无线-光纤混合宽带接入网络路由技术分析

无线-光纤混合宽带接入网(WOBAN)是一种新型的具有竞争力和广泛前景的混合接入网络,其集成了EPON光纤接入网高速、宽带的优点和WMN无线网络灵活、便利的长处。但需要注意的是,无线-光纤混合宽带接入网对于光域互联路由技术提出了较高的要求。基于以上,本文从无线-光纤混合宽带接入网络概述入手,探讨了其路由技术。     

光纤无线混合宽带接入网络节能关键技术研究

为减少光纤无线混合宽带接入网络(FiWi)中的能源消耗,在研究了FiWi网络中主要的接入技术及其网络架构的基础上,就FiWi节能技术所涉及的相关标准、MAC层休眠控制机制、网络层节能路由以及新型网络编码实现节能等关键技术进行了深入研究和展望。     

光纤无线融合网络(FiWi)能效改善综述

光纤无线宽带接入网架构(Fiber Wireless Broadband Access Network,FiWi)能随时随地为终端用户提供高质量的宽带接入服务.然而,由于大量智能设备的互联和指数级数据业务的增长,Fi-Wi接入网也面临着高能耗的潜在挑战.针对融合FiWi接入网中无线反复重传、业务共存转发以及跨域资源整合...     

宽带接入技术的发展与融合

随着各种宽带接入技术的不断发展以及用户的通信需求日益多元化,各种宽带接入技术的融合和综合应用成为一个重要发展趋势。本文对宽带接入技术的发展和融合趋势进行了分析,并在此基础上给出我国发展宽带接入的建议。     

宽带无线与光纤接入融合技术的研究

互联网时代的到来,使得网络通讯技术被广泛的运用于各个领域之中,对于人类的工作与生活产生了重要的影响.宽带作为网络通讯传播的通道,必须要长期保持安全、稳定的工作状态,尽可能的提高信号传播的速度与质量.我国目前的宽带接入形式主要有两种,分别为宽带无线与光纤接入融合技术,优劣明显.为了满足广大用户的通讯需求,本文对二者之间的融合技术进行了研究与分析.     

无线传感器网络优化生存时间的动态路由算法

 节能和延长网络生存时间是无线传感器网络研究领域的热点问题.该文综合考虑网络中节点的剩余能量和节点间传输数据的能耗,基于最短路径树算法,通过构造两种不同的权值函数,提出了"比例权值路由算法"(Ratio-W)与"和权值路由算法"(Sum-W).仿真分析表明,所提出的算法可以延长网络生存时间,并使能耗经济有效,比一些已有知名算法更优.     

一种新型光纤光栅无线传感网络及路由设计

传统的光纤光栅传感网络具有灵活性低、移动性差等缺点.文章作者构建了一种新型的光纤光栅无线传感网络,该网络融合了无线通信和光纤光栅传感的优点.同时还设计了节点结构,并根据实际应用场景提出了该传感网络的路由协议--RT(路由选择表)协议.在NS2(Network Simulator)中,从分组投递率、时延和能耗等3方面与Flooding协议进行了比较分析,结果显示RT协议更适合该新型传感网络.     

异构无线融合网络中无线资源管理关键技术探讨

异构无线融合网络并不是多种无线接入技术的叠加,各个网络之间资源形式和管理机制各不相同,如何有效的管理无线资源,提升异构无线融合网络中无线资源的利用效率至关重要。基于以上,本文从异构无线融合网络概述入手,探讨了其无线资源管理的关键技术。     

“无线光纤”—MMDS

作为直接面向最终用户的接入网,随着因特网的日益普及,其重要性已从“最后一公里”上升为“第一公里”,成了电信运营商的兵家必争之地。对于如何拓宽这一“瓶颈”,目前市场上有各种解决方案,如基于电话线的ＤＳＬ技术、基于有线电视的Ｃａｂｌｅ Ｍｏｄｅｍ技术、基于５类双绞线的高速以太网接入技术和无线接入技术等,这些都属于兼顾现有网络和技术的方案,它们各有特点,适应不同的应用场合。至于无源光网络技术属于完全面向未来的接入方案,是宽带接入的发展方向,由于工程量庞大,需巨额资金投入,所以近期难以一蹴而就。 目前,Ｄ…     

无线传感器网络中基于数据融合的路由算法

无线传感器网络（WSN）是远程通信方面一种极具潜力的关键技术。通过对无线传感器网络与典型通讯网络的对比分析,得出无线传感器网络路由协议都是以数据为中心进行工作的。详细分析了以MLR,GRAN,MFST和GROUP为代表的基于数据融合的路由算法。最后得出结论：将数据融合技术应用于无线传感器网络中可以明显地改善路由协议的进行效果,延长网络生存时间。     

Reliable transmission mechanism with differentiated protection in virtualized fiber-wireless access network

In view of the different reliability requirements of network service,a reliable transmission mechanism with differentiated protection was proposed in virtualized fiber-wireless access network.The quality of protection required by users and the fees that can be paid were used as a prerequisite.The backup protection resources were flexibly allocated by quantifying the multi-level protection quality with the probability of recovery.Then,for reducing traffic congestion and the unprotected services,the level service differentiation algorithm was used to choose protection link which was satisfied with the level of protection quality.The results show the proposed mechanism has more advantages in terms of long-term benefit-to-cost ratio and underlying network resource overhead,and provides users with a more flexible virtual network transmission while satisfying users’ reliability requirements.     

