关键词： mobile edge computing   deterministic transmission   delay and jitter   resource allocation  

摘要： Motivated by 5th generation wireless systems(5G),a large number of emerging applications appear,which put forward higher requirements for the task’s transmission determinacy,which refers to the delay and *** satisfy the deterministic requirement,mobile edge computing(MEC)is envisioned as a promising technique for reducing the end-to-end delay *** this paper,we consider delaysensitive task and jitter-sensitive task,and then formulate the joint communications and computing optimization problem under the latency,the total bandwidth,the total transmission power of base station(BS)and the computing ability of the MEC server constraints to minimize the delay and jitter in a multiuser MEC *** of the problems are nonconvex,we decouple them into some subproblems and propose the corresponding algorithms to obtain a suboptimal ***,numerical results show that the proposed algorithms have a significant performance gain over the traditional solution in terms of the delay and the jitter.

关键词： Task analysis   Games   Cloud computing   Heuristic algorithms   Statistics   Sociology   Load management   Task offloading   population game   evolutionary dynamics   nash equilibrium   mobile edge computing   Internet of Things  

摘要： Mobile edge computing (MEC) is an emerging paradigm that provides radio access networks with augmented resources to meet the requirements of Internet of Things (IoT) services. MEC allows IoT devices to offload delay sensitive and computation intensive tasks to edge clouds deployed at base stations (BSs). Offloading tasks to edge clouds can alleviate the computing and battery limitations of IoT devices. However, task offloading in MEC for IoT may face serious transmission latency and computation latency problems with massive number of IoT devices. Moreover, some edge clouds can be overloaded due to the spatially inhomogeneous distributions of IoT tasks. To solve these problems, we investigate the workload balancing problems to minimize the transmission latency and computation latency in task offloading process while considering the limited bandwidth resources of BSs and computation resources in edge clouds. We formulate the workload balancing problem as a population game in order to analyze the aggregate offloading decisions. We analyze the aggregate offloading decisions of mobile users through evolutionary game dynamics and show that the game always achieves a Nash equilibrium (NE). We further propose two workload balancing algorithms based on evolutionary dynamics and revision protocols. Simulation results show that our proposed workload balancing algorithms can achieve better performance than existing solutions.

关键词： Task analysis   Servers   6G mobile communication   Costs   Optimization   Computer architecture   Stochastic processes   Mobile edge computing   cybertwin   task offloading   hybrid energy supply   stochastic optimization  

摘要： With the development of 6G wireless communication technologies, various resource-intensive and delay-sensitive vehicle application tasks are generated. These application tasks can be offloaded to Mobile Edge Computing (MEC) which deploys computing resources at the edge of networks. Besides, the recent proposed Cybertwin, as the digital representation of the complicated physical end-systems, can help the terminals obtain the required services from networks. Vehicles enabled by Cybertwin can offload their tasks to MEC and achieve better performance. In this paper, we focus on the study of a hybrid energy-powered multi-server MEC system with Cybertwin. Vehicles enabled by Cybertwin and edge servers send the current network status and unprocessed vehicle application tasks to the macro base station (MBS) to achieve the better allocation of resources. Energy harvesting (EH) devices are deployed on edge servers to form a "green energy-grid" hybrid energy supply model. We formulate a stochastic offloading optimization problem, and the goal is to minimize the system cost. The stochastic optimization problem is decomposed into three sub-problems. Then, we design an efficient multi-vehicle task offloading (EMT) algorithm to achieve the trade-off between system cost and task queue length. Theoretical analysis shows that EMT algorithm can optimize the total cost of the MEC system and guarantee the system performance. According to experimental evaluation, we verify the performance of the EMT algorithm.

