US20190199485A1 - Redundant prp transmission system - Google Patents

Redundant prp transmission system Download PDF

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Publication number
US20190199485A1
US20190199485A1 US15/302,241 US201515302241A US2019199485A1 US 20190199485 A1 US20190199485 A1 US 20190199485A1 US 201515302241 A US201515302241 A US 201515302241A US 2019199485 A1 US2019199485 A1 US 2019199485A1
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US
United States
Prior art keywords
data
data packet
transmission
transmission path
network
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US15/302,241
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English (en)
Inventor
Tobias Heer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hirschmann Automation and Control GmbH
Original Assignee
Hirschmann Automation and Control GmbH
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Filing date
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Assigned to HIRSCHMANN AUTOMATION AND CONTROL GMBH reassignment HIRSCHMANN AUTOMATION AND CONTROL GMBH ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HEER, TOBIAS
Publication of US20190199485A1 publication Critical patent/US20190199485A1/en
Abandoned legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/22—Arrangements for detecting or preventing errors in the information received using redundant apparatus to increase reliability
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/004—Arrangements for detecting or preventing errors in the information received by using forward error control
    • H04L1/0041—Arrangements at the transmitter end
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L1/08—Arrangements for detecting or preventing errors in the information received by repeating transmission, e.g. Verdan system
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/28—Routing or path finding of packets in data switching networks using route fault recovery
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L1/00—Arrangements for detecting or preventing errors in the information received
    • H04L2001/0092—Error control systems characterised by the topology of the transmission link
    • H04L2001/0096—Channel splitting in point-to-point links

