Random Shift and XOR of Unequal-sized Packets (RaSOR) to Shave off Transmission Overhead

We propose the design of a novel coding scheme of unequal-sized packets. Unlike the conventional wisdom that consists of brute-force zero-padding in Random Linear Network Coding (RLNC), we exploit this heterogeneity to shave off this trailing overhead and transmit considerably less coded packets. Thanks to the very basic design, which consists of randomly shifting each original packet then applying XOR-wise operations on a macro-symbol basis (concatenated bytes) to create a coded packet, our scheme has a very low complexity compared to RLNC. The performance depends on the packet sizes distributions as well as the random choice of the shifts only. Our simulation results performed on a state-of-the-art video trace show that in average we need to send only the third of what RLNC for higher finite fields needs to transmit before decoding.