1 A J2ME transparent middleware to support HTTP connections over Bluetooth Vincenzo Auletta, Carlo Blundo, and Emiliano De Cristofaro SCNLab - Dipartimento di Informatica ed Applicazioni Universit` a di Salerno I-84084, Fisciano (SA), Italy Email: {auletta, carblu, emidec}@dia.unisa.it Abstract— Over the last years, a call for embedding computa- tion into the environment has been arisen. This philosophy has been often referred to as pervasive or ubiquitous computing, to remark the aim to a dense and widespread interaction among computing devices. User intervention and awareness are dis- carded, in opposition to an automatic adaptation of applications to location and context. To this aim, much attention is drawn to technologies supporting dynamicity and mobility over small devices which can follow the user anytime, anywhere. The Bluetooth standard particularly fits this idea, by providing a versatile and flexible wireless network technology with low power consumption. Operating in a license-free frequency, users are not charged for accessing the network nor they need an account with any company. Bluetooth dynamically sets up and manages evolving networks, by providing the possibility of auto- matically discovering devices and services within its transmission range. Research studies have forecasted that within a few years, most of the devices accessing the Web will be mobile, and presumably most of them will be Bluetooth-enabled. Therefore, we need solutions that encompass networking, systems, and application issues involved in realizing mobile and ubiquitous access to services. In this paper, we present a transparent middleware which extends the possibility of accessing Web resources also from Bluetooth-enabled smartphones. All the implementation details will be hidden both to users and to application developers, allowing an easy and complete portability of applications working on traditional TCP/IP communication protocols towards the Bluetooth technology. I. I NTRODUCTION The evolution of technology drove a deep transformation of users habits, with an increasing requirement of support to mobility and connectivity. Technology advances have also leaded to the need of providing a brand new set of applications, which fit the mobile environment and allow device interactions over wireless channels. Smartphones are nowadays small and powerful enough to turn into fundamental working instru- ments, and to be considered for the deployment of complex applications. In the last years, several protocols have been presented for wireless communications, such as IRDA, WLAN, and GPRS/UMTS. Among them Bluetooth [1] emerged as a low-cost, robust, and flexible short-range wireless network This work has been partially supported by the European Commission through the IST program under contracts FP6-1596 (AEOLUS). technology. Since it has been designed to achieve a low power consumption, it particularly fits the requirements of resource- constrained smartphones. Furthermore, it operates in a licence- free frequency range, so that user is not charged for accessing the network nor needs an account with a third-part entity. The Bluetooth technology is used by many widespread different devices, such as mobile phones, smartphones, laptops, PDAs. A thorough overview on Bluetooh is given in [3] and [12]. Research studies have forecasted that within a few years, most of the devices accessing the Web will be mobile, and pre- sumably most of them will be Bluetooth-enabled. Therefore, we need solutions that encompass networking, systems, and application issues involved in realizing mobile and ubiquitous access to services. In this paper, we analyze how to extend the possibility of accessing Web resources from Bluetooth-enabled smartphones. Our goal is to provide a transparent middleware which allows user to access Web resources by using a Bluetooth connection. To this aim, we provide programmers with a lightweight and transparent tool to let their smartphone- targeted applications instaurate HTTP connections over a Bluetooth channel. In this way, the cost of communication is brought to zero, and the power-consumption is kept low. Furthermore, the transparency of the middleware allows pro- grammers to ignore all the implementation details and to develop mobile applications in the standard and usual fashion. Useful applications massively using HTTP connections are Web browsers, such as Opera Mini [4], the Web browsed released by Opera Software [5]. Being written in Java, the Opera Mini browser is platform independent and can be easily deployed on every J2ME-powered smartphone. Whenever a user wants to surf the Internet, the application instaurates a HTTP connection over WAP, GPRS, or UMTS, which are the available protocols supporting TCP/IP. The use of our transparent middleware would allow Opera Software to release a version of Opera Mini which works on the free Bluetooth communication channel, without refactoring the source code. Finally, our performance evaluations confirmed the real applicability and lightness of our middleware, showing that it is efficient enough to be used in a real world scenario for a wide set of applications.