—Bluetooth Low Energy (BLE) is a widely-used low-power wireless standard in the Internet of Things (IoT) domain. This standard provides a set of advertisement channels, which are primarily used for device discovery, connection initiation, and information broadcast. Beacon transmission over these advertisement channels is the enabler of applications such as indoor positioning, product advertisement, and medical monitoring. Meanwhile, the performance and accuracy of these applications highly depend on the characteristics of communication over advertisement channels. Unfortunately, the existing literature does not offer an extensive characterization of these channels under various operational conditions. In this paper, we address this research gap through conducting extensive experiments in four different environments. We study the effect of environment and interference on noise floor and signal propagation, and we present a model for noise floor and extract the parameters of log-normal path loss model. The proposed models, in particular, can be directly used in simulation tools for modeling BLE wireless channels as well as applications such as indoor positioning.