UWB vs WiFi: Why Ultra-Wideband is Winning the Indoor Positioning Race
When it comes to tracking assets, equipment, or personnel indoors, two technologies dominate the conversation: WiFi and Ultra-Wideband (UWB). Both can locate objects within a facility, but the similarities end there. For applications where precision matters—manufacturing floors, warehouses, healthcare facilities—the difference between these technologies isn’t just technical. It’s operational.
The Accuracy Gap
Let’s start with the numbers that matter most:
| Technology | Typical Accuracy | Update Rate | Best Use Case |
|---|---|---|---|
| WiFi Positioning | 3-5 meters | 1 Hz | Zone-level tracking |
| UWB Positioning | 2-10 cm | 100+ Hz | Precision applications |
That’s not a minor difference—it’s an order of magnitude. A WiFi system might tell you a forklift is “somewhere in aisle 4.” A UWB system tells you it’s exactly 2.3 meters from the shelf, moving at 1.2 m/s toward the loading dock.
How Each Technology Works
WiFi Positioning: Signal Strength Guesswork
WiFi-based indoor positioning systems typically use Received Signal Strength Indication (RSSI) to estimate distance. The logic seems simple: stronger signal means closer proximity.
The problem? Radio signals don’t behave predictably indoors. Metal shelving, concrete walls, moving personnel, and even humidity affect signal strength. A device showing -60 dBm might be 5 meters away—or 15 meters away with a clear line of sight. Environmental factors introduce errors that no amount of fingerprinting or machine learning fully solves.
UWB: Time-of-Flight Precision
Ultra-Wideband takes a fundamentally different approach. Instead of measuring signal strength, UWB measures time-of-flight—the precise nanoseconds it takes for a pulse to travel from tag to anchor.
Because UWB uses extremely short pulses (less than 2 nanoseconds) across a wide frequency band, it can:
– Distinguish direct paths from reflected signals (multipath rejection)
– Achieve timing accuracy of ~10 picoseconds
– Calculate distances with centimeter precision
This isn’t theoretical—it’s physics. Light travels approximately 0.3 millimeters per picosecond. When you can measure time to picosecond precision, centimeter accuracy follows naturally.
Real-World Performance Comparison
Warehouse Inventory Management
WiFi approach: Zone-based tracking tells operators an item is “in the northeast quadrant.” Workers still spend 5-10 minutes searching.
UWB approach: Precise coordinates guide workers directly to the item. Search time drops to under 1 minute.
Manufacturing Line Coordination
WiFi approach: Coarse positioning triggers zone-based alerts but can’t coordinate tight tolerances between automated systems.
UWB approach: Sub-10cm accuracy enables precise coordination between AGVs, robotic arms, and human operators—essential for lights-out manufacturing goals.
Healthcare Asset Tracking
WiFi approach: Locate equipment by room or department. Acceptable for general asset management.
UWB approach: Track infusion pumps, crash carts, and mobile equipment to the specific bed. Critical for emergency response times.
The Infrastructure Question
A common objection: “We already have WiFi everywhere. Why invest in new infrastructure?”
It’s a fair question. WiFi infrastructure does have lower marginal costs if you’re adding positioning to an existing network. But consider the total cost equation:
- Labor costs from imprecise tracking often dwarf infrastructure investment
- Integration complexity with WiFi positioning typically requires extensive site surveys and ongoing calibration
- Reliability requirements for safety-critical applications often disqualify WiFi entirely
For organizations where positioning accuracy directly impacts productivity, safety, or compliance, UWB infrastructure pays for itself quickly.
When WiFi Positioning Makes Sense
UWB isn’t always the answer. WiFi positioning works well when:
– Zone-level accuracy (room or area) is sufficient
– Existing WiFi infrastructure is extensive and well-maintained
– Tagged assets number in the thousands with limited tracking frequency needs
– Budget constraints prevent new infrastructure investment
Many facilities use both: WiFi for general asset visibility across large areas, UWB for precision tracking in critical zones.
The IndoTraq Approach
IndoTraq’s UWB tracking systems are designed for environments where precision isn’t optional. Our solutions deliver:
- Sub-10cm 3D positioning in challenging industrial environments
- Update rates up to 100 Hz for real-time safety and control applications
- Seamless integration with existing warehouse management and ERP systems
- Rugged hardware rated for demanding operational conditions
Whether you’re optimizing warehouse operations, coordinating autonomous systems, or implementing proximity-based safety zones, the technology you choose determines what’s possible.
Ready to see UWB precision in action? Contact us for a demonstration, or explore our Development Kits to evaluate the technology in your environment.