BTESA performs detection, analysis, and diagnosis of interferences in TETRA networks

BTESA carried out a specialized engineering project for Andorra Telecom with the goal of detecting, analyzing, and identifying interferences in the uplink band of its TETRA network, a critical infrastructure for the country’s communications. 

The network had been experiencing recurring interference issues that triggered alarms at various sites. Although the operator had previously consulted specialized companies, the precise source of the interfering signals had not been determined, nor had definitive solutions been applied.
To address the situation, the project was structured into two measurement campaigns conducted throughout 2025. 

• The first campaign, carried out between August and September, focused on analyzing the radio environment in the TETRA uplink band (380–385 MHz). During this phase, IQ captures were performed in the field, along with continuous and threshold-based measurements, spectral analysis, and demodulation processes in the laboratory. Additionally, the detected signals were correlated with alarm logs and call data provided by the operator. 

The results made it possible to differentiate between persistent and intermittent interferences and confirm the presence of external signals. In particular, interferences associated with harmonics from FM radio transmissions were detected in specific environments. Evidence of potential internal phenomena was also identified, such as system nonlinearities, insufficient isolation between transmission and reception, degraded connectors, or passive intermodulation effects. 

• Based on these findings, BTESA conducted a second campaign in December 2025, focused on characterizing the RF infrastructure at several network sites. During the technical visits, base stations, duplexers, multicouplers, cabling, and connectors were inspected using spectrum and network analyzers along with monitoring systems. 

The work provided Andorra Telecom with a solid technical foundation to understand the source of the interferences and define potential mitigation measures and improvements to the network’s operational robustness. 

Through this project, BTESA demonstrates its capability to perform advanced diagnostics in critical communication networks, combining fieldwork, spectral analysis, hypothesis validation, and specialized knowledge of TETRA systems and RF behavior in complex radio environments.