TR-IIS-06-010    Fulltext

Effective File Transfer for Opportunistic Networks

Chen-Hung Yu, Yung-Chih Chen, Ling-Jyh Chen


As the sheer number of potential opportunistic application continues to surge (i.e., wireless sensor networks, underwater sensor networks, pocket switched networks, vehicular networks, and etc.), proper strategies for dealing with communication in various challenged network environments are of significance and remained desirable. In this study, we investigated two applications in opportunistic networks, namely file transfer and video transfer applications. Based on the H-EC approach, we proposed three message scheduling algorithms to effectively transfer data files in challenged networks. Moreover, targeting video file transfers, we designed LMDC (Layered Multiple Description Coding) based techniques that immensely improve the perceived video quality for end users. Using simulations as well as realistic network scenarios, we evaluated various proposed schemes in terms of latency and PSNR (Peak Signal-to-Noise Ratio). We showed that our proposed schemes can achieve much better latency performance for file transfers. Furthermore, we show that using LMDC-based techniques, the end user can enable lower quality video "previews" before the video file is completely transferred. The effectiveness and robustness of the proposed schemes render them ideal solutions that can go a long way toward effective file transfer in opportunistic networks.