Synthesizing high-quality tabular data is essential for privacy-preserving data analysis. However, this task remains challenging due to two key factors: (1) distribution complexity : imbalanced and skewed data make it challenging to learn the data distribution accurately; and (2) semantic coherence : implicit relationships and logical dependencies among fields must be preserved to ensure valid and meaningful synthetic samples. To address these issues, we propose SynDiSC, a high-quality tabular data synthesis approach that enforces both distributional and semantic consistency. It comprises three core designs: (1) a distribution-aware encoding that effectively handles heterogeneous data types and complex distributions; (2) a multi-dimensional semantic conditioning that leverages multi-dimensional conditional dependencies to enforce semantic validity during generation; and (3) a conditional consistency controller that guides the generator to produce diverse samples satisfying multiple conditional constraints while mitigating mode collapse. Extensive experiments on datasets from various application domains demonstrate that SynDiSC significantly improves data quality, conditional controllability, and downstream task performance compared to state-of-the-art methods. Our code and data samples are open-sourced in the GitHub repository. https://github.com/Knightz9/SynDiSC.

Generative language models (GLMs) are increasingly integrated into modern intelligent applications to power intelligent functionalities. Developers often fine-tune open-source GLMs on proprietary data and deploy them in real-world applications. In this paper, we reveal a novel model supply chain attack that exploits this workflow: by injecting backdoors into the source code of an open-source GLM, an adversary can induce the model to memorize fine-tuning data and later regenerate it via crafted prompts. We propose LURE, a new backdoor-based data recovery attack that exploits memorization capabilities of fine-tuned models. During fine-tuning, LURE stealthily injects unique and attacker-enumerable hash prompts, and incorporates a Position-Decay Weighted Aligned Cross-Entropy Loss into the original fine-tuning loss, strengthening the association between injected prompts and corresponding data samples for effective data recovery. To achieve stealthy and transparent attack injection, LURE employs a stealthy backdoor within the model’s source code, enabling automatic injection of hash prompts during fine-tuning and thus maintaining the user’s original fine-tuning workflow. LURE also proposes several optimizations to maintain minimal impact on the performance of the original task and external training state. Extensive evaluations demonstrate the remarkable efficacy of LURE, achieving a 45%-68% data recovery rate while maintaining the attack’s transparency, stealthiness, and showcasing its ability to evade existing defenses.

Vehicular metaverses enable immersive digital experiences through seamless Vehicle Twin (VT) services. As vehicles move, VT service instances must migrate between RoadSide Units (RSUs) to sustain low-latency interactions. However, RSUs face significant challenges from dynamic workload fluctuations and uneven geographical distribution. These limitations often result in service degradation during peak demand periods. Unmanned Aerial Vehicles (UAVs) offer promising solutions to augment fixed infrastructure capacity. Nevertheless, their energy constraints and trajectory optimization create additional complexity for resource management. To address these challenges, we develop a novel framework integrating workload forecasting with coordinated decision-making for VT migration and UAV routing. We first design a long short-term memory-based workload prediction model. This model predicts workload patterns by combining spatial feature extraction with temporal dependency modeling. We enhance the prediction capability through noise-augmented training to improve robustness. Then, we formulate the VT migration and UAV routing optimization as a markov decision process, which captures the sequential nature of decision-making. Finally, we propose a hierarchical control multi-agent deep reinforcement learning algorithm where the upper-layer controller uses multi-agent proximal policy optimization for collaborative decision-making, and the lower-layer controller handles VT migration and UAV routing execution. Simulation results show that the proposed approach reduces average latency by 25.70% and validation loss by 63.70% for workload prediction compared to baseline methods.

As edge devices grow smarter and application scenarios become more diverse, users' demands for lower latency and higher efficiency in data storage and processing have risen sharply. Individual edge devices and nodes are no longer sufficient to meet these expanding storage requirements. Consequently, developing efficient, low-latency, and cost-effective solutions for collaborative storage across edge devices and nodes has become a critical challenge. In this paper, we present a framework for the transaction and pricing of storage resources in an edge computing environment involving multiple edge service providers, to address trust and incentive issues in storage resource collaboration. Firstly, we propose a secure and decentralized storage resource trading mechanism by leveraging blockchain technology and smart contracts. We introduce Proof of Transaction Expectation (PoTE), an efficient, reliable, and lightweight consensus mechanism, to ensure transaction transparency, openness, and non-repudiation. Secondly, we introduce a game theory-based storage resource pricing model, where a leader interacts with multiple followers to optimize profits while maintaining service quality. To address dynamic pricing and storage resource allocation problems under incomplete information, we propose the Stackelberg Game Approach based on Multi-Agent Reinforcement Learning (SGA-MARL), which formulates the optimal pricing and trading share decisions in the two-stage Stackelberg game as a stochastic Markov Decision Process (MDP). Simulations and prototype testing validate the effectiveness of the proposed system, with results showing that the PoTE consensus achieves up to 40% higher throughput than Proof-of-Work while reducing latency by over 50% compared to PBFT, and the SGA-MARL algorithm improves leader profit by approximately 30% and resource satisfaction rates by over 80% compared to baseline methods like MA-PPO and DQN.

