Demand-assignment communication system

• US 4,870,642 A
• Filed: 03/22/1988
• Issued: 09/26/1989
• Est. Priority Date: 10/17/1985
• Status: Expired due to Term

• Current Assignee: KDDI Corporation
• Original Assignee: Kokusai Densin Denwa Kabushiki Kaisha
• Inventors: Nohara, Mitsuo, Takahata, Fumio
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): Marcelo, Melvin
• Application Number:
  US07/172,951
• Time in Patent Office: 553 Days
• Field of Search: 370/75, 370/118, 455/12, 455/17
• US Class Current: 370/319
• CPC Class Codes: H04B 7/208 Frequency-division multiple access [FDMA]

Abstract

A demand-assignment communication system is disclosed, in which a plurality of earth stations share a plurality of satellite communication channels in one satellite transponder frequency band, and in which a plurality of carriers with a plurality of transmission frequency bands determined according to transmission rate corresponding to plural kinds of communication circuits of different transmission rates are integrally handled and which, upon occurrence of a call from one of the earth stations to another, assigns to the call a satellite communication channel corresponding to the transmission frequency band necessary therefor. In accordance with the present invention, the frequency slot positions for the satellite communication channels and the order of assignment thereof are determined for each kind of transmission frequency bands necessary for the communication circuits, and each satellite communication channel is assigned to the frequency slot position therefor in the order of its assignment to comply with a request for assignment of one of the satellite communication channels to the call.

Claims

1. A demand-assignment communication system for a satellite used for communication between earth stations sharing communication channels in one satellite transponder comprising, a communication transponder having a transponder frequency band, a plurality of narrow band communication circuits assigned frequency bands in an upward order of channel selection from the lowest frequency of the transponder, a plurality of wide band communication circuits assigned frequency bands in a downward order of channel selection from the highest frequency of the transponder, and the narrow band communication circuits and the wide band communication circuits sharing frequency bands not more than the entire frequency band of the transponder for demand-assignment when a call between earth stations is made.

2. A demand-assignment communication system for a satellite used for communication between earth stations sharing communication channels in one satellite transponder comprising, a communication transponder having a transponder split frequency band, a plurality of narrow band communication circuits, satellite channels assigned to the narrow band communication circuits, a plurality of wide band communication circuits, satellite channels assigned to the wide band communication circuits, the transponder split frequency band consisting of frequency bands assigned to the narrow band communication circuits and frequency bands assigned to the wide band communication circuits, and the communication circuits having fixed orders of priority different from each other for kinds of narrow bands and wide bands, for demand-assignment when a call between earth stations is made, and the transponder split frequency band being not less than a sum of the frequency bands actually assigned.

3. A demand-assignment communication system for a satellite used for communication between earth stations sharing communication channels in one satellite transponder comprising, a communication transponder having a plurality of narrow band communication circuits and a plurality of wide band communication circuits, the transponder having a transponder frequency band wider than an effective frequency band determined by the transmission power of the transponder and assigned to the narrow band communication circuits corresponding to narrow band communication channels having frequencies A and B selected from lower frequencies of the transponder frequency band, a transponder frequency band assigned to the wide band communication circuits corresponding to a wide ban communication channel having a frequency A'"'"' selected from higher frequencies of the transponder frequency band, a transponder common frequency band assigned to narrow band communication circuits corresponding to narrow band communication channels having frequencies C, and D or to a wide band communication circuit corresponding to a wide band communication channel having a frequency B'"'"' in accordance with the occurrence orders of calls of the frequencies D and B'"'"', and the effective frequency band of the transponder frequency band being not less than the sum of the frequency bands actually assigned therein.

4. A demand-assignment communication system for a communication satellite having a plurality of satellite communication channels in one satellite transponder frequency band shared in operation by a plurality of earth stations, and in which a plurality of carriers with a plurality of transmission frequency bands determined according to transmission rate corresponding to plural kinds of communication circuits of different transmission rates are integrally handled and upon occurrence of a call from one of the earth stations to another, the transponder assigns to the call a satellite communication channel corresponding to the transmission frequency band necessary therefor, characterized in that frequency slot positions for the satellite communication channels and the orders of assignment thereof different from one another are determined on a fixed order of priority of each kind of transmission frequency band necessary for the communication circuits, and each satellite communication channel hving a frequency slot position therefor is assigned in operation in said fixed order of priority assignment to comply with a request for assignment of one of the satellite communication channels to a call in case where the satellite transponder frequency band is not less than a sum of the transmission frequency bands actually assigned.