Offloading Performance of Range Expansion in Picocell Networks: A Stochastic Geometry Analysis

Range Expansion (RE) can improve the capacity of heterogeneous networks by increasing the coverage of low power nodes like picocells. So far, however, there have been limited results on quantifying the performance of range expansion and the effect of Range Expansion Bias (REB). To address these issues, using stochastic geometry, we propose a practical load-aware model in which users´ minimum throughput requirements and Base Station (BS) load are taken into account. Furthermore, we get a closed-form expression for the outage probability in the heterogeneous network with RE. Compared to previous models which assume all BSs are always fully loaded, the proposed model is more reasonable for lightly-loaded networks. Additional, our results reveal the offloading benefits of RE and provide insights into the settings of system parameters such as REB.