Fixed systems in this frequency range operate in point-to-point or point-to-multipoint (point-to-point or point-to-multipoint microwave systems), one or two frequency transmission methods.

For one frequency transmission method, channel pattern is illustrated as in Figure 3 below:

Figure 3. Channel Pattern for one frequency transmission

Where:

f_n is the center frequency of the n^th channel

X is frequency separation between two adjacent channels

The center frequency of the n^th channel is expressed by following relationship:

f_n = (f₁ –X) + n.X

n = 1,2,3,...

For two frequency transmission method, channel pattern is illustrated as in Figure 4 below:

Figure 4. Channel Pattern for two frequency transmission

Where:

P is duplex spacing (MHz)

X is frequency spacing between two adjacent channels (MHz)

Y is receiving – transmitting gap (separation between innermost channels)

f₀ is the center frequency of the band (MHz)

fn is center frequency of the n^th channelin lower part of the band (MHz)

f’n is center frequency of the corresponding n^th channel in upper part of the band (MHz)

Center frequencies of the n^th channel are expressed by the following relationship:

f_n = f₀ –(P-Y/2+X) + n.X

f’_n = f₀ + (Y/2-X) + n.X

n = 1,2, 3,…