在CNGIIPv6上建立诚信安全的P2P环境和分布管理系统

文章指出中国为实施中国下一代互联网(CNGI)计划而大规模布设IPv6骨干网,这为发展P2P应用、建立诚信安全具有分布管理能力的P2P网络环境提供了机会:一方面在CNGI的IPv6网上一开始就可以实行实名制,从而发展建立网络新秩序;另外一方面可以在CNGI上以无缝和持续演进的方式建立智能结点重叠网,以支持P2P应用并提供分布式管理.文章认为CNGI发展的IPv6终端和IPv6用户网(如家庭网、传感器网等)可以通过在现有IPv4有线/无线接入网和城域网中建立IPv6隧道连接到IPv6骨干网P2P平台,以获得足够的通达能力,并在此基础上发展基于P2P的各种新应用.     

Monitoring emerging IPv6 wireless access networks

Foreseeing a future where IPv6 and mobile terminals play an important role in public access communication networks, this article introduces a monitoring system capable of identifying relevant traffic flows and tracking them while terminal equipment moves between network attachment points. The mobile flows are characterized and represented so that individual users and flows can perceive the quality of service they receive, and operators can have global traffic views of their heterogeneous access networks.     

A service level model and Internet mobility monitor

Mobility is gaining a tremendous interest among Internet users and wireless access networks are increasingly being installed to enable mobile usage. Internet mobility requires solutions to move between access networks with maintained network connectivity. Seamless mobility in turn means that the experience of using a service is unaffected while being mobile. Communication in next generation networks will use multiple access technologies, creating a heterogeneous network environment. Further, roaming between network service providers may take place. To enable mobile nodes to move between access networks within as well as between network service providers with minimal disruption, nodes should be able to maintain multiple active network connections. With the usage of multihomed nodes, seamless mobility can be achieved in already installed infrastructures, not providing mobility support. Mobility in heterogeneous access networks also requires network selections that scale for services. In this article we propose an architecture where application service providers and network service providers define service levels to be used by a mobile node and its user. The user selects a service and the service level from an application service provider. When performing access network selection, information received as part of an application service level will be used to find a network that supports the service required. The performance of available access networks will be monitored and considered when making the decision. Our proposed architecture provides solutions to move flows between interfaces in real-time based on network performance, quality of service signalling to correspondent nodes, and cancellation of flows to give way for more important traffic.     

A framework of handoffs in wireless overlay networks based on mobile IPv6

Although there are various wireless access network technologies with different characteristics and performance level have been developed, no single network that can satisfy the anytime, anywhere, and any service wireless access needs of mobile users. A truly seamless mobile environment can only be realized by considering vertical and horizontal handoffs together. With the advantages of Mobile IPv6, a more comprehensive and integrated framework of heterogeneous networks can be developed. In this paper, we discuss the issues related to handoffs including horizontal and vertical handoffs. We present a scheme for integrating wireless local area network and wide area access networks, and propose a micromobility management method called HiMIPv6+. We also propose a QoS-based (quality-of-service-based) vertical handoff scheme and algorithm that consider wireless network transport capacity and user service requirement. Our prototype evaluations and the simulations show that our framework performs as expected.     

移动通信网络安全发展前景分析

移动通信技术的飞速发展,日益丰富的数据增值业务诸如微博邮件、数据传输、手机支付、多媒体业务等得以应用。而用户更多的个人信息将在移动通信网络中传送,移动通信网络的安全也随之成为移动通信行业界重要的课题。笔者针对移动通信网络中所面临的各种安全威胁和攻击,重点从鉴权认证、用户身份保护、数据加密等方面对移动通信安全现有解决措施的发展情况进行了阐述,并结合移动通信技术的发展分析了其安全措施并提出一些改进方向,最后对移动通信网络安全的前景进行了展望。     

IPv6关键技术的分析

网络和业务正在趋向于进一步的融合，用一个网络完成电信网、计算机网、广电网的各种业务通信，一直是人们追求的目标。这种融合一定程度上更依赖于统一的网络技术平台的建立，IPv6技术无疑是未来的代表。广电行业在启动数字电视建设的同时，更应该关注IPv6技术的发展。就LPv6关键技术领域，包括高性能：IPv6路由器和交换机系统、IPv6主机和智能终端接入系统、IPv6移动接入系统和：IPv6网络安全系统等相关方面进行介绍。     

Mobile multi-user ATM platforms: architectures, design issues, andchallenges

Rapid growth in use of the Internet at and away from the workplace has spurred tremendous interest in the provision of anytime-anywhere network connectivity to mobile users. Commonly studied mobility scenarios involve users equipped with portable data terminals roaming around at slow to moderate speeds within a coverage area. Mobile IP and wireless ATM are examples of protocols designed for providing network connectivity to such mobiles in IP and ATM networks. A different application involving mobile multi-user platforms (MMUP) equipped with onboard private ATM networks is discussed in this article. Examples of such mobile platforms include airplanes, trains, and ships. The presence of an onboard network, multiple users, and potentially high speed of travel presents unique challenges in provision of internetwork connectivity to these MMUPs. Specific characteristics of MMUPs, architectural issues in design of the underlying cellular network, subnetwork mobility within ATM internetworks, location management of MMUPs, and multi-user connection handoffs on MMUP moves are the main issues addressed in the article. Network architectures and protocols developed for terminal mobility scenarios are evaluated for applicability in the present context, and new solutions are presented for problems unique to the MMUP application scenario     

