US 7,599,656 B2 · Spatial guardbands for terrestrial reuse of satellite frequencies

Abstract

Satellite radiotelephone systems include a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band. The satellite footprint is divided into a plurality of satellite cells, in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused. An ancillary terrestrial network is configured to terrestrially reuse at least one of the ancillary radiotelephone frequencies that is used in a satellite cell in the satellite footprint, outside the cell and in some embodiments separated therefrom by a spatial guardband.

Drawings

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Drawings

Claims43

Dependent claims

A satellite radiotelephone system comprising:

a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused;
and
an ancillary terrestrial network that is configured to refrain from terrestrially reusing at least one of the satellite radiotelephone frequencies that is used in a plurality of spaced apart satellite cells in the satellite footprint, within the plurality of spaced apart satellite cells and in respective spatial guardbands that are immediately outside and surround the plurality of spaced apart satellite cells,
wherein the ancillary terrestrial network comprises a plurality of ancillary terrestrial components, at least a first one of which is located in the plurality of spaced apart satellite cells or in the respective spatial guardbands and is configured to refrain from terrestrially reusing the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells for satellite communications, and at least a second one of which is located outside the plurality of spaced apart satellite cells and outside the respective spatial guardbands and is configured to terrestrially reuse the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells for satellite communications,
the spatial guardbands being sufficiently large so as to attenuate the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells to a desired degree by an antenna pattern of the space-based component, so as to allow the at least a second one of the ancillary terrestrial components that is located outside the plurality of spaced apart satellite cells and outside the respective spatial guardbands to reuse the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells.

2 more elements

An ancillary terrestrial component for a satellite radiotelephone system that includes a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused by the space-based component, the ancillary terrestrial component comprising:

an electronics system that is configured to terrestrially reuse at least one of the satellite radiotelephone frequencies that is used by the space-based component in a plurality of spaced apart satellite cells in the satellite footprint when the ancillary terrestrial component is located outside the plurality of spaced apart satellite cells and outside a respective plurality of spatial guardbands that are immediately outside and surround the plurality of spaced apart satellite cells and to refrain from terrestrially reusing the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells in the satellite footprint when the ancillary terrestrial component is located within one of the plurality of spaced apart satellite cells and/or within a spatial guardband that is immediately outside and surrounds the one of the plurality of spaced apart satellite cells,
wherein the spatial guardband is sufficiently large to reduce and/or prevent interference between the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells in the satellite footprint, and the at least one of the satellite radiotelephone frequencies that is terrestrially reused outside the plurality of spaced apart satellite cells and outside the spatial guardbands due to attenuation of the at least one of the satellite radiotelephone frequencies that is used by the space-based component in the plurality of spaced apart satellite cells by an antenna paffern of the space-based component.

A satellite radiotelephone communications method comprising:

providing space-based wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the satellite footprint being divided into a plurality of satellite cells in which satellite radiotelephone frequencies of the satellite radiotelephone frequency band are spatially reused;
and
terrestrially reusing at least one of the satellite radiotelephone frequencies that is used in a plurality of spaced apart satellite cells in the satellite footprint, outside the plurality of spaced apart satellite cells, and refraining from terrestrially reusing at least one of the satellite frequencies that is used in the plurality of spaced apart satellite cells in the satellite footprint, within the plurality of spaced apart satellite cells and in respective spatial guardbands that are immediately outside and surround the plurality of spaced apart satellite cells;
wherein the spatial guardbands are sufficiently large so as to attenuate the at least one of the satellite radiotelephone frequencies that is used in the plurality of spaced apart satellite cells to a desired degree due to an antenna pattern of the satellite, so as to allow terrestrial reuse of the at least one of the satellite radiotelephone frequencies outside the spatial guardbands.

1 more element

An ancillary terrestrial network for a satellite radiotelephone system that includes a space-based component that is configured to provide wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band, the ancillary terrestrial network comprising:

a first ancillary terrestrial component in the satellite footprint that is configured to selectively and/or preferentially use at least a portion of the satellite radiotelephone frequency band in a first ancillary terrestrial component footprint responsive to a first signal that is received at an element of the first ancillary terrestrial component from the satellite radiotelephone system;
and
a second ancillary terrestrial component in the satellite footprint that is configured to selectively and/or preferentially use at least a portion of the satellite radiotelephone frequency band in a second ancillary terrestrial component footprint that is non-overlapping with the first ancillary terrestrial component footprint in response to a second signal that is received at an element of the second ancillary terrestrial component from an element of the first ancillary terrestrial component, and without a need for the second ancillary terrestrial component to receive the first signal at an element of the second ancillary terrestrial component from the satellite radiotelephone system,
wherein the first signal identifies the at least a portion of the satellite radiotelephone frequency band to be used by the first and second ancillary terrestrial components;
or
wherein the first signal does not identify the at least a portion of the satellite radiotelephone frequency band to be used by the first and second ancillary terrestrial components and wherein the first and second ancillary terrestrial components are configured to determine the at least a portion of the satellite radiotelephone frequency band from the first signal.

