Bringing Bluetooth 6.0 Channel Sounding to Market

Agenda

• Technology Overview
• Channel Sounding Applications
• Silicon Labs Offerings
• Algorithm Performance Data
• Developer Tools
• Q&A

Why Bluetooth® Channel Sounding?

The Challenge:

• IoT applications need 'spatial' awareness to be more secure, reliable, and responsive.
• Earlier Bluetooth LE versions lack native support for precise ranging.
• RSSI-based ranging is noisy and unreliable in real-world use.
• Direction Finding needs complex antennas, adding cost & complexity.
• UWB is accurate but often too costly, and bulky for IoT.

The Opportunity:

• Channel Sounding for Bluetooth: Standardized approach for accurate, secure ranging in Bluetooth 6.0.
• Enables sub-meter accuracy with robust performance, even in NLOS.
• Works with single or dual antenna setups - flexible for different form factors.
• More cost efficient than UWB; requires minimal external components.

Built on existing Bluetooth infrastructure, simplifying adoption and ecosystem integration.

Bluetooth® Channel Sounding Overview

• Measure distance between two devices using Phase-based Ranging (PBR) and Round Trip Time (RTT).
• RTT and PBR operates across 2.4 GHz band, with standard specifying up to 72 channels and random channel hopping pattern.
• Connection-Oriented 2-way ranging with two roles: Initiator (device that wishes to calculate distance from itself to another device) and Reflector (device responding to initiator).
• Supports up to 4 antenna paths between devices, with 8 possible antenna combinations.
• Multiple security features included in the standard.
• Can be combined with Angle of Arrival / Departure (AoA/AoD) to enable position estimation with a single locator/tag pair.

Additional Resources

• Webpage - Learn more about Silicon Labs offerings and demos.
• Tech Talk - Explore Bluetooth Channel Sounding.
• Workswith 2024 - Enable Accurate Distance Estimation Using Channel Sounding.
• Blog - Learn more about Antenna Switching with Silicon Labs Channel Sounding.
• API Spec - Getting Started with Silicon Labs Bluetooth Channel Sounding.

Bluetooth® Channel Sounding Comparison

Bluetooth® Channel Sounding - Target Markets & Use Cases

Proximity Awareness

• Door locks
• Keyless entry
• Building access systems
• Geofencing - security alerts

Localization

• Indoor asset management - hospitals, warehouses
• Pet tracking
• Item finding - wallet, keys

Automapping

• Solar Trackers
• Luminaires, Access Points
• Accurate Mapping for Battery Storage

BG24: Optimized for Battery Powered, Channel Sounding-enabled IoT Devices

Differentiated Features

• Ultra small form-factor: 3.1 x 3.0 WLCSP package.
• +20 dBm output power: Eliminates need for external power amplify.
• AI/ML accelerator: Accelerates inferencing while reducing power consumption.
• Secure Vault High: Protects data and device from local and remote attacks.
• 20-bit ADC: 16-bit ENOB for advance sensing.
• Improved Coexistence: Ideal for gateways and hubs.
• PLFRCO: Eliminates need for 32 KHz xtal.

Device Specifications

• High Performance Radio: Up to +19.5 dBm TX, -97.6 dBm RX @ BLE 1 Mbps.
• Efficient ARM® Cortex®-M33: Up to 78 MHz, 1536kB Flash, 256kB RAM.
• Low Power: 49.1 μΑ/ΜΗz (CoreMark), 5.0 mA TX @ 0 dBm, 5.1 mA RX (802.15.4), 4.4 mA RX (BLE 1 Mbps), 1.3 μΑ ΕΜ2 sleep.
• Multiple protocol support: Bluetooth 6.0 (1M/2M/LR), Bluetooth mesh, Proprietary 2.4 GHz.

BG24L: Channel Sounding Optimized, High-Performance & Low-Cost AI/ML Wireless SoC

Differentiated Features

• Supports Bluetooth 6.0: Channel Sounding optimized BLE SOC, Single-connection two-way ranging, Ideal Solution for Channel Sounding tags.
• Lowest Power RF: Increases battery life.
• PLFRCO: Eliminates need for 32 KHz XTAL and lowers overall system cost.
• 16-bit ADC: Up to 14-bit ENOB for better analog sensing.
• AI/ML accelerator: Accelerates inferencing while reducing power consumption.
• Secure Vault Mid: Protects data and device from local and remote attacks.
• Improved Coexistence: Ideal for gateways and hubs.

