A dynamically adaptive Bluetooth system : Improving the range of Bluetooth classic 4.2 using Forward Error Correction

Abstract: Wireless technology has increased in popularity since its invention, being embedded in many devices, such as smartphones, laptops, earphones etcetera. One of those technologies is Bluetooth, which is a short-range technology that is widely used worldwide. While being a popular and important technology, it is not as optimized as it could be, especially the standard Bluetooth 4.2. According to (Bluetooth, 2023)Bluetooth version 5 has four times the range of Bluetooth version 4.2 which is one area of improvement in Bluetooth. While limited Forward Error Correction (FEC)functionality in terms of (15,10) Hamming codes is present in the Bluetooth classic4.2 stack, however, it is not utilized in that version of Bluetooth. This thesis aims to implement a functionality in Bluetooth that uses FEC to increase the range. Before the experiments were conducted, multiple measurements were done in order to check if the hardware, such as the Bluetooth modules, antennas, air sniffer, could provide reliable and valid data. The experiments were conducted by streaming an audio sample of 48 kHz via Bluetooth and increasing the range until a certain percentage of fail rate in data transmission has occurred. FEC was then enabled, and the same experiment was repeated. The results from the experiments show that the range can be increased up to a few meters. Not only that, but the transmission without FEC allows a high level of errors without a connection cut-off. With FEC, the connection does not allow high levels of errors which means that the audio quality would not drop as low as it would have without FEC which means that a certain audio quality is preserved. This also makes the case for the implementation of higher modes of FEC into the Bluetooth stack to potentially increase the range of Bluetooth classic multiple times, but that implementation is beyond the scope of this thesis.