WO2025170528A1 - Logging of early sync related timing information in an uplink report - Google Patents

Abstract

There is provided a method performed by a user equipment. The method comprises: initiating a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node; attempting to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance; logging, in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure; and transmitting the report message to a network node.

Description

LOGGING OF EARLY SYNC RELATED TIMING INFORMATION IN AN UPLINK REPORT

TECHNICAL FIELD

[0] Embodiments of the present disclosure relate to communication networks, and particularly to methods, apparatus and computer-readable media related to mobility and reporting.

INTRODUCTION

Layer 1 (LI)/ Layer 2 (L2)-Triggered Mobility (LTM) in 3^rd Generation Partnership Project (3GPP) Release 18 (Rel-18)

[1] LTM has been specified in Rel-18 as part of the Mobility enhancements Work Item. LTM is a procedure in which a gNB receives LI measurement report(s) from a User Equipment (UE), and on their basis the gNB changes UE’s serving cell by a cell switch command signalled via a Medium Access Control (MAC) Control Element (CE) (see, 3GPP R2-2312720, “38.300 running CR for introduction of NR further mobility enhancements”). The cell switch command indicates an LTM candidate cell configuration that the gNB previously prepared and provided to the UE through Radio Resource Control (RRC) signalling. Then the UE switches to the target cell according to the cell switch command.

[2] LTM currently supports both intra-gNB- Distributed Unit (DU) and intra-gNB- Centralized Unit (CU) inter-gNB-DU mobility. LTM supports both intra-frequency and interfrequency mobility, including mobility to inter-frequency cell that is not a current serving cell.

[3] The procedure for LTM is shown in Figure 1.

[4] In step 101, the UE sends a. Measurement Report message to the gNB. The gNB decides to configure LTM and initiates candidate cell(s) preparation.

[5] In step 102, the gNB transmits an RRCReconflguration message to the UE including the LTM candidate cell configurations of one or multiple candidate cells.

[6] In step 103, the UE stores the LTM candidate cell configurations and transmits an RRCReconfigurationComplete message to the gNB.

[7] In step 104a, the UE performs Downlink (DL) synchronization with the candidate cell(s) before receiving the cell switch command. [8] In step 104b, when UE-based Timing Advance (TA) measurement is configured, UE acquires the TA value(s) of the candidate cell(s) by measurement. Otherwise, UE performs early TA acquisition with the candidate cell(s) as requested by the network before receiving the cell switch command. This is done via Contention-Free Random Access (RA) (CFRA) triggered by a Physical Downlink Control Channel (PDCCH) order from the source cell, following which the UE sends preamble towards the indicated candidate cell. In order to minimize the data interruption of the source cell due to CFRA towards the candidate cell(s), the UE doesn’t receive random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell is indicated in the cell switch command. The UE doesn’t maintain the TA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[9] In step 105, the UE performs LI measurements on the configured candidate cell(s) and transmits LI measurement reports to the gNB. LI measurement should be performed as long as RRC reconfiguration (step 102) is applicable.

[10] In step 106, the gNB decides to execute cell switch to a target cell and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell. The UE switches to the target cell and applies the configuration indicated by candidate configuration index. The MAC CE for LTM cell switch may also include a beam indication (a Transmission Configuration Indicator (TCI) State Identifier (ID)) of the LTM candidate cell indicated by the the candidate configuration index. The network includes the beam indication based on the LI measurements reported by the UE.

[11] In step 107, the UE performs the random access procedure towards the target cell, if UE does not have valid TA of the target cell. The UE performs CFRA if the LTM cell switch command MAC CE contains information for CFRA.

[12] In step 108, the UE completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to target cell. If the UE has performed a RA procedure in step 107 the UE considers that LTM cell switch execution is successfully completed when the random access procedure is successfully completed. For Random Access Channel (RACH) -less LTM, the UE considers that LTM cell switch execution is successfully completed when the UE determines that the network has successfully received its first Uplink (UL) data. The UE determines successful reception of its first UL data by receiving a PDCCH addressing the UE’s Cell Radio Network Temporary Identifier (RNTI) (C-RNTI) in the target cell, which schedules a new transmission following the first UL data. The PDCCH carries either a DL assignment or an UL grant addressing the same Hybrid Automatic Repeat Request (HARQ) process as the first UL data.

SUMMARY

[13] There currently exist certain challenge(s).

[14] In LTM, the LTM Cell Switch command from the network to the UE may include a time advance value and an indication of an LTM candidate cell, based on which the UE accesses the indicated LTM candidate cell i.e. the UE performs the LTM cell switch and transmits an RRC complete message (e.g. RRC Reconfiguration Complete) without performing the random access procedure.

[15] This is possible via the so-called early UL synchronization procedure, where the source cell sends a PDCCH order to the UE, indicating a target cell, and UE sends a random access preamble to the indicate target cell. Once the target cell receives the preamble, it calculates the TA value and sends it to the source cell via a CU, and the source cell will include the received TA in the LTM cell switch command (if an LTM cell switch procedure is triggered toward that particular target cell).

[16] A further method that the network can use to indicate to the UE that no random access procedure should be performed when an LTM cell switch procedure is executed, is to let the UE estimate the TA value on its own (i.e., the UE-based TA measurement procedure).

[17] The way how the network indicates to the UE whether to perform the UE-based TA measurement procedure or not is via an identifier present in both the source cell configuration (ltm-ServingCellUE-Measured.TA-ID) and the LTM candidate cell configuration (Itm-UE- MeasuredTA-ID'). If the identifier of the source cell is equal to the identifier of the target cell, this is an indication for the UE that it is allowed to perform the UE-based TA acquisition procedure; otherwise, the network does not expect that the UE will calculate the TA value on its own (and thus it may provide the TA value within the LTM cell switch command).

[18] One problem associated with this process is that of when the network should trigger this procedure. This is because if the network triggers the early UL synchronization procedure too early, the TA value may become outdated and thus cannot be used by the UE during an LTM cell switch procedure. On the contrary, if the network triggers the early UL synchronization procedure too late, there is a risk that this procedure will not be completed before initiating an LTM cell switch and thus the UE will be forced to do a random access procedure (with a consequent increase in connection interruption and data delay). [19] Another problem associated with the process is that the UE-based TA acquisition procedure is entirely up to the UE implementation and thus it would be impossible for the network to understand whether the UE failed to acquire the TA, whether it was able to acquire the TA only for a short period of time, or whether the UE did not attempt to measure the TA at all. This also has an implication on the network side, since the network does not know whether it can rely on the UE to calculate its own TA, or whether it should reserve always random access resources and trigger the UL pre-synchronization every time.