The rise of vehicular edge computing (VEC) enables vehicles to offload resource-intensive tasks to roadside units (RSUs), improving efficiency and reducing latency. However, high mobility, dynamic resource availability, and heterogeneous quality-of-experience (QoE) requirements make task offloading and coordination highly challenging. In this paper, we investigate the heterogeneous task offloading problem in dynamic VEC environments by proposing a two-stage optimization framework, TOVEC. Our TOVEC decouples the spatio-temporally coupled decision space into two tractable subproblems and solves it with a two-stage design. In the first stage, we employ a TD3-based deep reinforcement learning algorithm to handle RSU-channel access decisions under dynamic network conditions. In the second stage, we formulate the interaction between vehicular users (VUs) and RSUs as a Stackelberg game, enabling joint task scheduling and dynamic pricing that balances VUs’ QoE optimization and RSUs’ revenue maximization. We theoretically prove the existence of a Stackelberg equilibrium and validate our TOVEC using real-world vehicular traces. The experimental results show that our method has improved the QoE (measured by task delay and energy cost) of VU and the benefits of RSU by 6.8%-41.3% and 2.2%-117.4%, respectively, compared with the baseline schemes.

Powerline inspection with UAVs significantly improves efficiency and safety in remote areas. However, the lack of cellular infrastructure necessitates the use of UAV-mesh networks, whose deployment presents challenges in jointly optimizing coverage, node load, robustness, and cost under complex terrain constraints. In this paper, we investigate the computational complexity of this deployment problem by formulating it as a multi-objective optimization task and proving its NP-hardness. To address this, we presentU-Mesh+, aterrain-aware, robust, and cost-efficientdeployment framework that integrates four key components: (i) identifying line-of-sight and non-line-of-sight links to model terrain-induced communication constraints; (ii)NetConsfor cost-effective coverage and connectivity network topology construction; (iii)NetOptfor network resilience and balance node-level load improvement without extra cost; and (iv)NetEnhfor service availability enhancement via targeted local refinements. We implementU-Mesh+in a real-world 270km2mountainous forest with 174 power towers and 48km of transmission lines. Extensive experiments demonstrate its efficacy in terms of deployment cost and network performance. On-site network data from the deployed wireless network further validate its effectiveness and scalability under real-world conditions.

UAV-assisted task execution is a promising approach to powerline inspections in remote areas where no cellular network infrastructure exists for inspection data transmission. In this paper, we investigate UAV-mesh network deployment in remote areas to empower UAV-assisted powerline inspection, which is challenging considering a mountainous environment with no power supply. Particularly, given the locations of a set of power towers, we first formulate the UAV-mesh network deployment problem with connectivity and coverage constraints, which is NP-hard. Then, we propose U-Mesh, which is a cost-effective and load-balanced deployment scheme. To be specific, U-Mesh integrates three components, i.e., link identification: identifying the link conditions between power towers based on geographical barriers, NetCons: conducting local search to gradually obtain a cost-effective initial mesh nodes with connectivity and coverage constraints, and NetOpti: optimizing the initial mesh node positions to improve the mesh load and robustness from the perspectives of overall network structure. Finally, we implement U-Mesh in a 270 km2mountain forest area, and demonstrate its efficacy in terms of both deployment cost and network performance via extensive evaluations.

The deployment of high-accuracy low-distinction and multi-scale object detection models on resource-constrained edge devices is essential for ubiquitous intelligent applications, from autonomous obstacle avoidance to anomaly object recognition. However, these models' computational burden, energy consumption, and memory footprint pose significant challenges for distributed and pervasive systems. In this paper, we propose HiPOD, a hierarchical pruning framework designed to prune low-distinction and multi-scale object detection models by jointly learning layer-wise and path-wise pruning strategies. HiPOD balances the accuracy-efficiency trade-off through two novel components: Layer-Adaptive Ratio Learning, named AdaLR, which leverages network structural characteristics and a reinforcement learning-based action-feedback mechanism to adaptively generate balanced layer-wise pruning ratios; and Genetic Path Optimization, named GenPath, which employs crossover and mutation operations to optimize inter-layer kernel pruning paths, preserving critical semantic and spatial information. Extensive experiments on three benchmark datasets demonstrate the effectiveness of HiPOD, with only a 3 % drop in mAP50 and a 2 % drop in mAP50:95 compared to the full models. The ablation studies and impact analysis further validate the effectiveness of each module and highlight the robustness of our framework. Furthermore, evaluations on an edge device demonstrate the practicality of the proposed solution for powerline inspection.

