- Research Article
- Open Access
New Trends on Ubiquitous Mobile Multimedia Applications
© Joel J. P. C. Rodrigues et al. 2010
- Received: 2 March 2010
- Accepted: 1 July 2010
- Published: 25 July 2010
Mobile devices present the opportunity to enhance our fast-growing and globally connected society, improving user-experience through novel approaches for information dissemination through mobile communication. The research community is developing new technologies, services, and applications to enable ubiquitous environments based on mobile technology. This paper tackles several important challenges such as communication cost and device limitations for development of ubiquitous multimedia applications. And we propose a system for news delivery using a set of wireless multimedia applications. For this purpose, we have performed a case study with Apple iPhone's platform, featuring two multimedia application contexts, namely, Web and native applications. The multimedia mobile applications draw on iPhone's assets, enabling context-awareness to distribute news, improving communication efficiency and setting-up viewing optimizations, thus enhancing user-experience. The proposed system is evaluated and validated through a series of real-life experiments on real devices, with online full availability. Moreover, due to the Web application availability, the system is not restrained to Apple's iPhone platform, but can also benefit users with other devices.
- Global Position System
- Mobile Device
- Ubiquitous Computing
- Domain Name System
- Native Application
Mobile devices have fulfilled the true aim of Internet by offering full connectivity anytime anywhere. The trend of going wireless goes beyond the walls of homes, university buildings, or hotels and reaches the open spaces of nature or the mobile spaces of trains and buses. The freedom of movements is used to speak everywhere without the need to log in a local wireless network, and to extend it to other Internet services such as Web surfing, email checking, reading news, listen to online radios, or even watching video streaming and television.
The mobile devices market is an emerging mass market with little data usage research available. Consumers are changing their habits, the Internet players are adapting their contents to adjust the new needs, and operators are maintaining a high cost and network restrictions to avoid massive usage. In this market, the business model is restricted to cost-per-use, so data porting to mobile devices have not really taken off.
With embedded technology, mobile devices have many features, so people tend to use mobile devices in order to access to Internet contents more frequently. In this paper, we want to explore and take advantage of this technology, study people habits, and understand their perspectives to this recent trends for the future to create new ways of content distribution. This paper also proposes a mobile system that tries to gather the above-mentioned characteristics for iPhone platform from Apple. We refer to iPhone assuming that mobile device incorporates iPhone, iPhone 3G, iPhone 3GS, and iPod Touch functionalities.
This work studies ubiquitous Internet services in two types of applications—Web applications and native applications. The delivery system incorporates context-awareness, industry standards, and users predefined settings to evaluate how the information is processed, transmitted and displayed. The proposed system improves mobile devices, communication, server side computation processes, user-experience, and usability. The benefits for clients are focused on what and how they want to see, speed, and Internet lower data transfers costs. The benefits for mobile devices will affect battery, memory, processor, and Internet connectivity performance . Furthermore, service providers should improve network availability, bandwidth, and reduce storage costs.
The native application resolves some of the wireless networks limitations such as low-bandwidth and unreliability, understands the user definitions, and reads some mobile devices context in order to adjust the dynamic content downloaded from the Web Service. This solution combines ubiquitous information in both sides of the provided system. On the server side, it calculates image quality, number of items to download, and text format. On the mobile device (client) side, it decides what, how and how many news information or images will be downloaded. This ubiquitous collaboration between mobile device and Web Service is a new approach of intelligent applications that brings out the betterment of two worlds—the server-side power and the client-side context, location, and sensor awareness . Moreover, for journalists and all the news related professionals, it is important to know if a mobile device is just a Web page extension or a new way of communication, more specifically—the seventh way of communication .
The rest of the paper is organized as follows. Section 2 reviews the related literature and the background for mobile and ubiquitous applications. Section 3 focuses on technology, specifications, tools, and methods used to create the proposed applications. Section 4 describes, in detail, the four proposed Web applications for news delivery and presents a comparison study between "Mobile", "News", "RSS", and "Edition" applications. Section 5 elaborates on the native application and addresses ubiquitous technology incorporated on the system. Section 6 concludes the paper and points out directions for further research works.