[20] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Some embodiments of the disclosure are directed towards the logging and reporting of information related to step 104b described above with respect to Figure 1.

[21] Some embodiments of the disclosure relate to a method performed by a wireless terminal (also called a UE). The method comprises:

1. Receiving configurations indicating one or more candidate target cells for the mobility procedures (Level 3 (L3) reconfiguration with synch, so called handover, or LTM cell Switch operation), from the serving Radio Access Network (RAN) node (e.g., from the gNB-CU). For example, the UE receives an RRC Reconfiguration message including the Information Element (IE) LTM-Config which includes a list of configuration(s) per LTM candidate cell e.g. ltm-CandidateToAddModList-rl8 SEQUENCE (SIZE

(L.maxNrofLTM-Configs-rl8)) OF LTM-Candidate-rl8.

2. Receiving configurations instructing the UE to perform UL pre-synchronization toward one or more candidate cell(s). For example, each configuration per LTM candidate cell (e.g. in the IE LTM-Candidate-rl 8) includes one or more early UL sync configurations (e.g. ltm-EarlyUL-SyncConfig-r!8 or ltm-EarlyUL-SyncConfigSUL-rl8). Each early UL sync configuration includes a frequency, a preamble index, and generic random access parameters.

3. Receiving a command to initiate the early UL synchronization procedure (e.g., a PDCCH order), the command indicating a candidate cell (e.g., by including a candidate cell identifier), a Synchronization Signal Blocks (SSB) index, a preamble index, and/or a random access occasion. The command is received before a command for a mobility procedure (e.g., before a MAC CE for LTM cell switch) and while the UE is connected to a source cell. In response to the command for early UL synchronization, the sends a random access preamble towards the indicated candidate cell and according to the received information in the command (e.g., preamble index, SSB index, random access occasions). 3a. As an alternative, the UE is configured to perform the early UL synchronization procedure via an indication which is part of the received LTM candidate cell configuration within e.g., LTM-Candidate-rl8. This indicates to the UE that is allowed to perform the early UL synchronization on its own and that it can estimate the TA value on its own towards the indicated LTM candidate cell (identifier) within the received LTM-Candidate- rl8.

4. Detecting an event which is either a successful mobility procedure or a failure, after having performed the UL pre-synchronization, wherein the failure may be one of: i) a Radio Link Failure (RLF) in the source cell (e.g. Primary Cell (PCell) before a mobility procedure); ii) a mobility related failure when the UE is leaving the source cell (e.g. handover failure, reconfiguration with sync failure, LTM cell switch failure, conditional handover execution failure); iii) a RLF in a target cell (e.g. Primary cell after the mobility procedure); iv) a successful mobility procedure (e.g. reconfiguration with sync, handover, Primary Secondary Cell (PScell) addition/ change, LTM cell switch, conditional handover execution). In some of these cases, the UE performs the mobility procedure towards a target cell either upon receiving an indication from the network node (e.g., from the gNB-CU for the L3 handover or from the gNB-DU for the LTM cell switch command) or upon fulfillment of execution condition for a conditional mobility configuration such as conditional handover configuration or conditional LTM cell switch configuration.

5. Logging in a Self-Optimized Network (SON) report in response of step 4 (e.g., an RLF report or a successful handover report, or a successful LTM report, or a successful PSCell change or addition report) timing-related information about related to the reception of a command to initiate the early UL sync procedure (whether the command is to initiate the early UL synchronization procedure or to indicate to the UE to calculate the TA value on its own), in relationship with the successful mobility procedure or failed mobility procedure.

[22] One aspect of the disclosure provides a method performed by a user equipment. The method comprises: initiating a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node; attempting to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance; logging, in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure; and transmitting the report message to a network node. [23] Another aspect of the disclosure provides a method performed by a network node. The method comprises: configuring a user equipment for one or more mobility procedures to one or more candidate cells or one or more candidate network nodes; instructing the user equipment to initiate a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node belonging to the one or more candidate network nodes or serving one of the one or more candidate cells; and receiving, from the user equipment, in a report message, timing information related to one or more of the synchronization procedure and a mobility procedure attempted by the user equipment to the first network node using the timing advance.

[24] Apparatus and/or computer readable media comprising code for performing the methods set out above is also provided.

[25] For the avoidance of doubt, the following statements set out embodiments of the disclosure:

Al) The method at a UE configured with a lower-layer triggered mobility configuration, comprising:

• Logging and/or reporting timing-related information related to an early UL synchronization procedure, where this procedure can either be sending a random access preamble to a candidate cell before executing an LTM cell switch procedure, or calculating the TA value of a candidate cell autonomously, and wherein the logging and reporting of such information is in response to an event associated to a mobility procedure, such as one or more of: o An indication of the time elapsed between the sending of a first random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards that candidate cell. o An indication of the time elapsed between the sending of a first random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards a candidate cell which is different to that one on which the random access preamble was sent. o An indication of the time elapsed between the sending of a last random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards that candidate cell. An indication of the time elapsed between the sending of a last random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards a candidate cell which is different to that one on which the random access preamble was sent. An indication of the time elapsed between the reception of an early UL sync command from the source cell and the sending of a random access preamble to a candidate cell indicated in the command. An indication of the time elapsed between the reception of an early UL sync command from the source cell and the calculation of a TA value referred to a candidate cell indicated in the command. An indication of the time elapsed between the calculation of two subsequent TA value calculated for a candidate cell before an LTM cell switch command is received from the source cell towards that candidate cell. An indication of the time elapsed between the reception of a early UL sync command from the source cell to a candidate cell and the point in time in which the UE is UL synchronized to the candidate cell. An indication of the time elapsed between the point in time in which the UE is UL synchronized to the candidate cell and the point in time in which the UE loses the UL synchronization to the same candidate cell. An indication of whether at the time of execution of mobility procedure by receiving from the source cell an LTM cell switch command including a TA value for a candidate cell, the UE had already a valid TA value for the candidate cell. An indication of whether at the time of execution of mobility procedure by receiving from the source cell an LTM cell switch command including a TA value for a candidate cell, the UE had already a valid TA value for other candidate cell(s) which were not the one indicated in the LTM cell switch command. An indication of whether a Time Advance command (e.g., Time Advance MAC CE) is received from the target cell after executing the mobility procedure. A2) The method according to Al, wherein some of the timing-related information are logged when the mobility procedure is executed towards a target cell for which an early UL synchronization command was received while the UE was connected to the source cell.

