Performance Evaluation of Spectrum Sharing in mmWave Cellular Networks using Ray-Tracing

In order to meet the expectations of future generation mobile networks, the mmwave spectrum has been considered along with new spectrum utilization methods that will ensure wider bandwidths and improved spectrum utilization. Spectrum sharing enables mobile operators to share all available resources, at anytime and anywhere. By doing so there is a significant increase in the inter-operator interference. At the same time, the propagation characteristics of mmwave frequencies and the deployment of directional antenna beam-forming can contribute towards lower interference and higher SINR levels. This paper investigates the performance of a multi-operator network that uses spectrum sharing and how it compares to the traditional exclusive license model. While previous works on this topic considered more theoretic assumptions and methodologies, this paper looks at this problem from a more realistic perspective. It employs a channel model obtained by ray tracing a real world environment and utilizes detailed antenna array modelling based on measurements of a real patch antenna. Our simulation results for a multi-operator mmwave mobile network show that spectrum sharing outperforms the exclusive license model in terms of capacity for the majority of users. However, users with low signal reception do not benefit from the availability of higher bandwidth links and an exclusive license approach consists of a better solution due to the lower interference levels involved. Given that extended simulations for higher network layers were not implemented, the purpose of this paper is to provide an accurate comparison between the performances of the models under investigation and not to test their actual performance. Spectrum sharing proved to be beneficial for high SINR users. Performance gain for the lowest SINR users is unlikely unless coordination techniques or other interference mitigation mechanisms are employed.