The all-reduce operation is critically important for communication-intensive workloads emerging at the convergence of High-Performance Computing (HPC) and Internet of Things (IoT) applications. However, existing optimization efforts primarily concentrate on offloading the all-reduce onto network switches, known as In-Network Aggregation, which are incompatible with switchless torus topologies. Driven by our systematic analysis, we identified two key factors that impact the performance of the standard ring all-reduce operation: i. The all-reduce computation process frequently interrupts the GPU/CPU’s computation tasks; ii. The GPU/CPU is, in fact, indifferent to intermediate computational results. Based on this insight, we propose DirectReduce, a fully offloading ring all-reduce architecture that is comprised of three components: (i) the GateKeeper module, responsible for evaluating outgoing data to decide its progression-either directing it to the Protocol Engine for packetization or intercepting it for reduction (e.g., sum, maximum); (ii) the DataDirector module, which classifies the incoming data either is for intermediate result reduction or final result storage; and (iii) the ComputeEnhancer module, designed to execute reduction operations directly on the SmartNIC. Extensive simulation results show that DirectReduce can reduce the ring all-reduce latency by up to 1.98X in a ring (1D-torus) topology, 1.97X in a 3D-torus topology, and 1.75X in a 6D-torus topology compared to the standard ring all-reduce.

While many existing movie recommendation systems have been integrated to personalize entertainment in FAVs, they face challenges in addressing the diverse and dynamic preferences of multiple passengers. To tackle these issues, this article introduces the multigate mixture of experts for multiinterest model (MEMI) specifically designed for FAVs. The proposed model employs a Transformer-based multi-interest extractor within a multigate mixture of experts (MMoE) structure to capture a range of person interests while managing network complexity. Additionally, a novel peak interest alignment (PIA) loss function is introduced to improve consistency between the training and inference phases, ensuring more accurate recommendations. Experimental evaluations using the Movielens dataset demonstrate that the proposed model significantly outperforms existing systems, providing more personalized and effective movie recommendations.

Syndrome-based early epidemic warning plays a vital role in preventing and controlling unknown epidemic outbreaks. It monitors the frequency of each syndrome, issues a warning if some frequency is aberrant, identifies potential epidemic outbreaks, and alerts governments as early as possible. Existing systems adopt a cloud-assisted paradigm to achieve cross-facility statistics on the syndrome frequencies. However, in these systems, all symptom data would be directly leaked to the cloud, which causes critical security and privacy issues. In this paper, we first analyze syndrome-based early epidemic warning systems and formalize two security notions, i.e., symptom confidentiality and frequency confidentiality, according to the inherent security requirements. We propose extsf{EpiOracle}, a cross-facility early warning scheme for unknown epidemics. EpiOracle ensures that the contents and frequencies of syndromes will not be leaked to any unrelated parties; moreover, our construction uses only a symmetric-key encryption algorithm and cryptographic hash functions (e.g., [CBC]AES and SHA-3), making it highly efficient. We formally prove the security of EpiOracle in the random oracle model. We also implement an EpiOracle prototype and evaluate its performance using a set of real-world symptom lists. The evaluation results demonstrate its practical efficiency.

Vehicle Twins (VTs) as digital representations of vehicles can provide users with immersive experiences in vehicular metaverse applications, e.g., Augmented Reality (AR) navigation and embodied intelligence. VT migration is an effective way that migrates the VT when the locations of physical entities keep changing to maintain seamless immersive VT services. However, an efficient VT migration is challenging due to the rapid movement of vehicles, dynamic workloads of Roadside Units (RSUs), and heterogeneous resources of the RSUs. To achieve efficient migration decisions and a minimum latency for the VT migration, we propose a multi-agent split Deep Reinforcement Learning (DRL) framework combined with spatio-temporal trajectory generation. In this framework, multiple split DRL agents utilize split architecture to efficiently determine VT migration decisions. Furthermore, we propose a spatio-temporal trajectory generation algorithm based on trajectory datasets and road network data to simulate vehicle trajectories, enhancing the generalization of the proposed scheme for managing VT migration in dynamic network environments. Finally, experimental results demonstrate that the proposed scheme not only enhances the Quality of Experience (QoE) by 29% but also reduces the computational parameter count by approximately 25% while maintaining similar performances, enhancing users' immersive experiences in vehicular metaverses.

