SOURCE SECONDARY NODE (S-SN) INITIATED CANCELLATION OF CONDITIONAL PSCELL CHANGE (CPC) IN A MULTI-RADIO DUAL-CONNECTIVITY (MR-DC) SYSTEM
20230379788 · 2023-11-23
Assignee
Inventors
Cpc classification
International classification
Abstract
The invention concerns MR-DC (multi-radio dual connectivity) in which a UE is connected to a master node (MN) and secondary nodes (SN). In a Conditional PSCell Change (CPC)—i.e. a PS-Cell Change which is executed by the UE when an execution condition is met—a source secondary node, S-SN, may send a cancellation indication to a master node, MN, when said S-SN desires cancellation of a CPC configuration. Subsequently, the MN transmits a cancellation indication to the target candidate SNs configured with CPC.
Claims
1. A method performed by a master node (MN) for cancellation of a conditional primary secondary cell (PSCell) change, the method comprising: transmitting to a target secondary node (T-SN) a request for a conditional PSCell change (CPC) configuration; receiving a response to the request; receiving a cancellation indication transmitted by a source secondary node (S-SN), the cancellation indication indicating that the CPC configuration is to be cancelled; and transmitting to the T-SN an indication that the CPC configuration is to be cancelled.
2. The method of claim 1, wherein the cancellation indication transmitted by the S-SN comprises: an S-NODE MODIFICATION REQUIRED message, an S-NODE RELEASE REQUIRED message, a CPC CANCEL message, or a CHO CANCEL.
3. The method of claim 1, further comprising: releasing of resources associated with the CPC configuration that has been indicated to be cancelled; and/or stopping a supervision timer.
4. (canceled)
5. The method of claim 1, wherein the indication transmitted to the T-SN comprises: an S-NODE MODIFICATION REQUEST message, a CPC CANCEL message, an SN ADDITION CANCEL message, or an S-NODE RELEASE REQUEST message.
6. The method of claim 1, further comprising: reconfiguring a UE to remove a conditional PSCell change associated with the S-SN.
7. The method of claim 1, further comprising: prior to transmitting the request to the T-SN, receiving from the S-SN a request to configure CPC.
8. The method of claim 7, wherein receiving the request transmitted by the S-SN comprises receiving: an S-NODE MODIFICATION REQUIRED message, or an S-NODE RELEASE REQUIRED message.
9. The method of claim 7, wherein the request transmitted by the S-SN comprises information indicating the T-SN.
10. The method of claim 1, wherein transmitting the request to the T-SN to prepare the CPC configuration comprises transmitting to the T-SN an S-NODE ADDITION REQUEST message.
11. A method performed by a source secondary node (S-SN) for cancellation of a conditional primary secondary cell (PSCell) change, the method comprising: transmitting a cancellation indication to a master node (MN) indicating that a configured conditional PSCell change (CPC) is to be cancelled.
12. The method of claim 11, wherein the cancellation indication comprises: an S-NODE MODIFICATION REQUEST message, an CPC CANCEL message, or an SN ADDITION CANCEL message.
13. The method of claim 11, further comprising: prior to transmitting the cancellation indication to the MN, transmitting a request to the MN to prepare a CPC configuration; and receiving a response message transmitted by the MN.
14. The method of claim 13, wherein the request comprises: an S-NODE MODIFICATION REQUIRED message, or an S-NODE RELEASE REQUIRED message.
15. The method of claim 13, wherein the response transmitted by the MN is an S-NODE MODIFICATION CONFIRM message.
16. The method of claim 13, wherein the cancellation indication is transmitted as a result of: detecting that a UE has moved away from a candidate target cell, detecting that a Secondary Cell Group, SCG, is going to be deactivated or suspended, or detecting that a conditional hand over, CHO, needs to be configured.
17-24. (canceled)
25. A network node, the network node being configured to perform a method comprising: transmitting to a target secondary node (T-SN) a request for a conditional primary secondary cell change (CPC) configuration; receiving a response to the request; and receiving a cancellation indication transmitted by a source secondary node, S-SN, the cancellation indication indicating that the CPC configuration is to be cancelled.
26. The network node of claim 25, wherein the method further comprises transmitting to the T-SN an indication that the CPC configuration is to be cancelled.
27-31. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0112] The disclosure describes the cancellation of one or multiple candidate cells (sometimes called target candidate cells) belonging to (or associated with) a target candidate SN (T-SN), after a successful SN Addition preparation
[0113] The disclosure refers to a UE operating in Multi-Radio Dual Connectivity (MR-DC) according to the NR specifications e.g., TS 37.340, TS 38.331, etc. The disclosure refers to a first network node (NN) operating as a Master Node (MN), e.g., having a Master Cell Group (MCG) configured to the UE and/or an MN-terminated bearer; that MN can be a gNodeB, or a Central Unit gNodeB (CU-gNB) or an eNodeB, or a Central Unit eNodeB (CU-gNB), or any network node. The disclosure also refers to a second network node operating as a Secondary Node (SN), or Source Secondary Node (S-SN) e.g. having a Secondary Cell Group (SCG) configured to the UE and/or an SN-terminated bearer; that SN can be a gNodeB, or a Central Unit gNodeB (CU-gNB) or an eNodeB, or a Central Unit eNodeB (CU-gNB), or any network node. Notice that MN, S-SN and T-SN may be from the same or different Radio Access Technologies (and possibly be associated to different Core Network nodes).
[0114] The disclosure refers to a target candidate SN, or target SN (T-SN) candidate, as the network node (e.g. gNodeB) that is prepared during the CPC procedure and that creates an RRC Reconfiguration message with an SCG configuration to be provided to the UE and stored, with an execution condition, wherein the UE only applies the message upon the fulfilment of the execution condition. That target candidate SN is associated to one or multiple target candidate cell(s) that the UE can be configured with. The UE then can execute the condition and accesses one of these target candidate cells, associated with a target candidate SN that becomes the T-SN after execution (i.e. upon fulfilment of the execution condition).
[0115] The disclosure refers to a Conditional PSCell Change (CPC) and/or Conditional PSCell Addition (CPA) and/or Conditional PSCell Change/Addition (CPAC) configuration and procedures (like CPAC execution). Other terms may be considered as synonyms such as conditional reconfiguration, or Conditional Configuration (since the message that is stored and applied upon fulfilment of a condition is an RRCReconfiguration or RRCConnectionReconfiguration). Terminology wise, one could also interpret conditional handover (CHO) in a broader sense, also covering CPC (Conditional PSCell Change) or CPAC (Conditional PSCell Addition/Change) procedures.
