BeaconGrid Blog

What is the best asset tracking technology?

[fa icon="calendar"] Jul 12, 2017 10:57:07 AM / by Lucy M

stadiums are excellent locations to have RTLS

So in our last article, I was able to talk a little bit about asset tracking. To recap: assets are any physical things--whether it’s personnel or high value objects, like portable printers, wheelchairs, or ECG machines--that need to be managed and effectively utilized on a large campus. Asset tracking is the means by which a manager, and potentially other staff members, can keep track of where any given asset is at a given time. That is, basically, if a campus has any kind of RTLS[real time location system] setup, the manager can look at a digital map of that campus and see the asset as an icon on that map. Also, if a manager prefers to go hands free and has an Amazon Echo, he or she can use Alexa to hear a verbal location of a given asset. Potentially, at least. All of this information can save time, increase efficiency, and prevent loss or damage to equipment. Which, you know, seems important if your equipment costs thousands of dollars already, yeah?  

That article largely covered why BLE systems are superior than Wi-Fi based systems when it comes to asset tracking. But, BLE and Wi-Fi aren’t the only options out there. In fact, there are two other major players in the RTLS game: Ultra Wide Band (UWB) systems, and Radio Frequency Identification (RFID) systems. So how do these systems measure up in terms of effectiveness, accuracy, and cost? And how can you make the best possible decision for your campus? It’s time to ask some tough investigative questions.Is there a best asset tracking technology?

What are UWB, RFID, and BLE systems? What are they doing differently?


Bluetooth Low Energy-- These systems use Bluetooth technology, specifically beacon hardware, to communicate identifying information and location data between receivers and beacon tags. To read more in depth about beaconing technology, check out the first blog post here. Bluetooth operates using radio waves exclusively on the 2.4ghz frequency.  


Ultra Wide Band (UWB) -- These systems utilize wide band radio waves to transmit and receive data. Wi-fi and Bluetooth technology also use radio waves, but UWB technology is not limited by the narrow frequency demanded by Wi-Fi or BLE systems. Since UWB utilizes a broader set of frequencies, they have a wider threshold that can be measured, minimizing noise. According to Electronic Design, The short bursts of signals [transmitted in Ultra Wide Band], with sharp rises and drops, makes the signals’ starts and stops inherently easier to measure. This means that the distance between two UWB devices can be measured precisely by measuring the time that it takes for a radio wave to pass between the two devices.” (Connell 2015).


Radio Frequency Identification (RFID) -- These location systems rely on tags. If the tags are battery powered, they constantly transmit data containing specific identifying information encoded onto them. RFID readers pick up this information, which is used to locate the asset with that ID tag. If the tags are passive, they rely on the RFID reader’s radio waves to transmit their information after being “asked” for it by the reader.


How accurate are these systems when it comes to locating assets?

This question has a pretty straightforward answer, surprisingly. All other aspects being equal (for example, assuming the same number of readers, sensors, or beacons were set up in the same geographical locations on a campus):  UWB systems are the most accurate, BLE systems are second-most accurate, and RFID systems are the least accurate.


Since UWB systems use a wider range of frequencies, their signals are much less likely to be misinterpreted due to noise and reflection of the waves from solid materials. Additionally, location is measured based solely on how long it takes a signal to traverse from one UWB port to another, rather than relying on information like signal strength. In an article in Electronic Design, technologist Ciaran Connell points out, “UWB signals are able to effectively measure distance between two devices with 5- to 10-cm accuracy, compared to roughly 1-5-m accuracy for Wi-Fi and Bluetooth.” That’s really tight, accuracy-wise. Nothing else comes close to that, currently.


BLE systems can be accurate within one meter, if the technology is implemented thoroughly, although moderate implementation could still result in 5-7 meter accuracy.


Passive RFID systems (the most common type currently on the market) really can’t give you any location information beyond, “this asset has / has not crossed this threshold”. According to Link Labs CTO Brian Ray, “...unless you’re using chokepoint RFID (which is what storefronts with large resonators use), you will need a lot of them for asset location tracking. In fact, you would need to position these readers every 10-15 feet for them to work as a real-time location system (RTLS).” Generally, that’s not going to be feasible or desirable.

UWB is effective at tracking agricultural assets

What are typical assets tracked by these types of systems?


UWB


Since UWB technology is accurate to a matter of centimeters, and the signals are sent out in short, frequent bursts, UWB technology is often used to track fast-moving assets. For instance, UWB technology could be used by coaches to track the movements of players on a football field or basketball court, in order to recognize patterns and create a sort of map, thus planning how to alter movements in future games. UWB real-time location systems are also used in agriculture to track grazing animals in large farms. Any asset whose movement would be largely unpredictable, and whose data down to the centimeter would be useful, might be tracked using UWB.


BLE


BLE location systems are frequently used to monitor assets such as expensive equipment in schools, factories, and hospitals. They are also used to track staff and personnel.


RFID


RFID systems are often installed at a checkpoint as a security measure. For an RFID reader to glean information from a passive RFID tag, the tag must pass under the reader so its information can be scanned. Because of this, RFID technology is often at the exit of a library or store, gleaning data from tagged items about whether or not they’ve been stolen. A reader might also be positioned at an entrance, using info from ID tags to allow a person to enter and denying them entry otherwise.

RTLS has a variance of costs depending on the technology

How much does each type of system cost?


Every real time location system requires devices that send signals to each other in order to locate your assets. BLE systems use beacons and sensors; RFID systems use readers and tags; UWB systems use UWB transmitters.


Each individual reader, tag, sensor, beacon, and transmitter has a price point with a great deal  of range between companies. Also, some systems require more readers / sensors / transmitters total in order to enable accurate location data gathering, which needs to be factored into cost. On top of that, replacement costs due to wear and tear over the years is something that needs to be considered, and installation costs might be bundled in with that.


So, for instance, passive RFID tags are significantly less expensive, per tag, than BLE beacons or UWB transmitters. But RFID readers are more expensive than BLE sensors. UWB transmitters are the most expensive by a significant margin, although they seem to require less replacement and repair, and one campus requires fewer total transmitters to do the job.


Ultimately, the work of finding which real time location system works for your campus and budget requires looking into the specific companies that provide asset tracking solutions. Understanding which assets are most valuable to you, and what degree of accuracy is required for your work, is vital to choosing the best tracking system for your needs. Here is a quick table for reference to the above differentiators for BLE, UWB, and RFID.

 

Accuracy

Uses

Cost

Bluetooth Low Energy

About 1m

Schools, hospitals, factories, tracking staff, personnel, industrial, healthcare. Great for RTLS

$

Ultra Wide Band

About 5-10cm

Fast moving assets, healthcare, military, agriculture, unpredictable assets

$$$

RFID

Very accuruate (but check-in/checkout only)

Security checkpoints, entrances and exits. Not good for RTLS

$$


Regardless of which system you ultimately choose, the ability to keep an eye on your campus’ most valuable resources is more vital than ever. Every wise step gives your business an edge; every inch of knowledge could be the power that saves your clients, students, or patients. And, as always, BeaconGrid’s own plugs and outlets are an energy-efficient asset tracking solution guaranteed to be half the cost of UWB systems. Get into asset tracking today.

Contact us at beacongrid!

Topics: asset tracking