This paper addresses the challenges of Online Action Recognition (OAR), a framework that involves instantaneous analysis and classification of behaviors in video streams. OAR must operate under stringent latency constraints, making it an indispensable component for real-time feedback for edge computing. Existing methods, which typically rely on the processing of entire video clips, fall short in scenarios requiring immediate recognition. To address this, we designed EdgeOAR, a novel framework specifically designed for OAR on edge devices. EdgeOAR includes the Early Exit-oriented Task-specific Feature Enhancement Module (TFEM), which comprises lightweight submodules to optimize features in both temporal and spatial dimensions. We design an iterative training method to enable TFEM learning features from the beginning of the video. Additionally, EdgeOAR includes an Inverse Information Entropy (IIE) and Modality Consistency (MC)-driven fusion module to fuse features and make better exit decisions. This design overcomes the two main challenges: robust modeling of spatio-temporal action representations with limited initial frames in online video streams and balancing accuracy and efficiency on resource-constrained edge devices. Experiments show that on the UCF-101 dataset, our method EdgeOAR reduces latency by 99.23% and energy consumption by 99.28% compared to state-of-the-art (SOTA) method. And achieves an adequate accuracy on edge devices.

Cellular operators face significant challenges in cutting operating expenses while maintaining the quality of service (QoS) for users due to growing network traffic and dynamic user connections. These challenges are addressed by the cloud radio access network (C-RAN) architecture, which includes a centralized pool of baseband units (BBUs) and distributes them from remote radio heads (RRHs). The key to improving C-RAN performance is to dynamically allocate large-scale RRHs to different BBUs in real time. In this paper, we propose a user behavior-aware RRH-BBU mapping framework to improve the performance of large-scale C-RANs by predicting RRH traffic and users in advance. First, we propose a Multivariate RRH time series Prediction Model (MRPM) that captures the spatio-temporal patterns in the data to predict the traffic volume and the number of users of RRHs, which represents key indicators of RRH connection states. Second, we formulate the RRH-BBU mapping as a Markov decision process problem to optimize cost and QoS by considering BBU utilization, BBU energy consumption, RRH migration frequency, and BBU load balancing. Third, we propose a prediction-based RRH-BBU mapping scheme (PB-RBM) to find the optimal RRH-BBU mapping strategy by leveraging the prediction information of MRPM. In the PB-RBM algorithm, we employ an A3C algorithm to learn the mapping policy and group the RRHs based on a defined popularity metric to reduce the state and action space of the reinforcement learning algorithm. Finally, extensive experiments are conducted on a real-world dataset, and our algorithm is compared with several matching algorithms, such as ACKTR, heuristic, etc., to demonstrate its superiority, especially reducing 17.5% in RMSE compared to the best-performing baseline.

Mobile Virtual Reality (MVR), which aims to provide high-quality VR services to mobile devices of end users, has become the latest trend in virtual reality developments. The current MVR solution is to remotely render frame data from a cloud server, while the potential of edge computing in MVR is underexploited. In this paper, we propose a new approach named MUCVR to achieve high-quality interactive MVR collaboration for multiple users by exploiting edge computing. Firstly, we design “vertical” edge–cloud collaboration for VR task rendering, in which foreground interaction is offloaded to an edge server for rendering, while the background environment is rendered by the cloud server. Correspondingly, the VR device of a user is only responsible for decoding and displaying. Secondly, we propose the “horizontal” multi-user collaboration based on edge–edge cooperation, which synchronizes the data among edge servers. Finally, we implement the proposed MUCVR on an MVR device and the Unity VR application engine. The results show that MUCVR can effectively reduce the MVR service latency, improve the rendering performance, reduce the computing load on the VR device, and, ultimately, improve users' quality of experience.

As critical infrastructure, smart grids require periodic power inspections to remain in good condition. Due to the complexities and variations in the geographical environment especially in remote areas, power inspections can be challenging. In this paper, we investigate efficient large-scale power inspections in remote areas with limited cellular network coverage by providing network support to inspection unmanned aerial vehicle (UAV) via wireless mesh networks. Specifically, we first formulate a network construction problem with the objective of balancing deployment cost and transmission delay, which is an NP-hard problem. Then, we propose U-Auto, i.e., UAV-Assisted Air-ground Network Construction (U-Auto) scheme, to construct a wireless network for UAV-assisted power inspection, which includes a group-coverage maximization selection (GMS) algorithm and two air-ground link handover rules. GMS generates a wireless network topology based on a structure termed group and a utility function. Based on the network topology constructed by GMS, two air-ground link handover rules are employed to optimize transmission delay and connection stability of the air-ground link, called minDelay and minSwitch. Finally, extensive simulations are conducted based on a real world environment of a forest in Hubei, China, and demonstrate the effectiveness of the proposed algorithm.

Systems that integrate distributed databases and existing blockchain platforms have recently emerged, which conveniently leverage their respective strengths to build efficient, secure, and usable data sharing and collaboration environments for different organizations. However, the performance of such systems can be limited by the native blockchain platforms due to the high latency of transactions. In this paper, we present CoralDB, a bottom-up fully redesigned hybrid system of blockchain and database, aimed at enabling untrusted organizations to collaborate and share data efficiently and securely at the database level. The storage layer of CoralDB ensures data security and system throughput through key modules such as customized block structure, consensus mechanism, and transaction pool. On top of the storage layer, a database layer is introduced, which extends the blockchain of the storage layer by incorporating connection pools, collaborative tables, and query interfaces, to enhance the usability and efficiency of data collaboration and sharing. Extensive experimental results demonstrate that CoralDB provides security assurances at the level of blockchain and enables efficient decentralized data collaboration and sharing.