3 more elements

A satellite radiotelephone communications method comprising:

providing space-based wireless radiotelephone communications in a satellite footprint over a satellite radiotelephone frequency band;
configuring a first ancillary terrestrial component in the satellite footprint to selectively and/or preferentially use at least a portion of the satellite radiotelephone frequency band in a first ancillary terrestrial component footprint responsive to a first signal that is received at an element of the ancillary terrestrial component from external of the first ancillary terrestrial component;
and
configuring a second ancillary terrestrial component in the satellite footprint to selectively and/or preferentially use at least a portion of the satellite radiotelephone frequency band in a second ancillary terrestrial component footprint that is non-overlapping with the first ancillary terrestrial component footprint in response to one a second signal that is received at an element of the second ancillary terrestrial component from an element of the first ancillary terrestrial component, and without a need for the second ancillary terrestrial component to receive the first signal at an element of the second ancillary terrestrial component from the satellite radiotelephone system,
wherein the first signal identifies the at least a portion of the satellite radiotelephone frequency band to be used by the first and second ancillary terrestrial components;
or
wherein the first signal does not identify the at least a portion of the satellite radiotelephone frequency band to be used by the first and second ancillary terrestrial components and wherein configuring the first and second ancillary terrestrial components comprises configuring the first and second ancillary terrestrial components to determine the at least a portion of the satellite radiotelephone frequency band from the first signal.

4 more elements

Dependencies are inferred from the claim text.

Description10,768 words

Summary1,737 words

#This invention relates to radiotelephone communications systems and methods, and more particularly to terrestrial cellular and satellite cellular radiotelephone communications systems and methods.

#Satellite radiotelephone communications systems and methods are widely used for radiotelephone communications. Satellite radiotelephone communications systems and methods generally employ at least one space-based component, such as one or more satellites that are configured to wirelessly communicate with a plurality of satellite radiotelephones.

#A satellite radiotelephone communications system or method may utilize a single antenna beam covering an entire area served by the system. Alternatively, in cellular satellite radiotelephone communications systems and methods, multiple beams are provided, each of which can serve distinct geographical areas in the overall service region, to collectively serve an overall satellite footprint. Thus, a cellular architecture similar to that used in conventional terrestrial cellular radiotelephone systems and methods can be implemented in cellular satellite-based systems and methods. The satellite typically communicates with radiotelephones over a bidirectional communications pathway, with radiotelephone communication signals being communicated from the satellite to the radiotelephone over a downlink or forward link, and from the radiotelephone to the satellite over an uplink or return link.

Brief description of the drawings13 figures

#FIG. 1 is a schematic diagram of cellular radiotelephone systems and methods according to embodiments of the invention.

#FIG. 2 is a block diagram of adaptive interference reducers according to embodiments of the present invention.

#FIG. 3 is a spectrum diagram that illustrates satellite L-band frequency allocations.

Detailed description8,782 words

#The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which typical embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.

#FIG. 1 is a schematic diagram of cellular satellite radiotelephone systems and methods according to embodiments of the invention. As shown in FIG. 1, these cellular satellite radiotelephone systems and methods 100 include at least one Space-Based Component (SBC) 110, such as a satellite. The space-based component 110 is configured to transmit wireless communications to a plurality of radiotelephones 120a, 120b in a satellite footprint comprising one or more satellite radiotelephone cells 130-130″″ over one or more satellite radiotelephone forward link (downlink) frequencies fD. The space-based component 110 is configured to receive wireless communications from, for example, a first radiotelephone 120a in the satellite radiotelephone cell 130 over a satellite radiotelephone return link (uplink) frequency fU. An ancillary terrestrial network, comprising at least one ancillary terrestrial component 140, which may include an antenna 140a and an electronics system 140b, is configured to receive wireless communications from, for example, a second radiotelephone 120b in the radiotelephone cell 130 over the satellite radiotelephone uplink frequency, denoted f′U, which may be the same as fU. Thus, as illustrated in FIG. 1, radiotelephone 120a may be communicating with the space-based component 110 while radiotelephone 120b may be communicating with the ancillary terrestrial component 140. As shown in FIG. 1, the space-based component 110 also undesirably receives the wireless communications from the second radiotelephone 120b in the satellite radiotelephone cell 130 over the satellite radiotelephone frequency f′U as interference. More specifically, a potential interference path is shown at 150. In this potential interference path 150, the return link signal of the second radiotelephone 120b at carrier frequency f′U interferes with satellite communications. This interference would generally be strongest when f′U=fU, because, in that case, the same return link frequency would be used for space-based component and ancillary terrestrial component communications over the same satellite radiotelephone cell, and no spatial discrimination between satellite radiotelephone cells would appear to exist.

