Apparatus and method for enhancing network availability

Abstract

An apparatus, such as a domain proxy implemented in an edge cloud of a private enterprise network, includes a processor configured to aggregate traffic for a citizen broadband radio service device (CBSD) in the private enterprise network. The apparatus also includes a transceiver configured to monitor communications with a geographically redundant instance of a spectrum access system (SAS) that allocates frequency bands in a shared spectrum to the CBSD. The processor is configured to instantiate a local SAS in response to a geographically redundant instance of the SAS becoming unavailable. The local SAS is configured to respond to a heartbeat message from the CBSD. The local SAS is also configured to attempt to establish a connection with an environmental sensing capability (ESC) in response to the geographically redundant SAS becoming unavailable.

Description

Technical Field

[0001] Various example embodiments relate to the field of communications, and more particularly, to apparatus and methods for enhancing network availability of a private enterprise network in a shared spectrum system. Background Art

[0002] Spectrum is the most valuable commodity when deploying wireless networks such as private enterprise networks. Cellular communication systems such as networks that provide wireless connectivity using the Long Term Evolution (LTE) or fifth generation (5G) standards provide more reliable services and higher quality of service (QoS) than comparable services provided by traditional contention-based services in unlicensed bands (such as Wi-Fi). The most valuable spectrum available for cellular communications is at frequencies below 6 gigahertz (GHz) because transmissions at these frequencies do not require a clear line of sight between the transmitter and the receiver. Most of the spectrum below 6 GHz has been auctioned as static licensed spectrum to various mobile network operators (MNOs) that implement cellular communication systems such as LTE networks. The 3.1-4.2 GHz spectrum is occupied by incumbent users such as fixed satellite systems (FSS) and federal incumbent users such as the U.S. government or military entities. This band of spectrum is generally extremely underutilized. Therefore, organizations and vertical industries such as package distribution companies, energy producers, ports, mines, hospitals, and universities cannot access the spectrum below 6 GHz and therefore cannot build private enterprise networks to provide cellular services such as LTE. Summary of the invention

[0003] In order to provide a basic understanding of some aspects of the disclosed subject matter, a simplified summary of the disclosed subject matter is presented below. This summary is not an exhaustive overview of the disclosed subject matter. It is not intended to identify the key or critical elements of the disclosed subject matter or to delineate the scope of the disclosed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to a more detailed description discussed later.

[0004] In some embodiments, an apparatus is provided. The apparatus includes a processor configured to aggregate traffic for a Citizen Broadband Radio Service Device (CBSD) in a private enterprise network. The apparatus also includes a transceiver configured to monitor communications with a geographically redundant instance of a spectrum access system (SAS) that allocates frequency bands in a shared spectrum to the CBSD. The processor is configured to instantiate a local SAS in response to the geographically redundant instance of the SAS becoming unavailable, and the local SAS is configured to respond to a heartbeat message from the CBSD.

[0005] In some embodiments, the local SAS is configured to provide information indicating valid channels in response to a spectrum query message received from the CBSD and to grant authorization requests from the CBSD for channels in the set of valid channels.

[0006] In some embodiments, the local SAS is configured to attempt to establish a connection with an environment sensing capability (ESC) in response to the geo-redundant SAS becoming unavailable.

[0007] In some embodiments, the local SAS determines whether a connection with the ESC has been established and whether a first channel in a first geographic area and a shared spectrum served by the CBSD overlaps with a dynamic protection area (DPA) defined by a second geographic area and a portion of the shared spectrum allocated to an incumbent user.

[0008] In some embodiments, the local SAS is configured to instruct the CBSD to switch to the second channel if a connection with the ESC is not established and if the first geographic area and the first channel overlap with the DPA.

[0009] In some embodiments, the second channel is calculated by at least one of the geographic redundancy instances of the SAS based on presence information for the CBSD and other CBSDs managed by other SAS providers proximate to the first geographic area.

[0010] In some embodiments, the second channel is spatially separated from the first channel by a frequency determined based on attributes of the incumbent user.

[0011] In some embodiments, in response to determining that a connection with the ESC is established and in response to the ESC reporting that there is an incumbent user on the first channel, the local SAS sends a heartbeat response to the CBSD that revokes authorization for the first channel.

[0012] In some embodiments, in response to receiving a message indicating the second channel after transmission of a heartbeat message deauthorizing the first channel, the local SAS authorizes the CBSD to access the second channel. In some embodiments, in response to the second channel being previously provided to the local SAS by at least one of the geographically redundant instances of the SAS, the local SAS authorizes the CBSD to access the second channel.

[0013] In some embodiments, the local SAS is configured to respond to the heartbeat message from the CBSD within a time interval determined based on a predetermined time interval for exchanging status information between peer instances of the SAS.

[0014] In some embodiments, the geographic redundant instance of the SAS determines channel and power assignments for the CBSD based on the status information, and the channel and power assignments are valid for a predetermined time interval.

[0015] In some embodiments, the local SAS receives status information from at least one of the geographically redundant instances of the SAS, and the local SAS receives information indicating the second channel and login credentials for the ESC.

[0016] In some embodiments, a method is provided. The method includes aggregating traffic for a Citizen Broadband Radio Service Device (CBSD) in a private enterprise network at a domain proxy. The method also includes monitoring, at the domain proxy, communications with a geographically redundant instance of a spectrum access system (SAS) that allocates frequency bands in a shared spectrum to the CBSD. The method also includes instantiating a local SAS at the domain proxy in response to the geographically redundant instance of the SAS becoming unavailable. The method also includes responding to a heartbeat message from the CBSD from the local SAS.

[0017] In some embodiments, responding to the heartbeat message includes providing information indicative of valid channels in response to a spectrum query message received from the CBSD.

[0018] In some embodiments, responding to the heartbeat message includes approving an authorization request from the CBSD for a channel in the set of valid channels.

[0019] Some embodiments of the method include attempting to establish a connection between a local SAS and an environment sensing capability (ESC) in response to a geographically redundant SAS becoming unavailable.

[0020] Some embodiments of the method include determining at a local SAS whether a connection with the ESC has been established and whether a first channel in a first geographic area and a shared spectrum served by a CBSD overlaps with a dynamic protection area (DPA) defined by a second geographic area and a portion of the shared spectrum allocated to an incumbent user.

[0021] Some embodiments of the method include instructing the CBSD at the local SAS to switch to the second channel if a connection with the ESC is not established and if the first geographic area and the first channel overlap with the DPA.

[0022] In some embodiments, the second channel is calculated by at least one of the geographic redundancy instances of the SAS based on presence information for the CBSD and other CBSDs managed by other SAS providers proximate to the first geographic area.

[0023] In some embodiments, the second channel is spatially separated from the first channel by a frequency determined based on attributes of the incumbent user.

[0024] Some embodiments of the method include sending a heartbeat response from the local SAS to the CBSD revoking authorization of the first channel in response to determining that a connection with the ESC is established and in response to the ESC reporting that an incumbent user exists on the first channel.

[0025] Some embodiments of the method include authorizing, at the local SAS, the CBSD to access the second channel in response to receiving a message indicating the second channel after transmission of a heartbeat message deauthorizing the first channel and in response to the second channel being previously provided to the local SAS by at least one of the geographically redundant instances of the SAS.

[0026] Some embodiments of the method include responding from the local SAS to a heartbeat message from the CBSD for a time interval determined based on a predetermined time interval for exchanging status information between peer instances of the SAS.

[0027] In some embodiments, the geographic redundant instance of the SAS determines channel and power assignments for the CBSD based on the status information, and the channel and power assignments are valid for a predetermined time interval.

[0028] Some embodiments of the method include receiving, at the local SAS, status information from at least one of the geographically redundant instances of the SAS, and receiving, at the local SAS, information indicating a second channel and login credentials for the ESC.

[0029] In some embodiments, an apparatus is provided. The apparatus includes at least one processor and at least one memory including computer program code. The at least one memory and the computer program code are configured to, together with the at least one processor, cause the apparatus to at least perform: aggregating traffic for a citizen broadband radio service device (CBSD) in a private enterprise network, monitoring communications with a geographically redundant instance of a spectrum access system (SAS) that allocates frequency bands in a shared spectrum to the CBSD, instantiating a local SAS in response to the geographically redundant instance of the SAS becoming unavailable, and responding to a heartbeat message from the CBSD. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] By referencing the accompanying drawings, the present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art. The use of the same reference numerals in different drawings indicates similar or identical items.

