Nokia TS344 User Manual

WAP SERVICE DEVELOPER'S GUIDE

FOR NOKIA SERIES 40

Version 1.0

13-02-02

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

Table of contents

1 INTRODUCTION..................................................................................................................................................................4

1.1 References..............................................................................................................................................................................4

1.2 Contact information............................................................................................................................................................5

2 GENERAL USABILITY ISSUES – GUIDELINES FOR DESIGN......................................................................................6

2.1 Mobile applications for mobile use.................................................................................................................................6

2.2 Validate your WML...............................................................................................................................................................6

2.3 GPRS usability.......................................................................................................................................................................6

2.4 Site organization..................................................................................................................................................................7

2.5 Pictures and tables...............................................................................................................................................................8

2.6 Take care of backward navigation...................................................................................................................................9

2.7 Use of card titles and element labels..............................................................................................................................9

2.8 Performing a usability test.................................................................................................................................................9

3 INTRODUCTION TO THE USER INTERFACE................................................................................................................10

3.1 Nokia Series 40 phones.....................................................................................................................................................10

3.2 User interface – display and keys...................................................................................................................................11

3.3 Display fonts........................................................................................................................................................................12

3.4 Accessing WAP browser....................................................................................................................................................12

3.5 Navigation, labels and titles............................................................................................................................................12

3.6 Scrolling................................................................................................................................................................................12

3.7 Picture viewer......................................................................................................................................................................13

3.8 Cache.....................................................................................................................................................................................13

4 WML ELEMENTS FOR THE NOKIA USER INTERFACE.............................................................................................14

4.1 Text formatting...................................................................................................................................................................14

4.2 Table.......................................................................................................................................................................................15

4.3 Images...................................................................................................................... .............................................................17

4.4 Links.......................................................................................................................................................................................18

4.5 Do element...........................................................................................................................................................................18

4.6 WML input processing.......................................................................................................................................................20

5 OPTIONAL WAP 1.2.1 FEATURES................................................................................................................................24

5.1 Push Service Indication .....................................................................................................................................................24

5.2 WTAI public library – Wireless Telephony Applications Interface public library...............................................24

5.3 Accesskey..............................................................................................................................................................................25

5.4 Cookies..................................................................................................................................................................................26

5.5 Content download over WAP..........................................................................................................................................26

A. WIRELESS APPLICATION PROTOCOL WAP................................................................................................................27

Introduction.......................................................................................................................................................................................27

WAP architecture..............................................................................................................................................................................27

Developing applications with WAP..............................................................................................................................................28

Further information..........................................................................................................................................................................29

B. LIST OF TERMS AND ABBREVIATIONS.......................................................................................................................30

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

Change history 13-03-02 Version 1.0 Document added into Forum Nokia

Disclaimer:

Nokia Corporation disclaims all liability, including liability for infringement of any proprietary rights, relating to the implementation of information presented in this document. Nokia Corporation does not warrant or represent that such use will not infringe such rights. Nokia Corporation retains the right to make changes to this specifica tion at any time without notice.

Licence:

A licence is hereby granted to download and print a copy of this specification for personal use only. No other licence to any other intellectual property rights is granted herein.

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

1 INTRODUCTION

This WAP Service Developer's Guide provides information and practical examples for developers who want to optimise their existing WAP services for the Series 40 phones. Series 40 is a UI category for Nokia 128 x128 pixel screen resolution. It comprises a passive matrix colour screen with two soft keys. The current Nokia handsets that belong to this cat e gory are introduced in Chapter 3. This document highlights the possibilities, limitations, and requirements of service development, and provides a good introduction to the Nokia style of designing user interfaces.

The Wireless Application Protocol (WAP) enhances the functionality of mobile handsets through real-time interactive services. The protocol has been designed especially for small screens and low bandwidths, and it offers a wide variety of wireless services over the Internet for handsets. It was also designed to allow content to be delivered over any bearer service, even when delivery of the services is enabled over GPRS, 3G or any other type of network. WAP over GPRS opens up new possibilities for application development, and there are also some optimizations in GPRS, that can be done by service developers.

Chapter 2 describes some general usability issues concerning WAP service development. Chapter 3 introduces the browser user interfaces elements, keys, display and browsing conventions. Chapter 4 outlines some general WML elements, which are mandatory features on WAP 1.2.1, according to WAP Forum specifications. Chapter 5 introduces some optional WAP 1.2.1 features that are supported in most of the WAP1. 2. 1 compliant phones.

