综合业务接入区业务承载方案

随着中国移动在全国范围内开展的综合业务接入区建设的基本完成,如何充分利用综合业务接入区资源,降低投入成本,有效地支撑业务发展,提高各接入区业务接入能力,是未来综合业务接入区发展的基本要求。本文通过对已建成的综合业务接入区承载业务诸多问题进行分析,提出了综合业务接入区内基站、WLAN、集团客户专线、家庭宽带等各类业务承载方案。     

ADSL宽带接入网业务分析

认为ADSL是一种全新、快捷和高效的接入方式。介绍了ADSL的发展过程、结构和所承载的业务,将ADSL与N-ISDN、DDN和CABLEModem进行了比较,提出了拓展ADSL市场的策略和要解决的问题等等。     

Integrated VP-Based Control Strategies for ATM Survivable Networks

ＩｎｔｅｇｒａｔｅｄＶＰ－ＢａｓｅｄＣｏｎｔｒｏｌＳｔｒａｔｅｇｉｅｓｆｏｒＡＴＭＳｕｒｖｉｖａｂｌｅＮｅｔｗｏｒｋｓ￥ＣｈｅｎＳｈａｎｚｈｉ；ＣｈｅｎｇＳｈｉｄｕａｎ；ａｎｄＣｈｅｎＪｕｎｌｉａｎｇ（ＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｏｆＳｗｉｔ...     

多层宽带网络生存性及其综合控制策略

介绍了宽带网络生存性的最新国内外研究动态，进而深入讨论了我层网络生存性综合控制策略，并提出了一种有效的ＳＤＨ／ＡＴＭ网络一存性控制策略，并给出一些有待研究的课题及研究方法。     

Dependable Traffic Control Strategies for Urban and Freeway Networks

Traffic congestion is a growing problem in many countries around the world. It has been recognized that instead of constructing more roads and freeways to counter this problem it is prudent to improve the utilization of existing road network through a judicious combination of advances in control engineering, communication and information technology. The traffic control architecture proposed in this paper is a combination of communicating Urban Traffic Control Architecture (UTCA) and Freeway Traffic Control Architecture (FTCA). The UTCA combines context-awareness, Cyber-Physical Systems (CPS) principles, and Autonomic Computing System (ACS) principles to optimize traffic congestion and enforce safety in urban traffic network. The UTCA includes a network of adaptive intersection traffic controllers and their immediate supervisory systems, who are also networked. The central piece of each traffic controller is an arbiter, which is a mini CPS. It is aware of the traffic dynamics at the intersection managed by it, by virtue of continuous input from monitoring sensors. Due to this context-awareness ability and its communication ability to exchange traffic information with its neighbors, it can execute policy-based reactions in order to enable safe and efficient traffic throughput at its intersection. Each urban traffic supervisory system is designed with ACS principles in order to minimize downtime caused by environmental emergencies and maximize security of the subsystem under it. A supervisory subsystem will also collect global traffic flow information and contextual constraints from its neighbors. Based on this input it will modify policies and communicate them to its traffic controller for timely adaptation. The urban traffic flowing into freeway traffic will be mediated by Intelligent Ramp Meters (IRM). An IRM interacts with the urban traffic control system and its nearest Intelligent Roadside Unit (IRSU) to regulate the flow of traffic from urban to freeway network. The FTCA consists of a network of mutually interacting IRSUs which monitor traffic flow, communicate with IRMs for providing traffic guidance for freeway drivers. An IRSU will communicate with the vehicles in the zone managed by it in order to provide information on rerouting when road and weather conditions warrant it. It also facilitates exchange of information between vehicles, guide them in lane changes and maintaining safe distance in order to avoid collision.     

综合业务数字网及宽带综合业务数字网

主要论述了综合业务数字网（ＩＳＤＮ）的概念及特点,简要介绍了ＩＳＤＮ发展的目标———宽带综合业务数字网（Ｂ＿ＩＳＤＮ）及其实现的技术基础。     

异构无线网络业务接入多目标优化控制算法

提出了一种应用于异构无线网络环境的基于多目标优化的业务接入控制算法.该算法以业务占用总资源最少、业务阻塞率最低和网络间负载最均衡为目标建立了多目标优化控制模型,采用高斯和戒上型组合隶属函数将多目标问题模糊化,利用最大化满意度指标法将多目标问题转化为单目标问题,并通过遗传算法求得最优解.仿真结果表明,所提算法能在兼顾各网络资源高效利用的同时,保证业务接入的可靠性,并相对于参考算法有效降低了业务阻塞率.     

