There are many application scenarios for the 5G millimeter wave band. The millimeter wave uses beamforming technology and needs to be implemented based on the antenna array. As the millimeter-wave RF front-end is highly integrated and generally does not have an RF test interface, almost all test cases have to be performed in an OTA(Over-the-Air) environment. Therefore, a reliable and stable test environment is a necessary condition to ensure accurate test results. However, the OTA system is a complex measurement environment composed of multiple parts such as an anechoic chamber, radio frequency cables, a positioner etc. Each part may introduce the corresponding measurement uncertainty and be transferred to the final measurement results. In addition, millimeter-wave measurement has the characteristics of high frequency and high loss, and it is more difficult to ensure the reliability of the measurement comparing system at relatively low frequencies. Therefore, the study of the uncertainty of millimeter-wave OTA systems is of great significance. This article describes and analyzes the uncertainty of the millimeter wave OTA system, and illustrates it with a typical 5G millimeter wave OTA measurement environment.

With the release of 5G license issued by the Ministry of Industry and Information Technology, there will be large area of construction and application of 5G network, therefore, the infrastructure of 5G network is more and more important to ensure the normal operation of the entire network. The standardization work of one of important infrastructure, which is 5G power, was analyzed in this paper, including the background information of establishing this Work Item, whole developing process and core technical points of the Recommendation ITU-T 1210 “Sustainable power-feeding solutions for 5G networks” that was published in December 2019. In addition, related standardization work in China was also introduced and standardization plan of 5G energy was described. This paper is aiming to provide a basis and support for 5G network energy designer, constructer, and standard developing experts.

according to structure of 5G network, this article made the analysis on the security risk points of 5G network,four security points are summarized: confidentiality and integrity of data, authenticity of user equipment, and availability of network functions. This article put forward suggestions to these security problems.

The electric power emergency communication system provides an important channel guarantee for real-time live broadcast of various emergencies and natural disasters. This article introduces the power emergency communication network structure, and focuses on key technologies and features such as 5G slicing. Based on the requirements of electric power emergency communication services, the application of 5G technology in electric power emergency communication is studied. Finally, a 5G technology-based power emergency communication network architecture solution is proposed, and the advantages of the application architecture are explained from the aspects of architecture characteristics, business flow, and security. This solution improves the reliable transmission capability of emergency scenes when broadcasting multiple high-definition pictures, and meets complex and changing application environments.

As an indispensable basic support network, 5G synchronization network urgently needs to be promoted in technology and industrial development as soon as possible. Based on the analysis of the time synchronization requirement of 5G system, the necessity of solving 5G system synchronization based on high precision time synchronization ground network is analyzed, and a general network model of high precision synchronization is proposed. The key technologies such as high precision source, high precision synchronization transmission and high precision synchronization monitoring are mainly studied.

The development of 5G mobile communication technology provides more technical possibilities for the highspeed reaction and safe driving of driverless vehicles, and the key technologies of driverless vehicles include navigation and positioning, environmental awareness, path planning, stable traction control, anti-lock braking and automatic parking technology. The realization of the above key technologies requires sensors, GPS and Beidou satellite navigation system, RFID radio frequency technology and other information technology support. The rapid development of driverless vehicles makes it can be put into practical use faster, solve people’s daily production and life problems, and ensure people��s life and property safety.

High frequency is an application direction of wireless mobile communication and 5G. 3GPP has made lots of research and standardization work for high frequency in R15, R16 and R17. In this paper, based on 3GPP international standardization development, various use cases and deployment scenarios of high frequency are introduced in detail.Then the key technologies of 3GPP standardization, such as frame structure design, access design, large-scale antenna design and frequency domain configuration, are analyzed. Finally, this paper summarizes and prospects the contents of 5g high frequency related international standardization.

Different from traditional infrastructure, “new infrastructure” refers to the infrastructure construction focused on the technology side, mainly including 5G base station construction, UHV, intercity high-speed railway and urban rail transportation, new energy vehicle charging piles, big data centers, Artificial Intelligence and Industrial Internet.The seven major areas of the Industrial Internet involve many industrial chains. As the downward pressure on the economy has increased, many local governments and enterprises have also increased their financial pressures, and they have begun to promote “new infrastructure. ” The strategic significance of digital “new infrastructure” is analyzed, the dilemma of traditional industry digitization is explained, the relationship between 5G, cloud computing, and AI in “new infrastructure” is discussed, and the early application of 5G + cloud + AI is analyzed.