[0116] The configuration of CPC can be done using the same IEs as conditional handover, which may be called at some point conditional configuration or conditional reconfiguration. The principle for the configuration is the same with configuring triggering/execution conditions and a reconfiguration message to be applied when the triggering conditions are fulfilled. The configuration IEs from TS 38.331 are shown and described below:
[0117] The ConditionalReconfiguration IE, shown in table below, is used to add, modify and release the configuration of conditional configuration.
TABLE-US-00001 ConditionalReconfiguration-r16 ::= SEQUENCE { attemptCcondReconfig-r16 ENUMERATED { true } OPTIONAL, -- Need N condConfigToRemoveList-r16 CondConfigToRemoveList-r16 OPTIONAL, -- Need N condConfigToAddModList-r16 CondConfigToAddModList-r16 OPTIONAL, - - Need N ... } CondConfigToRemoveList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells)) OF CondConfigId-r16 ConditionalReconfiguration field descriptions: condConfigToAddModList: List of the configuration of candidate SpCells to be added or modified for CHO or CPC. condConfigToRemoveList: List of the configuration of candidate SpCells to be removed. When the network removes the stored conditional configuration for a candidate cell, the network releases the measIDs associated to the condExecutionCond if it is not used by the condExecutionCond of other candidate cells.
[0118] The CondConfigId IE, which is shown in the table below, is used to identify a CHO or CPC configuration.
TABLE-US-00002 CondConfigId-r16 ::= INTEGER (1.. maxNrofCond-Cells)
[0119] The CondConfigToAddModList IE, which is shown in the table below, concerns a list of conditional configurations to add or modify, with for each entry the cho-ConfigId and the associated condExecutionCond and condRRCReconfig.
TABLE-US-00003 CondConfigToAddModList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells)) OF CondConfigToAddMod-r16 CondConfigToAddMod-r16 ::= SEQUENCE { condConfigId-r16 CondConfigId-r16, condExecutionCond-r16 SEQUENCE (SIZE (1..2)) OF MeasId OPTIONAL, -- Need S condRRCReconfig-r16 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Need S ... } FIELD DESCRIPTIONS: condExecutionCond: The execution condition that needs to be fulfilled in order to trigger the execution of a conditional configuration. The field is mandatory present when a condConfigId is being added. Otherwise, when the condRRCReconfig associated to a condConfigId is being modified it is optionally present and the UE uses the stored value if the field is absent. condRRCReconfig: The RRCReconfiguration message to be applied when the condition(s) are fulfilled. The field is mandatory present when a condConfigId is being added. Otherwise, when the condExecutionCond associated to a condConfigId is being modified it is optionally present and the UE uses the stored value if the field is absent.
[0120] Solutions for CPC configuration (SN-generated CPC and MN-generated CPC)
[0121] The current disclosure concerns S-SN-initiated CPC cancelling. However, it is assumed that there may be different ways to realize the CPC configuration between MN, S-SN and a target candidate (which is to be cancelled).
[0122] SN-Initiated CPC
[0123] In one embodiment, illustrated in
[0124] In another embodiment, illustrated in
[0125] MN-Initiated CPC
[0126] In MN-initiated CPC, the difference is that the first step is initiated by the MN. However, an SN Addition procedure is anyways required between the MN and a target candidate T-SN. Even if this is an MN-initiated CPC, in principle the CPC configuration can be created by the SN or by the MN. For a solution where the SN generates the CPC configuration, the MN needs to request the SN to generate the configuration, as in the embodiment for SN-initiated (see
[0127] For a solution where the MN generates CPC configuration, the MN does not need to request the SN to generate the configuration as in the embodiment for SN-initiated as shown in
[0128] In the different embodiment presented above for CPC configuration, regardless if SN-initiated or MN-initiated CPC, an aspect related to the disclosure is that the S-SN determines to cancel CPC. Then, the S-SN sends an indication of CPC cancelling to the MN. Upon reception the MN sends an indication of CPC cancelling to a target candidate SN configured with CPC.
[0129] The method comprises different embodiments for S-SN initiated cancel of conditional PSCell Change (CPC), in terms of inter-node signaling and inter-node procedures, for the cases inter-SN MN-initiated conditional PSCell Change and inter-SN SN-initiated conditional PSCell Change.
[0130] In one set of embodiments, a network node operating as Source Secondary Node (S-SN), decides to cancel the configuration of CPC for at least a given UE operating in MR-DC. The configuration of Conditional PSCell Change (CPC) for a UE operating in MR-DC has previously been initiated by a network node operating as Master Node (MN) and the MN has built the message towards the UE containing the CPC configuration. The determination to cancel CPC may be based on measurements reports received from the UE. Upon determining to cancel CPC, the MN may initiate a procedure according to the following.
[0131] Option A: The S-SN Cancels MN-Initiated CPC
[0132] In this option, the MN initiates the configuration of conditional PSCell Change (CPC). The final message to the UE containing the conditional reconfiguration may either be generated in the MN or in the S-SN.
[0133] If the message including CPC configuration is generated in the MN (CPC not provided as an SCG configuration to the UE) the message to be applied upon execution (i.e., when the conditions are fulfilled) contains an SCG configuration that is sent from the T-SN to the MN, so the MN adds the conditions and sends the message to the UE. This option is shown in
[0134] If the message including CPC configuration is generated in the S-SN (CPC provided as an SCG configuration to the UE), the MN forwards the SCG configuration (to be applied upon execution by the UE) from the T-SN to the S-SN which adds the conditions and replies back to the MN with the message including the CPC configuration to the UE. The MN then generates an RRC Reconfiguration message including an SCG Reconfiguration (e.g. nr-scg field) wherein that SCG Reconfiguration includes the conditional reconfiguration (IE ConditionalReconfiguration).
[0135] The steps shown in
[0136] (Step 1-6) contains the configuration of CPC with the MN generating the reconfiguration message towards the UE where CPC is configured. The configuration may be done in a different way using different messages and/or different signalling flow, but it does not make any difference for this invention.
[0137] (Step 7) The node operating as Secondary Node (SN) sends an indication to the MN that CPC is to be cancelled (e.g. for at least a target candidate cell and/or node). The indication can contain a reconfiguration to the UE (e.g. transmitted in an RRC container), so that CPC target candidate(s) are removed and, a list of candidate cell(s) to be cancelled for CPC, indicated as part of the inter-node message (e.g. XnAP message).
