WAP Forum - W3C Cooperation White Paper

W3C Note 30 October 1998

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Latest version
Johan Hjelm, W3C / Ericsson
Bruce Martin, WAP Forum / Unwired Planet
Peter King, WAP Forum / Unwired Planet

Status of this Document

Version 1.1, September 28, 1998

This document is a NOTE made available by the W3 Consortium for discussion only. This indicates no endorsement of its content, nor that the Consortium has, is, or will be allocating any resources to the issues addressed by this NOTE.


This paper outlines  possible areas of cooperation between the WAP Forum and the World Wide Web Consortium (W3C).

The WAP Forum is dedicated to enabling advanced services and applications on mobile wireless devices, such as cellular telephones. The W3C is dedicated to leading and advancing the development of the World Wide Web. This document describes the problem area of mobile access to information on the web, which is common to the two groups.

While the WAP Forum and the W3C have different organizational goals, we share goals for the future of the global information space. We also want to avoid unnecessary divergence between the recommendations and standards of the two organizations.

Direct overlaps in future development occur in the areas of intelligent proxies and protocol design; of XML applications; and in content adaption, e.g through the use of vector graphics and style sheets. Instead of developing diverging sets of solutions, it is the intent of both groups to find common solutions.

1.0 Introduction

1.1 W3C Background

The World Wide Web Consortium (W3C) was founded in 1994 by Tim Berners-Lee, the inventor of the World Wide Web. The web had then outgrown the European Centre for Nuclear Physics Research, CERN, where the web was developed.

From the beginning, Tim Berners-Lee has been the director of the consortium, and has been firmly committed to developing a neutral, open forum for the evolution of web technology.

Today, the W3C has three locations (at MIT in the USA; at INRIA in France; and at Keio University in Japan). The consortium has more than 270 members from industry and academia, and provides a vendor-neutral forum for its members to address web-related issues. Working with its staff and the global web community, the consortium aims to produce free, interoperable specifications; like its partner standards body, the Internet Engineering Task Force (IETF), the W3C is committed to backing its specifications by sample code. Funding from membership dues, public research funds, and external contracts underwrite these efforts. The work in the W3C follow a well-documented process, continuously involving representatives of the member companies in its efforts. More information can be found at the consortium web site.

In the autumn of 1997, it became evident that there was a considerable interest among the members of the W3C for access to the web via mobile and wireless devices. This area appeared to entail several aspects which constrained the usage in manners not considered in the current recommendations.

A workshop on mobile web access was organised in April of 1998 in Tokyo to address these topics, leading to the formation of a mobile access interest group that is chartered with the investigation of the impact of mobile access on the specifications and recommendations of the W3C.

Simultaneously, the W3C was approached by the WAP Forum, and a meeting was set up in June 1998. The results were very positive, and the meeting decided to create this joint white paper, outlining areas of potential cooperation between the two groups.

1.2 WAP Forum Background

The Wireless Application Protocol (WAP) Forum is an industry group dedicated to the goal of enabling sophisticated telephony and information services on hand-held wireless devices such as mobile telephones, pagers, personal digital assistants (PDAs) and other wireless terminals. Recognizing the value and utility of the World Wide Web architecture, the WAP Forum has chosen to align certain components of its technology very tightly with the Internet and the WWW. The WAP specifications extend and leverage mobile networking technologies (such as digital data networking standards) and Internet technologies (such as IP, HTTP, XML, URLs, scripting and other content formats).

The WAP specification initiative began in June 1997 and the WAP Forum was founded in December 1997. The WAP Forum has drafted a global wireless protocol specification for all wireless networks and will contribute it to appropriate industry and standards bodies. WAP will enable manufacturers, network operators, content providers and application developers to offer compatible products and secure services on all devices and networks, resulting in greater economies of scale and universal access to information. WAP Forum membership is open to all industry participants.

The objectives of the WAP Forum are:

To bring Internet content and advanced data services to digital cellular phones and other wireless terminals.
To create a global wireless protocol specification that will work across different wireless network technologies.
To enable the creation of content and applications that scale across a very wide range of wireless bearer networks and wireless device types.
To embrace and extend existing standards and technology wherever appropriate.

More information on the WAP Forum can be found at the Wap Forum Web server.

In keeping with its goals, the WAP Forum approached the W3C regarding collaboration in the area of WWW technologies in the wireless area.

2. Goals for the cooperation

2.1 Short-Term Goals

Bring Internet and WWW technologies to digital cellular phones and other wireless terminals, i.e., adapting the Web architecture to the wireless environment.
Establish productive working relationships between the W3C and WAP Forum in the areas where common organizational goals exist.
Reduce overlapping technical work between the W3C and WAP Forum.
Cross-reference technical specifications.
Joint test-bed and protocol validation work.

