The Application of 3-Colour Theorem and 4-Colour Theorem in the Problem of Repeaters’ Site Selection

In wireless networks, implementing repeaters can improve network capacity and CCTSS systems can be used to mitigate interference. This paper discussed the selection of covering shapes in a given area, and presented an optimum scheme of channel assignment and PL allocation. Meanwhile, the 3-colour theorem and 4-colour theorem in graph theory will be given. At last, we introduce the application of 3-colour theorem and 4-colour theorem in the problem of repeaters’ site selection. By the relevant calculation, we can prove the application is reasonable.