Control of reconfigurable intelligent surfaces

Abstract

Examples of the disclosure relate to migration of control of reconfigurable intelligent surfaces (RIS) between respective network nodes. In examples of the disclosure a source network node establishes a connection with a reconfigurable intelligent surface – mobile terminal (RIS-MT) of a RIS panel and controls the RIS panel by sending a configuration to the RIS-MT. The configuration enables enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node. The source network node determines that control of the RIS-MT is passed to or is to be passed to a target network node and sends a request to the target network node for a permission for the source network node to provide a configuration to the RIS-MT via the target network node. The source network node receives a response to the request and determines whether to send the configuration to the RIS-MT via the target network node in accordance with the received response.

Description

[0001] TITLE

[0002] Control of Reconfigurable Intelligent Surfaces

[0003] TECHNOLOGICAL FIELD

[0004] Examples of the disclosure relate to control of reconfigurable intelligent surfaces (RIS). Some relate to migration of control of RIS between respective network nodes.

[0005] BACKGROUND

[0006] RISs can be used in networks such as 5G or 6G radio networks or other cellular networks. RISs comprise multiple antenna elements that can be configured to change the parameters of a radio frequency (RF) signal path. The configuration of the antenna elements in the RIS can be controlled by a RIS- mobile termination (RIS-MT). The RIS- MT can be controlled by other network nodes such as a gNB.

[0007] BRIEF SUMMARY

[0008] According to various, but not necessarily all, examples of the disclosure there is provided a source network node comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the source network node to perform at least: establishing a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel; controlling the RIS panel by sending a configuration to the RIS-MT wherein the configuration enables enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; determining that control of the RIS-MT is passed to or is to be passed to a target network node; sending a request to the target network node for a permission for the source network node to provide a configuration to the RIS-MT via the target network node; receiving a response to the request; and determining whether to send the configuration to the RIS-MT via the target network node in accordance with the received response.

[0009] The processor and memory may be further configured to cause the source network node to perform sending the configuration to the RIS-MT via the target network node if the response indicates acceptance of the request. The processor and memory may be further configured to cause the source network node to perform, if the response indicates that the request is not accepted, determining whether to send a further request to the target network node wherein the further request indicates one or more types of control indicated by the target network node.

[0010] The processor and memory may be further configured to cause the source network node to refrain from sending the configuration to the RIS-MT via the target network node if the response indicates that the request is not accepted.

[0011] The processor and memory may be further configured to cause the source network node to perform receiving an indication from the target network node indicating that the target network node has capability for sending a configuration from the source network node to the RIS-MT after control of the RIS-MT is passed to the target network node.

[0012] The indication that the target network node has capability for sending a configuration from the source network node to the RIS-MT may comprise an indication of one or more types of control that can be used.

[0013] The indication that the target network node has capability for sending a configuration from the source network node to the RIS-MT may be received during a network interface setup procedure between the source network node and the target network node.

[0014] The request to the target network node may be sent during a handover procedure related to the RIS-MT between the source network node and the target network node.

[0015] The request sent to the target network node may comprise an indication requesting the target network node to reject the handover procedure if the target network node is not capable of sending of the configuration from the source network node to the RIS-MT.

[0016] The request to the target network node may be sent when a UE context of the RIS-MT is transferred to the target network node.

[0017] The request sent to the target network node may comprise an indication of one or more types of control requested. The request sent to the target network node may comprise an indication of a time of activation of the configuration for the RIS-MT via the target network node.

[0018] The processor and memory may be further configured to cause the source network node to perform sending, to the target network node, an update to the configuration for the RIS-MT via the target network node wherein the update to the configuration for the RIS- MT via the target network node comprises at least one of: a new configuration to be used by the RIS-MT; an indication of a time of activation for the update to the configuration for the RIS-MT via the target network node.

[0019] According to various, but not necessarily all, examples of the disclosure there is provided a method comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the source network node to perform at least: establishing a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel; controlling the RIS panel by sending a configuration to the RIS-MT wherein the configuration enables enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; determining that control of the RIS-MT is passed to or is to be passed to a target network node; sending a request to the target network node for a permission for the source network node to provide a configuration to the RIS-MT via the target network node; receiving a response to the request; and determining whether to send the configuration to the RIS-MT via the target network node in accordance with the received response.

[0020] According to various, but not necessarily all, examples of the disclosure there is provided a computer program comprising instructions which, when executed by a source network node, cause the source network node to perform: establishing a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel; controlling the RIS panel by sending a configuration to the RIS-MT wherein the configuration enables enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; determining that control of the RIS-MT is passed to or is to be passed to a target network node; sending a request to the target network node for a permission for the source network node to provide a configuration to the RIS-MT via the target network node; receiving a response to the request; and determining whether to send the configuration to the RIS-MT via the target network node in accordance with the received response.

[0021] According to various, but not necessarily all, examples of the disclosure there is provided a target network node comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the target network node to perform at least: receiving a request from a source network node for a permission for the source network node to provide a configuration to a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel via the target network node; determining whether the request can be accepted sending a response to the request; and providing a configuration from the source network node to the RIS-MT in accordance with whether the request is accepted.

[0022] The processor and memory may be further configured to cause the target network node to perform providing the configuration from the source network node to the RIS-MT if the request is accepted.

[0023] The processor and memory may be further configured to cause the target network node to perform refraining from providing the configuration from the source network node to the RIS-MT if the request is not accepted.

[0024] The response to the request may indicate that the request is not accepted and indicates one or more types of control.

[0025] The processor and memory may be further configured to cause the target network node to perform sending an indication to the source network node indicating that the target network node has capability for sending a configuration from the source network node to the RIS-MT after control of the RIS-MT is passed to the target network node. The indication may be sent during a network interface setup procedure between the source network node and the target network node.

[0026] The request from the source network node may be received during a handover procedure related to the RIS-MT between the source network node and the target network node.

[0027] The request from the source network node may comprise an indication requesting the target network node to reject the handover procedure if the target network node is not capable of sending of the configuration from the source network node to the RIS-MT after the control of the RIS-MT is passed to the target network node and the processor and memory are further configured to cause the target network node to perform considering the indication before determining to accept the handover procedure.

[0028] The processor and memory may be further configured to cause the target network node to perform creating a handover command comprising information indicative of the configuration from the source network node and sending the handover command to the RIS-MT

[0029] The request from the source network node may be received when a UE context of the RIS-MT is transferred to the target network node.

[0030] The request from the source network node may comprise an indication of one or more types of control requested and the processor and memory are further configured to cause the target network node to perform considering the indication before determining to accept the handover procedure.

[0031] The request from the source network node may comprise an indication of a time of activation of the configuration for the RIS-MT.

[0032] The processor and memory may be further configured to cause the target network node to perform sending an activation signal to the RIS-MT to activate the enhancement of signals between the source network node and one or more UEs at the activation time.

[0033] The processor and memory may be further configured to cause the target network node to perform receiving, from the source network node, an update to the configuration for the RIS-MT wherein the update to the configuration for the RIS-MT comprises at least one of: a new configuration to be used by the RIS-MT; an indication of a time of activation for the update to the configuration.

[0034] According to various, but not necessarily all, examples of the disclosure there is provided a method comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the target network node to perform at least: receiving a request from a source network node for a permission for the source network node to provide a configuration to a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel via the target network node; determining whether the request can be accepted sending a response to the request; and providing a configuration from the source network node to the RIS-MT in accordance with whether the request is accepted.

[0035] According to various, but not necessarily all, examples of the disclosure there is provided computer program comprising instructions which, when executed by a target network node, cause the target network node to perform: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the target network node to perform at least: receiving a request from a source network node for a permission for the source network node to provide a configuration to a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel via the target network node; determining whether the request can be accepted sending a response to the request; and providing a configuration from the source network node to the RIS-MT in accordance with whether the request is accepted.

[0036] According to various, but not necessarily all, examples of the disclosure there is provided a reconfigurable intelligent surface- mobile terminal (RIS-MT) of a RIS panel comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the RIS-MT to perform at least: establishing a connection with a source network node; receiving a configuration from the source network node wherein the configuration enables control of the RIS panel to perform enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; establishing a connection with a target network node; controlling the RIS panel to perform enhancement of signals between the source network node and one or more UEs connected to a cell of the source network node in accordance with the configuration received from the source network node, wherein the controlling occurs after the connection is established with the target network node.

[0037] The processor and memory may be further configured to cause the RIS-MT to perform receiving an activation signal and, in response to the activation signal from the target network node after the connection with the target network node is established, activating the enhancement of signals between the source network node and one or more UEs at the activation time.

