In this paper, we explore the potential applications of Optical Wireless Communications in the tourism industry, considering both indoor and outdoor scenarios and different transmission speeds. They range from high-speed atmospheric outdoor links (Free-Space Optics (FSO)) to indoor systems based on high-speed lighting networks (known under the trade name LiFi©) or low-speed services support the Internet of Things networks, using visible light (VLC) or IR emitters, with receivers based on either on classical photodiodes or in image sensors, known as Optical Camera Communications. The avant-garde applications of this technology have been studied focusing on three possible use scenarios: the traveler himself, in what we have called TAN (Tourist Area Network); the tourist facility, which includes not only the hotel but also leisure areas (theme parks, museums, natural protected areas) or services (restaurants, shopping areas, etc.); and the entire destination, which can be both the city or the territory where the tourist is received, within the paradigm of the Smart Tourist Destination (STD). In addition to the classic services based on radio frequency and wired broadband networks, these technologies will make it possible to meet the tourist’s challenging needs, the establishment, and the destination. Besides, they cover the services imposed by the new marketing services related to location or context and feed the big data systems used to study tourist behavior.

In rolling shutter-based optical camera communication (OCC), the camera’s exposure time limits the achievable reception bandwidth. In long-exposure settings, the image sensor pixels average the incident received power, producing inter-symbol interference (ISI), which is perceived in the images as a spatial mixture of the symbol bands. Hence, the shortest possible exposure configuration should be selected to alleviate ISI. However, in these conditions, the camera produces dark images with impracticable light conditions for human or machine-supervised applications. In this paper, a novel convolutional autoencoder-based equalizer is proposed to alleviate exposure-related ISI and noise. Furthermore, unlike other systems that use artificial neural networks for equalization and decoding, the training procedure is conducted offline using synthetic images for which no prior information about the deployment scenario is used. Hence the training can be performed for a wide range of cameras and signal-to-noise ratio (SNR) conditions, using a vast number of samples, improving the network fitting and the system decoding robustness. The results obtained in the experimental validation record the highest ISI mitigation potential for Manchester encoded on-off keying signals. The system can mitigate the ISI produced by exposure time windows that are up to seven times longer than the transmission symbol duration, with bit error rates (BER) lower than 10⁻⁵ under optimal SNR conditions. Consequently, the reception bandwidth improves up to 14 times compared to non-equalized systems. In addition, under harsh SNRs conditions, the system achieves BERs below the forward error correction limit for 1dB and 5 dB while operating with exposure times that are 2 and 4 times greater than the symbol time, respectively.

Distance estimation plays an important role in location-based services, which has become very popular in recent years. In this paper, a new short range cricket sensor-based approach is proposed for indoor location applications. This solution uses Time Difference of Arrival (TDoA) between an optical and an ultrasound signal which are transmitted simultaneously, to estimate the distance from the base station to the mobile receiver. The measurement of the TDoA at the mobile receiver endpoint is proportional to the distance. The use of optical and ultrasound signals instead of the conventional radio wave signal makes the proposed approach suitable for environments with high levels of electromagnetic interference or where the propagation of radio frequencies is entirely restricted. Furthermore, unlike classical cricket systems, a double-way measurement procedure is introduced, allowing both the base station and mobile node to perform distance estimation simultaneously.

In this paper, the use of visible light communications (VLC) technologies for providing data networking for passengers during flight is explored. An uplink channel based on infrared is also studied. The potential capabilities of this optical access technique are examined.

In this letter, a new synchronization scheme for color shift keying (CSK) modulation is presented. Proposed system uses pulse position modulation in combination with CSK to increase the bit rate and simultaneously control illumination intensity, avoiding flickering effects. Additionally, this modulation also provides synchronization for the color detection. CMOS sensors are also proposed as receiver devices in order to improve the bit error rate using a mean value calculation inside a region of interest. These devices give the RGB components in digital format, simplifying the receiver block.

Sandstorms can severely affect the reliability of outdoor optical wireless communications (OWC) by diminishing large regions’ visibility. In this work, the effect of a real sandstorm on optical camera communications (OCC) links is experimentally evaluated. Two link ranges are essayed using a cost-efficient telescope-based camera setup with commercial LEDs. Using on–off keying modulation, a data rate of 1035 and 630 bps with error probabilities of 9.14 ⋅ 10 − 5 and 4.1 ⋅ 10 − 3 for 100 m and 200 m, respectively, can be achieved. The signal-to-noise ratio of the links was optimized by tuning the analog amplifier’s gain of the camera, increasing it by up to 9 dB. It is shown that scattering due to the sandstorm can even be beneficial for increasing the data rate in OCC (contrary to classical photodetector-based OWC links), thanks to an increment of 33% on the region of interest dimensions compared to the expected clear air link.