移动IP的预测移动管理

移动IP使移动主机在移动中能够接入Internet而不中断正在的连接，但移动IP的切换时延较大，不能保证业务的平滑切换，本文提出了层次和预测移动管理的方法，结合无线域内的邻居单播，取得了移动IP的快速和平滑的切换，改善了业务的QOS，并减少了无线域内有线网络的负担。     

快速IP切换在无线局域网中的实现

在移动网络中,无缝切换是提供QoS的基础,也是支持实时业务应用(如视频点播和语音传输等)的保证。针对无线局域网(WLAN)的节点切换问题,建立了各种网络模型,提出了链路层、网络层和传输层的解决方案。文章根据切换过程的技术特征,研究了WLAN中网络层切换的各种方案,包括移动IP方案、TAP-DANCE方案以及网络辅助的IP移动支持,具体分析了上述方案的实现过程,比较了性能指标,指出了存在的问题及进一步研究方向。     

下一代无线网络的移动性管理

在下一代无线网络中,用户可以任意地在不同的无线接入网之间切换。移动IP(MIP:Mobile IP)是当前无线IP网络中的移动性管理协议。但是移动IP协议难以为网络的服务质量(QoS:Qualicy ofService)提供保障。将多协议标记交换(MPLS:Multiprotocol Label Switching)和MIPv6结合的技术是解决这个问题的方案之一。本文介绍了MPLS和移动IP技术的基本原理,研究了基本移动MPLS和分层移动MPLS的实现方案,并基于HMIPv6 over MPLS网络结构介绍了一种为无线网络提供Qos支持的实现方案。     

客服智能手机终端移动工单管理系统的设计与应用

本文介绍客服智能手机终端移动工单管理系统的设计与应用(以下简称移动工单系统),本系统将传统数字电视客户呼叫中心结合最新的网络移动技术、数据实时交换技术,从有线网络的计算机终端应用延伸到移动网络和智能手机终端上,实现了分布式的业务逻辑移动处理、有线网络和无线网络问的无缝切换,实时传递业务数据信息.     

WiMAX构架及其对移动性的管理

随着英特网及其技术的快速发展,无线移动技术需要支持基于IP的业务。WiMAx是一种可用于城域网的宽带无线接入技术,它的主要作用是提供无线“最后一公里”接入,可提供面向IP互联网的高速连接。文章介绍了WiMAX的网络总体架构以及架构中主要功能体的作用,同时介绍了支持移动的接入网特点。基于目前对WiMAX的移动性管理,分别详细介绍了有关系统内切换和系统间切换的过程。     

广播电视融合网业务及终端规划

本文主要介绍了有线无线卫星融合网开展的业务规划分类,详细介绍了各种业务的具体形式,并结合这些业务的规划,介绍了融合网络中的网络终端和用户终端,业务和终端规划将指导有线无线卫星融合网的建设和落实.     

基于业务感知的WLAN-UMTS跨层切换优化方案

下一代的异构无线网络环境是移动无线接入和异构分布的网络,近年来由于智能多模终端的发展以及多种无线接入网络并存的网络环境,使得无缝的垂直网络切换成为人们关注的热点。文章在分析当前WLAN-UMTS(无线局域网-通用移动通信系统)切换方案不足之处的基础上提出了改进和创新,主要将802.21 MIH(介质独立切换)运用到切换的过程中,在应用层加入业务感知模块,使得终端可以根据业务的类型选择网络,最后基于NIST(美国国家标准和技术协会)使用NS2对新的切换方案进行了仿真。     

异构网络中基于移动IP切换的TFRC改进

TCP-Friendly Rate Control（TFRC）是一种专门针对实时多媒体流在Internet中传输的拥塞控制方案,但在有线无线异构网络频繁的越区切换中,传统的TFRC存在数据流变化异常的问题。针对此问题,提出了基于移动IP切换的TFRC拥塞控制方案,并利用ns进行仿真分析。结果表明,在网络发生移动IP的切换后,该方案能够准确判断出网络切换状态,并快速增加发送速率,充分利用网络带宽,减小用于增加发送速率的时长,从而减小传输时延。     