Mobile devices, which maybe also referred to as hand-held, portable devices, or wearable devices, such as mobile phones and personal digital assistants (PDAs), are small and lightweight equipments that can be fit into a suit pocket, hand, or briefcase. For this work, we have considered mobile devices such as mobile phones and PDAs with Internet connection capabilities and a small-size screen. These gadgets can provide not only regular phone calls but also other features like electronic mail (email), gaming, infrared, Bluetooth and Wi-Fi connectivity, photo camera, video recording, music player, radio, and global positioning system (GPS).
Even though mobile devices have a screen limitation in terms of size, all the content available to other kind of displays (cinema, television, and personal computers) are being produced accordantly to mobile characteristics. The content from other types of media such as recordings, print, radio, and Internet access, can also be imported to these devices.
In 2009, the estimated number of mobile phones subscriptions around the world was about 4,6 billion for a population of 6.8 billion people. And the penetration of mobile phone in the industrialized world was about 133%. In the same period, the broadband Internet access penetration (in mobile devices) was 20 times bigger than in 2005. This makes the mobile phone the most widely spread technology and the most common electronic device in the world. We can predict that it will be the device of the future. According to , the enterprise mobile phones will replace desktop phones in North America by 2011. As the number of people that accessed the Internet via their portable devices have increased by 25% in the second and third quarters of 2008, among which the most audience is young generation, it can be predicted that the contents for these gadgets will continue to grow in future as well. Furthermore, in 2007, for the generation of USA Internet users between 18 and 24 years, the preferred consumer electronics was the mobile phone (47%) over the computer laptop or desktops (38%). Indeed, as a 2008 Nielsen Media Research report highlighted, mobile devices have increased traffic by an average of 13% across several popular websites .
The emergence of Web 2.0 has transformed the web into a more dynamic and interactive environment, offering a set of tools that enhance contact and collaboration between users. Several applications including online social networks, wikis and blogs, support such Web vision . Currently, the interconnectivity and interactivity of Web-delivered content, which were born for the desktop computers, have been extensively applied to mobile devices as well. This new vision of Web is gathering the best that these devices have to offer—portability and connection everywhere—, and the Internet providers are creating new and innovative services for this market .
In general, the integration techniques used to combine Web Services and mobile devices are Socket communication and messaging techniques. Web Services uses extensible markup language (XML) and simple object access protocol (SOAP) to provide a mechanism that facilitates the data exchange over the Internet. They are being widely developed to enable quick and cheap integration with existing services, by combining multiple services in a single workflow. This facilitates interoperability across different hardware and software implementations, as it will be discussed on next sections.
Nowadays, the application programming interfaces (APIs) created by several companies, such as Google, Amazon, and eBay, have robust Web server integration with desktops but when they migrate to mobile environment, new challenges should be addressed. The following aspects are identified: client-server data transfer optimization performance of the mobile application memory management security issues and user interface design with such display limitations. To overcome these issues, new techniques for caching, large data set handling, information on demand, data compression, paging, filtering, and performance improvement of network protocols are proposed for mobile computing.
The number of news and media content downloaded through Internet and portable devices are increasing , therefore, we can predict that the number of these kinds of media Web Services will also increase. We also have the perception that typical iPhone owners are bigger infotainment consumers. They are visiting, at least three times more than average, to several popular social, communication, and entertainment sites. The major newspapers and media groups of the world have already used the iPhone application for delivering news in this new format. So, at this point, several questions may be raised. What mobile Web Services can we choose? What about the design guidelines for mobile devices? Or, there are used mobile development best practices? These issues were considered and kept in mind when planning our approach for the mobile Web Services.
Furthermore, ubiquitous computing is an omnipresent relationship in terms of connections, management, and information interaction. This technology must create calm, and act as a quiet, invisible servant. It should help humans to extend their unconsciousness and intuition. This calm technology has the ability of going from the periphery of our attention, to the center, and back again . Computing, communications with other devices, relationship management, are empowering our periphery but not moving much to the center of our attention. The impact on everyday life is already huge and becoming so commonplace likes writing or electricity.
