Wireless telecommunications overlay system Number:7,426,400 from the United States Patent and Trademark Office (PTO) owispatent A wireless communication system includes first and second communication systems and a controller. The first communication system receives a first control signal indicating a first power level and receives first communications. The first communication system formats the first communications into a first communication signal having the first power level and a first communication protocol, and transfers the first communication signal. The second communication system receives a second control signal indicating a second power level and receives second communications. The second communication system formats the second communications into a second communication signal having the second power level and a second communication protocol, and transfers the second communication signal. The controller transfers the control signals, and combines the first communication signal and the second communication signal to form a wireless communication signal, and transfers the wireless communication signal.<H telecommunications, Wireless, Wireless, teleco, 7426400.html, Patent, pto, 7426400

Title: Wireless telecommunications overlay system

Abstract: A wireless communication system includes first and second communication systems and a controller. The first communication system receives a first control signal indicating a first power level and receives first communications. The first communication system formats the first communications into a first communication signal having the first power level and a first communication protocol, and transfers the first communication signal. The second communication system receives a second control signal indicating a second power level and receives second communications. The second communication system formats the second communications into a second communication signal having the second power level and a second communication protocol, and transfers the second communication signal. The controller transfers the control signals, and combines the first communication signal and the second communication signal to form a wireless communication signal, and transfers the wireless communication signal.

Patent Number: 7,426,400 Issued on 09/16/2008 to Linebarger, et al.

Inventors: Linebarger; John W. (Charlotte, NC), Satapathy; Durga P. (Olathe, KS)
Assignee: Sprint Communications Company L.P. (Overland Park, KS)

Appl. No.: 11/348,095

Filed: February 6, 2006

Related U.S. Patent Documents


Application Number	Filing Date	Patent Number	Issue Date
10017929	Oct., 2001	7035663

Current U.S. Class: 455/552.1 ; 370/209; 370/335; 370/341; 455/168.1; 455/443

Current International Class: H04Q 7/20 (20060101)

Field of Search: 455/444,446,447,449,450,452.1,452,552.1,453,168.1,443 370/209,328,338,335,342,441

References Cited [Referenced By]

U.S. Patent Documents


7035663	April 2006	Linebarger et al.
7123934	October 2006	Linebarger et al.

Primary Examiner: Gelin; Jean A

Parent Case Text

RELATED APPLICATIONS

This patent application is a continuation of U.S. patent application Ser. No. 10/017,929; filed on Oct. 30, 2001; now U.S. Pat. No. 7,035,663, entitled "WIRELESS TELECOMMUNICATIONS OVERLAY SYSTEM;" and hereby incorporated by reference into this patent application.

Claims

What is claimed is:

1. A wireless communication system comprising: a first communication system configured to receive a first control signal indicating a first power level, receive first communications, format the first communications into a first communication signal having the first power level and a first communication protocol in response to the first control signal, and transfer the first communication signal having the first power level and the first communication protocol; second communication system configured to receive a second control signal indicating a second power level, receive second communications, format the second communications into a second communication signal having the second power level and a second communication protocol in response to the second control signal, and transfer the second communication signal having the second power level and the second communication protocol; a controller configured to transfer the first control signal and the second control signal, receive the first communication signal having the first power level and the first communication protocol, receive the second communication signal having the second power level and the second communication protocol, combine the first communication signal and the second communication signal to form a wireless communication signal, and transfer the wireless communication signal.

2. The wireless communication system of claim 1 wherein the first communication protocol comprises Multichannel Multipoint Distribution Service (MMDS).

3. The wireless communication system of claim 1 wherein the second communication protocol comprises Code Division Multiple Access (CDMA).

4. The wireless communication system of claim 1 wherein the controller is configured to monitor received power in the first communication signal to generate the first control signal indicating the first power level.

5. The wireless communication system of claim 1 wherein the controller is configured to monitor received power in the second communication signal to generate the second control signal indicating the second power level.

6. The wireless communication system of claim 1 wherein the first communications comprise internet communications.

7. The wireless communication system of claim 1 wherein the second communications comprise voice communications.

8. The wireless communication system of claim 1 wherein the first control signal indicates a frequency.

9. The wireless communication system of claim 8 wherein the first communication system is further configured to format the first communications into the first communication signal having the frequency in response to the first control signal.

10. The wireless communication system of claim 1 wherein the second control signal indicates a frequency, and wherein the second communication system is further configured to format the second communications into the second communication signal having the frequency in response to the second control signal.

11. A method of operating a wireless communication system, the method comprising: in a first communication system, receiving a first control signal indicating a first power level, receiving first communications, formatting the first communications into a first communication signal having the first power level and a first communication protocol in response to the first control signal, and transferring the first communication signal having the first power level and the first communication protocol; in a second communication system, receiving a second control signal indicating a second power level, receiving second communications, formatting the second communications into a second communication signal having the second power level and a second communication protocol in response to the second control signal, and transferring the second communication signal having the second power level and the second communication protocol; and in a controller, transferring the first control signal and the second control signal, receiving the first communication signal having the first power level and the first communication protocol, receiving the second communication signal having the second power level and the second communication protocol, combining the first communication signal and the second communication signal to form a wireless communication signal, and transferring the wireless communication signal.

12. The method of claim 11 wherein the first communication protocol comprises Multichannel Multipoint Distribution Service (MMDS).

13. The method of claim 11 wherein the second communication protocol comprises Code Division Multiple Access (CDMA).

14. The method of claim 11, further comprising in the controller, monitoring received power in the first communication signal to generate the first control signal indicating the first power level.

15. The method of claim 11, further comprising in the controller, monitoring received power in the second communication signal to generate the second control signal indicating the second power level.

