A solving method for singly routing traffic demand in telecommunication networks

The problem of assigning single paths to point to point demands in a network arises in the telecommunications industry. The well known atm technology involves such a problem when each demand must be assigned to a single virtual channel in an atm backbone network. This problem is referred to as the Bandwidth Packing Problem. For a given network and a set of point to point demands with related bandwidth requirement and profit, the problem consists in determining the most rewarding subset of demands for which all demands are single path routed according to the link capacity constraints. We propose a heuristic derived from an exact method to solve this problem. We use cutting planes to strengthen a path-based linear relaxation embedded in a Branch&Cut scheme. The results particularly depend on the ratio of the average edge capacity to the average bandwidth required by the demands. The method provides optimum or nearly optimum solutions for practical telecommunications problems within small computational time.     

高性能单机路由器在中国移动互联网中的应用

本文介绍了高性能单机路由器出现的驱动力以及业界主流厂家高性能单机路由器的性能,最后重点探讨此类路由器在中国移动CMNet网络中的应用场景.     

Evolution of a narrowband exchange toward broadband

Today's telecommunications network is facing a continuing evolution, driven by the growing interest and demand for services requiring higher bandwidth and flexibility of transport. Replacing a narrowband switch fabric with a broadband switch fabric allows the operator to reuse existing narrowband hardware and software, while adding new capabilities such as SDH and ATM, making performance and capacity upgrades possible     

Strategic telecommunications networks planning in the context ofemerging technologies, architectures, and services

A methodology is presented for conducting strategic network planning studies under a new set of planning assumptions. The key element of the described methodology is a mathematical model of the equipment-replacement decision-making process that explicitly captures the economic impact of emerging technologies, architectures, and services. The general replacement decision model (GRDM) is a mathematical model that computes the optimal sequence of replacement times for particular pieces of telecommunications network equipment. GRDM takes information about costs and revenues and their trends in time associated with existing and emerging technologies and services and calculates the sequence of technology replacement intervals that minimizes the net present worth of expenditures associated with embedded plant and its replacements. The generality of the model supports its application to a broad range of network evolution issues, including the deployment of fiber optics and intelligent network features. An illustrative application of GRDM is presented which evaluates how the optimal economic lives of analog and digital switching equipment change as the assumed date of widespread broadband switching availability is varied     

WDM光网络的规划方法

近年来,光纤传输技术的发展使网络传输带宽不断增长,特别是波分复用(WDM)技术的引入使电信运营商可以把他们的网络容量提高数十倍。新技术的使用为网络设计和规划提出新的课题,作者主要讨论骨干WDM传送网的规划方法。     

Global expansion model for mobile networks

In this letter, we propose a global model to solve the expansion problem of universal mobile telecommunications system (UMTS) networks. Since the network expansion problem is a generalization of the network design problem, the proposed model can be used for the design of UMTS networks. The proposed model deals simultaneously with the cell, the access network and the core network planning subproblems. This global approach has the advantage of providing better results since, in general, optimal solutions to all subproblems do not provide an optimal solution to the global problem. Moreover, this model fits real life situations in which mobile users have the choice to subscribe or to leave a service providers. Numerical results are presented and analyzed.     

Addressing universal-broadband-service implications with wireless mesh networks

Fueled by some successes in urban areas, demand is increasing for broadband telecommunications in non-urban areas, but many of the latter areas lack adequate means of delivering the desired services to residential customers and businesses—at least for the last mile of connectivity. This research examines wireless’s potential to mitigate the so-called “last-mile” problem by supplying broadband services to non-urban areas using a wireless mesh network configuration. Methodologically, 270 randomly generated “last mile,” low-density neighborhoods are studied, each under nine different conditions indicating various quality-of-service (QoS) (bandwidth; number of hops) offerings. Results indicate that for the neighborhoods studied, wireless mesh networks are not a panacea providing broadband universally. Rather, it is first shown that even when bandwidth is reduced dramatically, Internet service providers must include in their planning of the mesh such factors as hops, bandwidth, visibility, network density, and interactions of these factors to ensure that favorable conditions exist for profitable operation. Then, guidelines are given assuming current equipment and service-provision costs. Finally, cost reductions and/or transmission-range improvements necessary to bring economic broadband service to areas that are more rural are prescribed.     

采用DOCSIS技术实现NGB接入网的升级改造

在三网融合的背景下,本文从现有及未来的业务出发,分析业务对接入网络的带宽要求;采用DOCSIS技术改造接入网络在现阶段能够满足业务发展的需要。     

一种基于SDN及人工智能的OTN资源规划及调度应用方法与系统

如今运营商面对的综合业务发展在各个领域对传输带宽及调度灵活性无不提出极为严格的要求。无线方面的5G建设浪潮即将来临,固网宽带方面的部署热度尚未褪去,政企专线的大颗粒业务需求日益增加。同时更多新业务、新技术的应用还将对基础承载的传送网提出更进一步的挑战与要求。本文就上述日益增加的需求为出发点,以OTN基础承载光网络为对象,通过对业务需求深入剖析,首先总结并归纳现有网络规划方法的缺陷及难点,并锁定主要改进目标。其次,文章引入一种创新性的网络规划方法,借助SDN理念通过自研改良型路由计算方法以及一种机器自我学习机制,实现具备人工智能的路由调度功能,并以此为基础对T、P级别的海量需求进行高效快速梳理与整合,以集中自动化方式进行网络资源计算,并快速精确输出结果,助力OTN网络规划及建设。最后,文章以上海本地网络建设需求为例,展示相关方法及自研系统的应用,验证并说明其价值。     