Mobile devices are getting smaller and powered up with add-ons, speed, and battery life-time. Combining those features and the growth of short-range ad hoc networks, the possibility of accomplishing the vision of ubiquitous computing, that was sketched out in the early nineties, is getting closer [9, 10]. With these significant improvements in the network and devices, the software is trying to catch up. Between them, the ubiquitous systems are still in their early phase.
The impact of this technological wave will alter the place of technology in our lives. By now, every mobile device has Internet connection capabilities. We can interconnect them with other devices and systems, creating a computational relationship between them in a calm and ubiquity context.
With increadingly use of mobile devices with GPS capabilities, location-awareness devices such as the iPhone have changed our daily life. We will be capable of pinpointing our location on a Google Map, tracking friends, finding the nearest place to eat and shop, finding information of the particular area and so on. The first application for the iPhone that uses the faux-GPS feature (which used cell tower information to triangulate your position) is Google Maps. Now, there are a large number of applications that use real GPS features and services. Some examples of location-aware applications that can be found in Apple App Store are the following: Loopt—Friend-finder application with virtual earth display, which allows user to share his location to the community; Whrrl—From Pelago's, is a friend-finder, business applications with browsing functionality; Urban Spoon is a restaurant picker based on your location; NearPics is a location-aware photo browser and uses Google's Panoramio service; Weatherbug is a location aware weather service with predefined cities; StreetFlow; Yelp; Twinkle (Twitter); BrightKite. The list is growing every day.
Mobile devices are equipped with wireless capabilities and users can go through several contextual changes as they move around. These changes are related to the movement of the user in his physical and social surroundings. By sensing their environment, mobile devices are capable of communicating and delivering ubiquitous services adequate to the situation. The dynamic nature of the system implies that as device context changes, delivered information can also change, due to an interoperation with the content server. The server will find the information, adapt it to the user context and format it for delivering. The history of the user is also taken in consideration, hence intelligent handling of the data.
Mobile Internet is about functionality opposed to entertainment and e-commerce on the screen-based systems. We also believe that mobile experience merits its own design, customized to their needs, having the best practices, efficiency, and accessibility. We know that a small screen size doesn't match a 22" liquid crystal display (LCD). People use the portable devices when the information or functionality they need cannot wait, so they go to a computer screen. Therefore, developing for these screens and devices also brings more new issues, paradigms, and semantics to the world of mobile devices applications.
Native applications have more functionalities than Web applications. Therefore, a native application is the best choice for iPhone users. iPhone native applications have four distinct layers. The first layer includes the source code, the compiled code, and the software development kit (SDK) frameworks. The second has the Nib files, which contains the user interface (UI) elements and other objects (the design), and details about how objects relate each other. The third contains resource files (images, sounds, string, video), and finally, the fourth includes the "Info.plist". This file saves details about application configuration. The proposed system assumes that all applications run natively on iPhone. The programs were created using iPhone SDK and Objective-C language. These tools offer several advantages in comparison with others. They include a more complete development environment, improved language depth, integration with SDK frameworks, iPhone emulator, and software debugging.
Main differences between iPhone Web and native applications.
Safari, limited iPhone OS
Just online access
Download or sync
Through Safari framework
App Store download
Communications speed and the fast information process need to be considered since the wireless communication tends to drain out the battery. Furthermore, assuming that access networking is limited in several locations, Web applications cease functioning.
Comparison of main technical characteristics between Web and native applications in the developer perspective.
"Add to main screen option"
Through App Store
Open Safari bookmark or insert URL
Click installed icon
User Web login
App and iPhone settings
Due to screen sizes and browser limitations, the proposed ubiquitous mobile multimedia applications also addresses design concerns. The user interface is designed to avoid horizontal scroll bars, and the most important news is located on top of the screen. The content design follows a top-down approach according to the importance and a left-right disposition, per levels, according to the intended detail of the news content. Furthermore, another important concern kept in mind regarding the design of user interface is Web accessibility on mobile devices, improving usability and user experience. Then, the Web content accessibility guidelines (WCAG) 2.0 is followed .