一种生存性军事虚拟网络映射新方法

针对生存性的军事虚拟网络映射问题,提出了生存性的军事虚拟网络映射需要遵循的原则。构建了虚拟网络映射模型,并采用蝙蝠算法进行求解。针对故障情况,提出了区分服务的故障恢复策略,对于高优先级虚网请求提前构建保护路径,对于低优先级虚网请求则提出基于链路可靠性的故障迁移算法,为了减少带宽消耗适当考虑了节点迁移策略。最后通过仿真验证了算法在虚拟网络运行成功率、故障修复率和链路利用率方面相比其他算法具有更好的性能。     

Dynamic recovery for survivable virtual network embedding

Network virtualization is a promising way to overcome the current ossification of the Intemet. It is essential challenge to find effective, efficient and robust embedding algorithms for recovering virtual network. The virtual network mapping algorithm based on integer programming which was proposed months ago. But it did consider the faults of physical network resources, which is so called survivable virtual network embedding （VNE） problem. Previous strategies for enabling survivability in network virtualization focused on providing protection for the physical network or enhancing the virtual networks by providing backup physical resources in advance, and treated all the physical failures as link failures. In the article, a dynamic recovery method is proposed to solve the survivable virtual network embedding problem based on the integer programming VNE algorithm. The dynamic recovery method doesn＇t need to backup physical resources and it makes more substrate resources which can be used in the embedding. The dynamic recovery process will be activated only when physical failures occur. Different algorithms are used to recovery node and link failures. Simulations show that the method helps to recover almost all of physical failures by finding the substitute nodes and paths, and its performance is very close to that of pure VNE method without considering physical failures.     

Dynamic survivable mapping through reconfiguration in IP over WDM network

A new approach for network survivability problem in Intemet protocol （IP） over wavelength division multiplexing （WDM） optical network is proposed to enhance the IP layer restorability under physical link failure through logical topology reconfiguration. More specifically, after traffic arrival and departure, reconfiguring the logical topology correspondingly is helpful to minimize the traffic disruption after physical link failure. So, in this paper, this problem is proposed for first time and formulated as an integer linear programming （ILP） problem. And then, two heuristic algorithms are proposed. The performance of proposed algorithms have been evaluated through simulations, and the results show that reconfiguring the logical topology dynamically could achieve more than 20% improvement of the restorability of traffic in IP layer, but with acceptable resource cost.     

虚拟网络可生存的启发式可靠映射算法

针对虚拟网络可靠映射问题,引入虚拟网络可生存约束条件,确保在底层网络单节点失效情况下,被映射虚拟网络剩余部分仍保持连通,最大程度确保虚拟网络的完整性和服务的连续性。以最小化底层网络映射开销为目标函数,建立虚拟网络可靠映射的整数线性规划模型,提出一种虚拟网络可生存的启发式可靠映射算法RHM-SVN并进行求解。实验结果表明,该算法能够有效降低资源平均利用率,提高映射成功率、底层网络平均收益和虚拟网络恢复成功率。     

WLAN无线接入网络规划及其网络性能优化研究

随着WLAN无线的发展,其覆盖区域、用户量、网络容量不断增加,使其接入网络规划的问题逐渐成为建设公共无线局域网的重要问题.同时,对WLAN无线接入网络性能优化是满足用户需求的关重要手段,网络性能优化主要有覆盖优化、容量优化、设备优化.     

专网安全防护系统规划设计

针对专用网络用户的业务信息安全防护需求,提出在同一网络按需交互或隔离多密级信息的规划思路,从安全防护规划原则、安全技术体系规划、安全管理体系规划和安全防护系统实现等方面进行了详细阐述;对专用网络安全防护系统的组成与功能进行设计,并按多密级信息防护能力配置网络安全系统与设备,构建了专用网络的安全防护体系。     

无线局域网网络规划

无线局域网(WLAN)正从有线局域网的补充手段向可运营的公众无线局域网演变,布网区域的扩大、用户数量的增加以及网络容量的加大,使得无线网络规划成为公共无线局域网建设的突出问题.文章着重分析了2.4 GHz频段WLAN在热点地区应用时所特别涉及的无线网络规划问题,包括频率规划、覆盖范围、功率选择、干扰避免和小区复用等问题.     

EPON:下一代宽带光接入网

介绍了EPON（以太网无源光网络）的体系结构，国内外的研究现状以及市场和应用，并对其前景进行了展望。     

Visualization of dynamic fault tolerance rerouting for data traffic in wireless sensor network

In wireless sensor network environments, a phenomenon of data concentration may occur in one or certain sensor nodes in the process of transmitting sensing data from a source sensor node to a sink node. In this case, the overhead that occurs in the sensor node affects the performance of the entire sensor network. In addition, in the sensor network, excessive sensing data traffic or data loss may occur depending on the variability of the topology of the sensor network. In this paper, visualization for dynamic rerouting is designed and implemented, which visibly provides packet movement routes between sensor nodes and transmitted packet traffic transmission capacity to Geography Markup Language‐based maps having GPS coordinate information. A mechanism for the visualization for dynamic rerouting to detect sensing data overheads and sensor node faults occurring in sensor networks and dynamically rerouting of data is proposed. In addition, information on rerouting route paths from source sensors to sink nodes is visually provided. Copyright © 2012 John Wiley & Sons, Ltd.