16. The method of claim 11 wherein the first communications comprise internet communications.

17. The method of claim 11 wherein the second communications comprise voice communications.

18. The method of claim 11 wherein the first control signal indicates a frequency.

19. The method of claim 18, further comprising in the first communication system, formatting the first communications into the first communication signal having the frequency in response to the first control signal.

20. The method of claim 11 wherein the second control signal indicates a frequency, and further comprising in the second communication system, formatting the second communications into the second communication signal having the frequency in response to the second control signal.

Description

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

MICROFICHE APPENDIX

Not Applicable.

FIELD OF THE INVENTION

The present invention relates to the fields of single carrier and spread spectrum wireless communications.

BACKGROUND OF THE INVENTION

Wireless communications currently are used in a number of communication systems. However, the communication systems often are limited in capacity due to limitations in the ability to place towers and other equipment and the ability to use spectrum. Typically, the equipment in a wireless communication system is used for a specific protocol or spectrum, such as personal communications service (PCS) or multichannel multipoint distribution service (MMDS). However, typically more than one protocol is not serviced by equipment in the communication system.

Some communication systems have attempted to combine different protocols and/or differing equipment to increase capacity or to deploy different services. For example, terrestrial systems exist that share spectrum with satellite systems.

However, new communication systems and methods are needed that enable using multiple wireless protocols to increase capacity, throughput, and/or improve services. The systems and methods of the present invention overlay multiple wireless protocols using dynamic channel sharing to increase capacity and throughput and to improve service delivery in a single communication system.

SUMMARY OF THE INVENTION

In one aspect, the present invention is directed to a system for generating a wireless complementary signal. The system comprises an incumbent system configured to format a first signal according to an incumbent protocol and an overlay system configured to format a second signal according to an overlay protocol. A controller is configured to overlay the first signal with the second signal to create the wireless complementary signal and to transmit the wireless complementary signal.

In another aspect, the present invention is directed to a system for generating a wireless complementary signal. The system comprises an incumbent system configured to format a first signal according to an incumbent protocol at a first transmission level and to generate the formatted first signal as an incumbent signal. The system includes an overlay system configured to format a second signal according to an overlay protocol at a second transmission level and to generate the formatted second signal as an overlay signal. The system also has a controller configured to overlay the incumbent signal with the overlay signal to create the wireless complementary signal and to transmit the wireless complementary signal. The system further includes a MAC entity configured to determine the first transmission level for the incumbent signal and the second transmission level for the overlay signal. The first transmission level is complementary to the second transmission level.

In still another aspect, the present invention is directed to a system for receiving a wireless complementary signal. The system comprises a controller configured to receive the wireless complementary signal and to transmit the wireless complementary signal, the wireless complementary signal comprising an incumbent signal portion and an overlay signal portion. The system includes an incumbent system configured to receive the wireless complementary signal from the controller and to demodulate the incumbent signal portion. The system also has an overlay system configured to receive the wireless complementary signal from the controller and to demodulate the overlay signal portion.

In yet another aspect, the present invention is directed to a method for generating a wireless complementary signal. The method comprises formatting a first signal according to an incumbent protocol using an incumbent system and formatting a second signal according to an overlay protocol using an overlay system. The method includes overlaying the first signal with the second signal using a controller to create the wireless complementary signal. The wireless complementary signal is transmitted.

In a further aspect, the present invention is directed to a method for generating a wireless complementary signal. The method comprises formatting a first signal according to an incumbent protocol at a first transmission level using an incumbent system and generating the formatted first signal as an incumbent signal. A second signal is formatted according to an overlay protocol at a second transmission level using an overlay system, and the formatted second signal is generated as an overlay signal. The incumbent signal is overlayed with the overlay signal to create the wireless complementary signal using a controller, and the wireless complementary signal is transmitted. The first transmission level for the incumbent signal and the second transmission level for the overlay signal are determined using a MAC entity. The first transmission level is complementary to the second transmission level.

In still a further aspect, the present invention is directed to a method for receiving a wireless complementary signal. The method comprises receiving a wireless complementary signal at a controller and transmitting the wireless complementary signal, the wireless complementary signal comprising an incumbent signal portion and an overlay signal portion. The wireless complementary signal is received from the controller at an incumbent system, and the incumbent signal portion is demodulated. The wireless complementary signal is received from the controller at an overlay system, and the overlay signal portion is demodulated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a communication system in accordance with an embodiment of the present invention.

FIG. 2 is a diagram of a complementary signal for an incumbent signal and an overlay signal in accordance with an embodiment of the present invention.

FIG. 3 is a block diagram of a communication system depicting a medium access control entity in accordance with an embodiment of the present invention.

FIG. 4 is a block diagram of a communication system depicting multiple medium access control entities in accordance with an embodiment of the present invention.

FIG. 5 is a block diagram of a communication system having an integrated transmitter and an integrated receiver in accordance with an embodiment of the present invention.

FIG. 6 is a block diagram of a communication system having an integrated transmitter in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Wireless communication systems often are limited in capacity due to equipment limitations and the limitations in available bandwidth for a particular wireless protocol. Improvements in modulation and compression have helped increase the capacity of wireless communication systems. In addition, improvements in equipment and the use of new protocols have increased capacity and efficiency. However, a need still exists for further throughput and efficiency, especially in geographic areas that limit the ability and/or effectiveness of the equipment to provide service through the wireless communication system.

The present invention uses an overlay of multiple wireless technologies to increase the capacity and effectiveness for communications. Preferably, a wideband system, such as code division multiple access (CDMA), is overlaid onto a narrowband single carrier system, such as multichannel multipoint distribution service (DS). Although, other systems may be used. The two systems dynamically share channels so that the systems retain acceptable performance.

