Reduce Transmission Delay for Caching-Aided Two-Layer Networks
Ke Wang, Youlong Wu, Jiahui Chen, Haoyu Yin · 2019
In this paper, we consider a two-layer caching-aided network, where a single server consisting of a library of N files connects with multiple relays, each equipped with a cache memory of M1files and each relay connects with a distinct set of users, each equipped with a cache memory of M2files. We design a caching scheme that exploits the spared transmission time resource by constructing a concurrent transmission between the two layers. It is shown that the caching scheme is order optimal and achieves an additive parallel gain compared to the previously known caching scheme. Also, we show that for the two-relay case, if each relay's caching size M1equals to 0.382N, our scheme achieves the optimal delay as M1= N, implying that increasing the relay's cache size will not always reduce the transmission delay.