This guide is not written for service developers only, but essentially for anyone involved in creating the wireless information society and who needs to know more about service creation on small mobile terminals. It can be used in conjunction with the Nokia Mobile Internet Toolkit.

The Nokia Mobile Internet Toolkit offers developers an environment for creating, testing, and demonstrating WAP applications. This a llows service providers to evaluate the usability of wireless applications and services together wit h their enduser organization. In this guide, we have collected a lot of what we have learned to help developers improve their services. We believe that good usability will increase use and satisfaction, and thus increase revenues for service providers.

This guide does not purport to describe WAP in detail, and it is not meant to replace any WAP specification.

1.1 References

User's guide for Nokia 7210 WAP Characteristics list can be found at http://www.forum.nokia.com/ The Nokia Mobile Internet Toolkit can be downloaded from

http://www.forum.nokia.com/

GPRS related documentation could be found at http://www.forum.nokia.com/

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

Wireless application protocol specifications can be found at

http://www.wapforum.org/

Information about Nokia products can be found at http://www.nokia.com/

1.2 Contact information

Developer support for WAP service development and GPRS bearer technology can be obtained through the Forum Nokia Web site at http://www.forum.nokia.com/

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

2 GENERAL USABILITY ISSUES – GUIDELINES FOR DESIGN

Nokia phones are renowned for their simple-to-use and intuitive user interface. In order to create a service that will be perceived as usable and easy to understand, Nokia Mobile Phones provides some general guidelines to help service providers develop their applications.

2.1 Mobile applications for mobile use

When deciding what information to include in the different applications on a mobile terminal, think about what information might be relevant in the situations where the mobile phone will be used. Mobile phone is primarily used when there is no access to the Internet with a PC. We believe that users of mobile applications will be interested primarily in brief and quick information. For instance, quick access to flight schedules from the mobile phone might be relevant for users. Similarly, several short newsflashes are more relevant than longer news articles. Quick access to weather information may also be of use in the mobile situation to quickly check the temperature at the destination of the traveler. However, it is less likely that users will surf using the application on the mobile terminal, but will prefer to surf the Internet on a PC from the office or home.

2.2 Validate your WML

There are several XML validators available that validate your documents against WML Document Type Definition. It is recommended that authors validate their WAP pages, because invalid WML is always treated as an error and is discarded by the WAP gateway (that is, it is not shown to the user).

Several XML validators can be found at http://www.wapdevelopers.org

2.3 GPRS usability

GPRS features efficient use of resources, instant access, fast delivery of information and innovative charging models. Together, WAP and GPRS not only improve the user experience of existing applications but also enable new services.

2.3.1 Not necessary for developers to make changes GPRS enhances the end user experience of the mobile services currently being delivered over

circuit switched data (CSD). Since the WAP standard was designed to allow content to be delivered over any bearer service, it is not necessary for developers to make changes to their WAP-compliant services or applications, even when delivery of the services is enabled over GPRS, 3G or any other type of network.

2.3.2 Cache utilization It is recommended to use HTTP proxy to cache WML content whenever the content is

accessed through the Internet. The proxy should be placed close to the WAP gateway to minimise the distance for data transfer between the two components. The home page (first page) might alternatively be kept on a local server, close to the WAP gateway.

Most clients have a cache and using it is an important way t o provide fa st user experience.

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

2.3.3 Usability tips for WAP over GPRS service development Round-trips in a network always cause a minimum of a two 2-second delay to th e response

time. Therefore, the number of round-trips should be minimised. For example, bitmaps cause additional round-trips. The response time can also be minimised by keeping the size of a WAP deck as compact as possible; this is especially important for pages that require an instant response. The response time of the first deck has a strong impact to on the user experience. Therefore, it is worthwhile to maximise Infrastructure optimisation.

Minimise latency between the WAP gateway and content server. Remember that each query traverses this link twice, once as a request and once as a response.

Place the WAP gateway close to the GPRS gatewa y. (The GPRS gateway is technically called a “Gateway GPRS Support Node”, or GGSN.) “Close” in t h is instance refers to both latency and probability of packet loss. Lost messages cause additiona l delay due to HTTPretransmission.