[0031] Figure 1 is a block diagram of a communication system according to some embodiments.

[0032] Figure 2 is a block diagram of a network function virtualization (NFV) architecture according to some embodiments.

[0033] Figure 3 is a block diagram illustrating frequency band allocation and access priorities for incumbent users, licensed users, and general access users according to some embodiments.

[0034] Figure 4 is a block diagram of a communication system implementing layered spectrum access in accordance with some embodiments.

[0035] Figure 5 is a block diagram of a communication system that implements a spectrum controller cloud to support deployment of private enterprise networks in a shared spectrum in accordance with some embodiments.

[0036] Figure 6 is a block diagram of a communication system including an interface between a CBSD and a SAS according to some embodiments.

[0037] Figure 7 is a block diagram of a communication system that implements primary and secondary SAS instances according to some embodiments.

[0038] Figure 8 is a flow chart of a method of instantiating and configuring a local SAS instance on a domain proxy according to some embodiments.

[0039] Fig. 9 is a flow chart of a method of operating a local SAS implemented in a domain proxy according to some embodiments.

[0040] Fig.10 is a flow diagram of a method 1100 of granting authority to a backup channel in response to the presence of an incumbent consumer in a DPA associated with a domain agent implementing a local SAS, according to some embodiments. DETAILED DESCRIPTION

[0041] The Federal Communications Commission (FCC) has begun offering spectrum bands owned by federal entities for sharing with commercial operations. For example, newly published FCC rules in 47 Code of Federal Regulations (CFR) Part 96 allow the sharing of the 3550-3700 MHz Citizen Broadband Radio Service (CBRS) between incumbent users and other operators. CBRS operates according to a tiered access architecture that distinguishes between incumbent users, operators that have received a Priority Access License (PAL) in accordance with 47 CFR § 96.23, etc., and General Authorized Access (GAA) operators that are authorized to implement one or more Citizen Broadband Radio Service Devices (CBSDs) in accordance with 47 CFR § 96.33, etc. Incumbent users, PAL licensees, and GAA operators need to request access from a Spectrum Access System (SAS), which allocates frequency bands to operators, such as CBRS in the 3550-3700 MHz band. Frequency bands are allocated to CBSDs associated with operators within specific geographic areas and sometimes within specific time intervals. The SAS uses an environmental sensing capability (ESC) that performs incumbent user detection to determine whether there is an incumbent user in the corresponding geographic area, for example, using radar to detect the presence of naval ships in a port. Each SAS can serve multiple private enterprise networks including a large number of CBSDs (such as base stations, eNodeBs, micro cells, pico cells, etc.).

[0042] The tiered access architecture provides priority access to incumbent users, including grandfathered wireless broadband licensees who are granted authority to operate primarily on the basis of frequencies specified in 47 CFR § 96.11. When an incumbent user exists in a particular area, the incumbent user is granted exclusive access to a portion of the CBRS spectrum. For example, if a Navy ship enters port, the communications system on the ship will be granted exclusive access to frequencies up to 20 MHz within the lower 100 MHz that may impact the CBRS 3550-3700 MHz band. Operators that have received PAL and GAA operators must vacate the band assigned to the ship. The PAL license grants exclusive access to a portion of the 3550-3700 MHz band within a predetermined geographic area, as long as no overlapping portions of the 3550-3700 MHz band within the predetermined geographic area are assigned to the incumbent user. Access to a portion of the 3550-3700 MHz band within the geographic area may be provided to the GAA operator as long as no overlapping portions are assigned to the incumbent user or PAL licensee within the same geographic area during the same time interval. GAA operators are also required to share the allocated portion of the 3550-3700 MHz band if other GAA operators are allocated the same portion.

[0043] Each CBSD that provides wireless connectivity in the CBRS spectrum must be under the direct control of the SAS. Therefore, the CBSD registers with the SAS to begin providing wireless connectivity. The status of the CBSD is monitored using heartbeat messages exchanged between the registered CBSD and its controlling SAS. Heartbeat messages are exchanged at predetermined time intervals (e.g., 20 seconds, 30 seconds, 60 seconds, etc.), and the CBSD is kept registered with the SAS as long as at least one heartbeat message is successfully received within a timeout interval (such as 240 seconds or 300 seconds or other timeout interval). Heartbeat message interruptions exceeding the timeout interval cause the CBSD to stop its transmission on the channels in the CBRS band authorized by the SAS, resulting in unacceptable service downtime for commercial deployment. In some cases, even if the controlling SAS is operating normally and continues to send heartbeat messages, the CBSD (or the domain agent DP that aggregates messages for multiple CBSDs) will detect a heartbeat message interruption due to a network connectivity problem. Network connectivity problems can include interruptions or degradations of bandwidth associated with the SAS interface network port, backhaul connections between the edge cloud infrastructure and the SAS regional cloud, and the like. Service downtime due to interruption and network connectivity between the CBSD or DP and the corresponding SAS instance is unacceptable for commercial deployment.

[0044] One way to provide high availability is to implement geographic redundancy, for example, by associating each CBSD with a primary SAS in one location and a secondary SAS in another location. If the primary SAS fails, the CBSD connects to the secondary SAS and resumes CBRS band operations. Switching between the primary and secondary SAS requires the CBSD to cease its current CBRS band operations on the channels authorized by the primary SAS to comply with CBRS band rules established by the FCC. The CBRS then sends a registration request to the secondary SAS to acquire a new channel in the shared spectrum to provide wireless connectivity. The secondary SAS assigns the channel to the CBSD by sending an authorization message. Implementing geographically redundant SASs (possibly in combination with techniques to reduce switching time between geographically redundant SASs) significantly improves the availability of the SASs to the CBSDs.

[0045] However, geo-redundant SASs are susceptible to other failure modes, such as the disruption of all backhaul links to the geo-redundant SAS (e.g., due to a natural disaster) or a distributed denial of service (DDOS) attack that renders the geo-redundant SAS unresponsive. If the geo-redundant SAS remains unresponsive for more than 240 seconds, the CBSD must shut down its transmitters in accordance with shared spectrum operation rules mandated by the FCC to protect incumbent users. As a result, private enterprise networks, especially those with no other connectivity options, may be disrupted indefinitely due to backhaul failures or DDOS attacks. Disrupting a private enterprise network by rendering all geo-redundant SASs unresponsive may disrupt mission-critical applications. For example, disrupting a private enterprise network implemented in an energy utility may disrupt energy supply to an entire community if the disruption lasts for more than 240 seconds.

[0046] Figures 1 to 10 Embodiments of techniques for maintaining service continuity for a citizen broadband radio service device (CBSD) in a private enterprise network by aggregating traffic for the CBSD at a domain proxy implementing a local spectrum access system (SAS) are disclosed despite the unavailability of a geographically redundant instance of the SAS. In response to detecting the unavailability of the geographically redundant SAS, the local SAS is configured to respond to a heartbeat request received from the CBSD. Some embodiments of the local SAS are also configured to provide information indicating valid channels and approve authorization requests for channels in a set of valid channels in response to a spectrum query message received from the CBSD.

[0047] The local SAS also attempts to establish a connection with the Environmental Sensing Capability (ESC) in response to the geographic redundant SAS becoming unavailable. If a connection cannot be established with the ESC, and if the geographic area and the spectrum served by the CBSD overlap with a portion of the spectrum allocated to the incumbent user in a dynamic protection area (DPA) defined by the geographic area, then if the previously authorized channel is located in the first part of the Citizens Broadband Radio Service (CBRS) spectrum (e.g., the lower 100MHz), then the local SAS forces or instructs the CBSD to switch to a backup channel. The backup channel is calculated by the primary SAS or the secondary SAS taking into account the presence of other CBSDs managed by other provider SASs in the same geographic area. The backup channel is located in the upper 50MHz or lower 100MHz of the CBRS band. If the backup channel is located in the lower 100MHz within the DPA, the primary SAS or the secondary SAS selects a backup channel that is spatially separated from the originally authorized channel by more than 20MHz (naval radar systems typically affect up to 20MHz of the lower 100MHz of the CBRS band). If a connection with the ESC is established, and if the ESC reports that there is an incumbent user on a channel previously granted to the CBSD, the local SAS sends a heartbeat response to the CBSD that revokes authority over the channel. Some embodiments of the CBSD respond with a message that includes a backup channel. If the backup channel was previously provided to the local SAS by one of the geographically redundant SASs, the local SAS grants the backup channel to the CBSD. If the channel does not overlap with the incumbent user channel, the local SAS continues to grant authority to the channel granted to the CBSD.

