信息中心网络体系结构研究综述

互联网应用需求逐渐转变为信息的分发和获取,而网络体系结构依然为主机间的端到端通信,二者矛盾日趋尖锐。信息中心网络（Information-Centric Networking,ICN）采用以信息为中心的设计为解决上述问题提供了新思路。本文提出了ICN的基本体系结构框架,从功能和特性两个维度探索了ICN可能的设计空间,然后讨论了ICN与其他未来网络技术的关系以及ICN实验平台和部署,最后指出当前主要问题及下一步研究方向。     

信息中心网络(ICN)网络架构浅析

随着信息技术的飞速发展,网络应用的主体逐步向内容获取和信息服务演进。同时,相关的硬件与通信技术的发展为网络具有更多的能力(包括计算、存储)提供基础。信息中心网络技术(Information-Centric Networking,ICN),以互联网的主要需求为导向,以信息/内容为中心构建网络体系架构,解耦信息与位置关系,增加网络感知、存储信息能力,从网络层面提升内容获取、移动性支持和面向内容的安全机制能力。文章介绍并分析了ICN网络架构设计原理、关键技术和应用场景,最后指出其未来的研究方向。     

基于ICN的未来媒体网络缓存放置策略

随着媒体用户规模的增大和数字媒体内容指数式的增长,现有的互联网、广播网和电信网已无法同时满足如此庞大数据量的高效传输和用户随时随地低成本消费的需求,这严重影响了网络性能和服务质量,并在一定程度上推动了对以信息中心网络(ICN)为代表的未来网络体系架构的研究。在信息中心网络中,缓存放置策略的优劣在一定程度上决定了网络性能的优劣。文章结合奇异值分解算法(SVD)提出基于ICN的未来媒体网络缓存放置策略,通过分析不同网络中请求内容的相似性决定每个网络的缓存内容;一方面,利用ICN数据与位置分离的思想,降低链路负载,另一方面,通过SVD算法提高ICN中的数据响应速率和网络缓存命中率,减小了网络传输开销和数据的传输时延,对于提升媒体网络性能和用户体验具有重要意义。     

5G IPRAN关联基站快速定位网络问题研究

4G、5G通信网络采用IP化无线接入网(IP Radio Access Network,IPRAN)进行承载,整个网络更加扁平化,可以降低数据时延,但IPRAN传输网络与无线基站分离,导致网络问题的定位过程烦琐,网络服务性能响应不及时.对此,研究通过简单网络管理协议(Simple Network Management ...     

SURPASS—共创宽带电信网络的美好明天

一、引言 西门子信息与通信网络(ICN)作为电信级网络和方案的提供者,在通信领域一直处于领先的位置。面对业界对下一代网络的思考,西门子关注的是能否为用户提供全IP融合的网络方案以及如何才能实现现有网络到全IP融合下一代网络的演进。西门子凭借其对通信     

面向5G-ICN切片的分层缓存策略

多接入边缘计算(Multiple Access Edge Computing,MEC)和网络切片在5G网络中扮演了重要角色。网络切片的灵活可编程性和MEC的去中心化促进了信息中心网络(Information Centric Network,ICN)的部署。但是,ICN中缓存资源分配的位置和数量严重影响了运营商的收益。为此,首先将移动虚拟网络运营商(Mobile Virtual Network Operator,MVNO)和多个内容提供商(Content Provider,CP)建模为一主多从的Stackelberg博弈;其次,将MVNO内部的缓存资源分配建模为一个联合缓存成本和传输能耗的混合整数规划问题,并利用改进的精英遗传算法得到最佳位置;最后,通过博弈迭代算法得到运营商的最优定价和CP的最优放置数量。仿真结果表明,该算法具有较高的有效性以及较好的缓存资源分配能力,能够降低传输能耗和缓存成本,与贪婪搜索(Iteration Greedy Search,IGS)算法、联合缓存分配和延时控制(Joint Cache Allocation and Delay Control,JCADC)算法相比传输能耗分别节省了5%、11%,运营商的收益分别提高了32%、44%。     

IP网络摄像机

1 IP网络摄像机的定义。IP网络摄像机(IP Network Canmera／Web Camera)实际上就是具有网络接入功能的摄像机，它内建Web Server和CCD图像传感器，内部增加了对模拟视频进行数字化处理的DSP芯片，可以将数字视频信号转成符合网络传输协议的数据流，送到网上传输，远端的浏览者只要用标准的网络浏览器即可实时观看该影像。     

IP网络与ICN网络互通研究

信息中心网络(Information Centric Networking,ICN)作为未来网络的架构被提出,旨在解决基于主机的TCP/IP网面临的诸多问题。随着ICN领域研究的不断深入,目前面对的一个关键问题是ICN网与现有IP网的融合问题,这对于未来网络的发展与演进具有重要的意义。针对这一问题,目前学术界提出了几种解决方案,主要包括了TCP/ICN与HTTP/ICN的方案。文章首先就这两种方案进行了介绍与对比,然后以此为基础对IP/ICN的两网融合问题进行了展望,如何做到对现有协议或应用尽可能小的改动,如何充分利用ICN固有特性如网内缓存、多播等优势,是研究中需要重点关注的问题。     

面向ICN切片的视频缓存与传输服务

随着视频流量爆炸式地增长,为了降低密集区域用户的视频检索时延和网络负载,利用网络功能虚拟化技术提出了一种将5G切片与信息中心网络(Information Center Network,ICN)相结合的内容分发服务系统集成的架构,并改进基于ICN的缓存策略.该缓存策略依据特定区域用户一个月与一周内的历史访问记录构建视频主...     

