METHOD AND APPARATUS FOR ENERGY-OPTIMIZED DATA TRANSMISSION USING THE OPC UA PROTOCOL IN RADIO NETWORKS

• US 20160073443A1
• Filed: 09/09/2015
• Published: 03/10/2016
• Est. Priority Date: 09/10/2014
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: DEIRETSBACHER, KARL-HEINZ, HOCK, CHRISTIAN, KAEFER, GERALD, VOLKMANN, FRANK
• Granted Patent: US 10,230,807 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 67/145 avoiding end of session, e.g. keep-alive, heartbeats, resumption message or wake-up for inactive or interrupted session
• CPC Class Codes: H04L 67/55 Push-based network services
• CPC Class Codes: H04W 76/19 Connection re-establishment

Abstract

A method and apparatus for energy-optimized data transmission by OPC UA protocol in radio networks is disclosed. When OPC UA communication is operated in a mobile device, e.g. as mobile access to part of a plant for maintenance, monitoring, parameterization, transmission is frequently implemented by the OPC UA'"'"'s own request-response based communication behavior. Since the device is rarely able to switch off the transmitter, the battery of the device is very quickly discharged. This poses a problem, particularly in the case of devices that are intended to respond promptly to infrequent warnings or events. However, when a client device is intended to provide notification in relation to one event only, the previous polling, i.e. the periodic interrogation is dispensed with and an alternative notification through means inherent in the mobile network is used. This method uses, for example, a mobile push service supplied by the network provider.

Claims

1. A method for communication between at least one client and at least one server in a client/server system using an OPC UA communication protocol and having a Keep Alive mechanism that ends a data connection between a server and a client when no data packets are transmitted during a given Keep Alive time period, said client/server system permitting only requests from the at least one client and only responses to requests from the at least one server, said method comprising the steps of:

receiving an initial trigger message sent from the at least one server to the at least one client device after the end of the Keep Alive time period, and

initiating the transmission of an OPC UA request by the at least one client to the at least one server in response to the initial trigger message received from the server by the client after the data connection between the OPC UA server and the OPC UA client is ended, so that communication between the server and the OPC UA client is initiated by the server after the Keep Alive mechanism ends the data connection between them.

2. The method of claim 1, wherein the communication transmitted by the server to the client in response to the request transmitted by the client is a single OPC UA event notification.

3. The method of claim 1, wherein the client/server system includes the Internet.

4. The method of claim 1, wherein the client/server system includes a mobile network using a conventional mobile communication standard.

5. The method of claim 4, wherein the client/server system includes a mobile network using a mobile communication standard that is one of the following:

GSM, GPRS, Edge, LTE, UMTS, or HSPA.

6. The method of claim 1, wherein the method is implemented using the HTTP protocol.

7. The method of claim 1, wherein the method is implemented using the HTTPS Tunnel Protocol.

8. The method of claim 1, wherein the method is implemented using a push service.

9. The method of claim 1, wherein the method is implemented using a push service interface.

10. The method of claim 1, wherein the trigger message sent as a Hidden Text message.

11. The method of claim 1, wherein the OPC UA Republish mechanism is used to implement a request for a data packet having a given unique sequence number, further comprising the step of repeatedly transmitting the request for the data packet having the given sequence number within the time period defined in the OPC UA when a confirmation of the receipt of the data packet having the given sequence number has not occurred, until the data packet is rejected by the requester.

12. The method of claim 1, wherein the network has multiple clients in a technical plant, each client monitoring the state of a respective technical component of the plant.

13. The method of claim 1, wherein a plurality of responses are transmitted by the server as a single response by using “

Chunked Data Encoding”

in response to a single request from the client.

14. The method of claim 1, further comprising the step of modifying the protocol layer of the client so that the client sends an OPC UA request to the server in response to the trigger message received from the server.

15. A Network apparatus for communication between at least one client device and at least one server in a client/server system using an OPC UA communication protocol and having a Keep Alive mechanism that ends a data connection between a server and a client when no data packets are transmitted during a given Keep Alive time period, said client/server system permitting only requests from the at least one client and only responses to requests by the at least one server, said network apparatus comprising:

a trigger transmitting device, said trigger transmitting device transmitting an initial trigger message to the client, device after the end of the Keep. Alive time period;

a trigger receiver in the client device; and

a protocol in the client device that initiates transmission of an OPC UA request from the OPC UA client to the OPC UA server in response to the trigger message so that communication between the server and the OPC UA client is initiated by the server after the Keep Alive mechanism ends the data connection between them.

16. The network apparatus of claim 15, wherein the network is in a technical plant and has multiple client devices, each client device monitoring the state of a technical component of the plant.

17. The network apparatus of claim 15, wherein the client device is a conventional Internet-enabled mobile device having a protocol layer that has been modified so that the client sends an OPC UA request to the server in response to the trigger message received from the server.

18. A client device adapted for communicating with a server device in a client/server system, said system using an OPC UA communication protocol and having a Keep Alive mechanism that ends a data connection between the server and the client when no data packets are transmitted within a Keep Alive time period, said client/server system permitting only requests from clients and only responses to requests by servers, said server transmitting a trigger message after the end of the Keep Alive time period, said client device comprising:

a trigger receiver in the client device; and

a protocol in the client device that initiates transmission of an OPC UA request from the OPC UA client to the OPC UA server in response to the trigger message so that communication between the server and the OPC UA client is initiated by the server after the Keep Alive mechanism ends the data connection between them.

19. The client device of claim 18, wherein the client device is energy-autonomous.

20. The client device of claim 18, wherein the client device is a conventional Internet-enabled mobile device having a protocol layer that has been modified so that the client sends an OPC UA request to the server in response to the trigger message received from the server.