Using Terahertz Networks for Speed and Reliability in Communications

Paving the Way to 6G with Terahertz

Imagine a city where autonomous vehicles navigate safely, communicating instantly to avoid collisions, while remote surgery is being performed across continents with zero room for delay. Both services—which require high-speed data for cars (eMBB) and ultra-reliable low-latency communications (URLLC) for surgery—must coexist in the same network without interfering with one another. 

Wireless communication is already shaping our daily lives, from video calls with family to online learning and connected cars. But with each new generation of technology, the demand for faster, more reliable, and energy-efficient connections increases. The upcoming 6G networks are expected to support not only smartphones, but also self-driving cars, immersive virtual reality, industrial robots, and smart cities.

The challenge is that current 5G networks struggle to deliver speed and reliability at the same time, particularly in dense, multi-cell environments such as downtown Montreal or Toronto.

A promising solution to meet this demand is to move beyond today’s frequency bands and explore the terahertz (THz) spectrum, which offers enormous bandwidth and the potential for ultra-high data rates. However, THz signals face a major challenge: they are easily blocked by walls, objects, even people, and they lose signal quickly over distance. This is where my research comes in.

Intelligent Surfaces as Signal Mirrors

Imagine being in a room with mirrors: light can reach dark corners by reflecting off the mirrors. Similarly, in wireless networks, we can guide THz signals by placing special “mirrors” called Intelligent Reconfigurable Surfaces (IRSs). These are thin, low-power panels made up of many tiny elements that can adjust how they reflect signals.

By deploying IRSs on buildings, drones, even satellites, we can redirect wireless signals to ensure that every user maintains a strong connection, even when the direct path is blocked. This is especially crucial for applications that require uninterrupted communication, such as remote surgery, automated factories or autonomous vehicles.

My Research Contributions

During my Ph.D. at ÉTS, I investigated how to make IRS-assisted THz networks practical and efficient. My main contributions include:

• New Channel Models: I developed mathematical models that provide a better understanding of how THz signals behave when reflected by IRSs, especially when the system has imperfect information about the environment.
• Smart Resource Allocation: I designed algorithms based on matching theory, a concept similar to that used by dating applications to pair compatible people, in order to optimally match users, IRSs and transmitters. This ensures that users with the highest needs get the best possible connection.
• Balancing Services: Modern networks must serve both high-speed users (eMBB) and ultra-reliable users (URLLC), such as emergency communications. I proposed solutions that balance these two requirements, maximizing speed while guaranteeing reliability.
• Future Networks Integration: I extended the study to hybrid networks combining terrestrial IRSs, high-altitude platforms, such as balloons or drones, and Low-Earth Orbit satellites. This multi-layer design offers global coverage and resilience, essential for the future of 6G.

Why It Matters

The impact of this research goes far beyond academic curiosity:

• Better Connectivity: It can help eliminate coverage “blind spots” in dense urban areas or remote regions.
• Reliability for Critical Services: It ensures the uninterrupted operation of applications such as remote healthcare and connected vehicles.
• Energy Efficiency: IRSs consume far less power than traditional antennas, making networks greener.
• Scalability: The methods developed can support the massive number of devices expected in 6G networks and the Internet of Things (IoT).

Future Directions

The next steps include experimenting with active IRSs that can amplify signals, integrating machine learning to make IRSs self-adaptive, and conducting large-scale simulations combining terrestrial, aerial, and satellite deployments. These innovations will accelerate the path toward a connected world where 6G networks can support every aspect of our digital lives.

Additional Information

For further information on our techniques, evaluations and simulation settings, please refer to the full study: “JPUSA in Coexistence of eMBB and URLLC Services in Multi-Cell IRS-Assisted Terahertz Networks”.