An Autonomic QoS-centric Architecture for Integrated Heterogeneous Wireless Networks

In this paper the problem of seamless mobility and proficient joint radio resource management over an all-IP internetworked wireless heterogeneous environment is addressed. Nodes’ autonomicity is envisioned as the enabler to devise a Quality of Service (QoS) aware architecture for supporting a variety of services, founded on a common utility based framework that provides enhanced flexibility in reflecting different access networks’ type of resources and diverse QoS prerequisites, under a unified QoS-aware resource allocation optimization problem. This allows a more in-depth intrinsic wireless network convergence, beyond All-IP, driven by QoS-oriented resource management. This vision is demonstrated and instantiated for integrated WLAN and cellular (both CDMA and OFDMA) networks, providing a viable path towards the evolution and realization of the future wireless networking paradigm. Initial numerical results demonstrate the effectiveness of the proposed architecture and reveal the benefits of such a service oriented paradigm against other existing access oriented autonomic designs.     

一种基于Contact的传感器网络查询策略研究

基于Contact的资源查询机制是依据小世界理论提出来的,该机制要求网络中各个节点不仅维护R跳以内的“邻居”节点的资源状态,而且还选择维护少数较远节点(Contact)的状态。Contact大大降低了查询源与目标的“分离度”。论文提出的SMQM查询机制在CARD和TRANSFER的研究成果基础上,对于Contact的选择方法进行了重要的改进。SMQM性能的仿真试验结论说明,SMQM查询机制的性能优于CARD协议。SMQM查询机制着眼于寻找“可行”的路径,而不是最“优”路径,由此降低了路径建立开销、单次查询的总能耗,提高了网络的生命周期。     

无线Ad hoc网络的安全体系

在敌对环境下,Ad hoc网络易受攻击,尤其来自网络内部的攻击更具威胁性。针对这种情况,本文介绍了一种无线Ad hoc网络安全体系模型,并着重介绍了利用不完全信任管理机制来防止网络内部的攻击。     

A Flexible QoS-aware Service Gateway for Heterogeneous Wireless Networks

The integration of different types of wireless access networks, or heterogeneous wireless networks (HWN), is emerging. This article investigates in particular how a combination of UMTS (Universal Mobile Telecommunications System) cellular networks, wireless LAN ad hoc networks, and DVB-H (digital video broadcasting - handheld) broadcasting networks, called UWD networks for short, is constructed and managed to provide users with QoS-aware services. Given the complexity of the UWD networks, a novel policy-based service gateway is proposed. As a software framework sitting over and communicating with the UWD network, this UWD service gateway makes network management decision by reasoning over a set of predefined policies that describe the behaviors of the UWD network. Network variables such as bandwidth, delay, and mobility in policies are fuzzified using fuzzy control theory to make the service gateway (as well as the whole UWD network) more flexible and robust. Both the prototype implementation and the evaluation results indicate the feasibility and effectiveness of the system     

基于环境感知的异构无线Mesh网络体系结构及关键技术

文章以蜂窝网、无线局域网(WLAN)、Ad Hoc网络3种典型网络环境为组成元素,研究集环境感知、协作通信与网络融合于一体的异构无线格状网(Mesh)网络体系架构及其相关理论与技术问题.文章设计与实现的软硬件平台,不仅达到了各种异构网络的兼容和融合的目的,而且显著提高了无线通信网的容量和质量,可提供更经济和更便利的服务.     

面向异构网管理的多级中间件体系

为了减少异构网网络管理方面所付出的代价，继续利用各专业子网已有的网络基础设施并对其进行跨域管理，提出了一种多级网络管理体系。该体系模型以面向对象、中问件技术为核心．利用CORBA的IDL接口封装网元层元素，将本地各专业子网抽象为分布式对象，使用CORBA平台完成对象问的互连。中问层使用CORBA/Web Services复合代理，上层则由Web Services直接联入Intemet。授权用户可在Intemet任意一点应用GUI终端（浏览器）访问网络系统，对异构网下层网元元素进行网络管理。     

