Joint Task Migration and Power Management in Wireless Computing

We investigate a wireless computing architecture, where mobile terminals can execute their computation tasks either 1) locally, at the terminal's processor, or 2) remotely, assisted by the network infrastructure, or even 3) combining the former two options. Remote execution involves: 1) sending the task to a computation server via the wireless network, 2) executing the task at the server, and 3) downloading the results of the computation back to the terminal. Hence, it results to energy savings at the terminal (sparing its processor from computations) and execution speed gains due to (typically) faster server processor(s), as well as overheads due to the terminal server wireless communication. The net gains (or losses) are contingent on network connectivity and server load. These may vary in time, depending on user mobility, network, and server congestion (due to the concurrent sessions/connections from other terminals). In local execution, the wireless terminal faces the dilemma of power managing the processor, trading-off fast execution versus low energy consumption. We model the system within a Markovian dynamic control framework, allowing the computation of optimal execution policies. We study the associated energy versus delay trade-off and assess the performance gains attained in various test cases in comparison to conventional benchmark policies.     

BT's Mobile Joint Ventures and Alliances

This paper outlines the current status of the BT Group mobile joint ventures, in terms of shareholding, and goes on to highlight the key challenges BT has faced in order to increase its global reach.A new mobile operator, as a fresh entrant into an already competitive market, has to face a range of major challenges. These key to-date challenges are discussed, along with experiences from a number of major mobile ventures within Europe.With an increasing number of the mobile ventures obtaining licences to operate 3rd generation mobile networks (i.e. UMTS) there is another set of 'new challenges' to be identified and overcome. The preparations for meeting these new challenges posed by the introduction of 3rd generation mobile networks are outlined, alongside some initiatives from BT Group as part of their contribution to the new 'wireless family'.     

Joint Task Scheduling,Resource Allocation,and UAV Trajectory under Clustering for FANETs

This paper establishes a new layered flying ad hoc networks(FANETs) system of mobile edge computing(MEC) supported by multiple UAVs,where the first layer of user UAVs can perform tasks such as area coverage, and the second layer of MEC UAVs are deployed as flying MEC sever for user UAVs with computing-intensive tasks. In this system, we first divide the user UAVs into multiple clusters, and transmit the tasks of the cluster members(CMs) within a cluster to its cluster head(CH). Then, we need to determine whether each CH’ tasks are executed locally or offloaded to one of the MEC UAVs for remote execution(i.e., task scheduling), and how much resources should be allocated to each CH(i.e., resource allocation), as well as the trajectories of all MEC UAVs.We formulate an optimization problem with the aim of minimizing the overall energy consumption of all user UAVs, under the constraints of task completion deadline and computing resource, which is a mixed integer non-convex problem and hard to solve. We propose an iterative algorithm by applying block coordinate descent methods. To be specific, the task scheduling between CH UAVs and MEC UAVs, computing resource allocation, and MEC UAV trajectory are alternately optimized in each iteration. For the joint task scheduling and computing resource allocation subproblem and MEC UAV trajectory subproblem, we employ branch and bound method and continuous convex approximation technique to solve them,respectively. Extensive simulation results validate the superiority of our proposed approach to several benchmarks.     

Joint Optimization of Trajectory and Task Offloading for Cellular-Connected Multi-UAV Mobile Edge Computing

Since the computing capacity and battery energy of unmanned aerial vehicle(UAV)are constrained,UAV as aerial user is hard to handle the high computational complexity and time-sensitive applications.This paper investigates a cellular-connected multi-UAV network supported by mobile edge computing.Multiple UAVs carrying tasksfly from a given initial position toa termination position within a specified time.To handle the large number of tasks carried by UAVs,we propose a energy cost of all UAVs based problem to determine how many tasks should be offloaded to high-altitude balloons(HABs)for computing,where UAV-HAB association,the trajectory of UAV,and calculation task splitting are jointly optimized.However,the formulated problem has nonconvex structure.Hence,an efficient iterative algorithm by applying successive convex approximation and the block coordinate descent methods is put forward.Specifically,in each iteration,the UAV-HAB association,calculation task splitting,and UAV trajec-tory are alternately optimized.Especially,for the nonconvex UAV trajectory optimization problem,an approximate convex optimization problem is settled.The numerical results indicate that the scheme of this paper proposed is guaranteed to converge and also significantly reduces the entire power consumption of all UAVs compared to the benchmark schemes.     

