APPARATUS AND METHODS FOR INTERFERENCE MANAGEMENT IN A QUASI-LICENSED WIRELESS SYSTEM
20230044092 · 2023-02-09
Inventors
Cpc classification
H04W16/14
ELECTRICITY
International classification
H04W16/14
ELECTRICITY
Abstract
Apparatus and methods for providing interference management and load balancing in a wireless network. In one embodiment, the method and apparatus utilize quasi-licensed CBRS (Citizens Broadband Radio Service) wireless spectrum in conjunction with enhanced SAS (Spectrum Access System) and base station (e.g., CBSD) components to enable creation and management of virtual clusters of bases stations connected to the network, so as to enable inter-cluster interference mitigation, while also supporting load balancing between the base stations using coverage area overlap. In one implementation, the SAS reduces the coverage area (transmit power) of one or more base stations on a cluster edge to mitigate inter-cluster interference, and increases or adjusts the coverage of one or more base stations inside of the cluster to enable load balancing.
Claims
1-20. (canceled)
21. Wireless access point apparatus for use within a wireless network, comprising: radio frequency interface apparatus; digital processor apparatus in data communication with the radio frequency interface apparatus; and computer readable apparatus in data communication with the digital processor apparatus and comprising storage medium, the storage medium comprising at least one computer program comprising a plurality of instructions which are configured to, when executed on the digital processor apparatus, cause the wireless access point apparatus to: generate and transmit a message to a network entity to notify its participation in a computerized optimization process; establish a connection with one or more neighboring wireless access point apparatus; generate and transmit at least one first message to one or more user devices utilizing the wireless access point apparatus to obtain and report data relating to other wireless access point apparatus; and generate and transmit at least one second message to the network entity, the at least one second message comprising at least a portion of the reported data relating to the other wireless access point apparatus.
22. The wireless access point apparatus of claim 21, wherein: the computerized optimization process comprises an inter-wireless access point apparatus load balancing process; and the at least portion of the reported data relating to the other wireless access point apparatus enables the network entity to create one or more virtual groupings or clusters of wireless access point apparatus within the wireless network, the one or more virtual groupings or clusters enabling performance of said inter-wireless access point apparatus load balancing process.
23. The wireless access point apparatus of claim 22, wherein: the wireless access point apparatus comprises a CBRS (Citizens Broadband Radio Service) compliant Citizens Broadband Radio Service Device (CBSD), and the inter-wireless access point apparatus load balancing process comprises inter-CBSD load balancing between two frequency bands each between 3.550 GHz and 3.700 Ghz, the two frequency bands assigned to respective ones of two CBSDs participating in the inter-wireless access point apparatus load balancing process.
24. The wireless access point apparatus of claim 23, wherein the network entity comprises either (i) a SAS (spectrum allocation system) in data communication with the wireless network, or (ii) a SAS proxy entity within the wireless network.
25. The wireless access point apparatus of claim 24, wherein: the network entity comprises the SAS proxy entity within the wireless network; and the SAS proxy entity, the wireless access point apparatus, and the other wireless access point apparatus are each operated by a common managed network operator.
26. The wireless access point apparatus of claim 21, wherein the reported data relating to other wireless access point apparatus comprises at least one of PCI (physical cell identifier) or transmit power associated with an individual one of a plurality of sectors of at least one of the other ones of wireless access points.
27. The wireless access point apparatus of claim 21, wherein: the wireless network comprises a wireless network utilizing 3GPP (Third Generation Partnership Project) 4G (fourth Generation) Long Term Evolution or 5G (Fifth Generation) New Radio compliant infrastructure utilizing Citizens Broadband Radio Service (CBRS) spectrum within a frequency range of 3.550 GHz to 3.700 GHz; and the network entity comprises a CBRS SAS (spectrum allocation system).
28. A method of operating a base station within a wireless network, the method comprising: transmitting data relating to a location of the base station to a computerized base station management process; establishing at least one communication channel between the base station and one or more geographically proximate base stations; obtaining data from the one or more geographically proximate base stations via the at least one communication channel; causing provision of at least a portion of the obtained data to the computerized base station management process; receiving, from the computerized base station management process, network data relating to one of increasing or decreasing a transmission power of the base station, the network data relating to the one of increasing or decreasing derived based at least on the at least portion of the obtained data provided to the computerized base station management process; and causing adjustment of the transmission power of the base station based at least on the network data.
29. The method of claim 28, further comprising notifying the computerized base station management process that the base station intends to participate in a load balancing process controlled by the wireless network.
30. The method of claim 28, further comprising receiving, from the computerized base station management process, data indicating that the base station must participate in a load balancing process controlled by the wireless network.
31. The method of claim 28, wherein: the base station comprises a base station disposed on an edge of a virtual cluster formed by the computerized base station management process; and the receiving, from the computerized base station management process, of the network data relating to the one of increasing or decreasing of the transmission power of the base station, comprises receiving data relating to a decreasing of the transmission power to reduce interference with another base station.
32. The method of claim 28, wherein: the base station comprises a base station disposed on a non-edge portion of a virtual cluster formed by the computerized base station management process; and the receiving, from the computerized base station management process, of the network data relating to the one of increasing or decreasing of the transmission power of the base station, comprises receiving data relating to an increasing of the transmission power to compensate for a loss of coverage area within the virtual cluster based on a transmission power reduction of another base station within the virtual cluster.
33. The method of claim 28, wherein the establishing of the at least one communication channel between the base station and the one or more geographically proximate base stations comprises: causing one or more user devices in data communication with the base station to detect identifying data associated with each of the one or more geographically proximate base stations; receiving at least a portion of the detected identifying data associated with each of the one or more geographically proximate base stations; transmitting at least a portion of the received at least portion of the detected identifying data to the computerized base station management process; and receiving, from the computerized base station management process, data indicative of network addresses of one or more base stations associated with the transmitted at least portion of the received at least portion of the detected identifying data.
34. A method for traffic load balancing among base stations connected to a wireless network, the method comprising: identifying a plurality of base stations; transmitting data relating to the plurality of base stations to a computerized network process; utilizing the computerized network process to determine a radio frequency (RF) interference condition between two or more of the plurality of base stations; and causing one or more power adjustments to mitigate the RF interference condition while permitting load balancing between two or more of the plurality of base stations.
35. The method of claim 34, wherein the identifying of the plurality of base stations comprises identifying a plurality of base stations participating in a load balancing process; and the method further comprises: creating one or more virtual clusters from the plurality of base stations participating in the load balancing process; identifying one or more of the plurality of base stations at an edge of the one or more virtual clusters creating interference on one or more neighboring virtual clusters; and enabling a mechanism to mitigate an effect of the interference from the one or more of the plurality of base stations at the edge of the one or more virtual clusters on the one or more neighboring virtual clusters while preserving a level of coverage area overlap thereof.
36. The method of claim 35, further comprising causing each of the plurality of base stations participating in the load balancing process to transmit identification data to a Citizens Broadband Radio Service (CBRS) spectrum access system (SAS).
37. The method of claim 36, further comprising causing each of the plurality of base stations participating in the load balancing process to instruct served client devices thereof to report physical cell identity (PCI) data of other ones of the plurality of bases stations participating in the load balancing process which the respective served client devices can detect, the PCI data enabling the CBRS SAS to create a virtual network overlap map from at least the reported PCI data.
38. The method of claim 35, wherein the utilizing of the network process to determine the RF interference condition between the two or more of the plurality of base stations comprises: estimating interference at one or more clusters edges by at least selecting an interference model; and computing a transmission power from the interference model which affects the one or more neighboring virtual clusters by the one or more of the plurality of base stations at the edge of the one or more virtual clusters.
39. The method of claim 38, wherein the enabling of the mechanism to mitigate the effect of the interference from the one or more of the plurality of base stations at the cluster edge on the one or more neighboring virtual clusters comprises: causing a reduction in the transmission power for the one or more of the plurality of base stations at the cluster edge; and causing an increase in the transmission power for one or more base stations within the one or more neighboring virtual clusters to increase coverage thereof in order to compensate for reduced coverage of the one or more of the plurality of base stations at the cluster edge.
40. The method of claim 35, further comprising dynamically updating location information of the plurality of base stations to the computerized network process.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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[0105] All figures © Copyright 2019-2020 Charter Communications Operating, LLC. All rights reserved.
DETAILED DESCRIPTION
[0106] Reference is now made to the drawings wherein like numerals refer to like parts throughout.
