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Space-based network architectures for satellite radiotelephone systemsRelated Patent Categories: Telecommunications, Carrier Wave Repeater Or Relay System (i.e., Retransmission Of Same Information), Portable Or Mobile Repeater, Space SatelliteSpace-based network architectures for satellite radiotelephone systems description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070072545, Space-based network architectures for satellite radiotelephone systems. Brief Patent Description - Full Patent Description - Patent Application Claims
CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. patent application Ser. No. 11/241,519, filed Sep. 30, 2005, entitled Space-Based Network Architecture for Satellite Radiotelephone Systems, which itself is a continuation of U.S. patent application Ser. No. 10/225,623, filed Aug. 22, 2002, now U.S. Pat. No. 7,006,789, entitled Space-Based Network Architectures for Satellite Radiotelephone Systems, which claims the benefit of provisional Application No. 60/322,240, filed Sep. 14, 2001, entitled Systems and Methods for Terrestrial Re-Use of Mobile Satellite Spectrum and provisional Application No. 60/392,771, filed Jul. 1, 2002, entitled Space-Based Network Architectures for Satellite Radiotelephone Systems, all of which are assigned to the assignee of the present application, the disclosures of all of which are hereby incorporated herein by reference in their entirety as if set forth fully herein. Application Ser. No. 10/225,623 also is a continuation-in-part (CIP) of application Ser. No. 10/074,097, filed Feb. 12, 2002, entitled Systems and Methods for Terrestrial Reuse of Cellular Satellite Frequency Spectrum, now U.S. Pat. No. 6,684,057, assigned to the assignee of the present application, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein. FIELD OF THE INVENTION [0002] This invention relates to radiotelephone communications systems and methods, and more particularly to terrestrial cellular and satellite cellular radiotelephone communications systems and methods. BACKGROUND OF THE INVENTION [0003] 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. [0004] 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. [0005] The overall design and operation of cellular satellite radiotelephone systems and methods are well known to those having skill in the art, and need not be described further herein. Moreover, as used herein, the term "radiotelephone" includes cellular and/or satellite radiotelephones with or without a multi-line display; Personal Communications System (PCS) terminals that may combine a radiotelephone with data processing, facsimile and/or data communications capabilities; Personal Digital Assistants (PDA) that can include a radio frequency transceiver and a pager, Internet/intranet access, Web browser, organizer, calendar and/or a global positioning system (GPS) receiver; and/or conventional laptop and/or palmtop computers or other appliances, which include a radio frequency transceiver. [0006] As is well known to those having skill in the art, terrestrial networks can enhance cellular satellite radiotelephone system availability, efficiency and/or economic viability by terrestrially reusing at least some of the frequency bands that are allocated to cellular satellite radiotelephone systems. In particular, it is known that it may be difficult for cellular satellite radiotelephone systems to reliably serve densely populated areas, because the satellite signal may be blocked by high-rise structures and/or may not penetrate into buildings. As a result, the satellite spectrum may be underutilized or unutilized in such areas. The use of terrestrial retransmission can reduce or eliminate this problem. [0007] Moreover, the capacity of the overall system can be increased significantly by the introduction of terrestrial retransmission, since terrestrial frequency reuse can be much denser than that of a satellite-only system. In fact, capacity can be enhanced where it may be mostly needed, i.e., densely populated urban/industrial/commercial areas. As a result, the overall system can become much more economically viable, as it may be able to serve a much larger subscriber base. Finally, satellite radiotelephones for a satellite radiotelephone system having a terrestrial component within the same satellite frequency band and using substantially the same air interface for both terrestrial and satellite communications can be more cost effective and/or aesthetically appealing. Conventional dual band/dual mode alternatives, such as the well known Thuraya, Iridium and/or Globalstar dual mode satellite/terrestrial radiotelephone systems, may duplicate some components, which may lead to increased cost, size and/or weight of the radiotelephone. [0008] One example of terrestrial reuse of satellite frequencies is described in U.S. Pat. No. 5,937,332 to the present inventor Karabinis entitled Satellite Telecommunications Repeaters and Retransmission Methods, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein. As described therein, satellite telecommunications repeaters are provided which receive, amplify, and locally retransmit the downlink signal received from a satellite thereby increasing the effective downlink margin in the vicinity of the satellite telecommunications repeaters and allowing an increase in the penetration of uplink and downlink signals into buildings, foliage, transportation vehicles, and other objects which can reduce link margin. Both portable and non-portable repeaters are provided. See the abstract of U.S. Pat. No. 5,937,332. [0009] In view of the above discussion, there continues to be a need for systems and methods for terrestrial reuse of cellular satellite frequencies that can allow improved reliability, capacity, cost effectiveness and/or aesthetic appeal for cellular satellite radiotelephone systems, methods and/or satellite radiotelephones. SUMMARY OF THE INVENTION [0010] Some embodiments of the present invention provide a space-based network for a satellite radiotelephone system that includes at least one receive-only satellite and at least one transmit satellite. In some embodiments, the transmit satellite is