Control of reconfigurable smart surfaces

Abstract

The invention relates to control of a reconfigurable smart surface. It is proposed a method comprising providing configuration information to one or more devices of a mobile communication system, where the mobile communication system comprises a reconfigurable smart surface (RIS) configurable to selectively support communications between devices of one or more of a plurality of cells of the mobile communication system and a network node, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells; receiving a sounding reference signal (SRS) from each of the plurality of devices, each SRS being transmitted according to the configuration information; and determining one or more cell metrics based on the SRS signals received from the plurality of devices.

Description

Technical Field

[0001] Example embodiments may involve devices, methods, and computer programs that combine the use of reconfigurable smart surfaces. Background Technology

[0002] Reconfigurable Smart Surfaces (RIS) are being researched as a technology for cellular communication systems. RIS typically consists of antenna elements that can be configured according to different use cases. RIS provides a programmable antenna array solution for controlling signal propagation. Summary of the Invention

[0003] The scope of protection sought with respect to the various embodiments of the invention is set forth in the independent claims. Embodiments and features (if any) described in this specification that do not fall within the scope of the independent claims should be interpreted as examples that aid in understanding the various embodiments of the invention.

[0004] In a first aspect, this specification describes a first apparatus (e.g., a user equipment UE) comprising: components (e.g., input) for receiving configuration information from a network node (e.g., a gNB or TRP) of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); components (e.g., a control module or processor) for determining whether a performance change experienced at the first apparatus in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells is higher than a threshold level, wherein the first apparatus is in one of the first and second cells, and the performance change is based on the difference between a performance metric (e.g., CSI, RSRP, etc.) determined at the apparatus before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; and components (e.g., output) for providing performance information based on configuration information in the event that the performance change is higher than the threshold level, wherein the performance information is determined at the apparatus. For example, the configuration information may instruct the first apparatus to provide performance information according to an algorithm (e.g., if the performance change is higher than the threshold level).

[0005] The apparatus may also include components (e.g., a processor or control module) for generating the performance information, wherein the performance information includes performance data compiled into a performance report. The performance data may include channel state information (CSI) and / or reference signal received power (RSRP) data.

[0006] The device may also include components (e.g., a processor or control module) for determining the extent of performance changes experienced at the device, wherein the performance information provided when the performance change exceeds a threshold level includes the extent of the performance change.

[0007] The device may also include components (e.g., a processor or control module) for determining performance metrics (e.g., UE performance metrics) at the device after a RIS configuration change.

[0008] Performance metrics can be based on one or more of the following, for example: Reference Signal Received Power (RSRP), Channel Quality Indicator (CQI), Rank Indicator (RI), and Modulation and Coding Scheme (MCS).

[0009] Configuration information may include performance metrics at the device that were determined before the RIS configuration change (e.g., for comparison with performance metrics determined after the RIS configuration change).

[0010] Configuration information may include the threshold level. In an alternative embodiment, the threshold level may be predefined (or otherwise obtained).

[0011] If the first device is in the second cell (i.e., the RIS has been changed to a supported cell), performance information is provided when the performance change indicates that the performance improvement exceeds a threshold level.

[0012] If the first device is in the first cell (i.e., the cell previously supported by RIS), performance information is provided when a performance change indicates a performance degradation exceeding a threshold level.

[0013] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots can be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0014] The device may also include components (e.g., inputs, such as radio inputs) for receiving CSI-RS transmissions based on configuration information, wherein performance variations are determined based on the received CSI-RS transmissions. When the first device is in a first cell, it can receive CSI-RS transmissions from a first network node, and when the first device is in a second cell, it can receive CSI-RS transmissions from a second network node. Performance information can be returned to the respective network nodes.

[0015] In a second aspect, this specification describes a second apparatus (e.g., a TRP or gNB) comprising: a component (e.g., an output) for providing configuration information to one or more devices (e.g., UEs) of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); and a component (e.g., an input) for receiving performance information from one or more of the one or more devices based on the configuration information, wherein the corresponding device is in one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the corresponding device before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change.

[0016] Performance information may include performance data compiled into a performance report, which may include channel state information (CSI) and / or reference signal received power (RSRP) data.

[0017] Performance information may include an indication of the degree of performance change experienced at the respective device.

[0018] The configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition. These time slots are received from a network node in a first cell of a plurality of cells.

[0019] The apparatus may also include components (e.g., a processor or control module) for determining one or more cell metrics based on the received performance information. Cell metrics may include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain. The apparatus may also include components (e.g., an output) for providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system.

[0020] In a third aspect, this specification describes a third apparatus (e.g., a bNB or TRP) comprising: components (e.g., an input or control module or processor) for receiving a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or for determining a potential need for sharing or switching of the RIS, wherein the RIS is configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); components (e.g., an output) for providing configuration information to one or more network nodes or devices of the mobile communication system; and components (e.g., an input, such as a radio input) for receiving cell metrics relating to one or more of the plurality of cells, wherein The cell metric is determined based on performance information of one or more devices in the corresponding cell, wherein the performance information is provided by the corresponding device when the performance change experienced at the corresponding device in response to a change in the RIS configuration from a first condition in which the RIS supports a first cell among a plurality of cells to a second condition in which the RIS supports a second cell among a plurality of cells is higher than a threshold level, wherein the corresponding device is within one of the first cell and the second cell, and wherein the performance change is based on the difference between the performance metric determined at the corresponding device before the RIS configuration change and the corresponding performance metric obtained after the RIS configuration change; and a component (e.g., a control module or processor) for determining whether to share or switch the RIS based at least in part on the received cell metric.

[0021] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots can be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0022] In a fourth aspect, this specification describes a first apparatus (e.g., a user equipment UE) comprising: components (e.g., inputs) for receiving configuration information from a network node (e.g., a TRP or gNB) of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); components (e.g., a control module or processor) for determining whether a performance change experienced at the first apparatus in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells is higher than a threshold level, wherein the first apparatus is in one of the first and second cells, and the performance change is based on the difference between a performance metric determined at the apparatus before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; components (e.g., a flag control module) for setting a flag to a first level if the performance change is higher than the threshold level; and components (e.g., a flag control module) for setting a flag to a second level if the performance change is lower than the threshold level.

[0023] Flags can be sent to the network node (or otherwise made available to the network node). For example, setting a flag can involve writing to a register available to the network node.

[0024] The device may also include components (e.g., a control module or processor) for determining performance metrics at the device after a RIS configuration change.

[0025] Performance metrics (e.g., UE performance metrics) may be based on one or more of the following: Reference Signal Received Power (RSRP), Channel Quality Indicator (CQI), Rank Indicator (RI), and Modulation and Coding Scheme (MCS).

[0026] The configuration information may include the performance metrics at the device that were determined prior to the RIS configuration change. The configuration information may include performance metrics at the device that were determined prior to the RIS configuration change (e.g., for comparison with performance metrics determined after the RIS configuration change).

[0027] The configuration information may include the threshold level. In an alternative embodiment, the threshold level may be predefined or otherwise obtained.

[0028] If the first device is in the second cell (i.e., the RIS has been changed to a supported cell), the flag can be set to the first level when the performance change indicates that the performance improvement exceeds a threshold level.

[0029] If the first device is in the first cell (i.e., the cell previously supported by RIS), the flag can be set to the first level when the performance change indicates a performance degradation exceeding a threshold level.

