Toronto Networking Seminar

Organized by Department of Computer Science and Department of Electrical and Computer Engineering, University of Toronto

Distributing Content Updates over a Mobile Social Network

Stratis Ioannidis
Thomson Research Lab
Paris, France

Date:  Wednesday, September 2,  2pm
Location: BA 5256 


The performance of a wireless network built over opportunistic contacts between mobile users depends crucially on the users' social behaviour. In our work, we illustrate this dependence by studying the dissemination of dynamic content, such as news or traffic information, over such a mobile social network. In this application, mobile users subscribe to a dynamic-content distribution service and share any updates they receive (e.g., through Bluetooth) whenever they meet.

We make two contributions. First, we show that the service provider can allocate its bandwidth optimally to make the content at users as “fresh” as possible. The optimal allocation will depend on the social behaviour of users, and we outline an algorithm for computing it. Second, we show that the above system is highly scalable if the social network formed by the mobile users is an expander graph: under this condition, even if the total bandwidth dedicated by the service provider remains fixed, the content age at each user will grow slowly (as log(n)) with the user population size n.

This is joint work with Augustin Chaintreau and Laurent Massoulie.


Stratis Ioannidis was born in Athens, Greece. He received a B.Sc. (2002) in electrical and computer engineering from the National Technical University in Athens, Greece, and an M.Sc. (2004) and a Ph.D. (2009) in computer science from the University of Toronto, Canada. He is currently a post-doctoral researcher at Thomson, in Paris, France. His research addresses problems arising in highly dynamic, self-organizing networks, such as unstructured peer-to-peer systems and mobile wireless networks.

Host of the talk

Peter Marbach (