Mobile Network performance analysis of UAV : A Simulation for UAVs utilizing 4G-LTE cellular networks

Sammanfattning: The usage of UAVs (Unmanned Aircraft Vehicle) is soaring, not just for hobbyists but increasingly for a range of professional and civil applications. Some of the more sophisticated applications that have high data usage and long-range flight requirements are being developed now. The range and capability of typical wireless connectivity technologies are not enough for such applications. Connecting UAVs to the mobile network is a solution. There are lots of benefits which mobile network can provide for UAVs and UTM (Unmanned Aircraft System Traffic Management). However, the anticipation of UAVs was not considered at first in network planning, which creates unexpected coverage conditions. The introduction of UAVs impacts LTE (Long Term Evolution) network in several ways and the network coverage and capacity of UAVs at low altitude is significantly different from that of terrestrial UEs. The thesis work includes investigation about how UAVs impact LTE network and how mobile network coverage and capacity for UAVs change when other factor changes. The impact of methods to enhance the mobile network for UAVs would also part of the research. In this work, a successful simulation in order to investigate UAV’s situation while using 4G LTE cellular networks is developed. In order to properly test the developed framework for a range of different inputs, various generic scenarios were successfully developed and executed. Using this simulation, we have shown that UAV’s network situation is affected by 2 parameters: the height of UAV and the load of the eNodeBs (Evolved Node B). We have successfully demonstrated that UAV at higher attitude may cause more serious network condition in the suburban area compared with the case in the urban area. Finally, an interference mitigation technique: antenna beam selection is applied and tested. We show that it can improve the network condition for UAV at a higher altitude. Some improvements to the model could be a modeling of inter-cell interference and multipath effects. Models of weather condition in UAV’s flying space would also greatly improve the framework. Besides a scheme for modulation and bit error calculation could be used to build a more generic model. In the thesis, antenna propagation and gain models are not perfect, so more accurate model would also be a great improvement. Only antenna beam selection is tested in this thesis and the implementation does not include antenna mechanical design and model building. For further research, more methods like interference cancellation, power control and inter-cell interference coordination can be tested in both simulation and hardware.