Definitions

  • the invention relates to a method of operating a data-transmission system having a first network and at least one second network where data is exchanged between these at least two networks in that data of the first network is fed to duplicating means, then is transmitted wirelessly to separating means via at least two transmission paths by PRP, and is forwarded by the separating means to the connected second network, according to the features of the preamble of claim 1 .
  • Such known transmission systems are used in safety-critical applications in process plants, or stationary or mobile work facilities—for example in work vehicles such as cranes or the like.
  • the—at least—second transmission path can be used to ensure the data transfer from the first to the second network.
  • the previously described data transmission via two, or more than two, transmission paths is advantageous with respect to the redundancy of data transmission from the perspective of safety.
  • this parallel data transmission via at least two transmission paths results in higher energy consumption, and also leads to higher thermal stress on the components of the transmission system. This leads disadvantageously to reduced longevity of the power supply, particularly batteries, and can also reduce the life expectancy of the components of the transmission system considerably if they are operated under higher temperature conditions.
  • the problem addressed by the invention is therefore that of improving a method of operating a transmission system, in terms of energy consumption, while simultaneously maintaining the redundancy characteristics for safety-critical issues.
  • the data is transmitted as data packets via the first data path and then, if a data packet was not transmitted, this data packet is retransmitted via at least the second transmission path.
  • the advantage of this is that data packets are transmitted in succession via the first data path, and each time that a data packet has been successfully transmitted via the transmission path, this is acknowledged by the receiver (separating means) and reported back to the transmitter (duplicating means). For the transmitter, this means that it is no longer necessary to resend a data packet via the first data path.
  • the receiver Only once a data packet has been sent, but has not arrived at the receiver for whatever reason (for example because of a faulty transmission line), this is reported to the transmitter by the receiver that then transmits this data packet again via at least the second transmission path—that is, not on the transmission path on which the first transmission should have taken place.
  • the receiver can determine for example, after a certain time has elapsed, that it has not received the data packet sent on the transmission path, and can then notify the sender that a data packet has been dropped, so that the same can once again transmit it via the—at least—second transmission path.
  • this retransmission of the data packet via the second transmission path is confirmed by the receiver, the sender is informed that this retransmitted data packet has arrived successfully and no retransmission of this data packet need take place. However, if there is a retransmission and the receipt of this retransmitted data packet does not occur, this as well can be reported by the receiver back to the transmitter, such that it again transmits the data packet that has already been transmitted unsuccessfully twice, via the second transmission path. This process can be repeated until a data packet has been successfully transmitted from the transmitter to the receiver.
  • this data packet is retransmitted, not only via the second transmission path, but via at least two transmission paths, and preferably via exactly two transmission paths.
  • This manner of transmission of the data packets is particularly significant, on the one hand, with respect to redundancy, and on the other hand in terms of energy savings, because a data packet can in any case be reliably transmitted from the transmitter to the receiver, yet at the same time the number of data packets that must be transmitted is reduced.
  • FIGS. 2 and 3 illustrate the difference in the number of data packets transmitted, comparing the prior art to data transmission according to the invention.
  • the retransmission of a data packet occurs more than twice. This ensures that a data packet is transmitted until the data packet transmitted by the transmitter arrives successfully at the receiver.
  • the number of retransmissions can be limited. This means that, in one implementation of the invention, the retransmission of a data packet is suppressed if the transmission of this data packet is carried out without error.
  • the number of retransmissions of a data packet is intended to be 2, 3 or 4.
  • Three attempts at transmission of a data packet is particularly advantageous, as this represents an advantageous compromise in terms of energy consumption, on the one hand, and on the other hand reliability and/or redundancy—as well as the performance of data transmission.
  • the presented method can be applied to a transmission system as shown in FIG. 1 .
  • FIG. 1 shows a basic arrangement of a transmission system comprising two networks 2 and 3 that are intended to exchange data. This data exchange can either be unidirectional from the network 2 to the network 3 (or vice versa), or can be bi-directional between the two networks 2 and 3 .
  • the networks 2 and 3 can be simple or complex networks, for example in a ring or linear topology or the like. However, it can also be contemplated that such a network 2 or 3 comprises only a single element, such as a sensor, an actuator, a controller or the like.
  • duplicator 4 To transmit the data of the network 2 , for example to the network 3 , duplicator 4 is provided. This duplicator 4 divides the supplied data stream into two data substreams. Then, the two data substreams are merged after their receipt by a separator 5 , and the received data streams are forwarded to the network after merging.
  • the transmission of data between the duplicator and the separator 5 occurs wirelessly, by PRP, via two identical or different transmission paths 6 , 7 . It can also be contemplated that one transmission path 6 is a radio transmission path, and the second transmission path 7 is an optical data transmission path.
  • both transmission paths 6 , 7 are radio transmission paths, for example, the data—and more specifically, the data packets—can be transmitted via these two radio transmission paths, for example on the same frequency or different frequencies, and with otherwise identical or differing transmission parameters.
  • Identical transmission paths a 6 , 7 are preferable in terms of their structure, although different transmission paths 6 , 7 (for example optical/radio, or different transmission parameters) are preferable in terms of increasing redundancy.
  • the duplicator 4 After the data has been relayed by the first network 2 to the duplicator 4 (where PRP is used, also termed the redundancy box), it functions such that each data packet is transmitted several times over the same transmission path 6 , 7 and/or an error correction value is assigned to each data packet. Subsequently, in a corresponding manner, the data packets are transmitted via the transmission paths 6 , 7 , and are accordingly evaluated by the separator 5 (where PRP is used, also termed the redundancy box), optionally processed, and relayed as data packets to the second network 3 .
  • PRP used, also termed the redundancy box
  • FIG. 1 relates to a unidirectional data transmission from the first network 2 to the additional, in particular the second, network 3 .
  • the duplicator 4 are designed to divide the data stream, and the separator 5 to merge the received data stream.
  • a duplicator 4 and/or separator 5 can be included in the transmission path between the network 3 and the network 2 , such that there is a doubled structure.
  • the means 4 , 5 can also be designed to double not only the relayed data stream, but also to separate the data streams relayed via the transmission paths 6 , 7 , which also applies to the separator 5 .
  • FIG. 2 shows the manner in which data packets are transmitted by devices that work via WLAN—that is, according to the 802.11 standard. These devices that use the 802.11 standard, are suitable for and designed to retransmit data packets on the second layer to compensate for loss of data packets.
  • FIG. 2 The manner of the retransmission of lost data packets with respect to the second layer is shown in FIG. 2 .
  • the figure shows that, if a data packet was not transmitted, this data packet is retransmitted via the at least two transmission paths (the upper and lower transmission paths in FIG. 2 ).
  • the first data packet “1” was sent via the upper transmission path, but has been lost. For this reason, it is marked with an X. This causes the transmitter to retransmit this data packet “1” via the upper transmission path. At the same time, it is also retransmitted via the further transmission path (lower transmission path). Since the upper packet data “1” arrives first at the receiver that is not shown, the data packet “1” on the lower transmission path can be rejected by the receiver. The data packet “2” is transmitted on the upper transmission path and arrives successfully at the receiver. This is reported back by the receiver to the transmitter, and a repeated transmission of the data packet “2” on the upper transmission route can be suppressed.
  • a data packet is first transmitted via the second transmission path. This is the case in the example according to FIG. 2 , with data packet “5”. Because in this case the data packet “5” transmitted first has been lost, it is retransmitted on this transmission path. Alternatively, it can be contemplated that it is resent on the upper transmission path after the first delivery on the lower transmission path. In the case shown in FIG. 2 , the data packet “5” resent on the lower transmission path arrives successfully at the receiver, such that retransmission does not occur.
  • the type of data transmission according to FIG. 3 is of particular interest and particularly advantageous.
  • the data is once again initially transmitted as data packets via the first (upper) data path. Since the first data packet “1” was not successful by the transmitter and receiver, this data packet is again transmitted via at least the second (lower) transmission path, but optionally also via the upper transmission path. If the receiver recognizes that the data packet “1” was successfully transmitted either via the upper transmission path or, preferably, via the lower transmission path, this is reported back to the transmitter. The same sends a further data packet “2” on the upper transmission path. This data packet “2” is successfully transmitted, such that the transmission of the next data packet “3” can then be initiated. Because this data packet “2” is lost on the first transmission path, it can be retransmitted on the upper transmission path and/or the lower transmission paths thereof.
  • the data packet “3” is lost on the upper transmission path, but is retransmitted successfully one the lower transmission path. Once this has been determined by the receiver and reported back to the transmitter, it allows the transmission of the next data packet “4”. This is successfully transmitted via the first data path, such that a retransmission can be suppressed, on whichever of the transmission paths.
  • the number of transmitted data packets, in particular on the lower transmission path, is significantly reduced such that a significantly reduced energy consumption and a lowering of the operating temperature is achieved as a result.
  • all data packets “1” to “6” were reliably transmitted from the transmitter (the first network 2 ) to the receiver (the second network 3 ). This approach therefore achieves a reduction in energy consumption, reduction in the operating temperature, and a redundant data transmission, in a particularly advantageous manner as concerns safety-critical aspects.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Detection And Prevention Of Errors In Transmission (AREA)
  • Data Exchanges In Wide-Area Networks (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Small-Scale Networks (AREA)
US15/302,241 2014-04-09 2015-04-09 Redundant prp transmission system Abandoned US20190199485A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102014206873.8 2014-04-09
DE102014206873 2014-04-09
PCT/EP2015/057787 WO2015155316A1 (de) 2014-04-09 2015-04-09 Verfahren für ein redundantes übertragungssystem mit prp und energieeinsparung

