Electronic Design

Navigation Systems To Go Beyond Turn-By-Turn Directions

RFID tages and cell-phone GPS will steer consumers directly to their products.

Picture a husband and wife back in the good old days before digital technology. The wife would ask the husband to get her something at the mall. The husband would grumble but go off on his quest, possibly getting lost on the way there and probably getting lost once inside the mall, sacrificing precious time watching sports on TV. Of course, he could have asked for directions, but that probably didn't happen.

Though those days are long gone, this scenario will play out even more differently in the near future. The husband will be watching sports on his HD flat panel when his wife asks him to go to the mall. This time, thanks to a combination of in-car and smart-phone navigation systems as well as RFID tags, the husband will be able to go right to the mall and find the item his wife requested and then return home long before halftime.

The Navigation Revolution
The first step toward simplification is via the in-car navigation system, which today can can do much more than offer turn-by-turn directions. They can also account for traffic, weather, and road conditions to assist in getting to your destination. Some TV commercials suggest you may fall in love with your GPS device because of everything it offers. That may not be that big of an exaggeration.

For example, wouldn't it be nice to know when you're approaching a construction zone? Or when a traffic signal is about to change? Or even benefit from collision-avoidance features based on position, heading, and speed data from surrounding cars? And don't be afraid to crank your radio when your favorite song comes on, since your navigation system will let you know if any emergency vehicles are approaching.

Before you even get in your car, you can use your cell phone to locate whatever you're shopping for. Imagine simply entering the name of the item, a keyword, model number, or UPC code. Based on your location, a list of local stores that carry the item will appear on your phone's display, along with pricing, availability, the store's address, and a map for getting there. This service—Slifter—from a company named GPShopper is already available on Sprint's network and is sure to make its way to other networks in the near future.

After using your in-car (or phone-based) navigation to get to the mall, your phone will direct you to the right store, give or take a few meters (Fig. 1). Previously, this kind of accuracy only was available in more expensive models. Now, it's becoming more common in smaller devices.

Additional features will take you beyond simple shopping, too. Integrated Internet connectivity will let you know which gas stations have the cheapest price per gallon while you're out on the road. Don't worry about getting separated in crowds, as location functionality will help you find other people. Throw in search engine capabilities like those provided by Google, and the possibilities for exploring the world around you become limitless.

But why use a cell phone for all of these features instead of a personal navigation device? Simple: The mandate to support wireless-enhanced 911 service (E911) requires phones to include GPS technology or wireless carriers to use radiolocation to provide the location of callers within 50 to 300 m in most cases (see www.fcc.gov/911/enhanced).

Also, cell phones will make it easy to add new navigation software via downloads over the cellular network, especially once 4G systems come into fruition. Directions will be available on an as-needed basis or via a subscription plan. And the smart cell-based approach is so appealing, research firm In-Stat believes 42 million people globally will give their phones their undivided attention while navigating to their destination by 2012.

Universal Tracking Device
So what happens once you get to the mall? Radio-frequency identification (RFID) technology will help you find what you're looking for (Fig. 2). RFID devices, like bar codes, provide a unique identification number for each item in a store. The difference is that RFID devices broadcast that number, and they can be used to determine an item's location, assuming active (battery-powered) tags are used in conjunction with a triangulation scheme. RF transponders can be embedded inside products or packaging (Fig. 3).

RFID tags will let you pay for a basket full of goodies—even a whole shopping cart—without rescanning the individual items. An RFID "portal" reader at the checkout would register all of your purchases, and separate short-range RFID technology in your phone or credit card would let you pay for the items. With an RFID infrastructure in place, an inventory control system at the store could automatically be updated and re-order the items when necessary.

"Smart card" standards for short-range payments have been incorporated into cell phones as Near Field Communications (NFC) protocols. NFC-enabled phones are in active use in South Korea and Japan and are currently rolling out in tests in the U.S. NFC only has an operating range of 20 cm, which helps ensure security, along with the smart-card standard's heavy-duty encryption and authentication (see "NFC Makes Great Progress In The Wireless World").

Even further down the road, you can forget about doing the shopping altogether. Just let your live-in android do it for you. Give it a shopping list and your android will use GPS and RFID to get the job done. In fact, you may not even need to tell your robot to get going. Your refrigerator could make use of RFID tags to keep track of what you need and send that list to the android (see "To Be Almost Human Or Not To Be, That Is The Question,").

For more information on how RFID devices work, see "RFID FAQs", "Tag It", and "Identity Heft: RFID Muscles Into Consumer Market". For a list of RFID vendors by application and format type, see "Active RFID Tag Suppliers". Finally, for a discussion on the ethical issues involved in tagging human beings, see "Implantable RFID May Be Easy, But That Doesn't Mean It's Ethical,".

Notes On Security And Privacy
The use of RFID tags will become ubiquitous over the next several years. The average consumer, then, will be savvy to the possibilities of identity theft and other security concerns. That's why it seems appropriate to discuss security and privacy with respect to wireless money transactions and the "Big Brother" possibilities that come with devices that can broadcast location.

After all, "tap and go" payment could make thievery easier, which is why you may need to provide a fingerprint along with your payment card (see "What About Security?"). Other means of security include encryption techniques like "rolling code," "challenge-response authentication," or more recently "collision avoidance" to make RFID and NFC transactions more secure.

The rolling code security measure, implemented by means of a pseudorandom number generator, helps reduce the risk of electronic eavesdropping, thwarting unwanted "guests" who attempt to record the RF transmission. A typical application of rolling code is keyless entry systems in which the tag identifier is changed after each scan.

Challenge-response authentication is a potentially encrypted question-and-answer mechanism used to implement security. In its most basic form, it may ask for one or more passwords, and the user is authenticated with the correct response. When implemented in RFID security, the reader communicates to the tag and challenges it. The tag must respond with a secret key devised with added cryptographic circuitry.

For some consumers, privacy is a greater concern than security. The idea that the anti-fungal cream you just purchased is broadcasting its location at all times without your knowledge may not be too appealing. That's why many companies are looking for ways to remove or deactivate the RFID tags after the item has been purchased.

Of course, the ability to track things such as casino chips would be highly desirable—both for the casinos and for their patrons, as legitimate players wouldn't have to check in at every table. Also, such a system would help prevent thefts and counterfeiting. Don't be surprised if you ever decide to pry into a chip used at the Wynn Casino, as you may find more than you bargained for. But hey, don't worry. The casinos will find a way to get that chip back in the blink of an eye.


  • Any cell phone will double as a navigation device using downloadable software and the phone's built-in or Bluetooth-connected GPS device.
  • Before you go shopping, use your cell phone to determine the nearest retail outlet carrying the item, price, number currently in stock, and directions to the store.
  • Future in-car navigation systems will be in tune with changing conditions and provide valuable information like when a traffic signal is about to change or if an emergency vehicle is approaching.
  • RFIDs will come to play a major role in the shopping experience, from helping you locate the item in the store to getting you on your way by purchasing all items in one shot.
  • Androids and Internet appliances will take care of your everyday shopping needs for you in the more distant future.
  • The future ubiquitous use of RFID tags raises security and privacy concerns, most of which can be overcome with encryption and authentication techniques and consumer education.
TAGS: Components
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