In the era of information, the green services of content-centric IoT are expected to offer users the better satisfaction of Quality of Experience (QoE) than that in a conventional IoT. Nevertheless, the network traffic and new demands from IoT users increase along with the promising of the content-centric computing system. Therefore, the satisfaction of QoE will become the major challenge in the content-centric computing system for IoT users. In this article, to enhance the satisfaction of QoE, we propose QoE models to evaluate the qualities of the IoT concerning both network and users. The value of QoE does not only refer to the network cost, but also the Mean Opinion Score (MOS) of users. Therefore, our models could capture the influence factors from network cost and services for IoT users based on IoT conditions. Specially, we mainly focus on the issues of cache allocation and transmission rate. Under this content-centric IoT, aiming to allocate the cache capacity among content-centric computing nodes and handle the transmission rates under a constrained total network cost and MOS for the whole IoT, we devote our efforts to the following two aspects. First, we formulate the QoE as a green resource allocation problem under the different transmission rate to acquire the best QoE. Then, in the basis of the node centrality, we will propose a suboptimal dynamic approach, which is suitable for IoT with content delivery frequently. Furthermore, we present a green resource allocation algorithm based on Deep Reinforcement Learning (DRL) to improve accuracy of QoE adaptively. Simulation results reveal that our proposals could achieve high QoE performance for content-centric IoT.

In recent years, the Metaverse has gained attention as a hub for technological revolution. However, its main platform suffers from issues like low‐quality content and lackluster virtual environments, leading to subpar user experiences. Concerns arise from declining interest in NFTs and failed virtual real estate ventures, casting doubt on the Metaverse's future. Artificial intelligence generated content (AIGC) emerges as a key driver of Metaverse advancement, using AI to create digital content efficiently and affordably. AIGC also enables personalized content, enhancing the Metaverse. This paper examines the link between the Metaverse and AIGC, exploring AIGC's applications, underlying technologies, and future challenges. It reveals that while AIGC shows promise for improving the Metaverse, its technologies must better align with development needs to deliver immersive experiences.

With the rapid advancement of artificial intelligence (AI) technology, the Internet of Vehicles (IoV) is becoming increasingly important in intelligent transportation systems (ITSs). At the same time, large language models (LLMs) and generative AI (GenAI) are gradually playing significant roles in the IoV. Multimodal LLMs (MLLMs) are models capable of integrating multiple modalities of information, enhancing the environmental perception capabilities of the IoV. GenAI can generate highly complex virtual driving scenarios, which are used to test and optimize intelligent driving algorithms, reducing the risks and costs of real-world road testing. Embodied AI can interact with the environment and make decisions, and can learn in the simulated environments that are provided by GenAI. To address issues like low correlation of multimodal data, high-uncertainty of driving environment, and insufficient intelligence in the IoV, this article proposes a perception and decision-making system empowered by embodied AI. First, we utilize a transformer to achieve multimodal data fusion integrated with vehicle-to-vehicle (V2V) data. Second, the MLLM analyzes the situation based on driving intentions, communication conditions, and the perceived environmental expressions. Finally, the MLLM makes the optimal decisions and adjustments based on the analysis. The experimental results show that the integration of V2V enables the IoV to more comprehensively perceive a complex driving environment. The MLLM can empower the IoV to make accurate decisions in high-uncertainty scenarios, significantly improving route completion rates.

Proactive caching in 6 G cloud-edge collaboration scenarios, intelligently and periodically updating the cached contents, can either alleviate the traffic congestion of backhaul link and edge cooperative link or bring multimedia services to mobile users. To further improve the network performance of 6 G cloud-edge, we consider the issue of multi-objective joint optimization, i.e. , maximizing edge hit ratio while minimizing content access latency and traffic cost. To solve this complex problem, we focus on the distributed deep reinforcement learning (DRL)-based method for proactive caching, including content prediction and content decision-making. Specifically, since the prior information of user requests is seldom available practically in the current time period, a novel method named temporal convolution sequence network (TCSN) based on the temporal convolution network (TCN) and attention model is used to improve the accuracy of content prediction. Furthermore, according to the value of content prediction, the distributional deep Q network (DDQN) seeks to build a distribution model on returns to optimize the policy of content decision-making. The generative adversarial network (GAN) is adapted in a distributed fashion, emphasizing learning the data distribution and generating compelling data across multiple nodes. In addition, the prioritized experience replay (PER) is helpful to learn from the most effective sample. So we propose a multivariate fusion algorithm called PG-DDQN. Finally, faced with such a complex scenario, a distributed learning architecture, i.e. , multi-agent learning architecture is efficiently used to learn DRL-based methods in a manner of centralized training and distributed inference. The experiments prove that our proposal achieves satisfactory performance in terms of edge hit ratio, traffic cost and content access latency.

Federated Learning (FL) is a promising distributed machine learning framework that allows clients to collaboratively train a global model without data leakage. The synchronous FL suffers from the inefficient training caused by the slow-speed clients, which are called stragglers. Though asynchronous FL can well address the efficiency challenge, it induces massive system overheads and model degradation. As a framework considering the trade-off between synchronous and asynchronous FL, semi-asynchronous FL gains increasing attention. However, when clients' resources become a bottleneck, an unfair client scheduling may degrade global training accuracy and increase system overheads, especially in heterogeneous environments. In this paper, we propose Libra, which is a new FL framework aiming to achieve fair client scheduling in semi-asynchronous FL mode. Libra restricts devices that train overly fast according to the model discrepancy. Furthermore, it selects stale local models according to the number of participating in FL training by clients. Additionally, Libra conducts a biased client selection while considering clients' resources and local losses. The experimental results show that Libra outperforms other baselines in terms of convergence accuracy, system overhead, and fairness of client participation. We also conduct an ablation study to further prove the effectiveness of Libra. In brief, Libra can achieve fair client scheduling and reduce inefficient local updates.

With the proliferation of intelligent applications, mobile devices are increasingly handling computation-intensive tasks but often struggle with limited computing power and energy resources. Mobile Edge Computing (MEC) offers a solution by enabling these devices to offload computation-intensive tasks to resource-rich edge servers, thus reducing processing latency and energy consumption. However, existing task-offloading strategies often neglect critical security concerns. In this paper, we propose a security-aware task-offloading framework that utilizes Deep Reinforcement Learning (DRL) to solve these challenges. Our framework is designed to minimize the latency of task accomplishment and energy consumption while ensuring data security. We model system utility as a Markov Decision Process (MDP) and design a Proximal Policy Optimization (PPO)-based algorithm to derive optimal offloading strategies. Experimental results demonstrate that the proposed algorithm outperforms traditional methods regarding task execution latency and energy consumption.