2.2 Long-Term Goals

Work toward a unified information space.
Work toward common standards and technologies.
Enable the delivery of sophisticated information and services to mobile wireless terminals.

3. The Technical Problem: Wireless System Requirements on Information Retrieval

Providing Internet and WWW services on a wireless data network presents many challenges. Most of the technology developed for the Internet has been designed for desktop and larger computers supporting medium to high bandwidth connectivity over generally reliable data networks.

Mass-market, hand-held wireless devices present a more constrained computing environment compared to desktop computers. Because of fundamental limitations of power and form factor, mass-market handheld devices tend to have:

Less powerful CPUs
Less memory (ROM and RAM)
Restricted power consumption
Smaller displays
Different input devices (e.g., a phone keypad, voice input, etc.)

Similarly, wireless data networks present a more constrained communication environment compared to wired networks. Because of fundamental limitations of power, available spectrum, and mobility, wireless data networks tend to have:

Less bandwidth than traditional networks
More latency than traditional networks
Less connection stability than other network technologies
Less predictable availability

Mobile networks are growing in complexity and the cost of providing new value-added services to wireless users is increasing. In order to meet the requirements of mobile network operators, solutions must be:

Interoperable – terminals from different manufacturers communicate with services in the mobile network.
Scalable – mobile network operators are able to scale services to customer needs.
Efficient – provides quality of service suited to the behaviour and characteristics of the mobile network; provide for maximum users for a given network configuration
Reliable – provides a consistent and predictable platform for deploying services.
Secure – enables services to be extended over potentially unprotected mobile networks while still preserving the integrity of user data; protects the devices and services from security problems such as denial of service.

3.1 Bearer Limitations

Wireless network bearers operate under several fundamental constraints, which place restrictions on the type of protocols and applications offered over the network:

Power consumption.
As bandwidth increases, power consumption increases. In a mobile device, this reduces battery life.
Cellular network economics.
Mobile networks are typically based on a cellular architecture. Cells are a resource shared by all mobile terminals in a geographic area, and typically have a fixed amount of bandwidth to be shared among all users. This characteristic rewards efficient use of bandwidth, as a means of reducing the overall cost of the network infrastructure.
The mobile wireless environment is characterized by a very wide range of network latency, ranging from sub-second round-trip communication time up to many tens of seconds. In addition, network latency can be highly variable, depending on the current radio transmission characteristics (e.g., in a tunnel or off network) and the network loading in a particular area. Latency is further increased by routing, error correction and congestion-avoidance characteristics of a particular network.
The mobile wireless environment is characterized by a very wide range of network characteristics, and typically has far less bandwidth available than a wireline environment. In addition, the economics of the wireless environment encourage the conservation of bandwidth to achieve greater density of subscribers.

3.2 Device Limitations

Wireless devices operate under a set of physical limitations, imposed by their mobility and form factor:

Limited power.
Any personal, or "hand held" mobile device will have a very limited power reserve, due to existing battery technology. This reduces available computational resources, transmission bandwidth, etc.
many mobile wireless are very small (hand-held).

Mobile wireless devices are characterized by a different set of user interface constraints than a personal computer. To enable a consistent application programming model, a very wide range of content scalability is required. In practice, a significant amount of the current WWW content is unsuitable for use on hand-held wireless devices. Problems include:

Output scalability.
 Existing content is designed for viewing on PC screens, whereas mobile devices will have a wide range of visual display sizes, formatting and other characteristics. In the near future, this will include voice-only output.
Input scalability.
Mobile devices feature a wide range of input models, including numeric keypad, very few or no programmable soft keys, etc. In the near future, this will include voice-only input.

3.3 Use Case Limitations

Many wireless devices, for example cellular phones and pagers, are consumer devices. These devices are used in a wide variety of environments and under a wide range of use scenarios. For example:

Simple user interfaces:
many mobile devices, in particular, cellular telephones, are mass-market consumer-oriented devices. Their user interface must be extremely simple and easy to use.
Single-purpose devices:
the goal and purpose of most mobile devices is very focused (e.g., voice communication). This is in contrast with the general-purpose tool-oriented nature of a personal computer. This motivates a very specific set of use cases, with very simple and focused behavior. For example, "place a voice call" or "find the nearest ATM."
Hands-free, "heads-up" operation:
many mobile devices are used in environments where the user should not be unnecessarily distracted (e.g., driving and talking).

4. Future Development from the W3C in this Field

The World Wide Web Consortium has as its motto "Leading the Web to its full potential", which means leading and participating in the continuing development of the Web and its standards. The new generation of Web technologies that is currently being specified by the W3C is intended to enhance the users' and publishers' control over the presentation of the information (e.g. through CSS), over the management of information (e.g. through RDF), and over its distribution (e.g. through P3P); based on technologies that structure and distribute data as objects, such as XML and HTTP-NG. Several areas will impact the use of  technologies developed by the W3C in mobile environments.