[0107] As used herein, the term “access node” refers generally and without limitation to a network node which enables communication between a user or client device and another entity within a network, such as for example a CBRS CBSD, FWA, or Wi-Fi AP.
[0108] As used herein, the term “application” (or “app”) refers generally and without limitation to a unit of executable software that implements a certain functionality or theme. The themes of applications vary broadly across any number of disciplines and functions (such as on-demand content management, e-commerce transactions, brokerage transactions, home entertainment, calculator etc.), and one application may have more than one theme. The unit of executable software generally runs in a predetermined environment; for example, the unit could include a downloadable Java Xlet™ that runs within the JavaTV™ environment.
[0109] As used herein, the term “CBRS” refers without limitation to the CBRS architecture and protocols described in Signaling Protocols and Procedures for Citizens Broadband Radio Service (CBRS): Spectrum Access System (SAS) - Citizens Broadband Radio Service Device (CBSD) Interface Technical Specification - Document WINNF-TS-0016, Version V1.2.1. 3, January 2018, incorporated herein by reference in its entirety, and any related documents or subsequent versions thereof.
[0110] As used herein, the terms “client device” or “user device” or “UE” include, but are not limited to, set-top boxes (e.g., DSTBs), gateways, modems, CBRS FWAs, personal computers (PCs), and minicomputers, whether desktop, laptop, or otherwise, and mobile devices such as handheld computers, PDAs, personal media devices (PMDs), tablets, “phablets”, smartphones, and vehicle infotainment systems or portions thereof.
[0111] As used herein, the term “computer program” or “software” is meant to include any sequence or human or machine cognizable steps which perform a function. Such program may be rendered in virtually any programming language or environment including, for example, C/C++, Fortran, COBOL, PASCAL, assembly language, markup languages (e.g., HTML, SGML, XML, VoXML), and the like, as well as object-oriented environments such as the Common Object Request Broker Architecture (CORBA), Java™ (including J2ME, Java Beans, etc.) and the like.
[0112] As used herein, the term “DOCSIS” refers to any of the existing or planned variants of the Data Over Cable Services Interface Specification, including for example DOCSIS versions 1.0, 1.1, 2.0, 3.0, 3.1 and 4.0.
[0113] As used herein, the term “headend” or “backend” refers generally to a networked system controlled by an operator (e.g., an MSO) that distributes programming to MSO clientele using client devices. Such programming may include literally any information source/receiver including, inter alia, free-to-air TV channels, pay TV channels, interactive TV, over-the-top services, streaming services, and the Internet.
[0114] As used herein, the terms “Internet” and “internet” are used interchangeably to refer to inter-networks including, without limitation, the Internet. Other common examples include but are not limited to: a network of external servers, “cloud” entities (such as memory or storage not local to a device, storage generally accessible at any time via a network connection, and the like), service nodes, access points, controller devices, client devices, etc.
[0115] As used herein, the term “LTE” refers to, without limitation and as applicable, any of the variants or Releases of the Long-Term Evolution wireless communication standard, including LTE-U (Long Term Evolution in unlicensed spectrum), LTE-LAA (Long Term Evolution, Licensed Assisted Access), LTE-A (LTE Advanced), and 4G/4.5G LTE.
[0116] As used herein, the term “memory” includes any type of integrated circuit or other storage device adapted for storing digital data including, without limitation, ROM, PROM, EEPROM, DRAM, SDRAM, DDR/2 SDRAM, EDO/FPMS, RLDRAM, SRAM, “flash” memory (e.g., NAND/NOR), 3D memory, and PSRAM.
[0117] As used herein, the terms “microprocessor” and “processor” or “digital processor” are meant generally to include all types of digital processing devices including, without limitation, digital signal processors (DSPs), reduced instruction set computers (RISC), general-purpose (CISC) processors, microprocessors, gate arrays (e.g., FPGAs), PLDs, reconfigurable computer fabrics (RCFs), array processors, secure microprocessors, and application-specific integrated circuits (ASICs). Such digital processors may be contained on a single unitary IC die, or distributed across multiple components.
[0118] As used herein, the terms “MSO” or “multiple systems operator” refer to a cable, satellite, or terrestrial network provider having infrastructure required to deliver services including programming and data over those mediums.
[0119] As used herein, the terms “MNO” or “mobile network operator” refer to a cellular, satellite phone, WMAN (e.g., 802.16), or other network service provider having infrastructure required to deliver services including without limitation voice and data over those mediums.
[0120] As used herein, the terms “network” and “bearer network” refer generally to any type of telecommunications or data network including, without limitation, hybrid fiber coax (HFC) networks, satellite networks, telco networks, and data networks (including MANs, WANs, LANs, WLANs, internets, and intranets). Such networks or portions thereof may utilize any one or more different topologies (e.g., ring, bus, star, loop, etc.), transmission media (e.g., wired/RF cable, RF wireless, millimeter wave, optical, etc.) and/or communications or networking protocols (e.g., SONET, DOCSIS, IEEE Std. 802.3, ATM, X.25, Frame Relay, 3GPP, 3GPP2, LTE/LTE-A/LTE-U/LTE-LAA, 5G NR, WAP, SIP, UDP, FTP, RTP/RTCP, H.323, etc.).
[0121] As used herein, the term “network interface” refers to any signal or data interface with a component or network including, without limitation, those of the FireWire (e.g., FW400, FW800, etc.), USB (e.g., USB 2.0, 3.0. OTG), Ethernet (e.g., 10/100, 10/100/1000 (Gigabit Ethernet), 10-Gig-E, etc.), MoCA, Coaxsys (e.g., TVnet™), radio frequency tuner (e.g., in-band or OOB, cable modem, etc.), LTE/LTE-A/LTE-U/LTE-LAA, Wi-Fi (802.11), WiMAX (802.16), Z-wave, PAN (e.g., 802.15), or power line carrier (PLC) families.
[0122] As used herein the terms “5G” and “New Radio (NR)” refer without limitation to apparatus, methods or systems compliant with 3GPP Release 15, 16 and/or 17, and any modifications, subsequent Releases, or amendments or supplements thereto which are directed to New Radio technology, whether licensed or unlicensed.
[0123] As used herein, the term “QAM” refers to modulation schemes used for sending signals over e.g., cable or other networks. Such modulation scheme might use any constellation level (e.g. QPSK, 16-QAM, 64-QAM, 256-QAM, etc.) depending on details of a network. A QAM may also refer to a physical channel modulated according to the schemes.
[0124] As used herein, the term “quasi-licensed” refers without limitation to spectrum which is at least temporarily granted, shared, or allocated for use on a dynamic or variable basis, whether such spectrum is unlicensed, shared, licensed, or otherwise. Examples of quasi-licensed spectrum include without limitation CBRS, DSA, GOGEU TVWS (TV White Space), and LSA (Licensed Shared Access) spectrum.
[0125] As used herein, the term “SAE (Spectrum Allocation Entity)” refers without limitation to one or more entities or processes which are tasked with or function to allocate quasi-licensed spectrum to users. Examples of SAEs include SAS (CBRS). PMSE management entities, and LSA Controllers or Repositories.
[0126] As used herein, the term “SAS (Spectrum Access System)” refers without limitation to one or more SAS entities which may be compliant with FCC Part 96 rules and certified for such purpose, including (i) Federal SAS (FSAS), (ii) Commercial SAS (e.g., those operated by private companies or entities), , and (iii) other forms of SAS.
[0127] As used herein, the term “server” refers to any computerized component, system or entity regardless of form which is adapted to provide data, files, applications, content, or other services to one or more other devices or entities on a computer network.
[0128] As used herein, the term “shared access” refers without limitation to (i) coordinated, licensed sharing such as e.g., traditional fixed link coordination in 70/80/90 GHz and the U.S. FCC’s current rulemaking on potential database-coordinated sharing by fixed point-to-multipoint deployments in the C-band (3.7-4.2 GHz); (ii) opportunistic, unlicensed use of unused spectrum by frequency and location such as TV White Space and the U.S. FCC’s proposal to authorize unlicensed sharing in the uplink C-band and other bands between 5925 and 7125 MHz; (iii) two-tier Licensed Shared Access (LSA) based on geographic areas and database assist such as e.g., within 3GPP LTE band 40 based on multi-year sharing contracts with tier-one incumbents; and (iv) three-tier shared access (including quasi-licensed uses) such as CBRS.
[0129] As used herein, the term “storage” refers to without limitation computer hard drives, DVR device, memory, RAID devices or arrays, optical media (e.g., CD-ROMs, Laserdiscs, Blu-Ray, etc.), or any other devices or media capable of storing content or other information.
