Carla Denise Castanho

uP: A Lightweight Protocol for Services in Smart Spaces

The use of mobile devices in a cooperative way is a growing trend, especially in ubiquitous environments. It has created a challenge in terms of how best to connect these devices with greater efficiency. The use of distributed service-oriented architectures (like DSOA - Device Service Oriented Architecture), which takes into account mobile devices restrictions, is shown as a natural candidate solution. In this article, we present the uP, a lightweight set of protocols designed to efficiently facilitate communication in a DSOA configuration. Empirical experiments indicate that this approach provides good results, allowing low consumption of energy in mobile devices within a DSOA environment.

DSOA: a service oriented architecture for ubiquitous applications

Ubiquitous environments are composed by a wide variety of devices, each one with different characteristics like communication protocol, programming and hardware platforms These devices range from powerful equipments, like PCs, to limited ones, like cell phones, sensors and actuators The services provided by an ubiquitous environment rely on the interaction among devices In order to support the development of applications in this context, the heterogeneity of communication protocols must be abstracted and the functionalities dynamically provided by devices should be easily available to application developers This paper proposes a Device Service Oriented Architecture (DSOA) as an abstraction layer to help organizing devices and its resources in a ubiquitous environment, while hiding details about communication protocols from developers Based on DSOA, a lightweight middleware (uOS) and a high level protocol (uP) were developed A use case is presented to illustrate the application of these concepts.

Proteus: an architecture for adapting web page on small-screen devices

Reading the contents ofWeb page with a small-screen device, such as a PDA or cell-phone, is still far from being a pleasant experience. Owing to the device limitations, current mobile browsers cannot handle all HTML tags, such as tables, for instance. Thus, most mobile browsers provide a linearized version of the source HTML page, leading to a large amount of scrolling, not to mention the difficulty in finding the desired content. The main contribution of this work is to propose an architecture for adapting web page on small-screen devices. Among the features that our architecture offers, we can cite on-the-fly Web page adaptation and customization according to the user and device characteristics; text summarization; page blocks identification and content mapping to easy the task of locating user interests.

Reconfigurable Games: Games that Change with the Environment

The purpose of ubiquitous computing lies on making computation invisible to users eyes. Ubiquitous games, on the other hand, try to embed electronic gaming experience into users lives, blending virtual and real components into the play. This type of games represents a challenge for game designers since they need to know which computing resources can be used to create the metaphors that will lead to new experiences. Reconfigurable games are a subset of such games. Their novelty resides in creating games that self-adapt to changes in the real world, creating an ever changing gaming experience. This paper discusses the concept of reconfigurable games. More specifically, we identify the main characteristics of such games and discuss some of the challenges in their development, focusing on the diversity of interaction capabilities available.

uOS: A Resource Rerouting Middleware for Ubiquitous Games

Ubiquitous computing (ubicomp) relies on the computation distributed over the environment to simplify the tasks performed by its users. A smart space is an instance of a ubiquitous environment, composed of a dynamic and heterogeneous set of devices that interact to support the execution of distributed smart applications. In this context, mobile devices provide new resources when they join the environment, which disappear when they leave it. This introduces the challenge of self-adaptation, in which smart applications may either include new resources as they become available or replace them when they become unavailable. Ubiquitous games combine ubicomp and computer game technologies to enrich users experience and fun. Such games may benefit from different input and output resources offered by mobile devices. To support the development and deployment of ubiquitous games, this work presents the uOS middleware. Using a DSOA (Device Service Oriented Architecture) based architecture and lightweight service discovery protocols, uOS ensures compatibility among resources, providing resource rerouting between heterogeneous and limited software and hardware platforms. The uMoleHunt game is presented to illustrate the practical application of uOS.

A game engine for building ubigames

Blurring the boundaries between the game world and the real world is the purpose of ubigames. This entices a higher level of engagement and immersion among players, an effect of great interest by the electronic game industry. Game engines have been employed by this industry to overcome several challenges and are a well established solution. However, ubigames still lack a solution that handles both the challenges of game development and those faced by ubiquitous computing applications. Here is presented a game engine that helps building such games, providing transparent dynamic integration of heterogeneous devices and technologies for game developers.

Gear2D: an extensible component-based game engine

Game engines boost software reuse during development activities by centralizing commonly used domain abstractions within a set of coherent application programming interfaces. Most current game engines focus on class hierarchies, which is the intuitive way to model entity taxonomies but may lead to naming conflicts and code duplication. Component based engines, conversely, minimize this problem by exposing features through components instead. However, due to strong coupling that can still be introduced when using direct access to provide component communication, dynamic entity adaptability may be hindered. Gear2D is a game engine that uses a different approach, providing dynamic entity adaptability through decoupled components. This design results in greater flexibility for creating games, a characteristic discussed through a superficial comparison with a well known game engine and through the development of two nontrivial components: an AI pathfinder and a Lua proxy.

Hydra: An Ubiquitous Application for Service Rerouting

Computing devices are increasingly being incorporated into the physical environment that surrounds us, with smaller, cheaper, more reliable and lower power consumption appliances being manufactured. Presently, there is a profusion of mobile devices with multiple resources such as cameras, screens, keyboards, speakers, recorders and many others. These resources are commonly replicated in the environment, making the task of allocating them in a seamless and shared way a challenge to the users. In this scenario, this work presents the modeling and implementation of Hydra, an application that recognizes the available resources and dynamically reroutes them, according to the users necessities. It runs on the uOS middleware, developed focusing on service adaptability in smart spaces. Thus, Hydra application integrates resources in the environment in order to provide the most adequate services to users.

DSOA: A Service Oriented Architecture for Ubiquitous Applications

Ubiquitous environments are composed by a wide variety of devices, each one with different characteristics like communication protocol, programming and hardware platforms. These devices range from powerful equipment, like PCs, to limited ones, like cell phones, sensors, and actuators. The services provided by a ubiquitous environment rely on the interaction among devices. In order to support the development of applications in this context, the heterogeneity of communication protocols must be abstracted and the functionalities dynamically provided by devices should be easily available to application developers. This paper proposes a Device Service Oriented Architecture DSOA as an abstraction layer to help organize devices and its resources in a ubiquitous environment, while hiding details about communication protocols from developers. Based on DSOA, a lightweight middleware uOS and a high level protocol uP were developed. A use case is presented to illustrate the application of these concepts.

An Ontology-Based Model for Context Information Management in Smart Spaces

Smart applications rely on middleware abstraction to interact with the environment in order to collect relevant information for context determination. Among the forms of representing context in smart spaces, ontologies have been used because of the possibility of sharing, reusing and also modelling the semantics of context, independent of programming language, operational system and/or middleware used. This work presents an ontology-based model to support applications in a ubiquitous environment. The proposed model was implemented and integrated into the uOS middleware, which has focus on service adaptability in smart spaces.