a transmit-only satellite, whereas in other embodiments, the transmit satellite is a transmit and receive satellite. The at least one receive-only satellite is configured to receive wireless communications from a radiotelephone at a predetermined location over a satellite frequency band. The at least one transmit satellite is configured to transmit wireless communications to the radiotelephone at the predetermined location over the satellite frequency band. By providing at least one receive-only satellite and at least one transmit satellite, space-based networks according to some embodiments of the present invention can offer a significant link margin, without the need to undesirably burden the radiotelephones themselves to achieve this link margin. [0011] Accordingly, some embodiments of the invention provide a space-based network for a satellite radiotelephone system that comprises more receive satellites than transmit satellites. Other embodiments of the invention provide a space-based network for a satellite radiotelephone system comprising a plurality of satellites that collectively provide greater uplink margin than downlink margin. [0012] In some embodiments of the invention, the at least one receive-only satellite consists of two receive-only satellites. In other embodiments, the at least one transmit satellite comprises at least one transmit-only satellite. In other embodiments, the at least one transmit-only satellite consists of a single transmit-only satellite. In some embodiments, one of the two receive-only satellites and a single transmit-only satellite are collocated in an orbital slot. [0013] In some embodiments, each of the receive-only satellites comprises first and second receive antennas. In other embodiments, the first and second receive-only antennas are about 24 meters in diameter. [0014] In other embodiments, the at least one transmit satellite comprises at least one transmit and receive satellite. In other embodiments, the at least one transmit and receive satellite consists of a single transmit and receive satellite that is collocated in an orbital slot with one of the two receive-only satellites. In other embodiments, the at least one transmit and receive satellite consists of two transmit and receive satellites, a respective one of which is collocated in an orbital slot with a respective one of the two receive-only satellites. [0015] In some embodiments, the single transmit and receive satellite includes a single transmit antenna and a single receive antenna. In other embodiments, the single transmit and receive satellite comprises a single transmit and receive antenna and a single receive antenna. In yet other embodiments, the two transmit and receive satellites each comprises a single transmit antenna and a single receive antenna. In still other embodiments, the two transmit and receive satellite antennas each comprises a single transmit and receive antenna and a single receive antenna. [0016] In other embodiments, each of the receive-only satellites includes first through fourth processors. The first processor is configured to process wireless communications that are received by the first receive-only antenna in a first type of circular polarization. The second processor is configured to process wireless communications that are received by the first receive-only antenna in a second type of circular polarization. The third processor is configured to process wireless communications that are received by the second receive-only antenna in the first polarization, and the fourth processor is configured to process wireless communications that are received by the second receive-only antenna in the second polarization. [0017] In other embodiments, each of the receive-only satellites includes a feeder link signal generator. The feeder link signal generator is configured to combine signals that are received by the first and second receive-only antennas into at least one feeder link signal, including a plurality of orthogonal dimensions and/or polarizations, such as in-phase and quadrature dimensions, horizontal and vertical polarizations, left hand circular and right hand circular polarizations and/or other orthogonal dimensions and/or polarizations. [0018] Space-based networks according to other embodiments of the invention also include a gateway that is configured to receive the feeder link signal from each of the two receive-only satellites. In other embodiments, the gateway may be configured to receive the feeder link signal from each of the two receive-only satellites when the feeder link signal has a bandwidth that is at least as wide as the signals that are received by the first and second receive-only antennas of one of the receive-only satellites. In other embodiments, the space-based network includes a plurality of gateways, a respective one of which is configured to receive a feeder link signal from each of the two receive-only satellites. In some embodiments, the signals that are received by the first and/or second receive-only antennas of one of the receive-only satellites have a bandwidth that is wider than the feeder link signal. [0019] Still other embodiments of the present invention include a combiner that is configured to combine the feeder link signals that are received at at least one of the plurality of gateways, in order to reconstruct the wireless communications from the radiotelephone. Still other embodiments of the present invention include an ancillary terrestrial network that is configured to wirelessly communicate with the radiotelephone at the predetermined location over at least some of the satellite radiotelephone frequency band, to thereby terrestrially reuse the at least some of the satellite radiotelephone frequency band. BRIEF DESCRIPTION OF THE DRAWINGS Continue reading about Space-based network architectures for satellite radiotelephone systems... Full patent description for Space-based network architectures for satellite radiotelephone systems Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Space-based network architectures for satellite radiotelephone systems patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. 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