Recently, beyond 3G systems have been drawing a great deal of attention concerning next generation wireless services that provide 100 Mbps at high mobility and 1 Gbps at nomadic mobility environment. In order to exploit new mobile radio spectrum resource below 6 GHz bands in Korean radio environment, the first important step consists in a proper understanding of propagation characteristics in candidate bands. Therefore, we propose a channel model which is based on measured path loss data in various topographic areas of Seoul metropolitan city at 5.3GHz and 2.1GHz bands. The proposed model is a modified 4-ray model which can consider road side building characteristics in urban street canyon LOS environment. Compared to 4-ray model, it can predict path loss more accurately.