Multiple Virtual Interfaces for Multi-homing Hosts to Support Inter-technology Handover in PMIPv6 Network

Proxy Mobile IPv6 (PMIPv6), a network-based mobility management protocol, supports multi-homing, inter-technology handover, and flow mobility, with the help of a host’s virtual interface (VI). Several single virtual interface (SVI) schemes have been proposed to support these functions. In the SVI schemes, the link-layer identifier (LL-ID) should be swapped while the host is processing neighbor discovery (ND) after inter-technology handover or flow mobility. That is, a host must replace the LL-ID of a VI contained in a neighbor advertisement with the LL-ID of a physical interface (PI) related to a real connection. Such LL-ID swapping cannot be executed under secure neighbor discovery, and it causes ND processing delay and high overhead to check all outgoing packets. In this paper, we propose a multiple virtual interfaces scheme to solve the problem related to the LL-ID swapping, and to provide good support to the inter-technology handover. In the proposed scheme, there are the same numbers of VIs as the PIs between the data link layer and the network layer of a host. Since each VI maintains its own neighbor cache, the proposed scheme does not require LL-ID swapping, so that it can keep the standard ND process. We explain the basic operation of PMIPv6 inter-technology handover under the proposed scheme and, through NS-3 simulation, evaluate the performance of the proposed scheme in terms of ND process delay and inter-technology handover latency.     

Enhancing QoS of Mobile Devices by a New Handover Process in PMIPv6 Networks

The handover processes in present IP mobility management protocols incur significant latency, thus aggravating QoS of consumer devices. In this paper, we introduce an enhanced handover process for the Proxy Mobile IPv6 (PMIPv6) protocol, which is a recently developed IP mobility management protocol aiming at providing network-based mobility support. The proposed handover process further improves handover performance of PMIPv6 by allowing a new access network obtains handover context before a consumer??s mobile node (MN) moves to the new access network. Data packets destined for the MN are buffered to prevent packet loss and immediately delivered to the MN as the MN moves to the new access network. We evaluate the handover latency and data packet loss of the proposed handover process compared to the basic one of PMIPv6. The conducted analysis results confirm that the proposed handover process yields the reduced handover latency compared to that of the basic PMIPv6 and also prevents data packet loss. We moreover evaluate the buffering cost of the proposed handover process.     

PMIPv6与MIH相结合的异构网切换方案及其性能分析

分析了PMIPv6的切换延迟,介绍了PMIPv6使用MIH（Media Independent Handover）提供异构网之间低的包丢失与低延时的无缝切换方案,其性能分析结果显示了该方案的有效性。     

层次移动IPv6的增强切换方案

随着互联网技术与移动通信技术飞速发展,移动IPv6技术已经成为下一代移动互联网的研究热点。切换技术是影响移动互联网实时运行质量的重要技术之一。低延迟、低丢包的无缝切换方案对移动IPv6的性能至关重要。层次移动IPv6(HMIPv6)利用移动锚点(MAP)降低了延迟和数据丢失。然而,只有移动节点在同一MAP域的网络上进行切换时,HMIPv6才能有效减少延迟。当移动节点在不同MAP域的网络移动时,其切换性能并不优于标准移动IPv6。文章针对层次移动IPv6提出了一种增强切换方案(EHMIPv6),该方案在HMIPv6的基础上实现并行重复地址检测(PDAD),以减少不同区域网络间切换的延迟。分析表明,该方案比HMIPv6具有更好的性能。     

Reactive Handover Optimization in IPv6-Based Mobile Networks

In recent years, there has been a rapid growth in the need to support moving hosts and moving networks in IPv6-based mobile networks. As the number of such hosts and networks grows, so will the demand for delay sensitive real-time applications, such as voice over IP (VoIP), that require seamless handover. Two well-known approaches to reduce the handover latency have been proposed in the literature: proactive and reactive approaches. While proactive handover is known to generally outperform reactive handover, its reliability and practicality are still questionable since it basically depends on predictive information which may be unreliable in some cases. In this paper, based on the standard specification for IPv6 mobility support, we analyze the existing movement detection and address configuration procedures which are the main components of reactive handover approach. We also propose a novel reactive handover procedure which employs our optimized movement detection and address configuration schemes. The proposal is simple and robust because it does not need any predictive information and it requires a minimum number of signaling messages. The performance evaluation shows that the proposal substantially reduces the signaling load on wireless/wired networks and its handover latency is reduced enough to support seamless services.     

