Milestones of Wireless Communication Networks and Technology Prospect of Next Generation (6G)

Since around 1980, a new generation of wireless technology has arisen approximately every 10 years. First-generation (1G) and second-generation (2G) began with voice and eventually introduced more and more data in third-generation (3G) and became highly popular in the fourth-generation (4G). To increase the data rate along with low latency and mass connectivity the fifth-generation (5G) networks are being installed from 2020. However, the 5G technology will not be able to fulfill the data demand at the end of this decade. Therefore, it is expected that 6G communication networks will rise, providing better services through the implementation of new enabling technologies and allowing users to connect everywhere. 6G technology would not be confined to cellular communications networks, but would also comply with non-terrestrial communication system requirements, such as satellite communication. The ultimate objectives of this work are to address the major challenges of the evolution of cellular communication networks and to discourse the recent growth of the industry based on the key scopes of application and challenges. The main areas of research topics are summarized into (i) major 6G wireless network milestones; (ii) key performance indicators; (iii) future new applications; and (iv) potential fields of research, challenges, and open issues.