Patent Description:
A communication system includes a downlink (DL) that conveys signals from transmission points, such as base stations (BSs), to reception points, such as user equipments (UEs). The communication system also includes an uplink (UL) that conveys signals from transmission points, such as UEs, to reception points, such as BSs.

To meet the demand for wireless data traffic having increased since deployment of 4th generation (<NUM>) communication systems, efforts have been made to develop an improved 5th generation (<NUM>) or pre-<NUM> communication system. The <NUM> or pre-<NUM> communication system is also called a 'beyond <NUM> network' or a 'post long term evolution (LTE) system'. To decrease propagation loss of the radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and large scale antenna techniques are discussed with respect to <NUM> communication systems. In the <NUM> system, hybrid frequency shift keying (FSK) and Feher's quadrature amplitude modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet of everything (IoE), which is a combination of the loT technology and the big data processing technology through connection with a cloud server, has emerged.

In line with this, various attempts have been made to apply <NUM> communication systems to loT networks. Application of a cloud RAN as the above-described big data processing technology may also be considered to be as an example of convergence between the <NUM> technology and the loT technology.

<CIT> describes a method for centralized radio resource allocation in a communication network including a Network Control and Management System and at least one Base Station Cluster having a set of Base Station Entities to which respective permutation zones and radio resources are to be allocated.

<CIT> is concerned with a wireless communication system which is comprised of multiple radio access networks, RANs, which at least partly share the same frequency spectrum.

Optional features of the invention are carried out according to the dependent claim.

In the following, <FIG> and their description is according to the claimed invention. The remaining description does not or does not fully correspond to the claimed invention but is useful for understanding the invention.

An electronic device, a base station, and methods for managing a shared spectrum are provided. The electronic device includes at least one processor configured to cause the electronic device to obtain coexistence measurement reports (CMRs) from the plurality of BSs, identify interference relationships among the plurality of BSs based on the CMRs, assign a set of BSs to one or more basic allocation units (BAUs) in a plurality of BAUs based on the interference relationships, and transmit a spectrum access grant (SAG) to the set of BSs.

For a more complete understanding of this disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:.

Embodiments of the present disclosure include an electronic device and corresponding method for managing a shared spectrum, and a base station (BS) for operating in a shared spectrum. One embodiment is directed to an electronic device that includes a memory storing instructions for managing the shared spectrum, and at least one processor operably connected to the memory and configured to execute the instructions to cause the electronic device to obtain coexistence measurement reports (CMRs) from the plurality of BSs; identify interference relationships among the plurality of BSs based on the CMRs; assign a set of BSs to one or more basic allocation units (BAUs) in a plurality of BAUs based on the interference relationships; and transmit a spectrum access grant (SAG) to the set of BSs, wherein the SAG includes BAU assignments for the set of BSs. Each BAU in the plurality of BAUs is a time/frequency unit and the set of BSs includes a primary BS and a secondary BS. The secondary BS can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of the primary BS.

In one embodiment, to assign the set of BSs to the one or more BAUs, the at least one processor is further configured to execute the instructions to assign the primary BS to a prioritized transmission period in the one or more BAUs, wherein the primary BS can transmit in the prioritized transmission period without performing channel sensing, and assign the secondary BS to an offset period in the one or more BAUs, wherein the secondary BS can transmit in the offset period after performing channel sensing.

In one embodiment, the at least one processor is configured to execute the instructions to further cause the electronic device to: assign another primary BS to one or more other BAUs in the plurality of BAUs based on the interference relationships, wherein the other primary BS interferes with the primary BS, and wherein the one or more other BAUs is orthogonal to the one or more BAUs.

In one embodiment, the at least one processor is configured to execute the instructions to further cause the electronic device to: assign a tertiary BS to the one or more BAUs for transmitting in an opportunistic data transmission period (ODTP) in the one or more BAUs, wherein the tertiary BS can transmit in the ODTP after performing a listen-before-talk procedure.

In one embodiment, the CMRs include at least one of a BS identifier, a mobile network operator identifier, a list of neighboring BSs, power levels associated with BSs in the list of neighboring BSs, a list of BSs causing detrimental interference, a transmit power, received signal strength indicator measurements, reference signal receive power measurements, reference signal received quality measurements, load information, channel occupancy measurements, indicators for protected BAUs that are no longer used, indicators for BAU indices experiencing interference, and timestamp data.

In one embodiment, the SAG further includes at least one of a BS identifier, a mobile network operator identifier, an overall frame structure for the shared spectrum, detection threshold function parameters, a maximum allowed transmission power, a contention window size, a protection margin for opportunistic channel access, a synchronization source identifier, BAU allocation for each mobile network, BAU allocation for each BS, transmission opportunity offset assignments, a maximum channel occupancy time, and timestamp data.

In one embodiment, to assign the primary BS to the one or more BAUs in the plurality of BAUs based on the interference relationships, the at least one processor is configured to execute the instructions to further cause the electronic device to: generate an interference graph that represents each BS in the plurality of BSs as a vertex with one or more of the interference relationships identified by edges between vertices; for each vertex, compute a resource reservation ratio based on vertex priority and a number of connected components; and assign the primary BS to the one or more BAUs based on the resource reservation ratio.

Another embodiment is directed to a BS for operating in a shared spectrum. The BS includes a transceiver and at least one processor connected to the transceiver. The at least one processor is configured to control the transceiver to transmit a coexistence measurement report (CMR) to a shared spectrum manager (SSM) and control the transceiver to receive a spectrum access grant (SAG) originating from the SSM which includes a set of assignments for one or more basic allocation units (BAUs) for the BS. The CMR indicates interference relationships between the BS and neighboring BSs. Each of the one or more BAUs is a time/frequency unit, and the set of assignments indicates that the BS is a primary BS or a secondary BS that can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of another primary BS assigned to the one or more BAUs. The BS also includes a processor operably connected to the transceiver, the at least one processor configured to generate the CMR and identify transmission opportunities for the BS based on the set of assignments for the one or more BAUs.

In another embodiment, when the SAG indicates that the BS is the primary BS in the one or more BAUs, the at least one processor is further configured to control the transceiver to transmit data in a prioritized transmission period in the one or more BAUs without channel sensing being performed on the channel. When the SAG indicates that the BS is the secondary BS in the one or more BAUs, to identify the transmission opportunities for the BS, the at least one processor is further configured to perform channel sensing prior to an offset period, and wherein the transceiver is further configured to transmit the data in the offset period after performance of the channel sensing. In another embodiment, when the SAG indicates that the BS is the primary BS in the one or more BAUs, when another SAG identifies another primary BS is assigned to the one or more other BAUs, and when the other primary BS interferes with the BS, the one or more other BAUs is orthogonal to the one or more BAUs.

In another embodiment, when the SAG indicates that the BS a tertiary BS in the one or more BAUs, the BS is assigned to transmit in an opportunistic data transmission period (ODTP) in the one or more BAUs after performing a listen-before-talk procedure.

In another embodiment, the CMR includes at least one of a BS identifier, a mobile network operator identifier, a list of neighboring BSs, power levels associated with BSs in the list of neighboring BSs, a list of BSs causing detrimental interference, a transmit power, received signal strength indicator measurements, reference signal receive power measurements, reference signal received quality measurements, load information, channel occupancy measurements, indicators for protected BAUs that are no longer used, indicators for BAU indices experiencing interference, and timestamp data.

In another embodiment, the SAG further includes at least one of a BS identifier, a mobile network operator identifier, an overall frame structure for the shared spectrum, detection threshold function parameters, a maximum allowed transmission power, a contention window size, a protection margin for opportunistic channel access, a synchronization source identifier, BAU allocation for each mobile network, BAU allocation for each BS, transmission opportunity offset assignments, a maximum channel occupancy time, and timestamp data.