This study analyses the differences between the four proposed versions of Web applications related to their frameworks in order to determine betterment for the ultimate client. The "Mobile" Web application was initially used to create software specifically for the iPhone because it has optimized code to work with this device. This version was also tested in different browsers outside iPhone and the results have shown a complete website with no information lost.
Two additional Web pages were created for displaying news through images ("Urbi in thumbnails" and "Urbi on images"), in order to navigate through the "touch control with slide effect" from iPhone. The Web application structure is based on a top-to-down item table to display the most important information on the page beginning. This structure is also organized in left-to-right navigation to access detailed information on the right, as recommended by the UI rules that Apple uses for Web applications.
The last version, called "Edition", uses WebApp.Net framework, which is an open source Web application framework, created by Chris Apers and it was designed to mimic the current iPhone graphic UI. All content of this application is dynamically loaded through AJAX requests. On the contrary of versions "News" and "RSS", "Edition" performs an asynchronous request only when the user needs it. Each request of detailed item information creates a different AJAX request. Image files with lower quality are created for this application in order to reduce costs-per-download. The CSS file retrieved with the first page of this version is also different regarding the access timestamp. This version also includes search possibility by providing a form to input queries.
A system prototype (testbed) was created to test and validate the proposal and to evaluate the performance in terms of speed and size. The procedure consisted of loading the Web application from different systems and platforms. To measure the size, requests, and loading speed, the following three different clients were used: (i) iPhone 3G connected through Wi-Fi; (ii) iPhone simulator; (iii) Safari browser running both on a Microsoft Windows XP machine and on Mac OS Leopard. Those latest clients were connected through cable network at 100 Mbps.
Performance evolution of the of Web applications taking in account size and speed of the transferred content between server and client.
First page access
1.8 to 2.4
0.7 to 4.2
0.4 to 0.6
0.7 to 1.9
Runtime parsing (seconds)
0.6 to 4.1
Number of files
Full site size
After describing and evaluating the Web applications, we focus on the Web server. The proposed model for server is based on standard Web-based client/server architecture. Web standards and simplified models were used to design the system architecture in order to improve portability and scalability. Designing with Web standards offers a major benefit because once designed, it can be published everywhere . The Web server is based on the Linux operating system, Apache HTTP server, PostgreSQL database management system, and PHP programming language, constituting the LAPP architecture.
Client requests from "Edition", "RSS", and "News" versions are received and handled by three Web services, one per Web application. For the 'Mobile' version, ubiquitous computing is performed on each page request taking into account that version requests page by page. Each Web service uses specific classes and rules to handle client requests in a ubiquitous perspective. When a Web server receives a client request, ubiquitous decisions influence the images treatment in order to create and deliver images and thumbnails. A rule to change the image size and quality was created to reduce the file size and drop cost per download. This rule applies different compression algorithms according to the Web application version request. Upon reception of a request, another rule is invocated to deliver a specific CSS file, according to the client's time stamp, trying to improve contrast on the mobile device. Domain name system (DNS) reverse lookup to give the location of the client is also used. The time stamp is calculated with client location and server local time. The application can choose specific news for each region, offering the content in a different text language. Furthermore, if the IP address belongs to the user intranet, maximum quality of images is applied.
A transmission of a big file is more efficient than a transmission of several small files . This approach is considered on "News" and "RSS" versions. The other versions use a single request for each webpage. Therefore, "News" and "RSS" have better performance in comparison with the others, as may be seen in Table 3, taking into account the number of files downloaded.
The server also stores other multimedia files not processed by ubiquitous rules, such as portable document format files (PDFs), audio and video files.
