公开(公告)号：US3843843A

公开(公告)日：1974-10-22

申请号：US30189772

申请日：1972-10-30

Applicant: RCA CORP

Inventor： SOLOMON K ,  ALLEN J

IPC: H04B7/212 ,  H04J3/06

CPC classification number: H04B7/2126

Abstract: A transmitting station gains access to a time division multiple access communication system without interferring with existing system communications by transmitting frequency shift modulated narrow band accessing signals to the system relay station which may be ground-based or in an orbiting satellite. By transmitting the accessing signals at a frequency located within the spectral null of the information signals being transmitted by the other stations in the system, the accessing signals can be processed to cause the signal transmission from the new station to occur in the correct time slot within the system time frame without interferring with the transmission of the other stations in the system.