移动IPv6快速切换在MBWA中的应用

目前的无线局域网和3G网络都还无法满足人们对移动多媒体通信的需求。IEEE802．20——移动宽带无线接入(MBWA)工作组的目标是使高速移动的用户也能获得与有线链路相媲美的数据业务体验。为了支持网络层的移动性，MBWA系统中引入了移动IPv6技术。介绍了一种可以应用于MBWA系统的移动IPv6快速切换机制，此机制是对标准IPv6切换的改进，从而能够在最大程度上减小由于IP协议操作引起的切换时延。     

一种移动IP快速平滑切换方案

无线IP网络中将采用移动IP实现移动性管理,但该方案应用在高频度切换环境,存在不可接受的切换时延和数据包丢失,很难保证通信业务的服务质量.提出了一种移动IP快速平滑切换方案,该方案利用后注册切换的概念,在切换过程中不存在数据包的丢失,并可以获得很小的切换时延,在实际系统中运行能够达到良好的效果.     

WiNoC中无线通信拥塞与故障感知的容错路由算法

在无线片上网络中,无线通信拥塞和故障对整个片上网络的通信效率具有严重影响.为此本文提出了一种针对无线通信拥塞和故障的容错路由算法,首先设计了无线通信拥塞和故障感知模型,该模型能够感知无线节点通信对的拥塞和故障信息,并对其编码发送给子网中的路由器;然后子网中的路由器根据接收到的无线节点通信对状态信息,判断数据包是否使用无线传输.实验表明,本文方案相较于对比对象能够在较小的额外面积、功耗开销下,保证较低的网络延迟和较高的网络吞吐率,并对无线节点通信对的永久性故障具有良好的容错能力.     

基于OLSR协议的无线MESH网络系统设计

本文针对传统单跳无线网络(WLAN)可伸缩性低、鲁棒性差等缺点,提出了一种基于OLSR协议的无线MESH网络系统设计方法,该方法在提高对网络拓扑变化动态适应性的同时, 达到减少控制开销的目的。每个子网选择部分节点作为网络控制分组的多点中继节点(MPR), 其它邻居节点收到该节点发送的控制分组时,只进行处理而不转发,通过这种方式显著地减少了传统先应式路由协议网络拓扑信息广播的控制分组数量。每一个 MPR 节点只报告自己与其 MPR 节点之间的链路,进一步地减少了网络控制开销。该方法在城市数字化、城市无线监控等领域具有较高应用前景。     

CPCA: An efficient wireless routing algorithm in WiNoC for cross path congestion awareness

Wireless network-on-chip (WiNoC) is a new paradigm to mitigate the long-distance transmission latency for conventional wired network-on-chip. The wireless routers in WiNoC have to handle a large number of packets which could cause data congestion, thus reducing the network performance. In this paper, we propose a novel wireless routing algorithm, called CPCA, which exploits the cross path congestion information as hints to route the packets. Under CPCA, the whole network is partitioned into sub-networks. In each subnet, the congestion information of the wireless router is propagated along the cross path. As a result, the routers in the same dimension can get the congestion degree of wireless router within the subnet. Based on the congestion information, CPCA can compute the suitable path for packets routing, which can prominently avoid the congestion aggravation in the wireless router. Experimental results show that our proposed method can effectively improve performance in terms of packets transmission latency and network throughput.     

基于ZigBee技术的智能家居系统内部组网

为了提高智能家居系统的快速部署能力、降低构建成本,提出了一种利用ZigBee无线组网技术,构建智能家居系统内部基础网络的设计方案。该方案采用无线射频收发CC2430芯片和外围电路设计终端设备与中心协调器的硬件电路。根据ZigBee协议栈使用C语言编写终端设备和中心协调器的通信应用软件。     