[0030] Configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). These time slots may be determined at network nodes (e.g., gNBs) and transmitted to other nodes in the communication system.

[0031] The device may also include components (e.g., inputs, such as radio inputs) for receiving CSI-RS transmissions based on configuration information, wherein performance variations are determined based on the received CSI-RS transmissions.

[0032] In a fifth aspect, this specification describes a second apparatus (e.g., a TRP or gNB) comprising: components (e.g., an output) for providing configuration information to one or more devices (e.g., UEs) of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS configured to selectively support communication between the devices and network nodes in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); and components (e.g., an input or register or some similar mechanism) for receiving (or accessing) flags from each of the one or more devices, wherein each flag indicates whether a performance change experienced at the corresponding device in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells is above a threshold level, wherein the corresponding device is in one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined before the RIS configuration change at the corresponding device and a corresponding performance metric obtained after the RIS configuration change, wherein each flag is set to a first level when the performance change of the corresponding device is above a threshold level, and each flag is set to a second level when the performance change of the corresponding device is below a threshold level.

[0033] The device may also include components (e.g., outputs) for providing at least some of the tags to the base station or gNB of the mobile communication system.

[0034] The apparatus may also include components (e.g., a control module or processor) for determining one or more cell metrics based on the state of the flags. Cell metrics include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain. The apparatus may also include components (e.g., an output) for providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system.

[0035] The configuration information may include the threshold level. In an alternative embodiment, the threshold level may be predefined (or otherwise obtained).

[0036] The configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition. These time slots can be received, for example, from a network node (e.g., a gNB) of a first cell among a plurality of cells.

[0037] In a sixth aspect, this specification describes a third apparatus (e.g., a gNB or TRP) comprising: components (e.g., an input or a processor / control module) for receiving a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or for determining a potential need for sharing or switching of the RIS, wherein the RIS is configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); components (e.g., an output) for providing configuration information to one or more network nodes or devices of the mobile communication system; and components (e.g., an input or a register or similar component) for receiving flags associated with one or more of the plurality of cells or cell metrics based on flags associated with one or more of the plurality of cells, wherein the flags are based on one or more of the respective cells. The device performance information is set, wherein the performance information is provided by the corresponding device in response to a performance change at the corresponding device exceeding a threshold level in response to a change in the RIS configuration from a first condition in which the RIS supports a first cell among a plurality of cells to a second condition in which the RIS supports a second cell among a plurality of cells, wherein the corresponding device is within one of the first cell and the second cell, wherein the performance change is based on the difference between a performance metric determined at the corresponding device before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change, wherein a flag is set to a first level when the performance change is above the threshold level and a flag is set to a second level when the performance change is below the threshold level; and a component (e.g., a processor or control module) for determining whether to share or switch the RIS based at least in part on the received flag or cell metric.

[0038] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots can be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0039] In a seventh aspect, this specification describes a first apparatus (e.g., a user equipment UE) comprising: a component (e.g., an input) for receiving configuration information from a network node of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells, wherein the first apparatus is in one of the first cell and the second cell (note that more than one RIS may be provided); and a component (e.g., an output) for providing a sounding reference signal SRS according to the configuration information.

[0040] SRS can be sent during the time slots defined by the configuration information.

[0041] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots may be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0042] In an eighth aspect, this specification describes a second apparatus (e.g., a TRP or gNB) comprising: components (e.g., an output) for providing configuration information to each of a plurality of devices in a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and a network node in one or more of a plurality of cells in the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells (note that more than one RIS may be provided); components (e.g., an input) for receiving a probe reference signal (SRS) from each of the plurality of devices, each SRS being transmitted according to the configuration information; and components (e.g., a control module or a processor) for determining one or more cell metrics based on the SRS signals received from the plurality of devices.

[0043] The apparatus may also include components (e.g., output) for providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system. Cell metrics may include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain.

[0044] SRS can be received during a time slot defined by the configuration information.

[0045] Configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots may be received from a network node (e.g., a gNB) of a first cell among a plurality of cells.

[0046] In a ninth aspect, this specification describes a third apparatus (e.g., a TRP or gNB) comprising: components (e.g., an input or processor / control module) for receiving a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or for determining a potential need for sharing or switching of the RIS, wherein the RIS is configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); components (e.g., an output) for providing configuration information to one or more network nodes or devices of the mobile communication system; and components for receiving cell metrics relating to one or more of the plurality of cells based on the configuration information, wherein small The cell metric is determined based on SRS signals received from one or more devices in the corresponding cell, wherein the cell metric involves a performance change experienced at the corresponding device in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of a plurality of cells to a second condition in which the RIS supports a second cell of a plurality of cells exceeding a threshold level, wherein the corresponding device is within one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the corresponding device before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; and a component (e.g., a control module or processor) for determining whether to share or switch the RIS based at least in part on the received cell metric.

[0047] In a tenth aspect, this specification describes a method comprising: receiving configuration information at a first device (e.g., UE) of a mobile communication system from a network node (e.g., TRP or gNB) of the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system; determining whether a performance change experienced at the first device in response to a change in the RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells exceeds a threshold level, wherein the first device is in one of the first and second cells, wherein the performance change is based on the difference between a performance metric determined at the first device prior to the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; and providing performance information based on the configuration information if the performance change exceeds the threshold level.

[0048] Configuration information may, for example, instruct the first device to provide performance information based on an algorithm (e.g., if the performance change exceeds a threshold level).

[0049] The method may further include generating the performance information, wherein the performance information includes performance data compiled into a performance report. The performance data may include channel state information (CSI) and / or reference signal received power (RSRP) data.

[0050] The method may also include determining the extent of performance changes experienced at the device, wherein performance information provided when the performance change exceeds a threshold level includes the extent of the performance change.

[0051] The method may also include determining performance metrics (e.g., UE performance metrics) at the device after a RIS configuration change.

[0052] If the first device is in the second cell (i.e., the RIS has been changed to a supported cell), performance information is provided when the performance change indicates that the performance improvement exceeds a threshold level.

[0053] If the first device is in the first cell (i.e., the cell previously supported by RIS), performance information is provided when a performance change indicates a performance degradation exceeding a threshold level.

[0054] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots can be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0055] The method may further include receiving CSI-RS transmissions based on configuration information, wherein performance changes are determined based on the received CSI-RS transmissions. When the first device is in a first cell, it can receive CSI-RS transmissions from a first network node, and when the first device is in a second cell, it can receive CSI-RS transmissions from a second network node. Performance information can be returned to the corresponding network node.

[0056] In an eleventh aspect, this specification describes a method comprising: providing configuration information to one or more devices of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and a network node in one or more of a plurality of cells of the mobile communication system; and, in the event that a performance change experienced at a corresponding device in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells exceeding a threshold level, receiving performance information from one or more of the one or more devices based on the configuration information, wherein the corresponding device is in one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the corresponding device prior to the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change.

[0057] Performance information may include performance data compiled into a performance report. Performance data may include channel state information (CSI) and / or reference signal received power (RSRP) data.

[0058] Performance information may include an indication of the degree of performance change experienced at the respective device.

[0059] The configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition. These time slots are received from a network node in a first cell of a plurality of cells.

[0060] The method may further include determining one or more cell metrics based on the received performance information. Cell metrics may include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain. The method may also include providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system.

