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Microbrowser
A microbrowser is an
internet or web
browser designed for use on a handheld
device such as a PDA
or mobile
phone. Microbrowsers have small file sizes to accommodate
the low memory capacity and low-bandwidth of wireless handheld
devices. Essentially it is a stripped-down web
browser. Sometimes it is referred to as micro-browser,
mini-browser or minibrowser.
Underlying
technology
The microbrowser usually sets up the
cellular networks themselves and gets content written in XHTML
Mobile Profile (WAP 2.0), or WML
(WAP 1.3 which was based on HDML).
WML and HDML are stripped-down formats suitable for transmission
across limited bandwidth, and wireless data connection called WAP.
In Japan, DoCoMo defined the i-mode
service based on i-mode HTML, which is an extension of Compact
HTML (C-HTML),
a simple subset of HTML.
WAP 2.0 specifies XHTML Mobile Profile plus WAP CSS, subsets of
the W3C's standard XHTML and CSS with minor mobile extensions.
Newer microbrowsers are full-featured Web browsers capable of
HTML, WML, i-mode HTML, cHTML, plus CSS, ECMAScript, and
plug-ins such as Macromedia Flash.
Pioneers
The so-called microbrowser technologies
such as WAP, NTTDocomo's i-mode
platform and Openwave's
HDML platform have fuelled the first wave of interest in
wireless data services.
A British company, STNC
Ltd., developed a microbrowser (HitchHiker)
intended to present the entire device UI in 1997. The
demonstration platform for this microbrowser (Webwalker) had 1 MIPS
total processing power. This was a single core platform, running
the GSM stack on the same processor as the application stack. In
1999 STNC
was accquired by Microsoft
and HitchHiker became Microsoft
Mobile Explorer 2.0, not related to the primitive Microsoft
Mobile Explorer 1.0. HitchHiker is believed to be the first
microbrowser with a unified rendering model, handling HTML and
WAP along with EcmaScript, WMLScript, POP3 and IMAP mail in a
single client. Although it was not used, it was possible to
combine HTML and WAP in the same pages although this would
render the pages invalid for any other device. In addition, Amstrad's
ill-fated e-m@iler
and e-m@iler+ products used HitchHiker as their operating
systems. Mobile Explorer 2.0 was available on the Benefon Q,
Sony CMD-Z5, CMD-J5, CMD-MZ5, CMD-Z7, CMD-J7 and CMD-J70.
A freeware (although later shareware) browser for the PalmOS was
Palmscape,
written in 1998 by Kazuho Oku in Japan, who went on to found Ilinx.
Still in limited use as late as 2003.
Released in 2001, Mobile
Explorer 3.0 added iMode compatibility (cHTML) plus numerous
proprietary schemes. By imaginatively combining these
proprietary schemes with WAP protocols, MME3.0 implemented OTA
database synchronisation, push email, push information clients
(not unlike a 'Today Screen') and PIM functionality. The
cancelled Sony Ericsson CMD-Z700 was to feature heavy
integration with MME3.0. Mobile Explorer development had ceased
by mid-2002.
Opera Software pioneered with its Small Screen Rendering
technology. Opera Browser is able to relayout regular web pages
for optimal fit on small screens and medium-sized (PDA) screens.
It was also first widely available mobile browser to support AJAX.
Small
Screen Rendering Limitations
As mentioned, not only do microbrowsers need to be small in file
size, the display screen is also much smaller. Extreme care and
meticulous detail must be considered in displaying HTML
information onto such a small screen. Bandwidth is also
extremely limited and so is the stability. Connections get cut
off as with ordinary cell phones and PDAs that are wirelessly
connected.
Popular
microbrowsers
The following are some of the more popular microbrowsers. Since
microbrowsers are really miniaturized web browsers, the
microbrowser companies also provide browsers for the PC.
External
link
This
content from Wikipedia
is licensed under the GNU
Free Documentation License.
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