[0138] In one option, the S-SN indicates the reason for cancelling the conditional PSCell change by means of an appropriate cause value. There may be different options on how that indication can be transmitted and actions associated to it. In a first option that indication can be an S-NODE MODIFICATION REQUIRED message including indication of cancellation of target candidate cells to the MN. The advantage is that the S-SN is indeed indicating to the MN that the UE's configuration is to be modified (as CPC configuration for at least one target candidate is to be removed). That option especially makes sense in the case CPC is an SCG configuration e.g. if the SN is the one generating the CPC configuration that is now being modified (i.e. at least one target candidate is being removed). The message to the MN contains an SCG RRCReconfiguration* message, releasing the CPC candidates. The MN uses the RRCReconfiguration* message and may add more MN related information when building the final message sent to the UE e.g. reconfiguring measurements, bearers, etc., especially if all candidates are being removed. The message to the MN also includes information of which target candidate cells and/or target candidate SNs are to be cancelled, so that the MN can indicate the cancelling to the correct target candidate SN and/or for the correct target candidate cell(s). The information may, e.g., be a list of cells or the identifiers (ID)s of the conditional reconfiguration for CPC. In the case of a cell list an addition issue may exists e.g. in case the UE is configured with CPC to the same cell as it is configured with CHO. Then the UE cannot know if it is the CHO or the CPC configuration that is to be cancelled. In that case the cell ID may be sent together with additional information, e.g. a CPC indication, a CHO indication, the measID for the conditional reconfiguration or some other indication.
[0139] Alternatively, that indication is an S-NODE RELEASE REQUIRED message including indication of cancellation of target candidate cells to the MN. The S-SN may send an S-NODE RELEASE REQUIRED message instead, containing similar information as in S-NODE MODIFICATION REQUIRED. In one sub-alternative, the S-NODE RELEASE REQUIRED message is used to release all CPC configurations, i.e., not a subset of the configured target candidate cells associated to that target candidate SN. The content of the messages and the actions between the network nodes described in the first option can also be included in this option. Alternatively, the SN may send a new message instead, e.g., a CPC CANCEL message, including indication of cancellation of target candidate cells to the MN. In one sub-option, if all target candidate cells associated to the target candidate SN receiving the message, the empty message (i.e. without a cell list) can indicate that. The content of the messages and the actions between the network nodes described in the first option can also be included in this option. Alternatively, the SN may send a CHO CANCEL message, including indication of cancellation of target candidate cells to the MN for CPC. The content of the messages and the actions between the network nodes described in the first option can also be included in this option. In yet another alternative, the request does NOT contain an SCG RRC Reconfiguration including the cells to be removed. Instead, this message in step 7 contains just the indication to the MN so the MN can cancel CPC with the target candidate SNs. Once that step is performed by the MN, and the MN possibly receives a confirmation from the target candidate SN, the MN indicates that to the S-SN, so that the S-SN can generate the CPC configuration (i.e., the SCG RRC Reconfiguration with CPC) including the CPC target candidate cells to be removed.
[0140] (Step 8) Upon reception of the indication from the S-SN to cancel CPC (towards a target candidate SN), the MN determines which target candidate SN(s) are to be CPC cancelled. Upon that determination, the node operating as Master Node (MN) sends an indication to the determined target candidate SN that CPC is to be cancelled (for at least one of its target candidate cells). There may be different options on how the MN can indicate CPC cancel to a target candidate SN.
[0141] In one option, the MN sends an S-NODE MODIFICATION REQUEST message including indication of cancellation of cells to the T-SN (e.g. a list of cells, a list of cell identifiers, a list of other type of identifiers, etc.). Alternatively, the MN may send an S-NODE RELEASE REQUEST message instead, containing similar information as in S-NODE MODIFICATION REQUEST. Notice that the legacy S-NODE RELEASE REQUEST indicates the complete release of configurations while according to this option, the message may contain an indication indicating that this is for releasing CPC for at least one target candidate cell. In case the MN determines to release all target candidate cells for a given target candidate SN, the message can be transmitted without any additional indication so that upon reception the target candidate SN releases all CPC configurations, stored context for that UE, release resources, etc.
[0142] Alternatively, the MN may send a new message instead, e.g. a CPC CANCEL message, including indication of cancellation of target candidate cells to the target candidate SN. In one sub-option, if all target candidate cells associated to the target candidate SN receiving the message, the empty message (i.e. without a cell list) can indicate that. The content of the messages and the actions between the network nodes described in the first option can also be included in this option. Alternatively, the MN may send a new message instead, e.g. a SN ADDITION CANCEL message, including indication of cancellation of target candidate cells to the target candidate SN. In one sub-option, if all target candidate cells associated to the target candidate SN receiving the message, the empty message (i.e. without a cell list) can indicate that. The content of the messages and the actions between the network nodes described in the first option can also be included in this option.
[0143] (Step 9) The node operating as target candidate SN (optionally) acknowledges the cancellation of CPC cells in the T-SN by transmitting to the MN an S-NODE MODIFICATION REQUEST ACKNOWLEDGE or alternatively by transmitting to the MN an S-NODE RELEASE REQUEST ACKNOWLEDGE message (or any other response message, transmitted by the T-SN in response to a request or indication to cancel CPC). That may be useful in case the target candidate SN determines to cancel more cells that the ones requested by the MN, to that response message may indicate which target candidate cells have been effectively cancelled at the target candidate SN. There is also an option that the target candidate SN does not acknowledge the cancellation of CPC (a Class 2 procedure), it is taken for granted that the cancellation is successful in the target candidate SN.
[0144] In yet another alternative, in case the request from the S-SN to the MN to cancel CPC did NOT contain an SCG RRC Reconfiguration including the cells to be removed, upon acknowledging that CPC has been cancelled towards a target candidate SN (e.g., by reception of a message from the T-SN), the MN indicates that to the S-SN, so that the S-SN can generate the CPC configuration (i.e., the SCG RRC Reconfiguration with CPC) including the CPC target candidate cells to be removed. At this point the MN has a CPC configuration from the S-SN for removing CPC in the UE with an RRC Reconfiguration.
