Performance of WLAN RSS-based SON for LTE/WLAN access network selection.

Mobile Network Operators (MNOs) are integrating carrier-grade Wireless Local Area Network (WLAN) to cellular networks to improve network performance and user experience. Access network selection (ANS) between cellular and WLAN plays a key role in the integration. Given the complexity of heterogeneous networks characterized by multiple network layer deployments and inhomogeneous traffic distribution, the ANS has to automatically adapt to dynamic network conditions. In this article, we present and evaluate a Self-Organizing Network (SON) algorithm for tuning the ANS between the Long Term Evolution (LTE) and WLAN systems. The proposed SON algorithm adopts a WLAN received signal strength (RSS) threshold to control the access selection. The RSS threshold is updated by the SON algorithm based on periodically monitored load in the LTE and WLAN systems. The SON algorithm is evaluated by simulations in realistic heterogeneous network scenarios and proved effective in improving user experience.