[0130] As used herein, the term “users” may include without limitation end users (e.g., individuals, whether subscribers of the MSO network, the MNO network, or other), the receiving and distribution equipment or infrastructure such as a CPE/FWA or CBSD, venue operators, third party service providers, or even entities within the MSO itself (e.g., a particular department, system or processing entity).
[0131] As used herein, the term “Wi-Fi” refers to, without limitation and as applicable, any of the variants of IEEE Std. 802.11 or related standards including 802.11 a/b/g/n/s/v/ac/ax/ay/ba or 802.11-2012/2013, 802.11-2016, as well as Wi-Fi Direct (including inter alia, the “Wi-Fi Peer-to-Peer (P2P) Specification”, incorporated herein by reference in its entirety).
[0132] As used herein, the term “wireless” means any wireless signal, data, communication, or other interface including without limitation Wi-Fi, Bluetooth/BLE, 3G (3GPP/3GPP2), HSDPA/HSUPA, TDMA, CBRS, CDMA (e.g., IS-95A, WCDMA, etc.), FHSS, DSSS, GSM, PAN/802.15, WiMAX (802.16), 802.20, Zigbee®, Z-wave, narrowband/FDMA, OFDM, PCS/DCS, LTE/LTE-A/LTE-U/LTE-LAA, 5G NR, LoRa, IoT-NB, SigFox, analog cellular, CDPD, satellite systems, millimeter wave or microwave systems, acoustic, and infrared (i.e., IrDA).
[0133] As used herein, the term “xNB” refers to any 3GPP-compliant node including without limitation eNBs (eUTRAN) and gNBs (5G NR).
Overview
[0134] In one exemplary aspect, the present disclosure provides improved methods and apparatus for interference management between two or more base stations (or individual sectors thereof) within a wireless system so that maximum throughput and coverage is achieved, including within densely packed deployment applications.
[0135] In one embodiment, the network is configured to utilize “quasi-licensed” CBRS spectrum and uses 3GPP-based infrastructure and protocols. In order to enable use of load-balancing algorithms that balance the traffic load between the individual base stations/sectors within the network, the base stations are specifically permitted to have overlaps in their coverage areas, and hence a user device connected to one band associated with one base station can be handed over or moved to another band associated to another base station. In one variant, an enhanced SAS (SASe) - or an operator based proxy therefor - is used to create a network overlap map, and divide the population of base stations (CBSDs) (including in some cases individual sectors thereof) into “virtual clusters” based on their locations and coverage overlaps. The virtual clusters can advantageously be dynamically created, modified, or torn down, such as based on network operational parameters (e.g., time of day) related to loading. Moreover, the virtual clusters can be shaped in various configurations (and numbers of CBSDs/sectors), and can have intersecting membership of CBSDs and/or their individual sectors.
[0136] In one implementation, the SASe (or proxy) first models the interference outside of the virtual clusters, and based on the interference model, estimates the interfering power of CBSDs on the outside edge or border of the cluster under consideration. The SASe may then cause reduction of transmit power on one or more cluster edge CBSDs if producing substantial levels of interfering power. One or more CBSDs within interior regions of the cluster can then be used to compensate for the “lost” coverage area and overlap created by the edge-CBSD power reduction(s) in needed.
[0137] The exemplary embodiment described above effectively improves, inter alia, coverage area and enables inter-CBSD traffic load balancing, without the need to use excessive power at the CBSDs (and the various issues associated therewith), or alter the general operational paradigm of the network; i.e., SAS-based reduction of power to reduce interference.
[0138] In addition, the interference management and load balancing scheme referenced above increases overall network capacity without the need to install additional infrastructure such as CBSDs and associated backhaul, thereby effectively adding more customers to the network with a given CAPEX (capital expenditure). Operator flexibility in placement of CBSDs within a given area is also enhanced; operators may place CBSDs for example at identified usage “hot spots,” and then via virtual clustering and load balancing, adapt operation of those CBSDs dynamically as operational conditions change (in contrast to e.g., a fixed-cell type of approach used in prior art cellular site planning).
[0139] The methods and apparatus described herein may also advantageously be extended to other shared-access architectures (i.e., other than CBRS) such as for example DSA, LSA, and TVWS systems.
Detailed Description of Exemplary Embodiments
[0140] Exemplary embodiments of the apparatus and methods of the present disclosure are now described in detail. While these exemplary embodiments are described in the context of the previously mentioned base station (e.g., CBSDs such as 3GPP-based xNB devices), using unlicensed or quasi-licensed spectrum associated with e.g., a managed network (e.g., hybrid fiber coax (HFC) cable architecture having a multiple systems operator (MSO), digital networking capability, IP delivery capability, and a plurality of client devices), or a mobile network operator (MNO), the general principles and advantages of the disclosure may be extended to other types of radio access technologies (“RATs”), networks and architectures that are configured to deliver digital data (e.g., text, images, games, software applications, video and/or voice or audio). Such other networks or architectures may be broadband, narrowband, or otherwise, the following therefore being merely exemplary in nature.
[0141] It will also be appreciated that while described generally in the context of a network providing service to a customer or consumer or end user or subscriber (i.e., within a prescribed venue, or other type of premises), the present disclosure may be readily adapted to other types of environments including, e.g., indoors, outdoors, commercial/retail, or enterprise domain (e.g., businesses), or even governmental uses, such as those outside the proscribed “incumbent” users such as U.S. DoD and the like. Yet other applications are possible.
[0142] Also, while certain aspects are described primarily in the context of the well-known Internet Protocol (described in, inter alia, Internet Protocol DARPA Internet Program Protocol Specification, IETF RCF 791 (September 1981) and Deering et al., Internet Protocol, Version 6 (IPv6) Specification, IETF RFC 2460 (December 1998), each of which is incorporated herein by reference in its entirety), it will be appreciated that the present disclosure may utilize other types of protocols (and in fact bearer networks to include other internets and intranets) to implement the described functionality.
[0143] Moreover, while the current SAS framework is configured to allocate spectrum in the 3.5 GHz band (specifically 3,550 to 3,700 MHz), it will be appreciated by those of ordinary skill when provided the present disclosure that the methods and apparatus described herein may be configured to utilize other “quasi licensed” or other spectrum, including without limitations above 4.0 GHz (e.g., currently proposed allocations up to 4.2 GHz).
[0144] Additionally, while some embodiments are described in terms of GAA 106 spectrum allocation (see
[0145] Moreover, while described in the context of quasi-licensed or unlicensed spectrum, it will be appreciated by those of ordinary skill given the present disclosure that various of the methods and apparatus described herein may be applied to delivery of heterogeneous services (including also allocation/assignment of spectrum or bandwidth to those services) within a licensed spectrum context; e.g., for cellular voice or data bandwidth/spectrum allocation, such as in cases where a given service provider must provide differentiated or heterogeneous service to users.
[0146] Moreover, while some aspects of the present disclosure are described in detail with respect to so-called “4G/4.5G” 3GPP Standards (aka LTE/LTE-A) and so-called 5G “New Radio” (3GPP Release 15/16/17 and TS 38.XXX Series Standards and beyond), such aspects - including allocation/use/withdrawal of CBRS spectrum - are generally access technology “agnostic” and hence may be used across different access technologies, and can be applied to, inter alia, any type of P2MP (point-to-multipoint) or MP2P (multipoint-to-point) technology, including e.g., Qualcomm Multefire.
[0147] Other features and advantages of the present disclosure will immediately be recognized by persons of ordinary skill in the art with reference to the attached drawings and detailed description of exemplary embodiments as given below.
Interference Management and Load Balancing Architecture
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[0149] As shown, the architecture 400 of
[0150] It will also be appreciated that while the following discussion is cast primarily in terms of base stations such as the exemplary CBSDe devices, the various principles may be readily applied to individual sectors of those base stations where so equipped (e.g., where sectorized versus omnidirectional antenna elements are used).
[0151] As illustrated, the CBSDe devices 406a, 406b can communicate with each other via a 3GPP X2 link 410, as well as with network entities (e.g., SASe) tasked with evaluating interference between the CBSDe devices and logically grouping them into “clusters,” as described in greater detail subsequently herein. The inter-CBSDe connectivity allows, inter alia, exchange of data between CBSDe within logical groupings or “virtual clusters’ of cells, such as to support load balancing and other types of cooperation between the individual cells.