Publications (1)

Publication Number Publication Date
US20190199485A1 true US20190199485A1 (en) 2019-06-27

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Family Applications (3)

Application Number Title Priority Date Filing Date
US15/302,241 Abandoned US20190199485A1 (en) 2014-04-09 2015-04-09 Redundant prp transmission system
US15/302,191 Active 2036-05-16 US11296834B2 (en) 2014-04-09 2015-04-09 Redundant transmission system for PRP and multiple data packets
US15/302,208 Active 2035-10-09 US10404416B2 (en) 2014-04-09 2015-04-09 Redundant transmission system with PRP and fault prediction

Family Applications After (2)

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US15/302,191 Active 2036-05-16 US11296834B2 (en) 2014-04-09 2015-04-09 Redundant transmission system for PRP and multiple data packets
US15/302,208 Active 2035-10-09 US10404416B2 (en) 2014-04-09 2015-04-09 Redundant transmission system with PRP and fault prediction

Country Status (4)

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US (3) US20190199485A1 (de)
EP (3) EP3130099B1 (de)
DE (3) DE102015206383A1 (de)
WO (3) WO2015155315A1 (de)

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EP4354772A1 (de) * 2022-10-11 2024-04-17 Nxp B.V. Netzwerkvorrichtung, kommunikationssystem und verfahren für die netzwerkvorrichtung

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Also Published As

Publication number Publication date
EP3130100B1 (de) 2021-10-20
EP3130100A1 (de) 2017-02-15
EP3130099B1 (de) 2022-12-21
DE102015206382A1 (de) 2015-10-15
US11296834B2 (en) 2022-04-05
US10404416B2 (en) 2019-09-03
DE102015206383A1 (de) 2015-10-15
WO2015155314A1 (de) 2015-10-15
EP3130097A1 (de) 2017-02-15
WO2015155316A1 (de) 2015-10-15
WO2015155315A1 (de) 2015-10-15
US20180262298A1 (en) 2018-09-13
EP3130099A1 (de) 2017-02-15
DE102015206380A1 (de) 2015-10-15
US20180351702A1 (en) 2018-12-06

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