In another embodiment, the BS is assigned to the one or more BAUs in a shared spectrum based on an interference graph that represents each BS in a plurality of BSs of the shared spectrum as a vertex with one or more of the interference relationships identified by edges between vertices. In addition, each vertex is associated with a resource reservation ratio based on vertex priority and a number of connected components.

Yet another embodiment is directed to a method for managing a shared spectrum. The method includes obtaining coexistence measurement reports (CMRs) from the plurality of BSs, identifying interference relationships among the plurality of BSs based on the CMRs, assigning a set of BSs to one or more (basic allocation units) BAUs in a plurality of BAUs based on the interference relationships, and transmitting a spectrum access grant (SAG) to the set of BSs which includes BAU assignments for the set of BSs. Each BAU in the plurality of BAUs is a time/frequency unit. In addition, the set of BSs includes a primary BS and a secondary BS that can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of the primary BS.

In yet another embodiment, assigning the set of BSs to the one or more BAUs may further include assigning the primary BS to a prioritized transmission period in the one or more BAUs, wherein the primary BS can transmit in the prioritized transmission period without performing channel sensing and assigning the secondary BS to an offset period in the one or more BAUs, wherein the secondary BS can transmit in the offset period after performing channel sensing.

In yet another embodiment, the method may further include assigning another primary BS to one or more other BAUs in the plurality of BAUs based on the interference relationships, wherein the other primary BS interferes with the primary BS, and wherein the one or more other BAUs is orthogonal to the one or more BAUs.

In yet another embodiment, the method may further include assigning a tertiary BS to the one or more BAUs for transmitting in an opportunistic data transmission period (ODTP) in the one or more BAUs, wherein the tertiary BS can transmit in the ODTP after performing a listen-before-talk procedure.

In yet another embodiment, the CMRs include at least one of a BS identifier, a mobile network operator identifier, a list of neighboring BSs, power levels associated with BSs in the list of neighboring BSs, a list of BSs causing detrimental interference, a transmit power, received signal strength indicator measurements, reference signal receive power measurements, reference signal received quality measurements, load information, channel occupancy measurements, indicators for protected BAUs that are no longer used, indicators for BAU indices experiencing interference, and timestamp data.

In yet another embodiment, the SAG further includes at least one of a BS identifier, a mobile network operator identifier, an overall frame structure for the shared spectrum, detection threshold function parameters, a maximum allowed transmission power, a contention window size, a protection margin for opportunistic channel access, a synchronization source identifier, BAU allocation for each mobile network, BAU allocation for each BS, transmission opportunity offset assignments, a maximum channel occupancy time, and timestamp data.

The figures included herein, and the various embodiments used to describe the principles of the present disclosure are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Further, those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged wireless communication system.

The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether those elements are in physical contact with one another. The term "processor" or "controller" means any device, system or part thereof that controls at least one operation. Likewise, the term "set" means one or more. Accordingly, a set of items can be a single item or a collection of two or more items.

Definitions for other certain words and phrases are provided throughout this disclosure.

Spectrum utilizations may fluctuate temporally and geographically. Sharing the spectrum via multiplexing between different entities will enable more efficient utilization of the spectrum, whether it is unlicensed or shared spectrum. As used herein, the term "shared spectrum" is used in an inclusive manner without the distinction between the shared spectrum and unlicensed spectrum and it also includes not only the currently available spectrums but also spectrums that will be made available in the future.

In existing unlicensed spectrums, e.g., <NUM>, <NUM>, channel access may be based on random access, i.e., carrier sense multiple access/collision avoidance (CSMA/CA). It is known that CSMA/CA with exponential backoff lowers the airtime utilization efficiency when the network densifies. Sharing may be non-cooperative as it is based on regulations set by regulatory bodies and controlled by fixed rules. Fundamentally, there is no guarantee of spectrum access. Therefore, it may be disadvantageous for operators to use these unlicensed spectrums to deploy infrastructure systems for providing paid services to mobile subscribers, since the reliability and accessibility of the service cannot be guaranteed.

Novel aspects of this disclosure may improve over this scheme by enabling multiplexing of users in the time dimension as well. Additionally, the medium access control scheme may allow a secondary user to opportunistically access resources when the primary user is idle, or in the case that the primary user will not be impacted by interference from the secondary user's transmission.

Increasing the deployment density of BSs may be a way to increase data throughput, via spatial reuse of frequencies. In fact, such spatial reuse may have been one of the main contributors for increase in system throughput since the early days of cellular communication. While improving spatial reuse, a dense BS deployment may be inevitable at millimeter wave (mm-wave) and terahertz (THz) frequencies to improve coverage, by compensating for the pathloss and blockage.

Another way of increasing data throughput in the United States may involve the opening of unlicensed or shared spectrums. For example, <NUM>-<NUM> Citizens Broadband Radio Service (CBRS) band may have a unique three-tiered, hierarchical access model, which includes incumbent (Federal user, Fixed Satellite Service), priority access licensees (PALs), and general authorized access (GAA) in descending order of priority. In another example, <NUM>-<NUM> band and <NUM>-<NUM> band are under consideration in United States and European Union, respectively, for unlicensed use. In yet another example, <NUM>-<NUM> band is expected to be opened and shared between commercial systems and future federal systems. The sharing framework is expected to be distinguished from general unlicensed spectrum.

<FIG> illustrates an exemplary networked computing system according to various embodiments of this disclosure. The embodiment of the wireless network <NUM> shown in <FIG> is for illustration only.

As shown in <FIG>, the wireless network <NUM> may include an gNodeB (gNB) <NUM>, an gNB <NUM>, and an gNB <NUM>. The gNB <NUM> may communicate with the gNB <NUM> and the gNB <NUM>. The gNB <NUM> may also communicate with at least one Internet Protocol (IP) network <NUM>, such as the Internet, a proprietary IP network, or other data network.

The gNB <NUM> may provide wireless broadband access to the network <NUM> for a first plurality of user equipments (UEs) within a coverage area <NUM> of the gNB <NUM>. The first plurality of UEs may include a UE <NUM>, which may be located in a small business (SB); a UE <NUM>, which may be located in an enterprise (E); a UE <NUM>, which may be located in a WiFi hotspot (HS); a UE <NUM>, which may be located in a first residence (R); a UE <NUM>, which may be located in a second residence (R); and a UE <NUM>, which may be a mobile device (M) like a cell phone, a wireless laptop, a wireless PDA, or the like. The gNB <NUM> may provide wireless broadband access to the network <NUM> for a second plurality of UEs within a coverage area <NUM> of the gNB <NUM>. The second plurality of UEs may include the UE <NUM> and the UE <NUM>. In some embodiments, one or more of the gNBs <NUM>-<NUM> may communicate with each other and with the UEs <NUM>-<NUM> using <NUM>, LTE, LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, other well-known terms may be used instead of "gNodeB" or "gNB," such as "base station" or "access point. " For the sake of convenience, the terms "gNodeB" and "gNB" are used in this disclosure to refer to network infrastructure components that provide wireless access to remote terminals. Also, depending on the network type, other well-known terms may be used instead of "user equipment" or "UE," such as "mobile station," "subscriber station," "remote terminal," "wireless terminal," or "user device. " For the sake of convenience, the terms "user equipment" and "UE" are used in this disclosure to refer to remote wireless equipment that wirelessly accesses an gNB, whether the UE is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer or vending machine).

Dotted lines may show the approximate extents of the coverage areas <NUM> and <NUM>, which are shown as approximately circular for the purposes of illustration and explanation only.

As described in more detail below, BSs in a networked computing system can be managed to allow spectrum sharing based on interference relationships between BSs. In some embodiments, a shared spectrum manager in the networked computing system can provide a centralized resource coordination and assignment scheme by transmitting spectrum access grants to the BSs based upon coexistence measurement reports received from the BSs. As discussed in more detail in the paragraphs that follow, the SSM may enable priority-based and opportunistic channel access through assigning different offsets to MNO and/or each base station.

