Method of operating a communication system that comprises at least four communication nodes (A, B, C, D) wherein - the communication system is operated in a time-division multiplexing technique wherein the communication is carried out in consecutive time frames (F1, F2) which are divided into slots (S1-S4), and - each of the communication nodes (A, B, C, D) has its own transmission sub-slot when transmitting data signals (DS1-DS4) to other communication nodes, and transmits its data signals (DS1-DS4) in its transmission sub-slot (TSS1-TSS4) to other communication nodes, - each of the slots (S1-S4) comprises at least two consecutive sub-slots, hereinafter referred to as transmission sub-slot (TSS1-TSS4) and echo sub-slot (ESS1-ESS4), - each of the communication nodes (A, B, C, D), or a predefined subset of the communication nodes (A, B, C, D), that has received a data signal (DS1-DS4) in the preceding transmission sub-slot (TSS1-TSS4) of the same slot, analyzes the data signal (DS1-DS4) regarding a correct reception, and - in case of a correct reception, each of the communication nodes (A, B, C, D), or said predefined subset of the communication nodes (A, B, C, D), determines whether the received data signal (DS1-DS4) is directed to itself or another communication node (A, B, C, D) of the communication system and - in the latter case - generates and transmits a corresponding echo signal (E(DS1)-E(DS4)) in the consecutive echo sub-slot (ESS1-ESS4) of the same slot, and otherwise processes the received data signal (DS1-DS4), - wherein the received data signal (DS1-DS4) and the corresponding echo signal (E(DS1)-E(DS4)) are identical, or differ at most in an identifier, preferably composed of a single bit or a single bit sequence, that identifies each signal as either a data signal (DS1-DS4) or an echo signal (E(DS1)-E(DS4)). - the communication system is operated in a time-division multiplexing technique wherein the communication is carried out in consecutive time frames (F1, F2) which are divided into slots (S1-S4), and - each of the communication nodes (A, B, C, D) has its own transmission sub-slot when transmitting data signals (DS1-DS4) to other communication nodes, and transmits its data signals (DS1-DS4) in its transmission sub-slot (TSS1-TSS4) to other communication nodes, - each of the slots (S1-S4) comprises at least two consecutive sub-slots, hereinafter referred to as transmission sub-slot (TSS1-TSS4) and echo sub-slot (ESS1-ESS4), - each of the communication nodes (A, B, C, D), or a predefined subset of the communication nodes (A, B, C, D), that has received a data signal (DS1-DS4) in the preceding transmission sub-slot (TSS1-TSS4) of the same slot, analyzes the data signal (DS1-DS4) regarding a correct reception, and - in case of a correct reception, each of the communication nodes (A, B, C, D), or said predefined subset of the communication nodes (A, B, C, D), determines whether the received data signal (DS1-DS4) is directed to itself or another communication node (A, B, C, D) of the communication system and - in the latter case - generates and transmits a corresponding echo signal (E(DS1)-E(DS4)) in the consecutive echo sub-slot (ESS1-ESS4) of the same slot, and otherwise processes the received data signal (DS1-DS4), - wherein the received data signal (DS1-DS4) and the corresponding echo signal (E(DS1)-E(DS4)) are identical, or differ at most in an identifier, preferably composed of a single bit or a single bit sequence, that identifies each signal as either a data signal (DS1-DS4) or an echo signal (E(DS1)-E(DS4)). <EOS>