In heterogeneous wireless networks, multi-interfaced mobile terminals may be connected to links with rapidly varying MAC and physical characteristics. On the other hand, current deployment of communication protocols rely on the information available at associated layer only. In order to improve transport layer performance for multi-homed mobile terminals, we propose a cross-layer approach to schedule data over multiple available paths. Our data-striping approach strengthens the cooperation between higher and lower layers and enables transport layer mechanism to exploit information provided by MAC layer. We compare our approach with existing techniques and prove that our cross-layer system improves multipath performance over single-layer multipath systems.