Employing opportunistic device-to-device connections among mobile devices has begun to be exploited as a means to alleviate overloaded cellular connections. We have developed a novel publish-subscribe based technique to drive device-to-device data exchange in situations when peers have overlapping interests. Our approach breaks large (media heavy) data into small chunks, and interested mobile peers issue subscriptions and publications over these chunks. An interested device can then receive chunks from the infrastructure or via opportunistic connections to mobile peers. We provide a very lightweight beacon mechanism to exchange interests, and each peer serves chunks of data based on its assessment of the information diversity in the neighborhood of peers. We have implemented our approach in an Android application. The protocol is called Disseminate. Our Android implementation runs on stock Android (assuming support for WiFi-Direct). Using this implementation and through simulation, we have demonstrated that Disseminate improves over state of the art alternatives in terms of overall network overhead and delivery latency.


Project Participants: Tomasz Kalbarczyk (Ph.D. student), Venkat Srinivasan (Undergraduate student), Dr. Christine Julien (MPC director)