# A Framework for Assessing the Interference from NGSO Satellite Systems to a Radio Astronomy System
## 5 Discussion and Conclusions  
The spatial distribution of the EIRP in an NGSO satellite is based on the assumption of a uniform distribution of users within the satellite's coverage area. However, in practice, the distribution of users is often uneven and may vary with longitude. To account for this, it is possible to modify the method presented in this paper to take into account the actual distribution of user resources. The spatial distribution of the EIRP is a function of the latitude and longitude of the satellite, and the probability of beam activation should be defined based on the actual demand for communication resources at a given location. The paper provided three methods for defining user demand, which can be used by satellite operators to determine the beam activation probability for their systems. For satellite communication systems with beams that are fixed in relation to the satellite, it is not necessary to generate a spatial distribution of the EIRP. In this case, the EIRP distribution of the satellite is constant within its coverage area. The method for calculating the EPFD presented in this paper is also applicable to fixed beams, with the spatial distribution of the satellite's EIRP replaced by the maximum EIRP of the beam, and the beam activation probability determined by the state of the beam. This would allow the simulation framework presented in the paper to be applied to mainstream NGSO satellite systems. The method presented in this paper for calculating the aggregate interference of multiple NGSO satellite constellations was based on the assumption that the interference of each constellation was independent of the others. However, in practice, this may not always be the case. The method simplified the calculation of the aggregate interference by dividing the constellation into smaller subconstellations, which allowed for the simulation of very large NGSO systems. While this approach may not fully capture the complex interactions between different NGSO satellite constellations, it can provide a useful approximation and can help to identify potential strategies for mitigating interference. The distribution of users within the satellite coverage area should be modelled according to the actual demand distribution rather than using a uniform distribution of users, as the actual demand distribution is often characterised by the hotspots in the ground. Multiple NGSO systems often need to coexist with each other, and individual NGSO systems should be designed to avoid interference with other NGSO systems. Interference generated by NGSO satellite systems is therefore often not independent of each other. The efforts in the future should focus on more accurate user modelling and updated methods for calculating the aggregate interference of multiple NGSO systems. This paper proposed a refined interference simulation framework for the interference of NGSO satellite systems with an RAS telescope. It was also sufficient to provide a validation for NGSO satellite system parameters and support the design of interference avoidance methods. In the future, we will explore the impact of interference avoidance strategies on the interference by using the proposed methods. Conceptualization, C.Z., L.S. and Y.H. ; methodology, C.Z., S.X., F.S. and L.S. ; software, C.Z., H.W. and J.C.; validation, J.C., F.S. and H.W. ; formal analysis, C.Z. and H.W. ; investigation, C.Z. and J.C.; resources, Y.H. and G.L. ; data curation, H.W. and F.S. ; writing--original draft preparation, C.Z. and S.X. ; writing--review and editing, H.W., J.C., F.S., L.S. and Y.H. ; visualization, H.W., F.S. and L.S. ; supervision, G.L. ; project administration, G.L. ; funding acquisition, G.L. and L.S. All authors have read and agreed to the published version of the manuscript. * [1] [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON]; [PERSON] On the Path to 6G: Embracing the Next Wave of Low Earth Orbit Satellite Access. _IEEE Commun. Mag._**2021**, _12_, 36-42.