User's Manual

Exalt Installation and Management Guide
EX-i Series GigE (FDD) Digital Microwave Radios
202675-008 49
2016-06-01
• Set the TX Frequency (GHz) and RX Frequency (GHz) parameters to the licensed center
frequencies. The frequencies must match the same pair at both ends of the link, but in opposite Tx/
Rx orientation.
• The Transmitter/Receiver (TR) frequency spacing is automatically determined based on the
frequency settings. This is reported to verify the intended frequency settings, as a confirmation to
proper input.
• Set the Receiver Configuration parameter to RX1 Only for typical (1+0) links.
– Enable RX1 Only/Enable RX2 Only (two receiver models only) allows manual selection of
the receiver to isolate the receiver which is helpful for troubleshooting.
– Enable Errorless Switching (primarily used for space diversity configurations) provides
errorless switching between the two internal receivers or when deployed in a 1 + 1 MHS
configuration, between the receivers of each terminal. This selection can also be used for
receiver protection configurations to errorlessly switch between the two internal receivers if
issues should arise.
– Enable Linear Combining (primarily used for receiver protection configurations) provides
additional system gain, however errorless switching may not occur during receiver switching
events. This selection can also be used for space diversity configurations where the added
system gain is more beneficial to the application than errorless switching. When linear
Notes:
• Changing Mode/Modulation will temporarily interrupt traffic. The Mode/Modulation
setting must match at each end. Adjust the far-end radio first, and then the near-end radio.
Changing Mode/Modulation changes the radio’s threshold, carrier-to-interference ratio,
and also may have impact on the Radio Transmit Power. A lower mode has better
threshold performance and carrier-to-interference ratio, and in some cases, higher output
power, therefore if changing to a higher mode (for example, from Mode 1 (QPSK) to
Mode 2 (16QAM)), there is an opportunity that the link may be lost and unrecoverable
through GUI control. Check the available fade margin and interference profile, and
determine if the impact to RF performance is sufficient to maintain the link and desired
performance. If the link is lost due to increasing the Mode parameter, travel to the radio
location(s) may be required to reset the value.
• As modulation is reduced, the capacity of the system is also reduced. If the radio system
is carrying TDM traffic (such as OC3, DS3, T1, E1), some interfaces that may be desired
when the link is running at full-capacity (target modulation) may not be able to be
supported. The
Allocation Page allows configuration of TDM and Ethernet traffic as the
radio changes modulation when ACM is enabled.
• Changing the ACM settings can cause a temporary link outage. To minimize issues,
change the far-end of the radio link first, and then adjust the near-end to match.
• If Adaptive Modulation is disabled, both ends of the radio link require matching settings
equivalent to the licensed modulation of the link.
Note: Changing RF Frequency will temporarily interrupt traffic. The RF Frequency
parameter pair must be opposite at each end. Adjust the far-end radio first, and then the
near-end radio. If the link is lost due to changing the RF Frequency parameter, travel to the
radio location(s) may be required to reset the value.