Method for time synchronization in a communication network comprising a multiplicity of network nodes (MA, SL1, SL2,..., SL6) with one master node and a plurality of slave nodes (SL1, SL2,..., SL6), wherein the master node detects a master time with a master clock and each slave node (SL1, SL2,..., SL6) detects a slave time with an internal clock, wherein synchronization messages (SYN1, SYN2) are transmitted in the communication network and the synchronization message (SYN1, SYN2) received in a slave node (SL1, SL2,..., SL6) contains synchronization information which is used for synchronizing the slave time of the slave node (SL1, SL2,..., SLN) with the master time, wherein: - a closed topology comprising communication paths (PA1, PA2,..., PA7) between neighboring network nodes (MA, SL1, SL2,...,SL6) is predefined, wherein the closed topology defines a first transmission direction and an opposite second transmission direction between neighboring network nodes (MA, SL1, SL2,..., SL6); - proceeding from the master node, the synchronization messages (SYN1, SYN2) are forwarded in the closed topology in such a way that at least one portion of the slave nodes (SL1, SL2,..., SL6) in each case receives a first synchronization message from the first transmission direction and a second synchronization message from the second transmission direction; - a respective slave node (SL1, SL2,..., SL6) of the at least one portion of the slave nodes (SL1, SL2,..., SL6) determines a first time, which is synchronized on the basis of the synchronization information of the first synchronization message, and a second time, which is synchronized on the basis of the synchronization information of the second synchronization message; - an averaged time (ta) is determined by the arithmetic averaging of the first and second times (t1, t2), wherein the items of synchronization information of the first and second synchronization messages (SYN1, SYN2) are configured in such a way that the averaged time (ta) corresponds to the master time, - characterized in that within a cycle of the communication of a first and second synchronization message (SYN1, SYN2) by the closed topology, a respective slave node (SL1, SL2,..., SL6), upon forwarding the first and second synchronization messages (SYN1, SYN2), adds to the synchronization information an internal processing time between reception and emission of the first and respectively second synchronization messages (SYN1, SYN2) and also a predetermined transmission time which is fixed within the cycle, wherein the predetermined transmission time is set or controlled in the master node to the average transmission time of the first and respectively second synchronization messages along a communication path (PA1, PA2,..., PA7). - a closed topology comprising communication paths (PA1, PA2,..., PA7) between neighboring network nodes (MA, SL1, SL2,...,SL6) is predefined, wherein the closed topology defines a first transmission direction and an opposite second transmission direction between neighboring network nodes (MA, SL1, SL2,..., SL6); - proceeding from the master node, the synchronization messages (SYN1, SYN2) are forwarded in the closed topology in such a way that at least one portion of the slave nodes (SL1, SL2,..., SL6) in each case receives a first synchronization message from the first transmission direction and a second synchronization message from the second transmission direction; - a respective slave node (SL1, SL2,..., SL6) of the at least one portion of the slave nodes (SL1, SL2,..., SL6) determines a first time, which is synchronized on the basis of the synchronization information of the first synchronization message, and a second time, which is synchronized on the basis of the synchronization information of the second synchronization message; - an averaged time (ta) is determined by the arithmetic averaging of the first and second times (t1, t2), wherein the items of synchronization information of the first and second synchronization messages (SYN1, SYN2) are configured in such a way that the averaged time (ta) corresponds to the master time, - characterized in that within a cycle of the communication of a first and second synchronization message (SYN1, SYN2) by the closed topology, a respective slave node (SL1, SL2,..., SL6), upon forwarding the first and second synchronization messages (SYN1, SYN2), adds to the synchronization information an internal processing time between reception and emission of the first and respectively second synchronization messages (SYN1, SYN2) and also a predetermined transmission time which is fixed within the cycle, wherein the predetermined transmission time is set or controlled in the master node to the average transmission time of the first and respectively second synchronization messages along a communication path (PA1, PA2,..., PA7).