[0048] When the geographically redundant SAS is unavailable, for example, due to a backhaul failure or a DDOS attack, the local SAS allows the CBSD to continue operating. In some embodiments, the local SAS supports the operation of the CBSD for time intervals determined based on a predetermined time interval for exchanging status information between peer SASs. For example, SAS instances of different suppliers are connected in a mesh configuration to exchange status information of their local CBSDs through a SAS to SAS interface. This information is used to determine the channel and power assignments of the CBSDs managed by the SAS instance and is exchanged at predetermined time intervals (such as every 24 hours). The configuration of the CBSD determined based on the exchanged information is valid for a predetermined time interval. The geographically redundant SAS provides status information to the local SAS so that the status information stored on the local SAS remains valid for up to 24 hours after the failure of the interruption geographically redundant SAS. The geographically redundant SAS also provides backup channel information and login credentials for the ESC to the local SAS. Therefore, in the absence of a geographically redundant SAS, the local SAS has the information required to respond to the heartbeat message from the CBSD, even if the current user appears and affects the current channel authorization. In some embodiments, the local SAS can extend the valid time interval of the status information beyond the predetermined time interval, for example, beyond 24 hours. For example, a local SAS serving a CBSD in an inland region that does not overlap with the geographic region served by any other SAS instance and is not affected by the presence of any incumbent consumers can use the state information to support the CBSD indefinitely or until connectivity issues with the geo-redundant SAS instances on the regional cloud are resolved.

[0049] For example, in the event of war, some embodiments of the domain proxy include an out-of-band signaling mechanism (e.g., utilizing a dial-up or satellite connection) to receive a presidential notification to cease operations in the CBRS band. This out-of-band signaling mechanism allows a private enterprise network on the edge cloud to comply with the presidential order and cease operations even though it may not be connected to a geographically redundant primary / secondary SAS instance that may have been rendered unresponsive due to, for example, a DDOS attack.

[0050] Each time a new CBSD from an edge cloud private enterprise network registers itself with a regional geo-redundant SAS instance and requests channel authorization, some embodiments of the geo-redundant SAS instance calculate additional information (such as a backup channel), which is downloaded to the local SAS together with the status information of the current user CBSD and other CBSDs managed by other SAS suppliers that are geographically adjacent to the edge cloud private enterprise network. The domain agent is configured to monitor the connection with the geo-redundant SAS instance, and then seamlessly switch the operation to the local SAS in response to determining that the connection with the geo-redundant SAS instance has been lost. As discussed herein, the local SAS agent assumes the responsibility of responding to CBSD requests within the edge cloud to keep the private enterprise network operating normally. Therefore, embodiments of the technology disclosed herein extend the operating window for CBSD from only 4 minutes to a maximum of 24 hours in the event of a connection failure with a regional geo-redundant SAS instance. This additional time provides operators with more opportunities to resolve the root cause of the problem and restore the connection between the domain agent on the edge cloud and the geo-redundant SAS instance on the regional cloud. If the edge cloud enterprise network happens to be located within a DPA, and if the domain proxy is unable to establish a connection with the ESC to receive incumbent user information within the DPA after losing connectivity with the geo-redundant SAS, the local SAS on the domain proxy ensures that the CBSD uses a channel in the upper 50MHz of the CBRS band (if the regional SAS has calculated that channel as a backup channel for the CBSD). However, if no backup channel is found in the upper 50MHz channels, the local SAS of the SAS instance that also enables DPA on the domain proxy performs operations, assuming that DPA is enabled for the entire lower 100MHz without ESC sensors. In this case, the transmit power of Class A (indoor) and Class B (outdoor) CBSDs can be configured based on parameters such as antenna height, tilt, distance to the coastline, and ESC sensors to keep the CBRS network operating normally while complying with incumbent user protection rules within the DPA.

[0051] Figure 1is a block diagram of a communication system 100 according to some embodiments. The communication system 100 operates in accordance with FCC rules set forth in 47 Code of Federal Regulations (CFR) Part 96, which allow the sharing of the Citizen Broadband Radio Service (CBRS) of 3550-3700 MHz between the incumbent user and other operators. However, some embodiments of the communication system 100 operate in accordance with other rules, standards, or protocols that support sharing of frequency bands between incumbent users and other devices, such that if an incumbent device is present in a certain geographic area, the frequency band is available for exclusive allocation to the incumbent device. In this case, other devices are required to vacate any portion of the frequency band that overlaps with another portion of the frequency band allocated to the incumbent user. For example, if the communication system 100 is deployed (at least partially) near a port and a naval vessel such as an aircraft carrier 101 arrives at the port, devices in the geographic area near the port that provide wireless connectivity in a portion of the frequency band allocated to the aircraft carrier 101 need to vacate a portion of the frequency band to provide the aircraft carrier 101 with exclusive access to the frequency band within the geographic area.

[0052] The communication system 100 includes a regional cloud 105 that provides cloud-based support for a private enterprise network 110. Certain embodiments of the regional cloud 105 include one or more servers configured to provide operations and maintenance (O&M) management, a customer portal, network analytics, software management, and central security for the private enterprise network 110. The regional cloud 105 also includes a SAS 115 that is used to allocate frequency bands to operators, for example, to the private enterprise network 110 for use with CBRS in the 3550-3700 MHz band. The communication system 100 also includes another regional cloud 106 that includes a SAS 116. In the illustrated embodiment, the regional clouds 105, 106 are located in different geographic locations and are therefore used to provide geographic redundancy. Therefore, in some cases, the SAS 116 is referred to as a geographically redundant SAS 116. The geographically redundant instances of the SAS 115, 116 are connected via a SAS-SAS interface (not shown in the figure for clarity). Figure 1 For example, the geographically redundant instances of SAS 115, 116 exchange status information at certain time intervals, such as once every 24 hours. Other SAS-SAS interfaces (not shown for clarity) Figure 1 115 and 116 may serve multiple private enterprise networks, although Figure 1A single private enterprise network 110 is shown for clarity in FIG. The operation of SAS 115, 116 is disclosed in more detail below.

[0053] The regional clouds 105, 106 are configured to one or more external computers 120 via a user interface portal, Figure 1 For example, the external computer 120 provides a customer user interface portal for service management, a digital automation cloud management user interface portal, and a SAS user interface portal for configuring the SAS 115 , 116 .

[0054] The private enterprise network 110 includes an edge cloud 125 that communicates with the regional clouds 105, 106 to support plug-and-play deployment of the private enterprise network 110. Certain embodiments of the edge cloud 125 support automatic configuration and self-service. , industrial protocols, local connectivity with low latency, LTE / 5G-based communications and local security, high availability, and other optional applications for the private enterprise network 110. In the illustrated embodiment, the edge cloud 125 implements a domain proxy 130 that provides managed access and policy control to a set of CBSDs 131, 132, 133, which are implemented using base stations, base station routers, micro-macro cells, micro-cells, indoor / outdoor pico cells, femto cells, etc. As used herein, the term "base station" refers to any device that provides wireless connectivity and operates as a Class A CBSD (indoor) or Class B CBSD (outdoor) or customer premises equipment (CPE) in the private enterprise network 110. Therefore, the CBSDs 131 , 132 , 133 are referred to herein as base stations 131 , 132 , 133 and collectively as “base stations 131 - 133 .” Some embodiments of the domain proxy 130 are implemented in the regional clouds 105 , 106 .

