17.02.2020

Indoor location tracking – Five technologies in brief

Indoor location tracking | Favendo GmbH

Indoor positioning of persons and / or production equipment or other moving assets is developing into a key competence in production companies and industry. The exact location of assets in a building enables the optimization of internal logistic processes as well as the staff management in numerous industries and can therefore be a valuable tool for increasing efficiency while reducing costs. Favendo specializes in indoor tracking and the determination of indoor asset positions.Discover 5 indoor location technologies in brief:

Indoor Location technologies and granularity

Depending on the required accuracy (granularity) of the positioning, there are solutions with different positioning methods, which can also be based on different technologies. Each has different advantages and disadvantages.

Although WLAN is available in most buildings, it is often not the first choice of technology for an indoor positioning system due to low accuracy and high susceptibility to signal interference. While GPS signals don’t penetrate buildings, they are ideal for outdoor locations. RFID is also often mentioned in the context of indoor positioning systems, and it is true that RFID systems are inexpensive, but since they can only determine a static position, they are not well suited for indoor location tracking.

Bluetooth Low Energy is one of today’s standard technologies for indoor location

Bluetooth Low Energy and Beacons have proven to be the ideal technology for indoor positioning. The location technology is affordable, reliable and offers a satisfactory accuracy of 3-5 meters to locate people or objects in indoors. In addition, advanced Angle of Arrival (AoA) positioning methods based on Bluetooth positioning can achieve sub-meter accuracy similar to systems based on ultra wideband technology (UWB). Since the price of a system, in addition to the granularity of the positioning, plays a major role in the decision for a particular technology, and UWB is by far the most expensive technology, BLE now also has major advantages over UWB.

Indoor positioning system – how does it work?

Indoor positioning is based on the same transmitter-receiver principle as the well-known Global Positioning System (GPS). GPS is a global navigation satellite system for positioning. To work reliably, it requires a clear “line of sight” to several satellites (theoretically three, in practice six to twelve). GPS receivers can calculate their own position and speed from the signal propagation times. In combination with geoinformation (topology, street, aerial or nautical maps), this position information can be used to guide the user to a selected location or to create a route taking into account desired criteria.

In summary: Transmitters send radio signals to a receiver. The receiver interprets these signals and calculates its position within a given topography. The principles behind this are trilateration and triangulation. The three elements mentioned – transmitter, receiver, environmental information – are also found in radio-based indoor positioning and navigation systems. Indoor navigation/wayfinding always requires an application.

Indoor positioning: Technologies in brief

UWB – Ultra-Wideband

UWB enables very accurate three-dimensional positioning, which has to be paid for with high acquisition costs and high effort during system setup. A continuous asset tracking can be realized with UWB.

RFID – Radio Frequency Identification

With the help of so-called RFID tags, RFID provides a static position indication with very inexpensive hardware. Continuous asset tracking is not possible, only information about whether an asset was registered in a certain location at a certain time.

BLE (RSSI method)

Bluetooth low energy technology enables continuous asset tracking with at least room-accurate location. RSSI refers to the method of indoor positioning and means Received Signal Strength Indicator, which is used as the main indicator of the position calculation.

BLE (AoA method)

Here, positioning is also based on Bluetooth Low Energy, but the position is calculated with a different method, using the Angle of Arrival. This calculation allows for much more accurate positioning, but comes at the cost of more effort in setting up the sensor infrastructure and slightly higher hardware costs. However, the cost is still less than a comparable UWB system.

WLAN

Indoor positioning via WiFi can be used for indoor navigation (not for iOS devices!) as well as for asset tracking. The positioning accuracy is between 5 and 15 meters. The accuracy depends on the shielding by walls, ceilings and people, but also on the number of access points. The biggest advantage of this technology is that in many cases a WLAN infrastructure – consisting of access points (AP) – already exists and no new infrastructure needs to be set up.

Which indoor location technology for which application?

The first step to success with an indoor tracking system is to be clear about what you are trying to accomplish with the implementation of such a system. This allows you to communicate these goals to potential indoor tracking solution providers, ensuring that they understand your objectives and can determine if the indoor tracking solution offered is a good fit for your needs based on your defined goals. The combination of a clear goal and an experienced tracking technology partner will help you keep the planning and implementation phase short and cost-effective.

The process of planning a project and selecting the appropriate technology is an intensive task, and it is essential that interested parties seek professional advice and support to help them through it.

Indoor Location tracking is not always enough

In the manufacturing industry, but especially in logistics, construction, mining and open-cast mining, there are tracking scenarios where indoor tracking is not sufficient because objects and people have to be tracked outside of buildings to ensure a continuous flow of data. It makes sense to extend the indoor positioning system with outdoor tracking. An extension of indoor tracking is possible at any time. 

Locating with multi-mode trackers

Multi-Mode Trackers are asset tags that can use different radio technologies for communication. These multi-mode trackers always use the best available signal source. Outside of buildings, these trackers then automatically use GPS or LoRaWAN TDoA to calculate their position.

When they move back inside, these trackers automatically switch to BLE or WiFi to locate objects or people inside. In this way, the same hardware can be used to locate and track machines and workers throughout a factory site. Favendo is a channel partner of Abeeway/Actility, the technological leader in geolocation solutions, and combines its expertise in installation and indoor positioning with the capabilities of these multi-mode devices.