Passive RFID

Passive RFID uses simple, battery-free tags and high-power readers. The reader sends out a lower-frequency, high-power RF signal, which transmits so much energy over the air that the tag’s collector antenna picks up the radio waves. This causes electricity to flow in the collector which wakes up the tag’s circuit.The tag then transmits back at a different frequency, which the reader receives. This is the type of technology you’ve seen if you’ve ever stolen a library book or bought something at Home Depot.

Passive RFID is one-directional communication that, with enough energy, could produce ranges of many meters. Furthermore, it useful for asset location management in a number of industries.

Near-Field Communication (NFC)

NFC is based on the same protocol as RFID, but the use cases are entirely different. In radio communications, “the near field” refers to the area close to antenna where the magnetic field being produced is still detectable. NFC applications need to be within an inch or two (or sometimes only a few centimeters) from the reader, which allows an efficient transmission of energy.

NFC is almost exclusively used for high-speed data transfer between two electronic systems:

  • A smartphone and some other “thing,” like a payment reader (i.e., putting your phone on a card machine at the grocery store in the checkout line).
  • Two smartphones exchanging data.
  • A smart device gathering data from promotional materials, similar to the way a QR code might.

While NFC is an excellent data transmission medium for transactions as it has two-way communication, it isn’t even remotely viable for asset location management.



  • High-frequency passive RFID is both mature and inexpensive. NFC, on the other hand, is a new technology and is more expensive to deploy.


  • Passive RFID tags can cost pennies. NFC stickers are similar in price to passive RFID tags, whereas NFC tags are more inexpensive (usually around $1 each).
  • While RFID tags are inexpensive, the readers are expensive. And unless you’re using chokepoint RFID (which is what storefronts with large resonators use), you will need a lot of them for location tracking. In fact, you need to position these readers every 10-15 feet for them to work for RFID.
  • Today, most smartphones have NFC chips built in. However, if you require an NFC reader, the infrastructure will get more costly (much like RFID).

NFC Vs. RFID Vs. Bluetooth

In comparing NFC to RFID, you may also run into some information on active Bluetooth-based RFID (or active RTLS). Active RFID uses battery-powered sensors that connect to various access points throughout the hospital and transfer data to the cloud. This solution use Bluetooth Low Energy (BLE) technology to reduce system and operational costs and enable asset location management.

Interestingly, at AirFinder, we are looking at NFC as one possible way to make a secure connection to an active RFID tag in order to better secure our asset location management system.


If you’d like more information about RFID vs. NFC, get in touch. We’ll help answer any additional questions you may have.

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Written by Brian Ray

Brian is the Founder and CTO of Link Labs. As the chief technical innovator and leader of the company, Brian has led the creation and deployment of a new type of ultra long-range, low-power wireless networking which is transforming the Internet of Things and M2M space.

Before starting Link Labs, Brian led a team at the Johns Hopkins University Applied Physics Lab that solved communications and geolocation problems for the national intelligence community. He was also the VP of Engineering at the network security company, Lookingglass, and served for eight years as a submarine officer in the U.S. Navy. He graduated from the U.S. Naval Academy and received his Master’s Degree from Oxford University.