[0055] The domain agent 130 mediates between the SAS 115, 116 and the base stations 131-133. In order to utilize the shared spectrum, the base stations 131-133 transmit a request to one of the SAS 115, 116 to request the allocation of a portion of the frequency band. As discussed herein, the domain agent 130 identifies one of the SAS 115, 116 as the primary SAS initially used to support communications in the shared spectrum, and identifies the other of the SAS 115, 116 as a secondary SAS, which is used as a fallback in the event of a primary SAS service interruption. The request includes information identifying the portion of the frequency band (such as one or more channels), a geographic area corresponding to the coverage area of ​​the requesting base station, and in some cases a time interval indicating when the requested portion of the frequency band is used for communications. In the illustrated embodiment, the coverage area of ​​the base stations 131-133 corresponds to an area covered by the private enterprise network 110. Some embodiments of the domain proxy 130 reduce the signal load between the domain proxy 130 and the SAS 115, 116 by aggregating requests from multiple base stations 131-133 into a small number of messages transmitted from the domain proxy 130 to the SAS 115. In response to the SAS 115, 116 allocating portions of the frequency band to the base stations 131-133, the base stations 131-133 provide wireless connections with corresponding user devices 135, 136, 137 (collectively referred to herein as user devices 135-137).

[0056] The requests transmitted by the base stations 131-133 do not have to include the same information. Some embodiments of the requests from the base stations 131-133 include information indicating different portions of the frequency band, different geographic areas, or different time intervals. For example, if the private enterprise network 110 is deployed in a mall or shopping center and the base stations 131-133 are used to provide wireless connectivity in different stores with different business hours, the base stations 131-133 request portions of the frequency band for use in different time intervals. Therefore, the domain agent 130 manages the base stations 131-133 using separate (and possibly different) policies on a per-CBSD basis. In some embodiments, the domain agent 130 accesses the policy of the base station 131-133 in response to receiving a request from the corresponding base station 131-133. The domain agent 130 determines whether to allow the base station 131-133 to access the SAS 115 based on the policy, for example by comparing the information in the policy with the information in one or more mandatory fields of the request. The domain agent 130 selectively provides the request to the SAS 115, 116 depending on whether the base station 131-133 is allowed to access the SAS 115, 116. If so, the request is transmitted to the SAS 115, 116 or aggregated with other requests for transmission to the SAS 115, 116. Otherwise, the request is rejected.

[0057] The domain agent 130 monitors the connection with the geographically redundant SAS 115, 116 to determine whether the instance is available. As discussed herein, the geographically redundant SAS 115, 116 may become unavailable due to backhaul failures, natural disasters, DDOS attacks, or other situations. Therefore, the domain agent 130 is able to instantiate a local SAS that supports base stations 131-133 when the geographically redundant SAS is unavailable. In response to detecting the unavailability of the geographically redundant SAS 115, 116, the local SAS is configured to respond to heartbeat requests received from base stations 131-133. Some embodiments of the local SAS are also configured to provide information indicating valid channels in response to spectrum query messages received from base stations 131-133, and approve authorization requests for channels in the valid channel set. In response to the geographically redundant SAS 115, 116 becoming unavailable, the local SAS also attempts to establish communication with an environmental sensing capability (ESC, not shown in the figure for clarity). Figure 1 The actions of the local SAS depend on the frequency channels assigned to (or requested by) base stations 131-133, the presence or absence of an incumbent user, and whether the local SAS is able to establish a connection with the ESC, as discussed in detail below.

[0058] Figure 2 is a block diagram of a network function virtualization (NFV) architecture 200 according to some embodiments. The NFV architecture 200 is used to implement Figure 1 Some embodiments of the communication system 100 shown. For example, the NFV architecture 200 provides a method for implementing Figure 1 The physical resources of the domain agent 130 shown, as well as the physical resources used to instantiate local SAS and other instances of SAS 115, 116. The NFV architecture 200 includes hardware resources 201, which include computing hardware 202 such as one or more processors or other processing units, storage hardware 203 such as one or more memories, and network hardware 204 such as one or more transmitters, receivers, or transceivers. The virtualization layer 205 provides an abstract representation of the hardware resources 201. The abstract representation supported by the virtualization layer 205 can be managed using a virtualization infrastructure manager 210, which is part of the NFV management and orchestration (M&O) module 215. Some embodiments of the manager 210 are configured to collect and forward performance measurements and events that may occur in the NFV architecture 200. For example, performance measurements can be forwarded to an orchestrator (ORCH) 217 ​​implemented in the NFV M&O 215. The hardware resources 201 and the virtualization layer 205 may be used to implement virtual resources 220 including virtual computing 221 , virtual storage 222 , and virtual networking 223 .

[0059] The virtual networking functions (VNF1, VNF2, VNF3) run on the NFV infrastructure (e.g., hardware resources 201) and utilize virtual resources 220. For example, the virtual networking functions (VNF1, VNF2, VNF3) can be implemented using virtual machines supported by virtual computing resources 221, virtual storage supported by virtual storage resources 222, or virtual networks supported by virtual network resources 223. The element management system (EMS1, EMS2, EMS3) is responsible for managing the virtual networking functions (VNF1, VNF2, VNF3). For example, the element management system (EMS1, EMS2, EMS3) can be responsible for fault and performance management. In some embodiments, each virtual networking function (VNF1, VNF2, VNF3) is controlled by a corresponding VNF manager 225, which exchanges information with the manager 210 or the coordinator 217 and coordinates actions.

[0060] The NFV architecture 200 may include an operations support system (OSS) / business support system (BSS) 230. The OSS / BSS 230 uses OSS functions to handle network management, including fault management. The OSS / BSS 230 also uses BSS functions to handle customer and product management. Some embodiments of the NFV architecture 200 use a set of descriptors 235 to store descriptions of services, virtual network functions, or infrastructure supported by the NFV architecture 200. The information in the descriptors 235 can be updated or modified by the NFV M&O 215.

[0061] The NFV architecture 200 can be used to implement a network slice 240 that provides user plane or control plane functionality. A network slice 240 is a complete logical network that provides communication services and network capabilities (which may vary between slices). A user device can access multiple slices simultaneously. Some embodiments of the user device provide network slice selection auxiliary information (NSSAI) parameters to the network to help select a slice instance for the user device. A single NSSAI may result in the selection of multiple slices. The NFV architecture 200 may also use device capabilities, subscription information, and local operator policies to make a selection. NSSAI is a collection of smaller components (i.e., a single NSSAI (S-NSSAI)), each of which includes a slice service type (SST) and a possible slice distinguisher (SD). The slice service type refers to the expected network behavior in terms of features and services (e.g., specifically for broadband or large-scale IoT), while the slice distinguisher can help select between several network slice instances of the same type, for example, to separate services related to different services into different slices.

[0062] Figure 33 is a block diagram showing frequency band allocation 300 and access priority 301 for incumbent users, licensed users, and general access users according to some embodiments. Allocation 300 and access priority 301 are used to determine such as Figure 1 The CBSDs shown, such as base stations 131-133, are provided with permission to establish wireless communication links in various parts of the frequency band. The frequency band extends from 3550 MHz to 3700 MHz and therefore corresponds to the spectrum allocated to CBRS. Figure 1 The SAS 115, 116, etc. shown allocate portions of a frequency band to devices for providing wireless connections within a geographic area. For example, a SAS may allocate a 20-40 MHz portion of a frequency band to different devices for use as communication channels.

[0063] From block 305, portions of the frequency band are allocated to incumbent federal radiolocation equipment, such as naval vessels, corresponding to all frequencies in the available frequency band. From block 310, portions of the frequency band are allocated to incumbent FSS receive-only earth stations. From block 315, portions of the frequency band are allocated to grandfathered incumbent wireless broadband services. As discussed herein, from blocks 305, 310, 315, portions of the frequency band are allocated for exclusive use by incumbent users.