IPTV transport architecture alternatives and economic considerations

Telecommunications companies are under increased pressure due to competition from multiple system operators, and the changing communications and entertainment needs of residential consumers. These pressures are driving the telecommunications companies to design and deploy metro networks capable of delivering broadcast video and VOD services through IP-based broadband connectivity (known as IPTV). One important architectural consideration for these IPTV networks is the core layer 1 transport infrastructure that supports economical delivery of these high-bandwidth services. This article surveys some of the major layer 1 optical transport network alternatives including DWDM, SONET, and Ethernet-on-fiber as well as its passive WDM/DWDM (PWDM) variation. The article analyzes the architectural and cost performance metrics for these transport options, and explores the economic crossover points with regard to the key network and service parameters such as bandwidth demand, number of subscribers, network topology, and operational constraints. DWDM technology, when coupled with native Ethernet aggregation, is found to have significant applicability for IPTV transport networks. DWDM offers value in capital cost and operations, while delivering the required bandwidth and performance. Ethernet aggregation capability within the transport infrastructure adds scalability, flexibility, and cost advantage for the multiservice network applications of the future.     

On the Role of Telecommunications in the Development of Nations

Both in developed and developing nations there is a clear need to discriminate among all the numerous choices of telecommunications technologies and services that have been, are, or can be developed. This discrimination should be based on a knowledge of the likely effects of each of those services on the community and its environment; discrimination can no longer be left open to the sole forces of the market and it is within the engineering function to provide value judgments on the technologies it produces. In developing nations where there is a strong shortage of capital, the telecommunication planner's problem is not one of satisfying demand indiscriminately at fair prices ensuring a reasonable financial return to the firm but rather to find a strategy of service growth that will be optimal for the country or parts thereof. The comparison of alternative investment plans in the telecommuncations sector should proceed, therefore, attending to the measure in which each one can contribute towards these general objectives. Inasmuch as progress towards the different national targets is unlikely to allow for a single measure common to all of them, investment plans that are optimal with regard to different targets will also not be comparable with one another and the choice between optimal plans escapes the sector and becomes a matter of subjective national policy. Telecommunication planners should be able to find such optimal strategies and to supply global planners with elements of judgment suitable to support the decision of allocation of resources to the telecommunication sector. A review of published material in this field shows that progress towards such a situation has been very small. The paper then discusses some ideas on how the study of interaction between telecommunications and society could be advanced within a frame of reference given by current knowledge in the social sciences and in telecommunication technology.     

The future of fibre access systems?

It is clear that there is a huge potential demand for high bandwidth services that, at some point in the future, could be deliveredover the fixed network. The most promising technology to provide the delivery mechanism to the customer is optical accessnetworks. The major issue for the telecommunications industry is how to do this at sufficiently low cost. This paper looks at theeconomic issues and suggests some possible ways forward if we are to move to delivery of services well beyond the capability ofADSL and cable-modem technologies.     

Multiservice access network upgrading in Europe: a techno-economicanalysis

The article presents a techno-economic evaluation of strategies for developing the traditional access network along a cost effective path toward a future-proof multiservice broadband network. A broad range of appropriate network alternatives have been assessed for each of five representative European upgrade cases. The technological options that have been evaluated range from conventional copper-based networks to emerging new technologies such as hybrid fiber coax networks and ATM-based broadband passive optical networks. The techno-economic assessment was carried out by the Eurescom P306 project “Access network evolution and preparation for implementation”, using the methodology and tool developed within the RACE 2087/TITAN project. The scenarios studied include gradual provisioning, from 1995 to 2005, of services like POTS, N-ISDN, asymmetric switched broadband, symmetric switched broadband, and broadcast broadband. The demand forecasts for the selected bearer services are extracted from a European Delphi survey, also carried out within TITAN. The quality of the existing infrastructure, the average subscriber capacity demand, and demography are among the key elements likely to affect the economic viability of access network upgrade strategies     

Network planning based on virtual path bandwidth management

Periodical performance evaluation and adaptive resource assignment, already proposed as performance-oriented management, seems to be the most suitable strategy for network planning under demand uncertainty. In this paper, we exploit the inherent capability of ATM networks to rearrange dynamically the already installed resources, and propose performance-oriented management combined with virtual path bandwidth (VPB) control for the planning of the extensions of bandwidth capacities of virtual paths (VPs) and transmission links of the network. We define a large network optimization problem and solve it by a rigorous, analytical procedure. The optimization model comprises specific requirements of the network-planning problem and a bandwidth distribution scheme ensuring network reliability. We reveal the efficiency of the proposed scheme by applying it on a model network, considering two realistic case-studies of network-traffic evolution. We show that in the presence of VPB control: (a) the initial distribution of the total bandwidth to VPs is of no importance, since it can be adaptively rearranged according to the offered traffic, (b) the network is well used and bandwidth investment could be saved, and (c) whenever additional bandwidth must be installed in VPs which have an unanticipated bad grade-of-service, time savings result. We present the network performance in detail, in figures, and compare this with the performance of the network in the absence of VPB control.     