Although <FIG> illustrates one example of a wireless network <NUM>, various changes may be made to <FIG>. For example, the wireless network <NUM> could include any number of gNBs and any number of UEs in any suitable arrangement. Further, the gNB <NUM>, <NUM>, and/or <NUM> could provide access to other or additional external networks, such as external telephone networks or other types of data networks.

<FIG> illustrates an exemplary base station (BS) according to various embodiments of this disclosure. However, gNBs come in a wide variety of configurations, and <FIG> does not limit the scope of this disclosure to any particular implementation of an gNB.

As shown in <FIG>, the gNB <NUM> may include multiple antennas 280a-280n, multiple RF transceivers 282a-282n, transmit (TX) processing circuitry <NUM>, and receive (RX) processing circuitry <NUM>. The gNB <NUM> may also include a controller/processor <NUM>, a memory <NUM>, and a backhaul or network interface <NUM>.

The RF transceivers 282a-282n may receive, from the antennas 280a-280n, incoming RF signals, such as signals transmitted by UEs in the network <NUM>. The RF transceivers 282a-282n may down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals may be sent to the RX processing circuitry <NUM>, which generates processed baseband signals by filtering, decoding, and/or digitizing the baseband or IF signals. The RX processing circuitry <NUM> may transmit the processed baseband signals to the controller/processor <NUM> for further processing.

The TX processing circuitry <NUM> may receive analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller/processor <NUM>. The TX processing circuitry <NUM> may encode, multiplex, and/or digitize the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers 282a-282n may receive the outgoing processed baseband or IF signals from the TX processing circuitry <NUM> and up-convert the baseband or IF signals to RF signals that are transmitted via the antennas 280a-280n.

The controller/processor <NUM> can include one or more processors or other processing devices that control the overall operation of the gNB <NUM>. For example, the controller/ processor <NUM> could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 282a-282n, the RX processing circuitry <NUM>, and the TX processing circuitry <NUM> in accordance with well-known principles. The controller/ processor <NUM> could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller/processor <NUM> could support beam forming or directional routing operations in which outgoing signals from multiple antennas 280a-280n are weighted differently to effectively steer the outgoing signals in a desired direction. Any of a wide variety of other functions could be supported in the gNB <NUM> by the controller/processor <NUM>. In some embodiments, the controller/processor <NUM> may include at least one microprocessor or microcontroller.

The controller/processor <NUM> may be also capable of executing programs and other processes resident in the memory <NUM>, such as a basic OS.

The controller/processor <NUM> may be also coupled to the backhaul or network interface <NUM>. The backhaul or network interface <NUM> may allow the gNB <NUM> to communicate with other devices or systems over a backhaul connection or over a network. The interface <NUM> may include any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver.

The memory <NUM> may be coupled to the controller/processor <NUM>.

As described in more detail below, base stations in a networked computing system can be assigned as primary, secondary, and/or tertiary users of shared spectrum resources (i.e., BAUs) based on interference relationships with other neighboring BSs. Primary base station stations can transmit on a channel without first sensing the channel. Secondary base stations can transmit on the channel after a sensing operation determines that its data transmissions would not interfere with data transmissions of primary base stations. Tertiary base stations can transmit data on a channel in an opportunistic data transmission period, if available.

<FIG> illustrates an exemplary electronic device for managing a shared spectrum in the networked computing system according to various embodiments of this disclosure. In one embodiment, the electronic device may be a shared spectrum manager implemented as a server <NUM>, which can represent server <NUM> in <FIG>.

As shown in <FIG>, the server <NUM> may include a bus system <NUM>, which supports communication between at least one processing device <NUM>, at least one storage device <NUM>, at least one communications unit <NUM>, and at least one input/output (I/O) unit <NUM>.

The processing device <NUM> may execute instructions that may be loaded into a memory <NUM>. The processing device <NUM> may include any suitable number(s) and type(s) of processors or other devices in any suitable arrangement. Example types of processing devices <NUM> include microprocessors, microcontrollers, digital signal processors, field programmable gate arrays, application specific integrated circuits, and discreet circuitry.

The memory <NUM> and a persistent storage <NUM> are examples of storage devices <NUM>, which represent any structure(s) capable of storing and facilitating retrieval of information (such as data, program code, and/or other suitable information on a temporary or permanent basis). The memory <NUM> may represent a random access memory or any other suitable volatile or non-volatile storage device(s). The persistent storage <NUM> may contain one or more components or devices supporting longer-term storage of data, such as a read only memory, hard drive, Flash memory, or optical disc.

The communications unit <NUM> may support communications with other systems or devices. For example, the communications unit <NUM> could include a network interface card or a wireless transceiver facilitating communications over the network <NUM>. The communications unit <NUM> may support communications through any suitable physical or wireless communication link(s).

The I/O unit <NUM> may allow for input and output of data. For example, the I/O unit <NUM> may provide a connection for user input through a keyboard, mouse, keypad, touchscreen, or other suitable input device. The I/O unit <NUM> may also send output to a display, printer, or other suitable output device.

As described in more detail below, the server <NUM> can serve as a shared spectrum manager in a networked computing system can coordinate resource assignment to enable priority-based and opportunistic channel access through use of offsets in base allocation units identifiable by time slots and frequency bands.

Although <FIG> illustrates an example of an electronic device in a computing system for managing a shared spectrum among a plurality of base stations, such as base stations <NUM>, <NUM>, and <NUM> in <FIG>, various changes may be made to <FIG>. For example, various components in <FIG> can be combined, further subdivided, or omitted and additional components could be added according to particular needs. In addition, as with computing and communication networks, servers can come in a wide variety of configurations, and <FIG> does not limit this disclosure to any particular server.

<FIG> illustrates a network for spectrum sharing according to various embodiments of this disclosure. Network <NUM> may be a network computing system such as networked computing system <NUM> in <FIG>.

The network <NUM> may include multiple BSs from different mobile network operators (MNOs), i.e., wireless service providers, coexisting in proximity with each other. As an example, BS <NUM> and BS <NUM> may belong to the same MNO, e.g., "MNO B", and BS <NUM> and BS <NUM> may belong to another operator, e.g., "MNO A". However, the particular depiction of the network in <FIG> is exemplary and not limiting. Thus, in other embodiments, the number of mobile network operators can differ, each with different systems and technologies sharing the spectrum.

In <FIG>, BSs that interfere with one another are connected by dashed lines <NUM>. For example, BS <NUM> and BS <NUM> may interfere with each other and be connected by dashed line 405a; BS <NUM> and BS <NUM> may interfere with each other and be connected by dashed line 405e; BS <NUM> and BS <NUM> may interfere with each other and be connected by dashed line 405d; BS <NUM> and BS <NUM> may interfere with each other and be connected by dashed line 405b; and BS <NUM> and BS <NUM> may interfere with each other and be connected by dashed line 405c. BS <NUM> and BS <NUM> may be separated by enough of a distance to prevent interference with one another.

Each of the BSs <NUM>, <NUM>, <NUM>, and <NUM> may be connected by their respective backhaul links <NUM> to shared spectrum manager (SSM) <NUM>. SSM <NUM> may be one or more electronic devices for managing the shared spectrum, such as electronic device <NUM> in <FIG>. In a non-limiting embodiment, the SSM <NUM> may be an entity in the core network of each MNO and configured to communicate with each other to manage the shared spectrum among BSs of all the MNOs. In another non-limiting embodiment, the SSM <NUM> may be a third-party entity that does not belong to any of the MNOs but be configured to communicate with the different operators' networks for managing the shared spectrum among BSs of the MNOs.

<FIG> illustrates another network for spectrum sharing according to various embodiments of this disclosure. Network <NUM> is a network computing system such as networked computing system <NUM> in <FIG>.

