Real-Time Visibility for Indoor and In-Transit Asset Tracking Pt.1 (Technology Comparison)
We’ve written before about the challenges of choosing the right beacon hardware for your RTLS deployment. We highlighted the point that, with so many options available, it can be difficult to understand the differences between them and how certain alternatives match well to particular use cases. However, a bit of research can turn confusion into certainty that you’re using the right tags or beacons for the job, ensuring a successful and beneficial project.
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Our goal is to show that no matter how intimidating all the acronyms, tech terms and new concepts might be for a beginner, the world proximity solutions can be understood.
The same applies to the software side of things, which is our focus in this post. Specifically, of course, the technologies that drive the hardware used in location-based applications. If you follow this blog, you know that we’ve already extensively documented why BLE (Bluetooth Low Energy) has established itself as the industry standard. The balance of low energy use, interoperability, range and stability make BLE the backbone of most RTLS deployments.
But our purpose here is to take a look at two other technologies that have found a number of applications in location-tracking applications in recent years and appear poised to spread further in industrial and manufacturing settings that are well suited to the strengths of these platforms.
As their names make clear, Ultra Wide Band (UWB) and Narrowband IoT (NBIoT) take different, almost opposite approaches to the technical architecture required to facilitate effective wireless communication. Consequently, their unique characteristics create advantages and disadvantages when set in different use cases.
In this first of two related posts, we’re going to give an overview of each of the platforms, focusing on their basic strengths and weaknesses without diving too deep into their technical specifications. In our next post, we’ll return to the subject but look at it from the perspective of the use cases and applications that are best suited to each of them.
So let’s get to the “bands”!
UWB – Ultra Wide Band
Although we’re talking about technologies that may shape the future of location-based tracking applications, the first one might be familiar to you from the past. UWB was first developed about fifteen years ago and, because of its short range, was primarily used in consumer electronics and personal area networks (PAN). It was ideal for wireless data transmission between computers, printers, speakers, etc. But UWB’s success was rather short-lived because of the rise of Wi-Fi as a communication standard that overtook the same niche markets where it was just establishing a foothold. Although it started behind UWB in terms of transmission capabilities, Wi-Fi caught up and surpassed UWB on its way to industry flagship we know today.
UWB has found a second life in the world of IoT. Its value has been rediscovered thanks to several key aspects of the way it operates and the concrete benefits it brings. First among them is extreme energy efficiency, which, thanks to BLE, has been established as absolutely fundamental to the success of any communication platform. The size and complexity of modern RTLS deployments mean that the time and costs associated with frequent losses of power due to battery depletion and changing those batteries makes minimal power consumption an absolute must.
Short burst, wide range
The reason for UWB’s low energy use is the short signal burst—just 30 picoseconds—it uses to communicate with receivers. Instead of transmitting continuously or much more frequently at a particular frequency, as other wireless standards do, it sends a signal over a short distance using a wide part of radio signal spectrum (hence the name). It’s all about transmitting large amounts of data over a short distance using as little energy as possible.
In terms of data transmission capacity, UWB far exceeds that of BLE while using approximately the same amount of power. UWB can transmit up to 480 Mbps compared to, at most, 3 Mbps for BLE. While this certainly is an extremely impressive advantage and obviously useful for things like video streaming, it’s important to remember that the enormous extra capacity of UWB is not really needed in the vast majority of location tracking applications.
Since the signal is focused on a short range, it’s more powerful and thus able to penetrate building features and other obstacles that can weaken or altogether block other transmissions. In this way, UWB’s performance is quite similar to that of BLE.
Another benefit of the UWB signal is that it doesn’t interfere with other transmissions on the same frequency band. Because its signal is spread across a wide frequency spectrum, it has what the industry calls a “low power spectral density”. Translated into more familiar terms, this means that it doesn’t interfere with other signals in the same parts of the radio band. This can be a strong asset in a number of contexts, like busy industrial or manufacturing environments with multiple wireless systems in place using the same segments of the radio spectrum. Since the UWB is spread over a larger range, it can communicate without crowding out or blocking other signals. Given the increasing reliance on wireless solutions in digitized IoT facilities, this ability to share bandwidth in close proximity to other signals gives UWB an edge and eliminates potential issues.