[0061] In a twelfth aspect, this specification describes a method comprising: receiving a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or determining a potential need for sharing or switching of the RIS, wherein the RIS is configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); providing configuration information to one or more network nodes or devices of the mobile communication system; receiving cell metrics relating to one or more of the plurality of cells, wherein the cell metrics are determined based on performance information of one or more devices in the respective cells, wherein the performance information is provided by the respective device in response to a performance change at the respective device exceeding a threshold level in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells, wherein the respective device is within one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the respective device before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; and determining whether to share or switch the RIS based at least in part on the received cell metrics.

[0062] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots can be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0063] In a thirteenth aspect, this specification describes a method comprising: receiving configuration information at a device of a mobile communication system from a network node of the mobile communication system (e.g., a TRP or gNB), wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system; determining whether a performance change experienced at a first device in response to a change in the RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells is greater than a threshold level, wherein: the first device is in either the first cell or the second cell; and the performance change is based on the difference between a performance metric determined at the first device prior to the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; setting a flag to a first level if the performance change is greater than the threshold level; and setting a flag to a second level if the performance change is less than the threshold level.

[0064] Flags can be sent to the network node (or otherwise made available to the network node). For example, setting a flag can involve writing to a register available to the network node.

[0065] The method may also include determining performance metrics at the device after a RIS configuration change.

[0066] Performance metrics (e.g., UE performance metrics) may be based on one or more of the following: Reference Signal Received Power (RSRP), Channel Quality Indicator (CQI), Rank Indicator (RI), and Modulation and Coding Scheme (MCS).

[0067] The configuration information may include the performance metrics at the device that were determined prior to the RIS configuration change. The configuration information may include performance metrics at the device that were determined prior to the RIS configuration change (e.g., for comparison with performance metrics determined after the RIS configuration change).

[0068] The configuration information may include the threshold level. In an alternative embodiment, the threshold level may be predefined or otherwise obtained.

[0069] If the first device is in the second cell (i.e., the RIS has been changed to a supported cell), the flag can be set to the first level when the performance change indicates that the performance improvement exceeds a threshold level.

[0070] If the first device is in the first cell (i.e., the cell previously supported by RIS), the flag can be set to the first level when the performance change indicates a performance degradation exceeding a threshold level.

[0071] Configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). These time slots may be determined at network nodes (e.g., gNBs) and transmitted to other nodes in the communication system.

[0072] The method may also include receiving CSI-RS transmissions based on configuration information, wherein performance changes are determined based on the received CSI-RS transmissions.

[0073] In a fourteenth aspect, this specification describes a method comprising: providing configuration information to one or more devices of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the devices and network nodes in one or more of a plurality of cells of the mobile communication system; and receiving or accessing a flag from each of the one or more devices, wherein each flag indicates whether a performance change experienced at the respective device in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells is above the threshold level, wherein the respective device is within one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the respective device prior to the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change, wherein each flag is set to a first level if the performance change of the respective device is above the threshold level, and each flag is set to a second level if the performance change is below the threshold level.

[0074] The method may also include providing at least some of the flags to the base station or gNB of the mobile communication system.

[0075] The method may further include determining one or more cell metrics based on the state of the flag. Cell metrics include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain. The method may further include providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system.

[0076] The configuration information may include the threshold level. In an alternative embodiment, the threshold level may be predefined (or otherwise obtained).

[0077] The configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition. The time slots may be received, for example, from a network node (e.g., a gNB) of a first cell among a plurality of cells.

[0078] In a fifteenth aspect, this specification describes a method comprising: receiving a request for sharing or handover of a reconfigurable smart surface (RIS) of a mobile communication system or determining a potential need for sharing or handover of the RIS, wherein the RIS is configurable to selectively support communication between devices and network nodes in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); providing configuration information to one or more network nodes or devices of the mobile communication system; receiving flags associated with one or more of the plurality of cells or cell metrics based on flags associated with one or more of the plurality of cells, wherein the flags are set based on performance information of one or more devices in the respective cell, wherein the RIS is received at the respective device in response to the RIS. If the IS configuration changes from a first condition where the RIS supports a first cell among multiple cells to a second condition where the RIS supports a second cell among multiple cells, and the resulting performance change exceeds a threshold level, performance information is provided by the corresponding device, wherein the corresponding device is in either the first cell or the second cell, wherein the performance change is based on the difference between a performance metric determined at the corresponding device before the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change, wherein a flag is set to a first level if the performance change exceeds a threshold level, and a flag is set to a second level if the performance change is below a threshold level; and whether to share or switch the RIS is determined at least in part based on the received flag or cell metric.

[0079] Configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). Time slots may be determined at network nodes (e.g., gNBs) and transmitted to other nodes in the communication system.

[0080] In a sixteenth aspect, this specification describes a method comprising: receiving configuration information from a network node of a mobile communication system at a first device of the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells, wherein the first device is in one of the first cell and the second cell; and providing a detection reference signal SRS according to the configuration information.

[0081] SRS can be sent during the time slots defined by the configuration information.

[0082] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots may be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0083] In a seventeenth aspect, this specification describes a method comprising: providing configuration information to one or more devices of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the devices and a network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells; receiving a probe reference signal SRS from each of the plurality of devices, each SRS being transmitted according to the configuration information; and determining one or more cell metrics based on the SRS signals received from the plurality of devices.

[0084] The method may include providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system. Cell metrics may include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain.

[0085] In some example embodiments, the SRS may be sent / received during a time slot defined by configuration information.

[0086] In some example embodiments, the configuration information includes time slots during which the RIS configuration changes from a first condition to a second condition (e.g., to determine the performance change). The time slots may be determined at a network node (e.g., a gNB) and transmitted to other nodes in the communication system.

[0087] In an eighteenth aspect, this specification describes a method comprising: receiving a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or determining a potential need for sharing or switching of the RIS, wherein the RIS is configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system (note that more than one RIS may be provided); providing configuration information to one or more network nodes or devices of the mobile communication system; receiving, based on the configuration information, cell metrics relating to one or more of the plurality of cells, wherein the cell metrics are determined based on SRS signals received from one or more devices in the respective cell, wherein the cell metrics relate to a performance change experienced at the respective device in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells exceeding a threshold level, wherein the respective device is within one of the first and second cells, and wherein the performance change is based on the difference between a performance metric determined at the respective device prior to the RIS configuration change and a corresponding performance metric obtained after the RIS configuration change; and determining whether to share or switch the RIS based at least in part on the received cell metrics.

[0088] In a nineteenth aspect, this specification describes a computer-readable instruction that, when executed by a computing device, causes the computing device to perform (at least) any of the methods described herein (including the methods described in aspects ten through eighteen above).

[0089] In a twentieth aspect, this specification describes a computer-readable medium (such as a non-transitory computer-readable medium) including program instructions stored thereon for (at least) performing any of the methods described herein (including the methods described in aspects ten through eighteen above).

[0090] In a twentieth aspect, this specification describes a computer program product including program instructions that, when executed by a device, cause the device to perform (at least) any of the methods described herein (including the methods described in aspects ten through eighteen above).

