TERRESTRIAL BASE STATIONS AND OPERATING METHODS FOR INCREASING CAPACITY AND/OR QUALITY OF SERVICE OF TERRESTRIAL CELLULAR AND SATELLITE SYSTEMS USING TERRESTRIAL RECEPTION OF SATELLITE BAND FREQUENCIES
The capacity of a terrestrial wireless communications system that uses a terrestrial frequency band for communications with wireless terminals is expanded by utilizing a satellite frequency band for terrestrially receiving terrestrial communications from the wireless terminals. Since the wireless terminals are configured to transmit communications to a space-based component such as a satellite via a satellite frequency band, these transmissions also may be picked up (received) terrestrially. Thus, terrestrial base stations can be equipped with satellite frequency band receivers that can receive communications from the wireless terminals over a satellite frequency band. By using the satellite frequency band receiver in a terrestrial base station, additional capacity and/or quality of service may be provided for a terrestrial and/or satellite communications system.
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This application is a divisional of application Ser. No. 10/317,320, filed Dec. 12, 2002, entitled Systems and Methods for Increasing Capacity and/or Quality of Service of Terrestrial Cellular and Satellite Systems Using Terrestrial Reception of Satellite Band Frequencies, 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 INVENTIONThis invention relates to wireless communications systems and methods, and more particularly to terrestrial wireless communications systems and methods.
BACKGROUND OF THE INVENTIONTerrestrial wireless communications systems and methods such as terrestrial cellular communications systems and methods are widely used to provide voice and/or data communications to subscribers within a prescribed geographic area. For example, analog terrestrial cellular communications systems and methods, such as those designated AMPS, ETACS, NMT-450 and NMT-900 have been deployed successfully throughout the world. Digital cellular radiotelephone systems and methods, such as those designated IS-136 in North America and GSM in Europe also are being widely used. Moreover, Personal Communication Services (PCS) cellular systems and methods, such as those designated IS-95, PCS-1900 and PACS in North America, DCS-1800 and DECT in Europe, and PHS in Japan, also have been deployed for voice and/or high bit-rate data communications.
As is well known to those having skill in the art, terrestrial cellular communications systems and methods may employ a plurality of terrestrial components, also referred to as base stations, which transmit communications to a plurality of wireless terminals over a terrestrial cellular frequency band and receive communications from the wireless terminals over the terrestrial cellular frequency band. The wireless links that are used to transmit communications from the base stations to the wireless terminals are also referred to as forward links, and the wireless links that are used to receive communications from the wireless terminals at the base stations are also referred to as return links.
The following Table illustrates frequency bands that have been designated for terrestrial cellular and satellite cellular use in the United States. These frequency bands are only representative, and other frequency bands may be used within or outside the United States.
The overall design and operation of terrestrial cellular communications 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 “wireless terminal” 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.
As the number of users and/or applications in a terrestrial wireless communications system or method continue to increase, it may be desirable to increase the capacity and/or quality of service of the forward and/or return links that are used for communications between the base stations and the wireless terminals. One way to increase this capacity and/or quality of service is to increase the frequency spectrum that is available for use by the terrestrial wireless communications systems and methods. However, as is well known, the radio frequency spectrum generally is tightly controlled by governmental agencies, such as the Federal Communications Commission (FCC) in the United States. The FCC regulates the frequency bands that electronic equipment may use to transmit information, and also regulates the maximum in-band and/or out-of-band power levels that may be radiated by the specific equipment type.
SUMMARY OF THE INVENTIONSome embodiments of the present invention expand the capacity and/or quality of service of a terrestrial wireless communications system or method that uses a terrestrial frequency band for communications with wireless terminals, by utilizing a satellite frequency band for terrestrially receiving terrestrial communications from the wireless terminals. In some embodiments, the satellite frequency band is not used for terrestrially transmitting communications to the wireless terminals. Embodiments of the invention may stem from a realization that if a wireless terminal is configured to transmit communications to a space-based component such as a satellite via a satellite frequency band, these transmissions also may be picked up (received) terrestrially without the need for additional regulatory approval. Thus, terrestrial base stations can be equipped with satellite frequency band receivers that can receive communications from the wireless terminals over the satellite frequency band. By using the satellite frequency band receiver in a terrestrial base station, additional capacity and/or quality of service may be provided for terrestrial and/or satellite wireless communications systems or methods.
Terrestrial base stations for terrestrial wireless communications systems according to some embodiments of the present invention include a transmitter that is configured to transmit communications to wireless terminals over a terrestrial frequency band and a receiver that is configured to receive communications from the wireless terminals over a satellite frequency band. In some embodiments, the transmitter is configured to transmit communications to the wireless terminals over forward link and return link portions of the terrestrial frequency band. In other embodiments, the transmitter is configured to transmit communications to the wireless terminals over the forward link and return link portions of the terrestrial frequency band without receiving communications from the wireless terminals over a terrestrial frequency band. Other embodiments may configure the receiver to also receive communications from the wireless terminals over a terrestrial frequency band.
