Automotive Ethernet as an in-vehicle networking paradigm has gradually become the main automotive backbone network. However, with the ever-increasing time-critical in-vehicle traffic, it is being confronted with enormous challenges to realize deterministic-latency communications, due to the inherent limitations of its distributed network architecture and the adopted MAC protocols, including limited-computing power, low-speed and unreliable traffic transmission. Furthermore, it is often incompatible with emerging vehicular functions and protocols, which can provide tremendous potential for better vehicular Quality-of-Service (QoS). Therefore, in this paper, we first design a Future Automotive Ethernet (FAE) architecture and then, built on the representative Time-Sensitive Networking (TSN) and industrial summation frame, propose a Deterministic-Latency MAC (DLM) protocol running in FAE to tackle these issues. The FAE architecture includes three functional domains, three in-vehicle computing units, and no fewer than three intelligent network processing modules, which can integrate with the emerging LAN protocols to realize cross-domain and intra-domain Ethernet-based communications. Under the umbrella of this architecture, DLM classifies the driving situations into driving, reversing, left turn, right turn and parking states, following the real-world vehicle behaviors, and assigns all traffic associated with driving safety in five states different recommended priorities to be delivered. Furthermore, an optimized deterministic-latency mechanism integrated with TSN and the industrial summation frame is developed to realize the timely and accurate transmission of high-priority and medium/low-priority traffic. Simulation results obtained from diversified scenarios demonstrate that the proposed DLM running in FAE can significantly improve transmission latency determinacy and reliability compared with the existing technical strategies.

The convergence of edge computing and Artificial Intelligence (AI) gives rise to Edge-AI, which enables the deployment of real-time AI applications at the network edge. A key research challenge in Edge-AI is edge inference acceleration, which aims to realize low-latency high-accuracy Deep Neural Network (DNN) inference by offloading partitioned inference tasks from end devices to edge servers. However, existing research has yet to adopt a practical Edge-AI market perspective, which would explore the personalized inference needs of AI users (e.g., inference accuracy, latency, and task complexity), the revenue incentives for AI service providers that offer edge inference services, and multi-stakeholder governance within a market-oriented context. To bridge this gap, we propose anAuction-basedEdge Inference Pricing Mechanism (AERIA) for revenue maximization to tackle the multi-dimensional optimization problem of DNN model partition, edge inference pricing, and resource allocation. We develop a multi-exit device-edge synergistic inference scheme for on-demand DNN inference acceleration, and theoretically analyze the auction dynamics amongst the AI service providers, AI users and edge infrastructure provider. Owing to the strategic mechanism design via randomized consensus estimate and cost sharing techniques, the Edge-AI market attains several desirable properties. These include competitiveness in revenue maximization, incentive compatibility, and envy-freeness, which are crucial to maintain the effectiveness, truthfulness, and fairness in auction outcomes. Extensive simulations based on four representative DNN inference workloads demonstrate that AERIA significantly outperforms several state-of-the-art approaches in revenue maximization. This validates the efficacy of AERIA for on-demand DNN inference in the Edge-AI market.

Personalized Federated Learning (PFL) has been widely adopted in Mobile Edge Computing (MEC) to enable tailored services without private user data ever leaving the devices. Previous efforts have illustrated that the weighted aggregation determined by the number of samples on clients will hurt the convergence of PFL. Furthermore, the over-personalization of PFL may result in model overfitting and lack of generalization capabilities. Therefore, in this paper, we propose novel quality/discrepancy-aware Multi-task Personalized Federated Learning (MPFL) for MEC to tackle these issues. Specifically, a number of personalized learning objectives of different clients in PFL are considered as multiple tasks. Both local private Batch Normalization (BN) and global shared BN layers are introduced into PFL as the specialized experts to better balance the personalization and generalization capabilities of the local models. Furthermore, the statistical discrepancies between such two BN layers and the model quality of clients are jointly taken into account to design aggregation weights for quick model aggregation with better performance gains. Extensive experiments conducted on three well-known datasets demonstrate that the proposed framework outperforms the state-of-the-art benchmarks in terms of convergence speed and learning accuracy.

Network Function Virtualization (NFV) often suffers from unexpected failures in some mission-critical applications due to the reliability-agnostic deployment of Virtual Network Functions (VNFs), thus achieving suboptimal service performance. To cope with this issue, we propose a Reliability-aware VNF service Provisioning (RVFP) approach for NFV-based networks via Multi-Agent Deep Reinforcement Learning (MADRL), where each VNF is hosted and backed up in appropriate hardware with reliability guarantees. Specifically, a novel MADRL-based framework for VNF placement is designed with two alternating optimization objectives, namely maximizing reliability and minimizing VNF instance failure probability, to incorporate diverse objective landscapes and encourage broader exploration within the solution space. Furthermore, two agent allocation strategies are developed to alternately arrange the tasks of collaborative agents for reliability-aware placement of VNFs in a parallel and cooperative manner. Besides, the newly-designed prioritized experience sampling, built on reward and sampling frequency, is used to better exploit valuable experiences for faster model training. Extensive simulation results obtained from various scenarios show that RVFP can significantly improve placement reliability and service acceptance ratios for VNF deployment compared with the state-of-the-art approaches.