基于覆盖网络的灾后通信网络恢复策略

为解决灾后通信网络损毁故障恢复问题,基于覆盖网络提出了通信网络恢复新策略,应用覆盖网络与源路由实现了通信网络路径的多样性,系统恢复中选取最佳landmark,为网络流量重新确定传输路径,保证节点传输中可有效绕过灾后故障区域.同时考虑到灾后区域通信故障中极容易出现的信息爆炸情况,加入了拥塞感知恢复系统,构建了一种灾后通信网络恢复急救系统(Post-disas-ter Communication Network Recovery Emergency System,PES).该系统可借助较少的网络探测开销及时绕过通信损毁故障区域与信息爆炸拥堵节点位置,提高网络流量的传输效率,在短时间内实现通信网络的恢复重连.     

Fuzzy Least-Congested Path Routing and Improved Remote-Path Routing based on Hierarchical Information in WDM Networks

Although routing schemes based on global knowledge make most optimal routing decisions, they will occupy many resources to keep the state information of the network up-to-date. In this work, we describe a fuzzy least-congested path (FLCP) routing algorithm based on hierarchical information. Simulation shows that the blocking probability using FLCP is very near to the blocking probability using the least-congested path routing (LCP) algorithm based on global information. Under heavy traffic load, the FLCP algorithm is superior to the exhaustive algorithm (EA) and the LCP algorithm with unit information cost. The FLCP algorithm provides better routing, even with incomplete information. Thus, the algorithm requires less information of the network, particularly under heavy traffic load. In addition, an improved remote-path routing approach is provided to reduce the blocking probability of connection requests to a node that is many hops away from the source node.     

基于最大化畅通概率优化模型的固定路由算法

针对以最小化网络阻塞率为目标的光网络路由及波长分配(RWA)问题,考虑到全网结构不均衡易导致部分链路负载过高,进而造成全网阻塞率过高问题,在基于爱尔兰损失公式的链路阻塞概率模型的基础上,建立了最大化路径畅通概率的优化模型。为了克服优化模型的非线性造成的求解困难,借鉴大系统中分解协调的思想对链路负载进行预估,将原优化问题转化成乘积最长路问题,并结合负载滚动预估更新及类Dijkstra算法进行近似求解。仿真比较实验表明,本文算法能够较好地近似求解所提出的最大化畅通概率模型,有效地均衡了全网负载,降低了全网阻塞率,提高了网络传输性能。     

A novel energy‐aware routing mechanism for SDN‐enabled WSAN

Energy consumption is one of the most important design constraints when building a wireless sensor and actuator network since each device in the network has a limited battery capacity, and prolonging the lifetime of the network depends on saving energy. Overcoming this challenge requires a smart and reconfigurable network energy management strategy. The Software‐Defined Networking (SDN) paradigm aims at building a flexible and dynamic network structure, especially in wireless sensor networks. In this study, we propose an SDN‐enabled wireless sensor and actuator network architecture that has a new routing discovery mechanism. To build a flexible and energy‐efficient network structure, a new routing decision approach that uses a fuzzy‐based Dijkstra's algorithm is developed in the study. The proposed architecture can change the existing path during data transmission, which is the key property of our model and is achieved through the adoption of the SDN approach. All the components and algorithms of the proposed system are modeled and simulated using the Riverbed Modeler software for more realistic performance evaluation. The results indicate that the proposed SDN‐enabled structure with fuzzy‐based Dijkstra's algorithm outperforms the one using the regular Dijkstra's and the ZigBee‐based counterpart, in terms of the energy consumption ratio, and the proposed architecture can provide an effective cluster routing while prolonging the network lifetime.     

基于频率域多目标MANETs可信路由决策研究

移动Ad-hoc网络(MANETs)具有开放的媒质,动态的拓扑结构,分布式的合作和受限的网络能力等基本特点。网络中移动节点具有匿名性和高度自治的特点,网络通讯依靠在通信路径上的中间节点转发数据包,实现无线传输范围外节点间的正常通信。该文提出了一种独特的MANETs中基于频率下多目标可信路由决策算法,它和现在大多数路由算法都是在时间域下使用单一约束参数选择路由的方式截然不同。利用概率理论分析安全和可信路由,基于概率密度函数的时频相互转化,减小计算复杂度,解决MEANTs中节点间缺乏物理安全以及在低信任水平和节点相互勾结扰乱网络操作情况下,发现可信安全路由难的问题。实例分析证明了此算法的可行性。     

