US-12628142-B2 - Dynamic incumbent protection

Abstract

In a CBRS system, a spectrum access system (SAS) ensures access by incumbents to specified CBRS channels by establishing temporary whisper zones as needed based on information about incumbent locations and channel usage received from an incumbent tracking system. The SAS relies on environmental sensing capability (ESC) sensors located within the whisper zones to detect actual incumbent use of the specified channels. Upon such detection, the SAS controls the allocation of CBRS channels to non-whisper-zone base stations to ensure incumbent access within dynamic protection zones (DPZs). Establishing temporary whisper zone only when needed and ensuring incumbent access within DPZs based on detection of actual incumbent use result in efficient allocation of the CBRS spectrum for commercial use.

Inventors

• Rauf HAFEEZ

Assignees

• CHARTER COMMUNICATIONS OPERATING, LLC

Dates

Publication Date

20260512

Application Date

20230526

Claims (20)

1. 1 . A spectrum controller for controlling allocation of wireless channels to base stations of a wireless communication network, wherein the spectrum controller comprises communication hardware controlled by a processor configured to cause the spectrum controller to: receive information indicating a need to establish a whisper zone for at least one specified wireless channel; control the allocation of the at least one specified wireless channel to at least one whisper-zone (WZ) base station to establish the whisper zone; receive an indication of detection of the at least one specified wireless channel within the whisper zone corresponding to use of the at least one specified wireless channel by a high-priority user; control the allocation of the at least one specified wireless channel to one or more non-whisper-zone (NWZ) base stations to ensure access to the at least one specified wireless channel by the high-priority user within a dynamic protection zone (DPZ) corresponding to the whisper zone; receive information indicating end of use of the at least one specified wireless channel by the high-priority user within the DPZ; and control the allocation of the at least one specified wireless channel to the at least one WZ base station and the one or more NWZ base stations to at least one of (i) cease to ensure the access to the at least one specified wireless channel by the high-priority user within the DPZ and (ii) terminate the whisper zone.
2. 2 . The spectrum controller of claim 1 , wherein the whisper zone is established by the spectrum controller by de-allocating the at least one specified wireless channel from the at least one WZ base station and/or reducing maximum transmit power level for the at least one specified wireless channel by the at least one WZ base station.
3. 3 . The spectrum controller of claim 1 , wherein the spectrum controller receives the indication of detection of the at least one specified wireless channel within the whisper zone corresponding to use of the at least one specified wireless channel by the high-priority user from an environmental sensing capability (ESC) sensor located within the whisper zone.
4. 4 . The spectrum controller of claim 3 , wherein the indication of detection corresponds to the ESC sensor detecting a received power level for the at least one specified wireless channel above a power level threshold value.
5. 5 . The spectrum controller of claim 3 , wherein the information indicating the end of use of the at least one specified wireless channel by the high-priority user within the DPZ is based on detecting a received power level for the at least one specified wireless channel below a power level threshold value.
6. 6 . The spectrum controller of claim 1 , wherein the information indicating the end of use of the at least one specified wireless channel by the high-priority user within the DPZ is based on an indication that the high-priority user has left the DPZ or has become inactive.
7. 7 . The spectrum controller of claim 1 , wherein the information indicating the need to establish the whisper zone for the at least one specified wireless channel is received from a tracking system configured to track one or more of the geographic location, height, or activity of the high-priority user.
8. 8 . The spectrum controller of claim 1 , wherein the whisper zone has a set of associated wireless channels that is different from a set of associated wireless channels for the DPZ.
9. 9 . The spectrum controller of claim 1 , wherein the spectrum controller is configured to control the allocation of the at least one specified wireless channel to the at least one WZ base station and the one or more NWZ base stations to (i) cease to ensure the access to the at least one specified wireless channel by the high-priority user within the DPZ and (ii) terminate the whisper zone.
10. 10 . The spectrum controller of claim 1 , wherein: the at least one specified wireless channel is a Citizens Broadband Radio Service (CBRS) channel; the spectrum controller is a CBRS spectrum access system (SAS); the base stations are CBRS base stations (CBSDs); and the high-priority user is a CBRS incumbent.
11. 11 . A machine-implemented method for controlling allocation of wireless channels to base stations of a wireless communication network, the method comprising a spectrum controller: receiving information indicating a need to establish a whisper zone for at least one specified wireless channel; controlling the allocation of the at least one specified wireless channel to at least one whisper-zone (WZ) base station to establish the whisper zone; receiving an indication of detection of the at least one specified wireless channel within the whisper zone corresponding to use of the at least one specified wireless channel by a high-priority user; controlling the allocation of the at least one specified wireless channel to one or more non-whisper-zone (NWZ) base stations to ensure access to the at least one specified wireless channel by the high-priority user within a dynamic protection zone (DPZ) corresponding to the whisper zone; receiving information indicating end of use of the at least one specified wireless channel by the high-priority user within the DPZ; and controlling the allocation of the at least one specified wireless channel to the at least one WZ base station and the one or more NWZ base stations to at least one of (i) cease to ensure the access to the at least one specified wireless channel by the high-priority user within the DPZ and (ii) terminate the whisper zone.
12. 12 . The method of claim 11 , wherein the whisper zone is established by the spectrum controller by de-allocating the at least one specified wireless channel from the at least one WZ base station and/or reducing maximum transmit power level for the at least one specified wireless channel by the at least one WZ base station.
13. 13 . The method of claim 11 wherein the spectrum controller receives the indication of detection of the at least one specified wireless channel within the whisper zone corresponding to use of the at least one specified wireless channel by the high-priority user from an environmental sensing capability (ESC) sensor located within the whisper zone.
14. 14 . The method of claim 13 , wherein the indication of detection corresponds to the ESC sensor detecting a received power level for the at least one specified wireless channel above a power level threshold value.
15. 15 . The method of claim 13 , wherein the information indicating the end of use of the at least one specified wireless channel by the high-priority user within the DPZ is based on detecting a received power level for the at least one specified wireless channel below a power level threshold value.
16. 16 . The method of claim 11 , wherein the information indicating the end of use of the at least one specified wireless channel by the high-priority user within the DPZ is based on an indication that the high-priority user has left the DPZ or has become inactive.
17. 17 . The method of claim 11 , wherein the information indicating the need to establish the whisper zone for the at least one specified wireless channel is received from a tracking system configured to track one or more of the geographic location, height, or activity of the high-priority user.
18. 18 . The method of claim 11 , wherein the whisper zone has a set of associated wireless channels that is different from a set of associated wireless channels for the DPZ.
19. 19 . The method of claim 11 , wherein the spectrum controller controls the allocation of the at least one specified wireless channel to the at least one WZ base station and the one or more NWZ base stations to (i) cease to ensure the access to the at least one specified wireless channel by the high-priority user within the DPZ and (ii) terminate the whisper zone.
20. 20 . The method of claim 11 , wherein: the at least one specified wireless channel is a Citizens Broadband Radio Service (CBRS) channel; the spectrum controller is a CBRS spectrum access system (SAS); the base stations are CBRS base stations (CBSDs); and the high-priority user is a CBRS incumbent.

