And with the popularity of various high bandwidth applications, it can be predicted that next generation passive optical network would develop towards high date rates and wide coverage ( long distance and large splitter ). 而随着各种高带宽应用的不断普及,可以预见到下一代无源光网络(NGPON)技术将向着高速率、广覆盖(长距离、大分支比)的方向发展。