Performance gain of precaching at users in small cell networks

The throughput of small cell networks (SCNs) is limited by intercell interference. Except numerous techniques of interference coordination, simply caching several popular files at each user provides an alternative approach to reduce interference by pre-offloading. This becomes possible nowadays due to the facts that the cost of memory devices is reducing quickly and content delivery is gradually dominating the traffic load. In this paper, we quantify the performance gain introduced by precaching at users. We derive the average throughput for non-coordinated downlink SCN with precaching, and compare with the SCN without caching and with existing prefetching policy. We use simulation to validate the analytical results and further evaluate the average download time of different policies. Our results show that the caching gain is remarkable when the traffic load is high and the popularity distribution is far from uniform.