[0038] According to various, but not necessarily all, examples of the disclosure there is provided a method comprising: establishing a connection with a source network node; receiving a configuration from the source network node wherein the configuration enables control of the RIS panel to perform enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; establishing a connection with a target network node; controlling the RIS panel to perform enhancement of signals between the source network node and one or more UEs connected to a cell of the source network node in accordance with the configuration received from the source network node, wherein the controlling occurs after the connection is established with the target network node.

[0039] According to various, but not necessarily all, examples of the disclosure there is provided a computer program comprising instructions which, when executed by a RIS-MT, cause the RIS-MT to perform: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the RIS-MT to perform at least: establishing a connection with a source network node; receiving a configuration from the source network node wherein the configuration enables control of the RIS panel to perform enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; establishing a connection with a target network node; controlling the RIS panel to perform enhancement of signals between the source network node and one or more UEs connected to a cell of the source network node in accordance with the configuration received from the source network node, wherein the controlling occurs after the connection is established with the target network node.

[0040] According to various, but not necessarily all, embodiments there is provided an apparatus comprising: at least one processor; and at least one memory including computer program code; the at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least a part of one or more methods described herein.

[0041] According to various, but not necessarily all, embodiments there is provided an apparatus comprising means for performing at least part of one or more methods described herein. The description of a function and / or action should additionally be considered to also disclose any means suitable for performing that function and / or action. Functions and / or actions described herein can be performed in any suitable way using any suitable method.

[0042] According to various, but not necessarily all, embodiments there is provided examples as claimed in the appended claims.

[0043] While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations and permutations is contained within the disclosure. It is to be understood that various examples of the disclosure can comprise any or all the features described in respect of other examples of the disclosure, and vice versa. Also, it is to be appreciated that any one or more or all the features, in any combination, may be implemented by / comprised in / performable by an apparatus, a method, and / or computer program instructions as desired, and as appropriate. The description of a function should additionally be considered to also disclose any means suitable for performing that function BRIEF DESCRIPTION

[0044] Some examples will now be described with reference to the accompanying drawings in which:

[0045] FIG. 1 shows an example RIS;

[0046] FIG. 2 shows an example RIS;

[0047] FIG. 3 shows an example RIS;

[0048] FIG. 4 shows an example architectural model for RIS;

[0049] FIG. 5 shows an example use case scenario for RIS;

[0050] FIGS. 6A to 60 show example methods;

[0051] FIG. 7 shows an example signal flow;

[0052] FIG. 8 shows an example signal flow;

[0053] FIG. 9 shows an example signal flow; and

[0054] FIG. 10 shows an example controller.

[0055] The figures are not necessarily to scale. Certain features and views of the figures can be shown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggerated relative to other elements to aid explication. Corresponding reference numerals are used in the figures to designate corresponding features. For clarity, all reference numerals are not necessarily displayed in all figures.

[0056] DEFINITIONS

[0057] DCI Downlink Control Information

[0058] DL Downlink

[0059] HO Handover

[0060] MAC-CE Medium Access Control - Control Element

[0061] RF Radio Frequency

[0062] RIS Reconfigurable Intelligent Surface

[0063] RIS-MT RIS - Mobile Termination

[0064] RLF Radio Link Failure

[0065] RRC Radio Resource Control

[0066] UE User Equipment

[0067] UL Uplink DETAILED DESCRIPTION

[0068] RIS panels can be used in networks such as 6G radio networks or other cellular networks. RIS panels can be used to complement the radio infrastructure of such networks.

[0069] RIS panels comprise multiple antenna elements that can be configured to change the parameters of a radio frequency (RF) signal path. These changes can cause time and phase shifting and / or changes in angle or reflection. The multiple antenna elements can be configured according to the use case. The electrical and magnetic properties of the reflective surface of RIS can be adjusted depending on the use case. There are alternative RIS panel implementations where rather than antennas, other metamaterials can be used to perform similar operations.

[0070] RIS panels can provide a cost-effective alternative to deploying new gNBs and / or acquiring new spectrum.

[0071] Figs. 1 to 3 show different use cases for RIS. Fig. 1 shows an example RIS panel 108 used for coverage enhancement. Fig. 1 shows part of a network 100. The network 100 could be a cellular network such as 6G network or any other suitable type of network. The network 100 comprises network nodes 102 and terminal nodes 104. The network nodes 102 can be access nodes such as gNBs. The terminal nodes 104 can comprise user equipments (UE) or any other suitable type of entities.

[0072] In the example of Fig. 1 there is a blockage 110 between the gNB 102 and the UE 104. This is blocking the line-of-sight signals between the gNB 102 and the UE 104.

[0073] In this case the RIS panel 108 can be configured to direct signals from the gNB 102 to the UE 104. Similarly, the RIS panel 108 can direct signals from the UE 104 towards the gNB 102. This helps signals to avoid the blockage 110. In this example the RIS panel 108 can be used to create a virtual line-of-sight path.

[0074] Fig. 2 shows an example RIS panel 108 used for spatial multiplexing enhancement. This can boost capacity of the network 100. Fig. 2 shows part of a network 100 comprising network nodes 102 and terminal nodes 104 and a RIS panel 108. In this example the network node 102 and the UE 104 comprise multiple-input multiple-output (MIMO) antennas 204. A line-of-sight path 200 is provided between the gNB 102 and the UE 104. In the example of Fig. 2 the RIS panel 108 is used to provide an additional path 202 between the gNB 102 and the UE 104. The additional path 202 provides additional capacity to the line-of-sight path 200 between the network node 102 and the terminal node 104.

[0075] Fig. 3 shows an example RIS 108 used for positioning or sensing. Fig. 3 shows part of a network 100 comprising network nodes 102 and terminal nodes 104 and a RIS panel 108. In this example the RIS panel 108 is used as a positioning anchor. The RIS panel 108 can receive signals from the network node 102 and forward beamformed signals 306 towards a target area 308. The beamformed signals 306 can comprise time division multiplexed positioning reference signals or any other suitable type of signals. This beamformed signals 306 can be used for positioning the terminal node 104 or for any other suitable purpose. The RIS panel 108 can also be used for passive sensing.

[0076] The RIS panel 108 used in the above examples can comprise a control unit 300 and an array of reflectors 302. The control unit 300 can be configured to receive a control signal 304 from the network node 102 and configure the array of reflectors 302 in accordance with the received signal. The control unit 300 and array of reflectors 302 are shown in more detail in Fig. 4.

[0077] Fig. 4 shows an example architectural model for a RIS panel 108. The RIS panel 108 comprises a control unit 300 and an array of reflectors 302. The control unit 300 provides a RIS- mobile termination (RIS-MT) part and the array of reflectors 302 provides a forwarding (RIS-Fwd) part.

[0078] The RIS-MT 300 is configured to establish a control link 400 with a network node 102. The control link 400 can be used to provide information from the network node 102 to the RIS-MT 300.

[0079] The array of reflectors 302 is configured to enhance downlink (DL) signals 402 from the network node 102 to the UE 104. The array of reflectors 302 is configured to enhance uplink (UL) signals 404 from the UE 104 to the network node 102. Enhancing of the signals 402, 404 can comprise amplifying and / or forwarding and / or any other suitable procedure.

[0080] The RIS-MT 300 can be configured to control the array of reflectors 302. The control of the array of reflectors 302 determines how the signals 402, 404 are enhanced. Information received from the network node 102 via the control link 400 can be used by the RIS-MT 300 to control the array of reflectors 302. This provides a mechanism that enables the network node 102 to control the RIS panel 108.

[0081] In some examples the RIS-MT 300 can operate in the same frequency band as the array of reflectors 302. In some examples the RIS-MT 300 can operate in a different frequency band than the array of reflectors 302. For example, the control signal 400 can use a different frequency band than the DL and UL signals 402, 404.

[0082] Different types of control can be used by the network node 102 to control the RIS 108. The different types of control can comprise aperiodic activation, periodic activation or semi-static activation.

[0083] In aperiodic activation the RIS-MT 300 can be given a configuration via radio resource control (RRC) signaling. The activation of the configuration can be provided via a downlink control information (DCI) that can be dynamically sent by the network node gNB 102. The DCIs from the network node 102 enable the enhancement of signals by the RIS panel 108 in a given slot to be controlled dynamically.

[0084] In periodic activation the RIS-MT 300 can be given a configuration via RRC signaling and can apply the configuration immediately. The configuration can be applied based on a periodicity provided in the configuration. In these cases, when the RIS-MT 300 obtains the configuration the RIS-MT 300 can start to periodically enhance the signals based on the configuration.

[0085] In semi-static activation the RIS-MT 300 can be given a configuration via RRC signaling. The activation of the configuration can be provided via a medium access control - control element (MAC-CE). When the RIS-MT 300 receives the MAC-CE the RIS-MT 300 applies the configuration based on a periodicity provided in the configuration received via RRC.

[0086] Control of a RIS-MT 300 can be passed from a source network node to a target network node. Fig. 5 shows an example use case scenario for control of a RIS-MT 300 being passed from a source network node 102_1 to a target network node 102_2.

