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 --
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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.
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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
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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.
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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
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Prototype Piconet Hardware
 size: 12cm x 7cm
 implemented in FPGA
 major components:
 radio
 protocol
 runtime environment
 attribute store
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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”
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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)
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Runtime Environment
 on-board kernel
 a message queue
 a scheduler
 on-board loader
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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
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What a Piconet Node Looks Like?
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Board and radio
piggy-back
Radio piggy-back
in place
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Application #1:
Automatic Temperature Report
 a temperature sensor with a Piconet interface
 another node coming close to this sensor
 a communication example:
Query
GetAttribute(“/name”)
GetAttribute(“/temp/C/value”)
WatchAttribute(“/temp/C/change5”)
UnwatchAttribute(01)
Sensor’s Reply
“/name=Temperature Sensor”
//discover sensor name
“/temp/C/value” = “17”
//get temperature
“WatchHandle 01”
01 “tmp/C” = “24”
//submit a handle, and
//watch for any temperature change
...
//release handle
//or timeout, if the node disappears
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Application #2: Pico + GPS in a Car
an in-car GPS with Pico
(can talk to many devices
in the car)
a PDA in briefcase
which logs
a “trace” of this trip
(when returning to
office, the log can
be automatically
entered to database)
a map system for
navigation
an “authorized” mobile phone
which can report the driver’s current
location to someone far away
(or, for location coordination)
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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!!
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Application #4: Tour Guide
Pico at road sign and
gateway to guide
direction and offer tour
info.
information terminals
at building (museum,
gallery, tourist site)
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Demo
 A music CD with a piconet!!
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