[0064] An operator that has received a priority access license (PAL) consistent with 47CFR§96.23 and other regulations is able to request the allocation of a portion of the frequency band in box 320. A portion of the frequency band allocated to an operator holding a PAL is available for exclusive use by the operator in the absence of any incumbent user in the overlapping frequency band and geographic area. For example, SAS can allocate a PAL channel in any part of the entire 150MHz CBRS band as long as the channel is not preempted by the existence of an incumbent user. The portion of the frequency band within box 325 can be used to allocate to a general authorized access (GAA) operator that is authorized to implement one or more CBSDs consistent with 47CFR§96.33 and other regulations. GAA operators provide wireless connections in the allocated portion without any incumbent user or PAL licensee in the overlapping frequency band and geographic area. If present, the GAA operator must also share the allocated portion with other GAA operators. According to the agreement defined by the Third Generation Partnership Project (3GPP), the portion of the frequency band within box 330 can be used for other users.

[0065] The access priority 301 indicates that the incumbent user has the highest priority 335. Therefore, the incumbent user is always granted exclusive access to the requested portion of the frequency band within the corresponding geographic area. The lower priority operator is required to vacate the portion of the frequency band allocated to the incumbent user within the geographic area. The access priority 301 indicates that the PAL licensee has the second highest priority 340, which indicates that the PAL licensee receives exclusive access to the allocated portion of the frequency band in the absence of any incumbent user. The PAL licensee also has the right to protection from interference from other PAL licensees within the defined time, geographic and frequency limits of its PAL. GAA operators (and in some cases, operators using other 3GPP protocols) receive the lowest priority 345. Therefore, the GAA operator is required to vacate the portion of the frequency band that overlaps with the portion of the frequency band allocated to the incumbent user or PAL licensee in the overlapping geographic area.

[0066] Figure 4 is a block diagram of a communication system 400 implementing layered spectrum access according to some embodiments. In the illustrated embodiment, the communication system 400 implements layered spectrum access in the 3550-3700 CBRS frequency band via the WINInForum architecture. The communication system 400 includes a SAS 405, which is for example for Figure 3 The CBRS channel shown performs operations including incumbent user interference determination and channel allocation. In the illustrated embodiment, SAS 405 is a primary SAS. FCC database 410 stores a frequency allocation table indicating frequencies allocated to incumbent users and PAL licensees. Notification of incumbent users 415 provides information indicating the presence of incumbent users to SAS405 (e.g., coverage areas associated with incumbent users, and allocated frequency ranges, time intervals, etc.). SAS 405 allocates other portions of the frequency range to provide exclusive access to notification incumbent users 415 within the coverage area. Environmental sensing capability (ESC) 420 performs incumbent user detection using a portion of the frequency range within a geographic area (e.g., using radar sensing equipment 425) to identify the incumbent user. Some embodiments of SAS 405 are connected to other SAS 430 via corresponding interfaces, so that SAS 405, 430 coordinate the allocation of portions of the frequency range within a geographic area or time interval. In the illustrated embodiment, SAS 430 is a secondary SAS that is geographically redundant with the primary SAS 415.

[0067] The domain agent 435 mediates the communication between the SAS 405 and one or more CBSDs 440, 445, 450 via corresponding interfaces. The domain agent 435 receives channel access requests from the CBSDs 440, 445, 450 and verifies whether the CBSDs 440, 445, 450 are allowed to request channel allocations from the SAS 405. The domain agent 435 forwards the request from the permitted CBSDs 440, 445, 450 to the SAS 405. As discussed herein, the domain agent 435 monitors the availability of the primary SAS 415 (and the availability of one or more geographically redundant SASs) and instantiates a local SAS in response to the primary SAS 415 and any geographically redundant SAS becoming unavailable. The local SAS selectively responds to heartbeat messages from the CBSDs 440, 445, 450.

[0068] In some embodiments, domain proxy 435 aggregates requests from licensed CBSDs 440, 445, 450 before providing the aggregated requests to SAS 405. Domain proxy 435 aggregates requests based on an aggregation function, which is a combination of two parameters: (1) the maximum number of requests that can be aggregated into a single message, and (2) the maximum wait time for the requests to arrive to be aggregated into a single message. For example, if the wait time is set to 300ms and the maximum number of requests is 500, the domain proxy accumulates received requests until the wait time reaches 300ms or the cumulative number of requests is 500 (whichever comes first). If only a single request arrives within the 300ms wait time, the "aggregate" message will include the single request.

[0069] Thus, from the perspective of the SAS 405, the domain proxy 435 acts as a single entity that hides or abstracts the presence of multiple CBSDs 440, 445, 450 and transmits communications between the SAS 405 and the CBSDs 440, 445, 450. One or more CBSDs 455 (only one is shown for clarity) are directly connected to the SAS 405 and can therefore transmit channel access requests directly to the SAS 405. Additional discussion of this architecture is provided in Appendix B (Wireless Innovation Forum (WinnForum), January 16, 2018, Version V1.4.130 of Working Paper WINNF-TS-0112, entitled "Requirements for Commercial Operation in the US3550-3700MHz Citizens Broadband Radio Service Band") (incorporated herein by reference in its entirety).

[0070] Figure 5is a block diagram of a communication system 500 that implements a spectrum controller cloud 505 to support the deployment of private enterprise networks in a shared spectrum in accordance with some embodiments. The spectrum cloud controller 505 instantiates a domain agent 510. In the illustrated embodiment, the domain agent is located on an edge cloud 512 to support mission control applications that require high network availability. In other embodiments, the domain agent 510 is implemented elsewhere in the communication system 500. For example, the domain agent 510 can be implemented as part of a regional cloud to manage one or more different edge cloud infrastructures. The domain agent 510 manages the edge cloud 512, which also includes a localized EPC core 514. The EPC core 514 provides functionality including LTE EPC operations support system (OSS) functionality, analysis such as business analysis for determining latency, and the like.

[0071] The spectrum controller cloud 505 instantiates multiple instances of domain agents 510 that support one or more private enterprise networks. The spectrum controller cloud 505 also instantiates multiple SAS instances 515 that support one or more private enterprise networks. Figure 5 505. Although not shown, the SAS instance 515 can be connected to other SAS instances in, for example, other clouds via corresponding interfaces. Some embodiments of the SAS instances 515 are geographically redundant with each other. Therefore, one of the SAS instances 515 can be selected as the primary SAS and another of the SAS instances 515 can be selected as the corresponding secondary SAS. Coexistence management (CXM) function 516 and spectrum analysis (SA) function 518 are also instantiated in the spectrum controller cloud 505.

[0072] One or more ESC instances 520 are instantiated and used to detect the presence of an incumbent user. In the illustrated embodiment, independent ESC sensors 521, 522, 523 (collectively referred to herein as "sensors 521-523") are used to monitor the frequency band to detect the presence of an incumbent user, such as a naval vessel adjacent to a port or harbor. The ESC instance 520 notifies the corresponding instance of the SAS 515 in response to detecting the presence of an incumbent user in the corresponding geographic area. The SAS 515 can then instruct non-incumbent devices serving the geographic area to vacate portions of the spectrum that overlap with the spectrum allocated to the incumbent user, for example by defining a DPA based on the frequency band in the geographic area reserved for the incumbent user.

[0073] One or more base stations 525, 526, 527 (collectively referred to herein as "base stations 525-527") in the private enterprise network communicate with one or more of the domain agent 510 and the SAS instance 515 via the evolved packet core (EPC) cloud 530. The base stations 525-527 have different operating properties. For example, base station 525 operates according to PAL in the 3.5 GHz band, base station 526 operates according to GAA in the 3.5 GHz band, and base station 525 operates according to PAL and GAA in the 3.5 GHz band. Base stations 525-527 are configured as Class A (indoor operation with a maximum power of 30 dBm), Class B (outdoor operation with a maximum power of 47 dBm), or CPE. However, in other embodiments, one or more of the base stations 525-527 are configured as Class A or Class B or CPE.

[0074] Figure 6 is a block diagram of a communication system 600 including an interface between a CBSD and a SAS 605 according to some embodiments. The SAS 605 is used to implement Figure 1 SAS115 shown, Figure 4 SAS 405, 430, and Figure 5 Some embodiments of an example of SAS 515 are shown. SAS 605 includes ports 610, 611, 612, 613 (collectively referred to herein as "ports 610-613") that provide access to SAS 605. In the illustrated embodiment, SAS 605 is selected as the primary SAS.

