Conditional reconfiguration recovery in a communication network

Abstract

In response to detecting a failure (13), a communication device (12) performs cell selection as part of a connection re-establishment procedure in order to select a cell. The communication device (12) may make a decision as to whether to apply any of multiple conditional reconfigurations (16S) stored at the communication device (12) for the selected cell (18S) to recover from the failure (13). Alternatively or additionally, the communication device (12) may select, from the multiple conditional reconfigurations (16S) stored at the communication device (12) for the selected cell (18S), a conditional reconfiguration to apply to recover from the failure (13).

Description

[0001] CONDITIONAL RECONFIGURATION RECOVERY IN A COMMUNICATION NETWORK

[0002] TECHNICAL FIELD

[0003] The present application relates generally to failure recovery in a communication network, and relates more particularly to conditional reconfiguration recovery in such a network.

[0004] BACKGROUND

[0005] Some reconfiguration procedures are particularly susceptible to failure, especially in New Radio (NR) systems whose radio links are more prone to fast fading due to their higher operating frequencies. Conditional reconfiguration is one approach to improve robustness against failure in this regard. Under this approach, the network transmits a conditional reconfiguration to a communication device and specifies a condition that is to trigger the communication device to execute that conditional reconfiguration. The communication device waits to execute the conditional reconfiguration until the communication device detects that the condition is fulfilled. Once the device detects that condition, the device may autonomously execute the conditional reconfiguration without receiving any other signaling, so that the reconfiguration proves robust to link deterioration.

[0006] Conditional reconfiguration may also be exploited for fast recovery from a detected failure, e.g., fast recovery from Radio Link Failure (RLF). A communication device performs cell selection upon detection of a failure. If the communication device selects a cell for which the device already has stored a conditional reconfiguration, the device can attempt to just apply that conditional reconfiguration for the selected cell, in order to recover from the failure faster than if the device had performed a Radio Resource Control (RRC) re-establishment procedure to the selected cell.

[0007] Although this conditional reconfiguration recovery approach can provide faster failure recovery than RRC re-establishment, its use proves challenging in some contexts. For example, multi-connectivity refers to the simultaneous connection of a communication device (e.g., at a radio resource control, RRC, layer) to multiple different radio network nodes, or to multiple different cells provided by different radio network nodes. Known approaches to conditional reconfiguration recovery fail to adequately account for the possibility of a communication device having stored multiple conditional reconfigurations for the selected cell, e.g., multiple conditional handover (CHO) configurations that have different conditional Primary Secondary Cell Group (SCG) Cell (PSCell) Change (CPC) execution conditions or different conditional PSCell Addition (CPA) execution conditions for multi-connectivity operation.

[0008] SUMMARY

[0009] Some embodiments herein facilitate conditional reconfiguration recovery from a failure in the context of multi-connectivity operation. One or more embodiments in this regard facilitate conditional reconfiguration recovery from a failure even when a communication device has multiple conditional reconfigurations stored for the same cell, e.g., multiple CHO configurations that have different CPC or CPA execution conditions. Some embodiments may thereby facilitate fast failure recovery using conditional reconfiguration, e.g., even in a multi-connectivity scenario whereby a CHO configuration includes a target Master Cell Group (MCG) and candidate SCGs.

[0010] More particularly, embodiments herein include a method performed by a communication device. The method comprises, in response to detecting a failure, performing cell selection as part of a connection re-establishment procedure in order to select a cell on which to camp. The method also comprises determining that multiple conditional reconfigurations are stored at the communication device for the selected cell. The method also comprises based on the multiple conditional reconfigurations being stored at the communication device for the selected cell, making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure and / or selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure.

[0011] Other embodiments herein include another method performed by a communication device. The method comprises detecting a failure. The method also comprises making a decision as to whether or not to perform cell selection to recover from the failure. The decision is made based on: (i) whether or not the communication device has stored any conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition for any cell; (ii) whether or not the communication device has stored multiple conditional reconfigurations for any cell; (iii) whether or not the communication device has stored multiple conditional reconfigurations for each of one or more cells that are candidates for cell selection; and / or (iv) whether or not the communication device has stored, for the same cell, multiple conditional reconfigurations that are associated with respective CPA execution conditions or CPC execution conditions or that include respective PSCells or SCGs. The method also comprises performing or not performing cell selection to recover from the failure according to the decision.

[0012] In some embodiments, this method is implemented separately or in combination with other communication device methods herein.

[0013] Embodiments herein also include a method performed by a network node. The method comprises making a decision as to whether or not a communication device is to apply a conditional reconfiguration for a target candidate cell in order to attempt to recover from a failure detected by the communication device. The decision is made based on: (i) whether or not the conditional reconfiguration includes an associated CPA execution condition or an associated CPC execution condition; and / or (ii) whether or not the conditional reconfiguration includes an associated PSCell or SCG for multi-connectivity operation. The method also comprises generating the conditional reconfiguration according to the decision, and transmitting the conditional reconfiguration to the communication device.

[0014] Other embodiments herein include corresponding apparatus, computer programs, or carriers of those computer programs.

[0015] BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a block diagram of a communication network according to some embodiments.

[0017] Figure 2 is a block diagram of a communication device configured to use conditional configuration(s) for recovery from a failure according to some embodiments.

[0018] Figure 3 is a block diagram of a communication device configured with multiple conditional reconfigurations for a selected cell according to certain other embodiments.

[0019] Figure 4 is a call flow diagram of the signaling flow for a conditional handover according to some embodiments.

[0020] Figure 5 is a logic flow diagram of a method for a User Equipment, UE, to perform recovery from radio related failures according to some embodiments.

[0021] Figure 6 is a logic flow diagram of a method performed by a communication device in accordance with particular embodiments.

[0022] Figure 7 is a logic flow diagram of a method performed by a communication device in accordance with other particular embodiments.

[0023] Figure 8 is a logic flow diagram of a method performed by a network node in accordance with other particular embodiments.

[0024] Figure 9 is a block diagram of a communication device according to some embodiments.

[0025] Figure 10 is a block diagram of a radio network node according to some embodiments.

[0026] Figure 11 is a block diagram of a communication system in accordance with some embodiments.

[0027] Figure 12 is a block diagram of a user equipment according to some embodiments.

[0028] Figure 13 is a block diagram of a network node according to some embodiments.

[0029] Figure 14 is a block diagram of a host according to some embodiments.

[0030] Figure 15 is a block diagram of a virtualization environment according to some embodiments.

[0031] Figure 16 is a block diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments.

[0032] DETAILED DESCRIPTION

[0033] Figure 1 shows a communication network 10 according to some embodiments. The communication network 10 is configured to provide communication service to a communication device 12, e.g., a user equipment (UE). The network 10 as shown includes radio network nodes 14A and 14B, e.g., in the form of base stations. The radio network nodes 14A and 14B may be included in a radio access network (RAN) portion of the network 10, which may in turn connect to a core network (CN) portion (not shown).

[0034] Each radio network node 14A, 14B serves one or more cells. As shown, for example, a first radio network node 14A provides a first cell group 16A that includes N cells 16A-1 ,...16A-N, for N > 1. A second radio network node 14B provides a second cell group 16B that includes M cells 16B-1 ,...16B-M, for M > 1. Different cells may for instance be provided on different carrier frequencies, with different frequency bandwidths, and / or using different radio access technologies.

[0035] In some embodiments, the communication device 12 is configured with and / or capable of multi-connectivity operation. In multi-connectivity operation, the communication device 12 simultaneously connects, e.g., at a radio resource control, RRC, layer, to multiple different radio network nodes 14A, 14B, or to multiple different cells served by different radio network nodes 14A, 14B. The multiple different radio network nodes or cells may use the same radio access technology, e.g., both may use Evolved Universal Terrestrial Radio Access (E-UTRA) or both may use New Radio (NR). Or, the multiple different radio network nodes or cells may use different radio access technologies, e.g., one may use E-UTRA and another may use NR.

[0036] One example of multi-connectivity is dual connectivity (DC) in which the communication device 12 is simultaneously connected to two different radio network nodes, or to two different cells served by two different radio network nodes. In this case, the communication device 12 may be configured with a so-called master cell group (MCG) and a secondary cell group (SCG). Here, the MCG includes one or more cells served by the radio network node acting as a master node, i.e., a group of serving cells associated with the master node. The MCG may include a primary cell and optionally one or more secondary cells. The primary cell of the MCG is referred to as a PCell. The SCG includes one or more cells served by the radio network node acting as a secondary node, i.e., a group of serving cells associated with the secondary node. The SCG may include a primary cell and optionally one or more secondary cells. The primary cell of the SCG is referred to as the PSCell.

[0037] The master node may be a master in the sense that it controls the secondary node. Alternatively or additionally, the master node may be a master in the sense that it is a radio access node that provides the control plane connection for the communication device 12 to the core network, whereas the secondary node lacks a control plane connection for the communication device 12 to the core network.

[0038] Different types of dual connectivity may be employed by different embodiments. In some embodiments, the communication device 12 operates with E-UTRA-NR (EN) DC, where the master node uses E-UTRA and the secondary node uses NR. In other embodiments, the communication device 12 operates with NR-E-UTRA (NE) DC, where the master node uses NR and the secondary node uses E-UTRA. In still other embodiments, the communication device 12 operates with NR-DC, where both the master node and secondary node use NR. Generally, though, the communication device 12 in some embodiments operates with multi-radio (MR) DC, which refers to dual connectivity between E-UTRA and NR nodes, or between two NR nodes. MR-DC therefore may be seen as a generalization of Intra-U-UTRA DC, where a multiple receiver / transmitter capable device is configured to utilize resources provided by two different nodes connected via a non-ideal backhaul, one providing NR access and the other providing either E-UTRA or NR access. Regardless, in MR-DC, the communication device 12 may have a single RRC state, based on the master node RRC and a single control plane connection towards the core network. RRC protocol data units (PDUs) generated by the secondary node can be transmitted via the master node to the communication device 12.

[0039] In this context, Figure 2 shows that the communication device 12 in some embodiments detects a failure 13, e.g., associated with its connection to a network node 14.

[0040] In some embodiments, the failure 13 is a radio-related failure. In these and other embodiments, the failure 13 may be a failure at one or more layers of a radio protocol stack at the communication device 12. In some embodiments, for example, the one or more layers at which the failure 13 occurs include at least a Physical layer (Layer 1), a Medium Access Control, MAC, layer (Layer 2), and / or a Radio Link Control (RLC) layer (Layer 3). In particular, in some embodiments, the failure 13 may be a Radio Link Failure (RLF) a failure in a handover procedure, a failure in a conditional handover procedure, a failure during a reconfiguration with sync procedure for an MCG, a mobility from New Radio (NR) failure, and / or a failure of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure. In still yet other embodiments, the failure 13 is detected due to expiration of timer T304. In some embodiments, timer T304 may be associated with timeout of an RRC Reconfiguration procedure for a handover.

[0041] Regardless, in response to detecting the failure 13, the communication device 12 performs cell selection as part of a connection re-establishment procedure (e.g., an RRC Re-establishment procedure) in order to select a cell on which to camp. Cell selection in this regard may be performed to look for a suitable cell to provide communication service to the communication device 12 and to tune to its control channel(s). Camping on a cell in this regard enables the communication device 12 to receive System Information, to initially access the communication network 10 on the control channel of the cell on which it is camped, receive paging messages, and / or receive cell broadcast messages. As shown in this regard, the communication device 12 performs cell selection in order to select, from among multiple candidate target cells 18-1 ...18-N, a cell 18S on which to camp.

[0042] In this context, though, the communication device 12 stores conditional reconfiguration(s) 16. Figure 2 shows in particular that the communication device 12 stores one or more conditional reconfigurations 16-1 for candidate target cell 18-1 , one or more conditional reconfigurations 16-N for candidate target cell 18-N, etc. Each conditional reconfiguration is associated with an execution condition that is to trigger the communication device 12 to execute that conditional reconfiguration. The communication device 12 waits to execute the conditional reconfiguration until the communication device 12 detects that the execution condition is fulfilled. Once the communication device 12 detects that execution condition, the device may autonomously execute the conditional reconfiguration without receiving any other signaling, e.g., so that the reconfiguration proves robust to link deterioration.

[0043] In the scenario of Figure 2, the communication device 12 determines that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S. If the selected cell 18S is candidate target cell 18-1 , for example, the multiple conditional reconfigurations 16S stored at the communication device 12 for the selected cell 18S would be represented by multiple conditional reconfigurations 16-1. In some embodiments, the communication device 12 determines that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S by determining that the selected cell 18S is a target cell of multiple conditional reconfigurations 16S that the communication device 12 has stored. In other embodiments, the communication device 12 determines that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S by determining that the communication device 12 is configured with multiple conditional reconfigurations 16S for the selected cell 18S.

[0044] Figure 3 illustrates an example in some embodiments. As shown, the communication device 12 stores multiple conditional reconfigurations 16S for the selected cell 18S as a candidate target PCell in multi-connectivity operation, i.e., belonging to an MCG. The multiple conditional reconfigurations 16S are therefore multiple conditional handover, CHO, configurations for the selected cell 18S.

