ONJava.com -- The Independent Source for Enterprise Java
oreilly.comSafari Books Online.Conferences.

advertisement

AddThis Social Bookmark Button

Are Device Independent Wireless Internet Applications Possible?

by Keith Bigelow
06/11/2001

As 2003 approaches,the point at which wireless Web users are expected to outnumber wireline users, there's little talk of the challenge to build wireless applications for them, applications to reach reach all of these users (as opposed to segments of these users whose devices support proprietary protocols).

Open source tools, apps, and projects are expected to consume the proprietary, wireless Internet, just as they consumed the wireline Internet with implementations of TCP/IP and HTTP. Further, the combination of open Internet standards and open implementations of these standards will fuel the convergence of the wireless and wireline Internet.

Dominant Wireless Infrastructures Today

There are two major wireless Internet technologies in broad deployment today,WAP and i-mode, with a third, Java 2 Micro Edition (J2ME), being adopted by PDA and handset manufacturers. The analyst group Eurotechnology reported in November 2000 that the global adoption rate of these technologies was about 60% for i-mode and 39% for WAP. 81% of these wireless Internet devices are in use in Japan today, with the rest scattered throughout Korea, the European Community, and a very tiny percentage in the United States.


Wireless users by country and technology.
(See http://www.eurotechnology.com/ for the full Eurotechnology report)

By "proprietary", the author means that there is no mechanism that exists for a corporation, non-commercial entity, or individual developer to contribute, implement, or extend these technologies without licensing or payment. Thus, proprietary is contrasted by "open", which implies that such a mechanism exists.

A handset or PDA manufacturer that intends to implement any of these technologies must obtain licenses from Sun, the WAP Forum, or NTT DoCoMo. In the case of WAP, developers are further threatened by patent litigation by Geoworks, which claims to have a patent on WML, and is pursuing patent license royalties from all companies that implement the language.

Each of these wireless technologies today is proprietary and offers dramatically different implementations. Clearly, this presents a daunting challenge to any entity hoping to provide either content (news, sports, stocks, etc.) or applications (games, entertainment, corporate field force automation, etc.) to a global audience. i-mode, which has 21 million subscribers as of this writing, uses Compact HTML (cHTML) for its presentation technology. WAP devices use the Wireless Markup Language (WML) for their presentation technology. The J2ME presentation technology is not a mark up language like cHTML or WML but, rather, Java code. In each of these cases, the technologies are copyrighted and licensed to device manufacturers (both handset and PDA vendors), and there are no open specifications or implementations of them.

The global wireline Internet, however, is built around non-proprietary standards and open implementations. History demonstrates that the underlying data transfer protocol (TCP/IP), the presentation and file transfer protocols (HTTP, FTP), and even the presentation technologies themselves (HTML 1.0, 2.0, 3.0, 4.0 and its successor XHTML 1.0) were successful precisely because they were open standards, which any vendor, non-commercial entity, or developer could implement.

Today's nascent wireless world reminds one of the Internet's early days: instead of conflicting implementations by Netscape and Microsoft of HTML and associated scripting facilities, we have WML/WAP, and cHTML/i-mode for Web phones and handhelds, and SMS for pagers . Like the early days of the wireline internet, wireless internet developers struggle to test their code on as many phones and devices as possible. The implementations of proprietary technologies are so inconsistent as to force a "write once, test everywhere" strategy. Indeed, an entirely new industry has sprung up, as a result of these conflicting implementations, which promises to test and then certify that content or applications that one develops will actually run on implementations of the intended protocols and devices. (See http://www.anywhereyougo.com/, a firm offering to certify that content and applications written to the WAP specification actually function on devices that claim to implement the WAP specification.)

As in the wireline Internet, however, proprietary and conflicting implementations are unsustainable. To succeed, the wireless Internet will move to open standards, and this migration has begun already.

What We've Learned from the Proprietary Wireless Internet So Far

The goal of this paper is not to harangue the existing wireless Internet implementations. The early presentation technologies and protocols substantially improved the wireless landscape by demonstrating to the world technologies and business models that were valuable and, in some cases, valueless.

Lessons from WAP
WAP is something of a contradiction in its technology, implementation, and intent. WAP is nearly open in its intent, with a strong leaning toward heterogeneous carrier networks and handsets. WAP is carrier and handset independent, meaning that any carrier can implement the specification and any handset manufacturer can implement the presentation technology inside a WAP browser. The size of WAP Forum, more than 500 members, demonstrates the compelling benefits of an open handset and carrier approach. However, this openness is clouded by a closed WAP Forum which only gives rights to its paying members, and which hose a technology implementation that worked with no existing tools and no existing development paradigm. I list below some of the compelling technology advantages, most of which were re-implementations of existing wireline Internet standards, as well as the technical and business flaws.

WAP Benefits:

  • WML is an XML language, which provides an outstanding mechanism to ensure that a document is well-formed, valid, and portable. Dominant Internet technologies such as Java and corresponding .NET technologies from Microsoft completely embrace an XML approach to application development.

  • WAP provides a lightweight scripting language, which is fairly easy to learn scripting language, inheriting from its Internet cousins JavaScript, VBScript, and ECMAScript.

  • WAP, as demonstrated by the chart above, has strong adoption among carriers and handset manufacturers, and holds second place in terms of handset units deployed.

