Japanese terahertz project claims to end fiber microwave trade-off

The R&D community is already looking beyond 5G and considering future generation advances, though nobody is yet daring to refer to these as ‘6G’. Researchers in Japan say they have developed a transmitter which can achieve data rates of over 100Gbps over a single channel in the 300 GHz band, bringing the advantages of fiber to microwave links at last.

The team of scientists from two academic institutions (Hiroshima University and the National Institute of Information and Communications Technology) plus Panasonic, said the technology enables data rates “10 times or more faster” than 5G. The group claims that terahertz wireless links to satellites could make gigabit speeds available around the world, even on planes in flight.

“We usually talk about wireless data rates in megabits per second or gigabits per second,” said Minori Fujishima of Hiroshima University in a statement. “But we are now approaching terabits per second using a plain simple single communication channel. Fiber optics could offer ultra-high speed links to satellites as well, which can only be wireless. That could, in turn, significantly boost in-flight network connection speeds, for example. Other possible applications include fast download from content servers to mobile devices and ultrafast wireless links between base stations.”

The researchers said they used QAM to increase data rates, harnessing a frequency range from 290 GHz to 315 GHz. This band is unallocated at present, but falls within one of the ranges (275 MHz to 450 MHz)  which is scheduled to be discussed at World Radiocommunication Conference in 2019, where global allocations for 5G will top the agenda.

“Optical fibers are made of glass and the speed of light slows down in fibers,” Fujishima said. “That makes fiber optics inadequate for applications requiring real time responses. Today, you must make a choice between ‘high data rate’ (fiber optics) and ‘minimum latency’ (microwave links). You can’t have them both. But with terahertz wireless, we could have light-speed minimum-latency links supporting fiber optic data rates.”