Cellular Internet card (IC) as a new business model emerges, which penetrates rapidly and holds the potential to foster a great business market. However, with the explosive growth of IC users, the user churn problem becomes severe, affecting the IC business significantly, while there is lacking appropriate techniques in the literature to deal with the issue. In this article, we take the lead to study one large-scale data set from a provincial network operator of China, which contains about 4 million IC users and 22 million traditional card (TC) users. We first justify the IC user churn issue with data, and categorize the user churning reasons. Then, we shed light on understanding user portraits, which is the building block to enable efficient model design. Particularly, we conduct a systematical analytics on usage data by studying the difference of two types of users, examining the impact of user properties, and characterizing the user Internet using behaviors. Finally, by using the IC user portraits and usage patterns, we propose anICuserChurnPrediction model, namedICCP, which consists of a feature extraction component and a learning-based churn prediction architecture design. For feature extraction, both the static portrait features and temporal sequential features are captured. In the learning architecture, we devise the principal component analysis (PCA) block and the embedding/transformer layers to learn the respective information of two types of features, which are collectively fed into the classification multilayer perceptron layer (MPL) for churn prediction. A reference implementation ofICCPis conducted within the telecom system and extensive experiments corroborate the efficiency ofICCP.

The increasing network traffic and dynamic user connections have posed challenges for cellular operators in reducing operating costs while ensuring the quality of service (QoS) for users. Cloud radio access network (C-RAN) addresses these issues by separating baseband units (BBUs) and remote radio heads (RRHs), creating a centralized BBU pool. To optimize C-RAN performance, the key is to dynamically assigning RRHs to BBUs, which is challenging due to cost and QoS constraints. In this paper, we propose a data-driven RRH-BBU mapping scheme (KC-A3C) with deep reinforcement learning (DRL) to improve the performance of large-scale C-RANs. First, we analyze a dataset from a cellular operator containing approximately 26,652 active base stations and use the features of the dataset to construct an RRH popularity metric to cluster RRHs. Second, we model the RRH-BBU mapping as a Markov decision process and use the synchronous Advantage Actor-Critic (A3C) algorithm to find the optimal mapping scheme with the highest long-term gain in a dynamic environment, considering resource utilization, RRH migration, and BBU load balancing. Evaluations using real-world datasets show that our proposed scheme outperforms baseline methods.

Mobile-edge computing (MEC) is a promising approach to support high-quality time-sensitive applications. With the increasing number of mobile devices, achieving efficient service migration management has become nontrivial in MEC. In addition, the service migration issue is difficult to be solved in real time due to user mobility and dynamic network conditions. In this article, we investigate the mobility-aware service migration problem in MEC by introducing a data-driven framework. First, service migration is formulated as an optimization problem for minimizing the long-term system delay that consists of computing, communication, and migration delays. Second, we propose a Mobility-aware Service Migration scheme, named MSM, consisting of three layers: 1) the data collection layer; 2) the association patterns analysis layer; and 3) the service migration layer. Specifically, we first collect users’ historical Wi-Fi traces to mine the association patterns. We then design a user management mechanism to reduce the complexity of decision making by using user association patterns. Finally, we formulate the service migration as a 2-D-Markov decision process and devise a deep reinforcement learning (DRL)-based algorithm to obtain service migration decisions in a large-scale MEC scenario. Extensive data-driven experiments are conducted to demonstrate the efficacy of MSM in reducing the system delay.

Mobile edge computing (MEC) is a promising computing paradigm enabling mobile devices to offload computation-intensive tasks to nearby edge servers for fast processing. In this paper, we investigate the computing task offloading in small-cell MEC systems. Considering the unevenly distributed mobile users, it is critical to balance the computing load among edge servers to better utilize the computing resources. To this end, we formulate a joint task offloading control and load balancing problem to minimize the average computational cost of users. The formulated problem is a mixed-integer nonlinear optimization problem and is intractable with system scale. To solve the problem in real time, we propose a reinforcement learning-based grouping and task offloading control (RLGTC) scheme. Specifically, we first decompose the problem into two sub-problems with the Tammer method, i.e., the task offloading control (ToC) and server grouping (SeG) sub-problems. Then, we devise two algorithms based on the Kalman Filter technique and reinforcement learning with Dueling Double DQN to solve them, respectively. Extensive data-driven experiments demonstrate the effectiveness of the RLGTC scheme in achieving load balancing and reducing UEs’ computational costs compared to the state-of-the-art benchmarks.