关键词： mobile edge computing   wireless metropolitan area network   workflow application   cloudlet placement   computation offloading  

摘要： With the rapid development of mobile technology, mobile applications have increasing requirements for computational resources, and mobile devices can no longer meet these requirements. Mobile edge computing (MEC) has emerged in this context and has brought innovation into the working mode of traditional cloud computing. By provisioning edge server placement, the computing power of the cloud center is distributed to the edge of the network. The abundant computational resources of edge servers compensate for the lack of mobile devices and shorten the communication delay between servers and users. Constituting a specific form of edge servers, cloudlets have been widely studied within academia and industry in recent years. However, existing studies have mainly focused on computation offloading for general computing tasks under fixed cloudlet placement positions. They ignored the impact on computation offloading results from cloudlet placement positions and data dependencies among mobile application components. In this paper, we study the cloudlet placement problem based on workflow applications (WAs) in wireless metropolitan area networks (WMANs). We devise a cloudlet placement strategy based on a particle swarm optimization algorithm using genetic algorithm operators with the encoding library updating mode (PGEL), which enables the cloudlet to be placed in appropriate positions. The simulation results show that the proposed strategy can obtain a near-optimal cloudlet placement scheme. Compared with other classic algorithms, this algorithm can reduce the execution time of WAs by 15.04-44.99%.

关键词： Mobile edge computing   synthetic theories   mobile device   suboptimal   security strategies   quality of service   deep learning  

摘要： The implementation of a variety of complex and energy-intensive mobile applications by resource-limited mobile devices (MDs) is a huge challenge. Fortunately, mobile edge computing (MEC) as a new computing paragon can offer rich resources to perform all or part of the MD's task, which greatly reduces the energy consumption of the MD and improves the quality of service (QoS) for applications. However, offloading tasks to the edge server is vulnerable to attacks such as tampering and snooping, resulting in a deep learning (DL) security feature developed by major cloud service providers. An effective security strategy method to minimize ongoing attacks in the MEC setting is proposed. The algorithm is based on the synthetic principle of a special set of strategies, and it can quickly construct suboptimal solutions even if the number of targets achieves hundreds of millions. In addition, for a given structure and a given number of patrollers, the upper bound of the protection level can be obtained, and the lower bound required for a given protection level can also be inferred. These bounds apply to universal strategies. By comparing with the previous three basic experiments, it can be proved that our algorithm is better than the previous ones in terms of security and running time.

关键词： QoS prediction   Tensor factorization   Time series   Collaborative filtering   Mobile edge computing  

摘要： Withthe rapid development of mobile Internet and wireless technologies, edge servers in mobile edge computing (MEC) provide a large number of mobile services to develop advanced and complex mobile applications. Quality of Service (QoS) is an essential indicator for recommendation and selection from such a huge number of candidate mobile services. However, QoS records are sparse in reality because users only invoke certain mobile services. How to predict missing QoS values is a key issue in operations related to mobile services. Some collaborative filtering (CF) methods have been used to solve QoS prediction problem of traditional Web services. Neverless, the high dimensionality, high sparsity and dynamic variability of QoS data in MEC limit the application of these methods. This paper proposes a temporal regularized tensor factorization method based on hybrid CF for QoS prediction of mobile services. The overall structure of QoS data is represented by constructing a user-service-time tensor model. As QoS data possesses certain characteristics of time series, a temporal regular term is introduced into CP decomposition to mine the relationship between QoS values in adjacent time intervals. The alternating least square (ALS) algorithm is used to optimize the approximate tensor iteratively. The low-rank estimation of the target tensor is obtaind to predict missing values. Extensive experimental studies on the large-scale QoS dataset WS-Dream show that our method has significantly better prediction accuracy than the other nine state-of-the-art methods under different data densities. Especially in the case of sparse data, the prediction effect is more prominent, and the accuracy increases up to 62.4% at most.

关键词： Task analysis   Servers   Games   Delays   Edge computing   Cloud computing   Energy consumption   Mobile edge computing   computation offloading   aggregative game   instantaneous load billing  

摘要： Mobile edge computing (MEC) is a promising approach that can reduce the latency of task processing by offloading tasks from user equipments (UEs) to MEC servers. Existing works always assume that the MEC server is capable of executing the offloaded tasks, without considering the impact of improper load on task processing efficiency. In this article, we present a two-stage computing offloading scheme to minimize the task processing delay while managing the server load properly. To minimize the task processing delay, each UE optimizes how much workload to be offloaded to the MEC server. To improve the task processing efficiency of the server, we arrange the processing order of offloading tasks by introducing an aggregative game with an instantaneous load billing mechanism. The proposed game can obtain the optimal task offloading and processing strategy with limited information and a small number of iterations. Simulation results show that our scheme approaches the optimal offloading strategy in terms of minimizing task processing delay for each UE and improving processing efficiency for the server.