• In one option, the early UL synchronization command from the source cell is received for the candidate cell to which the UE executes the mobility procedure.

• In one option, the early UL synchronization command from the source cell is received for a candidate cell different to which one the UE executes the mobility procedure.

A3) The method according to Al, wherein some of the timing-related information is logged when the mobility procedure is executed towards a target cell and the UE has calculated a TA value for the target cell while the UE was connected to the source cell prior to the mobility procedure execution.

A4) The method according to Al, wherein some of the timing-related information is logged when the mobility procedure is executed towards a target cell and the UE has had at least a valid TA value for the target cell while the UE was connected to the source cell prior to the mobility procedure execution.

A5) A method according to Al, wherein the information in Al is logged by the UE in a radio link failure report so-called RLF report triggered upon failure during the mobility procedure execution.

A6) A method according to Al, wherein the information in Al is logged by the UE in a radio link failure report so-called RLF report triggered upon a failure after a successful mobility procedure.

A7) A method according to Al, wherein the information in Al is logged by the UE in a radio link failure report so-called RLF report triggered upon a failure before any mobility procedure while being configured with the candidate cells for the LTM mobility operation.

A8) A method according to Al, wherein the information in Al is logged by the UE in a successful handover report so-called Successful Handover Report (SHR) triggered upon a successful execution of mobility procedure A9) A method according to any of the previous claims, wherein the mobility procedure is any of:

• A L3 (RRC) based reconfiguration with synch procedure such as normal handover (reconfigurationWithSynch) or conditional handover (reconfigurationWithSynch) performed between source and target primary cell (so called PCell) or between source and target primary secondary cell (PSCell)

• A Layer 1 or Layer 2 based mobility procedure so called LTM cell switch procedure performed between source and target primary cell (so called PCell) or between source and target primary secondary cell (PSCell).

A10) A method according to any of the previous claims, wherein the failure of the mobility procedure occurs while operating in a beam with a TCI state activated by the source cell

All) A method according to A8, wherein the successful handover report is logged due to a specific cause occurred during the successful execution of the mobility procedure.

A12) A method according to Al, wherein the LTM cell switch command is represented by the LTM cell switch MAC CE.

Al 3) A method according to Al, wherein the early UL synchronization command is a PDCCH order.

A14) A method according to Al, wherein the early UL synchronization command is a RRC configuration indicating to the UE that it can calculate the TA value autonomously towards one or more target cells.

[26] Certain embodiments may provide one or more of the following technical advantage(s). The main advantage of the proposed solution is to enable mobility-robust optimizations associated to the timing adopted to UL/DL synchronization and to the execution of the mobility procedure, such as an LTM cell switch.

[27] According to some methods, the serving/source network node becomes aware of whether the timing used to send the random access preamble to a candidate cell for early UL synchronization procedure or the time on which a TA value was calculated autonomously for a candidate cell is appropriate with respect to the time needed by the UE to get UL synchronized and the time the mobility procedure is executed. This enables the network to prevent the early UL synchronization command from being sent too early or too late and on the UE side to calculate the TA value for a candidate cell too early or too late. In fact, in case the timing is wrong, this may affect the UE power consumption and success of the synchronization but also the mobility procedure and data interruption delay.

[28] According to some other methods, the serving/source network node becomes aware of how long the UE was able to keep a TA value associated to a target cell after completing the mobility procedure. If the time is short, the serving/source network node may for example decide to provide the TA value directly in the mobility command or to instruct the UE to execute the early UL synchronization procedure more frequently.

[29] BRIEF DESCRIPTION OF THE DRAWINGS

[30] For a better understanding of the embodiments of the present disclosure, and to show how it may be put into effect, reference will now be made, by way of example only, to the accompanying drawings, in which:

Fig. 1 shows the signalling for an LTM procedure.

Fig. 2 is a flow chart illustrating a method in accordance with some embodiments;

Fig. 3 is a flow chart illustrating a method in accordance with some embodiments;

Fig. 4 shows an example of a communication system in accordance with some embodiments;

Fig. 5 shows a UE in accordance with some embodiments;

Fig. 6 shows a network node in accordance with some embodiments;

Fig. 7 is a block diagram of a host;

Fig. 8 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized; and

Fig. 9 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments.

DETAILED DESCRIPTION

[31] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art. [32] Figure 2 depicts a method in accordance with particular embodiments. The method of Figure 2 may be performed by a UE or wireless device (e.g. the UE 412 or UE 500 as described later with reference to Figures 4 and 5 respectively).

[33] The method begins at step 202, in which the UE receives one or more configurations (e.g., RRCReconfiguration messages) for mobility procedures to one or more candidate cells or one or more candidate network nodes. Here it is noted that mobility procedures in current standards are typically between cells served by network nodes. In future wireless communication standards, however, “cells” may be defined differently or not at all. For example, UEs may be served by beams or some other logical network grouping or entity. The present disclosure thus discusses mobility in terms of a mobility procedure to a network node. Such mobility may comprise or encompass mobility to a cell, beam or other network entity served by the network node.

[34] In step 204, the UE initiates a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node. For example, the first network node may belong to the one or more candidate network nodes for which configurations were received in step 202, or may serve a cell of the one or more candidates cells for which configurations were received in step 202. The synchronization procedure may be an early uplink synchronization procedure.

