第五部分 Odyssey Odyssey乃是第一个这样的系统,其设计利用了在中间地球轨道(ICO)上、或称中间圆形轨道上运行的入轨卫星作移动式电话卫星服务。Odyssey的设计者认识到:成本效益好的系统,若要不产生时间延迟,可以用比较少的卫星。还有,卫星星座越小则所需的地面天线的数目也就少,操作也就不那么复杂。但是无论如何,这意味着众卫星必需在Van Allen带以内运转。这些考虑导致选择MEO系统,这样,其初期服务只要6个卫星,而复盖全球只要9个卫 Part V Odyssey Odyssey is the first such system designed to make use of orbiting satellites operating on the mid-Earth orbit (ICO), or mid-circular orbit, as a mobile telephone satellite service. Odyssey designers realize that a cost-effective system can use fewer satellites without delay. Also, the smaller the constellation of satellites, the less number of terrestrial antennas required and the less complicated the operation. However, this means that all satellites must operate within the Van Allen Belt. These considerations led to the choice of the MEO system so that its initial service would be as long as 6 satellites and 9 worldwide coverage