All-IP 4G Network architecture for efficient mobility and resource management

In this article, we investigate 4G network architecture and consider two underlying layers: PHY and MAC. We compare two models of wireless access network: pure all-IP and subnet based networks. The pure all-IP model is simple and cost-efficient but causes implementation issues of mobility management and resource coordination. In contrast, the subnet based network enables layer 2 and layer 3 handoffs to be executed independently, deploying several access points under an access router. Further, to handle various cases efficiently according to traffic class and mobility, we present an advanced model of a hierarchical cellular system that combines multiple access techniques of OFDMA and FH-OFDMA with microcells and macrocells. Finally, as an integrated approach to support diverse QoS requirements, we consider an IP-triggered resource allocation strategy (ITRAS) that exploits IntServ and DiffServ of the network layer to interwork with channel allocation and multiple access of MAC and PHY layers, respectively. These cross layer approaches shed light on designing a QoS support model in a 4G network that cannot be handled properly by a single layer based approach     

Wireless Mesh Networks and Cooperative Relaying Technologies

The Wireless Mesh Network (WMN) has become a focus in research of wireless broadband communications . In a switching technologies - based wireless Mesh network, the entire network is regarded as an IP subnet, so it cannot be applied in situations where large coverage is required . The use of cooperative relaying technologies can improve the transmission rate and reliability of wireless link; while the wireless Mesh network, once integrated with cooperative relaying technologies and routing technologies , can improve its spectrum efficiency and cover a wide area . However, there are many problems to be solved with respect to standardization, key technologies research and industrialization. Therefore , the application of cooperative relaying technologies in wireless Mesh networks is still a great challenge .     

Novel Section‐Based Joint Network Coding and Scheduling Scheme in WMNs: JNCS

Guaranteeing quality of service over a multihop wireless network is difficult because end‐to‐end (ETE) delay is accumulated at each hop in a multihop flow. Recently, research has been conducted on network coding (NC) schemes as an alternative mechanism to significantly increase the utilization of valuable resources in multihop wireless networks. This paper proposes a new section‐based joint NC and scheduling scheme that can reduce ETE delay and enhance resource efficiency in a multihop wireless network. Next, this paper derives the average ETE delay of the proposed scheme and simulates a TDMA network where the proposed scheme is deployed. Finally, this paper compares the performance of the proposed scheme with that of the conventional sequential scheduling scheme. From the performance analysis and simulation results, the proposed scheme gives more delay‐ and energy‐efficient slot assignments even if the NC operation is applied, resulting in a use of fewer network resources and a reduction in ETE delay.     

一种基于网络编码协作的高能效无线传感器网络机制

Energy-efficient communications is crucial for wireless sensor networks (WSN) where energy consumption is constrained. The transmission and reception energy can be saved by applying network coding to many wireless communications systems. In this paper, we present a coded cooperation scheme which employs network coding to WSN. In the scheme, the partner node forwards the combination of the source data and its own data instead of sending the source data alone. Afterward, both of the system block error rates (BLERs) and energy performance are evaluated. Experiment results show that the proposed scheme has higher energy efficiency. When Noise power spectral density is -171dBm/Hz, the energy consumption of the coded cooperation scheme is 81.1% lower than that of the single-path scheme, 43.9% lower than that of the cooperation scheme to reach the target average BLER of 10-2. When the channel condition is getting worse, the energy saving effect is more obvious.     

物理层网络编码分组的机会中继

为提升物理层网络编码方案的抗衰落性能,该文提出了一种基于物理层网络编码的机会中继方案(Opportunistic Relaying based-on Physical-layer Network Coding,PNC-OR),该方案利用物理层网络编码的基本思想、有效提升网络吞吐的同时,通过中继节点的分布式选择,也能够使系统获得多用户分集增益,提高了系统的抗衰落性能。针对双向无线中继信道中端到端信息交换的情形,推导了准静态衰落环境下PNC-OR中多个目的节点接收信息的和容量。数值结果显示：和机会中继、传统网络编码两种方案相比,PNC-OR具有更高的频谱效率,并且随着中继节点的增多,频谱效率也越高。     

一种基于随机密钥的无线传感器网络加密方案

密钥的建立与管理是无线传感器网络安全的重要且基础的组成部分,是影响大规模应用的一个关键问题。近来,密钥建立与管理成为无线传感器网络安全领域一个活跃的研究分支。提出一种基于随机密钥预分配的无线传感器网络加密方案。该方案通过密钥互斥机制解决传统随机密钥预分配方案中点到点数据源认证问题。