[0087] In this example the source network node 102_1 controls a first cell, cell 1 and the target network node 102_2 controls a second cell, cell 2. At block 500 a connection is established between the RIS-MT 300 and the source network node 102_1. At block 502 the source network node 102_1 controls the Ris-Fwd 302 of a RIS panel 108 to enhance signals of cell 1 and at block 504 data transmission between the source network node 102_1 and the UE 104 is enhanced by the RIS-Fwd 302.

[0088] At block 506 the RIS-MT 300 determines that radio link failure (RLF) has occurred in the control link between the source network node 102_1 and the RIS-MT 300 and at block 508 determines RIS MT 300 determines that the best cell to connect is cell 2 which is controlled by the target network node 102_2. At block 510 a connection is established between the RIS-MT 300 and the target network node 102_2. At block 512 the target network node 102_2 controls the RIS panel 108 to enhance signals of cell 2.

[0089] This change of control of the RIS panel 108 can be problematic for any signals between the source network node 102_1 and the UE 104. In some cases the control link between the RIS-MT 300 and the source network node 102_1 can fail due to blockages appearing suddenly but the beamforming gain of the RIS-Fwd 302 could compensate for the possible degradation of a link between the RIS-Fwd 302 and the source network node 102_1 . In some cases the RIS-MT 300 and the RIS Fwd 302 can be physically separated and so might experience different channel conditions. Also, if the link between the source network node 102_1 and the RIS-MT 300 is on a different band to the link between the source network node 102_1 and the RIS-Fwd 302 a direct relation between the degradation of the respective signals would not be expected.

[0090] Once the control of the RIS_MT has been passed to the target network node 102_2 this means that the source network node 102_1 is now experiencing worse channel conditions and this can lead to failed reception of signals from the source network node 102_1 to the UE 104 due to the lack of RIS as shown at block 514.

[0091] Therefore, it could be useful if the RIS-Fwd 302 could still be used to enhance the signals of the source network node 102_1 after control of the RIS-MT 300 has been passed to the target network node 102_2.

[0092] Figs. 6A to 6C show example methods that can be used in examples of the disclosure. These methods can be used to enable a RIS-Fwd 302 to still be used to enhance the signals of the source network node 102_1 after control of the RIS-MT 300 has been passed to a target network node 102_2. This can help to maintain good channel conditions for the source network node 102 1 and avoid issues such as the failed reception shown in Fig. 5. Examples of the disclosure are described in relation to RIS but could also apply to other network entities such as network controlled repeaters or other types of repeater.

[0093] The example method of Fig. 6A can be implemented by a source network node 102_1. The source network node can be a gNB 102 or any other suitable entity. The source network node 102_1 can be the node that initially controls the RIS-MT 300. In the example of Fig. 5 the source network node 102_1 would be gNB1 which controls cell 1.

[0094] At block 600 the method comprises establishing a connection with a RIS-MT 300 of a RIS panel 108. The RIS-MT 300 is configured to control the RIS-Fwd 302 part of the RIS panel 108. The RIS-Fwd 302 part comprises an array of reflectors.

[0095] At block 602 the method comprises controlling the RIS panel 108 by sending a configuration to the RIS-MT 300. The configuration enables enhancement of signals between the source network node 102_1 and one or more UEs 104 connected to a cell of the source network node 102_1 .

[0096] The method also comprises determining, at block 604, that control of the RIS-MT 300 is passed to or is to be passed to a target network node 102_2. The control of the RIS-MT 300 could be passed to a target network node 102_2 due to a handover procedure, RLF or cell reselection or any other suitable trigger event.

[0097] At block 606 the source network node 102_1 sends a request to the target network node 102_2 for a permission for the source network node 102_1 to provide a configuration to the RIS_MT 300 via the target network node 102_2. This would enable the configuration of source network node 102_1 to be used by the RIS_MT 300 after control of the RIS_MT 300 has been passed to the target network node 102_2.

[0098] In some examples the request sent to the target network node 102_2 can comprise additional information such as an indication of one or more types of control requested. The types of control could be periodic, aperiodic or semi-static. The target network node 102_2 can accept or reject the request based on whether it can provide the appropriate type of control. In some examples the request sent to the target network node 102_2 can comprise an indication of a time of activation of the configuration for the RIS-MT 300 via the target network node 102_2.

[0099] The request can be sent during any suitable procedure or following any suitable trigger event. In some examples, the request to the target network node 102_2 is sent during a handover procedure related to the RIS-MT 300 between the source network node 102_1 and the target network node 102_2. In such cases the request that is sent to the target network node 102_2 can comprise an indication requesting the target network node 102_2 to reject the handover procedure if the target network node 102_2 is not capable of sending of the configuration from the source network node 102_1 to the RIS-MT 300.

[0100] In some examples, the request to the target network node 102_2 is sent when a UE context of the RIS-MT 300 is transferred to the target network node 102_1. The UE context of the RIS-MT 300 can be transferred following RLF or cell reselection or any other suitable trigger event. For example, the target network node 102_2 can retrieve the UE context of the RIS-MT 300 from the source network node 102_1 when the RIS-MT in RRCJNACTIVE state sends a resume request or when the RIS-MT 300 to the target network node 102_2 after experiencing RLF in the source network node 102_1 .

[0101] At block 608 the source network node 102_1 receives a response to the request. The response can indicate whether the request has been accepted by the target network node 102_2.

[0102] At block 610 the source network node 102_1 determines whether to send the configuration to the RIS-MT 300 via the target network node 102_2 in accordance with the received response. If the response indicates acceptance of the request the source network node 102_1 will send the configuration to the RIS-MT 300 via the target network node 102_2. Conversely, if the response indicates that the request is not accepted then the source network node 102_1 will refrain from sending the configuration to the RIS-MT 300 via the target network node 102_2.

[0103] In some examples if the response indicates that the request is not accepted then the source network node 102_1 can determine whether to send a further request to the target network node 102_2. The further request can indicate one or more types of control that have been indicated by the target network node. The one or more types of control could be indicated in the response to the request, or in any other suitable signalling. The types of control could comprise periodic control, aperiodic control or semi-static control.

[0104] In some examples the method can comprise additional blocks that are not shown in Fig. 6A. For instance, in some examples the method could comprise receiving an indication from the target network node 102_2 indicating that the target network node 102_2 has capability for sending a configuration from the source network node 102_1 to the RIS- MT 300 after control of the RIS-MT 300 is passed to the target network node 102_2. The indication that the target network node 102_2 has such capability can also comprise an indication of one or more types of control that can be used. The types of control could comprise periodic control, aperiodic control or semi-static control. The indication of this capability could be received using any suitable signalling. The indication of this capability could be received during a network interface setup procedure between the source network node 102_1 and the target network node 102_2.

[0105] In some examples the method can comprise sending an update to the configuration for the RIS-MT 300 to the target network node 102_2. The update is for the configuration that is sent via the target network node 102_2. The update to the configuration for the RIS-MT 300 that has been sent via the target network node 102_1 can comprise a new configuration to be used by the RIS-MT 300, an indication of a time of activation for the update to the configuration for the RIS-MT 300 that has been sent via the target network node 102_2, or any other suitable information.

[0106] Fig. 6B shows a corresponding method. The example method of Fig. 6B can be implemented by a target network node 102_2. The target network node 102_2 can be a gNB 102 or any other suitable entity. The target network node 102_2 can be the node to which control of the RIS-MT 300 is passed to. In the example of Fig. 5 the target network node 102_2 would be gNB2 which controls cell 2.

[0107] The method comprises, at block 620, receiving a request from a source network node 102_1 for a permission for the source network node 102_1 to provide a configuration to a RIS-MT 300 of a RIS panel 108 via the target network node 102_2. This could be the request that is sent at block 606 by a source network node 102_1 performing the method of Fig. 6A.

[0108] In some examples the request from the source network node 102_1 can comprise additional information such as an indication of one or more types of control requested. The types of control could be periodic, aperiodic or semi-static. The target network node 102_2 can accept or reject the request based on whether it can provide the appropriate type of control. The type of control to be used can be indicated explicitly in a request. In other examples the type of control to be used might not be indicated explicitly. In such cases the target network node 102_2 can inspect an existing configuration from the source network node 102_1 to determine the type of control that should be used.

[0109] In some examples the request received from the source network node 102_2 can comprise an indication of a time of activation of the configuration for the RIS-MT 300 via the target network node 102_2. In such cases the target network node 102_2 could also send an activation signal to the RIS-MT 300 to activate the enhancement of signals between the source network node 102_1 and one or more UEs 104 at the activation time.