[0045] In some embodiments, at least some of the multiple conditional reconfigurations 16S include or correspond to different associated PSCells or different associated SCGs for multiconnectivity operation of the communication device 12. Alternatively or additionally, at least some of the multiple conditional reconfigurations 16S include different associated Conditional PSCell Addition (CPA) execution conditions or different associated Conditional PSCell Change (CPC) execution conditions for multi-connectivity operation of the communication device 12. As shown, for example, the multiple conditional reconfigurations 16S include conditional reconfiguration 16S-1 for candidate target PCell 18S, where that conditional reconfiguration 16S-1 includes an SCG configuration 22-1 for candidate target PSCell 20-1 and includes an associated CPC / CPA execution condition 24-1. The multiple conditional reconfigurations 16S also include conditional reconfiguration 16S-2 for the same candidate target PCell 18S, where that conditional reconfiguration 16S-2 includes an SCG configuration 22-2 for a different candidate target PSCell 20-2 and includes an associated CPC / CPA execution condition 24-2. And so on with the multiple conditional reconfigurations 16S including conditional reconfiguration 16S-M for the same candidate target PCell 18S, where that conditional reconfiguration 16S-M includes an SCG configuration 22-M for candidate target PSCell 20-M and includes an associated CPC / CPA execution condition 24-M.

[0046] In any event, based on the multiple conditional reconfigurations 16S being stored at the communication device 12 for the selected cell 18, the communication device 12 herein in some embodiments makes a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13 (i.e., whether to actually exploit conditional reconfiguration recovery to recover from the failure 13, as opposed to requesting RRC Re-establishment from the selected cell 18S).

[0047] For example, in some embodiments, the communication device 12 makes the decision based on whether any of the multiple conditional reconfigurations 16S lack an associated CPA execution condition or an associated CPC execution condition for multi-connectivity operation of the communication device 12. The communication device 12 may for instance make the decision to not apply any of the multiple conditional reconfigurations 16 to recover from the failure, if none of the multiple conditional reconfigurations 16S lack an associated CPA execution condition or an associated CPC execution condition, but to make the decision to apply one of the multiple conditional reconfigurations 16 to recover from the failure if at least one of the multiple conditional reconfigurations 16 lacks an associated CPA execution condition or an associated CPC execution condition. In this latter case, the communication device 12 may select, from the multiple conditional reconfigurations 16S, a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition.

[0048] In another example, the communication device 12 makes the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if for any of the multiple conditional reconfigurations 16S that is associated with a CPA execution condition or CPC execution condition, the associated CPA execution condition or CPC execution condition is not fulfilled. In still another example, the communication device 12 may make the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, based on there being multiple conditional reconfigurations stored at the communication device for the selected cell. In fact, the communication device 12 may make this decision even if the communication device 12 receives an indication from a network node that the communication device 12 is to perform conditional reconfiguration if the selected cell is a target candidate cell and it is the first cell selection after the detected failure.

[0049] Alternatively or additionally, based on the multiple conditional reconfigurations 16S being stored at the communication device 12 for the selected cell 18, the communication device 12 selects, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13. In such a case, the communication device 12 may apply the selected conditional reconfiguration for the selected cell 18S to recover from the failure 13. In some embodiments, the communication device 12 selects a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition. In one example, selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition entails selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition and that includes an MCG or PCell configuration but excludes an SCG or PSCell configuration. In another example, selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition entails selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition and that includes an indication that any SCG configuration of the communication device is to be released. In yet another example, selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition and that includes both an MCG or PCell configuration and an SCG or PSCell configuration, but the SCG or PSCell configuration does not include any associated CPA execution condition or CPC execution condition.

[0050] Note, though, that in some embodiments the communication device 12 merely preferentially selects a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition. In some embodiments, for example, if at least one of the multiple conditional reconfigurations lacks an associated CPA execution condition or an associated CPC execution condition, the communication device 12 selects a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition. But otherwise, if none of the multiple conditional reconfigurations lacks an associated CPA execution condition or an associated CPC execution condition, the communication device 12 reverts to selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition.

[0051] In other embodiments, the communication device 12 selects (or preferentially selects) a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which is fulfilled. Or, the communication device 12 selects (or preferentially selects) a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered.

[0052] Regardless, in some embodiments, the communication device 12 transmits, in the selected cell 18S, a notification message according to the selected conditional reconfiguration. In some embodiments, the notification message is an RRC Reconfiguration Complete message. In some embodiments, the selected conditional reconfiguration includes an SCG configuration or a PSCell configuration, and the notification message includes an indication to a target PSCell or target Secondary Node (SN).

[0053] Other variations and alternatives will be described with respect to Figures 6-8.

[0054] Consider first though some embodiments herein that are applicable in the following context where the communication device 12 is exemplified as a user equipment (UE), e.g., in a 5G or NR network.

[0055] Handovers are normally triggered when the 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 UL is already bad it may lead to the network being unable to detect the measurement report transmitted by the UE, and hence cannot initiate the handover procedure. DL problems may lead to the handover command (i.e., the RRCReconfiguration message with a reconfigurationWithSync field) is unable to successfully reach 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 doesn’t reach the UE in time. Failed transmission of handover command is a common reason for unsuccessful handovers.

[0056] To improve mobility robustness and address the issues above, a concept known as conditional handover (CHO) is introduced in 3GPP Release 16. The idea in CHO is that transmission and execution of the handover command are separated. This allows the handover command to be sent earlier to 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 may be in the form a threshold, e.g., signal strength of candidate target cell becomes X dB better than the serving cell (so called A3 event), or signal strength of serving cell becomes worse than X dBm and signal strength of candidate target cell becomes better than Y dBm (so called A5 event).

[0057] In this context, 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 sense 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”. Figure 4 shows the signaling flow for a conditional handover according to some embodiments.

[0058] Steps 8001-8002.

[0059] The UE and source gNB have an established connection and exchange 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.

[0060] Step 8003.

[0061] 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.

[0062] Step 8004.

[0063] 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 Identity (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).

[0064] Steps 8005-8006.

[0065] To configure a candidate target cell, the source node sends the CHO configuration (i.e., a RRCReconfiguration message) to the UE which contains the handover command 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 8003-8004, and the execution condition is generated by the source node.

[0066] Steps 8007-8008.

[0067] 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.

[0068] Step 8009.

[0069] The target gNB sends a HANDOVER SUCCESS message to the source gNB indicating the UE has successfully established the target connection. Steps 8010-8011.

[0070] Upon reception of the handover success indication, the source gNB stops scheduling any further downlink (DL) or uplink (UL) data to the UE and sends a SN STATUS TRANSFER message to the target gNB indicating the latest Pack 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.

[0071] Step 8012.

[0072] 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 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.

[0073] 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 NR) or an RRCConnectionReconfiguration message (in LTE) upon a certain associated condition being triggered.

[0074] The Conditional PSCell Addition (CPA) and Conditional PSCell Change (CPC) are examples of two other types of reconfigurations which use the conditional reconfiguration framework but operate 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.

[0075] CHO with target SCG and CHO with candidate SCGs

[0076] In 3GPP Rel-16 the target configuration of Conditional Handover (CHO), i.e., the RRC configuration that the UE applies and executes when the associated execution conditions are fulfilled, can only include an MCG configuration, i.e., no SCG / PSCell configuration can be part of the configuration that the UE then applies.

[0077] 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.

[0078] 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 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. For 3GPP Rel-18, it is an objective to support CHO with different candidate SCGs, in particular to specify CHO including target MCG and candidate SCGs for CPC / CPA in NR-DC, where CHO including target MCG and target SCG is used as the baseline.

[0079] It is thus an objective 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).

[0080] Some embodiments operate as described below in relation to the configuration of the combined CHO+CPA / CPC configurations:

[0081] => For CHO with candidate SCGs for CPA / CPC, the RRCReconfiguration message in one CHO container includes one MCG configuration and one SCG configuration (i.e., similar to Rel-17 CHO with SCG configuration).

[0082] => The execution conditions associated with one CHO container include both CHO execution condition(s) and CPA / CPC execution condition(s), i.e., triggering conditions on both candidate PCell and candidate PSCell.

[0083] => If there are multiple candidate PSCells associated with one candidate PCell, the NW can provide multiple CHO configurations for the same candidate PCell, i.e., each one contains one MCG configuration (for the same candidate PCell) and one SCG configuration (for different candidate PSCell).

[0084] => When the CPA / CPC execution condition is met but no CHO execution condition is met, the UE continues to evaluate both CHO and CPA / CPC execution conditions.

[0085] => For CHO+CPC execution is considered only when BOTH conditions are met.

[0086] When the CHO execution condition is met but no CPC execution condition is met, if there is an available CHO-only or Rel-17 CHO with SCG configuration for which the CHO condition is met, the UE performs the CHO-only or Rel-17 CHO with SCG execution, and thus the network can handle such situation by providing proper configurations.

[0087] In some embodiments, in the case of CHO with candidate SCGs, the UE is configured with multiple CHO configurations for the same candidate PCell, one for each candidate SCG / PSCell with associated CPA / CPC conditions and one for CHO only without any associated CPA / CPC condition. The target configuration of the CHO configuration for CHO only, i.e., without any associated CPA / CPC condition, can either include both an MCG and an SCG configuration or just an MCG configuration.

[0088] Fast recovery using CHO configuration

[0089] In case there is a problem with the RRC connection for the UE, e.g., that a radio link failure of the MCG is detected by the UE, or that there is a re-configuration with sync failure of the MCG or mobility from NR failure, the RRC Re-establishment procedure may be triggered to re-establish the RRC connection. The UE then starts timer T311 and initiates a cell selection process. The UE then sends an RRCReestablishmentRequest message to the selected cell to try to re-establish / continue the RRC connection in that cell.

[0090] In case the UE has a Conditional Handover (CHO) configuration for the selected cell (i.e., where the selected cell is the candidate target PCell), and the UE is configured with attemptCondReconfig, the UE executes that CHO configuration towards the selected cell instead of sending the RRCReestablishmentRequest message (if it is the first cell selection after the failure). This procedure as implemented heretofore is described in sub-clause 5.3.7.3 in 3GPP TS 38.331 , v.17.5.0 (Rel-17):

[0091] 5.3.7.3 Actions following cell selection while T311 is running

[0092] Upon selecting a suitable NR cell, the UE shall:

[0093] 1 > ensure having valid and up to date essential system information as specified in clause 5.2.2.2;

[0094] 1 > stop timer T311 ;

[0095] 1 > if T390 is running:

[0096] 2> stop timer T390 for all access categories;

[0097] 2> perform the actions as specified in 5.3.14.4;

[0098] 1 > stop the relay (re)selection procedure, if ongoing;

[0099] 1 > if the cell selection is triggered by detecting radio link failure of the MCG or reconfiguration with sync failure of the MCG or mobility from NR failure, and

[0100] 1 > if attemptCondReconfig is configured; and

[0101] 1 > if the selected cell is not configured with CondEventTI, or the selected cell is configured with CondEventTI and leaving condition has not been fulfilled; and

[0102] 1 > if the selected cell is one of the candidate cells for which the reconfigurationWithSync is included in the masterCellGroup in the MCG VarConditionalReconfig-.

[0103] 2> if the UE supports RLF-Report for conditional handover, set the choCellld in the VarRLF-Report to the global cell identity, if available, otherwise to the physical cell identity and carrier frequency of the selected cell;

[0104] 2> apply the stored condRRCReconfig associated to the selected cell and perform actions as specified in 5.3.5.3;

[0105] NOTE 1 : It is left to network implementation to how to avoid keystream reuse in case of CHO based recovery after a failed handover without key change.

[0106] The configuration of attemptCondReconfig is included in ConditionalReconfiguration. From 3GPP TS 38.331 , v.17.5.0 (Rel-17):

[0107] - ConditionalReconfiguration

[0108] The IE ConditionalReconfiguration is used to add, modify and release the configuration of conditional reconfiguration.

[0109] ConditionalReconfiguration information element

[0110] - ASN1 START

[0111] - TAG-CONDITIONALRECONFIGURATION-START

[0112] ConditionalReconfiguration-r16 ::= SEQUENCE { attemptCondReconfig-r16 ENUMERATED {true} OPTIONAL, -

[0113] Cond CHO condReconfigT oRemovel_ist-r16 CondReconfigToRemoveList-r16 OPTIONAL,

[0114] -- Need N condReconfigT oAddModl_ist-r16 CondReconfigToAddModList-r16 OPTIONAL,

[0115] -- Need N

[0116] }

[0117] CondReconfigToRemoveList-r16 ::= SEQUENCE (SIZE (1.. maxNrofCondCells-r16))

[0118] OF CondReconfigld-r16

[0119] - TAG-CONDITIONALRECONFIGURATION-STOP

[0120] - ASN1STOP

[0121] ConditionalReconfiguration field descriptions attemptCondReconfig

[0122] If present, the UE shall perform conditional reconfiguration if selected cell is a target candidate cell and it is the first cell selection after failure as described in clause 5.3.7.3.