多媒体通信中基于ABR业务的融入凭证方式的速率控制机制

提出了一种融入基于凭证方式的基于速率的流量控制模型，该模型继承了基于凭证方法的记数机制，通过设定高低缓存门限和调节速率升降因数来控制源端速率。仿真结果表明，这种控制机制不仅能够保证缓存的充分利用，而且能够提高其在减少信元丢失、降低传输时延等方面的性能。     

Bandwidth Allocation Strategies in Wide-Band Integrated Networks

A common digital transmission facility in a wide-band integrated service digital network (ISDN) provides shared access to a community of heterogeneous users. Traffic demands from these users vary in their arrival rate, their service time, and their bit rate. In order for this type of communication system to handle its traffic demands with high efficiency and flexibility, a close control of access to the shared bandwidth is required. We model the system by a general multiserver queueing system where customers demand service from a random number of servers. If no waiting is allowed, this queueing model is readily analyzed, and various server allocation strategies can be studied. If the various access requests are queued for service, then the system calls for efficient strategies for allocating servers to waiting customers. In this case, exact analysis of the underlying queueing model becomes quite difficult. For this case, we present some analytic and simulation results of the performance of the system under several server allocation policies.     

综合业务接入集中器在广域网中的应用

本文研究了一个典型的企业网络的有关费用，分析为什么每月交给电信运营商的服务费用成为ＷＡＮ开销的最大部分，说明了企业用户怎样通过使用综合业务接入集中器来显著地节省ＷＡＮ的费用。另外，还提供了对综合业务接入集中器投资的回报分析。     

天地一体化应急信息网及多址方式研究

卫星通信作为传统地面通信在空间的拓展和补充,有许多地面通信手段无法比拟的优点,文中首先介绍了卫星通信在应急通信系统中的应用,针对目前通信体制多样、互联互通较困难、一些部门的应急通信系统不支持图像、视频等宽带多媒体业务的现状,提出了实现地基通信网和天基信息网的有效联动、构建天地一体化应急信息网的设想,并分析了在卫星的频率和功率资源受限的条件下宽带多媒体卫星和移动卫星的多址接入方式的选择。     

面向接入回传一体化的毫米波空地网络建模与分析

无人机(UAV)作为空中基站有望成为传统地面网络的有力补充,以提供灵活覆盖和容量增强的解决方案。然而,大多现有研究忽略空中基站的无线回传这一实际因素对网络性能和用户体验的影响。为此,考虑接入回传一体化的空地毫米波蜂窝网络场景,其中无人机提供热点流量传输服务,地面基站(TBS)提供无人机回传链路并且服务非热点区域用户,以及接入和回传采用正交资源分配方法。针对该场景,提取地面基站、无人机和用户的空间分布特性,以及不同链路信号的传播特性,该文采用随机几何理论建立与之匹配的毫米波空地网络模型,推导了非热点用户的接入链路覆盖率和热点用户的接入回传链路的联合覆盖率。进一步地,基于地面基站和无人机的负载特性分析,推导了两种用户的速率覆盖率以及总体用户性能。基于所提分析框架,该文研究了关键系统参数,如接入链路频谱分配比例、无人机密度和热点用户密度等对用户性能的影响。     

An Integrated Medium Access Control and Traffic Management Architecture for DVB-RCS SkyplexNet Satellite Systems

