Indoor Positioning and Types of Location Tracking
Indoor location tracking services create new opportunities for businesses looking to make faster and better decisions based on real-time data. With modern indoor tracking systems businesses can increase the productivity and safety of their workers, equipment, and work sites by:
- Ensuring assets are not lost or misplaced
- Faster asset retrieval times
- Improved capacity utilization
- Better worksite workflows and utilization
- More efficient responses to workplace emergencies and/or evacuations
- Less workplace injuries and accidents
- Ability to focus more on value added activities
- Less workflow interruptions through contract tracing
Indoor positioning systems are particularly useful for lone workers, roll-call, pandemic workplace practices, warehousing, logistics, and forklift operations.
What is an indoor positioning system?
Indoor positioning systems consist of a network of connected devices working together to provide location tracking services for people and assets unable to be tracked with traditional technologies such as GPS or satellite.
GPS and satellite systems for indoor positioning systems are limited by their lack of precision and/or lack of ability for their signals to reach their desired location.
In situations where GPS and satellite positioning systems will fail or not provide precise enough data, businesses will turn to indoor positioning systems to gain functional insights into the movement of people and assets within the workplace.
Examples where indoor positioning systems are useful include: airports, underground locations, remote workplaces, mining operations, and multistory buildings.
Real Time Location Systems
Real time location systems (RTLS) are indoor tracking systems capable of location and monitoring people and company assets operating within a defined zone covered by a radio frequency (RF) network. They work through a connected network of RF receivers and active RFID transmitters to provide precise and accurate indoor tracking services for each staff member, piece of equipment, and vehicle.
What is indoor location tracking?
Indoor location tracking is similar to GPS location services but for indoor environments. It allows users to determine the location of people and assets within a building by using smartphones, tracking tags, mobile devices, and other devices supporting indoor location tracking services.
The capabilities of indoor location tracking vary depending on what technology is being used to produce and receive location data. There are 5 distinct categories to take into consideration when choosing which indoor location tracking system will be best suited for the job:
Accuracy is the primary feature desired in indoor location tracking systems, and also the most difficult to obtain. Typically, as the desirability of highly accurate location tracking increases so does the cost of implementing a highly accurate location tracking solution. Ultra wide-band (UWB) offers the most accurate location positioning system at the lowest cost.
- Coverage and Scalability
Coverage is the second most desired characteristic of indoor tracking systems. There is often a trade off that occurs between coverage and accuracy (i.e. more cover = less accuracy and vice versa). Coverage is also heavily influenced by the presence of walls, equipment, other signals, and other people within the indoor tracking environment. Some systems may not be able to operate under certain environmental conditions. For example, indoor tracking systems using infrared are stopped by walls, which limits its coverage.
Indoor location tracking systems need to be able to function within a changing environment. Indoor work environments are not static, and suitable indoor location tracking systems need to be versatile enough to function inside of dynamic environments without sacrificing too much performance.
- Sampling rate
The sampling rate of indoor location tracking systems refers to the number of positions obtained for an object per second. The higher the sampling rate the more computational power and energy is required, but more up to date and accurate location information is obtained.
There are several costs associated with indoor location tracking systems. These costs are operational costs, deployment costs, and maintenance costs. Some systems even require calibration which adds to their costs, while others can use existing infrastructure resulting in lower costs.
What are types of indoor location tracking technology?
Many technologies are used for indoor tracking ranging from multi-purpose devices, such as cell phones, Wi-Fi and Bluetooth antennas, clocks, and digital cameras. Other indoor tracking is done through relays and beacons of location information using lights, radio waves, magnetic fields, behavioural analytics, acoustic signals, and/or ultra wide-band frequencies.
Each technology used for indoor tracking systems has pros and cons in terms of cost, practicality, flexibility, interference with other systems, ease of use, maintenance, precision, and accuracy.
What are the components of an indoor positioning system?
Indoor positioning systems (IPS) mostly operate using the same methods of producing and receiving different kinds of signals to determine the location of people and objects.
The term mostly used for devices capable of receiving location information are called anchors, and the devices generating location data for people or objects are called location tags.
Each system contains components unique for its style of location tracking, and possess varying degrees of accuracy, cost, and feasibility under certain conditions.
How does indoor positioning system work?
Indoor location tracking revolves primarily around 5 distinct types of tracking:
Wi-Fi based indoor positioning systems
Wi-Fi based indoor tracking systems work through Wi-Fi transmission tags sending small packets of information to Wi-Fi access points throughout the workplace. Each Wi-Fi access point uses information received from the Wi-Fi transmission tags to compute the position of the tags with between 3–5 meters of accuracy. Wi-Fi based indoor tracking systems may be expensive to implement within companies without Wi-Fi access points to support location tracking.
Acoustic systems work in a similar way to ultra wide-band (UWB) systems, but use sound waves instead of radio frequencies. They use a network of receivers and transmitters to send and receive ultrasonic sounds (sound you cannot hear) for location tracking. The most accurate acoustic systems are sonar-based systems which can almost be as accurate as UWB systems, however, they can be expensive to use and are mostly used for niche cases within the healthcare industry.
Light pulses are used in infrared systems similar to how TV remotes work. Each indoor area will have infrared (IR) receivers for communicating with IR tags. IR systems are highly accurate within indoor rooms, but cannot provide location tracking services that penetrate through walls. IR systems are best suited for locations with many individual rooms and clearly separated areas, and are least well suited for warehouses and manufacturing facilities.
Indoor positioning using proximity systems gives a general location of the object of interest, such as a person or object within a room. They do not provide highly precise locations like UWB systems.
Proximity-based systems work through either a reader-based or reference point-based system. Reader-based systems work through tags, continuously transmitting their identity to reader devices that can calculate the position of each tag. Reference point-based systems work using bluetooth low energy (BLE) to communicate between BLE beacons and specific reference points within an area to determine an object position.
Both types of proximity-based systems are the cheapest system to implement for indoor position tracking and are commonly used in both healthcare and manufacturing settings. However they do not provide the level of accuracy, precision, and intelligence of UWB systems.
Ultra wide-band systems
Ultra wide-band (UWB) systems are the most accurate and precise technology in use today for indoor location tracking.
They consist of UWB tags, anchor points, and a gateway to local servers and cloud servers to display location information. UWB tags generate pulses over a wide GHz spectrum to anchor points which are able to produce highly accurate location data based on the timing of receiving pulses from UWB tags.
UWB systems are primarily used for inventory management, material/equipment management within manufacturing facilities, and for workplace safety applications in a wide variety of industries. Since UWB systems can function over a wide GHz spectrum they do not interfere with other communication systems operating in the same environment like proximity and Wi-Fi based location tracking systems do.
Indoor positioning and types of indoor location tracking are done using several different methods, each varying in efficiency and cost depending on the location tracking requirements.
Thankfully, new developments in technology, and the scale of production of these technologies, is making highly accurate indoor location tracking more useful and affordable; especially for ultra wide-band (UWB) systems.