A brief introduction in applying wireless mesh networking to the geotechnical industry. Presented at the Field Measurements in Geomechanics symposium, Boston, MA in 2007. [Apologies for the malformed animations]

1. An Introduction to Wireless Monitoring Systems By Daniel Scott Technical Development Manager ITM-Soil Group [email_address]

5. Goal of a Monitoring System 0001100111001 Operators, Engineers, Consulting Engineers, Risk Ans, Neural Networks Spread Sheet, Software, Web Based Manual, CAN, RS485/Short Haul Modems, TCP/IP Binary, Hex, ASCII Voltage, Current, Frequency, Count, Digital mm, Hz , N, Pa, V, A, Ω , °C Observer Presentation Transport Data Signal Sensor Physical Phenomenon

9. Extreme environments

10. Extreme environments

11. Extreme environments

12. Why Wireless?

14. … disruptive environments Cabling sensors…

15. … machinery Cabling sensors…

16. … Problems with Safety … cable susceptible to damage Cabling sensors…

17. … Inter-Cable signal Interference Cabling sensors… … Cable Management … Complex Wiring Requirements … Difficult Access

18. … high cost of installation Cabling sensors…

21. Network Sensor Module (Node)

22. Network Sensor Module (Node) Sensors and nodes are put in place

23. Wireless Data Link The network collects, stores and shares sensor data

24. Network Gateway Wired Data Link Wireless Data Link A node is selected as the gateway Wired or wireless loggers are connected to the gateway

25. A data path may become blocked The network will reroute the data via a different node Network Gateway Wired Data Link Wireless Data Link

26. Network Gateway Rerouted Wireless Data Link Data are again rerouted when the obstruction is cleared This is a “Self Healing Network”

27. Network Gateway Wired Data Link Wireless Data Link Access to the network can be made from any node

28. Network Gateway If connection to the logger is lost… Data are stored within the network until connection with the logger is restored

29. Network Gateway When connection is restored, the logger can collect data from network

30. New wireless sensor nodes are installed in a nearby location The nodes are out of range of the working network … and a brick wall is in the way Placing two nodes as repeaters, the new sensors are able to connect to the existing network

31. Placing two nodes as repeaters, the new sensors are able to connect to the existing network

32. Wireless Network Module

42. Network Sensor Module (Node)

43. Wireless Data Link Network Sensor Module (Node)

44. Network Sensor Module (Node) Wireless Data Link

45. Network Sensor Module (Node) Wireless Data Link

46. Network Sensor Module (Node) Wireless Data Link

47. Network Sensor Module (Node) Wireless Data Link

48. Network Sensor Module (Node) Wireless Data Link

49. Network Gateway Wireless Data Link

50. Network Gateway Wireless Data Link

53. Intelligent Wireless Sensors A Case Study

54. Flood Monitoring

55. Flood Monitoring

56. SOLID STATE PRESSURE TRANSDUCER

57. TRANSDUCER IS INSTALLED INTO SLOTTED HDPE TUBE…

58. … AND INSTALLED BELOW THE WATER

59. GPRS MODEM LOGGER IS USED TO STORE AND COMMUNICATE DATA…

60. … AND IS CONNECTED TO THE PRESSURE TRANSDUCER

61. AT NORMAL WATER LEVELS, DATA TRANSMSSIONS NEED ONLY TO BE SENT ONCE A DAY Data sent every day

62. WHEN WATER LEVEL RISES TO PRECONDITIONED LEVELS, THE SENSOR DATA CAN BE TRANSMITTED MORE OFTEN Data sent every 10 minutes

63. IF FLOOD CONDITIONS ARE DETECTED, ALARMS CAN BE SENT AND SENSOR DATA TRANSMITTED MORE FREQUENTLY Alarms sent and data transmitted every 2 minutes

65. The Future What do you want to do?