基于终端干扰和链路稳定性的多终端协同维护机制

在泛在末梢环境中,为了减少协同方案维护代价,满足一定的业务质量需求,提出了一种基于终端干扰和链路稳定性的多终端协同维护机制(MDCMM)。该机制建立了协同方案维护模型,结合终端干扰和链路稳定性确定了维护指标,并使用动态规划思想优先选择可靠的协同方案,减少方案切换对用户的干扰,满足用户多样化的业务质量需求。经OPNET和MATLAB仿真实验,该机制具有较低的维护代价,并且协同方案切换更平滑,证明该机制能更好地保障用户体验。     

泛在末梢环境下基于动态备用的业务应急机制

在移动自组织网络(MANET)组成的泛在末梢环境下,由于终端能力有限及网络拓扑的动态变化,无法保证持续高质量的异构业务。该文提出一种基于动态备用的业务应急机制,实现备用指标函数的构建和业务修复策略的设计,包括业务发现、业务选择和业务维护3个阶段。首先,该文综合终端个体能力、协同能力及终端移动性预测,抽象出备用指标函数模型。其次,针对业务选择阶段提出基于时间预测算法(TPA)来构建稳健的业务执行及备用的终端集合。再次,针对业务维护过程的失效,提出全局备用算法(GBA)来动态维持业务的持续性。最后,通过仿真表明在该机制作用下,业务中断次数少于基于动态监督器的业务恢复方法(DMBSRS)和冷备用业务替代策略(CBSRS)约30%~45%和14%~28%,在效益方面分别高于这两者约10%~40%和0%~25%,同时具有最小重启时间,由此证明该机制具有较优的效率。     

基于多终端协同的业务流控制

文章基于IP多媒体子系统(IMS)分层网络架构模型,设计了一种基于多终端的业务流控制系统构架。根据该系统架构和多终端协同的特征,文章提炼出基于多终端协同的业务流控制所面临的关键技术需求。满足这些需求可充分发挥网络与终端融合协同所带来的个人化、智能化业务能力,改善信息传输服务质量,为用户提供智能化业务体验。文章通过阐述两种典型的多终端协同应用场景——多网协作传输和移动性管理,说明了基于多终端协同的业务流控制所具有的重要意义。     

移动泛在环境中的分布式终端技术

未来的无线接入技术的异构性使得终端向着可重构的方向发展,而个人周边的智能设备逐渐增多,成为未来移动业务不可忽视的一部分,两者的结合将引出一种新的重构方式,通过个人周边智能设备的协同工作,构成一个分布式的终端系统,不仅能够适应不同接入网的变化,而且能更充分地利用个人周边智能设备的业务能力,为用户提供更佳业务体验。     

普适计算与泛在网络

本文简要描述了普适计算的概念及普适计算的研究体系;泛在网络的概念及与普适计算的关系.简要介绍了移动泛在网络发展的愿景.在此基础上,较详细地讨论了我国专家们在泛在网络研究领域中提出的"环境感知泛在网络(AUN)"的概念和框架结构.     

面向业务的多终端动态协同构造机制

在MANET组成的泛在末梢环境中,网络的时变性和终端能力的有限性无法保证持续性的高质量异构业务。该文首先定义了通用的泛在个性化业务模型,并提出了综合业务上下文信息的多终端协同问题;在此基础上,提出了基于启发式的多终端协同构造机制,实现执行业务终端集合的构造,包括业务发起、多终端协同构造和质量监测3部分;最后,通过OPNET和MATLAB仿真,在支持差异性业务的同时,丢包率较动态嵌入式任务任播(DTA)提高了3%～17%,达到了面向业务的终端任播(SDA)相同的水平,并且在能耗方面相对于前两者节约了0%～20%,同时缩短了业务重启过程的时间,由此证明该机制具有较优的效率。     

无线泛在网络下虚拟终端技术研究综述

首先,简要介绍了虚拟终端技术的产生背景及定义,然后对虚拟终端典型应用场景进行了描述。之后系统的介绍了虚拟终端系统架构并分析其优缺点,提出一种全新的系统架构方式。再次,对于虚拟终端通信协议及机制、虚拟终端资源优化策略进行了描述,最后提出了未来的研究方向。     

FMC环境下的多终端绑定机制

随着固定移动融合网络和智能终端的高速发展,用户已经不满足于只通过一个终端获取业务,同一用户多个终端间的协同成为业界研究的重点.本文首先提出了一种基于网络侧的多终端绑定机制,通过这种绑定机制可以将FMC环境下的多个终端绑定起来构成一个虚拟终端,使接入固定网的终端和接入移动网络的终端联合起来为用户提供服务,实现多终端协同.为了解决绑定机制中的终端选择问题,本文构建了一个多属性加权数学模型,以辅助终端选择,并通过原型系统验证了所提出的绑定机制的有效性.     