Middleware Architecture for Next Generation Heterogeneous Networks

In this paper we present a framework, called Futon, which provides a platform to integrate heterogeneous radio access networks. Futon is a hybrid fibre-radio network that replaces legacy base stations with simple remote antenna units, which are connected to a central unit. As a part of the Futon framework, a generic middleware architecture is discussed in detail, which provides interoperability, cooperative management and service provisioning to both underlying radio access networks (RANs) and IP layer for a heterogeneous network scenario. One of the middleware??s functionality is to provide vertical handover between heterogeneous IP-based radio access technologies and to ensure seamless mobility and service continuity, which is implemented on top of an IPv4/IPv6 Mobile IP (MIP) core. In this paper, the Futon framework and a generic middleware architecture as a part of Futon framework for heterogeneous RANs is discussed. The main modules of the middleware, namely common radio resource management (CRRM), media independent handover, Service/Connection Manager and link selection are explained in detail. Radio over fibre (RoF) Manager is an important part of Central unit, which does performance, fault and security management of network elements. RoF manager helps middleware during handoff, by providing the status of fibre optic links. The implementation of Security management module as a part of RoF manager, and results of authentication with AAA protocol are explained. The CRRM as part of middleware is simulated and the results of experimental evaluation are presented.     

异构网络的资源控制体系

TISPAN从固定接入角度出发,提出了资源接纳控制子系统来解决NGN承载网的QoS问题;3GPP则从移动接入角度出发,在最新的3GPPR7草案中,把R6版中的策略控制功能和基于流的计费功能合并,提出了策略控制和计费。随着固定移动的融合,资源接纳控制体系在架构和接口上的不一致性对NGN相关设备制造和网络实施将产生重大的影响。目前,3GPP和TISPAN都开展了Gq＇／Rx参考点融合的研究课题。下一代移动网络论坛提出了和谐PCC的概念和需求,即异构网络的协同资源控制体系架构,代表了异构网络的资源控制技术和体系的演进方向。     

Heterogeneous HEED Protocol for Wireless Sensor Networks

One of the important protocols for increasing the network lifetime in wireless sensor networks (WSNs) is hybrid energy efficient distributed (HEED) protocol. This protocol considers two parameters for deciding the cluster heads, i.e., residual energy and node density and has been designed for the homogeneous WSNs. In this paper, we consider the implementation of HEED for a heterogeneous network. Depending upon the type of nodes, it defines one-level, two-level, and three-level heterogeneity and accordingly the implementation of HEED is referred to as hetHEED-1, hetHEED-2, and hetHEED-3, respectively. We also consider one more parameter, i.e., distance and apply fuzzy logic to determine the cluster heads and accordingly the hetHEED-1, hetHEED-2, and hetHEED-3 are named as HEED-FL, hetHEED-FL-2, hetHEED-FL-3, respectively. The simulation results show that as the level of heterogeneity increases in the network, the nodes remain alive for longer time and the rate of energy dissipation decreases. And also, increasing the heterogeneity level helps sending more packets to the base station and increases the network lifetime. The increase in the network energy increases the network lifetime manifold. In fact, using fuzzy logic, the network lifetime increases by 114.85 % that of the original HEED without any increase in the network energy. Thus, the hetHEED-FL-3 provides the longest lifetime (387.94 % increase) in lifetime at the cost of 19 % increase in network energy), sends maximum number of packets to the base station, and has minimum rate of energy dissipation.     

Resource Control Architecture in Heterogeneous Networks

TISPAN,from a fixed access perspective,proposes Resource and Admission Control Subsystem[0](RACS) as a solution to Quality of Service(QoS) problem for NGN bearer network.In contrast,3GPP has an approach to this from the perspective of mobile access.In the latest 3GPP R7 draft,integration of Policy Control Function(PCF) with Flow Based Charging(FBC) function of the R6 brought forward policy control and charging.With the development of fixed mobile convergence,the inconsistence in architectures and interfaces of different resource and admission control[0] solutions will have a huge impact on manufacture and network implementation of NGN related equipment.To solve this problem,both 3GPP and TISPAN have been working on the convergence of Gq’/Rx reference points.Harmonized Policy Control and Charging(PCC) proposed by the Next Generation Mobile Network(NGMN) forum,i.e.cooperative resource control architecture for heterogeneous networks,represents an evolutional sign post for resource control technology for heterogeneous network architecture.     

