WO2022031196A1

WO2022031196A1 - Failure reporting by wireless devices

Info

Publication number: WO2022031196A1
Application number: PCT/SE2021/050206
Authority: WO
Inventors: Ali PARICHEHREHTEROUJENI; Icaro L. J. Da Silva; Pradeepa Ramachandra; Marco BELLESCHI; Kristina Zetterberg
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2020-08-06
Filing date: 2021-03-09
Publication date: 2022-02-10

Abstract

According to one example embodiment, a wireless device (12) detects a failure (14)associated with a failed cell (16F). Responsive to such detection, the wireless device (12)selects a cell (16S) towards which to perform a mobility or access procedure and logsinformation (20) associated with the failure (14). The logged information (20) may indicate time elapsed between: (i) a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure(14); and (ii) a reference time associated with the failure (14). The wireless device (12) performsthe mobility or access procedure towards the selected cell (16S) and transmits a report (22)indicating the logged information (20).

Description

FAILURE REPORTING BY WIRELESS DEVICES

TECHNICAL FIELD

The present application relates generally to wireless communication and relates more particularly to failure reporting by wireless devices.

BACKGROUND

Robustness of mobility procedures to failure proves challenging, particularly in New Radio (NR) systems whose radio links are more prone to fast fading due to their higher operating frequencies. Conditional mobility is one approach to improve mobility robustness in this regard. Under this approach, a wireless device may be commanded to perform a mobility procedure, e.g., handover or resume, earlier than traditionally commanded, before the source radio link quality deteriorates below a certain threshold. But the wireless device is commanded to wait to perform that mobility procedure until the wireless device detects that a certain condition is fulfilled, e.g., the source radio link quality deteriorates even further below a different threshold. Once the device detects that condition, the device may autonomously perform the mobility procedure without receiving any other signaling on the source radio link, so that the procedure proves robust to source link deterioration.

Although this conditional mobility approach can improve mobility robustness, distributing more control over the mobility procedure to the wireless device threatens the network’s ability to adapt future mobility procedures based on the performance of past mobility procedures. This may in turn jeopardize the ability of the conditional mobility approach to avoid mobility failure and/or poor service performance.

SUMMARY

According to some embodiments herein, a wireless device logs and reports to a wireless communication network information associated with a failure detected by the wireless device. Responsive to detecting this failure, the wireless device selects a cell towards which to perform a mobility or access procedure, e.g., for re-establishing a connection to the network, and logs information associated with the failure. The logged information may for instance indicate whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure. Alternatively or additionally, the logged information may indicate time elapsed between (i) when the wireless device received a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure; and (ii) a reference time associated with the failure. Based on this and/or other information logged by the wireless device, the network in some embodiments may tune one or more parameters based on the logged information that the wireless device reports to the network. The parameter(s) may for example impact future mobility or access procedures, e.g., with the aim to reduce the chances of another failure in the future, mitigate the effects of such failure, or the like.

More particularly, embodiments herein include a method performed by a wireless device. The method may include detecting a failure associated with a failed cell. The method may further include, responsive to detecting the failure, selecting a cell towards which to perform a mobility or access procedure and logging information associated with the detected failure. The method may further comprise performing the mobility or access procedure towards the selected cell. The method may also comprise, during or after the mobility or access procedure, transmitting a report indicating the logged information.

In some embodiments, the logged information indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure. Alternatively or additionally, the logged information indicates whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure. Alternatively or additionally, the logged information indicates whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure.

Alternatively or additionally, the logged information indicates time elapsed between a time when the wireless device received a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure and a reference time associated with the failure. In some embodiments, the reference time is a time at which a reference event occurs. In this case, the reference event may be either detection of the failure, selection of the cell towards which to perform the mobility or access procedure, or starting of the mobility or access procedure. In one or more of these embodiments, the method further comprises starting a timer upon receiving a conditional reconfiguration, and stopping the timer upon occurrence of the reference event. In this case, the logged information may indicate the value of the timer when stopped.

Alternatively or additionally, the logged information indicates a list of one or more cells for which a conditional reconfiguration was stored at the wireless device when the wireless device detected the failure. Alternatively or additionally, the logged information indicates whether the detected failure was associated with a conditional reconfiguration. Alternatively or additionally, the logged information indicates one or more parameters of a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure.

In some embodiments, the failure is a radio link failure, RLF.

In some embodiments, the failure is a failure of a mobility or access procedure towards the failed cell, a failure detected during a mobility or access procedure towards the failed cell, or a failure detected while the wireless device was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell.

In some embodiments, the report is a radio link failure report.

In some embodiments, the method further comprises during or after the mobility or access procedure towards the selected cell, transmitting a message indicating availability of the logged information and/or availability of the report. The method further comprises after transmitting the message, receiving a request for the logged information and/or for the report, and transmitting the report with the logged information responsive to the request.

Embodiments herein also include a corresponding method performed by a radio network node. The method may comprise receiving the logged information associated with the failure detected by the wireless device. In some embodiments, the method also comprises analyzing a root cause of the failure, using the logged information. In this case, the method may also comprise adapting one or more parameters associated with a mobility or access procedure, based on the analyzing. Alternatively or additionally, the method may comprise sending at least a part of the logged information to another radio network node associated with the failure.

Alternatively or additionally, the logged information indicates time elapsed between a time when the wireless device received a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure and a reference time associated with the failure. In some embodiments, the reference time is a time at which a reference event occurs. In this case, the reference event may be either detection of the failure, selection of the cell towards which to perform the mobility or access procedure, or starting of the mobility or access procedure.

Alternatively or additionally, the logged information indicates a list of one or more cells for which a conditional reconfiguration was stored at the wireless device when the wireless device detected the failure. Alternatively or additionally, the logged information indicates whether the detected failure was associated with a conditional reconfiguration. Alternatively or additionally, the logged information indicates one or more parameters of a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure. In some embodiments, the failure is a radio link failure, RLF.

In some embodiments, the failure is a failure while the wireless device has a conditional reconfiguration stored.

In some embodiments, the logged information is included in a radio link failure report.

In some embodiments, the method further comprises during or after the mobility or access procedure, receiving a message indicating availability of the logged information and/or availability of a report including the logged information. The method further comprises after receiving the message, transmitting a request for the logged information and/or for the report, and receiving the logged information responsive to the request.

In some embodiments, the method further comprises sending at least a part of the logged information to another radio network node associated with the failure.

In some embodiments, the method further comprises analyzing a root cause of the failure, using the logged information. Additionally or alternatively, the method further comprises adapting one or more parameters associated with a mobility or access procedure, based on the logged information.

Other embodiments herein include a wireless device. The wireless device comprises communication circuitry and processing circuitry. The processing circuitry is configured to detect a failure associated with a failed cell, and responsive to detecting the failure, select a cell towards which to perform a mobility or access procedure and logging information associated with the detected failure as described above. The processing circuitry is also configured to perform the mobility or access procedure towards the selected cell and during or after the mobility or access procedure, transmit, via the communication circuitry, a report indicating the logged information.

Other embodiments herein include a radio network node comprising communication circuitry and processing circuitry. The processing circuitry is configured to receive, via the communication circuitry, logged information associated with a failure detected by a wireless device as described above.

In some embodiments, the processing circuitry is further configured to send at least a part of the logged information to another radio network node associated with the failure.

In some embodiments, the processing circuitry is further configured to analyze a root cause of the failure, using the logged information. Additionally or alternatively, the processing circuitry is further configured to adapt one or more parameters associated with a mobility or access procedure, based on the logged information. Other embodiments herein include a non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor of a wireless device, cause the wireless device to perform as described above.

Other embodiments herein include a non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor of a radio network node, cause the radio network node to perform as described above.

Other embodiments herein include a computer program comprising instructions which, when executed by at least one processor of a wireless device, causes the wireless device to perform the steps described above for the wireless device.

Other embodiments herein include a computer program comprising instructions which, when executed by at least one processor of radio network node, causes the radio network node to perform the steps described above for the radio network node.

Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a block diagram of a wireless communication network according to some embodiments.

Figure 2 is a logic flow diagram of a method performed by a wireless device according to some embodiments.

Figure 3 is a logic flow diagram of a method performed by a radio network node according to some embodiments.

Figure 4 is a block diagram of a wireless device according to some embodiments.

Figure 5 is a block diagram of a radio network node according to some embodiments.

Figure 6 is a block diagram of an RLF timing diagram according to some embodiments.

Figure 7 is a call flow diagram of conditional handover according to some embodiments.

Figure 8 is a logic flow diagram of a method performed by a UE according to some embodiments.

Figure 9 is a logic flow diagram of a method performed by a network node according to some embodiments.

Figure 10 is a block diagram of a wireless communication network according to some embodiments.

Figure 11 is a block diagram of a user equipment according to some embodiments.

Figure 12 is a block diagram of a virtualization environment according to some embodiments.

Figure 13 is a block diagram of a communication network with a host computer according to some embodiments. Figure 14 is a block diagram of a host computer according to some embodiments.

Figure 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 17 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

Figure 18 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment.

DETAILED DESCRIPTION

Figure 1 shows a wireless communication network 10 according to some embodiments. As shown, a wireless device 12 detects a failure 14 associated with a failed cell 16F, e.g., as served by a radio network node 13F. This failure 14 may for example be a radio link failure (RLF). Alternatively or additionally, the failure 14 may be a failure of a mobility or access procedure towards the failed cell 16F, a failure detected during a mobility or access procedure towards the failed cell 16F, or a failure detected while the wireless device 12 was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell 16F. In some embodiments, for example, the wireless device 12 detects this failure 14 while the wireless device 12 has a conditional reconfiguration (e.g., a conditional handover configuration) stored, e.g., such that the failure 14 is detected while the wireless device 12 is monitoring for fulfillment of a condition for triggering application of such conditional reconfiguration, or while the wireless device 12 is attempting to apply that conditional reconfiguration after the condition’s fulfillment.

Regardless, responsive to detecting the failure 14, the wireless device 12 selects a cell 16S towards which to perform a mobility or access procedure 18. Figure 1 shows this selected cell 16S as being served by radio network node 13S. Where the procedure 18 is a mobility procedure, the procedure 18 may be a handover procedure, a conditional handover procedure, a Radio Resource Control (RRC) re-establishment, or the like. In any event, responsive to detecting the failure 14, the wireless device 12 also logs information 20 associated with the detected failure 14. During or after performing the mobility or access procedure 18, the wireless device 12 transmits a report 22 (e.g., to radio network node 13S) indicating this logged information 20. In some embodiments, for example, the wireless device 12 transmits a notification that the report 22 is available, and then transmits the report 22 in response to a request for that report 22.

In some embodiments, the radio network node 13S sends at least a part of the logged information 20 to radio network node 13F associated with the failure 14. The radio network node 13S and/or radio network node 13F may analyze the logged information 20, e.g., as part of analyzing a root cause of the failure 14. Based on this analysis, the radio network node 13F and/or radio network node 13S (or some other network node) may adapt or tune one or more parameters associated with a mobility or access procedure, e.g., to prevent or mitigate an impact of another failure in the future.

Notably, in some embodiments, the logged information 20 indicates whether a conditional reconfiguration (e.g., conditional handover configuration) for the selected cell 16S was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Where the mobility or access procedure is a Radio Resource Control, RRC, Re-Establishment procedure, for example, this may be indicated by a reestablishmentCellCHOPrepared field as described herein. In other embodiments where the mobility or access procedure is an RRC Connection Setup procedure, this may be indicated by a reconnectCellCHOPrepared field as described herein.

Alternatively or additionally, the logged information 20 indicates whether the wireless device 12, when the wireless device 12 detected the failure 14, was configured to attempt to apply a conditional reconfiguration for the selected cell 16S in response to the detected failure 14. In some embodiments, this may be indicated by an attemptCondReconfig field.

Alternatively or additionally, the logged information 20 indicates whether a conditional reconfiguration for the failed cell 16F was stored at the wireless device 12 when the wireless device 12 detected the failure 14. This may be indicated for example by a failedPCellldCHOPrepared field as described herein.

Alternatively or additionally, the logged information 20 indicates time elapsed between a time when the wireless device 12 received a conditional reconfiguration that was stored at the wireless device 12 when the wireless device 12 detected the failure 14 and a reference time associated with the failure 14. This may be indicated for example by a timeSinceCHOreconfig field as described herein.

Alternatively or additionally, the logged information 20 indicates a list of one or more cells for which a conditional reconfiguration was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Alternatively or additionally, the logged information 20 indicates whether the detected failure 14 was associated with a conditional reconfiguration. Alternatively or additionally, the logged information 20 indicates one or more parameters of a conditional reconfiguration that was stored at the wireless device 12 when the wireless device 12 detected the failure 12.

Alternatively or additionally, the logged information 20 indicates a first list of measurements performed by the wireless device on any cells for which the wireless device had a conditional reconfiguration stored when the wireless device detected the failure and a second list of measurements performed by the wireless device on any cells for which the wireless device did not have a conditional reconfiguration stored when the wireless device detected the failure. The first list may for example be indicated by a measuResultListCHOPrepared-r17 field as described herein, and the second list may be indicated by a measResultListNonCHOPrepared-r17 field as described herein.

As used herein, a mobility procedure may include for example a handover procedure, a conditional handover procedure, a Radio Resource Control (RRC) re-establishment procedure, or the like. As used herein, an access procedure may include for example an RRC Connection Setup procedure, e.g., as part of an initial access attempt or otherwise a set up of an RRC connection from scratch.

In view of the modifications and variations herein, Figure 2 depicts a method performed by a wireless device 12 in accordance with particular embodiments. The method may include detecting a failure 14 associated with a failed cell 16F (Block 200).

The method may further include, responsive to detecting the failure 14, selecting a cell 16S towards which to perform a mobility or access procedure 18 and logging information 20 associated with the detected failure 14 (Block 210). In some embodiments, the logged information 20 indicates whether a conditional reconfiguration for the selected cell 16S was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Alternatively or additionally, the logged information 20 indicates whether the wireless device 12, when the wireless device 12 detected the failure 14, was configured to attempt to apply a conditional reconfiguration for the selected cell 16S in response to the detected failure 14. Alternatively or additionally, the logged information 20 indicates whether a conditional reconfiguration for the failed cell 16F was stored at the wireless device 12 when the wireless device 12 detected the failure 14.

Alternatively or additionally, the logged information 20 indicates time elapsed between a time when the wireless device 12 received a conditional reconfiguration that was stored at the wireless device 12 when the wireless device 12 detected the failure 14 and a reference time associated with the failure 14. In some embodiments, the reference time is a time at which a reference event occurs. In this case, the reference event may be either detection of the failure 14, selection of the cell towards which to perform the mobility or access procedure, or starting of the mobility or access procedure. In one or more of these embodiments, the method further comprises starting a timer upon receiving a conditional reconfiguration, and stopping the timer upon occurrence of the reference event. In this case, the logged information 20 may indicate the value of the timer when stopped.

Alternatively or additionally, the logged information 20 indicates a list of one or more cells for which a conditional reconfiguration was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Alternatively or additionally, the logged information 20 indicates whether the detected failure 14 was associated with a conditional reconfiguration. Alternatively or additionally, the logged information 20 indicates one or more parameters of a conditional reconfiguration that was stored at the wireless device 12 when the wireless device 12 detected the failure 14.

The method may optionally further comprise performing the mobility or access procedure 18 towards the selected cell 16S (Block 220). The method may optionally comprise, during or after the mobility or access procedure 18, transmitting a report 22 indicating the logged information 20 (Block 230).

In some embodiments, the failure 14 is a radio link failure, RLF.

In some embodiments, the failure 14 is a failure of a mobility or access procedure towards the failed cell 16F, a failure detected during a mobility or access procedure towards the failed cell 16F, or a failure detected while the wireless device 12 was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell 16F.

In some embodiments, the report 22 is a radio link failure report.

In some embodiments, the method further comprises, during or after the mobility or access procedure towards the selected cell 16S, transmitting a message indicating availability of the logged information 20 and/or availability of the report 22. The method further comprises after transmitting the message, receiving a request for the logged information 20 and/or for the report 22, and transmitting the report 22 with the logged information 20 responsive to the request.

Further aspects of this method are enumerated as examples in Group A Embodiments herein.

Note here that the failure 14 in Figure 1 may be the first failure associated with a first mobility or access procedure as described herein, or the second failure associated with a second mobility or access procedure that was attempted in response to the first failure.

Embodiments herein also include a corresponding method performed by a radio network node 13S or 13F, as shown in Figure 3. The method may comprise receiving logged information 20 associated with a failure 14 detected by the wireless device 12 (Block 300). The logged information 20 may for example be received from the wireless device 12 (e.g., where the method is performed by radio network node 13S). Or, the logged information 20 may be received from another radio network node (e.g., where the method is performed by radio network node 13F).

In some embodiments, the logged information 20 indicates whether a conditional reconfiguration for a selected cell 16S was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Here, the selected cell 16s is a cell towards which the wireless device 12 selected to perform a mobility or access procedure responsive to detecting the failure 14. Alternatively or additionally, the logged information 20 indicates whether the wireless device 12, when the wireless device 12 detected the failure 14, was configured to attempt to apply a conditional reconfiguration for the selected cell 16S in response to the detected failure 14. Alternatively or additionally, the logged information 20 indicates whether a conditional reconfiguration for a failed cell 16F was stored at the wireless device 12 when the wireless device 12 detected the failure 14. Here, the failed cell 16F is a cell associated with the failure 14.

Alternatively or additionally, the logged information 20 indicates time elapsed between a time when the wireless device 12 received a conditional reconfiguration that was stored at the wireless device 12 when the wireless device 12 detected the failure 14 and a reference time associated with the failure 14. In some embodiments, the reference time is a time at which a reference event occurs. In this case, the reference event may be either detection of the failure, selection of the cell towards which to perform the mobility or access procedure, or starting of the mobility or access procedure.

