Research activities in academia and industry worldwide towards the 6th generation (6G) mobile communication system have recently considerably gained momentum. In this overview we will highlight the anticipated 6G timeline and technology concepts which have to fulfil even more stringent requirements in comparison to 5G, such as ultra-high data rates, energy efficiency, global coverage and connectivity as well as extremely high reliability and low latency. One of the 6G technologies are sub-Terahertz and terahertz (THz) waves which have frequencies extending from 0.1 THz up to 10 THz and fall in the spectral region between microwave and optical waves. The prospect of offering large contiguous frequency bands to meet the demand for highest data transfer rates up to the terabit/sec range make it a key research area of 6G mobile communication. These efforts require an interdisciplinary approach, with close interaction of high-frequency semiconductor technology for RF electronics but also including alternative approaches using photonic technologies. The THz region also shows great promise for many applications areas ranging from imaging to spectroscopy and sensing. To fully exploit the potential of this frequency range it is also crucial to understand the propagation characteristics for the development of the future communication standards by performing channel measurements. We will highlight the characteristics of channel propagation in this frequency region and present new results from channel measurements at 158 GHz and 300 GHz.