The present invention enables a service provider to build an infrastructure using multiple systems with a reduction of total equipment, such as towers, used. Alternately, the present invention enables additional systems to be deployed by a service provider using existing infrastructures, such as existing towers. In addition, selection of a specific protocol or equipment to be used for short-term and future deployment phases can be optimized by using a first system for short-term or first service deployment and a second system for additional or expanded services for a future or second deployment. Other methods and deployments may be used.

The present invention facilitates co-existence of different service deployments by the same service provider. Thus, an incumbent system can be used for a first service, and an overlay system can be used for a second service. Moreover, spectrum use can be increased by using multiple protocols for the incumbent and overlay systems. In addition, dynamic channel sharing between the incumbent and overlay systems enables greater spectrum use and service deployment.

The present invention combines signals from the incumbent system with signals from the overlay system, thereby creating a single transmission. The incumbent and overlay signals are set at predefined negotiated transmission levels, including a frequency and power level, so that both the incumbent signal and the overlay signal can be transmitted and received with acceptable performance. For example, an MMDS incumbent signal can be overlaid with a CDMA overlay signal so that the MMDS signal can be modulated and demodulated within acceptable noise performance levels of the CDMA signal. The overlay signal can be spread across a wide spectrum, so that the spreading effect accounts for a negligible impact on the incumbent signal and the performance of both systems.

Because of the advancement of wireless communication systems, it is feasible to predict and attenuate the potential interference caused by overlay signals on incumbent signals and incumbent signals on overlay signals. This co-existence not only increases the spectral efficiency of scarce spectrum, but it also enables abstraction between service offerings by a single service provider.

Preferably, the present invention uses a medium access control (MAC) entity to monitor and control the dynamic channel sharing between the incumbent system and the overlay system. Real time updates and status of ongoing transmissions and resource allocations by the MAC entity help reduce the impact of reaction/response times when detecting if the incumbent system or the overlay system is idle or transmitting at low thresholds and responding by increasing transmission levels for the other system. In addition, the MAC entity can reduce or eliminate the near-far problem common to networks having channel access without centralized control. The MAC entity also may help cooperating entities, for example, in some instances by controlling power usage of each.

The present invention contemplates multiple architectures. For example, incumbent system customer provided equipment (CPE) can incorporate a transceiver for the overlay system. This architecture would enable multiple services to be delivered simultaneously over the incumbent system and the overlay system. For example, best effort services can be configured to be transmitted via the incumbent system, and guaranteed services can be configured to be transmitted via the overlay system. Other examples exist. In other architectures, CPE can incorporate only a transceiver for an overlay system. In this architecture, the overlay system uses all available spectrum resources in the absence of signals from the incumbent system. However, in this architecture, the overlay system is fully abstracted from the incumbent system.

The present invention uses complementary signals that are intentionally mixed. Thus, the incumbent signal is complementary to the overlay signal, and the two signals are overlaid to create a complementary transmission.

The use of the complementary signals is designed to reduce or eliminate problems with noise and interference that otherwise may exist. For example, the incumbent signal may have a specific power level and a frequency. In addition, the incumbent signal may have a certain noise level within its power and frequency range. The overlay signal can be overlaid on top of the incumbent signal at a viable power level and frequency such that it can be transmitted and received successfully. Prior systems do not intentionally mix signals. The prior systems only use multiple separate systems and different wireless spectrum.

Preferably, the mixing of the complementary signals is accomplished by dynamic channel sharing. In one embodiment, the dynamic channel sharing is achieved by sensing the power on channels used by the incumbent system. In one instance, the power sensing is achieved via input from the MAC entity. This method of using the MAC information for power sensing also reduces or eliminates the near-far problem that occurs in some communication systems and reduces reaction/response time delays for dynamically determining the channels to be shared by the incumbent system and the overlay system. Moreover, interference between the incumbent system and the overlay system is minimized due to the bandwidth spreading effect of the overlay system transceivers or receivers.

The present invention may be used with a wireless system. For example, the present invention may be used with television signals, two-way radios, wireless data signals, or another wireless systems. In addition, the present invention may be used for any spectrum, including licensed spectrum and unlicensed spectrum. Moreover, the present invention may be used for increased capacity, service deployment diversity, and/or other advances.

FIG. 1 depicts an exemplary embodiment of a communication system of the present invention. The communication system 102 of FIG. 1 comprises an incumbent system 104, an overlay system 106, and a multi-access controller 108. The incumbent system 104 and the overlay system 106 may communicate with a network device 110 and 112, respectively. Although, the incumbent system 104 and the overlay system 106 may communicate with the same network device or multiple network devices. The multi-access controller 108 may communicate via a network 114.

The incumbent system 104 may be configured to receive signals from, and transmit signals to, the multi-access controller 108 and the network device 110. When so configured, the incumbent system 104 receives signals from the network device 110, formats the signals according to a selected protocol, and transmits the formatted signals to the multi-access controller 108. Preferably, the incumbent system 104 is configured to format the signals according to protocols used for MMDS systems. The incumbent system 104 may be configured to encrypt, compress, or otherwise process a signal in accordance with a format or protocol for which the signal will be transmitted to the multi-access controller 108.

Preferably, the incumbent system 104 comprises a modulator configured to modulate the signals to be transmitted to the multi-access controller 108. More preferably, the incumbent system 104 comprises a modulator configured to modulate the signals according to protocols used for MMDS systems.

The incumbent system 104 may be configured to use a modulation technique. Preferably, the incumbent system 104 is configured to modulate the incumbent signal according to protocols used for single carrier systems, such as narrowband systems, including protocols for MMDS spectrum.

