Inter-node signaling of multiple CHO configurations for same pcell

Abstract

Systems and methods related to signaling of multiple Conditional Handover (CHO) configurations for a same Primary Cell (PCell) are disclosed. In one embodiment, a method performed by a candidate target Master Node (MN) for a User Equipment (UE) comprises receiving, from a source MN, a handover request message for a CHO of the UE to a candidate target PCell, transmitting a secondary node addition request message to one or more candidate target secondary nodes (SNs) for one or more Primary Secondary Cell Group (SCG) Cells (PSCells), and receiving acknowledge messages. The method further comprises generating CHO configurations for the candidate target SNs based on the acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, CHO configurations for candidate target SCGs or PSCells for each of the candidate target SNs. The method further comprises transmitting, to the source MN, a handover request acknowledge message comprising the CHO configurations.

Description

INTER-NODE SIGNALING OF MULTIPLE CHO CONFIGURATIONS FOR SAME PCELL Related Applications

[0001] This application claims the benefit of provisional patent application serial number 63 / 585,077, filed September 25, 2023, the disclosure of which is hereby incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to conditional handover in a cellular communications system. Background Conditional Handover (CHO)

[0003] In a cellular communications system such as, e.g., a 3rd Generation Partnership Project (3GPP) 5th Generation System (5GS), handovers are normally triggered when the User Equipment (UE) is at the cell edge and experiences poor radio conditions. If the UE enters poor radio conditions quickly, the conditions may already be so poor that the actual handover procedure may be hard to execute. If the uplink (UL) is already bad, it may lead to the network not being able to detect the measurement report transmitted by the UE and hence the network cannot initiate the handover procedure. Downlink (DL) problems may lead to the handover command (i.e. the RRCReconfiguration message with a reconfigurationWithSync field) not successfully reaching the UE. In poor radio conditions, the DL message is more often segmented, which increases the risk of retransmissions with an increased risk that the message does not reach the UE in time. Failed transmission of handover command is a common reason for unsuccessful handovers.

[0004] To improve mobility robustness and address the issues above, a concept known as Conditional Handover (CHO) was introduced in 3GPP Release 16. The key idea in CHO is that transmission and execution of the handover command are separated. This allows the handover command to be sent earlier to the UE when the radio conditions are still good, thus increasing the likelihood that the message is successfully transferred. The execution of the handover command is done at a later point in time based on an associated execution condition. The execution condition is typically in the form a threshold, e.g., signal strength of candidate target cell becomes X decibels (dB) better than the serving cell (so called A3 event) or signal strength ofserving cell becomes worse than X decibel milliwatts (dBm) and signal strength of candidate target cell becomes better than Y dBm (so called A5 event).

[0005] In the context of the present disclosure, a cell for which conditional handover (or other conditional mobility procedure) is configured is denoted “candidate target cell” or “potential target cell”. Similarly, a radio network node controlling a candidate / potential target cell is denoted “candidate target node” or “potential target node”. In a sense, once the CHO execution condition has been fulfilled for a candidate / potential target cell and CHO execution towards this candidate / potential target cell has been triggered, this cell is no longer “potential” or a “candidate” in the normal senses of the words, since it is no longer uncertain whether the CHO will be executed towards it. Hence, after the CHO execution condition has been fulfilled / triggered, the concerned candidate / potential target cell is herein sometimes referred to as “target cell”.

[0006] Figure 1 shows the signaling flow for a conditional handover in 3GPP New Radio (NR). The steps of the conditional handover procedure of Figure 1 are as follows.

[0007] Steps 101-102. The UE and source gNodeB (gNB) have an established connection and are exchanging user data. Due to some trigger, e.g. a measurement report from the UE, the source gNB decides to configure one or multiple CHO candidate cells. The threshold used for the measurement reporting should be chosen lower than the one in the handover execution condition. This allows the serving cell to prepare the handover when the radio link to the UE is still stable. The execution of the handover is done at a later point in time (and threshold) which is considered optimal for the handover execution.

[0008] Step 103. The source gNB sends a CHO REQUEST to the target gNB with necessary information to prepare a conditional handover at the target side. The information includes among other things the current source configuration and the UE capabilities.

[0009] Step 104. The target gNB prepares the handover and responds with a CHO REQUEST ACKNOWLEDGE to the source gNB, which includes the handover command (a RRCReconfiguration message) to be sent to the UE and later executed if / when the execution condition would be fulfilled. The handover command includes information needed by the UE to access the target cell, e.g., random access configuration, a new Cell Radio Network Temporary Identifier (C-RNTI) assigned by the target access node and security parameters enabling the UE to calculate the target security key so the UE can send the handover complete message (a RRCReconfigurationComplete message).

[0010] Steps 105-106. To configure a candidate target cell, the source node sends the CHO configuration (i.e., a RRCReconfiguration message) to the UE which contains the handovercommand and the associated execution condition. The handover command (also an RRCReconfiguration message) is the same as the one generated by the target node during the handover preparation phase in steps 103-104 and the execution condition is generated by the source node.

[0011] Steps 107-108. Later on, if the execution condition is met, the UE executes the handover by performing random access and sending the handover complete message (i.e., an RRCReconfigurationComplete message) to the target node.

[0012] Step 109. The target gNB sends a HANDOVER SUCCESS message to the source gNB indicating the UE has successfully established the target connection.

[0013] Steps 110-111. Upon reception of the handover success indication, the source gNB stops scheduling any further DL or UL data to the UE and sends a SN STATUS TRANSFER message to the target gNB indicating the latest Packet Data Convergence Protocol (PDCP) Sequence Number (SN) transmitter and receiver status. The source node now also starts to forward User Data to the target node.

[0014] Step 112. Upon receiving the handover complete message, the target node can start exchanging user data with the UE. The target node also requests the Access and Mobility Management Function (AMF) to switch the DL data path from the User Plane Function (UPF) from the source node to the target node (not shown). Once the path switch is completed the target node sends the UE CONTEXT RELEASE to the source node.

[0015] The conditional handover concept in 3GPP Rel-16 has been generalized into a generic conditional reconfiguration framework, wherein a UE may be configured in advance with also other types of reconfigurations which can be executed by an RRCReconfiguration message (in New Radio (NR)) or an RRCConnectionReconfiguration message (in Long Term Evolution (LTE)) upon a certain associated condition is triggered.

[0016] The Conditional Primary Secondary Cell Group (SCG) Cell (PSCell) Addition (CPA) and Conditional PSCell Change (CPC) are examples of two other types of reconfigurations, which use the conditional reconfiguration framework but operating on the PSCell in the Multi- Radio Dual Connectivity (MR-DC) scenario. In CPA and CPC, when an execution condition is met, rather than a handover, a PSCell Addition (in case of CPA) or a PSCell change (in case of CPC) is executed. CPC and CPA were introduced in 3GPP Rel-16 and Rel-17, respectively. Note that a PSCell may be referred to as either a Primary Secondary Cell or a Primary SCG Cell, depending on the particular 3GPP specification and these terms are used herein interchangeably.CHO with Target SCG and CHO with Candidate SCGs

[0017] In 3GPP Rel-16, the target configuration of CHO, i.e. the Radio Resource Control (RRC) configuration that the UE applies and executes when the associated execution conditions are fulfilled, can only include a Master Cell Group (MCG) configuration, i.e. no Secondary Cell Group (SCG) / PSCell configuration can be part of the configuration that the UE then applies.

[0018] In 3GPP Rel-17, support for including an SCG configuration in the CHO target configuration has been added, meaning that when the associated execution conditions for CHO are fulfilled, the UE can apply both a target MCG configuration and an associated target SCG configuration.

[0019] With the addition in Rel-17, the UE can thus also be configured with an SCG configuration when executing CHO. However, the associated execution conditions are then only for CHO, i.e., related to the Primary Cell (PCell). There is then a risk that the radio conditions for the associated SCG / PSCell are not so good when the CHO execution conditions are fulfilled and the configuration is executed.

[0020] For 3GPP Rel-18, the work item on mobility enhancements (see RP-223520, 3GPP work item description: Further NR mobility enhancements, MediaTek Inc, Apple, 3GPP TSG RAN Meeting #98-e, Electronic Meeting, December 12-16, 2022) include the following objective to support CHO with different candidate SCGs: 4. To specify CHO including target MCG and candidate SCGs for CPC / CPA in NR-DC [RAN3, RAN2] o CHO including target MCG and target SCG is used as the baseline

[0021] Work is thus ongoing in 3GPP to enable the UE to take the radio conditions of candidate SCGs / PSCells into account when determining what target MCG+SCG configurations to apply and execute. The CHO conditions for the candidate PCell are then combined with CPA / CPC conditions for one or more associated candidate PSCell(s).

[0022] At RAN2#123 the following agreements related to CHO including target MCG and candidate SCGs were reached: ⇒ UE does not remove the configuration for CHO including target MCG and candidate SCG configuration automatically when SCG is to be released. ⇒ R2 assumes Source MN initiates the preparation of the R18 CHO with candidate SCG(s), e.g., S-MN tells the T-MN whether it is allowed to configure candidate SCG(s). FFS the signalling details. ⇒ candidate MN recommends the candidate PSCells to candidate SN (for CHO with MN-initiated CPC). ⇒ CHO recovery details to handle the additions brought by this feature is FFS ⇒ R2 assumes for this R18 feature that the UE does not need to continue conditional reconfiguration evaluation for CHO with Candidate SCG(s) upon initiating SCG failure information procedure⇒ Recommendation of the candidate PSCells can be based on measurement results. ⇒ R2 assumes for this R18 feature that the evaluation of the execution conditions for CHO with Candidate SCG(s) do not need to continue once PSCell change is triggered. ⇒ maxNrofCondCells = max number of conditional configurations that the UE can store (is assumed to be a memory limitation), value FFS ⇒ selectedCondRRCReconfig-r17 is not reused to indicate the selected target SCG to the target MN, i.e., UE indicates physCellId and ARFCN-ValueNR of the selected PSCell to target MN. ⇒ condEventA3 or condEventA5 is not used for the execution conditions for candidate PSCells (can be revisited later if strong justification can be provided) ⇒ condEvent A4 to be used for current PSCell (i.e., in case it is configured as candidate PSCell for evaluation) for CHO with candidate SCGs case.

