Method and apparatus for providing wideband services using medium and low earth orbit satellites

• US 7,136,620 B2
• Filed: 11/19/2003
• Issued: 11/14/2006
• Est. Priority Date: 01/07/1999
• Status: Expired due to Term

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Wang, Arthur W.
• Primary Examiner(s): Vuong, Quochien B.
• Application Number:
  US10/718,024
• Publication Number:
  US 20040110467A1
• Time in Patent Office: 1,091 Days
• Field of Search: 455/12.1, 455/13.1, 455/427, 455/428, 455/429, 455/430, 455/450, 455/452.1, 455/561, 455/562.1, 455/3.01, 455/3.02
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18541 for handover of resources
• CPC Class Codes: H04B 7/18578 Satellite systems for providing broadband data service to individual earth stations for selecting H04W; provisions for broadband connection, H04Q11/0478
• CPC Class Codes: H04B 7/1858 Arrangements for data transmission on the physical system, i.e. for data bit transmission between network components
• CPC Class Codes: H04B 7/19 Earth-synchronous stations
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

A method and apparatus for mitigating communications interference between satellite communications systems in different orbits is disclosed. The method comprises the steps of evaluating a geometrical relationship between a second ground station and the satellites in the second satellite constellation, and directing communications between the second ground station and the second satellite according to the evaluated geometrical relationship. In one embodiment communications are handed over from a first satellite to another satellite when the first satellite is no longer at the highest elevation angle of visible satellites. In another embodiment, handover occurs when the first satellite drops below a minimum elevation angle.

Claims

1. A system for providing broadband access to a communication service to user terminals, comprising;

a network of satellites, each satellite having;

at least one communication antenna for generating at least one beam cluster including a plurality of proximally disposed steerable communication beams;

a flexible channelizer for dynamically directing the steerable communication beams according to user terminal communication service demands; and

a plurality of gateway nodes, each gateway node associated with the user terminals serviced by the beam cluster, each gateway node for forwarding messages received from at least one of the user terminals serviced by the beam cluster via the network of satellites to the communication service, and for forwarding messages received from the communication service to at least one of the user terminals serviced by the beam cluster via the network of satellites.

2. The system of claim 1, wherein the network of satellites are in non-geostationary orbits.

3. The system of claim 2, wherein the network of satellites includes a low earth orbit (LEO) system of satellites and a mid earth orbit (MEO) system of satellites.

4. The system of claim 1, wherein the beam cluster includes multiple overlapping beams to provide service at flexible data rates.

5. The system of claim 4, wherein the steerable communications beams further use frequency division multiple access (FDMA) and time division multiple access (TDMA) to provide service at flexible data rates.