[0091] In a twentieth aspect, this specification describes an apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the apparatus to perform at least any of the methods described herein (including the methods described in aspects ten through eighteen above). Attached Figure Description

[0092] Exemplary embodiments will now be described by way of non-limiting examples with reference to the accompanying drawings, in which: Figures 1 to 3 This is a block diagram of the example system; Figure 4 An example RIS architecture is shown; Figure 5 and Figure 6 This is a block diagram of the example system; Figure 7 This is a flowchart based on an example embodiment; Figure 8 It is a message stream sequence according to the example embodiment; Figures 9 to 11 This is a flowchart based on an example embodiment; Figure 12 and Figure 13 It is a message stream sequence according to the example embodiment; Figure 14 and Figure 15 This is a flowchart based on an example embodiment; Figure 16 and Figure 17 It is a message stream sequence according to the example embodiment; Figure 18 It is a schematic diagram of a system that can be used to implement one or more example embodiments; and Figure 19 A tangible medium for storing computer-readable code is shown, which, when run by a computer, can perform methods according to the example embodiments described herein. Detailed Implementation

[0093] Reconfigurable smart surfaces (RIS) are being researched in industry and academia as a technology to complement existing radio infrastructure for cellular communication systems. RIS comprises antenna elements (typically inexpensive) that can be configured according to different use cases. RIS provides a programmable antenna array solution for controlling signal propagation, for example, by changing the electrical and magnetic properties of the RIS's reflective surface according to the use case. In some cases, RIS may be able to provide a cost-effective alternative for deploying new gNBs / acquiring new spectrum.

[0094] Figure 1 This is a block diagram of an example system generally indicated by reference numeral 10. System 10 includes network nodes 12 (such as a transmit-receive point TRP, base station, or gNB), user equipment UE 14 (or some other mobile communication device or terminal device), and a reconfigurable smart surface RIS 16. Figure 1 As shown, system 10 also includes an obstacle 18 between network node 12 and UE 14, such that there is no direct communication between node 12 and UE 14. RIS 16 may include multiple antenna elements configured according to desired use cases. One configuration corresponds to a beam pointing in a given direction (e.g., a narrow beam).

[0095] In system 10, RIS 16 is configured to redirect signals from network node 12 to UE 14 and vice versa, so that network node 12 and UE 14 can still communicate despite the presence of obstacle 18. Therefore, system 10 provides a simple coverage enhancement use case for RIS.

[0096] Figure 2 This is a block diagram of an example system generally indicated by reference numeral 20. System 20 includes network node 22, UE 24, and RIS 26 (similar to network node 12, UE 14, and RIS 16 of System 10, but with obstacle 18 omitted). A line-of-sight (LOS) connection can be established between network node 22 and UE 24. However, a second communication link is also available via RIS 26. Providing an additional physical path can, for example, provide capacity improvements in the case of a primary LOS channel.

[0097] In system 20, RIS 26 can be used to increase the channel rank, and thus increase the spectral efficiency for applications requiring high throughput in the downlink. More specifically, there are scenarios where the link between network node 22 and UE 24 exhibits strong line-of-sight (LOS) components, and therefore, rank 1 MIMO transmission alone is possible. This is especially true in higher frequency bands, where RIS can be deployed (since the RIS antenna spacing is a fraction of the wavelength, the smaller wavelength facilitates RIS deployment, resulting in a smaller RIS array size). RIS 26 provides additional propagation paths, and the channel rank can be increased to 2 with appropriate configuration. It should also be noted that there are cases where the channel rank is greater than 1 without RIS (e.g., equal to 2 in the case of cross-polarized antennas), in which case providing RIS can be used to increase the rank to 3.

[0098] Figure 3 This is a block diagram of an example system generally indicated by reference numeral 30. System 30 includes network node 32, UE 34, and RIS 36 (similar to the network node, UE, and RIS in systems 10 and 20 described above). In system 30, RIS 36 can be used as a positioning anchor to improve positioning accuracy. RIS 36 is typically a cheaper alternative to deploying additional network nodes (e.g., Transmit / Receive Points (TRPs) for positioning purposes).

[0099] Figure 4 An example RIS architecture, generally indicated by reference numeral 40, is shown. RIS architecture 40 can, for example, be used to implement the aforementioned RIS 16, RIS 26, and RIS 36. RIS 40 includes multiple passive components (in... Figure 4 (shown in white) and active components (in) Figure 4 (shown in gray).

[0100] The RIS 40's passive components provide a planar array of passive reflective elements that can reflect input light with adjustable phase shift and gain. The passive nature of the reflective elements results in low hardware cost, low power consumption, and the ability to operate naturally in full-duplex (FD) mode. The phase of the passive elements can be configured to reflect the input signal in the desired direction.

[0101] The active components of RIS 40 can be controlled by the RIS controller. The active components can be used for functions such as transmitting control messages between the RIS and network nodes (such as any of the network nodes 12, 22, and 32 mentioned above) and / or for channel sensing by measuring reference signals.

[0102] Figure 5 This is a block diagram of the system, generally indicated by reference numeral 50. System 50 includes a network node 52, multiple UEs 54 (UE1 to UE4), and a RIS 56. System 50 shows a predefined mesh of beams at both the network node and the RIS. Here, the RIS can be configured to optimize communication within the cell where UE 54 resides.

[0103] System 50 illustrates the use of RIS in a single-cell scenario. However, RIS presents additional spatial degrees of freedom and can be used to optimize the performance of multi-cell networks by dynamically directing the RIS beam to the selected cell based on the cell's radio conditions.

[0104] Figure 6 This is a block diagram of an example system generally indicated by reference numeral 60. System 60 includes multiple network nodes (NN1 and NN2), multiple UEs (UE1 to UE6), and multiple RIS (RIS1 to RIS6). RIS can be deployed, for example, at the cell edge. As an example, depending on appropriately defined metrics, RIS3 can be used to serve cells NN1, NN2, or both.

[0105] For example, suppose a handover process occurs where RIS3 is initially configured to support the first cell of NN1 (rather than the second cell of NN2). An example condition controlling the handover would be considering the signal quality experienced by UEs (such as UE4, UE5, and UE6) in the second cell. For instance, a signal quality degradation experienced by a UE in the second cell below a certain threshold might trigger a RIS sharing request. In this case, NN2 might request NN1 to change the RIS3 configuration in order to improve radio conditions in the second cell.

[0106] The arrangement defined above has several potential drawbacks. For example, the conditions used to trigger a RIS handover from the first cell to the second cell may not be sufficient in all cases. Furthermore, in the arrangement defined above, a RIS handover can occur without considering the disadvantages to the first cell, and it is uncertain whether the handover will significantly improve performance in the second cell.

[0107] Figure 7 It is a flowchart generally indicated by reference numeral 70 according to an example embodiment.

[0108] Flowchart 70 is initiated by a request for RIS handover; for example, in the example above, the request is to transfer the RIS from a first cell supporting NN1 to a second cell supporting NN2.

[0109] Flowchart 70 begins at step 72, where beam scanning is performed using the RIS that supports the second cell (which may be referred to as the requesting cell).

[0110] In step 74, as a result of the beam scan, the UE metric is obtained. As discussed in detail below, the UE metric is obtained from both the first cell (cell NN1 in the example above) and the second cell (cell NN2 in the example above - the requesting cell).

[0111] In step 76, cell metrics are determined based on the UE metrics obtained in step 74. Cell metrics may include one or more of the following: • Gain / increment in spectral efficiency (SE) due to the second cell of RIS service.

[0112] • Utilize the energy efficiency (EE) gain of the RIS (e.g., the reduction in UE or TRP transmit power due to the RIS serving a second cell).

[0113] • Utilize the resource efficiency (RE) gain of RIS (e.g., the number or percentage of physical resource blocks (PRBs) released due to RIS serving a second cell).