[0023] At RAN3#121 meeting the following agreement related to CHO with multiple SCGs has been reached. For CHO with multiple SCGs among different T-SNs, include list of info of multiple SCGs in Handover Request Ack message, e.g., PDU Session admission results, data forwarding addresses and list of prepared PSCells for each prepared T-SN. This agreement can be revisited after RAN2 agreement.

[0024] Correspondingly, a list of Target Next Generation Radio Access Network (NG-RAN) node to Source NG-RAN node Transparent Container pointing to RRC HANDOVERCOMMAND message has been introduced with FFS within a list of PSCells as shown below. Conditional O YES reject Handover Information Acknowledge >Requested Target M Target Target cell – Cell ID Cell indicated in the Global corresponding ID HANDOVER 9.2.3.25 REQUEST message >Maximum Number O 9.2.3.101 – of CHO Preparations >Multiple Target S- 0..1 YES FFS NG-RAN Node List >>Multiple Target 1.. <maxnoofTargetSNs> – S-NG-RAN Node Item >>>Target S-NG- M Global – RAN node ID NG- RAN Node ID 9.2.2.3 >>>PDU Session M 9.2.1.2 – Resources Admitted List >>>Candidate 1 – PSCell List >>>>Candidate 1.. – PSCell Item <maxnoofPSCellCandidate>>>>>>PSCell ID M NR CGI – 9.2.2.7 >>>>>Target NG- M OCTET Includes the – RAN node To Source STRING HandoverCommand NG-RAN node FFS message as defined Transparent in subclause 11.2.2 Container of TS 38.331

[0010] , if the target NG- RAN node is a gNB. >>>>>Execution O FFS – Condition Information Summary

[0025] Systems and methods related to inter-node signaling of multiple Conditional Handover (CHO) configurations for a same Primary Cell (PCell) in a wireless network are disclosed. In one embodiment, a method performed by a network node acting as a candidate target Master Node (MN) for a User Equipment (UE) comprises receiving a handover request message from a source MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The method further comprises transmitting a secondary node addition request message to one or more candidate target secondary nodes (SNs) for one or more Primary Secondary Cell Group (SCG) Cells (PSCells) and receiving one or more secondary node addition request acknowledge messages from the one or more candidate target SNs. The method further comprises generating CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. The method further comprises transmitting, to the source MN, a handover request acknowledge message comprising the CHO configurations. In this manner, a structure of the handover request acknowledge can be simplified for a CHO with multiple candidate SCGs.

[0026] In one embodiment, the handover request acknowledge message comprises a separate handover command message for each of the CHO configurations. In one embodiment, the handover request acknowledge message further comprises, for each separate handover command message, execution conditions associated with the handover command message.

[0027] In one embodiment, the handover request acknowledge message comprises a single handover command message comprising the CHO configurations. In one embodiment, the handover request acknowledge message further comprises execution conditions associated with the handover command message.

[0028] In one embodiment, each of the one or more secondary node addition request acknowledge messages comprises one or more Radio Resource Control (RRC) reconfiguration messages that correspond to one or more candidate target SCG or PSCell configurations for CHO for a respective one of the one or more candidate target SNs. In one embodiment, the one or more RRC reconfiguration messages comprise multiple RRC reconfiguration messages for configuration of multiple candidate SCGs or PSCells from the same candidate target SN. In one embodiment, each RRC reconfiguration message is associated to a specific CHO with candidate SCG configuration.

[0029] Corresponding embodiments of a network node for acting as a candidate target MN for a UE are also disclosed. In one embodiment, a network node for acting as a candidate target MN for a UE is adapted to receive a handover request message from a source MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The network node is further adapted to transmit a secondary node addition request message to one or more candidate target SNs for one or more PSCells and receive one or more secondary node addition request acknowledge messages from the one or more candidate target SNs. The network node is further adapted to generate CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. The network node is further adapted to transmit, to the source MN, a handover request acknowledge message comprising the CHO configurations.

[0030] In one embodiment, a network node for acting as a candidate target MN for a UE comprises processing circuitry configured to cause the network node to receive a handover request message from a source MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The processing circuitry is further configured to cause the network node to transmit a secondary node addition request message to one or more candidate target SNs for one or more PSCells and receive one or more secondary node addition request acknowledge messages from the one or more candidate target SNs. The processing circuitry is further configured to cause the network node to generate CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. Theprocessing circuitry is further configured to cause the network node to transmit, to the source MN, a handover request acknowledge message comprising the CHO configurations.

[0031] Embodiments of a method performed by a network node acting as a source MN for a UE are also disclosed. In one embodiment, a method performed by a network node acting as a source MN for a UE comprises transmitting a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The method further comprises receiving, from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. The method further comprises generating and transmitting, to the UE, a RRC reconfiguration message that comprises the CHO configurations.

[0032] In one embodiment, the handover request acknowledge message comprises a separate handover command message for each of the CHO configurations. In one embodiment, the handover request acknowledge message further comprises, for each separate handover command message, execution conditions associated with the handover command message.

[0033] In one embodiment, the handover request acknowledge message comprises a single handover command message that comprises the CHO configurations. In one embodiment, the handover request acknowledge message further comprises execution conditions associated with the handover command message.

[0034] Corresponding embodiments of a network node for acting as a source MN for a UE are also disclosed. In one embodiment, a network node for acting as a source MN for a UE is adapted to transmit a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The network node is further adapted to receive, from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. The network node is further adapted to generate and transmit, to the UE, a RRC reconfiguration message that comprises the CHO configurations.

[0035] In one embodiment, a network node for acting as a source MN for a UE comprises processing circuitry configured to cause the network node to transmit a handover requestmessage to a candidate target MN, the handover request message indicating that the handover request is for a CHO of the UE to a candidate target PCell operated by the candidate target MN. The processing circuitry is further configured to cause the network node to receive, from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. The processing circuitry is further configured to cause the network node to generate and transmit, to the UE, a RRC reconfiguration message that comprises the CHO configurations.

[0036] Embodiments of a method performed by a network node acting as a candidate target MN for a UE are also disclosed. In one embodiment, the method performed by a network node acting as a candidate target MN for a UE comprises transmitting, to a source MN for the UE, a message to request release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

[0037] In one embodiment, the method further comprises receiving, from a candidate target SN to which the candidate target PSCell of a CHO configuration belongs, a request to release or modify the CHO configuration that includes the candidate target PSCell.

[0038] In one embodiment, the method further comprises receiving, from the source MN, a request for a new or updated CHO configuration for the same candidate target PCell. In one embodiment, the method further comprises generating the new or modified CHO configuration and sending the new or modified CHO configuration to the source MN. In one embodiment, the method further comprises generating a configuration for execution conditions associated with the new or modified CHO configuration, wherein sending the new or modified CHO configuration to the source MN comprises sending the new or modified CHO configuration and the configuration for the associated execution conditions to the source MN.

[0039] Corresponding embodiments of a network node for acting as a candidate target MN for a UE are also disclosed. In one embodiment, a network node for acting as a candidate target MN for a UE is adapted to transmit, to a source MN for the UE, a message to request release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

[0040] In one embodiment, a network node for acting as a candidate target MN for a UE comprises processing circuitry configured to cause the network node to transmit, to a source MNfor the UE, a message to request release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

[0041] In one embodiment, a method performed by a network node acting as a source MN for a UE comprises receiving, from a candidate target MN, a message to request a release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell. The method further comprises transmitting a request for a new or updated CHO configuration for the candidate target PCell, receiving, from the candidate target MN, the new or modified CHO configuration, and generating and transmitting, to the UE, a message that includes the new or modified CHO configuration.

[0042] In one embodiment, the method further comprises receiving, from the candidate target MN, a configuration for one or more execution conditions associated with the new or modified CHO configuration. In one embodiment, the message transmitted to the UE further comprises the one or more execution conditions.

[0043] In one embodiment, a network node for acting as a source MN for a UE is adapted to receive, from a candidate target MN, a message to request a release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell. The network node is further adapted to transmit a request for a new or updated CHO configuration for the candidate target PCell, receive, from the candidate target MN, the new or modified CHO configuration, and generate and transmit, to the UE, a message that includes the new or modified CHO configuration.

[0044] In one embodiment, a network node for acting as a source MN for a UE comprises processing circuitry configured to cause the network node to receive, from a candidate target MN, a message to request a release or modification of a CHO configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell. The processing circuitry is further configured to cause the network node to transmit a request for a new or updated CHO configuration for the candidate target PCell, receive, from the candidate target MN, the new or modified CHO configuration, and generate and transmit, to the UE, a message that includes the new or modified CHO configuration.Brief Description of the Drawings

[0045] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0046] Figure 1 shows the signaling flow for a conditional handover in 3GPP New Radio (NR);

[0047] Figure 2 is a flow chart that illustrates a method performed by a first network node acting as a candidate target Master Node (MN) for a User Equipment (UE), in accordance with some embodiments of the present disclosure;

[0048] Figure 3 is a flow chart that illustrates a method performed by a network node acting as a source MN for a UE, in accordance with some embodiments of the present disclosure;

[0049] Figure 4 is a flow chart that illustrates a method for a network node acting as a candidate target MN for a UE that is configured with multiple CHO configurations for a candidate target Primary Cell (PCell) belonging to the candidate target MN, including at least one Conditional Handover (CHO) configuration that also includes a candidate target Primary Secondary Cell Group (SCG) Cell (PSCell) (and associated execution conditions), to enable release or modification of a CHO configuration in accordance with some embodiments of the present disclosure;

[0050] Figure 5 is a flow chart that illustrates a method for a network node acting as a source MN for a UE, to request release or modification of a CHO configuration in accordance with some embodiments of the present disclosure;

[0051] Figure 6 shows an example of a communication system in accordance with some embodiments;

[0052] Figure 7 shows a UE in accordance with some embodiments;

[0053] Figure 8 shows a network node in accordance with some embodiments;

[0054] Figure 9 is a block diagram of a host, which may be an embodiment of the host of Figure 6, in accordance with various aspects described herein;

[0055] Figure 10 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized; and

[0056] Figure 11 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments.Detailed Description

[0057] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0058] There currently exist certain challenge(s). When the target Master Node (MN) (e.g., target Radio Access Network (RAN) node such as, e.g., a target gNodeB (gNB)) provides multiple Conditional Handover (CHO) configurations with candidate Secondary Cell Groups (SCGs) to the source MN (e.g., source RAN node such as, e.g., a source gNB), multiple Handover Command messages for each candidate Primary SCG Cell (PSCell) / SCG with parameters for associated Conditional PSCell Addition (CPA) / Conditional PSCell Change (CPC) execution conditions as well as one configuration for CHO only (i.e. without any associated CPA / CPC execution conditions) should be sent within the HANDOVER REQUEST ACKNOWLEDGE message.

