Call Admissibility for Multiservice Traffics in Low-Earth Orbit (LEO) Satellite Networks*

In a LEO system, a user’s call may be handed over constantly from one satellite to another due to visibility changes caused by satellites’ movements. The resultant system performance will degrade if handover calls occur frequently but few are transferred successfully. This paper considered a multiservice LEO system that allows different bandwidth/channel allocations (so-called multirate) on-demand for different calls. We proposed a novel call admission control (CAC) strategy called guard-channel policy over SMDP that applies SMDP theory to find optimal channel reservation and reserves appropriate channels for various types of handover calls. The study manifested that this SMDP-based guard-channel policy performed better than general ones like coordinate-convex type and ordinary SMDP, on the premise of CoS guarantee to handover calls, under various traffic conditions.