Delay-optimized small world model for base station caching

Distributed base station caching is an efficient way to reduce the network traffic load in advanced cellular networks, but suffers from a significant network delay due to the multi-hop transmission, leading to a poor quality of service. The presence of a few shortcut direct links transforms a regular network to a small world network resulting in achieving properties of high clustering coefficient and low average path length. In this paper, we propose a delay-optimized small world model for base station caching network to reduce the average network delay by decreasing multi-hop distance. In particular, we first study the degree-based and closeness-centrality shortcut addition strategies. To enhance these two strategies, we propose the delay-optimized shortcut addition strategy to decrease average network delay. The numerical results show that the proposed delay-optimized small world model can reduce the average network delay under remaining the clustering coefficient. Meanwhile, the average network delay with the proposal is 31.26% lower than that with the degree-based strategy, and is 18.78% lower than that with the closeness-centrality strategy.