Due to the tremendous growth of mobile data traffic, some technologies from small cell deployment are still ongoing as nominated solutions. Without enlarged wired backhaul capacity, however, the performance of small cell techniques are inevitably degraded. The approach employing the storage capacity in order to off-load the backhaul capacity, as known as femto-caching, has been proposed to minimize the delay within downloading data [1]. In this paper, we consider more practical scenario such as distribution of users' position in whole networks and extend the previous researches in the manner of file placement strategies. Simulation results verify that our proposed scheme has better performance gains with respect to increased opportunity to obtain more various downloading data if helpers' coverages are overlapped.