十堰本地网资源管理系统及其安全措施

根据中国电信集团公司南北拆分重组后的“五集中、五创新”战略规划和在全国范围推广的精神,十堰市电信分公司在湖北省通信公司的统一部署下,于2003年10月开始建设本地网络资源集中管理系统,现已完成系统软、硬件的调测并已投入运行。     

互联网中身份管理应对策略思考

随着Web2.0的出现,互联网进入第三个高速发展阶段,互联网已经成为日常生活中的重要组成部分,同时互联网上的个人隐私泄露与保护问题也日益凸显。因此,建立以身份管理为核心的信息网络基础设施,用于规范个人信息管理,提升政府的监管能力,促进ICT网络的融合与发展。本文从互联网典型身份管理技术方案分析入手,继而分析互联网中身份管理相关问题,提出身份管理作为信息网络重要基础设施的应对策略以及下一步的研究建议。     

A Survey on Traffic Management in Software-Defined Networks: Challenges,Effective Approaches,and Potential Measures

Software-defined networks (SDNs), as an emerging paradigm by separating the control plane from the data plane, increases flexibility and network utilization and reduces redundancy and operational cost. Traffic management of software-defined networks can be defined as network traffic monitoring and analyzing measures to improve network performance and quality of service metrics. Traffic management as an effective instrument for optimizing network traffic can offer the appropriate services according to network situation. Due to the inherent characteristics of SDN, special techniques are required to analyze, predict, and adapt the network traffic in order to achieve an efficient traffic management mechanism. This paper surveys traffic management techniques of SDN in four distinct categories including, routing, load balancing, congestion control, and flow control to cover the impressible issues. Moreover, the differences between SDN and traditional networks are analyzed in terms of traffic management necessities across the various groups to further determine the dimensions affecting research in this area. Furthermore, the available algorithms in each group and their role in traffic management are reviewed as well as the research challenges and future trends.

     

一类人机交互访问冲突控制策略及算法研究

对访问控制中的访问冲突检测及控制问题进行了研究,首先分析了访问冲突的研究现状和存在的不足,在经典的基于角色的访问控制思想基础上,加入人工干预环节,提出了人机交互访问冲突控制策略,分别给出了冲突检测算法和冲突控制算法,最后用一个实验验证了算法的有效性.     

Joint Optimum Linear Precoding and Power Control Strategies for Downlink MC-CDMA Systems

In this paper we derive two iterative joint precoding and power allocation methods for downlink MC-CDMA systems with multiple transmit antennas at the base station. The first method optimally solves the so called assigned target SINRs problem, i.e. determines the precoding coefficients and the minimum sum-power allocation under a constraint on the SINR of each user. The second method instead solves the maximum sum-rate problem, i.e. maximizes the system throughput under a constraint on the overall transmit power. The main result of this paper is that the proposed joint precoding and power control solutions provide an advantage with respect to suboptimal solutions for a fully loaded system, i.e. when the number of users is equal to the spreading factor times the number of transmit antennas. For lower loads, performance of the various schemes becomes closer.     

Using Fuzzy Cognitive Maps for Knowledge Management in a Conflict Environment

In modern military battlefield environments, the availability of data and information has increased exponentially. Through information and communications technology, individuals and teams can access real-time data about almost any aspect of their current conflict situation, but this instantaneous availability of information to individuals and teams in these conflict situations does not always result in better or faster decisions. Instead, the speed and volume of data made available through surveillance, monitoring, analysis, computer, and communications technology can quickly overwhelm decision makers. Worse, different decision makers that need to coordinate their actions as part of a team effort might use different filters to reduce their data to something more manageable, or what they perceive as more relevant, to their emerging situation. To better manage the information in real time, a mediator is necessary. Fuzzy cognitive maps are proposed as one possible technique for mediating the information made available to decision makers. Such maps were used as part of a research project that used novice teams to simulate an Airborne Warning and Control System (AWACS) crew managing air assets in a conflict situation. The process of constructing the maps, their role in the simulation, and preliminary results of the test runs of the AWACS simulation are presented     

Joint Transmitter Power Control and Mobile Cache Management in Wireless Computing

We investigate efficient schemes for data communication from a server (base station and access point) to a mobile terminal over a wireless channel of randomly fluctuating quality. The terminal user generates requests for data items. If the buffer (cache) of the terminal contains the requested data, no access delay/latency is incurred. If not, the data is downloaded from the server, and until becoming available locally at the terminal, the user incurs a delay cost. Moreover, a transmission/power cost is incurred to transmit the data over the wireless link at a dynamically selected power level. To lower both the access delay and transmission costs, the system may prefetch data predictively and cache them on the terminal (especially during high-link-quality periods), anticipating future user requests. The goal is to jointly minimize the overall latency and power costs by dynamically choosing what data to (pre)fetch, what power level to use, and when to use it. We develop a modeling framework (based on dynamic programming and controlled Markov chains) that captures essential performance trade-offs. It allows for the computation of optimal decisions regarding what data to (pre)fetch and what power levels to use. To cope with emerging complexities, we then design efficient online heuristics whose simulation analysis demonstrates substantial performance gains over standard approaches.     

