Limitations of Wireless

1
Understand WML
Chao-Hsien Chu, Ph.D. School of Information
Sciences and Technology The Pennsylvania State
University
2
Possible Service Types by WAP
Local Development Services
Messaging
Call Handling
WAP
Information Services
Gamming
Electronic Commerce
Transport
Database Access
3
Limitations of Wireless

• Physical Devices
• Size / Display
• Memory / Cache Size
• Battery
• Data Entry Methods
• Contents
• Different Standards
• Micro browser
• Scarcity of contents
• Block internet surfing.
• Character-based Info.

• Networks
• Bandwidth limitations.
• Incomplete service coverage.
• Lack of an installed user base.
• High customer cost.
• Changing communications standards.
• Latency
• Connection reliability
• Security.

4
Why New Standard
Info services
Telecom services
Unified mailbox
E-mail
Info
Security
Call control
WWW
Message Services
ITTP
HDML
Other
SIM toolkit
TTML
WAP
5
WAP Architecture
6
Sketch of WAP Network Architecture
WAP gateway
Web server
Corporate
Firewall
Filter
HTML
WML
WAP gateway
Wireless Network
Web server
WTA server
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Internet Protocol vs. WAP
8
Wireless Application Protocol
9
WAP Protocol Stack
10
Server Configuration
11
WML Structure

• Deck - File
• Card Screen
• Head XML, DTD Declarations
• Template lttemplategt, lt/templategt
• Root Element ltwmlgt, lt/wmlgt
• Card ltcardgt, lt/cardgt

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WML Structure
Process Instruction
lt?xml version"1.0"?gt lt!DOCTYPE wml PUBLIC
"-//WAPFORUM//DTD WML 1.2//EN" "http//www.wapforu
m.org/DTD/wml12.dtd"gt ltwmlgt lttemplategt
lt/templategt ltcardgt ltpgt lt/pgt
lt/cardgt lt/wmlgt
Document Type Declaration
Root Element
Template
Cards
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WMLs Functionality

• Text Presentation and Layout text formatting,
  line breaks, and alignment.
• Images Wireless Bitmap (WBMP) and image
  alignment.
• User Inputs Choice lists, multilevel choices,
  text entry, and task controls.
• Cards and Deck Organization.
• Navigation URL Naming and anchored links,
  between cards in a deck, between decks.
• State and Context Management Variable passing
  between decks, Cache both variables and decks.

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Text Presentations
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Paragraph

• ltpgt lt/pgt
• Two attributes
• align left, center or right
• mode wrap or nowrap

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Special Characters
17
Table
18
Image - ltimggt
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Navigation between Cards and Decks

• ltagt lt/agt
• ltanchorgt lt/anchorgt

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Events and Tasks
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Events

• ltonenterforwardgt Invoke a card via a GO
  statement.
• ltonenterbackwardgt Navigate to a card via the
  ltprevgt statement.
• ltonpickgt Select an option.
• ltontimergt Delay time for action.
• These events are invoked via an ltoneventgt
  element, an ltoptiongt element, or as part of a
  lttemplategt or ltcardgt element.

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Input Attributes
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Input Mask
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Attributes of Do Element
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Hardware Key Types
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Action Types
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Example of Do Element

• ltdo typeoptions labeltitles nametitlesgt
• ltgo hreftitles/gt
• lt/dogt
• ltdo typeoptions labelAuthors
  nameauthorsgt
• ltgo hrefauthors/gt
• lt/dogt
• ltdo typeoptions labelBooks namebooksgt
• ltgo hrefbooklist/gt
• lt/dogt

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Thank You? Any Question?