• optical wireless communication
• light emitting diode
• free space optics
• intra spacecraft communication

The interest in optical frequencies is very much alive and there are several studies that have been successful over the years aimed at developing wireless links that exploit this part of the electromagnetic spectrum that includes Infrared, Visible and Ultraviolet sub-bands (from 1 mm to 10 nm of wavelength). This kind of communication, called Optical Wireless Communication (OWC), has emerged as a cutting-edge technology in the field of communications, offering several advantages over traditional radio frequency communication systems. Currently, in fact, wireless technology is widespread and it is based on the use of this band of the electromagnetic spectrum that covers the frequencies between 30 kHz and 300 Ghz. The ever-increasing demand on the market by telephone companies, television broadcasters and many others, have made it necessary the presence of regulating and supervising local and international authorities for the management and licensing of these bands. From this point of view, the development of systems that exploit optical frequencies would lead to widening the bandwidth that can be used for these services. At the same time, the implementation of these systems for intra-spacecrfat applications would lead to a reliable, electro-magnetic interference free and cost-effective alternative to usual systems. In general OWC utilizes the transmission of modulated light signals, typically in the form of laser beams or LED-based communication, to establish high-speed, secure, and reliable data links. This technology has gained significant attention and adoption in space applications due to its unique features and capabilities. Key advantages will be: high data rate, low latency, immunity to interference, security, lightweight and compactness.
The work was, in fact, developed within the project Transmission of Optical Wireless Signals for Telecom Satellites (TOWS) carried out at the Scuola Superiore Sant'Anna of Pisa, aimed at generating interfaces for MIL-STD1553B and CAN busses to be used over an Optical Wireless Communication system, creating a lighter and less bulky alternative to data connector and cables and maintaining low power consumption, a very important aspect for a system to be implemented in space where the source of electrical power are often very limited. The thesis is focused on the characterization of a communication system for intra-spacecraft applications and it includes power, bit error rate and sensitivity measurements.
Before presenting this final results, the first part of the work offers an overview of the use of optical technology in space and a general understanding of the protocols of interest, it shows the status of the TOWS project, as it appeared at the end of the first phase and the next solutions chosen to make the transition to the new protocol.