Network node, user equipment, method and computer program product

Abstract

A network node for supporting providing radio coverage within a plurality of cells within a radio communications network. The network node is configured to evaluate a quality of service that can be provided to a user equipment within at least one radio coverage area provided by the network node, and to generate an indication of the quality of service for transmission to a further network node. A receiving network node may prioritize cells providing higher quality of service in handover decisions using quality of service indications.

Description

Technical Field

[0001] Various example embodiments relate to a radio communications network and a method of prioritizing cells in a handover decision. Background Art

[0002] When a user equipment (UE) moves in a wireless communication system, it may move among cells that include radio coverage areas supported or controlled by one or more network nodes. The ability to maintain effective communication between the UE and the wireless communication system as the UE moves through the radio coverage areas is generally referred to as mobility. The signal strength of different cells in the vicinity of the user equipment may be considered when selecting a cell to handover to. Different user equipment may have different requirements, and these requirements may also affect the suitability of potential target cells. Summary of the invention

[0003] The independent claims define the scope of protection sought by various exemplary embodiments of the invention. Exemplary embodiments and features described in this specification that do not fall within the scope of the independent claims, if any, are to be construed as examples that aid in understanding the various embodiments of the invention.

[0004] According to various but not necessarily all example embodiments of the present disclosure, there is provided a network node for supporting provision of radio coverage within multiple cells within a radio communication network, the network node comprising: at least one processor; and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the network node to at least perform: evaluating the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; generating at least one indication corresponding to the quality of service; and sending the at least one indication to another network node within the radio communication network.

[0005] It is recognized that different network nodes have different capabilities and may provide different levels of quality of service QoS in their different radio coverage areas, and that this may be a relevant factor in deciding a suitable or preferred target for handover to a particular user equipment. This information can only be used if it is available to the network node for making a handover decision. Therefore, embodiments seek to provide a mechanism that allows information about the QoS provided in a radio coverage area supported or controlled by the network node to be sent to the network nodes of one or more networks. This may allow the receiving network node to have visibility of the relevant QoS information when selecting a target cell.

[0006] The node may assess the QoS provided within the radio coverage area by measuring QoS factors such as average packet delay and bit rate within one or more cells it controls. The network node may then generate an indication of the measured or assessed QoS for a particular area, which may indicate the actual assessed QoS, or it may be a derivative of it, e.g. it may indicate that the measured value is below or above a certain threshold, or it may indicate an average value of one or several QoS parameters for an area.

[0007] In some example embodiments, the network node is caused to perform said evaluating, said generating and said sending during a process for establishing a link between the network node and the further network node.

[0008] In some example embodiments, the network node is caused to perform the evaluating, the generating and the sending in response to a request from the further network node.

[0009] In some example embodiments, the request includes an indication of the type of quality of service data required.There may be different types of quality of service data, such as cell packet loss rate, cell bit rate or cell packet delay, and the type to be sent out may be indicated in the request.

[0010] In some example embodiments, the request includes an indication of a predetermined time period after which the updated indication should be issued.

[0011] In some example embodiments, the network node is caused to perform: sending the at least one indication to the further network node during a process for establishing a link between the network node and the further network node.

[0012] In some example embodiments, the network node is further caused to perform: re-evaluating the quality of service, and generating and sending an updated at least one indication after a predetermined time period.

[0013] In some example embodiments, the network node is further caused to perform: determining when the assessed quality of service is below or above a predetermined threshold, and in response, generating and sending an updated at least one indication.

[0014] In some example embodiments, the network node is caused to perform said determining in response to receiving a request to update the quality of service indication from the further network node.

[0015] In some example embodiments, the network node is further caused to perform at least: receiving at least one indication of quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one other network node; storing the at least one indication; using the stored at least one indication as a factor in selecting a target cell during a handover process, with cells providing higher quality of service being prioritized over cells providing lower quality of service.

[0016] According to various but not necessarily all example embodiments of the present disclosure, there is provided a network node for supporting provision of radio coverage within multiple cells within a radio communication network, the network node comprising: a component for evaluating the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; a component for generating at least one indication corresponding to the quality of service; and a component for sending the at least one indication to another network node within the radio communication network.

[0017] This component may perform optional features associated with the device.

[0018] According to various but not necessarily all example embodiments of the present disclosure, there is provided a network node for supporting provision of radio coverage within multiple cells within a radio communication network, the network node comprising: a circuit system configured to evaluate the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; a circuit system configured to generate at least one indication corresponding to the quality of service; and a circuit system configured to send the at least one indication to another network node within the radio communication network.

[0019] The circuitry may be configured to perform optional features associated with the apparatus.

[0020] According to various but not necessarily all example embodiments of the present disclosure, there is provided a network node for supporting provision of radio coverage within multiple cells within a radio communication network, the network node comprising: at least one processor; and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the network node to at least perform: receiving at least one indication of quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one other network node; storing the at least one indication; and using the stored at least one indication as a factor in selecting a target cell during a switching process.

[0021] In some example embodiments, cells providing a higher quality of service are prioritized over cells providing a lower quality of service.

[0022] Providing information to a network node about the quality of service provided by another network node in one or more radio coverage areas allows the network node to use this as a factor when selecting a target cell during a handover procedure. QoS may be an important factor, depending on the service requirements of the user equipment, and therefore providing this information so that it can be taken into account when making handover decisions may improve handover decisions and help avoid or at least reduce handovers to cells where the quality of service required by the user equipment cannot be met or can only be met marginally.

[0023] In some example embodiments, the network node is caused to perform: prior to receiving the at least one indication: generating a request for the at least one indication; and sending the request to the at least one further network node.