[0059] By including additional containers for HandoverCommand messages in the XnAP Handover Request Acknowledge message, where the new containers are for candidate PSCells and the existing container for a HandoverCommand message in the same message needs to be included without a candidate PSCell, it is not possible to provide configurations for only CHO configurations with associated CPA / CPC execution. This prevents the candidate target MN from providing configurations that all are associated to CPA / CPC conditions, which would be useful in some scenarios, e.g. where the handover (HO) is only to be performed together with a PSCell addition or change.

[0060] It does also not allow the candidate target MN to provide an additional or an updated CHO target configurations (i.e. RRCReconfiguration / Handover Command message) with candidate SCG (i.e. CHO with CPA / CPC configuration) to the source MN.

[0061] Another issue is that, in case the target MN determines a need to change one of the CHO configurations for a PCell, e.g. to change from one candidate PSCell to another candidate PSCell, or to add a new CHO configuration and / or release one of the CHO configurations, it is not possible for the target MN to indicate this to the source MN. The only available means is to use the XnAP CHO CANCEL message to trigger a release of the CHO configuration for the PCell. It is thus not possible to release any of the multiple CHO configurations (including, e.g.,the CHO only configuration for the candidate target PCell) or to trigger a modification of any of the CHO configurations or an addition of another CHO configuration for the same PCell.

[0062] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Systems and methods are disclosed herein for a network node to send multiple CHO configurations, i.e., HandoverCommand messages and corresponding execution conditions, for the same Primary Cell (PCell) in the same message from the target MN to the source MN. This includes systems and methods that then allow that some, or all, of the HandoverCommand (RRCReconfiguration) messages for the same PCell include execution conditions for a candidate PSCell that is included in or associated to the HandoverCommand (RRCReconfiguration) message.

[0063] Systems and methods are also disclosed herein for the target MN to trigger the source MN to configure a new CHO configuration for a PCell for which there is already a CHO configuration, or to send a request for modification of a CHO configuration (e.g., to change candidate PSCell).

[0064] Systems and methods are disclosed herein for allowing multiple CHO configurations within one single message (e.g., within a single RRC container) to be transferred from the target MN to the source MN when they exist for the selected PCell.

[0065] Certain embodiments may provide one or more of the following technical advantage(s). One example advantage is that embodiments of the present disclosure may simplify the structure of RRC transparent container within HANDOVER REQUEST ACKNOWLEDGE message for CHO with multiple candidate SCGs.

[0066] A first set of embodiments includes methods for a first network node acting as a (candidate) target Master Node (MN) for a User Equipment (UE). In this regard, Figure 2 is a flow chart that illustrates a method performed by a first network node acting as a candidate target MN for a UE, in accordance with some embodiments of the present disclosure. Note that, in Figure 2, optional steps are represented by dashed lines / boxes. Further, while the actions performed by the first network node are referred to in the description of Figure 2 as “steps” and are shown in Figure 2 in a particular order, these steps may be performed in any desired order and some of these steps may be performed in parallel. The steps of the process performed by the first network node acting as the candidate target MN as shown in Figure 2 are as follows: - Step 200: The first network node (acting as the candidate target MN for the UE) receives a HANDOVER REQUEST message from a source MN, indicating that the request is for a conditional handover. In other words, the candidate target MN for the UE receives aHANDOVER REQUEST message from the source MN for a conditional handover of the UE to a candidate target PCell operated by the candidate target MN. o In one example, the message includes an indication that the request is for a conditional handover with candidate SCG(s) / PSCell(s) or that the target MN can provide conditional handover configurations with candidate SCG(s) / PSCell(s). - Step 202: The first network node (acting as the candidate target MN for the UE) transmits an S-NODE ADDITION REQUEST message to the candidate target SN(s) for one or more candidate target PSCell(s). - Step 204: The first network node (acting as the candidate target MN for the UE) receives an S-NODE ADDITION REQUEST ACKNOWLEDGE message from the candidate target SN(s) including one or more RRCReconfiguration message(s). o The RRCReconfiguration message(s) may correspond to one or more target SCG configurations for CHO with candidate SCG(s) configurations, i.e. that the candidate target SN provides multiple RRCReconfiguration messages for configuration of multiple candidate SCGs / PSCells from the same candidate target SN. Each RRCReconfiguration message can then be associated to a specific CHO with candidate SCG configuration. - Step 206: The first network node (acting as the candidate target MN for the UE) determines to generate the CHO configurations, i.e., one or more Handover Command messages, and include those and possibly also the associated CPA / CPC execution conditions within one container (e.g., within a single RRC container). In other words, the candidate target MN for the UE generates CHO configurations for the one or more candidate target SNs based on the received secondary node additional request acknowledge message(s), wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs. o In one embodiment, the XnAP HANDOVER REQUEST ACKNOWLEDGE message includes a single RRC container with a single HandoverCommand message, which includes multiple CHO configurations, o In one embodiment, the XnAP HANDOVER REQUEST ACKNOWLEDGE message includes a single RRC container with multiple HandoverCommand messages, one for each CHO configuration, o In one embodiment, the RRC container includes both the HandoverCommand message(s) and the associated CPA / CPC execution conditions.o In one embodiment, the RRC container only includes the HandoverCommand message(s). - Step 208: The first network node (acting as the candidate target MN for the UE) transmits a HANDOVER REQUEST ACKNOWLEDGE message to the source MN. The HANDOVER REQUEST ACKNOWLEDGE message includes the generated CHO configurations from step 206. In other words, the HANDOVER REQUEST ACKNOWLEDGE message contains the generated RRC message (e.g., the single RRC container including the one or more Handover Command messages and possibly also the associated CPA / CPC execution conditions), e.g., within the Target NG-RAN node to the Source NG-RAN node Transparent Container Information Element (IE) or in a new IE for container. As discussed above, the HANDOVER REQUEST ACKNOWLEDGE message includes, for the same candidate target PCell operated by the candidate target MN, multiple CHO configurations, where these multiple CHO configurations include, for each candidate target SN, one or more CHO configurations for one or more SCGs or PSCells operated by the candidate target SN, respectively.

[0067] One set of embodiments include methods for a network node acting as a source MN for a UE. In this regard, Figure 3 is a flow chart that illustrates a method performed by a network node acting as a source MN for a UE, in accordance with some embodiments of the present disclosure. Note that, in Figure 3, optional steps are represented by dashed lines / boxes. Further, while the actions performed by the network node are referred to in the description of Figure 3 as “steps” and are shown in Figure 3 in a particular order, these steps may be performed in any desired order and some of these steps may be performed in parallel. The steps of the process performed by the network node acting as the source MN shown in Figure 2 are as follows: - Step 300: The network node (acting as the source MN for the UE) transmits a HANDOVER REQUEST message to a candidate target MN, indicating that the request is for a conditional handover. In other words, the source MN for the UE sends a HANDOVER REQUEST message to the candidate target MN for a conditional handover of the UE to a candidate target PCell operated by the candidate target MN. o In one example, the message includes an indication that the request is for a conditional handover with candidate SCG(s) / PSCell(s) or that the target MN can provide conditional handover configurations with candidate SCG(s) / PSCell(s). - Step 302: The network node (acting as the source MN for the UE) receives a HANDOVER REQUEST ACKNOWLEDGE message from the candidate target MN, containing multiple CHO configurations and the associated CPA / CPC execution conditions, e.g., within theTarget NG-RAN node to the Source NG-RAN node Transparent Container IE or a new IE for container. In other words, the HANDOVER REQUEST ACKNOWLEDGE message includes, for the same candidate target PCell operated by the candidate target MN, multiple CHO configurations, where these multiple CHO configurations correspond to respective CHO configurations for SCGs or PSCells operated by one or more candidate target SNs, i.e., there is one CHO configuration for each SCG or PSCell for each candidate target SN. o In one embodiment, the HANDOVER REQUEST ACKNOWLEDGE message includes a single RRC container with a single HandoverCommand message, which includes multiple CHO configurations. o In one embodiment, the XnAP HANDOVER REQUEST ACKNOWLEDGE message includes a single RRC container with multiple HandoverCommand messages, one for each CHO configuration. o In one embodiment, the RRC container includes both the HandoverCommand message(s) and the associated CPA / CPC execution conditions. o In one embodiment, the RRC container only includes the HandoverCommand message(s). - Step 304: The network node (acting as the source MN for the UE) generates and transmits to the UE an RRCReconfiguration message that includes the one or more CHO configurations for the same PCell received from the candidate target MN. o In one embodiment, the source MN generates execution conditions for both the candidate target PCell (i.e., for CHO) and for the associated candidate target PSCell (i.e., for CPA / CPC), if any, and includes these in the RRCReconfiguration message that is sent to the UE. The execution conditions for CPA / CPC may be based on the corresponding execution condition information (for the CHO with candidate SCG / PSCell configuration) that it received from the candidate target MN.

