Webmaster''''s Guide to the Wireless Internet part 3 pptx

xx Contents
Using the <img> Tag 261
Using the <a> Tag 262
Using the <form> Tag 263
Using the <select> Tag 263
Using the <input> Tag 264
Web Clipping Extensions 266
Palm-Specific <meta> Tags 268
Identifying Users with a Device ID 268
Estimating User Location by ZIP Code 270
Selecting a Date with the Datepicker
Object 270
Choosing a Date with the Timepicker
Object 272
Web Clipping in Action: Examples 274
Using a mailto: Link with Parameters 274
Sending E-mail via a Web Server 276
Guidelines for Authoring your Web Clipping
Application 281
Summary 283
Solutions Fast Track 283
Frequently Asked Questions 286
Chapter 7 Deck of Cards: Designing
Small Viewpoint Content 289
Introduction 290
Thinking In the Hand, not On the Web 291
Common Mistakes Made by Webmasters 293
Wasting Bandwidth 293
Forgetting Task-Based Design 294
Providing Too Many Options or Too
Much Information 295

Using Branded Terminology Instead of
Plain Language 296
Thinking Like a Mobile User 297
Segregating Tasks 298
Optimizing Bandwidth 299
Designing Coherent Navigation 303
Avoiding the Common
Mistakes Made by
Webmasters
Some of the more
common mistakes made
by Webmasters include:
■
Wasting bandwidth
■
Forgetting task-based
design
■
Providing too many
options or too much
information
■
Using branded, Web-
like terminology
instead of plain
language
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Contents xxi
Stacking a Deck of Cards 304
Parceling Navigation and Content 305

Utilizing WML Variables 314
Examining Display Differences Between
Browsers 320
UP.Browser Interpretation 323
Nokia Interpretation 325
4thPass Kbrowser Interpretation 327
Directory.wml Example 328
Directory2.wml Example 329
Summary 332
Solutions Fast Track 333
Frequently Asked Questions 334
Chapter 8 Wireless Enabling Your
Big Bandwidth Site 337
Introduction 338
Defining WAP MIME Types 338
Selecting which MIME Types to Add 339
Adding MIME Types to Your Server
Configuration 340
Configuring the Apache Web Server 341
Adding MIME Types to Microsoft IIS 343
Detecting WAP Devices 344
Parsing Header Information 344
HTTP_USER_AGENT 345
HTTP_ACCEPT 349
Reading Other Environmental Variables 350
Redirecting Your Users to Static Content 352
Redirecting Users in PHP 353
Redirecting Users in Perl 353
Optimizing Content Distribution 356
Choosing Mobile Content 357

Convert or Redevelop? 357
Delivering Wireless Data 359
Making Your Applications Accessible 360
Implementing Wireless Graphics 362
Choosing Mobile
Content
One of the first steps to
building any site is
choosing what content to
display on the site. The
primary questions that
arise in adapting a large
existing site to the wireless
Internet are:
1. What content/services
might our users want
to access while they
are mobile?
2. What limitations are
there to the existing
mobile interfaces that
we must consider?
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xxii Contents
File Formats 362
Maintaining Accessibility 363
Converting Your Images 363
Summary 364
Solutions Fast Track 364
Frequently Asked Questions 366

Chapter 9 Microsoft Mobile Internet
Toolkit 367
Introduction 368
Overview of the .NET Mobile Architecture 368
Devices Supported by the Microsoft Mobile
Internet Toolkit 369
System Requirements 369
Obtaining and Installing the Microsoft
Mobile Internet Toolkit 370
Introduction to ASP.NET 371
The Content Components 376
HTML Server Controls 377
ASP.NET Server Controls 377
The Code Components 378
ASP.NET Architecture 380
Developing Mobile Web Forms 381
Using Multiple Forms in a Single Page 385
Linking to Forms on Other Pages 386
Dissecting Code 388
User Inputs 389
Text and Password Input 389
List Selection 393
Selecting from a List 394
Data Binding List Items 396
Dissecting the Codes 399
Events 400
Displaying Images 401
Validation Controls 405
Paginations 407
Calendar Control 409

The Architecture of ASP.NET
Web Clients
Internet Information Server (IIS)
ASP.NET
Application
.NET
Framework
Windows NT/2000 OS
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Contents xxiii
Accessing Data with ADO.NET 411
A Brief Look at ADO.NET 411
Data Providers 412
ADO.NET DataReader 414
Dissecting the Codes 415
ADO.NET Dataset 417
Summary 423
Solutions Fast Track 423
Frequently Asked Questions 426
Chapter 10 Securing Your Wireless Web 429
Introduction 430
Comparing Internet and Wireless Security 431
Security Challenges of the Wireless Web 433
Lack of Standards 434
Horsepower, Bandwidth, and Weak
Encryption 434
User Awareness and Unsecure Devices 435
Mistrust of Wireless ASPs 436
Potential for New Viruses 436
Understanding Your Security Objectives 437