[0114] As discussed in detail below, cell metrics can be calculated using data such as Received Reference Signal Power (RSRP) reports, Channel State Information (CSI) reports, and Received Sounding Reference Signals (SRS). The defined cell metrics can be instantaneous or averaged.

[0115] Finally, in step 78, the RIS transfer decision is made at least in part based on the cell metric determined in step 76.

[0116] In flowchart 70, cell metrics can be obtained for the first cell (which was previously supported by RIS) and the second cell (which requested RIS support). Therefore, relevant network nodes can compare the RIS gains in the two cells to make an informed decision on whether to initiate a RIS handover.

[0117] In some cases, the algorithm shown in flowchart 70 may preferably be preferred to simply use the UE Received Power (RSRP) in the requesting cell, as described above, for at least some of the following reasons: • UEs in two cells can have acceptable RSRP, but RIS still need to be optimally allocated between the two cells. Considering that RIS will be mainly deployed in the higher frequency range (7-24 GHz, 24-52 GHz), the cell radius will be smaller than that of cells in the lower 6 GHz range, increasing line-of-sight and the probability of having acceptable RSRP.

[0118] • Depending on the UE use case / Quality of Service (QoS) flow identifier, a UE with high throughput requirements in a given cell may need to be prioritized over another UE experiencing poor signal strength in a neighboring cell. This can be achieved using the SE gain / incremental metric discussed above.

[0119] Below are some examples of the advantages of the cell metrics discussed above. Note that these cell metrics are provided as examples only. Different cell metrics can be used in addition to or in place of some or all of these: • Spectral efficiency (SE) gain: If a given UE has high throughput requirements (e.g., a guaranteed bit rate (GBR) UE in 3GPP), using the RIS additional path can provide SE gain.

[0120] • Energy Efficiency (EE) Gain: If a given UE does not have high throughput requirements (e.g., a non-GBR UE in 3GPP), the RIS additional path provides increased spatial diversity / receive power observed at the TRP / UE. Equivalently, it can be used to reduce the transmit power of the TRP in the downlink or the transmit power of the UE in the uplink.

[0121] • Resource efficiency (RE) gain: This is usually closely related to the SE metric; that is, if RIS can increase the spectral efficiency per PRB, it means that the number of PRBs required to implement a GBR with RIS is reduced compared to the case without RIS.

[0122] Figure 8 This is the message flow sequence generally indicated by reference numeral 80 according to the example embodiment. Sequence 80 can be used in an example implementation of the algorithm shown in flowchart 70.

[0123] Sequence 80 illustrates the messages transmitted between the first gNB (gNB1), the second gNB (gNB2), the first transmit-receive point (TRP1), the second transmit-receive point (TRP2), the RIS, the first user equipment (UE1), and the second user equipment (UE2), and the actions taken at them. Sequence 80 illustrates operation in Frequency Division Duplex (FDD) mode. In the example described below, gNB1, TRP1, and UE1 all form part of the first cell; similarly, gNB2, TRP2, and UE2 all form part of the second cell. Initially, the RIS is configured to support the first cell.

[0124] As shown in the “RIS Usage Request” sequence of messages, due to increased activity in the second cell of TRP2, gNB2 sends a request to gNB1 to request sharing or switching of RIS (see step 1 of sequence 80).

[0125] After receiving the request, gNB1: • Select a set of time slots T1 and beam patterns for the RIS beam scan toward cell 2, while still maintaining control over the RIS (step 2 of sequence 80). This is the beam scan of step 72 of the flowchart above.

[0126] • Configure TRP1 and UE1 for CSI-RS transmission and CSI-RS reception respectively in the downlink (DL) of (any) time slot T1 (steps 3.a and 7).

[0127] • Based on the reception report (e.g., RSRP / CSI report) received from UE1 in subsequent steps, in the absence of RIS pointing to cell 1, i.e., in (any) time slot T1, TRP1 is configured to calculate and transmit cell metrics via signal transmission (step 3.b).

[0128] In step 4 of sequence 80, gNB1 transmits the group of time slots T1 to gNB2 via signaling, enabling gNB2 to configure TRP2 and UE2 for CSI-RS transmission and CSI-RS reception (steps 5.a and 8). Furthermore, based on the RSRP / CSI report received from UE2 in subsequent steps, if RIS points to cell 2, i.e., in (any) time slot T1, gNB2 configures TRP2 to calculate and transmit the cell metric via signaling (step 5.b).

[0129] In steps 9 and 10 of sequence 80, CSI-RS transmissions in cell 1 and cell 2 occur in (either) time slot T1. The UE can calculate the RSRP or CSI report in steps 11 and 12 and feed it back to its TRP; these are the UE metrics for step 74 of flowchart 70. TRP1 can then calculate the cell metric based on the report received from its UE, in the absence of a RIS pointing to cell 1. TRP1 can then compare the received UE metric with its last metric before the procedure began (before the RIS sharing / handover request) when the RIS pointed to cell 1. Similarly, TRP2 can then calculate the cell metric based on the report received from its UE, in the absence of a RIS pointing to cell 2. TRP2 can then compare the received UE metric with its last UE metric before the procedure began when the RIS did not point to cell 2.

[0130] At this stage of the algorithm, each TRP can now estimate / calculate the gain that RIS provides to the corresponding cell. These gains are transmitted to gNB1 and gNB2 via signaling in steps 15 and 16. gNB2 transmits the RIS gain to gNB1 via signaling in step 17. At the end of this process, gNB1 can compare the RIS gains of the two TRPs. If the measurement from TRP2 shows a benefit from RIS, a (partial) handover process can be triggered in step 18.

[0131] In another embodiment, in addition to the RIS metric gain in step 16, TRP2 may also send to gNB2 the time slot index (corresponding to the RIS beam index) where the RIS provides the maximum gain. This may be based on additional configuration requested from gNB1 and / or gNB2. By forwarding this information to gNB1, gNB1 can configure the appropriate RIS beam with the corresponding time slot information for cell 2 and notify gNB2 accordingly, without switching RIS control to gNB2.

[0132] Figure 9 This is a flowchart, generally indicated by reference numeral 90, according to an example embodiment. Algorithm 90 illustrates the actions taken at the UE in a variant of the above-described message sequence 80.

[0133] For ease of reference, algorithm 90 is described when used in scenarios similar to those described in reference message sequence 80 above. For example, gNB1 may initially use RIS, where gNB2 initiates a RIS sharing or switching process.

[0134] Algorithm 90 begins (in step 92) at the UE (such as UE1 or UE2) by receiving configuration information from a network node (e.g., TRP1 or TRP2) of the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, which can be configured to selectively support communication between devices and network nodes in one or more of a plurality of cells of the mobile communication system. The UE is then configured according to the configuration information.

[0135] Then (under the control of the relevant network nodes), the RIS configuration is changed from a first condition to a second condition. In the first condition, the RIS supports a first cell among multiple cells (e.g., including TRP1 and UE1), and in the second condition, the RIS supports a second cell among multiple cells (e.g., including TRP2 and UE2). The UE implementing algorithm 90 is located in either the first or second cell (and may be, for example, UE1 or UE2 of message sequence 70). The configuration information received in step 2 may include an indication of a time slot during which the RIS configuration will change from the first condition to the second condition.