[0075] Interface 620 supports communication between SAS 605 and CBSDs 625, 630 via a network such as the Internet 635 and ports 610, 611. CBSD 625 is directly connected to SAS 605 via interface 620. CBSD 630 is connected to SAS 605 via domain proxy 640, which is connected to SAS 605 through interface 620. Domain proxy 640 corresponds to Figure 1 The domain proxy 130 shown, Figure 4 The domain proxy 435 shown, and Figure 5 The interface 645 supports communication between the SAS 605 and one or more other SASs 650, 651 (represented in Figure 6 for clarity) via a network such as the Internet 655 and port 612. Figure 6 SAS 650 may be owned and operated by other providers. Some embodiments of SAS 650, 651 are selected as secondary SAS to support primary SAS 605. Interface 660 supports communication between SAS 605 and one or more other networks 665 (shown in Figure 6 for clarity) via port 613. Figure 6 Only one of the communications is shown.

[0076] Figure 7 It is a block diagram of a communication system 800 for implementing a primary SAS instance 805 and a secondary SAS instance 810 according to some embodiments. The primary SAS instance 805 and the secondary SAS instance 810 are implemented in corresponding geographic redundant regional clouds 815, 820. The primary SAS instance 805 and the secondary SAS instance 810 are accessed via corresponding ports using broadcast or publicly available IP addresses. The visibility of the IP addresses for identifying the geographical redundant primary SAS instance 805 and the secondary SAS instance 810 makes it vulnerable to malicious attacks, such as DDOS attacks, which may make the geographical redundant primary SAS instance 805 and the secondary SAS instance 810 inaccessible, unreachable or otherwise unavailable. Due to backhaul failures and other events, the primary SAS instance 805 and the secondary SAS instance 810 may also become unavailable.

[0077] The communication system 800 includes CBSDs such as base stations 835, 840, which are connected to an edge cloud 845 such as Figure 1 The edge cloud 125 shown in FIG. Base stations 835, 840 are connected to a domain proxy 850, such as Figure 1 The domain proxy 130 shown aggregates traffic and instantiates a local SAS 855, as discussed herein. The local SAS 855 is not published on external networks and is therefore less vulnerable to attacks such as DDOS attacks. The edge cloud 845 is interconnected with the regional clouds 815, 820, for example, using a backhaul network (not shown for clarity). Figure 7 ).

[0078] The primary SAS instance 805 and the secondary SAS instance 810 establish a connection with the ESC cloud 860 that provides ESC services, for example, notifying the primary SAS instance 805 and the secondary SAS instance 810 when an incumbent user is detected in a DPA that overlaps with the geographic area served by the primary SAS instance 805 and the secondary SAS instance 810. The domain agent 850 (or one of the base stations 835, 840) registers with one of the SAS instances 805, 810 as the primary SAS instance, and uses the other of the SAS instances 805, 810 as a geographically redundant secondary SAS instance. In the illustrated embodiment, the domain agent 850 establishes a connection 865 with the primary SAS 805, and the domain agent establishes a connection 870 with the secondary SAS 810. The domain agent 850 begins exchanging heartbeat messages with the primary SAS instance 805.

[0079] The domain agent 850 is configured to monitor the business with all available geographically redundant SAS instances (including the primary SAS instance 805 and the secondary SAS instance 810) to perform a seamless switch to the secondary SAS instance 810 when the domain agent 850 detects that the connection with the primary SAS 805 is interrupted for any reason to ensure the high availability of the private enterprise network. In addition, if the edge cloud 845 loses connection with all geographically redundant SAS instances 805, 810, the domain agent 850 switches to the local SAS instance 855 to extend network availability, for example, beyond the currently specified 4 minutes (240 seconds). The domain agent 850 also attempts to establish a connection 875 to the ESC cloud 860 to ensure high availability for deployments along the coastline or other geographic areas that fall under the control of the DPA, which requires ESC services to operate in the lower 100MHz of the CBRS band.

[0080] Figure 8 is a flow chart of a method 900 for instantiating and configuring a local SAS instance on a domain proxy according to some embodiments. Figure 1 The communication system 1 and Figure 7 Some of the illustrated embodiments of the communication system 8 are implemented in other embodiments of the domain proxy discussed herein.

[0081] At block 905, the domain agent instantiates a local SAS and then uses one or more geographically redundant instances of the SAS (such as Figure 7 The local SAS is configured using the information provided by the geographically redundant SAS instances 805, 810 shown. Once configured, the local SAS is able to configure the CBSD in the edge cloud including the domain proxy and respond to the heartbeat and other messages from the CBSD, as discussed herein.

[0082] At box 910, one or more geographically redundant SAS instances generate backup channel information for a CBSD associated with a domain agent. In some embodiments, the geographically redundant SAS instance generates the backup channel information, which takes into account the presence of other CBSDs managed by the SAS instance in the same geographic region associated with other providers. The backup channel indicated by the backup channel information is located in the upper 50 MHz or lower 100 MHz of the CBRS band. If the backup channel is located in the lower 100 MHz within the DPA, the geographically redundant instance of the SAS selects a backup channel that is spatially separated from the originally authorized channel by an amount determined by the characteristics of the incumbent user. For example, the geographically redundant instance of the SAS may select a backup channel that is more than 20 MHz away from the primary channel because naval radar systems typically affect up to 20 MHz in the lower 100 MHz of the CBRS band.

[0083] At block 915 , the geographically redundant instance of the SAS provides the backup channel information to the domain proxy, which stores the backup channel information in a database indicating valid channels used by the CBSDs in the edge cloud.

[0084] At block 920, the geographically redundant instance of the SAS provides additional status information to the domain agent. In some embodiments, the status information includes status information obtained during exchanges with other SAS instances, for example, via a mesh network. The exchanges are performed at predetermined time intervals, such as once every 24 hours. The status information includes credentials used by the local SAS to establish a connection with the ESC cloud, information identifying DPAs that overlap in frequency or geographic area with a frequency or geographic area associated with the edge cloud, an indication of whether there is an incumbent user in one of the DPAs, status information of other CBSDs adjacent to the CBSD in the edge cloud, channel and power assignments of the CBSD determined based on the status information, and the like.

[0085] At block 925, the domain agent begins monitoring the connection to the geographically redundant instance of the SAS to determine whether the instance is available or accessible. As discussed herein, the domain agent switches to the local SAS in response to the geographically redundant instance of the SAS becoming unavailable or inaccessible.

[0086] Fig. 9 is a flow chart of a method 1000 for operating a local SAS implemented in a domain proxy according to some embodiments. Figure 1 The communication system 1 and Figure 7 Some embodiments of the communication system 8 shown are implemented in other embodiments of the domain proxy discussed herein.The domain proxy performs an embodiment of method 1000 in response to the domain proxy determining that a geographically redundant instance of a SAS supporting the domain proxy is unavailable or inaccessible.

[0087] The domain proxy switches from the geographically redundant instance of the SAS to a local SAS implemented in the domain proxy at block 1005. As discussed herein, the domain proxy switches to the local SAS in response to determining that the geographically redundant instance of the SAS is unavailable or inaccessible.

[0088] At block 1010, the local SAS attempts to establish a connection with the ESC cloud using credentials previously provided by one of the geographically redundant instances of the SAS. If the edge cloud hosting the domain proxy is located in or overlaps with the DPA, the local SAS system establishes a connection. If the local SAS successfully establishes a connection, the ESC cloud provides information indicating the frequency band, geographic region, and presence information for the incumbent user associated with the DPA.

[0089] At decision block 1015 , the local SAS determines whether the connection was successfully established. If so, the method 1000 proceeds to block 1020 . If the local SAS fails to establish a connection with the ESC cloud, the method 1000 proceeds to decision block 1025 .

[0090] In box 1020, the local SAS responds to heartbeats and other messages received from a CBSD in the edge cloud associated with the domain agent. In some embodiments, the local SAS continues to send grant permission OK responses to heartbeat requests from CBSDs controlled by it on the edge cloud network. If the CBSD sends a spectrum query message, the local SAS responds by sending a response indicating valid channels available to the CBSD, for example, as a valid channel set. If the CBSD sends an authorization request for a channel in the valid channel set, the local SAS responds by sending a message to the CBSD authorizing the channel. If the channel is not in the valid channel set, the local SAS responds by sending a message denying the CBSD access to the channel.