[0068] When the UE has been configured with multiple CHO configurations for the same candidate target PCell, e.g. one or more CHO configurations with different associated candidate PSCell(s), thus with associated CPA / CPC execution conditions, and possibly one CHO configuration without any associated candidate PSCell (which could be with or without an SCG configuration), there may be a need for the network to update the CHO configurations for the candidate target PCell. For example, the candidate target MN (handling the candidate target PCell) may need to change the candidate PSCells for a CHO configuration, such as replacing a CHO configuration that includes a candidate target PSCell A with a CHO configuration that includes another candidate target PSCell B. This can, e.g., be triggered by an indication from thecandidate target SN that handles PSCell A that it is no longer a suitable candidate PSCell. The candidate target MN may then decide to configure another candidate target PSCell B with a CHO configuration for the candidate target PCell. This could either be triggered by the candidate target MN itself or it could be based on an indication from the candidate target SN.

[0069] One set of embodiments include methods for a network node acting as a candidate target MN for a UE that is configured with multiple CHO configurations for a candidate target PCell belonging to the candidate target MN, including at least one CHO configuration that also includes a candidate target PSCell (and associated CPA / CPC execution conditions). In this regard, Figure 4 is a flow chart that illustrates a method for a network node acting as a candidate target MN for a UE that is configured with multiple CHO configurations for a candidate target PCell belonging to the candidate target MN, including at least one CHO configuration that also includes a candidate target PSCell (and associated CPA / CPC execution conditions), in accordance with some embodiments of the present disclosure. Note that, in Figure 4, optional steps are represented by dashed lines / boxes. Further, while the actions performed by the network node are referred to in the description of Figure 4 as “steps” and are shown in Figure 4 in a particular order, these steps may be performed in any desired order and some of these steps may be performed in parallel. The steps of the process performed by the network node acting as the candidate target MN as shown in Figure 4 are as follows: - Step 400 (optional): The network node (acting as a candidate target MN) receives an indication from a candidate target SN, to which the candidate target PSCell of a CHO configuration belongs, to release or modify the CHO configuration that includes that candidate target PSCell. - Step 402: The network node (acting as a candidate target MN) transmits a message to the source MN (i.e. the current serving MN) for the UE, to request a release or modification of a CHO configuration for a candidate target PCell with multiple CHO configurations (e.g. where one or more of the CHO configurations include candidate SCG(s) / PSCell(s)), i.e. for a subset of the CHO configurations for the same candidate target PCell, and / or to request an addition of at least an CHO configuration for the same PCell. o In one option, the message includes information about the CHO configurations that are to be released, modified, and / or added. ^ In one example, the message includes the RRCReconfiguration (HandoverCommand) message and / or the configuration for execution conditions for CHO configurations that are indicated to be added or modified.^ In one example, the message includes an indication about which existing CHO configurations that are to be released or modified. The indication may consist of the identity of the candidate target PCell and of the of the candidate target PSCell (in case the CHO configuration to be released or modified includes both) or it may include another identity of the CHO configuration, where each CHO configuration (for the UE) from the same candidate target MN may be given a unique identity or where each CHO configuration (for the UE) for the same candidate target PCell is given a unique identity. In one alternative, for the case where the indication consist of the identity of the candidate target cells for the CHO configuration (PCell and PSCell) and the request for release or modification concerns the CHO configuration for the PCell that does not include any candidate PSCell (i.e. the “CHO only” configuration), the indication consists of a setting or value that corresponds to “no candidate SCG / PSCell”, i.e. that it is a “CHO only” configuration. o In one example, the message with the request for modification, release, or addition of one or more CHO configurations is a new XnAP message from the candidate target MN to the source MN, e.g. a CONDITIONAL HANDOVER MODIFICATION REQUIRED message or a CONDITIONAL HANDOVER MODIFICATION REQUEST message. - Step 404 (optional): The network node (acting as a candidate target MN) afterwards receives, from the source MN, a request for a new or updated CHO configuration for the same candidate target PCell. In one example, the request is received in a new XnAP message, which is sent from the source MN to the candidate target MN, such as a CONDITIONAL HANDOVER MODIFICATION REQUEST message. In another example, the request is received in an XnAP HANDOVER REQUEST message. o In some options, in case the new or (to be) modified CHO configuration should include an SCG configuration or a candidate SCG / PSCell, the candidate target MN then sends a request (e.g., S-NODE MODIFICATION REQUEST) for the corresponding new or modified SCG configuration from the corresponding candidate target SN. - Step 406 (optional): The network node (acting as a candidate target MN) then generates the new or modified CHO configuration and, if it includes a candidate target SCG / PSCell, optionally also the configuration for the associated CPA / CPC conditions, and sends theseto the source MN. In one example, the new or modified CHO configuration is sent in a new XnAP message, e.g. a CONDITIONAL HANDOVER MODIFICATION REQUEST ACKNOWLEDGE message. In another example, it is sent in the XnAP HANDOVER REQUEST ACKNOWLEDGE message.

[0070] One set of embodiments include methods for a network node acting as a source MN for a UE. In this regard, Figure 5 is a flow chart that illustrates a method for a network node acting as a source MN for a UE, in accordance with some embodiments of the present disclosure. Note that, in Figure 5, optional steps are represented by dashed lines / boxes. Further, while the actions performed by the network node are referred to in the description of Figure 5 as “steps” and are shown in Figure 5 in a particular order, these steps may be performed in any desired order and some of these steps may be performed in parallel. The steps of the process performed by the network node acting as the source MN as shown in Figure 5 are as follows: - Step 500: The network node (acting as a source MN) receives a message from the candidate target MN, to request a release or modification of a CHO configuration for a candidate target PCell with multiple CHO configurations (e.g. where one or more of the CHO configurations include candidate SCG(s) / PSCell(s)), i.e. for a subset of the CHO configurations for the same candidate target PCell, and / or to request an addition of at least an CHO configuration for the same PCell. o In one option, the message includes information about the CHO configurations that are to be released, modified, and / or added. ^ In one example, the message includes the RRCReconfiguration (HandoverCommand) message and / or the configuration for execution conditions for CHO configurations that are indicated to be added or modified. ^ In one example, the message includes an indication about which existing CHO configurations that are to be released or modified. The indication may consist of the identity of the candidate target PCell and of the of the candidate target PSCell (in case the CHO configuration to be released or modified includes both) or it may include another identity of the CHO configuration, where each CHO configuration (for the UE) from the same candidate target MN may be given a unique identity or where each CHO configuration (for the UE) for the same candidate target PCell is given a unique identity.o In one example, the message with the request for modification, release, or addition of one or more CHO configurations is a new XnAP message from the candidate target MN to the source MN, e.g. a CONDITIONAL HANDOVER MODIFICATION REQUIRED message. - Step 502: The network node (acting as a source MN) transmits a request for a new or updated CHO configuration for the same candidate target PCell. In one example, the request is sent in a new XnAP message, such as a CONDITIONAL HANDOVER MODIFICATION REQUEST message. In another example, the request is sent in an XnAP HANDOVER REQUEST message. - Step 504: The network node (acting as a source MN) receives from the candidate target MN the new or modified CHO configuration and, if it includes a candidate target SCG / PSCell, optionally also the configuration for the associated CPA / CPC conditions. In one example, the new or modified CHO configuration is received in a new XnAP message, e.g. a CONDITIONAL HANDOVER MODIFICATION REQUEST ACKNOWLEDGE message. In another example, it is received in the XnAP HANDOVER REQUEST ACKNOWLEDGE message. - Step 506: The network node (acting as a source MN) generates and transmits to the UE a message, e.g. an RRCReconfiguration message, which includes the new or modified CHO configuration and, if it includes a candidate target SCG / PSCell, optionally also the configuration for the associated CPA / CPC conditions. The message may also include explicit indications about CHO configurations that are to be released.

[0071] In one alternative, the source MN receives, from the candidate target MN, a message with a request to release or modify a CHO configuration for a candidate target PCell with multiple CHO configurations (e.g. where one or more of the CHO configurations include candidate SCG(s) / PSCell(s)), i.e. for a subset of the CHO configurations for the same candidate target PCell, and / or a request to add a CHO configuration for the same PCell, and the message also includes the target configuration and / or execution condition configuration, for any new (added) and / or modified CHO configuration. In one example, the message is a new XnAP message, e.g. a CONDITIONAL HANDOVER MODIFICATION REQUEST message that is sent from the candidate target MN to the source (serving) MN. After receiving the CONDITIONAL HANDOVER MODIFICATION REQUEST message, the source MN then generates and transmits a message to the UE, e.g. an RRCReconfiguration message, which includes the new or modified CHO configuration and, if it includes a candidate target SCG / PSCell, optionally also the configuration for the associated CPA / CPC conditions. In casethe request includes indications about CHO configurations to release, the source MN may also include indications about CHO configurations that are to be released in the message that is sent to the UE. In one alternative, the source MN sends a message back to the candidate target MN to confirm the modification of the CHO configurations, e.g. a new CONDITIONAL HANDOVER MODIFICATION REQUEST ACKNOWLEDGE message that is sent from the source MN to the candidate target MN.

[0072] In one alternative the candidate target MN indicates to the source MN, via the XnAP CONDITIONAL HANDOVER CANCEL message that it requests a modification of one or more CHO configurations for a candidate target PCell and / or that it wants to add one or more new CHO configurations for a candidate target PCell. This can be combined with that the CONDITIONAL HANDOVER CANCEL message request release of one or more CHO configurations for the candidate target PCell.

[0073] In one example, a cause value (e.g., a new cause value) is included in the CONDITIONAL HANDOVER CANCEL message to indicate that the candidate target MN requests a modification and / or addition of one or more CHO configurations for one or more candidate target PCell(s).

[0074] The source MN may then send a message to the candidate target MN to request new (or updated) CHO configurations for the one or more candidate target PCell(s), e.g. by transmission of the XnAP HANDOVER REQUEST message. The candidate target MN then responds to the source MN with a message that includes the new (or updated) CHO configurations for the one or more candidate target PCell(s), e.g. by transmission of the XnAP HANDOVER REQUEST ACKNOWLEDGE message. The source MN then generates and transmits to the UE a message, e.g. an RRCReconfiguration message, which includes the new or modified CHO configuration and, if it includes a candidate target SCG / PSCell, optionally also the configuration for the associated CPA / CPC conditions. The message may also include explicit indications about the CHO configurations that are to be released for the candidate target PCell.