[0136] In step 94, it is determined at the UE whether the performance change experienced by the UE in response to the RIS configuration change exceeds a threshold level. The performance change is based on the difference between the performance metrics (such as one or more of the following: RSRP, CSI, CQI, rank indicator, and modulation and coding scheme) determined at the UE before the RIS configuration change and the corresponding performance metrics obtained after the RIS configuration change. The threshold level may, for example, be included in the configuration information received in step 92; alternatively, for example, the threshold level may be predefined (or otherwise obtained).

[0137] If the performance change exceeds the threshold level, the algorithm moves to step 96 of the flowchart; otherwise, the flowchart terminates at step 98.

[0138] In step 96, if the performance change exceeds a threshold level, performance information is provided based on the configuration information received in step 92.

[0139] When message sequence 80 is implemented using the algorithm in flowchart 90, the UE served by TRP2 (the requesting node) is instructed to report UE parameters to TRP2. These parameters (typically from multiple UEs) are used to generate cell metrics. UE metrics are sent only if the impact of the RIS (Restricted Performance Indicator) is above a threshold (i.e., a significant performance increase). Meanwhile, the UE served by TRP1 is instructed to report parameters to TRP1, but only if the impact of the RIS is not above a threshold (i.e., a significant performance decrease). Sending UE metrics only when the performance change is above a threshold level can be used to establish meaningful cell metrics between the UE and TRP with minimal data transmission.

[0140] The performance information provided in operation 96 may be a performance report, such as an RSRP or CSI report. The performance report can be compiled based on UE performance data, such as CSI and / or RSRP. In an alternative embodiment, the performance information provided in operation 96 may include an indication of the degree of performance change experienced at the UE. The degree of performance change can be calculated at the respective UE based on the processing reference signal and the CSI-RS received under first and second conditions (i.e., before and after the RIS configuration change); thus, differences in RSRP, CSI, or some other metric can be determined.

[0141] In some example embodiments, in order to determine a change in performance metric, the configuration information received in operation 92 may include the corresponding performance metric determined before the RIS configuration change.

[0142] Figure 10 This is a flowchart, generally indicated by reference numeral 100, according to an exemplary embodiment. Flowchart 100 is a variation of the above-described flowchart 90.

[0143] The algorithm in flowchart 100 begins at step 102, receiving configuration information from a network node (e.g., TRP) of the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, which can be configured to selectively support communication between devices and the network node in one or more of the multiple cells of the mobile communication system. Therefore, step 102 is the same as step 92 described above.

[0144] In step 104, a flag is set or cleared based on whether the performance change experienced at the UE in response to a change in RIS configuration from a first condition (where the RIS supports a first cell among multiple cells) to a second condition (where the RIS supports a second cell among multiple cells) is higher than a threshold level. Specifically, if the performance change is higher than the threshold level, the flag can be set to the first level; and if the performance change is lower than the threshold level, the flag can be set to the second level (or cleared).

[0145] For example, when the UE is in a second cell (i.e., a cell that the RIS has changed to support), the flag can be set to the first level when the performance change indicates a performance improvement exceeding a threshold level. Similarly, when the UE is in a first cell (i.e., a cell previously supported by the RIS), the flag can be set to the second level when the performance change indicates a performance degradation exceeding a threshold level.

[0146] At step 106, the flag is made available to the network node (e.g., by sending the flag to the network node, by writing the flag value to a register accessible to the network node, or in some other way).

[0147] Therefore, in the algorithm of flowchart 100, instead of sending complete UE metric data (or details of UE metric changes), the UE sets a flag value based on whether the impact of the RIS configuration change exceeds a threshold (i.e., a significant performance change due to RIS reconfiguration). The flag values ​​from multiple UEs can then be sent to the gNB (or otherwise made available to it), indicating whether a significant change has occurred in either the TRP1 or TRP2 region in response to the RIS change. This information can be used to determine whether to make the RIS change permanent.

[0148] Figure 11 This is a flowchart generally indicated by reference numeral 110 according to an example embodiment. Flowchart 110 can be implemented at network nodes such as TRP1 or TRP2 in the example above.

[0149] Flowchart 110 begins at step 112, providing configuration information to one or more devices in a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, which can be configured to selectively support communication between devices and network nodes in one or more of a plurality of cells of the mobile communication system. Therefore, the configuration information provided in operation 112 may be the configuration information received in operations 92 and 102 described above.

[0150] In step 114, performance information is obtained. The performance information may be a performance report or indication of performance changes as described in step 96 of flowchart 90 above, or a flag provided or available in step 106 of flowchart 100.

[0151] As described above, the performance information indicates whether the performance change experienced at the corresponding device in response to a change in RIS configuration from a first condition (where the RIS supports a first cell among multiple cells) to a second condition (where the RIS supports a second cell among multiple cells) exceeds a threshold level.

[0152] In step 116, one or more cell metrics (such as spectral efficiency, energy efficiency, and / or resource efficiency gain) are determined (at least in part) based on the performance information obtained in step 114. Step 116 can be implemented at the network node or elsewhere (e.g., at the gNB).

[0153] In step 118, at least some of the determined cell metrics can be reported to the gNB of the mobile communication system.

[0154] Figure 12This is a message flow sequence generally indicated by reference numeral 120 according to an example embodiment. This message flow sequence illustrates an example implementation of the algorithms of flowcharts 90, 100, and 110 described above. Sequence 120 shows the messages sent between gNB2, TRP2, and UE2, and the actions taken at gNB2, TRP2, and UE2 (which may be the same as the corresponding elements of message flow sequence 80 described above). Therefore, as in message sequence 80, the TRPs of different cells are controlled by different gNBs.

[0155] Sequence 122 begins with the transmission of configuration information from gNB2 to TRP2 (see steps 5.a and 5.b of message sequence 80). As discussed in detail above, in one embodiment, if the gain is higher than a predefined threshold compared to the last report transmitted before RIS beam scanning, gNB2 can configure the UE to only transmit UE reports. To do this, gNB2 can send the CSI-RS resource set ID or measurement ID corresponding to that last report to the UE. In an alternative embodiment, gNB2 can configure the UE to report simple 0 / 1 flags, corresponding to whether RIS provides gain, based on a similar predefined threshold.

[0156] TRP2 sends configuration message 123 to the UE2 or each UE2 (see step 8 of message sequence 80 – CSI-RS configuration).

[0157] The UE2, or each UE2, sends report 124 to TRP2 (see step 12 of message sequence 80 – RERP / CSI report, i.e., UE metric report). Such metrics may include RSRP, CQI, RI, MCS gain, or any combination thereof. Relevant thresholds may be transmitted to the UE as part of configuration message 123.

[0158] TRP2 can calculate the cell metric in step 125 (see step 14 in message sequence 80).

[0159] Finally, TRP2 sends a report to gNB2 in step 126 (see step 16 in message sequence 80).

[0160] In the example embodiments described above, the TRP of different cells is controlled by different gNBs. This is not necessary for all example embodiments.

[0161] Figure 13 This is a message flow sequence generally indicated by reference numeral 130 according to an example embodiment. Unlike the example above, in message sequence 130, the TRPs of different cells are controlled by the same gNB (specifically, UE1 and TRP1 of cell 1 and UE2 and TRP2 of cell 2 are both controlled by the same gNB).

