Abstract: In a system for transmitting digital signals between two equipment units of a mobile radio network in accordance with a digital transmission protocol, the equipment units are interconnected by an analog link. The system includes digital-analog converters for converting the digital signals into an analog form and transmitting the converted digital signals on the analog link and analog-to-digital converters for reception of the analog signals and converting the received signal into digital form by one of the equipment units.

Abstract: A cellular mobile telephone system which can be used on board a vehicle enables conventional mobile telephones to be used on board an aircraft, for example. It includes a first transceiver on board the vehicle and connected to an antenna on the outside of the aircraft to set up an external radio link with a terrestrial mobile telephone network via a satellite. It further includes a second transceiver having an antenna inside the aircraft and connected to a base station controller. The second station and the base station controller have functions similar to those of a base station system in a conventional mobile telephone network, for example a GSM network. The base station controller is connected to the first transceiver. To prevent long signaling link set-up times, the base station controller includes software for setting up a signaling link between the aircraft and the terrestrial mobile telephone network in advance, as soon as at least one mobile telephone is switched on.

Abstract: In a system for transmitting digital signals between two equipment units of a mobile radio network in accordance with a digital transmission protocol, the equipment units are interconnected by an analog link. The system includes digital-analog converters for transmitting the signals on the analog link and analog-digital converters for reception of the signals by one of the equipment units in digital form.

Abstract: A cellular mobile telephone system which can be used on board a vehicle enables conventional mobile telephones to be used on board an aircraft, for example. It includes a first transceiver on board the vehicle and connected to an antenna on the outside of the aircraft to set up an external radio link with a terrestrial mobile telephone network via a satellite. It further includes a second transceiver having an antenna inside the aircraft and connected to a base station controller. The second station and the base station controller have functions similar to those of a base station system in a conventional mobile telephone network, for example a GSM network. The base station controller is connected to the first transceiver. To prevent long signaling link set-up times, the base station controller includes software for setting up a signaling link between the aircraft and the terrestrial mobile telephone network in advance, as soon as at least one mobile telephone is switched on.