Call control and traffic transport for connection-oriented highspeed wireless personal communications over metropolitan area networks

A distributed circuit-switched approach for supporting the deployment of high speed wireless personal communication services in urban areas through the interconnection of base stations via metropolitan area networks (MANs) is proposed. Broadband MANs minimize traffic congestion by dynamic sharing of link capacity and by serving as distributed switches for partitioning call control functions. While the DQDB protocol readily supports distributed packet-switching over the IEEE 802.6 MAN, isochronous traffic such as voice and video is best supported by circuit-switched connections. The authors present an enhanced bi-state pre-arbitrated (PA) transport mechanism, and associated call control and handoff management techniques, which enable distributed circuit-switching over the MAN. These capabilities are not currently addressed in the 802.6 standards. The bi-state PA transport mechanism facilitates statistical multiplexing of variable rate isochronous traffic sources. The network capacity is constrained by the call setup delay performance, and is analyzed by simulations. Alternative signaling architectures, involving different placements of call control network elements, are evaluated. The effects of erasure nodes, and close bus versus open bus architectures, are considered. The overlap inter-MAN call setup procedure is proposed to reduce delays. Different call handoff procedures are formulated according to the type of handoff and the resulting change in call connectivity. Most handoffs are intra-MAN, requiring simple procedures with short delays     

Performance analysis of interconnected metropolitan areacircuit-switched telecommunications networks

A circuit-switched telecommunications network is considered that consists of two metropolitan area networks (MANs) interconnectd by a multiaccess communications channel, such as a satellite or multiaccess multichannel terrestrial trunk. The blocking probability performance of this network is computed, using a finite-source-traffic model, by setting up a Markov chain model and applying results based on the reversibility of this chain to compute the underlying state probabilities. Local and long-distance blocking probabilities are calculated. each in terms of its two components: circuit-blocking and destination-busy probabilities. Both dedicated and shared circuit allocation policies are used in allocating the circuits of a MAN between its local and long-distance calls. Explicit performance equations are presented. Illustrative results and performance curves are given, indicating the various underlying system performance characteristics and tradeoffs     

A wavelength division multiple access network for computercommunication

A first-generation design, called Rainbow, for optical wavelength division multiaccess (WDMA) computer networks is described. The Rainbow research prototype takes the form of a direct detection, circuit-switched metropolitan-area-network (MAN) backbone consisting of 32 IBM PD/2's as gateway stations, communicating with each other at 200-Mb/s data rates and submillisecond switching times. The prototype architectural options for realizing WDMA networks are discussed, along with reasons for choosing this design point. Experimental measurements on the prototype are presented. Ways of extending this prototype to more stations, higher bit rates, and faster setup times are given     

建设具有移动特色的城域网

本文分析了移动城域网建设的现状及建设的必要性，结合城域网技术，探讨了如何建设具有移动特色的城域网。     

Media access control for high-speed local area and metropolitanarea communications networks

The features, architectures, and principles of key media access control (MAC) schemes for high-speed LAN and MAN systems are categorized and reviewed. These architectures are related to the hierarchical structure of a telecommunications network. An overview is given of the MAC protocol operation of key local- and metropolitan-area network systems, as defined by standards committees, covering current methods as well as approaches for future broadband integrated services digital networks. Modeling and analysis techniques are then reviewed for key classes of relevant MAC schemes, including fixed-assignment time-division-multiaccess (TDMA) schemes; demand-assignment reservation schemes, involving, in particular, pure packet-switched, pure circuit-switched and hybrid-switched integrated-services demand-assignment TDMA and time-division-multiplexing structures; demand-assigned polling procedures; and random-access policies     

802.6 MAN based personal communications network over CATV plants

An infrastructure shared 802.6 MAN based personal communication network(PCN) is to be discussed. Considering the network configurations of CATV and 802.6 MAN based PCNs, a possible architecture is proposed. It is shown that the unidirectional dual buses can be implemented over star topological CATV distribution cable networks with only two cores. The design considerations related to the network capacity and the signaling loads for wireless personal communications are investigated with numerical example. The MAN partitioning is considered to extend the capacity of the network. An analytical method to evaluate the signaling loads of 802.6 MAN based PCNs is presented with a new mobility model. It is shown that the signaling traffic increased by partitioning is not the critical constraint for the feasibility of 802.6 MAN based PCN     

Efficient multicasting and broadcasting in layer 2 provider backbone networks

Ethernet has grown from its roots in LANs to contend in previously unchartered territory of MANs and WANs. A slew of projects underway in the IEEE 802 standards bodies plan to groom Ethernet with carrier grade features like high availability, fault management, and resiliency thus far found only in other circuit-switched technologies. These include, among others, IEEE 802.1ag (connectivity fault management), IEEE 802.1ad (provider bridges), and IEEE 802.1ah (provider backbone bridges). IEEE 802.1ah addresses the service and MAC address scalability of provider backbone bridges. Since Ethernet has been architected and designed for a shared medium, it inherently handles broadcast and multicast traffic very efficiently, unlike layer 3 technologies, where multicasting and broadcasting rely on using multiple point-to-point connections. With IEEE 802.1ah, Ethernet would be able to provide millions of service instances in a provider backbone network. While flooding of frames in a LAN may provide for good multicasting, flooding of data in a MAN or WAN could mean huge bandwidth wastages, especially when the remote peers are geographically distant, and the traffic is not necessarily destined to any of its local ports of the peers. In this article we explore technologies to Address efficient multicasting in provider backbone networks. We also consider extending this technology to address unknown unicast floods and efficient proxy of customer multicast frames.     

