Broadcast Audio Transmission for Bluetooth LE on an Interfered ISM Band

The isochronous channel is a new feature of the next version of Bluetooth 5.0 and has been developed to enable audio transmission using Bluetooth low energy. This feature will include a scheme for audio broadcasting in public areas and in homes and office environments. However, this technology has only employed an n-repetition scheme for the broadcast method. In this scheme, the energy efficiency of the master device, which generally broadcasts audio data in cycles, can be increasingly aggravated owing to unnecessary retransmissions, even if the radio channel is not congested. To provide a solution, in this paper, an energy detection-based broadcast scheme is proposed using an appropriate analysis model based on a stochastic method to find the optimal retransmission number, where heterogeneous Wi-Fi communications coexist on the same 2.4-GHz band. The evaluation is also presented, wherein the experimental results are compared to the standard n-repetition scheme in the same environment.