Distributive ACB Factor Estimation for Delay-Sensitive Applications in Non-Terrestrial Networks

To meet the demanding need for global connectivity, non-terrestrial networks can provide essential support to complement and extend the terrestrial infrastructure. However, the presence of non-terrestrial networks comes up with new demands. For example, a critical problem is satisfying the latency constraints of delay-sensitive applications while reducing the signaling consumption to save valuable channel resources in the random access stage. To address this issue, we propose a distributed access class barring (ACB) factor determination algorithm in this paper to satisfy the specific latency constraints of delay-sensitive applications and reduce the signaling exchange between user equipments (UEs) and the base station simultaneously. With this algorithm, UEs can estimate the required ACB factor only by their previous experiences in an estimation period rather than relying on the base station. Simulations show that the proposed distributive ACB factor determination algorithm can satisfy the requirements of delay-sensitive applications well when the delay constraint is not too strict. Besides, the influence of the variation of UEs and the estimation period is also discussed. It is found that the estimation period plays an important role in the accurate estimation of the ACB factor and needs to adapt to the changes in the number of UEs.