Industrial Real-time Location or Locating Systems are a hot topic within the manufacturing, engineering, and logistic 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, its pros as well as its limitations. Real-time Location Systems, shortened to RTLS, 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.
In reality, RTLS is a more limited 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 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 Real-time Location Systems; 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 within the tracked facility. Trend (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. 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.
There are numerous use cases for Real-time Location Systems. From finding all types of assets in a hospital to locating and monitoring assets in a warehouse or factory. They can also be used to identify which workers are on a site, and how long they are there each day. 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.
Here are some 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 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. RTLS enabled access control systems 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. Realtime Location Systems are also used to monitor the health and safety of people in high security environments. An RTLS can monitor lone workers, patients in healthcare settings, or individuals working in hazardous environments. If system user reports an emergency or doesn’t meet a check-in deadline, others in the team are alerted.
Realtime 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 Realtime Location Systems 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. Whilst the technical specifications will be different provider by provider, RTLS solutions will usually share broadly similar hardware and software components: An RTLS tag attaches to an asset or person. This tag emits an identifier and provides location data to receivers over a wireless signal (see below).
These tags are also sometimes called beacons or transponders, depending on the RTLS company that manufactured it and the particular use case. They can also be incorporated into the asset, tool, clothing or even a badge. RTLS detectors are positioned strategically around the facility. They receive wireless signals from tags attached to the assets. Depending on the type of technology used, they will determine location. This will be to various levels of accuracy and can be calculated by either measuring the tag’s proximity to the detector or through the angle of arrival of the signal. 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. 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. Realtime 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; Bluetooth (BLE) is a shortrange 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-Wide Band (UWB) Realtime Location Systems are currently some of the most precise on the market, usually locating a tag to within a meter. They use a range of frequencies, not just one like Bluetooth or IR. These signals are powerful and not prone to interference. These benefits often come at a much higher price point than the alternatives. Because UWB works across a broader range of the electromagnetic spectrum, it can also be complicated to finetune UWB signals within indoor environments. This is particularly true where you use other wireless services. UWB’s precision also tends to drop off at longer ranges. Ultrawideband RTLSs are most suitable for indoor environments where exact asset locations are needed up to a medium range. Their cost also makes them most ideal for environments where security breaches are high risk and potentially costly. The RTLS detectors will send the location data via cable or wireless signal they collect to a central management system.
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 for further integration with other business data. Radiofrequency identification (RFID) tags come in two varieties: passive and active. Passive tags are smaller and have no onboard battery. They receive power wirelessly when someone brings the tag within several meters of a receiver. In a trade off for their shorter range, passive RFID tags cost much less and are more durable than other RTLS tags. Active RFID tags use an integral battery but otherwise they operate in a similar way to passive tags. However, active tags are larger, heavier, and more expensive. But in return, they have a much longer read range, sometimes up to 100 meters (333 feet) in ideal conditions. Like passive RFID, active RFID signals have trouble transmitting through water or metal surfaces. IR signals, such as those used by television remotes, can also be used in an RTLS. They’re suitable for different use cases than RFID as the tags need line of sight with receivers. An IR RTLS is an excellent choice when you need low cost, room level location intelligence. If your goal is to identify the room in which an asset is located, it can be a cost effective choice.
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.
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.
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 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.