Soliton transmission in telecommunication networks

Erbium-doped fiber amplifiers are a major breakthrough for soliton communication. Most of the difficult problems preventing soliton communication recently were solved using erbium-doped optical fiber amplifiers (EDFAs). Progress in optical soliton communication has been very rapid, since the invention of the 1.48 μm laser diode pumped EDFA, mainly because of its great potential for high-speed communication. This article describes how optical soliton communication has been established, together with the recently developed "soliton control" technique     

Future trends in digital telecommunication transmission networks

New technology is needed by digital transmission networks for the increased bandwidth, performance and reliability requirements of existing and future telecommunication services, such as broadband ISDN. Increased flexibility, automation and control are also major issues being addressed. The combination of these factors has led to the development of synchronous digital hierarchy (SDH) networks to replace existing asynchronous networks during the 1990s. These issues are reviewed and further developments to bandwidth-transparent optical networks indicated for the twenty-first century     

Evolution of optical core networks

Optical networks have developed rapidly over the last ten years and show every sign of continuing to grow and adapt to the newchallenges of supporting more traffic, more reliably and flexibly, at lower cost. We briefly review the developments of the last tenyears and then discuss current thinking on how core optical networks will develop into the future, exploring the similarities anddifferences with the previous generation of technologies. We have attempted to provide a low-jargon paper with links to moredetailed studies where appropriate.     

Evolution of optical core networks

Optical networks have developed rapidly over the last ten years and show every sign of continuing to grow and adapt to the new challenges of supporting more traffic, more reliably and flexibly, at lower cost. We briefly review the developments of the last ten years and then discuss current thinking on how core optical networks will develop into the future, exploring the similarities and differences with the previous generation of technologies. We have attempted to provide a ‘low-jargon’ paper with links to more detailed studies where appropriate.     

Number portability for telecommunication networks

Number portability is a telecommunication network function, which allows subscribers to switch services, service providers, or locations without changing their telephone numbers. Near-term number portability is typically implemented by existing telecommunication services such as remote call forwarding. Long-term number portability can be implemented under the advanced intelligent network (AIN) platform. This article focuses on the routing issues for number portability. We introduce the number portability issues and provide a tutorial on the AIN. We then show the AIN implementation for long-term number portability. Finally, a cache approach is proposed to speed up address transfer, which can effectively reduce the network overhead incurred by AIN query for number portability     

光网络传输技术在电信网中的应用分析

随着我国社会和经济的持续发展,我国电信行业发展的也越来越快,所使用的光网络传输技术在电信网络中也发挥着越来越重要的作用.这种传输技术具有非常多的优势,不仅能够大大降低数据的运输成本,而且还能在很大程度上增强电信网络的传输速度.文章详细的介绍了光网络传输技术的特点,同时对光网络传输技术在电信网络中发挥的作用进行了分析,指出了其中不足的地方,并且制定了相应的解决方案对光网络传输技术进行相应的完善和优化,从而促进我国电信事业能够更好、更快的发展,同时也为相关人员以后的网络传输工作提供了有价值的参考依据.     

Programming telecommunication networks

The move toward market deregulation and open competition has sparked a wave of serious introspection in the telecommunications service industry. Telecom providers and operators are now required to open up their primary revenue channels to competing industries. The competition for product differentiation increasingly depends on the level of sophistication, degree of flexibility, and speed of deployment of services that a future provider can offer. These factors in turn depend heavily on the flexibility of the software architecture in place in a provider's operational infrastructure. Within this context, we examine the service architecture of two major global communication networks-the telephone network and the Internet and explore their weaknesses and strengths. We discuss the realization of an open programmable networking environment based on a new service architecture for advanced telecommunication services that overcomes the limitations of the existing networks. Our approach to network programmability stems from two angles-one conceptual, the other implementational. In the first, we attempt to develop a service model that is open and reflects the economic market structure of the future telecommunications service industry. Furthermore, we introduce an extended reference model for realizing the service marketplace and present it as a vehicle for creating multimedia services with QoS guarantees. In the second, we investigate the feasibility of engineering the reference model from an implementation standpoint. We describe a realization of the open programmable networking environment as a broadband kernel. Called xbind, the broadband kernel incorporates IP and CORBA technologies for signaling, management, and service creation, and ATM for transport. We also address some of the important QoS, performance, scalability, and implementation issues     

