An Experimental Study on BLE 5 Mesh Applied to Public Transportation

Abstract

Today, In-Vehicle Wireless Sensor Networks (IVWSNs) are being used by car manufacturers because it saves time in the assembling process; saves costs in the harness and after-sales; and makes vehicles lighter, which helps lessen fuel consumption. There is no definition for wireless solution technology for IVWSNs, because each one has its own characteristics, and probably this is one of the reasons for its smooth usage in the automotive industry. A gap identified in wireless sensor networks for the automotive domain is that the related literature focuses only on ordinary cars with a star topology and few of them with mesh topology. This article aims to cover this gap by presenting an experimental study performed on verifying the new Bluetooth 5 technology working in a mesh topology applied to public transportation systems (buses). To perform this evaluation, a setup to emulate an IVWSN was deployed in a working city bus. Measuring the network metrics, the bus was placed in a variety of conditions during its trajectory to determine the influence of the passengers and the whole environment on the data transmission. The results suggest that Bluetooth 5 in a mesh topology is a promising candidate for IVWSNs because it shows the robustness of losing only 0.16% packets in the worst test, as well as its ability to cover a wider range compared to its previous version, indeed a better RSSI and jitter, with lower transmission power, compared to a star topology. The round trip time results can support the analysis for time-critical applications.