Ultimate guide to RTLS

RTLS (short for Real-time Location or Locating Systems) is a very hot topic within the manufacturing, engineering and logistic industries. However, sadly much of the discussion is based on speculation rather than reality. This guide is designed to be a detailed, accurate and unbiased look at the technology, its pro’s and limitations.

What is a RTLS?

Industrial RTLS is a red hot topic within the manufacturing, engineering, and logistics sectors. However, sadly much of the discussion is based on speculation rather than reality.

This guide provides a detailed, accurate, and unbiased look at the technology. It looks at the pros as well as its limitations. RTLS (which is short for Real-time Location or Locating Systems), are based on devices designed to track people and assets and are connected to cloud-based platforms. It manages the assets as they move through a manufacturing, engineering, or logistic process.

Contents

In reality, RTLS is a simpler version of Real-­time Asset Intelligence which is now available and is covered in detail elsewhere. Often RTLS is performed within an indoor setting, but this is not always the case. Some RTLS companies describe it as indoor tracking or sometimes even indoor GPS tracking. This is because they can provide a similar level of location and movement data. They both operate in real­-time as well as providing detailed tracking histories.

There are generally three main applications for RTLS;

1. In the moment tracking
2. Trend tracking
3. Geofencing

In the moment tracking

(also called real-time tracking) means that the location of an asset is seen in near real-­time throughout its life.

Trend tracking

(also known as long-term) tracking allows the operator to assess the passage of an asset through a facility such as a warehouse or a factory. This can help improve operational processes by, for example, removing un­needed steps.

Geofence tracking

A geofence is a virtual boundary created by Real-time Location Systems within a facility. When a tagged asset crosses one of these ‘virtual or digital boundaries’, the system alerts a nominated team or individual. This may be used to protect a person, asset, or area from contamination, or keep them from straying into a dangerous area etc..

What are the uses for RTLS?

There are numerous use cases for RTLS across many different sectors. From finding beds and medical equipment in a hospital to locating and monitoring assets in a warehouse or factory.

RTLS is a highly dynamic digital alternative to traditional physical record­keeping. A manual log of where tools or other equipment is kept or stored will often break down because of human error. This type of approach also doesn’t support the much wider variety of use cases that RTLS provides.

Example use cases

Real-time Location tracking is frequently an essential function provided by asset management systems. An attached access control system authenticates users who wish to sign an asset in or out.

Some industrial storage lockers have a built-­in RTLS tool called “content surveillance,” which can verify that a user returns the same high ­value asset that they signed out.

Personnel use cases

Access control systems can use RTLS to authorise employees and visitors to move through security checkpoints. If using geofencing, they record movements across those virtual boundaries.

Employees carry RTLS badges that authenticate them and provide location data to track them in real-time.

Emergency mustering systems can use RTLS tags carried by employees to monitor their locations during emergency evacuations.A

Tracking use cases

Real­-time tracking means that the location of an asset can be seen in near real ­time throughout its life. In reality, though, data will be updated periodically to preserve the battery life of the device.

Longer-term tracking allows the operator to assess the passage of an asset through a facility such as a warehouse or a factory. This will often be used to improve operational processes by, for example, removing un­needed steps.

A geofence is a virtual boundary created by RTLS in an open facility. When a tagged asset crosses one of these boundaries, the system issues an alert to a designated responder. This may be used to protect an asset or area from contamination etc.

Replacing paper...

There are numerous use cases for RTLS across many different sectors. From finding beds and medical equipment in a hospital to locating and monitoring assets in a warehouse or factory.

RTLS is a highly dynamic digital alternative to traditional physical record­keeping. A manual log of where tools or other equipment is kept or stored will often break down because of human error. This type of approach also doesn’t support the much wider variety of use cases that RTLS provides.

Locations are calculated either by assessing the time taken for the signal signals to reach the detectors, or by triangulating the angle of arrival of the signal to multiple detectors.

Increasing connectivity

The RTLS detectors will send location data they collect to a central management system via cable or wireless signal. Here the location data can be analysed to manage the asset being tracked or to optimise wider processes such as bottlenecks.

Often data can also be exported from the portal via API to 3rd party systems such as ERP’s. This allows for further integration with other business data. Real-­time Locations Systems rely on a robust connection between the tag and the detector.

Several different technologies are currently being used for this connectivity. These have implications on the performance of the overall system;

Using different technologies

Several different technologies are currently being used for this connectivity. These have implications on the performance of the overall system;

Bluetooth or BLE is a short­ range wireless communication standard popularly used to pair mobile devices, headsets, computers, and other electronics. Most smartphones, tablets, and other portable electronics already come with a Bluetooth antenna. You can often use those existing devices as part of a Bluetooth RTLS program. Bluetooth’s range of fewer than 10 meters (or 33 feet) makes it suitable for specific applications. Bluetooth uses part of an unlicensed radio frequency band nicknamed the “garbage band,” which might make Bluetooth prone to interference in the future.

Ultra-Wideband or UWB asset tracking uses two key signals – “Time of Flight” (ToF) and “Time Difference of Arrival” (TDoA). By algorithmically combining these two signals, systems can calculate a beacon’s position, with a much higher degree of accuracy than even Bluetooth low energy (BLE) can. In addition, whilst BLE can indicate an X/Y area, UWB can locate a beacon to a third Z dimension within a centimeter-level of accuracy. 

Finally, cellular bands (GSM, CDMA) can also provide real­ time location service. Much like Bluetooth, one of the main advantages of using cellular for location service is that many devices, such as smartphones, already come equipped with cellular antennas, which can be used as part of an RTLS detection network. However, cellular location service relies on a connection to outdoor cellular antennas. Cell service is frequently not reliable in large indoor facilities and may require installing expensive repeater antennas to provide adequate coverage. Cellular RTLS has a very long range but is less precise than many alternatives, often only locating a target within 10 meters.

What is the difference between RTLS and RFID?

While RTLS needs no intervention and manages to carry out automatic location readings to give precise locations of individuals or objects. RFID, on the other hand, detects if a tagged object has passed through a fixed designated stationary point.

This means that the asset must be close to the RFID detector and can therefore be located at a fixed point. RTLS allows for the asset to be located wherever they are so long as they are in the range of the detector.

Potential issues with RTLS

The basic issues of RTLS are standardised by the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) under the ISO/IEC 24730 series. In this series of standards, the basic standard ISO/IEC 24730-1 identifies the terms describing a form of RTLS used by a set of vendors but does not encompass the full scope of RTLS technology. Like most technology, there are some issues. Whilst many solution providers have worked hard to mitigate these, they must be considered by any organisation looking to source an RTLS system. These include lack of full industry certification and radiofrequency ‘noise’ causing false locations, jitter, or creep. As you can see, each of these standards is suited to different use cases.

How can RTLS help you?

Maybe you only want room-level tracking, so you’ll want to choose a less expensive line of sight standard. Perhaps you want a high ­precision, low interference option and choose UWB. Or maybe you want a cost ­effective solution for a wide range of asset tracking and workplace safety jobs and choose RFID. Regardless of which standard ends up suiting you best, you should now have a better understanding of the different available technologies so you can make the correct choice the first time. For more information about RTLS and Real-time asset intelligence download our complimentary buyer’s guide.

Pathfindr’s award winning Industrial IoT solutions provide customers with real­ time insights into their assets and processes. From indoor and outdoor asset tracking and asset monitoring, our consultative approach has helped transform businesses around the world.

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