The secure localisation of unknown nodes in Wireless Sensor Networks (WSNs) is a crucial research topic due to the vast range of applications of WSNs. These applications drive the development of WSNs, as real-world obstacles typically motivate them. WSN technology is rapidly evolving, and this paper provides a brief overview of WSNs, including key research findings on energy conservation and node deployment. The paper discusses the applications of WSNs in medical health, environment and agriculture, intelligent home furnishing and construction, and military, space, and marine exploration. The paper focuses on the research of RSS-based locating algorithms in WSNs and is divided into two sections. Firstly, accurate location depends on the accurate RSSI received from nodes. This experiment analyses the distribution trend of RSSI and derives the loss model of signal propagation by processing experimental data. Secondly, Gaussian fitting calculates the distance between receiving and sending nodes by processing individual RSSI at different distances. The primary challenge in studying this RSSI range-based technique is the low positioning accuracy, low energy, and high error rate. To solve this problem, a recommended GA is used to find the optimal site by minimising error, providing the best feasible solution, and being energy-sensitive, with accuracy based on the least error inside the network. The proposed approach aims to optimise sensor placements for improved performance
