User's Manual

Configuration MP.11 4954-R Installation and Management
Interface Parameters
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NOTE: The additional sensitivity is provided with the impact of using twice as much spectrum and thus increasing the
opportunity of interference and decreased ability for system collocation. Generally, Turbo mode is not
recommended except when the extra sensitivity is absolutely required.
• Frequency Channel: The frequency channel indicates the band center frequency the unit uses for communicating
with peers. This frequency channel can be set in several ranges, depending upon regulatory domain. Refer to
Frequency Bands and Channels for channelization information.
• Multicast Rate: The rate at which data is to be transferred. This drop down box is unavailable when DDRS is
enabled.
The default multicast rate for the unit is 36 Mbps. The SU must never be set to a lower data rate than the BSU
because timeouts will occur at the BSU and communication will fail.
Selections for multicast rate for 5, 10 and 20 MHz channel bandwidths are shown in the following table:
* Turbo Mode is available in the US only.
†
If you select 48 or 54 Mbps (96 or 108 in Turbo mode) DDRS is automatically turned on (enabled).
• Channel Bandwidth: Select 5 MHz, 10 MHz or 20 MHz channel bandwidth.
• Antenna Gain (BSU only): You can modify the sensitivity of the radio card when detecting radar signals in
accordance with ETSI and FCC Dynamic Frequency Selection (DFS) requirements. Given the radar detection
threshold is fixed by ETSI and the FCC and that a variety of antennas with different gains may be attached to the unit,
you must adjust this threshold to account for higher than expected antenna gains and avoid false radar detection
events. This can result in the units constantly changing frequency channels.
You can configure the threshold for radar detection at the radio card to compensate for increased external antenna
gains.
The Antenna Gain value ranges from 0 to 35. The default value is 0.
• Satellite Density: The Satellite Density setting is a valuable feature for achieving maximum bandwidth in a wireless
network. It influences the receive sensitivity of the radio interface and improves operation in environments with a high
noise level. Reducing the sensitivity of the unit enables unwanted “noise” to be filtered out (it disappears under the
threshold).
You can configure the Satellite Density to be Large, Medium, Small, Mini, or Micro. The default value for this
setting is Large. The smaller settings are appropriate for high noise environments; a setting of Large would be for a
low noise environment.
A long distance link may have difficulty maintaining a connection with a small density setting because the wanted
signal can disappear under the threshold. Consider both noise level and distance between the peers in a link when
configuring this setting. The threshold should be chosen higher than the noise level, but sufficiently below the signal
level. A safe value is 10 dB below the present signal strength.
If the Signal-to-Noise Ratio (SNR) is not sufficient, you may need to set a lower data rate or use antennas with higher
gain to increase the margin between wanted and unwanted signals. In a point-to-multipoint configuration, the BSU
should have a density setting suitable for all of its registered SUs, especially the ones with the lowest signal levels
(longest links).
Multicast Rates in Mbps
5 MHz 10 MHz 20 MHz Turbo Enabled
*
(40 MHz)
1.5 3 6 12
2.25 4,5 9 18
3 6 12 24
4.5 9 18 36
6122448
9183672
12 24 48 96
†
13.5 27 54 108
†