1. The Particle Computer System Christian Decker, Albert Krohn, Michael Beigl, Tobias Zimmer TecO, University of Karlsruhe Institut for Telematics Telecooperation Office (TecO) www.teco.edu

2. TecO The Particle Computer System, SPOTS/IPSN 2005 2 Outline  A brief history on Particle Computer  Design requirements  Hardware  Communication protocol / Energy consumption  Particle System software  Future directions

3. TecO The Particle Computer System, SPOTS/IPSN 2005 3 History of Particle Computer  Roots: EC project „Smart-Its“ (2001-2003)  Goal: Augment mundane everyday objects by small embedded electronic devices to form digital relationships  Typical Ubicomp approach Particle 1.01 (TecO) BTNode rev2 (ETH) DIY Smart-It (Lancs) Particle 2/29 (TecO) BTNode rev3 (ETH)

4. TecO The Particle Computer System, SPOTS/IPSN 2005 4 Domain  Researcher‘s office  ~1200 single items  Regular office  ~450 single items

5. TecO The Particle Computer System, SPOTS/IPSN 2005 5 Platform Design Requirements  Support highly-mobile settings  Support ad-hoc collaboration  Environmental and activity sensing capabilities  Seamless infrastructure integration

6. TecO The Particle Computer System, SPOTS/IPSN 2005 6 Particle System Architecture  Particle nodes + backend components  Flat architecture / no middleware Particle UDP Network Particle DB Particle Analyzer Particle Bridge...

7. TecO The Particle Computer System, SPOTS/IPSN 2005 7 Particle System Architecture  Particle nodes + backend components  Flat architecture / no middleware Particle UDP Network Particle DB Particle Analyzer Particle Bridge...

8. TecO The Particle Computer System, SPOTS/IPSN 2005 8 Particle System Architecture  Particle nodes + backend components  Flat architecture / no middleware Particle UDP Network Particle DB Particle Analyzer Particle Bridge...

9. TecO The Particle Computer System, SPOTS/IPSN 2005 9 Particle Communication Board Particle Core board  PIC18F6720 microcontroller  5 MIPS@20MHz  128 KB ROM, 4 KB RAM  TR1001 transceiver  512 KB flash memory  125 kbps data rate on 868MHz (AwareCon protocol)  Actuators (2 LED, 1 speaker)  On-board sensors: Battery Level, Movement  Single AAA battery  15x48 mm (AAA size)

10. TecO The Particle Computer System, SPOTS/IPSN 2005 10 Sensors  Sensor (a) 17x22 mm Acceleration sensor Temperature sensor Light sensor Infrared sensor Microphone  Sensor (b) Same features as sensor (a) Force sensor Additional PIC18F452 microcontroller  3rd party sensors can be integrated with the communication board over the microproto board interface

11. TecO The Particle Computer System, SPOTS/IPSN 2005 11 AwareCon Stack  Particle communication protocol, TDMA  Implemented on PIC microcontroller  Time frame commonly established  Fully distributed, no master needed  1 slot = 13ms ~ 8ms communication phase ~ 5ms application phase  Highly scalable through CAN-like arbitration on RF AwareCon Timeslot

12. TecO The Particle Computer System, SPOTS/IPSN 2005 12 AwareCon - Arbitration  CAN arbitration on RF layer for all sending nodes  Nodes select random number and interfere them on channel (1 bit is dominant)  Highest number wins  RF-CAN: 50 nodes, 97% no collsions  WLAN: 50 nodes, 58% no collisions

13. TecO The Particle Computer System, SPOTS/IPSN 2005 13 AwareCon – Ad hoc Capabilities  12 ms book in time in synchronized network  40 ms for sync to single partner

14. TecO The Particle Computer System, SPOTS/IPSN 2005 14 Energy Consumption Voltage (V) Date

15. TecO The Particle Computer System, SPOTS/IPSN 2005 15 ConCom  Data encoded as tuples, strictly typed Type: 3 bytes, freely selectable Length: 1byte, data length Data: data to transmit  Subject = first tuple, identifies application  Sentence = subject + [tuples]*  Publish/subscribe model Application subscribes on subject type Several application run parallel Tuple type reuse Cross-layer optimizations AwareCon ConCom Physical Link Network Transport Application

16. TecO The Particle Computer System, SPOTS/IPSN 2005 16 Cross layer optimization  Cross-layer optimization through ConCom Early shutoff for non-subscribed ConCom subjects saves up to 91% energy Sleep

17. TecO The Particle Computer System, SPOTS/IPSN 2005 17 Particle System Architecture  ConCom is common communication language throughout the system  no middleware required Particle UDP Network Particle DB Particle Analyzer Particle Bridge... ConCom

18. TecO The Particle Computer System, SPOTS/IPSN 2005 18 Particle System Software  AwareCon Communication stack Acts like scheduler (8ms communication, 5ms application) Hard realtime  Sensor library Access methods for all sensors Convert methods for sensor data Creates ConCom tuples  Application integrates with system libs to a single image AwareCon Hardware Sensors Application

19. TecO The Particle Computer System, SPOTS/IPSN 2005 19 Particle File System Uniform resource presentation and access model  Uniform, hierarchical namespace /dev/ - direct resources, e.g. sensors, memory, power supply, communication interface /context/ - mediated resources, which access direct resources for computation, exported application functions /usr/ - data files  Complete de-coupling of application from system libraries AwareCon Hardware Sensors Application File System

20. TecO The Particle Computer System, SPOTS/IPSN 2005 20 Access Model Fundamental operations  read(..) and write(..) – data transfer operations  Resources are coupled with specific r/w methods Example: read(1, buf, 1) Additional operations  open(..)  mount(..)/umount(..)  getType(..) Type System  Type of resource, developer decides  Compatibility in resource combinations Resource identifier Resource nameTypeReadWrite 1/dev/voltage3pFunc... VoltageSensorGet(int &v) {... } NOP() { ; }

21. TecO The Particle Computer System, SPOTS/IPSN 2005 21 FS Application: Shell Shell  Login on a single Particle  Shell functions are exported as resources in the file system  Interactively browse/call resources  Combine resources through pipes /bin/s_temp | /bin/ctupl ste | /bin/sendRF Future work  Shell scripts

22. TecO The Particle Computer System, SPOTS/IPSN 2005 22 FS Application: Over-the-Air- Programming  Programming is file copy! Bridge Compiled Program Particle FTP Proxy Network

23. TecO The Particle Computer System, SPOTS/IPSN 2005 23 Performance File system  Up to 2^13 resources  ~1900 bytes RAM  ~2100 bytes ROM File library  ~10 kilobytes ROM Access overhead  *buf = f() Call + store result 26 instruction cycles  read(fd,buf,1) lookup for function pointers + call + store result More parameters 100 instruction cycles

24. TecO The Particle Computer System, SPOTS/IPSN 2005 24 Future Directions Domain  Move out of the office domain  New target domain: business processes Hardware  Explore new communication standards (802.15.4 - zPart) System software  Build an OS around the file system Sensor fusion  Massive parallel sensor fusion in O(1) using radio channel computing

25. TecO The Particle Computer System, SPOTS/IPSN 2005 25 Further resources http://particle.teco.edu