[0110] The request can be received during any suitable procedure or following any suitable trigger event. In some examples, the request from the source network node 102_1 is received during a handover procedure related to the RIS-MT 300 between the source network node 102_1 and the target network node 102_2. In such cases the request that is received by the target network node 102_2 can comprise an indication requesting the target network node 102_2 to reject the handover procedure if the target network node 102_2 is not capable of sending of the configuration from the source network node 102_1 to the RIS-MT 300. The target network node 102_1 can consider this indication before determining to accept the handover procedure.

[0111] If the handover is accepted the target network node 102_1 can also create a handover command. The handover command can comprise information indicative of the configuration from the source network node 102_1. The target network node 102_1 can send the handover command to the RIS-MT 300.

[0112] In some examples, the request from the source network node 102_1 is received when a UE context of the RIS-MT 300 is transferred to the target network node 102_1. The UE context of the RIS-MT 300 can be transferred following RLF or cell reselection or any other suitable trigger event.

[0113] At block 622 the target network node 102_2 determines whether the request can be accepted. This can take into account the capabilities of the target network node 102_2 or any other parameters such as the cell load or processing load. At block 624 the target network node 102_2 sends a response to the request. The response is sent to the source network node 102_1 . The response to the request can indicate whether or not the request has been accepted. In some examples, the response to the request can also comprise additional information. For example, if the request is not accepted the response can indicate one or more types of control. These could be types of control that could be used by the target network node 102_2,

[0114] At block 626 the target network node 102_2 provides a configuration from the source network node 102_1 to the RIS-MT 300 in accordance with whether the request is accepted. If the request is accepted the target network node 102_2 provides the configuration from the source network node 102_1 to the RIS-MT 300. If the request is not accepted the target network node 102-2 refrains from providing the configuration from the source network node 102_1 to the RIS-MT 300.

[0115] In some examples the method can comprise additional blocks that are not shown in Fig. 6B. For instance, in some examples the method could comprise sending an indication to the source network node 102_1 indicating that the target network node 102_2 has capability for sending a configuration from the source network node 102_1 to the RIS- MT 300 after control of the RIS-MT 300 is passed to the target network node 102_2. The indication that the target network node 102_2 has such capability can also comprise an indication of one or more types of control that can be used. The types of control could comprise periodic control, aperiodic control or semi-static control. The indication of this capability could be sent using any suitable signalling. The indication of this capability could be sent during a network interface setup procedure between the source network node 102_1 and the target network node 102_2.

[0116] In some examples the method can comprise receiving an update to the configuration for the RIS-MT 300 from the source network node 102_1. The update is for the configuration that is sent via the target network node 102_2. The update to the configuration for the RIS-MT 300 that has been sent via the target network node 102_1 can comprise a new configuration to be used by the RIS-MT 300, an indication of a time of activation for the update to the configuration for the RIS-MT 300 that has been sent via the target network node 102_2, or any other suitable information.

[0117] Fig. 6C shows another corresponding method. The example method of Fig. 6C can be implemented by a RIS-MT 300. The RIS-MT 300 can control a RIS panel 108. At block 630 the method comprises establishing a connection with a source network node 102_1 . This can be a network node that can implement the method of Fig. 6A.

[0118] At block 632 the method comprises receiving a configuration from the source network node 102_1. The configuration enables control of the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more UEs 104 connected to a cell of the source network node 102_1.

[0119] At block 634 the method comprises establishing a connection with a target network node 102_2. This can be a network node that can implement the method of Fig. 6B.

[0120] At block 636 the method comprises controlling the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more UEs 104 connected to a cell of the source network node 102_1. The enhancement is performed in accordance with the configuration received from the source network node 102_1 and occurs after the connection is established with the target network node 102_2. That is, the RIS-MT 300 uses a configuration from the source network node 102_1 even though it is controlled by the target network node 102_2. The RIS-MT 300 might not be aware that the configuration that is used is from the source network node 102_1 . In some embodiments, RIS-MT 300 still uses the configuration it previously received while it was connected to the source network node 102_1 , although the control of the RIS-MT 300 is passed to the target network node 102_2. RIS-MT 300 may or may not be provided an indication to reuse the configuration it previously received.

[0121] In some examples the method could comprise additional blocks such as receiving an activation signal. The activation signal can be received from the target network node 102_2 after the connection with the target network node 102_2 is established. In response to receiving the activation signal the RIS_MT 300 can activate the enhancement of signals between the source network node 102_1 and one or more UEs 104 at the activation time.

[0122] In examples of the disclosure different methods can be used depending of the circumstances for the control of the RIS-MT 300 being passed to the target network node 102_2. For example, different methods could be used based on whether a handover is performed or if cell reselection or RLF has occurred. In some examples of the disclosure the synchronization between the respective signals might need to be considered.

[0123] When the target network node 102_2 accepts the request to forward the configuration for the RIS-MT 300 from the source network node 102_1 the synchronization of the signals of the source and target network nodes needs to be considered. In this scenario the RIS-MT 300 is controlled by the target network node 102_2 but the signals that are enhanced by the RIS-Fwd 302 are for the source network node 102_1. If the source network node 102_1 wants enhancement to be performed over a time period h to t2 (using timing of the source network node 102_1) then the source network node 102_1 can reserve some guard time. The guard time can signal switching over period ti-Di-D2 to t2+Di-D2. The first offset Di is determined by network synchronization accuracy, i.e. , maximum synchronization error assumed to exist between different gNBs / cells in the system. For example, in 5G, the transmission timing differences between respective network nodes 102 operating in same frequency bands can be presumably within 3 microsec, but the sign is not known. The second offset D2 is determined by the propagation delay differences for the respective signal paths (that is the signal path between the source network node 102_1 and the RIS-Fwd 302 and the signal path between the target network node 102_2 and the RIS-MT 300).

[0124] Having such Di and D2 guard intervals, such synchronization issue can be resolved. The source network node 102_1 controlling the RIS-Fwd 302 signals should naturally take care of it, i.e., the source network node 102_1 can signal RIS to be active more than a slot or regard some symbols corrupted because they belong to the guard interval.

[0125] Fig. 7 shows an example signal flow that can be used to implement examples of the disclosure in a handover (HO) scenario.

[0126] At block 700 a network interface setup procedure is performed between the source network node 102_1 and the target network node 102_2. The network interface setup / update procedure can comprise an Xn set up procedure, or any other suitable type of procedure. Such procedure can be initiated by the source network node 102_1 or the target network node 102_2 when the node requests to establish an interface with the other node, or when the node informs the other node about the updates in its configuration During the network interface setup procedure the network nodes 102_1 , 102_2 exchange information that can be used for controlling RIS. For example, the target network node 102_1 can provide an indication that the target network node 102_2 has capability for sending a configuration from the source network node 102_1 to the RIS- MT 300 after control of the RIS-MT 300 is passed to the target network node 102_2. In such cases the source network node 102_1 can use this indication to determine whether to send a request for HO. For example, the source network node 102_1 might only send HO requests to target network nodes 102_2 that have the forwarding capability.

[0127] At block 702 a connection is established between the RIS-MT 300 and the source network node 102_1. The source network node 102_1 controls the RIS panel 108 to enhance signals of cell 1 so that data transmission between the source network node 102_1 and a UE 104 is enhanced by the RIS panel 108.

[0128] At block 704 the source network node 102_1 makes a HO decision. The HO decision can be based on measurements reported from the RIS-MT 300 and / or any other suitable information such as congestion of Cell 1. In the example, of Fig. 7 the source network node 102_1 decides to handover the RIS-MT 300 to the target network node 102_2.

[0129] At block 706 a HO request is sent from the source network node 102_1 to the target network node 102_2. The HO request can be enhanced with one or more flags or information elements relating to the control of the RIS-MT 300. For instance, the HO request can comprise a request that the RIS-MT 300 keeps enhancement (for example, forwarding) for the source network node 102_1. That is, the RIS-MT 300 would remain with the configuration of the source network node 102_1 and not switch to the configuration of the target network node 102_2. The request can be a request for permission for the source network node 102_1 to provide a configuration for the RIS-MT 300 via the target network node 102_2.

[0130] In some examples the HO request could comprise an indication that the target network node 102_2 should only accept the HO request if the request that the RIS-MT 300 keeps forwarding for cell 1 can be met. Otherwise the target network node 102_2 should reject the HO request.

[0131] In some examples the HO request could comprise an indication of the type of control requested by the source network node 102_1. This can indicate if the type of control should be periodic, aperiodic or semi-static or any other suitable type of control. In some examples the HO request could comprise a forwarding configuration to be provided to the RIS-MT 300. For example the configuration that is to be sent to the RIS- MT 300 via the target network node 102_1 can be provided in the HO request.

[0132] In some examples the HO request could comprise a time of activation for the RIS-MT 300 configuration.

