Piconet: Embedded Mobile Networking

1. Piconet: Embedded Mobile Networking F. Bennett, D. Clarke, and J. B. Evans in IEEE Personal Communications, Vol. 4, No. 5, Oct. 1997, pp. 8-15 -- presented by Yu-Chee Tseng --

2. Embedded Mobile Networking • There already exist many simple communication devices around our everyday life: • phone, fax, copy machine • printer, portable computer, PDA • electronic access control to buildings and roads • banking machine • public information terminal, etc. • Imagine how much we may benefit if these devices can TALK with each other.

3. Benefit of Embedded Networks • Embedded Network: • a small, wireless, portable communication device • can be embedded in many communication devices • and thus connect them together • Enhanced personal connectivity • we have a multitude of connections to many devices • Context awareness • the connectivity differs as we move around

4. Piconet of ORL • Developed by ORL (Olivetti and Oracle Research): • general purpose • low powered • ad-hoc radio • Can talk to a multitude of computing and communication devices: • static, mobile, or embedded • used for sensing, communication, and control • to support only a “base level” of connectivity between things.

5. Technological Choices of Piconet • ubiquitous • periodically convey its state to others • indoor or outdoor, exposed or embedded, line-of-sight or diffused • low-power, low-rate, low-range • sleep (switched off) most of the time • radio-based • IrDA (infrared) was not chosen as its inappropriateness in outdoor use

6. Prototype Piconet Hardware • size: 12cm x 7cm • implemented in FPGA • major components: • radio • protocol • runtime environment • attribute store

7. Radio • 418 MHz FM transceiver • around 5 meters of transmission range • low-powered and cheap • greater re-use of radio channel • close to human’s definition of “proximity”

8. Protocol • ad-hoc, without base station • for short-lived transaction, not long-lived stream of data • 4b6b DC balanced encoding • support 2 kinds of multicast: • well-known (pre-assigned) • transient (dynamically created)

9. Runtime Environment • on-board kernel • a message queue • a scheduler • on-board loader

10. Attribute Store • In Piconet, each node is responsible for describing itself to the rest of the world. • any other node is thus able to determine what kind of services is provided by the device. • A mapping between a device’s name and service type should be supported. • called “attribute store” in Piconet

11. What a Piconet Node Looks Like?

12. Board and radio piggy-back Radio piggy-back in place

13. Application #1: Automatic Temperature Report • a temperature sensor with a Piconet interface • another node coming close to this sensor • a communication example: QuerySensor’s Reply GetAttribute(“/name”) “/name=Temperature Sensor” //discover sensor name GetAttribute(“/temp/C/value”) “/temp/C/value” = “17” //get temperature WatchAttribute(“/temp/C/change5”) “WatchHandle 01” 01 “tmp/C” = “24” //submit a handle, and //watch for any temperature change ... UnwatchAttribute(01) //release handle //or timeout, if the node disappears

14. Application #2: Pico + GPS in a Car an in-car GPS with Pico (can talk to many devices in the car) a map system for navigation a PDA in briefcase which logs a “trace” of this trip (when returning to office, the log can be automatically entered to database) an “authorized” mobile phone which can report the driver’s current location to someone far away (or, for location coordination)

15. Application #3: Integration with Existing Services • “authorized” phone, printer, etc • control of home appliances: • VCR, microwave, clock, radio, PDA • house heating system, control house lighting • connecting to networks for email, WWW, etc. • Only your imagination can limit!!

16. Application #4: Tour Guide information terminals at building (museum, gallery, tourist site) Pico at road sign and gateway to guide direction and offer tour info.

17. Demo • A music CD with a piconet!!