Abstract—In λ-grid networks, data files for job execution are stored on file servers as replicas, and computing servers, which execute jobs, download these replicas in parallel to reduce downloading time. However, parallel downloading raises blocking probability of lightpath establishments be¬cause it uses many links and thus wavelength resources are wasted. To resolve this problem, we propose a dynamic parallel downloading scheme with network coding which encodes data at intermediate nodes. The proposed scheme performs network coding by regarding file servers as in¬termediate nodes. In this scheme, a file is divided into multiple blocks. A file server creates an encoded block from those blocks and stores it as a replica. Computing servers download encoded blocks from multiple file servers in parallel. Through simulation experiments, we show that the proposed scheme can improve the blocking probability and the downloading time efficiently.

Index Terms— λ-grid, file replication, parallel downloading, network coding, WDM

Cite: Kouji Hirata , Khamisi Kalegele , Yoshinobu Higami , and Shin-ya Kobayashi , "Dynamic parallel downloading with network coding in λ-grid networks," Journal of Communications, vol. 5, no. 5, pp.425-435, 2010. Doi: 10.4304/jcm.5.5.425-435