#Still referring to FIG. 1, embodiments of satellite radiotelephone systems/methods 100 can include at least one gateway 160 that can include an antenna 160a and an electronics system 160b that can be connected to other networks 162 including terrestrial and/or other radiotelephone networks. The gateway 160 also communicates with the space-based component 110 over a satellite feeder link 112. The gateway 160 also communicates with the ancillary terrestrial component 140, generally over a terrestrial link 142.

Facts

Application

11/252,956Filed 18 Oct 2005 · continuation

Priority

14 Sep 2001

Published

US 2006/0040659 A123 Feb 2006

Granted

6 Oct 2009

Term ended

1 Nov 2023

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment, including 627 days of adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification7 codes

H04B 7/18543
Arrangements for managing radio, resources, i.e. for establishing or releasing a connection: for adaptation of transmission parameters, e.g. power…
H04B 7/18563
Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service: arrangements for interconnecting multiple…
H04B 7/216
Multiple access: code division or spread-spectrum multiple access [CDMA, SSMA]
H04B 7/18513
Systems using a satellite or space-based relay: transmission in a satellite or space-based system

Family

Application60/322,240Us provisional application · filed 14 Sep 2001

Application60/347,173Us provisional application · filed 9 Jan 2002

Application10/074,097Parent of this continuation-in-part · filed 12 Feb 2002

Application10/180,281Parent of this continuation · filed 26 Jun 2002

US 2006/0040659 A1Pre-grant publication · published 23 Feb 2006

US 6,999,720 B2Parent of this continuation

US 6,684,057 B2Parent of this continuation-in-part

Application10/180,281Parent of this continuation-in-part

US 2003/0054760 A1Published application

US 2003/0054761 A1Published application

US 7,599,656 B2This patent

From the US filing history. Foreign family members aren’t listed.

Timeline

14 Sep 2001Priority claimedParent application 60/322,240
18 Oct 2005Application filedUS 11/252,956
23 Feb 2006PublishedUS 2006/0040659 A1
24 Mar 2006Assigned to Mobile Satellite Ventures, LPassignment of assignor's interest
3 Apr 2006Assigned to Atc Technologies, LLCassignment of assignor's interest
10 Apr 2006Assigned to The Bank of New Yorksecurity agreement
6 Oct 2009GrantedUS 7,599,656 B2
7 Oct 2010Assigned to Atc Technologies, LLC, Lightsquared LP, Lightsquared Finance Co.release of security interest
12 Oct 2010Assigned to Wilmington Trust Fsb, AS Collateral Trusteesecurity agreement
14 Jun 2011Assigned to Wilmington Trust Fsb, AS Collateral Trusteesecurity agreement
22 Jan 2016Assigned to Credit Suisse AG, Cayman Islands Branchsecurity agreement (first lien)
22 Jan 2016Assigned to Jefferies Finance LLCsecurity agreement (second lien)
11 Sep 2020Assigned to Jefferies Finance LLCsecurity interest
22 Oct 2020Assigned to Cortland Capital Market Services LLCassignment of security interest
26 Oct 2020Assigned to Atc Technologies, LLCrelease of security interest
26 Oct 2020Assigned to Ligado Networks LLC, Atc Technologies, LLCrelease of security interest
26 Oct 2020Assigned to U.S. Bank National Associationu.s. assignment of and amendment to intellectual property security agreement
30 Oct 2020Assigned to U.S. Bank National Association, AS Collateral Trusteesecond lien patent security agreement
30 Oct 2020Assigned to U.S. Bank National Association, AS Collateral Trusteefirst lien patent security agreement
28 Dec 2022Assigned to U.S. Bank National Associationsecurity interest
3 Mar 2023Assigned to U.S. Bank Trust Company, National Association, AS Successor Collateral Agentu.s. assignment of and amendment to intellectual property security agreements
1 Nov 2023Term endedEstimated, includes 627 days of adjustment
13 Dec 2024Assigned to U.S. Bank Trust Company, National Association, AS Successor Collateral Agentassignment of and amendment to intellectual property security agreements

Spatial guardbands for terrestrial reuse of satellite frequencies

Life of this patent

Spatial guardbands for terrestrial reuse of satellite frequencies

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims43

Description10,768 words

Drawings

Classification7 codes

Life of this patent

Description10,768 words