Bluetooth Direction Finding: Angle of Arrival (AoA) and Angle of Departure (AoD)

The Bluetooth 5.1 specification enhances location services with a direction finding feature that makes it possible to detect the direction of a Bluetooth signal. With Bluetooth direction finding, developers can bring products to market that understand device direction and achieve sub-meter location accuracy.



Applications for Bluetooth Direction Finding

Point-of-Interest

Proximity marketing

Item Finding

Personal property tags

Real-Time Locating (RTLS)

Asset tracking

Indoor Positioning

Wayfinding

Angle of Arrival (AoA)

  • Assets broadcast (TX) their location to an AoA locator such as a wireless access point (AP), connected light or smart luminaire
  • Locators measure the signal’s arrival angle

Angle of Departure (AoD)

  • Beacons transmit AoD information such as coordinates using multiple antennas
  • Mobile devices, including smartphones receive the beacons and calculates position

Bluetooth Angle Estimation for Real-Time Locationing Whitepaper

Bluetooth Angle Estimation for Real- Time Locationing

AoA Design Considerations

  • Assets only need a single antenna, can be low power, and simultaneously support additional Bluetooth LE functionality
  • Locators require 3 x 3 or 4 x 4 antenna arrays and switches
  • Edge gateways process angle readings and communicate to an asset management system in the cloud to determine device location


AoD Design Considerations

  • Beacons require 3 x 3 or 4 x 4 antenna arrays and switches
  • Mobile devices like smartphones need to support AoD algorithms
  • Beacon coordinates must be known by the location services system


Bluetooth Modules for AoA Beacons

Part Number Buy Data Sheet Kit Bluetooth 5 Bluetooth Mesh Bluetooth 5.1  Dimensions (mm) TX Power (dBm) RX Sensitivity (dBm) MCU Core
BGM13S cart icon PDF icon SLWRB4305A and SLWRB4305C 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching 6.5 x 6.5 x 1.4 +18 or +8 -94.1 ARM® Cortex™-M4
BGM13P cart icon PDF icon SLWRB4306A and SLWRB4306B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching 12.9 x 15.0 x 2.2 
+8 -94.8 ARM Cortex-M4

Bluetooth SoCs for AoA Locators and AoD Beacons

Part Number Buy Data Sheet Kit Bluetooth 5 Bluetooth Mesh Bluetooth 5.1 Package TX Current RX Sensitivity (dBm) MCU Core
EFR32BG13P532F512GM32 SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN32 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P532F512GM48
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN48 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P632F512GM32
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN32 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P632F512GM48
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN48 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P632F512IM32
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN32 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P632F512IM48
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN48 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P732F512GM32
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN32 8.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P732F512GM48
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN48 9.5 -94.8 (1 Mbps 2 GFSK) ARM Cortex-M4
EFR32BG13P733F512GM48
SLWSTK6020B 2M PHY; LE Long Range; ADV Extensions Yes AoA, GATT caching QFN48 9.5 -103.3-94.8 (1 Mbps 2 GFSK); -126.2 (600 bps, GFSK, 915 MHz) ARM Cortex-M4

Silicon Labs Direction Finding Solution

  • Bluetooth 5.1 stack with Direction Finding
  • Wireless Gecko EFR32BG13 Bluetooth SoC and BGM13 modules
  • Antenna reference designs and radio boards
Close
Loading Results