Indoor Location Position Based on Bluetooth Signal Strength

Nowadays many systems with diverse technologies such as (GPS, Wi-Fi, Bluetooth, ZigBee, Ultra Wide Band, Ultrasounds, Infrared, etc) can be used for indoor location. One of the biggest challenges in indoor location systems is to determine the actual indoor position of the user using a smart device (Phone, PC, etc), due to their instability, cost, high-power consumption, low accuracy and low precision. To overcome those problems, we have designed, implemented and emulated an indoor location system based on RSSI (Receive Signal Strength indicator) of the Bluetooth low energy 4.0 (BLE). BLE 4.0 technology is more advantageous in terms of long life expectancy, our approach is based on the deployment of equidistant nodes on the ceiling. The nodes are programmed to broadcast a periodic beacon at a time pace of 400ms and then to enter sleep mode. When a smart device enters within the broadcasting range, it locates the three access points (nodes) with the highest signal strength. This information can be calculated using one of the several localization algorithms (Dilatation). The proposed Dilatation algorithm can be easily implemented in the hardware due to its low complexity, the method can be successful even when using a few numbers of nodes. In average the system has about 0.5~1 meters of error.