[0123] List of the configuration of candidate SpCells to be added or modified for CHO, CPA or CPC. condReconfigToRemoveList

[0124] List of the configuration of candidate SpCells to be removed. With the introduction of multiple CHO configurations for the same PCell, as may be done to support CHO with candidate SCGs, the UE may be configured with multiple CHO configurations for the selected PCell at the RRC Re-establishment procedure. It is heretofore not clear which of these multiple CHO configurations (and thus target configuration, condRRCReconfig) for the selected PCell that the UE shall apply / execute at CHO recovery (i.e., instead of sending RRCReestablishmentRequest message to the selected cell), if the UE is configured with attemptCondReconfig.

[0125] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Some embodiments herein include methods for a UE, that is configured with CHO with candidate SCGs, for selecting a CHO configuration to apply in case of RRC Reestablishment (for recovery using the CHO configuration). When the UE is configured with CHO with candidate SCGs, it may have multiple CHO configurations for the selected cell (e.g., it is configured with CHO with candidate SCGs for the selected cell).

[0126] The selection of the CHO configuration, according to the methods herein, may be based on specified rule(s) or it may be based on UE implementation.

[0127] In some embodiments, the methods for selection of CHO configuration for the selected PCell include one or more of the following:

[0128] (1) The UE selects a CHO configuration that does not include any associated CPA / CPC conditions

[0129] (2) The UE selects one of the CHO configurations for the selected cell (PCell) by taking the radio conditions for the candidate SCG(s) / PSCell(s) into account. In one alternative, the UE checks whether the associated CPA / CPC conditions for any of the CHO configurations for the selected cell (PCell) are fulfilled. If that is the case, the UE selects a CHO configuration for which the associated CPA / CPC conditions are fulfilled.

[0130] (3) The UE selects a CHO configuration with a target configuration (to apply when the associated conditions are fulfilled) that does not include any SCG configuration, i.e., where the UE is not configured with any SCG after applying the target configuration.

[0131] (4) The UE selects one of the CHO configurations where the target configuration includes an SCG configuration, i.e., where the UE is configured with an SCG after applying the target configuration.

[0132] (5) The UE does not select any CHO configuration for recovery if the UE has multiple CHO configurations for the selected cell (even if attemptCondReconfig is configured).

[0133] (6) In one alternative, the UE does not select a cell for CHO recovery or does not perform CHO recovery for the selected PCell, in case the UE is configured with CHO with associated CPA / CPC conditions configured for any cell. This would then be applicable even if attemptCondReconfig is configured.

[0134] Some embodiments herein provide selection of a target configuration for execution of CHO recovery (at RRC Re-establishment) when multiple CHO configurations exist for the selected PCell.

[0135] Certain embodiments may provide one or more of the following technical advantage(s). It is possible for the UE to utilize (perform selection of) a CHO configuration for a selected cell, for which the UE is configured with multiple CHO configurations (e.g., due to configuration of CHO with candidate SCGs for the selected cell).

[0136] Note that the text herein refers to the phrase radio related failure, which can correspond to e.g. (but is not limited to) that the UE experiences a Radio Link Failure (RLF), a failure in a handover procedure (e.g. due to that timer T304 expires) or failure in a conditional handover (CHO) procedure, a failure during a reconfiguration with sync procedure for the MCG or a failed L1 / L2 triggered mobility (LTM) cell switch procedure.

[0137] In some embodiments, the UE, in response to detecting a radio related failure, initiates an RRC Re-establishment procedure including selecting a suitable cell (after starting timer T311). If the UE is configured with attemptCondReconfig and the UE has one or more CHO configuration(s) for the selected cell, this disclosure includes methods for selecting whether to perform a conditional reconfiguration using any of those CHO configurations and, in that case, which of those CHO configurations to use.

[0138] Figure 5 shows a method for a User Equipment, UE, to perform recovery from radio related failures according to some embodiments.

[0139] The method comprises the UE receiving Conditional Handover (CHO) configurations for one or more candidate target PCell(s) (Block 500). In one example, the UE receives more than one CHO configuration for the same candidate target PCell. The multiple CHO configurations for the same PCell can correspond to different associated SCG / PSCell configurations and / or conditions for the associated PSCell.

[0140] The method also comprises the UE detecting a radio related failure (Block 510).

[0141] The method further comprises performing cell selection (Block 520).

[0142] The method also comprises determining that the selected cell is a target cell of more than one Conditional Handover (CHO) configuration(s) that the UE has stored, i.e., the UE is configured with more than one CHO configurations for the selected cell (Block 530).

[0143] The method further comprises selecting one of the CHO configurations for the selected cell (Block 540).

[0144] The method also comprises applying the selected CHO configuration associated to the selected cell (Block 550).

[0145] The method further comprises transmitting, in the selected cell, a notification message (e.g., RRC Reconfiguration Complete) to the selected target cell, according to the configuration in the CHO configuration (Block 560). In case the selected configuration includes an SCG / PSCell configuration, the notification message may include an indication to the target PSCell / target SN.

[0146] In some embodiments, the selection of the CHO configuration for the selected cell (Block 540) is done based on one or more of the following.

[0147] In some embodiments, the UE selects a CHO configuration that does not include any associated CPA / CPC conditions. In one alternative, the target configuration of the CHO configuration without any associated CPA / CPC conditions (i.e., the configuration to be applied at fulfillment of the CHO conditions) only includes an MCG configuration. In one example, the target configuration of the CHO configuration includes an indication that the SCG configuration of the UE is to be released. The UE then releases the SCG configuration, if any, when applying the configuration.

[0148] In another alternative, the target configuration of the CHO configuration without any associated CPA / CPC conditions (i.e., the configuration to be applied at fulfillment of the CHO conditions) includes both an MCG configuration and an SCG configuration. In one example, the target configuration of the CHO configuration only includes an MCG (re)configuration, such as a change of PCell, but no configuration related to the SCG. The UE then keeps the previous SCG configuration, if any, when applying the configuration.

[0149] In one example the UE is, for the selected PCell, configured with one CHO configuration with only CHO conditions and at least one CHO configuration with associated CPA / CPC conditions (for included SCG(s) / PSCell(s)), and the UE selects the CHO configuration that does not include any associated CPA / CPC conditions. The configuration that is applied may contain only an MCG configuration, or an MCG and an SCG configuration, but where the SCG configuration is not associated with any execution conditions for CPA / CPC.

[0150] In one example, if the UE is not configured with any CHO configuration without associated CPA / CPC conditions for the selected PCell the UE does not perform any CHO recovery for the selected PCell. In one example, if the UE is not configured with any CHO configuration without associated CPA / CPC conditions for the selected PCell the UE performs CHO recovery for the selected PCell using one of the CHO configurations with associated CPA / CPC conditions.

[0151] In other embodiments, the UE selects one of the CHO configurations for the selected cell (PCell) by taking the radio conditions for the candidate SCG(s) / PSCell(s) into account.

[0152] In one alternative, the UE checks whether the associated CPA / CPC conditions for any of the CHO configurations for the selected cell (PCell) are fulfilled. If that is the case, the UE selects a CHO configuration for which the associated CPA / CPC conditions are fulfilled.

[0153] In another alternative, if the associated CPA / CPC conditions are not fulfilled for any of the CHO configurations that include associated CPA / CPC conditions, the UE selects a CHO configuration without any associated CPA / CPC condition. In one example, if no CHO configuration without any associated CPA / CPC condition exists, the UE does then not perform any CHO recovery for the selected PCell. In another example, if the UE is not configured with any CHO configuration without associated CPA / CPC conditions for the selected PCell the UE performs CHO recovery for the selected PCell using one of the CHO configurations with associated CPA / CPC conditions, even if the associated CPA / CPC conditions are not fulfilled.

[0154] In yet another alternative, the UE checks whether the associated CPA / CPC conditions for any of the CHO configurations for the selected cell (PCell) have been fulfilled at least once during a certain time period prior to the trigger of the RRC re-establishment procedure, e.g., a certain time period prior to the start of timer T311 . If that is the case, the UE selects one of those CHO configurations for the selected cell (PCell).

[0155] In one alternative, the UE compares the latest radio measurements for the candidate target PSCells in the different CHO configurations, and selects the CHO configuration that includes the PSCell for which the radio conditions are the best.

[0156] In one example, the UE selects the CHO configuration for which the included candidate target PSCell (or the target SCG / PSCell without associated CPA / CPC condition) has the highest RSRP value. In another example, the UE selects the CHO configuration for which the included candidate target PSCell (or the target SCG / PSCell without associated CPA / CPC condition) has the highest RSRQ value. In another example, the UE selects the CHO configuration for which the included candidate target PSCell (or the target SCG / PSCell without associated CPA / CPC condition) has the highest SINR value. In another example, the UE selects the CHO configuration for which the included candidate target PSCell (or the target SCG / PSCell without associated CPA / CPC condition) has the beam with the highest beam measurement or has the highest number of beams for which measurements are above a certain threshold.

[0157] In yet another alternative, the UE only selects a CHO configuration with an included candidate target PSCell (i.e., with associated CPA / CPC conditions) or a target SCG / PSCell (without associated CPA / CPC condition) if it has a radio condition (e.g., measured RSRP, RSRQ or SINR value) for the PSCell that is above a minimum level. If none of the CHO configurations include a candidate target PSCell (with associated CPA / CPC conditions) or a target SCG / PSCell (without associated CPA / CPC condition) that is above the minimum level, the UE selects a CHO configuration without any candidate target PSCell (with associated CPA / CPC conditions) or target SCG / PSCell (without associated CPA / CPC condition). The UE then selects a CHO configuration with a target configuration where the UE is not configured with any SCG / PSCell after applying / executing the configuration, if any. In one example, the minimum level is a threshold that is configured by the network.

[0158] In still another alternative, the UE only selects a CHO configuration with an included candidate target PSCell (with associated CPA / CPC conditions) if it has a radio condition (e.g., measured RSRP, RSRQ or SINR value) for the candidate target PSCell that is above a minimum level. If none of the CHO configurations include a candidate target PSCell (with associated CPA / CPC conditions) that is above the minimum level, the UE selects a CHO configuration without any candidate target PSCell (with associated CPA / CPC conditions). The UE then selects a CHO configuration without any associated CPA / CPC configuration, if any. This may include CHO configurations with a target configuration where the UE is configured with or without an SCG / PSCell after applying / executing the configuration. In one example, the minimum level is a threshold that is configured by the network.

[0159] In yet other embodiments, the UE selects a CHO configuration with a target configuration (to apply when the associated conditions are fulfilled) that does not include any SCG configuration, i.e., where the UE is not configured with any SCG after applying the target configuration.

[0160] In one example, where the UE is configured with at least two CHO configurations (at least one that includes an SCG configuration and at least one that does not include any SCG configuration) for the selected cell, the UE selects a CHO configuration that does not include any SCG configuration. In another example, if the UE is configured with an SCG / PSCell at the time of selection of the cell (e.g. at the time of starting timer T311), the UE only considers CHO configurations for the selected PCell that include a release of the SCG, whereas if the UE is not configured with an SCG / PSCell at the time of selection of the cell (e.g. at the time of starting timer T311), the UE considers all the CHO configurations for the selected PCell that does not include any configuration for an SCG / PSCell.

[0161] In further embodiments, the UE selects one of the CHO configurations where the target configuration includes an SCG configuration, i.e., where the UE is configured with an SCG after applying the target configuration.

[0162] In one example, if the UE is configured with an SCG / PSCell at the time of selection of the cell (e.g., at the time of starting timer T311), the UE considers all the CHO configurations for the selected PCell that do not just release the SCG, i.e., it considers all the CHO configurations with a target configuration that modifies / changes the current SCG configuration or that does not change the current SCG configuration (i.e., the previous SCG configuration is kept). In another example, where the UE has several CHO configurations for the selected PCell, with different target PSCells, the UE selects a CHO configuration that has a target configuration where the target PSCell is the same as the PSCell that the UE was configured with at the trigger of the RRC Re-establishment procedure (e.g., the one that the UE had before start of timer T311).

[0163] In still further embodiments, the UE selects one of the CHO configurations for the selected cell (PCell) without any consideration of the PSCell(s). The selection of the target configuration may be based on UE implementation.

[0164] In another embodiment, the UE does not select any CHO configuration for recovery if the UE has multiple CHO configurations for the selected cell. In case the UE selects a cell (while timer T311 us running) for which the UE has multiple CHO configurations (e.g., the UE is configured with CHO with candidate SCGs), it does not apply the target configuration for any of those CHO configurations, even if attemptCondReconfig is configured.

[0165] In any of the embodiments herein, the selection of the CHO configuration may be based on specified rule(s) or it may be based on UE implementation.

[0166] In one alternative, the UE does not select a cell for CHO recovery or does not perform CHO recovery for the selected PCell, in case the UE is configured with CHO with associated CPA / CPC conditions configured for any cell. This would then be applicable even if attemptCondReconfig is configured.