关键词： opportunistic social network   federated learning   community restructuring   Internet of Things   deep reinforcement learning   mobile edge computing  

摘要： With the advent of the 5G era, the number of Internet of Things (IoT) devices has surged, and the population's demand for information and bandwidth is increasing. The mobile device networks in IoT can be regarded as independent "social nodes", and a large number of social nodes are combined to form a new "opportunistic social network". In this network, a large amount of data will be transmitted and the efficiency of data transmission is low. At the same time, the existence of "malicious nodes" in the opportunistic social network will cause problems of unstable data transmission and leakage of user privacy. In the information society, these problems will have a great impact on data transmission and data security;therefore, in order to solve the above problems, this paper first divides the nodes into "community divisions", and then proposes a more effective node selection algorithm, i.e., the FL node selection algorithm based on Distributed Proximal Policy Optimization in IoT (FABD) algorithm, based on Federated Learning (FL). The algorithm is mainly divided into two processes: multi-threaded interaction and a global network update. The device node selection problem in federated learning is constructed as a Markov decision process. It takes into account the training quality and efficiency of heterogeneous nodes and optimizes it according to the distributed near-end strategy. At the same time, malicious nodes are screened to ensure the reliability of data, prevent data loss, and alleviate the problem of user privacy leakage. Through experimental simulation, compared with other algorithms, the FABD algorithm has a higher delivery rate and lower data transmission delay and significantly improves the reliability of data transmission.

关键词： Training   Servers   Computational modeling   Analytical models   Wireless communication   Resource management   Energy consumption   Federated learning   energy efficiency   mobile edge computing  

摘要： In this letter, a novel joint dataset and computation management (DCM) scheme for energy-efficient federated learning (FL) in mobile edge computing (MEC) is proposed. For this purpose, with respect to the amount of dataset and computation resources, we rigorously formulated analytical models for i) learning efficiency, which considers the estimated global accuracy tendency according to the amount of dataset and service latency, and ii) the overall energy consumption of FL participants, including local training and model parameter transmission. To consider the trade-off between these two factors in the FL procedure with MEC, a theoretical framework for the DCM problem that jointly optimizes the amount of dataset and the computation resources used for local training over multiple FL clients was designed. Additionally, the extensive simulation-based performance evaluations validate the superior performance of the proposed DCM;compared to the various benchmarks in terms of the proposed cost function and test accuracy on the MNIST dataset with independent identically distributed (IID) / non-IID settings.

关键词： lightweight network   fast semantic segmentation   mobile edge computing   fundus image  

摘要： Fundus is the only structure that can be observed without trauma to the human body. By analyzing color fundus images, the diagnosis basis for various diseases can be obtained. Recently, fundus image segmentation has witnessed vast progress with the development of deep learning. However, the improvement of segmentation accuracy comes with the complexity of deep models. As a result, these models show low inference speeds and high memory usages when deploying to mobile edges. To promote the deployment of deep fundus segmentation models to mobile devices, we aim to design a lightweight fundus segmentation network. Our observation comes from the fact that high-resolution representations could boost the segmentation of tiny fundus structures, and the classification of small fundus structures depends more on local features. To this end, we propose a lightweight segmentation model called LightEyes. We first design a high-resolution backbone network to learn high-resolution representations, so that the spatial relationship between feature maps can be always retained. Meanwhile, considering high-resolution features means high memory usage;for each layer, we use at most 16 convolutional filters to reduce memory usage and decrease training difficulty. LightEyes has been verified on three kinds of fundus segmentation tasks, including the hard exudate, the microaneurysm, and the vessel, on five publicly available datasets. Experimental results show that LightEyes achieves highly competitive segmentation accuracy and segmentation speed compared with state-of-the-art fundus segmentation models, while running at 1.6 images/s Cambricon-1A speed and 51.3 images/s GPU speed with only 36k parameters.