What uses electronic tags and labels to identify objects wirelessly over short distances multiple choice?

When the RFID industry is able to lower the price of tags, it will lead to a ubiquitous network of smart packages that track every phase of the supply chain. Store ­shelves will be full of smart-labeled products that can be tracked from purchase to trash can. The shelves themselves will communicate wirelessly with the network. The tags will be just one component of this large product-tracking network.

The other two pieces to this network will be the readers that communicate with the tags and the Internet, which will provide communications lines for the network.

Let's look at a real-world scenario of this system:

• At the grocery store, you buy a carton of milk. The milk containers will have an RFID tag that stores the milk's expiration date and price. When you lift the milk from the shelf, the shelf may display the milk's specific expiration date, or the information could be wirelessly sent to your personal digital assistant or cell phone.
• As you exit the store, you pass through doors with an embedded tag reader. This reader tabulates the cost of all the items in your shopping cart and sends the grocery bill to your bank, which deducts the amount from your account. Product manufacturers know that you've bought their product, and the store's computers know exactly how many of each product need to be reordered.
• Once you get home, you put your milk in the refrigerator, which is also equipped with a tag reader. This smart refrigerator is capable of tracking all of the groceries stored in it. It can track the foods you use and how often you restock your refrigerator, and can let you know when that milk and other foods spoil.
• Products are also tracked when they are thrown into a trash can or recycle bin. At this point, your refrigerator could add milk to your grocery list, or you could program the fridge to order these items automatically.
• Based on the products you buy, your grocery store gets to know your unique preferences. Instead of receiving generic newsletters with weekly grocery specials, you might receive one created just for you. If you have two school-age children and a puppy, your grocery store can use customer-specific marketing by sending you coupons for items like juice boxes and dog food.

In order for this system to work, each product will be given a unique product number. MIT's Auto-ID Center is working on an Electronic Product Code (EPC) identifier that could replace the UPC. Every smart label could contain 96 bits of information, including the product manufacturer, product name and a 40-bit serial number. Using this system, a smart label would communicate with a network called the Object Naming Service. This database would retrieve information about a product and then direct information to the manufacturer's computers.

The information stored on the smart labels would be written in a Product Markup Language (PML), which is based on the eXtensible Markup Language (XML). PML would allow all computers to communicate with any computer system similar to the way that Web servers read Hyper Text Markup Language (HTML), the common language used to create Web pages.

We're not at this point yet, but RFID tags are more prominent in your life than you may realize. Wal-Mart and Best Buy are just two major merchandisers that use RFID tags for stocking and marketing purposes. Automated systems called intelligent software agents manage all the data coming in and going out from RFID tags and will carry out a specific course of action like sorting items [source: RFID Journal].

The United States retail market is on the cusp of embracing a major implementation of RFID technology through payment systems that use Near Field Communication. These are the credit cards of the future.

RFID (radio frequency identification) is a form of wireless communication that incorporates the use of electromagnetic or electrostatic coupling in the radio frequency portion of the electromagnetic spectrum to uniquely identify an object, animal or person.

How does RFID work?

Every RFID system consists of three components: a scanning antenna, a transceiver and a transponder. When the scanning antenna and transceiver are combined, they are referred to as an RFID reader or interrogator. There are two types of RFID readers -- fixed readers and mobile readers. The RFID reader is a network-connected device that can be portable or permanently attached. It uses radio waves to transmit signals that activate the tag. Once activated, the tag sends a wave back to the antenna, where it is translated into data.

The transponder is in the RFID tag itself. The read range for RFID tags varies based on factors including the type of tag, type of reader, RFID frequency and interference in the surrounding environment or from other RFID tags and readers. Tags that have a stronger power source also have a longer read range.

What are RFID tags and smart labels?

RFID tags are made up of an integrated circuit (IC), an antenna and a substrate. The part of an RFID tag that encodes identifying information is called the RFID inlay.

There are two main types of RFID tags:

• Active RFID. An active RFID tag has its own power source, often a battery.
• Passive RFID. A passive RFID tag receives its power from the reading antenna, whose electromagnetic wave induces a current in the RFID tag's antenna.

There are also semi-passive RFID tags, meaning a battery runs the circuitry while communication is powered by the RFID reader.

Low-power, embedded non-volatile memory plays an important role in every RFID system. RFID tags typically hold less than 2,000 KB of data, including a unique identifier/serial number. Tags can be read-only or read-write, where data can be added by the reader or existing data overwritten.

