GE MDS SD Series Technical Manual page 51

Table 12. Modem Selection vs. Speed, Bandwidth & Sensitivity
Modem Type
Selection
Modem 38400N
Modem 65000
Modem 65000N
Modem 32000
Modem 19200M
Modem 38400E
Modem NONE
1) For MDS x710-compatible operation.
2) 3200 bps not applicable to SD4.
3) Modem 65000 only available on SD2 Wide bandwidth hardware option (50 kHz) Modem 65000N is
available on both SD2 and SD9 wide band hardware options only.
4) This modem is only applicable on SD9 Band F Wideband Hardware.
5) SD1 sensitivity may be up to 2 dB less, due to MDS 1710 interoperability constraints.
•
Transmit/Receive Frequency —
here. If no frequencies have been entered, the fields will be blank and the radio's
LED will flash, indicating that an entry is needed. Frequencies must be entered for the
radio to operate. Consult your station license to determine the authorized frequencies for
your system, and enter them exactly as listed.
• Provides the possibility for Frequency Re-use. SysID offers nine unique
System ID —
choices including the default value of
works comprised of MDS legacy and SDx products. SDx-only networks can utilize the
Frequency Re-use feature by setting the System ID to a common value [
in a specific network. SysID (or System ID as it is referred to in the Device Manager) of-
fers approximately 20 dB of additional co-channel isolation when operating networks on
the same frequency. Note that proper system design is required.
Operational Example: SDx System "Alpha" has eight units and SDx System "Beta" has
eight units. A user wishes to occupy frequency 952.1235 MHz on both of these systems.
Proper system installation has been adhered to in both networks. System Alpha's units
would all be set to
systems will now operate on the same desired frequency.
Examples of valid and invalid arrangements are shown in Figure 29 and Figure 30, re-
spectively.
NOTE All radio sites must adhere to proper RF installation techniques. This is especially im-
portant for System ID arrangements. Contact your factory representative if additional
guidance is required.
MDS 05-4864A01, Rev. I
Over-the-air B/W (kHz)
Speed (bps)
38400
3
65000
3
65000
4
32000
19200
38400
For analog operation with an external modem.
The receive and transmit frequencies may be viewed or set
NONE
, System Beta's units would be set to
System ID = 1
SD Series Technical Manual
Approximate
5
Sensitivity
25.0 -99 dBm
50.0 -102 dBm
50.0 -94 dBm
50.0 -104 dBm
25.0 -106 dBm
25.0 -97 dBm
. The setting
NONE
ETSI
Compliance
X
X
PWR
is required for mixed net-
] for all radios
1-8
. Both
System ID = 5
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