Optimal placement of colocated and non-colocated LWA nodes in dense deployments

Heterogeneous networks mitigate the co-tier interference which arises due to densification of homogeneous small cells deployment. LTE-Wi-Fi Aggregation (LWA) is one such realization of Hetnet which enables a tighter interworking between LTE small cells and Wi-Fi Access Points (AP) at radio level. LWA node deployment can be realized in colocated and non-colocated fashion. In this work, we have addressed the problems pertaining to dense deployment of LWA nodes. The placement of LWA nodes is done with the following objectives (i) Minimizing the number of LWA nodes without coverage hole (ii) Maximizing the Signal-to-Interference-plus-Noise Ratio (SINR) in every subregion of a building (iii) Minimizing the power spent at the User Equipment (UE) and at the LWA node. We have formulated the problems as Mixed Integer Non-Linear Programming (MINLP) problems. The performance of the proposed optimal LWA placement has been compared with Minimum Interference Region (MIR) placement. We could observe that the proposed optimization problem has improved dual coverage region by 43% and improved SINR by 8 dB compared to MIR. Also, the proposed optimization has lead to 10% energy saving at LWA node and 36% energy saving at UE.