In some embodiments, the method also comprises analyzing a root cause of the failure 14, using the logged information 20 (Block 310). In this case, the method may also comprise adapting one or more parameters associated with a mobility or access procedure, based on the analyzing (Block 320). Alternatively or additionally, the method may comprise sending at least a part of the logged information 20 to another radio network node 13F associated with the failure 14 (Block 330).

In some embodiments, the failure 14 is a radio link failure, RLF.

In some embodiments, the failure 14 is a failure of a mobility or access procedure towards the failed cell 16F, a failure detected during a mobility or access procedure towards the failed cell 16F, or a failure detected while the wireless device was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell 16F.

In some embodiments, the failure 14 is a failure while the wireless device 12 has a conditional reconfiguration stored.

In some embodiments, the logged information 20 is included in a radio link failure report.

In some embodiments, the method further comprises during or after the mobility or access procedure, receiving a message indicating availability of the logged information 2j0 and/or availability of a report 22 including the logged information 20. The method further comprises after receiving the message, transmitting a request for the logged information 20 and/or for the report 22, and receiving the logged information 20 responsive to the request. Further aspects of this method are enumerated as examples in Group B Embodiments herein.

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

Embodiments also include a wireless 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 wireless device 12. The power supply circuitry is configured to supply power to the wireless device 12.

Embodiments further include a wireless 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 wireless device 12. In some embodiments, the wireless device 12 further comprises communication circuitry.

Embodiments further include a wireless device 12 comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the wireless device 12 is configured to perform any of the steps of any of the embodiments described above for the wireless 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 wireless 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.

Embodiments herein also include a radio network node 13F or 13S configured to perform any of the steps of any of the embodiments described above for the radio network node 13F or 13S.

Embodiments also include a radio network node 13F or 13S 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 radio network node 13F or 13S. The power supply circuitry is configured to supply power to the radio network node 13F or 13S.

Embodiments further include a radio network node 13F or 13S comprising processing circuitry. The processing circuitry is configured to perform any of the steps of any of the embodiments described above for the radio network node 13F or 13S. In some embodiments, the radio network node 13F or 13S further comprises communication circuitry.

Embodiments further include a radio network node 13F or 13S comprising processing circuitry and memory. The memory contains instructions executable by the processing circuitry whereby the radio network node 13F or 13S is configured to perform any of the steps of any of the embodiments described above for the radio network node 13F or 13S.

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.

Figure 4 for example illustrates a wireless device 12 as implemented in accordance with one or more embodiments. As shown, the wireless device 12 includes processing circuitry 410 and communication circuitry 420. The communication circuitry 420 (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 wireless device 12. The processing circuitry 410 is configured to perform processing described herein, e.g., in Figure 2, such as by executing instructions stored in memory 430. The processing circuitry 410 in this regard may implement certain functional means, units, or modules.

Figure 5 illustrates a radio network node 13F or 13S as implemented in accordance with one or more embodiments. As shown, the radio network node 13F or 13S includes processing circuitry 510 and communication circuitry 520. The communication circuitry 520 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 510 is configured to perform processing described herein, e.g., in Figure 3, such as by executing instructions stored in memory 530. The processing circuitry 510 in this regard may implement certain functional means, units, or modules.

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

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.

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.

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.

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.

Additional embodiments will now be described. At least some of these embodiments may be described as applicable in certain contexts and/or wireless network types for illustrative purposes, but the embodiments are similarly applicable in other contexts and/or wireless network types not explicitly described.

In some embodiments herein, the detected failure is a radio link failure (RLF) or is reported in an RLF report.

Consider details of an RLF report, e.g., in Long Term Evolution (LTE) and New Radio (NR) where the wireless device 12 herein is exemplified as a user equipment (UE). In connected mode, the wireless communication network 10 may configure the UE to perform and report Radio Resource Management (RRM) measurements to assist network-controlled mobility decisions. That is done via handovers, where the network decides to hand over the UE from one cell to another. As a fallback, in case handovers do not work properly, a failure detection and UE autonomous counter-action has been specified, the so-called Radio Link Failure (RLF) handling. That RLF procedure may be triggered when something unexpected happens in any of the mobility-related procedures. That is detected internally at the UE thanks to some interactions between Radio Resource Control (RRC) and lower layer protocols such as Layer 1 (L1), Medium Access Control (MAC), Radio Link Control (RLC), etc. A procedure called radio link monitoring exists at L1 in this regard. RLF and the content of RLF reports support Mobility Robustness Optimization (MRO) in some embodiments. Among different issues that may trigger RLF in LTE and NR, two of them include: (i) RLF due to radio link problem (expiry of timer T301) i.e. RLF due to problems indicated by physical layer; and (ii) RLF due to random access problem, i.e., RLF indicated by MAC layer.

First consider RLF triggered by radio link problems (L1) problems, e.g., in LTE. In some embodiments, lower layers of the UE provide to an upper layer Out-of-Sync (OOS) and In-Sync (IS) indications. In some embodiments, the UE may apply RRC I layer 3 (i.e. higher layer) filtering for the evaluation of Radio Link Failure (RLF). The higher-layer RLF related procedure according to some embodiments is illustrated in Figure 6.

As shown in Figure 6, the UE detects up to a certain number (referred to as N310) of consecutive out-of-sync indications from Layer 1 (L1). This triggers the UE to start an RLF timer T310. When the RLF timer T310 expires, the UE detects RLF as an example of the detected failure 14 herein. This RLF may in turn trigger the UE to search for and select a target cell, e.g., for RRC re-establishment as shown.

Some embodiments herein are applicable for Mobility Robustness Optimization (MRO), e.g., as supported by an RLF report. In this regard, seamless handovers are a key feature of 3GPP technologies. Successful handovers ensure that the UE moves around in the coverage area of different cells without causing interruptions in the data transmission. However, there will be scenarios when the network fails to handover the UE to the ‘correct’ neighbor cell in time and in such scenarios the UE will declare radio link failure (RLF), either before it sends a measurement report in the source cell, before receiving a handover command, quickly after the UE executes a successful handover to a target cell or experiences a Handover Failure (HOF), e.g., upon expiry of timer T304, started when the UE starts the synchronization with the target cell.

Upon HOF and RLF, the UE may take autonomous actions, e.g., trying to select a cell and initiate a reestablishment procedure in order to get back its connection as soon as it can, so that it can be reachable again. The RLF will cause a poor user experience as the RLF is declared by the UE only when it realizes that there is no reliable communication channel (radio link) available between itself and the network. Also, reestablishing the connection requires signaling with the newly selected cell (random access procedure, RRC Reestablishment Request, RRC Reestablishment Complete, RRC Reconfiguration and RRC Reconfiguration Complete) and adds some latency, until the UE can exchange data with the network again.

One of the functions of MRO is to detect connection failures that occur due to Too Early or Too Late Handovers, or Handover to Wrong Cell. These problems are defined as follows. With regard to Intra-system Too Late Handover, an RLF occurs after the UE has stayed for a long period of time in the cell; the UE attempts to re-establish the radio link connection in a different cell. With regard to Intra-system Too Early Handover, an RLF occurs shortly after a successful handover from a source cell to a target cell or a handover failure occurs during the handover procedure; the UE attempts to re-establish the radio link connection in the source cell. With regard to Intra-system Handover to Wrong Cell, an RLF occurs shortly after a successful handover from a source cell to a target cell or a handover failure occurs during the handover procedure; the UE attempts to re-establish the radio link connection in a cell other than the source cell and the target cell. In the definition above, the "successful handover" refers to the UE state, namely the successful completion of the random access (RA) procedure.

In some embodiments, the possible causes for the radio link failure (RLF) or HOF could be one of the following: (1) Expiry of the radio link monitoring related timer T310; (2) Expiry of the measurement reporting associated timer T312 (not receiving the handover command from the network within this timer’s duration despite sending the measurement report when T310 was running); (3) Upon reaching the maximum number of RLC retransmissions; or (4) Upon receiving a random access problem indication from the MAC entity.

As RLF leads to reestablishment which degrades performance and user experience, it is in the interest of the wireless communication network 10 to understand the reasons for RLF and try to optimize mobility related parameters (e.g. trigger conditions of measurement reports) to avoid later RLFs. Before the standardization of MRO related report handling in the network, only the UE was aware of some information associated to how did the radio quality looked like at the time of RLF, what is the actual reason for declaring RLF etc. For the wireless communication network 10 to identify the reason for the RLF, the wireless communication network 10 needs more information, both from the UE and also from the neighboring base stations. Some embodiments herein thereby provide this information via the logged information 20 described above.

As part of the MRO solution in NR, the UE in some embodiments logs relevant information at the moment of an RLF and later reports to a target cell the UE succeeds to connect (e.g. after reestablishment). A gNodeB receiving an RLF report may forward to the gNodeB where the failure has been originated.

The logged information 20 described herein may be included in an RLF report, e.g., along with other information in the RLF report. For example, the RLF report generated by the UE may include one or more of the following measurements:

1) Measurement quantities of the last serving cell (PCell), such as Reference Signal Received Power (RSRP) and/or Reference Signal Received Quality (RSRQ)

2) Measurement quantities of the neighbor cells in different frequencies of different radio access technologies (RATs), such as New Radio (NR), Universal Terrestrial Radio Access (UTRA), Evolved UTRA (EUTRA), Code Division Multiple Access 2000 (CDMA2000), or GERAN (GSM/EDGE Radio Access Network) 3) Random Access Channel (RACH) information

4) Reestablishment cell ID

5) Reconnect cell ID

6) Measurement quantity associated to Wireless Local Area Network (WLAN) Applications, such as Reference Signal Strength Indicator (RSSI).

7) Measurement quantity (e.g., RSSI) associated to Bluetooth beacons.

8) Location information, if available (including location coordinates and velocity)

9) Globally unique identity of the last serving cell, if available, otherwise the Physical Cell Identity (PCI) and the carrier frequency of the last serving cell.

10) Tracking area code of the PCell.

11) Time elapsed since the last reception of the ‘Handover command’ message.

12) Time elapsed since failure

13) Cell Radio Network Temporary Identity (C-RNTI) used in the previous serving cell.

14) Whether or not the UE was configured with a Data Radio Bearer (DRB) having Quality of Service (QoS) Class Identifier (QCI) value of 1. *************************************************************************************************

In some embodiments, after the RLF is declared, the RLF report is logged and, once the UE selects a cell and succeeds with a reestablishment, it includes an indication that it has an RLF report available in the RRC Reestablishment Complete message, to make the target cell aware of that availability. Then, upon receiving an UElnformationRequest message with a flag “rlf- ReportReq-r16” the UE shall include the RLF report (stored in a UE variable VarRLF-Report, as described above) in an UElnformationResponse message and send the UElnformationResponse message to the network. In this regard, the UElnformationRequest is the command used by E-UTRAN to retrieve information from the UE. The UElnformationResponse message is used by the UE to transfer information requested by the network. In this case, then, the RLF report included in the UElnformationResponse message may be an example of the report 22 described in Figure 1.

Based on the contents of the RLF report (e.g. the Globally unique identity of the last serving cell, where the failure was originated), the cell in which the UE reestablishes can forward the RLF report to the last serving cell. This forwarding of the RLF report is done to aid the original serving cell with tuning of the handover related parameters (e.g. measurement report triggering thresholds) as the original serving cell was the one who had configured the parameters associated to the UE that led to the RLF. In this case, with regard to the example in Figure 1 , the radio network node 13S providing the cell 16S in which the UE re-establishes its connection may receive the RLF report with the logged information 20 and forward the RLF report to the radio network node 13F providing the original serving cell 13F. The radio network node 13F providing the original serving cell 13F may accordingly receive the RLF report with the logged information 20 and tune the handover related parameters based on that RLF report.

In some embodiments, RLF report forwarding may be accomplished using any of two different types of inter-node messages; namely, the Failure indication and the handover report (e.g., as described in TS 38.423 v16.2.0).

The Radio link failure indication procedure is used to transfer information regarding RRC re-establishment attempts or received RLF reports between gNBs. This message is sent from the gNB in which the UE performs reestablishment to the gNB which provided the previous serving cell of the UE.

The report with logged information 20 may alternatively or additionally be a successful handover report according to some embodiments. A successful handover report includes some additional information sent to the target cell upon successfully completing the handover, so that some additional knowledge available at the UE about the radio conditions, failure possibilities etc. are transferred to the network 10 so that the network 10 can further tune its handover parameters.

More particularly, the MRO function in NR may provide more robust mobility via reporting failure events observed during successful handovers. In some embodiments in this regard, the UE is configured to compile a report associated to a successful handover. The report may comprise a set of measurements collected during the handover phase, i.e. measurement at the handover trigger, measurement at the end of handover execution or measurement after handover execution. The UE may be configured with triggering conditions to compile the Successful Handover Report, hence the report would be triggered only if the conditions are met. This limits UE reporting to relevant cases, such as underlying issues detected by RLM, or beam failure detection (BFD) detected upon a successful handover event.

The availability of a Successful Handover Report may be indicated by the Handover Complete message (RRCReconfigurationComplete) transmitted from UE to target NG-RAN node over RRC. The target NG-RAN node may fetch information of a successful handover report via UE Information Request/Response mechanism. In addition, the target NG-RAN node could then forward the Successful Handover Report to the source NR-RAN node to indicate failures experienced during a successful handover event.

Upon reception of a Successful handover (HO) Report, the receiving node is able to analyze whether its mobility configuration needs adjustment. Such adjustments may result in changes of mobility configurations, such as changes of RLM configurations or changes of mobility thresholds between the source and the target. In addition, the target Next Generation (NG) Radio Access Network (RAN) node, in the performed handover, may further optimize the dedicated RACH-beam resources based on the beam measurements reported upon successful handovers.

A conditional reconfiguration as described herein may be a conditional handover in some embodiments. More particularly in this regard, 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 uplink (UL) is already bad it may lead to that the network is not able to detect the measurement report transmitted by the UE and hence cannot initiate the handover procedure. Downlink (DL) problems may lead to that the handover command (i.e. the RRCReconfiguration message with a reconfigurationWithSync field) cannot 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.

A conditional handover (CHO) improves mobility robustness and addresses the issues above. In a CHO, transmission and execution of the handover command are separated. This allows the handover command to be sent earlier to the UE when the radio conditions are still good, thus increasing the likelihood that the message is successfully transferred. The execution of the handover command is done at a later point in time based on an associated execution condition. The execution condition 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).

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

Figure 7 shows the signaling flow for a conditional handover according to some embodiments. Here, the UE exemplifies the wireless device 12, the source gNB exemplifies radio network node 13F, and the target gNB exemplifies radio network node 13S from Figure 1. 4001-4002.

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

4003-4004.

The source gNB sends a handover request to the target gNB, indicating that the handover is a conditional handover. The target gNB acknowledges the request.

4005-4006.

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 generated by the target node during the handover preparation phase 4013 and the execution condition is generated by the source node.

4007-4008.

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.

4009. The target gNB sends a HANDOVER SUCCESS message to the source gNB indicating the UE has successfully established the target connection.

4010-4011.

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

4012. The target gNB sends a message to the source gNB indicating that the source gNB can release the UE’s context.

Some embodiments herein are applicable in the following scenario. In this scenario, a UE is configured with conditional HO to at least one target cell and the UE fails in execution of the first HO (e.g. expiry of timer T304) or an RLF happens while the UE is evaluating CHO conditions. The UE may select another cell (i.e. not the source) and perform a successful reestablishment or a handover toward the selected cell, if possible. When RLF is detected, UE logs the RLF related measurements, including the measurement of the radio link quality (e.g. RSRP, RSRQ, signal-to-interference-plus-noise-ratio) as well as an identity of the last serving cell, failed cell as well as re-establishment cell (upon the transmission of a re-establishment request).

Having such measurement information, the network (e.g. the source network node that has configured the UE with CHO) may analyze the regular handover-related issues, and possibly understand whether the target cell was correctly chosen (e.g. in case a HO command was transmitted but possibly not received by the network) and/or if parameters of an event- triggered A3/A5 measurement report are mistuned.

Advantageously, some embodiments herein additionally or alternatively enable the network to distinguish one of these legacy failures from the case where the UE was performing the evaluation of CHO conditions when RLF is detected or when a CHO execution failure occurs (e.g. T304 expires during CHO execution). And, a source network node may not configure CHO to all UEs and/or use the same parameters to all UEs (e.g. same target candidate cells, condition configurations, etc.). In this scenario, some embodiments herein advantageously avoid ambiguity that would otherwise exist at the network upon the reception of an RLF report in a source network node, where the node would not know whether it should optimize CHO and/or measurement reporting parameters. Some embodiments avoid this ambiguity even if the UE context containing CHO configuration for the UE associated with the RLF report is not available at the time the source network node receives the RLF report.

For example, some embodiments provide an RLF report so that it is possible for the last serving node to figure out if the re-establishment cell was a target candidate cell configured for conditional handover for that UE or not (note that the serving cell may receive the RLF report a long time after the time of failure and there might be cases that the UE context is removed from the serving cell).

Some embodiments enable a network (e.g. source node that has configured the UE with CHO) to have awareness that an RLF report is associated to a UE that has been configured with CHO when the RLF was detected, or e.g., a CHO execution has failed (e.g. T304). Alternatively or additionally, some embodiments enable the network to be aware of whether the re-establishment cell has been configured with conditional handover or not. Alternatively or additionally, in some embodiments, the network can advantageously figure out whether attemptCondReconfig was configured or not. Alternatively or additionally, if a re-establishment procedure fails, the UE may re-connect to a cell after transition from RRC_Connected to the RRCJDLE mode (due to the re-establishment failure). In this case, some embodiments enable the network to be aware of whether the re-connected cell was prepared for the conditional handover for the failed UE or not. Heretofore, the network would not be aware of any of this.