The network <NUM> may differ from the network <NUM> in that each BS communicates with an entity in its own MNO core network (CN) over backhaul links <NUM> rather than communicating directly to SSM <NUM>. In this embodiment in <FIG>, BSs <NUM> and <NUM> may communicate with CN entity 504a over backhaul links 507a and BSs <NUM> and <NUM> may communicate with CN entity 504b over backhaul links 507b. The CN entities 504a and 504b may communicate with SSM <NUM> over their respective communication links <NUM>. CN entities 504a and 504b can handle aggregation of data and/or transfer of messages, such as measurement reports, from the BSs to the SSM <NUM>. The CN entities may also handle reception of messages from the SSM <NUM> on behalf of the BSs along with handling configuration of the BSs based on the parameters in these messages.

<FIG> illustrates a data transmission frame structure for spectrum sharing according to various embodiments of this disclosure. The frame structure <NUM> may define the resources that are shared among BSs in a networked computing system, such as networked computing system <NUM> in <FIG>, network <NUM> in <FIG>, and network <NUM> in <FIG>.

Frame structure <NUM> may include data transmission phase (DTP) cycles 602a through 602n, which are repeated sequences of time slots that can occupy a number of frequency spectrum bands (i.e., channels) <NUM>. In <FIG>, frame structure <NUM> may have M spectrum bands f<NUM> through fM.

A time slot over one frequency band may be referred to as a Basic Allocation Unit (BAU). In the embodiment in <FIG>, each DTP cycle <NUM> may have K time slots 604a through <NUM> in the time dimension spanning M frequency bands. Thus, each DTP cycle can include a total of K x M BAUs. However, in other embodiments, the number of spectrum bands, time slots, bandwidth, center frequency, and duration of time slots can differ.

<FIG> illustrates assignment of base allocation units (BAUs) over one data transmission phage (DTP) cycle for spectrum sharing according to various embodiments of this disclosure. In this embodiment, DTP cycle <NUM> includes a set of BAUs <NUM> over a single frequency <NUM>.

BSs A1, A2, B1, and B2 may correspond to BSs <NUM>, <NUM>, <NUM>, and <NUM> in <FIG>, respectively. Thus, BS B1 and A2 may be geographically separated and not in an interfering relationship so that they can be assigned to the same BAUs 704b and 704e for transmission. In contrast, BSs <NUM>, <NUM>, and <NUM> may be in a mutually interfering relationship, as are BSs <NUM>, <NUM>, and <NUM>. Thus, BSs <NUM>, <NUM>, and <NUM> may be assigned BAUs in an orthogonal manner. Likewise, BSs <NUM>, <NUM>, and <NUM> may be assigned BAUs in an orthogonal manner. For example, BS A1 of MNO A can transmit in BAUs 704a and 704d. BS B2 of MNO B can transmit in BAU 704c, which is orthogonal to BAUs 704a and 704d.

BAUs <NUM> may be Not Allocated (NA) to any MNO/BS and may be accessed according to the opportunistic access scheme described in <FIG> that follows.

Each of the BAUs in the set of BAUs <NUM> can be shared between one or more primary base stations and one or more secondary base stations. BSs assigned to a BAU may also be referred to in the alternative as "a user" of the resource. Further, a primary base station may also be referred to as a "protected base station" or a "protected user".

MNOs or a set of BSs assigned to a BAU can be granted protected access to one or more BAUs, which effectively prioritizes the availability of these resources for the protected users over other users. Protected access may be controlled by issuing Spectrum Access Grants (SAGs) to MNOs and/or BSs by an SSM, such as SSM <NUM> in <FIG> and <FIG>. The SSM <NUM> may serve as a database of SAGs which can be accessed by the protected user. SAGs may be transmitted as messages to users over the connections depicted in <FIG> and <FIG>. In one embodiment, SAGs may include information elements indicating that BAUs are reserved for specific users. These are known as "protected BAUs". Protected BAU assignments may be issued to MNOs by a central spectrum licensing authority, such as a government regulator.

In another example, MNOs or network entities belonging to each MNO may negotiate among themselves to establish protected BAU assignments. The assignment of protected BAUs may change over time and may be periodically updated. In a SAG, BAU assignments are assigned to individual BSs (as like in the invention), a set of multiple BSs or an entire MNO network. As an example, the assignments for the BAUs in slots <NUM> may indicate that the MNO A network may access resources (f<NUM>,t<NUM>) of the DTP cycle. How the resources are utilized by different BSs belonging to MNO A may then be decided independently by the MNO.

Each BAU may be divided into symbols <NUM>. The primary assignees, i.e., primary base stations, of the BAU may begin transmitting in a prioritized transmission period 716a without first performing spectrum sensing. In the BAU 704e, the prioritized transmission period 716a may be found at the beginning of the BAU. In this example in <FIG>, BSs A2 and B1 may be the primary base stations assigned to BAU 704e. One or more BSs may also be assigned to one or more secondary transmission opportunity (TXOP) offsets 716b and 716c. These TXOP offsets may also be referred to herein as "offset periods". BSs may be assigned to a secondary TXOP by the SSM, which provides additional opportunities for BSs to transmit within the BAU. TXOP offset assignments may also be provided in the SAG and can also apply to assigned BAUs 704a, 704b, 704c, and 704d. Multiple BSs may be assigned to the same TXOP offset and a given BS may have multiple TXOP offsets assigned. In this illustrative embodiment, BS A1 and B2 may be secondary BSs transmitting in offset periods 716b and 716c, respectively.

Before transmitting at the secondary TXOP offsets, the corresponding BS may first sense the channel during the Clear Channel Assessment (CCA) periods <NUM>, as described below in flowchart <NUM> in <FIG>. If the channel is clear, the BS can begin transmitting at the following TXOP offset and may transmit for the remaining duration of the BAU, or for some Maximum Channel Occupancy Time (MCOT), if specified. The MCOT may be the maximum time duration that a BS may transmit within the BAU before releasing the resource. Additionally, a BAU may be configured with an Opportunistic Data Transmission Period (ODTP) <NUM>, which also may involve the CCA procedure in flowchart <NUM>. The location of the secondary TXOPs and ODTP within the BAU period may be indicated by the SSM in the SAG. Secondary TXOP and ODTP locations, along with the location and duration of the CCA periods, may be specified in terms of individual symbol, sample or time offsets. In another embodiment the TXOP and ODTP can be chosen by each BS or each MNO in a distributed fashion, either randomly or based on some metric.

In one embodiment, assignment of resources via SAGs may restrict access to BAUs by only protected users specified in the SAGs, which prevents other MNOs and/or BSs from transmitting in these resources regardless of whether they could cause interference with the protected user or users. In another embodiment, a "soft licensing" scheme may be employed where the protected users are considered the primary assignee of the protected BAUs and may transmit in these resources without first needing to sense the channel for ongoing transmissions from other users. However, this embodiment, secondary users may opportunistically access the same BAU if the primary users are not actively utilizing the BAU or if the secondary user's transmission would not cause significant interference to the primary users. As an example, LBT may be employed by a secondary user to avoid collision with a primary user in the same BAU. By specifying TXOP offsets in a SAG, secondary users may be granted priority access to protected BAUs but with lower priority than the primary users. Each TXOP offset may apply to one or more secondary users.

As an alternative embodiment, any user may operate as a secondary user and transmit at specified TXOP offsets, regardless of whether they have been granted explicit access to the BAU in a SAG. In another embodiment, secondary offsets durations can be extended, and a group of BSs may be assigned to contend for access of the duration of the slot via LBT. Thus, the TXOP offset will function as a higher priority ODTP window.

<FIG> illustrates a graph of a detection threshold function according to various embodiments of this disclosure. The detection threshold function represented by graph <NUM> can be used by a BS to determine whether transmission in a secondary transmission opportunity is permissible, as described in more detail in <FIG> that follows.

