1. Wireless Sensor Networks as The Next Tier of the Internet David E. Culler dculler@archrock.com Arch Rock Corp. University of California, Berkeley 6-6-06Sensors Expo

2. SensorExpo - Next Internet 2 The Internet Today

3. SensorExpo - Next Internet 3 The Internet Tomorrow

4. SensorExpo - Next Internet 4 The Internet ~ The World

5. SensorExpo - Next Internet 5 Physical Information Streams Sensors are everywhere –But the data is mostly dropped on the floor Physical => Digital => Information Each sensor becomes a network citizen 010010001… temp=35

6. SensorExpo - Next Internet 6 What are Wireless Sensor Networks? Network of tiny footprint computers Optimized for long life on low power Equipped to sense physical data Networked using low-power radio Function: –Sense any measurable parameter Light, motion, chemicals, proximity, biometrics –Form network and communicate Automatic meshing and routing over the air –Apply user-defined business logic Sampling, summarizing, reporting events Form: –Mote (Processor, Radio, Storage) + Sensors –Embedded Operating System and Networking –Gateways towards Enterprise IT systems Gateway Internet or Enterprise Gateway Wireless Sensor Nodes

7. SensorExpo - Next Internet 7 Why are they so Important? Enable New Knowledge Improve Productivity Protect Health High-Confidence Transport Enhance Safety & Security Improve Food & H20 Save Resources Preventing Failures Increase Comfort

8. SensorExpo - Next Internet 8 The Next Tier of the Internet” ? More than protocols - IP/TCP/HTTP Open Building blocks for physical information –platforms, systems, networks Open Process for Networking Excellence –Reference implementations leading to standardized protocols and interfaces Design philosophy – Expect Change, Failure, Uncertainty, Unexpected Enable broad applications –Web services

9. SensorExpo - Next Internet 9 Emergence of Open Platforms Physical World Silicon World StorageWireless Processing Sensors Berkeley open WSN “motes” Proprietary WSN nodes

10. SensorExpo - Next Internet 10 Emergence of Open Systems Physical World Silicon World Storage Processing Sensors Wireless Digital World WSN mote platform

11. SensorExpo - Next Internet 11 Snapshot of an International Community http://www.tinyos.net 346,000+ downloads from tinyos.net -plus sourceforge, crossbow, moteiv, www.tinyos.or.kr, … www.tinyos.or.kr Open TinyOS Alliance

12. SensorExpo - Next Internet 12 Storage ProcessingWireless Sensors WSN mote platform Wireless Embedded Systems Radio Serial FlashADC, Sensor I/F MCU, Timers, Bus,… Link Network Protocols Blocks, Logs, Files Scheduling, Management Streaming drivers Over-the-air Programming Applications and Services Communication Centric Resource-Constrained Event-driven Execution TinyOS 2.0

13. SensorExpo - Next Internet 13 Silicon World Storage ProcessingWireless Sensors WSN mote platform Wireless Embedded Networks Physical World Digital World Radio Serial FlashADC, Sensor I/F MCU, Timers, Bus,… Link Blocks, Logs, Files Scheduling, Management Streaming drivers Over-the-air Programming Applications and Services Network Protocols

14. SensorExpo - Next Internet 14 Multi-Hop Mesh Routing 0 1 1 2 2 2 2 2

15. SensorExpo - Next Internet 15 Applications => Network Characteristics Monitoring Spaces –Env. Monitoring, Conservation biology,... –Precision agriculture, –built environment comfort & efficiency... –alarms, security, surveillance, EPA, OSHA, treaty verification … Monitoring Things –condition-based maintenance –automated meter reading –disaster management –Civil infrastructure Interactions of Space and Things –manufacturing, asset tracking, fleet & franchise –context aware computing, non-verbal communication –Assistance - home/elder care Action and control –Optimizing processes –Automation

16. SensorExpo - Next Internet 16 Embedded Networking Requirements Reliable Dissemination Data Collection and Aggregation Point-to-point Transfers Reliably over lossy links At low power –Idle listening, management, monitoring Adapting to changing conditions Scalar and Bulk Versions

