In order to improve the cell boundary throughput performance and 10 extend the coverage area, relay transmission with relay stations (RSs) is becoming a promising architecture. However, if RSs are introduced, interference between cells increases and the throughput improvement effect with RSs is prone to be restricted. In this paper, we propose a scheme reducing the interference from other cells by using packet transmission control. The proposed scheme can improve the throughput around the cell boundary and the system throughput considering the users of whole cell by controlling the timing of transmission of each cell.