Installation guide

35
Cisco uBR7200 Series Universal Broadband Router Wireless Modem Card and Subsystem Installation and Configuration
78-6030-03
Configuring a Wireless Modem Card
Caution If the maximum cable loss parameters are used with short cables, the transmit signal from the
wireless modem card to the transverter can be too strong, resulting in damage to the transverter.
As the cable length increases, the cable loss increases. Your cable vendor’s guide can help determine
the expected loss per unit length (at 400 MHz), but Cisco recommends that you also measure
accurately when installing the cabling to account for lightning suppression, connectors, and exact
cable length.
The antenna-alignment command sends a voltage proportional to the received signal strength to the
transverter. For example, to adjust the antenna on UBR1, first enter a no shut command on uBR2 to turn
on the transmit signal. Then, enter the antenna-alignment command on uBR1 to make the adjustments.
UBR2(config-if)# no shut
This turns on the transmit signal from uBR2. The link does not need to come up.
UBR1(config-if)# shut
UBR1(config-if)# radio antenna-alignment
UBR1(config-if)# no shut
Attach a voltmeter to the test port on the transverter connected to uBR1. It will indicate a 0 to 5 volt
signal. The larger the voltage, the better the alignment. By pointing the antenna in slightly different
directions, the signal level will change. The largest signal expected is approximately 2.27 volts. Table 6
shows an example of some typical voltages for a range of receive signals.
Use the same procedure to align the antenna(s) on uBR2.
The antenna-alignment command is only for installation and should not be used for normal operation.
To cancel antenna alignment mode, use the following commands:
UBR1(config-if)# shut
UBR1(config-if)# no radio antenna-alignment
UBR1(config-if)# no shut
UBR2(config-if)# shut
UBR2(config-if)# no radio antenna-alignment
UBR2(config-if)# no shut
When the antennas are aligned and both ends of the link have initiated a no shut command, the link
should be established.
Table 6 Example Receive Signals and Voltages
Rx Level (dBm) DC Voltage (Volts
–26 2.27
–36 1.93
–46 1.51
–56 1.06
–66 0.69
–76 0.30