[0167] In one alternative, the UE does not select a cell for CHO recovery or does not perform CHO recovery for the selected PCell, in case the UE is configured with multiple CHO configurations for any cell. This would then be applicable even if attemptCondReconfig is configured.

[0168] In one alternative, the network is not allowed to configure attemptCondReconfig in case CHO with associated CPA / CPC conditions are configured. In one example, the UE then considers it an error if it is configured simultaneously with CHO with associated CPA / CPC conditions and the attemptCondReconfig.

[0169] In one alternative the UE does not select a cell for CHO recovery in case all of the cells have CHO with associated CPA / CPC conditions configured.

[0170] Below some example implementations in 3GPP TS 38.331 v17.5.0 are shown (where the additions here are included with underlined text):

[0171] 5.3.7.3 Actions following cell selection while T311 is running

[0172] Upon selecting a suitable NR cell, the UE shall:

[0173] 1 > ensure having valid and up to date essential system information as specified in clause 5.2.2.2;

[0174] 1 > stop timer T311 ;

[0175] 1 > if T390 is running:

[0176] 2> stop timer T390 for all access categories;

[0177] 2> perform the actions as specified in 5.3.14.4;

[0178] 1 > stop the relay (re)selection procedure, if ongoing;

[0179] 1 > if the cell selection is triggered by detecting radio link failure of the MCG or reconfiguration with sync failure of the MCG or mobility from NR failure, and

[0180] 1 > if attemptCondReconfig is configured; and

[0181] 1 > if the selected cell is not configured with CondEventTI, or the selected cell is configured with CondEventTI and leaving condition has not been fulfilled; and

[0182] 1 > if the selected cell is one of the candidate cells for which the reconfigurationWithSync is included in the masterCellGroup in the MCG VarConditional Recon fig.

[0183] 2> if the UE supports RLF-Report for conditional handover, set the choCellld in the VarRLF-Report to the global cell identity, if available, otherwise to the physical cell identity and carrier frequency of the selected cell;

[0184] 2> if multiple condRRCReconfig have been configured for the selected cell:

[0185] 3> select a condRRCReconfig which does not contain execution conditions for a CPC or CPA configuration:

[0186] 4> apply the selected condRRCReconfig and perform actions as specified in 5.3.5.3;

[0187] NOTE 1 : It is left to network implementation to how to avoid keystream reuse in case of CHO based recovery after a failed handover without key change.

[0188] In an alternative solution, the selection of the target configuration is done based on UE implementation. In one example, this is indicated through a note in 3GPP TS 38.331 v17.5.0 (where the additions here are included with underlined text):

[0189] 5.3.7.3 Actions following cell selection while T311 is running

[0190] Upon selecting a suitable NR cell, the UE shall:

[0191] 1 > ensure having valid and up to date essential system information as specified in clause 5.2.2.2;

[0192] 1 > stop timer T311 ;

[0193] 1 > if T390 is running:

[0194] 2> stop timer T390 for all access categories;

[0195] 2> perform the actions as specified in 5.3.14.4;

[0196] 1 > stop the relay (re)selection procedure, if ongoing;

[0197] 1 > if the cell selection is triggered by detecting radio link failure of the MCG or reconfiguration with sync failure of the MCG or mobility from NR failure, and

[0198] 1 > if attemptCondReconfig is configured; and

[0199] 1 > if the selected cell is not configured with CondEventTI, or the selected cell is configured with CondEventTI and leaving condition has not been fulfilled; and

[0200] 1 > if the selected cell is one of the candidate cells for which the reconfigurationWithSync is included in the masterCellGroup in the MCG VarConditionalReconfig-.

[0201] 2> if the UE supports RLF-Report for conditional handover, set the choCellld in the VarRLF-Report to the global cell identity, if available, otherwise to the physical cell identity and carrier frequency of the selected cell;

[0202] 2> apply the stored condRRCReconfig associated to the selected cell and perform actions as specified in 5.3.5.3;

[0203] NOTE 1 : It is left to network implementation to how to avoid keystream reuse in case of CHO based recovery after a failed handover without key change.

[0204] NOTE 2: It is left to UE implementation to select a condRRCReconfig to apply, if multiple condRRCReconfig have been configured for the selected cell.

[0205] In view of the modifications and variations herein, Figure 6 depicts a method performed by a communication device 12 in accordance with particular embodiments. The method includes, in response to detecting a failure 13, performing cell selection as part of a connection re-establishment procedure in order to select a cell 18S on which to camp (Block 600). The method also includes determining that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S (Block 610). The method also comprises, based on the multiple conditional reconfigurations 16S being stored at the communication device 12 for the selected cell 18S, making a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13 and / or selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 (Block 620).

[0206] In some embodiments, the method also includes receiving the multiple conditional reconfigurations 16S (Block 630).

[0207] In some embodiments, the method also includes, after receiving the multiple conditional reconfigurations 16S, storing the multiple conditional reconfigurations 16S at the communication device 12 (Block 640).

[0208] In some embodiments, the method also includes, after storing the multiple conditional reconfigurations 16S, the detecting the failure 13 (Block 650).

[0209] In some embodiments, the method also includes applying the selected conditional reconfiguration for the selected cell 18S to recover from the failure 13 (Block 660).

[0210] In some embodiments, the method also includes transmitting, in the selected cell 18S, a notification message according to the selected conditional reconfiguration (Block 670).

[0211] In some embodiments, the multiple conditional reconfigurations 16S are multiple conditional handover, CHO, configurations for the selected cell 18S.

[0212] In some embodiments, the selected cell 18S is a candidate target Primary Cell, PCell and / or is included in a Master Cell Group, MCG. In some embodiments, at least some of the multiple conditional reconfigurations 16S include or correspond to different associated Primary Secondary Cells, PSCells, for multi-connectivity operation of the communication device 12. In other embodiments, at least some of the multiple conditional reconfigurations 16S include or correspond to different associated Secondary Cell Groups, SCGs, for multi-connectivity operation of the communication device 12. In some embodiments, at least some of the multiple conditional reconfigurations 16S include different associated Conditional PSCell Addition, CPA, execution conditions 24-1 ...24-M or different associated Conditional PSCell Change, CPC, execution conditions 24-1 ...24-M for multi-connectivity operation of the communication device 12. In some embodiments, at least one of the multiple conditional reconfigurations 16S lacks any associated Conditional PSCell Addition, CPA, execution condition 24-1 ...24-M or any associated Conditional PSCell Change, CPC, execution condition 24-1 ...24-M for multiconnectivity operation of the communication device 12.

[0213] In some embodiments, the failure 13 is a radio-related failure.

[0214] In some embodiments, the failure 13 is a failure 13 at one or more layers of a radio protocol stack at the communication device 12. In some embodiments, the one or more layers at which the failure 13 occurs include at least a Physical layer or Layer 1. In other embodiments, the one or more layers at which the failure 13 occurs alternatively or additionally include at least a Medium Access Control, MAC, layer or Layer 2. In yet other embodiments, the one or more layers at which the failure 13 occurs alternatively or additionally include at least a Radio Link Control, RLC, layer or Layer 3.

[0215] In some embodiments, the failure 13 is a Radio Link Failure, RLF. In other embodiments, the failure 13 is an RLF of an MCG. In yet other embodiments, the failure 13 is a failure 13 in a handover procedure. In still yet other embodiments, the failure 13 is detected due to expiration of timer T304. In still yet other embodiments, the failure 13 is a failure 13 in a conditional handover procedure. In still yet other embodiments, the failure 13 is a failure 13 during a reconfiguration with sync procedure for an MCG. In still yet other embodiments, the failure 13 is a mobility from New Radio (NR) failure. In still yet other embodiments, the failure 13 is a failure 13 of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure.

[0216] In some embodiments, the connection re-establishment procedure is a Radio Resource Control, RRC, connection re-establishment procedure.

[0217] In some embodiments, performing cell selection comprises selecting a suitable cell on which to camp according to one or more criteria defining suitability of a cell.

[0218] In some embodiments, determining that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S comprises determining that the selected cell 18S is a target cell of multiple conditional reconfigurations 16S that the communication device 12 has stored. In other embodiments, determining that multiple conditional reconfigurations 16S are stored at the communication device 12 for the selected cell 18S comprises determining that the communication device 12 is configured with multiple conditional reconfigurations 16S for the selected cell 18S.

[0219] In some embodiments, making a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13 and / or selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13, and the method further comprises applying the selected conditional reconfiguration for the selected cell 18S to recover from the failure 13. In some embodiments, the method further comprises transmitting, in the selected cell 18S, a notification message according to the selected conditional reconfiguration. In some embodiments, the notification message is an RRC Reconfiguration Complete message. In some embodiments, the selected conditional reconfiguration includes an SCG configuration 22-1 ...22-M or a PSCell configuration, and the notification message includes an indication to a target PSCell or target Secondary Node, SN.

[0220] In some embodiments, making a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13 and / or selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M. In some embodiments, selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M and that includes an MCG or PCell configuration but excludes an SCG or PSCell configuration. In other embodiments, selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition 24- 1 ...24-M or CPC execution condition 24-1 ...24-M and that includes an indication that any SCG configuration 22-1...22-M of the communication device 12 is to be released. In yet other embodiments, selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition 24- 1 ...24-M or CPC execution condition 24-1 ...24-M and that includes both an MCG or PCell configuration and an SCG or PSCell configuration, but the SCG or PSCell configuration does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1...24-M.

[0221] In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises preferentially selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M. In some embodiments, selecting comprises, if at least one of the multiple conditional reconfigurations 16S lacks an associated CPA execution condition 24-1 ...24- M or an associated CPC execution condition 24-1 ...24- M, selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1 ...24- M or CPC execution condition 24-1 ...24-M. In some embodiments, selecting comprises, else if none of the multiple conditional reconfigurations 16S lacks an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M, selecting a conditional reconfiguration that includes an associated CPA execution condition 24- 1 ...24-M or CPC execution condition 24-1 ...24-M.

[0222] In some embodiments, selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M comprises selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1...24-M or CPC execution condition 24-1...24-M which is fulfilled. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M which is fulfilled. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered.

[0223] In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition 24- 1 ...24-M or CPC execution condition 24-1 ...24-M which is fulfilled. In some embodiments, said selecting comprises, if one of the multiple conditional reconfigurations 16S includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M which is fulfilled, selecting that conditional reconfiguration . In other embodiments, said selecting comprises, else if the associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M is not fulfilled for any of the multiple conditional reconfigurations 16S that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24- 1...24-M, and if the multiple conditional reconfigurations 16S include a conditional reconfiguration that lacks any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, selecting the conditional reconfiguration that lacks any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M. In some embodiments, preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M which is fulfilled further comprises, else if the associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M is not fulfilled for any of the multiple conditional reconfigurations 16S that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, and if none of the multiple conditional reconfigurations 16S lack any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, selecting a conditional reconfiguration that includes an associated CPA execution condition 24-

[0224] 1...24-M or CPC execution condition 24-1...24-M even if the associated CPA execution condition 24-1...24-M or CPC execution condition 24-1...24-M is not fulfilled.

[0225] In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition 24-

[0226] 1...24-M or CPC execution condition 24-1...24-M which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered. In some embodiments, said selecting comprises, if one of the multiple conditional reconfigurations 16S includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24- 1 ...24-M which has been fulfilled at least once during a time period prior to the connection reestablishment procedure being triggered, selecting that conditional reconfiguration . In other embodiments, said selecting comprises, else if the associated CPA execution condition 24-

[0227] 1...24-M or CPC execution condition 24-1...24-M has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered for any of the multiple conditional reconfigurations 16S that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, and if the multiple conditional reconfigurations 16S include a conditional reconfiguration that lacks any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, selecting the conditional reconfiguration that lacks any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M. In some embodiments, preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M which the associated CPA execution condition 24-1 ...24- M or CPC execution condition 24-1 ...24-M has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered further comprises, else if the associated CPA execution condition 24-1 ...24-M or CPC execution condition 24- 1 ...24-M has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered for any of the multiple conditional reconfigurations 16S that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, and if none of the multiple conditional reconfigurations 16S lack any associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, selecting a conditional reconfiguration that includes an associated CPA execution condition 24- 1...24-M or CPC execution condition 24-1 ...24-M even if the associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M has not been fulfilled at least once during the time period prior to the connection re-establishment procedure being triggered.