Terrestrial base stations for terrestrial wireless communications systems according to other embodiments of the invention include a receiver that is configured to receive communications from wireless terminals over a satellite frequency band, wherein the base station is free of a transmitter that is configured to transmit communications to the wireless terminals over a satellite frequency band. Other embodiments may configure the receiver to also receive communications from the wireless terminals over a terrestrial frequency band.
Wireless terminals according to some embodiments of the invention comprise a receiver that is configured to receive communications over forward link and return link portions of a terrestrial frequency band and a transmitter that is configured to transmit communications over a satellite frequency band. In other embodiments, the receiver is further configured to receive communications over a satellite frequency band, and the transmitter is further configured to transmit communications over a terrestrial frequency band.
Finally, wireless communications systems according to some embodiments of the present invention include a space-based component such as a satellite that is configured to transmit communications to wireless terminals over a satellite frequency band, and to receive communications from the wireless terminals over the satellite frequency band. A terrestrial component such as a base station is configured to transmit communications to the wireless terminals over a terrestrial frequency band, and to receive communications from the wireless terminals over the satellite frequency band. In other embodiments, the terrestrial component is further configured to receive communications from the wireless terminals over a terrestrial frequency band. In still other embodiments, the terrestrial component is further configured to transmit communications to the wireless terminals over forward link and return link portions of the terrestrial frequency band.
In some embodiments, the terrestrial frequency band is a terrestrial cellular frequency band and the satellite frequency band is a satellite cellular frequency band. In other embodiments, the terrestrial frequency band is a terrestrial cellular frequency band and the satellite frequency band is a satellite non-cellular frequency band. In yet other embodiments, the terrestrial frequency band is a terrestrial non-cellular frequency band, and the satellite frequency is a satellite cellular frequency band. Finally, in still other embodiments, both the satellite frequency band and the terrestrial frequency band are non-cellular. Accordingly, some embodiments of the present invention allow the capacity and/or quality of service of terrestrial wireless and/or satellite networks to be increased by terrestrially receiving communications from wireless terminals over a satellite frequency band.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention 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.
As shown in
The cells 120 generally serve as nodes in the wireless communications systems/methods 100, from which links are established between wireless terminals 130 and the MTSO 140. The communications systems/methods 100 allow a duplex radio communication link to be established between two wireless terminals 130 or between a wireless terminal 130 and a land line telephone and/or computer user via the Public Switched Telephone Network (PSTN) 142 and/or other wireless and/or wireline networks.
As also shown in
Accordingly,
Embodiments shown in
This added forward link capacity of embodiments of
Radiotelephone systems and methods, such as cellular radiotelephone systems and methods, according to embodiments of the present invention, may operate in multiple modes. In one mode, illustrated in
The wireless terminals 130 themselves also may be configured to operate in multiple modes. In one mode, as shown in
As was described above, some embodiments of the present invention stem from a recognition that governmental authorities generally do not regulate whether a particular equipment type can or cannot receive electromagnetic radiation that is being emitted by a source. As such, according to some embodiments of the present invention, satellite band receive antennas may be placed at predetermined terrestrial locations, to intercept and process transmissions of wireless terminals that transmit using a satellite frequency band. A terrestrial network wireless operator may, thus, use the return link frequencies of a satellite system, to enable additional communications on the return links of the terrestrial cellular network. As such, a terrestrial cellular network may provide itself added capacity and/or added quality of service by being able to use some, almost all, or all of its already acquired terrestrial cellular frequencies to serve the system's forward links.
In order to achieve the above, in some embodiments of the present invention, a wireless terminal may be equipped with a receiver and processor that are capable of receiving and processing terrestrial cellular transmissions over terrestrial cellular forward link and/or return link frequencies. The wireless terminal also may be equipped with a receiver that is capable of receiving transmissions from a space-based component over the space-based component's forward link frequencies, and/or may also be equipped to transmit over the space-based component return link frequencies. The satellite band transmissions of the wireless terminal may be intercepted and processed by either the space-based component or by a terrestrial base station, or by both (as may be determined, for example, by an integrated system controller based on received signal strength, signal quality metrics and/or other satellite/terrestrial network prioritization schemes). The wireless terminal also may be configured to transmit over the terrestrial return link frequencies.
Traditionally, driven by the statistically symmetrical nature of voice services, wireless network operators have generally allocated equal amounts of spectrum for their forward and return bands. However, with the advent of high speed packet data services, this strategy may change. Users in packet data mode may desire large data dumps to the wireless terminal in response to relatively few bits being transmitted from the wireless terminal. For example, relatively few bits of information being transmitted in response to, for example, a mouse click from the wireless terminal, a system may send a multi-megabyte file to the wireless terminal.
