Accessing Ubiquitous Services Using Smart Phones Nishkam Ravi, Peter Stern, Niket Desai, and Liviu Iftode Department of Computer Science, Rutgers University {nravi, peterst, nickd, iftode}@cs.rutgers.edu September 8, 2004 Abstract The integration of Bluetooth service discovery protocol (SDP), and GPRS internet con- nectivity into phones provides a simple yet powerful infrastructure for accessing services in nomadic environments. In this paper, we discuss the design and implementation of a proto- col, called SDIPP, which unifies service discovery, interaction and payment through the use of Smart Phones. Although several service discovery protocols have been proposed earlier, such as SLP, Jini, UPnP, Salutation, they all have their own infrastructure requirements and target audiences. Bluetooth SDP is an on-the-fly service discovery protocol. However, it is not nearly as powerful as its counterparts. SDIPP works by augmenting Bluetooth SDP with web access and personalization. Payment of services has been overlooked in the protocols proposed earlier. SDIPP provides a novel protocol for payment via Smart Phones, based on Millicent scrips. We have implemented a few services to illustrate our protocol. We report on our experiences and experimental results. In particular, we analyse and provide an application level solution to the Bluetooth inquiry clash problem that we discovered in the process. 1 Introduction Smart Phone technology is a result of the convergence of cell phones and PDAs and is steadily becoming ubiquitous with all the big mobile manufacturers like Nokia, Sony Ericsson and Motorola vigorously supporting it. Despite efforts by giants like Miscrosoft and Palm, and presence of Linux based Smart Phones like Motorola A760, Symbian OS remains the most dominant platform for Smart Phones, holding 67% of the market share which is expected to grow. Symbian OS supports Personal Java, J2ME, MIDP as well as C++. With ample memory and computing power, Smart Phones are expected to personify the abstract handheld that has so long been part of the picturesque visions of pervasive computing [30]. Many believe that Smart Phone technology will be instrumental in guiding and realising the visions of pervasive computing, by giving shape to abstract ideas and assumptions. Several service discovery protocols have been proposed, such as SLP [21], Jini [7], UPnP [8], Salutation [12], Bluetooth [13], DEAPspace [24], Intentional Naming System [15], Secure Service Discovery Service [19] and Splendor [31]. These protocols can be roughly classified into two cate- gories: client-service model and client-service-directory model, with the exception of Splendor which follows a client-service-proxy-directory model, where proxy is used to achieve privacy, authentication