[0145] In the previous steps, it has been assumed that the SN generates the CPC configuration as an SCG configuration, even if this is an MN-initiated CPC. However, in another alternative, it is the MN that generates the CPC configuration. The difference if it is the MN generating CPC is that the configuration towards the UE to remove the CPC target candidates is also generated by the MN. Hence, all previous steps remain the same, except the inclusion of SCG reconfiguration from the SN to the MN and/or requests/indications from the MN to the SN for the SN to generate an SCG RRC Reconfiguration to remove CPC candidates in the UE. At the reception of the acknowledge message, the MN considers that the target candidate SN is about to remove any reference to, and release any resources previously reserved for candidate cells associated to the UE-associated signalling identified by the MN node UE XnAP ID IE and the target candidate SN NG-RAN node UE XnAP ID IE.
[0146] (Step 10) The node operating as Master Node (MN) sends an RRCReconfiguration message to the UE, containing the new UE configuration where the previously configured CPC cells have been removed from the configuration. Step 10 and 11 may also be done before step 8 and 9 or in parallel with step 8 and 9.
[0147] (Step 11) The UE completes the reconfiguration (i.e. remove the indicated CPC candidates) and informs the MN in an RRCReconfigurationComplete message.
[0148] An example in RRC 38.331 is shown below with the overall procedure, for the case CPC is an MN-generated configuration (i.e. the IE ConditionalReconfiguration is provided to the UE in an RRCReconfiguration message including the condReconfigToRemoveList).
TABLE-US-00004 RRCReconfiguration-v1610-IEs ::= SEQUENCE { ... conditionalReconfiguration-r16 ConditionalReconfiguration-r16 OPTIONAL, -- Need M ... }
[0149] The ConditionalReconfiguration IE is used to add, modify and release the configuration of conditional reconfiguration.
TABLE-US-00005 ConditionalReconfiguration information element ConditionalReconfiguration-r16 ::= SEQUENCE { ... condReconfigToRemoveList-r16 CondReconfigToRemoveList-r16 OPTIONAL, -- Need N ... } CondReconfigToRemoveList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16)) OF CondReconfigId-r16
[0150] The UE actions are defined as follows. The UE shall: for each condReconfigId value included in the condReconfigToRemoveList that is part of the current UE conditional reconfiguration in VarConditionalReconfig: remove the entry with the matching condReconfigd from the VarConditionadReconfig.
[0151] Below is an example implementation of updated S-NODE RELEASE REQUIRED and sending of conditional reconfiguration ID. This message is sent by the S-NG-RAN node to request the release of resources for a specific UE at the S-NG-RAN node.
[0152] Direction: S-NG-RAN node NM-NG-RAN node.
TABLE-US-00006 IE type and Semantics IE/Group Name Presence Range reference description Message Type M 9.2.3.1 M-NG-RAN node M NG-RAN node UE Allocated at the UE XnAP ID XnAP ID M-NG-RAN 9.2.3.16 node S-NG-RAN node M NG-RAN node UE Allocated at the UE XnAP ID XnAP ID S-NG-RAN 9.2.3.16 node PDU sessions To Be 0 . . . 1 Released >PDU Session O PDU session List Resources to be with data forwarding released List - SN request info terminated 9.2.1.24 Cause M 9.2.3.2 S-NG-RAN node to O OCTET STRING Includes the M-NG-RAN node CG-Config Container message as defined in TS 38.331 [10]. Candidate Cells To 0 . . . <maxNrofCondCells> Be Cancelled List >Conditional M Conditional reconfiguration ID reconfiguration ID 9.2.3.x
TABLE-US-00007 Range bound Explanation maxNrofCondCells Maximum number of conditional reconfigurations. Value is 8.
[0153] 9.2.3.x Conditional Reconfiguration ID
[0154] This IE is defined in TS 38.331 [10] in CondReconfigID and is used to uniquely identify a CHO, CPC or CPA configuration.
TABLE-US-00008 IE/Group Name Presence Range IE type and reference CONDRECONFIGID M INTEGER (0 . . . maxNrofCondCells)
[0155] S-NG-RAN Node Initiated S-NG-RAN Node Release
[0156] This procedure, illustrated in
[0157] The S-NG-RAN node may start data forwarding and stop providing user data to the UE upon reception of the S-NODE RELEASE CONFIRM message, except if the S-NODE RELEASE REQUIRED was sent for a CPC cancelling.
[0158] If the S-NG-RAN node to M-NG-RAN node Container IE is included in the S-NODE RELEASE REQUIRED message, the M-NG-RAN node may use the contained information to apply delta configuration. In the case of CPC cancellation, it may contain the configuration to remove CPC target cell candidates.
[0159] Option B1:
[0160] In this option, the S-SN cancels SN-initiated CPC. Also in this option, illustrated in
[0161] The message can be sent directly to the UE in case SRB3 is configured, otherwise the message is transferred to the MN, which provided the message to the UE (in an SCG RRC container). For option B some different variants of when the UE reconfiguration is done is shown. These different variants exist also for option A, i.e., the UE reconfiguration may take place before or after informing T-SN about the cancellation also in option A. The new Information message in step 15 in option B2 and the new Error message in step 15 in option B3 may be sent in option A also. The reconfiguration towards the UE is in this option B1 done first, before informing T-SN about the cancellation. The steps shown in
[0162] (Step 1-8) contains the configuration of CPC with the S-SN building the reconfiguration message towards the UE where CPC is configured (RRCReconfiguration* as shown in the figure, in step 5, to be provided to the UE within an nr-scg field as a container within another RRCReconfiguration from the MN, as in step 6). The configuration may be done in a different way using different messages and/or different signalling flow, but it does not make any difference for this invention.
[0163] (Step 9) The node operating as Secondary Node (SN) sends a message including an indication of cancellation of target candidate cells (e.g. target candidate PSCells) to the MN.
[0164] The message to the MN contains an SCG RRCReconfiguration* message to be sent to the UE, releasing the CPC candidates. The message to the MN also includes information of which cells where CPC is cancelled, so that the MN can forward the release request to the correct target candidate SN. The information may e.g. be a list of cells or the ID of the conditional reconfiguration. In one option the message is an S-NODE MODIFICATION REQUIRED message including indication of cancellation of target candidate cells (e.g. target candidate PSCells) to the MN. In another option, an S-NODE RELEASE REQUIRED with a list of target candidate cells to be cancelled, or conditional reconfiguration IDs are sent from the S-SN.
[0165] (Step 10) The node operating as Master Node (MN) sends an RRCReconfiguration message to the UE (including the RRCReconfiguration* as the SCG RRC container), containing the new UE configuration where the previously configured CPC cells have been removed from the configuration within the RRCReconfiguration* in the SCG RRC container (in the case we assume that CPC is generated at the SN, as in Rel-16 CPC intra-node solution).