[0024] In some example embodiments, the request is sent during a process for establishing a link between the network node and the at least one further network node.

[0025] In some example embodiments, said receiving said at least one indication is performed during a process for establishing a link between said network node and said at least one further network node.

[0026] In some example embodiments, the network node is further caused to perform: before requesting the indication from the further network node: determining that the at least one further network node provides radio coverage in the area; and requesting the central network node for the right to receive a quality of service indication of the at least one further network node.

[0027] In some example embodiments, the network node is further caused to: in response to receiving a plurality of quality of service indications for a plurality of cells in a region, generate a combined value representative of the plurality of indications, and store the combined value as the indication of the region.

[0028] The network node generating the indication may generate a combined value for an area covered by multiple cells and reduce signaling by sending a single value to the receiving network node. Alternatively, the receiving network node may generate a combined value from multiple values ​​and store and use the combined value. The combined value may be an indication of the QoS as a number within a specific value range.

[0029] In some example embodiments, the central network node comprises a network repository functionality.

[0030] In some example embodiments, the network node is further caused to perform generating a request to receive an update of the at least one indication from the at least one further network node.

[0031] In some example embodiments, in response to the at least one indication indicating that the quality of service provided by the at least one further network node is below a predefined value, a message is generated for transmission to a user equipment, the message indicating that the user equipment should not report radio link quality of cells within the radio coverage area provided by the at least one further network node.

[0032] In some example embodiments, the message comprises an indication of times during which the user equipment should not report the radio link quality.

[0033] In some example embodiments, in response to expiry of the time, and in case the indication indicates that the quality of service is still below the predefined value, the network node is caused to remove a link between the network node and the further network node.

[0034] In some example embodiments, the quality of service includes at least one of: cell average bit rate; cell maximum bit rate; cell guaranteed minimum bit rate; cell average packet delay; cell average packet loss rate, and cell worst-case maximum packet loss rate.

[0035] In some example embodiments, the at least one radio coverage area comprises at least one cell, at least one cell identifier identifying the at least one cell being sent with the indication.

[0036] In some example embodiments, the radio coverage area comprises a plurality of cells, and the indication comprises an indication of the average quality of service of the plurality of cells.

[0037] In some example embodiments, the evaluating step comprises evaluating an average quality of service of the plurality of cells.

[0038] In some example embodiments, the at least one cell comprises at least one cell close to a boundary of the radio coverage provided by the network node.

[0039] In some example embodiments, the boundary is a boundary having radio coverage provided by the further network node.

[0040] According to various but not necessarily all example embodiments of the present disclosure, a network node for supporting provision of radio coverage within multiple cells within a radio communications network is provided, the network node comprising: a component for receiving at least one indication of quality of service, the quality of service being capable of being provided to user equipment within at least one radio coverage area provided by at least one other network node; a component for storing the at least one indication; and a component for selecting a target cell during a handover process, the component for selecting using the stored at least one indication as a factor in the selection such that a cell providing a higher quality of service is given priority over a cell providing a lower quality of service.

[0041] This component may perform optional features associated with the device.

[0042] According to various but not necessarily all example embodiments of the present disclosure, there is provided a network node for supporting provision of radio coverage within multiple cells within a radio communications network, the network node comprising: a circuit system configured to receive at least one indication of quality of service, the quality of service being capable of being provided to user equipment within at least one radio coverage area provided by at least one other network node; a circuit system configured to store the at least one indication; and a circuit system configured to select a target cell during a switching process, the circuit system configured to select being configured to use the stored at least one indication as a factor in the selection so that cells providing higher quality of service are prioritized over cells providing lower quality of service.

[0043] The circuitry may be configured to perform optional features associated with the apparatus.

[0044] According to various but not necessarily all example embodiments of the present disclosure, a central network node within a radio communication network is provided, the central network node comprising: at least one processor; and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the central network node to at least perform: receiving a list of served cells and an indication of an ability to generate a quality of service indication from at least some of a plurality of network nodes, the quality of service indication being for an area covered by one or more of the served cells; storing the received list of served cells and indication; and in response to receiving a request from the network node for access to quality of service information of one of the plurality of network nodes, providing the network node with access to the one of the plurality of network nodes.

[0045] The ability of network nodes to communicate information about the QoS they are able to provide in certain radio coverage areas may be centrally managed at a central network node. The central network node may receive information about the ability of network nodes to generate QoS indications and may use the information when receiving a request to access such information to grant access to the requesting network node.

[0046] In some example embodiments, the network node may be provided access to the network node by being provided with an identifier identifying the network node. In some example embodiments, this may be an address of a network node of a plurality of network nodes.

[0047] In some example embodiments, the network node may be provided access to a network node by being provided with an access token allowing it to securely communicate with the network node of the plurality of network nodes.

[0048] In some example embodiments, the central network node comprises a network repository functionality.

[0049] According to various but not necessarily all example embodiments of the present disclosure, a central network node within a radio communication network is provided, the central network node comprising: a component for receiving a list of served cells and an indication of an ability to perform generation of a quality of service indication from at least some of a plurality of network nodes, the quality of service indication being for an area covered by one or more of the served cells; a component for storing the received list of served cells and indications; and a component for providing the network node with access to one of the plurality of network nodes in response to receiving a request from the network node for quality of service information of the access to the one of the plurality of network nodes.

[0050] The central network node may comprise further components for performing optional features associated with the apparatus.

[0051] According to various but not necessarily all example embodiments of the present disclosure, a central network node within a radio communication network is provided, the central network node comprising: a circuit system configured to receive a list of served cells and an indication of an ability to perform generation of a quality of service indication from at least some of a plurality of network nodes, the quality of service indication being an area covered by one or more of the served cells; a circuit system configured to store the received list of served cells and indications; and a circuit system configured to provide the network node with access to one of the plurality of network nodes in response to receiving a request from the network node for quality of service information of the one of the plurality of network nodes.

