Contenu connexe Similaire à Introduction to Mobile Internet (20) Plus de Shujaa Solutions Ltd (6) Introduction to Mobile Internet1. Strathmore Mobile Boot Camp
November 2010
Mobile Website Development
Introduction to Mobile Internet
Facilitated by:
Michael Wakahe
Shujaa Solutions Ltd
2. Table of Contents
The Need for Mobile Web
Mobile Web History
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3. The Need for Mobile Web
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4. The Need for Mobile Web
Limitations of mobile phones
Limited Processor Power and Memory
Limited Battery Life
Limited Input and Output Facilities
Low Bandwidth
Unpredictable Availability and Stability
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5. The Need for Mobile Web
TCP/IP protocol suite was not designed for a
wireless environment
Bandwidth resource is expensive
HTML pages are not suitable for use in mobile
devices with limited processor power and
screen.
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6. The Need for Mobile Web
Users consume mobile services differently.
They buy and pay for their mobiles and mobile
software differently.
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7. The Need for Mobile Web
Mobile devices available today can be
broken down in to a few broad classes:
1. Feature Phones
2. Smart Phones
3. PDAs
4. Voice-Only Phones
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8. The Need for Mobile Web
Feature Phones are the most common device
type.
They usually come in candy bar, clamshell or
slider form.
They have a 12-key layout and typically come
with voice, messaging and data capabilities.
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9. The Need for Mobile Web
Figures: Feature
Phones
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10. The Need for Mobile Web
Smart phones share the same features as a
feature phone with two primary differences:
its ability to run additional third-party applications
a slightly larger screen.
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11. The Need for Mobile Web
Smart phones typically use a more full
featured operating system
Companies market them as them as advanced
multimedia devices to consumers or as
productivity devices to the business sector.
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12. The Need for Mobile Web
Figure: Smartphone
- iPhone
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13. The Need for Mobile Web
PDAs evolved from the PDAs of the ‘90s
Now often include voice, messaging, and data
capabilities.
PDAs have much in common with smart
phone
But differ in that much of their functionality is
oriented towards organizational tasks rather
then voice communications.
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14. The Need for Mobile Web
Figure: Personal
Digital Assistants
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15. The Need for Mobile Web
Voice-Only Phones are typically extremely
low-cost phones aimed at developing
markets
Are not relevant in the context of the Mobile
Web.
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16. The Need for Mobile Web
Feature Phones lead the market by a large margin
However the borderline between the Feature Phones
and Smart Phones is constantly shifting towards the
Smart Phone category
The newest Feature Phones are often equal in
functionality to yesterday’s Smart Phones.
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17. The Need for Mobile Web
Figure: Distribution
of Mobile Handsets
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18. The Need for Mobile Web
The Web is a vast collection of servers linked by
TCP/IP computer networks.
These web servers, implement the Hypertext
Transfer Protocol (HTTP) to share documents and
files.
Web servers provide access by Uniform Resource
Identifiers (URIs) to text files, markup documents,
and binary resources.
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19. The Need for Mobile Web
In an HTTP request, the client sends a web
server the URI of the desired resource and a
collection of request headers
One of the request headers contains a list of
MIME types that advertise the content types
supported on the client.
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20. The Need for Mobile Web
In an HTTP response, the web server sends
the client the document itself (markup, text,
or binary) and another set of headers
One of the response headers contains the
MIME type describing the file type of the
document transmitted to the client.
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22. Mobile Web History
Wireless Application Protocol (WAP) Forum was
founded in 1997 by Ericsson, Motorola, Nokia, and
Phone.com.
WAP 1.1 was published in 1999
WAP 2.0 was published in 2001
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23. Mobile Web History
In 2002, the WAP Forum consolidated into the Open
Mobile Alliance (OMA) and the specification work
from WAP continues within OMA
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24. Mobile Web History
WAP is designed with two main goals
to minimize bandwidth requirement
to maximize the number of supported network
types (e.g., 9.6 Kbps in GSM).
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26. Mobile Web History
WAP protocol stack is a lightweight protocol stack
that is designed to address the limitations of wireless
devices and the wireless network.
To access ordinary web servers, WAP-enabled mobile
devices can rely on a WAP gateway to provide
protocol conversion between WWW protocol stack
and WAP protocol stack.
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27. Mobile Web History
WAP tries to utilize existing Internet protocols and
standards as much as possible
For example XML, HTML, HTTP & TLS
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28. Mobile Web History
Each layer of the protocol stack is designed to
be scalable and efficient.
For example, in Wireless Transaction Protocol
(WTP), there is no explicit connection setup or
teardown
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29. Mobile Web History
To describe the capabilities of a mobile device, WAP
has defined a user agent profile (UAProf)
The capabilities of a mobile device are related to
software and hardware
This includes things like processor type, memory
capacity, display size, browser type and version,
network type, etc.
