Use of RSS feeds for Content Adaptation in Mobile Web Browsing Alexander Blekas John Garofalakis Vasilios Stefanis University of Patras University of Patras University of Patras Computer Engineering & Informatics Computer Engineering & Informatics Computer Engineering & Informatics Department Department Department 26500 Patras, Greece 26500 Patras, Greece 26500 Patras, Greece Computer Technology Institute Computer Technology Institute Computer Technology Institute 26500 Patras, Greece 26500 Patras, Greece 26500 Patras, Greece +306932321212 +302610997866 +306973281930 [email protected] [email protected] [email protected]

ABSTRACT device’ refers to a device specially designed for synchronous and While mobile phones are becoming more popular, wireless asynchronous communication while the user is on the move. It communication vendors and device manufacturers are seeking includes a wide variety of appliances such as PDAs and new applications for their products. Access to the large corpus of mobile/smart phones. Tablet PCs are also included in the category Internet information is a very prominent field, however the of mobile devices, however they are bigger in size and more technical limitations of mobile devices pose many challenges. costly to acquire. Mobile phones are by far the most popular Browsing the Internet using a mobile phone is a large scientific mobile devices. Among the many facilities they provide is access and cultural challenge. Web content must be adapted before it can to the Internet, however browsing using a mobile phone is not as be accessed by a mobile browser. In this work we build on the easy as browsing using a common desktop PC. Screen size and proxy server solution to present a new technique that uses Really resolution, number of supported colors, entering text method, Simple Syndication (RSS) feeds for the adaptation of web content computation power, memory size, rate of data transfer and energy for use in mobile phones. This technique is based in concrete required for proper functionality are the main limitations for design guidelines and supports different viewing modes. using a mobile device to browse through the Internet [7]. On the Experimentation shows a significant decrease in the transformed other hand, users demand access to information anytime, content of about 80% in size facilitating cost-effective web anywhere. Since within a few years, most of the devices accessing browsing. the Web will be mobile, there is a need for developing methods and techniques that will allow satisfactory web browsing using mobile devices. Categories and Subject Descriptors The problem of web browsing through a mobile phone has H.4.3 [ Communications Applications ]: Communications attracted much attention by the research community and the Applications - Information browsers; H.5.2 [ Information industry alike. One of the proposed solutions is to use a proxy interfaces and presentation ]: User Interfaces. - Graphical user server which adapts the web content for mobile devices on-the-fly interfaces and returns the result to the mobile user. In this paper we build on the proxy server idea to propose a novel solution that makes use General Terms of feeds in a web site in order to achieve better content adaptation. Algorithms, Performance, Design, Experimentation, Human RSS, an XML-like notation, is used mainly in large information- Factors. centric web sites to summarize web site information. By taking advantage of this information, it is possible to transform the Keywords content of the regular web site so that it can be accessed by a mobile phone. The new technique is able to scan any web site that Mobile devices, RSS feeds, content adaptation, mobile browsing, includes RSS, removes ‘unwanted’ information and presents a set web browsing. of different packed versions which are both comprehensive to the user and have a small size. The technique is available as an online 1. INTRODUCTION system that works even for web sites without RSS feeds. During the past decade the world has witnessed a revolution in the Experimental results show a significant reduction of about 80% in field of wireless networks and mobile devices. The term ‘mobile the size of the web page processed using this method. Although this technique also removes multimedia information (images, video, animation) its value relies on the very small size of the Permission to make digital or hard copies of all or part of this work for adapted content, making it accessible even by mobile phones of personal or classroom use is granted without fee provided that copies limited capacity through heavy-loaded or slow wireless networks. are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy This work is structured as follows. In section 2, a review of otherwise, or republish, to post on servers or to redistribute to lists, content adaptation methods for mobile devices is presented. In requires prior specific permission and/or a fee. section 3, RSS feeds are described while in section 4, the design W4A at WWW2006, 23rd-26th May 2006, Edinburgh, UK principles for mobile applications are discussed. Finally, section Copyright 2006 ACM 1-59593-281-x/06/05...$5.00.

5 provides a complete presentation of the application that we have downloaded to the mobile device. This presupposes the existence developed and in section 6 research suggestions and future work of enough main memory to the mobile devices for storing and are presented. running the page code. Furthermore, the user is usually billed according the amount of downloaded data, so downloading large 2. CONTENT ADAPTATION FOR USE IN content is costly. MOBILE DEVICES There are four general approaches for adapting web content for 3. RSS FEEDS small screen devices: device-specific authoring, multi-device Our approach is associated with the automatic re-authoring authoring, automatic re-authoring, and client-side navigation [1]. combined with RSS feeds with the purpose to improve web The first two approaches obtain high quality results by authoring browsing from mobile devices. RSS is a family of XML file device-specific web content. Having two versions of the same web formats which summarizes web site information. It is mainly used content (one for regular and one for mobile users) is costly and by news sites and, generally, sites that their content changes very the vast majority of web sites does not use it. This makes most of often, for example a weblog (a web-based publication consisting the Internet actually inaccessible for mobile phone users. On the primarily of periodic articles, normally in reverse chronological other hand, automatic re-authoring and client-side navigation order). Currently, most web sites use one of the three different techniques do not require the collaboration of page authors and RSS versions; version 0.91 [9], 1.0 [10] and 2.0 [11]. The number are therefore more widely applicable. of web sites that are RSS-enabled is increasing geometrically. According to feedster.com (a search and indexing engine for RSS Research prototypes that use automatic re-authoring fall into two feeds) more than sixteen million RSS feeds are available in the main categories: page reformatting and page scaling. An example web including more than 75.000 professionally published sources of techniques based on page reformatting is the Power Browser such as the BBC, CNN and The New York Times [5]. [3], where images and white space are removed, and the WEST browser [2], which uses flip zooming, a visualization technique that breaks pages into screen-sized tiles and presents them as a Table 1. RSS feeds tags stack. Difficulties with recognizing layout and leveraging the RSS tag Description desktop browsing experience are common to all these approaches, since they all have an impact on the page layout. Start RSS information Other techniques based on page reformatting include scaling the Chunks of summarized information page and return the result to mobile device as a thumbnail. An Time to live (in minutes). Denotes amount of example of this approach is the SmartView system [8]. time for which information is considered valid SmartView creates an image map thumbnail of the page based on its semantic content. The user is able to zoom to the preferred