The number of channels – the crux of the matter

Redakteur: Anna Kollmer                        Tour Guide Systems, Industry information

The more transmission channels to choose from the better? A wide-spread assumption – but essentially incorrect. The more groups that visit a tourist hot spot, the more difficult it becomes not to get in each others way with the frequency and avoid interference.

In Germany, transmission frequencies are defined and provided by the Federal Network Agency. Tour guide systems fall into the 800 MHz range allocated to mobile phones and wireless microphones. The majority of the frequencies (downlink and uplink) are allocated to O2, Vodafone and Telekom to provide mobile internet. The duplex gap from 822 MHz to 832 MHz is located between downlink and uplink. All other wireless microphone frequencies are permitted in this gap – in our case tour guide systems. This results in there being a constant range of 10 MHz available in Germany. <STRONG/> 2 MHz from 863 MHz to 865 MHz are provided for use in all EU countries including Switzerland and Liechtenstein. 2 MHz  

The following example illustrates how a higher number of channels is not always necessarily better:

The EU’s permitted frequency range of 2 Mhz must be split for use in channels. It is up to every trader into how many channels to split the range. Traditionally they opt for 16 channels in the EU range. Splitting this range into 100 channels is not uncommon but makes little sense. If you compare 2 Mhz to a cake that is cut into different pieces, you notice the cake does not get any bigger, whether it is cut into 16 or 100 pieces. The cake itself stays the same.

Conclusion: Tour guide systems with 100 channels have just as much or just as little output as tour guide systems with fewer channels. In this case, the number 100 is misleading. 

To be able to use as many channels as possible, our TOUR GUIDE SYSTEM TOM AUDIO TG-200 ETOUR has the option of using both ranges in the German duplex gap and in the EU range. It can switch between them as required. This provides a sufficient number of channels to choose from to avoid the problem in tourist hotspots and, consequently, avoid interference.


Duplex gap from 822 MHz to 832 MHz
Channel radio channel