Transmission route – this is a radio system that works in the so-called 868 MHz (ISM) frequency range for Europe. Other regions have different frequencies, so they are not necessarily compatible unless you can change the frequency range. This "self-powered" technology is now also used for other radio areas e.g. 2.4 GHz, therefore it is identical on the outside but sparks in a different BUS system. The range of the system has limits due to energy restrictions.