Route optimization using the distributed binding update for nested mobile networks

Although many researches on network mobility management have been carried out, a binding update storm, signaling overheads, and so on still exist in the past proposals. To avoid the binding update storm and to support route optimization as well as intra‐domain data communication, a specifically designed solution with a distributed manner is proposed in this paper. By applying the derived analytical results, we demonstrate that the proposed solution is able to significantly outperform the closely related work in the literature.Copyright © 2012 John Wiley & Sons, Ltd.     

GPRS骨干网内移动终端间路由的优化方案

分析了GPRS骨干网内移动终端之间相互通信的数据传输路由,针对其中存在的路由迂回问题,提出一种综合性能较优的路由优化方案。通过由SGSN分担部分数据处理使GGSN处理能力提高,通过GGSN的数据流量减少,缩短了数据迟延,同时SGSN的处理复杂度无显著增加。     

移动IPv6分层管理费用的分析与自适应优化

为综合优化分层域内外以网络传输花费和带宽占用为代表的通信管理费用,论文对实施分层移动IPv6前后的费用变化进行了理论分析,得出了判决是否适宜使用分层移动管理的准则,并在此基础上提出一种允许移动节点动态地根据切换频度和流量强度等参数选择适宜的移动管理机制的自适应优化方案.仿真结果表明该方案能获得比静止使用某种移动管理机制更好的资源使用效率,可望具有较好的实际应用价值.     

Morphing distribution trees—On the evolution of multicast states under mobility and an adaptive routing scheme for mobile SSM sources

Source Specific Multicast (SSM) promises a wider dissemination of group distribution services than Any Source Multicast, as it relies on simpler routing strategies with reduced demands on the infrastructure. However, SSM is designed for á priori known and changeless addresses of multicast sources and thus withstands any easy extension to mobility. Up until now only few approaches arose from the Internet research community, leaving SSM source mobility as a major open problem. The purpose of this paper is twofold. At first we analyze characteristic properties of multicast shortest path trees evolving under source mobility. Analytically and by stochastic simulations we derive measures on the complexity of SSM routing under source mobility. At second we introduce a straightforward extension to multicast routing for transforming (morphing) source specific delivery trees into optimal trees rooted at a relocated source. All packet forwarding is done free of tunneling. Multicast service disruption and signaling overhead for the algorithms remain close to minimal. Further on we evaluate the proposed scheme using both, analytical estimates and stochastic simulations based on a variety of real-world Internet topology data. Detailed comparisons are drawn to bi-directional tunneling, as well as to proposals on concurrent distribution trees.     

面向移动IPv6层次化网络的快速接入认证方案

提出了一个面向移动IPv6层次化网络的快速接入认证方案,从效率和安全性2个方面提高移动IPv6层次化网络接入认证的性能。首先,利用向量网络地址编码方法实现网络数据传输,提高家乡注册性能;其次,提出一种基于格的层次化签名方案,在接入认证过程中实现双向认证,提高认证过程的安全性。方案分析表明,所提出的接入认证方案具有强不可伪造性并可以抵御网络中的重放攻击,同时可以减少整个接入认证过程的延迟时间。     

基于扩展邻居发现协议的嵌套移动网络路由优化方案

嵌套移动网络在扩大通信范围的同时会带来严重的路由优化问题。针对已有优化方案在可部署性和性能等方面的不足提出了一种新的嵌套移动网络路由优化方案（NMNRO）,通过扩展邻居发现协议,在嵌套移动网络内通告相同的外地前缀,并更新接入路由器的邻居缓存和移动路由器的路由表,然后通过向对端发送绑定更新来实现路由优化。性能分析表明,该方案为嵌套移动网络提供了较为完整的路由优化方案,在降低优化开销的同时,具有较好的可部署性和兼容性。仿真实验结果表明该方案具有较低的切换时延和较高的有效吞吐量,且这些性能优势会随嵌套层数的增加而更加明显。     

Determinants of player acceptance of mobile social network games: An application of extended technology acceptance model

In recent years, mobile devices and social network games (SNGs) have gained wide popularity among the mainstream users. The present study aims to investigate the psychological elements that may contribute to user behaviors regarding mobile-social network games (M-SNGs). This study introduces an integrated model for M-SNGs. Statistical results from an online survey of players of M-SNGs indicate that the proposed research model effectively demonstrates and examines player acceptance of and attitudes toward M-SNGs. This research model is valid, and illustrates not only perceived enjoyment and usefulness as determinant variables of intention to use among players, but also perceived mobility together with perceived control and skill as motivational factors for players. The results also describe that satisfaction has a moderate role, which in turn has significant effects on multiple connections in the research model. Both theoretical and practical implications are provided based on the findings.     

