基于兴趣差异和中心性的AODV路由算法的改进

针对Ad Hoc网络中的消息传输问题,结合反应式路由算法AODV 和社会性路由算法Sim-Bet 基本思想,提出一种改进的路由算法---IC-AODV (基于兴趣因子和中心性的AODV 路由算法)。在选择转发节点时,综合跳数等物理因素和节点兴趣差异、中心性这两种社会性因素。随后用NS2对协议进行仿真,结果表明IC-AODV路由协议相比I-AODV (基于兴趣差异的AODV路由协议)等,在较低带宽开销的同时,获得更高可靠性与传输比。     

基于阵列波导光栅的大规模光交换系统研究

光交换系统是波长路由、中心数据传输中的核心部分,目前光网络的发展方向是实现高速、多端口数和大容量光交换。采用 AWG(阵列波导光栅)的波长路由技术结合高速波长可调激光器,是实现大规模光交换系统中纳秒级开关时间的最有效的技术方案。文章分别从 AWGR(阵列波导光栅路由器)的周期性、串联、并联以及串并联等4个方面,对不同的架构方案进行了阐述。     

认知无线电网络路由研究综述

 在对近期认知无线电网络路由研究成果进行研究的基础上,从邻居节点发现、“耳聋”、邻居节点消失、路由发现和跨层设计等5个方面,对认知无线电网络路由研究面临的重要挑战进行了分析;从研究方法的角度,对路由研究中对公共控制信道的依赖、路径延时,以及需要考虑的技术指标进行了讨论。最后,从介质、信道、节点和网络等4个方面,对路由研究场景设计进行了归纳总结;并从路由优化方案和路由拓扑算法协议两个方面,对主要研究成果进行了分析和讨论。     

LEO卫星网络中一种安全的按需路由协议

低地球轨道(LEO)卫星网络的路由是当前卫星通信领域的研究热点,其安全问题也日益受到研究人员的重视。本文通过分析LEO卫星网络按需路由协议面临的安全威胁,使用基于身份的签密方案,提出了一种适合卫星网络拓扑特性的安全的按需路由协议。针对协议的密码算法处理时间开销较大的特点,设计了自适应的概率性延迟验证机制,能够降低协议的平均路由建立时间。安全性分析和仿真实验结果表明,该协议能够抵抗多种外部攻击行为,以有限的路由建立时间和路由开销为代价,保证了稳定的包传输率。      

Load balancing routing for single-layered satellite networks

The varying population density leads to imbalanced utilization rate of satellites. To ensure an intelligent engineering of traffic over satellite networks, a distributed routing scheme for single-layered satellite network, load balancing routing protocol based on mobile agent (LBRP-MA) is proposed. For LBRP-MA, mobile agents explore route by migrating autonomously. Upon arriving at destination, mobile agents migrate back. On each intermediate satellite, mobile agents evaluate path cost considering satellite geographical position as well as inter-satellite link (ISL) cost, and finally take ISL congestion index into account to update routing tables. Through simulations on the Courier-like constellation, the proposed approach is shown to achieve guaranteed end-to-end delay bound and decrease packet loss ratio with better throughput, which is especially suitable for data transferring in case of high traffic load. Moreover, results of the complexity analysis demonstrate that LBRP-MA can have low onboard signaling, storage and computation requirements. Furthermore, issues of LBRP-MA such as ISL congestion index and cost modification factor are discussed.     

互联网路由扩展性研究状况分析

Internet的快速发展对路由扩展性造成了巨大的压力。为了Internet能够持续、稳定、快速的发展,互联网技术领域学术界和工业界提出了一些针对Internet的路由扩展性的解决方案。文章基于Internet面临的路由扩展性问题,分析导致问题的原因;在对影响Internet路由扩展性的若干因素进行分析的基础上,重点介绍互联网技术领域学术界和工业界提出的一些典型解决方案;在对Internet路由扩展性问题行总结的基础上,提出未来Internet路由系统的需求。     

Ad hoc网络安全与攻击探讨

介绍了Ad hoc网络的体系结构和特点,分析了其存在的网络安全问题,总结了对Ad hoc网络的多种攻击方法,并提出了几种改善Ad hoc网络安全的策略。     

A resource-efficient and scalable wireless mesh routing protocol

By binding logic addresses to the network topology, routing can be carried out without going through route discovery. This eliminates the initial route discovery latency, saves storage space otherwise needed for routing table, and reduces the communication overhead and energy consumption. In this paper, an adaptive block addressing (ABA) scheme is first introduced for logic address assignment as well as network auto-configuration purpose. The scheme takes into account the actual network topology and thus is fully topology-adaptive. Then a distributed link state (DLS) scheme is further proposed and put on top of the block addressing scheme to improve the quality of routes, in terms of hop count or other routing cost metrics used, robustness, and load balancing. The network topology reflected in logic addresses is used as a guideline to tell towards which direction (rather than next hop) a packet should be relayed. The next hop is derived from each relaying node’s local link state table. The routing scheme, named as topology-guided DLS (TDLS) as a whole, scales well with regard to various performance metrics. The ability of TDLS to provide multiple paths also precludes the need for explicit route repair, which is the most complicated part in many wireless routing protocols. While this paper targets low rate wireless mesh personal area networks (LR-WMPANs), including wireless mesh sensor networks (WMSNs), the TDLS itself is a general scheme and can be applied to other non-mobile wireless mesh networks.     

一种"北斗"导航星座数据上注的动态链路树路由方法

针对目前“北斗”导航系统星间链路维护中频繁进行的时隙表、路由表等数据上注耗时较长的问题,利用星座各星上注数据一致的特点,提出了一种“北斗”导航星座数据上注的动态链路树路由方法。该方法能够显著降低整个星座数据上注过程的资源占用,并较大幅度地提高完成数据上注任务速度,缩短数据上注的时间。     

Loosely coupled multi-bit flip-flop allocation for power reduction

Merging 1-bit flip-flops into multi-bit flip-flops in the post-placement stage is one of the most effective techniques for minimizing clock power. In this work, we introduce a new style of multi-bit flip-flop, called loosely coupled multi-bit flip-flop (LC-MBFF). The merit of LC-MBFF is that the logically constituent 1-bit flip-flops in LC-MBFF can be physically apart (i.e., no relocation), providing no need to set aside white space. Utilizing LC-MBFFs, we propose a multi-bit flip-flop allocation algorithm which fully explores the diverse allocation of LC-MBFF structures to maximally reduce clock power consumption. Experimental results with ISCAS89 and IWLS2005 benchmark circuits show that our proposed allocation algorithm using the newly designed multi-bit flip-flops is able to reduce on average the clock power by 8.51% while the best known multi-bit flip-flop allocation algorithm [7] reduces by 5.37%. Additionally, we extend our algorithm to support the multi-bit flip-flop allocation for circuits with clock polarity assignment.