1. Core Challenges & Differentiators from Standard Indoor Navigation

Standard indoor navigation (e.g., shopping malls, airports) prioritizes consumer convenience. Navigation in hazardous industrial environments is a mission-critical safety system with unique demands:

• Extreme Physical Conditions: Dust, humidity, water, explosive atmospheres (requiring intrinsic safety certifications), and significant metal structures causing severe multipath and signal attenuation.
• Dynamic & Unstructured Environments: Constantly changing layouts due to moving machinery, excavation (in mines), or temporary structures. GPS-denied entirely.
• Life-Safety Focus: The primary goal is worker safety, asset security, and emergency response, not convenience. Requirements include:
  • Man-Down/No-Motion Alerts: Automatic detection of worker immobility.
  • Geo-fencing & Exclusion Zones: Real-time alerts for unauthorized entry into dangerous areas.
  • Mustering & Evacuation Guidance: Quickly accounting for all personnel during an emergency and guiding them to safety.
  • Proximity Alerts: Warning workers and vehicle operators of close-range collisions.
• Infrastructure Limitations: Often no reliable power or data network backbone in all areas. Systems must be low-power and capable of offline/edge operation.
• Robustness & Redundancy: System failure is not an option. High reliability and fail-safe mechanisms are required.

1. Executive Summary

Achieving centimeter-level positioning with Bluetooth technology requires a fundamental rethinking of traditional approaches. While standard Bluetooth RSSI-based methods are limited to meter-level accuracy, this document outlines a comprehensive framework that combines cutting-edge signal processing, advanced antenna systems, and novel algorithms to push positioning precision to the 1-5 centimeter range.

Phase-Based AoA (Angle of Arrival) with Carrier-Phase Differential Enhancement

Bluetooth technology, ubiquitous in our daily lives, connects everything from wireless earbuds to smart home devices. Yet, beneath the surface of this convenient wireless communication lies a powerful and often misunderstood capability: Bluetooth sniffing. This technique, which involves intercepting and analyzing Bluetooth radio packets, presents a classic dual-use dilemma. For developers, it's an indispensable debugging tool; for privacy and security, it poses a significant potential threat.