高斯信道中32阶四维星座图的标识映射设计(英文)

In the bit-interleaved coded modulation with iterative decoding,it is desired that any two Hamming neighbors,i.e..signal constellation points whose binary labels are at unit Hamming distance,be separated by a large Euclidean distance.This paper determines the mappings for the 32-ary fourdimensional generalized cross constellation(32-4D-GCC) so that the minimum squared Euclidean distance d_(min)~2 between Hamming neighbors is maximized.Among such mappings,those with minimum multiplicity N(d_(min)~2) are selected.To reduce the large search space,a set of mapping templates, each producing a collection of mappings with the same set partitions of binary labels,is introduced.Via enumeration of mapping templates,it is shown that the optimum d_(min)~2=16and the optimum N(d_(min)~2)=16.Among thousands optimum mappings found by computer search,two of the best performance are presented.     

网络功能虚拟化弹性和可扩展性研究

在NFV(网络功能虚拟化)过程中,将PNF(物理网络功能)转换为VNF(虚拟化网络功能)会面临诸多挑战。VNF(虚拟化网络功能)支持网络服务的按需部署和弹性增长,助力提升NFV的弹性和可扩展性。文章介绍主机VNF(虚拟化网络功能)和中间盒VNF两种类型,探讨多路径和分布式VNF设计思路,列举与VNF弹性设计相关的v PE(虚拟提供商边缘)实例,阐述NFV和SDN(软件定义网络)之间的关系。     

电话机常用英文标识含义(续)

address 地址索引alarm 报警、响、闹AMP SW 放大器开关ANS(button) 应答(按键),回答、留守(录音电话) antenna 天线(无绳电话用) auto dialkey(auto button) 自动拨号键battery caver 电池盒板battery charge contacts 电池充电接点(无绳电话) batt low indicator 电量不足指示base station/base set/base unit 座机(无绳电话) cardphone 卡式电话     

一体化标识网络映射缓存DoS攻击防范方法研究

为了抵御一体化标识网络中接入路由器可能遭受的映射缓存DoS攻击,本文提出了一种基于双门限机制的映射缓存DoS攻击防范方法.该方法设计了一种基于迭代思想的谜题机制降低映射缓存中映射信息条目的增加速率,并采用了映射信息可信度算法识别和过滤映射缓存中恶意的映射信息条目.仿真实验与性能分析表明,该方法能够有效地抵御映射缓存DoS攻击,防止映射缓存溢出.     

业务需求感知的虚拟数据中心映射方法研究(英文)

Virtualization is a common technology for resource sharing in data center.To make efficient use of data center resources,the key challenge is to map customer demands(modeled as virtual data center,VDC) to the physical data center effectively.In this paper,we focus on this problem.Distinct with previous works,our study of VDC embedding problem is under the assumption that switch resource is the bottleneck of data center networks(DCNs).To this end,we not only propose relative cost to evaluate embedding strategy,decouple embedding problem into VM placement with marginal resource assignment and virtual link mapping with decided source-destination based on the property of fat-tree,but also design the traffic aware embedding algorithm(TAE) and first fit virtual link mapping(FFLM) to map virtual data center requests to a physical data center.Simulation results show that TAE+FFLM could increase acceptance rate and reduce network cost(about 49%in the case) at the same time.The traffic aware embedding algorithm reduces the load of core-link traffic and brings the optimization opportunity for data center network energy conservation.     

交换网络可扩展性能研究分析

随着互联网规模的迅速扩大，通信量与日俱增，作为网络核心节点的路由器逐渐成为网络发展的瓶颈。交换网络是路由器中限制其容量和性能的主要因素。文中分析了大容量交换网络的发展现状，对影响其扩展性的因素进行了深入研究，并在提出新型交换技术的基础上，指出了交换网络的发展趋势。     

浅谈软件定义网络中数据平面的通用性和控制平面的可扩展性(英)

The control and data planes are decoupled in software-defined networking(SDN),which enables both planes to evolve independently,and brings about many advantages such as high flexibility,programmability,and rapid implementation of new network protocols.However,in order to improve the scalability of the control plane at present,some control functionalities are added to the data plane,which is probably to impact on the generality of the data plane.The key challenge of adding control functionalities to the data plane is to strike a careful balance between the generality of the data plane and the scalability of the control plane.We propose some basic principles that both control and data planes should comply with,based on the evolutionary trend of SDN.Moreover,we take two approaches for reference according to the principles,viewed from the control messages in OpenFlow-based SDN.Our evaluations demonstrate that the approaches can maintain the generality of the data plane and improve the scalability of the control plane.     

