无人机辅助MEC系统：架构、关键技术与未来挑战

摘 要：随着5G加速部署和6G研究工作持续推进,无人机（unmanned aerial vehicle,UAV）辅助移动边缘计算（mobile edge computing,MEC）技术在克服复杂地域限制、解决终端设备计算需求和提高系统任务卸载速率等方面具有显著优势,得到了学术界和工业界的广泛关注。首先阐明了无人机辅助MEC系统的概念和技术优势,提出了一种无人机辅助MEC通用架构,并给出了各个功能模块定义;接着总结了典型应用场景,梳理了现有的关键性技术,获得了无人机MEC系统的设计方法;最后对未来的研究方向和存在的挑战进行了展望和阐述。     

Cloud-assisted body area networks: state-of-the-art and future challenges

Body area networks (BANs) are emerging as enabling technology for many human-centered application domains such as health-care, sport, fitness, wellness, ergonomics, emergency, safety, security, and sociality. A BAN, which basically consists of wireless wearable sensor nodes usually coordinated by a static or mobile device, is mainly exploited to monitor single assisted livings. Data generated by a BAN can be processed in real-time by the BAN coordinator and/or transmitted to a server-side for online/offline processing and long-term storing. A network of BANs worn by a community of people produces large amount of contextual data that require a scalable and efficient approach for elaboration and storage. Cloud computing can provide a flexible storage and processing infrastructure to perform both online and offline analysis of body sensor data streams. In this paper, we motivate the introduction of Cloud-assisted BANs along with the main challenges that need to be addressed for their development and management. The current state-of-the-art is overviewed and framed according to the main requirements for effective Cloud-assisted BAN architectures. Finally, relevant open research issues in terms of efficiency, scalability, security, interoperability, prototyping, dynamic deployment and management, are discussed.     

NOMA物联网下多UAV辅助MEC系统的资源分配

为解决偏远地区或突发灾害等场景中的物联网(Internet of Things, IoT)设备的任务计算问题,构建了一个非正交多址接入(Non-orthogonal Multiple Access, NOMA)-IoT(NOMA-IoT)下多无人机(Unmanned Aerial Vehicle, UAV)辅助的NOMA多址边缘计算(Multiple Access Edge Computing, MEC)系统。该系统中设备的计算能耗、卸载能耗和MEC服务器计算能耗直接受同信道干扰、计算资源和发射功率的影响,可通过联合优化卸载策略、计算资源和发射功率最小化系统加权总能耗。根据优化问题的非凸性和复杂性,提出了一种有效的迭代算法解决：首先,对固定卸载策略,计算资源和发射功率分配问题可通过连续凸逼近转化为可解的凸问题;其次,对固定计算资源和发射功率,利用联盟形成博弈解决卸载策略问题,以最小化IoT设备之间的同信道干扰。仿真结果表明,较OMA接入方式,NOMA接入方式减少本地计算能耗、卸载能耗及计算能耗约20%;较无卸载策略方法,包含卸载策略方法在减少系统加权总能耗方面效果较为明显。     

基于移动边缘计算的NOMA异构网络资源分配

以最大化缓存收益为目标,针对部署缓存的NOMA异构网络下的基站用户匹配及功率分配问题,结合消息传递及DC规划提出了NOMA联合优化算法。首先将约束条件合并到目标函数中,通过计算新的优化问题中函数节点与变量节点间消息传递的边缘得到用户协同结果;然后将原优化问题变形为2个凸函数差的形式,通过DC规划对功率资源进行分配;最后迭代计算得到最终的用户协同及功率分配结果。仿真结果证明所提算法有效地提升了网络性能。     

A state-of-the-art survey on wireless rechargeable sensor networks: perspectives and challenges

Wireless Networks - Wireless rechargeable sensor network (WRSN) is an emerging technology that has risen intending to enhance network lifetime of the conventional wireless sensor networks (WSNs)....     

