A middleware architecture supporting seamless and secure multimedia services across an intertechnology radio access network - seamless content delivery in the future mobile internet

This article presents a middleware architecture to support multimedia services across intertechnology radio access networks in a secure and seamless manner. The proposed architecture uses the media-independent handover framework, where the handover decision function is based on triggering/collecting statistics from the physical, network, and application layers so that an ongoing multimedia session (video) can be transferred seamlessly and securely (using context transfer) across intertechnology radio access networks. Simulation results show that when a vertical handover is based on the proposed MIH framework (including the context transfer of AAA information), handover latency is reduced by 38 percent during WiFi to UMTS handover and 20 percent during UMTS to WiFi handover compared to a non-MIH-based handover scheme.     

UMTS全IP无线网络的移动性管理

文章讨论了3GPP UMTS全IP无线网络中的两种运行模式:传输模式和本机模式,3个不同层次移动性支持:接入移动性、宽域移动性和微移动性.对基于路由和基于隧道两种移动性管理协议进行了比较,并介绍了基于多协议标志交换(MPLS)的分级移动性管理方案,该方案利用标志边界移动性代理的增强MPLS路由器,使网络具有灵活性、可升级性和无隙缝移动性.     

Performance analysis of IP mobility with multiple care-of addresses in heterogeneous wireless networks

This paper aims to suggest a host-based localized mobility management scheme which provides similar user experiences and seamless mobility of real time communications. The proposed scheme supports multiple care-of addresses and fast handover mechanism with a single unitary virtual interface among heterogeneous radio access technologies without network changes. We verify that the proposed scheme has significant vertical handover performance gains to support real time communication traffics through the experiment over the real network experimental environment consists of WiFi and 3GPP2 networks.     

A scalable network-based mobility management framework in heterogeneous IP-based networks

This paper proposes a mobility management scheme to provide a mobile node with high-quality handovers among heterogeneous wireless access networks. The proposed scheme employs a signaling architecture to support fast and reliable delivery of control messages by separating a control plane from a data transport plane in the core network. The proposed scheme is based on the network-based mobility management framework which requires the minimum modifications on terminal devices. With interaction between Layers 2 and 3, the proposed scheme accelerates the handover control procedures. It also enables a mobile subscriber to select a target network for a vertical handover with consideration of not only wireless signal strength but also user preference and quality-of-service status. The proposed scheme addresses the well-known problems of the Mobile IP-based approaches, triangular routing and bottleneck at the home agent, since it establishes a data tunnel for a mobile node along the shortest path between two different access networks. The simulation and experimental results indicate that our scheme provisions more efficient performance than the existing approaches in terms of handover latency, data packet loss, data delivery latency and load balancing.     

基于MPLS无线接入网中的快速切换

为了减少时延,克服协议的局限性,提出了一基于MPLS的无线接入微移动方案,对传统的微移动方案进行了延伸,采用在标记交换路由器上引入中间标记信息库（I-LIB）采达到减少时延,提高服务质量的目的。     

Service-oriented mobility management architecture for seamless handover in ubiquitous networks

In ubiquitous wireless LANs, a mobile node is likely to move between many access points while using certain applications. However, in the conventional Internet architecture, an MN can never inherently avoid the degradation in communication quality during handover. To achieve seamless handover, we propose a service-oriented mobility management scheme to address application quality. In this article, we first clarify three requirements for achieving seamless handover. We then describe our concept of the service-oriented mobility management scheme, which satisfies all three requirements. Our main contribution is the proposal of a scheme of how to properly use the number of frame retransmissions as a new handover-decision criterion to accomplish seamless handover. Performance evaluations show that our proposed scheme can maintain application quality during handover     

An Integrated Handover Authentication for FMIPv6 Over Heterogeneous Access Link Technologies

