Faster surfing in the Black Forest

Network modernisation in Simonswald

The population in and around the Baden-Württemberg municipality of Simonswald near Freiburg is set to get faster internet. The previous antenna equipment on the mobile phone towers was no longer up to the job. Deutsche Funkturm GmbH (DFMG) has engaged FUCHS Europoles to carry out a network modernization. Since the old mobile phone tower is at full capacity, a new tower will be installed next to it with the structural capability to support the new antenna equipment.

The network will be upgraded gradually

Deutsche Funkturm GmbH plans, realises and markets antenna supports and equipment carriers, e.g. on towers, roofs or mobile phone masts. To this end, its radio network planners travel around Germany testing the reception in various areas. They decide in which regions reception should be improved and send site acquisition agents to look for suitable sites and negotiate with the owners. At the same time, DFMG seeks customers to rent these locations: They include German network operators Deutsche Telekom, Vodafone and O2 as well as official agencies and amateur radio associations.

Several providers transmit from one tower

Distributed over several platforms, an antenna supporting pole can be fitted to the tower every 15 degrees. This means that generally, several providers share a tower. “It's all a question of statics. The towers are built to be structurally sound depending on the load, either in steel or spun concrete,” explains Wolfgang Weiss, the project manager responsible for Bavaria and Baden-Württemberg at the Infrastructure, Network Modernisation and Network Expansion Division of FUCHS Europoles. However, sometimes an older tower is not designed to meet the new requirements.

Tower swap

This was the situation in Simonswald. If a tower has to be swapped, first and foremost the network technology is modernised and/or upgraded. In the process, the new tower is placed next to the old one and the system technology prepared as far as possible. On a specified date the system is then taken off the network for a few hours. “The prepared cables are then connected to the new system technology in the switch cabinet. Once everything has been tested and is working, the new system can go onto the network,” says Weiss. Until this happens the old tower continues to operate as usual. Customers are informed by their network operators in advance when the old system will be finally disconnected and the new one operational. During this period there is a brief period of radio silence before people can then surf the internet faster than ever.

quotation-mark

Up on the hill there was virtually no room next to the old tower. We had to build the new foundation as close as 50 cm to the old one.


Wolfgang Weiss

Construction Manager, Infrastructure (radio network modernisation and expansion)

FUCHS Europoles GmbH

Restricted space

Because on the other side they were hitting sheer rock after just half a metre. The first step was then to dig out the old foundation and reinforce it to ensure stability during the building works. The 50 m high new mobile phone tower also had to be custom made. “Generally our standard towers consist of three sections that are joined together with flange plates. In this case we produced a tower in four parts, so that it could be transported up the hill in the first place,” recalls Weiss.

Replacing the switch cabinet

Within a week the tower had been erected, the antennae mounted and aligned, the cable laid and the system technology connected in the switch cabinet next to the base of the tower. “That was the next challenge, because there was definitely no room for both the old and new switch cabinets up there,” explains Weiss. So the old switch cabinet was removed there and then by crane to a nearby forest path. The length of the cable allowed the old system to be reconnected to the network until the new one had been prepared.

Approval process and soil report

Swapping a tower requires a certain lead time. District offices or municipalities have to approve the building application, while departments like nature conservation authorities or water management bodies need to approve the tower location – and they sometimes impose additional requirements to be met. “At times we had to do a count of the lizard population, hang up bat boxes or renovate a playground,” Weiss recalls. If there is an airport in the vicinity, air traffic control gets involved. If necessary an aircraft warning light will have to be fitted to the top of the tower, i.e. in the form of a beacon or aircraft warning paint.

Following approval for construction the soil conditions are investigated. An expert soil surveyor will produce the soil profile and suggest a preferred type of foundation. Sometimes it is possible to work with just a driven casing pipe that goes several metres into the ground and has just a slightly larger diameter than the mobile phone tower itself. In other cases the foundation has to be reinforced, e.g. if the soil is sandy or peaty. This also depends on the specified tower height that was calculated for the area, which is generally between 10 and 60 metres. Our own Structural Analysis and Engineering Department calculates the most economic foundation based on the soil report and the structural analysis of the tower.

Factory preassembly

Before the tower is put in the upright position, everything is mounted that makes it easier to fit it with the antennae afterwards: Before transport, the antenna support poles are bolted onto the horizontally-positioned tower, so that all that needs to be done later is to mount the antennae themselves and undertake the precision adjustment.

Cranes help to raise the tower, which is then aligned vertically using winches at the base. The tower sections are joined using flanges and the platforms are put over the top of the tower using the crane. The beam direction of the antennae is then set according to the diagram; the precise alignment is prescribed by the German Federal Network Agency.

If transmission is good it's all good

The connection is working smoothly and the new mobile phone tower has been operating since October 2017. Telekom and Vodafone are already using the new network. This project took a total of six months. The tower is now transmitting on an LTE frequency spectrum of 1800 and 2600 megahertz, which allows a transfer rate of up to 100 megabits per second, resulting in faster surfing in the internet.

Technical details


Project duration

July / August 2017


Project scope

Tower swap


Details

  • Four-part special tower
  • Height: 50 metres
  • Weight: 64 metrical tons
  • Diameter at base: 1,740 millimetres; at crown: 768 millimetres
  • Mobile phone networks: D1, D2, O2

Further information

Project participants

DFMG Deutsche Funkturm GmbH 

Radio masts and towers