比特交织编码调制(迭代译码)系统标识映射的对称性研究与应用

该文从群论的角度分析了比特交织编码调制(迭代译码)(BICM(-ID))系统中标识映射的对称性。首先给出了标识映射对称性的定义,并指出,二进制标识映射的对称性是BICM(-ID)系统的固有特性,该对称性同构于m阶超立方的对称群。然后基于BICM(-ID)的对称性,提出一种改进的二进制交换算法(IBSA)。该算法的搜索空间为标识映射对称群陪集的代表系。因此,与传统的二进制算法相比,IBSA的搜索效率得到了提高。最后,2维16阶星座图的仿真结果表明,在40000次的运行过程中,IBSA能提高4%的搜索效率;32阶相移键控星座图的仿真结果表明,该算法至少可提高3.5%的搜索效率,单个映射的计算时间缩短了约4000倍。     

自适应映射广义空移健控调制(英文)

Generalized Space Shift Keying (GSSK) modulation is a low-complexity spatial multiplexing technique for multiple-antenna wireless systems. However, effective transmit antenna combinations have to be preselected, and there exist redundant antenna combinations which are not used in GSSK. In this paper, a novel adaptive mapping scheme for GSSK modulation, named as Adaptive Mapping Generalized Space Shift Keying (AMGSSK), is presented. Compared with GSSK, the antenna combinations are updated adaptively according to the Channel State Information (CSI) in the proposed AMGSSK system, and the performance of average Symbol Error Rate (SER) is reduced considerably. In the proposed scheme, two algorithms for selecting the optimum antenna combinations are described. The SER performance of AMGSSK is analyzed theoretically, and validated by Monte Carlo simulation. It is shown that the proposed AMGSSK scheme has good performance in SER and spectral efficiency.     

虚拟网络映射模型和算法研究

虚拟网络映射是网络虚拟化的关键问题之一,其目的是在满足虚拟网络资源需求的前提下,为该虚拟网络分配合适的底层网络节点和链路资源,从而在共享的物理网络基础设施之上构建彼此隔离的多重异构虚拟网络,为网络基础创新研究提供实验环境和平台,为网络新应用提供承载服务。论述了虚拟网络映射模型和映射算法,并提出基于最小割集理论设计VN映射算法。     

基于身份位置分离系统的互联网安全模式研究

基础网络作为智能管道,应该在以开放、简单和共享为宗旨的技术优势基础上,建立完备的安全保障体系,从网络体系结构上保证网络信息的真实来源,实现可靠的网络、业务和用户综合管理能力。本文分析互联网安全问题的同时,提出了基于身份位置分离系统的互联网安全模式,通过建立互联网统一标识管理体系,逐步形成互联网事件因果关系逻辑结构的可信的生态系统。     

Node ID based detection of Sybil attack in mobile wireless sensor network

Security is the major issue in wireless sensor networks and many defence mechanisms have been developed to secure the network from these alarming attacks by detecting the malicious nodes which hinder the performance of the network. Sybil attack can make the network vulnerable. Sybil attack means a node which illegitimately claims multiple identities. This attack threatens wireless sensor network in routing, voting system, fair resource allocation, data aggregation and misbehaviour detection. Hence, the research is carried out to prevent the Sybil attack and improve the network performance. The node ID-based scheme is proposed, where the detection is based on node registration, consisting of two phases and the assignment of ID to the node is done dynamically. The ID's corresponding to the nodes registered is at the base station and the node active time is monitored, any abnormalities in the above phases confirm the presence of Sybil nodes in the network. The scheme is simulated using NS2. The energy consumed for this algorithm is 2.3?J. The proposed detection scheme is analysed based on the network's PDR and found that the throughput has improved, which prove that this scheme may be used in the environment where security is needed.     

