US 12,267,248 B2
Network infrastructure device, communication terminal and method for synchronizing control applications via a communication network for transferring time-critical data
Harald Albrecht, Nuremberg (DE); Franz-Josef Götz, Heideck (DE); and Jürgen Schmitt, Fürth (DE)
Assigned to Siemens Aktiengesellschaft, Munich (DE)
Appl. No. 17/802,383
Filed by Siemens Aktiengesellschaft, Munich (DE)
PCT Filed Jan. 29, 2021, PCT No. PCT/EP2021/052144
§ 371(c)(1), (2) Date Aug. 25, 2022,
PCT Pub. No. WO2021/170343, PCT Pub. Date Sep. 2, 2021.
Claims priority of application No. 20160114 (EP), filed on Feb. 28, 2020.
Prior Publication US 2023/0090803 A1, Mar. 23, 2023
Int. Cl. H04L 47/283 (2022.01); H04L 7/00 (2006.01); H04L 47/80 (2022.01)
CPC H04L 47/283 (2013.01) [H04L 7/0016 (2013.01); H04L 47/805 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method for synchronizing control applications via a communication network for transferring time-critical data, the communication network comprising a respective communication at a respective starting node and a respective end node of paths for data streams and network infrastructure devices at intermediate nodes, and selected data streams being associated with control applications running on communication terminals, the method comprising:
ascertaining, by the network infrastructure devices, a particular time delay between a scheduled time of transmission for a datagram and an actual time of transmission of the datagram when forwarding datagrams associated with the selected data streams;
sending, by the network infrastructure devices, particular information about the ascertained particular time delay to a network infrastructure device or a communication terminal which is subsequent along a respective path;
computing, by the network infrastructure devices, the scheduled time of transmission based on a particular time of reception of the datagrams and a time delay ascertained by a communication terminal or a network infrastructure device which is precedent along the respective path;
ascertaining an accumulated maximum time delay between starting nodes and end nodes for a transmission of the selected data streams;
wherein synchronization between transmission cycles of starting-node control applications and transmission cycles of end-node control applications is achieved by virtue of the starting-node control application taking the time delay ascertained by the precedent network infrastructure device, the accumulated maximum time delay and a time of transmission of the datagrams as a basis for ascertaining a particular start of a next end-node transmission cycle; and
wherein the communication terminals and the network infrastructure devices each comprise a timer which is independent of timers of other communication terminals or network infrastructure devices and which is not synchronized to timers of other communication terminals or other network infrastructure devices.