In a breakthrough that could revolutionize wireless communication, researchers have unveiled a new method of steering terahertz waves that allows them to bend around obstacles , rather than being blocked by them.
While cellular networks and Wi-Fi systems are more advanced than ever, they are also quickly reaching bandwidth limits. Scientists know that in the near future they will have to switch to much higher communication frequencies than those that current systems rely on, but before that happens, there are a number of obstacles standing in the way — literally — obstacles.
Researchers from Brown University and Rice University say they have taken another step closer to bypassing such solid obstacles as walls, furniture and even people — and they do it by bending light.
Advances in Terahertz Communications
In new research published in Communications Engineering , researchers describe how they are helping to solve one of the biggest challenges facing wireless communications. Current systems rely on microwave radiation to transmit data, but it has become clear that the future data transmission standard will use terahertz waves, which have 100 times the bandwidth of microwaves. One long-standing problem has been that, unlike microwaves, terahertz signals can be blocked by most solid objects, making a direct line of sight between transmitter and receiver a logistical requirement.
"Most people probably use a Wi-Fi base station that fills the room with wireless signals", — said Daniel Mittleman, a professor in the Brown School of Engineering and senior author of the study. "No matter where they go, they keep in touch. At the higher frequencies we're talking about here, you won't be able to do that anymore. Instead, it will be a directional beam. If you move, this beam will have to follow you to maintain communication, and if you move outside of the beam or something blocks that communication, you don't get any signal.
Researchers got around this , creating a terahertz signal that follows a curved path around an obstacle instead of being blocked by it.
«This is the world's first curved data channel, an important milestone in realizing the 6G vision of high data rates and high reliability», — said Edward Knightley, co-author of the study and professor of electrical and computer engineering at Rice University.
According to the researchers, the new method presented in the study could help revolutionize wireless communication and highlight the possibility of future wireless data networks operating at terahertz frequencies.
"We want more data per second." ;, — said Mittleman. "If you want to do that, you need more bandwidth, and that bandwidth just isn't there using conventional frequency bands.
New methods of signal transmission
In the study, Mittleman and his colleagues introduce the concept of self-accelerating beams. Rays — these are special configurations of electromagnetic waves that naturally bend or bend to one side as they travel through space. The beams were studied at optical frequencies, but are now being studied for terahertz communication.
The researchers used this idea as a starting point. They developed transmitters with carefully designed patterns so that the system could manipulate the strength, intensity and timing of the electromagnetic waves that were produced. With this ability to manipulate light, researchers make the waves work together more efficiently to maintain a signal when a solid object blocks part of the beam. Essentially, the light beam adapts to the jamming by scrambling data in patterns designed by the researchers into the transmitter. When one pattern is locked, data is passed to the next, and then to the next if it is locked. This keeps the signal connection completely intact. Without this level of control, when the beam is blocked, the system cannot make any adjustments, so the signal does not get through.
This effectively causes the signal to bend around objects unless the transmitter is completely blocked. If it is completely blocked, another method of transmitting data to the recipient will be required.
"Beam buckling doesn't solve all possible blocking problems, but it solves some of them, and it solves them in a way that is better than what others have tried,— said Gichem Gerbuha, who led the study as a doctoral student. at Brown, and is now an associate professor at the University of Missouri – Kansas City.
The researchers confirmed their findings through large-scale simulations and experiments, bypassing obstacles to maintain communication links with high reliability and integrity. The work builds on the team's previous research, which showed that terahertz data channels can bounce off walls in a room without losing too much data.
Practical applications and current research
Using these curved beams, researchers hope to one day make wireless networks more reliable, even in crowded or closed environments. This can result in a faster and more stable Internet connection in places like offices or cities where interference is common. However, before we get to that point, there is still a lot of fundamental research to be done and many challenges to overcome, as terahertz communication technology is still in its infancy.
«One of the key questions that we everyone asks, it's how much you can bend and how far», — said Mittleman. "We've made a rough estimate of these things, but we haven't quantified them yet, so we're hoping to map it out.