IPv6-based dynamic coordinated call admission control mechanism over integrated wireless networks

Many wireless access systems have been developed recently to support users mobility and ubiquitous communication. Nevertheless, these systems always work independently and cannot simultaneously serve users properly. In this paper, we aim to integrate IPv6-based wireless access systems and propose a coordinated call admission control mechanism to utilize the total bandwidth of these systems to minimize the call blocking probabilities, especially the handoff call dropping probabilities. First, we propose an integrated hierarchical wireless architecture over IPv6-based networks to combine the wireless access systems including cellular systems (second-generation, General Packet Radio Service, or third-generation), IEEE 802.11 a/b/g WLAN, and Bluetooth. In the proposed architecture, mobile user can request a call with quality-of-service (QoS) requirements by any wireless network interfaces that can be accessed. When the proposed coordinated call admission control (CCAC) mechanism receives a request, it takes the QoS requirements of the incoming call and the available and reserved bandwidth of this wireless system into consideration to accept or reject this request. Besides, the mechanism can coordinate with other wireless systems dynamically to adjust the bandwidth reserved for handoff calls at each wireless system in this architecture so as to reduce the call blocking probabilities. Once the call is admitted, the mobile user is able to access heterogeneous wireless access networks via multiple interfaces simultaneously. Finally, we evaluate this system to show that the CCAC on the proposed architecture outperforms other mechanisms proposed before.     

IP Flow Mobility in PMIPv6 Based Networks: Solution Design and Experimental Evaluation

The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in cellular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices. This paper, in line with the mentioned offload requirement, further extends PMIPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. Considering energy consumption as a critical aspect for hand-held devices and smart-phones, we assess the feasibility of the proposed solution and provide an experimental analysis showing the cost (in terms of energy consumption) of simultaneous packet transmission/reception using multiple network interfaces. The end-to-end system design has been implemented and validated by means of an experimental network setup.     

Urban 802.11 Community Networks for Mobile Users: Current Deployments and Prospectives

Few years ago some network operators launched a new service called Community Networks, where each subscriber shares its residential Internet connection with other subscribers of the same operator via his 802.11 access point. Due to the high access point density in urban areas, community networks have the potential to offer high data rate wireless Internet access for mobile users, going beyond the currently available hot-spots, which are typically deployed in a limited number of isolated locations (e.g., airports, cafes). Unlike cellular networks, the locations of community network access points is not centrally planned. We evaluate existing community networks using a participatory sensing application called Wi2Me. First, we analyze different metrics in order to characterize community networks. Second, we take advantage of this unique 802.11 network (in terms of density and coverage) to study how mobility can be supported by identifying drawbacks and proposing some possible solutions.     

Design Considerations of MoHotS and Wireless Chain Networks

This paper introduces and discusses MoHotS and wireless chain networks. The paper proposes integration of unused capacity in hot spots. We discuss the area of coverage and the probability of making connections in wider area wireless networks based on MoHotS. The area of coverage of MoHotS is evaluated for MoHotS on highways. It also addresses the limits of interference in networks of wireless MoHotS and chain networks. It is shown that the interference from other MoHotS converges for large N and is tamed by the path loss exponent. Terrain characteristics are described as well. Dr Johnson I Agbinya holds a doctorate degree from La Trobe University in Melbourne, Australia. He is an Adjunct Professor of Computer Science at the University of the Western Cape, Cape Town, South Africa and a Senior Lecturer at the University of Technology Sydney. He was a Principal Engineer at Vodafone Australia from 2000 to 2003 and a Senior Research Scientist at CSIRO from 1993 to 2000. His areas of research interests are personal area networks, networks on mobile platforms and in uncovered areas, ultra wideband communication, wireless communication networks, mobile network design, wireless access methods, air interface, planning, mobility and moving wireless networks. He also has extensive experience in DSP, signal processing and biometrics. He has published over 80 internationally refereed conference and journal publications, numerous confidentially research reports (CSIRO) and author of a couple of books internetworking.     

