Remote access virtual private network architecture for high‐speed wireless internet users

The new emerging broadband wireless network (BWN) technologies with high‐speed wireless internet access promotes corporations to provide their roaming employees with high‐speed wireless access to the computing resources on their corporate networks. Thus, a value added service to broadband wireless network is the remote access virtual private network (VPN), where the corporate legitimate users can connect to their offices wirelessly from different locations and get secure services as if they were connected to the corporate local area network (LAN). One of the most important challenges is to block out illegitimate user requests, which are wirelessly received, to protect corporate privacy. Registration (adding new users) and authentication (accepting current users) functions should be implemented with highly secured wireless connection. These functions are accomplished by encapsulating (i.e. tunneling) the user information in a secured form to the corporate authentication server through the internet traffic. The corporate authentication server then grants or denies the user access. In this paper, we propose a new operational design algorithm for remote access wireless VPN authentication and registration protocols that depends on modifying tunnel establishment as compared to existing dial‐in VPN mechanisms. The modifications proposed in this paper are made to support successful deployment of the remote access VPN services over high‐speed wireless network. The paper presents an overview of two tunneling approaches using Layer 3 and Layer 2 separately for implementing these functions. Then we propose how we establish the tunnel in both approaches, and compare it to similar operation steps previously reported for the dial‐in VPN protocols. The proposed algorithms are distinguished from previously developed dial‐in VPN protocols by using L2TP and IPSEC instead of mobile IP. It is also shown that the steps involved in the establishment of the tunnel are functionally different and more appropriate to our applications using communication environment of the BWN. Finally, a qualitative analysis of the added functions, and a comparison between L2TP‐based and IPSec‐based approaches are established. Copyright © 2004 John Wiley & Sons, Ltd.     

Radio Network Aggregation for 5G Mobile Terminals in Heterogeneous Wireless and Mobile Networks

This paper provides a novel design concept for advanced mobile multi interface terminals with radio network aggregation capability and enhanced quality of service (QoS) provisioning for multimedia services (voice, video and data) in heterogeneous wireless and mobile networks. A new module is established which provides the best QoS and lowest cost for any given multimedia service by using simultaneously all available wireless and mobile access networks for a given traffic flow. This novel adaptive QoS module with adaptive QoS routing algorithm is called advanced QoS routing algorithm (AQoSRA), which is defined independently from any existing and future radio access technology. The performance of our proposal is evaluated using simulations and analysis with multi-interface mobile stations with AQoSRA within, carrying multimedia traffic in heterogeneous mobile and wireless environment with coexistence of multiple Radio Access Technologies, such as 3G, 4G as well as future 5G radio access networks. The analysis of the proposed framework for radio networks aggregation in advanced mobile terminals has shown overall better performances regarding the achievable throughput and multimedia access probability in heterogeneous wireless and mobile environment.     

基于无线传感器网络的海水检测系统

针对海水检测周期长、范围小的特点,提出了使用无线传感器网络的海水指标实时在线检测方案。研究了精确检测的方法与算法,探讨了无线传感器网络节能路由协议。系统综合运用无线传感器智能信息处理技术、远程GPRS无线数据通信技术以及基于Internet显示平台的监测点管理查询技术,将功能相同或不同的传感器构成智能化传感器网络,从而全面提升了系统的自动化与监测水平。模拟实验结果表明系统具有良好的海水定量检测能力。     

基于媒体独立切换并提供QoS保证的跨UMTS和WiMAX无线异构网络的网络切换方案

The rapid growth and innovation of the various mobile communication technologies have caused a change in the paradigm of internet access. Wireless technologies such as WiMAX, WiFi and UMTS/LTE networks have shown great potential in dominating the wireless access markets. The existence of various access technologies requires a means for seamless internetworking to provide anywhere, anytime services without interruption in the ongoing session, especially in multimedia applications with rigid Quality of Services (QoS) requirements. The IEEE 802.21 Media Independent Handover (MIH) working group was formed to develop a set of mechanisms under a standard framework with the capability to support migration of mobile users across heterogeneous networks. Therefore, the implementation of handover is extremely important in the heterogeneous network environment. In order to guarantee various QoS requirements during handover execution especially in multimedia applications, in this paper we propose a novel MIH-based capacity estimation algorithm to execute handover with QoS provision supporting both horizontal and vertical handovers across UMTS and WiMAX networks. Simulation shows that the proposed mechanism achieves lower call dropping rate (highest approximate 3% ) and higher system throughput (average 92% ) than the basic handover method does.     