The incumbent system 104 formats signals received from the network device 110 as incumbent signals transmitted to the multi-access controller 108. The incumbent signals each have a transmission level, including a frequency and a power level. The transmission levels may be predefined, negotiated levels. Alternately the transmission levels may be set and/or changed dynamically according to control signals received by the multi-access controller 108. In either case, the incumbent signals are complementary to the overlay signals. The incumbent signals are formatted according to protocols used with incumbent systems, such as an MMDS system and a wireless communication system (WCS) system. These protocols will be referred to herein as incumbent protocols. Incumbent protocols used for formatting incumbent signals for wireless systems, such as an MMDS system and a WCS system, also may be referred to as wireless incumbent protocols.

The incumbent system 104 also may be configured to receive signals from the multi-access controller 108, process the signals, and transmit the signals to the network device 110. The incumbent system 104 is configured to process the signals to a format receivable by the network device 110 or another device. The incumbent system 104 may be configured to format the signals from a carrier band protocol, such as protocols used for MMDS spectrum, to a format receivable by the network device 110. The incumbent system 104 may be configured to de-encrypt, decompress, or otherwise process the signals so that they are receivable by the network device 110. The incumbent system 104 preferably is configured to receive a complementary signal from the multi-access controller 108 and to format the incumbent signal portion of the complementary signal for reception by a network device.

The incumbent system 104 may comprise a modulator configured to de-modulate signals received from the multi-access controller 108 prior to sending the signals to the network device 110. Preferably, the incumbent system 104 comprises a modulator configured to de-modulate MMDS signals so that they are receivable by the network device 110.

The incumbent system 104 may be configured with a variable power control mechanism. For example, the incumbent system 104 may be an MMDS system comprising a variable power control mechanism that can be used to dynamically obtain greater capacity for service deployment, such as best effort services or services requiring a minimum guaranteed capacity. In this example, an MMDS type incumbent system 104 can dynamically use a given channel of spectrum when the overlay system 106 is idle and not transmitting overlay signals.

The overlay system 106 may be configured to receive signals from, and transmit signals to, the multi-access controller 108 and the network device 112. When so configured, the overlay system 106 receives signals from the network device 112, formats the signals according to a selected protocol, and transmits the formatted signals to the multi-access controller 108. Preferably, the overlay system 106 is configured to format the signals according to protocols used for CDMA systems. The overlay system 106 may be configured to encrypt, compress, or otherwise process a signal in accordance with a format or protocol for which the signal will be transmitted to the multi-access controller 108.

Preferably, the overlay system 106 comprises a modulator configured to modulate the signals to be transmitted to the multi-access controller 108. More preferably, the overlay system 106 comprises a modulator configured to modulate the signals according to protocols used for CDMA systems.

The overlay system 106 may be configured to use a modulation technique. Preferably, the overlay system 106 is configured to modulate the overlay signal according to protocols used for wideband spread spectrum, such as protocols used for CDMA systems.

The overlay system 106 formats signals received from the network device 112 as overlay signals transmitted to the multi-access controller 108. The overlay signals each have a transmission level, including a frequency and a power level. The transmission levels may be predefined, negotiated levels. Alternately the transmission levels may be set and/or changed dynamically according to control signals received by the multi-access controller 108. In either case, the overlay signals are complementary to the incumbent signals. The overlay signals are formatted according to protocols used with overlay systems, such as a CDMA system, an orthogonal frequency division multiplexing (OFDM) system, and an ultra wide band (UWB) system. These protocols will be referred to herein as overlay protocols. Overlay protocols used for formatting overlay signals for wireless systems, such as a CDMA system, an OFDM system, and a UWB system, also may be referred to as wireless overlay protocols.

The overlay system 106 also may be configured to receive signals from the multi-access controller 108, process the signals, and transmit the signals to the network device 112. The overlay system 106 is configured to process the signals to a format receivable by the network device 112 or another device. The overlay system 106 may be configured to format the signals from a wideband protocol, such as protocols used for CDMA signals, to a format receivable by the network device 112. The overlay system 106 may be configured to de-encrypt, decompress, or otherwise process the signals so that they are receivable by the network device 112. The overlay system 106 preferably is configured to receive a complementary signal from the multi-access controller 108 and to format the overlay signal portion of the complementary signal for reception by a network device.

The overlay system 106 may comprise a modulator configured to de-modulate signals received from the multi-access controller 108 prior to sending the signals to the network device 112. Preferably, the overlay system 106 comprises a modulator configured to de-modulate CDMA signals so that they are receivable by the network device 112.

The overlay system 106 may be configured with a variable power control mechanism. For example, the overlay system 106 may be a CDMA system comprising a variable power control mechanism that can be used to dynamically obtain greater capacity for service deployment, such as best effort services or services requiring a minimum guaranteed capacity. In this example, a CDMA type overlay system 106 can dynamically use a given channel of spectrum when the incumbent system 104 is idle and not transmitting incumbent signals.

The transmission levels of the overlay signals are complementary to the transmission levels of the incumbent signals. The complementary transmission levels result in acceptable interference and performance for both the incumbent signals and the overlay signals, as explained more completely below. The complementary nature of the incumbent signals and the overlay signals enables them to co-exist in the same time and frequency domain.

The multi-access controller 108 may be configured to receive signals from, and/or transmit signals to, the incumbent system 104, the overlay system 106, and/or the network 114. The multi-access controller 108 is configured to receive an incumbent signal from the incumbent system 104 and an overlay signal from the overlay system 106. The multi-access controller 108 overlays the overlay signal on the incumbent signal to create a complementary signal that the multi-access controller transmits via the network 114. The multi-access controller 108 can overlay the signals using a selected process, method, or mechanism, such as mixing or otherwise combining the signals.

It will be appreciated that the multi-access controller 108 intentionally mixes or otherwise overlays the incumbent signal with the overlay signal to create the complementary signal. This enables the multi-access controller 108 to design around potential interference, using the respective transmission levels of the incumbent signal and the overlay signal to create the complementary signal.