基于GLV模型的异构网络联合无线资源管理

为使不同的无线接入网络协同工作,实现异构无线网络的接纳控制,基于生态学种群竞争与异构无线网络资源管理的映射关系,提出了一种分布式联合无线资源管理(JRRM)算法。建立了基于Gause-Lotka-Volterra(GLV)的异构网络业务量预测模型,根据预测的业务量是否达到共存状态来调整网络参数,以使各网络的业务量达到稳定平衡状态。性能分析与仿真结果表明,该算法可以均衡各个网络的业务量,减少竞争对于网络的影响,使不同网络运营商均获得了一定收益。     

破解技术及管理复杂度与网络信息安全的矛盾

随着信息化的不断深化与扩大．局域网的应用越来越普及,其网络服务的种类与网络资源也越来越多。局域网的网络服务与网络资源具有有限开放的特性,也就是说．除大多数的网络服务与网络资源只对某些特定的网络人群开放外,一部分网络服务与网络资源是共用的(例如邮件服务及提供此服务的网络服务器)。1     

通信工程项目中的风险管理与控制策略研究

现代通信技术的发展推动了通信工程市场的繁荣,通信工程建设规模不断扩大,通信工程项目建设中必然存在多重风险,为了获取更多的经济效益,就必须强化风险管控,提高风险管控工作效率,最大程度地控制风险,从而在风险管控工作中获得良好的经济效益。     

Ventricular Intramyocardial Electrograms and Their Expected Potential for Cardiac Risk Surveillance, Telemonitoring, and Therapy Management

Ventricular intramyocardial electrograms are recorded with electrodes directly from the heart either in intraventricular or epimyocardial position and may be acquired either from the spontaneously beating or from the paced heart. The morphology of these signals differs significantly from that of body surface ECG recordings. Although the morphology shows general characteristics, it additionally depends on different individual impacts. This problem of individual evaluation is briefly discussed. As an appropriate methodology for its solution, personalized referencing based on similarity averaging has been employed. A more general approach may be model-based signal interpretation, which is still under investigation. The preliminary results reveal a promising potential of intramyocardial electrograms for cardiac risk surveillance, e.g., for arrhythmia detection, recognition of rejection events in transplanted hearts, and assessment of hemodynamic performance. Employing implants with telemetric capabilities may render possible permanent and even continuous cardiac telemonitoring. Furthermore, the signals can be utilized for supporting therapy management, e.g., in patients with different kinds of cardiomyopathies. This paper shall demonstrate some preliminary results and discuss the expected potential.      

基于移动代理和信任机制的网格作业管理

介绍了网络计算环境下的作业管理,引入了移动代理技术和信任机制,并进行了深入分析,对所用到的关键技术进行了详细的解释,说明了基于移动代理和信任机制的网格作业管理运行步骤.     

基于XML的桌面个性化任务管理软件的设计与实现

桌面个性化任务管理软件是一种具有形象以及互动功能的桌面工具,它不但可以调节人们操作计算机时对屏幕的枯燥感,还同时在桌面提供更多有用的信息及实用的小功能。通过分析系统需求,设计了以Delphi为开发工具,以XML为数据存储工具,从而实现了开机自动运行管理功能、闹铃功能、碰撞动画功能、记事与提醒功能、皮肤设置等实用功能的开发。     

再流焊焊点可靠性自动管理系统

加热因子Q是描述SMT再流焊过程的一个量化参数,决定了再流焊工艺以及焊点的可靠性,其大小直接反映了焊点的吸热量以及焊接界面形成的金属间化合物的形态.通过自动再流焊管理系统(ARM)对温度曲线进行监控和优化,调整加热因子,实现可靠的产品焊接.     

IMT—2000及中国的频谱管理策略

本文简要汇总了ＩＭＴ－２０００及先进ＬＥＯ／ＭＥＯ／ＧＥＯ卫星通信新发展，进而论述了中国频谱规划的基本原则和针对ＩＭＴ－２０００中国的频谱管理策略。