## 6 Debate on the Results and on the Novelty of this Work  
In the context of electric vehicles gradually replacing combustion engine vehicles, a very important challenge is to find solutions for more efficient energy management and for situations where the electric vehicles remain with critical battery charge. Therefore, this article is focused on the usage of light dimming on electric vehicles, while supporting V2V VLC. The envisioned scenario assumes that in extreme conditions, with almost no more energy remaining, or in situations where the lighting functions are less necessary (i.e., in daytime urban conditions), the electric vehicle can activate a light-dimming function, while also using the VLC technology to transmit its state to approaching vehicles. In this context, although the effects of light dimming have been evaluated for indoor conditions in many studies, this is one of the very few articles which addresses this issue in middle-to-long-range automotive applications. For this purpose, a high-performance VLC system has been upgraded in order to evaluate the effect of light dimming on the reliability of a V2V VLC link. The experimental evaluation has been performed in controlled indoor conditions, and also in uncontrolled outdoor conditions. The results showed that an optimally designed VLC system, and adequate front-end design, with a proper signal processing plan, the VLC receiver can have good performances even in light dimming conditions. Therefore, communication ranges up to 40 m can be maintained with a relatively low bit-error-rate. The experimental results indicate that in moderate-to-strong parasitic light conditions, the duty cycle decrease can be compensated with a proper signal processing plan. However, when the amount of parasitic light increases over a critical limit, or when the distance between the VLC emitter and the VLC receiver is close to the maximum coverage, the communication performances are affected. Thus, in such conditions, the communication range can be reduced to half, whereas the BER can increase by several orders of magnitude. These results confirm the findings of [22; 44], which suggest that light dimming affects VLC performances. However, unlike in [44], where the communication distance reaches only 10 m, this new work provides a significantly higher communication range. It should be pointed out that the results presented in this work report communication ranges and noise robustness comparable to the results obtained by other VLC experiments without light dimming function. For example, [8; 9; 10; 11; 12; 13; 45] reported communication ranges that reached 50 m, while providing data rates between 10 and 100 kb/s. Along with all these works, this new article contributes to the demonstration of the high potential that VLC technology has in automotive applications. Thus, if a few years ago the reliability of VLC systems was rather questionable, whereas the communication ranges were rarely reaching 50 m, today's prototypes are able to provide reliable communications in strong sunlight conditions [8; 9], snowfall conditions [10], fog conditions [46], and mobile conditions [45], while providing low latencies [10; 11; 12] and high compatibility to 5.9 GHz RF-based communication solutions [2; 3]. Now, with the results reported in this article, it has been demonstrated that such communication ranges could be achieved while also supporting light dimming. Thus, as far as we know, this article reports the longest vehicular VLC link achieved while providing light dimming down to 1%. From a hardware design point of view, the implementation of the VLC prototype has shown that the light dimming function requires a significantly more powerful data processing unit.