MEC系统中基于多智能体深度增强学习的协作式任务卸载和资源分配

移动边缘计算(MEC)通过将计算任务卸载到MEC服务器上,在缓解智能移动设备计算负载的同时,可以降低服务时延。然而目前在MEC系统中,关于任务卸载和资源分配仍然存在以下问题：1)边缘节点间缺乏协作;2)计算任务到达与实际环境中动态变化的特征不匹配;3)协作式任务卸载和资源分配动态联合优化问题。为解决上述问题,文章在协作式MEC架构的基础上,提出了一种基于多智能体的深度确定性策略梯度算法(MADDPG)的任务卸载和资源分配算法,最小化系统中所有用户的长期平均成本。仿真结果表明,该算法可以有效降低系统的时延及能耗。     

Future Internet of Things: open issues and challenges

Internet of Things (IoT) and its relevant technologies have been attracting the attention of researchers from academia, industry, and government in recent years. However, since the requirements of the IoT are quite different from what the Internet today can offer, several innovative techniques have been gradually developed and incorporated into IoT, which is referred to as the Future Internet of Things (FIoT). Among them, how to extract “data” and transfer them into “knowledge” from sensing layer to application layer has become a vital issue. This paper begins with an overview of IoT and FIoT, followed by discussions on how to apply data mining and computational intelligence to FIoT. An intelligent data management framework inspired by swarm optimization will then given. Finally, open issues and future trends of this field will be addressed.     

Deep Reinforcement Learning Based Joint Partial Computation Offloading and Resource Allocation in Mobility-Aware MEC System

Mobile edge computing(MEC) emerges as a paradigm to free mobile devices(MDs) from increasingly dense computing workloads in 6G networks. The quality of computing experience can be greatly improved by offloading computing tasks from MDs to MEC servers. Renewable energy harvested by energy harvesting equipments(EHQs) is considered as a promising power supply for users to process and offload tasks. In this paper, we apply the uniform mobility model of MDs to derive a more realistic wireless channel...     

Control and management in next-generation networks: challenges andopportunities

This article discusses the challenges and opportunities associated with a fundamental transformation of current networks toward a multiservice ubiquitous infrastructure with a unified control and management architecture. After articulating the major driving forces for network evolution, we outline the fundamental reasons why neither the control infrastructure of the PSTN nor that of the present-day Internet is adequate to support the myriad of new services in next-generation networks. Although NGN will inherit heavily from both the Internet and the PSTN, its control and management architecture is likely to be radically different from both, and will be anchored on a clean separation between a QoS-enabled transport/network domain and an object-oriented service/application domain, with a distributed processing environment that glues things together and universally addresses issues of distribution, redundancy, and concurrency control for all applications. Finally, we allude to the transition issues and show how voice-over-packet services are emerging as the bootstrap application for marshaling in the NGN architecture     

Transmission power control in wireless ad hoc networks: challenges, solutions and open issues

Recently, power control in mobile ad hoc networks has been the focus of extensive research. Its main objectives are to reduce the total energy consumed in packet delivery and/or increase network throughput by increasing the channel's spatial reuse. In this article, we give an overview of various power control approaches that have been proposed in the literature. We discuss the factors that influence the selection of the transmission power, including the important interplay between the routing (network) and the medium access control (MAC) layers. Protocols that account for such interplay are presented.     

Key research challenges in network management

Although network management has always played a key role for industry, it only recently received a similar level of attention from many research communities, accelerated by funding opportunities from new initiatives, including the FP7 Program in Europe and GENI/FIND in the United States. Work is ongoing to assess the state of the art and identify the challenges for future research in the field, and this article contributes to this discussion. It presents major findings from a two-day workshop organized jointly by the IRTF/NMRG and the EMANICS Network of Excellence, at which researchers, operators, vendors, and technology developers discussed the research directions to be pursued over the next five years. The workshop identified several topic areas, including management architectures, distributed real-time monitoring, data analysis and visualization, ontologies, economic aspects of management, uncertainty and probabilistic approaches, as well as understanding the behavior of managed systems.     