The news for mobile devices (N4MD) is a simple application for viewing the weekly news produced in the Urbi et Orbi newspaper. This application runs natively on iPhone devices and the primary difference from the previous Web applications is that the content is available for offline reading. This section describes the native application called "N4MD.ap"'. It has been tested and validated. And it has the foundation for a worldwide quality application to be distributed through Apple App Store.
The "Detail View" appears when a row item on the first window is clicked. This is a subview of the primary view. Therefore, the Top Bar and relative content are related, which has the following three objects: the back button with the title of the table information "Urbi et Orbi News"; the new information index and total of news; and the segmented buttons with navigation through items details. The "Detail View" appears in the white area below the orange "Top Bar". This white area is a vertical scrollable object and with similar behavior to the above described in Web applications detail page. A user can find (from top to bottom) the following news elements: title, description, image, image caption, published date, category, author info, and full new corpus text. On the settings tab, the user can choose (through the slider button on the top) if he wants to see images or not. In the same view, user can find some "control information" that may be collected and sent to the server. These data (the device unique identification, the name, the system version, and the battery information) will be used to perform ubiquity. The iPhone OS Library at iPhone Dev Center  was used to create the application.
The usual touch screen of iPhone controls the navigation actions. The finger movements supported are "Flick" for scrolling and "Tap" for action or selecting. The N4MD user interface uses the Apple's suggested left-to-right navigation approach to go from top level to detail levels. It also uses a "Table View" and a "Scrollable View" to display more information in a top-down structure without zooming or panning. The N4MD application does not support "Rotation View" because we primarily tried to mimic some native Apple iPhone applications like Phone.app, Clock.app, or iTunes.app, which do not support "Rotation View" as well.
Normally, we wanted to use the iPhone's features and frameworks integrated in the device operating system, and available to the developer, in order to ubiquitously connect, download, manage, and display the news content. So, the content will have to be downloaded and saved in iPhone file system, allowing the application to access them offline. However, the application provides some form of user control to override the application and server ubiquitous decisions . Ubiquitous computing is an important matter for mobile computing. Therefore, two types of ubiquitous decisions were created, one for the server and other for the native application.
The N4MD application started with the creation of a default Xcode template—The iPhone OS "Window-base Application" . By doing that all the files and documents were automatic created, and some of them had a few lines of codes allowing us to "Build and Go", even without changing a line. Then we had to modify some of the existent bundle files (png images, visual elements on the Xib, and the application default .h and .m files).
In the "init" stage, while launching, the application gets user preferences and starts to build the window with components like the "Navigation Bar". Then, the application checks if it has a network connection. If it has network connection, it sends a request for server statistics. The next stage is getting the articles (the news). If there is a network connection, the application makes a XML http request, if not, it tries to load a previous saved "plist" file. In neither case, the application continues by parsing the information. Then, the display stage happens when the information is loaded and we can see the "Table View" with article title, description and thumbnail. After the first display stage, the application enters in a cycle (waiting for a user's input that change status in order to make new display changes) or quits. The "user-default" feature is used to save three state variables for user and application settings in the applications bundle directory. This information is useful as it seamless shows the last viewed window before exiting. Therefore, the user does not have to navigate through the application all over again. The data from the XML http request in a form of a "plist" file—which is also a XML format—is saved within the application sandbox. The downloaded images are saved on Documents directory. When user click on the reload button and the flag for Internet connectivity is on, the applications erase all the downloaded data from the bundle directory and starts the asynchronous communication with the server to get refreshed information. Moreover, screen size forces a top-down design for information display, the "Table View" is one of the most used components for the iPhone regarding its vertical characteristics. Mobile devices do not have characteristics that a desktop computer has, such as the following: all the mouse movements or click events; not all views have page zooming; text size adjustments, options for fonts sizes types, form controls or form saved information. Therefore, those characteristics cannot be used in the ubiquitous system. The iPhone OS recognizes some special links like: http:, https:, itunes:, phone:, mailto:, making communication between applications more dynamic.
