基于参考信号接收功率预测和负载的切换算法

针对密集异构网络中用户更容易发生频繁切换的问题,提出了一种基于参考信号接收功率(Reference Signal Received Power,RSRP)预测和负载的自适应切换算法,它不仅从用户的角度考虑了RSRP,而且从网络的角度考虑了基站的负载,同时还针对切换过程中用户的移动性和信道的时变性对RSRP产生的影响,对RSRP进行预测,从而使用户切换到更加合适的目标基站。仿真结果表明,相比于当前的切换算法,所提的切换算法能够获得更低的中断概率和乒乓切换率以及更高的吞吐量。     

移动式网络中快速认证方法设计与仿真

作为移动IP技术的新的发展方向,移动式网络技术是将节点移动性向网络移动性(NEMO)扩展的关键技术,降低移动式网络在注册和认证过程中的延时,能够提高移动式网络技术的实际应用.提出了新的基于Mobile IP/AAA模型的移动式网络认证方法,研究了AAAL与AAAH之间的距离以及本地切换率对认证延时的影响,并提交了NS2仿真试验结果和安全性分析.该方法能够实现低切换时延,并保证移动式网络注册和切换中的安全性.     

微移动协议下全IP无线网络的移动性管理研究

改善移动节点通信质量的移动性管理最有效的方式是IP微移动．它的核心是切换管理．分析微IP协议和IP网络的不足之处．对全IP无线网络的移动性管理最关心的问题进行详细阐述,介绍一种目前主流的区域移动性管理协议PMIPv6．并分析其域内切换移动性管理机制。提出一种优化的基于网络的区域移动性管理域内切换管理方法．并与已形成IETF标准的切换管理方法进行性能分析比较．证明该方法可以有效地减少切换时延和位置更新信令代价．     

一种基于P2P的IP网络分层移动性管理方法

针对传统网络技术不适合移动通信且移动IP和SIP有单失效点固有缺陷的问题,文章提出了一种基于对等网络的IP网络分层移动性管理方法.该方法首先将问题结构定义为本地接入域网络和Internet全局网络两层模型,使用本地和全局两级覆盖网来处理该模型中接入网内的水平切换和跨接入网的垂直切换,并使用HIP协议来解耦静态主机标识和实际的网络位置.文章通过仿真实验指明将对等网络与移动性管理相结合的方法可以有效改善网络的可扩展性,并且信令开销和时延增加较少,此外HIP协议还为应用提供了透明的移动性和安全性的支持.     

基于NNP预测和FNNC控制的交流伺服系统研究

提出了采用动态BP神经网络预测器(NNP)预测系统输出和基于正态型激活函数的模糊神经网络控制器(FNNC)对交流伺服系统进行控制的思想,对预测器、控制器及其程序设计进行分析。仿真表明该方法具有良好的控制效果。     

飞控系统传感器故障诊断研究

研究故障检测和诊断技术对提高系统可靠性具有重要意义,针对飞控系统中常见的传感器故障,提出了基于神经网络预测器的故障诊断方法。利用传感器输出时间序列构造神经网络预测器模型,网络结构使用多层感知器结构,根据网络输出和实际输出之差与某·阈值的大小比较关系判断故障。最后针对某型飞机建立仿真模型,并对单一及多个传感器故障诊断进行研究,给出了仿真实现结果,并加以分析。仿真结果表明,所提出的基于神经网络预测器的故障诊断方法是行之有效的,能够及时准确地确定故障的发生。     

融合分层呼叫协议与GCM-FIFO的移动管理方案

针对节点高速移动的UAVS通信网络中的移动性管理问题,提出了基于分层呼叫协议的位置管理方案以及融合滞后余量与门限结合的切换判决方法、UAV节点自主决策的紧急切换控制策略和GCM-FIFO信道分配策略的切换管理方案。通过相关理论分析和图形化的测试与仿真,结果表明:分层呼叫协议解决了UAVS通信网中节点高移动性问题;针对系统切换业务量高但信道数有限的特点提出了GCM-FIFO信道分配方案,在满足一定的新呼叫阻塞的同时减小了UAV节点切换失败的概率;针对中继机节点可能被击毁而提出的UAV节点自主决策的紧急切换策略,弥补了一般性切换方案的不足。     

基于SIP无线IP网络移动管理的研究

IETF组织提出的SIP是建立、修改和终止多媒体会话的端到端应用层协议,能够满足移动性的要求。但是在会话切换的过程中会丢失数据包,产生不能忍受的延迟。该文分析了延迟产生的原因,并在此基础上提出了充分利用网络资源、由用户终端发起的BS服务器来完成软切换的解决方法。并证明这种方法能够解决切换延迟问题,有效地提高了通话质量。     