Federated management of the Future Internet: status and challenges

The Internet's original static services have been superseded by rich multimedia services with stringent end‐to‐end quality‐of‐service requirements. Additionally, there has been a trend from simple applications offered by a single provider towards service compositions, managed across the bounds of multiple domains. It is widely accepted that the end‐to‐end requirements of multimedia and composed services cannot be satisfied by the current Internet, which does not support inter‐domain collaboration. The network federation paradigm was advanced to address these limitations. It envisions the automatic negotiation and management of dynamic agreements between network domains, allowing them to collaborate to achieve goals they cannot achieve alone. This article presents an overview of state‐of‐the‐art research in the area of federated network management. Specifically, existing definitions are compared and aligned. Moreover, the most important efforts towards an architecture for a federated Future Internet are discussed. Finally, we have identified several important research challenges that need to be tackled before the federated Future Internet vision can be fully achieved. For each of these challenges, existing research efforts are surveyed and remaining open issues identified. Copyright © 2012 John Wiley & Sons, Ltd.     

Resource prediction and management in active networks

Active networks provide a programmable user–network interface that supports dynamic modification of the network's behavior. Network nodes, in addition to forwarding packets, perform customized computation on the messages flowing through them. Resources in an active network mainly consist of CPU and bandwidth. The inherent unpredictability of processing times of active packet poses a significant challenge in CPU scheduling. It has been identified that prior estimation of the resource requirements of a packet is very difficult since it is platform dependent and also depends on processing load at the time of execution, operating system scheduling, etc. An efficient allocation is required for the optimal utilization of resources. In this paper, resources are estimated using prediction techniques such as single exponential smoothing (SES), adaptive‐response‐rate single exponential smoothing (ARRSES) and Holt's two‐parameter estimation models. The estimated results agreed most with the actual requirements. The estimation models were compared with model criteria. An algorithm was also designed for the allocation of resources. Effectiveness of the algorithm was measured through simulation and achieved almost perfect fairness for all flows and also provided much superior delay guarantees under a highly dynamic environment. Copyright © 2008 John Wiley & Sons, Ltd.     

Resource management and dimensioning in ATM networks

A general overview of resource management aspects of ATM networks is presented, and mechanisms of load control have been considered. A general framework of resource management is first addressed. Two main aspects of traffic characterization are then examined from the traffic engineering point of view: teleservice characterization and user characterization. These form the basis of the analysis that follows. In particular, a bandwidth assignment proposal is presented and evaluated by simulation. Policing issues are discussed. The advantages of the proposed assigned method over the peak bit rate allocation method is proved for two typical dimensioning cases     

无人机辅助传感器网络中吞吐量与节点能量优化方法

无人机凭借其高机动性可以对传感节点进行无线数据采集和无线供能,然而无线数据采集与无线供能是相互耦合的,如何对两者的资源分配和无人机飞行轨迹进行优化是无人机辅助无线供能传感器网络性能的关键。为此,提出了一种联合优化方案,通过交替优化节点接入、无人机三维飞行轨迹和能量数据传输时间分配,最大化最小节点效用。针对无线供能传感器网络模型中最大化最小节点效用问题提出了一个联合优化方案。由于该问题为非凸问题,提出了一个最大化最小节点效用算法(Maximized the Minimum Node Utility Algorithm,MMNUA),采用块坐标下降法将原始问题转化成4个子问题,并利用连续凸近似技术在每次迭代时依次优化4个子问题,使最大化最小节点效用逐渐收敛。与基础无人机方案相比,MMNUA使系统性能分别提升了14.1%、567.5%和177.0%,有效提高了无人机的工作效率,同时所提算法具有良好的收敛性和较小的复杂度。     

