The Telecom Regulatory Authority of India (TRAI) has recommended the creation of a TeraHertz Experimental Authorisation (THEA) for the 95 GHz to 3 THz spectrum. This proposal aims to drive innovation by facilitating research, testing, and trials and enabling the sale of experimental devices within this high-frequency range.
The authorisation, costing Rs. 1,000, should be available to Indian entities such as academic institutions, government bodies, TSPs, and tech parks. It should be valid for five years with an option for extension, the regulator proposed.
“THEA would help experimenters to evaluate the performance of products in the TeraHertz band in the conception, development and design stages which would, in turn, pave a path to ascertain the technical viability of technologies and services built on the TeraHertz spectrum,” the TRAI statement released on Wednesday said.
In December 2022, the Department of Telecommunications (DoT) requested the telecom regulator to provide recommendations on its proposal for opening and de-licensing the use of certain unused or limitedly used TeraHertz Spectrum for demand generation and experimentation.
The proposal included new "Spectrum-Terahertz Applications Licenses" and the delicensing of specific bands for unlicensed use, including the 77-81 GHz band for automotive radar. TRAI then issued a consultation paper in September 2023, gathered feedback from 17 stakeholders, held discussions, and released its final recommendations on August 21.
Additionally, the regulator recommended exempting certain frequency bands (116-123 GHz, 174.8-182 GHz, 185-190 GHz, and 244-246 GHz) from authorisation and assignment requirements.
TRAI also proposed opening the 77-81 GHz frequency range for automotive radar systems in India, enhancing vehicle safety. These radars, including long-range and short-range types, help detect obstacles, monitor blind spots, and provide collision warnings, significantly improving driver awareness and safety. Internationally, similar radar systems are already used to enhance road safety through various applications like lane departure and parking aids.
What is the TeraHertz spectrum and what are its use cases?
The radio spectrum spans from 3 Hz to 3,000 GHz. Lower frequencies travel long distances but carry less data, while higher frequencies carry more data over shorter distances. Mid-range frequencies (300 MHz to 6 GHz) balance distance and capacity, making them ideal for mobile and wireless communication services. The TeraHertz band, ranging from 100 GHz to 3,000 GHz, extends beyond the frequencies currently used by mobile phones and Wi-Fi.
Effective radiation could be produced with high-speed transistors at lower microwave frequencies and with semiconductor lasers at higher visible frequencies. Thus the ‘Tremendously high frequency’ band was once considered too high for electronics and too low for photonics, creating what is known as the TeraHertz gap for which very few practical technologies could be seen.
However, ongoing research into the TeraHertz band has revealed promising potential and future applications.
“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,” the recommendations said.
The recommendations paper also outlined that other potential uses for the spectrum include high-capacity applications such as high-resolution 3D imaging holography, sensing applications for health screening and product inspection, high-precision tasks like robotic assembly and accurate stocktaking, and short-range applications for closely spaced devices in factories and offices.