[0162] In message sequence 130, due to the report / information element sent by TRP2, the gNB will be aware of the increased activity in TRP2's cell and can trigger a beam scan toward TRP2's cell (without the triggering described above as in message sequence 80). In steps 2.a and 2.b, the TRP instructions for configuring the UE CSI-RS, transmitting the TRP CSI-RS, and sending metrics are sent to both TRPs. Subsequent steps are similar to those described above. At the end of the process, the RIS gain is sent from both TRPs to the gNB in ​​steps 14 and 15.a. TRP2 additionally sends the time slot where the RIS provides the maximum gain (corresponding to the RIS beam index) (step 15.b). This allows the gNB to configure the appropriate RIS beam toward TRP2's cell in step 15, if it decides to do so after comparing the RIS gains in cell 1 and cell 2 in step 16. In a variant of message sequence 130, UE metrics may be provided to the TRP as a UE metric report, a report of UE metric changes, or as a flag (as discussed in detail above).

[0163] The example embodiments described in detail above relate to FDD embodiments. The example embodiments described below relate to different methods of transmitting using Sounding Reference Signals (SRS). Here, UEs of gNB1 and gNB2 can be instructed to transmit SRS in specific time slots. Both TRP / gNB1 and TRP / gNB2 can determine cell metrics based on the received corresponding SRS. This relies on the fact that with TDD, the UL channel is the same as the DL channel (if FDD were used, the channels would be different because the UL and DL frequencies are different and therefore the channel responses are different).

[0164] Figure 14 This is a flowchart, generally indicated by reference numeral 140, according to an exemplary embodiment. Flowchart 140 is implemented at the UE (or some other device in a mobile communication system).

[0165] The algorithm in flowchart 140 begins at step 142, configuring the UE based on configuration information received from the network node of the mobile communication system. As in the above embodiment, the mobile communication system includes a RIS, which can be configured to selectively support communication between the device and the network node in one or more of a plurality of cells of the mobile communication system. The RIS can be configured between a first condition (where the RIS supports a first cell of the plurality of cells) and a second condition (where the RIS supports a second cell of the plurality of cells). The device is in either the first cell or the second cell.

[0166] In step 142, the configuration information may include a time slot during which the RIS configuration changes from a first condition to a second condition (in order to determine the performance changes discussed in detail above).

[0167] In step 144, the device provides a probe reference signal (SRS) based on the configuration information. Specifically, the SRS can be transmitted during a time slot defined by the configuration information.

[0168] Figure 15 This is a flowchart generally indicated by reference numeral 150 according to an example embodiment. Flowchart 150 is implemented at network nodes (such as TRPs).

[0169] In step 152 of flowchart 150, configuration information is provided to each of the multiple devices in the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, as described above. The configuration information may be the configuration information received in step 142 discussed above.

[0170] As described above, the configuration information may include time slots during which the RIS configuration changes from a first condition to a second condition (in order to determine the performance change).

[0171] In step 154, a probe reference signal (SRS) is received from each of the plurality of devices, each SRS being transmitted according to configuration information (e.g., received during a time slot defined by the configuration information transmitted in step 152). The SRS received in step 144 may be the SRS provided in step 144 as described above.

[0172] In step 156, one or more cell metrics (e.g., one or more of spectral efficiency, energy efficiency, and resource efficiency gain) are determined based on the SRS signal received in step 154. Optionally, at least some of the determined cell metrics may be provided to the gNB of the mobile communication system (see step 158 of flowchart 150).

[0173] Figure 16 It is a message flow sequence generally indicated by reference numeral 160 according to an example embodiment. Sequence 160 illustrates an example implementation of the algorithm of flowcharts 140 and 150 above.

[0174] Sequence 160 illustrates messages transmitted between a first gNB (gNB1), a second gNB (gNB2), a first transmit-receive point (TRP1), a second transmit-receive point (TRP2), a RIS, a first user equipment (UE1), and a second user equipment (UE2) operating in Time Division Duplex (TDD) mode, and the actions taken at them. In the example described below, gNB1, TRP1, and UE1 all form part of a first cell; similarly, gNB2, TRP2, and UE2 all form part of a second cell. Initially, the RIS is configured to support the first cell.

[0175] Steps 1-6 of message sequence 160 are similar to those of message sequence 80, except that the UE is configured to transmit a Sounding Reference Signal (SRS) in the UL in any time slot T1 (steps 3.a and 5.a), instead of receiving CSI-RS in the DL and subsequently RSRP / CSI report feedback. SRS reception at TRP1 allows it to calculate cell metrics even when the RIS is not pointing to cell 1. Similarly, SRS reception at TRP2 in any time slot T1 allows it to calculate cell metrics even when the RIS is pointing to cell 2.

[0176] After each TRP forwards the SRS configuration to its UE in any time slot T1 in steps 7 and 8, SRS transmissions in UL occur in cell 1 and cell 2 in steps 9 and 10.

[0177] In step 11, TRP1 calculates cell metrics without RIS and compares them to its last metrics with RIS before the procedure begins (before the RIS sharing / handover request). In step 12, TRP2 calculates cell metrics with RIS and compares them to its last metrics without RIS before the procedure begins. Thus, each TRP can now estimate / calculate the gain provided by RIS. The remainder of this process is similar to the remainder of message sequence 80 and will not be discussed further here.

[0178] In message sequence 160, TRP1 and TRP2 are controlled by different gNBs (gNB1 and gNB2, respectively).

[0179] Figure 17 This is the message flow sequence generally indicated by reference numeral 170 according to the example embodiment. Sequence 170 differs from sequence 160 in that both TRPs are controlled by the same gNB. Therefore, sequence 170 has some similarities to the message flow sequence 130 described above.

[0180] As in sequence 170, due to the report / information element sent by TRP2, the gNB will be aware of increased activity in TRP2's cell; therefore, the gNB can trigger a beam scan toward TRP2's own cell. In step 2, the UE's SRS configuration and the TRP instruction to send the aforementioned metric are sent to both TRPs. Subsequent steps are similar to those in sequence 130. At the end of the process, the RIS gain is sent from both TRPs to the gNB. TRP2 additionally sends the time slot where the RIS provides the maximum gain (corresponding to the RIS beam index) (step 13). This allows the gNB to configure the appropriate RIS beam toward TRP2's cell in step 15, if it decides to do so after comparing the RIS gains in cell 1 and cell 2 in step 14.

[0181] Example device Figure 18 An apparatus according to some example embodiments is shown. The apparatus can be configured to perform the operations described herein, such as those described with reference to any disclosed process. The apparatus includes at least one processor 312 and at least one memory 314 directly or closely connected to the processor. The memory 314 includes at least one random access memory (RAM) and at least one read-only memory (ROM). Computer program code (software) is stored in the memory 314 (typically in the ROM). The apparatus can be connected to a transmitter (TX) and a receiver (RX). The apparatus can optionally be connected to a user interface (UI) 318 for instructing the apparatus and / or for outputting data. At least one processor 312, together with at least one memory 314 and computer program code instructions 315, is arranged to cause the apparatus to perform at least one method according to any of the foregoing processes, for example, as per [the above description of the process]. Figures 7 to 17 The flowcharts and message sequences and their associated characteristics are disclosed.

[0182] Figure 19 A non-transitory medium 365 is illustrated according to some embodiments. The non-transitory medium 365 is a computer-readable storage medium. It may be, for example, a CD, DVD, USB stick, Blu-ray disc, etc. The non-transitory medium 365 stores computer program code that causes a device to perform methods, such as any of the aforementioned processes disclosed with respect to the flowchart and its related features.