[0152] The served UE/FWA 314a, 314b, 314c are within the coverage areas 408a, 408b of the CBSDe devices, and wirelessly connected to their serving CBSDe 406a, 406b respectively (e.g., via 3GPP RRC-Connected state). The UE/FWA 314b in this example is in the overlap region 404 between coverage areas 408a, 408b, and is connected to CBSDe 2 406b, and hence, due to the overlap, the UE 314b can seamlessly handover to CBSDe 1 406a (e.g., via transition to a different frequency band utilized by the recipient CBSDe). Herein lies a salient feature of the architecture of
[0153] In the embodiment of
[0154] The coverage areas 408a, 408b of the CBSDe devices 406a, 406b are managed by the SASe 402. The SASe allocates the operating spectrum bands to the various CBSDe/sectors, determines transmitter power levels for each, and determines any interference (including in the overlap area). In some scenarios, where the interference between the CBSDe devices 406 is higher than a prescribed value, the SASe may reduce transmission power for one or more of the CBSDe, and boost transmission power for others, as described in greater detail subsequently herein.
[0155] It will be appreciated that instead of base stations such as CBSDe 406a, 406b, other types of devices may be used as the basis for providing services. For instance, other CPE/FWA apparatus configured for supplementation or out-of-coverage service within a given area may be used within the architecture 400, such as those described in co-pending U.S. Pat. application Serial No. 16/738,889 filed Jan. 9, 2020 and entitled “METHODS AND APPARATUS FOR SERVICE PROVISION TO OUT-OF-COVERAGE APPARATUS IN WIRELESS SYSTEMS”, as well as U.S. Pat. Application Serial No. 16/676,188 filed Nov. 6, 2019 and entitled “METHODS AND APPARATUS FOR ENHANCING COVERAGE IN QUASI-LICENSED WIRELESS SYSTEMS,” each of the foregoing incorporated herein by reference in its entirety. For example, as described therein, wireless coverage for an exemplary unlicensed or quasi-licensed UE/FWA 314 that is at or beyond a coverage “edge” of a given network (or is otherwise experiencing less-than-adequate signal strength for whatever reason) may be provided service via “relay” and/or supplementation of services from a better-positioned “in coverage” CPE/FWA of the same network.
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[0157] As a brief aside, typical cellular network planning involves placement of base stations (e.g., eNBs) at locations such that a “honeycomb” or other cell pattern is adhered to. This approach allows maximal coverage via interlocking cells that may overlap one another to a limited degree. In contrast, in exemplary embodiments of the present disclosure, disposition of base stations (e.g., CBSDe devices) at a plurality of geographic locations within a given geographic region is based on actual or projected usage by users (e.g., “hotspots”). The placements may be irregular (unlike normal cellular cell planning which tends to be more regular), and any overlaps and interference between the CBSDe devices after placement is managed via use of the above-described clustering techniques and apparatus, including to allow maintenance of sufficient overlap for load balancing or other purposes. “Directional shaping” of virtual clusters (discussed in greater detail below) can also be used to help shape various cluster (VC) boundaries to maintain desired levels of coverage overlap. In some variants, load balancing is applied via the overlap at prescribed locations and/or times of day/days of the week (e.g., on an as-needed basis during peak traffic times and within peak traffic areas). As such, the network operator (e.g., MSO or MNO) is free to place its base stations where demand/user density will most likely be high, and adjust for the desired degree of overlap through VC membership and policies (as well as individual CBSDe transmit power levels as imposed by the SASe 402).
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[0159] As shown, load transfer 517 (i.e., of the UE/FWA within the overlap zone 404) between the two CBSDe devices can occur, such as under load balancing. As previously described, such load balancing may cause the UE/FWA to connect to the second CBSDe simultaneously while connected to the first CBSDe on a different frequency, and then terminate the connection to the first CBSDe so as to reduce load thereon. In this scenario, each CBSDe can be considered an interferer for the other CBSDe; their coverage areas 505, 507 have partial overlap 404. The SASe 402 may create a virtual cluster from just these two CBSDe' 406a, 406b, and store data relating to their coverage overlap 404, and any registered UE/FWA devices therein, in a network overlap map (as described in greater detail below).
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[0166] It will also be recognized that normally, a CBSDe will not be part of two different virtual clusters. One way such “common membership” can arise is via individual CBSDe sector overlap. Specifically, in some implementations, each of the CBSDe devices has multiple sectors (e.g., 3 sectors of 120 degrees azimuth coverage each, as shown in
[0167] Hence, as shown in the example of
[0168] It is noted that in the illustrated example, the coverage of sector 595 of CBSDe N and the coverage of two of the sectors of CBSDe 3 406c overlap, thereby allowing the UE/FWA 314 in
[0169] Moreover, it can be understood from the discussion above that individual sectors (versus entire CBSDe devices) can be considered “edge CBSD” devices as described elsewhere herein, and treated as such for purposes of e.g., load balancing or transmit power management.
[0170] It will be recognized that in each of the example configurations of
[0171]
[0172] As previously noted, one primary attribute of the disclosure relates to its ability to balance the traffic load among the base stations (or individual sectors thereof) while mitigating the interference. Specifically, when the base stations have overlaps in their coverage areas, the UEs located in the overlap can experience high levels of interference from the other base stations (and thereby reduced data rates). It will be appreciated that depending on the type of antenna elements (e.g., directional or omni-directional) used in the base stations 406 (e.g., 406a, 406b, 406c), even a UE/FWA 314 located in the overlap area may not be able to achieve high data rates and high quality of performance if the antenna geometry of the base stations do not support it. As such, highly directional antenna elements may be utilized on the base stations (to mitigate the interference in the overlap area), and they are aligned to serve to the UEs in specific part of the cell (e.g., to form the elongated elliptical shapes shown in
[0173] In another such implementation, the base stations 406 employing multiple directional antenna element technology are configured to measure the received signal (e.g., on an UL channel from a UE/FWA), and extract multipath wireless channel information relating to phase, amplitude and path loss from the received signal. Such information can be used to estimate the interference in the overlap area in such a way to form a directional beam towards the target area reducing the interference in the coverage overlap areas. Various other similar approaches for optimizing SINR or other signal-strength related parameters will be recognized by those of ordinary skill when given the present disclosure.
Methodology
[0174] Various methods and embodiments thereof for cluster-based interference management and load balancing via unlicensed or quasi-licensed (e.g., CBRS GAA or PAL) spectrum according to the present disclosure are now described with respect to
[0175]
[0176] Per step 703, interference is determined at one or edges of the formed cluster(s). For instance, the interference may be estimated such as via modeling (e.g., by the SASe 402), or actually measured/detected by e.g., CBSDe devices 406 or UE/FWA.
[0177] Per step 705, the transmit power of one or more base stations disposed at the edge of the cluster where the interference was estimated/detected is reduced, so as to mitigate the interference for at least one of the “conflicting” devices (which in reality may be both devices).
[0178] Per step 707, compensation for the reduction of coverage area resulting from the reduction of step 705 is performed (if required), such as by increasing power of an interior (non-edge) base station within the cluster. This compensation may be performed dynamically or transiently in some embodiments; e.g., to generate sufficient coverage overlap to enable handover of a user device from one base station to another, after which the overlap is collapsed.
[0179] Lastly, per step 709, any required load balancing is performed. In one embodiment, the load balancing is performed using methods and apparatus described in co-owned and co-pending U.S. Pat. Publication Nos. 20190394678A1 entitled “CAPACITY MANAGEMENT METHODS AND APPARATUS FOR USE IN A CITIZENS BROADBAND RADIO SERVICE NETWORK” and 20200128540A1 entitled “METHODS AND APPARATUS FOR ESTIMATING WIRELESS NETWORK COVERAGE,” each of which is incorporated herein by reference in its entirety, although other methods and apparatus may be used consistent with the present disclosure.
[0180]
[0181] Next, per step 805, the SASe 402 grants spectrum (e.g., GAA or PAL) to each CBSDe with which each may operate. These bands may be the same as or different from those used by other CBSDe devices, but typically will have some level of diversity for load balancing purposes.
[0182] At step 807, the SASe (or a network proxy therefor) creates a virtual cluster comprised of neighboring CBSDe devices (including individual sectors thereof as applicable) within the network which are participating in load balancing. In some variants, each CBSDe may or may not participate in load balancing based on one or more factors (e.g., its own current load, presence of a neighboring CBSDe with frequency diversity, etc.), and may affirmatively opt in or out of the clustering process. This decision may also be made on behalf of the CBSDe by a network (e.g., MSO or MNO) proxy process which decides whether each individual CBSDe is properly included within load balancing at that point in time.
