QoS-Aware Load Balancing Scheme for Integrated Terrestrial–Non-Terrestrial Networks
The rapid growth of data- and delay-sensitive applications is driving unprecedented mobile traffic demand, straining terrestrial networks (TNs). Integrated Terrestrial-NonTerrestrial Networks (IT-NTNs), envisioned for 6G, aim to expand coverage and enhance capacity via satellite connectivity. Efficient load balancing across TN and NTN domains remains challenging due to inherent heterogeneity between the networks. This paper proposes a QoS-aware load balancing (QALB) algorithm for IT-NTNs. We introduce a congestion-dependent latency model that captures the coupling between latency and resource utilization, embedded in a unified cost function for user-cell association. The resulting load balancing problem is addressed using a distributed heuristic, with simulation results showing that QALB improves network performance in load distribution, throughput, and QoS satisfaction compared to benchmark schemes.