In this paper, we consider a channel ordering problem that seeks to maximize the service quality in mobile radio communication systems. If a base station receives a connection request from a mobile user, one of the empty channels belonging to the base station is assigned to the mobile user. In case multiple empty channels are available, we can choose one that incurs least interference with other channels assigned to adjacent base stations. However, note that a pair of channels that are not separated enough generates interference only if both channels are assigned to mobile users. That is, interference between channels may vary depending on the channel assignment sequence for each base station and on the distribution of mobile users. To find a channel assignment sequence that seems to generate minimum interference, we develop an optimization model considering various scenarios of mobile user distribution. Simulation results show that channel assignment sequence determined by the scenario based optimization model significantly reduces the interference provided that scenarios and interference cost are properly generated.