[0133] At block 708 the target network node 102_2 determines the control type that has been requested. Block 708 might only be performed if the control type has not been explicitly indicated by the source network node 102_1 , for example, if the source network node 102_1 has not indicated the control type in the HO request. To determine the control type the target network node 102_1 can inspect an existing RRC configuration of the source network node 102_1 to understand the type of control requested by the source network node 102_1.

[0134] Block 710 shows the method that can be performed if the HO is rejected. At block 712 a HO reject message is sent from the target network node 102_2 to the source network node 102_1. The HO reject message can provide an indication that the enhancement of signals for the source target node 102_1 by the RIS panel 108 is not possible.

[0135] In some examples the target network node 102_2 might reject the HO request because the type of control that has been requested by the source network node 102_1 is not possible. In such examples, the HO reject message could comprise an indication of one or more alternative types of control that could be accepted by the target network node 102_2.

[0136] At block 714 the source network node 102_1 can determine whether to try again and make another HO request. The decision as to whether to try again can be made, based at least in part, on an indication of one or more alternative types of control that could be accepted by the target network node 102_2, and or any other relevant information that is provided in the HO reject message.

[0137] If the source network node 102_1 does determine to try again then the new HO request could request a different type of control to that used in the original HO request.

[0138] Block 716 shows the method that can be performed if the HO is accepted. At block 718 the target network node 102_2 creates a HO command. In some examples the HO command can comprise the configuration for the RIS-MT 300 that has been received from the source network node 102_1 . In some examples the HO command can comprise an extension of the configuration for the RIS-MT 300 that has been received from the source network node 102_1 . In some examples the HO command can comprise a delta configuration for the configuration for the RIS-MT 300 that has been received from the source network node 102_1. The delta configuration can comprise changes to the configuration that the RIS-MT has been using to enhance signals for the source network node 102_1.

[0139] In examples of the disclosure the configuration that is to be used by the RIS-MT 300 originates from the source network node 102_1 but is provided to the RIS-MT 300 via the target network node 102_2. The RIS-MT 300 does not need to know that the configuration originates from the source network node 102_1. The configuration can be received by the RIS-MT 300 as though it is performing enhancement for the target network node 102_2. In some examples the target network node 102_2 can make additions to the configuration for the RIS-MT 300 that relate to its own use of the RIS- MT 300.

[0140] At block 720 the target network node 102_2 sends a HO command to the source network node 102_1 and at block 722 the source network node 102_1 forwards the HO command to the RIS-MT 300.

[0141] At block 724 a connection is established between the RIS-MT 300 and the target network node 102_2.

[0142] In some cases, before the configuration can be activated, an activation signal is sent from the target network node 102_2 to the RIS-MT 300 as shown at block 726. The activation signal can be used if an activation time has been indicated for the configuration. The activation time could be indicated in the HO request or in any other suitable signaling. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal.

[0143] At block 728 the RIS-MT 300 controls the RIS panel 108 to enhance signals for the source network node 102_1 based on the configuration that is received from the target network node 102_2. Although the configuration can originate from the source network node 102_1 the RIS-MT 300 does not need to be aware of that. Block 730 shows the method that can be performed if updates to the configuration are received from the source network node 102_1 .

[0144] At block 732 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling.

[0145] The modification request can comprise any suitable information. In some examples the modification request can comprise the modified configuration that is to be provided to the RIS-MT 300.

[0146] In some examples the modification request can comprise an identification of the RIS-MT 300 to which the modification request applies. The identification can comprise a UE ID which has been used in previous signaling or a new UE ID can be created for the purpose of HO of the RIS-MT 300. If a new UE ID is created this could be created by the target network node 102_2 and communicated to the source network node 102_1 for use in further communications.

[0147] At block 734 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected. In some examples an explicit information element can be sent in the response to indicate acceptance or rejection of the modification request.

[0148] At block 736 the target network node 102_2 extends the configuration for the RIS-MT 300 and at block 738 the new configuration is sent from the target network node 102_2 to the RIS-MT 300. The extended configuration can be generated by modifying the existing configuration or by generating a delta configuration.

[0149] Block 740 shows the method that can be performed for activation or deactivation of enhancement of signals for the source network node 102_1.

[0150] At block 742 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling. The modification request can comprise an indication of the time of activation or deactivation for the configuration. At block 744 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected.

[0151] At block 746 an activation signal is sent from the target network node 102_2 to the RIS- MT 300. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal and can be sent based on the indicated activation time or deactivation time.

[0152] Fig. 8 shows an example signal flow that can be used to implement examples of the disclosure in a RLF scenario.

[0153] A network interface setup procedure can be performed between the source network node 102_1 and the target network node 102_2. The network interface setup procedure can comprise an Xn set up procedure, or any other suitable type of procedure. Such procedure can be initiated by the source network node 102_1 or the target network node 102_2 when the node requests to establish an interface with the other node, or when the node informs the other node about the updates in its configuration

[0154] During the network interface setup procedure the network nodes 102_1 , 102_2 exchange information that can be used for controlling RIS. For example, the target network node 102_1 can provide an indication that the target network node 102_2 has capability for sending a configuration from the source network node 102_1 to the RIS- MT 300 after control of the RIS-MT 300 is passed to the target network node 102_2.

[0155] At block 800 a connection is established between the RIS-MT 300 and the source network node 102_1. The source network node 102_1 controls the RIS panel 108 to enhance signals of cell 1 so that data transmission between the source network node 102_1 and a UE 104 is enhanced by the RIS panel 108.

[0156] At block 802 the RIS-MT 300 determines that RLF has occurred in the control link between the source network node 102_1 and the RIS-MT 300 The RIS-MT 300 can determine that the best cell to connect to is cell 2 which is controlled by the target network node 102_2. At block 804 a connection is established between the RIS-MT 300 and the target network node 102_2. Block 806 shows the method that can be performed for a handshake procedure. At block 808 the target network node 102_2 retrieves a UE context of the RIS-MT 300 from the source network node 102_1 . In some examples the target network node 102_2 can be aware that the UE is a RIS-MT 300. In such cases the target network node 102_2 can make an offer to the source network node 102_1 to keep the configuration of the source network node 102_1 for the RIS-MT 300 so that the RIS panel 108 can continue to enhance signals for the source network node 102_1 after the RLF. In some examples the target network node 102_2 can indicate a type of control that the source network node 102_1 can use.

[0157] At block 810 the UE context of the RIS-MT 300 is sent from the source network node 102_1 to the target network node 102_2. In some examples other information can be provided in addition to the UE context of the RIS-MT 300. The other information can comprise information relating to the control of the RIS-MT 300. For instance, the other information can comprise a request that the RIS-MT 300 keeps enhancement (for example, forwarding) for the source network node 102_1 . That is, the RIS-MT 300 would remain with the configuration of the source network node 102_1 and not switch to the configuration of the target network node 102_2. The request can be a request for permission for the source network node 102_1 to provide a configuration for the RIS-MT 300 via the target network node 102_2.

[0158] In some examples the other information could comprise an indication of the type of control requested by the source network node 102_1. This can indicate if the type of control should be periodic, aperiodic or semi-static or any other suitable type of control.

[0159] In some examples the other information could comprise a forwarding configuration to be provided to the RIS-MT 300. For example the configuration that is to be sent to the RIS- MT 300 via the target network node 102_1 can be provided with the UE context of the RIS-MT 300.

[0160] In some examples the other information could comprise a time of activation for the RIS- MT 300 configuration.

[0161] At block 812 the target network node 102_2 determines the control type that has been requested. Block 812 might only be performed if the control type has not been explicitly indicated by the source network node 102_1 , for example, if the source network node 102_1 has not indicated the control type with the UE context information. To determine the control type the target network node 102_1 can inspect an existing RRC configuration of the source network node 102_1 to understand the type of control requested by the source network node 102_1 .

[0162] At block 814 the target network node 102_2 sends a response to the request to maintain enhancement of signals by the RIS panel to the source network node 102_1. The response can indicate whether or not the request has been accepted.

[0163] If the request is not accepted the response can provide an indication that the enhancement of signals for the source target node 102_1 by the RIS panel 108 is not possible. In some examples the target network node 102_2 might reject the request because the type of control that has been requested by the source network node 102_1 is not possible. In such examples, the response to the request could comprise an indication of one or more alternative types of control that could be accepted by the target network node 102_2.

[0164] At block 816 the source network node 102_1 can determine whether to try again and make another request to the target network node 102_2. The decision as to whether to try again can be made, based at least in part, on an indication of one or more alternative types of control that could be accepted by the target network node 102_2, and or any other relevant information that is provided in the response to the request.

[0165] If the source network node 102_1 does determine to try again then the new request for controlling of the RIS panel 108 could request a different type of control to that used in the original request.