[0228] In some embodiments, at least some of the multiple conditional reconfigurations 16S are associated with different PSCells or SCGs, and selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations 16S. In some embodiments, selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations 16S comprises selecting the conditional reconfiguration associated with a PSCell or SCG whose radio measurement is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement. In some embodiments, selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations 16S comprises selecting the conditional reconfiguration associated with a PSCell or SCG whose radio measurement complies with a minimum requirement and is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement. In some embodiments, selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations 16S comprises, if at least one conditional reconfiguration is associated with a PSCell or SCG whose radio measurement complies with a minimum requirement, selecting a conditional reconfiguration associated with a PSCell or SCG whose radio measurement complies with the minimum requirement and is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement. In other embodiments, selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations 16S comprises, else if none of the conditional reconfigurations are associated with a PSCell or SCG whose radio measurement complies with the minimum requirement, selecting a conditional reconfiguration that is not associated with any PSCell or SCG. In some embodiments, a radio measurement complies with the minimum requirement if the radio measurement exceeds a minimum level. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises preferentially selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration. In some embodiments, said selecting comprises, if at least one of the conditional reconfigurations does not include any associated SCG or PSCell configuration, selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration. In other embodiments, said selecting comprises, else if none of the conditional reconfigurations lacks an associated SCG or PSCell configuration, selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises, if the communication device 12 is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations 16S include a release of the SCG or PSCell. In other embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises, if the communication device 12 is not configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations 16S does not include any associated SCG or PSCell configuration. In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration. In some embodiments, selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration comprises if the communication device 12 is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations 16S does not include a release of the SCG or PSCell. In other embodiments, selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration comprises if the communication device 12 is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations 16S includes an associated SCG or PSCell configuration with a target SCG or PSCell that is the same as the SCG or PSCell with which the communication device 12 is configured.

[0229] In some embodiments, making a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13 and / or selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises making a decision as to whether to apply any of the multiple conditional reconfigurations 16S to recover from the failure 13. In some embodiments, making the decision comprises making the decision based on whether any of the multiple conditional reconfigurations 16S lack an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M for multi-connectivity operation of the communication device 12. In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if none of the multiple conditional reconfigurations 16S lack an associated CPA execution condition 24- 1 ...24-M or an associated CPC execution condition 24-1 ...24-M. In some embodiments, making the decision comprises making the decision to apply one of the multiple conditional reconfigurations 16S to recover from the failure 13, if at least one of the multiple conditional reconfigurations 16S lack an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M, and selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition 24-1...24-M or CPC execution condition 24-1...24-M. In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if for any of the multiple conditional reconfigurations 16S that is associated with a CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M, the associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M is not fulfilled. In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if none of the multiple conditional reconfigurations 16S lacks an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1...24-M.

[0230] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, based on there being multiple conditional reconfigurations 16S stored at the communication device 12 for the selected cell 18S.

[0231] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, based on there being multiple conditional reconfigurations 16S stored at the communication device 12 for the selected cell 18S, even if the communication device 12 receives an indication from a network node that the communication device 12 is to perform conditional reconfiguration if the selected cell 18S is a target candidate cell and it is the first cell selection after the detected failure 13.

[0232] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if there are multiple conditional reconfigurations 16S stored at the communication device 12 for any cell.

[0233] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if there are multiple conditional reconfigurations 16S stored at the communication device 12 for any cell, even if the communication device 12 receives an indication from a network node that the communication device 12 is to perform conditional reconfiguration if the selected cell 18S is a target candidate cell and it is the first cell selection after the detected failure 13.

[0234] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if the communication device 12 is configured with a conditional reconfiguration with associated CPA or CPC execution conditions 24-1 ...24-M for any cell.

[0235] In some embodiments, making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations 16S to recover from the failure 13, if the communication device 12 is configured with a conditional reconfiguration with associated CPA or CPC execution conditions 24-1 .. ,24-M for any cell, even if the communication device 12 receives an indication from a network node that the communication device 12 is to perform conditional reconfiguration if the selected cell 18S is a target candidate cell and it is the first cell selection after the detected failure 13.

[0236] In some embodiments, selecting, from the multiple conditional reconfigurations 16S, a conditional reconfiguration to apply to recover from the failure 13 comprises, if multiple conditional reconfigurations 16S have been configured for the selected cell 18S, selecting a conditional reconfiguration which does not contain execution conditions 24-1 ...24-M for a CPC or CPA configuration, and wherein the method further comprises applying the selected conditional reconfiguration.

[0237] In some embodiments, making the decision or selecting the conditional reconfiguration is performed according to one or more rules with which the communication device 12 is configured.

[0238] In some embodiments, the method further comprises receiving, from a network node, signaling indicating the minimum requirement.

[0239] Figure 7 depicts a method performed by a communication device 12 in accordance with other particular embodiments. The method includes detecting a failure 13 (Block 700).

[0240] The method includes making a decision as to whether or not to perform cell selection to recover from the failure 13 (Block 710). The decision may be made based on: (i) whether or not the communication device 12 has stored any conditional reconfiguration that includes an associated CPA execution condition 24-1 ...24-M or CPC execution condition 24-1 ...24-M for any cell; (ii) whether or not the communication device 12 has stored multiple conditional reconfigurations 16S for any cell; (iii) whether or not the communication device 12 has stored multiple conditional reconfigurations 16S for each of one or more cells that are candidates for cell selection; and / or (iv) whether or not the communication device 12 has stored, for the same cell, multiple conditional reconfigurations 16S that are associated with respective CPA execution conditions 24-1 ...24-M or CPC execution conditions 24-1 ...24-M or that include respective PSCells or SCGs.

[0241] Regardless, the method further includes performing or not performing cell selection to recover from the failure 13 according to the decision (Block 720).

[0242] Figure 8 depicts a method performed by a network node 14 in accordance with other particular embodiments. The method comprises making a decision as to whether or not a communication device 12 is to apply a conditional reconfiguration for a target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12 (Block 800). The decision may be made based on: (i) whether or not the conditional reconfiguration includes an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M; and / or (ii) whether or not the conditional reconfiguration includes an associated PSCell or SCG for multi-connectivity operation. The method also comprises generating the conditional reconfiguration according to the decision (Block 810), and transmitting the conditional reconfiguration to the communication device 12 (Block 820).

[0243] In some embodiments, generating the conditional reconfiguration according to the decision comprises, according to the decision, generating the conditional reconfiguration to include or exclude an indication that the communication device 12 is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12. In some embodiments, the indication is, or is conveyed by, an attemptCondReconfig information element.

[0244] In some embodiments, making the decision comprises, if the conditional reconfiguration includes an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M, deciding that the communication device 12 is not to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12. In other embodiments, making the decision comprises, if the conditional reconfiguration does not include an associated CPA execution condition 24-1 ...24-M or an associated CPC execution condition 24-1 ...24-M, deciding that the communication device 12 is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12.

[0245] In some embodiments, making the decision comprises, if the conditional reconfiguration includes an associated PSCell or SCG for multi-connectivity operation, deciding that the communication device 12 is not to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12. In other embodiments, making the decision comprises, if the conditional reconfiguration does not include an associated PSCell or SCG for multi-connectivity operation, deciding that the communication device 12 is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure 13 detected by the communication device 12.

[0246] In some embodiments, the conditional reconfiguration is a CHO configuration.

[0247] In some embodiments, the failure 13 is a radio-related failure.

[0248] In some embodiments, the failure 13 is a failure 13 at one or more layers of a radio protocol stack at the communication device 12.

[0249] In some embodiments, the one or more layers at which the failure 13 occurs include one or more of: a Physical layer or Layer 1 ; a Medium Access Control, MAC, layer or Layer 2; and / or a Radio Link Control, RLC, layer or Layer 3.

[0250] In some embodiments, the failure 13 is: a Radio Link Failure, RLF; an RLF of an MCG; a failure 13 in a handover procedure; detected due to expiration of timer T304; a failure 13 in a conditional handover procedure; a failure 13 during a reconfiguration with sync procedure for an MCG; a mobility from New Radio (NR) failure; or a failure 13 of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure.

[0251] In some embodiments, the decision is a decision as to whether or not the communication device 12 is to apply a conditional reconfiguration for a target candidate cell if a cell on which the communication device 12 selects to camp as part of a connection re-establishment procedure is the target candidate cell and it is the first cell selection after the detected failure 13.

[0252] In some embodiments, the connection re-establishment procedure is a Radio Resource Control, RRC, connection re-establishment procedure.

[0253] Embodiments herein also include corresponding apparatuses. Embodiments herein for instance include a communication device 12 configured to perform any of the steps of any of the embodiments described above for the communication device 12.

[0254] Embodiments also include a communication device 12 comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the communication device 12. The power supply circuitry is configured to supply power to the communication device 12.

[0255] Embodiments further include a communication device 12 comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the communication device 12. In some embodiments, the communication device 12 further comprises communication circuitry.

[0256] Embodiments further include a communication device 12 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the communication device 12 is configured to perform any of the steps of any of the embodiments described above for the communication device 12. Embodiments moreover include a user equipment (UE). The UE comprises an antenna configured to send and receive wireless signals. The UE also comprises radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the communication device 12. In some embodiments, the UE also comprises an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry. The UE may comprise an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry. The UE may also comprise a battery connected to the processing circuitry and configured to supply power to the UE.

[0257] Embodiments herein also include a network node 14 configured to perform any of the steps of any of the embodiments described above for the network node 14.

[0258] Embodiments also include a network node 14 comprising processing circuitry and power supply circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the network node 14. The power supply circuitry is configured to supply power to the network node 14.

[0259] Embodiments further include a network node 14 comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the network node 14. In some embodiments, the network node 14 further comprises communication circuitry.

[0260] Embodiments further include a network node 14 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the network node 14 is configured to perform any of the steps of any of the embodiments described above for the network node 14.

[0261] More particularly, the apparatuses described above may perform the methods herein and any other processing by implementing any functional means, modules, units, or circuitry. In one embodiment, for example, the apparatuses comprise respective circuits or circuitry configured to perform the steps shown in the method figures. The circuits or circuitry in this regard may comprise circuits dedicated to performing certain functional processing and / or one or more microprocessors in conjunction with memory. For instance, the circuitry may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory, cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory may include program instructions for executing one or more telecommunications and / or data communications protocols as well as instructions for carrying out one or more of the techniques described herein, in several embodiments. In embodiments that employ memory, the memory stores program code that, when executed by the one or more processors, carries out the techniques described herein.

[0262] Figure 9 for example illustrates a communication device 12 as implemented in accordance with one or more embodiments. As shown, the communication device 12 includes processing circuitry 910 and communication circuitry 920. The communication circuitry 920 (e.g., radio circuitry) is configured to transmit and / or receive information to and / or from one or more other nodes, e.g., via any communication technology. Such communication may occur via one or more antennas that are either internal or external to the communication device 900. The processing circuitry 910 is configured to perform processing described above, e.g., in Figure 6 and / or Figure 7, such as by executing instructions stored in memory 930. The processing circuitry 910 in this regard may implement certain functional means, units, or modules.

[0263] Figure 10 illustrates a network node 14 as implemented in accordance with one or more embodiments. As shown, the network node 14 includes processing circuitry 1010 and communication circuitry 1020. The communication circuitry 1020 is configured to transmit and / or receive information to and / or from one or more other nodes, e.g., via any communication technology. The processing circuitry 1010 is configured to perform processing described above, e.g., in Figure 8, such as by executing instructions stored in memory 1030. The processing circuitry 1010 in this regard may implement certain functional means, units, or modules.

[0264] Those skilled in the art will also appreciate that embodiments herein further include corresponding computer programs.

[0265] A computer program comprises instructions which, when executed on at least one processor of an apparatus, cause the apparatus to carry out any of the respective processing described above. A computer program in this regard may comprise one or more code modules corresponding to the means or units described above.

[0266] Embodiments further include a carrier containing such a computer program. This carrier may comprise one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

[0267] In this regard, embodiments herein also include a computer program product stored on a non-transitory computer readable (storage or recording) medium and comprising instructions that, when executed by a processor of an apparatus, cause the apparatus to perform as described above.

[0268] Embodiments further include a computer program product comprising program code portions for performing the steps of any of the embodiments herein when the computer program product is executed by a computing device. This computer program product may be stored on a computer readable recording medium. Figure 11 shows an example of a communication system 1100 in accordance with some embodiments.

[0269] In the example, the communication system 1100 includes a telecommunication network 1102 that includes an access network 1104, such as a radio access network (RAN), and a core network 1106, which includes one or more core network nodes 1108. The access network 1104 includes one or more access network nodes, such as network nodes 1110a and 1110b (one or more of which may be generally referred to as network nodes 1110), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points. 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 include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 1102 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 1102 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 1102, including one or more network nodes 1110 and / or core network nodes 1108.

[0270] 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 1110 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1112a, 1112b, 1112c, and 1112d (one or more of which may be generally referred to as UEs 1112) to the core network 1106 over one or more wireless connections.

[0271] 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 1100 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 1100 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0272] The UEs 1112 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 1110 and other communication devices. Similarly, the network nodes 1110 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 1112 and / or with other network nodes or equipment in the telecommunication network 1102 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 1102.

[0273] In the depicted example, the core network 1106 connects the network nodes 1110 to one or more hosts, such as host 1116. 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 1106 includes one more core network nodes (e.g., core network node 1108) 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 1108. 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).

[0274] The host 1116 may be under the ownership or control of a service provider other than an operator or provider of the access network 1104 and / or the telecommunication network 1102, and may be operated by the service provider or on behalf of the service provider. The host 1116 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. As a whole, the communication system 1100 of Figure 11 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 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 other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 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.

[0275] In some examples, the telecommunication network 1102 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 1102 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1102. For example, the telecommunications network 1102 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)ZMassive loT services to yet further UEs.

