Westell Inc. CSI-DSP85201CP ユーザーズマニュアル

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Server port attenuation may also be necessary, particularly where a powered DAS is present.  The selection guidelines
below apply to both server and donor ports.  In order to properly measure uplink signal strength, a signal generator
should be used.  If a signal generator is not available, placing a test call while under the server antenna with the least
path loss to the repeater should provide reasonable data.
The following potential outcomes result from the use of attenuators on the server port(s) of the 

repeater

:  Downlink

output power, as reported by the unit, is reduced by the value of the attenuation.  Uplink incoming power from the DAS
is reduced, along with potentially strong and/or harmful out-of-band signals (including noise) that are generated by the
DAS.

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:

<-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

                                     -36.2 dBm

    74 dB

                                     -35.4 dBm

    73 dB

                                     -34.6 dBm

    72 dB

                                     -33.8 dBm

    71 dB

                                     -33 dBm

    70 dB

-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” (Analog to Digital

Converter  Protection).  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 (Automatic Gain Control), 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).

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 3 dB Cellular, or more than 5 dB PCS, the maximum

output power will be reduced.  Example:

                                                                                                Band 1 (Cellular)

                                                                                                In-Band Input -45 dBm

                                                                                                Composite Input -33 dBm

                                                                                                 Max Gain = 70 dB

                                                                                                 Max Output = 25 dBm