Predictive autonomic transmission for low-cost low-margin metro optical networks

Photonic Network Communications - Low-cost low-margin implementation plays an essential role in upgrading optical metro networks required for future 5G ecosystem. In this regard, low-resolution...     

Topology estimation method for telecommunication networks

In order to resolve the traditional limited lifetime problem, energy harvesting technology has been introduced into wireless sensor network (WSN) in recent years, engendering a new kind of network which is called energy harvesting wireless sensor network (EHWSN). In EHWSNs, besides the traditional issues, such as energy consumption, energy equilibrium, transmission efficiency, etc., there are still new challenges, such as how to utilize harvested energy efficiently and how to make more sensor nodes so as to achieve unlimited lifetime under actual situation. In this paper, inspired by slime mold Physarum polycephalum, a novel bionic routing protocol, abbreviated as EHPRP, is proposed for EHWSNs to address above problems without predicting harvestable energy value. Three distributed routing algorithms with low algorithm complexity are proposed which would prominently reduce the processing delay and conserve energy. Furthermore, the mathematic theoretical analysis is made to prove the stability of EHPRP routing strategy. Finally, simulation results present that, compared with other typical algorithms, EHPRP consumes less energy, always making the whole network obtain an unlimited lifetime, and displaying more uniform network energy distribution under different workload conditions.     

Future optical fiber transmission technology and networks

The authors contend that optical system developments, which so far have followed a straightforward and logical path from direct link replacement to the proposed transwitching networks, will evolve towards passive (fiber-only) networks that could ultimately see the eradication of the central office. To explain this view of the future, they briefly trace optical system developments to the present day before citing the technology developments that have led them to the conclusion. They discuss present network and technology trends, focusing on the reduction of the amount of electronic hardware, the disappearance of bandwidth efficiency as an important factor, and the state of the optical network today. They then turn to the future network and technology, showing how the central office can be dispensed with by operating the network on a radio mode, with each terminal assigned a specific frequency     

Wavelength reused upstream transmission scheme for WDM passive optical networks

A novel technique facilitating wavelength reused upstream transmission in a WDM passive optical network, eliminating wavelength source at ONUs, is proposed and experimentally demonstrated. A subcarrier frequency is used for downstream transmission and the pure optical carrier is filtered and reused for upstream transmission. The scheme requires only simple baseband receivers at both ONU and OLT terminals.     

A distributed software architecture for telecommunication networks

The authors present an overview of the major principles and concepts of the INA architecture, describe the requirements imposed by telecommunications applications on a software architecture for such applications, and outline the major principles of the INA architecture and how these principles meet the requirements of telecommunications applications. They also describe the services provided by the distributed processing environment (DPE), which provides the infrastructure for distributed applications, the use of the architecture concepts in a specific application, and the status of the INA laboratory experiments and field trials currently under way     

A new reliability measure for telecommunication networks

A new reliability measure is introduced. The measure takes into account service degradations once the network is disconnected. A network retailer can use this measure to choose an optimal set of paths such that the desired compromise between cost and reliability is achieved.     

An algorithm for configuring embedded networks in reconfigurable telecommunication networks

This paper considers a problem of configuring logical networks by employing a self-planning facility in a telecommunication network carrying voice-grade calls to make the least-cost configuration where the involved system cost includes hop cost and lost-call traffic cost. The hop cost depends on the number of self-planning facilities included on routing path connecting the associated node pairs, while the lost-call traffic cost is incurred due to link capacities. The configuration problem is analyzed through dimensioning and routing on a reconfigurable network in a mixed 0/1 nonlinear programming approach for which lower bounds are found by Lagrangian relaxation embedded in a hybrid search procedure for the associated dual problem. Heuristic solution procedures are exploited and their efficiencies are tested with various numerical examples.     