[0052] The central network node may include further circuitry configured to perform optional features associated with the apparatus.

[0053] According to various but not necessarily all example embodiments of the present disclosure, a user equipment is provided, the user equipment comprising: at least one processor; and at least one memory storing instructions, which instructions, when executed by the at least one processor, cause the user equipment to at least perform: receiving an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be lower than a predetermined value; and in response, not evaluating or reporting the radio link quality of the at least one cell.

[0054] The ability of network nodes to know the QoS of radio coverage areas provided by other network nodes allows them to know potential target cells that may not provide the required QoS to the UE. The UE may receive a signal indicating that it should no longer report the radio link quality of such cells. Since these cells are not suitable as target cells, power consumption and signaling can be reduced by instructing the UE to no longer report the radio link quality of such cells. In response to this, the UE may no longer perform measurements and send results.

[0055] In some example embodiments, the instruction comprises an indication of a time period during which the user equipment should not perform the reporting of the radio link quality.

[0056] In some example embodiments, the user equipment is further caused to perform: receiving a further instruction from the serving network node indicating that the reporting of the radio link quality should be reactivated, and in response, evaluating and reporting the radio link quality of the at least one cell controlled by the further network node.

[0057] In some example embodiments, the user equipment is further caused to perform: receiving a further instruction from the serving network node indicating that the user equipment should stop reporting the radio link quality of all cells provided by the further network node; and in response, not evaluating or reporting the radio link quality of all the cells provided by the further network node.

[0058] According to various but not necessarily all example embodiments of the present disclosure, a user equipment is provided, the user equipment comprising: a component for receiving an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be lower than a predetermined value; and a component for evaluating and reporting the radio link quality of the at least one cell, the component for evaluating and reporting the radio link quality being configured in response to receiving the instruction to stop reporting the radio link quality.

[0059] The user equipment may comprise further means for performing optional features related to the apparatus described.

[0060] According to various but not necessarily all example embodiments of the present disclosure, a user equipment is provided, which includes: a circuit system configured to receive an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be lower than a predetermined value; and a circuit system configured to evaluate and report the radio link quality of the at least one cell, the circuit system configured to evaluate and report the radio link quality being configured in response to receiving the instruction to stop reporting the radio link quality.

[0061] The user equipment may include further circuitry configured to perform optional features related to the apparatus described above.

[0062] According to various but not necessarily all example embodiments of the present disclosure, a method performed at a network node is provided, the method comprising: evaluating the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; generating at least one indication corresponding to the quality of service; and sending the at least one indication to another network node within the radio communications network.

[0063] In some example embodiments, the method comprises performing said evaluating, said generating and said sending in response to a request from said further network node.

[0064] In some example embodiments, the method comprises sending the at least one indication to the further network node during a procedure for establishing a link between the network node and the further network node.

[0065] In some example embodiments, the method comprises re-evaluating the quality of service and generating and sending an updated at least one indication after a predetermined period of time.

[0066] In some example embodiments, the method comprises determining when the assessed quality of service is below or above a predetermined threshold, and in response, generating and sending an updated at least one indication.

[0067] In some example embodiments, the method comprises performing said determining in response to receiving a request to update the quality of service indication from the further network node.

[0068] In some example embodiments, the method includes performing: receiving at least one indication of a quality of service that can be provided to a user equipment within at least one radio coverage area provided by at least one further network node; storing the at least one indication; and using the stored at least one indication as a factor in selecting a target cell during a handover process, with cells providing a higher quality of service being prioritized over cells providing a lower quality of service.

[0069] According to various but not necessarily all example embodiments of the present disclosure, a method performed at a network node is provided, the method comprising: receiving at least one indication of quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one other network node; storing the at least one indication; using the stored at least one indication as a factor in selecting a target cell during a handover process, with cells providing higher quality of service being prioritized over cells providing lower quality of service.

[0070] In some example embodiments, the method comprises performing: sending the request for the at least one indication during a process for establishing a link between the network node and the at least one further network node.

[0071] In some example embodiments, the method comprises performing: prior to requesting the indication from the further network node: determining that the at least one further network node provides radio coverage in an area; requesting from a central network node the right to receive a quality of service indication of the at least one further network node.

[0072] In some example embodiments, the method comprises, in response to receiving a plurality of quality of service indications for a plurality of cells in a region, generating a combined value representative of the plurality of indications, and storing the combined value as the indication for the region.

[0073] In some example embodiments, the method comprises generating a request to receive an update of the at least one indication from the at least one further network node.

[0074] In some example embodiments, in response to the at least one indication indicating that the quality of service provided by the at least one further network node is below a predefined value, a message is generated for transmission to a user equipment, the message indicating that the user equipment should not report radio link quality of cells within the radio coverage area provided by the at least one further network node.

[0075] In some example embodiments, the message comprises an indication of times during which the user equipment should not report the radio link quality.

[0076] In some example embodiments, in response to expiry of the time, and in case the indication indicates that the quality of service is still below the predefined value, the method comprises removing a link between the network node and the further network node.

[0077] In some example embodiments, the evaluating step comprises evaluating an average quality of service of the plurality of cells.

[0078] According to various but not necessarily all example embodiments of the present disclosure, there is provided a method performed at a central network node within a radio communications network, the method comprising: receiving a list of served cells and an indication of an ability to perform generation of a quality of service indication from at least some of a plurality of network nodes, the quality of service indication being for an area covered by one or more of the served cells; storing the received list of served cells and indications; and in response to receiving from the network node a request for quality of service information of access to one of the plurality of network nodes, providing the network node with access to the one of the plurality of network nodes.