新一代互联网移动管理机制研究

 传统互联网以"固定、有线"为主的连通方式,难以适应新的无线/移动网络的发展需求.本文提出了一种新一代互联网移动管理机制——标识分离映射机制ISMS,详细介绍了ISMS的基本理论和协议流程,并与移动IPv6协议进行了性能分析和对比.ISMS是一种基于网络的移动管理机制,其切换管理和位置管理均由网络完成,能够满足新一代互联网移动管理机制在快速切换、路由优化、可扩展、可控可管、保护位置隐私、安全性和降低无线链路开销等方面的需求.理论分析表明ISMS的网络层面平均切换时延远小于移动IPv6的平均切换时延,能够有效支持绝大部分实时应用.原型系统的实现和验证进一步说明了ISMS的可行性和有效性.     

DXX设备在北京移动传输网中的应用

利用ＤＸＸ系列传输设备对北京移动通信的基站传输网进行了改进,包括：设备组成、网络结构、网管系统结构和功能以及同步时钟方案等。     

A mobile spatial messaging service for a grassroots environmental network

Information and communication technology are potentially significant tools in strengthening local initiatives towards sustainability. The Science and Technology (S&T) Framework for Sustainable Development provides a context for such development. This article describes a study aimed at examining how the existing mobile technologies of standard messaging service and wireless application protocol can be used to support the activities of an environmental grassroots organisation–London 21 Sustainability Network (henceforth London 21). Following the S&T Framework, it is clear that to realise the potential of these technologies a new mobile service should be effectively embedded into the structure and activity of the network. Using a participatory research approach, an extensive user requirements study with 273 participants was carried out to ensure that the development of the mobile service for London 21 fulfils the purposes, goals and expectations of the organisation.

This article describes a Mobile Spatial Messaging Service, called EcoTEXT, which was developed and deployed for London 21. This service allows individuals to receive geographically targeted, action-orientated, time-relevant information via text messages on their mobile phones. The content of the service is information about upcoming local environmental events and activities, which match the interest of the user, when these events occur in close spatial proximity to where that user resides. This type of service represents a powerful new dimension for the provision of data-driven services in comparison to current text-based services. Location is giving the service additional meaning and value. The introduction of such a service into the organisation's communication toolkit offers the potential to create, supplement and strengthen social ties and interactions within the community.     

Performance Enhancement of Fast Handover for MIPv6 by Reducing Out-of-Sequence Packets

FMIPv6 can reduce packet loss using a tunnel-based handover mechanism which relies on L2 triggers, such as transmitting a packet from a previous access router (PAR) to a new access router (NAR). However, this mechanism may result in decreasing the performance of TCP due to out-of-sequence packets arriving between the tunneled packets from the Home Agent and PAR, and the directly transmitted packets from the correspondent node (CN). In this paper, we propose a new scheme called EF-MIPv6 that uses a modified snoop protocol to prevent the packet reordering problem. This new scheme can prevent sequence reordering of data packets and improve the performance of TCP using enhanced fast binding update (EF-BU). This approach requires modification of the TCP header to execute the last packet expression from the PAR, include a new polling data packet, and use the modified access point system. Simulation results demonstrate that managing the packet sequence in our proposed scheme greatly increases the overall TCP performance in a Mobile IPv6 and FMIPv6 networks.

SDH网络中网管监控优化方案设计

随着通信行业的高速发展和人力成本的提高,通信网管网络的稳定运行已成为运营商关注的焦点。本文通过对SDH网络中的ECC通信的特点、通信原则、组网能力等方面进行分析,结合实际应用中SDH网管有时会出现的网元大面积脱管、网元数据及告警信息提取更新速度慢等隐患,提出了解决的几个有效方法,并通过应用于实际日常维护工作中,使SDH传输设备网管的有效性和可靠性得到了大幅的提高。     

A fast seamless handover scheme and its CDT optimization for ping-pong type of movement

In mobile IPv6 networks, the ping-pong type of movement brings about frequent handovers and thus increases signaling burden. This letter proposes a fast seamless handover scheme where the access router keeps the mobile node＇s old reservation till the offline Count Down Timer （CDT） expires in order to reduce handover signaling and delay while the mobile node returns in a very short period of time. Based upon a poisson mobility model, an simple expression for CDT optimization is given out for the scheme to achieve the best cost performance of resource reservation.     

Dynamic and hierarchical IPv6 address configuration for a mobile ad hoc network

The paper proposes a dynamic and hierarchical IPv6 address configuration scheme for a mobile ad hoc network (MANET). The scheme proposes the hierarchical architecture and combines the distributed and centralized address configuration approaches. In the architecture, a central node assigns IPv6 addresses for cluster heads that are distributed around a MANET, and distributed cluster heads assign IPv6 addresses for cluster members. The generation algorithm of a cluster is proposed, and it uses the number of potential cluster members as a measurement unit and minimizes the number of cluster heads. Therefore, the address configuration cost for cluster heads is reduced. A central node/cluster head uses the unicast communication mode to achieve the real‐time address recovery in order to ensure that it has enough address resources for assignment. The paper also proposes the low‐cost MANET merging/partitioning algorithm that guarantees that no address collision happens during the MANET merging/partitioning process. This paper analyzes the performance parameters of the proposed scheme, including the address configuration cost, the address configuration delay, and the number of MANET merging. The analytical results show that the proposed scheme effectively reduces the address configuration cost, shortens the address configuration delay, and decreases the number of MANET merging. Copyright © 2013 John Wiley & Sons, Ltd.     

