In this paper, we describe the link budget design of the adaptive optical satellite network (AOSN) for the integrated non-terrestrial network (NTN). Our target optical links include the inter-satellite links and the ground-to-satellite links using relay geostationary Earth orbit (GEO) satellites, relay low Earth orbit (LEO) satellites and relay high altitude platform stations (HAPS). We also utilize the receiver sensitivity of multi-level modulated optical signals using digital coherent detection. Furthermore, we also describe the link budget design considering various communication services, which include high reliability service data and standard service data. Our link budget design shows that the AOSN can handle various communication services by controlling various modulation schemes, wavelength division multiplexing (WDM) channels and multiple symbol rates.