| 摘要 |
PURPOSE:To improve the accommodating efficiency of a line by sectioning a zone to be covered into >=2 areas in terms of radius, assigning separate frequencies to respective areas and selecting the attenuation of a span attenuator deciding both reception electric fields to a specific value. CONSTITUTION:Since the difference in the rainfall attenuation due to the difference of the range is a large cause of the deterioration in the D/U ratio, the cover zone is divided into two at a 1/2 radius. Then separate frequency pairs are assigned to the respective zones. As the next step, in order to minimize the fluctuation of the D/U in the same frequency pairs, the span attenuator is inserted. The span attenuator is selected in the center zone within the radius l1(m) to establish equation I, and equation II is used in the peripheral zone (l1<l<=l2). In the equations, RL(dBm) is the two-way reception input electric field at fine weather from a point of l(m) from the center, RL1(dBm) is the two-way reception input electric field at fine weather without a span attenuator from a point of l1(m) and RL2(dBm) is the two-way reception input electric field at fine weather without a span attenuator from a point of l2(m). Further, ML1(dB) is a required margin to satisfy the rainfall inoperation rate of a line at a point of radius l1 and ML2 is a required margin to satisfy the rainfall inoperation rate of a line at a point of radius l2. |
