Indoor Positioning Map: How to Build a Beacon-Based RTLS Coordinate System
Unlike standard GPS (3-10m accuracy) or RTK GPS (centimeter-level, but requires open sky and satellite visibility), indoor positioning systems track objects relative to stationary beacons — making beacon placement the foundation of every accurate RTLS deployment, indoors and outdoors.
Indoor navigation maps for humans and indoor positioning maps for autonomous robots, drones, precise tracking of people, forklifts, or other mobile objects are fundamentally different things:
- For humans — a basic 2D or 3D visualization of the building, warehouse, or plant with visual clues such as doors, halls, windows, etc., to localize themselves inside the building and find the way to points of interest. The map for humans is just a picture.
- For robots and automated systems — it is a complete indoor positioning system, not a picture — with stationary beacons (anchors), their coordinates, and the underlying communication between stationary and mobile beacons (tags). Thus, the correct wording is “an indoor positioning map of stationary beacons” rather than just “indoor navigation map,” because most real-life indoor positioning and RTLS systems rely on stationary beacons using different technologies: ultrasound, ultra-wideband (UWB) radio, BLE, or WiFi.
What Is an Indoor Positioning Map — And Why It's a Beacon Map, Not a Floor Plan
A map consists of one or more submaps.
Each submap — similar to a cell in a cellular network — covers its own territory. Submaps consist of 1, 2, 3, or 4 stationary beacons, enabling 1D, 2D, or 3D tracking depending on beacon count and placement.
Service zones are directly defined zones of responsibility for each submap. A submap tracks only within its service zone, even if its signal could reach further. This eliminates ambiguity and conflicting position reports from overlapping submaps.
Handover zones are thin overlap areas between neighboring service zones. When a tracked object crosses from one submap into another, the handover zone ensures the position is passed smoothly — with no gap, jump, or loss of tracking continuity.
Submaps, Service Zones, and Handover Zones — The Building Blocks of Your RTLS Map
Floor Plan Overlay — Visual Layer for Humans, Not Required by the IPS
A floor plan (substrate) is a visual, graphical overlay of your indoor space. The indoor positioning system does not use it for tracking — it is purely for human operators who need to see tracked objects against familiar visual cues: doors, entries, windows, and corners.
The easiest way to get a floor plan is to use the building’s evacuation plan. An actual construction drawing works even better if available.
Important: the floor plan is optional and required only for human operators. The IPS itself relies entirely on the coordinates of stationary beacons and the distances between them — not on any graphical representation of the space.
Real-World Example: Beacon Map for Warehouse and Assembly Plant Tracking
See a practical example of creating an indoor navigation map for a warehouse/assembly plan, including a floor plan, a beacon map, multiple submaps, and numerous service and handover zones.
Precise tracking of workers on a plant.