Analysis of Unicast/Broadcast Switch Over with Regard to Resource Allocation for Future Cellular Networks

The number and variety of mobile applications are increasing at an unprecedented and unforeseen rate. To cope with the traffic growth, simultaneous Base Stations (BSs) transmission in broadcast mode will play a particularly important role, as it has been identified as one of the candidate Fifth Generation (5G) technologies, as highlighted in the Third Generation Partnership Project (3GPP) research projects and standard documents. In this context, this paper starts from a scenario of dense BSs deployments and focuses on the study and analysis of the switching threshold between unicast and broadcast cellular downlink transmission modes. Specifically, we provide the threshold number of users per BS at which the broadcast mode becomes more advantageous than the unicast mode in terms of resource utilization. This objective is achieved by considering in the modeling of the cellular network that the location of the BSs is generated according to the Poisson Point Process (PPP) instead of the traditional hexagonal model, taking into account the intercellular interference. This work also addresses the issue of the impact of the variation of some parameters such as the transmission power of the BSs, the density of the BSs, the number of antennas per sector in unicast mode (with beamforming), the size of the simultaneous transmission area in broadcast mode and the outage probability of the system, on the switching threshold under various system conditions.