Disclosed are a method and a device for supplying electrical power for two or more technical systems, which are connected to an electrical supply line with a feed point, arranged in a connecting rod, and for data transmission between the feed point and the technical systems, supplying power to the technical systems is done with essentially constant current intensity. Data transmission from the feed point to the technical systems is done by modulating the current intensity, and data transmission from the technical systems to the feed point is done by modulating the voltage.

The present disclosure provides techniques and apparatus for discrete multitone (DMT) modulation communications for single-mode telemetry. An example technique involves a surface acquisition module initiating a first training sequence with a downhole telemetry module using a first bandwidth of a plurality of bandwidths via a communication link between the surface acquisition module and the downhole telemetry module. A second bandwidth of the plurality of bandwidths is automatically selected for a communication session between the surface acquisition module and the downhole telemetry module using the communication link, based on the first training sequence. The second bandwidth is greater than the first bandwidth. Data is exchanged with the downhole telemetry module during the communication session based on the second bandwidth.