Elevator system , comprising: an elevator car ; an elevator controller which is configured to control a movement of the elevator car along a travel path in a building; a transmission device for transmitting electrical energy and/or information between the elevator car and the elevator controller ; a sending device which is configured to send a measurement signal as electromagnetic radiation via an air path (D); a detection device which is arranged remote from and opposite the sending device in the direction of the air path (D), the detection device being configured to receive the measurement signal directly via the air path (D) and to convert it into an electrical signal (ES); and a processing device which is configured to receive the electrical signal (ES), to ascertain a propagation time of the measurement signal along the air path (D) by means of the electrical signal (ES), and to ascertain a distance (d) between the sending device and the detection device by means of the propagation time, the processing device also being configured to ascertain a position of the elevator car by means of the distance (d), characterized in that the transmission device comprises a traveling cable which is used in the elevator system for transmitting energy and/or information from and to the elevator car , the traveling cable having a fixed length (L), in that the transmission device additionally forms a communication channel between the sending device and the detection device , which communication channel closes a loop from the sending device via the air path (D) to the detection device and from there to the sending device , and in that the transmission device is configured for signal transmission to the sending device and to the detection device , the distance (d) being ascertainable on the side of the sending device or on the side of the detection device . an elevator car ; an elevator controller which is configured to control a movement of the elevator car along a travel path in a building; a transmission device for transmitting electrical energy and/or information between the elevator car and the elevator controller ; a sending device which is configured to send a measurement signal as electromagnetic radiation via an air path (D); a detection device which is arranged remote from and opposite the sending device in the direction of the air path (D), the detection device being configured to receive the measurement signal directly via the air path (D) and to convert it into an electrical signal (ES); and a processing device which is configured to receive the electrical signal (ES), to ascertain a propagation time of the measurement signal along the air path (D) by means of the electrical signal (ES), and to ascertain a distance (d) between the sending device and the detection device by means of the propagation time, the processing device also being configured to ascertain a position of the elevator car by means of the distance (d), characterized in that the transmission device comprises a traveling cable which is used in the elevator system for transmitting energy and/or information from and to the elevator car , the traveling cable having a fixed length (L), in that the transmission device additionally forms a communication channel between the sending device and the detection device , which communication channel closes a loop from the sending device via the air path (D) to the detection device and from there to the sending device , and in that the transmission device is configured for signal transmission to the sending device and to the detection device , the distance (d) being ascertainable on the side of the sending device or on the side of the detection device . <EOS>