Third Screen Networks

'Third Screen' devices such as smartphones and netbooks are ubiquitous and increasingly powerful computing platforms. Enabling such devices to inter-operate seamlessly with the wired Internet as well as other devices is a significant challenge. This project is centered around the problems posed by 3G devices in the space of networking and distributed systems.

[Mobile-to-Mobile Networking] Contrail is a system aimed at enabling applications that require selective data-sharing across 3G devices; for example, if Alice wants to receive photos taken by Bob at a particular location. Contrail uses sender-side content filters that devices install on each other, along with a cloud-based messaging layer (implemented in Windows Azure) that relays data and filters between devices. In comparison to conventional server-based solutions, Contrail provides better privacy, since the cloud acts as a dumb router with no visibility into either data or filters. It also provides better efficiency, since data is only uploaded from a device if explicitly requested by some other device.

[Geolocation] Our study in IMC 09 focused on the network end-host properties of 3G devices. We found that the IP addresses exposed by 3G devices to Internet servers can change rapidly across requests, on the order of minutes or even seconds. Additionally, IP addresses have no intrinsic locality, with devices in far-away geographical areas exhibiting similar IP addresses. These findings have important implications for the design of Internet services with 3G clients.

[Content Adaptation] Merlion is a system that enables end-users to create custom mobile applications from existing desktop applications. Users can select desired visual regions from existing applications, alter their layout to better suit a mobile display, and set up transitions. Merlion can improve user productivity by simplifying user interfaces, automate repetitive actions, make applications available across different mobile form factors, and can allow applications that run on different machines to operate in concert.

Publications