The prediction of network latency with partial measurements is of importance for ever-increasing personal devices to ensure their Quality of Service (QoS). However, the current matrix-factorization-based efforts, as a promising paradigm, for network latency prediction have failed to intelligently exploit inherent factors hidden in networks to accurately infer the unknown network latency. Furthermore, it is more complicated to execute extensive network measurements on pervasive personal devices due to unstable communication environments. To alleviate these problems, in this paper, a novel accurate network latency prediction (DALP) solution via Deep Reinforcement Learning (DRL) is proposed for personal devices under cost-aware sampling. Specifically, we first alternately implement cost-aware latency measurement based on temporal correlation, and model it as a network latency matrix, in which unmeasured and missing elements need to be inferred. In order to achieve accurate prediction performance, the DRL-based Matrix Factorization with Double Weights (DWMF) is designed to exploit the potential network factors and multiple rules of matrix factorization, which can be alternatively executed, to minimize the prediction errors. Furthermore, an angle-loss-based reward strategy is designed to enhance the quality of model training. Simulation results on real-world datasets illustrate that DALP outperforms the previous approaches with quicker convergence and lower prediction errors.

Foundation models (FMs) such as GPT-4 exhibit exceptional generative capabilities across diverse downstream tasks through fine-tuning. Split Federated Learning (SFL) facilitates privacy-preserving FM fine-tuning on resource-constrained local devices by offloading partial FM computations to edge servers, enabling device-edge synergistic fine-tuning. Practical edge networks often host multiple SFL tenants to support diversified downstream tasks. However, existing research primarily focuses on single-tenant SFL scenarios, and lacks tailored incentive mechanisms for multi-tenant settings, which are essential to effectively coordinate self-interested local devices for participation in various downstream tasks, ensuring that each SFL tenant’s distinct FM fine-tuning requirements (e.g., FM types, performance targets, and fine-tuning deadlines) are met. To address this gap, we propose a novel Price-Incentive Mechanism (PRINCE) that guides multiple SFL tenants to offer strategic price incentives, which solicit high-quality device participation for efficient FM fine-tuning. Specifically, we first develop a bias-resilient global SFL model aggregation scheme to eliminate model biases caused by independent device participation.We then derive a rigorous SFL convergence bound to evaluate the contributions of heterogeneous devices to FM performance improvements, guiding the incentive strategies of SFL tenants. Furthermore, we model inter-tenant device competition as a congestion game for Stackelberg equilibrium(SE) analysis, deriving each SFL tenant’s optimal incentive strategy. Extensive simulations involving four representative SFL tenant types (ViT, BERT, Whisper, and LLaMA) across diverse data modalities (text, images, and audio) demonstrate that PRINCE accelerates FM fine-tuning by up to 3.07x compared to state-of-the-art approaches, while consistently meeting fine-tuning performance targets.

Synchronization of vehicular digital twin (VDT) state data is essential for maintaining the accuracy of digital twin models. Existing studies show that VDT data synchronization typically requires a substantial amount of bandwidth and frequent data exchanges. However, real-world vehicle state data are prone to noise interference and bandwidth constraints, causing synchronization errors and significantly degrading VDT accuracy. To evaluate the impact of noise interference on VDT accuracy, we model vehicle state evolution as a discrete-time wiener process and employ a Kalman filter for optimal state estimation. By further analyzing the relationship between estimation error and update timeliness, we find that weighted scheduling based on Age of Information (AoI) effectively suppresses error accumulation and improves synchronization performance. Then, we propose an aoi error-aware scheduling mechanism maximum weighted noise age (MWNA), within a cloud-edge collaborative VDT framework, MWNA dynamically evaluates each vehicle’s state update and prioritizes the transmissions that yield the greatest reduction in estimation error. Compared with baselines, the MWNA policy achieves up to 25–40% lower average error across a range of correlation settings, particularly under high noise correlation and large-scale vehicular scenarios.

The accurate prediction of Quality of Service (QoS) in terms of response time, packet loss rate, latency and throughput for component services is essential for 5 G to fulfill specific Service Level Agreements (SLAs). However, most current efforts failed to fully exploit the time-varying mobility features of users and parallel iteration multi-rules to perform QoS prediction for component services, incurring poor prediction accuracy. Therefore, in this paper, we are devoted to accurate QoS Prediction of Component Services (QPCS) for 5 G via Graph-based Deep Reinforcement Learning (GDRL) to tackle this issue. Towards this end, the QoS prediction is modeled as GDRL-based QoS tensor factorization by designing a Spatio-Temporal-Recurrent-based Graph Attention Network (STR-GAT) and introducing it into Deep Deterministic Policy Gradient (DDPG) to factorize QoS tensor with multiple available rules in parallel. Specifically, a low-rank QoS tensor and an adjacency tensor are established, which include partial QoS observations of component services in each Base Station (BS), along with some missing elements, and evolving spatial information of users across these BSs, respectively. Then, the novel STR-GAT is designed by introducing spatio-temporal relations into conventional GAT to fully derive the mobility features of users to explore potential actions, while the derivative DDPG is adopted to perform tensor factorization with multiple available rules in parallel. Furthermore, the action smoothing and hierarchical-based replay buffer with priority-based and random sampling are designed and introduced into DDPG to stabilize training process and accelerate model convergence. Experimental simulation results on real-world datasets validate the superiorities of QPCS compared with the state-of-the-art approaches in predicting the QoS of component services in 5 G.

