Different queuing policies for handover requests in low earth orbit mobilesatellite systems

In this paper, a mobility model suitable for low earth orbit mobile satelli te systems (LEO-MSS's) has been presented, and its statistical parameters h ave been derived in order to evaluate the impact of the mobility on the per formance of the fixed channel allocation (FCA) strategy. Moreover, we have foreseen that interbeam handover requests, which do not i mmediately find service, can be queued to reduce the handover failure rate. Two different queuing disciplines have been assumed: 1) the first-input-fi rst-output (FIFO) scheme and 2) an idealized strategy that requires knowled ge of the last useful instant (LUI) within which the handover procedure mus t be completed in order to rank the queued handover requests. An analytical approach has been developed to compare these queuing techniqu es, and its results have been validated through simulations.