In some instances, the multi-access controller 108 may be configured to format or otherwise process the complementary signal prior to transmitting it via the network 114, either before or after combining the incumbent signal and the overlay signal to create the complementary signal. For example, the multi-access controller 108 may encrypt, compress, or effect signal processing to the complementary signal prior to transmitting the complementary signal via the network 114.

In addition or alternately, the multi-access controller 108 may be configured to receive a complementary signal via the network 114. The multi-access controller 108 may be configured to transmit the complementary signal to the incumbent system 104 and the overlay system 106. In some instances, the multi-access controller 108 may be configured to format or otherwise process the complementary signal prior to transmitting it to the incumbent system 104 and the overlay system 106. For example, the multi-access controller 108 may de-encrypt, decompress, or effect signal processing to the complementary signal prior to transmitting the complementary signal to the incumbent system 104 and the overlay system 106.

In some embodiments, the multi-access controller 108 also may include a multi-access transceiver to separate the incumbent signal and the overlay signal from the complementary signal. The multi-access controller 108 then transmits the incumbent signal to the incumbent system 104 and transmits the overlay signal to the overlay system 106. The multi-access controller 108 can separate the incumbent signal and overlay signal from the complementary signal using a selected method, process, or mechanism, such as de-modulating the complementary signal into the incumbent signal and the overlay signal.

In the embodiments where the multi-access controller 108 includes a multi-access transceiver, it may be configured to receive and transmit signals configured according to a modulation technique, including modulation for protocols used for narrowband systems and wideband systems, such as MMDS systems and CDMA systems, respectively. The multi-access controller 108 may be configured to combine and/or split incumbent signals, overlay signals, and complementary signals, each possibly using one or more modulation techniques.

The multi-access controller 108 operates as a central controller and resource allocater. The multi-access controller 108 may be configured to overlay signals having predefined, negotiated transmission levels. Alternately, the multi-access controller can be configured to dynamically determine the transmission levels of one or more incumbent signals and/or overlay signals. Thus, the multi-access controller 108 can be configured to transmit control signals to the incumbent system 104 and the overlay system 106 identifying transmission levels for the respective systems or otherwise control the systems.

The multi-access controller 108 effects dynamic channel sharing between the incumbent system 104 and the overlay system 106. The dynamic channel sharing occurs as a result of overlaying the overlay signals on respective incumbent signals using the complementary transmission levels. This dynamic channel sharing between the incumbent system 104 and the overlay system 106 enables greater use of scarce spectrum, especially by dynamically allocating spectrum use to the overlay system 106 when the spectrum is not used by the incumbent system 104 and/or vice versa. Moreover, this dynamic channel sharing enables dynamic reallocation of spectrum for the incumbent system 104 and the overlay system 106 for best effort services or to augment services requiring a minimum guaranteed capacity.

The multi-access controller 108 determines what resources and transmission levels are used by the incumbent system 104 and the overlay system 106. When the multi-access controller 108 is dynamically allocating resources and transmission levels to the incumbent system 104 and the overlay system 106, the multi-access controller may be configured to use that information to extrapolate and select a desired resource and transmission level so that the signals may be overlaid.

The multi-access controller 108 may be configured to determine what protocols are used when a complementary signal is received, including the transmission levels of the respective incumbent signal and overlay signal. The multi-access controller 108 may transmit that information to the incumbent system 104 and/or the overlay system 106.

The multi-access controller 108 may comprise a carrier sensing system (CSS) to dynamically allocate the resources and transmission levels of the incumbent system 104 and the overlay system 106. The CSS determines the resources and transmission levels currently being used by storing or caching the system status, such as frequency, time slot, and power level, for the incumbent system 104 and the overlay system 106. The CSS also may sense and store whether the transmissions are regular or irregular, whether the signals are constant bit rate (CBR) or variable bit rate (VBR), or other characteristics of the signals and performance of the incumbent system 104 and the overlay system 106.

The CSS may comprise signal detection hardware or a medium access control (MAC) entity. Signal detection hardware senses the power levels on signals received from the incumbent system 104 and the overlay system 106 and generates control signals to effect changes or retain the same levels as needed. The MAC entity receives or obtains real time updates of the status of ongoing signals and resource allocations by the incumbent system 104 and the overlay system 106. Use of the MAC entity can reduce the impact of reaction/response times of signal detection hardware and eliminate or reduce the near-far problem common to networks with channel access not having centralized control.

On the receiving side, the CSS may be configured to determine the transmission levels of the complementary signal. It will be appreciated that the CSS may be configured to use one or more carrier sensing techniques, such as listen before talk, two-way family radio techniques, and IEEE 802.11 wireless local area network (LAN) techniques.

The multi-access controller 108 may be configured to transmit control signals to the incumbent system 104 and the overlay system 106. These control signals identify transmission levels to be used for incumbent signals and overlay signals, respectively. The control signals may require the incumbent system 104 or the overlay system 106 to raise or lower transmission levels or the output of incumbent signals and/or the overlay signals to the multi-access controller 108 based on the output of the opposing incumbent system 104 or overlay system 106, capacity needs, capacity availability, and other factors. Thus, the multi-access controller 108 synchronizes the needs and availabilities of the incumbent system 104 and the overlay system 106 and may use control signals to achieve those ends.

It will be appreciated that, in some embodiments, the multi-access controller 108 may include a transmitter only. In this configuration, the multi-access controller 108 will be able to receive incumbent signals from the incumbent system 104 and overlay signals from the overlay system 106, overlay the signals to create the complementary signal, and transmit the complementary signal via the network 114.

Alternately, in some embodiments, the multi-access controller 108 may include a receiver only. In this configuration, the multi-access controller 108 will be configured to receive a complementary signal via the network 114, transmit the complementary signal to the incumbent system 104, and transmit the complementary signal to the overlay system 106.