[0183] At step 809, the SASe 402 determines interference for the participating CBSDe devices 406. This determination may be (i) estimated, such as based on path loss modeling for the known spatial relationships between the various CBSDe devices (including distance between them, presence of topological or other features, extant transmit power levels and frequencies, etc.) as described in greater detail subsequently herein, and/or (ii) measured, such as by way of actual SINR, iPerf (i.e., packet throughput), BER/PER, or other measurements taken at a given CBSDe (or supplied by served UE/FWA). The interference is in one embodiment determined with respect to one or more other CBSDe devices external to the cluster (i.e., an adjacent CBSDe operating individually or in another cluster), but intra-cluster interference level (e.g., between two edge CBSDe devices in the same cluster) may also be determined.
[0184] Per step 811, the SASe directs one or more CBSDe devices on the edge of the established VC (or individual sectors thereof) to reduce transmit power in order to mitigate the determined interference. This may include for instance a step-wise reduction and evaluation process; e.g., reduce power in a first increment, evaluate interference or data throughput via actual measurements, and then continue reductions as required.
[0185] Moreover, the power of each of the CBSDe devices experiencing interference may also be reduced concurrently. In that two (or more) CBSDe devices may each interfere with one another when transmitting (for instance, where their respective transmit power levels are roughly equivalent) due to assumed symmetric path loss models, satisfactory reduction of interference may require that both devices reduce transmit power. Similarly, for three interfering CBSDe devices, reduction of power for all three may be needed.
[0186] As can be appreciated, such reduction(s) of power can produce significantly reduced coverage areas for each reduced CBSDe, including loss of overlap with its neighbors. While this may help with e.g., interference with respect to a neighboring cluster edge, it may reduce or even eliminate opportunities for load balancing within that cluster. As such per step 813 of the method 800, the SASe compensates for such coverage reduction (as needed) by boosting transmit power levels associated with one or more interior cluster cells, and/or use of directional shaping of certain cells as previously described. Note that the compensation of step 813 may in some case be required only on a transient basis; e.g., to create sufficient overlap for UE/FWA handover, after which the power increase and/or shaping can be reduced so as to limit interference while still maintaining sufficient signal level at the receiving UE/FWA devices being served by the affected CBSDe devices.
[0187] It will also be recognized that under the exemplary 3GPP protocols used herein, various features such as UE data collection and load balancing transfers can be performed either in “idle” mode or in “connected” mode, thereby adding operational flexibility.
[0188]
[0189] Based on the location and other data reported to the SASe 402, the SASe creates per step 859 a virtual cluster map which groups two or more adjacent CBSDe devices into VCs within a given operating area or region. As discussed with respect to
[0190] Per step 861, the SASe identifies cluster edge CBSDe devices, and per step 863, identifies instances of one-way or two-way interference (i.e., where only one CBSDe or sector interferes with another, but not vice versa, or mutual interference, respectively, such as via the modeling and/or measurements previously described. If the identified CBSDe interferers are disposed ion a VC edge per step 865, the SASe implements a power reduction (step 867) and compensation (step 869) such as interior cell power increase or directional coverage area shaping.
[0191]
[0192] At step 903 of the method 900, each CBSDe sends registration request data to the SASe 402; if the SASe approves the registration request, it responds to each CBSDeB with a CBSD ID, and registers the CBSDe(s).
[0193] Per step 905, once the CBSDe devices are registered with the SASe, each sends the SAS its latitude and longitude information or other positional data enabling the SASe to determine its location (e.g., data such as azimuth of two or more other CBSDe devices or landmarks enabling triangulation). As can be appreciated, the location data may also be sent as part of the registration request.
[0194] Per step 907, after the SASe receives the position information from the CBSDe devices, the SASe allocates one or more PAL or GAA frequency channels to each CBSDe. The SASe response includes detailed information about the frequencies that are available for each CBSDe to use, and may include additional information which might be useful to the CBSDe when it selects a frequency range to utilize (such as an initial transmission power level). In one variant, the initial power level is selected based on (i) the maximum power allowed for the category (e.g., Category A or B as previously described herein), such that the power does not exceed such level, and (ii) its operational condition (e.g., initial post-installation startup, reboot, etc.). For example, in one such approach, the CBSDe includes logic which determines operational state (such as via one or more values loaded into registers on the CPSDe CPU or BB processor), and based on the determined state value, accesses a LUT or similar data structure to determine the appropriate “initial” power setting (none of which exceed its then-prevailing category limit).
[0195] Per step 909, each CBSDe creates an X2 connection with its neighbor CBSDe devices. The X2 interface is a peer-to-peer connection, and allows the CBSDe devices to share information related to e.g., load-balancing and management. For example, in one embodiment, load-balancing evaluation data (i.e., that needed to assess whether to move one or more UE/FWA devices 314 between CBSDe devices) and control/transfer data may be transacted over the X2 interface. In one variant, the X2 interface is implemented via the backhaul network of the MxO such as via a GbE or similar Layer ⅔ protocol, although other approaches may be used with equal success.
[0196] Various mechanisms can be used for determination of “neighbor” CBSD/CBSDe devices for a given CBSDe. In one approach, each CBSD/CBSDe maintains a neighbor list which lists the first-tier (i.e., immediately contiguous) neighbors of that device. This list can for example either be created manually (such as by the MSO at time of installation), or via use UE-based measurement reports as described elsewhere herein. For instance, a UE reports the PCI values of CBSDs that the UE can detect, and these reported PCI values are sent to core network by the CBSDe in order to obtain the IP address of the CBSD/CBSDe that transmits the given PCI (e.g., via a LUT or correlation process of the network which relates known CBSDs to then-assigned IP addresses, which notably may be either static or dynamically varied). In response to the look-up request, the core network sends the IP address for each requested PCI value back to the requesting CBSDe, and that CBSDe connects to the other (detected) CBSD/CBSDe using the provided IP address (once the X2 connection is established).
[0197] Per step 911, each CBSDe notifies the SASe whether it participates in traffic load balancing, such as by sending its unique identification data to a designated port/socket or API on the SASe. Alternatively, the SASe may poll CBSDe devices within a given area to determine if they are eligible to participate in load balancing, or an MSO node may inform the SASe on behalf of a group of CBSDe devices (e.g., via table or IE listing the participating CBSDe ID values) and a time window for eligibility. Myriad other approaches will be evident to those of ordinary skill given the present disclosure.
[0198] Per step 913, the SASe records each CBSDe participating in the traffic load balancing, and creates one or more VCs from the CBSDe devices (or individual sectors thereof) participating in the load balancing. It will be appreciated that the load balancing may be geographically or topologically restricted within the network, and as such the SASe may in some embodiments only consider limited subsets of the entire population feasibly available for load balancing at any given time when creating or configuring (including even tearing down) VCs. For instance, even though say thirty (30) CBSDe devices may be eligible for participating, the SASe may select a subset of only 15 for inclusion with one or more VCs at any given time, based on its analytical capabilities, the “optimum” size of a VC (from an efficacy or efficiency standpoint), and/or other factors.
[0199] Per step 915, each CBSDe notifies one or more UE/FWAs inside of its coverage area to report the Physical Cell Identities (PCI) of each other CBSDe/sector that each UE/FWA can measure. This data is reported back by the serving (connected) CBSDe 406 to the SASe 402. The latter which can use the data to identify proximate CBSDe devices for the serving CBSDe, including those which may be interfering or have overlap. For example, if a group of spatially proximate UE/FWA devices report a given PCI, then it can be presumed that the detected CBSDe is sufficiently proximate to the serving CBSDe, and has at least some degree of coverage overlap (i.e., if its signal can be detected it is at least sufficiently proximate to the serving CBSDe such that the UE/FWA could feasibly hand over to it at its current power level). Hence, in one approach, overlap can be presumed based simply on detection of a CBSDe. More sophisticated approaches may utilize e.g., curve-fitting for coverage area functions (e.g., based on “hits” or detection by multiple UE/FWA at different locations), the SASe can computationally determine a best-fit function representative of the coverage area, which may be in some cases an irregular shape in contrast to the simplified representations presented as examples herein.
[0200] It will be appreciated that the foregoing request/detect/reporting cycle can be conducted once, or repetitively or iteratively by UE/FWA devices, whether simultaneously or in sequence. Temporal coherence between UEs (i.e., reporting at roughly the same time) may be important for some classes of UE such as mobile devices, wherein their ability to detect a given CBSDe may vary with time.
