Improve ubiquitous Web applications with Context Awareness Claudio Venezia, Carlo Alberto Licciardi. Telecom Italia - via Reiss Romoli, 274 Torino 10148, Italy
[email protected];
[email protected] ABSTRACT Going towards a “ubiquitous” Web is a critical milestone for leading the Web to its full potential. Redefining the borders among Web, Telco services and businesses will be a logical consequence. Telecom Italia has been preparing to face these disruptive changes focusing on its assets and pursuing new service concepts, service enablers and platforms. This paper tries to identify both constraints and opportunities of these new scenarios taking into account emerging standards and research initiatives. Telecommunication services tend to be too general and can hardly compete with Web 2.0 ones. Nevertheless operators handle much information regarding their customers such as their profiles or the context (connectivity, location etc.) they’re operating in. Telecom Italia is planning to leverage on those data and is now creating the basis for future services to be sensitive to user context. This paper describes the achievement of a context aware service platform for developing new context aware service concepts. We take into account various eligible standards or standardization proposals, a context management platform and a Web 20 context aware application case study.
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Ubiquitous Web horizon
The number of devices the Web has been targeting is rapidly increasing. They range from TV and appliances to mobile devices like tablet PCs, PDA and of course phones. This trend explains the reason why World Wide Web Consortium has been identifying Telco operators as potential actors and valuable contributors to Internet standards defining the new ubiquitous Web. Mobile Web Initiative groups several technical activities chartered to produce recommendations and best practices to break the barriers of using the web from mobile devices in a seamless manner. Interacting with the Web won’t be just a matter of consuming contents or services, it will soon turn into becoming part of a network of individuals and services interconnected by various communication facilities. Web application clients are rapidly evolving from content fruition tools to fully capable collaborative communication tools. The user experience itself is
evolving from passive to active. The user acts both as content consumer or content producer. Nowadays Google and Yahoo are Web 2.0 services main players and are leading the evolution of this market. The main revenue stream is represented by advertising thanks to its high profitability. New business models [12] will easily find an effective endorsement on these new technology trends and Internet users’ habits. Telecom operators are bound to a passive role in this phase as companies such Yahoo and Google are giving themselves the ideal operational and research structure to storm Web 2.0 services market. While the Web is turning 2.0 Telecom Italia is working hard to be ready to enrich its future commoditized offers with appealing Web X.0 services leveraging on its assets. Integrating a context aware system into the existing infrastructure of a telecommunications provider creates the unique opportunity to offer context aware services to a wide range of users, by either pushing them onto their devices or by offering a pre-filtered number of on demand ones. There’s a wide range of services provided by Telco Operators that the average user is often not aware of. In addition, the offered support is often limited, e.g. location based services are often limited by the lack of fine granularity location information.
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Mobile Web Initiative
Within W3C MWI Best Practices, Device Description and Test Suites working groups belong directly to the so called Mobile Web Initiative [13]. They are chartered to produce guidelines and tools authoring mobile friendly Web contents. A critical facet is defining mechanisms for isolating data from their representation in order to be served in the most device independent way. Being able to understand type, location or context of the device it is serving makes a Web Application able to send contents in the most appropriate way. MWI suggests a “mobileOK” mark adoption to those content providers which will adhere to MWI guidelines. Adhering to the guidelines may produce positive effects to Web sites usability; in general they are reasonable Web design principles intended to exploit the contents at the maximum level. These guidelines are synergic or even overlapping with Web accessibility efforts. These are definitively a
step forward if compared with previous raw suggestions shown on a Web site “best viewed 800X600”. Apart from MWI other W3C activities such as Ubiquitous Web Applications and Rich Web Client are driving the technological convergence between Web and Mobile Telecommunication. Ubiquitous Web Applications is standardizing mechanisms for storing and querying static and dynamic (e.g. location) device properties. W3C is also cooperating either with OMA or with device vendors for devices’ proprietary static properties definition. The delivery context is thus a collection of attributes regarding access mechanism’s capabilities, user’s preferences and further details about whatever context into which a web page is to be delivered.
applications by defining novel languages and tools for client side Web application development. Web API Working Group is chartered to develop standard APIs for client-side Web Application development. The group effort encompasses either the documentation of existing APIs such as “XMLHttpRequest” or the development of new APIs in order to enable richer web applications. XMLHttpRequest API is the base element of AJAX engines on board of the Internet browsers. Web application format is chartered to develop client side languages for application development. Widget 1.0 is an interesting output of the group. Widgets are web applications such as clocks, stock tickers, news casters, games and weather forecasters able to display and update remote data and which run in a standard browser environment. Widgets are thus eligible instruments to collect information about the context in which the device is operating and to transmit them to a back end server to store and elaborate them. They can be relevant during the context capturing phase. These applications can access static or dynamics properties of devices and communicate them to a collector. These technologies at the same time contribute to improve mobile Web browsing capabilities and reduce the amount of data exchanged. This puts the basis for incrementing Web usage from mobile phones given that users are used to pay for data exchanged.
