Modern buildings strongly shield mobile phone signals. Energy-efficient facades, metal-coated windows, reinforced concrete, and deep building structures attenuate the radio signal to such an extent that coverage from the public mobile network is often insufficient indoors. This results in dead spots, unstable connections, and limited mobile communication, even in areas with good outdoor coverage.
Since mobile processes, accessibility, security, and many IoT applications rely on reliable mobile communications, in-house mobile coverage is becoming a key infrastructure issue. Especially in complex or heavily frequented buildings—from office complexes to underground parking garages to industrial halls—natural coverage from the public mobile network is insufficient and must be specifically improved.
What does in-house mobile communications mean?
With in-house mobile coverage, the public mobile signal is fed into the building in a controlled manner and distributed via an internal distribution network. Users can therefore continue to make calls and communicate via their usual networks (Telekom, Vodafone, Telefónica), but with reliable coverage. This also applies to building cores, adjoining rooms, and basements.
Unlike unauthorized mobile phone repeater solutions from specialist retailers, professional in-house mobile phone coverage is a system that has been planned and approved in accordance with telecommunications regulations and network operator specifications. This provides the building with a stable, legally compliant mobile phone system for all users.
Complementary technologies
FMB-E provides comprehensive support for in-house mobile communications projects—from analysis and planning in accordance with network operator standards to installation and final commissioning.
As a neutral host, we act as the central interface between the customer, planning participants, and mobile network operators. As part of the initial analysis, we check signal levels (dBm values), reception quality, and coverage quality in all areas of the building—including underground parking garages, stairwells, and technically challenging areas.
We evaluate building-specific attenuation, usage scenarios, and requirements in order to identify factors relevant to planning at an early stage. Building materials such as reinforced concrete, metal-coated glass, or solid ceilings can significantly weaken mobile phone signals.
The findings derived from this form a reliable basis for the preliminary concept, dimensioning, and technical design of the in-house mobile communications coverage.
Radio coverage is planned digitally and in accordance with network operator standards. The iBwave planning tool and 3D modeling are used to precisely simulate antenna positions, cable routes, coverage areas, and coverage forecasts.
Frequency specifications and requirements of all participating network operators (GSM, UMTS, LTE, 5G) are taken into account. FMBE plans LTE- and 5G-capable structures and designs the passive infrastructure to support future frequencies and capacity requirements.
The feed-in of mobile phone signals is subject to approval and must be coordinated with the network operators. We support building owners and TGA/project managers in technical discussions with network operators.
Our tasks include:
In this way, we ensure in-house mobile communications planning that complies with network operator requirements.
FMB-E implements the passive mobile communications network in the building, consisting of cable routes, antenna points, and distribution structures. The infrastructure is prepared in such a way that the network operator's active technology (e.g., BTS, 5G system technology) can be seamlessly integrated at a later date.
These include:
The entire system is fully documented—including measurement reports from RF and fiber optic measurements, planning documents, and installation details.
Measured signal values confirm the quality of coverage in all areas. Final handover takes place to operators, IT teams, or facility management.
Maintenance & operation of your in-house mobile communications coverage
A professionally installed mobile communications system requires regular maintenance to ensure long-term reliability. FMB-E offers maintenance contracts that include periodic inspections, measurements, and, if necessary, adaptation of the system to new frequencies or network operator specifications. This ensures long-term mobile communications reception and avoids costly outages.
A professionally planned interior supply system not only eliminates supply gaps, but also creates an infrastructure on which modern work and communication processes can function reliably.
The main advantages of a properly implemented in-house mobile network are:
The mobile signal is fed into the building via defined interfaces from the public mobile network. Depending on the size, use, and location of the property, two scenarios are used: For smaller properties, an outdoor antenna is usually mounted on the building, which receives the operator's signal and transmits it via fiber optic cable to a repeater inside the building.
If the repeater's performance is insufficient, a base station is used instead – the feed is then provided via a directional antenna instead of the outdoor antenna. In both cases, the aim is to provide a stable, powerful signal source as the basis for the entire in-house supply.
