Asset Tracking Technology


here are a lot of seemingly competitive technologies being deployed for asset tracking.  These technologies cover a wide spectrum of options such as RFID, Bluetooth, WiFi, satellite and celluar.  It is important to understand the limitations of each of these technologies when selecting the right product to support your business case.

RFID-TagRFID stands for radio-frequency identification.  The most basic diagram of this solution requires an RFID enabled tag (either active or passive which we will discuss in a moment) and some sort of reader device.  Information is stored inside the tag (such as a serial number or product information) and the reader is able to capture and relay this information into an asset management system.  An active tag is a powered device, meaning that it has an on-board power supply, which will essentially allow it to broadcast its information to a greater distance than a passive tag (think of your local electronic toll collection system).  A passive tag is a much less expensive item than an active tag since it does not include any power supply, but requires a powerful reader transmitting power in order to be read.

Some of the biggest challenges facing RFID is that they require close proximity to readers.  Even with the active tags, the range is approximately 2,000 feet.

There is significant cost in both the active RFID tags and their readers, particularly if you are trying to utilize RFID technology to get location based information on assets in transit in environments where you have no control (for example, along any highway across the country). 

No integrated, accessible RFID reader network exists with any level of quantity that would support asset tracking for individual business use.

Passive tags are extremely inexpensive, but due to the requirements of receiving significant power from a reader, the range is relatively short (up to approximately 36 feet in the most extreme conditions).  This is because of the dangers of radiation transmission and interference caused by the reader.  Obviously, the range limitations do not make this solution practical for asset tracking in transit, but it is an extremely viable tool for asset/inventory management within a controlled environment such as a warehouse facility.

wifi_bluetooth_logoBluetooth and WiFi are very different technologies from each other, but there are enough similarities for us to discuss them at the same time.  Each requires a powered device (albeit a potentially very low powered device that can last for extended periods of time) to establish a relationship with a secondary device.  You can think of your phone pairing with your car for a Bluetooth example or for WiFi, a laptop connecting to a wireless access point.

The advantages for both of these technologies is that they create a secure connection between the devices and allow for very accurate locating of a Bluetooth or WiFi enabled tag/device.  Since the devices are able to have a two-way communication between transmitter/receivers, they can allow for showing changing proximity in near real time

Unfortunately one of the strengths (accurate locating of devices) for Bluetooth and WiFi goes hand-in-hand with one of the critical weaknesses.

Bluetooth range is usually limited to approximately 32 feet without the use of extenders, and WiFi range is approximately 105 feet without the use of extenders.  The reason they can be so accurate to locating devices is partly because the devices are so close to within range of a transmitter/receiver.   Another big challenge is the required “handshaking” needed between the tag/device and the transmitter/receiver.  Remember when you paired your phone to your car?  You needed to enter a code.  Or remember when you tried to join that secured WiFi network without a password?  That means that if your asset moves outside the range that you have control over, it will be very difficult if not impossible to have your asset sign in to another network to continue communicating in order to track it.  Some manufacturers have gotten very clever in trying to create “peer networks” that allow anyone running an app that works with your specific device to extend your network range, but it still requires that person to be within 30 – 100 feet of your lost item.

This becomes increasingly unlikely if your pet runs off, let alone when you ship an exhibit to a convention center across the country.

So what do you do if you need location based, near-real time information for items or workforce in transit – anywhere in the state, country or even world?  There are really only two current technologies that are going to give that level of coverage with a level of positional accuracy that inspires confidence – satellite and cellular.  Of course, each has their pros and cons (you should have assumed that by now!).

satelliteSatellite devices will offer the highest level of global coverage as they communicate with – you guessed it – satellites!  These satellites are high up in orbit and are “accessible” from even the most remote regions; particularly useful for when items are traveling across oceans or in the most remote parts of countries.  The positional accuracy is at a “worst case” level of approximately 25 ½ feet, and is often more accurate than that.  The downside is the need for what is called “line of sight”.  The satellite GPS device needs to have a relatively unobstructed view of the sky to retrieve GPS positioning.

Think of when you have travelled with a portable navigational unit and put it into your rental car while you are still in the parking structure.  “Searching for satellite signal….” 

This means that burying your device inside a container or some other enclosure becomes prohibitive.  If you are trying to use your device covertly to monitor material handling or theft, it becomes a lot less covert sitting on the outside of your container.  Aside from the line of sight challenges, satellite based asset trackers are generally not budget-friendly, particularly on a larger scale.

Which leads us to the last option – cellular.  Cellular based asset tracking devices ride on the same networks as cell phones all over the world (yes, there are predominantly two different style networks but we will save that discussion for another blog post!).

A key advantage for these cellular-based devices is that they leverage a robust communication network at a fractional price for data transmission.

cellularThe cellular communication network is a globally established network with significant investment in infrastructure that is always improving.  Devices can be configured to work across international cellular networks.  The devices offer two-way communication, allowing for automated field reporting as well as adjusting configurations on the fly.  The drawbacks are that cellular towers till don’t cover 100% of terrain (think canyons, desolate areas or on the ocean) and can also be obstructed by external issues (such as steel enclosures or anything that may reduce cellular signal strength).  Lastly, the positioning is not as accurate as satellite GPS – meaning in worst case scenarios it can be up to 300 feet.

What is the best device for you?  Think about the proximity that you will be able to maintain with what you want to track.  Evaluate the costs of the devices, the services and the capability offered by the type of technology.  Or call us – we will be happy to help!

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