TM 11-5895-1412-12&P
Section IV COSITE PLAN
A cosite plan provides frequency separation from 0.5 to 5 MHz between nets. A
cosite plan is used when operating more than one net within a communications
van or close proximity to other nets or when mutual frequency interference may
result between radios.
A cosite plan allows these nets to communicate
simultaneously without mutual interference.
A cosite plan provides separation for up to 50 cosite groups. Each gruop can
contain up to 12 nets (1 base net and 11 others). One-frequency value
separation is selected for all 50 cosite groups.
The following items should be considered before constructing a cosite
1.
Determine whether enough frequencies are available for uti
cosite plan.
2.
Determine whether cositing
3.
Determine whether the nets
are also in a reuse plan.
of
plan:
lizing a
provides adequate frequency separation.
being considered for the cosite plan
4.
Determine whether the cosite problem can be resolved by other
means such as terrain masking, antenna remoting or use of low
power.
If FM transmitters operating on different frequencies are situated in the same
locale, it is not unusual for mutual interference problems to result. To
effectively reduce these interference problems, the BECS software adheres to
the following basic assignment standards:
1.
Frequencies with an exact separation factor of 5.75 or 23.00 MHz
to cosited nets.
2
Cosited nets are not assigned frequencies which are on the order
of the second harmonic.
For example, the frequency setting of
30.00, 32.65 and 35.00 will possibly interfere with a radio using
60.00, 65.30 and 70.00 MHz respectively.
To construct a cosite group, execute the following steps:
1.
Identify the nets to be entered in the cosite group (12 max).
2.
Identify the first base net and list the other nets.
3.
Identify the second base net and list the other nets.
4.
Continue the process until you reach one base net and one
remaining net.
The cosite nets are entered into a triangular table as shown in Table G-3.
G-29
