User's Manual

Horizon Compact Plus Release 1.0.1 Wireless Ethernet Product User Manual – Volume 2
10.0 Bandwidth Management
When you purchase a Horizon Compact Plus system you receive a unit capable of giving a throughput
speed of up to 400 Mbps. However, the actual throughput speed achievable for any given system
depends on the specific licensed speed key that you purchased with the system
You can upgrade your system to a higher licensed speed (see Section 3.2) by purchasing an upgrade
key and reprogramming your system. Any upgraded system can be reconfigured to a lower system
speed (CLI command set system speed) as required, without losing the ability to return to the
upgraded licensed speed.
You may also downgrade the licensed speed (see Section 3.3) to a lower value. Once downgraded new
upgrade keys will be required for future upgrading.
System speeds do not have to be symmetrical (same speed in both directions on the link). Asymmetric
speeds (different speeds in each direction) can also be configured.
10.1 Maximum Throughput Speed
The maximum throughput speed is determined by the Horizon Compact Plus licensed speed key you
purchase, however, it is important to note that the maximum speed is also determined by the Channel
bandwidth associated with the configured radio band, and the modulation scheme used. The channel
bandwidth is a function of the radio band and the modulation scheme is selected depending on the
desired maximum throughput. Configuring the Radio Band and System Mode determines the maximum
throughput capability and the modulation scheme applied.
Note that if a System Mode is set with a maximum throughput capability that exceeds the licensed
speed key purchased from DragonWave, then the maximum speed attainable will be limited to the
licensed speed purchased. By default the system speed is set to the licensed speed key purchased,
however, it can be reduced to a lower level without losing the ability to return to the purchased licensed
speed.
Table 10-1 shows some examples of the modulation schemes that are selected for various System
Modes (combination of channel bandwidth and average throughput).
Table 10-1 System Mode and Modulation Scheme Example
Modulation
scheme
Channel Bandwidth 50 MHz
Channel Bandwidth 40 MHz
Channel Bandwidth 30 MHz
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
QPSK
66
23.7
-83.2
52
23.7
-84.2
39
23.7
-85.5
16 QAM
154
21.1
-75.8
122
21.1
-76.8
92
21.1
-78.1
32 QAM
198
21.4
-72.5
157
21.4
-73.5
118
21.4
-74.8
64 QAM
241
20.0
-69.4
192
20.0
-70.4
144
20.0
-71.7
128 QAM
285
19.4
-66.3
227
19.4
-67.3
170
19.4
-68.6
256 QAM
329
19.5
-63.4
262
19.5
-64.4
196
19.5
-65.7
256 QAM (2)
351
19.5
-61.0
279
19.5
-62.0
209
19.5
-63.2
Modulation
scheme
Channel Bandwidth 55/56 MHz
Channel Bandwidth 28 MHz
Channel Bandwidth 14 MHz
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
Throughput
Mbps
TX
Power
dB
RX
Sensitivity
dB
QPSK
71
23.7
-82.9
38
23.7
-85.7
19
23.7
-88.7
16 QAM
166
21.1
-75.5
88
21.1
-78.3
43
21.1
-81.3
32 QAM
214
21.4
-72.2
113
21.4
-75.0
56
21.4
-78.0
64 QAM
261
20.0
-69.1
138
20.0
-71.9
68
20.0
-74.9
128 QAM
308
19.4
-66.0
163
19.4
-68.8
80
19.4
-71.8
256 QAM
356
19.5
-63.1
188
19.5
-65.9
93
19.5
-68.9
256 QAM (2)
380
19.5
-60.6
201
19.5
-63.4
99
19.5
-66.5