Center at MIT3, RFID promises to alter that equation completely.

The Gillette Company makes razors, blades and related leg shaving hair-scraping products.  Their Chicago, Illinois Chicago distribution center alone occupies 532,000 square feet (think of a square building over 730 feet or 220 meters on each side). This warehouse is designed to store 50,000 pallets of Gillette products with a retail value of over $60,000,000 U.S.  For their initial pilot program in the world of RFID, Gillette has announced that it will purchase five hundred million(!) RFID tags.  They will use these to tag every pallet and every case of product they ship.  Alien Technology, the company supplying Gillette is just the first big winner in the RFID lottery.

RFID will allow Gillette to follow each pallet and case as it proceeds from manufacturing, to the warehouse. From the warehouse to the shipping dock, onto the truck, and at the receiving dock at its final destination, say the local supermarket.  But wait, there's more.  At the supermercado, the Gillette products will be stocked on, "smart shelves," for consumer access.  These shelves will let the store know when they "need" more razor blades stocked, and the shelves in the back room will notify the store when it's time to reorder .  The cash registers will recognize the products without the clerk having to scan a barcode, and don't even think about stuffing that Gillette Mach 3 down your pants!

I'm going to extrapolate a little here and imagine that we actually have that Internet refrigerator touted by billG and the other techno luminaries. If you combine RFID, Internet-enabled appliances and an online grocery retailer like Peapod, the whole story could get really weird. Consider the RFID house that just orders all the crap you need without bothering to ask.  

My Palm Pilot 2005 sez aloud, when it senses that I've entered the room via my RFID wristwatch: 

"Don't worry your pretty little head about it Grouch, I already ordered a sushi platter and a case of that Australian Shiraz you liked. I'm still waiting for you to select some entree's for next week  (hint, hint), and by the way, don't forget your daughter's orthodontics appointment tomorrow... "

Meanwhile, a nondescript grey truck prowls the neighborhood slowly and suspiciously.  There's a small antenna on the top, 

And, I wince slightly and say, to my tiny electronic audience, "Thanks, guys, good job..."


1 http://www.gillette.com/homepage.asp
2 http://www.aimglobal.org/technologies/rfid/
3 http://www.autoidcenter.org/aboutthetech.asp

RFID Updates

- Sept 2003: Privacy advocates raised alarms regarding RFID technology in California State legislative hearings recently. Beth Givins of the Privacy Rights Clearinghouse said, "RFID is essentially invisible and can result in both profiling and locational tracking of consumers without their knowledge or consent." She was seconded by Liz McIntyre, spokeswoman for the advocacy group Against Supermarket Privacy Invasion and Numbering, who said, "Without some sort of oversight, this technology could create a very frightening society." RFID industry spokesmen have responded by describing plans for RFID tags that can be disabled on checkout for retail customers.

- Nov 2003: McCarran International Airport, in Las Vegas, Nevada has signed a five year contract with Matrics Inc. to purchase one hundred million RFID tags for deployment on passenger luggage. According to an airport spokeman, the tags will be used to ensure that all baggage has been processed by the airport security systems. Sam Ingalls, the airport IT manager says, "RFID is the only technology that allows us to get a 99.5+%" assurance that bags have been properly screened.

- 19 Jan 2004: Verisign, wins the contract to operate Object Naming Service (ONS) the equivalent of the Internet's DNS system for RFID. ONS will store all the Electronic Product Codes (EPC) assigned to products with RFID tags. The EPC system was created by the non-profit corporation EPCglobal, and the AutoID Center at MIT. The ONS root directory is already operational according to Stratton Sclavos, who heads Verisign.

- Jan 2004: In the wake of the recent bovine spongiform encephalopathy scare, the American meat industry has lined up behind a proposal for the RFID-based National Animal Identification Tag. Proponents claim that a similar system already in place in Michigan would have reduced the time required to track down the infected animal to minutes instead of the two weeks it took FDA scientists to wade through the mountain of paper records used to trace the affected herd and recall beef that might have been exposed. Meat industry experts say the RFID deployment could cost nearly $600 million over the next six years. <-p>

- Jan 2004: Infosys Technologies Ltd. an Indian service company is proposing a global delivery model for RFID processing, data storage and analysis. This service targets the growing concerns among IT managers about the logistics involved in managing the flood of data RFID systems are expected to produce. It has been estimated that RFID tracking of all the products in all the Walmart stores would generate hundreds of terabytes of data per day.

- Feb 2004: RSA Security Inc. has unveiled a RFID "Blocker Tag" intended to keep other nearby tags from being read. This is in response to the privacy concerns being voiced by civil libertarians, and consumer advocates. The blocker tag would be used to prevent RFID readers from gathering data from merchandise that consumers are carrying with them as they shop. The blocker "fools" RFID readers by responding multiple times to a single query thus preventing the reader from getting valid data.

Feb 2004: California State Senator Debra Bowen says she is planning to introduce legislation that will restrict the use of RFID tags in retail applications, while allowing it for pallet and case usage.

- Feb 2004: SAP recently unveiled new supply chain software that was created from the ground up to accommodate RFID functionality. According to InfoWorld Magazine, IBM, Oracle, Sun and Microsoft, all have RFID offerings under development.

- Feb 2004: International Paper Corporation reports that it's RFID deployment has been so successful that the company plans to market its RFID expertise to other companies under consulting agreements. According to Alan Clark at IP, "RFID promises to revolutionize the businesses manage their supply chains."

- April 2004: Shorecliff Communications presents RFID World, a conference and exhibition billed as, "The most important technology event you will attend in 2004." Industry experts anticipate that this will be the single most heavily attended IT event of the year. The research firm IDC projects the market for RFID services to grow from $23 million in 2003 to over $270 million in 2007. Over the same period, REID hardware spending is expected to reach $875 million per year.

Problems with RFID

  • Distance
    • Many tags, especially cheaper ones can be read from only a few feet away. 
  • Disruption
    • Tags are easily disrupted.  In credit cards it can be as simple as taking a hammer to the back of the card. 
    • Most signals can be blocked using aluminum
    • Radio signals can be diverted, reducing the distance of the reader
  • Price
    • For many products and applications the cost of RFID is simply too high to be a profitable business venture. 
  • Security Risks
    • There are issues regarding RFID security.  The main concern is that a person could hypothetically be tracked by anyone with a tracking device.  This poses a privacy risk. 
  • Standardization
    • There is no current global standard for the tags

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