The accurate prediction of required resources in terms of storage, computing and bandwidth is essential for 5G to host diverse services. The existing efforts illustrate that it is more promising to efficiently predict the unknown required resources with a third-order tensor compared to the 2D-matrix-based solutions. However, most of them fail to leverage the inherent features hidden in network traffic like temporal stability and service correlation to build a third-order tensor for the multi-dimensional required resource prediction in an intelligent manner, incurring coarse-grained prediction accuracy. Furthermore, it is difficult to build a third-order tensor with rate-varied measurements in 5G due to different lengths of measurement time slots. To address these issues, we propose an Accurate Prediction of Multi-Dimensional Required Resources (APMR) approach in 5G via Federated Deep Reinforcement Learning (FDRL). We first confirm the resource requests originated from different Base Stations (BSs) at varied measurement rates have similar features in service and time domains, but cannot directly form a series of regular tensors. Built on these observations, we reshape these measurement data to form a series of standard third-order tensors with the same size, which include many elements obtained from measurements and some unknown elements needed to be inferred. In order to obtain accurately predicted results, the FDRL-based tensor factorization approach is introduced to intelligently utilize multiple specific iteration rules for local model learning, and the accuracy-aware and latency-based depreciation strategies are exploited to aggregate local models for resource prediction. Extensive simulation experiments demonstrate that APMR can accurately predict the multi-dimensional required resources compared to the state-of-the-art approaches.

Recent years have witnessed the proliferation of wireless energy transfer for Wireless Sensor Networks (WSNs), which are mainly used for data gathering in real-world applications. A number of studies have investigated mobile vehicle scheduling to charge sensor nodes via wireless Mobile Chargers (MCs). Unfortunately, most of them cannot parallelly charge all nodes in an intelligent manner with the global network attributes. Furthermore, the time-variable charging ignores the optimal data gathering, resulting in poor Joint Energy Replenishment and Data Gathering (JERDG). To fill this gap, this paper proposes a Federated Deep Reinforcement Learning (FDRL)-based JERDG (FERG) solution for WSNs. To this end, FERG first partitions the networks into a set of clusters to distribute the workload evenly among multiple MCs, and then designs an FDRL-based framework that incorporates various time-variant network attributes to determine the optimal schedule for charging and data gathering via multiple MCs and a base station (BS). The BS as the cloud server is responsible for global training of JERDG models, while multiple MCs will parallelly train local models to jointly charge energy-exhausted nodes and gather the data from all nodes in clusters. To reserve more personalized characteristics of each cluster, a density-based partial aggregation strategy is designed to train the global model. Furthermore, a reward-weighted update and selection solution is proposed to generate and exploit reference samples with high rewards. Simulation results obtained from various scenarios demonstrate that FERG significantly outperforms the state-of-the-art approaches in terms of network lifetime, energy efficiency and data collection latency.

Trajectory synthesis with a series of fake locations has been deemed as a promising obfuscation technology to preserve the individual privacy of users in Location-Based Services (LBSs). However, a number of previous approaches fail to take into consideration the geographic distance and motion direction of the real locations to synthesize trajectories. As a result, most of them always cannot represent the statistical characteristics of real trajectories in a privacy-preserving manner, and thus suffer from various attacks through data analysis. To tackle this issue, this paper presents SPSD, a novel privacy-preserving trajectory synthesis approach with a$k$-anonymous guarantee, through extracting the semantic, geographic and directional similarity of locations from the real trajectories to create plausible trajectories. SPSD first classifies all historical trajectory data into a series of sets for location identity, by introducing the visiting time and visiting duration, which can clearly represent the semantic information of locations. Then,$4k$locations and$2k$of$4k$ones have been selected from each set to act as the initial disguises of each corresponding real location, with quantitative semantic and geographic similarities, respectively. In order to find enough fake locations for each real location in less time, the candidate locations have been narrowed down to$k$in direction recovery through step-by-step screening, with the$k$-anonymous property. Experiment results built on the real-world trajectory datasets indicate that SPSD has outperformed the previous approaches in terms of semantic similarity, directional accuracy and security resistance to synthesize privacy-preserving trajectories at the tolerable time cost.

Cooperative perception, based on vehicle-to-everything (V2X) communication technology, is a promising solution for connected and automated vehicles (CAVs) to improve their perception capabilities in intelligent transportation systems. The frequency of message transmission in cooperative perception among mobile vehicles plays a crucial role, as it directly impacts communication efficiency, perception accuracy, system response speed, and the safety of real-time applications. Higher transmission frequencies can provide more timely and rich sensory information. This also implies higher consumption of communication resources. However, in a dynamic and complex environment, it is difficult to quantitatively control the message transmission frequency so as to improve the utilization of limited communication resources, ensure the timeliness of perception messages, and maintain fast convergence. To address challenges of timeliness of messages, a timeliness performance metric age of information (AoI) is introduced to control message transmission frequency. This paper deduced the average AoI of the system and designed an AoI-aware decentralized congestion control (ADCC) algorithm for the V2X-based cooperative perception system. Simulation results show that the ADCC algorithm outperforms the classic congestion control algorithm linear adaptive message rate (LIMERIC) in terms of channel utilization and throughput. Specifically, AoI decreased by 47.3%, channel utilization increased by 6.5% and throughput increased by 48.6%.