基于NGPON系统的ONU配置管理技术

根据中国电信EPON设备技术要求V2.1中介绍的ONU能力属性,提出NGPON系统中ONU配置管理技术。详细介绍了传统ONU配置管理技术以及ONU能力集配置管理技术实现过程。该方法能很好地解决设备间的互通问题,能很好地管理厂商生产的各种类型ONU,具有很强的实用价值。     

ARMS — application of AI and OR methods to resource management

This paper documents work on automating resource management in BT Retail. BT Retail manages BT’s access network and provides telecommunications services to its customers. BT Retail’s field engineers are allocated jobs via an information system known as Work Manager. In order to proactively position the engineers (i.e. resources) so as to service jobs in an optimal manner, resource managers are involved in analysing the profiles of engineers in the light of incoming jobs and ’selecting’ those profiles that will yield best quality of service and reduce operational costs. A profile is a set of attributes that define a resource’s capabilities (i.e. skills), capacity (i.e. availability), and location (i.e. area). Resource planning involves identifying an ‘optimal’ set of resource profiles. Accurate workload forecasting is sine qua non for optimal resource planning. To this end we have developed ARMS, Automated Resource Management System, a suite of components for workload forecasting and resource planning.     

基于传输速率自适应的动态带宽分配算法

提出一种基于传输速率自适应的动态带宽分配算法,为异构无线网络中的多业务提供服务质量保证。根据所提的传输速率优先级决策模型,在传输速率QoS需求和异构网络容量约束的条件下,通过动态调整不同网络中各个移动终端所支持业务的传输速率来得到最优带宽重分配矩阵,以最大化整个异构网络的效用函数;将自适应带宽重分配问题描述为一个优化问题,采用动态优化的迭代算法自适应调节用户传输速率来进一步最大化该效用函数。理论分析和数值仿真结果表明,所提算法在给定传输速率且满足QoS需求的基础上,能够最大化网络的效用函数并减小新呼叫的阻塞概率。     

Building today's global computer internetworks

A paradigm that defines the wide area networks (WANs) of today and tomorrow is described. Characterized by increasingly higher speeds, a broader range of connectivity options, and the appearance of extremely dynamic topologies that are constantly changing, this paradigm features unprecedented levels of flexibility and configurability for network users everywhere. The factors driving the evolution of global telecommunications services are reviewed. The roles of the computer networking vendor, connectivity options, bandwidth and performance choices, and dynamic internetwork topologies in establishing WAN services are discussed     

Unified control infrastructure for carrier network evolution

Migration strategies for the network control infrastructure are discussed, to evolve carrier networks toward an optical transport backbone optimized for IP traffic. The strategies presented aim to protect carriers' investments in their current multiservice and IP-routed networks, while expediting the backbone migration toward a unified packet-over-optical core for IP and multiservice transport. This unified core network simplifies the network layers and control systems, and consolidates data and multiservice traffic to reduce network cost with improved bandwidth efficiency. The network control system, including signaling, addressing, and routing, is analyzed in detail to demonstrate the feasibility of the proposed infrastructure. Built on multiprotocol label switching (MPLS) technology, the presented solutions take phased evolution steps to reduce network cost, improve bandwidth efficiency, and offer practical options for internetworking during the migration. These solutions provide carriers with competitive advantages to consolidate multiple services onto an IP-centric optical transport network. The unified control infrastructure not only offers flexible options for network upgrade with reduced network management overhead, but also supports enhanced networking and traffic engineering capabilities to ensure no compromise in the service level agreement committed to end customers.     

Service overlay networks: SLAs, QoS, and bandwidth provisioning

We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular, end-to-end quality of service (QoS), plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. The SON purchases bandwidth with certain QoS guarantees from the individual network domains via bilateral service level agreement (SLA) to build a logical end-to-end service delivery infrastructure on top of the existing data transport networks. Via a service contract, users directly pay the SON for using the value-added services provided by the SON. In this paper, we study the bandwidth provisioning problem for a SON which buys bandwidth from the underlying network domains to provide end-to-end value-added QoS sensitive services such as VoIP and Video-on-Demand. A key problem in the SON deployment is the problem of bandwidth provisioning, which is critical to cost recovery in deploying and operating the value-added services over the SON. The paper is devoted to the study of this problem. We formulate the bandwidth provisioning problem mathematically, taking various factors such as SLA, service QoS, traffic demand distributions, and bandwidth costs. Analytical models and approximate solutions are developed for both static and dynamic bandwidth provisioning. Numerical studies are also performed to illustrate the properties of the proposed solutions and demonstrate the effect of traffic demand distributions and bandwidth costs on SON bandwidth provisioning.