2.4 Site organization

2.4.1 Avoid “doormat” pages The user accesses your WAP site over a GSM data call, and pays per second. It is not

recommended to start your site using a “doormat” page, which serves no purpose other than perhaps to greet the visitor and to display a logo. It is better if the user can go to your service directly. If there is a need to use a timer, it should not be longer than ~1.5 seconds. Otherwise, add a link incorporating the text “continue” to give the user the possibility t o exit the card.

2.4.2 Automatically detect the browser If you are using a modern Web site hosting environment, it is possible to detect th e browser

as well as the language mode and to supply correct content transparently without user interaction.

Nokia WAP phones send a user agent field in the WSP header to the WAP Gateway when they fetch content from the origin server. You can use this user agent field to define the browser type and then build the logic on the origin server to serve suitable content. From the WAP Gateway, it is then delivered inside the HTTP header.

The user agents for different Nokia phones can be found in the WAP Characteristics table on

www.forum.nokia.com

2.4.3 Optimize for size The size of the content is critical. If you have large decks (for example, lists and large tables),

consider splitting them into multiple parts for faster downloading. As for the total downloading time, some studies place an upper limit for an acceptable delay

on a PC-based browser at 10 to 15 seconds, including all images. It is highly recommended to have a response time (excluding connection time) in a mobile environment that is less than 10 seconds.

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

2.4.4 Choose descriptive card titles It is very useful to give a descriptive name for the card. It might be a good idea to start the

title with your service’s name and to keep the total length of the title short. It also pays to use meaningful URL addresses since the user sees the URL of the currently

selected link on the screen and can use it as a navigat ional help, especially when images have not been loaded.

2.4.5 Pay attention to the first screen The first (topmost) screen of any page is the most important one. All of the often-used

navigational links, search fields, login screens, and bulk of the information should reside there. The user is then able to navigate forward before the rest of the card has been loaded, and the user does not have to scroll the card.

Avoid wasting the top of the page for banner a dvertisements or non-informative graphics. It is better to place the advertisements at the left or right edges rather tha n on the top.

2.4.6 Do not use absolute values for the screen size When using images, the use of absolute values (in pixels) is not recommended. Sizes should

be specified as percentages of the total width or height.

2.4.7 Usage of do elements Always use descriptive and short labels for all do elements. Favour local do elements instead

of anchored links that do not fit into their surrounding context. G lobal do elements should be used only when especially needed at the end of the card. Always include a prev element in every card to enable backward navigation.

2.5 Pictures and tables

2.5.1 Avoid useless images Downloading images takes time, and many users may switch off the loading of images for

more speed. Try to optimise the size of images. If you have large pictures on your site, consider using thumbnails for the image index.

Always give an alternative text (using the alt attribute of the <img> element) for images that convey information. Always use a null alternative t ext (alt=””) for images that do not convey information, or are used for page layout or decorative purposes only.

2.5.2 Use reasonable table sizes If the table size exceeds the maximum width of the application screen due to the number of

columns, the table size will be scaled down to fit the screen. To keep the cell content readable, special attention should be paid to table structuring.

WAP Service Developer's Guide for Nokia Series 40 Version 1.0

2.6 Take care of backward navigation

Due to the differences between WAP and the Web in regard to the processing of the history, only the history processing described in the WML specifications is followed. This means that the service provider must be responsible for navigation as a whole.

2.7 Use of card titles and element labels

Card titles describe the content of the display and their use is recommended. They help the user to navigate in the application because they function as a reminder of where the user is in the application. The item previously selected by the user should determine the header text. For instance, the card title ‘Bookmarks’ tells the user that the display contains a list of bookmarks in the application and that the options item previously selected was Bookmarks.

Proportional fonts are used in header texts, and if the header text is too long, it is automatically truncated. Truncation is usually better than abbreviation, because the user might be confused by unfamiliar abbreviations that can be difficult to underst and.

2.8 Performing a usability test

It is always good to perform a usability test of new applications. People who have not been involved in the design or development of the applications tend to notice potential usabilit y problems that are often not obvious to those who know the design by heart. Usability tests should always be performed as early as possible in the development process. Any necessary changes resulting from the tests can then be implemented within the development timescale. Try to recruit users who are representative of the end users of the application, and try to conduct the usability test on a smaller scale, if the schedule does not allow for extensive testing.

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