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30. Mobile Web History
The aim of using UAProf is to allow all elements of
the WAP infrastructure (i.e., content servers,
application servers, gateways, etc.) to provide mobile
devices with device-specific contents.
A user agent profile is basically an XML document
containing information about hardware and software
characteristics of a mobile device and network to
which it will be connected.
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31. Mobile Web History
The user agent profile of a mobile device is stored in
its manufacturer's server, called the profile
repository.
In order to provide mobile devices with device-
specific contents, when a mobile device performs a
request to a server, the URL of its user agent profile
will be included in the header of the request
message.
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32. Mobile Web History
Example of UAProf: For Sony Ericsson K750i, found
at:
http://wap.sonyericsson.com/UAprof/K750iR101.xml
Open example XML
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33. Mobile Web History
To reduce transmission time, WAP uses binary-coded
WML (wireless markup language) pages.
Also WAP specifies a caching model and user agent
profile (UAProf) for efficient delivery of device-
specific content.
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34. Mobile Web History
HTML pages are not suitable for use in mobile
devices with limited processor power and screen.
Wireless Markup Language (WML) is designed to
describe data and the format that data should be
presented on mobile devices
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35. Mobile Web History
WML is a tagged language.
WML adopts a deck and card metaphor.
Each WML document is made up of multiple cards,
and cards are grouped into a deck.
WML pages can be encoded in a binary format
before transmission.
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36. Mobile Web History
<wml>
<card id=“Card1" title="First Card">
<p>
Hello World!
</p>
</card>
<card id="Card2" title="Second Card">
<p>
WAP is fun!
</p >
</card>
</wml>
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38. Mobile Web History
WMLScript is a scripting language which
complements WML.
Similar to JavaScript for HTML
WMLScript bytecode interpreter is compact in size,
which allows efficient execution of scripts will less
memory and processor requirements
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39. Mobile Web History
Three elements in a WAP architecture:
Client: the WML browser in a wireless device.
It issues WAP requests to a server.
Server: the entity which provides services and
where resources are located. This can be an
ordinary Internet-based server or a WAP-
capable server.
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40. Mobile Web History
Gateway: provides protocol conversion
between the WWW protocol stack and the
WAP protocol stack, by using content
encoders and decoders
Thus a gateway acts as a proxy server
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41. Mobile Web History
Figure: WAP infrastructure.
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42. Mobile Web History
When protocol conversion is performed at the
gateway, it can minimize wireless
communication overhead at the client side.
The gateway can also cache frequently
requested contents so as to reduce the
request - response time.
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43. Mobile Web History
The architecture discussed so far is the common pull
architecture based on the client - server paradigm
WAP system architecture also specifies a push
architecture to enhance the WAP services
Here the server sends messages to the client without
explicit request from the client.
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44. Mobile Web History
Push architecture is very useful in delivering
messages like instant news, email indication,
advertising etc
In the push architecture, the server and the
gateway are called the push initiator (PI) and
the push proxy gateway (PPG), respectively.
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45. Mobile Web History
Figure: WAP push architecture
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46. Mobile Web History
WAP is designed to meet the following requirements
Interoperability
Scalability
Efficiency
Reliability
Security
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47. Mobile Web History
Mobile Web uses the plumbing of Desktop Web
and adds new MIME types, markup languages,
document formats, and best practices
Web content provided is optimized for the small
screens, resource constraints, and usability
challenges of web browsers on mobile devices.
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48. Mobile Web History
The Mobile Web introduces new components into
the web ecosystem, including:
Markup languages and styles optimized for
mobile devices
MIME types that differentiate mobile markup
from desktop HTML
Browser clients with a wide variety of capabilities
Network proxies that further adapt your content
to cater for those clients
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49. Mobile Web History
Rich Web 2.0 features such as JavaScript
frameworks and Asynchronous JavaScript and
XML (AJAX) must be used judiciously, or you
risk draining battery power.
Operators frequently control and block traffic
to Mobile Web sites.
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50. Mobile Web History
Transcoding proxies often attempt to reformat
mobile markup en route to a mobile browser.
Defensive programming is essential to reduce
exposure to transcoders and mobile network
problems.
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51. Mobile Web History
Mobile users are keenly goal-directed and
location-aware.
Roaming in and out of coverage areas, mobile
users count network access problems among
the top factors affecting the Mobile Web
browsing experience.
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52. Mobile Web History
The mobile browser is totally new & has
unique benefits, quirks, and workarounds.
Partial and flawed implementations of web
standards are commonplace.
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53. Mobile Web History
Improperly formatted web pages can have
drastic effects on mobile devices, including
crashing the browser or resetting the device.
Advanced web features such as JavaScript and
AJAX are highly desirable but drain battery
life.
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