Before the 5G network has fully evolved into SA only mode

in the boundary area of NSA/SA and SA only networks

terminals that only support NSA will bring interference to the network and seriously affect user perception. Moreover

it takes a certain period for NSA stock users to change their machines

so such problems are expected to last for a long time. In order to ensure user perception

this paper proposes a new scheme of setting the isolation belt in the boundary area between the dual-mode and SA only base station on the basis of the traditional avoidance scheme. The scheme is proved to be effective in both scenarios of macro-room station and macro-macro station.