PRELIMINARY RELEASE
*** This is a confidential document. Do not distribute. ***
modulations, such as quadrature amplitude modulation (QAM) provide a mechanism for higher
bit rates, and thus more available throughput. These complex modulations, however, have a
negative impact on the receive threshold of the radio, the signal level at which the link is
unreliable.
Modulation modes are in order of net bit rate, with the highest bit rate at the top of the list. The
effective throughput of an RF link is based on the net bit rate, less the PHY and link-layer
overheads. Modulation modes in Cell Control include acronyms for modulation types and
abbreviations for FEC types. “Conv_Punct”, a 3/4 punctured convolutional coding rate, provides
25% FEC, reducing the available payload to 75% of the gross bit rate. “Conv” is a 1/2
convolutional coding rate. This 50% FEC produces a reliable communications channel, while
reducing the available payload to 50% of the gross bit rate.
Basestations will commonly use “Qpsk_1_Conv” for the Uplink and Downlink modulation modes.
This modulation mode provides a good link reliability and provides enough bandwidth for system
controls
Set your CPE stations with the modulation mode that meets the needs of the installation and
application. Stronger signal-to-noise ratios will allow the use of higher modulation modes,
providing higher throughput. An SNR of 25 or greater will allow the use of QAM16 with FEC,
while an SNR of 30 or greater is required before you can disable FEC (“QAM16_None”).
For troubleshooting RF links with errors and/or poor signals, select a lower modulation mode.
An “Adaptive Modulation” button is available, which will enable dynamic control of the link
modulation mode, to maintain link stability in varied conditions. Although this is useful feature, a
fixed modulation type will provide better performance.
5.7.
Station Properties
From many areas around the OMC, you can click on the “Id” or “Name”
hyperlink of a station to open a “Station Properties” pop-up window.
Clicking the ID will open a new webpage. Clicking the Name will open a
pop-up window.
Basestations and CPEs have similar properties, along with sections
unique to each role. The upper section includes the Stations Details. The
lower section includes various tabs for each control and status area of the
station.
Figure 31: Station Links
5.7.1.
Basestation Details
Figure 32: Basestation Details
For smaller screens, you can maximize the window by clicking its header/title bar.
Page | 22
