Programme Making and Special Events

On Bregenzer opera stage, the election parties at a Bundestag election or on the playing field edge after the final of a soccer world championship - wireless microphones are indispensable. In order to enable the interference-free use of PMSE equipment, the IRT offers the FreqScan software tool.

Since wireless systems are only so-called secondary services in their frequency spectrum, interference with primary services, such as TV transmitters, must always be expected. In order to be able to operate a microphone without interference, a channel not used by DVB-T2 must be found at the installation site. These so-called whitespaces are distributed differently across the federal territory, which means that it is important to know in advance what TV channels aren't used at the production site. Thus the finding of free frequencies for the use of wireless microphones is an important element and a frequency scanner for external production an important tool for the planners and coordinators of these productions.

Frequency Scanner FreqScan

In order to find free frequencies for PMSE applications, the web service FreqScan was developed by IRT. It gives a precise overview of the frequencies available for wireless microphones. It is used via a clickable card or an address search. Thus, FreqScan calculates a field strength forecast, which takes into account all the TV transmitters in Germany and partly also of neighboring countries. The result is displayed for indoor and outdoor cases in a table. FreqScan is always up-to-date: all transmitter data are regularly updated at least once a month.

Since April 2009, FreqScan has been available to broadcasters. FreqScan requires an Internet browser and access to the ARD Corporate Network (CN).


Wireless Camera Spectrum


Wireless camera applications have continued to grow over the past few years. The existing frequency spectrum, however, is limited. The primarily used frequencies in Germany range from 2.3 – 2.4 GHz. This range has to be shared with radio applications of state authorities and organizations with security tasks, e.g., the police and fire department. In addition, interference in the upper frequency range is often encountered due to the increasingly dense occupation of the adjoining ISM band (2.4 GHz) through WLAN and lacks sufficient reliability and quality to be usable for a live production. The IRT has been participating in the work in the responsible CEPT working groups to open more frequency ranges for video PMSE applications. First results of this work reveal that the mobile communication band 2010-2015 MHz – which is unused in Europe – can be used by PMSE in the future and thus seamlessly expands the 2025-2110 MHz band used in many European countries for PMSE. In the future, it will also be possible to use the 2.7-2.9 GHz range under specific conditions. These frequencies are selectively used by air traffic control to monitor airspace.

This complicates the coordination of these frequencies between the services for understandable reasons. It is therefore logical to license fixed-installation, local PMSE applications with these frequencies in sufficiently remote event locations such as football stadiums. Furthermore, the IRT will make an effort to open up usage of new spectrum ranges for PMSE. Currently, the usage of the ranges 1350-1400 MHz and 1492-1525 MHz is being discussed for audio-PMSE.

Das macht eine Koordinierung dieser Frequenzen zwischen den Diensten aus nachvollziehbaren Sicherheitsgründen aufwendig. Es bietet sich deshalb an, fest installierte, lokale PMSE-Anwendungen mit diesen Frequenzen an ausreichend weit entfernten Veranstaltungsorten, wie z. B. Fußballstadien, zu lizenzieren. Auch weiterhin wird sich das IRT um die Nutzung neuer Spektrumsbereiche für PMSE bemühen. Für Audio-PMSE wird derzeit z. B. die Nutzung der Bereiche 1350 – 1400 MHz und 1492 - 1525 MHz diskutiert.