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Figure 1. Ubiquitous Web clients
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New client side scripting paradigm
The said increasing number of Web enabled devices and Web document formats claims an additional standardization effort for handling heterogeneous resources. W3C has been specifying several Web document formats such as XHTML, SVG, SMIL or XForms, each one targeting a specific Web functionality like user data entry, interactive graphical interfaces or simple content displaying. The Web user interface is effective and appealing thanks to a seamless blending of these formats in a single Web page. The Compound Document Formats Working Group is specifying the behavior of some format combinations. Other branches of Rich Web client activity [10] are developing the foundation of Web 2.0 client
Semantic Web
Emphasizing the content rather then how it is presented is an inconvertible trend but it is probably timely to tackle the issue of assigning semantics. For legacy Web applications it was just a matter of presenting information to humans, now a fine grained content research is required and applications need to be able to process the content of information. As said, XML and its further enhancements are solely targeted at defining data structures. XML tags are thus intended for designing data structures and not for assigning semantics. Nevertheless a W3C’s satellite initiative named Microformats has been specifying several rich HTML micro-contents in such a way that they can be easily machine extracted. Microformats is an easy and intuitive way to tackle the problem of assigning semantics to Web resources. It is a lightweight alternative to the W3C semantic technologies to address “micro” problem domains. Within the Web Service Activity Telecom Italia joined Semantic Annotation for WSDL and XML schema working group. SAWSDL defines mechanisms for annotating standard WSDL components such as interfaces, operations and messages. These annotations
can be used also for annotating XML schema standard components such as elements, types or attributes. A ‘model reference’ is a XML attribute whose value is a URI pointing to the semantic definition of a resource. Lifting and Lowering schema mappings are in turn XML attributes pointing to XSLT transformers for specifying mappings between XML and semantic data. Within W3C, the Semantic Web activity [9] is chartered to provide a framework for handling the Semantic Web. Resource Description Framework is an extensible framework for describing resources. OWL is crafted for defining taxonomies, categorization schemes and models in several domains. OWL is built on other W3C standards, XML, XML Schema Datatypes, Resource Description Framework and RDF Schemas making the Web an ideal adoption ground. These outputs demonstrate the research efforts into the modeling, alignment and evolution of Semantic technologies. Recently, representation languages and related ontologies are becoming a key element of semantic modeling. The main focus is set on the specification of representation languages and resulting ontologies. Despite of the semantic Web activity’s research work the software engineering community counts a few successful initiatives in relation to the development of semantic-based systems.
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Context Aware services: what’s needed
In the previous paragraphs we outlined standardization trends and other environmental variables that will probably influence future business around ICT mobile communication services. This is a critical challenge for a Telco operator and it is urgent that Telecom Italia starts developing ideas for facing up these new scenarios. Mobile phones gather much information about the user both in terms of explicit user preferences and in terms of inferred users’ behavior. This information, in observance of customer’s privacy, could be used to understand the user environment for proposing context adaptive services. Indeed integrating a context aware service platform into the existing infrastructure of a telecommunications provider creates the unique opportunity to offer this kind of “intelligent” services to a wide range of users, by either pushing them onto their devices or by offering a pre-filtered number of on demand ones. At least three steps are required to be able to offer services: Context Capturing, Context Reasoning and Service Integration [Figure 2].
5.1 Context Capturing: Context capturing concerns physical and virtual sensors, and the raw data they generate. In Context awareness architectures a context provider represents a context capturing systems that collects data from a wide range of sources (devices, networks, user profiles, etc). 5.2 Context Interpreting and Modeling: The low level representations initially captured may not be meaningful to the application, while high level representations are easier to interpret and to use (e.g., an address is more significant that GPS coordinates). In context aware architectures, the context interpreter module makes the context interpretation and the context modeling makes the context representation. A fine grained reasoning requires a significant computational effort. A trade-off between computational complexity and accuracy needs to be found with respect to the application requirements. The challenge of defining a semantic model for context is critical for CAP platform interoperability. Building and maintaining a comprehensive ontology is critical for performing reasoning tasks such as context abstraction and inference. There are several context ontology standardization efforts but still a few consistencies among them. In fact context in its broader definition may be articulated and complex by spanning over different domains. So far We' ve been trying to refer to public available ontologies (SOUPA, FOAF) by managing the complexity of correlating them by the ontology alignment component. 5.3 Service Integration: A context aware application has to consume a part of the context. In service oriented architecture it must subscribe to the “context broker” that carries the pertinent data to each service in the application. While subscribing, the service tells the broker which part of the context is relevant. After this, the broker can provide a context view for each service. This view can be dynamically evolved during execution, requiring some intelligence in the brokering process. Services may pull context values each time they require it, or the context broker may push context to the subscribers every time it is updated. In the Service Integration step the context is delivered to the service. In order for the infrastructure to know which context to deliver, the service first has to subscribe to a particular subset of context information which can change during operation. This subset can either be pushed to or polled by the service.