[0166] (Step 11) The UE completes the reconfiguration and informs the MN in an RRCReconfigurationComplete message.
[0167] (Step 12) The node operating as Master Node (MN) sends a message, possibly including an SCG complete message to the S-SN (RRCReconfigurationComplete*), indicating that the configuration has been provided to the UE i.e. indicating that the UE has removed the CPC configurations as indicated by the S-SN in previous steps. In one option the message is an SN MODIFICATION CONFIRM (which is a response to step 9)
[0168] (Step 13) The node operating as Master Node (MN) sends a message to a target candidate SN including an indication of cancellation of target candidate cells (e.g., target candidate PSCells) to at least one target candidate SN. Upon reception the target candidate SN determines which target candidate cells are to be cancelled/removed for CPC configuration.
[0169] In one option that message is an S-NODE MODIFICATION REQUEST message including indication of cancellation of cells to the T-SN, e.g., a list of cells for which CPC configuration is to be cancelled. In one option that message is an S-NODE RELEASE REQUEST message including indication of cancellation of cells to the T-SN, e.g., a list of cells for which CPC configuration is to be cancelled. In another option, a new message, e.g., CPC CANCEL is sent to the target candidate SN. In one option, the node operating as target candidate SN sends an acknowledgement of the cancellation of CPC cells in the T-SN by responding the request to cancel with a message. In other words, in this option a class 1 procedure of an inter-node control protocol (like XnAP) would be used for the cancelling of CPC from the MN to a target candidate SN.
[0170] (Step 14) The target candidate (optionally) sends an acknowledgement that the resources have been removed (a Class 1 procedure). In case of a Class 2 procedure (another option), this step does not exist.
[0171] An example implementation in TS 38.423 is shown below.
[0172] In step 9, additional information related to what cells that are cancelled, needs to be transferred to the MN outside the SCG configuration, so that the MN knows which SN to inform about the cancellation of CPC. Below the target cell IDs are added (highlighted) in the S-NODE MODIFICATION REQUIRED message. Another alternative would be that the conditional reconfiguration IDs are transferred instead.
[0173] S-Node Modification Required
[0174] This message is sent by the S-NG-RAN node to the M-NG-RAN node to request the modification of S-NG-RAN node resources for a specific UE. Direction: S-NG-RAN node.fwdarw.M-NG-RAN node.
TABLE-US-00009 IE type and Semantics IE/Group Name Presence Range reference description Message Type M 9.2.3.1 M-NG-RAN M NG-RAN node Allocated at node UE XnAP UE XnAP ID the M-NG- ID 9.2.3.16 RAN node S-NG-RAN M NG-RAN node Allocated at node UE XnAP UE XnAP ID the S-NG- ID 9.2.3.16 RAN node Cause M 9.2.3.2 PDCP Change O 9.2.3.74 Indication PDU Session 0 . . . 1 Resources To Be Modified List >PDU Session 1 . . . Resources To <maxnoofPDUSessions> Be Modified Item >>PDU Session M 9.2.3.18 ID >>PDU Session O 9.2.1.20 Resource Modification Required Info - SN terminated >>PDU Session O 9.2.1.22 Resource Modification Required Info - MN terminated PDU Session 0 . . . 1 Resources To Be Released List >PDU Session 1 . . . Resources To <maxnoofPDUSessions> Be Released (e.g., 256) Item >PDU sessions O PDU session to be released List with data List - SN forwarding terminated request info 9.2.1.24 >PDU sessions O PDU session to be released List with List - MN Cause 9.2.1.26 terminated S-NG-RAN O OCTET Includes the node to M-NG- STRING CG-Config RAN node message as Container defined in subclause 11.2.2 of TS 38.331 [10]. Spare DRB IDs O DRB List Indicates the 9.2.1.29 list of unnecessary DRB IDs that had been used by the S-NG- RAN node. Required O Number of Indicates the Number of DRB DRBs 9.2.3.78 number of IDs DRB IDs that the S-NG- RAN node requests more. Location O Target Cell Contains Information at Global ID information to S-NODE 9.2.3.25 support localisation of the UE MR-DC O 9.2.2.33 Information Resource used to Coordination coordinate Information resource utilisation between M- NG-RAN node and S-NG- RAN node. RRC Config O 9.2.3.72 Indication Candidate Cells 0 . . . To Be <maxnoofCellsinCHO> Cancelled List >Target Cell ID M Target Cell Global ID9.2.3.25
[0175] In another embodiment, the cancellation information, e.g. the list of cells to be cancelled or the conditional reconfiguration ID, is contained in S-NODE RELEASE REQUIRED instead of S-NODE MODIFICATION REQUIRED and S-NODE RELEASE REQUEST instead of S-NODE MODIFICATION REQUEST.
[0176] Option 1B2:
[0177] In this option, the S-SN cancels SN-initiated CPC, and UE reconfiguration is done after T-SN is informed.
[0178] Also, in this option the S-SN initiates the configuration of conditional PSCell Change (CPC) and the final message sent to the UE with the conditional reconfiguration (for CPC) is built in S-SN (i.e. the IE ConditionalReconfiguration is provided within an SCG RRC Reconfiguration e.g. nr-scg). The message can be sent directly to the UE in case SRB3 is configured, otherwise the message is transferred to the MN, which provides the message to the UE (in an SCG RRC Reconfiguration, like the field nr-scg within an MN built message). Later, the S-SN decides/determines to cancel the configuration of CPC (and indicates that to the MN so the MN can cancel CPC towards a target candidate SN). The reconfiguration of the UE is in this option done after informing the target candidate SN about the cancellation.
[0179] (Step 1-8) contains the configuration of CPC with the S-SN building the reconfiguration message towards the UE where CPC is configured (RRCReconfiguration* as shown in the figure, in step 5, to be provided to the UE within an nr-scg field as a container within another RRCReconfiguration from the MN, as in step 6). The configuration may be done in a different way using different messages and/or different signalling flow, but it does not make any difference for this invention.
[0180] (Step 9) The node operating as Secondary Node (SN) sends a message including an indication of cancellation of target candidate cells (e.g. target candidate PSCells) to the MN.
[0181] The message to the MN contains an SCG RRCReconfiguration* message to be sent to the UE, releasing the CPC candidates. The message to the MN also includes information of which cells where CPC is cancelled, so that the MN can forward the release request to the correct target candidate SN. The information may e.g. be a list of cells or the ID of the conditional reconfiguration. In one option the message is an S-NODE MODIFICATION REQUIRED message including indication of cancellation of cells to the MN. In another option, an S-NODE RELEASE REQUIRED with a list of target candidate cells to be cancelled, or conditional reconfiguration IDs are sent from the S-SN.