<FIG> illustrates a flowchart for a general DTP access procedure according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in a BS, such as BS <NUM> in <FIG>.

In operation <NUM>, a check may be made for available assigned resources. A BS receiving assigned resources may be a primary or protected BS for the assigned resource. In operation <NUM>, a check may be made for available opportunistic resources. A BS receiving opportunistic resources may be secondary BS for the assigned resource. In a non-limiting embodiment, the assigned resources and opportunistic resources may be provided in a spectrum access grant (SAG). The SAG can be generated by a shared spectrum manager (SSM), such as SSM <NUM> in <FIG> and <FIG>.

Thereafter, in operation <NUM> transmission resources may be identified based on the checks made in operation <NUM> and <NUM>. The identified resources can be an assigned resource and/or an opportunistic resource. In operation <NUM>, data may be transmitted using the identified resources.

<FIG> illustrates another flowchart for a general DTP access procedure according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in a BS, such as BS <NUM> in <FIG>.

In operation <NUM>, a check may be made for available assigned resources. In operation <NUM>, if assigned resources are not available, a check may be made for available opportunistic resources. Thereafter, in operation <NUM> transmission resources may be identified based on the checks made in operation <NUM> and <NUM>. According to flowchart <NUM>, if assigned resources are available to a BS in operation <NUM>, then the BS will not perform a check for opportunistic resources in operation <NUM>. In operation <NUM>, data may be transmitted using the identified resources.

<FIG> illustrates a flowchart for determining transmission opportunities in a DTP by a base station according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in a BS, such as BS <NUM> in <FIG>, to access DTP resources for a specific BAU.

Flowchart <NUM> may begin at operation <NUM> with a determination as to whether the BS intends to transmit data, i.e., whether the BS has data to transmit. If the BS does not have data to transmit, then flowchart <NUM> may proceed to operation <NUM> where the BS remains in an idle state. However, at operation <NUM>, if the determination is made that the BS has data to transmit, then a determination may be made whether the BS is assigned to a protected BAU in operation <NUM>. If the BS is assigned to a protected BAU, then flowchart <NUM> may proceed to operation <NUM> and the BS may transmit its data on the protected BAU. In one embodiment, the BS can transmit its data at the start of its assigned BAU without first sensing the channel.

It may the case that the BAU is assigned to protected users, but the users are idle during the slot duration, possibly due to having an empty transmit data buffer or other reasons. Also, it is possible that secondary users (who are not allocated as primary users of the BAU), due to geographical separation and/or transmission power requirements, may be able to transmit in the protected BAU without causing high interference, which would affect the on-going transmission of the primary, protected users. It is also possible that the BAU is marked NA in the SAG and thus available to all users for opportunistic transmission. In the case of a NA BAU, the entire duration of the BAU may be treated as an ODTP and accessed in the manner described in more detail in <FIG>.

Returning back to operation <NUM>, if the determination is made that the BS is not assigned to a protected BAU, then flowchart <NUM> may proceed to operation <NUM> where a subsequent determination is made as to whether the BS is assigned to an alternate transmission opportunity, i.e., secondary transmission opportunity, in the BAU, such as secondary transmission opportunities 716b and 716c in <FIG>. If the BS is assigned an alternate transmission opportunity as determined in operation <NUM>, then flowchart <NUM> may proceed to operation <NUM> and the channel may be sensed during the clear channel assessment (CCA) period prior to transmission. In a non-limiting embodiment, the sensing may be performed by detecting RF energy over one or more CCA periods of duration TCCA. The location and duration of the CCA periods may be specified in terms of the symbol index, sample indices, or time or sample offset.

In operation <NUM>, the received power, PRX, may be computed over the CCA period. In one embodiment, PRX may be the total power from other transmitters. In another embodiment, the received power measurements may be considered for each neighboring BS in the comparison operation. In this embodiment, the BS may detect a signal transmitted by neighboring BSs allowing the BS to identify these neighbors.

In operation <NUM> the received power, PRX , may be compared to a threshold. In one embodiment, the threshold may be a function of the intended TX power of the BS, TH(PTX) , as illustrated in <FIG>. In some embodiments, the threshold function can incorporate a detection margin δ to control the spatial reuse. In one embodiment, δ can be set to zero. In another embodiment, δ can be set to a positive value to control the level of the spatial reuse by setting a larger δ value to further discourage opportunistic transmission. In one embodiment, the value δ can be fixed. In another embodiment, the value δ can be different between the BSs belonging to the same network and between the BSs belonging to different networks. That is, there could be δinter-op and δinter-op. With this distinction, a spatial reuse can be allowed more readily and generously between the BSs in the same network. In another embodiment, TH(·) can take the value δ as an input and may return the output threshold value adjusted according to the valueδ.

In one embodiment, the threshold or threshold function, along with the detection margin δ , may be fixed to a value or a specific function or selected among preconfigured values and functions. In another embodiment, it may be assigned dynamically by the SSM in the SAG or negotiated between MNOs with or without assistance from the SSM, or it may be determined by some other means.

Returning to operation <NUM>, if PRX is not greater than the threshold, then flowchart <NUM> may proceed from operation <NUM> to operation <NUM> where the BS may begin transmitting at the assigned transmission opportunity offset following the CCA period and continue transmitting for the remaining duration of the BAU. In another embodiment, the transmission may continue for a specified maximum channel occupancy time, which is less than the remaining BAU duration.

If PRX is greater than the threshold, then flowchart <NUM> may proceed from operation <NUM> to operation <NUM> where a determination is made as to whether the transmission power, PTX , can be decreased. If the transmission power cannot be decreased, then flowchart <NUM> may proceed from operation <NUM> to operation <NUM> to allow the BS to return to the idle state for the remainder of the BAU. If the transmission power can be decreased, then the transmission power may be updated in operation <NUM> and flowchart <NUM> cycles through operations <NUM>, <NUM>, <NUM>, and <NUM> until the received power does not exceed the threshold in operation <NUM> so that the BS can proceed to operation <NUM> to being transmission.

Even if a BS is not assigned to the BAU as a primary BS in operation <NUM> or a secondary base station in operation <NUM>, the BS may still have the opportunity to transmit in the opportunistic data transmission period (ODTP) as a tertiary base station. Thus, if the determination is made that an alternate transmission opportunity has not been assigned in operation <NUM>, then flowchart <NUM> can proceed to operation <NUM> where a determination is made as to whether an ODTP is available. If an ODTP is not available, then flowchart <NUM> may proceed to operation <NUM> and the BS may remain idle for the remainder of the BAU. However, if an ODTP is available in operation <NUM>, then flowchart <NUM> may proceed to operation <NUM> to sense the channel during the CCA period within the ODTP. In the case of transmission in the ODTP, the BS may have to defer transmission until after an additional backoff period, as illustrated by backoff period <NUM> in <FIG>.

From operation <NUM>, flowchart may proceed to operation <NUM> to evaluate the received power and provide the BS with an opportunity to reduce its transmit power, if possible. If the BS is not able to sufficiently reduce its power to avoid interference with an ongoing transmission of its neighbor in the ODTP, the BS will return to the idle state in operation <NUM>.

As already mentioned, ODTPs can be accessed opportunistically by any BS, regardless of protected BAU or secondary TXOP assignments. The ODTP can be accessed in a similar fashion to an assigned TXOPs by first performing the CCA procedure (e.g., operations <NUM>, <NUM>, and <NUM> in <FIG>) and transmitting if the channel is clear within the CCA period.

<FIG> illustrates an opportunistic data transmission period (ODTP) access scheme by a base station according to various embodiments of this disclosure. The ODTP access scheme can be implemented in ODTP <NUM>, which is similar to ODTP <NUM> in <FIG>. In another embodiment, the ODTP access scheme can be implemented in a non-allocated BAU, i.e., a non-assigned BAU, such as NA BAUs <NUM> in <FIG>.