[0079] According to various but not necessarily all example embodiments of the present disclosure, there is provided a method performed at a user equipment, the method comprising: receiving an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be below a predetermined value; and in response, not evaluating or reporting the radio link quality of the at least one cell.

[0080] In some example embodiments, the method further comprises receiving a further instruction from the serving network node indicating that the reporting of the radio link quality should be reactivated, and in response, evaluating and reporting the radio link quality of the at least one cell controlled by the further network node.

[0081] In some example embodiments, the method comprises: receiving a further instruction from the serving network node indicating that the user equipment should stop reporting the radio link quality of all cells provided by the further network node; and in response, not evaluating or reporting the radio link quality of all the cells provided by the further network node.

[0082] According to various but not necessarily all example embodiments of the present disclosure, a non-transitory computer-readable medium is provided, the medium including program instructions stored thereon, the program instructions being used to control a network node to at least perform: evaluating the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; generating at least one indication corresponding to the quality of service; and causing the at least one indication to be transmitted to another network node within the radio communications network.

[0083] According to various but not necessarily all example embodiments of the present disclosure, a computer program is provided, which includes instructions that, when executed by a processor on a network node, cause the network node to at least perform: evaluating the quality of service that can be provided to user equipment within at least one radio coverage area provided by the network node; generating at least one indication corresponding to the quality of service; and causing at least one indication to be transmitted to another network node within the radio communications network.

[0084] According to various but not necessarily all example embodiments of the present disclosure, a non-transitory computer-readable medium is provided, the medium including program instructions stored thereon, the program instructions being used to control a network node to at least perform: receiving at least one indication of quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one other network node; storing the at least one indication; using the at least one stored indication as a factor in selecting a target cell during a handover process, with cells providing higher quality of service being prioritized over cells providing lower quality of service.

[0085] According to various but not necessarily all example embodiments of the present disclosure, a computer program is provided, the computer program comprising instructions, which, when executed by a processor on a network node, causes the network node to at least perform: receiving at least one indication of the quality of service that can be provided to a user equipment within at least one radio coverage area provided by at least one other network node; storing the at least one indication; using the at least one stored indication as a factor in selecting a target cell during a handover process, with cells that provide higher quality of service being prioritized over cells that provide lower quality of service.

[0086] According to various but not necessarily all example embodiments of the present disclosure, a non-transitory computer-readable medium is provided, the medium including program instructions stored thereon, the program instructions being used to control a central network node to at least perform: receiving a list of served cells from at least some of a plurality of network nodes, and an indication of an ability to generate a quality of service indication for an area covered by one or more of the served cells; storing the received list of served cells and indications; and in response to receiving from a network node a request for quality of service information of access to one of the plurality of network nodes, providing the network node with access to the one of the plurality of network nodes.

[0087] According to various but not necessarily all example embodiments of the present disclosure, a computer program is provided, the computer program comprising instructions that, when executed by a processor on a central network node, cause the central network node to at least perform: receiving a list of served cells and an indication of an ability to generate a quality of service indication from at least some of a plurality of network nodes, the quality of service indication being for an area covered by one or more of the served cells; storing the received list of served cells and indication; and in response to receiving a request from a network node for access to quality of service information of one of the plurality of network nodes, providing the network node with access to the one of the plurality of network nodes.

[0088] According to various but not necessarily all example embodiments of the present disclosure, a non-transitory computer-readable medium is provided, the medium including program instructions stored thereon, the program instructions being used to control a user equipment to at least execute: receiving an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be below a predetermined value; and in response, not evaluating or reporting the radio link quality of the at least one cell.

[0089] According to various but not necessarily all example embodiments of the present disclosure, a computer program is provided, the computer program comprising instructions that, when executed by a processor on a user equipment, cause the user equipment to at least perform: receiving an instruction from a serving network node to stop reporting the radio link quality of at least one cell controlled by another network node, the at least one cell being a cell whose service quality has been indicated to be below a predetermined value; and in response, not evaluating or reporting the radio link quality of the at least one cell.

[0090] These instructions may be used to perform optional features associated with the method.

[0091] Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate and in other combinations than those explicitly listed in the claims.

[0092] Where an apparatus feature is described as being operable to provide a function, it will be understood that this includes apparatus features that provide that function or that are adapted or configured to provide that function. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0094] Figure 1 schematically illustrates an example of two network nodes supporting provision of radio coverage in a cell;

[0095] Figure 2 schematically illustrates signaling between two network nodes exchanging cell QoS parameters over an Xn interface according to an embodiment;

[0096] Figure 3 schematically illustrates signaling between two network nodes exchanging wide area QoS parameters over an Xn interface according to an embodiment;

[0097] Figure 4 schematically illustrates signaling between two network nodes exchanging cell QoS parameters in a service-based architecture network according to an embodiment; and

[0098] Figure 5 A wireless network comprising two network nodes and a central network node according to an embodiment is schematically illustrated. DETAILED DESCRIPTION

[0099] Before discussing example embodiments in greater detail, an overview will first be provided.

[0100] Different user equipment may have different service requirements, and this may affect the selection of the cell that provides the most appropriate service for that user equipment. The 5G system has defined different 5G Quality of Service (QoS) Identifiers (5QIs) for handling these different user equipment (UE) service requirements. Each 5QI corresponds to a different QoS parameter, such as packet error rate, packet delay budget, guaranteed bit rate, where the QoS flow profile is a guaranteed bit rate (GBR) profile (TS 23.501 Section 5.7). Embodiments seek to provide an enhanced method for implementing neighbor gNB / cell priority in a handover context by adaptively exchanging relevant QoS information between network nodes such as gNBs.

