Calculation of UL_TAR and UL_GAIN
UL_TAR and UL_GAIN are the key parameters for commissioning the uplink that must be calculated and set
up in the BDA.
• UL_TAR: Uplink Target Channel Power; Sets the MAX UL Channel Power for a channel filter. The
UL Channel AGC circuits will prevent the Channel Filter from exceeding this power level.
• UL_GAIN: Uplink Channel Gain; Sets the MAX UL Gain for each channel filter. The device will use
the MAX UL Gain for each channel. If a Channel’s UL input power is high such that the MAX UL
Gain is not needed to achieve full UL_TAR, the UL Channel AGC circuits will automatically reduce
the UL Gain accordingly to reach UL_TAR.
UL_TAR is calculated using the Donor Site MAX RX RSSI and the UL Total Loss. The user must choose
to use either UL Total Loss 1 or UL Total Loss 2 as previously described in this commissioning tool
procedure. The UL_TAR sets the MAX UL Channel Power such that it will be received at the donor site no
higher than the Donor Site MAX RX RSSI. UL_TAR is calculated using the formula below.
UL_TAR = Donor Site MAX RX RSSI (dBm) + UL Total Loss 1 (dB)
Example 1(Using UL Total Loss 1):
Donor Site MAX RX RSSI = -75dBm
UL Total Loss 1 = 85dB
UL_TAR = -75dBm + 85dB = 10dBm/Channel
Example 2(Using UL Total Loss 2):
Donor Site MAX RX RSSI = -75dBm
UL Total Loss 2 = 75dB
UL_TAR = -75dBm + 75dB = 0dBm/Channel
Note: Because UL Total Loss 2 does not include any additional clutter loss, and is based only on free
space loss, using it may cause lower than expected levels to be received at the Donor Site!
UL_GAIN is calculated using Donor Site MIN RX RSSI, UL Total Loss, and UL MIN Input. The UL Input test
must be completed before the UL_GAIN suggestion can be generated. The UL_GAIN sets the MAX UL Gain
to reach the donor site at the Donor Site MIN RX RSSI level. In other words, UL_GAIN is minimized as much
as possible so the “Far” radio can reach the Donor Site at the lowest level. UL_GAIN is calculated using the
formula below.
UL_GAIN = Donor Site MIN RX RSSI (dBm) + UL Total Loss - UL MIN Input
Example 1:
Donor Site MIN RX RSSI = -95dBm
UL Total Loss 1 = 85dB
UL MIN Input = -65dBm
UL_GAIN = -95dBm + 85dB – (-65dBm) = 55dB
Example 2:
Donor Site MIN RX RSSI = -95dBm
UL Total Loss 1 = 95dB
UL MIN Input = -75dBm
UL_GAIN = -95dBm + 95dB – (-75dBm) = 75dB
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