一种身份与位置分离环境下基于网络的安全移动性管理协议

针对身份与位置分离(Locator/Identifier Separation Protocol, LISP)环境下的移动性管理问题,提出一种基于网络的安全移动性管理协议LISP-SMCP(Secure Mobility Control Protocol)。以接入网为移动管理区域,LISP-SMCP有效地支持移动节点在区域内切换和区域间切换,并实现本地认证和双向认证。安全性和性能分析结果表明,LISP-SMCP可以防止中间人、重放和消息篡改等网络攻击,且具有较小的认证时延、切换时延和切换阻塞率。     

名址分离网络中一种新的双层映射系统研究

作为下一代互联网的关键技术,名址分离可以有效解决当前网络的可扩展性问题。映射系统的设计是名址分离网络中的核心问题。该文在LISP-DHT(Locator/Identifier Separation Protocol-Distributed Hash Table)基础上,提出一种D1HT与Chord相结合的双层映射系统;同时对现有Chord环结构进行改进,减少了Chord环中的信息冗余,解决了LISP映射系统中存在的物理拓扑与逻辑拓扑不匹配的问题。仿真结果表明,D1HT与Chord相结合的双层映射系统与LISP-DHT相比,缩短了平均查询时延和查询路径,提升了查询性能。     

无线传感器网络路由协议安全性研究

无线传感器网络的特性使它面临着比传统网络更大的安全挑战。路由协议作为无线传感器网络的关键因素,其安全更为重要。介绍了无线传感器网络路由协议分类及其脆弱性,分析了几种网络路由协议的攻击方法,阐述了网络路由协议的安全策略。     

位置与身份分离协议下一种基于信任度模型的新型映射机制

通过分析位置与身份分离协议中可能存在的映射欺骗所带来的安全隐患,提出了一种缓解映射欺骗威胁的新型映射机制。该机制在映射理论中引入了基于反馈评判的信任度模型,通过对信任度的动态评判,增加了映射信息的可信性。同时,采用自证明标识代表隧道路由器的身份信息,有效地保障了映射信息源的真实性。性能分析和仿真实验表明,该机制为位置与身份分离协议的映射理论提供了良好的安全保障,通过设定不同的信任度门限,能够有效缓解隧道路由器对虚假映射信息的使用,从而进一步降低了映射欺骗的危害。     

无线Mesh网络跨层优化及其安全机制研究

新兴的无线Mesh网络作为无线宽带接入网具有巨大的应用价值。基于最新无线通信技术标准,结合无线Mesh网络的特点,以网络性能及资源最大化利用为优化目标,提出对无线Mesh网络中物理层、媒体接入/数据链层、网络层各层间进行联合优化,并对无线Mesh网络相关的网络安全机制架构关键技术进行前瞻性的应用基础研究,为无线Mesh网络的组网与应用提供理论支持和技术保障。     

LTE/SAE系统接入层安全性的研究与实现

伴随着移动通信的迅速发展,多样数据业务的出现对信息的安全提出了更高的要求.针对当前热门的LTE/SAE系统,提出了一种有关接入层数据安全的可行性方案.首先研究了LTE/SAE安全体系结构,重点介绍了系统接入层的安全性实现过程.该方案实现简单,对用户平面数据的安全传输具有较重要的作用.     

无线网络数据安全模型研究及实现

根据无线网络的拓扑结构,比较了有线网络和无线网络存在的差异性,分析了无线网络存在的安全问题及其脆弱性;分析了WEP协议存在的严重缺陷,给出了改进方案;基于虚拟专用网技术,提出了无线网络的安全性架构;给出了针对无线网络的入侵检测模型和网络异常行为检测策略。