基于认知自选择决策树的垂直切换方法研究

在异构无线网络环境下高速移动的终端用户需要随时随地接入网络,然而,在垂直切换过程中,由于终端用户对网络选择的偏好不同以及切换之后网络连接时间和状态难以得到保障,无法满足用户的切换需求。因此,提出了一种支持终端用户高速移动的基于认知自选择决策树的垂直切换方法。该方法首先根据网络属性和终端运动趋势建立相应的切换概率分布,然后根据用户偏好选择相应的决策树进行决策,最后通过对切换后终端的业务类型和运动状态进行反馈分析,提出了反馈认知决策方法。仿真结果表明,所提的方法不仅能够保证高速移动终端在异构无线网络下的切换质量,而且减少了不必要的切换,保证了网络的及时更新。     

Traffic load metrics for multihomed mobile IP and global connectivity

Support for host mobility an essential and necessary feature for roaming users who connect to wireless networks via access points. Access points may have different capabilities, be connected to different networks and be installed by different providers. A mobile host will discover multiple access points in this environment. In such an environment, a mobile host should be able to use the best available connection to communicate with a correspondent host and perhaps use multiple connections for different hosts. In areas with wireless local area network access, pockets with limited or no coverage could exist. Such restricted connectivity could be compensated by neighbor hosts who form an ad hoc network and relay packets until they reach an access point. This paper describes and discusses a proposed solution towards enabling and supporting connectivity in wireless networks. In the proposed solution the network layer software will evaluate and decide which wireless network connections to use. A Running Variance Metric (RVM) and a Relative Network Load(RNL) are used to measure the traffic load of access points in wireless access networks. RVM and RNL can be efficiently used for both infrastructure networks and ad hoc networks. Multihomed Mobile IP (M-MIP) is an extension of Mobile IP that enables mobile hosts to use multiple care-of addresses simultaneously. The extension enhances network connectivity by enabling the mobile host, the home agent and correspondent hosts to evaluate and select the best connection. A proposed gateway architecture using M-MIP that integrates wired IP networks with ad hoc networks is described. The M-MIP and gateway architecture using the RVM and RNL metrics have been validated with simulation studies and results are presented.     

Addressing the interdependence in providing fair and efficient bandwidth distribution in hybrid optical‐wireless networks

The convergence of optical and wireless technologies may offer a compelling network access infrastructure because these technologies combine major benefits such as large coverage in the wireless part and huge bandwidth in the optical part of the converged access network. The convergence of the passive optical networks with 4G wireless standards, such as the Worldwide Interoperability for Microwave Access and the Long Term Evolution, constitutes a quite attractive solution to meet the challenges of the modern bandwidth‐hungry access networks. One of the most important objective a modern access network has to address is the adequate bandwidth distribution to the final users. In addition, several other aims are emerged towards this goal, such as fairness and quality of service provisioning. The adversity of designing an efficient bandwidth distribution scheme for hybrid optical‐wireless access networks lies in the interdependence of both domains: the bandwidth distribution in the wireless domain depends on the optical transmission grant opportunities, while the bandwidth coordinator in the optical part has to be aware of the mobile user heterogeneity in the wireless domain. Moreover, the bandwidth decision‐making module in both networks has to be aware of providing a fair allocation independently of the number of mobile users or the traffic requests in the network. In this work, we endeavor to address the aforementioned challenges. A novel, fair, and efficient bandwidth distribution scheme is proposed for hybrid optical‐wireless access networks. By using weighted fairness provisioning techniques, the proposed scheme intends to alleviate the interdependence of the two domains, offering a fair and efficient bandwidth distribution to the mobile users. The weights are properly defined, by utilizing suitable optimization techniques such as the Lagrange multiplies, so as to incorporate the underlying features of each traffic requests, such as the population density and the propagation delay. Extensive simulation results indicate the capability of the proposed scheme, compared with other competitive allocation schemes, in provisioning a more efficient and fair bandwidth distribution in terms of latency, throughput, and packet drop ratio. Copyright © 2015 John Wiley & Sons, Ltd.     

