Interest-Based Data Dissemination in Opportunistic Mobile Networks: Design, Implementation and Evaluation

This research focuses on providing pervasive data access to mobile users without support of cellular or Internet infrastructure. Two mobile users are able to communicate and share data with each other whenever they opportunistically move into the Bluetooth communication range of their smartphones. We designed and implemented our system on Android-based smartphones, and deployed our system to students at the Penn State University campus. Our system dynamically captures the interests of mobile users at runtime, and intelligently distribute to users with the data that they are interested in. It also provides a unique research facility for investigating the interests and the data access patterns of users in various mobile environments. With the recent technical advance and popularization of smartphones which are able to store, display and transmit various types of media content, it is important to provide pervasive data access to mobile users, and distribute media contents to these users promptly and efficiently. A straightforward solution is to provide such data access via the 3G cellular network infrastructure. However, the data access will create huge amount of data traffic for the 3G network, which imposes immense pressure on the limited spectrum and the backend resources of 3G networks, and hence deteriorating the quality of service. This also motivates research on offloading 3G traffic to other communication networks such as WiFi [23, 1], but the coverage of WiFi accessibility is still limited nowadays as reported in [1], especially for mobile users which keep moving. To address this challenge, in this paper we develop a practical system which enable mobile users to autonomously transmit and share data with each other by exploiting the unused opportunistic communication links between the short-range radios (i.e., Bluetooth) of their smartphones. Two users are able to communicate when they opportunistically contact each other, i.e., moving into the Bluetooth communication range of each other. The networks consisting of these users are called Opportunistic Mobile Networks, which are also known as Delay Tolerant Networks (DTNs) [7] or Pocket Switched Networks (PSNs) [14]. The contributions of our work are twofold. First, our system provides prompt and efficient access on categorized web data to mobile users, based on their interests in the data. More specifically, our system dynamically captures the interests of mobile users at runtime, and intelligently send them their interested data. The power constraints of smartphones are also taken into account, and we propose solutions to tradeoff between power …