Following the commercialization of 5G technologies, both academia and industry are initiating research activities to shape the next-generation communication system, namely 6G. Considering the general trend of successive generations of communication systems introducing new services with more stringent requirements, it is reasonable to expect 6G
to satisfy unprecedented requirements and expectations that 5G cannot meet. We expect that 6G will provide ultimate experience for all through hyper-connectivity involving humans and everything. In this white paper, we aim to provide readers with a comprehensive overview of various aspects related to 6G, including technical and societal
trends, services, requirements, and candidate technologies. The rest of this white paper is organized as follows:

O Section 1 introduces megatrends driving technology evolution towards 6G. 

O Section 2 discusses major services that have to be taken into account in developing 6G technologies. 

O Section 3 describes requirements to realize the expected services for 6G. They consist of performance requirements, architectural requirements, and trustworthiness requirements.

O Section 4 introduces candidate technologies that will be essential to satisfy the requirements for 6G, which currently include support of the terahertz band, novel antenna technologies, evolution of duplex technology, evolution of network topology, spectrum s
haring, comprehensive AI, split computing, and high-precision network. 

O Section 5 provides an initial expectation of the 6G timeline. We anticipate that the earliest commercialization could occur as early as 2028 while massive commercialization may emerge around 2030.

O Section 6 provides concluding remarks.