The Landscape of Pervasive & Mobile Computing Standards Sumi Helal Synthesis Lectures on Mobile and Pervasive Computing Preface
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4.6.1 ChallengesAlthough these services aim to increase access to a user’s critical information, they rely on users to create, change, or maintain configurations for this access. In addition, the burden of incorporating these many devices and services into a daily regimen is taxing on the user and highly error prone. The key shortfalls, however, rest in the personalization of the user’s interaction with each of these separate systems and in the changes and dynamics that individual users will need to coordinate and use these services effectively. This can be especially difficult for a user who has a disability, who is aging, or who might need or prefer a different interaction mode. To make these systems truly usable, service providers must bridge the user’s networks (office, mobile, and home), devices (phone, Web pad, and computer), and information spaces (email, documents, and news and information). Key to interaction across devices and information spaces is the ability to provide the solution in a ubiquitous form factor. Users should be able to interact with the devices and services around them in a consistent way, appropriate for the personal device they’re using and their own interaction preferences.
Several organizations are building systems based on the V2 draft specifications. They’ve publicly demonstrated their initial implementations in several venues over the last two years. The market is ripe for third-party developers to build products that carry out interface transformations for content, appearance, and user controls and to build applications that lend themselves to interface selection or transformation. Many of these already exist. The User Interface Markup Language uses Sun Microsystems’ Java Swing to modify rendering of interface elements. UIML is compatible with and expressible by XML. Sun is also pushing its Jini connection technology as a means of mediating access to alternative interfaces (the URC standard would run over Jini). Other venues include the Universal Plug and Play (UPnP) forum, HomeAPI, and HomeRF. The URC standard, if widely adopted, could enable consistent, personalized access to devices and services available in a pervasive computing environment. The V2 committee is looking forward to receiving comments on the draft standards during the public review period. Content and Web Services Converge: A Unified User Interface Smart phones are, in every respect, a first-class mobile computer. Today’s smart phone has the computing power of a full desktop computer from only a few years ago. Memory sizes are routinely 128 or 256 Mbytes, displays are full-color quarter VGA or better, and removable memory cards offer four Gbytes of nonvolatile storage. Advanced 3G networks such as wCDMA (wideband code division multiple access) provide data speeds of up to 384 kilobits per second, which surpasses the common dial-up access speeds used in the Internet’s early days. Likewise, smart phone operating systems now have advanced features similar to desktop PCs. Unlike their predecessors, these operating systems are open for the user to install new software applications. Microsoft Smartphone, Symbian OS, Palm OS, BREW, and even Linux are competing to be the operating system of choice for tomorrow’s smart phone. Desktop-like capabilities such as multiprocessing, dynamic linking, memory protection, MMU (memory management unit) support, and even multithreading are becoming increasingly common on smart phones. The smart phone is thus a new class of computing device, correspondingly demanding a new class of user interface. The smart phone is truly personal—it’s carried by just one individual and at all times. However, we need to personalize it not only for the individual user but also for the wireless operator delivering a custom bundle of wireless services. The new UI must be easy to customize, update, and maintain. We propose a new UI solution in which the Web browser broadens its role beyond browsing external content to also function as the handset UI. Seen in context, this is only the next step in the continuing evolution of today’s wireless ecosystem. Here we describe trends in mobile Web browsing that culminate in the browser as the handset UI. 4.7 THE UNIFIED WEBThe first trend we see is that today’s smart phones are increasingly able to display the Web standards developed for the desktop, resulting in a unified Web for both mobile and desktop content. Previously, developers had to create custom content for mobile displays. Mobile handsets couldn’t process complex markup languages and graphical displays weren’t very good—they were small, colorless, and low resolution. So, mobile Web browsing was limited to technologies such as the Wireless Application Protocol (WAP) 1.0, which required the Wireless Markup Language (WML), a custom markup language completely incompatible with today’s XHTML/HTML browsing standards. With the release of WAP 2.0 in 2001 (see www.openmobilealliance.org/tech/ affiliates/wap/wapindex.html#wap20), WAP moved toward an XHTML-based markup. Using XHTML Mobile Profile (a mobile subset of XHTML), WAP 2.0 became more aligned with both the HTML markup of the desktop Web and Compact HTML used in other mobile services. WAP 2.0 continues to evolve as OMA (Open Mobile Alliance) Browsing 2.2 and 2.3, with the addition of the ECMAScript Mobile Profile (see www. openmobilealliance.org/release_program/ browsing_v22.html) and other features. However, OMA Browsing is still only a subset of today’s desktop Web. 4.8 DESKTOP BROWSING ON MOBILE DEVICESThe second trend makes true desktop content accessible from the handset. With today’s available computation power, smart phones can now process a standard Web page designed for desktop browsing. Additionally, technologies to re-render content to display better on a small-screen device, with all computation done on the mobile device, are now becoming commonplace. ACCESS, an industry leader in non-PC Web browsers, offers Smart-Fit technology to transform a desktop Web page’s layout into a long, thin rectangle. So, the user can navigate on a mobile display using only up and down scrolling—left and right scrolling is eliminated. Another example, PC Site Viewer, also re-renders desktop content for a mobile device.4.2 By making any desktop content accessible to the handset, browsing a dramatically increased library of content is now possible. Download 0.57 Mb. Share with your friends:
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