[0101] The current standards specify in TS28.552 and TS 38.314 QoS parameter measurements to be performed or aggregated at the cell level. For example, the average packet delay and average UE throughput / bitrate can be measured by the gNB for each cell it controls (TS28.552 Sections 5.1.1.1 and 5.1.1.3). There are also QoS parameters required by the UE and they are part of the UE context and exchanged between gNBs in inter-gNB handover as part of the "PDU Session Resource List to Establish" information element in case of handover (TS 38.423 Section 9.1.1.1). They are related to the link quality of the PDUs (Protocol Data Units) that the UE may expect and that are exchanged during handover.

[0102] Currently, there is no exchange of measured cell QoS parameters / conditions between gNBs in New Radio NR. Therefore, there is no mechanism to enable a given gNB controlling a source cell to prioritize neighboring cells controlled by other gNBs based at least in part on the QoS of potential handovers.

[0103] For example, Figure 1 As shown, assuming that the UE is present in cell 1a controlled by gNB 1, a handover to cell 2a (controlled by gNB 2) may fail if cell 2a cannot meet the QoS parameters required by the user equipment. Alternatively, the UE may handover to cell 2a, but the latter can hardly meet the desired QoS requirements. In this case, if cell 2a becomes congested and can no longer meet the UE's QoS requirements, the UE is likely to handover to another cell (cell 3, controlled by gNB 3 and not shown) after a short period of time. This results in unnecessary handovers, more signaling traffic and possible interruption of the UE's service time.

[0104] Embodiments suggest exchanging QoS parameters between gNBs when establishing the relevant point-to-point backhaul link, i.e., this information may be part of the messages "Xn Setup Request" and "Xn Setup Response" (see 3GPP TS 38.423 Section 8.4.1) between two gNBs in future systems. Cell QoS parameters defined in 3GPP TS 28.552 and 38.314 (such as cell average or maximum bit rate, cell guaranteed (minimum) bit rate, cell average packet delay / loss rate, etc.) may be exchanged between gNBs. Alternatively, information corresponding to multiple cells may be summarized by an area-wide QoS score as detailed below.

[0105] Since the QoS situation in a cell may change over time due to various reasons (e.g. user traffic, desired slice, etc.), we propose two variants to keep the QoS parameters up to date between gNBs: first, using a timer to specify how often the parameters should be exchanged, and second, using a subscription notification procedure via which a given QoS parameter is exchanged if it exceeds / falls below a predefined threshold. The latter is best implemented in a service-based Radio Access Network (RAN) architecture.

[0106] Some example embodiments attempt to address the problems listed below.

[0107] 1. In current 5G implementations, for non-GBR (non-guaranteed bit rate) QoS flows, data radio bearers (DRBs) may not be released even if the bit rate experienced by the UE is very low. As a result, the UE may be trapped in a cell with very poor (low) maximum or average bit rate, and unable to handover to other cells. Embodiments help ensure that such scenarios do not occur by including QoS information already during backhaul link establishment. This ensures that the UE hands over to a cell with acceptable QoS support for non-GBR QoS flows.

[0108] 2. For GBR (guaranteed bit rate) flows, if two neighboring cells with similar link quality offer GBR of 10Mbit / s and 15Mbit / s respectively, and the user to be handed over requires a GBR of 9Mbit / s, the second neighboring cell may be selected for handover as a result of prioritizing the cells using a factor based on their QoS attributes. This decision preempts any future incoming traffic to the first neighboring cell that could push its GBR below 9Mbit / s, triggering an additional handover for the affected UE.

[0109] In practice, by providing the network node with information about the QoS of the target cells, the network node is able to prioritize the cells in the handover decision based on that QoS. Thus, for example, where the UE service requirements indicate that a certain QoS threshold level is required, certain target cells that are unable to provide such QoS may be removed from the list of target cells considered in the handover decision. In the case where a group of cells each provide the required QoS, but certain cells provide better QoS, the selection may use QoS as a factor in the decision, such that the better QoS cell may be selected preferentially, although signal strength will also be a factor in the decision.

[0110] The embodiments described below relate to: (1) the current 5G RAN architecture (gNBs are connected via a backhaul (Xn) interface) and (2) a new candidate service-based 6G RAN architecture.

[0111] Part 1 - 5G RAN Architecture:

[0112] Initial exchange of QoS parameters: The current specification (TS 38.423) has an information element (IE) "Served Cell Information NR" for the messages "Xn Setup Request" and "Xn Setup Response". This IE is specific to each served cell and contains several fields that may be related to neighboring cells. We propose to include cell QoS information in the cell specific IE "Served Cell Information IE". The QoS parameters that may be exchanged may include:

[0113] 1. Average cell bit rate (throughput),

[0114] 2. Maximum cell bit rate,

[0115] 3. The cell guarantees a (minimum) bit rate,

[0116] 4. Average cell packet delay,

[0117] 5. Average cell packet loss rate, and

[0118] 6. Worst case (maximum) packet loss rate of the cell.

[0119] In order to reduce signaling and avoid or at least reduce the exchange of QoS information of unrelated cells, only cells at the border of the area controlled by the respective gNB may be considered. For this purpose, the gNB may rely on the help of O&M and may also use historical information (e.g. information about neighboring cells where handovers have previously occurred and stored for this purpose). Figure 1 As shown, gNB1 is only interested in cells 2a, 2b, and 2c (controlled by gNB2). Similarly, gNB2 is only interested in cells 1a, 1b, and 1c (controlled by gNB 1).

