In Free Space Optical (FSO) backbone links, the operator owns both sides of the link and can opt for proprietary solutions. However, in LiFi links from the infrastructure to client end terminals and IoT devices, equipment from different vendors must cooperate. This requires standardization. Meanwhile, individual device and chip manufacturers need freedom to further innovate and optimize solutions within the standardized framework. The radio community relies on decades on building reference models and extensively verifying theories for the optimization of links and tolerable deviations, to ensure that compliant devices work anywhere any time.

Solar-blind ultraviolet (UV) communication and positioning have emerged as promising technologies for non-line-of-sight (NLOS) wireless links and robust localization in challenging environments. This talk provides a comprehensive survey of the fundamental principles, technological advances, and practical applications of solar-blind UV systems operating in the 200–280 nm wavelength range, where solar radiation is largely absorbed by the Earth’s atmosphere. Unlike conventional radio frequency and visible light systems, solar-blind UV offers high security, low background noise, and immunity to electromagnetic interference, making it attractive for scenarios such as disaster recovery, underground mining, atmospheric sensing, and defense operations.

We will review the key components and architectures of UV communication links, including modulation techniques, photodetectors, and transmitter design. The talk will also highlight recent research in UV-based positioning systems, emphasizing geometric models, accuracy trade-offs, and system implementation challenges. Finally, we will outline current limitations and identify future research directions needed to enable widespread deployment as a possible 6G enabling technology.

Non-Terrestrial Networks (NTNs) are poised to play a transformative role in the evolution of 6G by enabling seamless, resilient, and reliable connectivity on a global scale. Encompassing Unmanned Aerial Systems (UAS), High Altitude Platforms (HAPS), and Low Earth Orbit (LEO) satellites operating at various altitudes, NTNs are critical to addressing key performance indicators of 6G networks—namely reliability, robustness, and resilience. These capabilities are essential for supporting use cases such as public safety, emergency communications, and connectivity in underserved rural and remote regions.

This talk introduces a novel NTN layer architecture and reviews the spectrum of NTN platforms and their integration into terrestrial networks. The discussion will cover both device-level and network-level challenges, including power efficiency, antenna design, latency, and achievable data rates. Recent research results will also be presented, demonstrating the feasibility of establishing NTN connectivity using existing 5G mobile terminals with minimal or no modifications—thereby enhancing the robustness and resilience of future wireless communication systems.