利用MR数据进行WCDMA软切换参数优化的方法

对现网软切换优化的意义、目标、软切换参数影响及传统优化方法的不足进行了分析;首次提出了以MR原始数据统计分析结果为依据进行软切换参数本地化设置的方法,并结合2个城市的实际数据进行了案例分析。     

A New Enhanced Fast Handover Algorithm in Hierarchical Mobile IPv6 Network

1　Introduction　MobileIPv6requirestheMobileNode (MN)toregisterwiththeHomeAgent (HA)andtheCorre spondentNode (CN)whenitchangesitspointofattachmentintheInternet[1～ 3] .Therefore ,thiscauseMobileIPv6toincurlongdelayintheregis tration process,andaddsignalingtraffictothebackbonenetworkespeciallywhentheHAandCNarefarawayfromtheMN .Inordertominimizethisdelay ,andthesignalingoverhead presentinMobileIPv6,literatures[4～7] proposeHierarchicalMobileIPv6(HMIPv6)architectureandafasthan dover…     

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 Route Selection Scheme in MANET Using Enhanced AODV Protocol

Mobile Ad Hoc network comprises of mobile nodes communicating over wireless medium. Due to ease of communication and flexibility, MANET has become an active area of research in wireless communication. However, issues such as limited battery capacity, dynamic topology and node mobility cause frequent link breakage due to which reroute discovery process is required to be initiated resulting in increase in latency and routing overheads. Many research works have been carried out for improvement of an existing routing scheme, however they do not scale-up well to provide stable and energy efficient route. This paper introduces a novel routing algorithm ENH-AODV (Enhanced AODV) that focuses on selection of an efficient route on the basis of quality of both links and nodes impending during route discovery process. In addition, each node maintains a list, consisting of details of nearby nodes with good energy level through hello mechanism. Simulation is carried out over network simulator and results prove that the proposed scheme is more effective and advantageous than AODV in terms of normalized routing load, end to end delay, packet delivery ratio and throughput.

     

Adaptive Route Optimization in Hierarchical Mobile IPv6 Networks

By introducing a mobility anchor point (MAP), Hierarchical Mobile IPv6 (HMIP6) reduces the signaling overhead and handoff latency associated with Mobile IPv6. However, if a mobile node (MN)'s session activity is high and its mobility is relatively low, HMIPv6 may degrade end-to-end data throughput due to the additional packet tunneling at the MAP. In this paper, we propose an adaptive route optimization (ARO) scheme to improve the throughput performance in HMIPv6 networks. Depending on the measured session-to-mobility ratio (SMR), ARO chooses one of the two different route optimization algorithms adaptively. Specifically, an MN informs a correspondent node (CN) of its on-link care-of address (LCoA) if the CN's SMR is greater than a predefined threshold. If the SMR is equal to or lower than the threshold, the CN is informed with the MN's regional CoA (RCoA). We analyze the performance of ARO in terms of balancing the signaling overhead reduction and the data throughput improvement. We also derive the optimal SMR threshold explicitly to achieve such a balance. Analytical and simulation results demonstrate that ARO is a viable scheme for deployment in HMIPv6 networks.     

快速层次移动IPv6切换性能分析及优化

移动IPv6技术中切换延时对实时应用影响很大。介绍了目前移动IPv6常用的快速移动和层次移动切换技术,描述其切换原理和过程。结合2种技术的优缺点,给出了一种新的快速层次移动IPv6的切换方案。利用NS-2对这3种切换方法进行仿真得到的结果表明,快速层次移动IPv6切换延时要小于快速移动IPv6和层次移动IPv6的切换延时,且降低了数据包丢失率,提高了网络的性能。     

应用策略路由优化监测台网络结构

本文针对监测台内单路由器结构无法将来自不同网段的数据转发至不同接口地址的问题,应用策略路由并结合实际网络结构和实验结果,提出具体的解决方案.     

Dynamic multi-step paging scheme in PMIPv6-based wireless networks

In Proxy Mobile IP (PMIPv6) networks, proxy-registrations are performed even for idle MNs, resulting in unnecessary signaling traffic. Although there have been many IP paging techniques aimed at reducing the unnecessary location update, they focus only on Mobile IP (MIP) since they had been developed before PMIPv6 was proposed. Thus, adopting existing IP paging support is not sufficient to support mobility in PMIPv6 networks. For more efficient support, we propose a dynamic multi-step paging scheme that pages an MN in multiple incremental steps instead of flooding paging messages to a whole paging area to significantly reduce the signaling traffic caused by the proxy location updates in the PMIPv6 networks. In addition, to improve the paging delay performance that may be deteriorated by the multi-step paging, the proposed scheme configures paging area dynamically to raise the efficiency of locating MNs. The size of a paging area is designed to be determined based on the speed of an MN. We also develop a thorough analytical model for evaluating the performance of the proposed scheme compared with a static paging scheme in terms of the signaling cost and the paging delay. Thorough analysis and simulation demonstrate that in the PMIPv6 network, our paging scheme can significantly reduce the signaling cost for IP paging, achieving a shorter paging delay, compared to that of a paging scheme with a fixed paging area.     