The network devices 110 and 112 are devices configured to receive signals from, and/or transmit signals to, the incumbent system 104 and/or the overlay system 106. The network devices 110 and 112 may be, for example, a telephone, a computer, a service hub, a transceiver, or another device configured to transmit signals to, or receive signals from, the incumbent system 104 and/or the overlay system 106.

The network 114 is a network configured to carry signals, such as complementary signals, to and from the multi-access controller 108. The network 114 may include hardware, software, or a combination thereof. For example, the network 114 may include wireless switches, antennas, receivers, transceivers, and/or other devices configured to handle signals.

FIG. 2 depicts an exemplary embodiment of an incumbent signal, an overlay signal, and a complementary signal. In the embodiment of FIG. 2, an incumbent signal 202 is overlaid with an overlay signal 204 to create a complementary signal 206.

The incumbent signal 202 has a frequency and a power level. In addition, the incumbent signal has a noise level 208. In this example, the incumbent signal is modulated as an MMDS signal.

The overlay signal 204 has a frequency and a power level. The power level of the overlay signal 204 can be configured to be above, below, and/or at the noise level 208 of the incumbent signal 202. Because the overlay signal 204 is modulated and demodulated as a wideband signal using spreading codes, it can be decoded at any level above, below, and/or at the noise level 208 of the incumbent signal 202. In this example, the overlay signal 204 is a CDMA signal with a power level encompassing than the noise level of the incumbent signal 206.

The spread spectrum characteristics of the CDMA signal, i.e. spreading a narrowband signal over a wideband width, enables the signal to have a power spectral density level in the range of thermal noise spectral density. Thus, when the incumbent signal 202 is overlaid with the overlay signal 204 to create the complementary signal 206, the impact of the spread spectrum CDMA signal to the narrowband MMDS signal is a negligible rise in the noise level. Since the CDMA signal has a negotiated transmission level, either predefined or specified by a control signal, splitting of the complementary signal and later demodulation of the MMDS signal and the CDMA signal occurs with acceptable performance. The spreading effect of the CDMA signal accounts for a negligible impact on the MMDS signal and a negligible impact of the MMDS signal on the CDMA signal.

The complementary nature of the complementary signal 206 can be seen from FIG. 2. Once the overlay signal 204 is combined with the incumbent signal 202, the two signals exist in a single complementary signal 206 in the same time and frequency domain. Thus, the intentional complementary mixing of the two signals results in the dynamic channel sharing between the incumbent system 104 and the overlay system 106.

The system of FIG. 1 operates as follows. In a first example, the incumbent system 104 has primary transmission rights, and the overlay system 106 has secondary rights. The multi-access controller 108 determines the transmission levels of the incumbent signals to be generated by the incumbent system 104. Then, the multi-access controller 108 determines the transmission levels of the overlay signals to be generated by the overlay system 106. In this example, the overlay system 106 is constrained to use transmission levels that result in acceptable interference for the incumbent system 104. The incumbent system 104 and the overlay system 106 then operate at these predefined, negotiated transmission levels.

The network device 110 transmits a signal to the incumbent system 104. The incumbent system 104 modulates the signal according to the transmission levels identified by the multi-access controller 108. The incumbent system 104 then transmits the modulated signal as the incumbent signal to the multi-access controller 108.

The network device 112 transmits a signal to the overlay system 106. The overlay system 106 modulates the signal according to the transmission levels identified by the multi-access controller 108. The incumbent system 106 then transmits the modulated signal as an overlay signal to the multi-access controller 108.

The multi-access controller 108 receives the incumbent signal from the incumbent system 104 and the overlay signal from the overlay system 106. In this example, the multi-access controller 108 mixes the incumbent signal with the overlay signal to create the complementary signal. The multi-access controller 108 then transmits the complementary signal over the network 114.

In this example, the incumbent signal is a narrowband signal and the overlay signal is a wideband spread spectrum signal. Thus, the complementary signal is an overlay of a wideband spread spectrum signal with a narrowband signal.

In another example, 1.25 megahertz (MHz) CDMA signals are used for operation in MMDS spectrum. In this example, the incumbent system 104 uses 6 MHz MMDS spectrum.

The incumbent system 104 generates incumbent signals using the 6 MHz spectrum. The overlay system 106 uses four 1.25 MHz CDMA channels to generate overlay signals. The multi-access controller 108 receives the incumbent signals modulated in the 6 MHz spectrum and receives the overlay signals modulated in the 1.25 MHz spectrum. The multi-access controller 108 overlays the 1.25 MHz overlay signals onto the 6 MHz incumbent signals, using the remaining 1 MHz for guard channels.

In another example, the incumbent system 104 is configured to modulate incumbent signals using 6 MHz spectrum. The overlay system 106 is configured to use 5 MHz CDMA signals. The incumbent system 104 generates incumbent signals to the multi-access controller 108 using the 6 MHz MMDS spectrum. The overlay system 106 generates overlay signals to the multi-access controller 108 using the 5 MHz wideband CDMA signals. The multi-access controller 108 receives the incumbent signals and the overlay signals. The multi-access controller 108 overlays the incumbent signal with the overlay signal, using the remaining 1 MHz for guard channels.

It will be appreciated that other overlay configurations may be used. The above overlay configurations are examples, and other frequencies and configurations may be used.

In another example, the multi-access controller 108 comprises a MAC entity. When the incumbent system 104 modulates a signal to create an incumbent signal, the MAC entity senses the transmission levels of the incumbent signal. Likewise, when the overlay system 106 modulates a signal received from the network device 112 to create an overlay signal, the MAC entity senses the transmission level of the overlay signal. The MAC entity uses the sensed transmission levels of the incumbent signal and overlay signal to confirm that the incumbent system 104 and the overlay system 106 are modulating the respective signals according to the predefined negotiated levels. In addition, the MAC entity uses the sensed transmission levels of the respective signals to mix the incumbent signal and the overlay signal to create the complementary signal.

