Multiple accessing satellite communication system having standby central station
Channel switching system Patent #: 4984252
ApplicationNo. 012931 filed on 02/03/1993
US Classes:455/8, Failure compensation (e.g., spare channel)455/69, Transmitter controlled by signal feedback from receiver455/503Simulcast system
ExaminersPrimary: Urban, Edward F.
Assistant: Sobutka, Philip J.
Attorney, Agent or Firm
Foreign Patent References
International ClassH04B 007/14
Foreign Application Priority Data1992-02-04 JP
AbstractIn a point-to-multipoint communication network wherein communication channels are established between a transmitting station and a plurality of receiving stations for transmission of data as a multicast signal, a reception confirming arrangement confirms reception of the multicast signal by the receiving stations to locate failing stations that fail to receive at least portions of the multicast signal. A retransmitting arrangement establishes relevant ones of the communication channels between the transmitting station and the failing stations for transmission of the portions to the failing stations. For reception confirmation, the data may be identified by data identifiers, as by a serial number. Alternatively, each receiving station may send back for comparison at the transmitting station a predetermined portion of datum which may be each of the data or a datum received latest at the receiving station under consideration. Preferably, the portions are retransmitted to the failing stations concurrently and one after another when the failing stations are and are not greater in number than a predetermined threshold value.