Description

BACKGROUND Field of the Disclosure The present disclosure relates to wireless communications and, more specifically but not exclusively, to spectrum sharing between high-priority users such as incumbents and low-priority users such as wireless network operators in shared frequency bands such as CBRS. Description of the Related Art This section introduces aspects that may help facilitate a better understanding of the disclosure. Accordingly, the statements of this section are to be read in this light and are not to be understood as admissions about what is prior art or what is not prior art. The Citizens Broadband Radio Service (CBRS) spectrum is a set of wireless communication channels that is shared between the U.S. government and commercial entities. There are three different categories of CBRS users, in order of priority: government and non-government users also known as incumbents, commercial Priority Access License (PAL) users, and commercial General Authorized Access (GAA) users. Use of the CBRS spectrum by the commercial PAL and GAA users is orchestrated by commercial Spectrum Access Systems (SASs), each of which controls the allocation of CBRS channels to CBRS base stations (referred to as CBSDs) that are associated with the SAS. In order to ensure access by incumbents to specific CBRS channels, e.g., one or more of the ten lowest-frequency channels in the CBRS spectrum, conventional SASs employ one of two different schemes. In the so-called portal scheme, an incumbent operator reserves, with a SAS, specified CBRS channels during specified time periods within specified areas or volumes (referred to as Dynamic Protection Zones (DPZs)) within the continental U.S. for use by incumbents. The SAS controls the allocation of CBRS channels to its CBSDs within those DPZs during those time periods to ensure access to the specified CBRS channels by the incumbents. This control of CBRS channel allocation may involve temporarily preventing the CBSDs from using specific CBRS channels and/or reducing the maximum power level limits at which the CBSDs may transmit signals in those CBRS channels. One of the problems with the portal scheme is that incumbent operators are known to over-reserve CBRS spectrum resources, resulting in less-than-optimal spectrum availability for commercial operations. The other conventional scheme for ensuring incumbent access to the CBRS spectrum relies on environmental sensing capability (ESC) sensors to detect actual use of specific CBRS channels by incumbents in real time. Because ESC sensors simply measure received signal power levels, they are not able to distinguish between incumbents and commercial PAL/GAA users. As such, a SAS establishes so-called whisper zones, which are geographic areas/volumes within which use of specific CBRS channels is either permanently banned or severely limited in terms of transmit power levels. A whisper zone is a relatively small region having at least one ESC sensor within a larger DPZ. If and when use of one or more of the specific CBRS channels is detected by an ESC sensor above a threshold power level, the SAS will determine in real time that an incumbent is using those CBRS channels in or near the corresponding whisper zone. In that case, the SAS will control the relevant CBSDs to restrict commercial use of those CBRS channels within the corresponding larger DPZ as long as the ESC sensor continues to detect the use of those CBRS channels within the whisper zone. One of the problems with this sensor-based scheme is that the commercial use of those CBRS channels within the whisper zones is permanently restricted, even when no nearby incumbent use is present, again resulting in less-than-optimal spectrum availability for commercial operations. SUMMARY In at least one embodiment, the present disclosure is a spectrum controller for controlling allocation of wireless channels to base stations of a wireless communication network. The spectrum controller comprises communication hardware controlled by a processor configured to cause the spectrum controller to (i) receive information indicating a need to establish a whisper zone for at least one specified wireless channel; (ii) control the allocation of the at least one specified wireless channel to at least one whisper-zone (WZ) base station to establish the whisper zone; (iii) receive an indication of detection of the at least one specified wireless channel within the whisper zone corresponding to use of the at least one specified wireless channel by a high-priority user; (iv) control the allocation of the at least one specified wireless channel to one or more non-whisper-zone (NWZ) base stations to ensure access to the at least one specified wireless channel by the high-priority user within a dynamic protection zone (DPZ) corresponding to the whisper zone; (v) receive information indicating end of use of the at least one specified wireless channel by the high-priority user within the DPZ; and (vi) control