The work of the W3C in this field is initiated and maintained through its Mobile Access Interest Group. Work which touches on the mobility of the user access devices is conducted in several areas, however. Specifically, the Mobile Access Interest Group is reviewing the HTML 4.0 specification for mobile aspects; investigating how user agent profile information can be managed within the W3C technology framework; and investigating position dependent information services. Due to the scope of mobile access, all areas of the W3C might concievably be involved in the future. Below, we point to some of those where mobile access may have an immediate impact.

4.1 XML and the next generation of HTML

The W3C has recently decided to initiate an activity to create a new generation of HTML. This will be based on XML, and is likely to include features that makes it more efficient for mobile use.

Meanwhile, other XML applications such as the Wireless Markup Language, WML, and the Synchronised Multimedia, SMIL, will continue to appear. These are likely to have components where mobile access will have an impact.

XML is also contiuing to develop into a full-featured system for information structuring.

More information about the HTML-NG activity

More information about XML

4.2 Vector Graphics

The W3C has created a Working Group, which will be chartered to produce a specification for a Scalable Vector Graphics format, written as a modular XML tagset and usable as an XML namespace, which can be widely implemented in browsers and authoring tools and which is suitable for widespread adoption by the content authoring community as a replacement for many current uses of raster graphics. For simple cases such as trivial inline graphics, it should be possible to hand author the SVG format, and it should be possible to cut and paste SVG graphical objects between documents and preserve their appearance, linking behavior and style.

This will mean that the graphics in Web documents will be smaller, faster, more interactive, and be displayable on a wider range of device resolutions from small mobile devices through office computer monitors to high resolution printers.

More information on the working group

4.3 Document Object Model and Formatting Model

In the presentation model for the new generation of web technologies, the formatting of a document is conducted through the use of a style sheet. This is a separate document which allows authors and users to attach style (e.g., fonts, spacing, and aural cues) to structured documents (e.g., HTML documents and XML applications). By separating the presentation style of documents from the content of documents, CSS2 and XSL simplifies Web and XML authoring and site maintenance. Local processing of a document might in the future also be conducted using a similar technology, called action sheets. Style sheets can have media-specific properties, which makes them a possible candidate for use with mobile devices.

More information on style sheets.

The programmatical handling of a document is defined in the Document Object Model, a platform- and language-neutral interface that will allow programs and scripts to dynamically access and update the content, structure and style of documents. The Document Object Model provides a standard set of objects for representing HTML and XML documents, a standard model of how these objects can be combined, and a standard interface for accessing and manipulating them.

More information on the Document Object Model.


The purpose of the HTTP-NG activity is to design, implement, and test a new architecture for the HTTP protocol, based on a simple, extensible, distributed object-oriented model. This includes a protocol for the management of the network connections (WEBMUX), a protocol for transmitting messages between systems (WIRE), a set of methods, interfaces and objects that demonstrates a classical Web browsing case, as an example of what is possible with the new protocol; and a test bed to test the implementation.

More information on the HTTP-NG activity.

4.5 Accessibility

Accessibility for people with disabilities is relevant for mobile wireless devices as this is a potentially large marketplace (over 10% of the population), and in some cases accessibility is required (e.g. for sales in the US, under Section 255 of the US Telecommunications Act). In addition, functions, such as speech input or output, required to accommodate different kinds of disability have carry-over benefits for non-disabled users of mobile devices, who may be using the devices in "hands-free" or "eyes-free" situations.

W3C's Web Accessibility Initiative (WAI) in coordination with other organizations is addressing Web accessibility through several areas of work; two of these, technology and guidelines, relate to mobile wireless devices.

In the area of technology, WAI liaises with W3C Working Groups developing technologies which can facilitate accessibility, such as HTML, CSS, SMIL, SVG. In the area of guidelines, WAI is developing guidelines for accessible page authoring, for user agents, and for authoring tools, and coordinating with the development of guidelines by the Mobile Access Interest Group.

More information about the Web Accessibility Initiative.

4.6 Internationalization

The correct representations of characters is an issue in all formats of writing, not just the Latin alphabet. The aim of this activity is for the World Wide Web to live up to its name, and the W3C continues work on the internationalization of the Web, with the aim of ensuring that the necessary features are included in W3C protocols and data format recommendations. The general goal of W3C's work on internationalization is to ensure that W3C's formats and protocols are usable world wide in all languages and writing systems.

More information about the internationalisation activity.