Security Models of the Wireless Web 438
Public and Private Key Cryptography 439
WTLS and Point-to-Point Security Models 442
How WTLS Works 443
WTLS Classes 444
The WAP Gap 444
The Seven Layers of Point-to-Point Security 446
Embedded Security Technology 447
Mobile Operator Network Security 448
Secure Mobile Operator Gateways 448
Authentication 448
Data Center and Network Security 449
Secure Application Interfaces 452
Problems of a Point-to-Point Security Model 452
Sniffing and Spoofing 452
Session Management and URL Rewriting 453
Understanding the
Seven Layers of Point-
to-Point Security
Point-to-point security can
be broken down into
seven layers,
corresponding to the steps
in the communication
path between mobile
devices and Web servers
or applications:
1. Embedded Security
Technology
2. Secure Air-Connect

Technologies
3. Mobile Operator
Network Security
4. Secure Mobile operator
Gateways
5. Authentication
6. Data Center and
Network Security
7. Secure Application
Interfaces
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xxiv Contents
Man-in-the-Middle Attack 453
No Complete Solution 454
PKI Technology and End-to-End Security
Models 454
How to Deploy a PKI 456
Server Side PKI Integration 456
Client Side Devices 456
Choosing a Certificate Authority 456
Certificate Management Framework 457
Certificate Deployment 457
Practical Limits of PKI Technology 457
Using PDAs with PKI Security 458
The Future of Security on the Wireless Web 458
Summary 460
Solutions Fast Track 461
Frequently Asked Questions 464
Webmaster’s Guide to the Wireless
Internet Fast Track 467

Index 489
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Over the past several decades, advances in computing technology have created
widespread changes in the way that the world operates and the means by which we
deal with information. Computing has revolutionized the way that business is done,
bills are accounted for, and how records are stored.The invention of the underlying
sets of protocols to enable communication between computers in the early 1970s and
the advent of the personal computer in the 1980s, has helped to sow the seeds for
the most recent communications revolution—the Internet. In the mid-1990s, as the
World Wide Web matured to include graphics and multimedia components and more
and more individuals gained access to affordable computers and Internet accounts,
the popularity of the Internet exploded and the number of Web sites and people
online grew at an exponential rate. Since then, many Web sites have come and gone
and use of the Internet is something that many people in the United States take for
granted. In the case of individuals whose livelihood is enabled by the Internet, such
as Webmasters, it is something that we cannot live without.
We have also seen, over the past two decades, widespread adoption of mobile
devices that are capable of enabling communication. Cellular phones are now being
used by millions of individuals worldwide, and, in some areas, mobile phones are
more reliable and used more often than land-based telephone communications sys-
tems. Recently, many phones and other handheld devices now have the ability to
access the Internet and send messages between subscribers.These capabilities often
include e-mail and the ability to send and receive data via the Hypertext Transfer
Protocol (HTTP), although not all of these devices can view the type of HTML that
has been associated with the World Wide Web of recent years.The advent of ubiqui-
tous mobile Internet computing promises to be another revolution in the ways that
human beings interact with each other, manage information, and interact with data
applications.This revolution also promises a new landscape in which Webmasters may
apply their skills and learn some new ones.
xxv

Foreword
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xxvi Foreword
One common characteristic that most handheld wireless devices share, regardless
of the device category, is a relative lack of processing power, memory, and display
capabilities as compared to a desktop computer.Wireless networks, in addition, fea-
ture a mere trickle of bandwidth compared with a modem, let alone a DSL or T1
connection. It is very important to keep these constraints in mind as you build your
content and applications.
Furthermore, your wireless users will most likely be accessing your Web site
while they are mobile.This fact makes it imperative for you to consider the needs of
a mobile user as you consider what types of content you should make available, or
what kinds of applications make sense for a mobile user.Also, your user interface
should take into account the small viewpoint of the devices that will be accessing
your Web site and should also consider the difficulty that often exists with user input
on these devices.
Webmaster’s Guide to the Wireless Internet is intended to give you, the Webmaster,
the skills and knowledge that you will need to add wireless Internet capability to
your existing Web site, to build new wireless applications, and to help you understand
the issues, both global and domestic, that exist with deploying wireless Internet solu-
tions.The primary geographical focus of this book is the United States, but
Webmasters in other countries will certainly find the information useful. Webmaster’s
Guide to the Wireless Internet is not a lengthy work on the wide variety of protocols
that are used to deploy wireless technologies, nor does it focus unnecessarily on the
minute details of emerging technologies that are volatile in nature and constantly
changing. Rather, it focuses on hands-on examples that will allow you to adapt your
existing skills in HTML and server-side scripting to deploy content and applications
to a wireless audience using WML,WMLScript, and, in some cases, lean HTML.This
book is intended to demystify the wireless landscape and provide you with answers
on how to get your wireless Web site up and running quickly.