城域波分技术的新发展和新应用

城域网是目前通信网络运营商重点建设的网络。城域网基本特征是业务类型的多样化以及业务流向和流量的不确定性．基于丰富的应用需求，各种新技术层出不穷。首先阐述了城域网的现状，重点分析了基于ROADM的城域波分技术的特点和最新进展，并针对不同场景给出了相应的纽网应用，最后对城域波分进行了展望。     

移动宽带无线接入网(MBWA)协议简介

作为一种具有许多新特性的无线城域网,IEEE 802.20协议(MBWA,Mobile Broadband Wireless Access)受到了许多人的关注.虽然该协议还在制定过程中,但其所提出的许多参数和思路符合了下一代移动无线通信系统的发展方向.本文对IEEE 802.20协议进行了简单介绍.     

A cross-layer optical circuit provisioning framework for data intensive IP end hosts

Using circuit-switched optical networks for next generation e-science applications is gaining increasing interest. In such applications, circuits are provisioned for end hosts to accomplish data-intensive or QoS-stringent communication tasks. Existing provisioning methods provide point-to-point connectivity for end hosts, that is, an established circuit connects one end host to another, and during the lifetime of the circuit, only communication tasks between the connected end hosts can be served. This inhibits circuits from being used in more general cases, where each end host communicates with different remote parities simultaneously through a single network interface. We propose V-STONES - a data flow-based VLAN tagging and switching technique to increase the connectivity of end host network interfaces in circuit-switched networks. With V-STONES, not only can an IP end host communicate with different remote systems concurrently through bandwidth guaranteed connections, but also protocol entities at different stack layers can talk to their counterparts through dedicated bandwidth pipes. In this article, we review the existing circuit provisioning methods and then discuss V-STONES and the architecture of cross-layer circuit provisioning for end hosts. We also introduce a prototype implementation in an optical network testbed and present the experimental results.     

如何实现IP城域网的带外管理

本文介绍了IP城域网的带内、带外管理方式,并比较了二者的优缺点。提出一个好带外网管系统的标准,由此引出利用PSTN/企业DCN搭建IP城域网带外管理系统的方案。     

Metropolitan-area networks

Metropolitan-area networks (MAN), which fill the gap between local area networks (LANs) and wide-area networks (WANs), are discussed. MANs were originally oriented toward data, but now often carry voice and video traffic as well. Supplying more bandwidth than LANs, they support two-way communication over a shared medium such as an optical-fiber cable, and may offer point-to-point high-speed circuits or packet-switched communication. The two most favored topologies, double-star and double-ring, are described and emerging MAN protocols are examined     

TELBANK: a telecommunication network for banking system in Poland

A digital telecommunication network, TELBANK, developed and operated by a consortium of Polish banks is described. Four TELBANK subnetworks, i.e., TELBANK-M, TELBANK-T, TELBANK-P, and TELBANK-VSAT are presented. TELBANK-M is a subnetwork offering long-distance transmission channels. TELBANK-P and TELBANK-T are packet-switched and circuit-switched subnetworks, respectively. TELBANK-VSAT is a satellite communication network. Three examples of TELBANK use for connections to external services are also presented     

密集波分复用技术(DWDN)及其在城域网(MAN)中的应用

介绍了波分复用(WDN)的工作原理及其对系统部件的基本要求,讨论述了D-WDN技术在MAN网络中的应用及MAND-WDN光纤环型网络的基本结构和主要特点,认为D-WDN技术与光时分复用(OTDM)技术、光芯复用(OSDM)技术,特别是光集成(OIC)技术、光计算(OC)技术以及神经网络计算(NC：Neuralomputing)技术一样,会得到全面的发展,而且必将迎来全光通信美好的明天。     

Satellite capacity allocation

Several allocation strategies are investigated for sharing the satellite capacity among user communities requiring circuit-switched or store-and-forward (message-switched) communication service. Teletraffic and queueing models are used to obtain analytical results by which the allocation strategies are compared. It is shown that the capacity required to provide a specified grade of service is strongly dependent upon the particular allocation strategy chosen. Therefore, an allocation strategy can be selected which requires less capacity and hence provides more efficient utilization of the satellite capacity for a specified grade of service.     

IP over SDH在城域网中的应用

文章探讨了IP业务在光通信中采用SDH技术进行传输及IPoverSDH技术在宽带信息网中的应用。IPoverSDH是指一组IP/PPP/HDLC协议在同步光纤网上的传输,它提高了点到点之间的传输速率,特别适用于以IP业务量为主的宽带信息城域网或在电信骨干网上疏导高速率数据流。     

Network architecture and signaling for wireless personalcommunications

A distributed microcellular architecture based on the IEEE 802.6 Metropolitan Area Network (MAN) is proposed, and is shown to meet anticipated personal communications service (PCS) needs. A method is presented to calculate MAN coverage in urban areas, and is used to demonstrate coverage of approximately 50 city blocks per MAN. A distributed subscriber database architecture is proposed to facilitate call setup, tracking of roamers and handoffs. To fully utilize MAN bandwidth, a quick method for the heat stations to switch on/off isochronous slots is proposed to facilitate adaptation to PCS traffic level variations. Call setup and handoff procedures are detailed. The PCS signaling overhead is calculated to be 15% of the capacity required to carry voice traffic     

宽带光纤教育城域网项目实例剖析

文章首先对宽带光纤城域网作简要介绍,然后根据宽带光纤城域网项目的建设实例,从项目的需求分析、设计原则、总体规划及分层设计实施等方面进行论述,给出一个较为完整的解决方案。     

建设广电宽带城域网应注意的问题

广电宽带城域网的建设,在广泛调研和交流的基础上,应充分考虑到宽带技术发展的趋势,结合自身的特点,建设具有竞争力和可持续增值能力的符合我国技术规范的智能化网络.