Method and apparatus for adaptive routing in a satellite-based communication system

• US 5,924,014 A
• Filed: 09/30/1996
• Issued: 07/13/1999
• Est. Priority Date: 09/30/1996
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bishop, Jr., James William, Vanden Heuvel, Dean Paul, McKay, Brent Matthew, Schaefer, Bradley Robert
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Armstrong, Darnell R.
• Application Number:
  US08/724,607
• Time in Patent Office: 1,016 Days
• Field of Search: 455/427, 455/428, 455/430, 455/431, 455/445, 455/436, 455/8, 455/12.1, 455/11.1, 455/13.1, 455/67.1, 455/505, 370/323, 370/237, 370/325
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/1856 for call routing

Abstract

In satellite based communication systems (30), real time monitoring of communication links (23-25) and the subsequent adaptations to overcome problems with certain links (23,25) provides the communication system (30) with the ability to adapt to changing conditions. A satellite-based communication system (30) can be adapted to provide an improved method for establishing communication links (23,25) between ground stations (14) and space-based satellite switches (11). Common earth-based termination nodes are replaced by intelligent switches (14). Alternate links are established using links (20,21) between intelligent space-based switches (11), links (24) between intelligent earth-based switches (14), and links (23,25) between intelligent space-based switches (11) and intelligent earth-based switches (14). The controller (54) in the intelligent earth-based switch (14) allows the system to automatically adapt to failure, overload, and other conditions.

Claims

1. A method for routing data through a satellite communication system comprising a plurality of communication satellites which operate as intelligent space-based data packet switches, wherein said plurality of communication satellites are coupled to each other using crosslinks, are coupled to multiple ground stations, and are coupled to a plurality of communication nodes, the method comprising the steps of:

a) establishing, by a first ground station, an uplink communication channel for carrying native system data packets between said first ground station and a satellite of said plurality of communication satellites;

b) establishing, by said first ground station, one or more terrestrial connections between said first ground station and a second ground station, said one or more terrestrial connections establishing a terrestrial crosslink which provides an alternate communication channel for transporting said native system data packets between said first ground station and said second ground station;

c) determining whether a re-route condition exists for which re-routing of at least one native system data packet is desired, said re-route condition existing when said uplink communication channel experiences a service issue;

d) when said re-route condition exists, sending said at least one native system data packet over said alternative communication channel to said second ground station, without conversion to a format which is compatible with existing terrestrial telephone networks;

e) establishing, by said second ground station, an alternate uplink communication channel for carrying data as native system packets between said second ground station and a second satellite of said plurality of satellites; and

f) sending, by said second ground station, said at least one native system data packet to said second satellite using said alternate uplink communication channel.

2. The method as claimed in claim 1 further comprising the step of:

g) when said re-route condition does not exist, sending said at least one native system data packet on said uplink communication channel.

3. A method for receiving data from a satellite of a communication system, wherein said communication system comprises a plurality of satellites which operate as intelligent space-based data packet switches, wherein said plurality of satellites are coupled together using crosslinks and are coupled to multiple ground stations which act as intelligent earth-based data packet switches for said communication system, the method comprising the steps of:

a) establishing, by a first ground station, a downlink communication channel for carrying the data as native system packets between said first ground station and said satellite;

b) establishing, by said first ground station, one or more terrestrial connections between said first ground station and at least one other ground station, said one or more terrestrial connections establishing a terrestrial crosslink which provides an alternate link for transporting the data as said native system packets;

c) receiving a data packet via said downlink communication channel formatted as a native system packet;

d) evaluating, by said first ground station, a destination address within said data packet to determine whether said first ground station is a destination of said data packet;

e) when said first ground station is not the destination of said data packet, sending said data packet over a terrestrial connection to a second ground station as a native system packet;

f) establishing, by said second ground station, one or more uplink connections between said second ground station and a second satellite of said plurality of satellites, said one or more uplink connections providing an alternate uplink for transporting said native system packets;

g) evaluating, by said ground station, said destination address within said data packet to determine whether said second ground station is the destination of said data packet; and

h) when said second ground station is not the destination of said data packet, sending said data packet over said alternate uplink as a native system packet to said second satellite.

4. A method as claimed in claim 3, wherein step e) is preceded by the step of:

storing said data packet as a native system packet.

5. A ground station for use in a satellite communication system comprising said ground station, at least one other ground station, and a plurality of communication satellites which are coupled together using a plurality of crosslinks, wherein said ground station and said at least one other ground station are coupled together using at least one terrestrial channel and are coupled to certain ones of said plurality of communication satellites using at least one uplink communication channel and at least one downlink communication channel, said ground station comprising:

a) a ground station controller for controlling the operation of said ground station by routing a data packet over an uplink communication channel when said controller determines said uplink communication channel is not experiencing a problem, and by routing said data packet over a terrestrial channel without converting said data packet, when said controller determines said uplink communication channel is experiencing a problem, said terrestrial channel providing an alternate channel for transporting said data packet to a second ground station;

b) an uplink interface, coupled to said ground station controller, for establishing the uplink communication channel with said certain ones of said plurality of communication satellites;

c) a downlink interface, coupled to said ground station controller, for establishing a downlink communication channel with said certain ones of said plurality of communication satellites; and

d) a terrestrial connection interface, coupled to said ground station controller, for establishing said terrestrial channel between said first ground station and said second ground station to send said data packet without converting said data packet to a format which is compatible with existing terrestrial telephone networks,

wherein said ground station controller further operates as an intelligent earth-based packet switch for processing data packets formatted as native system packets, for determining when said data packets are destined for said ground station, for determining when to switch and route said data packets to said uplink interface, and for determining when to switch and route said data packets to said terrestrial connection interface.

6. A satellite communication system for allowing users to communicate with each other using at least one satellite in a constellation of interconnected satellites, said satellite communication system including a plurality of common ground stations which operate as termination nodes, wherein an improved satellite communication system comprises:

multiple ground stations located proximate to a surface of an earth, wherein a ground station of said multiple ground stations comprises at least one intelligent switch which allows said ground station to couple at least one satellite in said constellation to couple to another ground station of said multiple ground stations and said ground station sends data packets over an uplink communication channel when said uplink communication channel is not experiencing a problem and sends data packets over a terrestrial link to said another ground station when a problem exists with the uplink communication channel without converting said data packets to a format which is compatible with existing terrestrial telephone networks.