Fixed satellite service (FSS) and high altitude platform (HAP) interference assessment for adjacent channels inside HAPS coverage area

High Altitude Platform System (HAPS) is an exceptional technology in aerial communications systems. Some inimitable facets of HAPS compose it as a spectacular service provider. However, interference with other aerial or terrestrial communications systems is a significant issue. With regards to system interference as of other commercial products or systems which perform partially at the same frequency range as HAPS, escalating HAPS performance by bringing about in conjunction with these systems seems unavoidable. One of the most significant systems which operating at the same frequency of HAPS is Fixed Satellite Service (FSS). This article concentrates on tropical and subtropical areas' coexisting systems specifications Functioning in C-band. Foremost emphasis would be given to interference amount gauge churned out by FSS uplink (5925-6725 MHz) towards HAPS gateway links in commission at 5850-7075 MHz frequency range. The criteria are compatible to and derived out from the International Telecommunication Union (ITU) and World Radio-Communication Conferences (WRCs) publications.