Transcript EMBEDDED COMPUTATION MEETS THE WORLD WIDE WEB

EMBEDDED COMPUTATION
MEETS THE
WORLD WIDE WEB
Gaetano Borriello & Roy Want
Communications of the ACM, May 2000
Presented by
Lee, Richie (Chi-Chiang)
[email protected]
Presentation Outline
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Introduction
Communication Technologies
Device Technologies
Applications
Conclusion
Introduction
• Two important trends are converging:
(1) The computer industry’s ability to squeeze
ever-more transistors into an ever-smaller
area of silicon
(2) The proliferation of wired and wireless
networking
• We have migrated our work to electronic media
• The internet is the most vital of all the
computational components
Introduction (Cont.)
• 1970s:
(1) ARPANET - It was created by the
United States Defense Advanced
Research Project Agency.
(2) NSFNET - A wide-area network
developed under the auspices of the
National Science Foundation.
Introduction (Cont.)
• 1980s:
(1) The name INTERNET was coined.
(2) Unified by the TCP/IP protocol set.
(3) Moore’s Law – It predicts that the
number of devices that can be
fabricated on a chip doubles every 18
months.
Introduction (Cont.)
• Today:
A microcontroller + 1 megabyte memory
== A desktop computer in 1985
• New standards and mass-produced
transceivers continue to drive down the cost
of wireless connectivity
Communication Technologies
• The technologies – They are deriving the
revolutionary reorganization of our
information systems
• Standardized ubiquitous protocols – They
gather & deliver & present information to
user services through networks.
Embedded Web servers
• The Web’s basic functionality:
(1) Enables client programs and browsers
to fetch Web pages and display them
(2) Hyperlinks can reference other
local or remote files to that site
(3) A Link may reference a CGI script
• Who can build the smallest Web server?
Hydra, Xerox PARC’s embeddable Web server
Embedded Web servers (Cont.)
• Designed at Xerox PARC in 1998
• Its connector attach to a 10baseT Ethernet
• It runs the Spyglass Web server on top of
the VxWorks operating system
• 16MB DRAM & 1MB flash memory
Dallas Semiconductor’s Tini Web server
Embedded Web servers (Cont.)
• Commercial embeddable Web servers
• Some Web-server designs aim in a totally
different direction, using a serial line rather
than a direct Ethernet connection
A Web server on a Microchip PIC processor
A Web server on a FairchildACE1101MT8 processor
Embedded Web servers (Cont.)
• The challenge: implement as little as
possible of the HTTP/TCP/IP protocol stack
to meet the protocol standards while
remaining small
Java, applets, and Jini
• The java programming model provides a
way to bring computation to the client
• The code can execute locally by the local
JVM
• Java applets enable a device to export its
interface to a secondary machine
Java, applets, and Jini (Cont.)
• Jini Network Technology:
- Developed by Sun Microsystems
- Network-centric computing
- Enable local appliances to be located by
client processes
- Form ad hoc communities of devices
Jini Network Technology
• Enable devices to plug together to form an
impromptu community
• Lookup service: When a device plugs in, it goes
through an add-in protocol.
(1) Discovery - The device first locates the
lookup service
(2) join-in - then uploads an object that
implements all of its services' interfaces
Wireless Connectivity
• Among embedded devices is extremely desirable
• Allow unencumbered mobility and dynamic ad
hoc connection
• For example:
- Bluetooth
- Infrared communication
- Human-body-based communication schemes
Bluetooth
• A large consortium of computer and consumer
electronics companies
• Provide a low-cost wireless solution for
connecting components separated by no more
than several meters
• Enable links between mobile computers, mobile
phones, portable handheld devices, and
connectivity to the Internet
• Data rate around 721 Kbps
Infrared communication
• As standardized by the Infrared Data
Association (IrDA)
• Data rate ranging from 9600bps to 4Mbps
• The standard tried to encompass too many
operating modes
• Line-of-sight operation
Human-body-base communication schemes
• Sending low-power data signals through a
user’s skin
• For private communication and device
selection by touching or holding
Device Technologies
• MEMS sensors
• Tags
• Location, tracking, sensing
MEMS sensors
• Microelectromechanical systems
- An important solution to sensing,
integrating computation and communication
• Made from novel mechanical structures
constructed directly from silicon
• A common commercial application:
- The accelerometer for controlling deployment
of airbags
Photomicrograph of a MEMS accelerometer from Analog Devices
Tags
• The automatic identification industry
• Radio frequency identification (RFID)
• Electronic tags:
- For tracking everything from packages to
livestock
- Now containing onboard memory
- Have anticollision mechanisms to allow
multiple e-tags to be read in the same space
Texas Instruments’ Tag-it system
Location, tracking, sensing
• The global positioning system (GPS)
- Provide high-accuracy location data
• Indoor location sensing
• Tagging technologies
- Detect an object’s presence and its
position
Applications
• Home automation
• Experiment capture
• Health monitoring
Home automation
• Smart house
- A long-sought vision of the future
• A prototypical example
- Digital camera
• Many special challenges
Experiment capture
• Three main obstacles:
(1) No unified model for integrating the
knowledge of cell chemistry and mechanics
(2) Experiments can’t be completely recorded
(3) The lack of publication for the majority of
experiments
• Embedded Web servers can connect laboratory
instrumentation to the Web
Health monitoring
• Ubiquitous sensors and internetworking
• Provide chemical, temperature and
physiology data
• Collected by a embedded Web server over
an RF link
• New drugs along with their monitoring
sensors and releasing actuators
• Personalized drug dosages and mixtures
Conclusion
• Embedded processing is already powerful
enough to tackle the real-world applications
• Wireless and wired networking is
increasingly ubiquitous
• Achieve the interconnection of our physical
and virtual worlds
• Many challenges remaining