[0075] In one option, the CONDITIONAL HANDOVER CANCEL message that is sent from the candidate target MN to the source MN, also includes indication about CHO configurations to modify and / or to add. In one example it then also includes the corresponding target configuration and / or execution condition configuration, for any new (added) and / or modified CHO configuration for the one or more candidate target PCell(s). In that case, the source MN may generate and transmit the message to the UE that includes the new and / or modified CHO configuration(s), as well as the indications about CHO configurations that are tobe released, without first requesting the candidate target MN for the added / modified CHO configurations.

[0076] Below an example implementation in 3GPP TS 38.331 v 17.5.0 is shown (with additions included using underlined text). In the example, the inter-node HandoverCommand message is updated to include an optional configuration for execution conditions (for associated CPA / CPC conditions) for the first handoverCommandMessage (i.e., the already existing one in the message), and an optional list of additional handoverCommandMessage, each with an optional configuration for execution conditions (for associated CPA / CPC conditions). – HandoverCommand This message is used to transfer the handover command as generated by the target gNB. Direction: target gNB to source gNB / source RAN. HandoverCommand message -- ASN1START -- TAG-HANDOVER-COMMAND-START HandoverCommand ::= SEQUENCE { criticalExtensions CHOICE { c1 CHOICE{ handoverCommand HandoverCommand-IEs, spare3 NULL, spare2 NULL, spare1 NULL }, criticalExtensionsFuture SEQUENCE {} } HandoverCommand-IEs ::= SEQUENCE { handoverCommandMessage OCTET STRING (CONTAINING RRCReconfiguration), nonCriticalExtension HandoverCommand-v18xx-IEs OPTIONAL } HandoverCommand-v18xx-IEs ::= SEQUENCE { executionConditionFirstHOCommand-CPAC ExecutionConditionConfig-CPAC OPTIONAL, additionalCandidatesCHO-CPAC SEQUENCE (SIZE (1.. maxCHOwithCPAC-1)) OF AdditionalCandidateCHO-CPAC OPTIONAL, nonCriticalExtension SEQUENCE {} OPTIONAL } AdditionalCandidateCHO-CPAC ::= SEQUENCE { executionCondition-CPAC ExecutionConditionConfig-CPAC OPTIONAL, handoverCommandMessage-r18 OCTET STRING (CONTAINING RRCReconfiguration) } -- TAG-HANDOVER-COMMAND-STOP -- ASN1STOP HandoverCommand field descriptions handoverCommandMessage Contains the RRCReconfiguration message used to perform handover within NR or handover to NR, as generated (entirely) by the target gNB.

[0077] Below some example implementations in 3GPP TS 38.423 v 17.5.0 are shown:HANDOVER REQUEST ACKNOWLEDGE This message is sent by the target NG-RAN node to inform the source NG-RAN node about the prepared resources at the target. Direction: target NG-RAN node → source NG-RAN node.IE / Group Name Presenc Range IE type Semantics description Criticalit Assigne e and y d referenc Criticalit e y Message Type M 9.2.3.1 YES reject Source NG-RAN M NG-RAN Allocated at the source YES ignore node UE XnAP ID node UE NG-RAN node XnAP ID 9.2.3.16 Target NG-RAN M NG-RAN Allocated at the target YES ignore node UE XnAP ID node UE NG-RAN node XnAP ID 9.2.3.16 PDU Session M 9.2.1.2 YES ignore Resources Admitted List PDU Session O 9.2.1.3 YES ignore Resources Not Admitted List Target NG-RAN M OCTET Either includes the YES ignore node To Source STRING HandoverCommand NG-RAN node message as defined in Transparent subclause 10.2.2 of TS Container 36.331

[0014] , if the target NG-RAN node is an ng- eNB, or the HandoverCommand message as defined in subclause 11.2.2 of TS 38.331

[0010] , if the target NG-RAN node is a gNB. This IE shall be ignored if the MultipleCHO Configurations Container is included in the Conditional Handover Information Acknowledge IE. UE Context Kept O 9.2.3.68 YES ignore Indicator Criticality O 9.2.3.3 YES ignore Diagnostics DRBs transferred O DRB List In case of DC, indicates YES ignore to MN 9.2.1.29 that SN Status is needed for the listed DRBs from the S-NG- RAN node. DAPS Response O 9.2.1.34 YES reject Information Conditional O YES reject Handover Information Acknowledge >Requested M Target Target cell indicated in – Target Cell ID Cell the correspondingGlobal HANDOVER ID REQUEST message 9.2.3.25 >Maximum O 9.2.3.10 – Number of CHO 1 Preparations >Multiple 0..1 YES FFS Target S-NG- RAN Node List >>Multiple 1.. – Target S-NG- <maxnoofTargetS RAN Node Ns> Item >>>Target S- M Global – NG-RAN NG-RAN node ID Node ID 9.2.2.3 >>>PDU M 9.2.1.2 – Session Resources Admitted List >>>MultipleC M OCTET Includes the – HO STRING MultipleCHOConfigurati Configuration ons message as s Container defined in subclause 11.x.x of TS 38.331

[0010] , if the target NG- RAN node is a gNB. >>>Execution O Includes the – Condition CPACExecutionConditi Information ons message as defined in subclause 11.x.x of TS 38.331

[0010] , if the target NG- RAN node is a gNB. MBS Session O 9.2.1.38 YES ignore Information Response List Range bound Explanation maxnoofTargetSNs Maximum number of the target S-NG-RAN nodes. Value is FFS. maxnoofPSCellCandidate Maximum number of the candidate PSCells. Value is FFS.

[0078] Figure 6 shows an example of a communication system 600 in accordance with some embodiments.

[0079] In the example, the communication system 600 includes a telecommunication network 602 that includes an access network 604, such as a Radio Access Network (RAN), and a core network 606, which includes one or more core network nodes 608. The access network 604 includes one or more access network nodes, such as network nodes 610A and 610B (one or more of which may be generally referred to as network nodes 610), or any other similar Third Generation Partnership Project (3GPP) access nodes or non-3GPP Access Points (APs). Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes includedisaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 602 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 602 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 602, including one or more network nodes 610 and / or core network nodes 608.

[0080] Examples of an ORAN network node include an Open Radio Unit (O-RU), an Open Distributed Unit (O-DU), an Open Central Unit (O-CU), including an O-CU Control Plane (O- CU-CP) or an O-CU User Plane (O-CU-UP), a RAN intelligent controller (near-real time or non- real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an A1, F1, W1, E1, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 610 facilitate direct or indirect connection of User Equipment (UE), such as by connecting UEs 612A, 612B, 612C, and 612D (one or more of which may be generally referred to as UEs 612) to the core network 606 over one or more wireless connections.

[0081] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 600 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 600 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0082] The UEs 612 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 610 and other communication devices. Similarly, the network nodes 610 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 612 and / or with other network nodes or equipment in the telecommunication network 602 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 602.

[0083] In the depicted example, the core network 606 connects the network nodes 610 to one or more hosts, such as host 616. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 606 includes one more core network nodes (e.g., core network node 608) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 608. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-Concealing Function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0084] The host 616 may be under the ownership or control of a service provider other than an operator or provider of the access network 604 and / or the telecommunication network 602, and may be operated by the service provider or on behalf of the service provider. The host 616 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0085] As a whole, the communication system 600 of Figure 6 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 600 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or othersuitable Second, Third, Fourth, or Fifth Generation (2G, 3G, 4G, or 5G) standards, or any applicable future generation standard (e.g., Sixth Generation (6G)); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox.

[0086] In some examples, the telecommunication network 602 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunication network 602 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 602. For example, the telecommunication network 602 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing enhanced Mobile Broadband (eMBB) services to other UEs, and / or massive Machine Type Communication (mMTC) / massive Internet of Things (IoT) services to yet further UEs.

[0087] In some examples, the UEs 612 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 604 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 604. Additionally, a UE may be configured for operating in single- or multi-Radio Access Technology (RAT) or multi-standard mode. For example, a UE may operate with any one or combination of WiFi, New Radio (NR), and LTE, i.e. being configured for Multi-Radio Dual Connectivity (MR-DC), such as Evolved UMTS Terrestrial RAN (E-UTRAN) NR - Dual Connectivity (EN-DC).

[0088] In the example, a hub 614 communicates with the access network 604 to facilitate indirect communication between one or more UEs (e.g., UE 612C and / or 612D) and network nodes (e.g., network node 610B). In some examples, the hub 614 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 614 may be a broadband router enabling access to the core network 606 for the UEs. As another example, the hub 614 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 610, or by executable code, script, process, or other instructions in the hub 614. As another example, the hub 614 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 614 may be a content source. For example,for a UE that is a Virtual Reality (VR) headset, display, loudspeaker or other media delivery device, the hub 614 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 614 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 614 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy IoT devices.

[0089] The hub 614 may have a constant / persistent or intermittent connection to the network node 610B. The hub 614 may also allow for a different communication scheme and / or schedule between the hub 614 and UEs (e.g., UE 612C and / or 612D), and between the hub 614 and the core network 606. In other examples, the hub 614 is connected to the core network 606 and / or one or more UEs via a wired connection. Moreover, the hub 614 may be configured to connect to a Machine-to-Machine (M2M) service provider over the access network 604 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 610 while still connected via the hub 614 via a wired or wireless connection. In some embodiments, the hub 614 may be a dedicated hub – that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 610B. In other embodiments, the hub 614 may be a non-dedicated hub – that is, a device which is capable of operating to route communications between the UEs and the network node 610B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0090] Figure 7 shows a UE 700 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged, and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, Voice over Internet Protocol (VoIP) phone, wireless local loop phone, desktop computer, Personal Digital Assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), smart device, wireless Customer Premise Equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a Narrowband Internet of Things (NB-IoT) UE, a Machine Type Communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0091] A UE may support Device-to-Device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), Vehicle-to-Vehicle (V2V), Vehicle-to-Infrastructure (V2I), or Vehicle-to-Everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0092] The UE 700 includes processing circuitry 702 that is operatively coupled via a bus 704 to an input / output interface 706, a power source 708, memory 710, a communication interface 712, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 7. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0093] The processing circuitry 702 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 710. The processing circuitry 702 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 702 may include multiple Central Processing Units (CPUs).