Following the channel busy state <NUM>, there may be a minimum defer duration Dmin <NUM>, , left idle as the original user may resume its transmission. Thus, this minimum defer duration may be a means of providing higher priority to the BS which Dmin reserved the resource. After duration of inactivity, it may be assumed that the original owner has released the reserved resource. After the channel is sensed as idle for the defer duration, a BS will perform additional channel sensing with optional random backoff selected from backoff period <NUM>. The backoff period <NUM> may be formed from a set of time units <NUM>. In one embodiment, the number of random backoff time units <NUM> may be randomly determined. As an example, a random number can be uniformly drawn from [X, Y] value range, where X and Y are non-negative integers representing the minimum and maximum possible values, respectively, of the backoff period <NUM>. In one embodiment, X can be <NUM>. In one embodiment, Y, namely the contention window size (CWS), may be configured or informed to the BSs. In another embodiment, Y can be varying and negotiated between the operators. In one embodiment Y can be common. In another embodiment, Y can be cell specific. In yet another embodiment, Y can be operator specific. After successful channel sensing over the optional random backoff period, the BS may start data transmission in the data transmission state <NUM> until the end <NUM> of the ODTP. In another embodiment, there may be a specified MCOT after which the BS will cease transmitting and release the resource.

To facilitate configuration of BSs by the SSM, each BS may be configured to send Coexistence Measurement Reports (CMRs) to the SSM. A CMR sent by a given BS may include but is not limited to the following list of information elements. The SSM may also specify which of the following information elements are requested, so that the BS may send a subset of the following to the SSM or any required entities.

Identifying information for the MNO and BS. This information element can include the Mobile Network Code (MNC), Mobile Country Code (MCC), the Extended Cell Global Identifier (ECGI), the Physical Cell Identifier (PCI), and/or other similar and related identifiers.

A list of neighboring BSs. This information element can also include associated power levels measured either at the BS or its mobile users, if available. The measurements may be specified on a per-BAU basis.

A list of neighboring BSs and their power levels. This information element can be reported by the current mobile users connected to the BS. These measurements may be specified whenever there are changes in the extended interference map between other BSs and the reporting BS's connected mobile users. The list may contain all other BSs detected by the BS or may be restricted to the set of BSs exceeding a threshold over the reporting period, along with an indication of the BAUs in which the other BSs were detected. Received power may be determined at the BS's receiver by receiving the synchronization signals, reference signals or other signals transmitted by neighboring BSs and reported as a value, e.g., in dBm, measured at the receiver, or some quantized representation of the value. The list may also indicate whether neighboring BSs may be allowed to be assigned to the same protected BAU, or the BS is explicitly requesting to be assigned to the same BAU as these other BSs. This may occur when the BS has multiple neighboring BSs belonging to the same MNO network, which are able to coordinate access among themselves.

A list of specific BSs that have been detected as causing detrimental interference to its users. This information element may also include the indices of protected BAUs in which this interference is occurring. The BS may thus explicitly request to be assigned orthogonal resources from these indicated BSs.

The intended TX power of the BS. This information element can include a single value applying to all BAUs or a list of values per BAU may be provided.

RSSI, RSRP and/or RSRQ measurements reported by the mobile users of the BS. This information element can include individual measurements compiled and reported as a list or aggregated in some fashion, such as by taking the average measurement or other statistics, or by computing a histogram of measurement values. Measurements may be reported as the original values measured at the mobile receivers or by some quantized values, which are encoded from the original values. Separate measurements or aggregated measurements may be provided for each BAU.

Load or demand information for the BS. This information element can include an indicator of whether there is buffered data at the BS, the amount of buffered data (either represented as the total quantity of bytes or as a quantized or encoded value representing a range of byte quantities), as well as an estimate of how many BAUs are requested by the BS for data transmission in the DTP. Load information reports may also be differentiated by priority level of different traffic.

Channel occupancy measurement(s). This information element can indicate the percentage of time that the channel is measured as busy over the entire DTP or for individual slots or BAUs.

Indicator(s) specifying protected DTP BAUs that are no longer used or requested by the original assignee BS.

Indicator(s) specifying DTP BAU indices in which strong interference is detected by the BAU.

A timestamp or time index indicating when the above measurements were performed.

In some embodiments, transmission of CMRs may be triggered periodically with some fixed period, such as every N cycles for some positive integer N, as shown in <FIG>. In other embodiments, CMRs may also be triggered aperiodically based on a CMR Request sent from the SSM to the BS, as shown in <FIG>. A CMR may also be triggered by each individual BS or network provider upon noticing, for example, a significant change in the interference levels or the list of neighbors. The scope for this CMR update can be local (BS specific), network provider specific or global.

As previously described, SAG messages can be sent by an SSM to a BS, or a network entity controlling one or more BSs, in order to configure the BSs and assign resources in units of BAUs. SAGs may contain but are not limited to the following information elements.

Identifiers specifying the BSs or network entities for which the SAG is intended.

Overall frame structure. This information element can include the number of DTP cycles, DTP cycle size (i.e., the values of N and K from <FIG>) or, alternatively, the number of slots and slot length.

Detection threshold function parameters. This information element can specify the slope of function TH(PTX) and THmax, THmin.

Contention window size. This information element may provide for opportunistic channel access.

Protection margin δ for opportunistic channel access.

Assignment of a synchronization source. This information element may be used to derive the timing of DTP cycle transmissions.

The BAU allocation for each MNO or BS. This information element may include indicators specifying whether the BAU assignment is per-MNO or per-individual BS. In one embodiment, the protected BAU allocation may be specified by carrier frequency and bandwidth in the frequency dimension, slot indices in the time dimension (denoted by the pair {starting instance, duration} or {starting instance, end instance}), or any combination of these or equivalent encoded or representative parameters. In another embodiment, the BAU allocation may be specified by a bitmap where the allocation list is encoded into a binary number or vector, where each binary digit or place value being set to "<NUM>" or a pre-defined value can indicate the corresponding BAU index (or, equivalently, slot and/or frequency band index) is allocated to the recipient of the SAG. The location of the BAUs corresponding to binary digits in the bitmap may not be consecutive but may follow a pre-established pattern where BAUs are located non-consecutively in time and/or frequency. In yet another embodiment, the BAU allocation may follow some pre-established pattern, which is indicated by a parameter in the SAG.

The TXOP offset assignments for each MNO or BS. This information element may specify the location of assigned TXOPs and may follow the same formats as described above for the BAU assignments.

An indicator signaling the availability of the ODTP within a specified BAU. This information element may also specify the start and duration of the ODTP, if enabled. The Maximum Channel Occupancy Time. This information element can specify the maximum duration of transmissions.

A timestamp or time index for indicating when the above parameters may be applied by the BS.

<FIG> illustrates a flowchart for signaling of coexistence measurement reports (CMRs) and spectrum access grants (SAGs) according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in a BS, such as BS <NUM> in <FIG>. Further, flowchart <NUM> can be performed by a BS as a means to register itself with the SSM, such as SSM <NUM> in <FIG>, for onboarding onto the network.

In operation <NUM>, the BS may join the network. In operation <NUM>, an initial CMR may be sent to the SSM. The CMR can include some or all of the information elements described above and, optionally, a connection notification information element notifying the SSM that the cell is newly active. In one embodiment, the CMR may simply serve as a request for updating the resource allocation in the SAG and may not necessarily contain any additional information elements. In operation <NUM>, a SAG message may be received with initial configuration information, such as initial BAU or secondary transmission opportunity assignments along with any other configuration parameters. The SAG may be received from the SSM, or a CN entity connected to the SSM, such as CN entity <NUM> in <FIG>.

