In fact, the demand for mobile data has turned out to be one of the most pressing needs of the human race. In more details, the researcher deals with the voice calling performance and good network signal, which are needed to achieve the above. The femtocells are mostly designed for indoor environments. It enables voice calling and traffic loading, where it improves network coverage. Thus, a femtocell is deployed for signal improvement in the indoor setting. Interference occurs among femtocells. The optimisation of femtocells depends on system factors that require performance and capacity of the network for indoor users. In the above circumstance, the authors considered using the cost function to optimise the mobile coverage, whereby reducing the interference within the users. Adequate MATLAB simulation was utilised for this study. The simulated results were satisfactory since they illustrate the benefits of the methods for the service performance.