Bluetooth Low Energy is a wireless communication protocol widely used in Internet of Things systems. As a popular protocol operating in the 2.4 GHz frequency band, it is constantly confronted with interference challenges. For instance, in a Bluetooth Low Energy network, all connections see each other as a source of interference. In this paper, the interference and reliability issues are investigated among Bluetooth Low Energy connections. The impact of various factors on the interference, such as connection parameters and network size, is shown through simulation. The trade-off between application level throughput, i.e. goodput, and reliability in a Bluetooth Low Energy network is described, which can be used in the design or deployment of Bluetooth Low Energy devices or networks.

Bluetooth Low Energy is one of the most popular wireless protocols in the 2.4 GHz frequency band nowadays. There have been multiple studies investigating its performance under interference. However, these studies mostly follow some commonly adopted assumptions. For instance, the location of the interference source does not vary the performance metrics of the connection; the data exchange scheme does not impact the performance metrics of the connection; the performance metrics are the same on both sides of a Bluetooth Low Energy connection. Unfortunately these assumptions are never validated. As a result, this paper aims to verify/challenge these commonly adopted assumptions through experiments. According to the experiment results, the impact of the device role in the BLE connection, the data exchange scheme within the BLE connection, and the location of the interference source is investigated and discussed. This paper should be considered as a cornerstone for other research related to Bluetooth Low Energy performance under interference. It can also be used as a preliminary guideline when deploying Bluetooth Low Energy communication in an interference environment.

We noted that communication performance of a Bluetooth Low Energy (BLE) connection is heavily affected by the radio interference from other connections or networks. Reliability is becoming a key requirement in BLE for its use in various Internet of Things applications. Hence, there is a widely recognized need for an in-depth study to reveal the parameters impacting BLE reliability under such radio interference. In this article, we investigate how transmission parameters, e.g., number of packets and packet transmission time, influence reliability of the BLE protocol. Specifically, a mathematical model is presented to explore the impact of the transmission parameters on the reliability of a BLE pair under interference caused by other pairs. This mathematical model is able to show the reliability issues from both the side of the BLE connection under interference and the side of the interference itself. The model is validated and novel insights on the common usage of BLE parameters by a wide range of experimental evaluations are provided. Experimental results highlight the correctness of the mathematical model, thus quantify the interplay between transmission parameters and coexistence, also the influence of other related parameters. This research provides a design-level or system-level insight in BLE usage and deployment.