Webmaster''''s Guide to the Wireless Internet part 8 pot

The majority of current mobile devices are limited to wireless speeds of between 9.6 Kbps to 19.2 Kbps, with few exceptions.These connections are also inher-ently unreliable, with long c

Above all, the major shift in perspective required of the wireless Webmaster is

to realize that you’re authoring for a mobile audience, not just mobile devices Rather than simply using portable devices, visitors to your site may actually be

on the move, whether walking down the street or in a vehicle.They’re probably not donating 100 percent of their attention to the screen, and likely only have one hand for navigation In this situation, the browsing model of the wired Web will not work Users need simplified, quick access to just the information they need, in a concise format that downloads quickly.This is not simply a matter of shortening text and optimizing graphics; successful mobile Web sites need to pro-vide mobile users immediate access to just the information they need, when they need it, from anywhere and from any device

The wireless Web represents a revolution in access to online information that will have profound impact on our society—greater even than the Internet revolution

of the past decade Although the skills learned by Webmasters over the short but tumultuous life of the Web will provide a solid foundation for this new world, new skills will have to be developed and some old habits changed

The sheer variety of different mobile devices is the first big change a Webmaster will have to deal with, making the “browser wars” of the last few years seem like child’s play However, you’ll find that devices fall into a few gen-eral families with similar characteristics, simplifying the presentation task some-what Device detection, coupled with on-the-fly, server-side generation of markup is one way to solve this problem Here, XML transformed to appropriate markup via XSL, provides a future-proof option

How users connect to your site can be as important as which device they use

The majority of current mobile devices are limited to wireless speeds of between 9.6 Kbps to 19.2 Kbps, with few exceptions.These connections are also inher-ently unreliable, with long call setup times and latency.You’ll need to modify

your content and navigation to compensate for these limitations.The walled garden

approach of carriers, coupled with the inevitable backlash against WAP when users discovered it didn’t live up to the early hype, has left a lot of users disillu-sioned with WAP, but newly available wireless options for PDAs and laptops have revived interest in mobile computing.With the huge surge in interest in wireless data services—particularly from corporate users—carriers continue to offer newer and faster connectivity options 2.5G services such as GPRS are already being rolled out worldwide, and we can look forward to the much higher data speeds

of 3G introducing a world of broadband wireless within the next two to four years

For the purposes of the wireless Webmaster looking to provide content for mobile users, mobile wireless devices can be classified into three families: mobile phones, PDAs, and laptops Mobile phones have tiny screens and slow data speeds—9.6 Kbps is the current top speed on most networks User interaction is difficult, requiring users to enter data with a nine-key numeric keypad However, these are still the most prevalent wireless devices in circulation In the U.S and Europe,WAP is the predominant means of delivering Internet content to mobile phones.WAP compiles content to optimize transmission over wireless connec-tions, but it is still slow and difficult to use on current networks Japan has had

huge success with a similar service called i-Mode, but as yet this doesn’t seem to have made much impact outside of Japan

PDAs are a step up in functionality, providing relatively larger screens, color display, and support for both handwriting recognition and virtual keyboards Currently, PDAs are split into the subclasses of either Palm OS or Pocket PC, each of which has different display capabilities, memory, and processing power PCMCIA and Compact Flash modems are widely available for both varieties of PDA, offering data speeds up to 19.2 Kbps or even 28.8 Kbps

The same wireless options available to PDA users also offer the possibility of wireless Internet access to laptop users Here, users have the benefit of large, full-color screens and full keyboard/mouse interaction, but you’ll still need to be aware of their relatively slower data speeds and adapt your content to suit

The mobile wireless landscape is in a state of rapid flux, with new devices announced almost monthly Hybrid devices attempt to combine the mobility and voice capabilities of mobile phones with the organizational capabilities of PDAs Unfortunately, these tend to compromise the capabilities of each Microsoft Stinger is one device to watch, although its impact is still uncertain.Tablet PC holds some promise as a next-generation mobile device, but is not yet available to end-users.Voice interaction is another emergent technology that could radically affect the job of the wireless Webmaster