Mobile Edge Computing (MEC) is a promising paradigm to support high-quality time-sensitive applications. In this paper, we investigate the service migration (i.e., whether, when, and where to migrate the services) to seamlessly serve mobile users in small-cell MEC systems. The service migration is formulated as an optimization problem to minimize the long-term system average delay that consists of queuing, communication, and migration delays. Considering the dynamic user mobility and network conditions, the formulated problem is non-convex and difficult to solve in real time. To this end, we propose a Mobility-aware Service Migration scheme, named MSM, to make real-time decisions on service migrations by utilizing reinforcement learning (RL) approaches. Specifically, we first design a user classification mechanism based on users’ mobility patterns to reduce the complexity of decision-making. We then formulate the service migration as a Markov decision process and devise an RL-based framework to make service migration decisions in real time in the dynamic MEC environment. Extensive data-driven experiments demonstrate the efficacy of MSM in reducing the system average delay.

It is unpractical to conduct full-size data collection in ubiquitous IoT data systems due to the energy constraints of IoT sensors and large system scales. Although sparse sensing technologies have been proposed to infer missing data based on partial sampled data, they usually focus on data inference while neglecting the sampling process, restraining the inference efficiency. In addition, their inferring methods highly depend on data linearity correlations, which become less effective when data are not linearly correlated. In this paper, we propose, Compact IOT Data CollEction, namely CODE, to conduct precise data matrix sampling and efficient inference. Particularly, CODE integrates two major components, i.e., cluster-based matrix sampling and Generative Adversarial Networks (GAN)-based matrix inference, to reduce the data collection cost and guarantee the data benefits, respectively. In the sampling component, a cluster-based sampling approach is devised, in which data clustering is first conducted and then a two-step sampling is performed in accordance with the number of clusters and clustering errors. For the inference component, a GAN-based model is developed to estimate the full matrix, which consists of a generator network that learns to generate a fake matrix, and a discriminator network that learns to discriminate the fake matrix from the real one. A reference implementation of CODE is conducted under three operational large-scale IoT systems, and extensive data-driven experiment results are provided to demonstrate its efficiency and robustness.

Internet card (IC) as a new business model emerges, which penetrates rapidly and holds the potential to foster a great business market. However, the understanding of IC user portraits is insufficient, which is the building block to boost the IC business. In this paper, we take the lead to bridge the gap by studying one large-scale dataset collected from a provincial network operator of China, which contains about 4 million IC users and 22 million traditional card (TC) users. Particularly, we first conduct a systematical analysis on usage data by investigating the difference of two types of users, examining the impact of user properties, and characterizing the spatio-temporal networking patterns. After that, we shed light on one specific business case of churn prediction by devising an IC user Churn Prediction model, named ICCP, which consists of a feature extraction component and a learning architecture design. In ICCP, both the static portrait features and temporal sequential features are extracted, and one principal component analysis block and the embedding/transformer layers are devised to learn the respective information of two types of features, which are collectively fed into the classification multilayer perceptron layer for prediction. Extensive experiments corroborate the efficacy of ICCP.

Edge computing servers (ECSs) have been widely deployed in large-scale mobile edge computing (MEC) systems, which can provide nearby computing services by charging users a price. Service pricing schemes can regulate user task offloading and affect the total revenue of service providers. Investigating how to maximize the revenue of service provider and improve the utilization of edge computing resources becomes crucial while is challenging, considering the users mobility and the uncertainty of users service requests. In this paper, we model the dynamic pricing process of ECS as a Markov decision process and propose a dynamic pricing approach based on Dueling Double Deep Q Network (D3QN) by using the current load conditions and user characteristics, the goal of which is to maximize the revenue of service provider. In addition, considering more ECSs in the MEC system, with the dynamic variations of ECSs loads and the different arrival rate of user tasks, we propose a joint scheduling approach based on D3QN (called RLJS) to collectively improve the total service revenue of service providers. Specifically, we first use a data-driven method to group the ECSs and then devise a D3QN-based task scheduling scheme to distribute tasks among ECS groups by considering the load and price conditions in real time. Simulation results demonstrate the efficacy of RLJS in improving the total revenue of the system provider and reducing the user delays.