In another example, the multi-access controller 108 comprises signal detection hardware. When the incumbent system 104 modulates a signal to create an incumbent signal, the signal detection hardware senses the transmission levels of the incumbent signal. Likewise, when the overlay system 106 modulates a signal received from the network device 112 to create an overlay signal, the signal detection hardware senses the transmission level of the overlay signal. The signal detection hardware uses the sensed transmission levels of the incumbent signal and overlay signal to confirm that the incumbent system 104 and the overlay system 106 are modulating the respective signals according to the predefined negotiated levels. In addition, the signal detection hardware uses the sensed transmission levels of the respective signals to mix the incumbent signal and the overlay signal to create the complementary signal.

In another example, the multi-access controller 108 comprises a MAC entity. In this example, the incumbent system 104 and the overlay system 106 provide real time updates of system status when a received signal is modulated or demodulated. Thus, for example, when the incumbent system 104 modulates a signal received from the network device 110 and transmits that modulated signal to the multi-access controller 108, a status signal is transmitted to the MAC entity. Likewise, when the overlay system 106 receives a signal from the network device 112 and modulates the signal to create the overlay signal, the overlay system transmits a status signal to the MAC entity. The status signals identify transmission levels and the overall system status of the incumbent system 104 and/or the overlay system 106, respectively.

In this example, the MAC entity uses the real time status to allocate resources and to identify transmission levels to be used by the incumbent system 104 and the overlay system 106. The MAC entity identifies the power level used by the incumbent system 104 and the power level used by the overlay system 106.

The multi-access controller 108 dynamically allocates the power levels to be used by the incumbent system 104 and the overlay system 106. The multi-access controller 108 entity transmits a control signal to the incumbent system 104 identifying the power level to be used by the incumbent system 104 when modulating a signal to create the incumbent signal. Likewise, the multi-access controller 108 transmits a control signal to the overlay system 106 identifying the power level to be used when modulating the signal received from the network device 112 to create the overlay signal. Thus, the MAC entity dynamically determines the channel sharing for the incumbent system 104 and the overlay system 106.

It will be appreciated that the MAC entity can identify the modulation scheme to be used by either the incumbent system 104 or the overlay system 106. In addition, the MAC entity can identify protocols to be used for a designated spectrum, frequency, power levels, digital processing, and/or whether spectrum is available for use by the incumbent system 104 and/or the overlay system 106. In this example, the MAC entity is configured to raise or lower transmission levels of signals formatted by the incumbent system 104 or the overlay system 106 depending on requirements of the other system. The MAC entity is configured to transmit control signals to the incumbent system 104 or the overlay system 106 to effect that formatting.

In another example, the multi-access controller 108 comprises a MAC entity. However, in this example the incumbent system 104 and the overlay system 106 do not transmit status signals to the MAC entity. Instead, the MAC entity monitors the incumbent system 104 and the overlay system 106. Thus, the MAC entity monitors modulation schemes and their respective transmission levels. The MAC entity then determines whether a modulation scheme, including transmission levels and other signal characteristics, should remain the same or are changed. Thus, the MAC entity dynamically determines the channel sharing for the incumbent system 104 and the overlay system 106.

In another example, the multi-access controller 108 receives a complementary signal. The multi-access controller 108 estimates the transmission levels of the complementary signal. The multi-access controller 108 transmits the complementary signal to the incumbent system 104 and to the overlay system 106.

The incumbent system 104 receives the complementary signal and demodulates the incumbent signal portion to yield a signal receivable by the network device 110. The incumbent system 104 then transmits the signal to the network device 110.

The overlay system 106 receives the complementary signal from the multi-access controller 108 and demodulates the overlay signal portion to yield a format receivable by the network device 112. The overlay system 106 then transmits the signal to the network device 112.

In another example, the multi-access controller 108 comprises a MAC entity. The multi-access controller 108 receives a complementary signal and transmits the complementary signal to the incumbent system 104 and the overlay system 106. In this instance, the multi-access controller 108 does not process the complementary signal.

The incumbent system 104 comprises a demodulator that demodulates the complementary signal. In this example, the incumbent system 104 demodulates only the incumbent signal portion of the complementary signal to yield a signal receivable by the network device 110. The rest of the complementary signal, including the overlay signal portion of the complementary signal, appears to the incumbent system 104 as noise or other interference. In other examples, the incumbent system 104 may otherwise process the signal after it is demodulated, such as with de-encryption or other signal processing.

The overlay system 106 comprises a demodulator that demodulates the complementary signal. In this example, the overlay system 106 demodulates only the overlay signal portion of the complementary signal to yield a signal receivable by the network device 112. The rest of the complementary signal, including the incumbent signal portion of the complementary signal, appears to the overlay system 106 as noise or other interference. In other examples, the overlay system 106 may otherwise process the signal after it is demodulated, such as with de-encryption or other signal processing.

In another example, the multi-access controller 108 comprises a MAC entity. The multi-access controller 108 receives a complementary signal via the network 114. The MAC entity determines the signal characteristics of the complementary signal, including the power level. The multi-access controller 108 transmits the complementary signal to the incumbent system 104 and the overlay signal to the overlay system 106. Additionally, the multi-access controller 108 transmits a control signal to the incumbent system 104 and the overlay system 106 identifying the signal characteristics of the complementary signal.