Users tend to own multiple accounts on different location-based social network (LBSN) platforms, and they typically engage with diverse social circles on each platform within the same locations. Consequently, linking these accounts across separate networks becomes essential, playing a critical role in information fusion. Previous works accomplishing user identity linkage (UIL) utilize individual mobility records, which are significantly affected by the issue of data scarcity. In this paper, we propose EgoMUIL, a heterogeneous graph embedding approach specifically devised for information propagation, aiming to alleviate the scarcity problem to some extent. Considering that follow relations of respective networks also hold great significance for the UIL task, we are inspired to enrich individual limited mobility records through follow relations. Our preliminary research reveals that direct common follow relations are quite insufficient. Since the followers with the same spatio-temporal mode tend to have social connections, we first mine closely-related users for each user through topology and locality similarity, generating respective cross-domain ego-networks. Subsequently, we construct a heterogeneous ego-mo hypergraph consisting of mobility and ego-networks. We propose a novel graph convolutional network (GCN)-based approach to learn user representations, which enables the aggregation of information from surrounding nodes, incorporating topological similarities, stay locality similarities, and co-occurrence frequencies. The resulting embeddings provide comprehensive representations of users and locations, capturing their characteristics and relationships across platforms, which further facilitates the UIL task. Our experimental results on real-world check-in datasets from Foursquare and Twitter demonstrate that EgoMUIL outperforms the state-of-the-art methods on the UIL task. Notably, EgoMUIL exhibits superior performance in scenarios involving limited check-in records and follow relations.

A large number of distributed applications necessitate accurate network distance, for example, in the form of delay or latency, to ensure the Quality of Service (QoS). Due to high network measurement overhead and severe traffic congestion, network distance prediction has been introduced, instead of direct network measurements, to infer the unknown network distance with the partial measurements. However, most existing efforts neglect to fully capitalize on the potential latent factors, such as spatial correlations, long-existing temporal results and multi-rule exploration fusion, to achieve better accuracies with quicker convergence. To fill this gap, in this paper, we propose an Accurate Prediction of Network Distance (APND) solution via Federated Deep Reinforcement Learning (FDRL), which has four novel features distinguishing from the previous work. Firstly, a local feature-based matrix with low rank is established in each network cluster, referring to a set of neighbor nodes, to represent the potential spatial correlations among reachable node-pairs. Secondly, the parallel FDRL-based matrix factorization with multi-rule exploration fusion is introduced into APND and executed in all local clusters to minimize prediction errors and accelerate learning convergence. Thirdly, the long-existing learning experience is designed for local model training via Deep Reinforcement Learning (DRL) with rapid convergence. Fourthly, following the real-world routing paths, the cross-domain network nodes are simultaneously classified into adjacent clusters, built on the spatial correlations among them, and their coordinates will be further refined with error-based and average-based policies. Extensive experiments built on available real-world datasets illustrate that APND can accurately predict network distance compared with state-of-the-art approaches at the moderate computing cost.

Network Function Virtualization (NFV) introduces a new network architecture that offers different network services flexibly and dynamically in the form of Service Function Chains (SFCs), which refer to a set of Virtualization Network Functions (VNFs) chained in a specific order. However, the service latency often increases linearly with the length of SFCs due to the sequential execution of VNFs, resulting in sub-optimal performance for most delay-sensitive applications. In this paper, a novel Parallel VNF Placement (PVFP) approach is proposed for real-world networks via Federated Deep Reinforcement Learning (FDRL). PVFP has three remarkable characteristics distinguishing from previous work: 1) PVFP designs a specific parallel principle, with three parallelism identification rules, to reasonably decide partial VNF parallelism; 2) PVFP considers SFC partition in multi-domains built on their remaining resources and potential parallel VNFs to ensure that VNFs can be reasonably distributed for resource balancing among domains; 3) FDRL-based framework of parallel VNF placement is designed to train a global intelligent model, with time-variant local autonomy explorations, for cross-domain SFC deployment, avoiding data sharing among domains. Simulation results in different scenarios demonstrate that PVFP can significantly reduce the end-to-end latency of SFCs at the medium resource expenditures to place VNFs in multiple administrative domains, compared with the state-of-the-art mechanisms.

Resource provisioning for the ever-increasing applications to host the necessary network functions necessitates the efficient and accurate prediction of required resources. However, the current efforts fail to leverage the inherent features hidden in network traffic, such as temporal stability, service correlation and periodicity, to predict the required resources in an intelligent manner, incurring coarse-grain prediction accuracies. To tackle this problem, in this paper, we propose an Accurate Prediction of Required virtual Resources (APRR) approach via Deep Reinforcement Learning (DRL). We first confirm the resource requests have more similar features and identify the high-dimensional required resources in computing, storage and bandwidth can be effectively consolidated into a single standardized value. Built upon these observations, we then model the required resources as a time-variant network matrix, which includes a number of elements, obtained from the network measurements, and some missing elements needed to be inferred. To obtain accurately predicted results, DRL-based matrix factorization with a set of available rules has been introduced into APRR and alternately executed in agent to minimize the prediction errors. Moreover, the error-prioritized designed for model training with quicker convergence. Simulation experiments on real-world datasets illustrate that APRR can accurately predict the required virtual resources compared with the related approaches.