[35] The timing advance itself may be determined by the user equipment or the communication network to which the first network node belongs. In the former case, the synchronization procedure may comprise the user equipment determining the timing advance based at least in part on transmissions by the first network node, such as system information transmissions e.g., System Information Block (SIB); and/or synchronization signal transmissions, e.g., SSB. The user equipment may further determine the timing advance based on one or more of: transmissions in a second, serving cell; and a timing advance used in the second, serving cell. For example, the timing advance may be determined based on a timing difference between transmissions in the second cell (e.g., transmissions by a second, serving network node) and transmissions by the first network node. In the latter case, the synchronization procedure may comprise transmitting a random-access preamble to the first network node. The random-access preamble may be a contention-free random access, with the first network node determining the appropriate timing advance based on the preamble (e.g., based on a timing of the preamble as received by the first network node) and then forwarding that determined timing advance value to a serving network node of the UE. [36] The nature of the synchronization procedure (e.g., whether the timing advance is to be determined by the UE autonomously or the network) and/or the timing of the synchronization procedure may be indicated in the configurations received in step 202 or different configurations dedicated to the synchronization procedure. Thus the synchronization procedure may be initiated responsive to an instruction from a network node, e.g., in either of these configurations, or a separate command that the UE is to initiate the synchronization procedure (e.g., immediately or at some defined time).

[37] In step 206, the UE attempts to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance determined by way of the synchronization procedure initiated in step 204. The mobility procedure may comprise handover (e.g., cell switch, Pcell switch, PScell switch etc), or addition of a secondary cell.

[38] The mobility procedure may be initiated responsive to receipt of a command to initiate the mobility procedure from a second network node (e.g., a serving or source network node). The command to initiate the mobility procedure comprises a lower-layer signal, such as a MAC control element (e.g., where the mobility procedure comprises an LTM procedure). In alternative embodiments, the mobility procedure may comprise a conditional mobility procedure. In such a case, the mobility procedure may be initiated without a command from the network, but rather responsive to fulfilment of some condition, e.g., related to the radio conditions or the relative radio conditions of a serving cell and the candidate cell(s).

[39] In step 208, the UE logs, in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure. The report message may comprise one or more of: a self-organizing network report message; a RLF report; and a SHR.

[40] The timing information may be logged responsive to detection of a first trigger event, such as one of: failure of the mobility procedure in step 206 or a different mobility procedure; success of the mobility procedure in step 206 or a different mobility procedure; radio link failure.

[41] The timing information may comprise one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

[42] In step 210, the UE transmits the report message to a network node. It should be noted that the network node to which the report message is transmitted may be a different network node to that which transmitted the configurations in step 202, and/or instructed the UE to perform the synchronization procedure or the mobility procedure.

[43] The report message may be transmitted responsive to detection of a second trigger event, either the same as the first trigger event or different. In the latter case, the second trigger event may comprise one or more of: an amount of logged information for the report message exceeding a threshold; an amount of logged timing information exceeding a threshold; expiry of a timer; success of a second mobility procedure; failure of a second mobility procedure.

[44] According to embodiments of the disclosure, therefore, the UE logs and reports to a network e.g. to a cell (served by a network node), timing-related information about uplink presynchronization performed by the UE toward candidate cells of the mobility procedures. In such a case, uplink pre-synchronization refers to any procedure (and/or steps in a procedure) in which the UE connected to a source cell is further configured with one or more candidate cell(s) for mobility e.g. configured with LTM candidate cell(s). In that procedure (or in steps of that procedure) the UE synchronizes in uplink with one or more of the candidate cells, e.g. based on a command from the network or autonomously (still based on an indication from the network). This is called uplink pre-synchronization because the UE synchronizes with one or more candidate cell(s) before the UE receives a mobility command. In such a case, the UE synchronizing in uplink before receiving a mobility command basically means that the TA value used to synchronize on the uplink direction with the network, and which is usually obtained by the UE during the random access procedure, is calculated in advance (e.g., before receiving a mobility command or before a condition for the mobility is fulfilled).

[45] For example, in the case of LTM, the UE may be configured (e.g., in step 202) with an LTM candidate cell or network node. Before it receives an LTM cell switch command, while connected to the source cell, the UE synchronizes with the LTM candidate cell. In one embodiment, the pre-synchronization refers to the calculation of a TA value (e.g., as specified in Technical Specification (TS) 38.321 V18.0.0, and TS 38.300 V18.0.0). Examples of the logged information include, for example, candidate identifier(s) of candidate cells which the UE was uplink synchronized with SSB indexes used to either calculate the TA or to send the random access preamble towards a candidate cell upon the reception of a PDCCH order. Further logged information can also be whether the UE was able to estimate a TA value on its own or which random access preamble was received in the PDCCH order.

[46] According to the disclosed methods, in the scenario with the LTM cell switch procedure, the UE is configured with a set of LTM candidate cells (e.g. received in an RRC Reconfiguration message), and an early UL synchronization configuration for at least one of the LTM candidate cell(s), and further receives a command (e.g., a PDCCH order) including an indication of the LTM candidate cell (e.g. candidate cell ID) for which the UE shall perform the uplink pre-synchronization, a preamble index, an SSB index, a random access occasion, and an indication of whether the UE should send a random access preamble on the normal uplink or on a supplementary uplink. Upon reception of the command from the network, for example, the UE sends a random access preamble to the candidate target cell, which will calculate the TA value and send it to the source cell via the CU. The UE may also or alternatively be configured by the source cell to estimate the TA value on its own, and this means that is up to the UE to estimate the TA and not the network. Further, later upon a network request (e.g., LTM cell switch command) or upon fulfilment of some mobility execution conditions (e.g., conditional handover execution condition(s)) executes a mobility procedure.

[47] According to the method, the UE may log time-related information about a “time elapsed”. In this case, the “time elapsed” can be expressed by the UE using one or more of the following formats:

• dd hh:mm:ss.ffffffff, where: o “dd” represents days o “hh” represents hours o “mm” represents minutes o “ss” represents seconds o “ffffffff’ represents the fractions of a second up to 8 decimal places.

• ssssssss fffffff, where: o “ssssssss” represents seconds o “ffffffff’ represents the fraction of a second up to 8 decimal places

[48] The timing-related information may comprise one or more of the following information and/or parameters:

• An indication indicating the time elapsed between the sending of a first random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards that candidate cell. o According to this method, the source cell may send an early UL synchronization command by indicating to the UE to send a random access preamble to a candidate cell. However, if the random access preamble is not successfully received by the target node, the source cell my send another early UL synchronization command to trigger a re-transmission of the random access preamble toward the same candidate cell. In such a case, the UE may compute the time elapsed between the sending of the first random access preamble (so not the subsequent re-transmissions) and the mobility procedure execution.