泛在融合网络下的个性化业务动态合成技术研究

在融合多种异构网络的泛在网络中,网络需要实时地发布、发现、聚合和适配多样的个性化业务。个性化业务动态合成能快速搜索合适业务组件进行协同工作以满足丰富多彩的用户体验。本文首先基于SOA架构对业务合成进行建模．然后引入由调用监控器、业务路由器、业务发现器和接口适配器四部分组成的基于用户活动的动态业务融合管理器,并对其内部的各个功能模块进行了具体的说明分析,最后设计场景描述了个性化业务动态合成的工作流程。     

基于网络中多终端融合通信业务实现研究

随着社会经济的变革发展,各个行业领域发生前所未有的变化,对网络的需求日益强烈,使得网络通信业务得到质的飞跃。网络通信出现的重要变化则是多终端融合通信业务实现,此项变化对于网络通信行业而言是一项革命性的转变,使用户体验与宽带水平之间存在的矛盾问题得以有效解决,使通信更加规范、标准之智能化。鉴于此,文章对网络中多终端融合通信业务实现展开分析研究,因此为相关人员提供帮助。     

Theil Utility Based Multi-Device Cooperation Mechanism for Service Quality Equilibrium in Ubiquitous Stub Environments

An approach to make heterogeneous devices cooperate with each other to provide ubiquitous service remains a longstanding challenge in ubiquitous environments. In addition, when multi-user request ubiquitous services simultaneously, the arbitrariness in resource allocation process easily leads to non-equilibrium of qualities of multi- user＇s services. Thus, How to design an effective heterogeneous devices cooperation mechanism that meet the QoS requirements and also equilibrate QoS among multi-user＇s services becomes a very tough problem. In the paper, Equilibrium Index and Theil Utility function are imported to establish a multi- device equilibrium cooperation model, which is benefit for resource allocation in ubiquitous environments. Then a Theil-Equilibrium based Cooperation Mechanism for multi-service is proposed. Firstly, in order to simplify calculating, a dimensionless processing is introduced. After that, a cooperation approach with Theil-Utility Heuristic algorithm is designed to choose the best solution for the simplified model. At last, the mechanism is simulated in a smart home scenario. The simulation results show that this mechanism outperforms non-equilibrium method by improving almost 40% in internal equilibrium with just reducing 0-2% in the total utility of all the requested ubiquitous services. These data show that the proposed mechanism performs well in equilibrating qualities of multi-user＇s ubiquitous services.     

An optimal solution to resource allocation among soft QoS traffic in wireless network

Optimization theory and nonlinear programming method have successfully been applied into wire‐lined networks (e.g., the Internet) in developing efficient resource allocation and congestion control schemes. The resource (e.g., bandwidth) allocation in a communication network has been modeled into an optimization problem: the objective is to maximize the source aggregate utility subject to the network resource constraint. However, for wireless networks, how to allocate the resource among the soft quality of service (QoS) traffic remains an important design challenge. Mathematically, the most difficult comes from the non‐concave utility function of soft QoS traffic in the network utility maximization (NUM) problem. Previous result on this problem has only been able to find its sub‐optimal solution. Facing this challenge, this paper establishes some key theorems to find the optimal solution and then present a complete algorithm called utility‐based allocation for soft QoS to obtain the desired optimal solution. The proposed theorems and algorithm act as designing guidelines for resource allocation of soft QoS traffic in a wireless network, which take into account the total available resource of network, the users’ traffic characteristics, and the users’ channel qualities. By numerical examples, we illustrate the explicit solution procedures.Copyright © 2013 John Wiley & Sons, Ltd.     