[0120] This information helps a given gNB controlling the source cell to prioritize neighboring cells controlled by different gNBs for potential handover.

[0121] Update QoS parameters: We recommend to include the updated QoS information in the IE "Update Served Cell for NR" of the "NG-RAN Node Configuration Update" message in TS 38.423. This information can be updated according to a predefined timer.

[0122] Figure 2The proposed signaling additions to the current 5G RAN system are illustrated. As shown, gNB1 issues an initial setup request message 1 that includes served cell information. This IE information element is specific to each served cell and contains several fields that may be related to neighboring cells. In some embodiments, QoS information is included in this IE to indicate the QoS information for the identified cells that the network node gNB1 can provide to the UE. These may be cells that are close to the border of the radio coverage area provided by the network node gNB2. In this embodiment, an update timer value is also indicated and indicates how often the cell information needs to be updated. In other embodiments, the QoS information included in the IE may indicate the type of QoS information requested and, in some cases, may also indicate the cell ID that identifies the cell in gNB2 for which the QoS is requested. These may be cells that are close to the border of the radio coverage area provided by the network node gNB1. Likewise, an update timer value may be indicated and indicates how often the cell information needs to be updated.

[0123] The network node gNB2 responds in message 2 with an Xn Setup Response comprising served cell information of the cells served by node gNB2, as well as cell IDs and QoS parameters of at least some of these cells, and an update timer indicating how often updates are issued.

[0124] The signaling diagram also shows an additional message, message 3, which is sent by gNB1 after the update timer of gNB1 expires and which provides a configuration update related to the served cell of gNB1, including the cell ID and updated QoS parameters.

[0125] For each node gNB1 and gNB2 that receives QoS information, this information is stored in a data memory and can then be used for handover decisions.

[0126] After Message 3 is sent, the timer is reset so that after the predetermined time has passed again, gNB1 will send out further information.

[0127] In some embodiments, in case the initial exchange and further updates of multiple QoS parameters are signaling intensive, even if the cells whose information can be exchanged are limited to the neighboring cells, in some implementations a given gNB may map the QoS parameters of the concerned cells to a QoS score, e.g. between 0 and 100. This may be done based on machine learning or optimization methods. This unique QoS score is an area-wide average score: it may represent the concerned cells controlled by the target gNB and being neighbors of the cells controlled by the source gNB.

[0128] In the above Figure 1Based on this, two QoS scores can be created, corresponding to the area represented by cells (1a, 1b, 1c) and (2a, 2b, 2c). This score can then be exchanged between gNBs in a similar way as described above and can also be slice dependent. This also helps with prioritization: if the QoS parameters of most cells are bad, the corresponding QoS score will be low. Handovers to any cell in this area will be deprioritized or avoided.

[0129] In another embodiment, the source gNB may receive different QoS parameters corresponding to multiple neighboring cells from the target gNB, but process them itself into a combined QoS score, which will be stored and used as a factor in the handover decision.

[0130] In some embodiments, based on the QoS score, the source gNB may ask the UE to stop reporting the radio link quality to the above neighboring cells controlled by another gNB if a given QoS score of that other gNB is below a certain threshold. This may be some configured time interval (Toff,1), after which reporting may be activated again. If the QoS score remains below the given threshold for a time interval greater than (Toff,2), the UE may be instructed to stop reporting again. The Xn connection may even be removed if the transport plane needs to be offloaded. In this case, we have area scope limitations due to bad QoS conditions.

[0131] Figure 3 The figure shows the proposed QoS score embodiment signaling between gNBs. Figure 2 Instead, the QoS scores now correspond to multiple cells (denoted by cell ID1, cell ID2, ...).

[0132] In the first message 10, if Figure 2 As shown, an Xn setup request is issued to gNB1 to gNB2, but in this case the combined QoS score of these cells is the offered or requested QoS. Again a timer value is issued. At message 20 there is a response from gNB2, and in this particular example the average combined QoS score for the combined area of ​​the multiple cells is issued along with the cell ID indicating the combined area and the timer value.

[0133] When the timer expires at 30, an updated configuration message is sent along with the new evaluated QoS score for the combined area of ​​cells. At step 40, if gNB2 determines that the area-wide QoS score is below a predefined threshold based on the received updated QoS value, it may generate and send a message to the UE served by gNB2 at step 50 to indicate that the UE should stop reporting signal strength measurements for cells controlled by gNB1. At step 60, gNB2 may remove the backhaul link connection with gNB1.

[0134] In some embodiments where the configuration update indicates that the QoS score is below a predefined threshold for an individual cell of gNB1, the user equipment may receive a signal from gNB2 indicating that it should no longer report the signal strength of that particular cell. In this case, the backhaul link is not removed and the UE may still report other potential target cells of gNB1.

[0135] Part 2 - Service-Based Architecture (SBA):

[0136] We present below an embodiment of SBA assuming a RAN. Here, there are no point-to-point Xn links between gNBs. Instead, gNBs have URI / IP addresses and are connected via a service bus interface. This architecture facilitates "subscribe to notify" interactions between gNBs. We define a new gNB service, called QoS Communication Service, which allows a given gNB to communicate cell-specific QoS parameter changes to other authorized entities (e.g., other gNBs). Subscription permissions can be managed by the RAN Network Repository Function (NRF) (or O&M), and new services can be registered with the NRF in an initial step (e.g., at system startup).

[0137] As an example of a subscription notification process, if the cell average bit rate or cell guaranteed bit rate is above or below a certain threshold, the gNB controlling the above cell can immediately notify the gNB controlling the neighboring cell of the update (under the condition that it has previously subscribed to the QoS communication service of the preceding gNB). The preceding gNB can then update its gNB / neighboring cell priority.

