Mitigating packet loss in connectionless Bluetooth Low Energy

In this paper, we investigate various methods to combat packet loss in a residential communication system based on the Bluetooth Low Energy (BLE) standard, focusing on BLE´s connectionless mode (undirected advertising) in which no retransmissions are possible. We start by introducing two orthogonally polarised antennas at the receiver, thus improving the probability of successful reception. This is followed by enabling error correction using redundancy introduced by the Cyclic Redundancy Check (CRC) code of BLE. The CRC error correction is based on a novel approach of applying iterative decoding algorithms. We then consider a BLE system deployed in a residential environment and utilise the presence of multiple receivers that are necessary to provide coverage. These three techniques come at no cost for the transmitter, thus preserving its energy efficiency. The final technique deals with error control coding in the application layer, in which some redundancy is added at the transmitter before data is sent to the physical layer. By combining all four methods, a distributed error correction algorithm is developed. Using real BLE packets collected in a typical 2-storey house, it is shown that the designed system can correct 80% of all corrupted packets.