System.Bluetooth.TBluetoothLEManager.RssiToDistance

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Delphi

function RssiToDistance(ARssi, ATxPower: Integer; ASignalPropagationConst: Single): Double;

C++

double __fastcall RssiToDistance(int ARssi, int ATxPower, float ASignalPropagationConst);

Properties

Type Visibility Source Unit Parent
function public
System.Bluetooth.pas
System.Bluetooth.hpp
System.Bluetooth TBluetoothLEManager

Description

Implementation of the algorithm that transforms RSSI to distance. Accepts as parameters ARssi (received signal strength indication in dBm), ATxPower (signal strength at 1m distance in dBm) and a constant ASignalPropagationConst. Returns an approximation of the distance to a device in meters. The parameters needed to call this function are stored in the AdvertisedData property of the device.

Distance formula taken from: IEEE Xplore library paper: RSSI-Based Real-Time User Location Tracking System for Indoor and Outdoor Environments (DOI: 10.1109/ICCIT.2007.253 Pages: 1213 - 1218).

The formula for RSSI is RSSI = -(10*n*log10(d) + A).

See Also