Research on serial assembling scheme for network coding in the Internet

摘要

As an elegant and novel technique, network coding (NC) has been studied extensively, especially its IP layer application. IP packets usually have unequal lengths; however, prior NC researches primarily considered encoding packets with the same size. As a result, research results cannot be applied into Internet directly. In this paper, we propose a novel scheme named serial assembling scheme (SAS) to align IP packets. Our scheme is not only compatible with the TCP/IP protocols but also introduces padding bytes (PB) with a mathematical expectation half the in-degree, and the ratio of PB decreases sharply as average packet length increases. On this account, IP packets can be encoded and SAS-based NC is feasible in Internet. Numerical analysis based on queuing theory and simulations demonstrate that SAS occupies ns-level processing time, which is 1‰ of time spent by NC and store-and-forwarding. Further, combined with SAS, queue length and system load of NC in Internet maintains almost flat while that of store-and-forwarding mechanism rises sharply.