Chapter 1 covers the basics of what makes up the wireless Internet, and how it
contrasts with the World Wide Web.
Chapter 2 covers the basic architecture of the wireless architecture and provides
a comprehensive overview of the components of the wireless Internet and how they
fit together.
Chapter 3 explains the nuts and bolts of the Wireless Markup Language, the
client-side, XML-based markup language that allows devices using the Wireless
Application Protocol (WAP) to display Internet content.This chapter will give you
an understanding of how this language differs from HTML and will give you the
skills to start building your own wireless content.
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Foreword xxvii
Chapter 4 explains how to add client-side scripting to your WML pages.
WMLScript is loosely based on ECMAScript, which is the language that gave rise to
both JavaScript and Jscript. Users familiar with these scripting languages will notice a
similar syntax and structure, but the means of deployment will differ. Depending on
the market in which you want to deploy your content, you may or may not be able
to make much real-world use of WMLScript.
Chapter 5 explains how to install and use the many Software Development Kits
(SDKs) supplied by wireless browser programmers and handset manufacturers to pro-
vide you with an emulator and debugger to develop your content or application.
Chapter 6 provides an introduction to the proprietary system that allows users of
Palm-powered handheld devices to access content located on the Internet.This
chapter will give you the information that you will need to start building Web
Clipping Applications (WCAs).These special HTML-based applications can be inte-
grated with local applications or interact with Web servers located on the Internet.
Chapter 7 explains the issues surrounding usability on wireless devices.This
chapter will help you build effective small-viewpoint navigation and give you some
handy tips on how to make your wireless site more user-friendly by working within

the constraints of narrow bandwidth and limited user input.
Chapter 8 will give you information and guidelines on how to add wireless capa-
bilities to your existing Web site and choose content that is of interest to mobile
users. It also covers how to detect wireless devices and discusses the issues sur-
rounding automated or on-the-fly conversion of your content for wireless users.
Chapter 9 explains how you can use the Microsoft Mobile Internet Toolkit and
Mobile Web Forms to deploy content to a wide variety of devices using the same
code. It covers how you can maintain state during a wireless or Web transaction and
how you can integrate Microsoft’s ActiveX Data Object (ADO) technology to pro-
vide interfaces to your data to many different devices.
Chapter 10 discusses the technology used to provide secure transactions for wire-
less devices and covers the issues surrounding security as it applies within the wireless
landscape. Point-to-point and end-to-end security models and the various pitfalls
surrounding both models are discussed.
The wireless revolution, like any revolution, is not without its challenges.The
global market for wireless Internet technologies is highly diverse, with different rates
of adoption, competing protocols and technologies, and existing infrastructures that
are in some cases more economical to use in the short term than building a new
global wireless communications architecture.At present in the United States, there
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xxviii Foreword
exists a fragmented landscape of telecommunications companies that offer mobile
phone service and not all of them are yet capable of offering wireless Internet access
(but most are). In Europe, standardized networks and compatible handsets have
enabled the wireless Internet to become popular very quickly.Asia has seen similar
growth in the use of the wireless Internet, most notably in Japan with
NTT/DoCoMo’s iMode system. Many individuals in these markets find that the
wireless Internet is an indispensable part of their lives, while the U.S. market has been
slow to adopt the technology.There are many reasons for this, including legacy hand-

sets, widespread Internet access via personal computers, and a telecommunications
market that features competing incompatible protocols and technologies.
This book, while comprehensively covering the technologies that already exist on
the wireless Internet (and the general principles behind them), does not attempt to
address developing technologies that are not yet deployed.There has recently been
much speculation and hype about so-called third generation, or 3G networks, which
are “just around the corner.” In addition, handset manufacturers have promised many
new developments in wireless technology, and, in particular, location-based services.
These dreams, at the time of this writing, are not yet a reality.
However, the wireless Internet is up and running and more subscribers join in
every day.The future certainly promises to be interesting, and Webmaster’s Guide to the
Wireless Internet holds much value for Webmasters who wish to add the ability to
develop wireless-accessible Web sites to their toolkit.The first step to the future
begins today, and we can only expect that the number of mobile devices that are
capable of accessing the Internet will grow as time progresses. It’s your job to make
sure that there is something worthwhile for individuals to access on the wireless
Internet, and this book provides the hands-on examples and explanations that will
allow you to do so!
—Dan A. Olsen
Technical Editor and Contributor
www.syngress.com
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Moving from the
Web to Wireless
Solutions in this chapter:
■
Explaining Wireless
■
Types of Wireless Connectivity
■

Evolving Mobile Devices
■
Something Old, Something New
■
Moving from a Wired to a Wireless
Internet
 Summary
 Solutions Fast Track
 Frequently Asked Questions
Chapter 1
1
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