| 1. | The satellite - telecommunication has a serial of characteristic such as long distance , large coverage area , wide communication band , big transmission capacity , high quality , it has made a rapid progress in the last decades and become one of the most powerful communication methods today 而卫星通信具有通信距离远、费用与通信距离无关、覆盖面积大、不受地理条件限制、通信频带宽、传输容量大、适于多种业务传输、可进行多址通信、通信质量高等一系列特点,几十年来获得了迅速的发展,成为现代强有力的通信手段之一。 |