The growing development of standard Internet services and the emerging exploitation of several broadband multimedia contents disclosing in the last years, significantly promoted scenarios where Satellite Networks can play key roles. Several satellite networks are currently implemented according to the Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) standard, assuming to operate with a transparent satellite and an hub-centric (star) network topology. The present work addresses the SkyplexNet (SKN) system: an advanced Broadband Satellite Network for meshed connectivity developed by Alenia Spazio, within the framework of ESA Artes 3 – Line 1 Program, according to the DVB-RCS standard with duly extensions for the on-Board multiplexing capability of the Skyplex Units currently embarked on HotBird VI and W3A satellites. In this paper an architecture design study aiming at integrating the Medium Access Control (MAC) and Traffic Management (TM) functionality in a DVB-RCS like Network is presented. The envisaged Traffic Management schemes shall enable the SKN System to guarantee an adequate support of various Quality of Service (QoS) requirements and their application according to pre-defined Traffic Profiles established at connection set up phase with the support of physical medium access management functions. The functional architectures studied for the SKN Inter-Working Layer, from Internet protocols to SkyplexNet ones, and the SKN MAC layer have been also analysed on the interoperability level of these layers in order to deploy such functions as SKN connection mapping, packet scheduling and Bandwidth on Demand (BoD) policies. In this paper two different schemes of Traffic Management and MAC are presented reporting a detailed analysis of advantages and drawbacks of both approaches to be taken into account for future SkyplexNet system implementations. Fabrizio Di Cola is a Network and System Engineer of the Telecommunication Mission Unit of Alenia Spazio company (Italy). He received the M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1998 and he is in Alenia Spazio since 2000. He is currently involved in the design and deployment of the Ground Segment of EuroSkyWay and SkyplexNet satellite systems as responsible for the Satellite User terminals Design and Development. He also contributes to System Engineering in the framework of several ESA and EC projects. From 1999 up to 2000, he worked as Researcher in the University of Bradford (Bradford, UK), Telecommunication Research Centre, within the “Satellite Mobile Group”. His activity focused on several aspects of the Mobility Management within telecommunications network integrating satellite and terrestrial networks. Emiliano Micaloni was born in Rome, Italy, in 1977. He is a Junior Telecommunication System Engineer involved since 2003 in a collaboration between University of Rome “La Sapienza” and the TLC Mission Unit of Alenia Spazio company (Italy). He received his Master Degree in Electronic Engineering from the University of Rome “La Sapienza”, Italy, in 2002, defending a thesis on Connection and Congestion Control for Geostationary Satellite Networks. Currently his area of interest concerns the Medium Access Control in the SkyplexNet Satellite Network, also contributing at the development activities for the SkyplexNet Satellite Terminals. In 2002–03 he collaborated with the “Computer Science and Systems” Department of “La Sapienza“ implementing solutions for Traffic Management and Quality of Service in Satellite Networks. All his activities are carried out in the framework of different ESA and EU IST projects. Luigi Secondiani received his M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1997. From 1998 to 1999 he received a post-degree grant issued by the “Infocom” Department of the University of Rome “La Sapienza” in the frame of the ACTS 4th framework programme. Since December 1999 he works as a Network Engineer in Alenia Spazio-TLC Mission Unit, and he is currently involved in Alenia's activities on EC, ESA and NATO programmes. His main research interests mainly lie on interworking between Next Generation Satellite Systems (NGSS) and IP networks, with particular emphasis on network architectures, terminal's architectures and routing issues. Giuseppe Tomasicchio is a Senior Telecommunication System Engineer of the TLC Mission Unit of Alenia Spazio company (Italy). He received his degree in 1989 from University of Bari (Italy) in the Artificial Intelligence field. He received a Post-degree Diploma on Technologies of Educational Communication in 1991 and a Post-degree Engineering Specialisation Diploma in Signal Processing in 1994 from University of Bari. Currently he is responsible of the Ground System Design of EuroSkyWay/SkyplexNet satellite systems and of the Network Operations and Service Centres engineering in satellite networks devoted to multimedia applications in the framework of different ESA and EC projects. In 1997–98 he was responsible at CERN (Geneva, Switzerland) of the Data Acquisition System involving the readout, calibration, event display and the networking setup tasks of high energy physics experiments. From 1994 to 1998 he was at INFN (Italian Institute for Nuclear Physics) as researcher. In 1994 he was an IS-specialist in the Italian Government data processing centre and collaborated with the Government Seismic Service for GIS processing. He worked in 1991–92 as a fellow of DIGITAL Corporation for a join research activity at INFN in the field of Image processing and Pattern recognition applied to raw-data images produced from detectors in high energy physics experiments at CERN. He is author of several scientific and engineering papers.     

