  Due to the ongoing standardization and deployment activities, satellite
networks will be supplementing the 5G and beyond Terrestrial Networks (TNs).
For the satellite communications involved to be as efficient as possible,
techniques to achieve that should be used. Multi-Connectivity (MC), in which a
user can be connected to multiple Next Generation Node Bs simultaneously, is
one such technique. However, the technique is not well-researched in the
satellite environment. In this paper, an algorithm to activate MC for users in
the weakest radio conditions is introduced. The algorithm operates dynamically,
considering deactivation of MC to prioritize users in weaker conditions when
necessary. The algorithm is evaluated with a packet-level 5G non-terrestrial
network system simulator in a scenario that consists of a TN and transparent
payload low earth orbit satellite. The algorithm outperforms the benchmark
algorithms. The usage of MC with the algorithm increases the mean throughput of
the users by 20.3% and the 5th percentile throughput by 83.5% compared to when
MC is turned off.