[0201] It will also be appreciated that the foregoing detection can be used to validate cluster maps and/or path loss models or estimates generated by the SASe (or MSO proxy). For example, a SASe estimate may indicate the presence of an overlap area between two cells of a cluster; however, if an UE/FWA disposed within the putative overlap area cannot actually detect the second (non-connected) CBSDe, such as due to an atmospheric effect, topological feature, or other condition not properly accounted for within the modeling, then the model may be adjusted, and/or the calculated overlap area reduced. As such, the UE/FWA 314 can act as in situ detectors for the SASe when constructing cluster maps and performing/updating path loss estimates.
[0202] Returning again to
[0203] Per step 919, once the CBSDe devices receive the PCIs from the UEs, and then report them to the SASe.
[0204] Per step 921, after the SASe receives the reported PCI from the CBSDe devices, it creates a network overlap map. In one embodiment, the map includes data indicative of (i) each CBSDe location, and (ii) coverage area of each CBSDe, based on a presumed or initial transmitter power level. It will be appreciated that this “map” may take any number of different forms, and may vary from quite simple to more detailed. For instance, in one variant, the map comprises a table or listing of each CBSDe, associated PCI, location (e.g., lat/lon), and a radius of coverage (e.g., in km) for a presumed power level (or sets of levels). Overlap can be calculated using readily known geometric/spatial relationships and equations, such as calculating the points of intersection of the two coverage area equations (r.sub.i.sup.2 = x.sub.i.sup.2+y.sub.i.sup.2) centered at respective CBSDe locations. Exemplary methods and apparatus for determining wireless coverage area, power headroom, and other useful data are described in co-owned U.S. Pat. No. 10,368,351 issued Jul. 30, 2019 and entitled “METHODS AND APPARATUS FOR ESTIMATING CITIZENS BROADBAND RADIO SERVICE NETWORK COVERAGE”, incorporated herein by reference in its entirety, although it will be recognized that other techniques and apparatus may be used consistent with the disclosure, the foregoing being merely illustrative.
[0205] Per step 923, the SASe estimates the interference from the CBSDe devices located at cluster edge on the neighbor cells or clusters in the network. Estimated SINR levels may be mapped for each location based on the calculated path loss and assumed transmitter power, treating the other CBSDe(s) as interferers for a given CBSDe being evaluated. More sophisticated approaches may be used as well (including multivariate modeling), consideration of topological features, known in-band emitters which may act as noise sources, etc. In some embodiment, the SASe receives the wireless propagation channels information from the CBSDe devices (e.g., phase amplitude, path loss), and estimates the interference based at least in part on these parameters.
[0206] Per step 924, the SASe compares the interference level with one or more criteria (e.g., a maximum threshold), and if interference is higher than the threshold, the method 900 proceeds to step 925, wherein a mechanism to mitigate the interference is employed.
[0207] For instance, in the illustrated embodiment, per step 925, the SASe may signal the edge CBSDe devices causing the interference to reduce power. This may in some embodiments be a “blanket” reduction; i.e., across all energized sectors of that CBSDe. Alternatively, the SASe may cause the edge CBSDe devices to adjust the shape of their coverage area, such as via reduction of power only on certain sectors; i.e., those “pointing” in azimuth towards the external cluster(s) experiencing the interference. The SASe may also implement a “trial and error” or other scheme to determine the effects on interference from incremental step reductions on various CBSDe sectors, whether singularly or in combination with others.
[0208] Per step 927, to account for any lost coverage area from power reduction that needs to be compensated, the SASe increase the coverage area of the neighboring cells (e.g., one within the same cluster adjacent to the cell(s) for which power was reduced. This may include compensation for two or more adjacent cells within the cluster (e.g., those on either side of the reduced cell), and may also include interior or non-edge cells within the cluster (if any). Directional shaping may also be used where possible to alter the shape of the coverage area, such as to achieve (i) closing of any gaps left in the coverage area of the power-reduced CBSDe, so as to avoid “stranding” of UE/FWA in such areas, and/or (ii) creating a desired overlap between two or more cells so as to facilitate load balancing or other functions which require such overlap.
[0209] Per step 929, after the coverage optimization is performed at step 927, the relevant CBSDe(s) instruct the UE/FWA to which they are connected to again measure the neighboring CBSDe signals, and report the detected PCI and other data for forwarding to the SASe at step 931. It will be appreciated that targeted subsets of the UE/FWA may be used for such purposes; e.g., those known to reside within a prescribed sector of the adjusted CBSDe, whether based on connection/association with that sector, or known location (e.g., via lat/lon data from time of installation). For instance, in one variant, the SASe 402 may instruct the adjusted CBSDe to poll specific UE/FWA devices only, or the CBSDe may simply issue a broadcast or blanket request to all served UE/FWA. As another alternative, only UE/FWA slated for transfer to another serving CBSDe (e.g., by way of load balancing) may be selected to report PCI and related data. Many such variants will be recognized by those of ordinary skill given the present disclosure.
[0210] Lastly, per step 935, the SASe updates its network overlap “map” according to the updated CBSDe detection data as correlated to various locations within the coverage area(s).
[0211] Referring now to
[0212] As a brief aside, a short discussion on path loss propagation models is useful at this juncture.
[0213] Path Loss models are used to predict large-scale coverage for wireless communication system design, implementation and deployment. By using path loss models, processes such as the CPE/FWA 507 can estimate the received power as a function of e.g., distance, and can predict the SINR which should be achievable from e.g., certain sector of a CBSD transmitting at a certain power level.
[0214] The propagation models used generally indicate that average received signal power decreases logarithmically with the distance between transmitter and receiver. A path loss model for an arbitrary transmitter receiver separation can be expressed as a function of distance, and an exponent, n as in Eqn. (1):
[0215] Where: [0216] n is the path loss exponent which indicates the rate at which path loss increases with distance; [0217] d0 is the close-in reference distance; and [0218] d is the transmitter receiver distance.
[0219] Equation (1) shows that the power decreases proportional to (1/d).sup.n, as the distance d between transmitter and receiver increases. The exponent n depends on the specific propagation environment. Table 4 shows exemplary values of the exponent n for different environments.
TABLE-US-00004 Environment Path Loss Exponent n Free Space 2 Urban Area 2.7 to 3.5 Shadowed Urban Area 3 to 5 In Building Line-of-Sight 1.6 to 1.8 Obstructed in Building 4 to 6 Obstructed in Factories 2 to 3
[0220] The reference model of Eqn. (1) is defined via field measurement at distance d0 from the transmitter.
Log-Normal Shadowing
[0221] The model in Eqn. (1) does not consider the fact the propagation environment can have different propagation characteristic. Therefore, in some scenarios where the environment surrounding transmitter and receiver are different, the estimated power from Eqn. (1) is vastly different than the measured signal. As the measurement in the field has shown, the path loss PL(d) at distance d from a transmitter is random has a log-normal distribution as defined by Eqns. (2) and (3):
where Xσ is a zero-mean Gaussian random variable with standard deviation σ, and
[0222] The log-normal distribution describes the shadowing effects which occur in in applications which have the same transmitter receiver distance, but have different propagation environments such as different presence of obstacles (e.g., building, mountains, towers). The close-in reference distance d0, the path loss exponent n, and the standard deviation σ define the path loss model for transmitter receiver separation distance d. The path-loss model of Eqn. (2) can be used to estimate the received power from a given CBSD 206 at the CPE/FWA antenna elements 723.
[0223] Table 5 below shows exemplary path loss exponent n values and shadowing standard variation σ for different environments based on measurements, reported in “Wireless and Cellular Communications”, Thomas Schwengler, First Edition, December 2019 which is incorporated here herein by reference in its entirety.
TABLE-US-00005 Source Frequency (GHz) Path Loss Exponent n σ(dB) Comments Seidel 0.9 2.8 2.8 Suburban Erceg 1.9 4.0 4.0 Terrain category Feuerstein 1.9 2.6 2.6 Medium Antenna height Abhayawardhana 3.5 2.13 2.13 Durgin 5.8 2.93 2.93 Residential Porter 3.7 3.2 3.2 Rautianinen 5.3 4.0 4.0 Schwengler 5.8 2.0 3.5 LOS 5.8 3.5 9.5 NLOS 3.5 2.7 11.7 Near LOS
[0224] The n and σ values depend on different propagation environments (e.g., downtown, urban, rural) and operating frequencies as specified in Tables 1-2 above. The values n and σ are initially determined at the time of the installation according to propagation environment as specified in Table 1-2. However, since the propagation environment may change, embodiment of the CPE/FWA 507 may dynamically perform parameter estimation and update n and σ values during e.g., the training period of the received data frame, and report the new values to the SASe 802. The value PL(d0) is generally a fixed value, and is measured at the time of installation of CPE/FWA in close-in measurement at distance d0 from transmitter, such as by an installer or other approach.