[0276] In some examples, the UEs 1112 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 1104 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1104. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0277] In the example, the hub 1114 communicates with the access network 1104 to facilitate indirect communication between one or more UEs (e.g., UE 1112c and / or 1112d) and network nodes (e.g., network node 1110b). In some examples, the hub 1114 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1114 may be a broadband router enabling access to the core network 1106 for the UEs. As another example, the hub 1114 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 1110, or by executable code, script, process, or other instructions in the hub 1114. As another example, the hub 1114 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 1114 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 1114 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1114 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1114 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0278] The hub 1114 may have a constant / persistent or intermittent connection to the network node 1110b. The hub 1114 may also allow for a different communication scheme and / or schedule between the hub 1114 and UEs (e.g., UE 1112c and / or 1112d), and between the hub 1114 and the core network 1106. In other examples, the hub 1114 is connected to the core network 1106 and / or one or more UEs via a wired connection. Moreover, the hub 1114 may be configured to connect to an M2M service provider over the access network 1104 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1110 while still connected via the hub 1114 via a wired or wireless connection. In some embodiments, the hub 1114 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 1110b. In other embodiments, the hub 1114 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1110b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0279] Figure 12 shows a UE 1200 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 IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, 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 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB- loT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0280] 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).

[0281] The UE 1200 includes processing circuitry 1202 that is operatively coupled via a bus 1204 to an input / output interface 1206, a power source 1208, a memory 1210, a communication interface 1212, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 12. 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.

[0282] The processing circuitry 1202 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 1210. The processing circuitry 1202 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 1202 may include multiple central processing units (CPUs).

[0283] In the example, the input / output interface 1206 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 1200. 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. An output 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.

[0284] In some embodiments, the power source 1208 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 1208 may further include power circuitry for delivering power from the power source 1208 itself, and / or an external power source, to the various parts of the UE 1200 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 1208. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 1208 to make the power suitable for the respective components of the UE 1200 to which power is supplied.

[0285] The memory 1210 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 1210 includes one or more application programs 1214, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1216. The memory 1210 may store, for use by the UE 1200, any of a variety of various operating systems or combinations of operating systems.

[0286] The memory 1210 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 random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUlCC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 1210 may allow the UE 1200 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 1210, which may be or comprise a device-readable storage medium.

[0287] The processing circuitry 1202 may be configured to communicate with an access network or other network using the communication interface 1212. The communication interface 1212 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1222. The communication interface 1212 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 1218 and / or a receiver 1220 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1218 and receiver 1220 may be coupled to one or more antennas (e.g., antenna 1222) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0288] In the illustrated embodiment, communication functions of the communication interface 1212 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, 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 in according to one or more communication protocols and / or standards, such as IEEE 802.11 , Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0289] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1212, 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).

[0290] 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 surfaces or 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.

[0291] A UE, when in the form of an Internet of Things (loT) 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 loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, 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 Virtual Reality (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 loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 1200 shown in Figure 12.

[0292] As yet another specific example, in an loT 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-loT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0293] 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.

[0294] Figure 13 shows a network node 1300 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, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0295] 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 remote radio units 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).

[0296] 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 base station 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).

[0297] The network node 1300 includes a processing circuitry 1302, a memory 1304, a communication interface 1306, and a power source 1308. The network node 1300 may be composed of multiple physically separate components (e.g., a NodeB component and a 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 1300 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 1300 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1304 for different RATs) and some components may be reused (e.g., a same antenna 1310 may be shared by different RATs). The network node 1300 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1300, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, 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 network node 1300.

[0298] The processing circuitry 1302 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, 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 1300 components, such as the memory 1304, to provide network node 1300 functionality.

[0299] In some embodiments, the processing circuitry 1302 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1302 includes one or more of radio frequency (RF) transceiver circuitry 1312 and baseband processing circuitry 1314. In some embodiments, the radio frequency (RF) transceiver circuitry 1312 and the baseband processing circuitry 1314 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 RF transceiver circuitry 1312 and baseband processing circuitry 1314 may be on the same chip or set of chips, boards, or units.

[0300] The memory 1304 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, random access memory (RAM), read-only memory (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 1302. The memory 1304 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 1302 and utilized by the network node 1300. The memory 1304 may be used to store any calculations made by the processing circuitry 1302 and / or any data received via the communication interface 1306. In some embodiments, the processing circuitry 1302 and memory 1304 is integrated.

[0301] The communication interface 1306 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 1306 comprises port(s) / terminal(s) 1316 to send and receive data, for example to and from a network over a wired connection. The communication interface 1306 also includes radio front-end circuitry 1318 that may be coupled to, or in certain embodiments a part of, the antenna 1310. Radio front-end circuitry 1318 comprises filters 1320 and amplifiers 1322. The radio front-end circuitry 1318 may be connected to an antenna 1310 and processing circuitry 1302. The radio front-end circuitry may be configured to condition signals communicated between antenna 1310 and processing circuitry 1302. The radio front-end circuitry 1318 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 1318 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1320 and / or amplifiers 1322. The radio signal may then be transmitted via the antenna 1310. Similarly, when receiving data, the antenna 1310 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1318. The digital data may be passed to the processing circuitry 1302. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0302] In certain alternative embodiments, the network node 1300 does not include separate radio front-end circuitry 1318, instead, the processing circuitry 1302 includes radio front-end circuitry and is connected to the antenna 1310. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1312 is part of the communication interface 1306. In still other embodiments, the communication interface 1306 includes one or more ports or terminals 1316, the radio front-end circuitry 1318, and the RF transceiver circuitry 1312, as part of a radio unit (not shown), and the communication interface 1306 communicates with the baseband processing circuitry 1314, which is part of a digital unit (not shown).

[0303] The antenna 1310 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1310 may be coupled to the radio front-end circuitry 1318 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1310 is separate from the network node 1300 and connectable to the network node 1300 through an interface or port.

[0304] The antenna 1310, communication interface 1306, and / or the processing circuitry 1302 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1310, the communication interface 1306, and / or the processing circuitry 1302 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0305] The power source 1308 provides power to the various components of network node 1300 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1308 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1300 with power for performing the functionality described herein. For example, the network node 1300 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1308. As a further example, the power source 1308 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.

[0306] Embodiments of the network node 1300 may include additional components beyond those shown in Figure 13 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 1300 may include user interface equipment to allow input of information into the network node 1300 and to allow output of information from the network node 1300. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1300.

[0307] Figure 14 is a block diagram of a host 1400, which may be an embodiment of the host 1116 of Figure 11 , in accordance with various aspects described herein. As used herein, the host 1400 may be or comprise various combinations 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 1400 may provide one or more services to one or more UEs.

[0308] The host 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to an input / output interface 1406, a network interface 1408, a power source 1410, and a memory 1412. 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 12 and 13, such that the descriptions thereof are generally applicable to the corresponding components of host 1400.

[0309] The memory 1412 may include one or more computer programs including one or more host application programs 1414 and data 1416, which may include user data, e.g., data generated by a UE for the host 1400 or data generated by the host 1400 for a UE. Embodiments of the host 1400 may utilize only a subset or all of the components shown. The host application programs 1414 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (WC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., 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, heads-up display systems). The host application programs 1414 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 1400 may select and / or indicate a different host for over-the-top services for a UE. The host application programs 1414 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 (MPEG-DASH), etc.

[0310] Figure 15 is a block diagram illustrating a virtualization environment 1500 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 1500 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 1500 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface.

[0311] Applications 1502 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0312] Hardware 1504 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 1506 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1508a and 1508b (one or more of which may be generally referred to as VMs 1508), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1506 may present a virtual operating platform that appears like networking hardware to the VMs 1508.

[0313] The VMs 1508 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1506. Different embodiments of the instance of a virtual appliance 1502 may be implemented on one or more of VMs 1508, 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.

[0314] In the context of NFV, a VM 1508 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 1508, and that part of hardware 1504 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, 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 1508 on top of the hardware 1504 and corresponds to the application 1502.

[0315] Hardware 1504 may be implemented in a standalone network node with generic or specific components. Hardware 1504 may implement some functions via virtualization. Alternatively, hardware 1504 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 1510, which, among others, oversees lifecycle management of applications 1502. In some embodiments, hardware 1504 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 radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1512 which may alternatively be used for communication between hardware nodes and radio units.

[0316] Figure 16 shows a communication diagram of a host 1602 communicating via a network node 1604 with a UE 1606 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 1112a of Figure 11 and / or UE 1200 of Figure 12), network node (such as network node 1110a of Figure 11 and / or network node 1300 of Figure 13), and host (such as host 1116 of Figure 11 and / or host 1400 of Figure 14) discussed in the preceding paragraphs will now be described with reference to Figure 16.

[0317] Like host 1400, embodiments of host 1602 include hardware, such as a communication interface, processing circuitry, and memory. The host 1602 also includes software, which is stored in or accessible by the host 1602 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 1606 connecting via an over-the-top (OTT) connection 1650 extending between the UE 1606 and host 1602. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1650.

[0318] The network node 1604 includes hardware enabling it to communicate with the host 1602 and UE 1606. The connection 1660 may be direct or pass through a core network (like core network 1106 of Figure 11) 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.

[0319] The UE 1606 includes hardware and software, which is stored in or accessible by UE 1606 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 UE 1606 with the support of the host 1602. In the host 1602, an executing host application may communicate with the executing client application via the OTT connection 1650 terminating at the UE 1606 and host 1602. 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 1650 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 1650. The OTT connection 1650 may extend via a connection 1660 between the host 1602 and the network node 1604 and via a wireless connection 1670 between the network node 1604 and the UE 1606 to provide the connection between the host 1602 and the UE 1606. The connection 1660 and wireless connection 1670, over which the OTT connection 1650 may be provided, have been drawn abstractly to illustrate the communication between the host 1602 and the UE 1606 via the network node 1604, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

[0320] As an example of transmitting data via the OTT connection 1650, in step 1608, the host 1602 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 1606. In other embodiments, the user data is associated with a UE 1606 that shares data with the host 1602 without explicit human interaction. In step 1610, the host 1602 initiates a transmission carrying the user data towards the UE 1606. The host 1602 may initiate the transmission responsive to a request transmitted by the UE 1606. The request may be caused by human interaction with the UE 1606 or by operation of the client application executing on the UE 1606. The transmission may pass via the network node 1604, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1612, the network node 1604 transmits to the UE 1606 the user data that was carried in the transmission that the host 1602 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1614, the UE 1606 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1606 associated with the host application executed by the host 1602.

[0321] In some examples, the UE 1606 executes a client application which provides user data to the host 1602. The user data may be provided in reaction or response to the data received from the host 1602. Accordingly, in step 1616, the UE 1606 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 1606. Regardless of the specific manner in which the user data was provided, the UE 1606 initiates, in step 1618, transmission of the user data towards the host 1602 via the network node 1604. In step 1620, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1604 receives user data from the UE 1606 and initiates transmission of the received user data towards the host 1602. In step 1622, the host 1602 receives the user data carried in the transmission initiated by the UE 1606.

[0322] One or more of the various embodiments improve the performance of OTT services provided to the UE 1606 using the OTT connection 1650, in which the wireless connection 1670 forms the last segment. In an example scenario, factory status information may be collected and analyzed by the host 1602. As another example, the host 1602 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1602 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 1602 may store surveillance video uploaded by a UE. As another example, the host 1602 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 1602 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.

[0323] 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 1650 between the host 1602 and UE 1606, in response to variations in the measurement results. The measurement procedure and / or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1602 and / or UE 1606. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1650 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1650 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1604. 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 1602. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 1650 while monitoring propagation times, errors, etc.

[0324] 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.

[0325] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on 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 hard-wired 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.

[0326] Some embodiments herein may be enumerated as follows:

[0327] Group A Embodiments

[0328] A1 . A method performed by a communication device, the method comprising: in response to detecting a failure, performing cell selection as part of a connection re-establishment procedure in order to select a cell on which to camp; determining that multiple conditional reconfigurations are stored at the communication device for the selected cell; and based on the multiple conditional reconfigurations being stored at the communication device for the selected cell, making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure and / or selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure.

[0329] A2. The method of embodiment A1 , wherein the multiple conditional reconfigurations are multiple conditional handover, CHO, configurations for the selected cell. A3. The method of any of embodiments A1 -A2, wherein the selected cell is a candidate target Primary Cell, PCell and / or is included in a Master Cell Group, MCG.

[0330] A4. The method of embodiment A3, wherein at least some of the multiple conditional reconfigurations include or correspond to: different associated Primary Secondary Cells, PSCells, for multi-connectivity operation of the communication device; or different associated Secondary Cell Groups, SCGs, for multi-connectivity operation of the communication device.

[0331] A5. The method of any of embodiments A3-A4, wherein at least some of the multiple conditional reconfigurations include different associated Conditional PSCell Addition, CPA, execution conditions or different associated Conditional PSCell Change, CPC, execution conditions for multi-connectivity operation of the communication device.