Network Functions Virtualization (NFV), which decouples network functions from the underlying hardware, has been regarded as an emerging paradigm to provide flexible virtual resources for various applications through the ordered interconnection of Virtual Network Functions (VNFs), in the form of Service Function Chains (SFCs). In order to achieve the desired performance as dedicated hardware, how to efficiently deploy SFCs in NFV-enabled networks with limited resources is still a tremendous challenge. In this article, RQAP, an effective Resource and Quality of Service (QoS) Aware SFC Placement approach is proposed to mitigate this issue with the QoS-guaranteed service provisioning at acceptable resource consumption. With the Markov property of VNFs, the resource and QoS aware placement of SFCs is modeled as a Markov-chain-based optimization problem, where the set of all possible placement states on diverse nodes is regarded as a state space in the Markov chain and each state is jointly determined by the initial state and transition matrices. Furthermore, the SFCs associated with traffic requests are re-sorted so as to efficiently instantiate VNFs of the same type in a resource-saving manner. On this basis, an efficient Backward-Viterbi-based heuristic mechanism is presented to conduct the optimal VNF placement in Markov chain space, with the aim of consumed-resource reduction, along with the QoS-based instantiation of virtual links between adjacent VNFs. Simulation results conducted in several scenarios demonstrate that RQAP can significantly achieve a trade-off between resource consumption optimization and QoS guarantee. Besides, the results show that our proposed approach can also effectively improve the SFC acceptance ratio and achieve desirable load balancing and scalability.

Blockchain has recently been regarded as an important enabler for building secure energy trading in microgrid systems because of its inherent features of distributively providing immutable data record, storage, and sharing across networks in a peer-to-peer (P2P) manner. However, designing highly efficient and scalable blockchain-enabled energy trading mechanisms is extremely challenging because of the unique features of microgrid systems, e.g., bandwidth-constrained and high-latency communications and large-scale renewable energy source (RES) integration. To address this challenge, in this article, we propose a novel scalable blockchain-based energy trading framework for cooperative microgrid systems, which include four planes, i.e., data plane, consensus plane, smart plane, and application plane. Different from the existing solutions without consideration of network transmission, these four planes are designed with the capability of perceiving the status of block generation and transmission over interrupted P2P networks, and thus proactively improving the consensus process to guarantee the reliability of energy trading in cooperative microgrids. Meanwhile, built on this framework, a novel redundant data exchange strategy is proposed to improve the scalability of block creation with the presence of large-scale RES penetration and interrupted and dynamic communication links. Simulation results show that the proposed system framework outperforms the benchmark blockchain solutions. Furthermore, we investigate the potential applications of the proposed solutions in the practical microgrid systems to facilitate a clear understanding of the mechanisms of the proposed solutions.

As an indispensable part of modern critical infrastructures, cameras deployed at strategic places and prime junctions in an intelligent transportation system can help operators in observing traffic flow, identifying any emergency situation, or making decisions regarding road congestion without arriving on the scene. However, these cameras are usually equipped with heterogeneous and turbulent networks, making the real-time smooth playback of traffic monitoring videos with high quality a grand challenge. In this article, we propose a lightweight Deep Reinforcement Learning-based approach, namely, sRC-C (smart bitRate Control with a Continuous action space) , to enhance the quality of real-time traffic monitoring by adjusting the video bitrate adaptively. Distinguished from the existing bitrate adjusting approaches, sRC-C can overcome the bias incurred by deterministic discretization of candidate bitrates by adjusting the video bitrate with more fine-grained control from a continuous action space, thus significantly improving the Quality-of-Service (QoS). With carefully designed state space and neural network model, sRC-C can be implemented on cameras with scarce resources to support real-time live video streaming with low inference time. Extensive experiments show that sRC-C can reduce the frame loss counts and hold time by 24% and 15.5%, respectively, even with comparable bandwidth utilization. Meanwhile, compared to the-state-of-art approaches, sRC-C can improve the QoS by 30.4%.

The knowledge of network distances, in the form of delay or latency, for example, is beneficial to a number of distributed applications. Notice that it is difficult and expensive to implement global network measurements to obtain network distance, a feasible idea is to predict unknown distances by introducing network coordinates with limited network measurements. The existing solutions always represent the unknown network distances in a rather unique number. However, research and applications indicate that the real network distances are hard to be accurately figured out and changes subtly in an interval over time with the dynamic network environments. Accordingly, this article proposes a tensor-based network distance prediction (TNDP) approach to represent network distance with confidence intervals, by exploiting the random distance tensor and distributed matrix factorization. With a small set of network measurements among the nodes selected randomly, a distance matrix tensor has been established and factorized into the product of two location matrixes with the adaptive SGD-based learning solution. By introducing the important training determinants, including weight matrix, regularization coefficient, and minibatch gradient descent with the exponential decay rates, the unknown distances among nodes can be accurately inferred in the forms of confidence intervals, with quick convergence and less overfitting. Extensive experimental simulations on a wide variety of available data sets demonstrate that TNDP is superior to other approaches in terms of accuracy for network distance prediction.

