Short Answer
GSM Inhouse usually refers to the mobile coverage within a building. It encompasses not only historical GSM but also today's mobile networks with LTE, 5G, and VoLTE. Poor mobile reception, connection issues, call dropouts, and slow data often result from building attenuation. A solution may involve a professionally planned repeater, a distributed antenna system, or operator-compliant inhouse coverage.
Typical Symptoms
Poor mobile reception is not always indicated by a missing signal bar. Users frequently report call dropouts, one-sided audio, long call setup times, slow data, undelivered SMS, unstable apps, or connection issues in conference rooms, underground garages, technical rooms, and basements.
It is important to note: Such symptoms affect public mobile networks. They should therefore be treated differently than range issues with operational radio devices or requirements for POLYCOM object supply.
Why Buildings Weaken Mobile Signals
| Cause | Effect |
|---|---|
| Reinforced concrete and metal | Significantly attenuate mobile signals, especially in basements and interior rooms. |
| Coated windows | Can significantly deteriorate reception despite a view outside. |
| Large buildings | Interior areas are too far from external coverage. |
| Frequency band | Lower bands often penetrate better, while higher bands provide more capacity but require denser coverage. |
| Network load | Evens with a signal, poor capacity can lead to unstable usage. |
What Solutions Are Available?
The first step is an on-site measurement. This will check which providers, technologies, and areas are affected. Only then can a decision be made whether WLAN Calling is sufficient or if a genuine mobile inhouse service is necessary.
- WLAN Calling: useful as a simple aid for individual workplaces if stable WLAN is available.
- Mobile repeaters: can amplify signals and distribute them via indoor antennas but must be planned in accordance with operator standards.
- DAS: a distributed antenna system provides controlled coverage for larger buildings, underground garages, or complex areas.
- Small Cells: small cellular solutions may be a viable option for capacity and coverage depending on the provider and project.
- Hybrid concepts: mobile radio, WLAN, operational radio, and alerting are clearly separated or coordinated depending on the process.
Distinction from POLYCOM, Object Radio, and Operational Radio
Poor mobile reception primarily concerns mobile radio: GSM, LTE, 5G, VoLTE, and the networks of mobile providers. POLYCOM is the Swiss security radio network for authorities and organizations involved in rescue and safety. Operational radio is a professional radio solution for companies with their own radios, channels, repeaters, and group communication.
This distinction is particularly important in Swiss buildings. A building may simultaneously need mobile inhouse coverage for users, POLYCOM object supply for emergency organizations, and an operational radio system for internal teams. However, these are separate requirements with differing responsibilities.
Typical Errors
- Cheap signal amplifiers are installed without verification and can disrupt mobile networks.
- Connection problems are confused with operational radio or POLYCOM.
- Only the reception bars are considered, not voice, data, capacity, and emergency processes.
- The operator clarification is done too late.
- Indoor antennas, cable routes, fire protection, and maintenance are not adequately planned.
Practical Example
In an administrative building, smartphones work at the window but not in conference rooms and basements. Employees report poor mobile reception and connection issues with mobile data and phone calls. A measurement shows that external coverage is available, but the building significantly attenuates the signals. In this case, a mobile radio repeater is not the first solution, but rather an inhouse mobile planning with operator clarification, suitable antenna sectors, and a clear separation from any POLYCOM object radio.
FAQ
What to do in case of poor mobile reception inside the building?
First, measurements should be conducted to determine which mobile provider, frequency ranges, and rooms are affected. Afterward, a legally compliant mobile inhouse solution can be planned, including operator clarification, repeaters, distributed antenna systems, or small cells.
Are mobile repeaters allowed?
Mobile repeaters may not be used arbitrarily. In Switzerland, operator approvals, technical requirements, and regulatory standards must be adhered to, ensuring that no mobile networks are disrupted.
Is GSM Inhouse the same as POLYCOM or operational radio?
No. GSM Inhouse or mobile inhouse concerns mobile reception in public mobile networks. POLYCOM, object radio, and operational radio represent different radio domains with different users, obligations, frequencies, and planning objectives.
Does WLAN Calling help with connection problems?
WLAN Calling can assist in individual offices or apartments but does not replace a planned mobile coverage for entire buildings, underground garages, technical rooms, or critical operational areas.
Sources and Currency
This page was created on July 7, 2026. Mobile inhouse projects must always be coordinated with the current specifications of operators, regulatory requirements, and the specific building situation.