[0332] A6. The method of any of embodiments A3-A5, wherein at least one of the multiple conditional reconfigurations lacks any associated Conditional PSCell Addition, CPA, execution condition or any associated Conditional PSCell Change, CPC, execution condition for multi-connectivity operation of the communication device.

[0333] A7. The method of any of embodiments A1 -A6, wherein the failure is a radio-related failure.

[0334] A8. The method of any of embodiments A1 -A7, wherein the failure is a failure at one or more layers of a radio protocol stack at the communication device.

[0335] A9. The method of embodiment A8, wherein the one or more layers at which the failure occurs include one or more of: a Physical layer or Layer 1 ; a Medium Access Control, MAC, layer or Layer 2; and / or a Radio Link Control, RLC, layer or Layer 3.

[0336] A9. The method of any of embodiments A1 -A8, wherein the failure is: a Radio Link Failure, RLF; an RLF of an MCG; a failure in a handover procedure; detected due to expiration of timer T304; a failure in a conditional handover procedure; a failure during a reconfiguration with sync procedure for an MCG; a mobility from New Radio (NR) failure; or a failure of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure.

[0337] A10. The method of any of embodiments A1-A9, wherein the connection re-establishment procedure is a Radio Resource Control, RRC, connection re-establishment procedure.

[0338] A11 . The method of any of embodiments A1 -A10, wherein performing cell selection comprises selecting a suitable cell on which to camp according to one or more criteria defining suitability of a cell.

[0339] A12. The method of any of embodiments A1-A11 , further comprising: receiving the multiple conditional reconfigurations; after receiving the multiple conditional reconfigurations, storing the multiple conditional reconfigurations at the communication device; and after storing the multiple conditional reconfigurations, detecting the failure.

[0340] A13. The method of any of embodiments A1 -A12, wherein determining that multiple conditional reconfigurations are stored at the communication device for the selected cell comprises: determining that the selected cell is a target cell of multiple conditional reconfigurations that the communication device has stored; or determining that the communication device is configured with multiple conditional reconfigurations for the selected cell.

[0341] A14. The method of any of embodiments A1 -A13, wherein making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure and / or selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure, and wherein the method further comprises applying the selected conditional reconfiguration for the selected cell to recover from the failure.

[0342] A15. The method of embodiment A14, further comprising transmitting, in the selected cell, a notification message according to the selected conditional reconfiguration.

[0343] A16. The method of embodiment A15, wherein the notification message is an RRC Reconfiguration Complete message.

[0344] A17. The method of any of embodiments A15-A16, wherein the selected conditional reconfiguration includes an SCG configuration or a PSCell configuration, and wherein the notification message includes an indication to a target PSCell or target Secondary Node, SN.

[0345] A18. The method of any of embodiments A1 -A13, wherein making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure and / or selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure.

[0346] A19. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition.

[0347] A20. The method of embodiment A19, wherein selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition and that: includes an MCG or PCell configuration but excludes an SCG or PSCell configuration; or includes an indication that any SCG configuration of the communication device is to be released; or includes both an MCG or PCell configuration and an SCG or PSCell configuration, but the SCG or PSCell configuration does not include any associated CPA execution condition or CPC execution condition.

[0348] A21. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises preferentially selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition, by: if at least one of the multiple conditional reconfigurations lacks an associated CPA execution condition or an associated CPC execution condition, selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition; and else if none of the multiple conditional reconfigurations lacks an associated CPA execution condition or an associated CPC execution condition, selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition.

[0349] A22. The method of embodiment A21 , wherein selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition comprises selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which is fulfilled.

[0350] A22. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which is fulfilled.

[0351] A23. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered.

[0352] A24. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which is fulfilled, by: if one of the multiple conditional reconfigurations includes an associated CPA execution condition or CPC execution condition which is fulfilled, selecting that conditional reconfiguration; or else if the associated CPA execution condition or CPC execution condition is not fulfilled for any of the multiple conditional reconfigurations that includes an associated CPA execution condition or CPC execution condition, and if the multiple conditional reconfigurations include a conditional reconfiguration that lacks any associated CPA execution condition or CPC execution condition, selecting the conditional reconfiguration that lacks any associated CPA execution condition or CPC execution condition.

[0353] A25. The method of embodiment A24, preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which is fulfilled further comprises: else if the associated CPA execution condition or CPC execution condition is not fulfilled for any of the multiple conditional reconfigurations that includes an associated CPA execution condition or CPC execution condition, and if none of the multiple conditional reconfigurations lack any associated CPA execution condition or CPC execution condition, selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition even if the associated CPA execution condition or CPC execution condition is not fulfilled.

[0354] A26. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered, by: if one of the multiple conditional reconfigurations includes an associated CPA execution condition or CPC execution condition which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered, selecting that conditional reconfiguration; or else if the associated CPA execution condition or CPC execution condition has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered for any of the multiple conditional reconfigurations that includes an associated CPA execution condition or CPC execution condition, and if the multiple conditional reconfigurations include a conditional reconfiguration that lacks any associated CPA execution condition or CPC execution condition, selecting the conditional reconfiguration that lacks any associated CPA execution condition or CPC execution condition.

[0355] A27. The method of embodiment A26, preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition which the associated CPA execution condition or CPC execution condition has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered further comprises: else if the associated CPA execution condition or CPC execution condition has not been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered for any of the multiple conditional reconfigurations that includes an associated CPA execution condition or CPC execution condition, and if none of the multiple conditional reconfigurations lack any associated CPA execution condition or CPC execution condition, selecting a conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition even if the associated CPA execution condition or CPC execution condition has not been fulfilled at least once during the time period prior to the connection re-establishment procedure being triggered.

[0356] A28. The method of embodiment A18, wherein at least some of the multiple conditional reconfigurations are associated with different PSCells or SCGs, and wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations.

[0357] A29. The method of embodiment A28, wherein selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations comprises selecting the conditional reconfiguration associated with a PSCell or SCG whose radio measurement is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement.

[0358] A30. The method of embodiment A28, wherein selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations comprises selecting the conditional reconfiguration associated with a PSCell or SCG whose radio measurement complies with a minimum requirement and is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement.

[0359] A31. The method of embodiment A28, wherein selecting the conditional reconfiguration based on radio measurements for the PSCells or SCGs associated with the at least some of the multiple conditional reconfigurations comprises: if at least one conditional reconfiguration is associated with a PSCell or SCG whose radio measurement complies with a minimum requirement, selecting a conditional reconfiguration associated with a PSCell or SCG whose radio measurement complies with the minimum requirement and is best, as compared to the radio measurements for one or more other PSCells or SCGs associated with one or more other conditional reconfigurations, according to one or more rules for determining whether one radio measurement is better than another radio measurement; or else if none of the conditional reconfigurations are associated with a PSCell or SCG whose radio measurement complies with the minimum requirement, selecting a conditional reconfiguration that is not associated with any PSCell or SCG.

[0360] A32. The method of any of embodiments A30-A31 , wherein a radio measurement complies with the minimum requirement if the radio measurement exceeds a minimum level.

[0361] A33. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration.

[0362] A34. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises preferentially selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration, by: if at least one of the conditional reconfigurations does not include any associated SCG or PSCell configuration, selecting a conditional reconfiguration that does not include any associated SCG or PSCell configuration; or else if none of the conditional reconfigurations lacks an associated SCG or PSCell configuration, selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration.

[0363] A35. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises: if the communication device is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations include a release of the SCG or PSCell; or if the communication device is not configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations does not include any associated SCG or PSCell configuration.

[0364] A36. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration.

[0365] A37. The method of embodiment A36, wherein selecting a conditional reconfiguration that includes an associated SCG or PSCell configuration comprises: if the communication device is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations does not include a release of the SCG or PSCell; or if the communication device is configured with an SCG or PSCell when performing cell selection, selecting the conditional reconfiguration from among whichever of the multiple conditional reconfigurations includes an associated SCG or PSCell configuration with a target SCG or PSCell that is the same as the SCG or PSCell with which the communication device is configured.

[0366] A38. The method of any of embodiments A1-A37, wherein making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure and / or selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises making a decision as to whether to apply any of the multiple conditional reconfigurations to recover from the failure.

[0367] A39. The method of embodiment A38, wherein making the decision comprises making the decision based on whether any of the multiple conditional reconfigurations lack an associated CPA execution condition or an associated CPC execution condition for multi-connectivity operation of the communication device.

[0368] A40. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if none of the multiple conditional reconfigurations lack an associated CPA execution condition or an associated CPC execution condition.

[0369] A41 . The method of embodiment A38, wherein making the decision comprises making the decision to apply one of the multiple conditional reconfigurations to recover from the failure, if at least one of the multiple conditional reconfigurations lack an associated CPA execution condition or an associated CPC execution condition, and wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition or CPC execution condition.

[0370] A42. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if: for any of the multiple conditional reconfigurations that is associated with a CPA execution condition or CPC execution condition, the associated CPA execution condition or CPC execution condition is not fulfilled; and none of the multiple conditional reconfigurations lacks an associated CPA execution condition or an associated CPC execution condition.

[0371] A43. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, based on there being multiple conditional reconfigurations stored at the communication device for the selected cell.

[0372] A44. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, based on there being multiple conditional reconfigurations stored at the communication device for the selected cell, even if the communication device receives an indication from a network node that the communication device is to perform conditional reconfiguration if the selected cell is a target candidate cell and it is the first cell selection after the detected failure.

[0373] A45. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if there are multiple conditional reconfigurations stored at the communication device for any cell.

[0374] A46. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if there are multiple conditional reconfigurations stored at the communication device for any cell, even if the communication device receives an indication from a network node that the communication device is to perform conditional reconfiguration if the selected cell is a target candidate cell and it is the first cell selection after the detected failure.

[0375] A47. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if the communication device is configured with a conditional reconfiguration with associated CPA or CPC execution conditions for any cell.

[0376] A48. The method of embodiment A38, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations to recover from the failure, if the communication device is configured with a conditional reconfiguration with associated CPA or CPC execution conditions for any cell, even if the communication device receives an indication from a network node that the communication device is to perform conditional reconfiguration if the selected cell is a target candidate cell and it is the first cell selection after the detected failure.

[0377] A49. The method of embodiment A18, wherein selecting, from the multiple conditional reconfigurations, a conditional reconfiguration to apply to recover from the failure comprises, if multiple conditional reconfigurations have been configured for the selected cell, selecting a conditional reconfiguration which does not contain execution conditions for a CPC or CPA configuration, and wherein the method further comprises applying the selected conditional reconfiguration.

[0378] A50. The method of any of embodiments A1 -A49, wherein making the decision or selecting the conditional reconfiguration is performed according to one or more rules with which the communication device is configured.

[0379] A51 . The method of any of embodiments A30-A31 , further comprising receiving, from a network node, signaling indicating the minimum requirement.

[0380] AA1. A method performed by a communication device, the method comprising: detecting a failure; making a decision as to whether or not to perform cell selection to recover from the failure, based on: whether or not the communication device has stored any conditional reconfiguration that includes an associated CPA execution condition or CPC execution condition for any cell; whether or not the communication device has stored multiple conditional reconfigurations for any cell; whether or not the communication device has stored multiple conditional reconfigurations for each of one or more cells that are candidates for cell selection; and / or whether or not the communication device has stored, for the same cell, multiple conditional reconfigurations that are associated with respective CPA execution conditions or CPC execution conditions or that include respective PSCells or SCGs; and performing or not performing cell selection to recover from the failure according to the decision.

[0381] AA2. The method of embodiment AA1 , further comprising any of the steps of any of embodiments A1 -A51 .

[0382] AA. The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host computer via the transmission to a base station.

[0383] Group B Embodiments

[0384] B1 . A method performed by a network node, the method comprising: making a decision as to whether or not a communication device is to apply a conditional reconfiguration for a target candidate cell in order to attempt to recover from a failure detected by the communication device, wherein the decision is made based on: whether or not the conditional reconfiguration includes an associated CPA execution condition or an associated CPC execution condition; and / or whether or not the conditional reconfiguration includes an associated PSCell or SCG for multi-connectivity operation; generating the conditional reconfiguration according to the decision; and transmitting the conditional reconfiguration to the communication device.

[0385] B2. The method of embodiment B1 , wherein generating the conditional reconfiguration according to the decision comprises, according to the decision, generating the conditional reconfiguration to include or exclude an indication that the communication device is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure detected by the communication device.

[0386] B3. The method of embodiment B2, wherein the indication is, or is conveyed by, an attemptCondReconfig information element.

[0387] B4. The method of any of embodiments B1 -B3, wherein making the decision comprises: if the conditional reconfiguration includes an associated CPA execution condition or an associated CPC execution condition, deciding that the communication device is not to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure detected by the communication device; or if the conditional reconfiguration does not include an associated CPA execution condition or an associated CPC execution condition, deciding that the communication device is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure detected by the communication device.

