Use of reference phone in point-to-point satellite...

Details Use of reference phone in point-to-point satellite... Use of reference phone in point-to-point satellite...

1996-09-13

2001-03-13

Eisenzopf, Reinhard J. (Department: 2745)

Telecommunications

Radiotelephone system

Zoned or cellular telephone system

C455S526000, C455S427000, C455S069000, C370S316000, C342S352000

Reexamination Certificate

active

06201961

ABSTRACT:

FIELD OF THE INVENTION
This invention relates generally to satellite communication systems and, in particular, to a system that employs at least one earth orbiting satellite, at least one ground station or gateway, and a plurality of user or subscriber terminals.
BACKGROUND OF THE INVENTION
Many current or proposed satellite communication systems are designed for point-to-point telephony or data transmission. One such system is described in U.S. Pat. No. 5,448,623, issued Sep. 5, 1995, entitled “Satellite Telecommunications System Using Network Coordinating Gateways Operative with a Terrestrial Communications System”, by R. Wiedeman and P. Monte. In such point-to-point systems a need may arise to operate the system in a broadcast mode of operation, wherein the same signal is transmitted to two or more terrestrial receivers. Unfortunately, the implementation of a broadcast mode of operation is not possible unless the ground segment of the satellite communications system (e.g., gateways and user terminals) incorporates the appropriate software. However, the addition of the appropriate software to the ground segment to enable broadcast service may have unacceptable cost and schedule implications. This is especially true in code division multiple access (CDMA) systems wherein system capacity depends critically on effective power control, and this power control is implemented by appropriate signalling between the gateway and the individual subscriber terminal.
OBJECTS OF THE INVENTION
It is a first object of this invention to provide a point-to-point satellite communication system that overcomes the foregoing and other problems.
It is a second object of this invention to provide a point-to-point satellite communication system having a mechanism to implement a broadcast mode of operation for an authorized sub-set of user terminals that are located in the vicinity (e.g., within or on the skirts of a same satellite beam) of a reference terminal or phone.
It is a further object of this invention to provide a point-to-point satellite communication system having a reference terminal or phone that is designated to receive a point-to-point transmission from a broadcast service provider, wherein an authorized sub-set of user terminals that are located in the vicinity (e.g., within a same satellite beam) of the reference phone are enabled to also receive the broadcast service provider's transmission, thereby enabling the sub-set of user terminals to “eavesdrop” on the transmission in a broadcast mode of operation.
SUMMARY OF THE INVENTION
The foregoing and other problems are overcome and the objects of the invention are realized by methods and apparatus in accordance with embodiments of this invention, wherein a local broadcast mode operation is implemented in a point-to-point satellite communications system by utilizing a terrestrial reference terminal or phone that is located within a desired zone of broadcast operation. A broadcast service provider places a call to this reference phone through a terrestrial gateway and then continuously transmits desired broadcast data (e.g., stock market quotations, weather forecasts, etc.) to the reference phone via the gateway and at least one satellite. The reference phone receives the broadcast data and functions in a conventional manner to provide power control and related satellite handoff feedback information to the gateway on a return link, via the at least one satellite. Authorized user terminals within the zone of broadcast operation are enabled to receive the same signal transmitted to the reference phone by placing a call through the gateway to the broadcast service provider. The broadcast service provider verifies that the calling user terminal or the user is authorized to receive the transmission, and the calling user terminal is then directed to switch to the same frequency, spreading code (for a CDMA embodiment), and encryption key (if employed) that is assigned to the reference phone. In an alternate implementation, this authentication could be performed in the gateway itself. The authorized calling user terminal then switches to the indicated channel, employs the same spreading and encryption codes, and thus receives the same signal being transmitted to the reference phone, thereby implementing a broadcast mode of operation.
Preferably the authorized user terminal also disables its return channel transmissions, thereby enabling only the reference phone to close a power control link with the gateway through the satellite. This provides the necessary feedback path to insure that efficient power control is maintained.


