CSI CSI-DSP85-250-AW, Руководство по эксплуатации продукта

Страница: 11 / 40

-11 -
Attenuator Selection Guidelines:
Accurate attenuator values need to be chosen to ensure that the maximum total power (higher of Composite or In-
Band Input) applied to the donor and server port(s) does not exceed the following thresholds:
Input Signal Max Gain Input Signal Max Gain
<-45 dBm 85 dB -32.2 dBm 69 dB
-44.3 dBm 84 dB -31.4 dBm 68 dB
-43.6 dBm 83 dB -30.6 dBm 67 dB
-42.9 dBm 82 dB -29.8 dBm 66 dB
-42.2 dBm 81 dB -29 dBm 65 dB
-41.5 dBm 80 dB -28.2 dBm 64 dB
-40.6 dBm 79 dB -27.4 dBm 63 dB
-39.7 dBm 78 dB -26.6 dBm 62 dB
-38.8 dBm 77 dB -25.8 dBm 61 dB
-37.9 dBm 76 dB -25 dBm 60 dB
-37 dBm 75 dB -24.4 dBm 59 dB*
-36.2 dBm 74 dB -23.8 dBm 58 dB*
-35.4 dBm 73 dB -23.2 dBm 57 dB*
-34.6 dBm 72 dB -22.6 dBm 56 dB*
-33.8 dBm 71 dB -22 dBm < 55 dB*
-33 dBm 70 dB
*We recommend padding this level due to potential for fluctuating signal.
-25 dBm is the maximum input signal level that should be applied to the repeater, even if the gain is lower than 55 dB.
Input signals exceeding these thresholds will result in composite input attenuation, called “ADC Protect” ( A nalog to D igital
C onverter P rotection). Output power is reduced whenever the above thresholds are exceeded by reducing the gain by 1dB for
each 1 dB that the threshold is exceeded. ADC Protect should not be confused with AGC ( A utomatic G ain C ontrol), which
reduces gain to prevent In-Band (measured) output power from exceeding the specified maximum output level.
To determine the total power applied to the donor and server ports, please reference the “Composite Input” values as reported in
the Web (“System Status”) or Menu (“Link Status”) interfaces (depicted and explained later in this manual).
Large delta’s between in-band and composite input signals:
Care should be taken to isolate the best donor site to ensure the least possible delta between in-band and composite downlink
signals.
If the (downlink) composite input exceeds the in-band input by more than 5 dB, the maximum output power will be reduced.
Example:
AWS Band
In-Band Input -45 dBm
Composite Input -38 dBm
Max Gain = 68 dB
Max Output = 23 dBm