[0138] Figure 4 use Figure 1 The cell in FIG. 1 shows the QoS parameter signaling envisioned in the SBA, including the initial service registration with the NRF.

[0139] Figure 4 The signaling of a service-based architecture network is shown, where there is a central network node supporting a network repository function. In this embodiment, there is an initial registration phase, where each of the network nodes gNB1 and gNB2 issues a message to the network repository function at 100 and 110, respectively. The message lists its served cells and indicates its ability to determine QoS parameters for these cells and report the determined QoS. They may also indicate the network node's ability to process received QoS indications of cells of other network nodes and use them in its handover decisions.

[0140] Messages 100 and 110 are issued during initial registration and some time later when the two nodes gNB1 and gNB2 discover each other, possibly in response to a user equipment indication that a cell from one of these nodes may be a target cell, and gNB1 may then issue a message to the Network Repository Function requesting permission to use the QoS communication services of gNB2. The NRF may grant the requested permission at message 140. This may be in the form of a message indicating an identifier of network node gNB2 so that gNB1 may communicate with it, and / or it may include one or more tokens that allow a secure link to be established between the two network nodes.

[0141] After this, at steps 150 and 160, initial signaling of QoS parameters is performed between the two nodes, such that at message 150, gNB1 requests QoS parameters for cell 2a from gNB2, and indicates the desired QoS parameters in the message. In this case, it is a guaranteed bit rate and a maximum bit rate. At step 160, gNB2 responds and issues the requested QoS parameters for that cell. At message 170, gNB1 may subscribe to the QoS communication service, perhaps for a specific cell, namely cell 2A of gNB2, so that it will receive future updates on any changes to that cell. After a period of time at step 180, if the guaranteed bit rate of cell 2A is below a certain threshold, then in response to this, gNB2 may issue a message 190 to inform gNB1 of the updated guaranteed bit rate of cell 2A. After a period of time, the average bit rate of the cell may exceed a predetermined threshold, and at this point, at step 200, gNB2 may issue a message at 210 to inform gNB1 of the updated average bit rate. In this way, the network nodes can keep abreast of changes in the quality of service provided by other network nodes for the cell of interest.

[0142] Alternatively, the service may only include a QoS zone-wide score as described above. However, this is less important in SBA since gNBs are always connected to each other and thus sub-area (at cell-level granularity) prioritization / barring can be done based on cell-specific QoS parameters.

[0143] Figure 5 A wireless communication network comprising two network nodes and a central network node according to an embodiment is schematically illustrated.

[0144] Figure 5 Schematically illustrates a wireless communication network according to an embodiment. Figure 5 In the example, there are two network nodes gNB1 20a and gNB2 20b. There is a backhaul link between these two network nodes to allow them to send signals between each other. In some embodiments, the link between them can be provided by a service bus interface instead of having a backhaul link.

[0145] The network node 20a comprises a sending and receiving circuit system 21 for sending signals to the user equipment 50 and the central network node 30 and for receiving signals from these entities. It also comprises a circuit system 22 for evaluating the QoS it provides in one or more of its cells. There is an indication generating circuit system 23 configured to generate an indication of the evaluated QoS. The generating circuit system 23 may generate an indication of the actual value, or may generate an indication of the value relative to a threshold, or an indication of an average of several values ​​for several cells or an indication of the value. An advantage of sending an indication of the QoS value rather than the value itself is that a reduction in signaling may be achieved.

[0146] There is a data store 24 for storing indications of QoS received from other network nodes, such as gNB2 20b. These may be received, for example, via a backhaul link during a setup process, or during some update process, or because the network node has subscribed to updates of that information. The network node 20a also has a handover determination circuitry 25 for selecting a target cell for handover for a user equipment 50 that is currently served by the network node 20a and is moving towards the network node 20b. The handover determination circuitry 25 may receive signal strength measurements relating to potential target cells from the UE 50. It may also take into account the QoS indications of those target cells received from the network node gNB2 20b stored in the data store 24. The service requirements of the user equipment 50 may also be taken into account, as these requirements may affect the QoS required by the user equipment.

[0147] The network node gNB2 20b includes a circuit system corresponding to the circuit system of the network node 20a.

[0148] In this embodiment, there is a central network node 30, which may include a network repository function and includes a data store 32 for storing a list of served cells for each network node and an indication of whether they are capable of providing QoS indications for these cells and / or using such QoS indications in their handover decisions. The central network node 30 may also include a transmission and reception circuit system 38 for sending signals to and receiving signals from network nodes, and a user management circuit system 36 configured to process a request received from a network node requesting the right to receive QoS communications from another network node and grant or deny the right. The granting of rights may be performed by generating an identifier identifying the other network node, which is issued to the requesting network node to allow it to communicate with the other node. In some cases where the communication will be a secure communication token, the secure communication token generation circuit system 36 within the user management circuit system may generate a secure token that is transmitted to the network node and allows the network nodes to communicate securely with each other.

[0149] The user equipment 50, which may be a smartphone, comprises a transmission and reception circuit system 52 for transmitting and receiving signals with different network nodes 20a, 20b. The user equipment 50 also comprises a measurement circuit system 54 for measuring the radio quality link and a report generation circuit system 56 for generating a radio quality link report. The user equipment 50 also comprises a control circuit system 58, which is configured to control the measurement circuit system 54 and the report generation circuit system 56 to stop link quality estimation and reporting in response to receiving an instruction from the network node indicating that radio link quality reporting for a particular cell or a particular network node should be stopped. The control circuit system 58 is also configured to control the circuit systems 54, 56 to start monitoring and reporting radio link quality again in response to receiving a signal indicating that radio link quality monitoring should be started again.

