Cooperative Networking of Mobile Devices

MicroCast: Proximal Video Sharing on Mobile Devices

Video streaming over the cellular connection is one of the increasingly popular, as well as demanding, applications on smartphones. In this work, we consider a group of smartphone users, within proximity of each other, who are interested in streaming the same video from the Internet at the same time. The common practice today is that each user downloads the video independently using one connection (e.g., cellular or WiFi), which often leads to poor quality.

We design, implement, and evaluate a novel system, called MicroCast, that cooperatively uses the resources on all smartphones of the group so as to improve the streaming experience. Each phone uses simultaneously two network interfaces: one (cellular) to connect to the video server and another (WiFi) to connect to the rest of the group. Key ingredients of our design include the following. First, we propose a scheduling algorithm, MicroDownload, that decides what parts of the video each phone should download from the server, based on the phones’ download rates and the congestion in the local network. Second, we propose a novel all-to-all local dissemination scheme, MicroNC-P2, for sharing content among group members, which outperforms state-of-the-art peer-to-peer schemes in our setting. MicroNC-P2 is explicitly designed to exploit WiFi overhearing and network coding, based on a local broadcast framework, MicroBroadcast, which we developed specifically for Android phones.


  • Oct 2015: MicroCast got accepted to IEEE/ACM Transactions on Networking.
  • We received Innogrant: Innovation and tech transfer at EPFL
  • We were selected for support by the NSF-ICORPS program (Georgia Tech, Fall 2012 cohort) to explore potential commercialization of this project. Here are some lessons learnt at the end of the training.
  • MicroCast was one of the 5 finalists (out of 32) for the Best Paper Award at MobiSys 2012!
  • MicroCast and MicroPlay won the first place of the general category in AMASE 2012! This is a mobile application showcase event that highlights mobile applications developed by ICS students at UC Irvine.


Presentations and Videos

  • Here is the video with the lessons learnt at the end of the NSF I-CORPS training. Georgia Tech, Atlanta, Nov. 2012.
  • Technical description: short video and longer video.
  • YouTube Video of Anh presenting this poster at the Information Theory and Applications Workshop 2012 (ITA 2012), San Diego, CA, USA, Feb 5-10, 2012. Extended abstract here.
  • Demo and poster at the International Workshop on Mobile Computing Systems and Applications 2012 (HotMobile 2012), San Diego, CA, USA, Feb 28-29, 2012.
  • Overview Talk presented at AFOSR Program Review on “Complex Networks”, Washington, DC, Dec. 2011.


  • For the network coding part, we used the NCUtils library developed by L.Keller.