This is the website of the Mobil4 project, a research effort to enhance user mobility using layer 4 technologies.
Funded by UEFISCDI as project 11/2012.


Traditionally, aspect relating to mobility have been addressed at layer 2 in both wireless and cellular connections. Unfortunately, these solutions are limited in scope as they only function when the L2 networks are within the same administrative control, and they use the same technology (e.g. WiFi to 3G handover is not possible).
Mobil4 is a research project that addresses all networking aspects related to mobile user mobility - such as throughput, latency, availability and even energy consumption - by replacing TCP with a multipath transport protocol such as MPTCP. MPTCP allows connection to migrate between interfaces, thus allowing mobile users to dynamically switch their traffic between 3G and Wifi interfaces.
More importantly, MPTCP allows us to change the traditional "fast-handover" mechanisms now prevalent in L2 networks (be they cellular or WiFi) to a slow-handover where both access points are used for a longer period of time, and traffic is dynamically shifted back and forth depending on channel conditions. Slow handover has the potential to offer better robustness and performance.
Mobil4 studies changes needed to both higher and lower layers that can improve throughput, latency and energy consumption.


University Politehnica of Bucharest
People involved:
  • Dr. Costin Raiciu - Project Coordinator (Homepage)
  • Dr. Dragos Niculescu - Senior Researcher (Homepage)
Intel Software Development S.R.L. People involved:
  • Eng. Bogdan Diaconescu - Partner Coordinator
  • Dr. George Milescu - Senior Researcher
  • Eng. Andra Paraschiv - Researcher
  • Eng. Silviu Petria - Researcher

Research Directions

Mobility tests in the Bucharest underground have been performed to see how much traffic can offloaded to Wifi from 3G.
The Mobile Kibbutz aims to improve energy consumption and delay characteristics of cellular links by using opportunistic networking. The Kibbuts has been implemented on Galaxy Nexus devices, and preliminary results show that 50-66% of the energy of the cellular interface can be saved for typical applications. Watch the Mobile Kibbutz in action here
Revisiting Wifi Mobility: we use MPTCP to optimize Wifi handovers and to provide a seamless wireless experience. We have implemented channel switching in the madwifi driver and are now experimenting with mobility in practice.