Siemens ICN (Information and Communication Networks) is a leading supplier of technology for communication networks for ordinary customers on the one hand and telecommunication companies and service providers on the other.

The extensive portfolio covers classic telephone networks as well as convergence solutions for speach and data which are based on the internet protocol (IP). The offer covers a general solution range for broadband access, optical transport nets and extensive service provisions for network users. With this Siemens offers complete solutions from one source for the infrastructure of highly modern communication networks, which are called Next Generation Networks.

For the network user Surpass is the Siemens communication platform software and hardware, which links both large worldwide networks, the telephone network and the internet network with all their advantages. Networks which are run with this technical solution correspond to the demands for high quality by the network users and make it possible for them to migrate from the classic TDM networks to the IP based networks.

For network users to bring their networks up to the latest technical standards with Surpass, enclosure cabinets are required not only to possess certain technical properties, but to correspond to the varying standards of the worldwide markets.

The two main demands are: high EMC shielding and safety during earthquakes. Apart from that, Siemens ICN demands certain product features which enable a structured integration of components into the enclosure in a simple and unified manner.

To realise the enclosure concept (Picture 1) Siemens relied on a partner of many years, Schroff GmbH in Straubenhardt. Together a so-called "Technical Delivery Obligation" was created, which contains all demands on Schroff. This does not only concern the delivery of empty cabinets, but also the integration of a breaker panel including power distribution, i.e. corresponding power inputs, network input filters as well as the pre-cabling between the automatic fuses and the OEM appliances according to the power supply plans. The cabinets are delivered to the manufacturing plant of Siemens in Bruchsal by Schroff for the installation of the active components, of which the SUN server is part.

During the course of cooperation the technical delivery obligation changed again and again, partly on account of new demands from Siemens' customers and partly due to new worldwide guide lines, laws and EU standards. Both sides contributed their know-how and the final catalogue of demands emerged during the project work with Schroff. Due to their fast and non-bureaucratic manner Schroff have been confirmed as the right choice of cabinet supplier.

The most suitable cabinet is the HF version of the eurorack from Schroff. This has the assembly required by Siemens in respects of EMC shielding as standard. The top cover construction of the cabinet was equipped with a specifically requested modification for shielded versions and filters on the power inputs.

In contrast to the standard version additional heat dissipation from the cabinets was demanded. When the cabinet is equipped with 20 to 22 servers (Picture 2) this results in a lot of heat and additional cooling facilities have to be provided. The servers used are cooled horizontally, i.e. they suck in air at the front and expel it at the rear with fans. The doors, which cover the cabinet at the front and rear were equipped with corresponding perforations, without the loss of stability of the cabinet. The possibility of an active cooling system was taken into account, but heat measurements at Siemens showed that the optimum perforation of the cabinet doors was sufficient.

Surpass is used worldwide and in particular in the Asiatic and American regions the safety during earthquakes if especially important.

Generally the eurorack cabinet in an upgraded version is certified as earthquake proof, but the demands by Siemens were higher: The cabinet had to withstand an earthquake to the scale of 8. Major forces are at work that last for approx. 30 seconds and cover various levels. With a fully assembled cabinet with a weight of approx. 400 kg, a relatively small base of 600 mm x 700 mm and a height of 2200 mm, forces would be activated which could lead to the damage of the cabinet structure. In order to withstand these conditions, the stability of the cabinet had to be improved and this without a considerable increase in the total weight and manufacturing costs, if feasible. An additional strengthening cross at the rear of the cabinet (Picture 3), other materials and manufacturing processes for the basic frame achieved the desired result.

The customer was clearly to recognise the Surpass cabinet as a Siemens product. Other cabinets manufactured by Siemens were manufactured in stainless steel throughout and had a specific design with additional colours and logos. The eurorack cabinets had to be adapted to this optical appearance. A finish and colours were chosen which came very close to the Siemens corporate design.

A complete Next Generation Networks solution depending on the demands by the carriers usually consists of several cabinets: At the Siemens factory in Bruchsal all cabinets are pre-assembled. The complete hardware and software is assembled in the Surpass and then extensive testing is carried out. Packed in horizontal transport packaging the fully assembled cabinets reach the customers, where highly trained experts will start the installation and "go live".