India gets behind terahertz push for 6G

India's telecom regulator is urging the government and operators to explore the use of terahertz spectrum for new 6G technologies and services.  

"The government should introduce a new experimental authorization for the spectrum in the 95 GHz to 3 THz range termed as 'Tera Hertz Experimental Authorization' [THEA]," said a press release issued by the Telecom Regulatory Authority of India (TRAI).

 THEA's primary objective would be to promote "research and development (R&D), indoor and outdoor testing, technology trial, experimentation and demonstration in the 95 GHz to 3 TZ range," said TRAI. Any Indian entity, including academic institutes, R&D labs, telecom service providers, central or state government bodies and original equipment makers, will be eligible for an authorization covering a maximum of five years.  

Like other parts of the global telecom industry, TRAI believes the terahertz frequency band is likely to play a crucial role in upcoming 6G technology. "The high-speed point-to-point wireless data link is an emerging usage of Terahertz radiation," said TRAI in its recommendations. "For this reason, communications in the Terahertz band are expected to play a pivotal role in the upcoming 6th generation (6G) of wireless mobile communications, enabling ultra-high bandwidth communication paradigms."

"The large Terahertz bandwidths and massive antenna arrays, combined with the inherent densification caused by machine-type communications, will result in an enhanced communication system performance," added TRAI. 

"TRAI is laying the groundwork for India to become a global powerhouse in testing as well as in research and development so that we are fully geared to produce cutting-edge technologies and services in the near future," said TV Ramachandran, the president of the Broadband India Forum (BIF), in his response to the announcement.

The recommendations are a further sign of India's interest in shaping the 6G standard, likely to appear around 2030. Vocal about its ambitions, India has already set up the Bharat 6G Alliance to actively contribute to 6G activities. It has also collaborated with several organizations, including the US-based Next G Alliance, Europe's 6G Smart Networks and Services Industry Association (6G IA) and the 6G Flagship of Oulu University as it tries to position itself as a "global leader" in digital infrastructure and innovation. 

The terahertz band has been attracting attention as an option for 6G deployment, with the European Telecommunications Standards Institute (ETSI) recently releasing two reports on the band and the use cases it could support. 

"Due to their shorter wavelengths, Terahertz communication systems can support higher link directionality, are less susceptible to free-space diffraction and inter-antenna interference, can be realized in much smaller footprints, and possess a higher resilience to eavesdropping," said the TRAI report.

Even so, there are several challenges that would need to be addressed before terahertz could be feasible for widespread usage. Above all, signal propagation is generally weak in higher frequency bands and power limitations can also result in poor coverage, said TRAI.