ONT-reflection is used, additionally to GPON-EMS, to identify termination points in FTTH-PON-networks. OTN-reflectivity vs. wavelength is investigated. In-service OTDR-measurements from Central Office allow testing PON-branches and to distinguish optical length differences down to 2m.

In recent years, large-scale data centers have continued to be built out as the global Internet traffic has grown exponentially. These include both multi-tenant carrier-neutral ones and private data centers, and host many Internet application servers.

This paper describes the Deutsche Telekom’s access network evolution to support via multiple technologies broadband services to residential and business customers culminating in the current FTTH rollout in Germany.

Local resolution of OTDR-measurements in concatenated PON and in-house networks depending on the reflectance of the demarcation point was investigated. Termination points of the PON from the Central Office with 1m length difference were distinguishable.

Optical fibre step by step substitutes existing copper cable infrastructure in the carriers' access networks, enabling new broadband services. One common approach, a passive optical network (PON) infrastructure, basically consists of optical fibres and splitters, which are lit up by G-PON (Gigabit/s-PON) or XG-PON (10 Gigabit/s-PON). These systems are attenuation limited, therefore the loss budget of a PON is of high importance. For the deployment process the total attenuation of the PON, between Central Office (CO, OLT) and customer site (ONT), must be accurately monitored and kept below the values specified in G.984.x and G.987.x standards. In FTTH scenarios the PON attenuation measurements must include the in-house networks up to the subscriber fibre cable termination unit. During operation, the Optical Line Supervision (OLS) parameters (e.g. G.984.2, Amd2) are continuously monitored, processed and correlated for appropriate alarm generation. In the case of a fibre failure, additionally non-intrusive in-service measurements from the CO site must be supported for fault localisation. This is enabled by an appropriate WDM-filter per PON in the CO, providing access to the PON for OTDR measurements at wavelengths of 1625/1650 nm. In this paper possible solutions for PON measurement and monitoring for the deployment and operation of FTTH networks will be described in detail from a carrier's perspective. All these activities must be carried out in a minimum of time and with low operational efforts in order to guarantee a cost efficient network operation.

In the access network area the optical fibre step by step substitutes the existing copper cable infrastructure in order to enable new services requiring a steadily increasing bandwidth. The optical fibre is capable to transmit significantly higher data rates over longer distances than the copper links. In the next years new architectures like Fibre-to-the-Building and Fibre-to-the-Home will be implemented in the access networks. These fibre links require a monitoring of the infrastructure by the network operator in order the guarantee a high quality of service. The monitoring is necessary during the fibre installation with final test, regular operation of the network and for fault location. The possibilities and particularities of fibre monitoring in transparent optical access networks in comparison to the core network are described. Considering the operational conditions the preferred and suitable solutions from a view point of a network operator are shown and described in detail.

Integration and full interoperability are challenging areas of research in wide area networks today. A European project, MUPBED, has recently concluded and achieved the main result of integrating and demonstrating technologies and network solutions that enable the operation of future European research infrastructures capable of supporting advanced applications. The achieved results are largely valid for any multidomain network scenario. The test network set up by the project is a prototype multidomain optical network able to provide connectivity on demand services across multiple domains directly driven by the applications. Rather than implementing ex novo a unified control plane and replacing existing equipment, the project approach has been to enable seamless interworking of different control planes by means of ASON/GMPLS and standardized network interfaces. This was done in accomplishment of the project target, which was to test and trial a common migration path toward the future European research network that should be followed by national research and education network operators, together with commercial operators. This article describes the main aspects of the MUPBED experience, which by its own peculiar nature provides deep insight into the most recent evolution of control-plane-enabled optical networking toward multidomain integration. Topics covered by the project and briefly related here include network architecture, applications, protocol and control software development, standardization issues, design, analysis and simulation, testing, measurement, and monitoring.

An overview is given of ASON/GMPLS control plane capabilities and opportunities, the current status of standardisation as well as of application -g control plane interworking solutions. Finally examples of practical implementations are highlighted from field trails in the frame of R&D activities up to carrier deployments.

The IST project MUPBED (www.ist-mupbed.eu) has been successfully completed in December 2007. The objectives of the project MUPBED have been centred on the establishment of an innovative, multi-layer and multidomain European test network by means of ASON/GMPLS-enabled networks and on the experimental validation of application scenarios. The key highlights of the last project phase are presented in this paper, including the final pan-European multi-layer and multi-domain network configuration and its successful integration in the OIF Worldwide Interoperability Demonstration 2007.

This paper investigates how the progress in optical communication technologies can contribute to a radical redesign of the Internet, also known as Clean Slate Internet Design. Whilst the initial focus in the redesign efforts still is on the actual architecture and the related protocols on the network layer and above, the technological progress in transport technologies enables radically new topologies and network design principles. Optical technologies are sufficiently mature to be deployed widely to the end customer, overcoming all limits of traditional copper infrastructure. It is shown how optical technologies could lead to radically new solutions for network layout from the core to access and aggregation.