5G NR RSRP测量算法研究

RSRP(Reference Signal Receiving Power)是代表无线信号强度的关键参数,也是物理层测量的重要指标之一。当前5G NR中RSRP的测量算法多是均值法和其衍生算法,通过对现有算法的研究提出一种基于子集的共轭相乘算法。根据均值算法和共轭相乘算法进行测量值估计,并对相应算法进行测量结果的比较,进而得到子集共轭相乘算法在不同信噪比情况下可以使用不同子集数来提高RSRP估计值。将提出的新算法结合5G系统的特点与均值算法和共轭相乘算法进行比较分析,得到三种算法各自的特点。     

基于PMIPv6的移动性管理方案研究

PMIPv6协议是MIPv6协议的扩展,是一种基于网络的移动性管理技术。在PMIPv6协议中,由网络负责探测节点的移动路径并初始化所必须的移动信令,MN不参与切换过程,能量消耗低,但是PMIPv6依赖于一个独一无二的处于网络中央的本地移动锚点( LMA),容易导致瓶颈问题,且带来切换时延长、通信路径非最优等问题。基于此,提出了一种基于PMIPv6的移动性管理方案,使用簇对移动接入网关(MAG)进行分组。在每个簇中选举出一个头移动接入网关(HMAG)作为簇头,由HMAG代替LMA负责执行本簇内的移动切换以及最优化数据通信路径,这样就减少了LMA的负载,延长了网络寿命。分析及仿真结果表明所提方案与PMIPv6相比在总开销、LMA负载等方面都有较大的改善。     

Energy-aware allocation for delay-sensitive multitask in mobile edge computing

With lower network latency and powerful hardware, mobile edge computing (MEC) is effective for computation-intensive and delay-sensitive tasks. The rising energy and low-latency demands of mobile applications for MEC pose challenges to task allocation. In this work, we consider computation offloading in MEC that is composed of a set of mobile devices, each with multiple tasks to offload to a nearby MEC server, with both single and multiple access points (APs). With multiple APs deployed, each mobile device can directly communicate with one or more APs, and their tasks can offload to different MEC servers that are within direct communication range. By considering binary computation offloading mode and limited subchannels, we formulate the multitask allocation problem as an integer programming problem, with the objective of minimizing the total energy consumption of all mobile devices while meeting deadline requirements. To solve this complicated problem, we propose efficient algorithms for single and multiple APs, and analyze related properties, including the approximation ratio and complexity. Experiments show that the algorithm can find high-quality solutions in a short time.

     

基于安卓5 G信号参数获取上报的APP设计与实现

随着互联网和移动网络通信技术的快速发展,移动网络通信在短短的几年间就由2G时代、3G时代发展为目前的5G时代.在5G部署的过程中,为方便计算机能获取与分析5G信号参数,设计了一款基于安卓移动端的5G信号获取上报软件.该安卓软件以手机端为基础,通过5G移动传输网络和内部传输网络为传输途径,第一:实现了5G信号中的重要参数...     

移动边缘计算技术在高铁通信网络中的应用

随着高铁的日益普及,在高铁列车与地面之间建立移动数据通道,满足车地数据传输以及旅客上网的需求,成为越来越迫切的问题.现有GSM-R和LTE-R的解决方案,还存在带宽小、时延大、传输不稳定等问题.为此,本文提出采用移动边缘计算（Mobile Edge Computing,简称为MEC）技术来优化高铁通信网络.主要思想是在车厢和基站部署MEC服务器,经过两级MEC服务器的协同配合,达到复用空口链路、提升无线传输稳定性和降低时延的目的,并最终提升用户体验.通过实际网络试验结果显示,该方案可显著提升传输速率、减小传输时延.     

基于移动边缘计算的任务卸载优化

随着智慧物联体系的发展,物联网中应用程序的种类与数量不断增加.在移动边缘计算(mobile edge computing, MEC)中,通过允许移动用户将任务卸载至附近MEC服务器以加快移动应用程序的速度.本文通过考虑不同任务属性、用户的移动性和时间延迟约束模拟移动边缘场景.根据用户移动轨迹,将目标建模为寻找满足时延约束条件且在卸载过程中产生最小能耗MEC服务器优化模型,并提出一种最小能耗卸载算法求解该问题的最优解.仿真结果表明,在约束条件下,提出的算法可以找到在用户移动轨迹中产生最小能耗的MEC服务器,并显著降低任务卸载过程的能耗与时延,提高应用程序服务质量.     