For improvement of speed, the application depends on the network speed and number of items to be downloaded. It only occurs when threaded url connections are used to speed up the application, and it is provided by the asyncimageview class. The application contacts the server in two distinct stages. The first contains information about the device (name, model, localized model, system name, system version, and unique identifier). The second communication occurs when the application makes a request for data (news content feed), and at this point the information to server contains battery status and client type. These stages are important for the success of the ubiquitous system. Other requests are motivated by references of thumbnails and images included in the XML file. This request just happens if the user allows image loading on settings, and if the used network is 3G or Wi-Fi.
In order to create ubiquity in N4MD application, the communication between server and client was forced. The client has to collect context-aware information and send it back to the server . Then, the server must determine the location-awareness of the device (so far we do not use GPS), save the user statistics, and use the information received in order to deliver the desired information content in a specific format.
Applications for mobile devices are gaining their own market as the seventh way of communications by being less equal to small online versions of the bigger brothers, and taking advantage of the opportunities as they pop-up. Web applications and native applications must co-exist due to connectivity issues and offline reading. In terms of design, they are similar in many ways and also share architectural and structural models. But their final purposes make them unique to each other and have usefulness on their own way. Moreover, Web applications are oriented for cloud computing, peer collaboration and synchronous connectivity. On the other hand, Native applications take advantages of mobile devices characteristics and access to more frameworks.
Applications for mobile devices must use ubiquitous computing techniques in more effective way. By addressing fundamental topics, in a quest to unleash the full potential of data consumption, the usage of location and context-awareness in mobile devices are changing our life quality for the betterment. Those above described systems combine the portability of a Web Service with the mobility of users to overcome the limitations of mobile devices.
This paper proposed and described in detail a system for delivering news using wireless multimedia applications and transmission techniques to mobile devices, using proposed platform to Apple's iPhone. For study purposes, four different versions of a University online newspaper were created. These versions were produced to specifically provide an important parameter of their target mobile device. While testing size, runtime speed, connections, design, and usability, our study shows that each version has its own advantages as we have expected. Ultimately, the server decides the best version for the specific client and delivers the corresponding application. But, the standard default (to be used with all around mobile devices) is the "Mobile" version. This version was developed with the iWebKit, that proved to be, the best all around accessibility platform for general mobile devices multimedia Web applications.
The decisions for ubiquity occur in the server-side and in the application itself. They use the information of each other to decide the best for several parameters, and, ultimately, the best for the user client. This new level of ubiquitous collaboration brings out the best of two worlds—the server-side power, and, the client-side context, location and sensor awareness, making the delivering of news seamless, visually effective, communication efficient, configurable, or ubiquitously personal.
The application resolves some of the wireless networks limitations, reads the context-awareness of mobile devices, communicates with the server and understands the information received.
The proposed applications are conceptually simple as they proved to be the best way. Like the open software, the usage of standards in mobile development is a necessity ("must have"). It opens doors to new applications or services, improves compatibility with other devices, and all is under control of the programmer. The news delivery to all kinds of the readers was also studied. The proposed ubiquitous computing, software design engineering, service architecture, and news content, bring innovation and contribute to improve communication in this modern world.
In a near future, the proposed applications can be improved in several ways. The following items are suggested during tests and debugging stages and can be found in other applications studied. It seems worthy to make it for the application. In the Web applications, the following may be performed: (i) create advanced client information—client history and online statistics that would be added on the ubiquitous system to create more personal, seamless, and user-oriented news content; (ii) add multimedia capabilities to the Web application and Web server (streaming server)—enlarge compatibility with automatic conversion on codecs, containers, sizes, and file formats; (iii) add user registration—access to post comments, news, suggestions, uploading files, images, and slideshows; (iv) add options like—Send content to email; and (v) add them to Twitter, Facebook, LinkedIn, Hi5, or other social networks.
For Native applications, some features for the server side of the Web applications type may also be proposed. We can also perform the following: (i) add location-awareness given by GPS to ubiquitously choose news, language and design for a specific region; (ii) improve native application ubiquity by using more information from sensors, location services, settings, connectivity, and specific device characteristics; (iii) embeded multimedia elements such as video, audio, photo slideshow, and other Web pages without quitting from the application; and (iv) as recommended by Apple improve the software design. "Make it iPhone", by bringing innovation on design, more information on display, new features or services, usability, and accessibility.
