基于定向天线的移动自组网技术研究综述

对基于定向天线的移动自组网邻居发现和接入控制关键技术进行研究.首先,介绍了其研究背景和意义;其次,分析了当前基于定向天线的MANET中存在的问题,并针对国内外研究现状,介绍了几种解决这些问题的方案.再次,着重介绍了两种比较成熟的基于定向天线的移动自组网邻居发现和接入控制算法SAND和PAMC.最后给出了基于定向天线的邻居发现和接入控制算法的下一步研究方向.     

基于 IBE 的移动自组网安全接入机制

文中研究基于IBE的移动自组网安全接入机制,解决移动自组网拓扑动态变化、高时效性、快速切换等条件下的高效认证问题。对比分析各种认证机制的优缺点以及适用的环境,针对移动自组网内部的接入认证、动态组网认证、跨域认证,分别设计相关的认证流程及安全接入实现途径,保证骨干网、接入子网互联互通时的安全可控,为建设移动自组网安全防护体系提供理论依据和技术支撑。     

移动自组网中支持实时业务的接入机制

针对异步MANETs网络提出了一种新的有效支持实时业务的接入协议———分布式异步PRMA。该协议在不依赖于中心控制器及全网的时钟同步的前提下提供资源预留机制,实现了话音业务的传输并保证了其时延要求。     

移动自组网与Internet互连的动态网关策略

移动自组网(MANET)是自治的无基础设施的网络,它通过IP路由支持多跳无线通信。它与Internet 相比存在着许多差异,不仅有网络拓扑结构的不同,还存在通信方式的不同。因此,MANET与Internet组合成混杂网络(hybrid network)是一个具有挑战性的课题。移动自组网(MANET)的结点要进行Internet连接,就必须寻找Internet网关。如何寻找和维持与Internet网关的连接是这个问题的关键,再者,就是如何切换到一个更合适的相邻网关。在这篇文章中,首次提出动态网关的概念,动态网关作为MANET和Internet之间的接口起桥梁作用。通过模型分析,证明动态网关体系结构适合于自组网与Internet互联。仿真结果显示,利用动态网关的网络性能优于单一固定网关的体系结构的网络性能。     

移动自组网与Internet互联技术研究

随着Ad hoc网络技术的不断发展成熟,移动自组织网（MANET）与Internet的互联已经成为扩展无线应用的关键。文章详细分析MANET与Internet互联中的地址分配、路由发现、网关发现、协议转换几项关键技术,讨论现有MANET与Internet互联的方案,最后指出互联技术研究中的要点及未来研究的方向。     

移动自组网MAC协议的误码性能分析

考虑到节点的定时精度和侦听数据传输的节点带来了网络节点间的干扰（INI）,从而严重影响网络的性能,文中分析了移动自组网误码率性能。采用理论分析与Mento Carlo仿真相结合的方法,仿真结果示出了几种不同参数的取值对系统误码率的影响程度,对加速移动自组网技术的发展与应用具有一定意义。     

移动自组网QoS保证技术的探讨

如何为用户提供相应的Qos保证是移动自组网发展的技术瓶颈之一。文章分别从QoS信令、QoS路由和QoS MAC方面比较全面地探讨了如何实现Qos保证;详细阐述了每个方面的关键技术,并结合主流协议介绍了具体操作过程,剖析了实现过程中的难点。     

移动自组网安全性的研究

移动自组网(MANET)是新型的无线移动网络，它不依赖固定网络设施，是能快速展开、自治、多跳的网络结构。它由一组带有无线收发装置的节点组成，整个网络通过移动节点间的相互协作保持网络互联。网络中的每个节点都能快速移动，同时具备主机和路由器功能。移动自组网的前身是分组无线     

基于嵌入式Linux平台的移动自组织网Internet接入方案及实现

随着通信技术的发展,移动自组织网络得到了越来越广泛的应用,同时多网的互联互通也是大势所趋.基于在分层移动自组织网中实现Internet接入的意义和功能,提出并实现了一种Internet接入方案.结合设计方案,介绍了基于Motorola公司的ColdFire嵌入式处理器MCF5272和uClinux操作系统所建立的系统软硬件平台.     

移动自组网IP地址分配技术综述

对近年来提出的多种移动自组网(MANET)地址分配技术进行了较详细地分类评价和性能比较,包括基于状态维护的算法,基于冲突检测的算法和基于网络分层的算法等,并在最后指出了未来的技术发展方向。     

IP connectivity for gateway GPRS support node

In the Universal Mobile Telecommunications System, the gateway GPRS support node (GGSN) provides IP connection between the mobile telecommunications network and external packet data networks (e.g., the Internet). Specifically, the GGSN exercises session management to transfer user packets between mobile stations and external data networks. In this article we focus on the GGSN functions for IP connection including access point name processing, IP address allocation, tunneling technologies, and QoS management. Based on our experience as a mobile operator, we give several examples to show how these functions can actually be implemented in a commercial mobile network.     

