Wireless Sensor Networks as The Next Tier of the Internet

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

2. The Internet Today SensorExpo - Next Internet

3. The Internet Tomorrow SensorExpo - Next Internet

4. The Internet ~ The World SensorExpo - Next Internet

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

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

7. 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 SensorExpo - Next Internet

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

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

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

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

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

13. 2 2 2 2 1 1 2 Multi-Hop Mesh Routing 0 SensorExpo - Next Internet

14. 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 SensorExpo - Next Internet

15. 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 SensorExpo - Next Internet

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

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

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

19. 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 SensorExpo - Next Internet

20. 1st Internet Principle: IP “hour glass” Application XML / RPC / REST / SOAP / OSGI Session HTTP / FTP / SNMP Transport TCP / UDP Network routing IP Link Ethernet Sonet 802.11 … Physical Fiber 10BT Coax Serial DSS QPSK SensorExpo - Next Internet

21. 2nd Internet Principle: End-to-End Architecture SensorExpo - Next Internet

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

23. 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 SensorExpo - Next Internet

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

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

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

27. 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 SensorExpo - Next Internet

28. 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 SensorExpo - Next Internet

29. 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 SensorExpo - Next Internet

30. 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 SensorExpo - Next Internet

31. 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) SensorExpo - Next Internet

32. 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 SensorExpo - Next Internet

33. Service Description find publish bind Service Oriented Architecture Service Registry • 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 Requestor Service Provider SensorExpo - Next Internet

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

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

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

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

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

39. Sensor Web Services SensorExpo - Next Internet

40. Pick your favorite client SensorExpo - Next Internet

41. Real World Webs SensorExpo - Next Internet

42. 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, … SensorExpo - Next Internet

43. Client tier1 J2EE SOAP Enterprise Server tier2 SensorNet GW/Proxy physical info net SensorNet mote sensor Physical World 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 internet tier3 tier4 SensorExpo - Next Internet

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