With the rapid development of cloud computing, network architectures are moving towards distributed computing, which performs data processing at edge nodes to reduce latency, enabling more efficient and scalable network services. Nevertheless, this shift introduces significant security challenges due to the heterogeneity of communications protocols and the vulnerabilities of edge devices. To effectively secure these distributed networks, it is essential to perform multiple traffic analysis tasks, e.g. Network Intrusion Detection, Encrypted Traffic Classification, and Application Traffic Classification. However, existing methods have limited generic feature extraction and require the deployment of multiple models to solve multiple tasks, which exceeds the resource capacity of edge nodes. To address these challenges, we introduce a Lightweight Multitask Traffic Analysis Framework LiMTa, which novelly proposes a traffic pre-training method, FreqRec, and a lightweight multi-task model fine-tune method, MT-Adapter. FreqRec enables high-level semantic feature extraction by reconstructing the frequency features of traffic samples, and MT-Adapter efficiently performs multiple tasks by computing the pre-trained model only once. Experimental results demonstrate that our approach achieves state-of-the-art (SOTA) performance on six traffic analysis tasks. Moreover, the MT-Adapter module only fine-tunes a small number of parameters, accounting for only 6.37% of the pre-trained model’s parameters, and achieves the same result as the full fine-tuning. Compared to full fine-tuning, LiMTa reduces the time cost by 50.9% and the space cost by 57.4% in six edge traffic analysis tasks.

The combination of self-supervised learning and adversarial training (AT) can significantly improve the adversarial robustness of self-supervised models. However, the robustness of self-supervised adversarial training (self-AT) still lags behind that of state-of-the-art (SOTA) supervised AT (sup-AT), even though the performance of current self-supervised learning models has already matched or even surpassed that of SOTA supervised learning models. This issue raises concerns about the secure application of self-supervised learning models. The inclusion of adversarial training turns self-AT into a challenging joint optimization problem, and recent studies have shown that the data augmentation methods necessary for constructing positive pairs in self-supervised learning negatively impact the robustness improvement in self-AT. Inspired by this, we propose 3SAT, a simple self-supervised adversarial training framework. 3SAT conducts adversarial training on original, unaugmented samples, reducing the difficulty of optimizing the adversarial training subproblem and fundamentally eliminating the negative impact of data augmentation on robustness improvement. Additionally, 3SAT introduces a dynamic training objective scheduling strategy to address the issue of model training collapse during the joint optimization process when using original samples directly. 3SAT is not only structurally simple and computationally efficient, reducing self-AT training time by half, but it also improves the SOTA self-AT robustness accuracy by 16.19\% and standard accuracy by 11.41\% under Auto-Attack on the CIFAR-10 dataset. Even more impressively, 3SAT surpasses the SOTA sup-AT method in robust accuracy by a significant margin of 11.25\%. This marks the first time that self-AT has outperformed SOTA sup-AT in robustness, indicating that self-AT is a superior method for improving model robustness.

The signaling collected in mobile communication networks can intuitively display the operational status of the system, which can use to locate faults. This paper proposes a novel signaling-based end-to-end fine-grained troubleshooting (simFGT) method for 6G NTN networks. First, the signaling collected from the core network is analyzed to extract multidimensional KPIs and attribute information. Second, a root cause localization algorithm is employed for fine-grained fault localization. Third, a lightweight data-driven ensemble learning method is adopted, with the abnormal KPI of the localized root cause node as inputs, and precise fault classification is achieved through data-driven weight optimization. Experiments results show that the proposed lightweight SimFGT method achieves best balance between precision and recall, resulting in highest F1 score, outperforming current state-of-the-art solutions.

The ever-increasing complexity and scale of 5G communication networks pose huge challenges to network operations. Root cause analysis is considered as a promising method for fault detection. However, it still suffers challenges of severely uneven distribution of fault data, low accuracy in root cause detection, and long time consumption due to a large search space in 5G cellular networks. To address the above challenges, we introduce SimRCA to effectively analyze the faults’ root causes in 5G networks using signalling messages. By designing a novel confidence threshold value and pruning technique, SimRCA can significantly reduce the search space of signalling messages while maintaining the accuracy of root cause analysis. Moreover, SimRCA is proven to be able to handle unbalanced data distribution in 5G networks. We collected over 10GB of signalling data from Huawei 5G commercial network and conducted extensive experiments on this dataset. Experimental results demonstrate that SimRCA can complete root cause localization and fault classification within 11 seconds with an average F1-score over 0.93 which outperforms the current state-of-the-art solutions.

Recently, Self-Supervised Learning (SSL) has achieved great success in various famous applications e.g., BERT and ChatGPT. However, when applying SSL to safety-critical downstream tasks, such as self-driving cars, potential adversarial attacks can completely change the final decisions and thus lead to serious security issues. To overcome this issue, existing methods combine adversarial training with pre-training to improve the adversarial robustness of SSL. However, combining these two computationally complex processes may largely amplify the computation cost. Moreover, whether performing adversarial training in pre-training or fine-tuning, current methods may degrade the accuracy due to the famous catastrophic forgetting problem. The computation cost of current adversarial training methods based on full parameter updating is still high even in the fine-tuning stage.To address the above challenges, we propose an effective robust fine-tuning framework for SSL based on Low-Rank Adaptation (LoRA), named LoFT. First, LoFT performs adversarial training in the fine-tuning stage rather than in the pre-training stage. Second, LoFT innovatively and elaborately integrates LoRA into adversarial training to avoid the catastrophic forgetting problem. Third, LoFT exploits a low-rank matrix in LoRA which enables efficient fine-tuning by updating only a small set of parameters, which contains only 1%-5% of the parameters of the pre-trained model. The whole pre-training and fine-tuning stages take only 9.44 hours, which reduces training time by 3× over the current SOTA method. Furthermore, compared with existing SOTA robust pre-training methods for SSL, LoFT improves accuracy by 5.97% (77.41%⇒83.38%) and robustness by 13% (45.04%⇒58.44%) on the CIFAR-10 dataset.