User's Manual

Exalt Installation and Management Guide
EX-r Series GigE Digital Microwave Radios
201872-003 52
2015-10-23
• Set the TX/RX Throughput Ratio (%) parameter to program radio symmetry. The default setting is
50/50 for symmetrical, full-duplex throughput. Other throughput ratio options are 20/80, 80/20,
and 65/35, 35/65. See Link Symmetry
.
For asymmetric throughput, only TDD frame size settings of 2ms and 5ms and RF Bandwidth
settings of 16MHz and higher are supported.
• Set the Radio Collocation parameter to control parameters related to the internal or GPS
Synchronization feature (see Radio Synchronization
).
This parameter can be enabled when an Exalt radio's Sync Out is connected to a collocated radio's
Sync In, or when a GPS receiver is connected to Radio A. There are two additional features:
– Set the Flywheel Period parameter to ‘Normal’ (default) or ‘Infinite.’ This is the period of time
that the radio will run on the internal timing signal if the timing signal is lost.
– The Normal parameter is a time period that allows the timing signal to be recovered. The
default time to wait is set between 5 and 10 min. The system then resynchronizes to the
signal without impact to traffic. If Normal is selected and timing is not recovered within
the set time period, the system stops transmitting (loss of link) until timing is recovered.
This prevents self-interference to local systems, but loses the link.
– The Infinite parameter allows the radio to run on the internal clock source with no limit
and attempts to resynchronize when the timing source is detected. This allows the link to
continue to operate, however, if a signal is not detected within approximately 10 minutes,
the radio may start to cause interference to other collocated systems, and other collocated
systems may start to cause interference with it. If after this interval timing is restored, a
temporary outage due to the resynchronization requirement may occur.
– Set the Tx Timing Offset (µSec) parameter to allow the administrator to delay transmitter
timing from the timing pulse by a fixed time, in microseconds. This is useful if multiple
synchronized Exalt radio systems are present, separated by distance, such as when using a
repeater. This delay is required to offset the difference in speed-of-light between the two
locations. It is recommended to add a 5µSec delay for every mile of difference in path length.
For example, if there is one link with no delay, delay the link within the field-of-view of the
first link on the same or overlapping frequency channel accordingly so that it is synchronized,
including the speed-of-light delay between the two sites.
• Antenna Port parameter
– EX-4.5r GigE and EX-5r GigE: The antenna port selection toggles between the vertically and
horizontally polarized integrated antennas or the dual-polarized setting. Ensure that both link
ends match polarization.
– EX-4.5r-c GigE and EX-5r-c GigE: The antenna port selection allows selection of either the
V, H, or both connectors for dual-polarized operation.
Note: Changing the TDD Frame Size parameter will temporarily interrupt traffic. TDD
Frame Size parameters must match at each end. Adjust the far-end radio first, and then the
near-end radio. If the TDD Frame Size parameter is set to a value that cannot be supported for
the link distance, the link may be lost and unrecoverable through GUI control. If the link is
lost due to this situation, travel to the radio location(s) may be required to reset the value.