• An indication indicating the time elapsed between the sending of a first random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards a candidate cell which is different to that one on which the random access preamble was sent. o According to this method, the source cell may send multiple early UL synchronization command by indicating to the UE to send a random access preamble a candidate cell (so the UE will do the early UL synchronization procedure on multiple target cells). However, if the random access preamble is not successfully received by a target node, the source cell may send another early UL synchronization command to trigger a re-transmission of the random access preamble toward the same candidate cell. In such a case, the UE may compute the time elapsed between the sending of the first random access preamble (so not the subsequent re-transmissions) to one of the target cells which are not the target cell to which the UE executed the mobility procedure execution.

• An indication indicating the time elapsed between the sending of a last random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards that candidate cell. o According to this method, the source cell may send an early UL synchronization command by indicating to the UE to send a random access preamble to a candidate cell. However, if the random access preamble is not successfully received by the target node, the source cell may send another early UL synchronization command to trigger a re-transmission of the random access preamble toward the same candidate cell. In such a case, the UE may compute the time elapsed between the sending of the last random access preamble (so the last re-transmitted random access preamble) and the mobility procedure execution.

• An indication indicating the time elapsed between the sending of a last random access preamble to a candidate cell and the mobility procedure execution (e.g., the reception of an LTM cell switch command) towards a candidate cell which is different to that one on which the random access preamble was sent. o According to this method, the source cell may send multiple early UL synchronization command by indicating to the UE to send a random access preamble a candidate cell (so the UE will do the early UL synchronization procedure on multiple target cells). However, if the random access preamble is not successfully received by a target node, the source cell may send another early UL synchronization command to trigger a re-transmission of the random access preamble toward the same candidate cell. In such a case, the UE may compute the time elapsed between the sending of the last random access preamble (so the last re-transmitted random access preamble) to one of the target cells which are not the target cell to which the UE executed the mobility procedure execution.

An indication indicating the time elapsed between the reception of an early UL sync command from the source cell and the sending of a random access preamble to a candidate cell indicated in the command. • An indication indicating the time elapsed between the reception of an early UL sync command from the source cell and the calculation of a TA value for a candidate cell indicated in the command.

• According to this method, the UE may receive an early UL synchronization command where it is indicated that the UE is allowed to calculate the TA value autonomously towards one or more target cells. In such a case, the UE may compute the time elapsed between the reception of the early UL synchronization command and the successful calculation of the TA value towards a target cell indicated in the command.

• An indication indicating the time elapsed between the calculation of two subsequent (or sequential) TA values calculated for a candidate cell before an LTM cell switch command is received from the source cell towards that candidate cell.

• According to this method, the UE may receive an early UL synchronization command where it is indicated that the UE is allowed to calculate the TA value autonomously towards one or more target cells. However, since the check on the validity of the TA value is left to the UE, the UE, when realizing that the TA value is not valid anymore, may re-calculate the TA value. In such a case, the UE may compute the time elapsed between the first and the second time a TA value was calculated and recalculated for a target cell.

• In one example, the UE may compute the time elapsed between the Xth and Yth time a TA value was calculated, where X and Y are consecutive calculations of the TA value.

• An indication indicating the time elapsed between the reception of an early UL sync command from the source cell to a candidate cell and the point in time at which the UE is UL synchronized to the candidate cell. o According to this method, the UE may receive an early UL synchronization command where it is indicated that the UE is allowed to calculate the TA value autonomously towards one or more target (or candidate) cells. Once the TA value has been successfully calculated for a target cell, the UE may consider itself as UL synched with the target cell. In such a case, the UE may compute the time elapsed between the reception of the early UL synchronization command, and the point in time in which the UE considers itself as UL synched with the target cell. • An indication indicating the time elapsed between the point in time at which the UE is UL synchronized to the candidate cell and the point in time at which the UE loses the UL synchronization to the same candidate cell. o According to this method, the UE may receive an early UL synchronization command where it is indicated that the UE is allowed to calculate the TA value autonomously towards one or more target (or candidate) cells. Once the TA value has been successfully calculated for a target cell, the UE may consider itself as UL synched with the target cell. At the same time, if the UE considers the calculated TA value as not valid, this means that the UE has lost its synchronization towards the target cell and is not UL synched anymore. In such a case, the UE may compute the time elapsed between the point in time at which the UE considered itself as UL synched with the target cell and the point in time at which the UE considered itself as not UL synched anymore with the target cell.

• An indication indicating whether at the time of execution of a mobility procedure by receiving from the source cell an LTM cell switch command including a TA value for a candidate cell, the UE already had a valid TA value for the candidate cell.

• An indication indicating whether at the time of execution of a mobility procedure by receiving from the source cell an LTM cell switch command including a TA value for a candidate cell, the UE already had a valid TA value for other candidate cell(s) which were not indicated in the LTM cell switch command.

• An indication indicating whether a Time Advance command (e.g., Time Advance MAC CE) is received from the target cell after executing the mobility procedure.

[49] The information above may be logged by the UE, in response to any of the following events:

• Successful completion of the mobility procedure, in which case the information may be logged in the SHR (if the mobility procedure is for the change of the PCell, i.e. classical Handover (HO)), or in the Successful PSCell Change Report (SPR) (if the mobility procedure is for the addition or change of the PSCell).

• Radio link failure during the mobility procedure execution, in which case the information may be logged in the RLF-Report. • Radio link failure before the mobility procedure was executed and the UE was configured with LTM candidate cells. In which case the information may be logged in the RLF-Report

• Radio link failure after the mobility procedure was executed, i.e. the failure occurs in the target cell. In which case the information may be logged in the RLF-Report.

[50] Figure 3 depicts a method in accordance with particular embodiments. The method of Figure 3 may be performed by a network node (e.g. the network node 410 or network node 600 as described later with reference to Figures 4 and 6 respectively). The method of Figure 3 describes steps taken by a network node (e.g. a serving network node for a user equipment), and in some embodiments these steps correspond to the method described above with respect to Figure 2 but from the network’s perspective. Accordingly the reader is directed towards the description above for further detail regarding the method of Figure 3.

