Following the large-scale 5G commercialization, major countries and regions in the world have launched 6G R&D to seize the dominance in the development of next-generation mobile communications. At present, IMT industry is actively discussing 6G vision and key technologies, but no final conclusion yet. This paper presents usage scenarios that 6G may provide in the future, the expected main key capability indicators, and the key technical directions that need to be considered to support the realization of typical scenarios and capability indicators. The paper also provides the analysis of the innovative potential technologies that IMT industry currently focuses on, such as the integration of artificial intelligence(AI) and wireless communication, the integration of sensing and communications, intelligent reconfigurable surfaces(RIS), Terahertz communications technology, and wireless network architecture. Those future research directions are proposed for the industry’s reference.
Radio waves can be used to“see”the physical world, implement sensing functions such as locating, detecting, imaging, and identifying objects. Obtaining information about the surrounding physical environment to form cyber world can help to explore communication capabilities and enhance user experience. 6G will integrate sensing and communication in a single system. In this regard, network sensing will also enable 6G as the intelligent network of things in the future. This paper introduces the concept of integrated sensing and communication (ISAC) and typical use cases, then discusses the research challenges of implementing ISAC in practice. Based on terahertz, two case studies are provided to illustrate how 6G ISAC can be used as a key technology for future UE and base station sensing.
As 5G goes into commercial use, 6G has increasingly become a research hotspot by academics and industries. The integrated air-space-terrestrial communication (IASTC) is regarded as an important key technology of 6G, due to its advantages such as expanding coverage and saving cost. In this paper, the system design and key technologies of 6G IASTC are studied. Firstly, the driving force of 6G IASTC is analyzed, then the basic concept of system design is discussed, and then the difficulties and challenges are analyzed. Finally, a series of key technologies for 6G IASTC are proposed and discussed in depth. The research of this paper will provide reference for future work on 6G, including key technology research, system design, standard promotion and also industrialization.
The performance impact of Reconfigurable Intelligent Surface (RIS) technology in the practical multi-cell scenarios is analyzed based on the passive characteristics of the RIS hardware. Based on the amplitude-frequency and phase-frequency response characteristics of RIS technology, this paper proposes a statistical model for RIS reflected signals, which is a uniformed methodology to model the behavior of RIS reflections for the signals at different frequency bands. In addition, a system level simulation is provided to evaluate the interferences related to RIS assisted communication systems in the multiple cell scenarios, and an analysis and outlook on the deployment requirements for RIS assisted communication are provided.
Terahertz (0.1~10 THz) communications are envisioned as a key technology for sixth generation (6G) wireless systems. The study of underlying THz wireless propagation channels provides the foundations for the development of reliable THz communication systems and their applications. This article provides a comprehensive overview of the study of THz wireless channels. First, the three most popular THz channel measurement methodologies, namely, frequency-domain channel measurement based on a vector network analyzer (VNA), time-domain channel measurement based on sliding correlation, and time-domain channel measurement based on THz pulses from time-domain spectroscopy (THz-TDS), are introduced and compared. Then, existing channel modeling methodologies are categorized into deterministic, stochastic, and hybrid approaches. Next, an in-depth review of channel characteristics in the THz band is presented. Finally, open problems and future research directions for research studies on THz wireless channels for 6G are elaborated.
Virtual Reality (VR) is an important scenario in the future 6G era, but traditional traffic models can no longer accurately describe the characteristics of VR. In this paper, a measurement-based study is reported for data collection and analysis of VR. Considering the differences between different types of VR traffic, we choose VR 3D panoramic video and VR online game for the research of basic traffic characteristics and traffic modeling. Basic traffic characteristics include the data rate, probability distribution of the packet length and packet interval for both uplink and downlink. In addition, a generalized deterministic arrival curve modeling scheme is proposed based on the cumulative arrival process and network calculus, and the parameter values of the arrival curve are deduced based on the measured data.
The application scenarios and technological development trends of 6G have gradually become more apparent with the advancement of research. To further promote the network towards automation, intelligence, and openness, edge cloud-network integration has been considered as an important direction for network architecture evolution. This paper first introduces the vision and drivers of 6G edge cloud-network integration, then proposes a reference architecture for deep edge nodes, and further elaborates on native artificial intelligence(AI) and cross-domain AI design. Finally, the challenges and suggestions brought by architectural innovation are analyzed.
This paper first introduces the architecture and function of the current definition of 5G user plane. Combined with the new service demand scenarios of 5G-A and 6G in the future, the driving force of user plane evolution is analyzed. Then, it reviews the research progress of user plane and its enhancement technology in the standard groups. Finally, it identifies and analyzes the key evolution trend of the user plane in the future, including deep integration with the edge, centralized and distributed collaboration, customization, and open sharing, etc., and provides a reference for further promoting the evolution of the user plane and helping the network to empower thousands of industries and industries.
The fifth-generation (5G) mobile networks will open the era of the internet of everything, and the sixth generation(6G) mobile networks will open a new era of “intelligent connectivity of everything and digital twins”, realizing a wide range of intelligent interconnection of people, machines and things. As 6G technology research starts, the attention of representative countries is increasingly shifting towards 6G. They initiated 6G vision research, technology research, standard research by developing strategic plans, financial support, 6G projects and global cooperation, so as to enhance the international competitiveness of the 6G industry. This paper analyzes the layout and characteristics of 6G research in China, the United States, Europe, Japan, South Korea, etc., and makes several relevant policy recommendations on how to promote high-quality 6G research.
With the evolution of mobile communication network, the sensing capability generated from mobile communication network will bring clear social value and economic benefit in many industries. For the transportation industry, its sensing capability can monitor moving vehicles in real time, improve road traffic efficiency, and provide more reliable assurance for autonomous driving in the future. For low-altitude security, it can monitor the airspace of a specific area and quickly detect unmanned aerial vehicles that intrude into a specific area. Harmonized communication and sensing proposed in 5G-Advanced, can build competitive sensing capabilities on cellular networks and greatly improve sensing accuracy and coverage by making innovations in high-isolation antennas, super-resolution sensing algorithms, and cooperative sensing technologies, which will open up new industry market space for mobile communication networks.
This paper designes a link-level simulation platform for integrated sensing and communication aiming at the rapid development of integrated sensing and communication technology and the demand for simulation verification. Also, it introduces the architecture and process of the simulation platform and the principle of joint estimation of range and speed of target. Besides, it illustrates the simulation platform’s signal generation module, wireless communication channel and sensing channel modeling, echo reception and parameter estimation. At last, the sensing performance of the simulation platform is evaluated by simulation, which proves the accuracy of the platform’s estimation of the sensing target.
With the development of smart cities, Internet of Vehicles (IoV), and Industrial Internet, mobile communications network services have an obvious upward trend. Large uplink broadband communication has become an important evolution direction of 5G-Advanced. This document greatly improves the uplink capability of 5G-Advanced networks in the time domain, frequency domain, space domain, and power domain, meeting the service requirements of the Industrial Internet. Innovative interference cancellation methods in the time domain enable more uplink transmission opportunities for TDD networks. In the frequency domain, the innovative full-spectrum flexible access mechanism introduces more uplink frequency resources. In the space domain, uplink multi-layer MIMO enhancement increases the number of concurrent uplink multi-user flows. In the power domain, a transmission mechanism for multiple terminals is proposed. This mechanism maximizes the effective power and makes full use of the diversity effect of the channel state to ensure stable uplink user experience.