The future of cellular data transfer may lie in “bending” light beams in the air to deliver 6G wireless networks at lightning-fast speeds – bypassing the need for line of sight between transmitter and receivers.
In a new study published March 30 in the journal Nature Communications Engineeringresearchers explained how they developed a transmitter that can dynamically adjust the waves needed to support future 6G signals.
The most advanced cellular communication standard is 5G. It is expected to be thousands of times faster, 6G will begin to be implemented in 2030, according to the GSMA commercial entity. Unlike 5G, which operates primarily in bands below 6 gigahertz (GHz) in electromagnetic spectrum, 6G is expected to operate in subterahertz (THz) between 100 GHz and 300 GHz, and in the THz bands — just below infrared. The closer this radiation is visible light, the more likely the signals will be blocked by physical objects. A major challenge with high-frequency 5G and future 6G is that signals need a direct line of sight between a transmitter and receiver.
But in experiments, scientists have shown that it is possible to effectively “bend” high-frequency signals around obstacles like buildings.
“This is the world’s first curved data link, a critical milestone in realizing the 6G vision of high data rate and high reliability,” he said Eduardo Cavaleiroco-author of the study and professor of electrical and computer engineering at Rice University, in a declaration.
Related: Scientists create light-based semiconductor chip that will pave the way for 6G
O photonsor particles of light, which make up THz radiation in this region of the electromagnetic spectrum generally travel in straight lines, unless space and time are distorted by massive gravitational forces – the kind that black holes exercise. But researchers discovered that self-accelerating beams of light – demonstrated for the first time in 2007 survey — form special configurations of electromagnetic waves that can bend or bend to one side as they move through space.
By designing transmitters with patterns that manipulate the strength, intensity and timing of signals carrying data, researchers created waves that worked together to create a signal that remained intact even if its route to a receiver was partially blocked. They discovered that a beam of light can be formed that matches any object in its path, shuffling the data into an unlocked pattern. So, although the photons still travel in a straight line, the THz signal effectively curves around an object.
Towards a 6G future
While bending light without the power of a black hole isn’t new research, what’s significant about this study is that it could make 6G networks a practical reality.
5G millimeter wave (mmWave) currently offers the fastest network bandwidth, occupying the highest 5G radio frequencies between 24 GHz and 100 GHz of the electromagnetic spectrum to provide theoretical maximum download speeds of 10 to 50 gigabits (billions of bits) per second. THz rays sit above mmWave at a frequency between 100 GHz and 10,000 GHz (10 THz), which is necessary to provide data transfer speeds of one terabit per second – nearly 5,000 times faster than average 5G speeds in the US.
“We want more data per second”, Daniel Mittlemanprofessor at the Brown School of Engineering, said in a declaration. “If you want to do that, you need more bandwidth, and that bandwidth simply doesn’t exist using conventional frequency bands.”
But because of the high frequencies at which they operate, both 5G mmWave signals and future 6G signals need a direct line of sight between a transmitter and a receiver. But by virtually delivering a signal along a curved trajectory, future 6G networks would not need buildings covered in receivers and transmitters.
However, a receiver needs to be within the near-field range of the transmitter for signal bending to work. When using high-frequency THz rays, that means about 10 meters of distance, which isn’t good for citywide 6G, but could be practical for next-generation Wi-Fi networks.
“One of the main questions everyone asks us is how much can you bend and how far,” Mittleman said. “We’ve made rough estimates of these things, but we haven’t quantified them yet, so we’re hoping to map them.”
Although the bending of THz signals holds great promise for future 6G networks, the use of THz spectrum is still in its infancy. With this study, scientists said we are one step closer to creating wireless cellular networks with unparalleled speeds.