Network selection in heterogeneous access networks simultaneously satisfying user profile and QoS

Multimode capability empowers mobile devices to select the appropriate network to meet the requirements of user and applications. However, network selection is a challenging task owing to heterogeneous nature of network access links. At the same time, pervasiveness of mobile communication networks accompanied by the advances in wireless devices has raised the user expectations of persistent service and quality. Therefore, it is important for a mobile device to take situation‐based and timely decisions while selecting an access network to ensure both user's and operator's demand. The existing standard, called IEEE 802.21 (media‐independent handover), considers mobile device signal‐strength parameter for network selection from a list of networks. This research has proposed a ranking algorithm to rank heterogeneous networks based on a set of parameters including user profile and QoS. It selects most suitable network owing to multiple handover scenarios. The simulation results have shown that the proposed scheme has successfully satisfied apparently the contradictory requirements related to user profiles and QoS simultaneously.     

无线异构网络的关键安全技术

异构网络的融合及协同工作在下一代公众移动网络中将是一个很普遍的问题,无线异构网络融合技术作为改善公众移动网络的覆盖和容量以及提供无处不在的通信能力、接入Internet的能力和无处不在的移动计算能力的有效手段,已引起广泛的关注,有着良好的应用前景。构建无线异构网络的安全防护体系,研究新型的安全模型、关键安全技术和方法,是无线异构网络发展过程中所必须关注的重要问题。无线异构网络中的关键安全技术包括安全路由协议、接入认证技术、入侵检测技术、节点间协作通信等。     

移动IPv6及其切换

对未来移动网络首选的移动Ipv6的工作原理作了详尽的介绍,在此基础上,对移动IPv6的各种切换方案作了深入的探讨,进而引入了类比于3G移动通信系统切换的思想,最后提出了移动IPv6切换的下一步研究方向。     

LTE深度覆盖评估体系及专项优化工具

本文从用户感知的角度出发,综合考虑覆盖水平、干扰、VoLTE业务体验等方面,提出了一套建立以客户感知为主的深度覆盖体系,同时运用研发的一系列专项优化工具,用以全方位评估网络的深度覆盖能力.     

Security in enterprise networking: A quick tour

Enterprise networks are complex environments that involve the interconnection of a wide variety of computer systems such as portable PCs and personal digital assistants (PDAs), desktop PCs and workstations, servers, and mainframes, with a wide variety of communication channels such as dial-in and mobile access via modems, local area networks (LANs), wide area networks (WANs), and the Internet. The authors provide an overview of the major areas in the security of enterprise networks to show the variety of issues and techniques developed to address them. Our focus is on the ideas behind these techniques, which can be combined in many ways to create solutions that apply to different situations. The following areas are covered: confidentiality, preventing the disclosure of transmitted data to unauthorized parties; integrity, detecting modification, insertion, deletion, or replay of transmitted data; data-origin authentication, demonstrating that the origin of transmitted data is as claimed; nonrepudiation, preventing either the sender or receiver in a communication from denying their participation; user authentication, demonstrating that the identity of a user or system is as claimed; and access control, guarding against unauthorized use of resources, including the use of resources in an improper manner. We also look at some of the considerations that come into play in designing security solutions for the enterprise networking environment     

移动IPv6切换时延优化新方法

移动IPv6中,移动节点(MN)在不同子网间移动时,既不中断与通信对端(CN)的通信,也不用改变其本身的IP地址.但是当MN与其家乡代理(HA)之间相距较远时,移动IPv6切换时延较大,对于实时性要求较高的业务无法适用.本文分析比较了目前移动IPv6常用的切换时延优化方法,提出了一种自适应快速层次移动IPv6切换时延优化方法,减小了移动IPv6切换时延,提高了网络的性能.     

Efficient Handover with Load Balancing: A Quality Perspective Approach

The heterogeneous wireless networking environment determined by the latest developments in wireless access technologies promises a high level of communication resources for mobile computational devices. Although the communication resources provided, especially referring to bandwidth, enable multimedia streaming to mobile users, maintaining a high user perceived quality is still a challenging task. The main factors which affect quality in multimedia streaming over wireless networks are mainly the error-prone nature of the wireless channels and the user mobility. These factors determine a high level of dynamics of wireless communication resources, namely variations in throughput and packet loss as well as network availability and delays in delivering the data packets. Under these conditions maintaining a high level of quality, as perceived by the user, requires a quality oriented mobility management scheme. Consequently a proposed smooth adaptive soft-handover algorithm, a novel quality oriented handover management scheme which unlike other similar solutions, smoothly transfer the data traffic from one network to another using multiple simultaneous connections.     

移动网络中HTTP视频流终端数据分析及应用

伴随移动通信技术的发展,越来越多的用户选择通过移动网络随时随地观看网络视频,移动视频业务迅速增长.在现有的无线视频传输方式中,由于TCP的可靠性以及易穿透防火墙和网络地址转化等优点,基于TCP的HTTP流逐渐成为网络视频的主流传榆方式.另一方面,用户对业务体验需求的上升,也给移动数据的传输带来巨大挑战.该文通过采集和分析HTTP流的终端数据,获到了HTTP流在HSPA+中传输特性及关键参数的特征,分析结果表明其视频块传输速率变化与自回归模型近似,并在此基础上,提出一种视频等级自适应控制算法,能够有效地改善用户体验.