Enhancing Service Continuity in Non-Terrestrial Networks via Multi-Connectivity Offloading

Non-terrestrial networks (NTNs) have recently emerged as a promising paradigm for computation-intensive six-generation (6G) applications, which may range from augmented reality to disaster relief. Moreover, NTNs can cater to uninterrupted connectivity needs in both rural and urban areas. In urban settings, uncrewed aerial vehicles (UAVs) and high-altitude platform stations (HAPS) play crucial roles in supporting delay-sensitive computation applications for terrestrial UEs when terrestrial networks face limitations. Given the emerging interest in multi-connectivity for NTNs, this letter investigates UAV- and HAPS-assisted multi-connectivity computation offloading in urban areas. Specifically, we propose two novel multi-connectivity offloading strategies to improve the probability of timely task computation, along with a framework for optimizing the corresponding offloading probabilities onto HAPS and UAVs. Our results demonstrate that utilizing multi-connectivity in NTN-assisted offloading can achieve a 75% reduction in task computation delay as compared to scenarios with no offloading.