UWB-BLE Protocol Suite

Low-cost location tracking for underground mines with the following features and advantages:

• No need for cable installations - only battery-powered BLE beacons, which can operate for 3-5 years without recharging.
• Location accuracy of 10-20 meters with BLE beacons placed every 40-60 meters.
• Intelligent data buffering and synchronization for places without Wi-Fi coverage.
• Works well in NLOS (Non Line of Sight) and noisy RF environments - resolves the typical drawbacks of RSSI-based tracking algorithms. 
• Good scalability to thousands of workers in underground mines.
• Works over QoS2 MQTT with guaranteed data deliveries.
• Included telemetry from methane, CO, pressure and temperature sensors.
• Included SOS and broadcast alarming features for underground mines. 
• Multiple BLE GATT and MQTT configuration parameters for tuning the protocol per project requirements.

One-dimensional RTLS for underground mines, which works with one or two RTLS anchors:

• Tuned for the best possible accuracy: 3-9 centimeters
• Suitable for positioning the rail-based equipment and the tunnelling machinery.
• Up to 150 meters range by default; up to 1200 meters range with the long-range UWB anchors.
• Native support for the CAS-PDS protocol together with precise location tracking in underground mines (same hardware).
• Included SOS and broadcast alarming features for underground mines. 
• Only one RTLS anchor is enough in some cases.

Modified UWB TWR implementation to consider the typical CAS-PDS scenarios:

• Up to 100 meters detection range with 50 cm accuracy.
• Three modes of operation: driving, boarding, parked. 
• Each mode has different UWB parameters and UWB traffic prioritization.
• Fast detection of the new UWB tags to discover obstacles quickly.
• Master-slave setup with several RTLS anchors: up to 4 anchors per vehicle.
• Data streaming and configuration parameters via BLE GATT.
• RS-485 serial connectivity among the on-vehicle RTLS anchors.

Low-power and scalable UWB RTLS algorithm to address some drawbacks of the TWR-based protocols:

• No need for precise clock synchronizations using cables. Only wireless message exchanges among RTLS anchors.
• Much less battery consumption on UWB tags than TWR.
• Higher UWB tag densities and better scalability - hundreds of UWB tags per room/zone.
• Good enough location accuracy of 50-60 centimeters.
• Suitable for 2D and 3D RTLS scenarios.

• Short-range and long-range P2P data transfers over UWB: from 1 meter to 1000+ meters.
• File transfer protocol with CRC, retransmissions and status indications over UWB.
• UWB OTA firmware upgrade in the UWB modules for cap lamps and RTLS anchors.
• Can become a good alternative to the following: 
• Wireless mesh networks, when it’s not possible / optimal to install multiple devices in a chain.
• Places without WLAN / LAN coverage inside mines.
• Collecting telemetry from the mining equipment in hazardous areas, where BLE or Wi-Fi can not be used.

The RTLS engine is available in two versions:

• JavaScript sources for Node.js server applications
• C/C++ sources for on-device RTLS engine

The engine includes Levenberg-Marquardt and Kalman filtering modules in a single pipeline for 2D-3D RTLS calculations.

The resulting data is available via MQTT and AMQP protocols.

The generic IoT protocol for sensor readings and two-way commands, such as SOS initiation and mirroring BLE GATT parameters via MQTT commands.

The protocol is currently used for the following scenarios:

• Reading and calibrating gas sensors: methane, CO
• Sending broadcast alarms or P2P messages 
• Gateway between Modbus commands and MQTT / BLE GATT parameters