Page 419 - Satellite Communications, Fourth Edition

Chapter
13

Interference

13.1 Introduction
With many telecommunications services using radio transmissions, inter-
ference between services can arise in a number of ways. Figure 13.1 shows
in a rather general way the possible interference paths between services.
It will be seen in Fig. 13.1 that the terms earth station and terrestrial sta-
tion are used, and the distinction must be carefully noted. Earth stations
are specifically associated with satellite circuits, and terrestrial stations
are specifically associated with ground-based microwave line-of-sight cir-
cuits. The possible modes of interference shown in Fig. 13.1 are classified
by the International Telecommunications Union (ITU, 1985) as follows:

A : terrestrial station transmissions, possibly causing interference to
1
reception by an earth station
A : earth station transmissions, possibly causing interference to recep-
2
tion by a terrestrial station
B : space station transmission of one space system, possibly causing
1
interference to reception by an earth station of another space system
B : earth station transmissions of one space system, possibly causing
2
interference to reception by a space station of another space system
C : space station transmission, possibly causing interference to recep-
1
tion by a terrestrial station
C : terrestrial station transmission, possibly causing interference to
2
reception by a space station
E: space station transmission of one space system, possibly causing
interference to reception by a space station of another space system
F: earth station transmission of one space system, possibly causing
interference to reception by an earth station of another space system

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