The Hitchhiker’s Guide to Successful Residential Sensing Deployments Timothy W. Hnat, Vijay Shrinivasan, Jiakang Lu, Tamim I. Sookoor, Raymond Dawson, John Stankovic, and Kamin Whitehouse 1 Sensing in Homes Medical Monitoring Home Automation Energy Management People spend 65% of time in their homes 2 Sensing in Homes Extreme Environments Indoors is hard too! Photo courtesy of: Jan Beutel 3 Sensing in Homes Difficulty 1200 sensors Over 20 homes Up to 1 year/home #Sensors 4 Sensing in Homes Difficulty 1200 sensors Over 20 homes Up to 1 year/home #Sensors #Homes 5 Sensing in Homes Difficulty 1200 sensors Over 20 homes Up to 1 year/home #Sensors #Homes #Days 6 Outline Deployment Overview Reliability and Failure Analysis A Hitchhiker’s Guide 7 Deployments Overview 8 Deployments Overview 9 Deployments Overview 10 Deployment # Homes Weeks Motion Object Use Door Heights Wearable Tracking Light Switch Power (Plugs) Power (Circuits) Power (Mains) Water Mains Custom Thermostat Active Register Light/Temp Humidity Our Deployments A 11 1-2 2530 1220 - - - - - - - - - - B 1 1 - - 12 12 - - - - - - - - C 3 3-4 1525 - - - - - - - - - - 1225 D 1 2 4 - - - - 2 - - - - - - E 1 2 5 - - - - - 1 - - - - - F 1 28 65 13 13 16 22 - - 1 1 1 12 86 G 1 44 54 7 31 14 22 8 37 1 1 1 12 29 H 1 39 15 7 14 - 11 4 - 1 1 - - - I 1 32 25 10 30 - 31 3 48 1 1 - - 8 J 1 25 14 5 17 - 7 2 - 1 1 - - 11 Outline Deployment Overview Reliability and Failure Analysis A Hitchhiker’s Guide 12 Sensors Fault Analysis … Time 13 Failure Analysis Internet Central Database Thermostat Relay Machine … … Temperature Sensors Light Switches Doorway Sensors 14 Power Outage Sensors Fault Analysis … Time Sensor-Days – down time × number of sensors 15 Fault Analysis Reinstall Hard drive failure Plug disconnections Sub-system failure 16 Outline Deployment Overview Reliability and Failure Analysis A Hitchhiker’s Guide 17 Homes are Not a Power Panacea 30-40 outlets per house Long wires 2.3x more down time than batteries More maintenance calls 18 Homes Have Poor Connectivity Wireless connectivity Power line communications Wires 180bit/s 5 min polling rate Exploiting Home Automation Protocols for Load Monitoring in Smart Buildings 19 Homes are Hazardous Environments Children Mobile objects Roomba Guests and cleaning services 20 Homes are Remote Environments Minimize installation time Scout Lab assembly and configuration Checklists 21 Expect Limited User Participation Button Tracking Wearable Tracking Self-reporting Surveys 22 Aesthetics Matter in Homes Disappear into the woodwork Leave no trace No LEDS at night Noise 23 Simplify the Architecture Internet Central Database Thermostat Relay Machine … … Temperature Sensors Light Switches Doorway Sensors 24 Similar Work Infrastructure-based Neural Network House, Aware-Home, MavHome, PlaceLab Infrastructure-less Tapia, Cook, Kasteren Lessons Learned Edwards and Grinter – 7 challenges “Hitchhiker’s guides for WSN deployments” 25 Summary AC Power is not abundant or reliable Wireless connectivity is worse than expected Unexpected environmental hazards Houses are remote environments User participation is limited Aesthetics are important COTS are a double-edged sword 26 Thank You Any questions? 27 Root Failures Root Cause House G House H House I House J Sensing sub-system 4107 642 4757 274 Gateway Down 5596 0 3 136 Plug Disconnected 509 30 474 10 Battery Dead 452 17 168 0 Wireless Link Loss 410 0 122 1 Internet Down 251 97 178 9 Power Outage 21 0 87 2 28