# Optical Camera Communication as an Enabling Technology for Microalgae Cultivation +
## 6 Conclusions  
In this work, OCC was proposed as a suitable communication technology for monitoring microalgae production plants based on artificial lighting. The theoretical channel model was introduced alongside the analysis of the parameters that significantly impact the achievable data rate, such as the nodes' geometrical configuration and the camera sampling frequency and exposure time. This research highlighted the importance of optimising plant distribution in terms of link quality, channel capacity and efficient space exploitation. A multidimensional metric was designed for this purpose and tested in the conducted case study, where three different node arrangements were classified. This study's main result was that the configuration in which the camera observes the reactor shelf from the side is the preferred solution. On the one hand, it provides comparable link qualities between all containers without incurring detrimental losses of the signal strength due to the camera's viewing angle. On the other hand, it better exploits the scarce space available than a camera watching the containers frontally. In addition, the experimental evaluation of the proposed flat-panel photobioreactor prototype was carried out in indoor and outdoor environments for two different microalgae species: _A. platensis_ and _R. marinus_ (green and brown algae, respectively). In the indoor experiment, the container surface's radiation pattern was measured for each image channel at different concentrations. This analysis reveals significant differences in the SNR between channels due to the algae absorption spectrum. Moreover, notable differences can be observed between the borders and the central part of the surface. These differences tend to reduce as the concentration of microalgae increases due to the phenomenon of scattering. Despite that the viewpoint must be taken into account when designing the system, it additionally provides valuable information for in situ sensing the algae's biomass and its growth state. In the outdoor experiment, the blue and green channels were highly attenuated, which compelled discarding these wavelengths for data transmission. Furthermore, in this scenario, the sunlight decreased the available dynamic range considerably for signal transmission, especially for low biomass concentration. Finally, examining the obtained results for the two microalgae species with different absorption profiles determined that the selected strain and its temporal evolution must be considered in the development of the optical link. Future research should further develop and confirm these initial findings by extending the SNR's evaluation to the actual achievable BER for this deployment in both indoor and outdoor scenarios. It should examine more deeply how the presence of aeration bubbles might affect the signal reception. It could also focus on comparing and developing novel framing strategies for sensor data, reducing packet overhead, easing transmitter discovery and data synchronisation and equalisation. In terms of culture sensing, artificial intelligence for biomass estimation may constitute the object of future studies. In conclusion, it was demonstrated that microalgae production plants are a potential use case for OCC. This technology provides simultaneous node monitoring capabilities using a cost-effective deployment, paving the way to develop smart farming strategies within the microalgae cultivation field. **Author Contributions:** Conceptualization, C.J.-V. and V.G. ; data curation, C.J.-V.; formal analysis, C.J.-V., V.G. and J.R.; funding acquisition, J.R.; Investigation, C.J.-V., V.M. and C.A. ; methodology, C.J.-V. and V.G. ; project administration, J.R.; resources, C.A. and J.R.; software, C.J.-V.; supervision, V.G. and J.R.; validation, C.J.-V.; visualization, C.J. [PERSON]; writing--original draft, [PERSON]; writing--review and editing, [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON]. All authors read and agreed to the published version of the manuscript.