<FIG> illustrates a flowchart for periodic and aperiodic signaling of CMRs and SAGs according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in a BS, such as BS <NUM> in <FIG>. In addition, the operations of flowchart <NUM> can be performed after operations in flowchart <NUM>, i.e., after a BS has already been onboarded onto the network.

In operation <NUM>, a trigger may be received to send a CMR. The trigger can be received periodically after some fixed duration, as described in <FIG>, or received /aperiodically, as described in <FIG>.

In operation <NUM>, a CMR may be sent to the SSM. Thereafter, a SAG may be received from the SSM for updating BAU allocation in operation <NUM> if changes are required. Thus, in some embodiments, a SAG received in operation <NUM> may not the BS with protected BAUs.

In between receiving SAG list updates, each BS may query its local cache of SAG allocations to determine its assigned configuration parameters and current BAU allocation. In an alternative embodiment, a separate network entity, such as a core network node within the MNO network of the BS, e.g., CN entity <NUM> in <FIG>, may contact the SSM, on behalf of the BS, and handle reception of CMRs or constituent data elements from the BS, SAG messages from the SSM and/or configuration of the BS based on the SAG parameters. In an alternative embodiment, a BS may send an updated CMR of its own volition to request new BAU allocation from the SSM. This can be done, for example, in instances where there are changes to the circumstances of the BS's connected mobile users, including connection status, location, or link performance.

<FIG> illustrates a signal flow diagram for periodic signaling of CMRs and SAGs according to various embodiments of this disclosure. The steps depicted in signal flow diagram <NUM> can be implemented between a BS <NUM> and an SSM <NUM> in a communications network. As an example, the steps in signal flow diagram <NUM> can represent signal transmission between BS <NUM> and SSM <NUM> in <FIG>.

In signal flow diagram <NUM>, a periodic coexistence measurement report timer may be triggered in s1506. In response, the BS <NUM> may transmit a CMR to SSM <NUM> in s1508. In s1510 the SSM <NUM> may transmit a SAG to the BS <NUM>.

<FIG> illustrates a signal flow diagram for aperiodic signaling of CMRs and SAGs according to various embodiments of this disclosure. The steps depicted in signal flow diagram <NUM> can be implemented between a BS <NUM> and an SSM <NUM> in a communications network. As an example, the steps in signal flow diagram <NUM> can represent signal transmission between BS <NUM> and SSM <NUM> in <FIG>.

In s1606, the SSM <NUM> may transmit a CMR request to BS <NUM>. In response, the BS <NUM> may transmit the requested CMR in s1608. Thereafter, the SSM <NUM> may transmit a SAG to the BS <NUM> in s1610.

<FIG> illustrates a flowchart for computing a network interference graph and connected components according to various embodiments of this disclosure. Operations of flowchart <NUM> can be implemented in an SSM, such as SSM <NUM> in <FIG> and <FIG>.

An SSM may generate a network interference graph based on information provided in the CMRs. The network interference graph may facilitate the allocation of BAUs to different users. The interference graph may represent the interference relationships between BSs in the network.

In operation <NUM>, an interference graph GI may be computed. The interference graph GI = (VI, EI) may be a function of VI and EI , where VI is the set of vertices v representing BSs in the network and EI is the set of edges e representing interference relationships between BSs. An edge e = (vTX,vRX) may be included in EI if the received power at BS vRX from BS vTX (reported by the BSs to the SSM in CMR messages) exceeds a threshold. This threshold may be a function of the intended TX power of vRX, as in operation <NUM> of <FIG>, and determined by the SSM based on the intended TX power reported in a CMR.

In some embodiments, interference graph GI may be not a connected graph. A connected graph may be defined as a graph where, for all pairs of vertices v<NUM>, v<NUM> ∈ V , a path exists connecting v<NUM> and v<NUM>. Thus GI may have one or more connected component subgraphs, where there is exists no path between the vertices of each component subgraph. In other words,GI may be partitioned into one or more connected Gc components in the set SG = {G<NUM>, G<NUM>,. ,GM} , where M is the number of connected components and there exists no edge between any pair of subgraphs in SG.

In operation <NUM>, the interference graph GI may be partitioned into subgraphs SG. Connected components of GI can be computed by applying one of the well-known algorithms used for this purpose.

In operation <NUM>, the set SG may be returned and may be used by the SSM for assigning resources (i.e. BAUs) to BSs. The BAUs can be orthogonal or even non-orthogonal in cases to allow for higher resource efficiency. The SSM may be able to perform the resource assignment independently for each connected componentGc due to the constituent BSs of each component having no mutual interference relationship.

An exemplary algorithm is provided in <FIG> which may be used by an SSM or equivalent entity for assigning BSs to BAUs within a time/frequency/code slot or channel. The algorithm may be performed by the SSM in order to partition the network into a set of nodes that may be assigned to orthogonal resources, while the remaining set of nodes may share resources to improve spatial reuse. The SSM may proceed by evaluating each BS in order of the number of interference relationships. For each BS, a new graph may be computed by taking the subgraph of the BS and its neighbors in the interference graph, along with any edges between these nodes, and then removing the BS and its adjacent edges from this subgraph. The resource reservation ratio, which determines the fraction of resources the BS may be assigned under equal sharing, can then be computed as a function of the number of nodes in each connected component (isolated subgraph) of the resulting graph. Formally, the SSM can perform the below operations on one of the connected components of the interference graph G, which for simplicity is denoted G = (V,E), where V is the set of vertices representing BSs and E is the set of edges representing interference relationships between BSs.

<FIG> illustrates a flowchart for computing resource reservation ratios according to various embodiments of this disclosure. The operations depicted in flowchart <NUM> can be implemented in an SSM, such as SSM <NUM> in <FIG> and <FIG>.

Flowchart <NUM> may begin at operation <NUM> by identifying the vertex i in V having the most edges in E, i.e., <MAT>, where Ev is the set of edges adjacent to vertex v, with ties broken arbitrarily.

In operation <NUM>, the subgraph Gi = (Vi,Ei) of G may be computed, where Vi is the set containing vertex i and its adjacent vertices u ∈ V , s. ∃e ∈ E where e = (i, u), and Ei contains all edges in E shared by vertices in Vi (i.e., i and its neighbors u).

In operation <NUM>, the graph G'i = (V'i,E'i) may be computed by removing vertex i and all of its edges Ei from Gi. In operation <NUM>, the graph G'i may be partitioned into connected components G'ik= (V'ik,E'ik), k ∈{<NUM>,. The SSM may initially consider the subgraph G'ik=<NUM> for further processing.

In operation <NUM>, the maximum number of vertices Ni over all connected components G'ik may be computed. In operation <NUM>, the SSM may compute the reservation ratio as <MAT> where αi is a parameter that may be used to control the priority of different BSs or MNO users. The resource reservation ratio may be the fraction of resources in each DTP cycle allocated to BS i. By setting αi = <NUM> , equal priority may be offered to each user. However, by increasing αi > <NUM> , BS i may be given a larger portion of the time-domain resources.

In operation <NUM>, a determination may be made as to whether all vertices for this connected component of G have been evaluated. If all vertices for the connected component of G has been evaluated, then flowchart <NUM> may proceed to operation <NUM> and return the vector of resource reservation ratios R ={Rv} for all v ∈ V. However, if all vertices for the connected component of G has not been evaluated, then flowchart <NUM> may proceed to operation <NUM> and select the vertex with the next most edges in E and set i equal to the index of this vertex in operation <NUM> and return to operation <NUM>.

<FIG> illustrate steps for assigning BAUs from a network interference graph according to various embodiments of this disclosure. The steps depicted in flowchart <NUM> can be implemented in an SSM, such as SSM <NUM> in <FIG> and <FIG>.