A Cost Function Model for CRRM over Heterogeneous Wireless Networks

Heterogeneous cellular networks performance is usually analysed by taking several Key Performance Indicators (KPIs) into account, their proper balance being required in order to guarantee a desired Quality of Service (QoS). An approach to simplify and integrate a set of KPIs into a single one is presented, by using the proposed Cost Function model that includes these KPIs, providing a single evaluation parameter as output, and reflecting network conditions and Common Radio Resource Management (CRRM) strategies performance. This paper proposes a Cost Function that enables the implementation of different CRRM algorithms and policies, by manipulating KPIs according to user’s or operator’s perspectives, allowing for a better QoS. Results show that different policies can in fact be established, with a different impact on the network, e.g., with median values ranging by a factor higher than two.     

Location-Aided Handover in Heterogeneous Wireless Networks

The concept of being always online, regardless of the time and place, has been one of the hot topics in the commercial and scientific forums during the last years. The term itself is not solidly defined, however it is often used to refer to user's ability to get the same services via changing variety of underlying networks. In order to really work, this kind of multiaccess in heterogeneous networks still requires research, technological achievements and even compromises. The key to successfully implement the multiaccess is vertical handover that allows the application services to be seamlessly transferred between different networks.     

无线异构网络的垂直切换判决算法

传统上的水平切换处理方法已经应用在同一接入技术的网络中（如无线蜂窝网络）。随着多种异构无线网络的出现,下一代网络必须支持垂直切换技术以保证用户从一个网络切换到内一个网络时仍然保持连接,垂直切换作为多网融合的基础,受到了学术界和工业界的广泛关注。对使用层次分析法进行垂直切换技术的工作原理及应用环境进行了分析,提出同时使用多种切换技术以解决不同环境下的切换问题。     

Energy Efficiency Architecture Design for Heterogeneous Cellular Networks

Heterogeneous cellular networks (HetNets) have emerged as a new promising paradigm to further enhance capacity, where multiple types of low power smallcells are overlaid in a high power macrocell. They provide more opportunities to explore the potential cognition and cooperation diversities to improve the spectral efficiency. On the other hand, energy efficiency is a critical performance metric, which deserves more attention from academia, industry, and standardization, in particular, in scenarios where smallcells are densely deployed. In this paper, a systematic architecture is presented to efficiently utilize network resources and thus improve the overall energy efficiency. The architecture is referred to as OCRT because it combines a multi‐tier energy efficiency considerations of operators, core networks, radio access networks and terminals (e.g., OCRT). Furthermore, a corresponding triply‐cycle‐based functional structure is proposed for the OCRT to make various interactions between the corresponding functional entities clear. An implementation scheme of OCRT based on cognitive information interaction cycle and an energy efficiency‐aware protocol is presented. Finally, a use case of the presented OCRT green design is provided for energy efficiency optimization in a cognition‐and‐cooperation‐characterized HetNet. Copyright © 2015 John Wiley & Sons, Ltd.     

异构无线网络干扰效率最大顽健资源分配算法

针对能效提升、宏用户干扰减小的问题,该文研究了基于干扰效率最大的异构无线网络顽健资源分配算法.首先,考虑宏用户干扰约束、微蜂窝用户速率需求约束和最大发射功率约束,将资源优化问题建模为多变量非线性规划问题.其次,考虑有界信道不确定性模型,利用Dinkelbach辅助变量方法和连续凸近似方法结合对数变换方法,将原分式规划顽健资源分配问题转换为等价的确定性凸优化问题,并利用拉格朗日对偶算法获得解析解.理论分析了计算复杂度和参数不确定性对性能的影响.仿真结果表明该算法具有较好的干扰效率和鲁棒性.     