A Directory Service for Perspective Access Networks

Network fragmentation occurs when the accessibility of a network-based resource to an observer is a function of how the observer is connected to the network. In the context of the Internet, network fragmentation is well known and occurs in many situations, including an increasing preponderance of network address translation, firewalls, and virtual private networks. Recently, however, new threats to Internet consistency have received media attention. Alternative namespaces have emerged as the result of formal objections to the process by which Internet names and addresses are provisioned. In addition, various governments and service providers around the world have deployed network technology that (accidentally or intentionally) restricts access to certain Internet content. Combined with the aforementioned sources of fragmentation, these new concerns provide ample motivation for a network that allows users the ability to specify not only the network location of Internet resources they want to view but also the perspectives from which they want to view them. Our vision of a perspective access network (PAN) is a peer-to-peer overlay network that incorporates routing and directory services that allow network perspective-sharing and nonhierarchical organization of the Internet. In this paper, we present the design, implementation, and evaluation of a directory service for such networks. We demonstrate its feasibility and efficacy using measurements from a test deployment on PlanetLab.     

Quality of Service Management in GPRS-Based Radio Access Networks

In this article, the performance and capacity gain achievable with quality of service (QoS) management in packet switched radio networks based on the General Packet Radio Service (GPRS) are examined. Both the functions defined in the GPRS specification for QoS support and implementation-specific strategies for subscriber- and application-based Connection Admission Control (CAC) and scheduling are introduced. The feasibility of QoS provisioning in mobile core networks with use of DiffServ compared to present IP technology realizing a pure Best-effort service is examined in addition. To achieve this, simulation results of GPRS performance and system measures for different load situations are produced with the simulation tool GPRSim that models the realistic traffic behavior of a GPRS network.     

站在新高度构建新一代综合业务接入网

随着接入网的出现，使整个电信网络的结构更加合理，网络资源的利用更加充分。同时随着IP等宽带业务的出现，传统的电信接入网也正向着数字化、综合化、宽带化的方向转变，因此接入网的发展目标是建立一个全业务接入网，真正在接入层首先实现多网的融台。港湾网络IONE新一代综合业务接入网产品正是适应这种需求．提出了对于新建网络应该“立足现在、放眼未来”，为充分保护运营商的投资而设计。     

Asymptotic Analysis and Precoding Design of Integrated Access and Backhaul in Full-Duplex mmWave Networks

In this paper, we consider a full-duplex(FD) millimeter wave(mmWave) multiuser integrated access and backhaul(IAB) system with massive MIMO, and the system asymptotic performance and interference cancellation schemes are investigated.First, the asymptotic performance of the IAB system with massive MIMO is analyzed. As the number of macro base station(MBS) and small base station(SBS) antennas approaches infinity, the FD selfinterference(SI), inter-tier interference and noise can be eliminated, wh...     

NGN中的主要协议及接入层综合接入业务的实现

NGN(下一代通信网络Next Generation Network)以软交换为核心技术,通过开放的接口规范,具有实现与传统网络互连互通、通用移动性,融合固定与移动网络业务等特征.介绍了NGN的特点及其主要协议:呼叫控制协议、传输控制协议,媒体控制协议、业务应用协议、维护管理协议等.分析与比较了NGN接入层的不同接入方法,给出了无线局域网用户接入NGN的具体实现方法.     

警用交通信息综合应用服务平台关键技术研究

近年来,信息化技术在交通管理中得到了广泛的应用,交通管理部门根据各个板块的业务特扇建立了独立的信息化管理系统。实际上交通管理业务错综复杂,每个板块各具特性却又息息相关,冀充分发挥信息化技术在交通管理中的作用,该文提出了一种集信息技术、数据通讯传输技术、自动拦制技术等于一体的警用交通信息综合应用服务平台,讨论了平台的系统结构,对平台的硬件和软件孬统架构进行了研究与设计,并对实现的关键技术和方法进行了研究,该平台能够较好地服务于交通管理部门。     

ATM网络中的业务控制

本文主要分析在宽带综合业务数字网（Ｂ－ＩＳＤＮ）中，以ＡＴＭ为传递方式的业务控制机制，主要从控制机制所应具备的特点及控制功能的划分角度进行讨论，并对控制机制中的业务监测和业务描述器两个主要问题进行了深入地分析。