This paper proposes an integrated handover authentication for NGN equipped with FMIPv6-based IP mobility over various kinds of access links. In ITU-T, an integrated authentication model has been introduced to support network attachment with mobility in NGN. Since existing studies for handover authentication have focused on the link layer or network layer respectively, there are additional authentication overhead such as duplicated authentication procedures and authentication messages delivery cost. The proposed integrated handover authentication contributes to reducing complexity of the authentication procedure and to enhancing the efficiency of it by means of the combined key management architecture; a mobile node generates a handover key to transfer it to the next access router through the AAA server, and hierarchical key management scheme addresses the locality of movement to authenticate the mobile node at the link layer. The evaluation of the handover authentication costs shows that it reduces the average number of handover authentication events and the authentication message delivery cost during moves in mobile networks. Also, the security aspects of the proposed scheme are discussed.     

An energy-efficient interface selection for multi-mode terminals by utilizing out-of-band paging channels

With the advent of a number of wireless network technologies such as WCDMA and WLAN, current mobiles are equipped with multiple network interfaces, so called Multi-Mode Terminal (MMT). MMTs are capable to access different kinds of networks by performing a vertical handover between heterogeneous wireless networks, where during the idle state, the MMTs consume a lot of energy since their WLAN interface must wake up for listening to periodical beacons. However, previous studies on the vertical handover did not address how to select the optimal interface taking into account the characteristics of MMTs, especially energy consumption. Therefore, in this paper, we propose an energy-efficient interface selection scheme for MMTs in the integrated WLAN and cellular networks. The proposed interface selection scheme takes advantage of existing out-of-band paging channel of cellular networks, so that the WLAN interface can be completely turned off during the idle state leading to reduction in energy consumption. Simulation results show that the proposed scheme outperforms conventional approaches in terms of energy consumption with reduced signaling overhead and handover delay.     

Improvements to seamless vertical handover between mobile WiMAX and 3GPP UTRAN through the evolved packet core - [LTE part II: 3GPP release 8]

Recent mobile devices are integrated with multiple network interfaces. Users want their devices connected to the network anytime anywhere. It is highly feasible for a user to change connection to another network for users that leave the service area of its current serving network, where handover needs to be executed seamlessly such that ongoing service sessions are not interrupted. The handover operation not only requires switching the interfaces within a device but also involves seamless reconfiguration of the supporting networks. In this article, an improved IP-based vertical handover technology for mobile WiMAX [1, 2], 3GPP legacy systems (i.e., Global System for Mobile communications and Universal Mobile Telecommunications System) [3, 4], and 3G Long Term Evolution [5, 6] is presented, which is based on existing optimized handover techniques between mobile WiMAX and 3GPP accesses [7?9]. Formerly proposed 3GPP WiMAX optimized VHO solutions introduced new elements, such as the forward attachment function and access network discovery and selection function. The ANDSF supports the discovery of target access, and the FAF provides the functionality that authenticates the UE before the execution of VHO. However, the previous technique has limitations that result in data loss and abnormal disconnection to the source access [7?9]. This article provides a solution by introducing an additional network element called the data forwarding function (DFF) that eliminates the data loss during VHO execution. In addition, the DFF resolves the problem of abrupt disconnection to the source network. The simulation results show that the proposed VHO technique is effective in minimizing data loss during VHO execution between mobile WiMAX and 3GPP networks. As the proposed solution of this article is an IP based handover solution, it can be similarly applied to other communication networks.     

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.     

Active overload prevention based adaptive MAP selection in HMIPv6 networks

Multi-level mobile anchor points (MAP) architecture is deployed in large-scale wireless/mobile networks using HMIPv6 to achieve better mobility service, while selecting the most suitable serving MAP for the mobile nodes (MNs) to enhance the whole network performance has been a critical issue. An adaptive MAP selection based on active overload prevention (MAP-AOP) hence is proposed. The MAP periodically evaluates the load status by using dynamic weighted load evaluation algorithm, and then sends the load information to the covered access routers (AR) by using the expanded routing advertisement message in a dynamic manner. Taking achieving the load balancing among the available MAPs, the current serving AR executes the active overload prevention to select MAP candidates for the MN pending a handover, and then adaptively selects an optimal one from the candidates by comprehensively considering the system cost and the average handover latency caused by each candidate. The simulation conducted on the NS-2 platform indicates that MAP-AOP outperforms the comparative MAP selection schemes with the optimized system cost and average handover latency, and better load balancing.     