(based on GPS receivers, compass, accelerometers, gyroscopes ...); • Network enablers: Address Book providers, Location providers, Presence providers, Calendar providers…; • 3 party enablers.
Figure 2. Context management process
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Context management platform
Services rely on three main functional blocks: the context Aware Platform, the Context Enablers set and the Application Service Layer. The context aware platform [7]acts as a mediator between the Context Enablers and the Application/ServiceLayer, allowing the collection of a large number of context data, which can be used to generate higher level context information. The context information can be retrieved by services from the platform through the context broker. Some core functionalities add value to the raw context data collected correlating them with information about the user profile or the user device and storing them on catalogs. The system injects additional context information through semantic inference on the collected context data. The system is thus able to suggest appropriate services, take actions on behalf of its user and to be proactive. The reasoning and learning algorithms used depend on the reasoning intended to be performed, on the available system resources, on the granularity and amount of context available. The system also counts several “external” functionalities such as Context Information Brokering and Monitoring, Context Data Caching and Context Data History. These functionalities are devoted to threat data collected both client and server side. The client side collects context information from devices (e.g.: Bluetooth nearby devices, local sensors, device capabilities, network connections…), the server side collects context information from networks (e.g.: presence status, device location, calendar information …). The system is also endorsed with several interfaces for application environments. The Context Enablers provide low level Context Information and can be categorized into four groups: • End-user device: PDA, mobile phone…; • Intelligent Sensors: Body Area sensors (ECG monitors...), Environmental sensors (humidity, temperature, light, imaging…), Movement sensors
Figure 3. Context management architecture
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Teamlife: a context aware application case study
Teamlife [14] is a context-based application which fully exploits Tilab’s Context aware platform. Users can share media (photo, video, recorded audio) and files (txt, MS powerpoint) exploiting the user context knowledge. The user’s mobile phone hosts a multiplatform client application. When a picture is taken the application automatically collects context data, by inquiring the context broker [Figure 3], and proceeds to a seamless machine tagging of the image. A summary with photo thumbnails and a tags’ list is thus presented to the user who in turn choose weather to publish it or not [Figure 4]. The service paradigm is not new as such: Flicker is a well known example of “Web Photo sharing album”. The novel here is that picture upload phase is almost seamless but taking the picture and entering optional custom description. Users can also browse their contacts’ pictures by downloading into their phones via a RSS feed mechanisms. At the same time all pictures and multimedia contents are collected and presented in a Web 20 and Mobile enabled portal named “Teamlife” [Figure 5]. Teamlife hosts users’ galleries allowing advanced visualization and research options. It is also endowed with a voting and commenting system. A Tilab research on collaborative filtering techniques will soon enable an automatic sorting of the most “relevant” pictures according to the user profile and/or context.
Furthermore our current research will soon provide to the system image similarity search features based on pictures’ texture rather then on the associated semantics.
5 Conclusions The ICT community pursues Service Oriented architectures and Web 2.0 for speeding the process of service creation and management. Despite these new tools and methodologies ICT services tend to be too general and we want such services to be aware and sensitive to the user context. This would suggest new business models as well as new roles and revenue streams for Telecom Italia. Inferring and elaborating context information along with aiming higher level representation of context (useful for applications) is a real challenge. That is why we are investing on semantic technologies’ research as well as pursuing a standard representation of context. We believe the platform for context-aware applications and services presented in this paper has the potential, together with context sources, reasoning and learning algorithms, to support a new generation of ICT services able to adapt to a wide variety of user needs and behavioral patterns depending on the user’s context.
Figure 4. Mobile phone application snapshot
Besides location information the mobile phone application lists the users’ contacts nearby sorting the registered Bluetooth devices scanned.
Figure 5. Web 2.0 Photo sharing portal
Among the advanced research features users can search for picture taken with same people around, by someone nearby, same location or ZIP code, same kind of camera and so on.
References
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