User's Manual

Navini Networks, Inc. Ripwave Base Station I&C Guide
113
Min Tx Power= Min SYN Card Input
+ Max Cal Board Loss [Formula 4]
+ CAL Cable Loss
+ Back Plane Loss
Let’s now determine the maximum and minimum RX Sensitivity at which the BTS can be
calibrated. During the RX Paths calibration, the SYN card generates an RF signal that must
travel to (and suffer losses at) the BTS Back Plane, the CAL Cable, and the Calibration Board
before it arrives at the base of the antenna elements. The maximum and minimum level of power
that can be delivered at the antenna elements during this simulated reception (that is, the possible
range for the RX Sensitivity) are determined, respectively, by the maximum and minimum level
of the signal output by the SYN card. Setting the RX Sensitivity outside this range will make the
system impossible to calibrate.
Max Rx Sensitivity = Max SYN Card Output
+ Min Cal Board Loss [Formula 5]
+ CAL Cable Loss
+ Back Plane Loss
Min Rx Sensitivity = Min SYN Card Output
+ Max Cal Board Loss [Formula 6]
+ CAL Cable Loss
+ Back Plane Loss
Notice that when determining maximum power levels (formulas 3 and 5) we assume the Cal
Board path that introduces the minimum possible loss (27 dB), while when determining
minimum power levels (formulas 4 and 6) we assume the Cal Board path that introduces the
maximum possible loss (31 dB).
The Procedure
1. Eliminate the Main Cables with Bend Radius exceeding the minimum required
Compare the Bend Radius for each type of Main Cable (last row in Table I2) with the Minimum
Required Bend Radius given as input data. Eliminate from further consideration the Main
Cables that have a Bend Radius exceeding the minimum required.
2. Eliminate combinations of cables that weight too much
Calculate the weight of the Higher Jumper cable for the selected type of Jumper Cable
Weight of Higher Jumper Cable= [Formula 7]
Length of the Higher Jumper Cable
× Weight of one foot of the Selected type of Jumper Cable