Part of this work has been supported by Instituto de Telecomunicações, Next Generation Networks and Applications Group (NetGNA), Portugal, and by Online Communications Lab (LabCom), University of Beira Interior, Portugal.
- Da Costa CA, Yamin AC, Geyer CFR: Toward a general software infrastructure for ubiquitous computing. IEEE Pervasive Computing 2008, 7(1):64-73.View ArticleGoogle Scholar
- Ortiz G, De Prado AG: Mobile-aware web services. 3rd International Conference on Mobile Ubiquitous Computing, Systems, Services, and Technologies, (UBICOMM '09), October 2009 65-70.Google Scholar
- Ahonen TT, Moore A: Communities Dominate Brands: Business and Marketing Challenges for the 21st Century. Futuretext; 2002.Google Scholar
- Pettey C, Stevens H: Gartner Says Enterprise Mobile Phones Will Replace Desktop Phones in North America by 2011. Gartner, 2009, http://www.gartner.com/it/page.jsp?id=874012Google Scholar
- Covey N: Mobile Internet Extends the Reach of Leading Internet Sites by 13%. Nielsen Media Research, 2008, http://www.cellular-news.com/story/30926.phpGoogle Scholar
- O'Relly T: What is Web 2.0. O'Reilly Media Inc., 2005, http://oreilly.com/web2/archive/what-is-web-20.htmlGoogle Scholar
- Zhang J, Hämäläinen A, Porras J: Addressing mobility issues in mobile environment. Proceedings of the 1st Workshop on Mobile Middleware: Embracing the Personal Communication Device, Co-located with ACM/IFIP/USENIX International Middleware Conference (MobMid '08), December 2008, Leuven, BelgiumGoogle Scholar
- Weiser M, Brown JS: The coming age of calm technology. In Beyond Calculation: The Next Fifty Years of Computing. Edited by: Denning PJ, Metcalf RM. Springer, New York, NY, USA; 1997.Google Scholar
- Steele J: comScore Reports 6.5 Million Americans Watched Mobile Video in August. comScore, Inc., 2008, http://www.comscore.com/Press_Events/Press_Releases/2008/10/Mobile_VideoGoogle Scholar
- Mostefaoui SK, Maamar Z, Giaglis GM: Advances in Ubiquitous Computing: Future Paradigms and Directions. IGI Publishing, New York, NY, USA; 2008.View ArticleGoogle Scholar
- Sadun E: The iPhone Developer's Cookbook: Building Mobile Applications with the iPhone SDK. Addison-Wesley, Boston, Mass, USA; 2009.Google Scholar
- Caldwell B, Cooper M, Reid LG, Venderheiden G: Web Content Accessibility Guidelines (WCAG) 2.0. W3C; 2008. http://www.w3.org/TR/WCAG/Google Scholar
- Hazaël-Massieux D: Return of the mobile style sheet. A List Apart 2009., (275): http://www.alistapart.com/articles/return-of-the-mobile-stylesheetGoogle Scholar
- Zilora SJ, Ketha SS: Think inside the box! optimizing web services performance today. IEEE Communications Magazine 2008, 46(3):112-117.View ArticleGoogle Scholar
- Mark D, LaMarche : Beginning iPhone 3 Development: Exploring the iPhone SDK. Apress, New York, NY, USA; 2009.Google Scholar
- Tarasewich P: Designing mobile commerce applications. Communications of the ACM 2003, 46(12):57-60. 10.1145/953460.953489View ArticleGoogle Scholar
- Abowd GD, Hayes GR, Iachello G, Kientz JA, Patel SN, Stevens MM, Truong KN: Prototypes and paratypes: designing mobile and ubiquitous computing applications. IEEE Pervasive Computing 2005, 4(4):67-73. 10.1109/MPRV.2005.83View ArticleGoogle Scholar
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