[0225] Exemplary path loss models which may be used consistent with the present disclosure are also described in co-owned and co-pending U.S. Pat. Application Serial Nos. 16/214,070 filed Dec. 8, 2018 and entitled “METHODS AND APPARATUS FOR TRANSMISSION POWER MANAGEMENT OF CITIZEN BROADBAND SERVICE,” 16/221951 filed Dec. 17, 2018 and entitled “PRIORITY ACCESS LICENSE HOLDER,” and US Pat. No. 10,368,351 issued Jul. 30, 2019 and entitled “METHODS AND APPARATUS FOR ESTIMATING CITIZENS BROADBAND SERVICE NETWORK COVERAGE,” each of the foregoing incorporated herein by reference in its entirety, although other approaches may be used consistent with the present disclosure.
[0226] Returning to
[0227] It will be appreciated that different models may be selected for different applications and contexts; for example, one model may be better suited to propagation characteristics in one geographic service area of a given geographic region (such as one with hills and valleys) as compared to another service area within the same region (e.g., one that is largely flat and backs up to a large body of water).
[0228] At step 955, the SASe estimates the path loss model parameters for use with the model, including e.g., distance between the two nodes (e.g., two CBSDe devices) being modeled, exponent n, variance σ, etc., or retrieves these from a database of such data. The model parameters are estimated in one embodiment by application of curve fitting method that minimizes the mean error between the estimated values and real (measured) values. The distance d between transmitter and receiver is estimated from e.g., sounding reference signals, or can be determined by way of data provided to the SASe or the MSO proxy by the MSO core (the latter having knowledge of its own CBSDe placements) and the location of the CBSDe devices - e.g., via use of lat/lon data for both devices to determine straight-line distance.
[0229] Various aspects of the foregoing analysis and model/parameter selection can be performed by algorithms resident on the SASe (such as stored in program memory or mass storage), and/or can be offloaded in whole or part to e.g., cloud processes, including in more sophisticated approaches such as those based on ML or DL (machine learning or deep learning), whether within an MSO compute environment or an external cloud process such as AWS or Azure. As such, the MSO may also build their own more detailed or customized path loss models and parameter sets for its own CBSDe devices, rather than relying on more generic models which may be provided by the SASe 402 in some cases.
[0230] Lastly, per step 957 of the method of
[0231] It will also be appreciated that the path loss model parameters depend on wireless channel characteristics, and are defined (primarily) at the time of the installation. Once a new CBSDe is installed, it performs an initialization process to determine the path loss model parameters. The CBSDe measures the reference signals to estimate its specific wireless channel information and path loss parameters. Since the SASe maintains data on the CBSDe transmit power, it utilizes the associated path loss model to estimate the interference power from this CBSDe on the neighboring cluster/cell.
[0232] Moreover, the CBSDe devices (as well as UE/FWA devices connected thereto) may also be configured to utilize one or more signals indigenous within the underlying air interface protocols (e.g., 3GPP LTE/LTE-A or 5G NR in the exemplary configurations) to assess signal quality (and hence interference level) for a given sector or at a given location within a coverage area, such as the CRS (cell-specific reference signal). As a brief aside, reference signals such as CRS in LTE support various functions, including channel estimation for MIMO decoding (demodulation), determination of PMI/CQI/RI feedback, and determination of multi-user resource allocation (scheduling). In a downlink (DL), the cell-specific reference signals (CRS) are transmitted by the xNB on unique resource elements for each antenna port, and are allocated in frequency and time. Since the CRS for each antenna port are mutually orthogonal to one another, channel estimation techniques such as interpolation can be used to determine estimates for the MIMO channel. This channel estimate can be used to derive PMI, CQI and RI feedback to determine the transmission scheme, and additional CQI reports may be requested from a given CPE/FWA by the xNB (CBSDe) for the purpose of multi-user scheduling.
[0233] Hence, the mechanisms for assessing channel quality present within for example the underlying LTE (or 5G NR) protocols may be leveraged by the logic of the CBSDe in gathering information for subsequent evaluation/analysis by the SASe 402 or MSO proxy process. For instance, a CBSDe may cause its connected UE/FWA to make channel measurements and provide such data back to the CBSDe for reporting to, and utilization by, the SASe in channel modeling or interference determination assessments, as well as development of the aforementioned heat map.
[0234] It will further be appreciated that while the SASe estimates the effect of the interference outside of or on an edge of a cluster in the embodiment of
[0235] It will be recognized that the foregoing approach also advantageously allows for a very low-overhead and efficient mechanism by which to both optimize coverage area (and hence served user count), and balance the traffic load among the participating CBSDe devices. Specifically, using an interference power estimation mechanism in the exemplary embodiments obviates more sophisticated analyses of channel conditions; the transmission power levels of the various CBSDe devices (known to the SASe) are readily determined and used in the pre-defined model in the SASe or MSO proxy node to estimate the interference level, and decide whether any coverage area optimization is required. In low-load environments (e.g., at off-peak times of day), no VC creation/optimization or load balancing may be used in certain parts of the infrastructure, or if used, it readily may be dynamically adjusted.
[0236]
[0237]
SASe Apparatus
[0238]
[0239] In the exemplary embodiment, the processor 1145 may include one or more of a CPU (e.g., multi-core CPU), digital signal processor, RISC core, microprocessor, field-programmable gate array, GPU, and/or plurality of processing components mounted on one or more substrates. The processor may also comprise an internal cache memory, and is in communication with a memory subsystem 1150, which can comprise, e.g., SRAM, flash and/or SDRAM components. The memory subsystem may implement one or more of DMA type hardware, so as to facilitate data accesses as is well known in the art. The memory subsystem of the exemplary embodiment contains computer-executable instructions which are executable by the processor 1145 or other data.
[0240] The processor 1145 is configured to execute at least one computer program stored in memory 1150 (e.g., a non-transitory computer readable storage medium); in the illustrated embodiment, such programs include logic to implement the cluster control (formation, modification, tear-down, etc.) functions, as well as API logic 1151 which enables external devices such as the CBSDe devices or MxO network processes to access data from the SASe via application programming interface (API) calls. Other embodiments may implement such functionality within dedicated hardware, logic, and/or specialized co-processors (not shown).
[0241] Also included (not shown) is logic to manage spectrum allocation to the CBSDe devices across the three tiers of access (PAL, GAA, Incumbents).
[0242] The map and path loss processing module 1147 may be implemented as a separate co-processor or ASIC as shown, or alternatively as code executing on the CPU 1145. The map/path loss module 1147 utilizes path loss model data stored within the mass storage 1148 (or a network accessible storage device) to select and implement various path loss estimates as previously described herein. CPE (e.g., UE/FWA 314) data and CBSDe data, such as locations, number of sectors, azimuths of sectors, installed height, etc. may be maintained in the mass storage or network storage device(s) as well, so as to facilitate e.g., determination of spatial relations for the various components, and determination of path loss parameters for the various models. Cluster participation data may also be retained by the SASe, such as historical cluster membership, known “neighbors” for a given CBSDe, and the like.
[0243] In one variant the SASe includes data structures (such as LUTs with identities of CBSDe devices) which permit correlation of data such as location, CBSD/CBSDe ID, and other data. Transmit power and frequency band(s) assigned to each CBSDe may also be maintained in such structures, and dynamically modified as they change.
[0244]
[0245] As with the embodiment of
[0246] The processor 1245 is configured to execute at least one computer program stored in memory 1250 (e.g., a non-transitory computer readable storage medium); in the illustrated embodiment, such programs include logic to implement the cluster control (formation, modification, tear-down, etc.) functions, as well as API logic 1251 which enables external devices such as the CBSDe devices or SAS or DP to access data from the Proxy 1052 via application programming interface (API) calls. Other embodiments may implement such functionality within dedicated hardware, logic, and/or specialized co-processors (not shown).
