The effect of platform instability on the system level performance of HAPS UMTS

High Altitude Platform Stations (HAPS) are a new, promising means of providing Third Generation (3G) mobile services. One of the potential problems of the system is the platform positional instability due to stratospheric winds. In this letter, we present a study of the effect of positional instability on the system level performance of a Universal Mobile Telecommunications System (UMTS) served by HAPS. A platform instability model obtained through measurements of stratospheric winds gives input into a UMTS system level dynamic simulator and the effect of instability on the system capacity and call blocking probability is examined. Finally, it is shown that the positional instability can be counterbalanced by a simple propulsion mechanism, thus reducing the performance degradation.