[0094] In the example, the input / output interface 706 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 700. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. Anoutput device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0095] In some embodiments, the power source 708 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 708 may further include power circuitry for delivering power from the power source 708 itself, and / or an external power source, to the various parts of the UE 700 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 708. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 708 to make the power suitable for the respective components of the UE 700 to which power is supplied.

[0096] The memory 710 may be or be configured to include memory such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 710 includes one or more application programs 714, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 716. The memory 710 may store, for use by the UE 700, any of a variety of various operating systems or combinations of operating systems.

[0097] The memory 710 may be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, High Density Digital Versatile Disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, Holographic Digital Data Storage (HDDS) optical disc drive, external mini Dual In-line Memory Module (DIMM), Synchronous Dynamic RAM (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a tamper resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a Universal SIM (USIM) and / or Internet Protocol Multimedia Services Identity Module (ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as a ‘SIM card.’ The memory 710 may allow the UE 700 to access instructions, application programs, and the like stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system, may be tangibly embodied as or in the memory 710, which may be or comprise a device-readable storage medium.

[0098] The processing circuitry 702 may be configured to communicate with an access network or other network using the communication interface 712. The communication interface 712 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 722. The communication interface 712 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 718 and / or a receiver 720 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 718 and receiver 720 may be coupled to one or more antennas (e.g., the antenna 722) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0099] In the illustrated embodiment, communication functions of the communication interface 712 may include cellular communication, WiFi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, NFC, location-based communication such as the use of the Global Positioning System (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband CDMA (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol / Internet Protocol (TCP / IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), Quick User Datagram Protocol Internet Connection (QUIC), Hypertext Transfer Protocol (HTTP), and so forth.

[0100] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 712, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0101] As another example, a UE comprises an actuator, a motor, or a switch related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfacesor rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0102] A UE, when in the form of an IoT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application, and healthcare. Non-limiting examples of such an IoT device are a device which is or which is embedded in: a connected refrigerator or freezer, a television, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or VR, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item- tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an IoT device comprises circuitry and / or software in dependence of the intended application of the IoT device in addition to other components as described in relation to the UE 700 shown in Figure 7.

[0103] As yet another specific example, in an IoT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship, an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0104] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator and handle communication of data for both the speed sensor and the actuators.

[0105] Figure 8 shows a network node 800 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment in a telecommunication network. Examples of network nodes include, but are not limited to, APs (e.g., radio APs), Base Stations (BSs) (e.g., radio BSs, Node Bs, evolved Node Bs (eNBs), NR Node Bs (gNBs)), and O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O- CU).

[0106] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node), and / or Remote Radio Units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such RRUs may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a Distributed Antenna System (DAS).

[0107] Other examples of network nodes include multiple Transmission Point (multi-TRP) 5G access nodes, Multi-Standard Radio (MSR) equipment such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or BS Controllers (BSCs), Base Transceiver Stations (BTSs), transmission points, transmission nodes, Multi-Cell / Multicast Coordination Entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0108] The network node 800 includes processing circuitry 802, memory 804, a communication interface 806, and a power source 808. The network node 800 may be composed of multiple physically separate components (e.g., a NodeB component and an RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 800 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair may in some instances be considered a single separate network node. In some embodiments, the network node 800 may be configured to support multiple RATs. In such embodiments, some components may be duplicated (e.g.,separate memory 804 for different RATs) and some components may be reused (e.g., a same antenna 810 may be shared by different RATs). The network node 800 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 800, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, Long Range Wide Area Network (LoRaWAN), Radio Frequency Identification (RFID), or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within the network node 800.

[0109] The processing circuitry 802 may comprise a combination of one or more of a microprocessor, controller, microcontroller, CPU, DSP, ASIC, FPGA, or any other suitable computing device, resource, or combination of hardware, software, and / or encoded logic operable to provide, either alone or in conjunction with other network node 800 components, such as the memory 804, to provide network node 800 functionality.

[0110] In some embodiments, the processing circuitry 802 includes a System on a Chip (SOC). In some embodiments, the processing circuitry 802 includes one or more of Radio Frequency (RF) transceiver circuitry 812 and baseband processing circuitry 814. In some embodiments, the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on the same chip or set of chips, boards, or units.

[0111] The memory 804 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD), or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable, and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 802. The memory 804 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 802 and utilized by the network node 800. The memory 804 may be used to store any calculations made by the processing circuitry 802 and / or any data received via the communication interface 806. In some embodiments, the processing circuitry 802 and the memory 804 are integrated.

[0112] The communication interface 806 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, thecommunication interface 806 comprises port(s) / terminal(s) 816 to send and receive data, for example to and from a network over a wired connection. The communication interface 806 also includes radio front-end circuitry 818 that may be coupled to, or in certain embodiments a part of, the antenna 810. The radio front-end circuitry 818 comprises filters 820 and amplifiers 822. The radio front-end circuitry 818 may be connected to the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may be configured to condition signals communicated between the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 818 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of the filters 820 and / or the amplifiers 822. The radio signal may then be transmitted via the antenna 810. Similarly, when receiving data, the antenna 810 may collect radio signals which are then converted into digital data by the radio front-end circuitry 818. The digital data may be passed to the processing circuitry 802. In other embodiments, the communication interface 806 may comprise different components and / or different combinations of components.

[0113] In certain alternative embodiments, the network node 800 does not include separate radio front-end circuitry 818; instead, the processing circuitry 802 includes radio front-end circuitry and is connected to the antenna 810. Similarly, in some embodiments, all or some of the RF transceiver circuitry 812 is part of the communication interface 806. In still other embodiments, the communication interface 806 includes the one or more ports or terminals 816, the radio front-end circuitry 818, and the RF transceiver circuitry 812 as part of a radio unit (not shown), and the communication interface 806 communicates with the baseband processing circuitry 814, which is part of a digital unit (not shown).

[0114] The antenna 810 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 810 may be coupled to the radio front-end circuitry 818 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 810 is separate from the network node 800 and connectable to the network node 800 through an interface or port.

[0115] The antenna 810, the communication interface 806, and / or the processing circuitry 802 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node 800. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 810, the communication interface 806, and / or the processing circuitry 802 may be configured to perform any transmitting operations described herein as being performedby the network node 800. Any information, data, and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0116] The power source 808 provides power to the various components of the network node 800 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 808 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 800 with power for performing the functionality described herein. For example, the network node 800 may be connectable to an external power source (e.g., the power grid or an electricity outlet) via input circuitry or an interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 808. As a further example, the power source 808 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0117] Embodiments of the network node 800 may include additional components beyond those shown in Figure 8 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 800 may include user interface equipment to allow input of information into the network node 800 and to allow output of information from the network node 800. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 800.

[0118] Figure 9 is a block diagram of a host 900, which may be an embodiment of the host 616 of Figure 6, in accordance with various aspects described herein. As used herein, the host 900 may be or comprise various combinations of hardware and / or software including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 900 may provide one or more services to one or more UEs.

[0119] The host 900 includes processing circuitry 902 that is operatively coupled via a bus 904 to an input / output interface 906, a network interface 908, a power source 910, and memory 912. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 7 and 8, such that the descriptions thereof are generally applicable to the corresponding components of the host 900.

[0120] The memory 912 may include one or more computer programs including one or more host application programs 914 and data 916, which may include user data, e.g. data generated bya UE for the host 900 or data generated by the host 900 for a UE. Embodiments of the host 900 may utilize only a subset or all of the components shown. The host application programs 914 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), Moving Picture Experts Group (MPEG), VP9) and audio codecs (e.g., Free Lossless Audio Codec (FLAC), Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, and heads-up display systems). The host application programs 914 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 900 may select and / or indicate a different host for Over-The-Top (OTT) services for a UE. The host application programs 914 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (DASH or MPEG-DASH), etc.

[0121] Figure 10 is a block diagram illustrating a virtualization environment 1000 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices, and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more Virtual Machines (VMs) implemented in one or more virtual environments 1000 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1000 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[0122] Applications 1002 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1000 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0123] Hardware 1004 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1006 (also referred to as hypervisors or VM Monitors (VMMs)), provide VMs 1008A and 1008B (one or more of which may be generally referred to as VMs 1008), and / or perform any of the functions, features, and / or benefits described in relation with some embodiments described herein. The virtualization layer 1006 may present a virtual operating platform that appears like networking hardware to the VMs 1008.

[0124] The VMs 1008 comprise virtual processing, virtual memory, virtual networking, or interface and virtual storage, and may be run by a corresponding virtualization layer 1006. Different embodiments of the instance of a virtual appliance 1002 may be implemented on one or more of the VMs 1008, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as Network Function Virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers and customer premise equipment.

[0125] In the context of NFV, a VM 1008 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1008, and that part of the hardware 1004 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs 1008, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1008 on top of the hardware 1004 and corresponds to the application 1002.

[0126] The hardware 1004 may be implemented in a standalone network node with generic or specific components. The hardware 1004 may implement some functions via virtualization. Alternatively, the hardware 1004 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1010, which, among others, oversees lifecycle management of the applications 1002. In some embodiments, the hardware 1004 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a RAN or a base station. Insome embodiments, some signaling can be provided with the use of a control system 1012 which may alternatively be used for communication between hardware nodes and radio units.

[0127] Figure 11 shows a communication diagram of a host 1102 communicating via a network node 1104 with a UE 1106 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as the UE 612A of Figure 6 and / or the UE 700 of Figure 7), the network node (such as the network node 610A of Figure 6 and / or the network node 800 of Figure 8), and the host (such as the host 616 of Figure 6 and / or the host 900 of Figure 9) discussed in the preceding paragraphs will now be described with reference to Figure 11.