[51] The method begins in step 302, in which the network node configures a user equipment for one or more mobility procedures to one or more candidate cells or one or more candidate network nodes. For example, the network node may transmit one or more configurations (e.g., RRCReconfiguration messages) for mobility procedures to one or more candidate cells or one or more candidate network nodes. Here it is noted that mobility procedures in current standards are typically between cells served by network nodes. In future wireless communication standards, however, “cells” may be defined differently or not at all. For example, UEs may be served by beams or some other logical network grouping or entity. The present disclosure thus discusses mobility in terms of a mobility procedure to a network node. Such mobility may comprise or encompass mobility to a cell, beam or other network entity served by the network node.

[52] In step 304, the network node instructs the user equipment to initiate a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node belonging to the one or more candidate network nodes or serving one of the one or more candidate cells (e.g., for which mobility procedures were configured in step 302). The synchronization procedure may be an early uplink synchronization procedure.

[53] The timing advance itself may be determined by the user equipment or the communication network to which the first network node belongs. In the former case, the synchronization procedure may comprise the user equipment determining the timing advance based at least in part on transmissions by the first network node, such as system information transmissions e.g., SIB; and/or synchronization signal transmissions, e.g., SSB. The user equipment may further determine the timing advance based on one or more of: transmissions in a second, serving cell; and a timing advance used in the second, serving cell. For example, the timing advance may be determined based on a timing difference between transmissions in the second cell (e.g., transmissions by a second, serving network node) and transmissions by the first network node. In the latter case, the synchronization procedure may comprise transmitting a random-access preamble to the first network node. The random-access preamble may be a contention-free random access, with the first network node determining the appropriate timing advance based on the preamble (e.g., based on a timing of the preamble as received by the first network node) and then forwarding that determined timing advance value to a serving network node of the UE.

[54] The nature of the synchronization procedure (e.g., whether the timing advance is to be determined by the UE autonomously or the network) and/or the timing of the synchronization procedure may be indicated in the configurations transmitted in step 302 or different configurations dedicated to the synchronization procedure. Thus the synchronization procedure may be initiated responsive to an instruction from a network node, e.g., in either of these configurations, or a separate command that the UE is to initiate the synchronization procedure (e.g., immediately or at some defined time).

[55] The UE may subsequently attempt to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance determined by way of the synchronization procedure initiated in step 304 (e.g., without using random access). The mobility procedure may comprise handover (e.g., cell switch, Pcell switch, PScell switch etc), or addition of a secondary cell.

[56] The mobility procedure may be initiated responsive to receipt of a command to initiate the mobility procedure from the network node (e.g., a serving or source network node). The command to initiate the mobility procedure comprises a lower-layer signal, such as a MAC control element (e.g., where the mobility procedure comprises an LTM procedure). The command to initiate the mobility procedure may comprise an indication of the TA value to be used, e.g., where the TA value is calculated by the network. In alternative embodiments, the mobility procedure may comprise a conditional mobility procedure. In such a case, the mobility procedure may be initiated without a command from the network, but rather responsive to fulfilment of some condition, e.g., related to the radio conditions or the relative radio conditions of a serving cell and the candidate cell(s). [57] In step 306, the network node receives, from the user equipment, in a report message, timing information related to one or more of the synchronization procedure and a mobility procedure attempted by the user equipment to the first network node using the timing advance. The report message may comprise one or more of: a self-organizing network report message; a RLF report; and a SHR.

[58] The timing information may comprise one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

[59] Figure 4 shows an example of a communication system 400 in accordance with some embodiments.

[60] In the example, the communication system 400 includes a telecommunication network 402 that includes an access network 404, such as a radio access network (RAN), and a core network 406, which includes one or more core network nodes 408. The access network 404 includes one or more access network nodes, such as network nodes 410a and 410b (one or more of which may be generally referred to as network nodes 410), or any other similar 3 ^rd Generation Partnership Project (3GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 402 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 402 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 402, including one or more network nodes 410 and/or core network nodes 408.

[61] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O- CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 410 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 412a, 412b, 412c, and 412d (one or more of which may be generally referred to as UEs 412) to the core network 406 over one or more wireless connections.

[62] Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 400 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 400 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

[63] The UEs 412 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 410 and other communication devices. Similarly, the network nodes 410 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 412 and/or with other network nodes or equipment in the telecommunication network 402 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 402.

[64] In the depicted example, the core network 406 connects the network nodes 410 to one or more hosts, such as host 416. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 406 includes one more core network nodes (e.g., core network node 408) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 408. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

[65] The host 416 may be under the ownership or control of a service provider other than an operator or provider of the access network 404 and/or the telecommunication network 402, and may be operated by the service provider or on behalf of the service provider. The host 416 may host a variety of applications to provide one or more services. Examples of such applications include the provision of live and/or pre-recorded audio/video content, data collection services, for example, retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[66] As a whole, the communication system 400 of Figure 4 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[67] In some examples, the telecommunication network 402 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 402 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 402. For example, the telecommunications network 402 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

[68] In some examples, the UEs 412 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 404 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 404. Additionally, a UE may be configured for operating in single- or multi-RAT or multi -standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[69] In the example illustrated in Figure 4, the hub 414 communicates with the access network 404 to facilitate indirect communication between one or more UEs (e.g., UE 412c and/or 412d) and network nodes (e.g., network node 410b). In some examples, the hub 414 may be a controller, router, a content source and analytics node, or any of the other communication devices described herein regarding UEs. For example, the hub 414 may be a broadband router enabling access to the core network 406 for the UEs. As another example, the hub 414 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 410, or by executable code, script, process, or other instructions in the hub 414. As another example, the hub 414 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 414 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 414 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 414 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 414 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[70] The hub 414 may have a constant/persi stent or intermittent connection to the network node 410b. The hub 414 may also allow for a different communication scheme and/or schedule between the hub 414 and UEs (e.g., UE 412c and/or 412d), and between the hub 414 and the core network 406. In other examples, the hub 414 is connected to the core network 406 and/or one or more UEs via a wired connection. Moreover, the hub 414 may be configured to connect to an M2M service provider over the access network 404 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 410 while still connected via the hub 414 via a wired or wireless connection. In some embodiments, the hub 414 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 410b. In other embodiments, the hub 414 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 410b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

[71] Figure 5 shows a UE 500 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

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

[73] The UE 500 includes processing circuitry 502 that is operatively coupled via a bus 504 to an input/ output interface 506, a power source 508, a memory 510, a communication interface 512, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 5. 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.