The choice of active technology depends on the size of the building, the intensity of use, and the specifications of the network operators involved. As a rule, base stations are installed in a dedicated technical room for this purpose, which process the fed-in signal and transfer it to the distribution network in a controlled manner.
At the same time, the mobile communications standard to be used is a key planning issue: While LTE is currently considered the minimum requirement in most properties, 5G is becoming increasingly relevant with data rates of up to 10 Gbit/s and very low latency values—especially where IoT systems, machine communication, or data-intensive applications such as telemedicine are used. GSM and UMTS are included in the planning if the network operators require this for their network.
The repeater or base station distributes the signal via splitters to decentralized service antennas inside the building. An internal distribution network consisting of coaxial or fiber optic cables transmits the signal to the designated antenna points, whose positions are precisely planned using iBwave. The antennas form internal mobile radio cells that ensure uniform coverage without overlaps or gaps. It is important to note that the hardware must be operator-independent and broadband-capable so that the building meets the requirements of all network operators. The systems support all required mobile radio frequencies—GSM, UMTS, LTE, and 5G—and can be expanded depending on the design.
A stable indoor mobile communications supply is important wherever mobile communications or digital processes must function reliably. Especially in complex buildings or areas with high usage intensity, outdoor coverage alone is not sufficient. Typical areas of application include:
Complex floor plans, glass facades, and reinforced concrete cores significantly reduce natural signal strength. However, employees and visitors expect reliable mobile reception on every floor and in every meeting room.
Machine communication, IoT systems, and mobile devices require stable connections. The object radio solution connects all frequency standards and also supports 5G campus networks as a supplement to in-house coverage.
Scanners, warehouse technology, and mobile work processes rely on robust mobile communications connections. Large halls with metal roofs or high racks are classic problem areas for mobile reception.
Accessibility and communication security are particularly important here. At the same time, mobile phone systems in hospitals must be EMC-compliant and must not interfere with medical devices.
Underground parking garages are classic dead spots: the ground and concrete ceilings shield mobile phone signals almost completely. At the same time, the need for mobile phone reception in underground parking garages is increasing due to parking guidance systems, emergency calls, and mobile payment systems. FMBE plans and implements mobile phone coverage even in these challenging areas.
High traffic and the highest guest expectations require reliable network coverage in every corner of the building—from the hotel lobby to the wellness area.
The first step is a structured assessment: FMBE analyzes the supply situation in the building, evaluates structural damping, and works with you to clarify usage requirements and project goals. Based on this, we create a preliminary concept with a realistic assessment of the technical possibilities and expected costs. Only then do we move on to concrete planning and coordination with the network operators, step by step, until commissioning.
The clear recommendation: as early as possible and ideally in parallel with the design or approval planning. After all, anyone who has to integrate in-house supply into a finished building at a later date will pay significantly more and have less leeway in terms of cable routes, technical rooms, and antenna positions.
The most important factor in determining the right time to start is whether decisions have already been made about building materials, facade types, or floor plans—these directly influence the attenuation situation in the building. Planned underground parking garages, publicly accessible areas, or specific tenant requirements for mobile phone coverage should also be incorporated into the planning at an early stage.
FMB-E gets involved in every phase of the project—the earlier, the more can be designed instead of just reacting.
No. Repeaters that amplify the public mobile phone signal require a license in Germany and may not be operated without permission. Uncoordinated or freely purchased repeaters can:
The Federal Network Agency actively takes action against unauthorized repeaters. A professional in-house solution is essential for stable, legally compliant indoor coverage.
No. The feed-in of the mobile phone signal is always subject to approval and is only authorized by the mobile network operators (Telekom, Vodafone, Telefónica). FMB-E takes care of this coordination and clarifies technical questions as a partner.
No. Wi-Fi is intended for local data transmission and does not replace mobile phone coverage. Mobile communications are indispensable for accessibility, voice quality, emergency call availability, mobile processes, and IoT devices. Both systems complement each other but fulfill different tasks.
Yes. Modern in-house solutions support LTE and 5G frequency ranges. Where necessary and depending on the network operator, FMB-E always plans the active or passive infrastructure in such a way that subsequent frequency updates or capacity expansions are possible.