Smart contracts, one of the success stories in blockchain 2.0, have been widely utilized in a broad range of applications, including those involving Internet of Things (IoT). Given the fast-pace nature of the topic, it can be challenging for the research community to keep track of the latest advances. Hence, in this article, we perform a comprehensive, in-depth review of known security challenges (e.g., inherently vulnerable particularities, programming vulnerabilities, and attacks) and potential research opportunities associated with the deploying of smart contracts in an IoT setting. We hope this survey will serve as a starting point for the readers seeking to understand and explore the potential applications of smart contracts.

Network function virtualization (NFV) is critical to the scalability and flexibility of various network services in the form of service function chains (SFCs), which refer to a set of Virtual Network Functions (VNFs) chained in a specific order. However, the NFV performance is hard to fulfill the ever-increasing requirements of network services mainly due to the static orchestrations of SFCs. To tackle this issue, a novel Scalable SFC Orchestration (SSCO) scheme is proposed in this paper for NFV-enabled networks via federated reinforcement learning. SSCO has three remarkable characteristics distinguishing from the previous work: (1) A federated-learning-based framework is designed to train a global learning model, with time-variant local model explorations, for scalable SFC orchestration, while avoiding data sharing among stakeholders; (2) SSCO allows for parameter update among local clients and the cloud server just at the first and last epochs of each episode to ensure that distributed clients can make model optimization at a low communication cost; (3) SSCO introduces an efficient deep reinforcement learning (DRL) approach, with the local learning knowledge of available resources and instantiation cost, to map VNFs into networks flexibly. Furthermore, a loss-weight-based mechanism is proposed to generate and exploit reference samples in replay buffers for future training, avoiding the strong relevance of samples. Simulation results obtained from different working scenarios demonstrate that SSCO can significantly reduce placement errors and improve resource utilization ratio to place time-variant VNFs compared with the state-of-the-art mechanisms. Furthermore, the results show that the proposed approach can achieve desirable scalability.

5G networks are expected to provide cost-efficient, reliable, and flexible services for industrial productions and applications potentially, by introducing emerging network technologies like blockchain and network functions virtualization (NFV), which virtualizes network functions and runs them on standard infrastructure rather than customized hardware. However, how to deal with the emerging security challenges and fulfil the requirement of ultra-reliable and low-latency communications (URLLC) has not been fully resolved. In this article, we present an NFV-enabled 5G paradigm for the industry with the guarantee of URLLC through service chain acceleration and dynamic blockchain-based spectrum resource sharing among a variety of industry applications running in NVF-based equipment. First, we elaborate the benefits and shortcomings of NFV for industry, by executing an industry application experiment in virtualized and nonvirtualized data center networks. Then, we illustrate an NFV-enabled 5G paradigm for URLLC in detail, with a special focus on the service chain acceleration and spectrum sharing built on NFV, blockchain, software-defined networking, and mobile edge computing. Finally, we establish a mathematical model to study the worst-cast transmission latency of NFV-enabled 5G with the input of the bursty traffic. The proposed model can be exploited to support the plan, management, and optimization of NFV-enabled 5G URLLC systems for industry.

The decision of request mapping-which server to handle user request and response routing-which transit route to carry response back to user has great impact on the performance and cost of Content Delivery Networks (CDNs). Request mapping and response routing are traditionally treated independently. The information invisibility and inconsistent objectives may lead to worse performance and high cost. However, the rapid globalization of Internet eXchange Points (IXPs) has facilitated the cooperation between CDN and ISP. In this paper, we consider request mapping and response routing jointly. We formulate the joint problem to navigate the performance and cost tradeoff. To solve the large-scale optimization, we develop a distributed tide algorithm based on Gauss-Seidel. The joint problem can be decomposed to sub-problems which allows for a parallel implementation. Experiment result shows that the relative error between our distributed tide algorithm that iterates within 50 rounds and theoretical optimum is about 0.7 percent. Furthermore, the parallel runtime demonstrates the efficiency of our algorithm.

Mobile-edge computing (MEC) has emerged to enable users to offload their location data into the MEC server, and at the same time, the MEC server executes the location-aware data processing to compute the statistical results about these collected locations. However, malicious users may deliberately generate poisoning locations and send these poisoning locations to the MEC server, aiming to poison the statistical results learned by the MEC server and even the other users' location privacy. Existing work concerning privacy preservation in MEC has not studied such poisoning attacks in MEC. Another line of somehow related work focused on poisoning attacks in a different scenario-adversarial machine learning. However, MEC exhibits different features with the machine learning settings, and thus, the privacy preservation against poisoning attacks in MEC faces significantly new challenges. To address the problem, we propose the privacy-preserving scheme, i.e., privacy-preserving scheme against poisoning (P3), that utilizes the feature learning model to infer the social relationships among users from their location data and then constructs the inferred social graph. Thereafter, it searches the optimal map between the inferred social graph and the social graph from social networks to identify the poisoning locations. Experiments on two real-world data sets, two baseline works, and two kinds of poisoning attacks have demonstrated the privacy preservation against the poisoning attacks in MEC P3provides.

