Parallel Downloading Method using HTTP over UDP for High Loss Rate and Delay Networks

"Parallel downloading" is one of the most effective technologies which speed up downloading large files on the Internet. As ubiquitous networks will be realized in the near future, downloading large files quickly is also very important on various types of networks. However, if we use the parallel downloading method on dynamic networks, such as ad hoc networks, it will not work well because of high loss rate and delay. To address this issue, we adopt UDP as a transport layer protocol instead of TCP which guarantees perfect in-order delivery unnecessary for file downloading. We have implemented a prototype of the parallel downloading method using HTTP over UDP, and it is confirmed that our method outperforms the traditional method which adopts TCP, especially when loss rate is high and delay is large. Our proposal will be effective on dynamic networks such as ad hoc networks included in the ubiquitous network environments