REFERENCES:
patent: Re. 32905 (1989-04-01), Baran
patent: 4901307 (1990-02-01), Gilhousen et al.
patent: 5010317 (1991-04-01), Schwendeman et al.
patent: 5073900 (1991-12-01), Mallinckrodt
patent: 5081703 (1992-01-01), Lee
patent: 5109390 (1992-04-01), Gilhousen et al.
patent: 5119225 (1992-06-01), Grant et al.
patent: 5216427 (1993-06-01), Yan et al.
patent: 5233626 (1993-08-01), Ames
patent: 5239671 (1993-08-01), Linquist et al.
patent: 5303286 (1994-04-01), Wiedeman
patent: 5339330 (1994-08-01), Mallinckrodt
patent: 5410728 (1995-04-01), Bertiger et al.
patent: 5415368 (1995-05-01), Horstein et al.
patent: 5422647 (1995-06-01), Hirshfield et al.
patent: 5433726 (1995-07-01), Horstein et al.
patent: 5439190 (1995-08-01), Horstein et al.
patent: 5446756 (1995-08-01), Mallinckrodt
patent: 5448623 (1995-09-01), Wiedeman et al.
patent: 0 421 698 A3 (1991-10-01), None
patent: WO 90/13186 (1990-11-01), None
patent: WO 91/09473 (1991-06-01), None
patent: WO 93/09613 (1993-05-01), None
Petition of American Mobile Satellite Corporation Before the FCC, Washington, DC 20554, dated Jun. 3, 1991, pp. 1-15.
Application of Motorola Satellite Communications, Inc. for Iridium A Low Earth Orbit Mobile Satellite System before the FCC, Washington, D.C. Dec. 1990, pp. 49-96.
Before the FCC, Washington, D.C. 20554, Aries Constellation Low Earth Orbit Satellite System Proposal of Constellation Communications, Inc. Jun. 3, 1991, Appendix A, B, and C.
Application of TRW Inc. for Authority to Construct a New Communications Satellite System Odyssey before the FCC, Washington, D.C. 20554, May 31, 1991 pp. 33-51.
Application of Ellipsat Corporation Ellipsat for the Authority to Construct EllipsoRI An Elliptical Orbit Satellite System, before the FCC, Washington, D.C. 20554, Nov. 2, 1990, pp. 5-34.
Application of Loral Cellular Systems, Corp., Globalstar Mobile Communications Wherever You Are, before the FCC, Washington, D.C. Jun. 3, 1991, pp. 94-187.
“An Integrated Satellite-Cellular Land Mobile System for Europe”, E. Del Re, University of Florence, Dept. of Electronics Engineering, italy, Sep. 21, 1989.
Current and Future Mobile Satellite Communication Systems, S. Kato et al., IEICE Transactions, vol. E 74, No. 8 Aug. 1991, pp. 2201-2210
“Digital Network Oriented Mobile Radio Satellite System as an Integrated Part of the GSM Cellular Radio System in Europe”, P. Dondl, Deutsch BUndespost/Fernmeldetechniches Zentralmt/Darmstadt, Sep. 21, 1989, Fed. Rep. Germ.
“The OmniTRACSRMobile Satellite Communications and Positioning System”, E. Tiedemann, Jr. et al., Vehicle Electronics in the 90's: Proceedings of the In'l Congress on Transporation Electronics, Oct. 1990.
“Software Implementation of a PN Spread Spectrum Receiver to Accommodate Dynamics”, C. Cahn et al., IEEE Trans. on Comm., vol. COM-25, No. 8, Aug. 1977,.
“A Communication Technique for Multipath Channels”, R. Price, Proceedings of the IR, Mar. 1958, pp. 555-570.
“Increased Capacity Using CDMA for Mobile Satellite Communication”, K. Gilhousen et al., IEEE Journal on Selected Areas in Communications, vol. 8, No. 4, May 1990, pp. 503-514.
“The IridiumTM1A Revolutionary Satellite Communications System Developed with Innovative Applications of Technology”, D. Sterling et al., IEEE, MILCOM 1991, Nov. 4-7.
“Iridium: Key to Worldwide Cellular Communications”, J. Foley, Telecommunications, Oct. 1991, pp. 23-28.

Affiliated with

Also associated with

Rating

Use of reference phone in point-to-point satellite... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Use of reference phone in point-to-point satellite..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Use of reference phone in point-to-point satellite... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2488554