In the autonomous driving era, high-definition (HD) maps are an essential building block to enable fine-grained environmental perception, precise localization, and path planning. However, with rich multidimensional information, the size of HD map data is huge and cannot be stored onboard, where the dynamic map data need to be distributed in real time via vehicular networks and how to design the distribution mechanism (i.e., determining the data source for requests) becomes crucial. For the end-to-end communication protocols (i.e., TCP/IP), the main limitation is the vehicle mobility and high dynamic of the network topology, which can degrade the transmission performance dramatically. Therefore, in this article, we propose a reinforcement learning-based data source selection scheme, named RLSS, for efficient HD map distribution in vehicular named data networking (NDN) scenarios, which aims at seeking the best data source (roadside infrastructures or nearby vehicles) in accordance with the map data requests. Specifically, in RLSS, we adopt a deep reinforcement learning-based architecture to learn a neural network as an agent to make the decision of data source selection, which can work online after offline training based on historical selection action performance. In addition, to solve the “cold start” problem for a new vehicle, we propose a model aggregation algorithm and weight update approach to learn the model parameters from its nearby vehicles, which can guarantee the performance while saving the communication cost. Finally, we implement RLSS in NS-3 by adopting the tools of the ndnSIM, SUMO, and Gym. Extensive simulations demonstrate that RLSS can significantly improve the transmission performance in terms of delay, throughput, and packet loss when compared with state-of-the-art data source selection schemes.

Different from cloud computing, edge computing moves computing away from the centralized data center and closer to the end-user. Therefore, with the large-scale deployment of edge services, it becomes a new challenge of how to dynamically select the appropriate edge server for computing requesters based on the edge server and network status. In the TCP/IP architecture, edge computing applications rely on centralized proxy servers to select an appropriate edge server, which leads to additional network overhead and increases service response latency. Due to its powerful forwarding plane, Information-Centric Networking (ICN) has the potential to provide more efficient networking support for edge computing than TCP/IP. However, traditional ICN only addresses named data and cannot well support the handle of dynamic content. In this article, we propose an edge computing service architecture based on ICN, which contains the edge computing service session model, service request forwarding strategies, and service dynamic deployment mechanism. The proposed service session model can not only keep the overhead low but also push the results to the computing requester immediately once the computing is completed. However, the service request forwarding strategies can forward computing requests to an appropriate edge server in a distributed manner. Compared with the TCP/IP-based proxy solution, our forwarding strategy can avoid unnecessary network transmissions, thereby reducing the service completion time. Moreover, the service dynamic deployment mechanism decides whether to deploy an edge service on an edge server based on service popularity, so that edge services can be dynamically deployed to hotspot, further reducing the service completion time.

The multi-path protocol improves end-to-end throughput and becomes one of the solutions to improve video streaming Quality of Experience (QoE). Scalable Video Coding (SVC) encodes a video segment into multi-layer, and different layers can be transmitted on heterogeneous paths. SVC has great potential to make use of the multipath protocol. Meanwhile, multipath QUIC (MPQUIC) provides multiplexing and instant handshake compared with multipath transmission control protocol (MPTCP). Thus MPQUIC has great potential in Dynamic Adaptive Streaming over HTTP (DASH) with SVC. However, mismatches between streams with different priorities and paths, network congestion caused by the suddenly increased data traffic are new challenges of MPQUIC for DASH-SVC. Adaptive Stream-scheduler Multipath QUIC (ASMQ) framework is proposed to improve the user’s QoE in DASH-SVC, prioritizing the streams based on the DASH-SVC application information and evaluates the qualities of multipath. ASMQ schedule prioritized streams to the path with different qualities. In addition, the server-client feedback mechanism of ASMQ can adapt to network congestion conditions in real-time. Emulation with real network traces demonstrates that the ASMQ improves user’s QoE compared to MPTCP and traditional MPQUIC.

In this article, we proposeFLAGfor flexible, accurate, and long-time user load prediction in a large-scale WiFi system.FLAGenables prediction customization in both time granularity and prediction length. Under an operating WiFi system with more than 7000 APs, a reference implementation ofFLAGis developed, which consists of three major components. Fordata acquisition, we process 25 074 733 association records contributed by 55 809 users, to extract the ground truth of AP-level user load. Forfeature extraction, we perform a comprehensive data analytics to mine vital features to label each AP, which are extracted and classified into three categories, i.e., individual features, spatial features, and temporal features. For themodel design, we design a deep recurrent neural network (RNN) model, which contains two separate RNNs, i.e., the encoder RNN and decoder RNN. Particularly, the sequential feature vectors are injected into the encoder RNN to learn the “semantic” information, based on which the decoder RNN conducts sequential AP-level predictions. As the semantic vector is injected for each time step prediction, it can effectively reduce the accumulated prediction errors, which enable long period of time predictions. Real data set-based experiments corroborate the efficacy ofFLAG.