Proximate sharing of geo data using the credit-considered mobile edge computing server switching control scheme

This paper proposed a mobile edge computing (MEC)-based point of interests (POIs) downloading and proximate sharing system for a group of people, who belong to the same mobile social networks in proximity (MSN-P) and whose handheld devices are connected in a tree-like structure. Using the proposed system, the root handheld device plays the role of an MEC server and is charge of downloading POIs' contents from the remote cloud server using 4G/5G cellular network and then forwarding POIs' contents to other group members' handheld devices using device-to-device (D2D) communication. Since the number of connected handheld devices in each handheld device is limited using D2D communication, this work proposed a control scheme called k-Connection-Limited and n-Hop (kCL-nH) tree topology's construction scheme to achieve the proximate sharing of POIs' contents. Additionally, since the root handheld device consumes more battery power than others, this work proposed a control scheme that has each group member's handheld device to be the root handheld device alternatively. A credit scheme was thus proposed to denote each handheld device's contribution, which is referred for the selecting of the next root handheld device, to achieve the fairness concern. Then, the control scheme, which is executed in the corresponding MEC server, considering both remaining battery power and credit for the switching of the root handheld device was designed. The proposed method was developed using Wi-Fi Direct over the iOS system. Experimental results have shown some interested results among power consumption, downloaded data volume and fairness among all handheld devices.     

边缘计算场景中基于虚拟映射的隐私保护卸载算法

随着移动边缘计算(Mobile Edge Computing,MEC)和无线充电技术(Wireless Power Transmission,WPT)的诞生和发展,越来越多的计算任务被卸载至MEC服务器以进行处理,并借助WPT技术为终端设备供电,以缓解终端设备计算能力受限和设备能耗过高的问题.由于卸载的任务和数据往往携...     

A review on the computation offloading approaches in mobile edge computing: A game-theoretic perspective

In recent years, novel mobile applications such as augmented reality, virtual reality, and three-dimensional gaming, running on handy mobile devices have been pervasively popular. With rapid developments of such mobile applications, decentralized mobile edge computing (MEC) as an emerging distributed computing paradigm is developed for serving them near the smart devices, usually in one hop, to meet their computation, and delay requirements. In the literature, offloading mechanisms are designed to execute such mobile applications in the MEC environments through transferring resource-intensive tasks to the MEC servers. On the other hand, due to the resource limitations, resource heterogeneity, dynamic nature, and unpredictable behavior of MEC environments, it is necessary to consider the computation offloading issues as the challenging problem in the MEC environment. However, to the best of our knowledge, despite its importance, there is not any systematic, comprehensive, and detailed survey in game theory (GT)-based computation offloading mechanisms in the MEC environment. In this article, we provide a systematic literature review on the GT-based computation offloading approaches in the MEC environment in the form of a classical taxonomy to recognize the state-of-the-art mechanisms on this important topic and to provide open issues as well. The proposed taxonomy is classified into four main fields: classical game mechanisms, auction theory, evolutionary game mechanisms, and hybrid-base game mechanisms. Next, these classes are compared with each other according to the important factors such as performance metrics, case studies, utilized techniques, and evaluation tools, and their advantages and disadvantages are discussed, as well. Finally, open issues and future uncovered or weakly covered research challenges are discussed and the survey is concluded.     

面向海洋节能边缘计算的任务卸载研究

针对海洋通信网络能源不稳定、时延较长的问题,提出一种混合能量供应的边缘计算卸载方案。对于能量供应问题,移动边缘计算(MEC)服务器集成混合电源和混合接入点,混合电源利用可再生能源为MEC服务器供应能量,采用电力电网作为其补充能源,保证边缘计算系统的可靠运行,船舶用户通过混合接入点广播的射频(RF)信号收集能量。针对任务卸载优化问题,以能耗-时延权衡优化为目标,联合能量收集方法制定任务卸载比例、本地计算能力和发射功率的优化方案,最后利用降维优化算法,将目标函数简化为关于任务卸载比例的一维多约束问题,并利用改进的鲸鱼优化算法获得最优的执行总代价。利用边缘云模拟器EdgeCloudSim仿真的结果表明,所提方案较具有能量收集的资源分配方案和基本海上通信网络优化的方案执行成本分别降低了13.4%和9.6%。     

面向5G车联网场景的移动任务动态卸载策略研究

由于车辆自身的高速移动性和资源有限性等特征,使得采用传统通信和计算手段的车联网场景无法满足用户日益增长的数据计算需求和体验质量需求。采用5G和边缘计算技术构建的新型车联网架构可以满足以上需求,但由于网络结构的变化,需设计适合新场景下的车辆任务通信和计算策略。针对5G车联网场景下的移动车辆任务动态卸载问题进行研究,提出了对应的动态任务分配策略和卸载调度低时延算法。车辆会根据提出的策略和算法将未完成的计算任务卸载到相应的 MEC 服务器或车辆上,并且计算结果将通过边缘服务器之间的联合通信或直接从被选择接受卸载任务的附近空闲车辆上直接返回给车主。仿真结果表明,所提出的策略和算法在优化卸载延迟方面具有良好的性能,并提高了用户体验质量。     

Performance evaluation and optimization of a task offloading strategy on the mobile edge computing with edge heterogeneity

The Journal of Supercomputing - With the development for the technology of mobile edge computing (MEC) and the grave situation for the shortage of global energy, the problem of computation...