| Abstract [eng] |
As number of devices, that need network access, increases one of the main challenges is to designate and use spectrum as efficiently as possible. One approach is to allow multiple systems to share their designated radio frequency spectrum. However, in order to ensure both systems work reliably, an electromagnetic compatibility analysis is needed. In this work fixed service, Starlink, ESIM, mobile service in the 1.5 GHz band. Tolerated threshold degradation for FS links is 0.4 dB. Starlink earth stations’ caused interference was calculated using rec. ITU-R P.452, time percentage probability set to 20 % and taking into account earth surface topography and clutter of Vilnius city and screening of Starlink earth station. Analysis determined that no harmful interference is present to RRL systems, therefore license for Starlink earth station operations was granted. The compatibility analysis of ESIM interference to RRL systems were conducted in two parts, real Vilnius city and statistical using SEAMCAT software. Both analyses conducted using Monte-Carlo method, iterating 100000 times, evaluating both short-term and long-term interference criteria. Rec. ITU-R P.452 with 20 % and 0.001 % time probabilities was used as model for radio wave propagation. Effects of topography, clutter, different antennas were considered. As expected, taking into account topography and clutter probability of interference to RRL links are lowest. Compatibility analysis of TRRL and mobile service systems was conducted using Monte-Carlo method, using SEAMCAT software. For comparison, rec. ITU-R P.2001 and ITU-R P.1546 with 10% time probability were used. In this analysis, different layouts of single IMT cell and IMT network were tested and it was determined that cumulative effect of network is around 9 dB. Both systems are incompatible with each other as shown in this work. For reference, fade margin and reliability of TRRL systems were calculated. |