UAV-based LoRaWAN flying gateway for the internet of flying things

The Internet of Things (IoT) is one of the paradigms related to the evolution of telecommunication networks which is contributing to the evolution of numerous use cases, such as smart city and smart agriculture. However, the current communication infrastructure and wireless communication technologies are not always able to guarantee a proper service for these IoT scenarios. Smart solutions are needed to overcome current terrestrial network limitations offering a cost-effective way to extend the current terrestrial network coverage. For example, temporary extensions “on-request” of the terrestrial infrastructure may be a viable solution to allow collecting data generated by nodes outside the current network coverage. Flying objects can help achieve this goal. Various studies supported the use of unmanned aerial vehicles (UAVs) as intermediate nodes between IoT devices and the network. However, such solutions have not been exhaustively tested yet in real-case scenarios. This paper proposes an efficient solution to collect data from multiple IoT sensors in rural and remote areas based on UAVs. It describes the implementation of the proposed UAV-based Long RangeWide Area Network (LoRaWAN) flying gateway able to collect data directly from LoRaWAN sensors during its flight, keep them stored in an onboard memory, and forward them at the end of its flying path to a platform where the authorized users can access them. A prototype of the gateway has been developed to assess the proposed solution through both indoor and outdoor tests aiming to test its feasibility both in terms of communication performance and UAV-required hardware resources.     

Convergence of residential gateway technology

A new OSI-based model is described that can be used for the classification of residential gateways. It is applied to analyze current gateway solutions and draw evolutionary paths for the medium to long term. From this it is concluded that particularly set-top boxes and broadband modems, as opposed to game consoles and PCs, have a strong potential to evolve toward gateways that deliver network services to the home on all OSI layers, although they probably will not converge. In our model, we have not found any compelling reasons for the residential gateway industry to support concurrent multiple broadband access network connections on a single residential gateway in the near future.     

Novel approach of distributed & adaptive trust metrics for MANET

It is known to all that mobile ad hoc network (MANET) is more vulnerable to all sorts of malicious attacks which affects the reliability of data transmission because the network has the characteristics of wireless, multi-hop, etc. We put forward novel approach of distributed & adaptive trust metrics for MANET in this paper. Firstly, the method calculates the communication trust by using the number of data packets between nodes, and predicts the trust based on the trend of this value, and calculates the comprehensive trust by considering the history trust with the predict value; then calculates the energy trust based on the residual energy of nodes and the direct trust based on the communication trust and energy trust. Secondly, the method calculates the recommendation trust based on the recommendation reliability and the recommendation familiarity; adopts the adaptive weighting, and calculates the integrate direct trust by considering the direct trust with recommendation trust. Thirdly, according to the integrate direct trust, considering the factor of trust propagation distance, the indirect trust between nodes is calculated. The feature of the proposed method is its ability to discover malicious nodes which can partition the network by falsely reporting other nodes as misbehaving and then proceeds to protect the network. Simulation experiments and tests of the practical applications of MANET show that the proposed approach can effectively avoid the attacks of malicious nodes, besides, the calculated direct trust and indirect trust about normal nodes are more conformable to the actual situation.

     

Quasi-tree mobility management for internet connectivity of mobile ad hoc networks

The location of mobile nodes must be managed to enable Internet connectivity of mobile ad hoc networks. Node mobility can be managed efficiently using a tree topology in which a mobile node registers with an Internet gateway along a tree path without using flooding. However, a node that loses connectivity to its parent has to find and connect to a new parent through a join-handshaking process. This tends to increase control overhead and impose some delay on on-going communication. Furthermore, the node may join its descendant because of the synchronization delay in updating topology change, creating a loop that significantly increases control overhead. We improve these problems by maintaining a quasi-tree topology in which a node maintains multiple parents. We also present a technique for detection and resolution of loops. The simulation results show that the quasi-tree mobility management approach far outperforms the traditional approaches and is highly robust against the significant increases in tree size and node mobility.     

基于互联网的我国旅游业竞争策略研究

随着在线旅游服务的兴起和蓬勃发展，介入互联网已成为我国旅游业不可避免的趋势。但是在我国旅游业使用互联网的过程中，仍然存在诸多问题。因此，通过发现并分析这些问题，来探寻我国旅游业未来发展的竞争策略就显得尤为必要。     

高性能VPN网关的并行技术研究

本文针对国内VPN网关的速度瓶颈,采用多卡并行及CompactPCI硬件集群平台等理论和技术,来提高VPN网关的加密速度。这一研究将为国产VPN在高性能网络的应用奠定良好的基础。     

基于FSO技术的“最后1km”宽带接入

自由空间光 (FSO)技术作为地下光纤网的补充 ,在提供“最后 1km”宽带接入方面与其他的固定无线设备相比有很强的竞争力。虽然通过空气传输光信号仍然存在技术上的挑战 ,但是与敷设光纤网相比 ,FSO成本低、安装快捷 ;与安装其他固定无线网络相比 ,FSO还具有高速宽带和无需许可的特点 ,具有非常好的应用前景。     

基于ZigBee技术的病人综合信息网关设计

为了实现病人监护设备的智能化,提出了一种基于ZigBee无线传感技术的医疗监护系统网关解决方案。该方案将测量到的人体体温、血压等数据通过ZigBee无线传感器网络传输到网关节点,再由网关节点对这些生理参数进行详细处理,医生可根据这些数据对病人的生理情况做出诊断评估。经试验证明,终端节点在60米内可保证通信效果,及数据准确性。