Despite the wide range of new devices and connection options, a certain amount of overlap still exists with the skills Webmasters have developed on the wired Web HTML, with some modifications, is still a very viable option for both Pocket PC and Palm OS PDAs, and WML should present no major problems for

a competent Web coder XHTML, XML, and XSL are the next evolution in markup, and wireless Webmasters would do well to become proficient in these technologies Location-based services are another new area worth exploring, uti-lizing technologies such as GPS to customize content for a users physical loca-tion Personalization is another option for users with less time and limited screen sizes and access speeds

Perhaps the largest change required of Webmasters is to adapt UI and presen-tation to suit the different needs of mobile users, who need rapid access to tar-geted information, rather than the browsing paradigm of the wired Web In most cases, this means rethinking both content presentation and user interaction, rather than simply formatting with a new markup language QA testing is important, to ensure a satisfactory user experience

Solutions Fast Track

Explaining Wireless

 The emphasis on mobility is one of the defining characteristics of this new wireless paradigm, and from a Webmaster’s point of view this mobility, not simply the lack of wires, is likely to be the most important aspect you have to deal with

 Low bandwidth, differing standards, multiple network carriers, and a multitude of radically different devices means that the job of the wireless Webmaster just got immensely more complicated

Types of Wireless Connectivity

 The Wireless Application Protocol (WAP) is the first widely available method of accessing Internet content from a mobile device.WAP gateways enable legacy browsers to understand WML content However, due to differences in the WAP gateway configuration, and the particular microbrowser installed on the handset, a WAP page may display

differently on different handsets

 With Short Message Service (SMS), users can send short text messages

to each other at a fraction of the cost of a voice call SMS can also be used to send configuration settings to your phone SMS is a huge success

in Europe, and it is gradually becoming available on U.S wireless phone plans, although in a limited fashion

 Japan’s NTT DoCoMo mobile data service i-Mode offers users the ability to browse a huge range of Web sites with cheap, full-color handsets that maintain an always-on connection to the Internet It could possibly become an alternative to WAP but currently is in use only in Japan

 The European wireless standard, Global System for Mobile Communications (GSM), is available on a limited basis in the US.The General Packet Radio System (GPRS) will soon offer higher data speeds and an always-on connection worldwide; it is already available in some European countries, and on a trial basis in a few U.S cities

 A recent option for wireless connectivity in the U.S is Cellular Digital Packet Data (CDPD), a packet-switched network this is an always-on connection.The major drawback of CDPD is limited availability

 The 802.11b standard has found ready acceptance as a short-range radio replacement for traditional Ethernet connections Bluetooth is another short-range wireless standard

Evolving Mobile Devices

 The three main categories of mobile devices, mobile phones, PDAs, and laptop computers, are differentiated by connectivity, screen size, memory, and processing power

 Data-capable phones use the WAP protocol, and content needs to be coded in Wireless Markup Language (WML).They have minimal requirements for memory and processing power A mobile phone never communicates directly with your Web server; there is always a WAP gateway acting on its behalf (the gateway may alter the content somewhat on its way through)

 The market for Personal Digital Assistants (PDAs) is split mainly between those running the Palm operating system from both Palm, Inc and its licensees, and devices based on Microsoft’s Pocket PC or Windows CE One feature of Pocket PCs that’s especially relevant to wireless is that most come with an industry-standard expansion slot, either CF or PCMCIA Type II

 PDAs come in a wide range of configurations of connectivity, screen size, memory, and processing power

 Several manufacturers have begun shipping laptops with built-in wireless LAN (802.11b) cards, with antennas integrated into the casing.These same manufacturers will soon begin offering Bluetooth-equipped laptops However, with larger screens, keyboards, and more memory and storage, Handheld PCs are beginning to offer a viable alternative to bulky laptops

 Also, several devices are available that seek to combine aspects of each category—a mobile phone with an integrated Palm screen, PDAs that can be used as phones, and laptop-size devices without keyboards that you use by writing directly on the screen