[74] The processing circuitry 502 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 510. The processing circuitry 502 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 502 may include multiple central processing units (CPUs). The processing circuitry 502 may be operable to provide, either alone or in conjunction with other UE 500 components, such as the memory 510, UE 500 functionality. For example, the processing circuitry 502 may be configured to cause the UE 502 to perform the methods as described with reference to Figure 2.

[75] In the example, the input/output interface 506 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 500. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[76] In some embodiments, the power source 508 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 508 may further include power circuitry for delivering power from the power source 508 itself, and/or an external power source, to the various parts of the UE 500 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 508. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 508 to make the power suitable for the respective components of the UE 500 to which power is supplied.

[77] The memory 510 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 510 includes one or more application programs 514, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 516. The memory 510 may store, for use by the UE 500, any of a variety of various operating systems or combinations of operating systems. [78] The memory 510 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card. ’ The memory 510 may allow the UE 500 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 510, which may be or comprise a device-readable storage medium.

[79] The processing circuitry 502 may be configured to communicate with an access network or other network using the communication interface 512. The communication interface 512 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 522. The communication interface 512 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 518 and/or a receiver 520 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 518 and receiver 520 may be coupled to one or more antennas (e.g., antenna 522) and may share circuit components, software or firmware, or alternatively be implemented separately.

[80] In some embodiments, communication functions of the communication interface 512 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/intemet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[81] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 512, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

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

[83] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are devices which are or which are embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence on the intended application of the loT device in addition to other components as described in relation to the UE 500 shown in Figure 5.

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

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

[86] Figure 6 shows a network node 600 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), O-RAN nodes or components of an O-RAN node (e g., O-RU, O-DU, O-CU).

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

[88] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

[89] The network node 600 includes processing circuitry 602, a memory 604, a communication interface 606, and a power source 608, and/or any other component, or any combination thereof. The network node 600 may be composed of multiple physically separate components (e.g., aNodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 600 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 600 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 604 for different RATs) and some components may be reused (e.g., a same antenna 610 may be shared by different RATs). The network node 600 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 600, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z- wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 600.

[90] The processing circuitry 602 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 600 components, such as the memory 604, network node 600 functionality. For example, the processing circuitry 602 may be configured to cause the network node to perform the methods as described with reference to Figure 3.

[91] In some embodiments, the processing circuitry 602 includes a system on a chip (SOC). In some embodiments, the processing circuitry 602 includes one or more of radio frequency (RF) transceiver circuitry 612 and baseband processing circuitry 614. In some embodiments, the radio frequency (RF) transceiver circuitry 612 and the baseband processing circuitry 614 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 612 and baseband processing circuitry 614 may be on the same chip or set of chips, boards, or units.

[92] The memory 604 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 602. The memory 604 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 602 and utilized by the network node 600. The memory 604 may be used to store any calculations made by the processing circuitry 602 and/or any data received via the communication interface 606. In some embodiments, the processing circuitry 602 and memory 604 is integrated.

[93] The communication interface 606 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, the communication interface 606 comprises port(s)/terminal(s) 616 to send and receive data, for example to and from a network over a wired connection. The communication interface 606 also includes radio front-end circuitry 618 that may be coupled to, or in certain embodiments a part of, the antenna 610. Radio front-end circuitry 618 comprises filters 620 and amplifiers 622. The radio front-end circuitry 618 may be connected to an antenna 610 and processing circuitry 602. The radio front-end circuitry may be configured to condition signals communicated between antenna 610 and processing circuitry 602. The radio front-end circuitry 618 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 618 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 620 and/or amplifiers 622. The radio signal may then be transmitted via the antenna 610. Similarly, when receiving data, the antenna 610 may collect radio signals which are then converted into digital data by the radio front-end circuitry 618. The digital data may be passed to the processing circuitry 602. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

[94] In certain alternative embodiments, the network node 600 does not include separate radio front-end circuitry 618, instead, the processing circuitry 602 includes radio front-end circuitry and is connected to the antenna 610. Similarly, in some embodiments, all or some of the RF transceiver circuitry 612 is part of the communication interface 606. In still other embodiments, the communication interface 606 includes one or more ports or terminals 616, the radio frontend circuitry 618, and the RF transceiver circuitry 612, as part of a radio unit (not shown), and the communication interface 606 communicates with the baseband processing circuitry 614, which is part of a digital unit (not shown).

[95] The antenna 610 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 610 may be coupled to the radio front-end circuitry 618 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 610 is separate from the network node 600 and connectable to the network node 600 through an interface or port.

[96] The antenna 610, communication interface 606, and/or the processing circuitry 602 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 610, the communication interface 606, and/or the processing circuitry 602 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

[97] The power source 608 provides power to the various components of network node 600 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 608 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 600 with power for performing the functionality described herein. For example, the network node 600 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 608. As a further example, the power source 608 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[98] Embodiments of the network node 600 may include additional components beyond those shown in Figure 6 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 600 may include user interface equipment to allow input of information into the network node 600 and to allow output of information from the network node 600. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 600.

[99] Figure 7 is a block diagram of a host 700, which may be an embodiment of the host 416 of Figure 4, in accordance with various aspects described herein. As used herein, the host 700 may be or comprise various combinations hardware and/or software, including a standalone server, a blade server, a cloud-implemented server, a distributed server, a virtual machine, container, or processing resources in a server farm. The host 700 may provide one or more services to one or more UEs.

[100] The host 700 includes processing circuitry 702 that is operatively coupled via a bus 704 to an input/output interface 706, a network interface 708, a power source 710, and a memory 712. Other components may be included in other embodiments. Features of these components may be substantially similar to those described with respect to the devices of previous figures, such as Figures 5 and 6, such that the descriptions thereof are generally applicable to the corresponding components of host 700.

