Abstract:

Specialized cards and readers are used commonly used in access control systems. The use of cards and readers equipped with a BLE interface in such systems eliminates the need to bring the card close to the reader in order to gain access to the organization's resources. A study of the quality of distance measurement with the use of popular microcontrollers and beacons was presented  in a research study by Arciuch (2022) where the accuracy and repeatability of RSSI measurement in BLE systems designed to control users' access to rooms was assessed. The results of the measurements indicated that in order to increase the accuracy of the distance determination based on the measurement of RSSI parameters, using the devices used in the experiments, it is necessary to calibrate each sensor-marker pair independently, during the system installation phase. In these measurements, the markers and sensors were placed close to each other – the maximum distance between the markers did not exceed 0.02 m, and the distance between the sensors did not exceed 0.1 m. On the other hand, no measurements were carried out in the one-marker-one sensor configuration. Therefore, it seemed reasonable to check the influence of signals from other markers on the quality of RSSI measurement carried out by the particular configuration of one marker – one sensor. For the purposes of the study which is the subject of the publication, a method has been developed. The method consists in measuring the RSSI value for the signal between the marker and the sensor, in two configurations: without other BLE markers located close to the particular marker and in the presence of other BLE markers located in close proximity of the particular marker. For the obtained results, a classical verification of the hypothesis about the equality of means from the measurements of RSSI parameters for two measurement configurations was carried out. The results of measurements obtained for a marker-sensor pair made without the presence of other markers in the vicinity of the measurement and the results obtained for the same pair with the markers turned on in the vicinity differ. In most cases (4 out of 6) this is a statistically significant difference.