Faster surfing in the Black Forest

Around the Baden-Württemberg municipality of Simonswald near Freiburg, the population is to be equipped with faster internet. The previous antenna equipment of the mobile phone mast is no longer sufficient for this. Deutsche Funkturm GmbH (DFMG) commissions FUCHS Europoles to modernize its network. Since the old mobile phone mast is working at full capacity, a new mast is being erected next to it, which has grown statically to accommodate the new antenna equipment.

The network is gradually being upgraded

Deutsche Funkturm GmbH plans, implements and markets antenna support and technical areas, for example on towers, roofs or mobile phone masts. For this purpose, radio network planners are on the move all over Germany and check the reception. They decide in which regions the reception should be improved and send recruiters who look for suitable locations and negotiate with the owners. At the same time, DFMG is looking for customers who rent these locations: These include the German network operators Deutsche Telekom, Vodafone and O2 as well as government and amateur radio.

Several providers transmit from one mast

Distributed on several platforms, an antenna support tube can be attached to the mast every 15 degrees – so several providers usually share one mast. "It's all a question of statics. Depending on the load, the masts are built to be stable, either from steel or from spun concrete," explains Wolfgang Weiss, the site manager responsible for infrastructure, network modernization and network expansion at FUCHS Europoles for Bavaria and Baden-Württemberg. However, sometimes an older mast is not designed for the new requirements.

Mast exchange (SWAP)

This is also the case in Simonswald. When the mast replacement (SWAP) becomes necessary, the network technology is primarily modernized or upgraded. The new mast is placed next to the old one, and the system technology is prepared as far as possible. On a specified date, the system then goes offline for a few hours. “Then the prepared cables are connected to the new system technology in the control box. When everything has been checked and is working properly, the new system can be connected to the grid" says Weiss. Until then, the old one will continue to run. Customers are informed in advance by their network operator when the old system will be finally switched off and the new one will be connected to the network – during this period there is a brief radio silence before surfing is then all the faster.

Cramped conditions

Because: On the other side, after almost half a meter, they came across bare rock. The first step was to dig up and reinforce the old foundation to ensure stability during the construction work. The 50 meter high new mobile phone mast also had to be custom-made. “As a rule, our standard masts consist of three parts, which are then assembled with flange plates. Here we produced the mast in four parts to make it possible to transport it up the mountain at all” Weiss remembers.

Exchange of switch boxes

The mast is erected within a week, the antennas are mounted and aligned, the cables are laid and connected to the system technology in the switch box next to the mast base. "That was the next challenge, because the old and the new control box definitely didn't fit up there together" explains Wolfgang Weiss. So the old switch box was quickly transported by crane to a nearby forest path. The cable length allowed the old system to be brought back online until the new one was ready.

Approval and soil survey

A mast replacement needs lead time. District offices or responsible municipalities must approve the building application, specialist departments involved such as nature conservation authorities or water management authorities the mast location – sometimes under additional conditions. "We had to have lizards counted, put up bat boxes or renovate a playground" Weiss remembers. If an airport is nearby, air traffic control intervenes. If necessary, obstacle lighting must be attached to the top of the mast, i.e. signal lights or obstacle painting.

After the building permit, the ground conditions are checked. A soil expert creates the soil profile and suggests a preferred foundation variant. Sometimes all that can be done is a ram pipe that reaches several meters into the ground and is only slightly larger in diameter than the cell tower itself. In other cases, the foundation must be reinforced, for example in sandy or peaty soils. This also depends on the default mast height calculated for the area; their standard is between ten and 60 meters. The in-house statics and technology department calculates the most economical foundation based on the soil report and the mast statics.

Pre-assembly at the factory

Before the mast goes into the vertical position, everything is assembled to make it easier to later equip it with the antennas: the antenna support tubes are screwed onto the lying mast in the factory before transport; then later only the antennas themselves have to be mounted and the fine adjustment made.

Cranes help set up. The mast is aligned vertically with the help of winches at the base of the mast. The mast parts are assembled with flanges, the platforms are put over the top of the mast by a crane. Then the radiation direction of the antennas is made according to the plan. The Federal Network Agency specifies the exact alignment.

Send good, all good

The connection works without problems. The new mobile phone mast has been in operation since October 2017. Telekom has been broadcasting since the beginning, and Vodafone also went to the new network in December 2017. All in all, this project took half a year. The mast now transmits on an LTE frequency spectrum of 1800 and 2600 megahertz, which allows a transmission rate of up to 100 megabits per second and thus fast surfing on the Internet.


Location: Simonswald, Baden-Württemberg
Execution period: July 2017 to August 2017

  • Mast exchange
  • Project participants: DFMG Deutsche Funkturm GmbH
  • Special mast: 4 parts
  • Height: 50 meters
  • Weight: 64 tons
  • Diameter at the base: 1740 Millimeter
  • Diameter at the top: 768 Millimeter
  • Networks: D1, D2, O2