| dc.description.abstract | Massive demand for mobile data has tremendously increased over past few years, putting pressure to existing infrastructures. This trend is expected to continue in the near future. To cater for this trend, an efficient radio link with enough spectrum is needed. Such radio links are considered in future networks viz multi-tier fifth generation (5G) networks. However, such radio links can operate in higher bands of the spectrum since current bands used for mobile communications are close to their theoretical limits. 5G network is expected to be a revolution in wireless communications having features like higher bandwidth and data rates, accompanied with less transmission delays, enabling a host of many new services like robotics and automation, connected cars, and the Internet of Things (IoT). However, to meet these features, hybrid mobile networks (Heterogeneous Networks) must be deployed as the appropriate solution for possible propagation di cults that can be met by 5G signals operating at millimeter wave (mmWave) wavelengths. HetNets combine different base station (BS) types and different technology in the same network, hence dens ed. However, the BS density to be deployed in a network is a vital design issue since an inappropriate BS deployment could give rise to excess interferences, idle cells (that is cells without users), excessive power consumption and high operating costs. In this research, we optimized the power consumed by BSs in a multi-tier HetNet to determine the optimal BS densities, achieved by the simplex method of linear programming based on maximizing the service area. The hybrid cellular network was modeled to operate in both the Ultra-High Frequency (UHF) and mmWave bands considering their respective transmission impairments. The research aim was to optimize the BS densities in a multi-tier hybrid 5G network towards achieving enhanced connectivity and energy performance of the network. Results show that the hybrid network outperforms both the standalone 4G and 5G networks in terms of data rate and signal to interference ratio (SIR) coverage probabilities, sum data rate and EE. Furthermore, the network performances based on EE and sum data rate can be improved by introducing biasing cell association towards 5G BSs and introduction of indoor BSs in the network. However, there are optimal bias values at which sum rate and EE are maximized. | en_US |