4.7 Metadata, Digital Signatures, and Trust Management

Our current focus is, broadly, on establishing trust in the new medium of the Web. This is a difficult problem, involving both social and technical issues. Trust is established through a complex and ill-understood social mechanism including relationships, social norms, laws, regulations, traditions, and track records. Our activities are chosen to focus on specific areas that are both important and tractable.

There is a core of technical issues that are required in any system that is to be trusted:

The ability to make statements that have agreed-upon meanings.
The W3C Metadata Activity provides a means to create machine-readable statements.
The ability to know who made the statement and to be assured that the statement is really theirs.
The W3C Digital Signature Initiative provides a mechanism for signing metadata in order to establish who is making the machine-readable statement.
The ability to establish rules that permit actions to be taken, based on the statements and a relationship to those who made the statements.
The PICS Rules specification allows rules to be written down so they can be understood by machines and exchanged by users.
The ability to negotiate binding terms and conditions.
The now-completed JEPI project created the Protocol Extension Protocol (PEP) to provide for negotiation on the Web. Negotiation is also at the core of the Platform for Privacy Preferences Project (P3P).
Electronic commerce markup and payment.
Currently, the W3C has two working groups in this field, on markup for electronic commerce, and for payment initiation.

More information on the metadata activity

5. Future Development From the WAP Forum in this Field

The WAP Forum's exclusive focus is mobile wireless technologies. The goal of  WAP is to create recommendations and specifications that support the creation of advanced services on wireless devices, with particular emphasis on the mobile telephone. The WAP Forum is creating recommendations and technologies which enable these services on all mobile devices and on all networks.

The WAP Forum has undertaken a variety of technical specification work relevant to the W3C/WAP Forum collaborative efforts. These efforts all relate to the use of World Wide Web technology on mobile devices, and ensuring that the quality of these services is sufficient for mass deployment.

5.1 Achieving the Mobile Wireless Web

WAP is focused on enabling the interconnection of the Web and wireless terminals. Significant focus has been given to mobile telephones and pagers, but all technology has been developed with broader applicability in mind. The goal of WAP is to enable an extremely wide range of wireless terminals, range from mass-market mobile telephones and pagers to more powerful devices, to enjoy the benefits of Web technology and interconnection.

Mobile devices have a unique set of features which must be exposed into the Web, in order to enable the creation of advanced telephony services, including:

Location-based services
Intelligent network functionality, including integration into the voice network
Voice/data integration

The WAP Forum is actively exploring solutions and specifications in these areas. Future technical work will address the ongoing evolution of wireless networks and mobile communication devices, including such issues as the integration of Third Generation wireless networking technology.

5.2 Bandwidth Efficiency

The WAP Forum is working to increase the bandwidth efficiency of Web technology, to make it more applicable to the wireless environment. WAP Forum work includes:

Smart Web Proxies
- proxies capable of performing intelligent transformation of protocols and content, enabling more efficient use of the network, adaptation to device characteristics and adaptation to network characteristics.
Efficient Content Encoding
- bandwidth efficient encodings of standard Web data formats such as XML.
Efficient Protocols
- bandwidth efficient adaptations of standard web protocols, such as HTTP.

5.3 Latency Constraints

The WAP Forum is working to improve the behavior of Web technology in the face of high network latencies, and in particular is focusing on the problems of:

Tuning network protocols
to be adaptive and efficient given wide ranging latencies.
Creating Web applications
which are resilient to either high latency environments or highly variable latency situations.

WAP Forum work in this area includes:

User agent state management
Protocol design (e.g., session state, fast session resumption, etc.)

5.4 Content Scalability

Mobile wireless devices are characterized by a different set of user interface constraints than a personal computer. The WAP Forum work in this area includes:

Content adaptation
- mechanisms allowing a Web application to adapt gracefully to the characteristics of the device (beyond the current HTTP/1.1 content negotiation model).
User interface scalability
- content formats, e.g., markup and display languages, that are suitable to improverished devices, but which scale well to more sophisticated devices.

6. Conclusion

In the area of Web technologies, the focus of the WAP Forum and the W3C overlap to a significant degree. Direct overlaps occur in the areas of intelligent proxies and protocol design; of XML applications; and in content adaptation, e.g., through the use of vector graphics and style sheets. Future cooperation may also occur in the area of electronic payment, where the work of the two groups has potential overlap.

Instead of developing diverging solutions, it is the intent of both groups to find common solutions that will address mobile requirements. In the area of web technology, our goals overlap, especially in the long run, allowing significant cooperation and shared development. To avoid fragmentation of the Web standards, the groups should cooperate, and focus on achieving the seamless integration of mobile devices into the Web.

Bruce Martin, WAP/Unwired Planet, September 23

Johan Hjelm, W3C/Ericsson, September 28