Device Specifications

• High Performance Radio: Up to +10 dBm TX, -97.6 dBm RX @ BLE 1 Mbps.
• Efficient ARM® Cortex®-M33: Up to 78 MHz, 768kB Flash, 96kB RAM.
• Low Power: 49.1 μΑ/ΜΗz (CoreMark), 5.0 mA TX @ 0 dBm, 5.1 mA RX (802.15.4), 4.4 mA RX (BLE 1 Mbps), 1.3 μΑ ΕΜ2 (16kB RAM retention).
• Wide Operating Range: 1.71 to 3.8 volts, +125°C operating temperature.
• Multiple protocol support: Bluetooth 6.0 (1M/2M/LR), Bluetooth mesh, Proprietary 2.4 GHz.

Bluetooth® Channel Sounding Dual Antenna Development Kit

• xG24 Channel Sounding Development Kit: Available since March 2025.
• Development Kit with two PCB antennas.
• Antenna diversity offers increased robustness and accuracy.
• Intra-event antenna switching for optimal non-line of sight performance.
• Includes IMU sensor to detect movement & wake-up the tag.
• Small form factor: Ideal for size-constrained applications like key fobs.
• AEC-Q100 Compliant.
• SoC/NCP Sample Apps: Initiator and Reflector examples supported.
• Ranging Library: Process IQ samples, post-filtering, and compute distance using configurable algorithm.

Antenna Diversity – What does it bring?

Demonstration of antenna diversity impact on distance measurement accuracy:

• 1 Path: 6.1 m
• 2 Paths: 6.7 m
• 4 Paths: 4.5 m

Actual Distance: 5 meters

Silicon Labs Channel Sounding Algorithm

Algorithm Features

• Supports Multiple Channel Sounding Ranging Modes: PBR, RTT, PBR with RTT as sub mode.
• Antenna Switching: Built-in support for antenna diversity, supports 1, 2 and 4 antenna paths.
• Supported Algorithm modes:
  • Static mode – Delivers the highest accuracy with high measurement latency; optimized for ranging between stationary devices.
  • Real Time Basic – Provides high accuracy with increased computational and measurement latency; supports tracking at speeds up to 1 m/s.
  • Real Time Fast - Balances moderate accuracy and range with low latency; supports tracking at speeds up to 2.1 m/s, additionally produces velocity metric.
• Configurable Channel Selection (72, 37, or 20 Channels): Selectable based on accuracy needs and power constraints.

Key Benefits

• Licensing cost free: Eliminates third-party royalties, simplifying BOM cost structure.
• Optimized HW-SW Co-Design: Tight coupling between silicon & firmware ensures seamless performance & efficiency.
• Single-Vendor Lifecycle Support: Unified hardware & software ownership streamlines debugging, validation, and updates.

Algorithm Performance Test Setup

The test setup involved various node pairs with different distances and obstacles:

Algorithm Performance Data

Note: 1. CS mode - PBR, CS channels – 72, number of antenna paths – 4. 2. ~100 CS Procedures used to produce single distance estimate.

Fit For Purpose Algorithm Modes

Energy Consumption Profile – Reflector

Antenna Diversity Increases Total Energy Per Measurement

Visualizer Tool

Visualizer Tool displays real-time CS data:

• CS configuration:
  • Channel map selection
  • Antenna path configuration
  • Algorithm mode selection
• CS data visualization:
  • RSSI based distance for comparison
  • Raw distance estimate and likeliness
  • Filtered distance estimate
  • IQ data visualization
• Interfaces with CS enabled EVKs.

Silicon Labs Bluetooth® Channel Sounding Offering

CS & DEVELOPMENT KITS

• Channel Sounding Supported by B/MG24 Kits:
• xG24-RB4198A single antenna kit
• xG24-DK2606A dual antenna kit

BLUETOOTH 6.0 STACK

• In-house developed stack, supported and maintained stack.
• Bluetooth 6.0 qualified PBR & RTT Modes.

RTL Library

• Computes distance from raw I/Q data.
• Developed and supported by Silicon Labs.
• New features added based on market needs.
• No 3rd party license fees.

SDK & TOOLS

• Initiator & Reflector examples.
• Real-time visualization tool for Bluetooth Channel Sounding.
• Energy Profiler etc.

EFR32xG24 Channel Sounding Dev Kit attached to drone

Image description: A demonstration of the EFR32xG24 Channel Sounding Dev Kit attached to a drone, showcasing its application in real-world scenarios.

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