基于IPSec的MVPN原理和实现

随着Internet和无线数据技术的发展,移动虚拟专用网(MVPN)技术越来越受业界关注。MVPN把虚拟专用网(VPN)扩展到无线接入环境与无线数据应用结合,是建立在移动网资源上的虚拟专用网络,由移动IP(MIP)支持终端的移动性,使远程移动用户能简单、安全、高速地访问企业内部的网络资源。文中介绍了MVPN的基本概念及基于IP安全协议(IPSec)的MVPN基本原理,讨论了端到端自愿型隧道MVPN和基于网络的强制型隧道MVPN的实现方法和原理,最后对MVPN的市场应用进行了简要分析。     

移动互联服务与隐私保护的研究进展

随着宽带无线接入技术和移动终端技术的飞速发展,人们迫切希望能够随时随地从互联网获取信息和服务,移动互联网应运而生并迅猛发展。然而,由于云计算平台、移动通信网络和移动终端的开放性,传统互联网服务中信息传播和管控机制不再适应于移动互联网,信息安全和用户隐私保护已经成为移动互联网用户迫切关心和亟待解决的问题。结合国内外移动互联网发展的最新趋势,对移动互联网服务和隐私保护方面的研究进行了展望。首先对当前移动互联网服务模型和移动互联网服务架构进行了评述;其次对当前的移动互联网数据传播控制机制以及隐私保护机制进行了分析和讨论;最终给出了一些潜在的研究热点,为未来研究工作指明方向。     

多业务无线网络中基于最佳等信干比的功率控制

功率控制技术是无线网络的关键技术之一。为改进多业务无线网络中基于非合作博弈的功率控制算法中纳什均衡的帕累托有效性,引入数据终端的最佳等信干比概念,使得系统中所有数据终端都工作在最佳的等信干比下,语音终端工作在语音通信服务质量门限的目标信干比门限之下。推导出一个新的分布式基于最佳等信干比的功率控制算法。仿真表明,该算法明显提高了系统的服务质量,系统中终端均具有相对较高的效用和较低的发射功率,还使得无线网络资源的使用更加合理和公平。     

SATELLITE-ENHANCED PERSONAL COMMUNICATIONS EXPERIMENTS

Users of future generation wireless information services will have diverse needs for voice, data, and potentially even video communications in a wide variety of circumstances. For users in dense, inner-city areas, low power personal communications services (PCS) technology should be ideal. Vehicular-based users travelling at high speeds will need high-power cellular technology. For users in remote or inaccessible locations, or for applications that are broadcast over a wide geographic area, a satellite technology would be the best choice. Packet data networks provide an excellent solution for users requiring occasional small messages, whereas circuit switched networks provide more economical solutions for larger messages. To provide ubiquitous personal communications service, it is necessary to capitalize on the strength of each wireless technology and network to create one seamless internetwork including both current and future wired and wireless networks. As an initial step in exploring the opportunities afforded by the merging of satellite and terrestrial networks, Bellcore and JPL conducted several experiments. These experiments utilized Bellcore's experimental personal communications system (including several messaging applications with adaptations to wireless networks), NASA's advanced communications technology satellite (ACTS), JPL's ACTS mobile terminal, and various commercial data networks (such as the wireline Internet and the RAM wireless packet data network). Looking at loss of bits, packets and higher layer blocks (over the satellite-terrestrial internetworks with mobile and stationary users under various conditions) our initial results indicate that the communication channel can vary dramatically, even within a single network. We show that these conditions necessitate powerful and adaptive protocols if we are to achieve a seamless internetworking of satellite and terrestrial networks.     