[0166] Block 818 shows the method that can be performed if the request for providing the configuration to the RIS-MT 300 via the target network node 102_2 is accepted. At block 820 the target network node 102_2 extends the configuration for the RIS-MT 300. The extended configuration can be generated by modifying the existing configuration or by generating a delta configuration.

[0167] At block 822 an RRC reconfiguration is sent from the target network node 102_2 to the RIS-MT 300. The RRC reconfiguration can comprise the configuration for the RIS-MT 300. This can be the configuration that originates from the source network node 102_1. The configuration can be a forwarding configuration or can be for any other suitable enhancements of the signals between the RIS panel 108 and the source network node 102_1 .

[0168] In some cases, before the configuration can be activated, an activation signal is sent from the target network node 102_2 to the RIS-MT 300 as shown at block 824. The activation signal can be used if an activation time has been indicated for the configuration. The activation time could be indicated in the request or in any other suitable signaling. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal.

[0169] At block 826 the RIS-MT 300 controls the RIS panel 108 to enhance signals for the source network node 102_1 based on the configuration that is received from the target network node 102_2. Although the configuration can originate from the source network node 102_1 the RIS-MT 300 does not need to be aware of that.

[0170] Block 828 shows the method that can be performed if updates to the configuration are received from the source network node 102_1 .

[0171] At block 830 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling.

[0172] The modification request can comprise any suitable information. In some examples the modification request can comprise the modified configuration that is to be provided to the RIS-MT 300.

[0173] In some examples the modification request can comprise an identification of the RIS-MT 300 to which the modification request applies. The identification can comprise a UE ID which has been used in previous signaling or a new UE ID. If a new UE ID is created this could be created by the target network node 102_2 and communicated to the source network node 102_1 for use in further communications.

[0174] At block 832 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected. In some examples an explicit information element can be sent in the response to indicate acceptance or rejection of the modification request. At block 834 the target network node 102_2 extends the configuration for the RIS-MT 300 and at block 836 the new configuration is sent from the target network node 102_2 to the RIS-MT 300. The extended configuration can be generated by modifying the existing configuration or by generating a delta configuration.

[0175] Block 838 shows the method that can be performed for activation or deactivation of enhancement of signals for the source network node 102_1.

[0176] At block 840 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling. The modification request can comprise an indication of the time of activation or deactivation for the configuration.

[0177] At block 842 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected.

[0178] At block 844 an activation signal is sent from the target network node 102_2 to the RIS- MT 300. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal and can be sent based on the indicated activation time or deactivation time.

[0179] Fig. 9 shows an example signal flow that can be used to implement examples of the disclosure in a cell reselection scenario.

[0180] At block 900 a network interface setup procedure is performed between the source network node 102_1 and the target network node 102_2. The network interface setup procedure can comprise an Xn set up procedure, or any other suitable type of procedure. Such procedure can be initiated by the source network node 102_1 or the target network node 102_2 when the node requests to establish an interface with the other node, or when the node informs the other node about the updates in its configuration

[0181] During the network interface setup procedure the network nodes 102_1 , 102_2 exchange information that can be used for controlling RIS. For example, the target network node 102_1 can provide an indication that the target network node 102_2 has capability for sending a configuration from the source network node 102_1 to the RIS- MT 300 after control of the RIS-MT 300 is passed to the target network node 102_2. In such cases the source network node 102_1 can use this indication to determine whether to send a request for HO. For example, the source network node 102_1 might only send HO requests to target network nodes 102_2 that have the forwarding capability.

[0182] At block 902 a connection is established between the RIS-MT 300 and the source network node 102_1. The source network node 102_1 controls the RIS panel 108 to enhance signals of cell 1 so that data transmission between the source network node 102_1 and a UE 104 is enhanced by the RIS panel 108.

[0183] At block 904 an RRC release signal is sent from the source network node 102_1 to the RIS-MT 300. This sends the RIS-MT 300 to RRCJNACTIVE state. When the RIS-MT is in RRCJNACTIVE state, at block 906, the RIS-MT 300 controls the RIS panel 108 using the configuration that has been received in RRC_CONNECTED.

[0184] Block 908 shows the method that can be performed for a handshake procedure. At block 910 the RIS-MT 300 performs cell reselection. Cell reselection can be performed using measurements from the RIS-MT 300 and / or any other suitable information. In this example, the RIS-MT selects cell 2 from the target network node 102_2 for cell reselection. At block 912 an RRC resume request is sent from the RIS-MT 300 to the target network node 102_2.

[0185] At block 914 the target network node 102_2 retrieves a UE context of the RIS-MT 300 from the source network node 102_1. In some examples the target network node 102_2 can be aware that the UE is a RIS-MT 300. In such cases the target network node 102_2 can make an offer to the source network node 102_1 to keep the configuration of the source network node 102_1 for the RIS-MT 300 so that the RIS panel 108 can continue to enhance signals for the source network node 102_1 after the RLF. In some examples the target network node 102_2 can indicate a type of control that the source network node 102_1 can use.

[0186] At block 916 the UE context of the RIS-MT 300 is sent from the source network node 102_1 to the target network node 102_2. In some examples other information can be provided in addition to the UE context of the RIS-MT 300. The other information can comprise information relating to the control of the RIS-MT 300. For instance, the other information can comprise a request that the RIS-MT 300 keeps enhancement (for example, forwarding) for the source network node 102_1 . That is, the RIS-MT 300 would remain with the configuration of the source network node 102_1 and not switch to the configuration of the target network node 102_2. The request can be a request for permission for the source network node 102_1 to provide a configuration for the RIS-MT 300 via the target network node 102_2.

[0187] In some examples the other information could comprise an indication of the type of control requested by the source network node 102_1. This can indicate if the type of control should be periodic, aperiodic or semi-static or any other suitable type of control.

[0188] In some examples the other information could comprise a forwarding configuration to be provided to the RIS-MT 300. For example the configuration that is to be sent to the RIS- MT 300 via the target network node 102_1 can be provided with the UE context of the RIS-MT 300.

[0189] In some examples the other information could comprise a time of activation for the RIS- MT 300 configuration.

[0190] At block 918 the target network node 102_2 determines the control type that has been requested. Block 918 might only be performed if the control type has not been explicitly indicated by the source network node 102_1 , for example, if the source network node 102_1 has not indicated the control type with the UE context information. To determine the control type the target network node 102_1 can inspect an existing RRC configuration of the source network node 102_1 to understand the type of control requested by the source network node 102_1 .

[0191] At block 920 the target network node 102_2 sends a response to the request to maintain enhancement of signals by the RIS panel to the source network node 102_1. The response can indicate whether or not the request has been accepted.

[0192] If the request is not accepted the response can provide an indication that the enhancement of signals for the source target node 102_1 by the RIS panel 108 is not possible. In some examples the target network node 102_2 might reject the request because the type of control that has been requested by the source network node 102_1 is not possible. In such examples, the response to the request could comprise an indication of one or more alternative types of control that could be accepted by the target network node 102_2.

[0193] Block 922 shows an example method that can be performed if the request for forwarding of the configuration by the target network node 102_2 is accepted. At block 924 the target network node 102_2 extends the configuration for the RIS-MT 300. The extended configuration can be generated by modifying the existing configuration or by generating a delta configuration.

[0194] At block 926 an RRC reconfiguration is sent from the target network node 102_2 to the RIS-MT 300. The RRC reconfiguration can comprise the configuration for the RIS-MT 300. This can be the configuration that originates from the source network node 102_1. The configuration can be a forwarding configuration or can be for any other suitable enhancements of the signals between the RIS panel 108 and the source network node 102_1 .

[0195] In some cases, before the configuration can be activated, an activation signal is sent from the target network node 102_2 to the RIS-MT 300 as shown at block 928. The activation signal can be used if an activation time has been indicated for the configuration. The activation time could be indicated in the request or in any other suitable signaling. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal.

[0196] At block 930 the RIS-MT 300 controls the RIS panel 108 to enhance signals for the source network node 102_1 based on the configuration that is received from the target network node 102_2. Although the configuration can originate from the source network node 102_1 the RIS-MT 300 does not need to be aware of that.

[0197] Block 932 shows the method that can be performed if updates to the configuration are received from the source network node 102_1 .

[0198] At block 934 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling.

[0199] The modification request can comprise any suitable information. In some examples the modification request can comprise the modified configuration that is to be provided to the RIS-MT 300.

[0200] In some examples the modification request can comprise an identification of the RIS-MT 300 to which the modification request applies. The identification can comprise a UE ID which has been used in previous signaling or a new UE ID. If a new UE ID is created this could be created by the target network node 102_2 and communicated to the source network node 102_1 for use in further communications.

[0201] At block 936 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected. In some examples an explicit information element can be sent in the response to indicate acceptance or rejection of the modification request.

