Latency-Aware Base Station Selection Scheme for Cellular-Connected UAVs

Wireless communication system incorporating unmanned aerial vehicles (UAVs) has gained much popularity recently, especially in video transmission application. This paper investigates the base station (BS) selection scheme for cellular-connected UAVs that possess the function of video collection and streaming to BS for online decision in remote processing center. We aim to minimize the expected access latency while the throughput requirement is satisfied. To this end, a sequential BS selection scheme is proposed by designing an optimal transmission rate threshold for each candidate BS. Due to the mission-driven nature, the access rate varies as the UAV moves, so an effective average transmission rate rather than instantaneous transmission rate is considered. A recursive algorithm is proposed to obtain the rate thresholds which can be used to guide whether UAV should stop or continue measuring the links of the remaining candidate BSs. The proof of the optimality of this algorithm is given. Simulation results validate the effectiveness of the proposed scheme on access latency performance compared with conventional throughput-oriented scheme.