An End-To-End Approach for Transparent Mobility Across Heterogeneous Wireless Networks

With the advent of a myriad of wireless networking technologies, a mobile host today can potentially be equipped with multiple wireless interfaces that have access to different wireless networks. It is widely perceived that future generation wireless networks will exhibit a similar trend in supporting a large variety of heterogeneous wireless access technologies that a mobile host can choose from. In this paper, we consider such a multi-homed mobile host and propose an end-to-end solution that enables the seamless use of heterogeneous wireless access technologies. The unique features of the proposed solution include: (i) a purely end-to-end approach to handle host mobility that requires no support from the underlying network infrastructure, (ii) seamless vertical handoffs when the mobile host migrates from one access network to another, (iii) ability to support different congestion control schemes for a live connection traversing different interfaces, and (iv) effective bandwidth aggregation when the mobile host has simultaneous access to multiple networks. We present the design and details of the proposed approach, and evaluate its performance through simulations and real-life field experiments.     

Effect of mobile terminal heterogeneity on call blocking/dropping probability in cooperative heterogeneous cellular networks

It is envisaged that next generation wireless networks (NGWN) will be heterogeneous, consisting of multiple radio access technologies (RATs) coexisting in the same geographical area. In these heterogeneous wireless networks, mobile terminals of different capabilities (heterogeneous terminals) will be used by subscribers to access network services. We investigate the effect of using heterogeneous mobile terminals (e.g. single-mode, dual-mode, triple-mode, etc.) on call blocking and call dropping probabilities in cooperative heterogeneous wireless networks. We develop analytical models for heterogeneous mobile terminals and joint radio resource management in heterogeneous wireless networks. Using a two-class three-RAT heterogeneous wireless network as an example, the effect of using heterogeneous terminals in the network is evaluated. Results show the overall call blocking/dropping probability experienced by subscribers in heterogeneous wireless networks depends on the capabilities of mobile terminals used by the subscribers. In the worst case scenario, when all subscribers use single-mode mobile terminals, each subscriber is confined to a single RAT and consequently, joint radio resource management in heterogeneous wireless network has no improvement on new call blocking and handoff call dropping probabilities. However, in the best case scenario, when all subscribers use three-mode terminals, new class-1 call blocking probability decreases from 0.37 (for 100% single-mode terminals) to 0.05, at the arrival rate of 6 calls per minute. New class-2 call blocking probability also decreases from 0.8 to 0.52. Similarly, handoff class-1 call dropping probability decreases from 0.14 to 0.003, and handoff class-2 call dropping probability decreases from 0.44 to 0.09.     

基于UMA技术的话音业务互切换技术的研究

在我国,中国移动已成为全球为数不多的几个同时拥有固定网络与移动网络的大运营商之一,如何充分利用固定网络资源与移动网络资源成为了全球通信业界研究的热点之一。本平台的目标是利用UMA技术有效的将Wi-Fi网络与TD-SCDMA网络和GSM网络结合在一起,实现三网融合,将话音业务和数据业务进行分流;由一个具有自主开发产权的UMA控制器(UNC)和双模手机构成。在不影响现有移动网络的基础上,通过增加UMA控制器,双模手机能够通过Wi-Fi网络无缝接入移动通信网络,实现WLAN、TD-SCDMA网络和GSM网络相互切换、漫游、无线上网等功能,移动用户不需改变号码即可享受该功能。     

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.     

NetCAPE: Enabling Seamless IMS Service Delivery across Heterogeneous Mobile Networks

An evolving wireless world is constantly providing users with a wider set of access technologies to choose from, each with different capabilities and properties. In this world, IMS as defined by 3GPP provides an enabling, standardized multimedia architecture that is access independent, hence, providing service convergence. This trend is accompanied by an increasing number of multimode terminals so that inter-access- system-service continuity gains relevance. This article presents the architectural framework of NetCAPE (networking context aware policy environment), which addresses the optimization of mobility management in such a heterogeneous environment while interacting with IMS applications to enable seamless service delivery across heterogeneous mobile networks; even as the mobility offered by the underlying network remains transparent to IMS applications. Although the focus is on 3GPP-based mobile networks, the framework also incorporates wired access technologies, hence, taking a further step toward fixed mobile convergence (FMC). First results are presented highlighting the improvements gained by applying NetCAPE concepts.     