[0128] Like the host 900, embodiments of the host 1102 include hardware, such as a communication interface, processing circuitry, and memory. The host 1102 also includes software, which is stored in or is accessible by the host 1102 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1106 connecting via an OTT connection 1150 extending between the UE 1106 and the host 1102. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1150.

[0129] The network node 1104 includes hardware enabling it to communicate with the host 1102 and the UE 1106. The connection 1160 may be direct or pass through a core network (like the core network 606 of Figure 6) and / or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[0130] The UE 1106 includes hardware and software, which is stored in or accessible by the UE 1106 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via the UE 1106 with the support of the host 1102. In the host 1102, an executing host application may communicate with the executing client application via the OTT connection 1150 terminating at the UE 1106 and the host 1102. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1150.

[0131] The OTT connection 1150 may extend via the connection 1160 between the host 1102 and the network node 1104 and via a wireless connection 1170 between the network node 1104and the UE 1106 to provide the connection between the host 1102 and the UE 1106. The connection 1160 and the wireless connection 1170, over which the OTT connection 1150 may be provided, have been drawn abstractly to illustrate the communication between the host 1102 and the UE 1106 via the network node 1104, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0132] As an example of transmitting data via the OTT connection 1150, in step 1108, the host 1102 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1106. In other embodiments, the user data is associated with a UE 1106 that shares data with the host 1102 without explicit human interaction. In step 1110, the host 1102 initiates a transmission carrying the user data towards the UE 1106. The host 1102 may initiate the transmission responsive to a request transmitted by the UE 1106. The request may be caused by human interaction with the UE 1106 or by operation of the client application executing on the UE 1106. The transmission may pass via the network node 1104 in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1112, the network node 1104 transmits to the UE 1106 the user data that was carried in the transmission that the host 1102 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1114, the UE 1106 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1106 associated with the host application executed by the host 1102.

[0133] In some examples, the UE 1106 executes a client application which provides user data to the host 1102. The user data may be provided in reaction or response to the data received from the host 1102. Accordingly, in step 1116, the UE 1106 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input / output interface of the UE 1106. Regardless of the specific manner in which the user data was provided, the UE 1106 initiates, in step 1118, transmission of the user data towards the host 1102 via the network node 1104. In step 1120, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1104 receives user data from the UE 1106 and initiates transmission of the received user data towards the host 1102. In step 1122, the host 1102 receives the user data carried in the transmission initiated by the UE 1106.

[0134] One or more of the various embodiments improve the performance of OTT services provided to the UE 1106 using the OTT connection 1150, in which the wireless connection 1170 forms the last segment.

[0135] In an example scenario, factory status information may be collected and analyzed by the host 1102. As another example, the host 1102 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1102 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1102 may store surveillance video uploaded by a UE. As another example, the host 1102 may store or control access to media content such as video, audio, VR, or AR which it can broadcast, multicast, or unicast to UEs. As other examples, the host 1102 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing, and / or transmitting data.

[0136] In some examples, 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 the OTT connection 1150 between the host 1102 and the UE 1106 in response to variations in the measurement results. The measurement procedure and / or the network functionality for reconfiguring the OTT connection 1150 may be implemented in software and hardware of the host 1102 and / or the UE 1106. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or by supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1150 may include message format, retransmission settings, preferred routing, etc.; the reconfiguring need not directly alter the operation of the network node 1104. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency, and the like by the host 1102. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1150 while monitoring propagation times, errors, etc.

[0137] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions, and methods disclosed herein.Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box or nested within multiple boxes, in practice computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0138] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hardwired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole and / or by end users and a wireless network generally.

[0139] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

[0140] Some example embodiments of the present disclosure are as follows:

[0141] Embodiment 1: A method performed by a network node acting as a candidate target Master Node, MN, for a User Equipment, UE, the method comprising any one or more of the following: receiving (200) a handover request message from a source MN, the handover request message indicating that the handover request is for a conditional handover, CHO; transmitting (202) a secondary node addition request message to one or more candidate target secondarynodes, SNs, for one or more primary cells, PCells; receiving (204), from the one or more candidate target SNs, a secondary node addition request acknowledge message; generating (206) CHO configurations for the one or more candidate target SNs; transmitting (208), to the source MN, a handover request acknowledge message comprising the CHO configurations in a single container (e.g., a single RRC container).

[0142] Embodiment 2: The method of embodiment 1, wherein the secondary node addition request acknowledge message comprises one or more Radio Resource Control, RRC, reconfiguration messages.

[0143] Embodiment 3: The method of embodiment 2, wherein the one or more RRC reconfiguration messages correspond to one or more target Secondary Cell Group, SCG, configurations for CHO with candidate SCG(s) configurations, i.e. the candidate target SN provides multiple RRC Reconfiguration messages for configuration of multiple candidate SCGs / PSCells from the same candidate target SN.

[0144] Embodiment 4: The method of embodiment 3, wherein each RRC reconfiguration message is associated to a specific CHO with candidate SCG configuration.

[0145] Embodiment 5: The method of any of embodiments 1 to 4, wherein the CHO configurations for the one or more candidate target SN comprise handover command messages, and the handover command messages are comprised in the single container.

[0146] Embodiment 6: The method of embodiment 5, wherein the single container further comprises CPA and / or CPC execution conditions associated with the handover command messages.

[0147] Embodiment 7: The method of any of embodiments 1 to 6, wherein the handover request acknowledge message comprises the single container with a single handover command message that comprises CHO configurations.

[0148] Embodiment 8: The method of any of embodiments 1 to 6, wherein the handover request acknowledge message comprises the single container with multiple handover command messages, one for each of the CHO configurations.

[0149] Embodiment 9: The method of any of embodiments 1 to 6, wherein the handover request acknowledge message comprises the single container, and the single container comprises both the handover command messages and the associated CPA / CPC execution conditions.

[0150] Embodiment 10: The method of any of embodiments 1 to 6, wherein the handover request acknowledge message comprises the single container comprising only the handover command messages.

[0151] Embodiment 11: A method performed by a network node acting as a source Master Node, MN, for a User Equipment, UE, the method comprising any one or more of the following: transmitting (300) a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a conditional handover, CHO; receiving (302), from the candidate target MN, a handover request acknowledge message comprising two or more CHO configurations (e.g., for a same PCell) in a single container (e.g., a single RRC container); generating and transmitting (304), to the UE, an RRC reconfiguration message that comprises the two or more CHO configurations.

[0152] Embodiment 12: The method of embodiment 11, wherein the CHO configurations comprise handover command messages, and the handover command messages are comprised in the single container.

[0153] Embodiment 13: The method of embodiment 12, wherein the single container further comprises CPA and / or CPC execution conditions associated with the handover command messages.

[0154] Embodiment 14: The method of embodiment 11, wherein the handover request acknowledge message comprises the single container with a single handover command message that comprises CHO configurations.

[0155] Embodiment 15: The method of embodiment 11, wherein the handover request acknowledge message comprises the single container with multiple handover command messages, one for each of the CHO configurations.

[0156] Embodiment 16: The method of embodiment 11, wherein the handover request acknowledge message comprises the single container, and the single container comprises both the handover command messages and the associated CPA / CPC execution conditions.

[0157] Embodiment 17: The method of any of embodiments 1 to 6, wherein the handover request acknowledge message comprises the single container comprising only the handover command messages.

[0158] Embodiment 18: A method performed by a network node acting as a candidate target Master Node, MN, for a User Equipment, UE, the method comprising any one or more of the following: transmitting (402), to a source MN for the UE, a message to request release or modification of a conditional handover, CHO, configuration for a candidate target primary cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

[0159] Embodiment 19: The method of embodiment 18, further comprising: receiving (400), from a candidate target secondary node, SN, to which the candidate target PSCell of a CHOconfiguration belongs, to release or modify the CHO configuration that includes the candidate target PSCell.

[0160] Embodiment 20: The method of embodiment 18 or 19, further comprising: receiving (404), from the source MN, a request for a new or updated CHO configuration for the same candidate target PCell.

[0161] Embodiment 21: The method of embodiment 20, further comprising generating (406) the new or modified CHO configuration and sending (406) the new or modified CHO configuration to the source MN.

[0162] Embodiment 22: The method of embodiment 21, further comprising generating (406) a configuration for CPA / CPC conditions associated with the new or modified CHO configuration, wherein sending (406) the new or modified CHO configuration to the source MN comprises sending (406) the new or modified CHO configuration and the configuration for the associated CPA / CPC conditions to the source MN.

[0163] Embodiment 23: A method performed by a network node acting as a source Master Node, MN, for a User Equipment, UE, the method comprising any one or more of the following: receiving (500), from a candidate target MN, a message to request a release or modification of a conditional handover, CHO, configuration for a candidate target PCell with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell; transmitting (502) a request for a new or updated CHO configuration for the candidate target PCell; receiving (504), from the candidate target MN, the new or modified CHO configuration; generating and transmitting (506), to the UE, a message that includes the new or modified CHO configuration.

[0164] Embodiment 24: The method of embodiment 23, further comprising receiving (504), from the candidate target MN, a configuration for one or more CPA / CPC conditions associated with the new or modified CHO configuration.

[0165] Embodiment 25: The method of embodiment 24, wherein the message transmitted to the UE further comprises the one or more CPA / CPC conditions.

[0166] Embodiment 26: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

[0167] Embodiment 27: A network node comprising: processing circuitry configured to perform any of the steps of any of embodiments 1 to 26; and power supply circuitry configured to supply power to the processing circuitry.

[0168] Embodiment 28: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provideuser data; and a network interface configured to initiate transmission of the user data to a network node in a cellular network for transmission to a user equipment (UE), the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of embodiments 1 to 26 to transmit the user data from the host to the UE.

[0169] Embodiment 29: The host of the previous embodiment, wherein: the processing circuitry of the host is configured to execute a host application that provides the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application to receive the transmission of user data from the host.

[0170] Embodiment 30: A method implemented in a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the network node performs any of the operations of any of embodiments 1 to 26 to transmit the user data from the host to the UE.