In a first step <NUM> the interference graph G may be computed. In one embodiment, the interference graph may be computed in the manner described in operation <NUM> in <FIG> with each vertex representing a BS and each edge representing an interference relationship between nearby BSs. In this case, there is only one connected component, which is the entire graph G.

In a second step <NUM>, vertex A may be determined to have the most edges and the subgraph GA may be constructed. This step <NUM> may correspond with operations <NUM> and <NUM> in <FIG>.

In a third step <NUM>, the graph G'A may be computed by removing vertex A and its edges. Also, in the third step <NUM>, G'A may be partitioned into three connected components. Two of the connected components contain two vertices, so following operation <NUM> in <FIG>, NA=<NUM> and, by operation <NUM> in <FIG>, R = <NUM>/<NUM> (assuming αi = <NUM> ).

In the fourth step <NUM> and the fifth step <NUM>, the operations <NUM> through <NUM> in <FIG> may be repeated for vertex B, which has the next most edges of all vertices in G. The procedure may be then repeated for vertices G, C, D, E, H, F, and I, in this order and by breaking ties between edge counts arbitrarily, until the reservation ratios {Ri} have been computed for all vertices. Finally, the resource allocation shown in the final step <NUM> of <FIG> can be derived from the ratios {Ri}.

<FIG> illustrates a flowchart for managing a shared spectrum according to the invention. The operations of flowchart <NUM> can be implemented in an SSM, such as SSM <NUM> in <FIG> and <FIG>.

Flowchart <NUM> begins at operation <NUM> by obtaining coexistence measurement reports (CMRs) from the plurality of BSs. The CMRs may be obtained periodically or aperiodically. In some embodiments, the CMR may be obtained from the plurality of BSs after the SSM sends a CMR request.

In operation <NUM>, interference relationships is identified among the plurality of BSs based on the CMRs. In one embodiment, interference between BSs may be determined based on a threshold power level so that at least some interference between base stations can be tolerated. Interference can be determined as described in operation <NUM> in <FIG>.

In operation <NUM>, a set of BSs are assigned to one or more basic allocation units (BAUs) in a plurality of BAUs based on the interference relationships. The set of BSs may include a primary BS and a secondary BS, and the secondary BS can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of the primary BS.

In the invention, operation <NUM> includes assigning the primary BS to a prioritized transmission period in the one or more BAUs, which allows the primary BS to transmit in the prioritized transmission period without performing channel sensing; and assigning the secondary BS to an offset period in the one or more BAUs, which allows the secondary BS to transmit in the offset period after performing channel sensing.

In some embodiments, operation <NUM> may include assigning another primary BS to one or more other BAUs in the plurality of BAUs based on the interference relationships. When the other primary BS interferes with the primary BS, the one or more other BAUs may be orthogonal to the one or more BAUs.

In some embodiments, operation <NUM> may also include assigning a tertiary BS to the one or more BAUs for transmitting in an opportunistic data transmission period (ODTP) in the one or more BAUs. The tertiary BS can transmit in the ODTP after performing a listen-before-talk procedure.

In operation <NUM>, a spectrum access grant (SAG) is transmitted to the set of BSs, the SAG including BAU assignments for the set of BSs.

<FIG> illustrates an exemplary electronic device for managing a shared spectrum in the networked computing system according to the invention.

Referring to the <FIG>, the electronic device <NUM> for managing a shared spectrum in the networked computing system includes a processor <NUM>, a transceiver <NUM> and a memory <NUM>. The electronic device <NUM> may correspond to a server <NUM> of <FIG>. The electronic device <NUM> may be implemented by more components than those illustrated in <FIG> In addition, the processor <NUM> and the transceiver <NUM> and the memory <NUM> may be implemented as a single chip according to another embodiment. The processor <NUM> may correspond to a processor <NUM> of <FIG>. The transceiver <NUM> may correspond to communication interface <NUM> and I/O UNIT <NUM> of <FIG>.

The processor <NUM> may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the device <NUM> may be implemented by the processor <NUM>.

In one embodiment, the processor <NUM> may obtain coexistence measurement reports (CMRs) from the plurality of BSs, identify interference relationships among the plurality of BSs based on the CMRs, assign a set of BSs to one or more basic allocation units (BAUs) in a plurality of BAUs based on the interference relationships, wherein each BAU in the plurality of BAUs is a time/frequency unit; wherein the set of BSs includes a primary BS and a secondary BS, and wherein the secondary BS can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of the primary BS, and transmit a spectrum access grant (SAG) to the set of BSs, wherein the SAG includes BAU assignments for the set of BSs.

The memory <NUM> may store the control information or the data included in a signal obtained by the electronic device <NUM>. The memory <NUM> may correspond to storage devices <NUM>, memory <NUM>, or persistent storage <NUM>. The memory <NUM> may be connected to the processor <NUM> and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory <NUM> may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

<FIG> illustrates a base station (BS) according to the invention.

The gNBs, eNBs or BSs described above may correspond to the BS <NUM>. For example, the base station <NUM> illustrated in <FIG> may correspond to the BS <NUM>.

Referring to the <FIG>, the BS <NUM> includes a processor <NUM>, a transceiver <NUM> and a memory <NUM>. The BS <NUM> may be implemented by more components than those illustrated in <FIG>. In addition, the processor <NUM> and the transceiver <NUM> and the memory <NUM> may be implemented as a single chip according to another embodiment.

The processor <NUM> may include one or more processors or other processing devices that control the proposed function, process, and/or method. Operation of the BS <NUM> may be implemented by the processor <NUM>.

In one embodiment, the processor <NUM> may control the transceiver <NUM> to transmit a coexistence measurement report (CMR) to a shared spectrum manager (SSM), wherein the CMR indicates interference relationships between the BS and neighboring BSs, and receive a spectrum access grant (SAG) originating from the SSM, wherein the SAG includes a set of assignments for one or more basic allocation units (BAUs) for the BS, wherein each of the one or more BAUs is a time/frequency unit, and wherein the set of assignments indicates that the BS is a primary BS or a secondary BS that can transmit in the one or more BAUs when a transmission of the secondary BS does not interfere with a transmission of another primary BS assigned to the one or more BAUs. In addition, the processor <NUM> may generate the CMR and identify transmission opportunities for the BS based on the set of assignments for the one or more BAUs.

The memory <NUM> may store the control information or the data included in a signal obtained by the BS <NUM>. The memory <NUM> may be connected to the processor <NUM> and store at least one instruction or a protocol or a parameter for the proposed function, process, and/or method. The memory <NUM> may include read-only memory (ROM) and/or random access memory (RAM) and/or hard disk and/or CD-ROM and/or DVD and/or other storage devices.

Claim 1:
An electronic device (<NUM>) for managing a shared spectrum or an unlicensed spectrum among a plurality of base stations, BSs, the electronic device comprising:
memory comprising instructions for managing the shared spectrum or the unlicensed spectrum; and
at least one processor operably connected to the memory, the at least one processor configured to execute the instructions to cause the electronic device to:
obtain reports related to coexistence measurement from the plurality of BSs;
identify interference relationship among the plurality of BSs based on the reports;
assign a primary BS and a secondary BS among the plurality of BSs to at least one basic allocation unit based on the interference relationship, wherein the basic allocation unit is at least one of time or frequency unit, wherein the primary BS is assigned to a prioritized transmission period in the at least one basic allocation unit and data related to the primary BS is transmitted in the prioritized transmission period without channel sensing, and wherein the secondary BS is assigned to a secondary transmission opportunity period in the at least one basic allocation unit and data related to the secondary BS is transmitted in the secondary transmission opportunity period after channel sensing;
transmit first information for granting a spectrum access to the primary BS, wherein the first information for granting the spectrum access includes an assignment of a basic allocation unit for the primary BS; and
transmit second information for granting a spectrum access to the secondary BS, wherein the second information for granting the spectrum access includes an assignment of a basic allocation unit for the secondary BS.