异构无线网络的自组织功能及其演进

随着无线网络的不断发展、多层次多制式的异构网络部署逐渐成为热点。针对异构网络中出现的资源受限、运维困难等问题,文章研究了通过网络自组织技术实施的解决方案,并探讨了异构网中自组织技术未来的发展趋势。     

Enabling Intelligent Handovers in Heterogeneous Wireless Networks

In the future Wireless Internet, mobile nodes will be able to choose between providers offering competing services at a much finer granularity than we find today. Rather than months, service contracts may span hours or minutes. Connectivity, however, is just one of many possible services. Providers will begin to offer network and application-level services targeted at improving the overall wireless experience of the user. Determining the best path through the various networks will require accurate information describing which services are being offered by each provider. In this paper, we model the process of propagating this information as an instance of a distributed, hierarchical cache. Access routers actively discover and collect information about the immediate network neighborhood on behalf of mobile nodes. Mobiles fill their own caches through queries to their local access routers, and then employ the cached information to make informed, intelligent handover decisions. Through simulation, we show that high cache hit rates at the mobile node can be achieved even when the discovery process at the access router is incomplete. In comparison to static and centralized approaches, our dynamic approach requires less configuration and maintenance, avoids single points of failure, and provides a scalable solution that spans administrative domains. Robert C. Chalmers received his B.S. in Computer Science from the California State Polytechnic University, Pomona in 1997, and his M.S. in 2003 from the University of California in Santa Barbara. He is currently a Ph.D. candidate at the University of California in Santa Barbara where his main research interests focus around leveraging intelligence within the network. Particularly, he has studied multicast and its effect on resource utilization, as well as how to provide services for small, mobile devices in edge networks. He was awarded the Ericsson Fellowship in 2001 and is currently a Eugene Cota-Robles Fellow. Govind Krishnamurthi received an M.S. (Electrical Engineering) and Ph.D. degree (Computer Engineering) from the University of Washington and the Iowa State University, in 1997 and 1999 respectively. He spent the summer of 1995 as an intern at Bellcore, Morristown, NJ. He is a recipient of the Research Excellence Award from the Iowa State University for his Ph.D. thesis. Since the summer of 1999 he has been a Senior Research Engineer at the Nokia Research Center, Boston, MA. He has authored several publications and holds 3 patents. His current interests deal with QoS, location based services and security issues in IP based wireless networks. Kevin C. Almeroth earned his Ph.D. in Computer Science from the Georgia Institute of Technology in 1997. He is currently an associate professor at the University of California in Santa Barbara where his main research interests include computer networks and protocols, multicast communication, large-scale multimedia systems, and performance evaluation. At UCSB, Dr. Almeroth is a founding member of the Media Arts and Technology Program (MATP), Associate Director of the Center for Information Technology and Society (CITS), and on the Executive Committee for the University of California Digital Media Innovation (DiMI) program. In the research community, Dr. Almeroth is on the Editorial Board of IEEE Network, has co-chaired NGC 2000, Global Internet 2001, NOSSDAV 2002, and MMNS 2002; has served as tutorial chair for several conferences, and has been on the program committee of numerous conferences. Dr. Almeroth is serving as the chair of the Internet2 Working Group on Multicast, and is a member of the IETF Multicast Directorate (MADDOGS). He is also serving on the advisory boards of several startups including Occam Networks, NCast, Hidden Footprint, and the Santa Barbara Technology Incubator.     

A Cross-Layer Architecture of Wireless Sensor Networks for Target Tracking

We propose the Low Energy Self-Organizing Protocol (LESOP) for target tracking in dense wireless sensor networks. A cross-layer design perspective is adopted in LESOP for high protocol efficiency, where direct interactions between the Application layer and the Medium Access Control (MAC) layer are exploited. Unlike the classical Open Systems Interconnect (OSI) paradigm of communication networks, the Transport and Network layers are excluded in LESOP to simplify the protocol stack. A lightweight yet efficient target localization algorithm is proposed and implemented, and a Quality of Service (QoS) knob is found to control the tradeoff between the tracking error and the network energy consumption. Furthermore, LESOP serves as the first example in demonstrating the migration from the OSI paradigm to the Embedded Wireless Interconnect (EWI) architecture platform, a two-layer efficient architecture proposed here for wireless sensor networks     

基于P2P的无线传感器网络应用架构研究

通过基础网络互联多个传感器网络，为用户提供大规模、大范围、多样化的信息服务成为未来无线传感器网络的应用模式之一。据此，提出了一种基于P2P（Peer-to—Peer）技术的无线传感器网络应用架构。采用P2P技术，解决了大数据量的通信瓶颈，传感器网络亦可自由加入、变更或退出，方便部署，网络可扩展性好．同时屏蔽底层网络差异及多种接入方式．为用户提供多个访问入口。