Method for the bidirectional transmission of data, in particular sensor data, and radio-capable node

A method for transmitting data or sensor data by radio between a preferably fixed battery-operated node and base station in a communication system with bidirectional radio transmission, includes providing a base station communication module having a first frequency transmitter, and a node communication module having a first frequency transmitter and second frequency transmitter with lower frequency. The node communication module transmits data in the uplink to the base station communication module by splitting a radio telegram into data packets transmitted successively with temporal spacing. The base station communication module transmits data in the downlink to the node communication module by splitting a radio telegram into data packets transmitted successively with temporal spacing. To improve downlink reception quality, two calibrations of first and second node frequency transmitters occur during transmission of the sum of a sequence of uplink data packets and subsequent sequence of downlink data packets including periods therebetween.