Abstract: A method for identifying an object as the source of a V2X signal. The method includes: receiving a V2X signal from a source by a receiver of a first vehicle; performing a relative position estimation using an environment sensor system of the first vehicle, an object from the surroundings of the first vehicle being detected, and a relative position between the first vehicle and the object being determined, the environment sensor system receiving environment signals of the object, and the object modulating the environment signals at least with a part of a V2X signal of the object; receiving the modulated environment signals by the environment sensor system of the first vehicle, and demodulating the received environment signals by the first vehicle, and ascertaining a V2X identifier of the object; comparing the V2X identifier of the object with the V2X signal of the source.

Abstract: A method for displaying a warning message in a first vehicle, includes transmitting from a second vehicle a warning and position data relating to a position of the second vehicle to the first vehicle, wherein if, after reception of the warning and of the position data by the first vehicle, it is concluded on the basis of the received position data that the second vehicle can be seen by a driver of the first vehicle in a region of a head-up display of the first vehicle, the warning message is displayed in such a way that the second vehicle is characterized visually for the driver of the first vehicle in the head-up display of the first vehicle.

Abstract: A method for displaying a warning message in a first vehicle, includes transmitting from a second vehicle a warning and position data relating to a position of the second vehicle to the first vehicle, wherein if, after reception of the warning and of the position data by the first vehicle, it is concluded on the basis of the received position data that the second vehicle can be seen by a driver of the first vehicle in a region of a head-up display of the first vehicle, the warning message is displayed in such a way that the second vehicle is characterized visually for the driver of the first vehicle in the head-up display of the first vehicle.

Abstract: In a method for operating a heads-up display system of a vehicle, the roadway state of the roadway to be traveled by the vehicle is checked using at least one suitable sensor, and a warning message is displayed at a location on the windshield in the case of detection of a critical roadway state, the location of the warning message corresponding to the dangerous, driving area of the roadway as viewed from the driver's perspective.

Abstract: For checking the transmission in an optical transmission installation with optical fibers for conducting optical useful signals between signal sources and signal acceptors (S/D), at which optical useful signals are coupled into or outcoupled from the optical fibers, which signals can be diverted to substitute paths at nodes (OCC) of the transmission device, checking signals (LS) are transmitted in both directions between the signal sources and signal acceptors (S/D) and nodes (OCC) as applicable in the respective optical fiber for at least one useful signal. The presence of the checking signals (LS) is checked, and in the absence of a checking signal (LS) from one line direction, the transmission of a checking signal (LS) in the opposite direction is suppressed. In this way it is assured that on both sides of a line problem, this problem will be detected and an alarm will be tripped if necessary, or a switchover will be made to a substitute path.

Abstract: An integrated optical circuit is described for coupling an optical fiber amplifier with two or four terminals in such a way that the optical fiber amplifier is supplied with optical signals in a prescribed direction, and the optical signals are coupled out to an optical network via a directed directional coupler. The necessary optical switches, couplers, terminals and light guides are integrated into the integrated optical circuit.