In some embodiments, when CHO is configured, for each target cell candidate, the UE receives a CondReconfigToAddMod IE containing an RRC Reconfiguration to be applied upon the fulfillment of an execution condition, and a configuration for that execution condition, as shown below:

CondReconfigToAddMod-r16 ::= SEQUENCE { condReconfigld-r16 CondReconfigld-r16, condExecutionCond-r16 SEQUENCE (SIZE (1..2)) OF Measld OPTIONAL, -- Cond condReconfigAdd condRRCReconfig-r16 OCTET STRING (CONTAINING RRCReconfiguration) OPTIONAL, -- Cond condReconfigAdd

}

As shown above, the configuration of the execution condition is a set of one or two MeaslD(s), each of these pointing to the measurement configuration whose reportConfig has a reportType set to condTrigerConfig IE, received as part of ReportConfigNR. A typical configuration for two MeaslD(s) is each of them are configured with the same event e.g. A3, but different trigger quantities e.g. RSRP and RSRQ. Hence, execution of CHO only occurs when both conditions are fulfilled.

Hence, an RLF may have occurred because only one of the conditions was fulfilled. An RLF report according to some embodiments herein includes information that indicates this as being the cause of the RLF, something that would not be visible in RLF reports heretofore.

Moreover, each MeasID for the execution of a conditional HO can be triggered on a conditional A3 or an A5 type event. In order to have an efficient on-time conditional handover execution, CondTriggerConfig should be tuned properly. Otherwise a UE may experience Too late or Too Early conditional handover execution or conditional handover execution to a wrong cell. Optimization of such parameters is conditioned on providing sufficient measurement when a radio link failure occurs. Some embodiments herein enable the network to figure out (after receiving an RLF report) which cells had been prepared with conditional handover and which cells had not been configured. Some embodiments enable this even if the UE context does not exist at the time of analyzing the RLF report. Accordingly, the last serving cell may be able to tune the CHO related parameters and configurations to optimally trigger the conditional handover execution before any radio link failure.

Conditional handover is designed to improve the robustness of the handover, reducing the probability of too Late handover by early preparation and configuration of the required resources at multiple potential target cells. Hence it improves the robustness with a cost of extra network resources. Sub-optimal configuration of conditional handover from preparation to the execution may cause a long delay in handover execution and thus causing a waste of resources at the network side. Some embodiments herein accordingly facilitate minimizing the resource reservation time for a conditional handover with a proper configuration in such a way that the time in between conditional handover preparation and execution is minimized. Some embodiments do so by equipping the network with information about the total time spent while the resources of the prepared cells were reserved for a conditional handover.

More particularly, some embodiments herein include a method executed by a wireless terminal (also called a User Equipment - UE) for reporting CHO related measurement information for mobility parameter optimization. In some embodiments, the method comprises logging information regarding an RLF, and/or information regarding one or more failed attempts of HO execution, and/or information regarding one or more failed attempts of CHO execution and/or information regarding one or more attempts of CHO execution. In one or more of these embodiments, the RLF, failed attempt(s) of HO execution, and/or failed attempt(s) of CHO execution may have occurred before a successful HO completion, or before a successful CHO completion, or before a successful re-establishment procedure, or before a successful connection setup procedure, or after a successful conditional handover execution.

In some embodiments of this method, upon detection of a radio link failure or a handover failure, or a CHO execution failure, when UE is configured with a conditional handover configuration, the UE may log at least some of the following information.

Upon cell selection after failure, the UE may log whether the selected cell has been already prepared with conditional handover i.e. it is in the list of the cells the UE received in the CHO configuration. Upon cell selection after failure, the UE may log whether the selected cell was configured for conditional reconfiguration for the case of handover towards a first selected cell failing, i.e. the UE logs whether the attemptCondReconfig has been set to true or not for the cells toward which the cell selection is performed.

Upon connection failure (radio link failure or handover failure), the UE may log the elapsed time between reception of the conditional handover configuration to the time it experienced the first failure. To log such information, the UE may start a first supervision timer of conditional handover, upon receiving the configuration including the conditional handover execution configurations. The UE may then stop the first supervision timer upon failure of a handover or a failure of a conditional handover.

Upon re-establishment failure (or failure second handover attempt via CHO configuration toward the selected cell after radio link failure), the UE may log the time elapsed between reception of the conditional handover configuration to the time it experienced the second failure. To log such information, the UE may start a second supervision timer of conditional handover, upon receiving conditional handover, or the UE may use the first supervision timer of conditional handover. The UE may stop the second supervision timer upon failed re-establishment or failed second handover attempt by applying CHO configuration.

Upon radio link failure, the UE may log whether the failed cell was prepared with conditional handover or not.

Upon failure of a re-establishment procedure and transition from IDLE to connected mode, the UE may log whether the reconnect cell was prepared for conditional handover or not.

In some embodiments, the UE logs the radio link measurement of the re-establishment cell upon first radio link failure.

In some embodiments, upon radio link failure or successful HO completion, the UE logs whether the concerned report is associated to an ordinary handover failure or CHO failure. In some embodiments, upon first and/or second radio link failures, the UE may log two lists of measurements, one list of measurements of the cells which have been prepared for conditional handover and one list of measurements of the cells not prepared for conditional handover. The measurements in each list may include the cell-level and beam-level measurement (layer 3 filtered or layer 1 filtered) including at least RSRP, RSRQ, SINR, etc, for the reference signals such as Synchronization Signal Block (SSB) and or Channel State Information Reference Signal (CSI-RS) beams. The UE shall log the above-mentioned measurements for the source cell, re-establishment cell, failed cell, previous serving cell in which the CHO was received, reconnect cell, and/or prepared cells, if the measurement information is available/measured by the UE. For example, the UE shall log the latest available measurements associated to those cells when the concerned RLF report is generated.

In yet another embodiment, each cell in the provided measurement may be flagged whether it was prepared for CHO handover or not. In yet another embodiment, the UE may log a list of cell IDs of the conditional handover prepared cells as part of the RLF report.

In some embodiments, upon successful CHO completion or upon radio link failure, or upon triggering the execution of conditional handover, the UE logs the elapsed time between reception of the conditional handover configuration to the time the handover is executed by the UE (i.e. the time the handover conditions in the conditional configuration are fulfilled, or the time the UE initiates the random access towards the candidate target cell), or to the time the handover is successful. The latter case is applicable only to the case of successful CHO completion, and it may correspond to the time in which the UE sends RRCReconfigurationComplete, in one of the cells that was included in the list of prepared cell.

In some embodiments, the method also comprises storing conditional handover failure information for one or multiple attempted conditional handover target cells in the UE. The UE may indicate the existence of the report to the network. The network may request the report and the UE may send the report. The network may forward the report to the original source cell and possibly the attempted target cells.

Certain embodiments may provide one or more of the following technical advantage(s). As a first advantage, the source RAN node owning the source cell of the conditional handover can realize the failed access towards the first and/or second target cell and can change the event threshold/offset of the conditional handover towards the first and/or second target cell for the future conditional handovers accordingly. As a second advantage, if the UE indicates whether the re-establishment cell was prepared for conditional handover or not, the source cell of the handover can prepare the re-establishment cell with the conditional handover, so that a conditional handover configuration can be used the next time for the re-establishment cell. Hence, the network may include this cell in which the UE successfully reestablished its connection in the list of target candidate cells in the CHO configuration. In this way, the UE does not need to initiate the re-establishment toward that cell as it has been prepared with conditional handover.

As a third advantage, based on the measurement provided for the selected cell after a first radio link failure, the serving cell can tune the conditional handover execution triggering parameters so the selected cell may be used as a suitable target cell for conditional handover for the first CHO execution attempt. As a fourth advantage, based on the measurement provided for the re-connect cell (the cell selected by the UE to make the transition from RRC DLE to RRC_Connected mode after a second failure), the serving cell may prepare the reconnect cell for the conditional handover with suitable conditional handover execution triggering parameters, so that next time the UE can execute a conditional handover toward the reconnect cell. As a fifth advantage, based on the measurements associated to the candidate target cells and possible RLF or HO success reports associated to those cells, the network may decide to keep or remove some of the cells in the list of candidate target CHO cells.

As a sixth advantage, based on the supervision timer values, the serving cell may decide to postpone the preparation of the conditional handover (i.e. postponing the transmission of the handover request to the target candidate cells and postponing the transmission of the CHO configuration to the UE), or change the conditional handover execution triggering parameters to minimize the time period that the network resources are reserved for the conditional handover of the UE.

As a seventh advantage, instead of providing the measurement of all the cells configured for CHO execution, some embodiments flag whether the re-establishment cell and reconnect cell were configured with CHO or not. These embodiments will bring the knowledge to the network to optimize the candidate cells (e.g., preparing the re-establishment cell and or the reconnect cell for the CHO execution) with the minimum amount of the information logged and provided by the UE.

As an eight advantage, a UE using a supervision timer measures the exact time elapsed from the time the UE receives the CHO configuration to a successful or failed CHO execution. Having this information, the network may be able to optimize the allocated resources for the CHO purpose e.g., if the elapsed time is too long, the network may delay the CHO preparation.

Consider now some additional details regarding the UE storing the conditional handover failure related information (including the measurements of the cells prepared for conditional handover and the cells not configured for conditional handovers), when the access towards the first and/or second target cell fails. Detailed non-limiting examples of logging the CHO related measurement are considered in the following different cases.

“Re-establishment Case A” herein will refer to the case where, after detection of the first radio link failure, the UE selects a cell that is not in the list of CHO prepared cells (i.e. UE did not receive CHO execution configuration for the selected cell). Hence, the UE re-establishes the connection to the selected cell.

“Re-establishment Case B” herein will refer to the case where, after detection of the first radio link failure, the UE selects a cell that is in the list of CHO prepared cells (i.e. UE received CHO execution configuration for the selected cell), but attemptCondReconfig is not set to true. Hence, the UE re-establishes the connection to the selected cell.

“CHO Case A” herein will refer to the case where, after detection of the first radio link failure, the UE selects a cell that is in the list of CHO prepared cells (i.e. UE received CHO execution configuration for the selected cell), and attemptCondReconfig is set to true. Hence, the UE executes a handover towards the selected cell using the CHO configuration received for the selected cell.

“CHO Case B” herein will refer to the case where, after detection of the first radio link failure led the UE to select a cell that was in the list of CHO prepared cells (i.e. UE received CHO execution configuration for the selected cell), with attemptCondReconfig set to true, the UE executed a handover towards the selected cell using the CHO configuration received for the selected cell, but that led to a second radio link failure.

With these cases in mind, some embodiments herein include a method executed by a wireless terminal (also called a User Equipment - UE) for reporting CHO related information for mobility parameter optimization, as shown in the flowchart in Figure 8.

The method as shown comprises logging information regarding an RLF, and/or information regarding one or more failed attempts of HO execution and/or information regarding one or more failed attempts of CHO execution or failure that occurred before a successful HO completion, or before a successful CHO completion, or before a successful re-establishment procedure or before a successful connection setup procedure (Step 800). These types of failures are examples of the failure 14 described with respect to Figure 1. In some embodiments, the logging may comprise the creation of a report, e.g., an RLF report that is enhanced with the information as described above. The information logged in this Step 800 is an example of the logged information 20 referred to in Figure 1.

Consider a few examples of Step 800 for the various cases above. A first example of Step 800 applies for Re-establishment Case A. Here, the UE has first detected the failure (RLF while monitoring CHO and/or CHO execution failure), logged the information as described above, has selected a cell for which it has NOT stored a CHO configuration, and the attemptCondReconfig (or equivalent) is NOT configured (if the feature is configurable). Hence, the UE initiates a re-establishment procedure. In this case, the UE may log information regarding the RLF (e.g. in an RLF report) that led to the cell selection, that led to the reestablishment. The information may include one or more of the following for Re-establishment Case A.

In this first example of Step 800, the UE may log that the re-establishment cell has not been already prepared with conditional handover so the UE initiated the re-establishment procedure towards the selected cell. In one alternative, the UE includes in the RLF report an identifier of the re-establishment cell and an indication that the re-establishment cell was not one of the CHO target candidate cells the UE was configured with when the failure was detected and the RLF report was logged. In another alternative, the UE includes information for one or multiple CHO target candidate cells, if the UE was configured with CHO when RLF was detected, or if the RLF report is being logged due to a HO execution failure for a UE with stored CHO configurations, or if the RLF report is being logged due to a CHO execution failure. In another alternative, the UE sets a flag to TRUE in the RLF report if the re-establishment cell is one of the CHO target candidates the UE was configured with. In yet another alternative, the UE delays the deletion of the CHO configuration (stored in the UE variable VarConditionalReconfig) until the UE actually determines the cell towards which to perform re-establishment, e.g., upon the transmission of the Reestablishment Request, or to the time UE successfully gained access after a CHO failure. By delaying the deletion of the CHO configuration in this way, rather than deleting it before the UE initiates the transmission of the Reestablishment Request, the UE can advantageously compare the re-establishment cell with the target candidates.

The UE may alternatively or additionally log that attemptCondReconfig was not configured i.e. , has not been set to true for the selected cell. For example, the UE may log that attemptCondreconfig was set to false, if the attemptCondReconfig was not set to T rue as part of configuration.

The UE may log the time elapsed between reception of the conditional handover configuration until the time it experienced the first failure (e.g. corresponding to T304 timer expiry), or until the time the UE selects this candidate target cell for HO (i.e. the time the handover conditions in the conditional configuration are fulfilled), or the time the UE initiates the random access towards the candidate target cell. To log such information, the UE may start a first supervision timer of conditional handover, upon receiving conditional handover.

The UE may log the latest available radio link measurement of the re-establishment cell upon the first radio link failure. Alternatively or additionally, the UE may log the latest available radio link measurement of the re-establishment cell upon executing RACH procedure as part of re-establishment.

The UE may log whether the failed cell was prepared with conditional handover or not. The UE may indicate whether the RLF report is associated to CHO failure (i.e. the HO towards the first candidate target cell selected failed) or a non-CHO failure.

The UE may log the latest available radio link measurement of the failed cell upon the first radio link failure. Alternatively or additionally, the UE may log the latest available radio link measurement of the failed cell upon executing the Random Access Channel (RACH) procedure as part of re-establishment. Alternatively or additionally, the UE may log the latest available radio link measurements associated to the prepared cells, i.e. the candidate target cells included in the CHO configuration.

Consider now a second example of Step 800 that applies for CHO Case A. In this second example, the UE has first detected the failure (RLF while monitoring CHO and/or CHO execution failure), logged the information as described above, has selected a cell for which it has stored a CHO configuration, and the attemptCondReconfig (or equivalent) is configured (if the feature is configurable), and applies the CHO configuration toward the selected cell, i.e., executes the second CHO attempt.

In a first scenario for CHO Case A, if the first failure is an RLF, the UE logs information regarding the RLF (e.g. in an RLF report) that led to the cell selection that led to the successful CHO execution. The logged information may include any one or more of the following.

The UE may log that the selected cell has been already prepared with conditional handover and the UE applied the CHO configuration towards the selected cell. In one alternative, the UE includes in the RLF report an identifier of the re-establishment/selected cell and an indication if that re-establishment cell was one of the CHO target candidate cells the UE was configured with when the failure was detected and the RLF report was logged. In another alternative, the UE includes information for one or multiple CHO target candidate CHO cells, if the UE was configured with CHO when RLF was detected, or if the RLF report is being logged due to a HO execution failure for a UE with stored CHO configurations, or if the RLF report is being logged due to a CHO execution failure. In another alternative, the UE sets a flag to TRUE in the RLF report if the re-establishment cell is one of the CHO target candidates the UE was configured with. In yet another alternative, the UE delays the deletion of the CHO configuration (stored in the UE variable VarConditionalReconfig) until the UE actually determines the cell towards which to perform re-establishment, e.g., upon the transmission of the Reestablishment Request, or to the time UE successfully gained access after a CHO failure. By delaying the deletion of the CHO configuration in this way, rather than deleting it before the UE initiates the transmission of the Reestablishment Request, the UE can advantageously compare the reestablishment cell with the target candidates.

The UE may log that attemptCondReconfig was configured i.e., has been set to True for the selected cell.

The UE may log the time elapsed between reception of the conditional handover configuration to the time it experienced the first failure (e.g. corresponding to T304 timer expiry), or until the time the UE selects this candidate target cell for HO (i.e. the time the handover conditions in the conditional configuration are fulfilled), or to the time the UE initiates the random access towards the candidate target cell. To log such information, the UE may start a first supervision timer of conditional handover, upon receiving conditional handover. The time elapsed The UE may log the radio link measurement of the re-establishment cell upon the first radio link failure. Alternatively or additionally, the UE may log the radio link measurement of the re-establishment cell upon executing RACH procedure as part of re-establishment.

The UE may log that the failed cell was prepared with conditional handover or not.

The UE may indicate whether the RLF report is associated to CHO failure (i.e. the HO towards the first candidate target cell selected failed) or a non-CHO failure.

The UE may log the latest available radio link measurement of the failed cell upon the first radio link failure. The UE may alternatively or additionally log the latest available radio link measurement of the failed cell upon executing RACH procedure as part of re-establishment. The UE may alternatively or additionally log the latest available radio link measurements associated to the prepared cells, i.e. the candidate target cells included in the CHO configuration.

In a second scenario for CHO Case A, if the first failure is a legacy HO failure, the UE logs information regarding the HO failure (e.g. in a HO failure report) that led to the cell selection that led to the successful CHO execution. The logged information may include any one or more of the following.

The UE may log that the re-establishment cell has been already prepared with conditional handover and the UE has used the conditional HO configuration to access the selected cell in a re-establishment procedure.

The UE may alternatively or additionally log that attemptCondReconfig was configured i.e., has been set to true.

The UE may alternatively or additionally log the time elapsed between reception of the conditional handover configuration and the time it experienced the first failure. To log such information, the UE may start a first supervision timer of conditional handover, upon receiving conditional handover.

Alternatively or additionally, the UE may log the radio link measurement of the reestablishment cell upon the first radio link failure. Measurement may include at least cell-level and beam-level measurements, including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc. The UE may alternatively or additionally log the radio link measurement of the re-establishment cell upon executing the RACH procedure as part of reestablishment. Measurement again may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc.