[0150] In this way, a wireless communication network is provided which allows information relating to the quality of service they can provide in one or more cells to be communicated between network nodes. This information allows them to factor quality of service provisions into handover decisions for such cells and helps to reduce the risk of user equipment being transferred to a cell which is unable to provide the desired level of quality of service.

[0151] The UE impacts identified include:

[0152] 1. Reduced signaling on the air interface (to the source cell / gNB) in case the neighbor cell QoS parameters are below / above a certain threshold, as the UE can be instructed to stop reporting the radio link quality of the neighbor cells

[0153] 2. Reduce service interruption time and unnecessary switching

[0154] Those skilled in the art will readily recognize that the steps of various above-mentioned methods can be performed by a programmed computer.Here, some embodiments are also intended to encompass program storage devices, such as digital data storage media, which are machine or computer readable and encode machine executable or computer executable instruction programs, wherein the above-mentioned instructions perform some or all of the steps of the above-mentioned methods.The program storage device can be, for example, a digital memory, a magnetic storage medium such as a disk and a tape, a hard drive, or an optically readable digital data storage medium.Embodiments are also intended to encompass computers programmed to perform the above-mentioned steps of the above-mentioned methods.The term non-transient used herein is a limitation on the medium itself (i.e., tangible, rather than a signal), rather than a limitation on data storage persistence (e.g., RAM vs. ROM).

[0155] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0156] (a) Hardware circuit implementation only (such as implementation in analog and / or digital circuitry only)

[0157] as well as

[0158] (b) a combination of hardware circuitry and software such as (where applicable):

[0159] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0160] (ii) any portion of hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device such as a mobile phone or server to perform various functions), and

[0161] (c) Hardware circuit(s) and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), that require software (e.g., firmware) to operate, but where the software may not be present, for operation.

[0162] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry also includes a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0163] Although example embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the invention as claimed.

[0164] Features described in the preceding description may be used in other combinations than the combinations explicitly described.

[0165] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0166] Although features have been described with reference to certain embodiments, those features may also be present in other embodiments whether described or not.

[0167] While efforts have been made in the foregoing description to call attention to those features of the present invention regarded as particularly important, it is to be understood that the applicant claims protection for any patentable feature or combination of features mentioned above and / or shown in the accompanying drawings, whether or not specifically emphasized.

Claims

1. A network node for supporting provision of radio coverage in a plurality of cells in a radio communications network, the network node comprising: at least one processor; as well as At least one memory storing instructions, which, when executed by the at least one processor, cause the network node to at least perform: evaluating a quality of service that can be provided to user equipment within at least one radio coverage area provided by said network node; generating a corresponding at least one indication of the quality of service; and The at least one indication is sent to a further network node within the radio communications network.

2. A network node for supporting provision of radio coverage in a plurality of cells in a radio communications network, the network node comprising: at least one processor; as well as At least one memory storing instructions, which, when executed by the at least one processor, cause the network node to at least perform: receiving at least one indication of a quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one further network node; storing the at least one indication; Using the stored at least one indication as a factor in selecting a target cell during a handover procedure, cells providing a higher quality of service are prioritized over cells providing a lower quality of service.

3. A central network node in a radio communications network, the central network node comprising: at least one processor; as well as at least one memory storing instructions, which when executed by the at least one processor, cause the central network node to at least perform: receiving, from at least some of the plurality of network nodes, a list of served cells and an indication of a capability to generate at least one quality of service indication for an area covered by one or more of the served cells; storing the received list of served cells and at least one indication; as well as In response to receiving a request from a network node for access to quality of service information of one of the plurality of network nodes, providing the network node with access to the one of the plurality of network nodes.

4. A user equipment, comprising: at least one processor; as well as At least one memory stores instructions, which, when executed by the at least one processor, cause the user equipment to at least perform: receiving from the serving network node an instruction to stop reporting the radio link quality of at least one cell controlled by the further network node, the at least one cell being a cell whose service quality has been indicated as being below a predetermined value; and In response, the radio link quality of the at least one cell is not evaluated or reported.

5. The user equipment according to claim 4, wherein the user equipment is further configured to execute: A further instruction is received from the serving network node, the further instruction indicating that the reporting of the radio link quality should be reactivated, and in response, the radio link quality of the at least one cell controlled by the further network node is evaluated and reported.

6. The user equipment according to claim 4 or 5, wherein the user equipment is further configured to execute: receiving a further instruction from the serving network node, the further instruction indicating that the user equipment should stop reporting radio link quality of all cells provided by the further network node; and In response, radio link qualities of all said cells provided by said further network node are not evaluated or reported.

7. A method performed at a network node, the method comprising: evaluating a quality of service that can be provided to user equipment within at least one radio coverage area provided by said network node; generating a corresponding at least one indication of the quality of service; and The at least one indication is sent to a further network node within the radio communications network.

8. A method performed at a network node, the method comprising: receiving at least one indication of a quality of service that can be provided to user equipment within at least one radio coverage area provided by at least one further network node; storing the at least one indication; Using the stored at least one indication as a factor in selecting a target cell during a handover procedure, cells providing a higher quality of service are prioritized over cells providing a lower quality of service.

9. A method performed at a user equipment, the method comprising: receiving from the serving network node an instruction to stop reporting the radio link quality of at least one cell controlled by the further network node, the at least one cell being a cell whose service quality has been indicated as being below a predetermined value; and In response, the radio link quality of the at least one cell is not evaluated or reported.

10. A computer program product, when executed by a processor on a device, is configured to control the device to perform the method according to any one of claims 7 to 9.

Images