Today's data transport networks are evolving continuously towards customer oriented and application aware networks. This evolution happens in Europe in a highly diverse network environment, covering multiple network domains, layers, technologies, control and management approaches. In this paper, the issues, challenges and the solutions developed in the IST project MUPBED ("Multi-Partner European Test Beds for Research Networking"; www.ist-mupbed.eu) for seamless interworking in a typical European heterogeneous network environment are described, addressing horizontal, interdomain, and vertical, inter-layer topics related to data plane, control plane and applications.

European research networks are often seen as early adopters of new network functions, which is mostly due to their goal to support future looking, highly demanding applications in terms of e.g. bandwidth, availability, or dynamic behaviour. In the IST project MUPBED („Multi-Partner European Test Beds for Research Networking“) ASON/GMPLS solutions for next generation research networks are evaluated and a European scale test network is setup for experimental assessments. This paper gives an overview on the MUPBED ASON/GMPLS network architecture and network solutions, and their relation to the European research networks, enabling seamless multi-domain multi-layer interworking among multiple network domains for supporting new, upcoming applications. The paper also describes the implementation of the pan-European MUPBED test bed and how this test bed allows to investigate the developed networking concepts in a field trial environment.

Optical systems and technologies have been radically changing the telecommunication networks for past 15 years; today wavelength division multiplexing (WDM) technology, optical amplifiers, and simple optical switching elements like optical add-drop multiplexers (OADMs) are used in the backbone networks of all operators worldwide. Optical systems nowadays provide the basis for cost-effective transmission of large amounts of bandwidth over the Internet, and will enable its future growth and the spreading of new applications and services. This paper summarizes the main trends in optical networking and investigates potential future application areas. Optical system technology has become so pervasive in network design that it needs to be considered in the context of provisioning new applications and services. Therefore, the analysis is not limited to the aspects of physical transmission, but also takes into account recent developments in integrated network design as well as network control and management. The following sections describe the key functionalities of future optical network architectures, and the key findings of the theoretical analysis are supported by the results of a field trial of advanced transmission technology

IST project MUPBED has setup the first pan-European ASON/GMPLS test network based on five heterogeneous network domains and interconnections over the European NREN/GEANT2 networks. Seamless multi-domain interworking solutions and two worldwide first interworking demonstrations have been achieved.

This article reports on the continuous activities of Deutsche Telekom in setting up comprehensive ASON/GMPLS network demonstrators. The goal is to enable practical evaluations and early experiences with prototype implementations related to new standards and specifications from ITU-T, IETF, and OIF. Evolving from the GSN Demonstrator toward the current GSN+ Demonstrator configuration, this field testbed comprises ASON/GMPLS-based backbone network domains, as well as key client networks such as IP, Ethernet (metro and access networks), Storage area networks, and broadband video applications to exemplify the wide range of network functions enabled by these new technologies. These ASON/GMPLS demonstrator activities were embedded in the OIF World Interoperability Tests and Demonstration in 2004, and are linked with the German national (VIOLA) and pan-European (MUPBED) project activities ensuring the highest level of interoperable implementations.

In this paper, PMD measurements that were carried out in the installed fiber plant of Deutsche Telekom, which consists solely of G.652 fiber, are presented. The measurements are performed all over Germany during the last three years on nearly 10,000 fiber sections whereby these fiber cables were installed from 1985 to 2001. It should be noted that pre-1994 cables PMD was not yet specified by cable manufacturers and PMD specification were only added around 1995. Fibers with lowest PMD were identified and reserved for high capacity transmission. The data indicate that no direct correlation of the first-order PMD coefficient value with the rollout of the PMD specification by the fiber and cable manufacturers is feasible. Even for cables which were installed during 1985 till 1991 a reasonable number of fibers is suitable for 40 Gbit/s transmission. For 10 Gbit/s selected fibers are used, thus PMD does not impose any limitations and therefore avoiding expensive exchange of fibers.

A carrier grade demonstrator, composed of an automatic switched transport network backbone, the main ASTN clients (IP, Ethernet), an integrated upper monitoring system, and broadband applications covering a realistic end-to-end network scenario is presented.

The Global Seamless Network (GSN) Demonstrator is presented, a joint effort of system vendors and Deutsche Telekom Group R&D to demonstrate network functions and management integration and enable, for the first time, experiences with a carrier grade Automatically Switched Transport Network (ASTN) implementation and the envisaged main ASTN clients, IP and Ethernet. For end-to-end monitoring capability, integrating the view on the ASTN and Ethernet-MAN configuration, an UMS (Upper Monitoring System) is being developed. Furthermore broadband application were implemented to visualise the network functions. The ASTN backbone consists of four cross connects and an ULH-WDM system with 3x 10Gbit/s channels (OCh) between Berlin and Darmstadt, whereby each OCh is treated as a virtual fibre.