The UE may alternatively or additionally log that the failed cell was prepared with conditional handover or not

The UE may in some embodiments log the radio link measurement of the failed cell upon the first radio link failure. Measurement similarly may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc. The UE may alternatively or additionally log the radio link measurement of the failed cell upon executing the RACH procedure as part of re-establishment. Again, measurement may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc.

In some embodiments, the UE logs the latest available radio link measurements associated to the prepared cells, i.e. the candidate target cells included in the CHO configuration.

In a third scenario for CHO Case A, if the first failure is a CHO failure, the UE logs information regarding the CHO failure (e.g. in a CHO failure report or HO failure report) that led to the cell selection that led to the successful CHO execution. The logged information may include any one or more of the following.

In some embodiments, the UE logs that the re-establishment cell has been already prepared with conditional handover and the UE has used the conditional HO configuration to access the selected cell in a re-establishment procedure.

In some embodiments, the UE logs the time elapsed between reception of the conditional handover configuration and the time it experienced the first failure. To log such information, the may UE start a first supervision timer of conditional handover, upon receiving the conditional handover.

The UE may alternatively or additionally log the radio link measurement of the reestablishment cell upon the first radio link failure. Measurement may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc. Alternatively or additionally, the UE may log the radio link measurement of the re-establishment cell upon executing a RACH procedure as part of reestablishment. Measurement again may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc.

Alternatively or additionally, the UE logs that the failed cell was prepared with conditional handover or not.

In some embodiments, the UE indicates whether the RLF report is associated to CHO failure (i.e. the HO towards the first candidate target cell selected failed) or a non-CHO failure.

The UE may alternatively or additionally log the radio link measurement of the failed cell upon the first radio link failure. Measurement here may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc. Alternatively or additionally, the UE may log the latest available radio link measurements associated to the prepared cells, i.e. the candidate target cells included in the CHO configuration. In some embodiments, the UE logs the radio link measurement of the failed cell upon executing the RACH procedure as part of re-establishment. Measurement again may include at least cell-level and beam-level measurements including at least RSRP and RSRQ, SINR of the reference signals such as SSB and CSI-RS, etc.

A third example of Step 800 applies for CHO Case B. Here, the UE has first detected the failure, logged the information as described above, and in the second attempt the UE selects a cell for which it has stored a CHO configuration (i.e. an RRCReconfiguration with reconfigurationWithSync) and the attemptCondReconfig (or equivalent) is configured (if the feature is configurable). The UE applies that stored CHO configuration but the second attempt also fails, leading the UE to transition from RRC_Connected mode to the RRCJDLE mode. The UE then performs cell selection and a reconnection procedure (e.g., RRC Connection Setup) that finally succeeds.

In a first scenario for CHO Case B, if the first failure is an RLF, then the UE logs information regarding the RLF (e.g. in an RLF report) that led to the cell selection that led to the failed CHO execution, that led to transition to the IDLE mode and a successful reconnection, and the UE also logs the information regarding the failed CHO attempt. The logged information may include any one or more of the following.

In some embodiments, the UE logs that the selected cell after the first failure has been already prepared with conditional handover and the UE has used the conditional HO configuration to access the selected cell in a re-establishment procedure.

In some embodiments, the UE logs the time elapsed between reception of the conditional handover configuration and the time it experienced the second failure, e.g. corresponding to T304 timer associated to this second cell expiry, or until the time the UE selects this second candidate target cell for HO, i.e. the time the handover conditions in the conditional configuration are fulfilled, or the time the UE initiates the random access towards the candidate target cell. To log such information, the UE may start a second supervision timer of conditional handover, upon receiving conditional handover.

In some embodiments, the UE logs that the reconnect cell has been already prepared for conditional handover or not.

The UE may log the radio link measurement of the reconnect cell upon executing a RACH procedure as part of the reconnection procedure.

In a second scenario for CHO Case B, if the first failure is a HO failure, and the UE has logged information regarding the HO failure (e.g. in a HO failure report) that led to the cell selection that led to the failed CHO execution, that led to transition to the IDLE mode and a successful reconnection, the UE logs the information regarding the failed CHO attempt. The logged information may include any one or more of the following.

In some embodiments, the UE logs that the re-establishment cell has been already prepared with conditional handover and UE has used the conditional HO configuration to access the selected cell at re-establishment procedure.

Alternatively or additionally, the UE logs that attemptCondReconfig was configured i.e., has been set to true.

The UE may alternatively or additionally log the time elapsed between reception of the conditional handover configuration and the time it experienced the second failure, e.g. corresponding to T304 timer associated to this second cell expiry, or until the time the UE selects this candidate target cell for HO, i.e. the time the handover conditions in the conditional configuration are fulfilled, or the time the UE initiates the random access towards the second candidate target cell. To log such information, the UE may start a second supervision timer of conditional handover, upon receiving conditional handover.

The UE may alternatively or additionally log the radio link measurement of the reconnect cell upon executing a RACH procedure as part of reconnection procedure.

In a third scenario for CHO Case B, if the first failure is a CHO failure, then the UE logs information regarding the CHO failure (e.g. in a CHO failure report or HO failure report) that led to the cell selection (as part of a re-establishment procedure) that led to the failed CHO execution, that led to transition to the IDLE mode and a successful reconnection, and the UE also logs the information regarding the failed CHO attempt. The logged information may include any one or more of the following.

Alternatively or additionally, the UE may log that attemptCondReconfig was configured i.e., has been set to true.

In some embodiments, the UE logs the time elapsed between reception of the conditional handover configuration and the time it experienced the second failure, e.g. corresponding to T304 timer expiry, or until the time the UE selects this candidate target cell for HO, i.e. the time the handover conditions in the conditional configuration are fulfilled, or the time the UE initiates the random access towards the candidate target cell. To log such information, the UE may start a second supervision timer of conditional handover, upon receiving conditional handover.

The UE may alternatively or additionally log that the reconnect cell has been already prepared for conditional handover or not.

In some embodiments, the UE logs the radio link measurement of the reconnect cell upon executing a RACH procedure as part of the reconnection procedure.

In all the above mentioned scenarios for CHO Case B, upon reconnection to the network, the UE may set the time since the second failure based on a supervision timer starting after the second failure and measure the time since the second failure until the time the UE comes back to the RRC_Connected mode, or until the time the UE sends the RLF report including the information related to the second radio link failure caused by a re-establishment applied with conditional handover configuration.

Alternatively or additionally, in all the above-mentioned scenarios for CHO Case B, upon reconnection to the network, the UE may set the timeSinceFailure value of the second radio link failure report based on the same supervision timer that the UE started after the first radio link failure (RLF, HO failure or CHO failure). timeSinceFailure may be set to the time of the second failure until the time of successful reconnection, or until the time UE sends the RLF report to the network.

In some embodiments for CHO Case A, the UE logs information regarding a successful CHO, either after successful handover, i.e. HO completed, towards the first target candidate cell, or any other candidate cell in the list of target candidate cells configured in the CHO configuration. The following information can be for example included in the success handover report or even in the RLF report (e.g. in the case the UE fails HO towards a first cell and succeeds HO towards a second cell belonging to the list of candidate target cells, or succeeds in reestablishment towards a second cell not belonging to the list of candidate target cells.

The information included in the success handover report or RLF report may include the time elapsed between reception of the CHO configuration from the source cell until CHO execution, in one of the target candidate cells included in the CHO configuration. Here, the CHO execution may be represented by the point in time in which the CHO triggering conditions were fulfilled, or the handover command is received (this latter case is for the scenario in which the UE has been configured for CHO, but the actual HO is triggered by an ordinary HO command). Or, the CHO execution may be represented by the point in time in which the random access in the first target cell is executed. Here, the first target cell maybe the first cell belonging to the list of CHO configured cells, or the cell indicated in the HO command. Alternatively, the CHO execution may be represented by the point in time in which the CHO or the ordinary HO is completed, i.e. the UE sends RRCReconfigurationComplete. In yet other embodiments, the CHO execution is represented by the point in time in which reestablishment is successful, i.e. RRCReestablishmentComplete received.

In any event, in case the UE is configured with CHO, but the UE then receives a HO command for an ordinary, i.e. non-CHO, HO, the UE may include the above information with respect to the target cell indicated in the HO command and include the time elapsed in the successful handover report.

No matter the case, though, the UE in any of the above embodiments may log two lists of measurements, one list of measurements for the list of the cells which have been prepared for conditional handover and one list of measurements for a list of the cells not prepared for conditional handover. The measurements in each list may include the cell-level and beam-level measurement (layer 3 filtered or layer 1 filtered) including at least RSRP, RSRQ, SINR, etc., for the reference signals such as SSB and/or CSI-RS beams.

Referring now back to Figure 8, the method may further include indicating to the network the existence of the logged information (Step 810). Again, the logged information here is logged information regarding an RLF, or information regarding one or more failed attempts of HO execution or information regarding one or more failed attempt of CHO execution that occurred before a successful HO completion, before a successful re-establishment procedure, or before a successful connection setup procedure.

In an embodiment, the UE indicates in an RRC complete message the availability of the report. That may be one or multiple flag(s) in the RRCReconfigurationComplete, or RRCReestablishmentComplete or RRCSetupComplete that is transmitted after random access in the cell that the UE succeeds to re-establish the connection or make the transition from RRCJDLE to RRC_Connected mode. The UE may use multiple flags to indicates that the RLF report includes the conditional handover related measurements, and/or the regular handover related measurements and/or both of them.

The method in Figure 8 may further comprise reporting the logged information regarding an RLF (Step 820). The logged information may for example include the measurement information related to the conditional handover (as described above) while the UE was monitoring CHO, and/or information regarding one or more failed attempts of HO execution and/or information regarding one or more failed attempts of CHO execution that has failed before a successful HO or CHO completion. The report may be transmitted upon request from the network in a message such as a UElnformationRequest. That may contain the request of at least one of the multiple reports the UE may have stored. The request may be related to the regular handover-related RLF report or conditional handover-related RLF report or, both of them.

Figure 9 shows a corresponding method performed by the network according to some embodiments. The method may for instance be performed by a radio access network (RAN) node in the network. The method as shown may include receiving the logged information from the UE (Step S900). The logged information may correspond to that described above with respect to the UE.

In some embodiments, the method further comprises forwarding the logged information provided by the UE to a different RAN node, e.g., serving the cell where the UE connected after the information was logged (Step 910).

In one embodiment, the RAN node that received the report provided by the UE analyses such report and deduces information about the cells and RAN nodes that were involved in the mobility failure while conditional handover has been prepared. For example, the RAN node receiving the report from the UE may deduce the cell where the UE attempted to connect unsuccessfully (e.g. a CHO target cell) or it might deduce the cell where the UE managed to connect successfully just to be subject to a connection failure shortly after that, or it might deduce the cell where the UE was served at the time it received the CHO configuration (i.e. the source cell). With such information at hand, the RAN node receiving the report from the UE is able to forward such report to a RAN node for the purpose of allowing the receiving RAN node to optimize its conditional handover configuration and remove the root cause of mobility failure for the next upcoming handovers.

In one embodiment of this method, the target RAN node receiving the forwarded information is the RAN node that configured the UE with the CHO configuration. This is the case where for example the failure is caused by too early handover. The RAN node where the information is forwarded owns the last serving cell before the failure. The source node can use the logged information from the UE to adjust its CHO configuration and therefore avoid future failures. For example, the RAN node may prepare the re-establishment cell with conditional handover with a proper triggering condition so the next handovers take place successfully toward the re-establishment cell which was not prepared for conditional handover in the failure case. In another example, the last serving cell may set attemptCondReconfig to true, if the ereestablishment cell was configured for conditional handover but attemptCondreconfig was not set to true.

In another embodiment of this method, the target RAN node receiving the forwarded information is the RAN node that last served the UE but not the RAN node that configured the UE with the CHO configuration. This is the case of for example an HO to wrong cell, where the UE attempted to connect to a cell of a target RAN node (either a cell configured via CHO configuration or another cell) but where such first connection failed shortly after the UE was able to establish connection, and where the UE shortly after such failure successfully connected to a different cell of a different target RAN node. In this embodiment, the first node receiving the forwarded information will further forward the information to the RAN node that provided the CHO configuration to the UE (i.e. the source node). The source node can use/compare the list of the measurements provided for the list of the cells prepared for conditional handover and the list of the measurements for the list of the cells not prepared for the conditional handover, correct any misconfiguration that caused the failures for the UE, and reduce or prevent such failures in the future. In view of the modifications and variations herein, then, the UE in some embodiments logs information upon RLF declaration while CHO is being monitored, or upon RLF during execution of CHO or shortly after CHO execution. The information may comprise at least one of the following.

The information may comprise CHO configuration(s). CHO configuration(s) may include information regarding at least one of the candidate target cell(s), such as a cell identity (e.g. a physical cell identifier - PCI, or Cell Global Identity), configuration for a candidate target cell the UE has stored, such as any content of ServingCellConfigCommon, or ReconfigurationWithSync. In another alternative, the UE stores the content of the UE variable where CHO configurations are stored when the UE is configured/re-configured with CHO. CHO configuration(s) logged may include configurations of target candidates, which may be useful to be included in a RLF report so the source network node that has configured the UE with CHO may be aware that an RLF occurred while the UE was configured with CHO for a certain candidate. Upon reception, the network may use this information to compare the target candidate cells reported with the best neighbour cells being reported and, if they don’t match, the network could, for later CHO procedures to be configured, replace some target candidates for CHO with some of the best neighbours that were included in the RLF report. CHO configuration(s) logged may alternatively or additionally include configuration of condition(s), or may include information indicating which of the cells are CHO candidates.

Alternatively or additionally, the information logged may include CHO information, e.g., measurements. The logged information may indicate for each neighbour whether the neighbour was a CHO candidate or not.

If RLF occurs while monitoring, inclusion of CHO information in some embodiments is an implicit indication of CHO failure. Alternatively, a flag is used (not a cause value as in RLF). The same may be said for HO failure due to a CHO execution failure.

Re-establishment cell includes a flag indicating whether that was a CHO candidate or not. Being a candidate may indicate that nothing would necessarily need to be changed in a CHO algorithm, except thresholds.

Example Implementation

The following exemplifies how the list of RLF reports including conditional handover information can be captured e.g., as part of ASN.1 of 3GPP TS 38.331 V16.0.0 (2020-03), according to some embodiments: *************************************************************************************************

5.3.7.3 Actions following cell selection while T311 is running

Upon selecting a suitable NR cell, the UE shall:

1 > if the cell selection is triggered by detecting radio link failure of the MCG or re- configuration with sync failure of the MCG, and

1> if attemptCondReconfig is configured; and

1 > if the selected cell is one of the candidate cells which the reconfigurationWithSync is included in the masterCellGroup in VarConditional Reconfig'.

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

1> else:

2> if UE is configured with conditionalReconfiguration'.

2> remove all the entries within VarConditional Reconfig, if any;

2> initiate transmission of the RRCReestablishmentRequest message in accordance with 5.3.7.4;

NOTE: This procedure applies also if the UE returns to the source PCell.

Upon selecting an inter-RAT cell, the UE shall:

1> perform the actions upon going to RRCJDLE as specified in 5.3.11 , with release cause 'RRC connection failure'.

5.3.7.4 Actions related to transmission of RRCReestablishmentRequest message

The UE shall set the contents of RRCReestablishmentRequest message as follows: 1> if the procedure was initiated due to radio link failure as specified in 5.3.10.3 or handover failure as specified in 5.3.5.8.3:

2> set the reestablishmentCellld in the VarRLF-Report to the global cell identity of the selected cell;

2> if the selected cell is one of the target candidate cells within VarConditional Reconfig, if configured, set the flag reestablishmentCellCHOPrepared to ‘true’’,

2> remove all the entries within VarConditionalReconfig, if any;

1 > submit the RRCReestablishmentRequest message to lower layers for transmission.

*************************************************************************************************

6.2.2 Message definitions

/*unaffected lEs are omitted*/

/*start of change*/

- UElnformationResponse

The UElnformationResponse message is used by the UE to transfer information requested by the network.

