The Evolution of Indoor Positioning

April 22, 2021
Indoor positioning

Indoor positioning – i.e. knowing where things are in a building – is not a new concept, but it is becoming increasingly more important as we move to higher levels of automation and need for greater efficiency in Industry 4.0 and the smart factory.

There are a variety of indoor positioning technologies that have proven to be very effective across a range of use cases, but their specific shortcomings are more apparent as their requirements become more demanding. Here, we will briefly outline some of the most common solutions used for accurate indoor location, and explain why cloud-based cellular location tops them all.

Yesterday’s Indoor Positioning Technologies

GPS Repeaters

We will begin by addressing why the most universally used positioning technology, traditional GPS, is not suitable for indoor positioning. It may seem obvious, but we find it worth stating: GPS is useless without a direct line of sight to a satellite.

Using GPS indoors can only be possible when there is a host of GPS repeaters placed inside a building to repeat the GPS signal from a main receiver placed outside the facility. Apart from requiring new infrastructure used solely for this purpose, it is not a viable option for many industrial use cases that use low-cost devices for tracking assets – a GPS chip comes with the inherent problems of being both power-hungry and costly.

Wi-Fi

The second solution to indoor tracking is Wi-Fi Positioning Systems (WPS). This form of technology features Wi-Fi sniffing modules: a process which allows the device to scan its environment for any possible Wi-Fi access points to achieve an accurate reading. WPS does not just connect to existing Wi-Fi networks, it explores all networks that are available around it, and measures the strength of those specific signals. This form of process enables companies to locate assets inside factories, warehouses, underground areas, and other structures.

There are a few core benefits for using WPS for indoor positioning. Wi-Fi networks are commonplace, so setting up new infrastructure isn’t necessary. WPS are also low power – it only takes the device a few seconds to scan for access points while GPS can take up to 30 seconds or longer.

However, there are a few issues. WPS does not provide the most accurate indoor location, especially if the device can’t find Wi-Fi access points to sync up with. So, if there is an insufficient number of access points, then positioning will be limited. Security is another disadvantage of WPS. Since Wi-Fi is so widespread and readily available, it makes it a prime target for hackers and cybercriminal activity. Similar to the power problems of GPS, WPS is continuously scanning for access points, which drains the battery of the asset tracking device.

BLE

The third common indoor positioning method uses Bluetooth Low Energy (BLE) beacons. By connecting to a phone, watch, or any other BLE-enabled device, the emitted signal is detected by the beacon and the distance is calculated. BLE-enabled trackers are relatively inexpensive, take up little space, and have a lasting battery life while being able to provide accurate indoor location.

However, it’s not all sunshine and rainbows. The downfall of using BLE signals is that setup and maintenance is expensive and time-consuming. Even though BLE beacons can last between five to eight years before the batteries need to be changed, erecting an ecosystem with hundreds, maybe thousands, of beacons in a single environment is costly. Plus, changing every beacon battery or even a select few is time and labor intensive. Using BLE systems are also prone to the same fate as WPS in that they can be easily hacked.

RFID

Finally, Radio-Frequency Identification (RFID). With RFID, data encoded in smart labels is received by a reader via radio waves. RFID is described as similar to barcoding, whereby data emitted by a tag is captured by a device, which is then stored in a database. However, RFID fares better than other technologies using barcoding due to the fact data can be received outside the line-of-sight. In contrast, actual barcodes must be aligned with a visual scanner.

For indoor tracking, RFID is best used when a company wants to identify and log items that are nearby. For example, if you want to make sure that all the train cars passed gate A and gate B or to know whether an employee swiped into a certain building.

Though RFID can have more precision over other indoor location solutions, one major downfall is bleed-through. Like most RF signals, these penetrate walls, making it difficult to determine the room where a tag is transmitting. Additionally, active trackers use high bandwidths and tend to be highly subject to interference. And as with BLE, the deployment of the beacons can be very expensive.

Why Use Cloud-based Cellular Location for Indoor Positioning?

The combination of cloud-based cellular location and Massive IoT in the context of indoor tracking is the widespread implementation of IoT devices on trackable assets, connecting to a cloud system. By simply listening to existing cellular infrastructure, location can be determined both outdoors and indoors seamlessly. Without this, enterprises are often forced to use amalgamations of traditional technologies and expensive infrastructure deployments to achieve an adequate level of visibility. (For more on why the concept of “yield” is important, visit our blog “Give Me Yield, or Give Me Lost Assets” here.) In addition, pushing location data to the cloud in a cloud-based cellular approach helps make positioning more secure and power efficient.

With the advent of 5G, the benefits of cellular become even more apparent with a substantial improvement on accuracy – even down to sub-meter 3D accuracy – depending on the network topology.

More importantly, by having a single technology for the wide area as well as for the localized indoor use case, there is significant cost savings on the device as well as a continuity of tracking that other technologies can’t achieve. This demand for universal asset visibility is not only creating new use cases, but it is impassioning the importance of cellular location. 5G-powered cloud-based cellular location will soon render other solutions redundant.

For more blogs like “The Evolution of Indoor Positioning,” keep checking our Blogs page here. To learn more about how Polte can leverage 4G/5G cellular networks to track what’s most important to you indoors and out around the world, send us a form here.

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