移动IPv6路由优化中的安全威胁及解决方案

分析了移动IPv6的路由优化过程中存在的各种安全威胁。针对虚假绑定更新消息介绍了一种基于返回路由可达过程的路由优化安全认证解决方案,使得通信节点只有在确认移动节点的家乡地址和转交地址均可到达后,方接受来自该移动节点的绑定更新消息,并建立二者间的直接路由。     

Route Optimization Using Tree Information Option for Nested Mobile Networks

Mobile IP is the basic solution to provide host mobility, whereas network mobility refers to the concept of collective mobility of a set of nodes. In the simplest scenario, a mobile network moves as a single unit with one mobile router (MR) that connects it to the global Internet. Also, multiple mobile networks can be nested in a hierarchical form, e.g., a wireless personal area network (PAN) in a vehicular network. In a nested mobile network, multiple MRs form a tree hierarchy in which the root MR is called the top-level mobile router (TLMR). Nested mobile networks exhibit the pinball routing problem, which becomes worse in proportion to the number of nested levels in the hierarchy. To solve this problem, we propose a routing optimization scheme using a tree information option (ROTIO) that extends the NEMO basic support protocol. In the ROTIO scheme, each MR in the nested mobile network sends two binding updates (BUs): one to its home agent and the other to the TLMR. The former BU contains the TLMR's home address, while the latter contains routing information between the issuing MR and the TLMR. This alleviates the pinball routing problem significantly. Now, a packet from a correspondent node only needs to visit two transit nodes (the home agents of the MR and the TLMR), regardless of the degree of nesting. Moreover, the ROTIO scheme provides location privacy and mobility transparency. We also extend ROTIO to perform routing between two mobile network nodes inside the same nested mobile network more efficiently and to substantially reduce the disruption when a mobile network hands off.     

Enhancing the Route Optimization Using Hybrid MAF Optimization Algorithm for the Internet of Vehicle

Wireless Personal Communications - Wireless Sensor Networks (WSNs) in modern times enables security techniques to secure the information transmitted via the interconnected network. The poor...     

Handover Management in Enhanced MIH Framework for Heterogeneous Wireless Networks Environment

Vertical handover decision making is one of the key problems in heterogeneous networks environment. In IEEE 802.21 standard, a Media Independent Handover (MIH) framework is proposed to improve user experience of mobile devices by facilitating handover in heterogeneous networks with measurements and triggers from link layers. However, vertical handover decision making can benefit from the information more than link layers. In this paper, an Enhanced Media Independent Handover (EMIH) framework is proposed by integrating more information from application layers, user context and network context. Given such information, there is also another important problem on how to select a favorite network. Two quite important problems from realistic scenario are as follows: (1) how to make use of partial knowledge due to incomplete value measurement on decision factors; (2) how to deal with robustness problem due to inaccurate measurement on decision factors. In order to tackle these problems, two novel Weighted Markov Chain (WMC) approaches based on rank aggregation are proposed in this paper, in which a favorite network is selected as the top one of rank aggregation result fused from multiple ranking lists based on decision factors. Moreover, an entropy weighting method, combined with WMC approach, is studied. The simulations demonstrate the effectiveness of these proposed approaches.     

Optimization of Handover Parameters for Traffic Sharing in GERAN

Cellular network traffic is unevenly distributed both in time and space, which greatly complicates network dimensioning. As a result, some cells in the network are permanently congested, while others are underutilized. In a previous paper, the authors showed that this problem can be effectively solved in GSM/EDGE Radio Access Networks (GERAN) by modifying handover boundaries. However, several drawbacks prevent operators from fully exploiting the potential of this technique. This paper investigates the limitations of current traffic-sharing approaches with tight frequency reuses in GERAN. To deal with such limitations, an algorithm is proposed to jointly optimize handover margins and signal-level constraints based on network statistics for traffic sharing in GERAN. A complementary algorithm is proposed to adjust cell (re)selection offsets to minimize the number of handovers. Simulation results show that the proposed method achieves a significant reduction in call blocking without excessive call quality impairment or increase of network signaling load when compared to the current approaches. More traffic can thus be handled without the need for any hardware upgrades, providing a cost-effective means to increase network capacity.