Signalling radio bearer: SRB1 or SRB2 (when logged measurement information is included)

RLC-SAP: AM

Logical channel: DCCH

Direction: UE to network

UElnformationResponse message

- ASN1 START

- TAG-UEINFORMATIONRESPONSE-START

UEInformationResponse-r16 ::= SEQUENCE { rrc-T ransaction Identifier RRC-T ransactionldentifier, critical Extensions CHOICE { uelnformationResponse-r16 U ElnformationResponse-r16-I Es, criticalExtensionsFuture SEQUENCE R } }

UEInformationResponse-r16-IE ::= SEQUENCE { measResultldleEUTRA-r16 MeasResultldleEUTRA-r16 OPTIONAL measResultldleNR-r16 MeasResultldleNR-r16

logMeasReport-r16 LogMeasReport-r16 OPTIONAL connEstFailReport-r16 ConnEstFailReport-r16 OPTIONAL ra-ReportList-r16 RA-ReportList-r16 OPTIONAL rlf-Report-r16 RLF-Report-r16 OPTIONAL mobilityHistoryReport-r16 MobilityHistoryReport-r16 OPTIONAL lateNonCriticalExtension OCTET STRING OPTIONAL nonCritical Extension SEQUENCE R OPTIONAL }

RLF-ReportList-r17 ::=

r17)) OF RLF-Report-r16

RLF-Report-r16 ::= CHOICE { nr-RLF-Report-r16 SEQUENCE { measResultLastServCell- r16 MeasResultRLFNR-r16, measResultRLF-r17 SEQUENCE {measuResultListCHOPrepared-r17 measResultNeighCells-r16 OPTIONAL, measResultListNonCHOPrepared-r17 measResultNeighCells-r16 OPTIONAL

measResultNeighCells-r16 SEQUENCE { measResultListNR-r16 MeasResultList2NR-r16 OPTIONAL, measResultListEUTRA-r16 MeasResultList2EUTRA-r16 OPTIONAL

OPTIONAL, c-RNTI-r16 RNTI-Value, previousPCellld-r16 CHOICE { nrPreviousCell-r16 CGI-lnfo-LoggingDetailed-r16, eutraPreviousCell-r16 CGI-InfoEUTRALogging

OPTIONAL, failedPCellld-r16 CHOICE { cellGloballd-r16 CGI-lnfo-LoggingDetailed-r16, pci-arfcn-r16 SEQUENCE { physCellld-r16 PhysCellld, carrierFreq-r16 ARFCN-ValueNR

OPTIONAL, failed PCellld-EUTRA CGI-InfoEUTRALogging, OPTIONAL, failedPCellCHOPrepared-r17 BOOLEAN OPTIONAL reconnectCellld-r16 CGI-lnfo-LoggingDetailed-r16 OPTIONAL, reconnectCellCHOPrepared-r17 BOOLEAN OPTIONAL, reconnectTimeSinceFailure-16 ReconnectTimeSinceFailure-16 OPTIONAL, reestablishmentCellld-r16 CGI-lnfo-Logging-r16 OPTIONAL, reestablishmentCellCHOPrepared BOOLEAN OPTIONAL, attemptCondReconfig BOOLEAN OPTIONAL, timeConnFailure-r16 INTEGER (0..1023) OPTIONAL, timeSinceFailure-r16 TimeSinceFailure-r16, timeSinceCHOReconfig-r17 TimeSinceCHOReconfig-r17, OPTIONAL, connectionFailureType-r16 ENUMERATED {rlf, hof} OPTIONAL, rlf-Cause-r16 ENUMERATED {t310-Expiry, randomAccessProblem, rlc-MaxNumRetx, beamFailureRecoveryFailure, spare4, spare3, spare2, spare"!},

Iocationlnfo-r16 Locationlnfo-r16 OPTIONAL, absoluteFrequencyPointA-r16 ARFCN-ValueNR OPTIONAL, locationAndBandwidth-r16 INTEGER (0..37949) OPTIONAL, subcarrierSpacing-r16 SubcarrierSpacing OPTIONAL, msg1-FrequencyStart-r16 INTEGER(0..maxNrofPhysicalResourceBlocks-1) OPTIONAL, msg 1 -SubcarrierSpacing-r16 SubcarrierSpacing OPTIONAL, msg1-FDM-r16 ENUMERATED {one, two, four, eight} OPTIONAL, perRAInfoList-r16 PerRAInfoList-r16 OPTIONAL, noSuitableCellFound-r16 ENUMERATED {true} OPTIONAL

}, eutra-RLF-Report-r16 SEQUENCE { failedPCellld-EUTRA CGI-InfoEUTRALogging, measResult-RLF-Report-EUTRA-r16 OCTET STRING

MeasResultList2NR-r16 ::= SEQUENCE(SIZE (1 ..maxFreq)) OF

MeasResult2NR-r16

MeasResultList2EUTRA-r16 ::= SEQUENCE(SIZE (1.. maxFreq)) OF

MeasResult2EUTRA-r16

MeasResult2NR-r16 ::= SEQUENCE { ssbFrequency-r16 ARFCN-ValueNR OPTIONAL, refFreqCSI-RS-r16 ARFCN-ValueNR OPTIONAL, measResultList-r16 MeasResultListNR

}

MeasResultListLogging2NR-r16 ::= SEQUENCE(SIZE (1 ..maxFreq)) OF

MeasResultListLoggingNR-r16

MeasResultListLoggingNR-r16 ::= SEQUENCE (SIZE (1..maxCellReport)) OF MeasResultLoggingNR-r16

MeasResultLoggingNR-r16 ::= SEQUENCE { physCellld-r16 PhysCellld, resultsSSB-Cell-r16 MeasQuantityResults, numberOfGoodSSB-r16 INTEGER (1..maxNrofSSBs-r16) OPTIONAL

} MeasResult2EUTRA-r16 ::= SEQUENCE { carrierFreq-r16 ARFCN-ValueEUTRA, measResultList-r16 MeasResultListEUTRA

}

MeasResultRLFNR-r16 ::= SEQUENCE { measResult-r16 SEQUENCE { cellResults-r16 SEQUENCE{ resultsSSB-Cell-r16 MeasQuantityResults OPTIONAL, resultsCSI-RS-Cell-r16 MeasQuantityResults OPTIONAL rslndexResults-r16 SEQUENCE{ resultsSSB-lndexes-r16 ResultsPerSSB-lndexList OPTIONAL, ssbRLMConfigBitmap-r16 BIT STRING (SIZE (64)) OPTIONAL, resultsCSI-RS-lndexes-r16 ResultsPerCSI-RS-lndexList OPTIONAL, csi-rsRLMConfigBitmap-r16 BIT STRING (SIZE (96)) OPTIONAL } OPTIONAL

TimeSinceFailure-r16 ::= INTEGER (0..172800)

ReconnectTimeSinceFailure-16 ::= INTEGER (0..172800)

TimeSinceCHOReconfig-r17 ::= INTEGER (0..172800)

- TAG-UEINFORMATIONRESPONSE-STOP

- ASN1STOP

Note that, as used herein, the re-establishment cell and cell selected after a CHO execution failure are used interchangeably and they indicate the same cell which has been selected after a failure via cell (re)selection procedure. This is due to the fact that the selected cell may be used as a re-establishment cell under certain conditions and may be used as a target cell for handover (for second CHO execution attempt) if configured.

Also as used herein, the terminology “prepared cells” is used to indicate the cells included by the source node in the list of target candidate cells within the ConditionalReconfiguration message.

Although the subject matter described herein may be implemented in any appropriate type of system using any suitable components, the embodiments disclosed herein are described in relation to a wireless network, such as the example wireless network illustrated in Figure 10. For simplicity, the wireless network of Figure 10 only depicts network 1006, network nodes 1060 and 1060b, and WDs 1010, 1010b, and 1010c. In practice, a wireless network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone, a service provider, or any other network node or end device. Of the illustrated components, network node 1060 and wireless device (WD) 1010 are depicted with additional detail. The wireless network may provide communication and other types of services to one or more wireless devices to facilitate the wireless devices’ access to and/or use of the services provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type of communication, telecommunication, data, cellular, and/or radio network or other similar type of system. In some embodiments, the wireless network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), Narrowband Internet of Things (NB-loT), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless local area network (WLAN) standards, such as the IEEE 802.11 standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave and/or ZigBee standards.

Network 1006 may comprise one or more backhaul networks, core networks, IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide-area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

Network node 1060 and WD 1010 comprise various components described in more detail below. These components work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, 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.

As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the wireless network to enable and/or provide wireless access to the wireless device and/or to perform other functions (e.g., administration) in the wireless 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)). Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and may then also 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 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). Yet further examples of network nodes include 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-cel l/multicast coordination entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As another example, a network node may be a virtual network node as described in more detail below. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device with access to the wireless network or to provide some service to a wireless device that has accessed the wireless network.

In Figure 10, network node 1060 includes processing circuitry 1070, device readable medium 1080, interface 1090, auxiliary equipment 1084, power source 1086, power circuitry 1087, and antenna 1062. Although network node 1060 illustrated in the example wireless network of Figure 10 may represent a device that includes the illustrated combination of hardware components, other embodiments may comprise network nodes with different combinations of components. It is to be understood that a network node comprises any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Moreover, while the components of network node 1060 are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., device readable medium 1080 may comprise multiple separate hard drives as well as multiple RAM modules).

Similarly, network node 1060 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 network node 1060 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 NodeB’s. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1060 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate device readable medium 1080 for the different RATs) and some components may be reused (e.g., the same antenna 1062 may be shared by the RATs). Network node 1060 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1060, such as, for example, GSM, WCDMA, LTE, NR, WiFi, 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 1060.

Processing circuitry 1070 is configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being provided by a network node. These operations performed by processing circuitry 1070 may include processing information obtained by processing circuitry 1070 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.

Processing circuitry 1070 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 1060 components, such as device readable medium 1080, network node 1060 functionality. For example, processing circuitry 1070 may execute instructions stored in device readable medium 1080 or in memory within processing circuitry 1070. Such functionality may include providing any of the various wireless features, functions, or benefits discussed herein. In some embodiments, processing circuitry 1070 may include a system on a chip (SOC). In some embodiments, processing circuitry 1070 may include one or more of radio frequency (RF) transceiver circuitry 1072 and baseband processing circuitry 1074. In some embodiments, radio frequency (RF) transceiver circuitry 1072 and baseband processing circuitry 1074 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 1072 and baseband processing circuitry 1074 may be on the same chip or set of chips, boards, or units In certain embodiments, some or all of the functionality described herein as being provided by a network node, base station, eNB or other such network device may be performed by processing circuitry 1070 executing instructions stored on device readable medium 1080 or memory within processing circuitry 1070. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1070 without executing instructions stored on a separate or discrete device readable medium, such as in a hard-wired manner. In any of those embodiments, whether executing instructions stored on a device readable storage medium or not, processing circuitry 1070 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1070 alone or to other components of network node 1060, but are enjoyed by network node 1060 as a whole, and/or by end users and the wireless network generally.

Device readable medium 1080 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 processing circuitry 1070. Device readable medium 1080 may store any suitable instructions, data or information, including a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1070 and, utilized by network node 1060. Device readable medium 1080 may be used to store any calculations made by processing circuitry 1070 and/or any data received via interface 1090. In some embodiments, processing circuitry 1070 and device readable medium 1080 may be considered to be integrated.

Interface 1090 is used in the wired or wireless communication of signalling and/or data between network node 1060, network 1006, and/or WDs 1010. As illustrated, interface 1090 comprises port(s)/terminal(s) 1094 to send and receive data, for example to and from network 1006 over a wired connection. Interface 1090 also includes radio front end circuitry 1092 that may be coupled to, or in certain embodiments a part of, antenna 1062. Radio front end circuitry 1092 comprises filters 1098 and amplifiers 1096. Radio front end circuitry 1092 may be connected to antenna 1062 and processing circuitry 1070. Radio front end circuitry may be configured to condition signals communicated between antenna 1062 and processing circuitry 1070. Radio front end circuitry 1092 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1092 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1098 and/or amplifiers 1096. The radio signal may then be transmitted via antenna 1062. Similarly, when receiving data, antenna 1062 may collect radio signals which are then converted into digital data by radio front end circuitry 1092. The digital data may be passed to processing circuitry 1070. In other embodiments, the interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1060 may not include separate radio front end circuitry 1092, instead, processing circuitry 1070 may comprise radio front end circuitry and may be connected to antenna 1062 without separate radio front end circuitry 1092. Similarly, in some embodiments, all or some of RF transceiver circuitry 1072 may be considered a part of interface 1090. In still other embodiments, interface 1090 may include one or more ports or terminals 1094, radio front end circuitry 1092, and RF transceiver circuitry 1072, as part of a radio unit (not shown), and interface 1090 may communicate with baseband processing circuitry 1074, which is part of a digital unit (not shown).

Antenna 1062 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1062 may be coupled to radio front end circuitry 1090 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 1062 may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, 2 GHz and 66 GHz. An omni-directional antenna may be used to transmit/receive radio signals in any direction, a sector antenna may be used to transmit/receive radio signals from devices within a particular area, and a panel antenna may be a line of sight antenna used to transmit/receive radio signals in a relatively straight line. In some instances, the use of more than one antenna may be referred to as Ml MO. In certain embodiments, antenna 1062 may be separate from network node 1060 and may be connectable to network node 1060 through an interface or port.

Antenna 1062, interface 1090, and/or processing circuitry 1070 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by a network node. Any information, data and/or signals may be received from a wireless device, another network node and/or any other network equipment. Similarly, antenna 1062, interface 1090, and/or processing circuitry 1070 may be configured to perform any transmitting operations described herein as being performed by a network node. Any information, data and/or signals may be transmitted to a wireless device, another network node and/or any other network equipment.

Power circuitry 1087 may comprise, or be coupled to, power management circuitry and is configured to supply the components of network node 1060 with power for performing the functionality described herein. Power circuitry 1087 may receive power from power source 1086. Power source 1086 and/or power circuitry 1087 may be configured to provide power to the various components of network node 1060 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1086 may either be included in, or external to, power circuitry 1087 and/or network node 1060. For example, network node 1060 may be connectable to an external power source (e.g., an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry 1087. As a further example, power source 1086 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry 1087. The battery may provide backup power should the external power source fail. Other types of power sources, such as photovoltaic devices, may also be used.

Alternative embodiments of network node 1060 may include additional components beyond those shown in Figure 10 that may be responsible 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, network node 1060 may include user interface equipment to allow input of information into network node 1060 and to allow output of information from network node 1060. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1060.

As used herein, wireless device (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Unless otherwise noted, the term WD may be used interchangeably herein with user equipment (UE). Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. In some embodiments, a WD may be configured to transmit and/or receive information without direct human interaction. For instance, a WD may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Examples of a WD include, but are not limited to, a smart phone, a mobile phone, a cell phone, a voice over IP (VoIP) phone, a wireless local loop phone, a desktop computer, a personal digital assistant (PDA), a wireless cameras, a gaming console or device, a music storage device, a playback appliance, a wearable terminal device, a wireless endpoint, a mobile station, a tablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mounted equipment (LME), a smart device, a wireless customer-premise equipment (CPE), a vehicle-mounted wireless terminal device, etc.. A WD may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-everything (V2X) and may in this case be referred to as a D2D communication device. As yet another specific example, in an Internet of Things (loT) scenario, a WD 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 WD and/or a network node. The WD may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the WD may be a UE implementing the 3GPP narrow band internet of things (NB-loT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances (e.g. refrigerators, televisions, etc.) personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, a WD may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation. A WD as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a WD as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As illustrated, wireless device 1010 includes antenna 1011, interface 1014, processing circuitry 1020, device readable medium 1030, user interface equipment 1032, auxiliary equipment 1034, power source 1036 and power circuitry 1037. WD 1010 may include multiple sets of one or more of the illustrated components for different wireless technologies supported by WD 1010, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, NB-loT, or Bluetooth wireless technologies, just to mention a few. These wireless technologies may be integrated into the same or different chips or set of chips as other components within WD 1010.

Antenna 1011 may include one or more antennas or antenna arrays, configured to send and/or receive wireless signals, and is connected to interface 1014. In certain alternative embodiments, antenna 1011 may be separate from WD 1010 and be connectable to WD 1010 through an interface or port. Antenna 1011, interface 1014, and/or processing circuitry 1020 may be configured to perform any receiving or transmitting operations described herein as being performed by a WD. Any information, data and/or signals may be received from a network node and/or another WD. In some embodiments, radio front end circuitry and/or antenna 1011 may be considered an interface.

As illustrated, interface 1014 comprises radio front end circuitry 1012 and antenna 1011. Radio front end circuitry 1012 comprise one or more filters 1018 and amplifiers 1016. Radio front end circuitry 1014 is connected to antenna 1011 and processing circuitry 1020, and is configured to condition signals communicated between antenna 1011 and processing circuitry 1020. Radio front end circuitry 1012 may be coupled to or a part of antenna 1011. In some embodiments, WD 1010 may not include separate radio front end circuitry 1012; rather, processing circuitry 1020 may comprise radio front end circuitry and may be connected to antenna 1011. Similarly, in some embodiments, some or all of RF transceiver circuitry 1022 may be considered a part of interface 1014. Radio front end circuitry 1012 may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. Radio front end circuitry 1012 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1018 and/or amplifiers 1016. The radio signal may then be transmitted via antenna 1011. Similarly, when receiving data, antenna 1011 may collect radio signals which are then converted into digital data by radio front end circuitry 1012. The digital data may be passed to processing circuitry 1020. In other embodiments, the interface may comprise different components and/or different combinations of components.

Processing circuitry 1020 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 WD 1010 components, such as device readable medium 1030, WD 1010 functionality. Such functionality may include providing any of the various wireless features or benefits discussed herein. For example, processing circuitry 1020 may execute instructions stored in device readable medium 1030 or in memory within processing circuitry 1020 to provide the functionality disclosed herein.

As illustrated, processing circuitry 1020 includes one or more of RF transceiver circuitry 1022, baseband processing circuitry 1024, and application processing circuitry 1026. In other embodiments, the processing circuitry may comprise different components and/or different combinations of components. In certain embodiments processing circuitry 1020 of WD 1010 may comprise a SOC. In some embodiments, RF transceiver circuitry 1022, baseband processing circuitry 1024, and application processing circuitry 1026 may be on separate chips or sets of chips. In alternative embodiments, part or all of baseband processing circuitry 1024 and application processing circuitry 1026 may be combined into one chip or set of chips, and RF transceiver circuitry 1022 may be on a separate chip or set of chips. In still alternative embodiments, part or all of RF transceiver circuitry 1022 and baseband processing circuitry 1024 may be on the same chip or set of chips, and application processing circuitry 1026 may be on a separate chip or set of chips. In yet other alternative embodiments, part or all of RF transceiver circuitry 1022, baseband processing circuitry 1024, and application processing circuitry 1026 may be combined in the same chip or set of chips. In some embodiments, RF transceiver circuitry 1022 may be a part of interface 1014. RF transceiver circuitry 1022 may condition RF signals for processing circuitry 1020.

In certain embodiments, some or all of the functionality described herein as being performed by a WD may be provided by processing circuitry 1020 executing instructions stored on device readable medium 1030, which in certain embodiments may be a computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by processing circuitry 1020 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 device readable storage medium or not, processing circuitry 1020 can be configured to perform the described functionality. The benefits provided by such functionality are not limited to processing circuitry 1020 alone or to other components of WD 1010, but are enjoyed by WD 1010 as a whole, and/or by end users and the wireless network generally.

Processing circuitry 1020 may be configured to perform any determining, calculating, or similar operations (e.g., certain obtaining operations) described herein as being performed by a WD. These operations, as performed by processing circuitry 1020, may include processing information obtained by processing circuitry 1020 by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored by WD 1010, 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.