Knowledge of node locations is essential to Wireless Sensor Networks (WSNs) in a wide range of potential applications and their function-dependent network protocols. A number of localization approaches have already been proposed to fulfill this requirement, but few of them can be applicable to mobile sensor networks, due to their low-dimensional embeddings, Euclidean distance representation limitations, frequent node mobility and additional measurement overhead in the network. In this paper, a resilient range-based d-dimensional localization (RRDL) approach is proposed for mobile WSNs to resolve the issues. RRDL distinguishes itself from previous work with three remarkable characteristics: (1) it works for mobile networks embedded in d-dimensional Non-Euclidean space; (2) it allows static ordinary nodes with pre-known locations to act as the alternative anchor nodes, thus tolerating the motion of the original anchor nodes to ensure that other ordinary nodes can obtain their locations in an efficient manner; and (3) it introduces an efficient path-learning approach, with the knowledge of the existing paths, to represent the real network distances as far as possible, thereby eliminating additional measurement overhead and tolerating node mobility in localization. With these characteristics, RRDL exploits the iterative factorization of the random distance matrix, formed by the distances to and from a set of k-hop static neighbors, to assign each current node d-dimensional Non-Euclidean coordinate in a distributed manner. Simulation results demonstrate that RRDL achieves higher localization accuracy with a moderate communication cost in mobile sensor networks.

Understanding the statistical latency between two groups of hosts in a period of time is of great significance to a wide variety of Internet applications and services, such as Service-Level Agreement (SLA) compliance monitoring and Virtual Network Function (VNF) placement. However, direct latency measurement methods are not always applicable to large-scale situations while the existing indirect methods often incur extra deployment costs or security problems. To address this challenge, we design an indirect method based on widely-distributed clients calledSSL(Surrogate-based method for large-scale Statistical Latency measurement).SSLestimates the latency between two arbitrary hosts using the measured latencies from several selected clients near one end host, which are called the host's surrogates, to the other end host. To overcome the limited capacity of the volatile clients with unstable CPU, memory, and bandwidth resources, we propose an innovative two-step measurement task assignment mechanism forSSLthat can achieve high accuracy measurement results while satisfying the resource constraints simultaneously. Moreover,SSLadopts a sampling technique to reduce the overhead in large-scale measurements, and a resampling technique to determine the confidence interval. Simulation experiments show thatSSLcan achieve more than 90 percent accuracy in most situations with 10 percent client density and 15 percent sampling rate.

The emerging of machine learning has massively promoted the abilities of computational sustainability in natural resource management and allocation. Many Internet giants such as Google, Amazon, and Microsoft now provide Machine Learning as a Service (MLaaS) to meet the increasing demand for machine learning services. However, the prediction results of training data and testing data with the same machine learning model in MLaaS have remarkable differences, and thus the attackers can leverage machine learning techniques to launch the so-called membership inference attacks, i.e., to infer whether a record is in the training data or not. In this paper, we propose MIASec that can guarantee the data indistinguishability of the training data and thereby has the ability to defend against membership inference attacks in MLaaS. The key idea of MIASec is to narrow the dynamic ranges of vital features in the training data, such that the training data, the testing data, and even the synthetic data have almost semblable prediction results by the same machine learning model. With elaborated design on modifying the values of vital features in the training data, MIASec can thus reduce the differences between the model's outcomes of training data and testing data, thereby protecting the training data in effect while keeping the model's accuracy stable. We empirically evaluate MIASec on machine learning models trained by off-line neural networks and on-line MLaaS. Using realistic data and classification tasks, our experiment results show that MIASec can defend the membership inference attacks effectively. In particular, MIASec can reduce the precision and recall of attacks respectively by 11.7 and 15.4 percent in average, and by 18.6 and 21.8 percent at best.

As the prevalence of computing-intensive and delay-sensitive Internet of Things (IoT) applications, IoT service providers (SP) begin to deploy micro data centers in the edge and offload functions to them. However, more and more complex IoT applications require an ordered sequence of services across geographically distributed infrastructure to fulfil their functions, which poses grand challenges for IoT SP to deploy applications with low costs and high efficiency. To the best of our knowledge, no existing works have studied the deployment for an application with multilevel services (referred to as application deployment with multilevel services (ADMS) problem). To fill in the gap, we formulate the ADMS problem as an optimization problem with the aim of minimizing the overall deployment cost under the latency/computation/storage/bandwidth requirements and the infrastructure capacity limitations. We design a workflow-based heuristic algorithm called AMS, which can determine how many virtual machines (VMs) should be placed for each type of service and where to place them. AMS supports the services to scale up or scale down on demand in real time. Simulation experiments based on real network measurement demonstrate that AMS can reduce the number of deployed VMs by 28.4% and the deployment cost by 33.9% subject to comparable satisfied user ratio.

Internet of Things (IoT) applications bring in a great convenience for human’s life, but users’ data privacy concern is the major barrier toward the development of IoT.${k}$-anonymity is a method to protect users’ data privacy, but it is presently known to suffer from inference attacks. Thus far, existing work only relies on a number of experimental examples to validate${k}$-anonymity’s performance against inference attacks, and thereby lacks of a theoretical guarantee. To tackle this issue, in this paper we propose the first theoretical foundation that gives a nonasymptotic bound on the performance of${k}$-anonymity against inference attacks, taking into consideration of adversaries’ background information. The main idea is to first quantify adversaries’ background information, and from the point of the view of adversaries, classify users’ data into four kinds: 1) independent with unknown data values; 2) local dependent with unknown data values; 3) independent with certain known data values; and 4) local dependent with certain known data values. We then move one step further, theoretically proving the bound on the performance of${k}$-anonymity corresponding to each of the four kinds of users’ data through cooperating with the noiseless privacy. We argue that such a theoretical foundation links${k}$-anonymity with noiseless privacy, theoretically proving${k}$-anonymity provides noiseless privacy. Additionally, this paper theoretically explains why${k}$-anonymity is vulnerable to inference attacks using the modified Stein method. Simulations on real check-in dataset from the location-based social network have validated our results. We believe that this paper can bridge the gap between design and evaluation, enabling a designer to construct a more practical${k}$-anonymity technique in real-life scenarios to resist inference attacks.