Named Data Networking (NDN) is considered as a prominent architecture towards future Wireless Local Area Networks (WLAN), and multicast plays an important role in data delivery such as media streaming, multipoint videoconferencing, etc. However, to achieve high-efficiency multicast in NDN WLAN is challenging for two significant reasons. First, without feedback mechanism in IEEE 802.11 standards, to guarantee reliability, the current multicast scheme transmits the multicast data with the basic rate (e.g., 1 Mbps for IEEE 802.11b), which inevitably increases the transmission delay for high-speed consumers. Second, as a NDN multicast group is constituted by consumers who are requesting the same content, multicast groups are easy to form and evolve rapidly, where a data rate adaptation scheme is requisite to accommodate differential multicast groups. In this paper, we propose a multi-stage multicast rate adaptation scheme for NDN WLAN, namedNDN-MMRA, to minimize the total transmission time with reliability guarantee for multicast group members. InNDN-MMRA, by checking the Pending Interest Table (PIT) status information, the number of consumers in each multicast group as well as their receiving capabilities are known ahead; with the available data rates in a specific 802.11 standard,NDN-MMRAdetermines: 1) how many transmission stages are required; and 2) in each stage, which data rate should be adopted. The merit is that with multi-stage transmissions, the data rate can be adapted in descending order to accommodate high-speed consumers with delay minimized, and low-speed consumers with reliability guaranteed. We implementNDN-MMRAin NS-3 by adopting the ndnSIM module, and conduct extensive experiments to demonstrate its efficacy under different IEEE 802.11 standards and various underlying WLAN topologies.

In Named Data Networking (NDN) architecture, data can be obtained from multiple content sources (i.e., producers or caching nodes) with multiple paths, making the traditional end-to-end (i.e., TCP/IP) congestion control scheme invalid. In addition, the NDN multi-path discovery and management are still an open issue as the dynamic network topology changes. In this article, we propose a multi-path congestion control mechanism, named MPCC, which includes two major components, i.e., multi-path discovery and multi-path congestion control. Particularly, for multi-path discovery, we first devise apath tagto uniquely mark each sub-path in the forwarding process, and then propose a tag-aware forwarding strategy to discover and manage sub-paths. For multi-path selection and congestion control, we first integrate the metrics of packet loss, bandwidth, round trip time, and path centrality, for path assessment, based on which, we then leverage the Upper Confidence Bound (UCB) algorithm to select sub-paths in order to maximize the network throughput. In addition, for selected sub-paths, we have devised a sub-path window adaptation algorithm to avoid multi-path congestions. At last, we implement MPCC in ndnSIM and conduct extensive experiments for performance evaluation. Our results demonstrate that MPCC can discover all sub-paths in real-time for the multi-path scenario, and can effectively avoid multi-path congestions with improving throughput and reducing transmission time.

The energy consumption for wireless interface is important for the power-constraint mobile and sensor devices. To improve energy efficiency in WLAN (such as Wi-Fi), power saving mode (PSM) is proposed, with an attempt to manage the time spent in idle listening (IL) state. The challenge is that the receiver has no knowledge about when the pending data will arrival under end-to-end communication protocols (TCP/IP); therefore each station has to spend more time in IL to wait for the pending data. To address this problem, we propose NDN-PSM, in which NDN communication architecture is leveraged to cut down unnecessary IL time. In particular, we introduce two new power states in NDN-PSM, i.e., light doze and deep doze. As stations can check pending interest table (PIT) information to predict data arrival precisely, they can switch to deep doze or light doze intelligently. The inherent receiver-driven patterns of NDN can make each station effectively go to deep doze state for power saving. We have implemented NDN-PSM in NS-3 through ndnSIM and the simulation results demonstrate that NDN-PSM can effectively reduce IL time as well as total power consumption and meanwhile retain low transmission delay. Specifically, compared to the PSM mechanism, NDN-PSM can reduce the average power consumption up to 56%.

Multicast rate adaptation in WLAN has become a hot topic from the research community. However, wireless IP multicast lacks in feedback mechanism from the receiver and also no retransmission mechanism from packet loss. To achieve multicast reliability, multicast data is always transmitted at the basic data rate (e.g., 1Mbps for 802.11b). Moreover, wireless NDN multicast is essentially different from traditional wireless IP multicast. NDN multicast composition is based on Pending Interest Table (PIT) state information, which significantly increases the dynamics of the multicast groups. In this paper, we propose a multicast rate adaptation scheme to dynamically select the multicast transmission rate for NDN multicast communication. We present a mapping mechanism between the PIT entry and the MAC address of the station. To reduce the multicast transmission time, we propose a multi-rate multicast transmission scheme for the dynamic NDN multicast groups. In addition, we use the NDN caching mechanism to improve the reliability and reduce the transmission delay when the multicast data loss. Simulation results show that the proposed multicast rate adaptation scheme can effectively reduce transmission time while achieving lower delay and packet loss rate.

In current wireless local area networks, power saving mode (PSM) attempt to reduce the power consumption of station. However, WiFi devices typically spend more than 80% of time in idle listening (IL) state even when the PSM is deployed. To solve the problem, we propose NDN-PSM, which leverages NDN communication patterns to reduce the energy consumption. In NDN-PSM, station checks pending interest table (PIT) information to predict the pending data packet so that it can determine whether switch to doze state. The evaluation result shows that our proposal can effectively reduce IL time as well as total power consumption. Compared to PSM mechanism, NDN-PSM can reduce the power consumption up to 56.2%.