Device readable medium 1030 may be operable to store a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by processing circuitry 1020. Device readable medium 1030 may include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., 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 processing circuitry 1020. In some embodiments, processing circuitry 1020 and device readable medium 1030 may be considered to be integrated.

User interface equipment 1032 may provide components that allow for a human user to interact with WD 1010. Such interaction may be of many forms, such as visual, audial, tactile, etc. User interface equipment 1032 may be operable to produce output to the user and to allow the user to provide input to WD 1010. The type of interaction may vary depending on the type of user interface equipment 1032 installed in WD 1010. For example, if WD 1010 is a smart phone, the interaction may be via a touch screen; if WD 1010 is a smart meter, the interaction may be through a screen that provides usage (e.g., the number of gallons used) or a speaker that provides an audible alert (e.g., if smoke is detected). User interface equipment 1032 may include input interfaces, devices and circuits, and output interfaces, devices and circuits. User interface equipment 1032 is configured to allow input of information into WD 1010, and is connected to processing circuitry 1020 to allow processing circuitry 1020 to process the input information. User interface equipment 1032 may include, for example, a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input circuitry. User interface equipment 1032 is also configured to allow output of information from WD 1010, and to allow processing circuitry 1020 to output information from WD 1010. User interface equipment 1032 may include, for example, a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output circuitry. Using one or more input and output interfaces, devices, and circuits, of user interface equipment 1032, WD 1010 may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

Auxiliary equipment 1034 is operable to provide more specific functionality which may not be generally performed by WDs. This may comprise specialized sensors for doing measurements for various purposes, interfaces for additional types of communication such as wired communications etc. The inclusion and type of components of auxiliary equipment 1034 may vary depending on the embodiment and/or scenario.

Power source 1036 may, in some embodiments, be in the form of a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic devices or power cells, may also be used. WD 1010 may further comprise power circuitry 1037 for delivering power from power source 1036 to the various parts of WD 1010 which need power from power source 1036 to carry out any functionality described or indicated herein. Power circuitry 1037 may in certain embodiments comprise power management circuitry. Power circuitry 1037 may additionally or alternatively be operable to receive power from an external power source; in which case WD 1010 may be connectable to the external power source (such as an electricity outlet) via input circuitry or an interface such as an electrical power cable. Power circuitry 1037 may also in certain embodiments be operable to deliver power from an external power source to power source 1036. This may be, for example, for the charging of power source 1036. Power circuitry 1037 may perform any formatting, converting, or other modification to the power from power source 1036 to make the power suitable for the respective components of WD 1010 to which power is supplied.

Figure 11 illustrates one embodiment of a UE in accordance with various aspects described herein. As used herein, a user equipment or 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). UE 11200 may be any UE identified by the 3rd Generation Partnership Project (3GPP), including a NB-loT UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE. UE 1100, as illustrated in Figure 11 , is one example of a WD configured for communication in accordance with one or more communication standards promulgated by the 3rd Generation Partnership Project (3GPP), such as 3GPP’s GSM, UMTS, LTE, and/or 5G standards. As mentioned previously, the term WD and UE may be used interchangeable. Accordingly, although Figure 11 is a UE, the components discussed herein are equally applicable to a WD, and vice-versa.

In Figure 11, UE 1100 includes processing circuitry 1101 that is operatively coupled to input/output interface 1105, radio frequency (RF) interface 1109, network connection interface 1111, memory 1115 including random access memory (RAM) 1117, read-only memory (ROM) 1119, and storage medium 1121 or the like, communication subsystem 1131, power source 1133, and/or any other component, or any combination thereof. Storage medium 1121 includes operating system 1123, application program 1125, and data 1127. In other embodiments, storage medium 1121 may include other similar types of information. Certain UEs may utilize all of the components shown in Figure 11, or only a subset of the components. 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.

In Figure 11, processing circuitry 1101 may be configured to process computer instructions and data. Processing circuitry 1101 may be configured to implement any sequential state machine operative to execute machine instructions stored as machine-readable computer programs in the memory, such as one or more hardware-implemented state machines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logic together with appropriate firmware; one or more stored program, 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 1101 may include two central processing units (CPUs). Data may be information in a form suitable for use by a computer.

In the depicted embodiment, input/output interface 1105 may be configured to provide a communication interface to an input device, output device, or input and output device. UE 1100 may be configured to use an output device via input/output interface 1105. An output device may use the same type of interface port as an input device. For example, a USB port may be used to provide input to and output from UE 1100. The output device may be 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. UE 1100 may be configured to use an input device via input/output interface 1105 to allow a user to capture information into UE 1100. The input device may 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 presencesensitive 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, another like sensor, or any combination thereof. For example, the input device may be an accelerometer, a magnetometer, a digital camera, a microphone, and an optical sensor.

In Figure 11, RF interface 1109 may be configured to provide a communication interface to RF components such as a transmitter, a receiver, and an antenna. Network connection interface 1111 may be configured to provide a communication interface to network 1143a. Network 1143a may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1143a may comprise a Wi-Fi network. Network connection interface 1111 may be configured to include a receiver and a transmitter interface used to communicate with one or more other devices over a communication network according to one or more communication protocols, such as Ethernet, TCP/IP, SONET, ATM, or the like. Network connection interface 1111 may implement receiver and transmitter functionality appropriate to the communication network links (e.g., optical, electrical, and the like). The transmitter and receiver functions may share circuit components, software or firmware, or alternatively may be implemented separately.

RAM 1117 may be configured to interface via bus 1102 to processing circuitry 1101 to provide storage or caching of data or computer instructions during the execution of software programs such as the operating system, application programs, and device drivers. ROM 1119 may be configured to provide computer instructions or data to processing circuitry 1101. For example, ROM 1119 may be configured to store invariant low-level system code or data for basic system functions such as basic input and output (I/O), startup, or reception of keystrokes from a keyboard that are stored in a non-volatile memory. Storage medium 1121 may be configured to include memory such as RAM, ROM, programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable readonly memory (EEPROM), magnetic disks, optical disks, floppy disks, hard disks, removable cartridges, or flash drives. In one example, storage medium 1121 may be configured to include operating system 1123, application program 1125 such as a web browser application, a widget or gadget engine or another application, and data file 1127. Storage medium 1121 may store, for use by UE 1100, any of a variety of various operating systems or combinations of operating systems.

Storage medium 1121 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), floppy disk drive, 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 a subscriber identity module or a removable user identity (SIM/RUIM) module, other memory, or any combination thereof. Storage medium 1121 may allow UE 1100 to access computer-executable instructions, application programs or 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 in storage medium 1121, which may comprise a device readable medium.

In Figure 11, processing circuitry 1101 may be configured to communicate with network 1143b using communication subsystem 1131. Network 1143a and network 1143b may be the same network or networks or different network or networks. Communication subsystem 1131 may be configured to include one or more transceivers used to communicate with network 1143b. For example, communication subsystem 1131 may be configured to include one or more transceivers used to communicate with one or more remote transceivers of another device capable of wireless communication such as another WD, UE, or base station of a radio access network (RAN) according to one or more communication protocols, such as IEEE 802.11 , CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver may include transmitter 1133 and/or receiver 1135 to implement transmitter or receiver functionality, respectively, appropriate to the RAN links (e.g., frequency allocations and the like). Further, transmitter 1133 and receiver 1135 of each transceiver may share circuit components, software or firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions of communication subsystem 1131 may include 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. For example, communication subsystem 1131 may include cellular communication, Wi-Fi communication, Bluetooth communication, and GPS communication. Network 1143b may encompass wired and/or wireless networks such as a local-area network (LAN), a wide-area network (WAN), a computer network, a wireless network, a telecommunications network, another like network or any combination thereof. For example, network 1143b may be a cellular network, a Wi-Fi network, and/or a near-field network. Power source 1113 may be configured to provide alternating current (AC) or direct current (DC) power to components of UE 1100.

The features, benefits and/or functions described herein may be implemented in one of the components of UE 1100 or partitioned across multiple components of UE 1100. Further, the features, benefits, and/or functions described herein may be implemented in any combination of hardware, software or firmware. In one example, communication subsystem 1131 may be configured to include any of the components described herein. Further, processing circuitry 1101 may be configured to communicate with any of such components over bus 1102. In another example, any of such components may be represented by program instructions stored in memory that when executed by processing circuitry 1101 perform the corresponding functions described herein. In another example, the functionality of any of such components may be partitioned between processing circuitry 1101 and communication subsystem 1131. In another example, the non-computationally intensive functions of any of such components may be implemented in software or firmware and the computationally intensive functions may be implemented in hardware.

Figure 12 is a schematic block diagram illustrating a virtualization environment 1200 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 a node (e.g., a virtualized base station or a virtualized radio access node) or to a device (e.g., a UE, a wireless device or any other type of communication device) 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 (e.g., via one or more applications, components, functions, virtual machines or containers executing on one or more physical processing nodes in one or more networks).

In some embodiments, some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines implemented in one or more virtual environments 1200 hosted by one or more of hardware nodes 1230. Further, in embodiments in which the virtual node is not a radio access node or does not require radio connectivity (e.g., a core network node), then the network node may be entirely virtualized.

The functions may be implemented by one or more applications 1220 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) operative to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. Applications 1220 are run in virtualization environment 1200 which provides hardware 1230 comprising processing circuitry 1260 and memory 1290. Memory 1290 contains instructions 1295 executable by processing circuitry 1260 whereby application 1220 is operative to provide one or more of the features, benefits, and/or functions disclosed herein.

Virtualization environment 1200, comprises general-purpose or special-purpose network hardware devices 1230 comprising a set of one or more processors or processing circuitry 1260, which may be commercial off-the-shelf (COTS) processors, dedicated Application Specific Integrated Circuits (ASICs), or any other type of processing circuitry including digital or analog hardware components or special purpose processors. Each hardware device may comprise memory 1290-1 which may be non-persistent memory for temporarily storing instructions 1295 or software executed by processing circuitry 1260. Each hardware device may comprise one or more network interface controllers (NICs) 1270, also known as network interface cards, which include physical network interface 1280. Each hardware device may also include non-transitory, persistent, machine-readable storage media 1290-2 having stored therein software 1295 and/or instructions executable by processing circuitry 1260. Software 1295 may include any type of software including software for instantiating one or more virtualization layers 1250 (also referred to as hypervisors), software to execute virtual machines 1240 as well as software allowing it to execute functions, features and/or benefits described in relation with some embodiments described herein.

Virtual machines 1240, comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1250 or hypervisor. Different embodiments of the instance of virtual appliance 1220 may be implemented on one or more of virtual machines 1240, and the implementations may be made in different ways.

During operation, processing circuitry 1260 executes software 1295 to instantiate the hypervisor or virtualization layer 1250, which may sometimes be referred to as a virtual machine monitor (VMM). Virtualization layer 1250 may present a virtual operating platform that appears like networking hardware to virtual machine 1240.

As shown in Figure 12, hardware 1230 may be a standalone network node with generic or specific components. Hardware 1230 may comprise antenna 12225 and may implement some functions via virtualization. Alternatively, hardware 1230 may be part of a larger cluster of hardware (e.g. such as in a data center or customer premise equipment (CPE)) where many hardware nodes work together and are managed via management and orchestration (MANO) 12100, which, among others, oversees lifecycle management of applications 1220.

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. In the context of NFV, virtual machine 1240 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 virtual machines 1240, and that part of hardware 1230 that executes that virtual machine, be it hardware dedicated to that virtual machine and/or hardware shared by that virtual machine with others of the virtual machines 1240, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) is responsible for handling specific network functions that run in one or more virtual machines 1240 on top of hardware networking infrastructure 1230 and corresponds to application 1220 in Figure 12.

In some embodiments, one or more radio units 12200 that each include one or more transmitters 12220 and one or more receivers 12210 may be coupled to one or more antennas 12225. Radio units 12200 may communicate directly with hardware nodes 1230 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 signalling can be effected with the use of control system 12230 which may alternatively be used for communication between the hardware nodes 1230 and radio units 12200.

Figure 13 illustrates a telecommunication network connected via an intermediate network to a host computer in accordance with some embodiments. In particular, with reference to FIGURE 13, in accordance with an embodiment, a communication system includes telecommunication network 1310, such as a 3GPP-type cellular network, which comprises access network 1311, such as a radio access network, and core network 1314. Access network 1311 comprises a plurality of base stations 1312a, 1312b, 1312c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1313a, 1313b, 1313c. Each base station 1312a, 1312b, 1312c is connectable to core network 1314 over a wired or wireless connection 1315. A first UE 1391 located in coverage area 1313c is configured to wirelessly connect to, or be paged by, the corresponding base station 1312c. A second UE 1392 in coverage area 1313a is wirelessly connectable to the corresponding base station 1312a. While a plurality of UEs 1391, 1392 are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole UE is in the coverage area or where a sole UE is connecting to the corresponding base station 1312.

Telecommunication network 1310 is itself connected to host computer 1330, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. Host computer 1330 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. Connections 1321 and 1322 between telecommunication network 1310 and host computer 1330 may extend directly from core network 1314 to host computer 1330 or may go via an optional intermediate network 1320. Intermediate network 1320 may be one of, or a combination of more than one of, a public, private or hosted network; intermediate network 1320, if any, may be a backbone network or the Internet; in particular, intermediate network 1320 may comprise two or more sub-networks (not shown).

The communication system of Figure 13 as a whole enables connectivity between the connected UEs 1391, 1392 and host computer 1330. The connectivity may be described as an over-the-top (OTT) connection 1350. Host computer 1330 and the connected UEs 1391, 1392 are configured to communicate data and/or signaling via OTT connection 1350, using access network 1311, core network 1314, any intermediate network 1320 and possible further infrastructure (not shown) as intermediaries. OTT connection 1350 may be transparent in the sense that the participating communication devices through which OTT connection 1350 passes are unaware of routing of uplink and downlink communications. For example, base station 1312 may not or need not be informed about the past routing of an incoming downlink communication with data originating from host computer 1330 to be forwarded (e.g., handed over) to a connected UE 1391. Similarly, base station 1312 need not be aware of the future routing of an outgoing uplink communication originating from the UE 1391 towards the host computer 1330.

Example implementations, in accordance with an embodiment, of the UE, base station and host computer discussed in the preceding paragraphs will now be described with reference to Figure 14. Figure 14 illustrates host computer communicating via a base station with a user equipment over a partially wireless connection in accordance with some embodiments In communication system 1400, host computer 1410 comprises hardware 1415 including communication interface 1416 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of communication system 1400. Host computer 1410 further comprises processing circuitry 1418, which may have storage and/or processing capabilities. In particular, processing circuitry 1418 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Host computer 1410 further comprises software 1411 , which is stored in or accessible by host computer 1410 and executable by processing circuitry 1418. Software 1411 includes host application 1412. Host application 1412 may be operable to provide a service to a remote user, such as UE 1430 connecting via OTT connection 1450 terminating at UE 1430 and host computer 1410. In providing the service to the remote user, host application 1412 may provide user data which is transmitted using OTT connection 1450.

Communication system 1400 further includes base station 1420 provided in a telecommunication system and comprising hardware 1425 enabling it to communicate with host computer 1410 and with UE 1430. Hardware 1425 may include communication interface 1426 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of communication system 1400, as well as radio interface 1427 for setting up and maintaining at least wireless connection 1470 with UE 1430 located in a coverage area (not shown in Figure 14) served by base station 1420. Communication interface 1426 may be configured to facilitate connection 1460 to host computer 1410. Connection 1460 may be direct or it may pass through a core network (not shown in Figure 14) of the telecommunication system and/or through one or more intermediate networks outside the telecommunication system. In the embodiment shown, hardware 1425 of base station 1420 further includes processing circuitry 1428, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. Base station 1420 further has software 1421 stored internally or accessible via an external connection.

Communication system 1400 further includes UE 1430 already referred to. Its hardware 1435 may include radio interface 1437 configured to set up and maintain wireless connection 1470 with a base station serving a coverage area in which UE 1430 is currently located. Hardware 1435 of UE 1430 further includes processing circuitry 1438, which may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these (not shown) adapted to execute instructions. UE 1430 further comprises software 1431, which is stored in or accessible by UE 1430 and executable by processing circuitry 1438. Software 1431 includes client application 1432. Client application 1432 may be operable to provide a service to a human or non-human user via UE 1430, with the support of host computer 1410. In host computer 1410, an executing host application 1412 may communicate with the executing client application 1432 via OTT connection 1450 terminating at UE 1430 and host computer 1410. In providing the service to the user, client application 1432 may receive request data from host application 1412 and provide user data in response to the request data. OTT connection 1450 may transfer both the request data and the user data. Client application 1432 may interact with the user to generate the user data that it provides.

It is noted that host computer 1410, base station 1420 and UE 1430 illustrated in Figure 14 may be similar or identical to host computer 1330, one of base stations 1312a, 1312b, 1312c and one of UEs 1391, 1392 of Figure 13, respectively. This is to say, the inner workings of these entities may be as shown in Figure 14 and independently, the surrounding network topology may be that of Figure 13.

In Figure 14, OTT connection 1450 has been drawn abstractly to illustrate the communication between host computer 1410 and UE 1430 via base station 1420, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from UE 1430 or from the service provider operating host computer 1410, or both. While OTT connection 1450 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

Wireless connection 1470 between UE 1430 and base station 1420 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to UE 1430 using OTT connection 1450, in which wireless connection 1470 forms the last segment.

A measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring OTT connection 1450 between host computer 1410 and UE 1430, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring OTT connection 1450 may be implemented in software 1411 and hardware 1415 of host computer 1410 or in software 1431 and hardware 1435 of UE 1430, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which OTT connection 1450 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 1411, 1431 may compute or estimate the monitored quantities. The reconfiguring of OTT connection 1450 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect base station 1420, and it may be unknown or imperceptible to base station 1420. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling facilitating host computer 1410’s measurements of throughput, propagation times, latency and the like. The measurements may be implemented in that software 1411 and 1431 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using OTT connection 1450 while it monitors propagation times, errors etc.

