To ensure the access security of 6G, physical-layer authentication (PLA) leverages the randomness and space-time-frequency uniqueness of the channel to provide unique identity signatures for transmitters. Furthermore, the introduction of artificial intelligence (AI) facilitates the learning of the distribution characteristics of channel fingerprints, effectively addressing the uncertainties and unknown dynamic challenges in wireless link modeling. This paper reviews representative AI-enabled PLA schemes and proposes a graph neural network (GNN)-based PLA approach in response to the challenges existing methods face in identifying mobile users. Simulation results demonstrate that the proposed method outperforms six baseline schemes in terms of authentication accuracy. Furthermore, this paper outlines the future development directions of PLA.

The research of three-dimensional integrated communication technology plays a key role in achieving the ubiquitous connectivity, ultra-high data rates, and emergency communications in the sixth generation (6G) networks. Aerial networking provides a promising solution to flexible, scalable, low-cost and reliable coverage for wireless devices. The integration of aerial network and terrestrial network has been an inevitable paradigm in the 6G era. However, energy-efficient communications and networking among aerial network and terrestrial network face great challenges. This paper is dedicated to discussing green communications of the air-ground integrated heterogeneous network (AGIHN). We first provide a brief introduction to the characteristics of AGIHN in 6G networks. Further, we analyze the challenges of green AGIHN from the aspects of green terrestrial networks and green aerial networks. Finally, several solutions to and key technologies of the green AGIHN are discussed.

To meet the booming development of diversified services and new applications in the future, the fifth-generation mobile communication system (5G) has arisen. Resources are increasingly scarce in the dynamic time-varying of 5G networks. Allocating resources effectively and ensuring quality of service (QoS) requirements of multi-services come to be a research focus. In this paper, we utilize effective capacity to build a utility function with multi-QoS metrics, including rate, delay bound and packet loss ratio. Taking advantage of opportunity cost (OC), we also propose a multi-QoS guaranteed resource allocation algorithm for multi-services to consider the future condition of system. In the algorithm, according to different business characteristics and the theory of OC, we propose different selection conditions for QoS users and best effort (BE) users to choose more reasonable resources. Finally, simulation results show that our proposed algorithm achieves superior system utility and relatively better fairness in multi-service scenarios.

Combining the performance advantages of both Wireless Local Area Network (WLAN) and Ad hoc network, Wireless Mesh Network (WMN) is characterized by large capacity, high rate and wide coverage . It has become an effective means for broadband wireless access and can be applied flexibly in various wireless environments . The wired connections between base stations in traditional cellular mobile communications systems can no longer satisfy the requirements for flexible deployment, low cost, high scalability and good reliability. The wireless Mesh architecture for IP - based base stations is thus introduced as an optional solution to support the flat and simplified next generation mobile communications networks . The key technologies used to support self- organization of IP - based base stations involve several aspects , including on - demand self- organization of base stations , joint radio resource scheduling mechanism, routing , security and network management.