全IP移动通信网接入网的QoS保证机制研究

移动性管理和服务质量(Q0S)保证一直是移动通信网络中两个关键性问题.文章介绍了全IP移动通信网接入网部分的几种QoS实现机制,通过扩展QoS保证机制与微移动管理协议之间的耦合,提出了一种资源预留协议(RSVP)和Hawaii协议松耦合的方案,并以集成了RSVP和Hawaii的仿真平台对该方案进行了仿真.仿真结果表明,松耦合方案可以显著地提高切换过程中的QoS.     

An efficient handover decision method based on frame retransmission and data rate for multi-rate WLANs

To enhance the communication performance at handover between multi-rate WLANs, we propose a new handover decision method that can be applied to our previously reported handover management scheme, which handled a handover by utilizing two WLAN interfaces (IFs) through cross-layer collaboration between layer 2 and layer 4. It should be noted that we here propose a new handover decision scheme for traversing between multi-rate WLANs, while our previous decision scheme works only in fixed-rate WLANs. In this paper, to treat a handover between multi-rate WLANs, we employ two kinds of information: (1) the most frequently used data rate (MFDR) for assessing the stable communication performance of a multi-rate WLAN, and (2) the frame retransmission ratio (FRR) for assessing its exact communication performance. The MFDR enables us to estimate the area where we should start handover. If the MFDRs of two interfaces are same in the area, the FRR allows us to compare the wireless condition on the two interfaces precisely to give an optimal handover point. Through simulation experiments, we show that our proposed scheme certainly estimates an appropriate handover point as a result of multi-path transmission (s), thereby providing handover successfully. That is, the proposed method can determine handover at an optimal point depending on the various distances between access points, the mobile node (MN) velocity, and the MN moving pattern. Moreover, our proposed scheme prevents the redundant network load caused by multi-path transmission as much as possible, thereby providing the ideal TCP communication performance.     

Terminal-Controlled Mobility Management in Heterogeneous Wireless Networks

The coexistence of multiple access technologies deployed by different operators is fundamental for future fourth-generation mobile networks. In spite of this heterogeneity, seamless interoperator/intersystem mobility is a mandatory requirement. In this article we present a seamless mobility management approach that does not require changes to existing network infrastructure. The novelty of the proposed approach is that mobility management is fully controlled by the terminal, and network selection is user-centric, power-saving, cost-aware, and performance-aware. Total mobility management, including interface management, handover decision, and execution, is also detailed     

Research on distributed mobile management of satellite network based on software define network

Distributed mobility management (DMM) was an effective method to solve the mobile address handover.Therefore,it was considered to be a technology that can be applied to satellite network mobility management.A distributed mobile management scheme which based on software definition network (SDN) was proposed to solve the traffic redirection problem in satellite network.Different from the traditional DMM application scenario which was network-based or terminal-based,the SDN-DMM scheme implements location management and address handover in SDN controllers.Therefore,SDN-based satellite network distributed mobile management scheme can realize packet forwarding path optimization compared with traditional scheme,and it shows significant advantages in managementcost and traffic management.     

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.     

适用于车载边缘计算网络的高效匿名认证协议

为了解决车载边缘计算网络中无线网络传输特性导致的窃听、重放、拦截、篡改等安全威胁,考虑到车载终端资源有限的特点,提出了一种轻量级匿名高效身份认证协议。基于切比雪夫混沌映射算法,避免了多数方案所采用的指数、双线性映射等复杂算法,有效降低了身份认证与密钥协商过程中的计算复杂度。此外,在实现接入认证及切换认证的同时,能够实现终端匿名性及可追溯、可撤销等安全功能。通过Scyther工具验证结果表明该协议能够满足认证过程中的安全需求并且能够抵抗多种协议攻击。相比已有方案,所提接入认证方案总计算开销最低可节省67%,带宽开销最低可节省11%。此外,相比于接入认证方案,所提域内切换认证方案总计算开销可节省99.8%,带宽开销可节省52%;域间切换认证方案总计算开销可节省80%,带宽开销可节省37%。性能分析结果表明该协议具备更良好的计算和通信性能,因此可以解决车载边缘计算网络中的终端高效安全接入及切换问题。     