Figure 15 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 15 will be included in this section. In step 1510, the host computer provides user data. In substep 1511 (which may be optional) of step 1510, the host computer provides the user data by executing a host application. In step 1520, the host computer initiates a transmission carrying the user data to the UE. In step 1530 (which may be optional), the base station transmits to the UE the user data which was carried in the transmission that the host computer initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1540 (which may also be optional), the UE executes a client application associated with the host application executed by the host computer.

Figure 16 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 16 will be included in this section. In step 1610 of the method, the host computer provides user data. In an optional substep (not shown) the host computer provides the user data by executing a host application. In step 1620, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass via the base station, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1630 (which may be optional), the UE receives the user data carried in the transmission.

Figure 17 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 17 will be included in this section. In step 1710 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 1720, the UE provides user data. In substep 1721 (which may be optional) of step 1720, the UE provides the user data by executing a client application. In substep 1711 (which may be optional) of step 1710, the UE executes a client application which provides the user data in reaction to the received input data provided by the host computer. In providing the user data, the executed client application may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the UE initiates, in substep 1730 (which may be optional), transmission of the user data to the host computer. In step 1740 of the method, the host computer receives the user data transmitted from the UE, in accordance with the teachings of the embodiments described throughout this disclosure.

Figure 18 is a flowchart illustrating a method implemented in a communication system, in accordance with one embodiment. The communication system includes a host computer, a base station and a UE which may be those described with reference to Figures 13 and 14. For simplicity of the present disclosure, only drawing references to Figure 18 will be included in this section. In step 1810 (which may be optional), in accordance with the teachings of the embodiments described throughout this disclosure, the base station receives user data from the UE. In step 1820 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 1830 (which may be optional), the host computer receives the user data carried in the transmission initiated by the base station. Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include digital signal processors (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as read-only memory (ROM), random-access memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

In view of the above, then, embodiments herein generally include a communication system including a host computer. The host computer may comprise processing circuitry configured to provide user data. The host computer may also comprise a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE). The cellular network may comprise a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the base station.

In some embodiments, the communication system further includes the UE, wherein the UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. In this case, the UE comprises processing circuitry configured to execute a client application associated with the host application.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data. The method may also comprise, at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The base station performs any of the steps of any of the embodiments described above for a base station.

In some embodiments, the method further comprising, at the base station, transmitting the user data. In some embodiments, the user data is provided at the host computer by executing a host application. In this case, the method further comprises, at the UE, executing a client application associated with the host application.

Embodiments herein also include a user equipment (UE) configured to communicate with a base station. The UE comprises a radio interface and processing circuitry configured to perform any of the embodiments above described for a UE.

Embodiments herein further include a communication system including a host computer. The host computer comprises processing circuitry configured to provide user data, and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE). The UE comprises a radio interface and processing circuitry. The UE’s components are configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments, the cellular network further includes a base station configured to communicate with the UE.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data. The UE’s processing circuitry is configured to execute a client application associated with the host application.

Embodiments also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, providing user data and initiating a transmission carrying the user data to the UE via a cellular network comprising the base station. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the UE, receiving the user data from the base station.

Embodiments herein further include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The UE comprises a radio interface and processing circuitry. The UE’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a UE.

In some embodiments the communication system further includes the UE.

In some embodiments, the communication system further including the base station. In this case, the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data. In some embodiments, the processing circuitry of the host computer is configured to execute a host application, thereby providing request data. And the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

Embodiments herein also include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving user data transmitted to the base station from the UE. The UE performs any of the steps of any of the embodiments described above for the UE.

In some embodiments, the method further comprises, at the UE, providing the user data to the base station.

In some embodiments, the method also comprises, at the UE, executing a client application, thereby providing the user data to be transmitted. The method may further comprise, at the host computer, executing a host application associated with the client application.

In some embodiments, the method further comprises, at the UE, executing a client application, and, at the UE, receiving input data to the client application. The input data is provided at the host computer by executing a host application associated with the client application. The user data to be transmitted is provided by the client application in response to the input data.

Embodiments also include a communication system including a host computer. The host computer comprises a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station. The base station comprises a radio interface and processing circuitry. The base station’s processing circuitry is configured to perform any of the steps of any of the embodiments described above for a base station.

In some embodiments, the communication system further includes the UE. The UE is configured to communicate with the base station.

In some embodiments, the processing circuitry of the host computer is configured to execute a host application. And the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

Embodiments moreover include a method implemented in a communication system including a host computer, a base station and a user equipment (UE). The method comprises, at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE. The UE performs any of the steps of any of the embodiments described above for a UE.

In some embodiments, the method further comprises, at the base station, receiving the user data from the UE. In some embodiments, the method further comprises, at the base station, initiating a transmission of the received user data to the host computer.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the description.

The term unit may have conventional meaning in the field of electronics, electrical devices and/or electronic devices and may include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

The term “A and/or B” as used herein covers embodiments having A alone, B alone, or both A and B together. The term “A and/or B” may therefore equivalently mean “at least one of any one or more of A and B”.

Some of the embodiments contemplated herein are described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein. The disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Example embodiments of the techniques and apparatus described herein include, but are not limited to, the following enumerated examples: Group A Embodiments

A1. A method performed by a wireless device, the method comprising: detecting a failure associated with a failed cell; responsive to detecting the failure, selecting a cell towards which to perform a mobility or access procedure and logging information associated with the detected failure, wherein the logged information indicates at least one of any one or more of: whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure; whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure; whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure; time elapsed between a time when the wireless device received a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure and a reference time associated with the failure; a list of one or more cells for which a conditional reconfiguration was stored at the wireless device when the wireless device detected the failure; whether the detected failure was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure; performing the mobility or access procedure towards the selected cell; and during or after the mobility or access procedure, transmitting a report indicating the logged information.

A2. The method of embodiment A1 , wherein the logged information indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

A3. The method of embodiment A2, wherein the conditional reconfiguration is a conditional handover configuration such that the logged information indicates whether a conditional handover configuration for the selected cell was stored at the wireless device when the wireless device detected the failure.

A4. The method of any of embodiments A1-A3, wherein the logged information includes a Boolean field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

A5. The method of any of embodiments A1-A4, wherein the mobility or access procedure is a Radio Resource Control, RRC, Re-Establishment procedure.

A6. The method of embodiment A5, wherein the logged information includes a reestablishmentCellCHOPrepared field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

A7. The method of any of embodiments A1-A4, wherein the mobility or access procedure is a conditional handover procedure.

A8. The method of any of embodiments A1-A4, wherein the mobility or access procedure is an RRC Connection Setup procedure.

A9. The method of embodiment A8, wherein the logged information includes a reconnectCellCHOPrepared field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

A10. The method of any of embodiments A1-A4, wherein the mobility or access procedure is a cell selection or reselection procedure.

A11. The method of any of embodiments A1-A10, wherein the failure is a radio link failure, RLF.

A12. The method of any of embodiments A1-A11 , wherein the failure is a failure of a mobility or access procedure towards the failed cell, a failure detected during a mobility or access procedure towards the failed cell, or a failure detected while the wireless device was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell.

A13. The method of any of embodiments A1-A12, wherein the failure is a failure while the wireless device has a conditional reconfiguration stored.

A14. The method of any of embodiments A1-A13, wherein the logged information indicates whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure.

A15. The method of embodiment A14, wherein the logged information includes a Boolean field that indicates whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure. A16. The method of embodiment A15, wherein the Boolean field is an attemptCondReconfig field.

A17. The method of any of embodiments A1-A16, wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure; selection of the cell towards which to perform the mobility or access procedure; or starting of the mobility or access procedure.

A18. The method of embodiment A17, further comprising: starting a timer upon receiving a conditional reconfiguration; and stopping the timer upon occurrence of the reference event, wherein the logged information indicates the value of the timer when stopped.

A19. The method of any of embodiments A1-A18, wherein the logged information includes a timeSinceCHOreconfig field that indicates said time elapsed.

A20. The method of any of embodiments A1-A19, wherein the logged information indicates whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure.

A21. The method of embodiment A20, wherein the logged information includes a Boolean field that indicates whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure.

A22. The method of embodiment A21 , wherein the Boolean field is a failedPCellldCHOPrepared field.

A23. The method of any of embodiments A1-A22, wherein the report is a radio link failure report.

A24. The method of any of embodiments A1-A23, wherein the mobility or access procedure is a Radio Resource Control, RRC, Re-Establishment procedure, and wherein the method further comprises, as part of performing actions to set the contents of an RRC Re-establishment Request message: setting a field in the logged information to indicate whether the selected cell is a target candidate cell within a list of conditional reconfigurations stored at the wireless device; and after setting the field, removing all entries within the list.

A25. The method of any of embodiments A1-A24, wherein the logged information further indicates a first list of measurements performed by the wireless device on any cells for which the wireless device had a conditional reconfiguration stored when the wireless device detected the failure and a second list of measurements performed by the wireless device on any cells for which the wireless device did not have a conditional reconfiguration stored when the wireless device detected the failure.

A26. The method of any of embodiments A1-A25, further comprising: during or after the mobility or access procedure towards the selected cell, transmitting a message indicating availability of the logged information and/or availability of the report; after transmitting the message, receiving a request for the logged information and/or for the report; and transmitting the report with the logged information responsive to the request.

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.

Group B Embodiments

B1. A method performed by a radio network node, the method comprising: receiving logged information associated with a failure detected by a wireless device, wherein the logged information indicates at least one of any one or more of: whether a conditional reconfiguration for a selected cell was stored at the wireless device when the wireless device detected the failure, wherein the selected cell is a cell towards which the wireless device selected to perform a mobility or access procedure responsive to detecting the failure; whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure; whether a conditional reconfiguration for a failed cell was stored at the wireless device when the wireless device detected the failure, wherein the failed cell is a cell associated with the failure; time elapsed between a time when the wireless device received a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure and a reference time associated with the failure; a list of one or more cells for which a conditional reconfiguration was stored at the wireless device when the wireless device detected the failure; whether the detected failure was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device when the wireless device detected the failure.

B2. The method of embodiment B1 , wherein the logged information indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

B3. The method of embodiment B2, wherein the conditional reconfiguration is a conditional handover configuration such that the logged information indicates whether a conditional handover configuration for the selected cell was stored at the wireless device when the wireless device detected the failure.

B4. The method of any of embodiments B1-B3, wherein the logged information includes a Boolean field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

B5. The method of any of embodiments B1-B4, wherein the mobility or access procedure is a Radio Resource Control, RRC, Re-Establishment procedure.

B6. The method of embodiment B5, wherein the logged information includes a reestablishmentCellCHOPrepared field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

B7. The method of any of embodiments B1-B4, wherein the mobility or access procedure is a conditional handover procedure.

B8. The method of any of embodiments B1-B4, wherein the mobility or access procedure is an RRC Connection Setup procedure. B9. The method of embodiment B8, wherein the logged information includes a reconnectCellCHOPrepared field that indicates whether a conditional reconfiguration for the selected cell was stored at the wireless device when the wireless device detected the failure.

B10. The method of any of embodiments B1-B4, wherein the mobility or access procedure is a cell selection or reselection procedure.

B11. The method of any of embodiments B1-B10, wherein the failure is a radio link failure, RLF.

B12. The method of any of embodiments B1-B11 , wherein the failure is a failure of a mobility or access procedure towards the failed cell, a failure detected during a mobility or access procedure towards the failed cell, or a failure detected while the wireless device was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell.

B13. The method of any of embodiments B1-B12, wherein the failure is a failure while the wireless device has a conditional reconfiguration stored.

B14. The method of any of embodiments B1-B13, wherein the logged information indicates whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure.

B15. The method of embodiment B14, wherein the logged information includes a Boolean field that indicates whether the wireless device, when the wireless device detected the failure, was configured to attempt to apply a conditional reconfiguration for the selected cell in response to the detected failure.

B16. The method of embodiment B15, wherein the Boolean field is an attemptCondReconfig field.

B17. The method of any of embodiments B1-B16, wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure; selection of the cell towards which to perform the mobility or access procedure; or starting of the mobility or access procedure. B18. The method of any of embodiments B1-B17, wherein the logged information includes a timeSinceCHOreconfig field that indicates said time elapsed.

B19. The method of any of embodiments B1-B18, wherein the logged information indicates whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure.

B20. The method of embodiment B19, wherein the logged information includes a Boolean field that indicates whether a conditional reconfiguration for the failed cell was stored at the wireless device when the wireless device detected the failure.

B21. The method of embodiment B20, wherein the Boolean field is a failedPCellldCHOPrepared field.

B22. The method of any of embodiments B1-B21 , wherein the logged information is included in a radio link failure report.

B23. The method of any of embodiments B1-B22, wherein the logged information further indicates a first list of measurements performed by the wireless device on any cells for which the wireless device had a conditional reconfiguration stored when the wireless device detected the failure and a second list of measurements performed by the wireless device on any cells for which the wireless device did not have a conditional reconfiguration stored when the wireless device detected the failure.

B24. The method of any of embodiments B1-B23, further comprising: during or after the mobility or access procedure, receiving a message indicating availability of the logged information and/or availability of a report including the logged information; after receiving the message, transmitting a request for the logged information and/or for the report; and receiving the logged information responsive to the request.

B25. The method of any of embodiments B1-B24, further comprising analyzing a root cause of the failure, using the logged information.

B26. The method of embodiment B25, further comprising adapting one or more parameters associated with a mobility or access procedure, based on said analyzing.

B27. The method of any of embodiments B1-B26, further comprising sending at least a part of the logged information to another radio network node associated with the failure.

B28. The method of any of embodiments B1-B27, wherein the radio network node serves the selected cell.

B29. The method of any of embodiments B1-B28, wherein the logged information is received from the wireless device.

B30. The method of any of embodiments B1-B27, wherein the radio network node serves the failed cell.

B31. The method of any of embodiments B1-B27 and B30, wherein the logged information is received from another radio network node.

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 wireless device.

Group C Embodiments

C1. A wireless device configured to perform any of the steps of any of the Group A embodiments.

C2. A wireless device comprising processing circuitry configured to perform any of the steps of any of the Group A embodiments.

C3. A wireless device comprising: communication circuitry; and processing circuitry configured to perform any of the steps of any of the Group A embodiments.

C4. A wireless device comprising: processing circuitry configured to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the wireless device.

C5. A wireless device comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the wireless device is configured to perform any of the steps of any of the Group A embodiments.

C6. 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 any of the steps 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.

C7. A computer program comprising instructions which, when executed by at least one processor of a wireless device, causes the wireless device to carry out the steps of any of the Group A embodiments.

C8. 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.

C9. A radio network node configured to perform any of the steps of any of the Group B embodiments.

C10. A radio network node comprising processing circuitry configured to perform any of the steps of any of the Group B embodiments.

C11 . A radio network node comprising: communication circuitry; and processing circuitry configured to perform any of the steps of any of the Group B embodiments.

C12. A radio network node comprising: processing circuitry configured to perform any of the steps of any of the Group B embodiments; power supply circuitry configured to supply power to the radio network node.

C13. A radio network node comprising: processing circuitry and memory, the memory containing instructions executable by the processing circuitry whereby the radio network node is configured to perform any of the steps of any of the Group B embodiments.

C14. The radio network node of any of embodiments C9-C13, wherein the radio network node is a base station.

C15. A computer program comprising instructions which, when executed by at least one processor of a radio network node, causes the radio network node to carry out the steps of any of the Group B embodiments.

C16. The computer program of embodiment C14, wherein the radio network node is a base station.

C17. A carrier containing the computer program of any of embodiments C15-C16, wherein the carrier is one of an electronic signal, optical signal, radio signal, or computer readable storage medium.

Group D Embodiments

D1 . A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward the user data to a cellular network for transmission to a user equipment (UE), wherein the cellular network comprises a base station having a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments.

D2. The communication system of the previous embodiment further including the base station.

D3. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

D4. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application.

D5. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the base station performs any of the steps of any of the Group B embodiments.

D6. The method of the previous embodiment, further comprising, at the base station, transmitting the user data.

D7. The method of the previous 2 embodiments, wherein the user data is provided at the host computer by executing a host application, the method further comprising, at the UE, executing a client application associated with the host application.

D8. A user equipment (UE) configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform any of the previous 3 embodiments.

D9. A communication system including a host computer comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a radio interface and processing circuitry, the UE’s components configured to perform any of the steps of any of the Group A embodiments.

D10. The communication system of the previous embodiment, wherein the cellular network further includes a base station configured to communicate with the UE.

D11 . The communication system of the previous 2 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing the user data; and the UE’s processing circuitry is configured to execute a client application associated with the host application.

D12. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, providing user data; and at the host computer, initiating a transmission carrying the user data to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the Group A embodiments.

D13. The method of the previous embodiment, further comprising at the UE, receiving the user data from the base station.

D14. A communication system including a host computer comprising: communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the UE comprises a radio interface and processing circuitry, the UE’s processing circuitry configured to perform any of the steps of any of the Group A embodiments.

D15. The communication system of the previous embodiment, further including the UE.

D16. The communication system of the previous 2 embodiments, further including the base station, wherein the base station comprises a radio interface configured to communicate with the UE and a communication interface configured to forward to the host computer the user data carried by a transmission from the UE to the base station. D17. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data.

D18. The communication system of the previous 4 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application, thereby providing request data; and the UE’s processing circuitry is configured to execute a client application associated with the host application, thereby providing the user data in response to the request data.

D19. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving user data transmitted to the base station from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

D20. The method of the previous embodiment, further comprising, at the UE, providing the user data to the base station.

D21 . The method of the previous 2 embodiments, further comprising: at the UE, executing a client application, thereby providing the user data to be transmitted; and at the host computer, executing a host application associated with the client application.

D22. The method of the previous 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data to the client application, the input data being provided at the host computer by executing a host application associated with the client application, wherein the user data to be transmitted is provided by the client application in response to the input data.

