SYSTEMS AND METHODS FOR TERRESTRIAL REUSE OF CELLULAR SATELLITE FREQUENCY SPECTRUM IN A TIME-DIVISION DUPLEX MODE

• US 20100035606A1
• Filed: 08/31/2009
• Published: 02/11/2010
• Est. Priority Date: 09/14/2001
• Status: Active Grant

• Current Assignee: ATC Technology Corporation (FedEx Corporation)
• Original Assignee: ATC Technology Corporation (FedEx Corporation)
• Inventors: Karabinis, Peter D.
• Granted Patent: US 8,068,828 B2
• Time in Patent Office: Days
• US Class Current: 455/427
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/1853 Satellite systems for providing telephony service to a mobile station, i.e. mobile satellite service for selecting H04W
• CPC Class Codes: H04B 7/18563 Arrangements for interconnecting multiple systems data switching networks H04L12/00
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/367 Power values between minimum and maximum limits, e.g. dynamic range

Abstract

A space-based component, such as a satellite, is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency, and to transmit wireless communications to the radiotelephones over a downlink radiotelephone frequency. An ancillary terrestrial network, that may include one or more ancillary terrestrial components, is configured to transmit wireless communications to, and receive wireless communications from, the radiotelephones over the downlink satellite radiotelephone frequency in a time-division duplex mode. By terrestrially transmitting and receiving wireless communications over the downlink satellite radiotelephone frequency in a time-division duplex mode, interference at the space-based component and/or at the gateway, by the ancillary terrestrial network and/or the radiotelephones due to terrestrial reuse of cellular satellite frequency spectrum, may be reduced or eliminated.

Claims

1. A satellite radiotelephone system comprising:

a space-based component that is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency and to transmit wireless communications to radiotelephones over a downlink satellite radiotelephone frequency; and

an ancillary terrestrial network that is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the downlink satellite radiotelephone frequency in a time-division duplex mode.

2. A satellite radiotelephone system according to claim 1 wherein the ancillary terrestrial network also is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the uplink satellite radiotelephone frequency in a time-division duplex mode.

3. A satellite radiotelephone system according to claim 1 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency.

4. A satellite radiotelephone system according to claim 1 wherein the downlink satellite radiotelephone frequency comprises a downlink satellite radiotelephone frequency band and wherein the ancillary terrestrial network is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the downlink satellite radiotelephone frequency band in a time-division duplex mode.

5. A satellite radiotelephone system according to claim 1 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein a first number of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency and wherein a second number of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency, wherein the first number is greater than the second number.

6. A satellite radiotelephone system according to claim 1 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency using EDGE modulation and/or protocol and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency using GPRS modulation and/or protocol.

7. A satellite radiotelephone system according to claim 1 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency using a first modulation and/or protocol and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency using a second modulation and/or protocol, wherein the first modulation and/or protocol is more spectrally efficient than the second modulation and/or protocol.

8. An ancillary terrestrial component for a satellite radiotelephone system that includes a space-based component that is configured to receive wireless communications from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency and to transmit wireless communications to radiotelephones over a downlink satellite radiotelephone frequency, the ancillary terrestrial component comprising:

an electronics system that is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the downlink satellite radiotelephone frequency in a time-division duplex mode.

9. An ancillary terrestrial component according to claim 8 wherein the electronics system also is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the uplink satellite radiotelephone frequency in a time-division duplex mode.

10. An ancillary terrestrial component according to claim 8 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency.

11. An ancillary terrestrial component according to claim 8 wherein the downlink satellite radiotelephone frequency comprises a downlink satellite radiotelephone frequency band and wherein the electronics system is configured to transmit wireless communications to, and receive wireless communications from, radiotelephones over the downlink satellite radiotelephone frequency band in a time-division duplex mode.

12. An ancillary terrestrial component according to claim 8 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein a first number of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency and wherein a second number of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency, wherein the first number is greater than the second number.

13. An ancillary terrestrial component according to claim 8 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency using EDGE modulation and/or protocol and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency using GPRS modulation and/or protocol.

14. An ancillary terrestrial component according to claim 8 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications to radiotelephones over the downlink satellite radiotelephone frequency using a first modulation and/or protocol and wherein at least a second one of the slots is used to receive wireless communications from radiotelephones over the downlink satellite radiotelephone frequency using a second modulation and/or protocol, wherein the first modulation and/or protocol is more spectrally efficient than the second modulation and/or protocol.

15. A satellite radiotelephone communication method comprising:

receiving wireless communications at a space-based component from radiotelephones in a satellite footprint over an uplink satellite radiotelephone frequency;

transmitting wireless communications from the space-based component to radiotelephones over a downlink radiotelephone frequency; and

transmitting wireless communications from an ancillary terrestrial network to radiotelephones and transmitting wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency in a time-division duplex mode.

16. A method according to claim 15 further comprising:

transmitting wireless communications from the ancillary terrestrial network to radiotelephones and transmitting wireless communications from radiotelephones to the ancillary terrestrial network over uplink satellite radiotelephone frequency in a time-division duplex mode.

17. A method according to claim 15 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications from the ancillary terrestrial network to radiotelephones over the downlink satellite radiotelephone frequency and wherein at least a second one of the slots is used to transmit wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency.

18. A method according to claim 15 wherein the downlink satellite radiotelephone frequency comprises a downlink satellite radiotelephone frequency band and wherein the method further comprises transmitting wireless communications from the ancillary terrestrial network to radiotelephones and transmitting wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency band in a time-division duplex mode.

19. A method according to claim 15 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein a first number of the slots is used to transmit wireless communications from the ancillary terrestrial network to radiotelephones over the downlink satellite radiotelephone frequency and wherein a second number of the slots is used to transmit wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency, wherein the first number is greater than the second number.

20. A method according to claim 15 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications from the ancillary terrestrial network to radiotelephones over the downlink satellite radiotelephone frequency using EDGE modulation and/or protocol and wherein at least a second one of the slots is used to transmit wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency using GPRS modulation and/or protocol.

21. A method according to claim 15 wherein the time-division duplex mode includes a frame including a plurality of slots, wherein at least a first one of the slots is used to transmit wireless communications from the ancillary terrestrial network to radiotelephones over the downlink satellite radiotelephone frequency using a first modulation and/or protocol and wherein at least a second one of the slots is used to transmit wireless communications from radiotelephones to the ancillary terrestrial network over the downlink satellite radiotelephone frequency using a second modulation and/or protocol, wherein the first modulation and/or protocol is more spectrally efficient than the second modulation and/or protocol.