基于服务质量的相控阵雷达网目标分配方法

针对目前相控阵雷达网目标分配模型中约束条件构建不合理以及求解算法性能不高的问题,该文构建了基于服务质量(QoS)的雷达网目标分配模型,并提出基于强凹曲线逼近的模型求解算法。通过QoS模型中资源空间、环境空间的建立准确描述雷达的资源限制以及雷达与目标的可见性约束;通过库恩-塔克(KKT)条件推导出QoS模型最优解存在的充分条件,利用2维快速遍历方法逼近得到强凹函数曲线,最后对每个目标强凹曲线中的操作设定点进行逐步迭代得出优化分配方案。仿真结果表明：模型能够有效完成雷达网任务分配,且所提模型求解算法相比典型的智能搜索算法有更好的性能。     

Design and performance analysis of an efficient single flow IP traceback technique in the AS level

Network security is a major challenge for big and small companies. The Internet topology is vulnerable to Distributed Denial of Service (DDoS) attacks as it provides an opportunity to an attacker to send a large volume of traffic to a victim, which can limit its Internet availability. The main problem in the prevention of the DDoS attack, also known as the flooding attack, is how to find the source of traffic flooding. This is because the spoofed source Internet protocol (IP) address of packets is not affected on its routing. As a result, IP traceback techniques are proposed to find the source of attack and in general, to find the source of any packet. Doing so, the IP traceback techniques can help us to prevent the Denial of Service (DoS) and DDoS attacks. In this paper, we propose an efficient Single Flow IP Traceback (SFT) technique in the Autonomous System (AS) level. Furthermore, a path signature generation algorithm is presented for detecting and filtering the spoofed traffic. Our solution assumes a secure Border Gateway Protocol (BGP)‐routing infrastructure for exchanging authenticated messages in order to learn the path signatures, and it uses a marking algorithm in the flow level for transmission of the traceback messages. Because in our technique less bits are required to mark the IP header packet, the required storage space for any unique path to the victim is significantly decreased. Compared with the other existing techniques, the obtained results demonstrate that our technique has the least marking rate, overhead processing on the middle nodes, and destination's computational cost while offering the highest accuracy in tracebacking attack.     

Overview on Technical Issues for Future Mobile Network and a Proposal of DLC Scheme in Wireless Link

This paper gives an overview on technical issues for future mobile networks. the QoS control for multimedia services, security function, expansion of network capacity, expansion of address space, multicast function, radio link quality and mobility control of terminals are taken up as technical issues.Then, a novel DLC scheme in wireless link named EREP-ARQ (Estimation and Report of Error Pattern ARQ) which can reduce the retransmission ratio is proposed. In this scheme, error pattern generated in the radio link is estimated at the receiver side and the estimated error pattern is returned to the transmission side. If the estimation is correct, no retransmission is needed. Compared to conventional SR-ARQ, throughput can be improved by17% and Cell Loss Ratio (or Packet Loss Rate) can be reduced to less than 1/10 by the proposed EREP-ARQ.     

Design Method of Logical Topologies with Quality of Reliability in WDM Networks

As the bandwidth capacity of WDM networks continues to grow rapidly,traffic loss caused by a failure of network components is becoming unacceptable. To prevent such traffic loss and thus enhance network reliability, a protection method that prepares backup lightpaths for each working path is now being developed. In this paper, we first introduce the concept of QoR (quality of reliability), which is a realization of QoS with respect to the reliability needed in a WDM network. We define QoR in terms of the recovery time from when a failure occurs to when traffic on the affected primary lightpath is switched to the backup lightpath. After that, we propose a heuristic algorithm that can be used to design a logical topology that satisfies the QoR requirement for every node pair. The objective is to minimize the number of wavelengths needed for a fiber in the logical topology to carry the traffic with the required QoR. We compare this algorithm with two existing algorithms and show that it enables more effective use of wavelength resources; with the proposed algorithm, up to 25% fewer wavelengths are needed than with the other algorithms.     

Performance of adaptive token allocation in the leaky bucket

The leaky bucket is a popular method that can regulate traffic into an ATM broadband network. This paper examines a simple but innovative modification that would also provide priority to access the network. This is done by requiring cells of different classes to obtain different numbers of tokens before receiving their services. As a step further, a dynamic scheme can be used in which the tokens allocated to each class are changed according to the traffic load. Performance evaluations of mean cell delays and cell loss probabilities are obtained to provide insight into the behaviour of the system and to provide guideline for furture design.