Choosing the Right Indoor Asset Tracking Technology: A Practical Guide

Tracking the indoor location of tools, personnel, or equipment is a complex challenge. While GPS is ubiquitous for outdoor navigation, its satellite signals are too weak to penetrate most building envelopes.

To locate assets indoors, you need an infrastructure that includes readers or reference points—there is no “stand‑alone” solution that can map tags without installing hardware in the facility.

Indoor tracking systems can be grouped into three primary categories:

• Presence‑Based – Detects whether a tag is within the range of a reader. It provides a binary result: present or absent. Examples include Passive RFID, BLE presence tags, and infrared (IR) detection, which is widely used in hospitals.
• Proximity‑Based – Estimates how close a tag is by measuring Received Signal Strength Indicator (RSSI). Active tags, such as BLE beacons, broadcast signals whose “loudness” allows the reader to infer distance. Wi‑Fi‑based RSSI systems also use the signal strength from multiple access points.
• Time‑Based – Determines distance by measuring the time it takes for a signal to travel between tag and reader. Because radio waves travel at the speed of light, these systems require highly accurate timing. Technologies include Ultra‑Wide Band (UWB), certain Wi‑Fi solutions, and ultrasound (which uses slower sound waves, traveling ~1 ft per millisecond).

Which Technology Should You Choose?

The answer depends on your business needs, not just technical specifications. Consider the level of precision your workflow demands and whether the added accuracy delivers measurable value.

For applications that require pinpoint accuracy—such as locating a specific shelf in a large warehouse—an UWB system may be justified, despite its higher cost. Conversely, if you simply need to locate a large object in a largely empty space, a proximity‑ or presence‑based system can suffice.

A notable example is AirFinder. Its proximity‑based approach uses fixed location beacons that allow precision to scale with space density. A crowded storeroom might host eight beacons, while a wide loading dock could operate with a single beacon, reducing both cost and complexity.