Internet域间路由系统：问题与挑战

作为Internet的核心基础设施,基于BGP协议的域问路由系统目前在扩展性、端到端性能、安全性与可信性等方面存在问题。由于部署的厂域性、AS的自治性以及ISP之间交互的复杂性、域间路由行为的动态性,使得人们对域间路由系统的结构和行为规律尚未充分理解,缺乏全面有效的解决方案,大规模的系统的网络实验难以开展。理想的域问路由系统及其支撑的Internet在性能上应具有快速恢复和全局优化的能力,在安全上应具有自主防范和协同控制能力,在运营上应具有自主配置和协同管理能力。     

模糊QoS路由算法及其性能分析

我们将模糊理论引入QoS路由领域中,提出了模糊QoS路由算法,在只增加相对较少的计算开销的基础上,有效地提高了QoS路由在离网络负载下的路由成功率和对链路信息滞后性的适应性。     

MADCR:Mobility Aware Dynamic Clustering-Based Routing Protocol in Internet of Vehicles

Internet of Vehicles (IoV) is an evolution of the Internet of Things (IoT) to improve the capabil-ities of vehicular ad-hoc networks (VANETs) in in-telligence t...     

无线Mesh网络跨层路由技术研究

无线Mesh网络(WMN:wireless mesh networks)作为一种新型的无线网络,成为近几年研究的热点。由于无线信道不稳定等特性,如何设计WMN的路由协议成为决定其性能的关键因素之一。近几年来的研究表明,通过跨层设计的方式综合其他层的重要参数来实现路由选择,能够很好地解决这一难题。介绍了几种先进的跨层路由设计方案,总结了现有的跨层路由协议的优缺点,并对如何设计并实现跨层路由协议进行了分析和总结。     

Cross-Layer Design and Ant-Colony Optimization Based Routing Algorithm for Low Earth Orbit Satellite Networks

To improve the robustness of the Low Earth Orbit （LEO） satellites networks and realise load balancing, a Cross-layer design and Ant-colony optimization based Load-balancing routing algorithm for LEO Satellite Networks （CAL-LSN） is proposed in this paper. In CAL- LSN, mobile agents are used to gather routing information actively. CAL-LSN can utilise the information of the physical layer to make routing decision during the route construction phase. In order to achieve load balancing, CAL- LSN makes use of a multi-objective optimization model. Meanwhile, how to take the value of some key parameters is discussed while designing the algorithm so as to improve the reliability. The performance is measured by the packet delivery rate, the end-to-end delay, the link utilization and delay jitter. Simulation res- ults show that CAL-LSN performs well in bal- ancing traffic load and increasing the packet delivery rate. Meanwhile, the end-to-end delay and delay jitter performance can meet the re- quirement of video transmission.     

Cross-Layer Design Based N-ary Huffman Coding for Performance Analysis of DSDV Routing Protocol in MANETs

Wireless Personal Communications - The implementation of the optimal Huffman coding technique for achieving proficient data compression, lower information redundancy and minimal utilization of the...     

Cross-Layer Rate Control, Routing and Scheduling Design for Multicast with Network Coding in Ad Hoc Networks

Network coding is a powerful coding technique that has been proved to be very effective in achieving the maximum multicast capacity. It is especially suited for new emerging networks such as ad-hoc and sensor networks. In this paper, we develop a distributed rate control algorithm for multicast session in ad hoc networks. With random network coding, the algorithm can be implemented in a distributed manner, and work at transport layer to adjust source rates and at network layer to carry out network coding. The scheduling element of our algorithm is a dynamic scheduling policy. The stability of the resulted system is established, and simulation results are provided to support our conclusions.     

因特网路由选择技术

路由技术是因特网实现世界范围的连通性的关键技术之一.从不同角度及应用环境介绍了路由问题,综述了相关的最新研究成果,以期对因特网路由技术问题的现在和将来的研究提供必要的背景知识.     

卫星通信网络中的跨层设计

随着通信技术的发展，各种多媒体应用被引入到无线和卫星网络，然而由于无线及卫星网络的信道特性并不理想，传统的分层设计方法对于无线环境来说有相当大的局限性，因此近年来另外一个设计方法——跨层设计成为了一个研究热点．本文首先简单介绍了跨层设计方法的背景、思路，之后论述了该方法在卫星通信网络中的应用，最后分析讨论了跨层设计的特点、代价和折衷．     

Ad hoc 网路由协议设计及性能评估问题

Adhoc网是由多个节点为了某种特定目的彼此连接的无线网络。本文首先对Adhoc网的特性、近期的发展及应用做了简要介绍,随后着重小结了目前其路由协议的设计思路,最后指出了在进行协议性能测定时应注意的问题并简要介绍了广泛应用的仿真平台。     

Adaptive Cross-Layer Routing Protocol for Optimizing Energy Harvesting Time in WSN

Wireless Personal Communications - Trade-off between energy conservation and efficiency is one of the most important issues in designing Wireless Sensor Network (WSN) based applications. Network...     

