Using LTE Networks for UAV Command and Control Link: A Rural-Area Coverage Analysis

In this paper we investigate the ability of Long-Term Evolution (LTE) network to provide coverage for Unmanned Aerial Vehicles (UAVs) in a rural area, in particular for the Command and Control (C2) downlink. The study takes into consideration the dependency of the large-scale path loss on the height of the UAV, which is derived from actual measurements, and a real-world cellular network layout and configuration. The results indicate that interference is the dominant factor limiting the cellular coverage for UAVs in the downlink: outage level increases from 4.2% at 1.5 m height to 51.7% at 120 m under full load condition. Lower network loads or larger inter-site distances reduces the interference and thus improves the coverage significantly: outage at 120 m is reduced to only 1.9% under network load of 25% for example. Similar effects are expected to be achievable by static or dynamic interference coordination schemes. In addition, ideal Interference Cancellation (IC) scheme with ability to remove completely the dominant interferer shows less effective for UAVs than for users on the ground. On the other hand, macro network diversity has very good potential for drones, as not only it improves the coverage, but also the reliability of the C2 link.