This Special Issue originates from the international conference EuCNC 2020 (European Conference on Networks and Communications), which was planned to be held in June 2020 in Dubrovnik (Croatia), but due to the COVID-19 pandemic was changed to an Online Conference. The Technical Programme Chairs of the conference have selected the best papers and invited authors to submit an extended version of their paper, by at least one third of their length. Only the top ranked papers were invited to this Special Issue, in order to fulfil its purpose. The main target was to collect and present quality research contributions in the most recent activities related to systems and networks beyond 5G, already presenting ideas for 6G. Through this Special Issue, the state-of-the-art is presented and the new challenges are highlighted, regarding the latest advances on systems and network perspectives that are already being positioned beyond 5G, bridging as well with the evolution of 5G, including applications and trials. Therefore, the motivation for this Special Issue is to present the latest and finest results on the evolution of research of mobile and wireless communications, coming, but not exclusively (since EuCNC is a conference open to the whole research community), from projects co-financed by the European Commission within its R&D programmes.

本特刊源自计划于2020年6月在杜布罗夫尼克（克罗地亚）举行的国际会议EuCNC 2020（欧洲网络和通信会议），但由于COVID-19大流行改为在线会议。会议的技术计划主席已选出最佳论文，并邀请作者提交其论文的扩展版本，其长度至少为论文长度的三分之一。为了实现其目的，仅邀请排名靠前的论文参加本期特刊。主要目标是在与5G以外的系统和网络相关的最新活动中收集和展示高质量的研究成果，已经提出了6G的想法。通过本期特刊介绍了最新技术，并重点介绍了新的挑战，关于已经定位于5G之外的系统和网络前景的最新进展，以及与5G演进（包括应用和试验）的桥梁。因此，本期特刊的动机是提供有关移动和无线通信研究进展的最新，最好的结果，但并非排他性的（因为EuCNC是对整个研究界开放的会议），来自以下项目：由欧盟委员会在其研发计划内提供资金。