embedded computation meets the world wide web gaetano borriello & roy want communications of the...
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EMBEDDED COMPUTATION MEETS THE
WORLD WIDE WEB
Gaetano Borriello & Roy WantCommunications of the ACM, May 2000
Presented by
Lee, Richie (Chi-Chiang)[email protected]
Presentation Outline
• 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 construc
ted 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