A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants. Florian Kauer, Florian Meyer, Volker Turau

Transcription

1 A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants Florian Kauer, Florian Meyer, Volker Turau June 13 th, 2017 Institute of Telematics Hamburg University of Technology TUHH

2 Motivation Motivation Motivation Industrial Wireless Networks Concentrated Solar Power Plants 1,000-1,000,000 heliostats Wired Wireless Field Bus Cost reduction Software maintenance required for Florian Florian Kauer, Kauer, Florian Florian Meyer, Meyer, Volker Volker Turau Turau Network components Third-party devices A A Holistic Holistic Solution Solution for for Reliable Reliable Over-the-Air Over-the-Air Software Software Updates Updates in in Large Large Industrial Industrial Plants Plants 22

3 Motivation Components Control Room Radio Gateway Motor Controller Radio Transceiver Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 3

4 Motivation Motivation Radio Transceiver IEEE Transceiver RS-485 Bus to Motor Florian Florian Kauer, Kauer, Florian Florian Meyer, Meyer, Volker Volker Turau Turau 16 Mbytes Flash A A Holistic Holistic Solution Solution for for Reliable Reliable Over-the-Air Over-the-Air Software Software Updates Updates in in Large Large Industrial Industrial Plants Plants 44

5 Motivation Motivation Motivation How to realize reliable and efficient software updates in such large scale wireless networks? Florian Florian Kauer, Kauer, Florian Florian Meyer, Meyer, Volker Volker Turau Turau A A Holistic Holistic Solution Solution for for Reliable Reliable Over-the-Air Over-the-Air Software Software Updates Updates in in Large Large Industrial Industrial Plants Plants 55

6 Requirements Requirements Scalable to thousands of devices Suitable for a IEEE network Low data rate (250 kbit/s) Small packets (< 127 Bytes) Forwarding over multiple hops Sufficiently fast Updating the whole plant over night Fail-safe Maintain a working system if something goes wrong. Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 6

7 Requirements Requirements Scalable to thousands of devices Suitable for a IEEE network Low data rate (250 kbit/s) Small packets (< 127 Bytes) Forwarding over multiple hops Sufficiently fast Updating the whole plant over night Fail-safe Maintain a working system if something goes wrong. S. Unterschütz and V. Turau, Fail-Safe Over-The-Air Programming and Error Recovery in Wireless Networks in Proceedings of the 10th International Workshop on Intelligent Solutions in Embedded Systems (WISES). Klagenfurt, Austria, Jul Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 6

8 Deluge and Coffee Deluge Fast and efficient data dissemination for multi-hop networks Split large file into multiple pages Exchange page informations via Trickle algorithm Send pages via link-layer broadcasts Pages can be redirected before whole file was received Spatial multiplexing J. W. Hui and D. Culler, The Dynamic Behavior of a Data Dissemination Protocol for Network Programming at Scale in Proceedings of the 2nd International Conference on Embedded Networked Sensor Systems (SenSys). Baltimore, MD, USA, Nov Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 7

9 Deluge and Coffee Coffee File System File system abstraction for resource-constraint devices Efficient usage of Flash storage Problem: Overwriting data only possible by erasing whole sector Solution: Micro Logs Write to empty memory first, write back occasionally N. Tsiftes, A. Dunkels, Z. He, and T. Voigt, Enabling Large-Scale Storage in Sensor Networks with the Coffee File System in Proceedings of the 8th International Conference on Information Processing in Sensor Networks (IPSN), San Francisco, CA, USA, Apr Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 8

10 Deluge and Coffee Interplay of Deluge and Coffee :Node A :Node B D data Advertisement Advertisement Request Data Data Data D write Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 9

11 Deluge and Coffee Interplay of Deluge and Coffee :Node A :Node B Advertisement Advertisement Request D data too high Transmission takes too long D data Data Data Data D write Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 9

12 Deluge and Coffee Interplay of Deluge and Coffee :Node A :Node B Advertisement Advertisement Request D data too high Transmission takes too long D data Data Data Data D write Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 9

13 Deluge and Coffee Interplay of Deluge and Coffee :Node A :Node B D data Advertisement Advertisement Request Data Data Data D write D data too high Transmission takes too long D data too low Sometimes writing not finished Retransmissions required Transmission takes too long Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 9

14 Deluge and Coffee Interplay of Deluge and Coffee Repeated writes to file when new packets arrive Micro Logs grow fast Write-back can occur at any time and takes very long Severe delays for data dissemination Proposed Solutions: Cache larger chunks in RAM Optimize the write back Selective direct memory access Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 10

15 Deluge and Coffee Comparison of Flash Access Techniques 500 Duration for a file of 20 kb [s] Naive Cache Optimized Optimized & Cache Direct Direct & Cache Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 11

16 Analytical Model Analytical Model Topology Channel Utilization Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 12

17 Analytical Model Analytical Model Topology Channel Utilization Per-link probabilities for a successful { data transmission request transmission F. Meier and V. Turau, An Analytical Model for Fast and Verifiable Assessment of Large Scale Wireless Mesh Networks, in Proceedings of the 11th International Conference on the Design of Reliable Communication Networks (DRCN), Kansas City, MO, USA, Mar Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 12

18 Analytical Model Analytical Model Topology Channel Utilization Per-link probabilities for a successful { data transmission request transmission Per-link duration T pg (i,j) for transmitting a single page Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 12

19 Analytical Model Analytical Model Topology Channel Utilization Per-link probabilities for a successful { data transmission request transmission Per-link duration T pg (i,j) for transmitting a single page Recursively calculate duration for multiple hops and pages ( ) T mh p,j = T pg (p j,j) + max T mh p,p j, T mh p 1,j, T mh p 1,c j,1,..., T mh p 1,c j, C j Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 12

20 Analytical Model Duration of Firmware Distribution Overall duration for a file of 128 kb [min] ,185 Nodes Model Simulation Analytical model matches simulation Spatial multiplexing allows for fast firmware distribution Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 13

21 Analytical Model Components Control Room Radio Gateway Motor Controller Radio Transceiver Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 14

22 Analytical Model Procedure - 1. Phase :Control Room PC :Radio Gateway :Radio Transceiver :Motor Controller Conversion Switch to Maintenance Mode OK File Transmission Verify OK Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 15

23 Analytical Model Procedure - 2. Phase :Control Room PC :Radio Gateway :Radio Transceiver :Motor Controller Start Deluge Deluge Verify. Pending. Verify. OK. Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 16

24 Analytical Model Procedure - 3. Phase :Control Room PC :Radio Gateway :Radio Transceiver :Motor Controller Start Update Update Switch to Normal Mode. OK. Finished Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 17

25 Analytical Model Summary Software updates in large-scale industrial wireless networks Using Deluge and the Coffee File System Interplay optimized Delay largely reduced Analytical model developed Shows good conformance to the simulation Spatial multiplexing allows for fast firmware distribution Holistic approach tested with real-world components Florian Kauer, Florian Meyer, Volker Turau A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants 18

26 A Holistic Solution for Reliable Over-the-Air Software Updates in Large Industrial Plants Florian Kauer, Florian Meyer, Volker Turau Florian Kauer June 13 th, 2017 Ph.D. Student Phone +49 / (0) florian.kauer@tuhh.de Institute of Telematics Hamburg University of Technology TUHH