[0182] (Step 10) The node operating as Master Node (MN) sends a message to a target candidate SN including an indication of cancellation of target candidate cells (e.g. target candidate PSCells) to at least one target candidate SN. Upon reception the target candidate SN determines which target candidate cells are to be cancelled/removed for CPC configuration.
[0183] In one option that message is an S-NODE MODIFICATION REQUEST message including indication of cancellation of cells to the T-SN e.g. a list of cells for which CPC configuration is to be cancelled. In one option that message is an S-NODE RELEASE REQUEST message including indication of cancellation of cells to the T-SN e.g. a list of cells for which CPC configuration is to be cancelled. In another option, a new message, e.g. CPC CANCEL is sent to the target candidate SN.
[0184] (Step 11) In one option, the node operating as T-SN acknowledges the cancellation of CPC cells in the T-SN by responding the request to cancel with a message. In other words, in this option a class 1 procedure of an inter-node control protocol (like XnAP) would be used for the cancelling of CPC from the MN to a target candidate SN.
[0185] (Step 12) The node operating as Master Node (MN) sends an RRCReconfiguration message to the UE (including the RRCReconfiguration* as the SCG RRC container), containing the new UE configuration where the previously configured CPC cells have been removed from the configuration within the RRCReconfiguration* in the SCG RRC container (in the case we assume that CPC is generated at the SN, as in Rel-16 CPC intra-node solution).
[0186] (Step 13) The UE completes the reconfiguration and informs the MN in an RRCReconfigurationComplete message.
[0187] (Step 14) The MN informs the S-SN that the UE reconfiguration is complete.
[0188] (Step 15) In this step the MN informs the T-SN in a new message that the UE reconfiguration is complete and that the T-SN may release the resources. The resources cannot be released in T-SN before the UE has been reconfigured, as the UE may otherwise try to access the T-SN in case the conditions are fulfilled before the CPC is removed in the UE. This case is new, as three different nodes are involved, with one node initiating the cancellation of the conditional reconfiguration, one node reconfiguring the UE and a third node having the resources reserved for the UE. For conditional handover, only two nodes are involved in the cancellation, the source node and the target node. This new message may also be sent in MN-initiated CPC, option A above.
[0189] Option B3:
[0190] In this option, the S-SN cancels SN-initiated CPC, and UE reconfiguration is done after T-SN is informed. Also in this option, the S-SN initiates the configuration of conditional PSCell Change (CPC) and the final message sent to the UE with the conditional reconfiguration is built in S-SN. The message can be sent directly to the UE in case SRB3 is configured, otherwise the message is transferred to the MN, which forwards the message to the UE. Later, the S-SN decides to cancel the configuration of CPC. The reconfiguration of the UE is done after informing the T-SN about the cancellation. The difference compared to option B1 is that there is no message sent to the T-SN, informing it that the reconfiguration in the UE is completed. Instead an error message is sent in case the reconfiguration fails. Option B3 is illustrated in
[0191] (Step 1-8) contains the configuration of CPC with the S-SN building the reconfiguration message towards the UE where CPC is configured (RRCReconfiguration* as shown in the figure, in step 5, to be provided to the UE within an nr-scg field as a container within another RRCReconfiguration from the MN, as in step 6). The configuration may be done in a different way using different messages and/or different signalling flow, but it does not make any difference for this invention.
[0192] (Step 9) The node operating as Secondary Node (SN) sends a message including an indication of cancellation of target candidate cells (e.g. target candidate PSCells) to the MN.
[0193] The message to the MN contains an SCG RRCReconfiguration* message to be sent to the UE, releasing the CPC candidates. The message to the MN also includes information of which cells where CPC is cancelled, so that the MN can forward the release request to the correct target candidate SN. The information may e.g. be a list of cells or the ID of the conditional reconfiguration. In one option the message is an S-NODE MODIFICATION REQUIRED message including indication of cancellation of cells to the MN. In another option, an S-NODE RELEASE REQUIRED with a list of target candidate cells to be cancelled, or conditional reconfiguration IDs are sent from the S-SN.
[0194] (Step 10) The node operating as Master Node (MN) sends a message to a target candidate SN including an indication of cancellation of target candidate cells (e.g. target candidate PSCells) to at least one target candidate SN. Upon reception the target candidate SN determines which target candidate cells are to be cancelled/removed for CPC configuration.
[0195] In one option that message is an S-NODE MODIFICATION REQUEST message including indication of cancellation of cells to the T-SN e.g. a list of cells for which CPC configuration is to be cancelled. In one option that message is an S-NODE RELEASE REQUEST message including indication of cancellation of cells to the T-SN, e.g., a list of cells for which CPC configuration is to be cancelled. In another option, a new message, e.g., CPC CANCEL is sent to the target candidate SN.
[0196] (Step 11) In one option, the node operating as T-SN acknowledges the cancellation of CPC cells in the T-SN by responding the request to cancel with a message. In other words, in this option a class 1 procedure of an inter-node control protocol (like XnAP) would be used for the cancelling of CPC from the MN to a target candidate SN.
[0197] (Step 12) The node operating as Master Node (MN) sends an RRCReconfiguration message to the UE (including the RRCReconfiguration* as the SCG RRC container), containing the new UE configuration where the previously configured CPC cells have been removed from the configuration within the RRCReconfiguration* in the SCG RRC container (in the case we assume that CPC is generated at the SN, as in Rel-16 CPC intra-node solution).
[0198] (Step 13) The UE completes the reconfiguration and informs the MN in an RRCReconfigurationComplete message.
[0199] (Step 14) The MN informs the S-SN that the UE reconfiguration is complete.
[0200] (Step 15) In this step the MN informs the T-SN in a new message that the UE reconfiguration has failed and that the T-SN may not release the resources. The T-SN has likely kept the resourced for a while, possibly with a timer in the implementation, to ensure that the resources are not released too early. This new message may also be sent in MN-initiated CPC, option A above.
[0201]
[0202] In some embodiments, wherein the cancellation indication transmitted by the S-SN comprises one of: an S-NODE MODIFICATION REQUIRED message, an S-NODE RELEASE REQUIRED message, a CPC CANCEL message, or a CHO CANCEL.
