1 Thomas EDERC Introduction to Sensor Networks
2 Section 1 - Overview 1. Introduction to Sensor Networks 1.1From Smart Dust to Smart Plants 1.2Applications 1.3The Nature of Wireless 1.4Conclusions Thomas EDERC 2010
3 1.1 From Smart Dust to Smart Plants
4 The Promise of Wireless time $ sensing computation communication Thomas EDERC 2010
5 1997, the Smart Dust vision Thomas EDERC 2010
6 Off-the-Shelf Hardware Thomas EDERC 2010
7 1999, Optical Communication 15km Thomas EDERC 2010
8 2001, Intel Developers Forum 800 motes 8-level dynamic network Thomas EDERC 2010
9 2001, 29 Palms Demo Thomas EDERC 2010
10 S. Oh et al, "Tracking and coordination of multiple agents using sensor networks: system design, algorithms and experiments," Proc. of the IEEE, S. Kim et al, “Health Monitoring of Civil Infrastructures Using Wireless Sensor Networks,” IPSN, Cambridge, MA, April 2007 A. Ledezci, J. Lees et al, “Reventador Volcano 2005: Eruptive Activity Inferred from Seismo-Acoustic Observation”, Jnl, of of Volcanology and Geothermal Research, 2007 Wireless Sensor Networks Sensor Networks for Security Structural Monitoring Sniper Localization Environmental Monitoring Thomas EDERC 2010
11 Thomas EDERC Applications
12 We all agree… Thomas EDERC 2010
13 Building Monitoring UC Berkeley’s Center for Built Environment Seismic testing demo: real- time data acquisition hundreds of sensors on 3 floors wiring cost by far outweighs sensor cost. $200 vs. $5,000 per node in a wireless version. A few days installation (vs. weeks) Thomas EDERC 2010
14 Habitat Monitoring Overview – Study the Leach's Storm Petrel's Habitat – UC Berkeley, Prof. Dave Culler – Deployed during summer 2002 for 4 months on an uninhabited island 15km off the coast of Maine, USA Platform – 43 mica motes – TinyOS – Humidity, pressure, temperature, light, IR radiation Networking – Transmit-only nodes – One transmission every 70 seconds – 1.7% duty cycle – Simple CSMA MAC Thomas EDERC 2010
15 Precision Agriculture Overview – Micro-climate study in a potato field – Delft U. Technology, Prof. Langendoen – Deployed during Summer 2005 for 3 months in a potato field in Holland Platform – 100 motes (AtMega128L, CC1000) – TinyOS – Humidity, temperature Networking – T-MAC – Single-hop (Mint routing) – 11% duty cycle Thomas EDERC 2010
16 Automated Meter Reading Overview – Urban-wide Water Meter Reading – Coronis Systems, Elster group – Deployed since 2005 in Sable- d'Olonne, France Platform – 25,000 proprietary nodes Networking – Static routing tree – Parent association done at deployment – 10+ years (<.1% duty cycle) Thomas EDERC 2010
17 Building Automation Smart Grid Applications Industrial Automation Industrial Applications Thomas EDERC 2010
18 Thomas EDERC The Nature of Wireless
19 The Cost of Wireless Thomas EDERC %? time $ sensors computation & communication installation, connection, commissioning wired cost reduced wiring cost cellular M2M capillary M2M
20 Barriers to Adoption Thomas EDERC 2010 Reliability Standards Ease of use Power consumption Development cycles Node size 0%20% 60%80%100%
21 Energy Efficiency OperationTimePower Energy Required Technology Fill a packet with analog samples 1 s0.025 mW25 µJ 4 MHz, 80 Samples Transmit or Receive a packet s50 mW400 µJCC mJ to generate and pass this packet along 100x more than to build it Thomas EDERC 2010
22 Interoperability Thomas EDERC 2010 The Internet
23 Connectivity Thomas EDERC 2010
24 Reliability Reliability is challenged by: external interference multi-path fading Thomas EDERC 2010
25 External Interference Thomas EDERC 2010
26 First Challenge: External Interference IEEE (Wi-Fi) IEEE (Bluetooth) IEEE (ZigBee) Thomas EDERC 2010
27 Typical Tx power IEEE : 100mW IEEE : 1mW First Challenge: External Interference 2.4 GHz Channels GHz 5 MHz 2.4 GHz PHY Thomas EDERC 2010
28 IEEE802.11b/g/n IEEE802.11a/n First Challenge: External Interference 868 MHz 433 MHz 2.4 GHz5 GHz IEEE Thomas EDERC 2010
29 First Challenge: External Interference 45 motes * 50x50m office environment 12 million packets exchanged, equaly over all 16 channels *data collected by Jorge Ortiz and David Culler, UCB Publicly available at wsn.eecs.berkeley.edu Thomas EDERC 2010
30 Second Challenge: Multipath Fading Thomas EDERC 2010
31 Second Challenge: Multipath Fading Separate sender and receiver by 100cm Have sender send bursts of 1000 packets Have receiver count the number of received packets Move transmitter around in a 20cmx35cm square and start over Thomas EDERC 2010
32 Second Challenge: Multipath Fading ch.11 Thomas EDERC 2010
33 Second Challenge: Multipath Fading ch.11ch.12 0% reliability100% reliability Thomas EDERC 2010
34 Second Challenge: Multipath Fading ch.11 ch.13 ch.15 ch.17 ch.12 ch.14 ch.16 ch.18 ch.19 ch.21 ch.23 ch.25 ch.20 ch.22 ch.24 ch.26 changing channel improves performance Thomas EDERC 2010
35 Taking A Real-World Example Doherty, Lindsay, Simon. “Channel- Specific Wireless Sensor Network Path Data”, ICCCN nodes, 26 days Thomas EDERC 2010
39 Pathloss RSSI does not give an indication about distance Thomas EDERC 2010
40 Stability over all paths, all channels Thomas EDERC 2010
GHz GHz Channels bg Channels * each dot represents 15 minutes Stability over all paths, all channels Thomas EDERC 2010
42 Stability over all paths, all channels Thomas EDERC 2010
43 Stability over all paths, all channels Thomas EDERC 2010
44 Thomas EDERC Conclusions
45 Conclusions Research – many network degrees of freedom, hence a lot of work – focus is on intra wireless sensor network communication – impact era has passed but numerous problems are still open Development – keep it simple and tailor to required application – focus is on communication between WSN and Internet – impact era is yet to come Business – WSN promise significant financial cost savings – business takes off slower than anticipated due to various reasons Thomas EDERC 2010