Non-Terrestrial Networks (NTNs) can be used to provide ubiquitous 5G and beyond services to un(der)served areas. To ensure reliable communication in such networks, packet duplication (PD) through multi-connectivity is a promising solution. However, the existing PD schemes developed for terrestrial environments may not be reactive enough for the NTN environment where propagation delays are significantly longer. This paper proposes a dynamic PD activation scheme for NTNs based on hybrid automatic repeat request feedback. The scheme aims to reduce the number of duplicated packets while maintaining high reliability. To evaluate the proposed scheme, simulations are conducted in a scenario with two transparent payload lowearth orbit satellites. The results show a significant reduction of 87.2% in the number of duplicated packets compared to blind duplication, with only marginal compromise in reliability.

翻译：非地面网络可向欠发达及无服务区域提供泛在的5G及后续服务。为确保此类网络的可靠通信，基于多连接的分组复制是一种极具前景的解决方案。然而，现有面向地面环境设计的PD方案在传播延迟显著更长的NTN环境中可能缺乏足够的响应性。本文提出一种基于混合自动重传请求反馈的NTN动态PD激活方案，旨在维持高可靠性的同时减少重复分组数量。通过在包含两颗透明载荷低轨卫星的场景下进行仿真，结果表明：与盲复制相比，所提方案在仅对可靠性产生微小影响的情况下，重复分组数量减少了87.2%。