As such, it may be desirable for a terrestrial wireless operator to identify additional spectrum that can be allocated to the forward link. If some or all of the satellite return link spectrum can be used by such terrestrial operators to serve the statistically lower data capacity needs of the terrestrial return link, some or all of the terrestrial spectrum owned by the wireless operator may be reallocated to serving the higher capacity desires of the terrestrial forward link.
In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
Claims
1. A terrestrial base station for a wireless communications system comprising:
- a transmitter that is configured to transmit communications to wireless terminals over a terrestrial frequency band; and
- a receiver that is configured to receive communications from the wireless terminals over a satellite frequency band.
2. A terrestrial base station according to claim 1 wherein the transmitter is configured to transmit communications to the wireless terminals over forward link and/or return link portions of the terrestrial frequency band.
3. A terrestrial base station according to claim 1 wherein the receiver is further configured to receive communications from the wireless terminals over a terrestrial frequency band.
4. A terrestrial base station according to claim 1 wherein the transmitter is configured to transmit communications to the wireless terminals over the terrestrial frequency band and the receiver is configured to receive communications from the wireless terminals over the satellite frequency band in a first operational mode and wherein the transmitter is configured to transmit communications to the wireless terminals over the terrestrial frequency band and the receiver is configured to receive communications from the wireless terminals over the terrestrial frequency band in a second operational mode.
5. A terrestrial base station according to claim 4 wherein the transmitter is further configured to transmit communications to the wireless terminals over forward link and/or return link portions of the terrestrial frequency band in the first operational mode.
6. A terrestrial base station according to claim 4 wherein the receiver is further configured to receive communications from the wireless terminals over the terrestrial frequency band in the first operational mode.
7. A terrestrial base station according to claim 1 in combination with the wireless terminals.
8. A terrestrial base station according to claim 1 wherein the satellite frequency band is a cellular satellite frequency band and/or wherein the terrestrial frequency band is a terrestrial cellular frequency band.
9. A terrestrial base station according to claim 1 wherein the transmitter is further configured to refrain from transmitting communications to the wireless terminals over a satellite frequency band.
10. A terrestrial base station for a terrestrial wireless communications system comprising:
- a receiver that is configured to receive communications from wireless terminals over a satellite frequency band, the base station being free of a transmitter that is configured to transmit communications to the wireless terminals over a satellite frequency band.
11. A terrestrial base station according to claim 10 wherein the receiver is further configured to receive communications from the wireless terminals over a terrestrial frequency band.
12. A terrestrial base station according to claim 10 in combination with the wireless terminals.
13. A terrestrial base station according to claim 10 wherein the satellite frequency band is a cellular satellite frequency band and/or wherein the terrestrial frequency band is a terrestrial cellular frequency band.
14. A method of operating a terrestrial base station of a wireless communications system comprising:
- transmitting communications to wireless terminals over a terrestrial frequency band; and
- receiving communications from the wireless terminals over a satellite frequency band.
15. A method according to claim 14 wherein the transmitting comprises transmitting communications to the wireless terminals over forward link and/or return link portions of the terrestrial frequency band.
16. A method according to claim 14 wherein the receiving comprises receiving communications from the wireless terminals over a terrestrial frequency band.
17. A method according to claim 14 wherein the transmitting and the receiving are performed in a first operational mode and wherein the method further comprises transmitting communications to the wireless terminals over the terrestrial frequency band and receiving communications from the wireless terminals over the terrestrial frequency band in a second operational mode.
18. A method according to claim 17 further comprising transmitting communications to the wireless terminals over forward link and/or return link portions of the terrestrial frequency band in the first operational mode.
19. A method according to claim 17 further comprising receiving communications from the wireless terminals over the terrestrial frequency band in the first operational mode.
20. A method according to claim 14 wherein the satellite frequency band is a cellular satellite frequency band and/or wherein the terrestrial frequency band is a terrestrial cellular frequency band.
21. A method according to claim 14 further comprising refraining from transmitting communications to the wireless terminals over a satellite frequency band.
22. A method of operating a terrestrial base station of a terrestrial wireless communications system comprising:
- receiving communications from wireless terminals over a satellite frequency band; and
- refraining from transmitting communications to the wireless terminals over a satellite frequency band.
23. A method according to claim 22 further comprising receiving communications from the wireless terminals over a terrestrial frequency band.
24. A method according to claim 22 wherein the satellite frequency band is a cellular satellite frequency band and/or wherein the terrestrial frequency band is a terrestrial cellular frequency band.
Type: Application
Filed: May 19, 2006
Publication Date: Sep 21, 2006
Applicant:
Inventor: Peter Karabinis (Cary, NC)
Application Number: 11/419,260
International Classification: H04B 1/38 (20060101);