TITAN Director Professor Harald Haas has shared his vision for the future of 6G in a recent Coursera course on ‘6G Vision: ML, Intelligent Surfaces & Optical Networks’. Professor Haas…
TITAN Director Professor Harald Haas has shared his vision for the future of 6G in a recent Coursera course on ‘6G Vision: ML, Intelligent Surfaces & Optical Networks’. Professor Haas appeared as a podcast guest on the course hosted by Professor Hanaa Abumarshoud and Professor Lina Mohjazi of the University of Glasgow.
The discussion covered the history of mobile generations, the promise of optical wireless communications (OWC), and the disruptive role of LiFi. Professor Haas conveyed the importance of the broader societal value of building truly inclusive, trustworthy, and resilient networks.
Looking Back to Look Forward: What Defines a Generation?
Professor Haas suggested that optical wireless communications may leave a defining legacy on 6G. For him, 6G is not simply about faster connectivity. It represents a paradigm shift centred on inclusion, security, low carbon footprint, trustworthiness, and resilience. Around 60% of the global population remains unconnected, and 6G must address this digital divide. At the same time, the networks of the future will need to support not only humans but also robots, machines, and autonomous systems, which demand both resilient infrastructure and trustworthy communications.
Yet 6G will not be defined by a single technology. Professor Haas stressed the importance of integrating multiple wired and wireless interfaces into ‘networks of networks.’ Today’s landscape is fragmented, with Wi-Fi, 4G, 5G, Bluetooth, ZigBee, LoRa, and many more co-existing. Technically, integration is possible because they all transmit packet data, but commercial barriers often stand in the way.
Progress in Optical Wireless Communications Matters
Optical wireless communication is uniquely suited to the needs of the future. By transmitting data using light, OWC unlocks a vast, unlicensed spectrum, providing unprecedented capacity. It also offers enhanced security, as light cannot penetrate walls, reducing interception risks. Moreover, it enables more efficient energy use by avoiding the waste associated with forcing signals through obstacles using brute-force high power. These qualities make OWC and LiFi powerful complements to existing radio-based technologies, especially indoors, where most data traffic originates and terminates.
The societal value of OWC is equally important. Beyond indoor networking, optical wireless is already used in satellite constellations, providing secure inter-satellite links and satellite-to-ground communication. Its directionality and low divergence also make it ideal for drones, aerial platforms, and underwater vehicles where radio struggles and acoustics fall short. Optical free-space communication is also emerging as an alternative to millimetre wave in fixed wireless access. In Professor Haas’s words, OWC provides connectivity everywhere: in space, in the air, on the ground, and sub-sea.
Looking further ahead, he noted that today’s OWC systems convert optical signals into electrical ones, creating bandwidth limitations. Researchers are therefore pushing toward all-optical transmission and reception, which could ultimately extend to all-optical computing and quantum communications. He envisions a future where these worlds converge, driving a transformative wave of digital connectivity.
Also Read: TITAN Director Harald Haas at Berlin 6G Conference 2025
‘Usefulness per Bit’
A central idea Professor Haas introduced in his podcast segment of the course is “usefulness per bit.” Rather than measuring performance only in terms of bits per second, we should consider whether those bits are transmitted in the most resourceful way. Power, spectrum, and energy efficiency all feed into this new metric, and artificial intelligence will be the key enabler for balancing these trade-offs.
LiFi’s Journey: From TED Talk to Deployment
LiFi itself has travelled a remarkable journey since Professor Haas first introduced the concept in his 2011 TED talk. With its virtually limitless optical spectrum, LiFi could one day deliver terabit-per-second connectivity—essential to meet the exponential growth in data demand, which continues to increase by 40–60% annually even before factoring in machines and autonomous systems.
Professor Haas pointed to important progress in LiFi adoption. It is already deployed in defence operations, where its secure, undetectable links save lives in hostile environments and eliminate the need for heavy cabling. It is also used by intelligence agencies and embassies where Wi-Fi is banned, providing ultra-secure alternatives. Commercial applications are emerging as well. The next milestone will be smartphone integration, enabled by miniaturised “light antennas” and the arrival of the IEEE 802.11bb standard. Standards, he emphasised, are critical for interoperability and mass adoption.
Also Read: Professor Harald Haas at Free Space Optical Communication Workshop
The Spectrum of Light: Infrared, Visible, and Beyond
Professor Haas explained that LiFi can operate across a broad spectrum, from ultraviolet to visible to infrared. While infrared dominates current LiFi systems, visible light communications are still a major research frontier. They offer the possibility of dual-use infrastructure, where the same LEDs that provide lighting also deliver connectivity. The challenge lies in physics: most white light LEDs rely on blue light filtered through a phosphor, which slows the modulation speed and reduces data capacity.
Thanks to the short wavelength of light, LiFi can provide centimetre and even sub-centimetre positioning accuracy, which is invaluable for robotics and autonomous systems. This sensing capability, Professor Haas argued, is a vital complement to AI. More data about the environment means smarter resource allocation, better optimisation, and more autonomous interaction between connected systems.
Looking ahead, Professor Haas envisions two breakthroughs. Commercially, he hopes smartphone manufacturers will take a bold leap beyond incremental updates—embedding LiFi to deliver 10–100 gigabit connectivity and enable immersive applications like holographic displays. Technically, his dream is to see the “grid of beams” LiFi concept come to life: ceilings filled with hundreds of agile light beams that seamlessly switch to deliver terabit indoor connectivity without the need for complex beam steering.
TITAN is part of the Federated Telecoms Hubs (FTH) alongside CHEDDAR, HASC, and JOINER. Together, we conduct world-leading R&D and create a new knowledge-sharing framework, roadmap technology, develop skills, and engage with standards while instilling a commercialisation-focused mindset across academia.
If you have any questions about the research discussed in this article, please contact titan-enquiries@eng.cam.ac.uk.