[0091] At decision block 1025, the local SAS determines whether the edge cloud is located in or overlaps with the DPA. In some embodiments, the local SAS determines whether the edge cloud is located in or overlaps with the DPA based on information provided to the local SAS by the geographically redundant instance of the SAS before the geographically redundant instance of the SAS became unavailable or inaccessible. If the edge cloud is not located in or overlaps with the DPA, the method 100 proceeds to block 1020. Otherwise, the method proceeds to decision block 1030.

[0092] At decision block 1030, the local SAS determines whether a backup channel in the upper 50 MHz of the CBRS band is available when a connection cannot be established with the ESC cloud. For example, a geographic redundant instance of the SAS may have provided a backup channel in the upper 50 MHz of the CBRS band for use by the CBSD, as discussed herein. If a backup channel is available, the method 1000 proceeds to block 1035 and the local SAS instructs the CBSD to switch to the backup channel. If no backup channel is available, the method 1000 proceeds to block 1040.

[0093] At block 1040, the local SAS (also the DPA-enabled SAS) assumes that incumbents exist throughout the lower 100 MHz of the CBRS band and attempts to calculate channel grants and transmit powers for each CBSD based on its type (Class A or Class B), antenna height, tile, distance to the ESC sensor, and coastline. If the DPA-enabled SAS successfully finds the appropriate channel grant and transmit power to safely operate the CBSD in DPA without connecting to the ESC cloud, it will relay it to the CBSD in an attempt to keep the private enterprise network operating normally even after losing connectivity to the regional SAS for a period of more than 4 minutes (240 seconds).

[0094] Fig.10 is a flow chart of a method 1100 for granting authority to a backup channel in response to the presence of an incumbent user in a DPA associated with a domain agent implementing a local SAS, according to some embodiments. Figure 1 The communication system 1 and Figure 7 Some embodiments of the communication system 8 shown are implemented in other embodiments of the domain proxy discussed herein.The domain proxy performs an embodiment of method 1100 in response to the domain proxy determining that a geographically redundant instance of a SAS supporting the domain proxy is unavailable or inaccessible.

[0095] At block 1105 , the local SAS successfully establishes a connection with the ESC cloud using the credentials provided by the (currently unavailable or inaccessible) geo-redundant instance of the SAS.

[0096] At block 1110, the local SAS receives a report from the ESC cloud indicating that there is an incumbent user in a DPA that overlaps with the edge cloud. The local SAS determines that the CBSD served by the local SAS is operating on a primary channel that overlaps with a channel defined by the DPA. For example, the local SAS determines that the primary channel authorized to the CBSD is affected by the presence of an incumbent user.

[0097] At block 1115, the local SAS sends a heartbeat response message to revoke the channel authorization provided to the CBSD for the primary channel, and forces or instructs the CBSD to enter the backup channel for operation.

[0098] At decision block 1125, the local SAS determines whether the backup channel is a valid channel for use by the CBSD. In some embodiments, the local SAS previously stored information indicating a valid backup channel identified by a geographic redundant instance of the SAS and provided to the local SAS. If the backup channel is valid and is not affected by the presence of an incumbent user, the method 1100 proceeds to block 1130 and the local SAS sends a heartbeat response that grants permission for the backup channel for use by the CBSD. If the backup channel is not available or is in the lower 100 MHz of the CBRS band and is also affected by the presence of an incumbent user, the method 1100 proceeds to block 1135.

[0099] At block 1135, the local SAS, which is also a DPA-enabled SAS, assumes that incumbents exist throughout the lower 100 MHz of the CBRS band and attempts to calculate channel grants and transmit powers for each CBSD based on its type (Class A or Class B), antenna height, tile, distance from the ESC sensor, and proximity to the coastline. If the DPA-enabled SAS successfully finds the appropriate channel grants and transmit powers to safely operate the CBSD in DPA when not connected to the ESC cloud, the DPA-enabled SAS relays this information to the CBSD to attempt to keep the private enterprise network operating normally even after losing connectivity to the regional SAS for a period of more than 4 minutes (240 seconds).

[0100] Some embodiments of the local SAS operate in a hold mode for a predetermined time interval (such as 24 hours), which is determined by the time interval between SAS-SAS message exchanges for exchanging status information. For example, all SASs download data from the FCC, WINNFORUM database, and peer SAS every 24 hours. The message exchange allows the SAS instance to obtain and distribute CBSD data for newly registered CBSDs, and delete data related to unregistered CBSDs. The message exchange also distributes data for new incumbent users and static incumbent users (such as FSS, GW, new portal DPA, etc.). In some embodiments, SAS instances from all suppliers are connected in a mesh configuration, and the SAS instances exchange status information of their CBSDs via a SAS to SAS interface. However, the local SAS instantiated by the domain agent on the edge cloud is not connected to the SAS instances of other suppliers.

[0101] SAS regional instances operated by different providers perform a coordinated periodic activity (CPAS) between SASs every 24 hours by exchanging state information of the CBSDs they are managing. The SAS instances use the exchanged state information to calculate or update the channel and power assignments of the CBSDs based on new snapshots of the CBSDs managed by all SAS instances from all SAS administrators. Considering the properties of different CBSDs allows each instance of the SAS to appropriately protect the incumbent user via accurate interference calculations performed based on the state information of all CBSDs deployed in the geographic area. If the CBSD in the edge cloud network belongs to the DPA, in addition to the primary channel authorization, the instance of the SAS also calculates a backup channel authorization list for the CBSD. As discussed in this article, information indicating the backup channel authorization list is relayed to the local SAS instantiated by the domain agent on the edge cloud. The local SAS stores the backup channel authorization in case the incumbent user appears when the regional instance of the SAS is inaccessible, and the primary channel authorization is affected by the appearance of the incumbent user in the lower 100MHz.

[0102] If the edge cloud belongs to the DPA, the regional instance of the SAS also relays the login credentials to the domain proxy in the edge cloud. As discussed in this article, the login credentials are used to establish a connection with the ESC cloud so that if the domain proxy loses connection with all regional instances of the SAS, the local SAS can receive services from the ESC region. The local SAS on the domain proxy uses the incumbent user and backup channel authorization information to grant permission or deny requests in the heartbeat REQ-RESP from the CBSD. The local SAS allows the CBSD to stay on air even if the connection to the regional geo-redundant instance of the SAS is interrupted and the incumbent user appears and affects the current channel authorization.

[0103] The results obtained from the CPAS are valid for a predetermined time interval, such as 24 hours. By computing all possible (primary and backup channel authorizations) for CBSDs in a given edge cloud network, and relaying the channel authorization list to the local SAS on the domain proxy, embodiments of the technology disclosed herein ensure that if connectivity to all geographically redundant instances of the SAS on the regional cloud is lost, the local SAS instance on the domain proxy on the edge cloud has access to the information required to keep the network operating normally for up to 24 hours (not just 4 minutes as per CBRS rules). The local SAS also uses state information to move CBSDs operating in the lower 100MHz to an idle 3650-3700 timeslot in the event that both the geographically redundant instances of the SAS and the ESC network go offline. In some embodiments, the state information stored in the local SAS does not change significantly, which allows the local SAS to continue to respond to heartbeat messages from the CBSD and keep the CBSD online for time intervals exceeding 24 hours, and in some cases, indefinitely.

[0104] In some embodiments, certain aspects of the above-mentioned technology can be implemented by one or more processors of a processing system that executes software. The software includes one or more sets of executable instructions stored or tangibly embodied on a non-transitory computer-readable storage medium. The software may include instructions and certain data that manipulate one or more processors to perform one or more aspects of the above-mentioned technology when executed by one or more processors. Non-volatile computer-readable storage media may include, for example, magnetic or optical disk storage devices, solid-state storage devices such as flash memory, caches, random access memories (RAM), or one or more other non-volatile storage devices, etc. The executable instructions stored on the non-transitory computer-readable storage medium may be source code, assembly language code, object code, or other instruction formats that are interpreted or otherwise executable by one or more processors.

