Evaluating Bluetooth Low Energy in realistic wireless environments

Abstract

The 2.4 GHz ISM band is crowded with a wide variety of wireless devices operating under various access protocols, Bluetooth Low Energy (BLE) among them. Low power requirements, low cost, and ease of integration have promoted BLE's rapidly growing popularity. BLE applications range from providing wireless interface for monitoring household equipment status to reporting critical information from medical devices that might have less tolerance for transmission errors to function properly. In this paper, we identify risks in a real world wireless environment that adversely affect BLE system functionality. We also propose a methodology utilizing spectrum surveys to quantify probability of transmission failure relative to the system's interference detection threshold. Spectrum surveys were conducted in a basketball sport facility, a university student union and a hospital intensive care unit (ICU). Results demonstrate how a BLE system selects data transmission channels in the presence of interference. Moreover, findings of this study confirm that a BLE system is able to maintain a low probability of failed transmission while operating in the presence of high interference unless the environment noise floor is close to the employed interference detection threshold.