With the acceleration of 5G network deployment, the importance of 5G transport network sliceing management and control is increasingly prominent. This paper first introduces the standardization progress of transport network management and control technology, then analyzes the key points of transport network slicing management and control, puts forward the architecture of transport network slicing management and control, the modeling scheme of northbound interface, and analyzes the control process of network slicing, the introduction of AI to realize intelligent slicing operation and maintenance and other scenarios.

This paper discusses the technology and industrial development process of 5G optical transceiver module, and analyzes the advantages and disadvantages of four kinds of WDM technologies applied to 5G front-haul network, then it offers the suggestions of 5G optical transceiver module in the future.

This article introduces the typical architecture of 5G fronthaul WDM bearer. On this basis, it analyzes the implementation difference of the four types WDM technology solution and the current industry and standardization progress. Finally, it puts forward relevant suggestions for the development of 5G fronthaul WDM solution.

China Telecom and China Unicom have reached an agreement that they launch the plan and action of the co-construction and network sharing of 5G and its bearer network, which will run through the entire life cycle and lead to the globally largest scale inter-telco co-operation. The co-construction and sharing of the 5G bearer network are important parts of this plan and action. Based on the above scenario, this paper focuses on the requirements analysis for 5G bearer network, the bearer networking solutions, the construction progress of the bearer network and the key research actions on 5G bearer network in the next steps.

This paper analyzes major application scenario and network requirements, introduces evolved network architecture and enhanced technology of IP RAN for 5G backhaul, espacially network slicing, segment routing, EVPN and network intelligence, and relvant innovative practice in IP RAN of China Unicom.

This paper introduces the SPN architecture and technical features for 5G transport. It also analyzes the technical scheme of SPN-carrying 5G network slicing and MEC interconnecting.

The 5G-scale commercial and 5G + vertical industry applications are gradually developing, which will promote the development of 5G transport network related technologies, standards and industrialization. This article introduces the current status and progress of 5G fronthaul, mid-backhaul, and optical module-related technologies and standardization, and prospects for 5G transmission technology and future development.

In 2020, China will accelerate 5G network construction and 5G commercial development will enter the fast lane. At the same time, China will pay more attention to 5G and other new infrastructure construction, accelerating the promotion of 5G to play a positive role in improving quality and efficiency in the transformation and development of various industries. These new changes put forward higher requirements for 5G network construction, making it more urgent to plan and test 5G network by scenarios and to improve the corresponding indicator. This paper first focuses on the coverage, capacity and quality objectives that are most relevant to network planning and testing, explores and designs the key indicators of 5G network planning and testing, and then calculates the reference values of relevant indicators based on the actual 5G scenario business model, which provides an effective reference for 5G network planning and testing, and is of great significance to support the high-quality development of 5G network.

To clarify the understanding of new infrastructure, define 5G networks and data centers as new infrastructures, and strive for government policy support, this article discusses the concepts of infrastructures and new infrastructures. Based on the essential characteristics of infrastructure, this article analyzes the main challenges of 5G network and data center construction, then proposes measures for government to accelerate the construction.

System capacity (channel capacity) is an important factor to measure the communication capacity of wireless systems. Taking 5G network as the research object, this paper analyzes how to improve the system capacity in the case of massive MIMO from the aspect of beam management. Finally, this paper puts forward a new idea for using DenseNet for channel estimation.

The new generation of information networks promotes the rapid growth of digital economy. In the process of accelerating global digitization, fixed networks have become a strategic public infrastructure, and their development level is an important indicator for measuring the country's comprehensive strength. This paper describes the background,definition, development status, and trend of F5G, and provides suggestions on the development of F5G networks.

This paper discusses the usage scenarios, the key technologies and the standardization progress of artificial intelligence in 5G wireless network. Also, it investigates the challenges of AI in 5G wireless network and provides the recommendations.