[0105] Computer-readable storage media may include any storage media or combination of storage media that a computer system can access during use to provide instructions and / or data to the computer system. Such storage media may include, but are not limited to, optical media (e.g., compact disks (CDs), digital versatile disks (DVDs), Blu-ray disks), magnetic media (e.g., floppy disks, tapes, or magnetic hard drives), volatile memory (e.g., random access memory (RAM) or cache), non-volatile memory (e.g., read-only memory (ROM) or flash memory), or micro-electromechanical system (MEMS)-based storage media. Computer-readable storage media may be embedded in a computing system (e.g., system RAM or ROM), fixedly attached to a computing system (e.g., a magnetic hard drive), removably attached to a computing system (e.g., an optical disk or flash memory based on a universal serial bus (USB)), or coupled to a computer system via a wired or wireless network (e.g., a network accessible storage (NAS)).

[0106] As used herein, the term "circuitry" may refer to one or more or all of the following:

[0107] a) hardware circuit implementation only (such as implementation of only analog and / or digital circuitry) and

[0108] b) a combination of hardware circuitry and software such as (where applicable):

[0109] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0110] (ii) any portion of a hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions) and

[0111] c) (multiple) hardware circuits and / or (multiple) processors, such as (multiple) microprocessors or portions of (multiple) microprocessors, which require software (e.g. firmware) to operate, but where the software is not required for operation, the software may not be present.

[0112] This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and where applicable to a particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0113] Note that not all of the above activities or elements in the general description are required, a portion of a particular activity or device may not be required, and one or more other activities may be performed, or other elements may be included in addition to the described elements. Furthermore, the order in which the activities are listed is not necessarily the order in which the activities are performed. Moreover, the concepts have been described with reference to specific embodiments. However, it will be appreciated by those of ordinary skill in the art that various modifications and changes may be made without departing from the scope of the present disclosure as set forth in the appended claims. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive, and all such modifications are intended to be included within the scope of the present disclosure.

[0114] Benefits, other advantages and solutions to problems have been described above with respect to specific embodiments. However, benefits, advantages, solutions to problems, and any features that may cause any benefit, advantage or solution to appear or become more obvious should not be interpreted as key, essential or necessary features of any or all claims. In addition, the specific embodiments disclosed above are merely illustrative, because the disclosed subject matter can be modified and practiced in different but equivalent ways that are clear to those skilled in the art who benefit from the teachings herein. Except as described in the claims below, there is no intention to limit any details of the construction or design shown herein. Therefore, it is clear that the specific embodiments disclosed above can be changed or modified, and all such changes are considered to be within the scope of the disclosed subject matter. Therefore, the protection sought herein is as described in the following claims.

Claims

1. A domain proxy device, comprising: A processor configured to aggregate traffic of base stations in the private enterprise network and instantiate a local spectrum access system SAS; as well as a transceiver configured to monitor communications with a geographically redundant instance of the SAS external to the domain agent, the geographically redundant instance allocating frequency bands in a shared spectrum to the base station, wherein the processor is configured to switch from the geographically redundant instance of the SAS to the local SAS in response to the geographically redundant instance of the SAS becoming unavailable, and The local SAS is configured to respond to a heartbeat message from the base station.

2. The apparatus of claim 1, wherein the local SAS is configured to provide information indicating valid channels in response to a spectrum query message received from the base station, and approve a grant request from the base station for a channel in the valid channel set.

3. The apparatus of claim 1, wherein the local SAS is configured to attempt to establish a connection with an environment sensing capability (ESC) in response to the geographically redundant instance of the SAS becoming unavailable.

4. An apparatus according to claim 3, wherein the local SAS determines whether the connection with the ESC has been established, and whether a first geographical area and a first channel in the shared spectrum served by the base station overlap with a dynamic protection area DPA defined by a second geographical area and a portion of the shared spectrum allocated to an incumbent user.

5. The apparatus of claim 4, wherein the local SAS is configured to instruct the base station to switch to a second channel if the connection with the ESC is not established and if the first geographic area and the first channel overlap with the DPA.

6. The apparatus of claim 5, wherein the second channel is calculated by at least one of the geographic redundancy instances of the SAS based on presence information for the base station and other base stations managed by other SAS providers proximate to the first geographic area. 7 . The apparatus of claim 6 , wherein the second channel is spatially separated from the first channel by a frequency determined based on attributes of the incumbent user.

8. The apparatus of claim 4, wherein in response to determining that the connection with the ESC is established and in response to the ESC reporting the presence of the incumbent user on the first channel, the local SAS sends a heartbeat response to the base station, the heartbeat response revoking authorization of the first channel.

9. The apparatus of claim 8, wherein the local SAS authorizes the base station to access the second channel in response to receiving a message indicating a second channel after transmission of the heartbeat message revoking the authorization of the first channel, and wherein the local SAS authorizes the base station to access the second channel in response to the second channel being previously provided to the local SAS by at least one of the geographically redundant instances of the SAS.

10. The apparatus of claim 5, wherein the local SAS is configured to respond to the heartbeat message from the base station within a time interval determined based on a predetermined time interval for exchanging status information between peer instances of the SAS.

11. The apparatus of claim 10, wherein the geographic redundant instance of the SAS determines channel and power assignments for the base station based on the status information, and wherein the channel and power assignments are valid for the predetermined time interval.

12. The apparatus of claim 11, wherein the local SAS receives the status information from at least one of the geographically redundant instances of the SAS, and wherein the local SAS receives information indicating the second channel and login credentials for the ESC.

13. A domain proxy method, comprising: aggregating, at the domain proxy, traffic for base stations in the private enterprise network; Instantiating a local spectrum access system SAS at the domain agent; monitoring, at the domain proxy, communications with a geographically redundant instance of the SAS external to the domain proxy, the geographically redundant instance allocating frequency bands in a shared spectrum to the base station; switching at the domain proxy from the geographically redundant instance of the SAS to the local SAS in response to the geographically redundant instance of the SAS becoming unavailable, and A response is made from the local SAS to a heartbeat message from the base station.

14. The method according to claim 13, further comprising: In response to the geographically redundant instance of the SAS becoming unavailable, an attempt is made to establish a connection between the local SAS and an environment sensing capability (ESC).

15. The method according to claim 14, further comprising: Determine at the local SAS whether the connection with the ESC has been established, and whether a first geographic area and a first channel in the shared spectrum served by the base station overlap with a dynamic protection area DPA defined by a second geographic area and a portion of the shared spectrum allocated to an incumbent user.

16. The method according to claim 15, further comprising: instructing the base station at the local SAS to switch to a second channel if the connection with the ESC is not established and if the first geographic area and the first channel overlap with the DPA; wherein the second channel is calculated by at least one of the geographic redundancy instances of the SAS based on presence information for the base station and other base stations managed by other SAS providers proximate to the first geographic area; The second channel is spatially separated from the first channel by a frequency determined based on the attributes of the current user.

17. The method according to claim 15, further comprising: In response to determining that the connection with the ESC is established and in response to the ESC reporting the presence of an incumbent user on the first channel, a heartbeat response is sent from the local SAS to the base station, the heartbeat response revoking authorization of the first channel.

18. The method according to claim 17, further comprising: In response to receiving a message indicating a second channel after transmission of the heartbeat message revoking the authorization of the first channel and in response to the second channel being previously provided to the local SAS by at least one of the geographically redundant instances of the SAS, authorizing the base station at the local SAS to access the second channel.

19. The method according to claim 16, further comprising: responding from the local SAS to the heartbeat message from the base station for a time interval determined based on a predetermined time interval for exchanging status information between peer instances of the SAS; receiving, at the local SAS, status information of at least one of the geographically redundant instances of the SAS; as well as Information indicative of the second channel and login credentials for the ESC is received at the local SAS.

20. A domain proxy device, comprising: at least one processor; as well as at least one memory including computer program code; The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus to at least perform: Aggregate services for base stations in private enterprise networks; Instantiate the local spectrum access system SAS; monitoring communications with a geographically redundant instance of the SAS external to the domain proxy, the geographically redundant instance allocating frequency bands in a shared spectrum to the base station; switching from the geographically redundant instance of the SAS to the local SAS in response to the geographically redundant instance of the SAS becoming unavailable, and Responding to a heartbeat message from the base station.

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