[LINK] W3C "Efficient XML Interchange" (EXI) Standard

Tom Worthington tom.worthington at tomw.net.au
Wed Mar 16 13:39:16 AEDT 2011


stephen at melbpc.org.au wrote:
>...  <http://www.w3.org/2011/03/exi-pr.html.en>
> ...The "Efficient XML Interchange" (EXI) standard dramatically improves the 
> performance, network efficiency, and power consumption of applications 
> that use XML. ...

When I first read this it sounded like something from Professor
Klerphell, that is a wildly exaggerated claim.

> EXI is a very compact representation of XML information ...

Compression should take care of most of the bandwidth issues for devices
such as smart phones. However, if very large amounts of data are being
transmitted by sensor devices, then this would be of use. It would also
be interesting to see if it would be feasible to apply XML to areas
where it has not been used before, such as the surveillance data being
transmitted from a UAV (robot aircraft).

Some of the benefits of XML are lost with EXI, such as its human
readable format. But than while the text of XML could be read, in most
cases the format of the data is so complex that without the schema used
it will make little sense to anyone. At least with EXI as soon as the
reader (human or machine) realises the data is in EXI, they will have a
standardised format to interpret.

There is also the potential to use EXI to compress XML data for
transmission or storage, without the cooperation of the creating and
consuming applications. It might also be used to make XML based document
formats, such as OOXML, ODF and ePub more efficient. But given these
already use compression algorithms, so the savings may be too small to
be worth the additional complexity.

> "We are amazed with what our customers have accomplished," ... W3C Community Resolves Fragmentation; Creates Single Interoperable 
> Standard ... EXI is Exciting ...  accelerates financial trading systems ... defense applications ...

About the only application so far appears to be in version 2.0 of the
"ZigBee Smart Energy Standard", for smart electricity meters and
appliances:
<http://www.zigbee.org/Standards/ZigBeeSmartEnergy/Version20Documents.aspx>.

If applied to air conditioners, refrigerators, and electric vehicles
this could be significant in fixing Australia's electricity grid and
reducing greenhouse gas emissions. As Professor Robin Eckermann pointed
out in his talk on "The SMART GRID - The looming energy revolution" in
Canberra 2 March 2001, the electricity generation and distribution
system has little information as to what the power is used for, making
efficient management difficult. If large power using devices could
report cooperate with the grid, that would make the system more
efficient and robust. In the case of electric cars, they could also
provide supplementary power back into the
grid.<http://blog.tomw.net.au/2011/03/smart-grid-energy-revolution-for.html>.

ps: There is a Go Get modified Prius parked at a charge point in Glebe
Point Road Sydney:
<http://www.goget.com.au/bookings/show_vehicle.php?vehicle_id=378>.


-- 
Tom Worthington FACS CP HLM, TomW Communications Pty Ltd. t: 0419496150
PO Box 13, Belconnen ACT 2617, Australia  http://www.tomw.net.au
Adjunct Senior Lecturer, School of Computer Science, The
Australian National University http://cs.anu.edu.au/courses/COMP7310/
Visiting Scientist, CSIRO ICT Centre: http://bit.ly/csiro_ict_canberra






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