[0183] The names of network elements, protocols, and methods are based on current standards. In other versions or other technologies, the names of these network elements and / or protocols and / or methods may differ, as long as they provide the corresponding functionality. For example, embodiments may be deployed in 2G / 3G / 4G / 5G networks and subsequent generations of 3GPP, but may also be deployed in non-3GPP radio networks such as WiFi.

[0184] The memory can be volatile or non-volatile. It can be, for example, RAM, SRAM, flash memory, FPGA block RAM, DCD, CD, USB stick, and Blu-ray disc.

[0185] Unless otherwise stated or clearly indicated from the context, different statements about two entities mean that they perform different functions. This does not necessarily mean that they are based on different hardware. That is, each entity described in this specification may be based on different hardware, or some or all of the entities may be based on the same hardware. This does not necessarily mean that they are based on different software. That is, each entity described in this specification may be based on different software, or some or all of the entities may be based on the same software. Each entity described in this specification may be embodied in the cloud.

[0186] By way of non-limiting example, implementations of any of the foregoing boxes, apparatuses, systems, techniques, or methods include implementations as hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof. Some embodiments may be implemented in the cloud.

[0187] It should be understood that the above description represents the preferred embodiments currently considered. However, it should be noted that the description of the preferred embodiments is given by way of example only, and various modifications can be made without departing from the scope defined by the appended claims.

[0188] Furthermore, the various implementations of this disclosure can be described with reference to the following terms, and their features can be combined in any reasonable manner.

[0189] Clause 1. A first device comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the first device to at least: receive configuration information from a network node of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells, wherein the first device is located in one of the first cell and the second cell; and provide a probe reference signal SRS according to the configuration information.

[0190] Clause 2. The apparatus according to Clause 1, wherein the SRS is transmitted during a time slot defined by the configuration information.

[0191] Clause 3. The apparatus according to Clause 1 or Clause 2, wherein the configuration information includes a time slot during which the RIS configuration changes from the first condition to the second condition.

[0192] Clause 4. The device according to any one of the preceding clauses, wherein the device is a user equipment or is included in a user equipment.

[0193] Clause 5. A second apparatus comprising: at least one processor; and at least one memory storing instructions, which, when executed by the at least one processor, cause the second apparatus to at least: provide configuration information to each of a plurality of devices of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between devices and network nodes in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells; receive a probe reference signal (SRS) from each of the plurality of devices, each SRS being transmitted according to the configuration information; and determine one or more cell metrics based on the SRS signals received from the plurality of devices.

[0194] Clause 6. The apparatus according to Clause 5, wherein the instructions, when executed by the at least one processor, further cause the apparatus to: provide at least some of the determined cell metrics of the one or more cell metrics to a base station or gNB of the mobile communication system.

[0195] Clause 7. The apparatus according to Clause 5 or Clause 6, wherein the one or more cell metrics include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain.

[0196] Clause 8. The apparatus according to any one of Clauses 5 to 7, wherein the SRS is received during a time slot defined by the configuration information.

[0197] Clause 9. The apparatus according to any one of Clauses 5 to 8, wherein the configuration information includes a time slot during which the RIS configuration changes from the first condition to the second condition.

[0198] Clause 10. The apparatus according to Clause 9, wherein the time slot is received from the network node of the first cell of the plurality of cells.

[0199] Clause 11. A third apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the third apparatus to at least: receive a request for sharing or switching of a reconfigurable smart surface (RIS) of a mobile communication system or determine a potential need for sharing or switching of the RIS, wherein the RIS is configured to selectively support communication between devices and network nodes in one or more of a plurality of cells of the mobile communication system; provide configuration information to one or more network nodes or devices of the mobile communication system; receive, based on the configuration information, cell metrics relating to one or more of the plurality of cells, wherein the cell metrics are determined based on SRS signals received from one or more devices in the respective cell, wherein the cell metrics relate to a performance change experienced at the respective device exceeding a threshold level in response to a change in RIS configuration from a first condition in which the RIS supports a first cell of the plurality of cells to a second condition in which the RIS supports a second cell of the plurality of cells, wherein the respective device is in one of the first cell and the second cell, and wherein the performance change is based on a difference between a performance metric determined before the RIS configuration change at the respective device and a corresponding performance metric obtained after the RIS configuration change; and determine whether to share or switch the RIS based at least in part on the received cell metrics.

[0200] Clause 12. A method comprising: receiving configuration information from a network node of a mobile communication system at a first device of the mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the network node of the mobile communication system and devices of one or more of a plurality of cells, wherein the RIS is configurable between the first condition that the RIS supports a first cell of the plurality of cells and the second condition that the RIS supports a second cell of the plurality of cells, wherein the first device is located in one of the first cell and the second cell; and providing a probe reference signal SRS according to the configuration information.

[0201] Clause 13. A method comprising: providing configuration information to one or more devices of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between the devices and a network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells; receiving a probe reference signal (SRS) from each of the plurality of devices, each SRS being transmitted according to the configuration information; and determining one or more cell metrics based on the SRS signals received from the plurality of devices.

[0202] Clause 14. The method according to Clause 13 further comprises: providing at least some of the determined cell metrics to a base station or gNB of the mobile communication system.

[0203] Clause 15. The method according to any one of Clauses 12 to 14, wherein the SRS is transmitted during a time slot defined by the configuration information.

[0204] Clause 16. The method according to any one of Clauses 12 to 15, wherein the configuration information includes a time slot during which the RIS configuration changes from the first condition to the second condition.

[0205] Clause 17. A computer program product comprising program instructions that, when executed by a device, cause the device to perform the method according to any one of Clauses 12 to 16.

Claims

1. A first device for a reconfigurable smart surface, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the first device to at least: Configuration information is received from a network node of a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between a device and a network node in one or more of a plurality of cells of the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells, wherein the first device is located in one of the first cell and the second cell; as well as A detection reference signal (SRS) is provided based on the configuration information.

2. The apparatus of claim 1, wherein the SRS is transmitted during a time slot defined by the configuration information.

3. The apparatus of claim 1 or claim 2, wherein the configuration information includes a time slot during which the RIS configuration changes from the first condition to the second condition.

4. The apparatus according to claim 1 or claim 2, wherein the apparatus is a user equipment or is included in a user equipment.

5. A second means for a reconfigurable smart surface, 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 second device to at least: Configuration information is provided to each of a plurality of devices in a mobile communication system, wherein the mobile communication system includes a reconfigurable smart surface RIS, the RIS being configurable to selectively support communication between a device and a network node in one or more of a plurality of cells in the mobile communication system, wherein the RIS is configurable between a first condition in which the RIS supports a first cell of the plurality of cells and a second condition in which the RIS supports a second cell of the plurality of cells; Receive a probe reference signal (SRS) from each of a plurality of devices, each SRS being transmitted according to the configuration information; as well as One or more cell metrics are determined based on SRS signals received from multiple devices.

6. The apparatus of claim 5, wherein the instructions, when executed by the at least one processor, further cause the apparatus to: At least some of the determined cell metrics are provided to the base station or gNB of the mobile communication system.

7. The apparatus of claim 5 or claim 6, wherein the one or more cell metrics include one or more of the following: spectral efficiency, energy efficiency, and resource efficiency gain.

8. The apparatus of claim 5 or claim 6, wherein the SRS is received during a time slot defined by the configuration information.

9. The apparatus of claim 5 or claim 6, wherein the configuration information includes a time slot during which the RIS configuration changes from the first condition to the second condition.

10. The apparatus of claim 9, wherein the time slot is received from the network node of the first cell of the plurality of cells.

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