GMPLS operations and management: today's challenges and solutions for tomorrow

This article examines the technical challenges involved in the delivery of GMPLS, and in particular the challenges in managing these networks. This article focuses first on requirements gathered from customers who are deploying GMPLS in their networks, or will be doing so in the near future. The motivations for these requirements are often based on a service provider's next-generation network designs that are motivated primarily by network convergence, and the promised operational and capital expense reductions and architectural simplifications over existing segregated network designs. This article then considers various solution options to manage GMPLS networks based on these requirements. The key areas examined include provisioning/configuration, performance monitoring and operations and management, and tools that can be used for these purposes. We conclude with a recap of standardization issues and opportunities.     

Cooperative caching algorithm of UAV and user in UAV-assisted cellular network

Aiming at the problem of mass data content transmission and limited wireless backhaul resource of UAV in UAV-assisted cellular network,a cooperative caching algorithm for cache-enabled UAV and user was proposed.By deploying caches on UAV and user device,the popular content requested by user was cached and delivered,which alleviated the backhaul resource and energy consumption of UAV,reduced the traffic load and user delay.A joint optimization problem of UAV and user caching was established with the goal of minimizing user content acquisition delay,and decomposed into UAV caching sub-problem and user caching sub-problem,which were solved based on alternating direction method of multiplier and global greedy algorithm respectively.The iterative way was used to obtain convergent optimization result,and the cooperative caching of UAV and user was realized.Simulation results show that the proposed algorithm can effectively reduce user content acquisition delay and improve system performance.     

OFDM for cognitive radio: merits and challenges [accepted from open call]

Cognitive radio is a novel concept that enables wireless systems to sense the environment, adapt, and learn from previous experience to improve the quality of the communication. However, CR requires a flexible and adaptive physical layer in order to perform the required tasks efficiently. In this article, CR systems and their requirement of a physical layer are discussed, and the orthogonal frequency division multiplexing technique is investigated as a candidate transmission technology for CR. The challenges that arise from employing OFDM in CR systems are identified. The cognitive properties of some OFDM-based wireless standards also are discussed to indicate the trend toward a more cognitive radio.     

Signal processing challenges in active queue management

The publication of Floyd and Jacobson's seminal paper "Random early detection gateways for congestion avoidance" (1993), marked a new direction in networking research and began what is perhaps the most investigated example of cross-layer optimization. While this paper has inspired an immense amount of work in research, many open problems in active queue management (AQM) still remain. This article seeks to frame these problems in terms accessible to the signal processing researchers. The basic idea of AQM has been provided as well as its objective and overviews of a sample of different approaches. The signal processing aspects of the AQM are discussed, specifically the problem of predicting congestion, approaches to detecting changes in network traffic, an estimation problem, dithering, and quantization.     

Resource management in software-programmable router operatingsystems

Future routers will not only forward data packets but also provide value-added services, such as security, accounting, caching, and resource management. These services ran be implemented as general programs, to be invoked by traversing packets embedding router program calls. Software-programmable routers pose new challenges in the design of router operating systems (OS). First, router programs will require access to diverse system resources. The resource demands of a large community of heterogeneous resource consumers must either be coordinated to enable cooperation or arbitrated to resolve competition. Second, it is beneficial to concurrently support multiple virtual machines, each with a guaranteed share of physical resources. This allows services to be customized and to seamlessly evolve. We present the design and implementation of a next generation router OS that can meet the above challenges. We define an orthogonal kernel abstraction of resource allocation, which can schedule various time-shared and space-shared resources with quality of service (QoS) differentiation and guarantees. A scalable and flexible packet classifier enables dynamic resource binding and per-flow processing of received packets. We have prototyped our system on a network of UltraSPARC and Pentium II computers. Currently, QoS-aware schedulers for CPU time, forwarding bandwidth, memory-store capacity, and capacity for secondary data stores have been integrated. We present experimental results on various aspects of resource management in our system