[0388] B5. The method of any of embodiments B1 -B3, wherein making the decision comprises: if the conditional reconfiguration includes an associated PSCell or SCG for multiconnectivity operation, deciding that the communication device is not to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure detected by the communication device; or if the conditional reconfiguration does not include an associated PSCell or SCG for multiconnectivity operation, deciding that the communication device is to apply the conditional reconfiguration for the target candidate cell in order to attempt to recover from a failure detected by the communication device.

[0389] B6. The method of any of embodiments B1 -B5, wherein the conditional reconfiguration is a CHO configuration.

[0390] B7. The method of any of embodiments B1 -B6, wherein the failure is a radio-related failure.

[0391] B8. The method of any of embodiments B1 -B7, wherein the failure is a failure at one or more layers of a radio protocol stack at the communication device.

[0392] B9. The method of embodiment B8, wherein the one or more layers at which the failure occurs include one or more of: a Physical layer or Layer 1 ; a Medium Access Control, MAC, layer or Layer 2; and / or a Radio Link Control, RLC, layer or Layer 3.

[0393] B9. The method of any of embodiments B1 -B8, wherein the failure is: a Radio Link Failure, RLF; an RLF of an MCG; a failure in a handover procedure; detected due to expiration of timer T304; a failure in a conditional handover procedure; a failure during a reconfiguration with sync procedure for an MCG; a mobility from New Radio (NR) failure; or a failure of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure.

[0394] B10. The method of any of embodiments B1 -B9, wherein the decision is a decision as to whether or not the communication device is to apply a conditional reconfiguration for a target candidate cell if a cell on which the communication device selects to camp as part of a connection re-establishment procedure is the target candidate cell and it is the first cell selection after the detected failure.

[0395] B11. The method of embodiment B10, wherein the connection re-establishment procedure is a Radio Resource Control, RRC, connection re-establishment procedure.

[0396] BB. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host computer or a communication device.

[0397] Group C Embodiments

[0398] C1. A communication device configured to perform the method of any of the Group A embodiments.

[0399] C2. A communication device comprising processing circuitry configured to perform the method of any of the Group A embodiments.

[0400] C3. A communication device comprising: communication circuitry; and processing circuitry configured to perform the method of any of the Group A embodiments.

[0401] C4. A communication device comprising: processing circuitry configured to perform the method of any of the Group A embodiments; and power supply circuitry configured to supply power to the communication device.

[0402] C5. A communication device comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the communication device is configured to perform the method of any of the Group A embodiments.

[0403] C6. The communication device of any of embodiments C1 -C5, wherein the communication device is a wireless communication device.

[0404] C7. A user equipment (UE) comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform the method of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

[0405] C8. A computer program comprising instructions which, when executed by at least one processor of a communication device, causes the communication device to perform the method of any of the Group A embodiments.

[0406] C9. A carrier containing the computer program of embodiment C7, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

[0407] C10. A network node configured to perform the method of any of the Group B embodiments.

[0408] C11 . A network node comprising processing circuitry configured to perform the method of any of the Group B embodiments.

[0409] C12. A network node comprising: communication circuitry; and processing circuitry configured to perform the method of any of the Group B embodiments. C13. A network node comprising: processing circuitry configured to perform the method of any of the Group B embodiments; power supply circuitry configured to supply power to the network node.

[0410] C14. A network node comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the network node is configured to perform the method of any of the Group B embodiments.

[0411] C15. The network node of any of embodiments C10-C14, wherein the network node is a base station.

[0412] C16. A computer program comprising instructions which, when executed by at least one processor of a network node, causes the network node to perform the method of any of the Group B embodiments.

[0413] C17. The computer program of embodiment C16, wherein the network node is a base station.

[0414] C18. A carrier containing the computer program of any of embodiments C16-C17, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

[0415] Group D Embodiments

[0416] D1 . A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user 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 the Group B embodiments to transmit the user data from the host to the UE.

[0417] D2. 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.

[0418] D3. 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 the Group B embodiments to transmit the user data from the host to the UE.

[0419] D4. The method of the previous embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.

[0420] D5. 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.

[0421] D6. 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 the Group B embodiments to transmit the user data from the host to the UE.

[0422] D7. The communication system of the previous embodiment, further comprising: the network node; and / or the UE.

[0423] D8. 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 processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to receive the user data from a user equipment (UE) for the host.

[0424] D9. 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.

[0425] D10. The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.

[0426] D11 . 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 the Group B embodiments to receive the user data from the UE for the host.

[0427] D12. The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.

[0428] D13. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the operations of any of the Group A embodiments to receive the user data from the host. D14. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host.

[0429] D15. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing 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.

[0430] D16. A method implemented by a host operating 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 UE performs any of the operations of any of the Group A embodiments to receive the user data from the host.

[0431] D17. The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the host application.

[0432] D18. The method of the previous embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

[0433] D19. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to transmit the user data to the host. D20. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.

[0434] D21 . The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing 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.

[0435] D22. 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, receiving user data transmitted to the host via the network node by the UE, wherein the UE performs any of the steps of any of the Group A embodiments to transmit the user data to the host.

[0436] D23. The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

[0437] D24. The method of the previous 2 embodiments, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

Claims

CLAIMS1 . A method performed by a communication device (12), the method comprising: in response to detecting a failure (13), performing (600) cell selection as part of a connection re-establishment procedure in order to select a cell; and making (620) a decision as to whether to apply any of multiple conditional reconfigurations (16S) stored at the communication device (12) for the selected cell (18S) to recover from the failure (13) and / or selecting (620), from the multiple conditional reconfigurations (16S) stored at the communication device (12) for the selected cell (18S), a conditional reconfiguration to apply to recover from the failure (13).

2. The method of claim 1 , wherein the multiple conditional reconfigurations (16S) are multiple conditional handover, CHO, configurations for the selected cell (18S).

3. The method of any of claims 1-2, wherein the selected cell (18S) is a candidate target Primary Cell, PCell and / or is included in a Master Cell Group, MCG.

4. The method of claim 3, wherein at least some of the multiple conditional reconfigurations (16S) include or correspond to: different associated Primary Secondary Cells, PSCells, for multi-connectivity operation of the communication device (12); or different associated Secondary Cell Groups, SCGs, for multi-connectivity operation of the communication device (12).

5. The method of any of claims 3-4, wherein at least some of the multiple conditional reconfigurations (16S) include different associated Conditional PSCell Addition, CPA, execution conditions (24-1 ...24-M) or different associated Conditional PSCell Change, CPC, execution conditions (24-1 ...24-M) for multi-connectivity operation of the communication device (12).

6. The method of any of claims 3-5, wherein at least one of the multiple conditional reconfigurations (16S) lacks any associated Conditional PSCell Addition, CPA, execution condition (24-1 ...24-M) or any associated Conditional PSCell Change, CPC, execution condition (24-1 ...24-M) for multi-connectivity operation of the communication device (12).

7. The method of any of claims 1-6, wherein the failure (13) is: a Radio Link Failure, RLF; an RLF of an MCG;a failure (13) in a handover procedure; detected due to expiration of timer T304; a failure (13) in a conditional handover procedure; a failure (13) during a reconfiguration with sync procedure for an MCG; a mobility from New Radio (NR) failure; or a failure (13) of a Layer 1 I Layer 2 triggered mobility (LTM) cell switch procedure.

8. The method of any of claims 1-7, wherein the connection re-establishment procedure is a Radio Resource Control, RRC, connection re-establishment procedure.

9. The method of any of claims 1-8, further comprising: receiving (630) the multiple conditional reconfigurations (16S); after receiving the multiple conditional reconfigurations (16S), storing (640) the multiple conditional reconfigurations (16S) at the communication device (12); and after storing the multiple conditional reconfigurations (16S), detecting (650) the failure (13).

10. The method of any of claims 1-9, further comprising determining (610) that the multiple conditional reconfigurations (16S) are stored at the communication device (12) for the selected cell (18S) by: determining that the selected cell (18S) is a target cell of multiple conditional reconfigurations (16S) that the communication device (12) has stored; or determining that the communication device (12) is configured with multiple conditional reconfigurations (16S) for the selected cell (18S).

11. The method of any of claims 1-10, wherein making a decision as to whether to apply any of the multiple conditional reconfigurations (16S) to recover from the failure (13) and / or selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13), and wherein the method further comprises applying the selected conditional reconfiguration for the selected cell (18S) to recover from the failure (13).

12. The method of claim 11 , wherein selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition (24- 1 ...24-M) or CPC execution condition (24-1 ...24-M).

13. The method of claim 12, wherein selecting a conditional reconfiguration that does not include any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) comprises selecting a conditional reconfiguration that does not include any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) and that: includes an MCG or PCell configuration but excludes an SCG or PSCell configuration; or includes an indication that any SCG configuration (22-1 ...22-M) of the communication device (12) is to be released; or includes both an MCG or PCell configuration and an SCG or PSCell configuration, but the SCG or PSCell configuration does not include any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M).

14. The method of claim 12, wherein selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises preferentially selecting a conditional reconfiguration that does not include any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M), by: if at least one of the multiple conditional reconfigurations (16S) lacks an associated CPA execution condition (24-1 ...24-M) or an associated CPC execution condition (24- 1 ...24-M), selecting a conditional reconfiguration that does not include any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1...24-M); and else if none of the multiple conditional reconfigurations (16S) lacks an associated CPA execution condition (24-1 ...24-M) or an associated CPC execution condition (24- 1...24-M), selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1...24- M).

15. The method of claim 14, wherein selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) comprises selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) which is fulfilled.

16. The method of claim 12, wherein selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) which is fulfilled.

17. The method of claim 12, wherein selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) which has been fulfilled at least once during a time period prior to the connection re-establishment procedure being triggered.

18. The method of claim 12, wherein selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises preferentially selecting a conditional reconfiguration that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) which is fulfilled, by: if one of the multiple conditional reconfigurations (16S) includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) which is fulfilled, selecting that conditional reconfiguration; or else if the associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M) is not fulfilled for any of the multiple conditional reconfigurations (16S) that includes an associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M), and if the multiple conditional reconfigurations (16S) include a conditional reconfiguration that lacks any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M), selecting the conditional reconfiguration that lacks any associated CPA execution condition (24-1 ...24-M) or CPC execution condition (24-1 ...24-M).

19. The method of any of claims 11-18, further comprising transmitting (670), in the selected cell (18S), a notification message according to the selected conditional reconfiguration.

20. The method of claim 19, wherein the notification message is an RRC Reconfiguration Complete message.21 . The method of any of claims 19-20, wherein the selected conditional reconfiguration includes an SCG configuration (22-1 ...22-M) or a PSCell configuration, and wherein the notification message includes an indication to a target PSCell or target Secondary Node, SN.

22. The method of any of claims 1 -21 , wherein making a decision as to whether to apply any of the multiple conditional reconfigurations (16S) to recover from the failure (13) and / or selecting, from the multiple conditional reconfigurations (16S), a conditional reconfiguration to apply to recover from the failure (13) comprises making a decision as to whether to apply any of the multiple conditional reconfigurations (16S) to recover from the failure (13).

23. The method of claim 22, wherein making the decision comprises making the decision based on whether any of the multiple conditional reconfigurations (16S) lack an associated CPA execution condition (24-1 ...24-M) or an associated CPC execution condition (24-1 ...24-M) for multi-connectivity operation of the communication device (12), and wherein the method further comprises applying or not applying one of the multiple conditional reconfigurations (16S) to recover from the failure (13), according to the decision.

24. The method of any of claims 22-23, wherein making the decision comprises making the decision to not apply any of the multiple conditional reconfigurations (16S) to recover from the failure (13), based on none of the multiple conditional reconfigurations (16S) lacking an associated CPA execution condition (24-1 ...24-M) or an associated CPC execution condition (24-1 ...24-M), and wherein the method further comprises, based on the decision, performing a Radio Resource Control (RRC) re-establishment procedure to the selected cell (18S).

25. A method performed by a communication device (12), the method comprising: detecting (700) a failure (13); making (710) a decision as to whether or not to perform cell selection to recover from the failure (13), based on: whether or not the communication device (12) has stored any conditional reconfiguration that includes an associated CPA execution condition (24- 1 ...24-M) or CPC execution condition (24-1 ...24-M) for any cell; whether or not the communication device (12) has stored multiple conditional reconfigurations (16S) for any cell; whether or not the communication device (12) has stored multiple conditional reconfigurations (16S) for each of one or more cells that are candidates for cell selection; and / or whether or not the communication device (12) has stored, for the same cell, multiple conditional reconfigurations (16S) that are associated with respective CPA execution conditions (24-1 ...24-M) or CPC execution conditions (24-1 ...24-M) or that include respective PSCells or SCGs; and performing or not performing (720) cell selection to recover from the failure (13) according to the decision.

26. A communication device (12) comprising: processing circuitry (910) and memory (930), the memory (930) containing instructions executable by the processing circuitry (910) whereby the communication device(12) is configured to perform the method of any of claims 1-25.

27. A computer program comprising instructions which, when executed by at least one processor of a communication device (12), causes the communication device (12) to perform the method of any of claims 1 -25.

28. A carrier containing the computer program of claim 27, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

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