XCP-based transmission control mechanism for optical packet switched networks with very small optical RAM

According to a famous rule-of-thumb, buffer size of each output link of a router should be set to bandwidth-delay product of the network, in order to achieve high utilization with TCP flows. However, ultra high speed of optical networks makes it very hard to satisfy this rule-of-thumb, especially with limited choices of buffering in the optical domain, because optical RAM is under research and it is not expected to have a large capacity, soon. In this article, we evaluate the performance of our explicit congestion control protocol-based architecture designed for very small Optical RAM-buffered optical packet switched wavelength division multiplexing networks with pacing at edge nodes in order to decrease the required buffer size at core nodes. By using a mesh topology and applying TCP traffic, we evaluate the optical buffer size requirements of this architecture and compare with a common proposal in the literature.

Alternative multiplexing and transmission strategies forinteroffice optical networks

A fundamental multiplexing and transmission issue associated with interoffice optical transmission-how traffic originating in one central office (CO) and terminating in another should be handled at intermediate sites-is addressed. Using specific network examples, as well as a general analysis of linear chains of COs, major quantitative and qualitative differences between two alternative strategies are identified. The relative difference in installed first costs between the strategies is further evaluated in terms of their sensitivity to cost trends in fiber and electronics. The general conclusion drawn is that based on several criteria such as relative first cost, uniformity of fiber cross sections, optical repeater requirements, and applications of efficient high bit rate multiplexers, a cascaded multiplexing strategy is preferable to a dedicated multiplexing strategy. However, where route growth and diversity are primary considerations, dedicated multiplexing is more economical on a first-cost basis     

Revenue optimization of telecommunication networks

The optimal routing and dimensioning of circuit-switched networks operating with call revenues is examined, and F.P. Kelly's (1988) model is extended in two directions. First, the formulation is transformed in such a way that the optimality equations are significantly easier to derive, and another interpretation of Kelly's induced costs is given. Alternative routing is introduced, the corresponding values for the induced costs and the net path revenue are given, and it is shown that the optimal routing is given by an equal-revenue rule. It is also shown that the dimensioning aspect is easily decomposed into individual link dimensioning problems if the fixed-point multipliers are known. Some results for networks operating with state protection are presented to show that the method also works quite well for networks with heterogeneous traffic     

Alarm driven supervision for telecommunication network: I - Off-line scenarios generation

The use of model-based reasoning techniques allows the needed supervision knowledge to be acquired in a more systematic, robust and evolutive way than expertise. Nevertheless, one of the main problems is that the combinatory complexity associated with model-based techniques rarely satisfies real-time constraints of supervision system. We propose a supervision system for telecommunication networks based on the offline generation of temporal sequences of alarms (scenarios or chronicles), and the on-line recognition of these sequences. We present here only the first part of this system: the off-line generation which is necessary in order to reduce the computing time during the on-line supervision. It relies on a structural and functional model of the network, and takes into account the temporal constraints linked to alarm propagation and the probability of loss of these alarms.     

光缆传输设备集中监控网管系统简介

着重阐述了光缆传输设备集中监控系统的工作原理、系统功能及网络结构，并结合本局实际情况提出了接入该系统的实现方式。     

传感信号在接入网中传输的技术分析

文章提出了光纤通信网与传感网融合的设想,即利用已有光纤接入网的通信信道,让传感网络发出的传感信号在光纤接入网中传输.首先分析了这种设想的可行性,然后提出了按固定帧复用的方式对传感信号和通信信号进行耦合,并根据已有光纤接入网的结构建立了该系统的网络基本结构,重点分析了传感信号与通信信号复用时的时隙及带宽分配问题.