[0247] The map and path loss processing module 1247, similar to that for
[0248] As shown, the mass storage device 1248 may also include one or more SAS request “templates” 1277 which can be used for communication with the SAS. In one variant, the SAS 202 is effectively a COTS/prior art SAS (i.e., unenhanced), and as such is restricted in the types and content of data which it may receive, the processing it may perform, and the output it may provide. Hence, the Proxy 1052 may be configured to package its communications with the SAS 202 in proper/extant protocols and formats using the templates 1277, thereby maintaining compatibility between the SAS and the Proxy 1052. For instance, the Proxy 1052 may parse or disassemble more complex cluster-related data or requests into individual components which can be processed by the SAS, including via the sequential or incremental “negotiation” protocols referenced above.
CBSDe Apparatus
[0249]
[0250] As shown, the CBSDe 406 includes, inter alia, a processor apparatus or subsystem 1345, a program memory module 1350, mass storage 1348 (e.g., HDD, SSD such as NAND-based flash memory, or other), baseband processor/MAC 1333, one or more network interfaces 1356, as well as one or more radio frequency (RF) devices (e.g., LTE or 5G NR radios) 1331 having, inter alia, antenna(e) 1321 and one or more RF front end modules for e.g., DAC/ADC, downconversion/upconversion/mixer functions, etc. Also included is a load balancing logic module 1311 which implements load balancing functions for the CBSDe. The radios 1331 may utilize for example OFDM-based modulation consistent with 3GPP protocols.
[0251] At a high level, the CBSDe maintains in effect two “stacks”; (i) a CBRS-compliant stack for communication of the CBSDe (acting as a CBRS-compliant entity) with other CBRS entities such as SASe/DP, according to e.g., the Signaling Protocols and Procedures for Citizens Broadband Radio Service (CBRS): Spectrum Access System (SAS) - Citizens Broadband Radio Service Device (CBSD) Interface Technical Specification - Document WINNF-TS-0016, Version V1.2.1. 3, January 2018, incorporated herein by reference in its entirety; and (ii) a 3GPP-coompliant LTE/LTE-A/5G NR “stack” for CBSDe (acting as a EUTRAN eNB or gNB) communications with 3GPP-compliant UEs (mobile devices or FWA 314 - see
[0252] The load balancing module 1311 (here, implemented as a separate ASIC or processor) manages the load balancing between different CBSDe 406. For example, in one embodiment, the LB module 1311 is configured to evaluate loading on the CBSDe 406 from e.g., UE/FWA 314, and determine situations where load balancing may be appropriate. Such situations may be e.g., where data throughput associated with a particular sector is approaching or at capacity, when the backhaul is depleted (e.g., high packet latency on a DOCSIS backhaul), or other such conditions exist. In such cases, the LB logic 1311 may generate a message or request to another CBSDe (e.g., via the X2 interface) to transfer load, such as by moving one or more served UE/FWA to the target CBSDe on another frequency band. In that load balancing may be best served via a network-wide view of all CBSDe devices, the LB module 1311 may also be communicative with a network-based LB logic module 1477 (see
[0253] The CBSDe 406 of
[0254] The RF antenna(s) 1321 are configured to detect and transceive signals from radio access technologies (RATs) in the service area or venue with which the CBSDe is associated. For example, LTE (including, e.g., LTE, LTE-A, LTE-U, LTE-LAA) signals may be used as the basis of communication between the CBSDe 406 and the various mobile devices (e.g., UEs) and/or FWA devices. The antenna(s) 1321 may include multiple spatially diverse individual elements in e.g., a MIMO- or MISO-type configuration, such that spatial diversity of the transceived signals can be utilized, and likewise may be sectorized (e.g., wherein each of a plurality of elements only covers a prescribed azimuth or sector, as described with respect to
[0255] In the exemplary embodiment, the radio interface(s) 1331 comprise one or more LTE/5G-based radios compliant with 3GPP. Additional unlicensed, licensed, or quasi-licensed air interfaces may also be used within the CBSDe, including e.g., Wi-Fi, non-CBRS band LTE, 5G NR mmWave, or others. Moreover, the LTE radio functionality may be extended to incipient 3GPP-based 5G NR protocols; e.g., at maturation of LTE deployment and when 5G NR-enabled handsets are fielded, such adaptation being accomplished by those of ordinary skill given the contents of the present disclosure.
[0256] As a brief aside, NG-RAN or “NextGen RAN (Radio Area Network)” is part of the 3GPP “5G” next generation radio system. 3GPP is currently specifying Release 17 NG-RAN, its components, and interactions among the involved nodes including so-called “gNBs” (next generation Node B's or eNBs). NG-RAN will provide very high-bandwidth, very low-latency (e.g., on the order of 1 ms or less “round trip”) wireless communication and efficiently utilize, depending on application, both licensed and unlicensed spectrum of the type described supra in a wide variety of deployment scenarios, including indoor “spot” use, urban “macro” (large cell) coverage, rural coverage, use in vehicles, and “smart” grids and structures. NG-RAN will also integrate with 4G/4.5G systems and infrastructure, and moreover new LTE entities are used (e.g., an “evolved” LTE eNB or “eLTE eNB” which supports connectivity to both the EPC (Evolved Packet Core) and the NR “NGC” (Next Generation Core).
[0257] As such, the various aspects of the present disclosure can be readily adapted for use within the 5G NR context, including use of a CBSDe/gNB, and associated CU/DU functionality and “splits” to implement the cluster management and load balancing functions described herein. For instance, in one variant, the DU devices of a given CBSDe (“gNBe”) may be individually managed as cluster participants, such as where a DU from one gNBe and a proximate DU from another gNBe are grouped into a common cluster and managed as such, even though their respective CUs may not be proximate to one another. Similarly, where a given gNBe has multiple DU (e.g., say ten), the individual DU can be clustered in subsets (and with DU of other gNBe) such that intra-gNBe clustering, overlap management, and load balancing can be performed.
[0258] Moreover, individual sectors of individual DU (each sector with its own PCI) can be grouped within clusters as previously described, and hence in some variants sectors of the same DU may be part of respective different VCs.
[0259] The RF radios 1331 in one embodiment comprises a digitally controlled RF tuner capable of reception of signals via the RF front end (receive chain) of the RF radio(s) in the aforementioned bands, including in one variant simultaneous reception of CBRS and non-CBRS bands (e.g., both 2.300 to 2.500 and 3.550 to 3.700 GHz bands at the same time).
Service Provider Network
[0260]
[0261] The exemplary service provider network 1400 is used in the embodiment of
[0262] The individual CBSDe devices 406 are backhauled by the CMs 1405 to the MSO core 307, and the MSO core 307 includes at least some of the EPC/5GC core functions. Each of the CPE/FWA 1411 and UE 314 are communicative with their respective CBSDe devices 406 via CBRS wireless links. Client devices 1414 such as tablets, smartphones, SmartTVs, etc. at each premises are served by respective WLAN routers 1409, the latter which are backhauled to the MSO core or backbone via their respective CPE/FWA 1411.
[0263] In addition, some of the individual CBSDe devices 406 are backhauled by the MNO core 1423, and the MNO core includes at least some of the EPC/5GC core functions as well. Each of UE 314 are communicative with their respective CBSDe’s 406. In one such scenario, UE users are customers of the MSO (e.g., subscribers), and the MSO and MNO have a contractual relationship to provide services to MSO subscribers when they are out of coverage areas maintained by the MSO (e.g., “out of network” for CBRS coverage, or roaming).
[0264] The approach of
[0265] It will be recognized that while certain aspects of the disclosure are described in terms of a specific sequence of steps of a method, these descriptions are only illustrative of the broader methods of the disclosure, and may be modified as required by the particular application. Certain steps may be rendered unnecessary or optional under certain circumstances. Additionally, certain steps or functionality may be added to the disclosed embodiments, or the order of performance of two or more steps permuted. All such variations are considered to be encompassed within the disclosure disclosed and claimed herein.
[0266] While the above detailed description has shown, described, and pointed out novel features of the disclosure as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or process illustrated may be made by those skilled in the art without departing from the disclosure. This description is in no way meant to be limiting, but rather should be taken as illustrative of the general principles of the disclosure. The scope of the disclosure should be determined with reference to the claims.
[0267] It will be further appreciated that while certain steps and aspects of the various methods and apparatus described herein may be performed by a human being, the disclosed aspects and individual methods and apparatus are generally computerized/computer-implemented. Computerized apparatus and methods are necessary to fully implement these aspects for any number of reasons including, without limitation, commercial viability, practicality, and even feasibility (i.e., certain steps/processes simply cannot be performed by a human being in any viable fashion).