Abstract: The working crosslink beams distributed in space was used to provide services for the external users, and the availability was discussed for the general users. The mathematical model based on the typical constellation structure and crosslink working strategy was established, and the simulation experiments were conducted. Furthermore, the static and dynamic coverage characteristics of the celestial sphere was analyzed. The results show that the users in the vicinity of the constellation orbit plane get the more chance to receive the crosslink signals. And the sphere coverage rate is up to 45% when the height is 40%~50% of the constellation orbit radius, and is below 15% with the radius increasing. As a result, the link planning was recommended for the general users. The conclusions and suggestions may offer new ideas for the crosslink design and provide references for the service scope extending.

Key words: Crosslink, Space, Celestial sphere, Coverage characteristics, Navigation constellati