Future uncrewed aerial vehicle (UAV) systems increasingly combine heterogeneous communication technologies, such as low-latency aerial mesh, terrestrial cellular, and satellite links, to improve robustness and coverage. Multipath transport is a natural mechanism for aggregating these links, yet its ability to support real-time UAV services in highly heterogeneous environments remains insufficiently characterized. We present a measurement-driven study based on UAV flight experiments in an integrated network comprising UAV-to-UAV aerial mesh, private cellular, and low Earth orbit (LEO) satellite connectivity. Using Multipath TCP (MPTCP) as a representative lossless, in-order multipath transport framework, we find that aggregation can preserve end-to-end connectivity under severe link outages. However, large round-trip time (RTT) heterogeneity amplifies packet reordering, leading to substantial receiver-side buffering and bursty delivery. In addition, when the available links do not provide sufficient capacity for the offered load, pronounced sender-side buffering emerges. These effects cause real-time streaming to violate delay constraints, including cases where aggregate capacity is sufficient. To interpret these results, we formalize the distinction between connectivity continuity and service continuity and show empirically that maintaining connectivity is necessary but not sufficient for timely real-time delivery in multi-technology UAV networks. The findings motivate multipath designs that explicitly account for delay constraints, rather than optimizing for connectivity alone.

翻译：未来无人机系统日益融合异构通信技术（如低延迟空中网格、地面蜂窝和卫星链路）以提升鲁棒性与覆盖范围。多路径传输作为聚合这些链路的自然机制，其在高度异构环境中支持实时无人机服务的能力仍缺乏充分表征。我们通过融合无人机间空中网格、私有蜂窝与低轨卫星连接的集成网络开展了基于无人机飞行实验的测量驱动研究。以多路径TCP作为代表性无损有序多路径传输框架，我们发现聚合能在严重链路中断下保持端到端连接性。然而，往返时间的大幅异构性加剧了数据包重排序，导致接收端缓冲区激增与突发性交付。此外，当可用链路无法提供足够容量承载负载时，发送端缓冲区显著增加。这些效应使实时流违反延迟约束，即便在聚合容量充足的情况下依然如此。为解释上述结果，我们形式化定义了连接连续性与服务连续性的区别，并通过实验证明：在多技术无人机网络中，维持连接性是实现实时交付的必要但非充分条件。研究发现表明多路径设计需显式考虑延迟约束，而非仅优化连接性能。