GRA Based Network Selection in Heterogeneous Wireless Networks

4G wireless networks will integrate heterogeneous technologies such as Wireless LAN and third generation (3G) cellular networks and have the capability to offer various services at any time as per user requirements, anywhere with seamless interoperability at affordable cost. One important challenge in such a heterogeneous wireless environment is to enable network selection mechanisms in order to keep the mobile users always best connected anywhere and at any time. In this paper, a multi-criteria access network selection algorithm is proposed in Worldwide Interoperability for Microwave Access–Wireless Fidelity environment, in order to facilitate the provision of high quality services and at the same time to satisfy different types of user service level agreements. Analytical hierarchy process (AHP) and grey relational analysis (GRA) methods are applying for optimal access network selection. The proposed methodology combines the AHP to decide the relative weights of criteria set according to network’s performance, as well as the GRA to rank the network alternatives. The advantages of the GRA method are that the results are based on the original data, the calculations are simple and straightforward, and finally it is one of the best methods to make decision under heterogeneous wireless network environment.     

Immune optimization algorithm for solving vertical handoff decision problem in heterogeneous wireless network

In heterogeneous wireless network environment, wireless local area network (WLAN) is usually deployed within the coverage of a cellular network to provide users with the convenience of seamless roaming among heterogeneous wireless access networks. Vertical handoffs between the WLAN and the cellular network maybe occur frequently. As for the vertical handoff performance, there is a critical requirement for developing algorithms for connection management and optimal resource allocation for seamless mobility. In this paper, we develop a mathematical model for vertical handoff decision problem, and propose a multi-objective optimization immune algorithm-based vertical handoff decision scheme. The proposed scheme can enable a wireless access network not only to balance the overall load among all base stations and access points but also maximize the collective battery lifetime of mobile terminals. Results based on a detailed performance evaluation study are also presented here to demonstrate the efficacy of the proposed scheme.     

End-to-end QoS provisioning in mobile heterogeneous networks

The remarkable advances in information technologies bring a heterogeneous environment for mobile users and service providers. This heterogeneity exists in wireless access technologies, networks, user terminals, applications, service providers, and so on. The ability to provide seamless and adaptive quality of service in such a heterogeneous environment is key to the success of next-generation wireless communications systems. There has been a considerable amount of QoS research recently. However, the main part of this research has been in the context of individual architectural components, and much less progress has been made in addressing the issue of an overall QoS architecture for the mobile Internet. This article first summarizes the state-of-the-art QoS techniques and standardization activities, then examines in detail important challenges in building a ubiquitous QoS framework over the heterogeneous environment, and finally proposes a QoS framework integrating a three-plane network infrastructure and a unified terminal cross-layer adaptation platform to provide seamless support for future applications.     

Heterogeneous Network Selection Optimization Algorithm Based on a Markov Decision Model

A network selection optimization algorithm based on the Markov decision process(MDP)is proposed so that mobile terminals can always connect to the best wireless network in a heterogeneous network environment.Considering the different types of service requirements,the MDP model and its reward function are constructed based on the quality of service(QoS)attribute parameters of the mobile users,and the network attribute weights are calculated by using the analytic hierarchy process(AHP).The network handoff decision condition is designed according to the different types of user services and the time-varying characteristics of the network,and the MDP model is solved by using the genetic algorithm and simulated annealing(GA-SA),thus,users can seamlessly switch to the network with the best long-term expected reward value.Simulation results show that the proposed algorithm has good convergence performance,and can guarantee that users with different service types will obtain satisfactory expected total reward values and have low numbers of network handoffs.