The read range for RFID tags varies based on factors including type of tag, type of reader, RFID frequency, and interference in the surrounding environment or from other RFID tags and readers. Active RFID tags have a longer read range than passive RFID tags due to the stronger power source.

smart labels are simple RFID tags. These labels have an RFID tag embedded into an adhesive label and feature a barcode. They can also be used by both RFID and barcode readers. Smart labels can be printed on-demand using desktop printers, where RFID tags require more advanced equipment.

What are the types of RFID systems?

There are three main types of RFID systems: low frequency (LF), high frequency (HF) and ultra-high frequency (UHF). Microwave RFID is also available. Frequencies vary greatly by country and region.

• Low-frequency RFID systems. These range from 30 KHzto 500 KHz, though the typical frequency is 125 KHz. LF RFID has short transmission ranges, generally anywhere from a few inches to less than six feet.
• High-frequency RFID system These range from 3 MHzto 30 MHz, with the typical HF frequency being 13.56 MHz. The standard range is anywhere from a few inches to several feet.
• UHF RFID systems. These range from 300 MHz to 960 MHz, with the typical frequency of 433 MHz and can generally be read from 25-plus feet away.
• Microwave RFID systems. These run at 2.45 Ghzand can be read from 30-plus feet away.

The frequency used will depend on the RFID application, with actual obtained distances sometimes varying from what is expected. For example, when the U.S. State Department announced it would issue electronic passports enabled with an RFID chip, it said the chips would only be able to be read from approximately 4 inches away. However, the State Department soon received evidence that RFID readers could skim the information from the RFID tags from much farther than 4 inches -- sometimes upward of 33 feet away.

If longer read ranges are needed, using tags with additional power can boost read ranges to 300-plus feet.

RFID applications and use cases

RFID dates back to the 1940s; however, it was used more frequently in the 1970s. For a long time, the high cost of the tags and readers prohibited widespread commercial use. As hardware costs have decreased, RFID adoption has also increased.

Some common uses for RFID applications include:

• pet and livestock tracking
• inventory management
• asset tracking and equipment tracking
• inventory control
• cargo and supply chain logistics
• vehicle tracking
• customer service and loss control
• improved visibility and distribution in the supply chain
• access control in security situations
• shipping
• healthcare
• manufacturing
• retail sales
• tap-and-go credit card payments

RFID vs. barcodes

Using RFID as an alternative for barcodes is increasing in use. RFID and barcode technologies are used in similar ways to track inventory, but there are some important differences between them.

RFID vs. NFC

Near-field communication (NFC) enables data to be exchanged between devices by using short-range, high-frequency wireless communication technology. NFC combines the interface of a smart card and reader into a single device.

RFID challenges

RFID is prone to two main issues:

• Reader collision. Reader collision, when a signal from one RFID reader interferes with a second reader, can be prevented by using an anti-collision protocol to make RFID tags take turns transmitting to their appropriate reader.
• Tag collision. Tag collision occurs when too many tags confuse an RFID reader by transmitting data at the same time. Choosing a reader that gathers tag info one at a time will prevent this issue.

RFID security and privacy

A common RFID security or privacy concern is that RFID tag data can be read by anyone with a compatible reader. Tags can often be read after an item leaves a store or supply chain. They can also be read without a user's knowledge using unauthorized readers, and if a tag has a unique serial number, it can be associated to a consumer. While a privacy concern for individuals, in military or medical settings this can be a national security concern or life-or-death matter.

Because RFID tags do not have a lot of compute power, they are unable to accommodate encryption, such as might be used in a challenge-response authentication system. One exception to this, however, is specific to RFID tags used in passports -- basic access control (BAC). Here, the chip has sufficient compute power to decode an encrypted token from the reader, thus proving the validity of the reader.

At the reader, information printed on the passport is machine-scanned and used to derive a key for the passport. There are three pieces of information used -- the passport number, the passport holder's birth date and the passport's expiration date -- along with a checksum digit for each of the three.

Researchers say this means passports are protected by a password with considerably less entropy than is normally used in e-commerce. They key is also static for the life of the passport, so once an entity has had one-time access to the printed key information, the passport is readable with or without the consent of the passport bearer until the passport expires.

The U.S. State Department, which adopted the BAC system in 2007, has added an anti-skimming material to electronic passports to mitigate the threat of undetected attempts to steal users' personal information.

RFID standards

There are several guidelines and specifications for RFID technology, but the main standards organizations are:  

Each radio frequency has associated standards, including ISO 14223 and ISO/IEC 18000-2 for LF RFID, ISO 15693 and ISO/IEC 14443 for HF RFID, and ISO 18000-6C for UHF RFID.

Next-generation RFID use

RFID systems are becoming increasingly used to support internet of things deployments. Combining the technology with smart sensors and/or GPS technology enables sensor data including temperature, movement and location to be wirelessly transmitted.