An Experimental Study on BLE 5 Mesh Applied to Public Transportation

Nowadays In-Vehicle Wireless Sensor Networks (IVWSN) are taking place in car manufacturers because it saves time in the assembling process, saves costs in harness and after-sales, and represents less weight on vehicles helping in diminishing fuel consumption. There is no definition for wireless solution technology for IVWSN, 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 (WSN) 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 paper 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). In order 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 under work in a variety of conditions during its trajectory to determine the influence of the passengers and the whole environment in the data transmission. The results suggest Bluetooth 5 in a mesh topology as a promising candidate for IVWSN because it showed 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 supports the analysis for time-critical applications.