Something Old, Something New

 TCP/IP has been able to adapt and grow with the increasing demands

of the Internet; both the Palm and Pocket PC use the same HTTP to communicate with your content server; and HTML has also proven to

be extremely adaptable and long-lasting Another Web concept that has been maintained in the wireless realm is the browser

 WAP provides for a mapping between all layers of HTTP and the corresponding layers of WAP.This translation is performed transparently

by the WAP gateway, so as a Webmaster you really don’t have to worry too much about it

 Microbrowsers installed on mobile phones tend to be proprietary to the handset manufacturer and impossible to change, but in the future it’s likely that they will coalesce around a common standard, and be user-changeable

Moving from a Wired to a Wireless Internet

 The new wireless medium requires a change in perspective from a large-screen desktop browser to a small mobile device with limited user-interaction mechanisms and, for now, a slow wireless connection

 Probably the main adjustment Webmasters will need to make to the wireless Web is to realize that users of mobile devices need quick access

to relevant information only

 You’ll need to test and verify your code on a variety of handsets, through as many carrier gateways as you can Similarly,Web Clipping applications can look quite different depending on the transcoding proxy server used On Pocket Internet Explorer, you’ll need to test how your content looks with the different view settings and different user

preferences

 The best way to deal with differing browser capabilities, and build a truly scalable Web site publishing system, is to completely separate content from presentation

Q: What are Tri-Band mobile phones?

A:Tri-Band phones are typically available on the GSM system.Two different fre-quencies are used on the continent Almost all European phones are Dual-Band, which automatically sense and switch to the appropriate frequency Tri-Band phones add the capability to work on the totally different GSM fre-quencies used in the US Although not widespread yet, GSM is offered by several carriers in the U.S A Tri-Band phone allows international travelers to use the same phone both in the U.S and Europe

Q:Do I need a special WAP server to deliver WML pages?

A:No, the connection to your server is just a standard HTTP request.You can serve this request with any regular Web server—IIS, Apache, and so on.You will have to configure MIME type settings on the server, so that it knows what to do with pages with a wml extension

Q:If I code for the Palm Pilot—will the Visor be able to see the same thing?

A:Yes, the Handspring Visor, as well as the Sony Clié and other devices running the Palm OS, should display your pages identically, provided that your markup

is error-free

Q:My Web site is heavy in tables—will it display on PDAs?

A:Palm Web Clipping does not support nested tables Any <TABLE> tags

beyond the first one will be ignored, giving a result that’s rarely what you intended Pocket PC devices can display much more complicated table struc-tures, but remember that the maximum viewable width is 240 pixels, unless you want your visitors to have to scroll both horizontally and vertically

Frequently Asked Questions

The following Frequently Asked Questions, answered by the authors of this book, are designed to both measure your understanding of the concepts presented in this chapter and to assist you with real-life implementation of these concepts To have your questions about this chapter answered by the author, browse to

www.syngress.com/solutions and click on the “Ask the Author” form.

Q:Why do wireless devices get their transmissions cut off?

A:Wireless devices must be within a certain distance of a base station to pick up

a strong enough signal.They can lose this signal if they move outside the cov-erage area of the base station or if they enter the radio shadow of a large building

Q:If I program in Web Clippings—will it show up in other PDAs?

A:Yes, because Web Clipping pages are basically HTML 3.2, they will generally display relatively well on other PDAs However, if you use the Palm-propri-etary method of compiling graphics into the Web Clipping Application, these will not show up

Q:Will I have to learn different programming if i-Mode comes to the U.S.?

A:I-Mode uses a subset of HTML called Compact HTML (cHTML) Anyone familiar with HTML should have no problem learning this However, there are signs that the industry may move towards XHTML as the preferred markup language for these devices

Wireless Architecture

Solutions in this chapter:

■ Components of a Wireless Network

■ Adjusting the Metaphor for the Wireless Internet

■ Accepting the Challenge of WAP-Enabled Devices

■ Adopting Wireless Standards

■ Noting the Market for Wireless Browsers and Other Applications

 Summary

 Solutions Fast Track

 Frequently Asked Questions

Chapter 2

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