THz – to be or not to be in 6G?

With 5G still to deliver on its promises, and mm-wave bands largely underutilised in comparison with the Sub-7GHz range, the research community is already investigating the next generation of communication technology. The 6G specifications are expected to be developed and released around 2026 to 2027 and at the moment it is challenging to provide a clear and concise vision for 6G.

However, three things about 6G appear to be certain:

• 6G is expected to be more capable, intelligent, reliable, scalable and power efficient, satisfying all the requirements that cannot be realised at present with 5G
• 6G will employ a combination of technologies already used in 5G and other previous generation wireless networks, as well as new technologies that were either deemed too immature for 5G or will be adopted or developed specifically for 6G
• 6G will most likely continue the trend of using higher and higher carrier frequencies beyond the mm-waves through THz bands and up to visible light to provide high-capacity point-to-point communication with an aim to achieve spectral efficiency five times greater than 5G

6G will inevitably continue the expansion into higher frequencies, with a 100 to 300GHz range being considered as the first opportunity window where a number of services for radio astronomy, satellite earth exploration, mobile satellite and inter-satellite already allocated between in the 141.8 to 275GHz band. Federal Communication Commission (FCC10) has designated 21.2GHz of spectrum for unlicensed use in the 116 to 123GHz, 174.8 to 182GHz, 185 to 190GHz and the 244 to 246GHz bands.

KPIs of 6G

The basic 6G requirements for peak data rate are expected to be 50x that of 5G, with the user data speed experience at least 10 times better than that with 5G networks. Additionally, 6G is to offer much higher area traffic capacity and connect even greater number of devices than 5G. With even lower latency and much improved reliability, 6G will truly address the needs of autonomous mobility, industrial automation and robotics. A detailed comparison of current 5G and expected 6G KPIs is provided in the table below.

Table 1. KPI comparison of 5G and 6G

THz as a key enabler of 6G

Achieving this next step in wireless communications evolution will require much better understanding of technology limitations compared to previous generations: 3G, 4G and 5G. There are a number of key enablers that the success of 6G will rely on. For the purpose of this article, we will concentrate only on the enablers that expand and unlock additional spectrum bands for the purpose of wireless communications.

While there are already plans to extend the upper limit of 5G to 71GHz, the studies of 6G focus on upper millimetre wave bands (mm-waves), also known as sub-THz, with frequencies ranging from 100 to 300GHz. This band will most likely be the most interesting band for research on new wireless communication systems. One thing to note however is that 6G will not go about providing enhancements over 5G by just employing new parts of the spectrum, it will do so by utilising legacy and new bands in a seamless and dynamic way to provide the required quality of service for the given use cases.

For more information on 6G from Farran, visit the original version of this article here.