内容中心网络状态感知路由设计

为了提高内容中心网络的内容分发效率及降低网络开销,提出了网络状态感知的路由机制NSAR(network status aware routing)。NSAR利用从内容服务节点返回的数据分组收集当前网络状态信息,并在回传过程中对路径上各节点上匹配端口的转发概率进行更新,在对后续的兴趣分组进行转发决策时引入转发概率,从而提高内容分发效率。仿真实验表明,与传统内容中心网络路由算法相比,NSAR可以有效地降低内容请求平均时延,减少网络流通分组数以及降低网络带宽开销。     

A comparative study of name resolution and routing mechanisms in information-centric networks

Information-Centric Networking (ICN) is an innovative paradigm for the future internet architecture, which addresses IP network limitations in supporting content distribution and information access by decoupling content from hosts and providing the ability to retrieve a content object by its name (identifier), rather than its storage location (IP address). Name resolution and routing is critical for content retrieval in ICN networks. In this research, we perform a comparative study of two widely used classes of ICN name resolution and routing schemes, namely flooding and Distributed Hash Table (DHT). We consider the flooding-based routing in Content-Centric Networks due to its wide acceptance. For the DHT scheme, we design a multi-level DHT that takes into account the underlying network topology and uses name aggregation to further reduce control overhead and improve network efficiency. Then, we compare the characteristics and performance of these two classes of name resolution and routing through extensive simulations. The evaluation results show that the performances of these two approaches are reliant on several factors, including network size, content location dynamics, and content popularity. Our study reveals insights into the design tradeoffs and offers guidelines for design strategies.     

一种基于深度增强学习的智能路由技术

随着网络规模的不断增大以及网络复杂度的不断提高,传统路由算法面对网络流量在时空分布上的剧烈波动难以兼顾计算复杂度和算法效率.近年来,随着软件定义网络和人工智能技术的兴起,基于机器学习的自动路由策略生成逐渐受到关注.本文提出一种基于深度增强学习的智能路由技术SmartPath,通过动态收集网络状态,使用深度增强学习自动生成路由策略,从而保证路由策略能够动态适应网络流量变化.实验结果表明,本文所提出的方案能够不依赖人工流量建模动态更新网络路由,在测试环境下比当前最优方案减少至少10%的平均端到端传输时延.     

Routing algorithm design of satellite network architecture based on SDN and ICN

In view of the problems of low routing efficiency, complex control process, and difficult network management in big data environment in the traditional integrated space‐terrestrial network, in the paper, we propose a satellite network architecture called software‐defined information centric satellite networking (SDICSN) based on software‐defined networking (SDN) and information‐centric networking (ICN), and we design a virtual node matrix routing algorithm (VNMR) under the SDICSN architecture. The SDICSN architecture realizes the flexibility of network management and business deployment through the features of the separation of forwarding and controlling by the SDN architecture and improves the response speed of requests in the network by the centric of “content” as the ICN idea. According to the periodicity and predictability of the satellite network, the VNMR algorithm obtains the routing matrix through the relative orientation of the source and destination nodes, thus reducing the spatial complexity of the input matrix of the Dijkstra algorithm and then reducing the time complexity of the routing algorithm. For forwarding information base (FIB), the mechanism of combination of event driven and polling can be quickly updated in real time. Finally, the advantages of the SDICSN architecture in routing efficiency, request delay, and request aggregation are verified by simulation.     

An Ant-Based Approach for Dynamic RWA in Optical WDM Networks

In this paper, we propose a new ant-based algorithm for the dynamic routing and wavelength assignment (RWA) problem in optical WDM networks under the wavelength continuity constraint. Unlike conventional approaches, which usually require centralized global network information, our new RWA algorithm constructs the routing solution in a distributed manner by means of cooperative ants. To facilitate the ants’ foraging task, we adopt in our algorithm a probabilistic routing table structure for route selection. The new algorithm is highly adaptive in that it always keeps a suitable number of ants in the network to cooperatively explore the network states and continuously update the routing tables, so that the route for a connection request can be determined promptly by the current states of routing tables with only a small setup delay. Some new schemes for path scoring and path searching are also proposed to enhance the performance of our ant-based algorithm. Extensive simulation results upon three typical network topologies indicate that the proposed algorithm has a very good adaptability to traffic variations and it outperforms both the fixed routing algorithm and the promising fixed–alternate routing algorithm in terms of blocking probability. The ability to guarantee both a low blocking probability and a small setup delay makes the new ant-based routing algorithm very attractive for both the optical circuit switching networks and future optical burst switching networks     

光网络中基于路径计算单元的路由机制研究

针对大规模多层多域光网络群故障发生时的网络受损情况,提出基于路径计算单元(PCE)架构的跨域路由算法进行快速恢复,并基于OMNet平台对多层多域路由方案进行了性能仿真分析。结果表明,基于PCE架构的路由策略在群故障发生时能够大大减少网络中的路径计算请求泛洪信息,降低路由计算收敛时间,可以提高全网剩余资源的资源利用率,为业务的快速恢复提供了路由基础。