17. SensorExpo - Next Internet 17 Storage ProcessingWireless Sensors WSN mote platform Diversity of Networks FlashADC, Sensor I/F MCU, Timers, Bus,… Ember ZNet Zigbee Network Blocks, Logs, Files Scheduling, Management Streaming drivers Applications and Services

18. SensorExpo - Next Internet 18 Patch Network Sensor Node Gateway Canonical SensorNet Network Architecture Transit Network (IP or not) Access point - Base station - Proxy Sensor Patch Data Service Intranet/Internet (IP) Client Data Browsing and Processing Other information sources

19. SensorExpo - Next Internet 19 How will SensorNets and IP play together? 802.15.4, CC, … 802.11 EthernetSonet IP TCP / UDP HTTP / FTP / SNMP XML / RPC / REST / SOAP / OSGI

20. SensorExpo - Next Internet 20 Beware “IP hype” Pushing HTML over a wireless connection to a serial port attached to a PC is NOT running IP on the sensorNet Nor is packet-scraping into XML-RPC

21. SensorExpo - Next Internet 21 1st Internet Principle: IP “hour glass” Network routing Link Physical Transport EthernetSonet IP TCP / UDP HTTP / FTP / SNMP XML / RPC / REST / SOAP / OSGI 802.11 Session Application Coax10BTFiberSerialDSSQPSK …

22. SensorExpo - Next Internet 22 2 nd Internet Principle: End-to-End Architecture

23. SensorExpo - Next Internet 23 Full IP stack throughout 802.15.4, CC, … 802.11 EthernetSonet TCP / UDP HTTP / FTP / SNMP XML / RPC / REST / SOAP / OSGI IP

24. SensorExpo - Next Internet 24 Sensor Net Challenges for traditional IP Large headers <> small packets Very different protocol assumptions –Low-power –Intermittent connectivity (mostly sleeping) –Loss ≠ > Congestion Very different traffic patterns –Not universal point-to-point file transfer –Aggregate collection, dissemination Naming –The data is important, not the machine Mobility

25. SensorExpo - Next Internet 25 Enterprise-Scale Sensor Nets Internet Gateways SensorNet Patch

26. SensorExpo - Next Internet 26 The Internet: End-to-End no more… Network Address Translation Firewall Load Leveler Switch

27. SensorExpo - Next Internet 27 Edge Network Approach 802.15.4, CC, … 802.11EthernetSonet IP TCP / UDP HTTP / FTP / SNMP XML / RPC / REST / SOAP / OSGI Proxy / Gateway

28. SensorExpo - Next Internet 28 Hybrid approach Security –No IP to the nodes, attacks have to get through the gateway or be physically close Namespace management –Name nodes, networks, services –Hosts, URLs, … Mask intermittent connectivity –Terminate IP on the powered side –Loosely couple, energy aware protocols on the other Distillation proxies –Small binary packets where constrained –Expanded to full text, XML, HTML, web services Rich suite of networking techniques in the Patch unimpeded by overall internet-scale process

29. SensorExpo - Next Internet 29 SensorNets need the Wisdom of the “Internet Architecture” Design for change! Network protocols must work over a wide variety of links –Links will evolve Network protocols must work for a variety of applications –Applications will evolve Provide only simple primitives –Don’t confuse the networking standard with a programming methodology Don’t try to lock-in your advantage in the spec Open process Rough consensus AND running code

30. SensorExpo - Next Internet 30 Networking vs Distributed Applications IP, 802.15.4, Zigbee are still “plumbing” Enterprise information infrastructure means Integration with Applications –The data, how it is represented, what it means –The operations you can do on it –How it is obtained from the physical world –Actions based on it

31. SensorExpo - Next Internet 31 Database View of the World The World is a Database –SQL, ODBC/JDBC –The good old days of client-server –Data warehouses and distributed databases –Network taken for granted