[0203] In some embodiments, process 1400 also includes releasing of resources associated with the CPC configuration that has been indicated to be cancelled and/or stopping a supervision timer.
[0204] In some embodiments, process 1400 also includes transmitting to the T-SN an indication that the CPC configuration is to be cancelled. In some embodiments, the indication transmitted to the T-SN comprises one of: an S-NODE MODIFICATION REQUEST message, a CPC CANCEL message, an SN ADDITION CANCEL message, or an S-NODE RELEASE REQUEST message.
[0205] In some embodiments, process 1400 also includes reconfiguring a UE to remove a conditional PSCell change associated with the S-SN.
[0206] In some embodiments, process 1400 also includes, prior to transmitting the request to the T-SN, receiving from the S-SN a request to configure CPC. In some embodiments, receiving the request transmitted by the S-SN comprises receiving one of: an S-NODE MODIFICATION REQUIRED message, or an S-NODE RELEASE REQUIRED message. In some embodiments, the request transmitted by the S-SN comprises information indicating the T-SN.
[0207] In some embodiments, transmitting the request to the T-SN to prepare the CPC configuration comprises transmitting to the T-SN an S-NODE ADDITION REQUEST message.
[0208]
[0209] In some embodiments, the cancellation indication comprises one of: an S-NODE MODIFICATION REQUEST message, an CPC CANCEL message, or an SN ADDITION CANCEL message.
[0210] In some embodiments, process 1500 also includes, prior to transmitting the cancellation indication to the MN, transmitting a request to the MN to prepare a CPC configuration; and receiving a response message transmitted by the MN. In some embodiments, the request comprises: an S-NODE MODIFICATION REQUIRED message, or an S-NODE RELEASE REQUIRED message. In some embodiments, the response transmitted by the MN is an S-NODE MODIFICATION CONFIRM message.
[0211] In some embodiments, the cancellation indication is transmitted as a result of: detecting that a UE has moved away from a candidate target cell, detecting that a Secondary Cell Group, SCG, is going to be deactivated or suspended, or detecting that a conditional hand over, CHO, needs to be configured.
[0212]
[0213] In some embodiments, the cancellation indication is one of: an S-NODE MODIFICATION REQUIRED message, an S-NODE RELEASE REQUIRED message, an S-NODE MODIFICATION REQUEST message, an S-NODE RELEASE REQUEST message, or a CPC CANCEL message.
[0214] In some embodiments, the request to prepare the CPC configuration comprises: a conditional PSCell Addition, an S-NODE MODIFICATION REQUIRED message, or an S-NODE RELEASE REQUIRED message.
[0215] In some embodiments, the response to the request to configure the CPC comprises: a conditional PSCell Addition Acknowledgement or an SN MODIFICATION REQUEST ACKNOWLEDGE message.
[0216] In some embodiments, process 1600 also includes acknowledging the cancellation of CPC cells to the MN. In some embodiments, acknowledging the cancellation of CPC cells comprises transmitting to the MN one of: an S-NODE MODIFICATION REQUEST ACKNOWLEDGE message or an S-NODE RELEASE REQUEST ACKNOWLEDGE message.
[0217]
[0218] With reference to
[0219] Telecommunication network 1810 is itself connected to host computer 1830, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 1830 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 1821 and 1822 between telecommunication network 1810 and host computer 1830 may extend directly from core network 1814 to host computer 1830 or may go via an optional intermediate network 1820. Intermediate network 1820 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 1820, if any, may be a backbone network or the Internet; in particular, intermediate network 1820 may comprise two or more sub-networks (not shown).
[0220] The communication system of
[0221] Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to
[0222] Communication system 1900 further includes base station 1920 provided in a telecommunication system and comprising hardware 1925 enabling it to communicate with host computer 1910 and with UE 1930. Hardware 1925 may include communication interface 1926 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 1900, as well as radio interface 1927 for setting up and maintaining at least wireless connection 1970 with UE 1930 located in a coverage area (not shown in
[0223] Communication system 1900 further includes UE 1930 already referred to. Its hardware 1935 may include radio interface 1937 configured to set up and maintain wireless connection 1970 with a base station serving a coverage area in which UE 1930 is currently located. Hardware 1935 of UE 1930 further includes processing circuitry 1938, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 1930 further comprises software 1931, which is stored in or accessible by UE 1930 and executable by processing circuitry 1938. Software 1931 includes client application 1932. Client application 1932 may be operable to provide a service to a human or non-human user via UE 1930, with the support of host computer 1910. In host computer 1910, an executing host application 1912 may communicate with the executing client application 1932 via OTT connection 1950 terminating at UE 1930 and host computer 1910. In providing the service to the user, client application 1932 may receive request data from host application 1912 and provide user data in response to the request data. OTT connection 1950 may transfer both the request data and the user data. Client application 1932 may interact with the user to generate the user data that it provides.
[0224] It is noted that host computer 1910, base station 1920 and UE 1930 illustrated in
[0225] In
[0226] Wireless connection 1970 between UE 1930 and base station 1920 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 1930 using OTT connection 1950, in which wireless connection 1970 forms the last segment. More precisely, the teachings of these embodiments may improve one or more of the date rate, latency, and power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, and/or extended battery lifetime.
[0227] A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 1950 between host computer 1910 and UE 1930, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 1950 may be implemented in software 1911 and hardware 1915 of host computer 1910 or in software 1931 and hardware 1935 of UE 1930, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 1950 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 1911, 1931 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1950 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 1920, and it may be unknown or imperceptible to base station 1920. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 1910's measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 1911 and 1931 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1950 while it monitors propagation times, errors etc.
[0228]
[0229]
[0230]
[0231]
[0232] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.
[0233] Summary of Additional Embodiments [0234] 1. A method performed by a base station operating as a master node (MN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: transmitting a request to a T-SN to configure conditional PSCell change; receiving a response to the request confirming that a UE may be accepted; receiving a cancellation indication from the S-SN indicating that a previously provided conditional PSCell change configuration is to be cancelled; transmitting an indication to a target candidate SN that a configured conditional PSCell change is to be cancelled; and reconfiguring a UE to remove a conditional PSCell change associated with the SN that has sent the cancelling indication for at least one target candidate PSCell. [0235] 2. The method of embodiment 1, wherein the cancellation indication comprises one of an S-NODE MODIFICATION REQUIRED message, an S-NODE RELEASE REQUIRED message, a CPC CANCEL message, and a CHO CANCEL. [0236] 3. The method of any of the above embodiments, further comprising performing one or more actions upon receiving the cancelling indication, including one or more of releasing of resources associated with the CPC that has been indicated to be cancelled and stopping a supervision timer.