WAP Problems:

  • It has high carrier and developer Costs, requiring a gateway to transcode Internet content and protocols into WAP content and protocols. These gateways are costly, inconsistently implemented, and offer no compatibility test suite to ensure that applications and content are predictably transcoded by the competing vendors who implement the gateways, which leads to high deployment and debugging costs.

  • Application and Content developers must acquire new, or upgrade existing, tools in order to author WML pages, as traditional web development tools are generally incapable of properly authoring and checking the syntax of WML documents. They must learn new application development concepts (cards, decks, etc.) that are non-trivial.

  • Due to the necessity of the WAP gateway to transcode content and protocols, there are security concerns about data being decoded and re-encrypted between the server of origin, hosting the application, and the WAP gateway as it transforms HTTPS to WAP/WTLS.

Lessons from i-mode
In the i-mode implementation by NTT DoCoMo, carriers and businesses around the world have witnessed the first viable wireless Internet business model for developers of wireless content and applications. Not surprisingly, NTT learned most of these lessons NTT by observing the wireline Internet.

Under the i-mode network, content and applications developers are able to sell their content for a monthly fee. All three elements of the network are satisfied: the end user receives the content they require; the developer is compensated for creating the content; and the carrier derives income from a commission drawn from the developers' fees, as well as per-packet network revenues.

Further, i-mode has taught carriers and businesses the technical benefits of a nearly open wireless implementation. Specifically, the i-mode network's use of cHTML has resulted in three key business technology benefits:

  • Rapid Application and Content Development -- because existing HTML developer tools easily author cHTML pages, existing skilled employees can rapidly create i-mode content and applications.

  • Reduced Costs of Implementation -- because no gateways are required to transcode content or applications in order for that content to reach end users' devices, carriers need not purchase gateways, nor absorb the costs of testing an application to determine its compatibility with different gateways.

  • Superior Security -- because there are no gateways on an i-mode network, there is no capacity for security breaches at a gateway, and thus there is end-to-end security for applications and content.

i-mode also taught a rather significant lesson, the impact of which is only now being realized:

Note, NTT DoCoMo has purchased a 16% interest in AT&T Wireless. The i-mode protocol will be brought to the United States and rest of world via the AT&T network as well.

  • Renegade Implementation -- a proprietary network protocol like cHTML/PDC-P is not easily shared by other carriers, and thus even a handset capable of viewing cHTML cannot access cHTML content if the end user is a SprintPCS, Nextel, or KDDI subscriber. NTT DoCoMo has exclusive control of the protocol, the presentation technology, and the billing mechanisms. Thus, for all the benefits listed above, these benefits can only be realized on the NTT network; developers who want to contribute to, implement, or modify the specifications cannot.

  • Surprisingly, for a company that learned so many lessons from the wireline Internet, i-mode does not implement any scripting language. The end user experience is limited by the static nature of the pages.

  • Finally, although NTT DoCoMo was the first to implement Java on the i-mode network, the implementation is a proprietary derivation of the Java 2 Micro Edition specification and not compliant with the tests that Sun provides to ensure application portability between handsets and carriers.

Lessons Learned from Java 2 Platform, Micro Edition (J2ME)
Sun, with its "the network is the computer" approach, handles wireless development in a way that demonstrates its background in enterprise application development and deployment platforms. Sun's historical strength within the telecommunications marketplace was not lost on the Java team, and all of the expertise of Sun has been brought to J2ME. Indeed, with J2ME, Sun has completed the evolution of the Java 2 Platform. Java, first implemented as a client technology, then embraced as a portable server technology, has come full circle to find a place on wireless Internet client devices in the form of J2ME.

Benefits of the J2ME platform include the following.

  • J2ME applications persist on the client -- the single greatest asset to the J2ME approach to wireless applications is the fact that J2ME applications reside on the client and can function on the client device even when the device cannot connect to the network. Network dropouts are inconsequential when the application can persist on the device, capable of caching newly entered data until a new connection is established.

  • J2ME applications are secure -- the J2ME application developer has full access to HTTPS for end-to-end application security.

  • J2ME applications are cost effective to carriers -- like i-mode, J2ME requires neither transcoding nor gateways, thus lowering infrastructure costs and simplifying testing.

  • J2ME applications are pervasive -- nearly every handset, PDA, and carrier has adopted the J2ME specification.

  • Applications are far more graphically rich, with far higher control of the end user experience (full-motion graphics, business logic executing on the client, etc.)

Constraints of the J2ME platform are as follows.

  • J2ME in not yet pervasive -- while every manufacturer has licensed the technology, there are precious few devices on the market today (approximately 1 million). New cellular phone adoption has been extremely rapid, however, although with current market conditions this is unknown.

  • J2ME designers are not HTML/WMP/cHTML designers -- J2ME requires that a content or application developer re-author their application to target J2ME devices (a problem shared with WAP and i-mode). However, a designer can purchase an upgraded tool to author WML and learn these skills. In contrast, a designer is unlikely to take a crash course in Java programming to learn to design presentations in Java, thus forcing the designer to work with Java developers in order to implement their application.

  • J2ME applications may have installation overhead -- in the USA, carriers have commented that J2ME/MIDlet applications must be installed on the device via a process of connecting to a PC (not unlike how Palm Pilots are synchronized with their PC hosts). This overhead will be costly for large organizations. Note, this is a choice of the carriers, however, as the J2ME applications rolling out in Japan install dynamically over the network.

Pages: 1, 2

Next Pagearrow