| 摘要 |
The communication system connects users of the system by one or more two-way links or loops, through intermediately transponders or nodes. A control carrier having a characteristic control carrier frequency is assigned to each system user. The control carrier is a signal which does not contain intelligence or information (modulation), but which establishes the linkage between subscribers, enables the intelligence in specific directions and hence along specific paths. To use the system, the calling part selects a control carrier frequency which is complementary to the control carrier frequency of the called party. Selection of this control carrier frequency automatically enables a transmission path between the calling party and the called party.
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