基于DNS的代理移动IPv6位置管理机制

Proxy Mobile IPv6 (PMIPv6) is designed to provide a network-based localized mobility management protocol, but it does not handle the global mobility of hosts. In this paper, we propose a location management scheme based on Domain Name System (DNS) for PMIPv6 which can support global mobility by using DNS as a location manager. In addition, to support large numbers of mobile terminals and enhance network scalability a paging extension scheme is introduced to PMIPv6.To evaluate the proposed location management scheme, we establish an analytical model, formulate the location update cost and the paging cost,and analyze the influence of the different factors on the total signaling cost. The performance results show that our proposed scheme outperforms the basic PMIPv6 under various parameters in terms of reducing the signaling overhead and the proposed scheme reduces signaling overhead compared to the basic PMIPv6.     

Mobility management schemes for real‐time traffic and resource allocation in IEEE 802.16e mobile network

In this paper, our aim is to develop in IEEE802.16e Wireless Networks with link adaptation, in the presence of real‐time traffic call admission control (CAC) schemes. These CAC propose various scenarios of resource splitting and handling the intracell mobility. In particular, we consider two types of intracell mobility classes : low mobility class for mobiles moving usually with low speed between the neighboring regions of the cell and high mobility class for those moving with high speed and that can skip more than one region before changing their modulation. For this reason, we assume a time threshold T _th that determines the minimum time a call must remain in a region before the base station changes its modulation. And we compare it with the time that a call may spend in a region to decide whether the base station will change its modulation or not. In the beginning, we introduce two CAC schemes. In the first one, we reserve a portion of resources to mobiles in migration with both high and low mobility. And in the second one, we give the priority just to mobiles in migration with high mobility. Then, we calculate the impact in the blocking and dropping probabilities. We show by numerical results that by the proposed CAC schemes, we can find a resource management that outperforms well under different types of mobility. But, to find a good tradeoff between dropping the calls in migration and blocking the new calls, we introduce the optimization problem in the second part. So, we are faced to the necessity of optimizing the results found in the first part. Therefore, we define an objective function to optimize, in order to ensure the highest quality of service for users and to give a better stability state between the dropping and blocking probability. We show that the proposed objective function gives the optimal resources allocation between the migrating and new arriving calls in the cell. Copyright © 2015 John Wiley & Sons, Ltd.     

Mobile IPv6中建立IPSec安全关联的一种新方案

Mobile IPv6的消息交互需要IPSec来提供安全保护，但什么时候建立IPSec安全关联会对Mobile IPv6的安全性、效率、计算量产生较大影响。传统的方法是当移动节点移动到外地网络之后需要时才建立，分析表明该方法效率低、计算量大、安全性差，不符合应用要求。本文提出移动节点在家乡网络中提前建立保护Mobile IPv6消息交互的安全关联，并给出了具体的方法。分析表明新方案较传统方法具有时延少、计算量小、效率高、安全性强的特点。     

Low-cost binding update scheme based on pointer forwarding in HMIPv6 network

By introducing a mobility anchor point(MAP),hierarchical mobile IPv6(HMIPv6)reduces the binding update signaling cost associated with mobile IPv6,but there still exist deficiencies.For instance,a mobile node(MN)needs to orderly accomplish two binding updates with the MAP and home agent(HA)when the MN performs inter-MAP mobility.This results in a high signaling cost,thus affecting network performance.To reduce the inter-MAP binding update cost of idle MN in HMIPv6,an optimization scheme based on pointer forwarding with a threshold is proposed.The scheme can reduces the binding update cost of idle MN by using the binding update between MAP to replace several home binding updates.The signaling cost difference is derived by analyzing the cost of the basic scheme and the optimization scheme between two successive sessions.Simulation results show that,the optimization scheme can reduce the binding update signaling cost and improve the network performance as long as a suitable threshold is chosen.The discussions on the sensitivity of tele-parameters are also given.     

电力通信综合数据网市县互联优化方案

针对某市综合数据网市县互联链路现状,文章分析了目前市县互联链路存在的问题,阐述了优化原则,重点探讨并制定了市县骨干综合数据网互联优化方案。在实际应用中证明了这一方案的可行性。     

IPv6的移动性支持及其优化

随着IPv6技术的稳步发展以及移动IPv4面临移动性、安全性差等越来越多的问题，移动IPv6由于其优良的性能而日益引起人们的关注。由于目前并未出现移动IPv6的标准，本文根据IETF关于IPv6的移动性支持的草案，首先详细介绍了移动IPv6的基本概念和工作原理，主要包括3个基本功能：路由器搜索、注册和分组传送。然后，文章对移动IPv6的优化问题进行了初步探讨。最后简单分析了移动IPv6技术未来的发展和实现。