  In this paper, we investigate the problem of distributed transmission control
for unmanned aerial vehicles (UAVs) operating in unlicensed spectrum bands. We
develop a rigorous interference-aware queuing analysis framework that jointly
considers two inter-dependent factors: (i) limited-size queues with
delay-constrained packet arrival, and (ii) in-band interference introduced by
other ground/aerial users. We aim to optimize the expected throughput by
jointly analyzing these factors. In the queuing analysis, we explore two packet
loss probabilities including, buffer overflow model and time threshold model.
For interference analysis, we investigate the outage probability and packet
losses due to low signal-to-interference-plus-noise ratio (SINR). We introduce
two algorithms namely, Interference-Aware Transmission Control (IA-TC), and
Interference-Aware Distributed Transmission Control (IA-DTC). These algorithms
maximize the expected throughput by adjusting transmission policies to balance
the trade-offs between packet drop from queues vs. transmission errors due to
low SINRs. We implement the proposed algorithms and demonstrate that the
optimal transmission policy under various scenarios is found.
