Optimal Deployment of Heterogeneous Wireless Nodes in Integrated LTE/Wi-Fi Networks

Optimal placement of small cells in integrated LTE/Wi-Fi heterogeneous network architecture is considered one of the key approaches that can be used to increase the system capacity and enhance the coverage to meet the unexpected explosion of mobile data traffic. Co-operation and interworking between different Radio Access Technologies (RATs) introduce the LTE/Wi-Fi Aggregation (LWA) which allows the traffic aggregation between Wi-Fi Access Point (WAP) and LTE small cell on the level of Radio Access Network (RAN). In this paper, the effectiveness of the optimal deployment of heterogeneous wireless small nodes in a hotspot zone is considered and explored. The deployment of different wireless small nodes is formulated as an optimization problem with the objective of (i) Maximizing the total system throughput while considering the minimum received Signal-to-Interference-plus-Noise Ratio (SINR)/Signal-to-Noise Ratio (SNR) requirements for LTE/Wi-Fi coverage (ii) Choosing the optimal number of small cells which can guarantee the coverage of the considered hotspot zone (iii) Choosing the optimal formation of WAPs Basic Service Sets (BSSs). The objective function is formulated as a Mixed Integer Non-Linear Programming (MINLP) problem and solved using genetic algorithm. The performance of the proposed optimal deployment approach is compared to the uniform distributed deployment algorithm in terms of system throughput in which a significant improvement is noticed when the proposed approach is adopted.