A method for simulating a communication system, and simulation system for a communication system and computer program, the communication system having a communication protocol which regulates a communication between at least two transmitter-receivers of the communication system via a common communication channel in such a way that a first transmitter-receiver transmits a data packet only when no use of the communication channel by a second transmitter-receiver is indicated to the first transmitter-receiver, includes sending a data packet by at least the first transmitter-receiver via the common communication channel even when at least the second transmitter-receiver is using the communication channel.