D23. A communication system including a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment (UE) to a base station, wherein the base station comprises a radio interface and processing circuitry, the base station’s processing circuitry configured to perform any of the steps of any of the Group B embodiments.

D24. The communication system of the previous embodiment further including the base station.

D25. The communication system of the previous 2 embodiments, further including the UE, wherein the UE is configured to communicate with the base station.

D26. The communication system of the previous 3 embodiments, wherein: the processing circuitry of the host computer is configured to execute a host application; the UE is configured to execute a client application associated with the host application, thereby providing the user data to be received by the host computer.

D27. A method implemented in a communication system including a host computer, a base station and a user equipment (UE), the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission which the base station has received from the UE, wherein the UE performs any of the steps of any of the Group A embodiments.

D28. The method of the previous embodiment, further comprising at the base station, receiving the user data from the UE.

D29. The method of the previous 2 embodiments, further comprising at the base station, initiating a transmission of the received user data to the host computer.

At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

1x RTT CDMA2000 1x Radio Transmission Technology

3GPP 3rd Generation Partnership Project

5G 5th Generation

ABS Almost Blank Subframe

ARQ Automatic Repeat Request

AWGN Additive White Gaussian Noise

BCCH Broadcast Control Channel

BCH Broadcast Channel

CA Carrier Aggregation

CC Carrier Component

CCCH SDU Common Control Channel SDU

CDMA Code Division Multiplexing Access

CGI Cell Global Identifier

CIR Channel Impulse Response

CP Cyclic Prefix

CPICH Common Pilot Channel

CPICH Ec/No CPICH Received energy per chip divided by the power density in the band

CQI Channel Quality information C-RNTI Cell RNTI CSI Channel State Information DCCH Dedicated Control Channel DL Downlink DM Demodulation DMRS Demodulation Reference Signal DRX Discontinuous Reception DTX Discontinuous Transmission DTCH Dedicated Traffic Channel DUT Device Under Test E-CID Enhanced Cell-ID (positioning method) E-SMLC Evolved-Serving Mobile Location Centre ECGI Evolved CGI eNB E-UTRAN NodeB ePDCCH enhanced Physical Downlink Control Channel E-SMLC evolved Serving Mobile Location Center E-UTRA Evolved UTRA E-UTRAN Evolved UTRAN FDD Frequency Division Duplex FFS For Further Study GE RAN GSM EDGE Radio Access Network gNB Base station in NR GNSS Global Navigation Satellite System GSM Global System for Mobile communication HARQ Hybrid Automatic Repeat Request HO Handover HSPA High Speed Packet Access HRPD High Rate Packet Data LOS Line of Sight LPP LTE Positioning Protocol

LTE Long-Term Evolution

MAC Medium Access Control

MBMS Multimedia Broadcast Multicast Services

MBSFN Multimedia Broadcast multicast service Single Frequency Network

MBSFN ABS MBSFN Almost Blank Subframe

MDT Minimization of Drive Tests

MIB Master Information Block

MME Mobility Management Entity

MSC Mobile Switching Center

NPDCCH Narrowband Physical Downlink Control Channel

NR New Radio

OCNG OFDMA Channel Noise Generator

OFDM Orthogonal Frequency Division Multiplexing

OFDMA Orthogonal Frequency Division Multiple Access

OSS Operations Support System

OTDOA Observed Time Difference of Arrival

O&M Operation and Maintenance

PBCH Physical Broadcast Channel

P-CCPCH Primary Common Control Physical Channel

PCell Primary Cell

PCFICH Physical Control Format Indicator Channel

PDCCH Physical Downlink Control Channel

PDP Profile Delay Profile

PDSCH Physical Downlink Shared Channel

PGW Packet Gateway

PHICH Physical Hybrid-ARQ Indicator Channel

PLMN Public Land Mobile Network

PM I Precoder Matrix Indicator

PRACH Physical Random Access Channel

PRS Positioning Reference Signal

PSS Primary Synchronization Signal

PUCCH Physical Uplink Control Channel

PUSCH Physical Uplink Shared Channel

RACH Random Access Channel

QAM Quadrature Amplitude Modulation

RAN Radio Access Network

RAT Radio Access Technology

RLM Radio Link Management

RNC Radio Network Controller

RNTI Radio Network Temporary Identifier

RRC Radio Resource Control

RRM Radio Resource Management

RS Reference Signal

RSCP Received Signal Code Power

RSRP Reference Symbol Received Power OR

Reference Signal Received Power

RSRQ Reference Signal Received Quality OR

Reference Symbol Received Quality

RSSI Received Signal Strength Indicator

RSTD Reference Signal Time Difference SCH Synchronization Channel

SCell Secondary Cell

SDU Service Data Unit

SFN System Frame Number

SGW Serving Gateway

SI System Information

SIB System Information Block

SNR Signal to Noise Ratio

SON Self Optimized Network

SS Synchronization Signal

SSS Secondary Synchronization Signal

TDD Time Division Duplex

TDOA Time Difference of Arrival

TOA Time of Arrival

TSS Tertiary Synchronization Signal

TTI Transmission Time Interval

UE User Equipment

UL Uplink

UMTS Universal Mobile Telecommunication System

USIM Universal Subscriber Identity Module

UTDOA Uplink Time Difference of Arrival

UTRA Universal Terrestrial Radio Access

UTRAN Universal Terrestrial Radio Access Network

WCDMA Wide CDMA

WLAN Wide Local Area Network

BFD Beam failure detection

CHO Conditional handover

CHOF CHO failure

C-RNTI Cell Radio Network Temporary Identifier (RNTI)

CSI-RS Channel State Information (CSI) Reference Signal (RS)

DL Downlink

DRB Data radio bearer eNB eNodeB (base station supporting the LTE air interface) gNB gNodeB (base station supporting the NR air interface)

HO Handover

HOF Handover Failure

IS In-Sync

L1 Layer 1 (also referred to as physical layer)

LTE Long Term Evolution

MAC Medium Access Control

MDT Minimization of Drive Tests

MRO Mobility Robustness Optimization

NG-RAN node Next Generation Radio Access Network node

NR New Radio

OOS Out-of-Sync

PCell Primary Cell

PCI Physical Cell Identifier

PDCP Packet Data Convergence Protocol

PDCP SN Packet Data Convergence Protocol Sequence Number

QCI Quality of Service Class Indicator

RA Random Access RACH Random Access Channel RAT Radio Access Technology RLC Radio Link Control RLM Radio Link Monitoring RLF Radio Link Failure

RRC Radio Resource Control RRM Radio Resource Management RSRP Reference Signal Received Power RSRQ Reference Signal Received Quality RSSI Received Signal Strength Indicator

SINR Signal-to-noise and interference ratio SON Self-Organizing Networks SSB Synchronization Signal Block UE User Equipment XnAP Xn Application Protocol

Claims

CLAIMS What is claimed is:

1. A method performed by a wireless device (12), the method comprising: detecting (200) a failure (14) associated with a failed cell (16F); responsive to detecting (200) the failure (14), selecting (210) a cell (16S) towards which to perform a mobility or access procedure and logging information (20) associated with the detected failure (14), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14); performing (220) the mobility or access procedure towards the selected cell (16S); and during or after the mobility or access procedure, transmitting (230) a report (22) indicating the logged information (20).

2. The method of claim 1 , wherein the logged information (20) further indicates at least one of any one or more of: whether a conditional reconfiguration for the selected cell (16S) was stored at the wireless device (12) when the wireless device (12) detected the failure (14); whether a conditional reconfiguration for the failed cell (16F) was stored at the wireless device (12) when the wireless device (12) detected the failure (14); a list of one or more cells for which a conditional reconfiguration was stored at the wireless device (12) when the wireless device (12) detected the failure (14); whether the wireless device (12), when the wireless device (12) detected the failure (14), was configured to attempt to apply a conditional reconfiguration for the selected cell (16S) in response to the detected failure (14); whether the detected failure (14) was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14);

3. The method of any of claims 1-2, wherein the failure (14) is a radio link failure, RLF.

4. The method of any of claims 1-3, wherein the failure (14) is a failure of a mobility or access procedure towards the failed cell (16F), a failure detected during a mobility or access procedure towards the failed cell (16F), or a failure detected while the wireless device (12) was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the

85 failed cell (16F).

5. The method of any of claims 1-4, wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure (14); selection of the cell (16S) towards which to perform the mobility or access procedure; or starting of the mobility or access procedure.

6. The method of claim 5, further comprising: starting a timer upon receiving a conditional reconfiguration; and stopping the timer upon occurrence of the reference event, wherein the logged information (20) indicates the value of the timer when stopped.

7. The method of any of claims 1-6, wherein the report (22) is a radio link failure report.

8. The method of any of claims 1-7, further comprising: during or after the mobility or access procedure towards the selected cell (16S), transmitting a message indicating availability of the logged information (20) and/or availability of the report (22); after transmitting the message, receiving a request for the logged information (20) and/or for the report (22); and transmitting the report (22) with the logged information (20) responsive to the request.

9. A method performed by a radio network node (13F, 13S), the method comprising: receiving (300) logged information (20) associated with a failure (14) detected by a wireless device (12), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14).

10. The method of claim 9, wherein the logged information (20) further indicates at least one of any one or more of: whether a conditional reconfiguration for a selected cell (16S) was stored at the wireless device (12) when the wireless device (12) detected the failure (14), wherein the

86 selected cell (16S) is a cell towards which the wireless device (12) selected to perform a mobility or access procedure responsive to detecting the failure (14); whether a conditional reconfiguration for a failed cell (16F) was stored at the wireless device (12) when the wireless device (12) detected the failure (14), wherein the failed cell (16F) is a cell associated with the failure (14); a list of one or more cells for which a conditional reconfiguration was stored at the wireless device (12) when the wireless device (12) detected the failure (14); whether the wireless device (12), when the wireless device (12) detected the failure (14), was configured to attempt to apply a conditional reconfiguration for the selected cell (16S) in response to the detected failure (14); whether the detected failure (14) was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14).

11. The method of any of claims 9-10, wherein the failure (14) is a radio link failure, RLF.

12. The method of any of claims 9-11 , wherein the failure (14) is a failure of a mobility or access procedure towards the failed cell (16F), a failure detected during a mobility or access procedure towards the failed cell (16F), or a failure detected while the wireless device (12) was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell (16F).

13. The method of any of claims 9-12, wherein the failure (14) is a failure while the wireless device (12) has a conditional reconfiguration stored.

14. The method of any of claims 9-13, wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure (14); selection of the cell (16S) towards which to perform the mobility or access procedure; or starting of the mobility or access procedure.

15. The method of any of claims 9-14, wherein the logged information (20) is included in a radio link failure report.

16. The method of any of claims 9-15, further comprising: during or after the mobility or access procedure, receiving a message indicating availability of the logged information (20) and/or availability of a report (22)

87 including the logged information (20); after receiving the message, transmitting a request for the logged information (20) and/or for the report (22); and receiving the logged information (20) responsive to the request.

17. The method of any of claims 9-16, further comprising sending (330) at least a part of the logged information (20) to another radio network node associated with the failure (14).

18. The method of any of claims 9-17, further comprising: analyzing (310) a root cause of the failure (14), using the logged information (20); and/or adapting (320) one or more parameters associated with a mobility or access procedure, based on the logged information (20).

19. A wireless device (12) comprising: communication circuitry (420); and processing circuitry (410) configured to: detect a failure (14) associated with a failed cell (16F); responsive to detecting the failure (14), select a cell (16S) towards which to perform a mobility or access procedure and logging information (20) associated with the detected failure (14), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14); perform the mobility or access procedure towards the selected cell (16S); and during or after the mobility or access procedure, transmit, via the communication circuitry, a report (22) indicating the logged information (20).

20. The wireless device (12) of claim 19, wherein the logged information (20) further indicates at least one of any one or more of: whether a conditional reconfiguration for the selected cell (16S) was stored at the wireless device (12) when the wireless device (12) detected the failure (14); whether a conditional reconfiguration for the failed cell (16F) was stored at the wireless device (12) when the wireless device (12) detected the failure (14); a list of one or more cells for which a conditional reconfiguration was stored at the wireless device (12) when the wireless device (12) detected the failure (14);

88 whether the wireless device (12), when the wireless device (12) detected the failure (14), was configured to attempt to apply a conditional reconfiguration for the selected cell (16S) in response to the detected failure (14); whether the detected failure (14) was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14);

21. The wireless device (12) of any of claims 19-20, wherein the failure (14) is a radio link failure, RLF.

22. The wireless device (12) of any of claims 19-21 , wherein the failure (14) is a failure of a mobility or access procedure towards the failed cell (16F), a failure detected during a mobility or access procedure towards the failed cell (16F), or a failure detected while the wireless device (12) was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell (16F).

23. The wireless device (12) of any of claims 19-22, wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure (14); selection of the cell (16S) towards which to perform the mobility or access procedure; or starting of the mobility or access procedure.

24. The wireless device (12) of claim 23, the processing circuitry (410) further configured to: start a timer upon receiving a conditional reconfiguration; and stop the timer upon occurrence of the reference event, wherein the logged information (20) indicates the value of the timer when stopped.

25. The wireless device (12) of any of claims 19-24, wherein the report (22) is a radio link failure report.

26. The wireless device (12) of any of claims 19-25, the processing circuitry (410) further configured to: during or after the mobility or access procedure towards the selected cell (16S), transmit a message indicating availability of the logged information (20) and/or availability of the report (22);

89 after transmitting the message, receive a request for the logged information (20) and/or for the report (22); and transmit the report (22) with the logged information (20) responsive to the request.

27. A radio network node (13F, 13S) comprising: communication circuitry (520); and processing circuitry (510) configured to receive, via the communication circuitry (520), logged information (20) associated with a failure (14) detected by a wireless device (12), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14).

28. The radio network node of claim 27, wherein the logged information (20) further indicates at least one of any one or more of: whether a conditional reconfiguration for a selected cell (16S) was stored at the wireless device (12) when the wireless device (12) detected the failure (14), wherein the selected cell (16S) is a cell towards which the wireless device (12) selected to perform a mobility or access procedure responsive to detecting the failure (14); whether a conditional reconfiguration for a failed cell (16F) was stored at the wireless device (12) when the wireless device (12) detected the failure (14), wherein the failed cell (16F) is a cell associated with the failure (14); a list of one or more cells for which a conditional reconfiguration was stored at the wireless device (12) when the wireless device (12) detected the failure (14); whether the wireless device (12), when the wireless device (12) detected the failure (14), was configured to attempt to apply a conditional reconfiguration for the selected cell (16S) in response to the detected failure (14); whether the detected failure (14) was associated with a conditional reconfiguration; and one or more parameters of a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14).

29. The radio network node of any of claims 27-28, wherein the failure (14) is a radio link failure, RLF.

30. The radio network node of any of claims 27-29, wherein the failure (14) is a failure of a mobility or access procedure towards the failed cell (16F), a failure detected during a mobility or

90 access procedure towards the failed cell (16F), or a failure detected while the wireless device (12) was monitoring for fulfillment of a condition to trigger a mobility or access procedure towards the failed cell (16F).

31. The radio network node of any of claims 27-30, wherein the failure (14) is a failure while the wireless device (12) has a conditional reconfiguration stored.

32. The radio network node of any of claims 27-31 , wherein the reference time is a time at which a reference event occurs, wherein the reference event is either: detection of the failure (14); selection of the cell (16S) towards which to perform the mobility or access procedure; or starting of the mobility or access procedure.

33. The radio network node of any of claims 27-32, wherein the logged information (20) is included in a radio link failure report.

34. The radio network node of any of claims 27-33, the processing circuitry (510) further configured to: during or after the mobility or access procedure, receive a message indicating availability of the logged information (20) and/or availability of a report (22) including the logged information (20); after receiving the message, transmit a request for the logged information (20) and/or for the report (22); and receive the logged information (20) responsive to the request.

35. The radio network node of any of claims 27-34, the processing circuitry (510) further configured to send at least a part of the logged information (20) to another radio network node associated with the failure (14).

36. The radio network node of any of claims 27-35, the processing circuitry (510) further configured to: analyze a root cause of the failure (14), using the logged information (20); and/or adapt one or more parameters associated with a mobility or access procedure, based on the logged information (20).

37. A non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor of a wireless device (12), cause the wireless device (12) to:

91 detect a failure (14) associated with a failed cell (16F); responsive to detecting the failure (14), select a cell (16S) towards which to perform a mobility or access procedure and logging information (20) associated with the detected failure (14), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14); perform the mobility or access procedure towards the selected cell (16S); and during or after the mobility or access procedure, transmit a report (22) indicating the logged information (20).

38. A non-transitory computer-readable medium having stored thereon instructions that, when executed by a processor of a radio network node (13F, 13S), cause the radio network node (13F, 13S) to: receive logged information (20) associated with a failure (14) detected by a wireless device (12), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14).

39. A wireless device (12) configured to: detect a failure (14) associated with a failed cell (16F); responsive to detecting the failure (14), select a cell (16S) towards which to perform a mobility or access procedure and logging information (20) associated with the detected failure (14), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14); perform the mobility or access procedure towards the selected cell (16S); and during or after the mobility or access procedure, transmit a report (22) indicating the logged information (20).

92

40. The wireless device (12) of claim 39, configured to perform the method of any of claims 2-8.

41. A radio network node (13F, 13S) configured to: receive logged information (20) associated with a failure (14) detected by a wireless device (12), wherein the logged information (20) indicates time elapsed between: a time when the wireless device (12) received a conditional reconfiguration that was stored at the wireless device (12) when the wireless device (12) detected the failure (14); and a reference time associated with the failure (14).

42. The radio network node of claim 41 , configured to perform the method of any of claims 10-18.

43. A computer program comprising instructions which, when executed by at least one processor of a wireless device (12), causes the wireless device (12) to perform the method of any of claims 1-8.

44. A computer program comprising instructions which, when executed by at least one processor of a radio network node (13F, 13S), causes the radio network node (13F, 13S) to perform the method of any of claims 9-18.