[0171] Embodiment 31: The method of the previous embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.

[0172] Embodiment 32: The method of any of the previous 2 embodiments, wherein the user data is provided at the host by executing a host application that interacts with a client application executing on the UE, the client application being associated with the host application.

[0173] Embodiment 33: A communication system configured to provide an over-the-top (OTT) service, the communication system comprising a host comprising: processing circuitry configured to provide user data for a user equipment (UE), the user data being associated with the over-the-top service; and a network interface configured to initiate transmission of the user data toward a cellular network node for transmission to the UE, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of embodiments 1 to 26 to transmit the user data from the host to the UE.

[0174] Embodiment 34: The communication system of the previous embodiment, further comprising: the network node; and / or the UE.

[0175] Embodiment 35: A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to initiate receipt of user data; and a network interface configured to receive the user data from a network node in a cellular network, the network node having a communication interface and processingcircuitry, the processing circuitry of the network node configured to perform any of the operations of any of embodiments 1 to 26 to receive the user data from a user equipment (UE) for the host.

[0176] Embodiment 36: The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application that receives the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

[0177] Embodiment 37: The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.

[0178] Embodiment 38: A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, initiating receipt of user data from the UE, the user data originating from a transmission which the network node has received from the UE, wherein the network node performs any of the steps of any of embodiments 1 to 26 to receive the user data from the UE for the host.

[0179] Embodiment 39: The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.

[0180] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims 1. A method performed by a network node acting as a candidate target Master Node, MN, for a User Equipment, UE, the method comprising: receiving (200) a handover request message from a source MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; transmitting (202) a secondary node addition request message to one or more candidate target secondary nodes, SNs, for one or more Primary Secondary Cell Group, SCG, Cells, PSCells; receiving (204) one or more secondary node addition request acknowledge messages from the one or more candidate target SNs; generating (206) CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs; and transmitting (208), to the source MN, a handover request acknowledge message comprising the CHO configurations.

2. The method of claim 1, wherein the handover request acknowledge message comprises a separate handover command message for each of the CHO configurations.

3. The method of claim 2, wherein the handover request acknowledge message further comprises, for each separate handover command message, execution conditions associated with the handover command message.

4. The method of claim 1, wherein the handover request acknowledge message comprises a single handover command message comprising the CHO configurations.

5. The method of claim 4, wherein the handover request acknowledge message further comprises execution conditions associated with the handover command message.

6. The method of any of claims 1 to 5, wherein each of the one or more secondary node addition request acknowledge messages comprises one or more Radio Resource Control, RRC, reconfiguration messages that correspond to one or more candidate target SCG or PSCellconfigurations for CHO for a respective one of the one or more candidate target SNs.

7. The method of claim 6, wherein the one or more RRC reconfiguration messages comprise multiple RRC reconfiguration messages for configuration of multiple candidate SCGs or PSCells from the same candidate target SN.

8. The method of claim 7, wherein each RRC reconfiguration message is associated to a specific CHO with candidate SCG configuration.

9. A network node for acting as a candidate target Master Node, MN, for a User Equipment, UE, the network node adapted to: receive (200) a handover request message from a source MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; transmit (202) a secondary node addition request message to one or more candidate target secondary nodes, SNs, for one or more Primary Secondary Cell Group, SCG, Cells, PSCells; receive (204) one or more secondary node addition request acknowledge messages from the one or more candidate target SNs; generate (206) CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs; transmit (208), to the source MN, a handover request acknowledge message comprising the CHO configurations.

10. The network node of claim 9, further adapted to perform the method of any of claims 2 to 8.

11. A network node for acting as a candidate target Master Node, MN, for a User Equipment, UE, the network node comprising processing circuitry configured to cause the network node to: receive (200) a handover request message from a source MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; transmit (202) a secondary node addition request message to one or more candidate targetsecondary nodes, SNs, for one or more Primary Secondary Cell Group, SCG, Cells, PSCells; receive (204) one or more secondary node addition request acknowledge messages from the one or more candidate target SNs; generate (206) CHO configurations for the one or more candidate target SNs based on the one or more secondary node addition request acknowledge messages, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target SCGs or PSCells for each of the one or more candidate target SNs; transmit (208), to the source MN, a handover request acknowledge message comprising the CHO configurations.

12. The network node of claim 11, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 2 to 8.

13. A method performed by a network node acting as a source Master Node, MN, for a User Equipment, UE, the method comprising: transmitting (300) a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; receiving (302), from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target secondary nodes, SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target Secondary Cell Groups, SCGs, or Primary SCG Cells, PSCells, for each of the one or more candidate target SNs ; generating and transmitting (304), to the UE, a Radio Resource Control, RRC, reconfiguration message that comprises the CHO configurations.

14. The method of claim 13, wherein the handover request acknowledge message comprises a separate handover command message for each of the CHO configurations.

15. The method of claim 14, wherein the handover request acknowledge message further comprises, for each separate handover command message, execution conditions associated with the handover command message.

16. The method of claim 13, wherein the handover request acknowledge message comprises asingle handover command message that comprises the CHO configurations.

17. The method of claim 16, wherein the handover request acknowledge message further comprises execution conditions associated with the handover command message.

18. A network node for acting as a source Master Node, MN, for a User Equipment, UE, the network node adapted to: transmit (300) a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; receive (302), from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target secondary nodes, SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target Secondary Cell Groups, SCGs, or Primary SCG Cells, PSCells, for each of the one or more candidate target SNs ; generate and transmit (304), to the UE, a Radio Resource Control, RRC, reconfiguration message that comprises the CHO configurations.

19. The network node of claim 18, further adapted to perform the method of any of claims 14 to 17.

20. A network node for acting as a source Master Node, MN, for a User Equipment, UE, the network node comprising processing circuitry configured to cause the network node to: transmit (300) a handover request message to a candidate target MN, the handover request message indicating that the handover request is for a conditional handover, CHO, of the UE to a candidate target Primary Cell, PCell, operated by the candidate target MN; receive (302), from the candidate target MN, a handover request acknowledge message comprising CHO configurations for one or more candidate target secondary nodes, SNs, wherein the CHO configurations comprise, for the candidate target PCell, one or more CHO configurations for one or more candidate target Secondary Cell Groups, SCGs, or Primary SCG Cells, PSCells, for each of the one or more candidate target SNs ; generate and transmitting (304), to the UE, a Radio Resource Control, RRC, reconfiguration message that comprises the CHO configurations.

21. The network node of claim 20, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 14 to 17.

22. A method performed by a network node acting as a candidate target Master Node, MN, for a User Equipment, UE, the method comprising: transmitting (402), to a source MN for the UE, a message to request release or modification of a conditional handover, CHO, configuration for a candidate target primary cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

23. The method of claim 22, further comprising: receiving (400), from a candidate target secondary node, SN, to which the candidate target PSCell of a CHO configuration belongs, a request to release or modify the CHO configuration that includes the candidate target PSCell.

24. The method of claim 22 or 23, further comprising: receiving (404), from the source MN, a request for a new or updated CHO configuration for the same candidate target PCell.

25. The method of claim 24, further comprising generating (406) the new or modified CHO configuration and sending (406) the new or modified CHO configuration to the source MN.

26. The method of claim 25, further comprising generating (406) a configuration for execution conditions associated with the new or modified CHO configuration, wherein sending (406) the new or modified CHO configuration to the source MN comprises sending (406) the new or modified CHO configuration and the configuration for the associated execution conditions to the source MN.

27. A network node for acting as a candidate target Master Node, MN, for a User Equipment, UE, the network node adapted to: transmit (402), to a source MN for the UE, a message to request release or modification of a conditional handover, CHO, configuration for a candidate target primary cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

28. The network node of claim 27, further adapted to perform the method of any of claims 23 to 26.

29. A network node for acting as a candidate target Master Node, MN, for a User Equipment, UE, the network node comprising processing circuitry configured to cause the network node to: transmit (402), to a source MN for the UE, a message to request release or modification of a conditional handover, CHO, configuration for a candidate target primary cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the candidate target PCell.

30. The network node of claim 29, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 23 to 26.

31. A method performed by a network node acting as a source Master Node, MN, for a User Equipment, UE, the method comprising: receiving (500), from a candidate target MN, a message to request a release or modification of a conditional handover, CHO, configuration for a candidate target Primary Cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell; transmitting (502) a request for a new or updated CHO configuration for the candidate target PCell; receiving (504), from the candidate target MN, the new or modified CHO configuration; generating and transmitting (506), to the UE, a message that includes the new or modified CHO configuration.

32. The method of claim 31, further comprising receiving (504), from the candidate target MN, a configuration for one or more execution conditions associated with the new or modified CHO configuration.

33. The method of claim 32, wherein the message transmitted to the UE further comprises the one or more execution conditions.

34. A network node for acting as a source Master Node, MN, for a User Equipment, UE, thenetwork node adapted to: receive (500), from a candidate target MN, a message to request a release or modification of a conditional handover, CHO, configuration for a candidate target Primary Cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell; transmit (502) a request for a new or updated CHO configuration for the candidate target PCell; receive (504), from the candidate target MN, the new or modified CHO configuration; generate and transmit (506), to the UE, a message that includes the new or modified CHO configuration.

35. The network node of claim 34, further adapted to perform the method of any of claims 32 to 33.

36. A network node for acting as a source Master Node, MN, for a User Equipment, UE, the network node comprising processing circuitry configured to cause the network node to: receive (500), from a candidate target MN, a message to request a release or modification of a conditional handover, CHO, configuration for a candidate target Primary Cell, PCell, with two or more CHO configurations and / or to request an addition of at least a CHO configuration for the same PCell; transmit (502) a request for a new or updated CHO configuration for the candidate target PCell; receive (504), from the candidate target MN, the new or modified CHO configuration; generate and transmit (506), to the UE, a message that includes the new or modified CHO configuration.

37. The network node of claim 36, wherein the processing circuitry is further configured to cause the network node to perform the method of any of claims 32 to 33.

Images