高校问答ec6003 g6:计算机网络高手帮我翻译一下
来源：百度文库 编辑：高校问答 时间：2024/04/29 16:48:04
First, initial deployment simply placed cells in regions where there was high density of human or vehicle population. Once they were there, the operator often did not want to go to the trouble of moving them. Second, antennas are typically placed on tall buildings or mountains. Depending on the exact location of such structures, the area covered by a cell may be irregular due to There are ten 4000 Hz signals. We need nine guard bands to avoid any interference. The minimum bandwidth required is 4000×40010×9 =43,600 Hzobstacles near the transmitter. Third, some communities or property owners do not allow building a tower at a location where the center of a cell falls. In such cases, directional antennas are placed at a location not at the cell center.