Home Internet of Things Aerospace Apparel Energy Defense Health Care Logistics Manufacturing Retail

Ask The Experts Forum

BlogsAsk The Experts ForumWhich RFID Technology (LF, HF or UHF) Would Be Best Suited for Student Cards on a Campus With Approximately 500 Students?

Which RFID Technology (LF, HF or UHF) Would Be Best Suited for Student Cards on a Campus With Approximately 500 Students?

Posted By RFID Journal, 12.12.2012
In addition, can we use UHF RFID if we want to scan and register students entering together, in the form of a group, through the campus gate?

—Name withheld

Unfortunately, there is no ideal solution for this application. Passive high-frequency (HF) tags would require that each student present his or her card to a reader. Unless there was a way to restrict entry to only one student at a time, you would not get accurate data. Students would forget to present their RFID badges to the reader if there was nothing forcing them to do so—and even with a gate, several students could enter using a single person's badge.

Ultrahigh-frequency (UHF) tags would present a challenge, since radio waves in the UHF spectrum are absorbed by water, of which the human body is mostly composed. This would make it difficult to get enough energy to the tag to enable it to respond. Data would be inaccurate if one or more bodies shielded the tag from the interrogator.

Active tags broadcast a signal, so it would be easier to pick up that signal and receive accurate data. However, such tags are expensive, and would require you to replace batteries (or the entire tag) every few years.

Perhaps the best compromise would be a battery-assisted passive (BAP) tag, which communicates with a reader like a passive tag, but uses a battery to obtain extra read range and consistence. Convergence Systems Ltd. just introduced a new BAP tag for just this application. See CSL Solves Long-Range Event and Personnel Monitoring With the Affordable BAP ID Card.

—Mark Roberti, Founder and Editor,
RFID Journal

Login and post your comment!

Not a member?

Signup for an account now to access all of the features of RFIDJournal.com!

Next Post
Does RFID Journal Publish RFID Procedure...
Previous Post
Where Can I Learn About the Strengths an...
Case Studies Features Best Practices How-Tos
Live Events Virtual Events Webinars
Simply enter a question for our experts.
RFID Journal LIVE! RFID in Health Care LIVE! LatAm LIVE! Brasil LIVE! Europe RFID Connect Virtual Events RFID Journal Awards Webinars Presentations