32. SensorExpo - Next Internet 32 Web Services The ultimate interoperability unify within and between enterprises –Service Oriented Architecture –Widely adopted standards Backed by OASIS and W3C Open-source reference implementations, e.g., Apache SOAP + WSDL (+ UDDI) Or XML-RPC over HTTP (REST)

33. SensorExpo - Next Internet 33 Web Service* Platform and implementation independent software component that can be Described using a service description language Published to a registry of services Discovered through a standard mechanism Invoked through a declared API –Usually over a network Composed with other services * Building Web Services with Java, Graham et al, SAMS 2002

34. SensorExpo - Next Internet 34 Service Oriented Architecture Service Description => interface & implementation –Operations supported, input/output objects –Bindings to network and data encoding schemes –Network address where service can be invoked Enough that client can generate code to access the service well Service Provider Service Requestor Service Registry Service Description publishfind bind

35. SensorExpo - Next Internet 35 Sensors Embedded Application Tier tier1 tier2 client server tier3 SensorNet GW/Proxy physical info net MCURadioSensors Hardware Abstraction Layer TinyOS Runtime Services Common Link Abstraction Networking Protocols Management Embedded applications built on a rich set of node services. –Timing, sensor streams, storage –Local processing –Reliable, low-power communication –Platform independent + extensions Embedded Application tier4 “mote” Physical World

36. SensorExpo - Next Internet 36 WSNs and Web Services tier1 tier2 client server tier3 SensorNet GW/Proxy tier4 sensor SensorNet mote physical info net MCURadioSensors Hardware Abstraction Layer TinyOS Runtime Services Common Link Abstraction Networking Protocols Management Decorate external interface points –Attributes (shared data) –RPCs (control points) –Events (signals) Embedded Application @attribute @event @rpc temp alarm test

37. SensorExpo - Next Internet 37 WSNs and Web Services tier1 tier2 client server tier3 SensorNet GW/Proxy tier4 sensor SensorNet mote physical info net MCURadioSensors Hardware Abstraction Layer TinyOS Runtime Services Common Link Abstraction Networking Protocols Management Auto-generate Web Services –Service description –Service implementation Embedded Application Embedded Web Service

38. SensorExpo - Next Internet 38 WSNs and Web Services tier1 tier2 client server tier3 SensorNet GW/Proxy tier4 sensor SensorNet mote physical info net Auto-generate Web Services –Service description –Service implementation Embedded Web Service

39. SensorExpo - Next Internet 39 A new WSN world tier1 tier2 client server tier3 SensorNet GW/Proxy tier4 sensor SensorNet mote physical info net Embedded Services Perl Python Excel NetWeaver AquaLogic C#

40. SensorExpo - Next Internet 40 Sensor Web Services

41. SensorExpo - Next Internet 41 Pick your favorite client

42. SensorExpo - Next Internet 42 Real World Webs

43. SensorExpo - Next Internet 43 Take-aways WSN building blocks are here Enterprise Integration IS the key to the WSN future –Enterprises large, small, distributed, indoor, outdoor, residential, industrial, … Integrate the applications, not just the network –Independent of the transport, platform,.. (plumbing) Web Services provide the framework –But the underlying infrastructure must be Rock Solid and extensible –The “plumbing” has to really really work Reliability, power, management, adaptation, life-cycle, …

44. SensorExpo - Next Internet 44 Arch Rock Connecting the physical world to the information enterprise Solid Foundation –High-quality, Cross-Platform embedded application infrastructure Standard-based –OS, Networking, Services –Reliable, efficient, extensible Novel information in familiar forms –IP-accessible web services –Auto-generated from embedded application tier1 tier2 sensor SensorNet mote tier3 SensorNet GW/Proxy tier4 physical info net Physical World Client Enterprise Server J2EE SOAP internet

45. SensorExpo - Next Internet 45 Uniting long-lost relatives General Purpose Computing Instrumentation Computers Mainframe Minicomputer Workstation PC VME Dedicated Controllers Home Automation Building Automation