[0202] At block 938 the target network node 102_2 extends the configuration for the RIS-MT 300 and at block 940 the new configuration is sent from the target network node 102_2 to the RIS-MT 300. The extended configuration can be generated by modifying the existing configuration or by generating a delta configuration.

[0203] Block 942 shows the method that can be performed for activation or deactivation of enhancement of signals for the source network node 102_1.

[0204] At block 944 the source network node 102_1 sends a modification request to the target network node 102_2. The modification request can be a network interface request or can use any other suitable type of signaling. The modification request can comprise an indication of the time of activation or deactivation for the configuration.

[0205] At block 946 a response to the modification request is sent from the target network node 102_2 to the source network node 102_1. The response to the modification request can indicate whether the modification request has been accepted or rejected.

[0206] At block 948 an activation signal is sent from the target network node 102_2 to the RIS- MT 300. MAC-CE or DCI or any other suitable type of signal can be used for the activation signal and can be sent based on the indicated activation time or deactivation time.

[0207] In some examples the RIS-MT 300 can be configured prior RLF or switching to RRCJNACTIVE to only re-establish or re-select if connectivity for UEs to the source network node 102_1 can be maintained. In this case a RIS-MT may re-establish / re-select with explicit indication to the target network node 102_2 that it needs to maintain connectivity to the source network node 102_1 . Fig. 10 shows an example controller 1000. The controller 1000 could be provided within an entity such as a source network node 102_1 , a target network node 102_2, a RIS-MT 300 or any other suitable entity. Implementation of the controller 1000 may be as controller circuitry. The controller 1000 may be implemented in hardware alone, have certain aspects in software including firmware alone or can be a combination of hardware and software (including firmware).

[0208] As illustrated in Fig. 10 the controller 1000 can be implemented using instructions that enable hardware functionality, for example, by using executable instructions of a computer program 1006 in a general-purpose or special-purpose processor 1002 that may be stored on a computer readable storage medium (disk, memory etc.) to be executed by such a processor 1002.

[0209] The processor 1002 is configured to read from and write to the memory 1004. The processor 1002 may also comprise an output interface via which data and / or commands are output by the processor 1002 and an input interface via which data and / or commands are input to the processor 1002.

[0210] The memory 1004 stores a computer program 1006 comprising computer program instructions (computer program code) that controls the operation of the apparatus when loaded into the processor 1002. The computer program instructions, of the computer program 1006, provide the logic and routines that enables the apparatus to perform the methods illustrated in the Figs. The processor 1002 by reading the memory 1004 is able to load and execute the computer program 1006.

[0211] In some examples where the controller 1000 is provided within a device such as a source network node 102_1 the controller 1000 therefore comprises means for: establishing 600 a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) 300 of a RIS panel 108; controlling 602 the RIS panel 108 by sending a configuration to the RIS-MT 300 wherein the configuration enables enhancement of signals between the source network node 102_1 and one or more user equipments (UEs) connected to a cell of the source network node 102_1 ; determining 604 that control of the RIS-MT 300 is passed to or is to be passed to a target network node 102_2; sending 606 a request to the target network node 102_2 for a permission for the source network node 102_1 to provide a configuration to the RIS-MT 300 via the target network node 102_1 ; receiving 608 a response to the request; and determining 610 whether to send the configuration to the RIS-MT 300 via the target network node 102_1 in accordance with the received response.

[0212] In some examples where the controller 1000 is provided within a device such as a target network node 102_2 the controller 1000 therefore comprises means for: receiving 620 a request from a source network node 102_1 for a permission for the source network node 102_1 to provide a configuration to a reconfigurable intelligent surface - mobile terminal RIS-MT 300 of a RIS panel 108 via the target network node 102_2; determining 622 whether the request can be accepted sending 624 a response to the request; and providing 626 a configuration from the source network node 102_1 to the RIS- MT 300 in accordance with whether the request is accepted.

[0213] In some examples where the controller 1000 is provided within a device such as a RIS- MT 300 the controller 1000 therefore comprises means for: establishing 630 a connection with a source network node 102_1 ; receiving 632 a configuration from the source network node 102_1 wherein the configuration enables control of the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more user equipments (UEs) connected to a cell of the source network node 102_1 ; establishing 634 a connection with a target network node 102_1 ; controlling 636 the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more UEs connected to a cell of the source network node 102_1 in accordance with the configuration received from the source network node 102_1 , wherein the controlling occurs after the connection is established with the target network node 102_2.

[0214] The computer program 1006 may arrive at the apparatus via any suitable delivery mechanism 1008. The delivery mechanism 1008 may be, for example, a machine- readable medium, a computer-readable medium, a non-transitory computer-readable storage medium, a computer program product, a memory device, a record medium such as a Compact Disc Read-Only Memory (CD-ROM) or a Digital Versatile Disc (DVD) or a solid-state memory, an article of manufacture that comprises or tangibly embodies the computer program 1006. The delivery mechanism may be a signal configured to reliably transfer the computer program 1006. The apparatus may propagate or transmit the computer program 1006 as a computer data signal.

[0215] The computer program 1006 can comprise computer program instructions for causing a source network node 102_1 to perform at least the following or for performing at least the following: establishing 600 a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) 300 of a RIS panel 108; controlling 602 the RIS panel 108 by sending a configuration to the RIS-MT 300 wherein the configuration enables enhancement of signals between the source network node 102_1 and one or more user equipments (UEs) connected to a cell of the source network node 102_1 ; determining 604 that control of the RIS-MT 300 is passed to or is to be passed to a target network node 102_2; sending 606 a request to the target network node 102_2 for a permission for the source network node 102_1 to provide a configuration to the RIS-MT 300 via the target network node 102_1 ; receiving 608 a response to the request; and determining 610 whether to send the configuration to the RIS-MT 300 via the target network node 102_1 in accordance with the received response.

[0216] The computer program 1006 can comprise computer program instructions for causing a target network node 102_2 to perform at least the following or for performing at least the following: receiving 620 a request from a source network node 102_1 for a permission for the source network node 102_1 to provide a configuration to a reconfigurable intelligent surface - mobile terminal RIS-MT 300 of a RIS panel 108 via the target network node 102_2; determining 622 whether the request can be accepted sending 624 a response to the request; and providing 626 a configuration from the source network node 102_1 to the RIS- MT 300 in accordance with whether the request is accepted.

[0217] The computer program 1006 can comprise computer program instructions for causing a RIS-MT 300 to perform at least the following or for performing at least the following: establishing 630 a connection with a source network node 102_1 ; receiving 632 a configuration from the source network node 102_1 wherein the configuration enables control of the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more user equipments (UEs) connected to a cell of the source network node 102_1 ; establishing 634 a connection with a target network node 102_1 ; controlling 636 the RIS panel 108 to perform enhancement of signals between the source network node 102_1 and one or more UEs connected to a cell of the source network node 102_1 in accordance with the configuration received from the source network node 102_1 , wherein the controlling occurs after the connection is established with the target network node 102_2.

[0218] The computer program instructions may be comprised in a computer program, a non- transitory computer readable medium, a computer program product, a machine-readable medium. In some but not necessarily all examples, the computer program instructions may be distributed over more than one computer program.

[0219] Although the memory 1004 is illustrated as a single component / circuitry it may be implemented as one or more separate components / circuitry some or all of which may be integrated / removable and / or may provide permanent / semi-permanent / dynamic / cached storage.

[0220] Although the processor 1002 is illustrated as a single component / circuitry it may be implemented as one or more separate components / circuitry some or all of which may be integrated / removable. The processor 1002 may be a single core or multi-core processor.

[0221] References to “computer-readable storage medium”, “computer program product”, “tangibly embodied computer program” etc. or a “controller”, “computer”, “processor” etc. should be understood to encompass not only computers having different architectures such as single / multi- processor architectures and sequential (Von Neumann) / parallel architectures but also specialized circuits such as field-programmable gate arrays (FPGA), application specific circuits (ASIC), signal processing devices and other processing circuitry. References to computer program, instructions, code etc. should be understood to encompass software for a programmable processor or firmware such as, for example, the programmable content of a hardware device whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device etc. As used in this application, the term “circuitry” can refer to one or more or all of the following:

[0222] (a) hardware-only circuitry implementations (such as implementations in only analog and / or digital circuitry) and

[0223] (b) combinations of hardware circuits and software, such as (as applicable):

[0224] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0225] (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions and

[0226] (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g. firmware) for operation, but the software might not be present when it is not needed for operation.

[0227] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit for a mobile device or a similar integrated circuit in a server, a cellular network device, or other computing or network device.

[0228] The blocks illustrated in the Figs, can represent steps in a method and / or sections of code in the computer program 1006. The illustration of a particular order to the blocks does not necessarily imply that there is a required or preferred order for the blocks and the order and arrangement of the block can be varied. Furthermore, it can be possible for some blocks to be omitted.