The incumbent system 104 receives the complementary signal and the control signal. The incumbent system uses the signal characteristics identified by the control signal to format the incumbent signal portion of the complementary signal into a signal receivable by the network device 110. In this example, the incumbent signal portion of the complementary signal is modulated with an incumbent protocol for the MMDS spectrum. In other examples, the signal characteristics may identify bandwidth, spreading codes, encryption, compression, or other processing characteristics.

The overlay system 106 receives the complementary signal and the control signal from the multi-access controller 108. The overlay system 106 uses the signal characteristics identified in the control signal to format the overlay signal portion of the complementary signal to a form receivable by the network device 112. In this example, the signal characteristics identify the incumbent signal portion of the complementary signal as having an incumbent protocol for a CDMA signal. In other examples, the signal characteristics may identify bandwidth, spreading codes, encryption, compression, or other processing characteristics.

In another example, the multi-access controller 108 comprises a MAC entity. In this example, the multi-access controller 108 does not transmit control signals to the incumbent system 104 and the overlay system 106. In this example, the MAC entity directly monitors and controls the incumbent system 104 and the overlay system 106.

The multi-access controller 108 receives a complementary signal over the network 114. The multi-access controller 108 transmits the complementary signal to the incumbent system 104 and to the overlay system 106.

The incumbent system 104 receives the complementary signal from the multi-access controller 108. The MAC entity identifies the signal characteristics of the complementary signal. The incumbent system 104 uses the signal characteristics of the complementary signal to format the complementary signal to a format receivable by the network device 110. In this example, the incumbent system 104 demodulates and de-encrypts the complementary signal to a form receivable by the network device 110.

The overlay system 106 receives the complementary signal from the multi-access controller 108. The MAC entity communicates the signal characteristics of the complementary signal to the overlay system 106. The overlay system uses the signal characteristics of the complementary signal to format the overlay signal to a form receivable by the network device 112. In this example, the overlay system demodulates and decompresses the complementary signal consistent with the signal characteristics to a format receivable by the network device 112.

FIG. 3 depicts an exemplary embodiment of another communication system 102A. In the embodiment of FIG. 3, the communication system 102A comprises a MAC entity 302. It will be appreciated that the incumbent system 104, the overlay system 106, the multi-access controller 108, and/or the MAC entity 302 may be co-located or distributed. Also, each may include one or more software or hardware components. For example, they may be in a single service hub or other device, or one or more components may be distributed in one or more separate devices. Moreover, as depicted in FIG. 3, the network device 110, the network device 112, and the network 114 may communicate with any of the incumbent system 104, the overlay system 106, and the multi-access controller 108. Moreover, other network devices may be included in the communication system 102A, or one or more of the network devices 110 or 112 may be eliminated from the communication system. The same is true for the communication system 102 of FIG. 1.

The MAC entity 302 monitors reception and transmission of signals to and from each of the incumbent system 104, the overlay system 106, and the multi-access controller 108. The MAC entity 302 monitors the signal characteristics of each signal transmitted or received. The signal characteristics may include bandwidth, spreading codes, modulation schemes, transmission levels, protocol formatting, and signal processing, such as encryption, de-encryption, compression, decompression, and other processing techniques. For example, the MAC entity 302 monitors and senses received power on signals received from the incumbent system 104 at the multi-access controller 108, signals received from the overlay system 106 at the multi-access controller, and signals received from the network 114 or other network device at the multi-access controller.

The MAC entity 302 may be configured to directly monitor and control signal characteristics, such as bandwidth, spreading codes, modulation schemes and transmission levels, of signals formatted at the incumbent system 104 and the overlay system 106. Alternately, the MAC entity 302 may be configured to transmit control signals to the incumbent system 104 or the overlay system 106. In addition, the MAC entity 302 may be configured to communicate monitored status or received status signals to the multi-access controller 108, and the multi-access controller 108 then may be configured to transmit control signals to the incumbent system 104 and the overlay system 106 or otherwise provide control.

The monitoring and control of the MAC entity 302 enables the multi-access controller 108 to combine incumbent signals and overlay signals and to identify signal characteristics for formatting received complementary signals. The MAC entity 302 generates real time status information of the incumbent system 104 and the overlay system 106 to the multi-access controller 108, either through direct communication or transmission and reception of status signals. Thus, the MAC entity 302 enables the multi-access controller 108 to dynamically control channel sharing on a real time basis.

In the embodiment of FIG. 3, the MAC entity 302 is depicted as separate from the multi-access controller 108. However, FIG. 3 depicts logical components for ease of understanding. The MAC entity 302 may be a part of the multi-access controller 108 or separate from the multi-access controller. Likewise, the MAC entity 302 may have multiple sub-MAC entities included in one or more of the incumbent system 104 and the overlay system 106.

The communication system 102A of FIG. 3 operates as follows. In a first example, the MAC entity 302 is a part of the multi-access controller 108. The network device 110 transmits a signal that is received by the overlay system 106, and the network device 112 transmits a signal that is received by the incumbent system 104. In this example, the network devices 110 and 112 are not directly connected to either of the incumbent system 104 or the overlay system 106, and intervening devices may route the signals to the respective incumbent system and overlay system. In this example, the signal from the network device 110 is a voice telephone call, and the signal from the network device 112 is multi-media Internet Protocol (IP) connection.

In this example, the protocols with which the signals are to be formatted, including their modulation schemes, are predefined and negotiated for each of the incumbent system 104 and the overlay system 106. The incumbent system 104 receives the signal generated from the network device 112, formats the signal according to an incumbent protocol to create an incumbent signal, and transmits the incumbent signal to the multi-access controller 108. The overlay system 106 receives the signal generated from the network device 110, formats the signal according to an overlay protocol to create an overlay signal, and transmits the overlay signal to the multi-access controller 108.

While the incumbent system 104 and the overlay system 106 are creating the respective incumbent signal and overlay sig