The “low power spectral density” of UWB also means that it is difficult to detect, and thus difficult to intercept. This gives it an added measure of security and protection from hacking and spoofing.
With its very low energy use, high data capacity and a penetrating, secure signal, UWB has a lot going for it in the world of tracking applications. There are, however, some drawbacks. The biggest limitation of UWB is its short range. It’s meant to have an effective reach of about ten meters, significantly less than that of BLE. This limitation automatically excludes it from a great number of asset tracking applications. From a technical perspective, UWB receivers and antennas can be more difficult to calibrate given the highly precise nature of the transmission of the signal.
Two more issues among the factors on the down side of UWB are its price and lack of ecosystem. The price is a result of having to install a more dense infrastructure as a result of its small range. Also, UWB currently has nothing like the deep market penetration of BLE, with its billions of connected devices and all the opportunities for interoperability that come with it.
Like other wireless communication platforms, UWB has unique properties that make it ideal for some applications and less so for others. In the near term, look for its adoption to spread as it finds new industrial applications and benefits from the cost advantages and interoperability made possible by open standards.
UWB wireless communication
- Precise but limited location tracking
- Highly secure
- Very low power consumption
- Good in environments with multiple wireless signals
- Fast transfer of high volumes of data
Narrowband IoT (NBIoT), is designed to enable a wide range of IoT devices and services, connecting objects to the internet that require small amounts of data over long periods of time. Think of wearables, smart home components and other devices that primarily transmit very digitally small status updates periodically over a comparatively long operating lifetime.
NBIoT uses low-bandwidth workloads with a maximum of just 200Kbits/s, which allows many devices to connect to a single receiver. This is what puts the “narrow” in NBIoT—the tiny sliver of the spectrum that it uses.
Like UWB, Narrowband IoT is built on the key attribute of low energy consumption, which, as shown by BLE’s success, is fundamental to any modern data transmission standard. And like UWB, it accomplishes this through intermittent broadcasting as opposed to constantly searching the area around it. Thanks in part to this configuration, its energy use is so low that it can deliver a battery life of up to ten years.
Unlike UWB, however, NBIoT is rather weak when it comes to data handling capacity from a single signal. It’s designed to handle lots of small transmissions—very small. NBIoT is built to handle certain types of devices at scale, something we’ll get to in a second, but that comes at the cost of being completely inadequate for applications that involve larger individual data transmissions.
Built to cover massive ranges
This brings us to NBIoT’s biggest selling point after energy consumption—its scalability. It was intentionally designed to handle small amounts of data, infrequently transmitted over an extended time period in order to be able to handle a massive number of connections. This asset is further leveraged by the fact that NBIoT is compatible with existing cellular infrastructures, meaning that there is already a massive, worldwide physical infrastructure ready to deploy applications based on it. When cell towers are properly equipped, each will be able to connect to thousands of devices. This is all possible because NBIoT uses a part of the #800MHz spectrum that has long been used by cellular networks. The benefits of this include the same penetrating ability of a cell network frequency and the accessibility of a universal standard.
Dramatically reduced energy use and massive scalability are a great start for any new technology but, like UWB, NBIoT has its drawbacks. While its low data handling capacity makes it ideal for things that don’t move, mobile physical assets would be very difficult to track with NBIoT. Also, as mentioned, NBIoT is meant for very small, almost micro updates from mass distributed devices, not transmission of significant amounts of data.
As with UWB, BLE and much else, getting the most out of NBIoT starts with matching it to use cases where it can excel.
- Extremely low energy consumption
- Capacity for massive amounts of connections
- Only suitable for small data amounts transmitted infrequently
- Compatible with existing cellular infrastructure
- Designed for very large scale use cases
With that basic info about these platforms out of the way, we’re ready to look in more detail at the use cases that are and are not well suited to UWB and NBIoT, something we’ll do in our next post.