Network function virtualization (NFV) has been considered as a promising technology for future Internet to increase the network flexibility, accelerate the service innovation, and reduce the Capital Expenditures and Operational Expenditures costs through migrating network functions from dedicated network devices to commodity hardware. Recent studies reveal that although this migration of network function brings the network operation unprecedented flexibility and controllability, NFV-based architecture suffers from serious performance degradation compared with traditional service provisioning on dedicated devices. In order to achieve a comprehensive understanding of the service provisioning capability of NFV, this paper proposes a novel analytical model based on Stochastic Network Calculus (SNC) to quantitatively investigate the end-to-end performance bound of the NFV networks. To capture the dynamic and on-demand NFV features, both the non-bursty traffic, e.g., the Poisson process, and the bursty traffic, e.g., the Markov Modulated Poisson Process, are jointly considered in the developed model to characterize the arriving traffic. To address the challenges of resource competition and end-to-end NFV chaining, the property of convolution associativity and leftover service technologies of SNC are exploited to calculate the available resources of the Virtual Network Function nodes in the presence of multiple competing traffic and transfer the complex NFV chain into an equivalent system for performance derivation and analysis. Both the numerical analysis and extensive simulation experiments are conducted to validate the accuracy of the proposed analytical model. Results demonstrate that the analytical performance metrics match well with those obtained from the simulation experiments and numerical analysis. In addition, the developed model is used as a practical and cost-effective tool to investigate the strategies of the service chain design and resource allocations in the NFV networks.

Social media networks have shown rapid growth in the past, and massive social data are generated which can reveal behavior or emotion propensities of users. Numerous social researchers leverage machine learning technology to build social media analytic models which can detect the abnormal behaviors or mental illnesses from the social media data effectively. Although the researchers only public the prediction interfaces of the machine learning models, in general, these interfaces may leak information about the individual data records on which the models were trained. Knowing a certain user's social media record was used to train a model can breach user privacy. In this paper, we present SocInf and focus on the fundamental problem known as membership inference. The key idea of SocInf is to construct a mimic model which has a similar prediction behavior with the public model, and then we can disclose the prediction differences between the training and testing data set by abusing the mimic model. With elaborated analytics on the predictions of the mimic model, SocInf can thus infer whether a given record is in the victim model's training set or not. We empirically evaluate the attack performance of SocInf on machine learning models trained by Xgboost, logistics, and online cloud platform. Using the realistic data, the experiment results show that SocInf can achieve an inference accuracy and precision of 73% and 84%, respectively, in average, and of 83% and 91% at best.

Geographic routing has been considered as an attractive approach for resource-constrained wireless sensor networks (WSNs) since it exploits local location information instead of global topology information to route data. However, this routing approach often suffers from the routing hole (i.e., an area free of nodes in the direction closer to destination) in various environments such as buildings and obstacles during data delivery, resulting in route failure. Currently, existing geographic routing protocols tend to walk along only one side of the routing holes to recover the route, thus achieving suboptimal network performance such as longer delivery delay and lower delivery ratio. Furthermore, these protocols cannot guarantee that all packets are delivered in an energy-efficient manner once encountering routing holes. In this paper, we focus on addressing these issues and propose an energy-aware dual-path geographic routing (EDGR) protocol for better route recovery from routing holes. EDGR adaptively utilizes the location information, residual energy, and the characteristics of energy consumption to make routing decisions, and dynamically exploits two node-disjoint anchor lists, passing through two sides of the routing holes, to shift routing path for load balance. Moreover, we extend EDGR into threedimensional (3D) sensor networks to provide energy-aware routing for routing hole detour. Simulation results demonstrate that EDGR exhibits higher energy efficiency, and has moderate performance improvements on network lifetime, packet delivery ratio, and delivery delay, compared to other geographic routing protocols in WSNs over a variety of communication scenarios passing through routing holes. The proposed EDGR is much applicable to resource-constrained WSNs with routing holes.

Energy conservation and interference reduction are the two ultimate goals in the design of network protocols for wireless sensor networks (WSNs). Energy-aware geographic routing has been considered as an attractive routing scheme for energy conservation in WSNs owing to its desirable scalability and simplicity. However, most energy-aware geographic routing protocols seldom consider interference reduction. The authors present an energy-aware interference-sensitive geographic routing (EIGR) protocol, which focuses on minimising the total network energy consumption and reducing interference. EIGR adaptively uses an anchor list to guide data delivery, and selects the minimum-interference link from energy-optimal relay region for data delivery. To further reduce the energy consumption and interference, EIGR adjusts the transmission power of each forwarding node so as just to reach the selected next forwarding node. Simulation results demonstrate that the proposed approach exhibits noticeably higher energy efficiency, shorter end-to-end delay and higher packet delivery ratio compared with other geographic routing protocols.