基于软件定义基础设施的“互联网+”开放平台架构设计

"互联网+"背景下传统产业的升级需要IT基础架构的支撑。软件定义基础设施(SDI)通过软件来管理、调配和运行数据中心,涵盖计算、存储和网络三大部分,可提供更快响应速度和更高可用性来满足企业的需求。文章首先论述软件定义基础设施资源管理平台的设计和实现,在此基础上提出基于软件定义基础设施的"互联网+"开放平台,阐述了业务编排、大数据分析、自动化运维等开放平台核心模块的设计方案,最后提出该平台在工业互联网及车联网的应用前景和发展方向。     

Cross-Layer Interaction of TCP and Ad Hoc Routing Protocols in Multihop IEEE 802.11 Networks

In this research, we first investigate the cross-layer interaction between TCP and routing protocols in the IEEE 802.11 ad hoc network. On-demand ad hoc routing protocols respond to network events such as channel noise, mobility, and congestion in the same manner, which, in association with TCP, deteriorates the quality of an existing end-to-end connection. The poor end-to-end connectivity deteriorates TCP's performance in turn. Based on the well-known TCP-friendly equation, we conduct a quantitative study on the TCP operation range using static routing and long-lived TCP flows and show that the additive-increase, multiplicative-decrease (AIMD) behavior of the TCP window mechanism is aggressive for a typical multihop IEEE 802.11 network with a low-bandwidth-delay product. Then, to address these problems, we propose two complementary mechanisms, that is, the TCP fractional window increment (FeW) scheme and the Route-failure notification using BUIk-losS Trigger (ROBUST) policy. The TCP FeW scheme is a preventive solution used to reduce the congestion-driven wireless link loss. The ROBUST policy is a corrective solution that enables on-demand routing protocols to suppress overreactions induced by the aggressive TCP behavior. It is shown by computer simulation that these two mechanisms result in a significant improvement of TCP throughput without modifying the basic TCP window or the wireless MAC mechanisms.     

A Study on Various Technologies to Solve the Routing Problem in Internet of Vehicles (IoV)

Wireless Personal Communications - Internet of Vehicles (IoV) can be pivotal factor towards realization of Intelligent Transportation Systems. IoV principle focus is to have time decisive safety...     

The Adaptive PSAM Design in Cross-Layer

The purpose is to design the pilot symbols efficiently and adaptively in communication systems to guarantee the minimum channel estimation error and the required quality of service (QoS). The various adaptive schemes about pilot symbols assisted modulation (PSAM) are obtained in terms of the pilot-insertion frequency and the power arrangement. The pilot-insertion frequency is redefined according to the sampling theory and the characteristics of fading channels, such as the level crossing rate (LCR) and the average fading duration (AFD). The power arrangement is optimized by maximizing the average spectral efficiency (ASE) in cross-layer design system. Besides, the ASE function in such a system is modified taking the imperfect channel state information caused by channel estimation into considered. The closed-form expression of modified ASE is present in this paper. From both the theoretical analysis and simulation points of view, a suitable scheme about PSAM design is obtained for cross-layer design.

面向移动互联网的业务能力开放平台设计与应用

在移动互联网时代,电信运营商作为传统行业,面临来自移动互联网运营商的业务挤压,电信运营商的传统业务与增值业务不同程度面临停滞不前甚至被取代的风险,因此,通过开放平台来进行业务创新,是电信运营商进行积极尝试的方向与选择。文章对电信运营商建设面向移动互联网的业务能力开放的平台设计进行了系统地研究,并对平台的应用做了概述,为电信运营商开放平台业务的开展提供了参考。     

CLEAR: A Cross-Layer Enhanced and Adaptive Routing Framework for Wireless Mesh Networks

Wireless Mesh Networks (WMNs) provide a new and promising solution for broadband Internet services. The distinguishing features and the wide range of WMNs’ applications have attracted both academic and industrial communities. Routing protocols play a crucial role in the functionality and the performance of WMNs due to their direct effect on network throughput, connectivity, supported Quality of Service (QoS) levels, etc. In this paper, a cross-layer based routing framework for multi-interface/multi-channel WMNs, called Cross-Layer Enhanced and Adaptive Routing (CLEAR), is proposed. This framework embodies optimal as well as heuristic solutions. The major component of CLEAR is a new bio-inspired routing protocol called Birds’ Migration Routing protocol (BMR). BMR adopts a newly developed routing metric called Multi-Level Routing metric (MLR) to efficiently utilize the advantages of both multi-radio/multi-channel WMNs and cross-layer design. We also provide an exact solution based on dynamic programming to solve the optimal routing problem in WMNs. Simulation results show that our framework outperforms other routing schemes in terms of network throughput, end-to-end delay, and interference reduction, in addition to being the closest one to the optimal solution.     

Cross-Layer Design of Sequential Detectors in Sensor Networks

A network of sensors polled by a mobile agent (the SENMA paradigm) is used for detection purposes, with both the remote nodes and the mobile agent implementing Wald's sequential tests. When polled, each remote node transmits its local decision (if any) to the agent, and two network/agent communication schemes are considered. One of these is designed with specific care to the network's energy consumption. In both cases, collisions over the common communication channel are precluded by the sequentiality of the sensors' query. The system performances in terms of average decision time, error probability, and network energy consumption are derived in exact analytical form. A tradeoff exists between the amount and the reliability of the information that the rover may collect: At optimality, the decentralized system overcomes a single supernode by orders of magnitude in terms of decision time, while only 30% of the sensors encountered by the mobile agent spend energy to reveal themselves. The remaining sensors contribute to the detection process by their silence.     

IMS路由相关问题及安全分析

IMS采用会话启动协议（SIP）作为主要信令协议,运行于IP网络之上,是下一代融合网络核心的可选方案之一。IMS中和路由相关的描述主要包括：SIP消息中与路由有关的消息头描述、用户注册路由描述、用户会话发起路由描述,用以解决注册路由和会话路由等。在IMS的部署结构和路由的过程中,接口受到的安全威胁最大,需要设备商和运营商之间根据实际情况达成共识,来提高网络的健壮性和安全性.由于普遍采用简单易实现的递归查询方式,从而导致一级服务器查询量大,需要减少查询开销。