Success Story

Fast, Flexible, Independent: Telemark Offers High-performance Fiber Optic Infrastructure with Open Access in the District Märkischer Kreis

Private persons and businesspeople in the district Märkischer Kreis have a wide-ranging choice in terms of telecommunications providers. The company Telemark Telekommunikationsgesellschaft Mark mbH makes it possible: In contrast to many other companies which were founded after the liberalisation of the telecommunications market, Telemark offer their high-performance and independent network to other telecommunications providers as an open layer-2 infrastructure. Without discrimination, at the same conditions. Quality, reliability, and a sufficient bandwidth of the transmission network are the top priority for the subsidiaries of the Public Services in Lüdenscheid, Iserlohn, and Menden. On the trunk from Iserlohn to Lüdenscheid, however, the fiber optic lines of Telemark are installed at extreme heights: They are led along the high-voltage trunk. This leads to a correspondingly high effort when adding new fiber pairs. The company has now multiplied this limited capacity with wavelength multiplexers of MICROSENS GmbH & Co. KG.

Data Transfer without Discrimination
In the district Märkischer Kreis, people were quick to identify the chances offered by the liberalized telecommunications market offered in the year 1998, and as a result, the Public Services of Lüdenscheid, Iserlohn, and Menden founded the company Telemark. The company bundled the transmission networks, which had been separate ones up to then, and took over the responsibility for the further expansion of this overall network. In addition to telecommunications tasks for the Public Services themselves as well as for the various communal institutions, private persons and companies were also meant to profit from the infrastructure. This was not achieved in the classic way, where all services are set up and marketed on one's  own behalf. Telemark decided instead to provide their own transmission links to other carriers without discrimination. This is a decision is quite a special one on the German telecommunications market and was accepted in a very positive manner by the customers in the district Märkischer Kreis. As a result, they are offered a wide range of options when selecting an appropriate carrier.

Multiplying the Data Transfer
Today, the telecommunications network of Telemark spans more than 260 kilometres of optical fiber. The company in part provides newly created industrial areas and housing estates with fiber optic connections in the building. In other areas, Telekom continues to provide the last mile, which is bridged by the carrier with VDSL vectoring. Here, the backbone connections of the network are primarily installed terrestrially. The trunk from Iserlohn to Lüdenscheid is the exception from this rule. The fiber optic lines are installed over the high-voltage trunk. This is practical in one sense, but the increasing demand for bandwidth presents a special challenge for Telemark: To install additional fibers was not a feasible option in this context. The only possible solution was the application of wavelength multiplexing. The parallel transfer of several wavelengths over a fiber pair makes it possible to reach transmission capacities of several hundred Gigabits per second without the necessity to install additional optical fibers. For Stefan Döbbe, technical director of IT and backbone planning at Telemark, this technology fulfils all prerequisites. In terms of the demanded components, he defined the following requirements:

  • Modularly extensible system
  • Expansion to DWDM possible
  • Central management system

Availability of different building types (HE)

Convincing Quality
Due to the existing business relations to MICROSENS, Stefan Döbbe directly requested the support from the German vendor. The company with headquarters in Hamm/Westphalia does not only fulfil all requirements. MICROSENS convinced Telemark both in terms of the product quality of the WDM components and in terms of the forward-looking consulting for and planning of the CWDM trunk. Both companies quickly came to an agreement: The network connection was implemented with the Optical Transport Platform MSP 1000. The CWDM technology transfers up to 16 independent high-speed services over a mono-mode trunk. The individual channels are transparent for the data transferred. Different service protocols can be transmitted with data rates from 2 Mbps up to 16 Gbps. At Telemark, the systems transport 10 Gbps or 1 Gbps over different wavelengths according to demand. Both STM-1 and STM-4 connections are offered. The backbone was set up in a ring-shaped structure and provides two transmission links each with 20 Gbps each for reasons of redundancy. Stefan Döbbe has identified a decisive differentiation feature in the form of the consulting as to which wavelengths are to be assigned to which service. "A good provider is the one who assigns wavelengths in such a way that they are also able to fulfil the future customer requirements.  This is where MICROSENS provided an absolutely convincing service."

Top Grade in the Field of Service
In total, Telemark was very content with the CWDM solution. Essentially, four carriers are using different services which are transferred over the CWDM backbone. The concept works excellently, and the availability of the trunk also meets the high expectations of Telemark. In part, even under adverse conditions. A wavelength multiplexer with only one height unit had to be installed in a multi-functional casing without air-conditioning. Nevertheless, it worked smoothly and without fault. To be able to detect interferences on the trunk immediately, Telemark additionally monitored the optical fibers via the Optical Power Monitor OM1. This MICROSENS device continuously measures the attenuation of the optical fiber from start to end, detects even minute changes at a threshold value of 0.1 dB, and forwards them to the management system. As in each technical project, there were two minor incidents at Telemark in the course of the past two years, which required the fast support by the vendor. In this context, the benefits of a cooperation with a German company became evident. Fast response times and non-bureaucratic help confirmed Stefan Döbbe in the choice he had made: "In terms of service and support, we award grade 1 again to MICROSENS. The customer support is actually excellent and best practice."


Transmitting information via fiber optic connections offers numerous benefits. MICROSENS GmbH & Co. KG recognised this very early on. As one of the pioneers, the company has developed and produced high-performance communications and transmission systems in Germany since 1993. Individually matched to the demands of diverse usage areas and embedded in comprehensive concepts for individual sectors. But, above all, close to the customer. Technical challenges from customer projects are incorporated directly into product development. This way, IP-based automation solutions are created for modern buildings, cost-efficient network concepts for the office and workspace, robust and fail-safe solutions for industrial environments, optical transport systems future-oriented wide area networks and efficient coupling of sites and computer centres.