Mario Cappitelli

On the SIR of a cellular infrared optical wireless system for an aircraft

In this paper, first, path loss models are developed for infrared optical wireless transmission inside an aircraft cabin. Second, a cellular network in the aircraft is considered and signal-to-interference ratio (SIR) maps are determined via simulation. For this purpose, a Monte Carlo ray-tracing (MCRT) simulation is performed in a geometric computer-aided design (CAD) cabin model with defined position, azimuth (AZ), elevation (EL) and field of view (FOV) properties of transmitters and receivers. Mathematical models are developed for line-of-sight (LOS) and non-line-of-sight (NLOS) path losses along particular paths, including estimation of the path loss exponent and the shadowing component. The shadowing is modeled according to a log-normal distribution with zero mean and standard deviation sigma. The validity of this model is confirmed in the paper. It is shown that irradiance distribution under LOS conditions experiences an attenuation with a path loss exponent of 1.92 and a shadowing standard deviation of 0.81 dB. In NLOS conditions, however, the path loss exponent varies, depending on the nature of the NLOS cases considered. The presented NLOS scenarios yield path loss exponent values of 2.26 and 1.28, and shadowing standard deviation values of 1.27 dB and 0.7 dB, respectively. Finally, the cabin is divided into cells and SIR maps are presented for different frequency reuse factors. It is shown that at the edges of the circular cells with diameter of 2.8 m, a SIR of -5.5 dB is achieved in a horizontal cross section of the cabin for frequency reuse of 1, and -2 dB and 3 dB for frequency reuse factors of 2 and 3, respectively. This means that in an aircraft cabin, for reuse factors less than three, viable communication at the cell edges is not feasible without additional interference avoidance or interference mitigation techniques.

Path Loss Simulation of an Infrared Optical Wireless System for Aircrafts

In this paper, the infrared optical wireless path loss inside an aircraft cabin is estimated. To this end, a Monte Carlo ray-tracing (MCRT) simulation is performed in a geometric computer-aided design (CAD) cabin model. Position, azimuth (AZ), elevation (EL) and field of view (FOV) properties of transmitters and receivers are defined. Key path loss parameters such as the path loss exponent and the standard deviation of the shadowing component are determined for particular line-of-sight (LOS) and non-line-of-sight (NLOS) cases. A LOS path loss exponent of 1.92 and a shadowing standard deviation of 0.81dB are obtained. In NLOS conditions, however, the path loss exponent varies depending on the nature of the particular NLOS case considered. The presented scenarios yield NLOS path loss exponent values of 2.26 and 1.28, and shadowing standard deviation values of 1.27dB and 0.7dB, respectively.

Demonstration: VR-HYPERSPACE — The innovative use of virtual reality to increase comfort by changing the perception of self and space

Our vision is that regardless of future variations in the interior of airplane cabins, we can utilize ever-advancing state-of-the-art virtual and mixed reality technologies with the latest research in neuroscience and psychology to achieve high levels of comfort for passengers. Current surveys on passengers experience during air travel reveal that they are least satisfied with the amount and effectiveness of their personal space, and their ability to work, sleep or rest. Moreover, considering current trends it is likely that the amount of available space is likely to decrease and therefore the passengers physical comfort during a flight is likely to worsen significantly. Therefore, the main challenge is to enable the passengers to maintain a high level of comfort and satisfaction while being placed in a restricted physical space.

Real time compensation of in aging effects in solid-state lighting

All available Solid-State Lighting (SSL) systems like LED or OLED suffer from the burden of intrinsic and extrinsic aging effects. These aging effects lead to a degeneration of brightness and color inside the light source, which can be observed far before the failure time (D70). The paper presents a solution for a real time compensation system, which is able to compensate the color and brightness of a lighting system by optical sensing and real time optimization. This approach offers the opportunity to oper ate independently from the implemented light source type and number of primary colors. The benefit is an enhancement in the overall quality and durability of the light source parameters and an elongation of the system use. The solution utilizes a full color sensor and miniaturized embedded computing capabilities to ensure the dedicated performance. Compared to the cost of LED and OLED lighting systems, the overall benefit in quality justifies the additional costs.

Design of experiments for simulated non imaging light sources

Today numerical simulation is a major tool in the design process of non imaging illumination sources. The numerical simulation is in use for different integration levels of light sources, where various numbers of design parameters exist. A variation of all available parameters leads to high amount of samples, which must be simulated and analysed. To reduce the number of variants, a statistical relevant number of samples are used. For this purpose the methods of DoE (Design of Experiments) are applied. In connection with computational methods, the simulation process itself could be automated. This leads to a very efficient design process for non imaging illumination systems. Main challenges are the parameter definition for the DoE, the design of the automated process, and a correct approximation of the achieved result. After solving of all challenges, an efficient system for the prediction of the technical parameters of new illumination is created. This paper describes the general problem of variant analyses and the achievements in automatic DoE studies for illumination systems. An outlook shows how this method could be beneficial in the design process of daylight systems.