基于强化学习的异构网络垂直切换方法

网络切换技术不仅可以保证用户的网络连接,同时能够以较强的信号传输网络数据。网络切换技术的性能对网络服务质量(quality of service, QoS)的影响至关重要。然而,现有的切换算法多数存在严重的乒乓效应,这不仅造成网络资源的严重浪费,还会损害用户的QoS。为此,提出了一种基于强化学习的异构网络垂直切换方案,主要从触发切换、网络选择及判决切换等方面进行优化。在触发切换时将垂直切换考虑成必要切换和择优切换,通过Q-Learning（QL）算法在选择网络时优化垂直切换;然后以QoS为条件,在判决切换时加入驻留定时器,从多角度减少用户切换次数,降低乒乓效应对异构网络垂直切换的影响。仿真结果表明,基于强化学习的异构网络垂直切换方法可以在保证QoS的条件下有效减少用户切换网络的次数,短时间内频繁切换的情况也有所改善,降低了乒乓效应的影响。     

Local and Global Handovers Based on In-Band Signaling in Wireless ATM Networks

This paper presents a handover protocol for wireless ATM networks, which makes use of in-band signaling, i.e., of ATM resource management cells, to process network handovers and guarantee the in-sequence and loss-free delivery of the ATM cells containing user data. The goal of the proposed approach is to minimize the modifications of the ATM signaling standard required to overlay user mobility onto the fixed network infrastructure, and provide for a gradual upgrade of the fixed network to handle mobility. The proposed protocol handles both local handovers, in which the connection access point needs not migrate to a new ATM local exchange, and global handovers, in which the connection access point must migrate to a new local exchange. The handover scheme is devised so as to grant in-sequence delivery of cells. The performance of the network during handover is analyzed in case of connections requiring loss-free operation. The considered performance figures are the cell transmission delay introduced by the handover and the cell buffering requirements posed to the network. The behavior of the proposed protocol in presence of multiple handovers is studied via simulation, while a simple analytical method is derived for the performance evaluation of a single handover in isolation.     

Mobility Management in Identifier/Locator Split Networks

In the traditional Transmission Control Protocol/Internet Protocol (TCP/IP) stack, IP address represents not only the identifier but also the location of a node so that it can not provide global roaming seamless. To address this problem, MIP (Mobile IP) uses dynamical care-of-address to indicate the location of a mobile node (MN) and stable home address to indicate its identifier. However, such a separation of MIP can not support routing scalability, location privacy, and manageability. In this paper, we propose an identifier/locator split architecture which contains an overlay mapping system to store identifier-to-locator mappings and manage mobile nodes?? behavior. In addition, we design a novel mobility management scheme based on the identifier/locator split architecture (MMILS) which can address the above issues of MIP. To reduce the amount of signaling and enhance the performance, we distinguish micro-mobility and macro-mobility by introducing an Agent Tunnel Router (ATR). For micro-mobility, the ATR keeps the MN??s identifier-to-locator mapping invariable, so it avoids the mapping update in the mapping system and the Tunnel Route (TR) of each correspondent node. For macro-mobility, to support fast update and handover, we design a united mapping table in the ATR. And then, we estimate the number of entries and the required storage space to validate it feasible. To evaluate the efficiency of MMILS, we analyze the signaling cost by establishing an analytical model and implement it in our test-bed. The results demonstrate that the proposed scheme can effectively reduce signaling traffic and has a low handover delay compared to MIP and HMIP (Hierarchical Mobile IP).