[0237] The method of any of the above embodiments, and further comprising sending an indication to a determined target candidate SN that CPC is to be cancelled. [0238] 5. The method of any of the above embodiments, wherein the indication to the determined target candidate is one of an S-NODE MODIFICATION REQUEST message, a CPC CANCEL message, and an SN ADDITION CANCEL message. [0239] 6. A method performed by a base station operating as a source secondary node (S-SN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: transmitting a cancellation indication to a master node indicating that a configured conditional PSCell change is to be cancelled. [0240] 7. The method of embodiment 6, wherein the transmitted indication comprises one of an S-NODE MODIFICATION REQUEST message, an CPC CANCEL message, and an SN ADDITION CANCEL message. [0241] 8. A method performed by a base station operating as a target candidate secondary node (T-SN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: receiving a request from a master node (MN) to configure a CPC; transmitting a response to the request to the MN to configure the CPC; and receiving a cancellation indication from the MN indicating that a configured conditional PSCell change is to be cancelled. [0242] 9. The method of embodiment 8, wherein the cancellation indication is one of a S-NODE MODIFICATION REQUIRED message and a S-NODE RELEASE REQUIRED message. [0243] 10. The method of any of the above two embodiments, wherein the request to configure a CPC comprises a conditional PSCell Addition. [0244] 11. The method of any of embodiments 8-10, wherein the response to the request to configure a CPC comprises a conditional PSCell Addition Ack. [0245] 12. The method of Claim 8, further comprising acknowledging the cancellation of CPC cells to the MN. [0246] 13. The method of embodiment 12, wherein acknowledging the cancellation of CPC cells further comprises transmitting to the MN one an S-NODE MODIFICATION REQUEST ACKNOWLEDGE message and an S-NODE RELEASE REQUEST ACKNOWLEDGE message. [0247] 14. A method performed by a base station operating as a source secondary node (S-SN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: transmitting a request to a master Node (MN) to prepare a conditional PSCell change; receiving from the MN a response to the conditional SN reconfiguration request confirming that a UE may be accepted; and transmitting a cancellation indication to the MN indicating that a previously provided conditional SN addition configuration is not valid. [0248] 15. The method of embodiment 14, wherein the request comprises an S-NODE MODIFICATION REQUIRED message or an S-NODE RELEASE REQUIRED message. [0249] 16. The method of any of the previous two embodiments, wherein the response from the MN is an S-NODE MODIFICATION CONFIRM message. [0250] 17. The method of embodiment previous three embodiments, wherein the previously provided conditional SN addition configuration is not valid because the UE has moved away from a candidate target cell and that a CPC is not likely anymore or that the SCG is going to be deactivated or suspended or that CHO needs to be configured. [0251] 18. A method performed by a base station operating as a master node (MN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: receiving a request from a S-SN to configure conditional PSCell change; transmitting a request to a T-SN (target candidate) to configure conditional PSCell change; receiving a response to the conditional reconfiguration request, confirming that a UE may be accepted; receiving a cancellation indication from a S-SN indicating that a previously provided conditional PSCell change configuration is to be cancelled; transmitting a request to a T-SN that a previously provided conditional PSCell change configuration is to be cancelled; and reconfiguring a UE to cancel or update a conditional PSCell change associated with the SN that has sent the cancelling indication. [0252] 19. The method of the previous embodiment, wherein receiving a request from a S-SN to configure conditional PSCell change comprises receive one of an S-NODE MODIFICATION REQUIRED message and an S-NODE RELEASE REQUIRED message. [0253] 20. The method of any of the previous two embodiments, wherein transmitting a request to a T-SN that a previously provided conditional PSCell change configuration is to be cancelled comprises transmitting one of an S-NODE MODIFICATION REQUEST message, an S-NODE RELEASE REQUEST message, and an CPC CANCEL message. [0254] 21. The method of any of the previous three embodiments, wherein transmitting a request to a T-SN (target candidate) to configure conditional PSCell change comprises transmitting an S-NODE MODIFICATION CONFIRM message. [0255] 22. The method of any of the previous four embodiments, further comprising performing one or more actions, upon receiving the cancelling indications, including releasing of resources associated with the CPC that has been indicated to be cancelled and stopping supervision of a timer. [0256] 23. A method performed by a base station operating as a target candidate secondary node (T-SN) for source secondary node initiated cancel of conditional PSCell change (CPC), the method comprising: receiving a request from a master node (MN) to configure CPC; transmitting a response to the request to the MN to configure CPC; and receiving a cancellation indication from the MN indicating that a configured conditional PSCell change is to be cancelled. [0257] 24. The method of the previous embodiment, wherein the request comprises an S-NODE MODIFICATION REQUIRED message or an S-NODE RELEASE REQUIRED message. [0258] 25. The method of any of the previous two embodiments, wherein the response comprises an SN MODIFICATION REQUEST ACKNOWLEDGE message. [0259] 26. The method of any of the previous three embodiments, wherein the cancellation indication from the MN indicating that a configured conditional PSCell change is to be cancelled comprises one of an S-NODE MODIFICATION REQUEST message, and S-NODE RELEASE REQUEST, message, and a CPC CANCEL message. [0260] 27. The method of any of the previous four embodiments, wherein receiving a request comprises receiving a conditional PSCell Addition. [0261] 28. The method of any of the previous four embodiments, wherein receiving a response to the request comprises receiving a conditional PSCell Addition Ack. [0262] 29. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a wireless device. [0263] 30. A base station for source secondary node initiated cancel of conditional PSCell change (CPC), the base station comprising: processing circuitry and power supply circuitry configured to supply power to the base station, wherein the processing circuitry I configured to perform any of the steps of any of embodiments 1-29. [0264] 31. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station's processing circuitry configured to perform any of the steps of any of the embodiments 1-29. [0265] 32. The communication system of the previous embodiment further including the base station. [0266] 33. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station. [0267] 34. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application. [0268] 35. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the embodiments 1-29. [0269] 36. The method of the previous embodiment, further comprising, at the base station, transmitting the user data. [0270] 37. The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application. [0271] 38. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to performs the of the previous 3 embodiments. [0272] 39. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station's processing circuitry configured to perform any of the steps of any of the embodiments 1-29. [0273] 40. The communication system of the previous embodiment further including the base station. [0274] 41. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station. [0275] 42. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.
[0276] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.