[0229] The apparatus can be provided in an electronic device, for example, a mobile terminal, according to an example of the present disclosure. It should be understood, however, that a mobile terminal is merely illustrative of an electronic device that would benefit from examples of implementations of the present disclosure and, therefore, should not be taken to limit the scope of the present disclosure to the same. While in certain implementation examples, the apparatus can be provided in a mobile terminal, other types of electronic devices, such as, but not limited to: mobile communication devices, hand portable electronic devices, wearable computing devices, portable digital assistants (PDAs), pagers, mobile computers, desktop computers, televisions, gaming devices, laptop computers, cameras, video recorders, GPS devices and other types of electronic systems, can readily employ examples of the present disclosure. Furthermore, devices can readily employ examples of the present disclosure regardless of their intent to provide mobility.

[0230] The term ‘comprise’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to ‘comprising only one...’ or by using ‘consisting.’

[0231] In this description, the wording ‘connect’, ‘couple’ and ‘communication’ and their derivatives mean operationally connected / coupled / in communication. It should be appreciated that any number or combination of intervening components can exist (including no intervening components), i.e., to provide direct or indirect connection / coupling / communication. Any such intervening components can include hardware and / or software components.

[0232] As used herein, the term "determine / determining" (and grammatical variants thereof) can include, not least: calculating, computing, processing, deriving, measuring, investigating, identifying, looking up (for example, looking up in a table, a database, or another data structure), ascertaining and the like. Also, "determining" can include receiving (for example, receiving information), accessing (for example, accessing data in a memory), obtaining and the like. Also, " determine / determining" can include resolving, selecting, choosing, establishing, and the like.

[0233] In this description, reference has been made to various examples. The description of features or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples. Thus ‘example’, ‘for example’, ‘can’, or ‘may’ refers to a particular instance in a class of examples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all the instances in the class. It is therefore implicitly disclosed that a feature described with reference to one example but not with reference to another example, can where possible be used in that other example as part of a working combination but does not necessarily have to be used in that other example.

[0234] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or” mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0235] Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

[0236] Features described in the preceding description may be used in combinations other than the combinations explicitly described above.

[0237] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0238] The description of a feature, such as an apparatus or a component of an apparatus, configured to perform a function, or for performing a function, should additionally be considered to also disclose a method of performing that function. For example, description of an apparatus configured to perform one or more actions, or for performing one or more actions, should additionally be considered to disclose a method of performing those one or more actions with or without the apparatus.

[0239] Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

[0240] The term ‘a’, ‘an’ or ‘the’ is used in this document with an inclusive not an exclusive meaning. That is any reference to X comprising a / an / the Y indicates that X may comprise only one Y or may comprise more than one Y unless the context clearly indicates the contrary. If it is intended to use ‘a’, ‘an’ or ‘the’ with an exclusive meaning then it will be made clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these terms should not be taken to infer any exclusive meaning.

[0241] The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and to features that achieve substantially the same technical effect (equivalent features). The equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result.

[0242] In this description, reference has been made to various examples using adjectives or adjectival phrases to describe characteristics of the examples. Such a description of a characteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described.

[0243] The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity and clarity have been omitted from the above description. Nonetheless, the above description should be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure.

[0244] Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance the Applicant may seek protection via the claims in respect of any patentable feature or combination of features hereinbefore referred to and / or shown in the drawings whether or not emphasis has been placed thereon. l / we claim:

Claims

CLAIMS1 . A source network node comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the source network node to perform at least: establishing a connection with a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel; controlling the RIS panel by sending a configuration to the RIS-MT wherein the configuration enables enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; determining that control of the RIS-MT is passed to or is to be passed to a target network node; sending a request to the target network node for a permission for the source network node to provide a configuration to the RIS-MT via the target network node; receiving a response to the request; and determining whether to send the configuration to the RIS-MT via the target network node in accordance with the received response.

2. The source network node of claim 1 wherein the processor and memory are further configured to cause the source network node to perform sending the configuration to the RIS-MT via the target network node if the response indicates acceptance of the request.

3. The source network node of any preceding claim wherein the processor and memory are further configured to cause the source network node to perform, if the response indicates that the request is not accepted, determining whether to send a further request to the target network node wherein the further request indicates one or more types of control indicated by the target network node.

4. The source network node of any preceding claim wherein the processor and memory are further configured to cause the source network node to refrain from sending the configuration to the RIS-MT via the target network node if the response indicates that the request is not accepted.

5. The source network node of any preceding claim wherein the processor and memory are further configured to cause the source network node to perform receivingan indication from the target network node indicating that the target network node has capability for sending a configuration from the source network node to the RIS-MT after control of the RIS-MT is passed to the target network node.

6. The source network node of claim 5 wherein the indication that the target network node has capability for sending a configuration from the source network node to the RIS- MT comprises an indication of one or more types of control that can be used.

7. The source network node of claims 5 or 6 wherein the indication that the target network node has capability for sending a configuration from the source network node to the RIS-MT is received during a network interface setup procedure between the source network node and the target network node.

8. The source network node of any preceding claim wherein the request to the target network node is sent during a handover procedure related to the RIS-MT between the source network node and the target network node.

9. The source network node of claim 8 wherein the request sent to the target network node comprises an indication requesting the target network node to reject the handover procedure if the target network node is not capable of sending of the configuration from the source network node to the RIS-MT.

10. The source network node of any of claims 1 to 7 wherein the request to the target network node is sent when a UE context of the RIS-MT is transferred to the target network node.11 . The source network node of any preceding claim wherein the request sent to the target network node comprises an indication of one or more types of control requested.

12. The source network node of any preceding claim wherein the request sent to the target network node comprises an indication of a time of activation of the configuration for the RIS-MT via the target network node.

13. The source network node of any preceding claim wherein the processor and memory are further configured to cause the source network node to perform sending, to the target network node, an update to the configuration for the RIS-MT via the targetnetwork node wherein the update to the configuration for the RIS-MT via the target network node comprises at least one of: a new configuration to be used by the RIS-MT; an indication of a time of activation for the update to the configuration for the RIS-MT via the target network node.

14. A target network node comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the target network node to perform at least: receiving a request from a source network node for a permission for the source network node to provide a configuration to a reconfigurable intelligent surface - mobile terminal (RIS-MT) of a RIS panel via the target network node; determining whether the request can be accepted sending a response to the request; and providing a configuration from the source network node to the RIS-MT in accordance with whether the request is accepted.

15. The target network node of claim 14 wherein the processor and memory are further configured to cause the target network node to perform providing the configuration from the source network node to the RIS-MT if the request is accepted.

16. The target network node of any of claims 14 to 15 wherein the processor and memory are further configured to cause the target network node to perform refraining from providing the configuration from the source network node to the RIS-MT if the request is not accepted.

17. The target network node of claim 16 wherein the response to the request indicates that the request is not accepted and indicates one or more types of control.

18. The target network node of any of claims 14 to 17 wherein the processor and memory are further configured to cause the target network node to perform sending an indication to the source network node indicating that the target network node has capability for sending a configuration from the source network node to the RIS-MT after control of the RIS-MT is passed to the target network node.

19. The target network node of claim 18 wherein the indication is sent during a network interface setup procedure between the source network node and the target network node.

20. The target network node of any of claims 14 to 19 wherein the request from the source network node is received during a handover procedure related to the RIS-MT between the source network node and the target network node.21 . The target network node of claim 20 wherein the request from the source network node comprises an indication requesting the target network node to reject the handover procedure if the target network node is not capable of sending of the configuration from the source network node to the RIS-MT after the control of the RIS-MT is passed to the target network node and the processor and memory are further configured to cause the target network node to perform considering the indication before determining to accept the handover procedure.

22. The target network node of any of claims 20 to 21 wherein the processor and memory are further configured to cause the target network node to perform creating a handover command comprising information indicative of the configuration from the source network node and sending the handover command to the RIS-MT23. The target network node of any of claims 14 to 19 wherein the request from the source network node is received when a UE context of the RIS-MT is transferred to the target network node.

24. A reconfigurable intelligent surface- mobile terminal (RIS-MT) of a RIS panel comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the RIS-MT to perform at least: establishing a connection with a source network node; receiving a configuration from the source network node wherein the configuration enables control of the RIS panel to perform enhancement of signals between the source network node and one or more user equipments (UEs) connected to a cell of the source network node; establishing a connection with a target network node;controlling the RIS panel to perform enhancement of signals between the source network node and one or more UEs connected to a cell of the source network node in accordance with the configuration received from the source network node, wherein the controlling occurs after the connection is established with the target network node.

25. The RIS-MT of claim 24 wherein the processor and memory are further configured to cause the RIS-MT to perform receiving an activation signal and, in response to the activation signal from the target network node after the connection with the target network node is established, activating the enhancement of signals between the source network node and one or more UEs at the activation time.

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