Cache-Aware Source Coding

In this letter, we show that Huffman's source coding method is not optimal for cache-aided networks. To that end, we propose an optimal algorithm for the cache-aided source coding problem. We define cache-aided entropy, which represents a lower bound on the average number of transmitted bits for cached-aided networks. A sub-optimal low-complexity cache-aided coding algorithm is presented. In addition, we propose a novel polynomial-time algorithm that obtains the global-optimal source code for wide range of cache sizes. Simulation results show a reduction in the average number of transmitted bits by more than 50% over Huffman's method at moderate cache sizes. © 1997-2012 IEEE.