[101] The memory 712 may include one or more computer programs including one or more host application programs 714 and data 716, which may include user data, e.g., data generated by a UE for the host 700 or data generated by the host 700 for a UE. Embodiments of the host 700 may utilize only a subset or all of the components shown. The host application programs 714 may be implemented in a container-based architecture and may provide support for video codecs (e.g., Versatile Video Coding (VVC), High Efficiency Video Coding (HEVC), Advanced Video Coding (AVC), MPEG, VP9) and audio codecs (e.g., FL AC, Advanced Audio Coding (AAC), MPEG, G.711), including transcoding for multiple different classes, types, or implementations of UEs (e.g., handsets, desktop computers, wearable display systems, heads-up display systems). The host application programs 714 may also provide for user authentication and licensing checks and may periodically report health, routes, and content availability to a central node, such as a device in or on the edge of a core network. Accordingly, the host 700 may select and/or indicate a different host for over-the-top services for a UE. The host application programs 714 may support various protocols, such as the HTTP Live Streaming (HLS) protocol, Real-Time Messaging Protocol (RTMP), Real-Time Streaming Protocol (RTSP), Dynamic Adaptive Streaming over HTTP (MPEG-DASH), etc.

[102] Figure 8 is a block diagram illustrating a virtualization environment 800 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 800 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 800 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[103] Applications 802 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

[104] Hardware 804 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 806 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 808a and 808b (one or more of which may be generally referred to as VMs 808), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer 806 may present a virtual operating platform that appears like networking hardware to the VMs 808.

[105] The VMs 808 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 806. Different embodiments of the instance of a virtual appliance 802 may be implemented on one or more of VMs 808, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[106] In the context of NFV, a VM 808 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 808, and that part of hardware 804 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 808 on top of the hardware 804 and corresponds to the application 802.

[107] Hardware 804 may be implemented in a standalone network node with generic or specific components. Hardware 804 may implement some functions via virtualization. Alternatively, hardware 804 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 810, which, among others, oversees lifecycle management of applications 802. In some embodiments, hardware 804 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 812 which may alternatively be used for communication between hardware nodes and radio units.

[108] Figure 9 shows a communication diagram of a host 902 communicating via a network node 904 with a UE 906 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 412a of Figure 4 and/or UE 500 of Figure 5), network node (such as network node 410a of Figure 4 and/or network node 600 of Figure 6), and host (such as host 416 of Figure 4 and/or host 700 of Figure 7) discussed in the preceding paragraphs will now be described with reference to Figure 9.

[109] Like host 700, embodiments of host 902 include hardware, such as a communication interface, processing circuitry, and memory. The host 902 also includes software, which is stored in or accessible by the host 902 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 906 connecting via an over-the-top (OTT) connection 950 extending between the UE 906 and host 902. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 950.

[HO] The network node 904 includes hardware enabling it to communicate with the host 902 and UE 906. The connection 960 may be direct or pass through a core network (like core network 406 of Figure 4) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

[Hl] The UE 906 includes hardware and software, which is stored in or accessible by UE 906 and executable by the UE’s processing circuitry. The software includes a client application, such as a web browser or operator-specific “app” that may be operable to provide a service to a human or non-human user via UE 906 with the support of the host 902. In the host 902, an executing host application may communicate with the executing client application via the OTT connection 950 terminating at the UE 906 and host 902. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 950 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 950.

[112] The OTT connection 950 may extend via a connection 960 between the host 902 and the network node 904 and via a wireless connection 970 between the network node 904 and the UE 906 to provide the connection between the host 902 and the UE 906. The connection 960 and wireless connection 970, over which the OTT connection 950 may be provided, have been drawn abstractly to illustrate the communication between the host 902 and the UE 906 via the network node 904, without explicit reference to any intermediary devices and the precise routing of messages via these devices. [113] As an example of transmiting data via the OTT connection 950, in step 908, the host 902 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 906. In other embodiments, the user data is associated with a UE 906 that shares data with the host 902 without explicit human interaction. In step 910, the host 902 initiates a transmission carrying the user data towards the UE 906. The host 902 may initiate the transmission responsive to a request transmited by the UE 906. The request may be caused by human interaction with the UE 906 or by operation of the client application executing on the UE 906. The transmission may pass via the network node 904, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 912, the network node 904 transmits to the UE 906 the user data that was carried in the transmission that the host 902 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 914, the UE 906 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 906 associated with the host application executed by the host 902.

[114] In some examples, the UE 906 executes a client application which provides user data to the host 902. The user data may be provided in reaction or response to the data received from the host 902. Accordingly, in step 916, the UE 906 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 906. Regardless of the specific manner in which the user data was provided, the UE 906 initiates, in step 918, transmission of the user data towards the host 902 via the network node 904. In step 920, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 904 receives user data from the UE 906 and initiates transmission of the received user data towards the host 902. In step 922, the host 902 receives the user data carried in the transmission initiated by the UE 906.

[115] One or more of the various embodiments improve the performance of OTT services provided to the UE 906 using the OTT connection 950, in which the wireless connection 970 forms the last segment. More precisely, the teachings of these embodiments may improve power consumption and the robustness of a wireless connection with the network (e.g., by improving the reliability and/or success rate of mobility procedures) and thereby provide benefits such as extended batery lifetime, reduced user waiting time and reduced session dropouts. [116] In an example scenario, factory status information may be collected and analyzed by the host 902. As another example, the host 902 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 902 may collect and analyze real-time data to assist in controlling vehicle congestion (e.g., controlling traffic lights). As another example, the host 902 may store surveillance video uploaded by a UE. As another example, the host 902 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host 902 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analyzing and/or transmitting data.

[117] In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 950 between the host 902 and UE 906, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 902 and/or UE 906. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 950 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 950 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 904. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signaling that facilitates measurements of throughput, propagation times, latency and the like, by the host 902. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 950 while monitoring propagation times, errors, etc.

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

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

[120] The following groups of numbered statements set out embodiments of the disclosure:

Group A Embodiments

1. A method performed by a user equipment, the method comprising: initiating a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node; attempting to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance; logging, in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure; and transmitting the report message to a network node. . The method of embodiment 1, wherein logging timing information is responsive to detection of a first trigger event. . The method of embodiment 2, wherein the first trigger event comprises one of: failure of the mobility procedure; success of the mobility procedure; radio link failure. . The method according to any one of the preceding embodiments, wherein the report message is transmitted responsive to detection of a second trigger event. . The method according to embodiment 4, wherein the second trigger event is the same as the first trigger event. . The method according to embodiment 4, wherein the second trigger event differs from the first trigger event, and comprises one or more of: an amount of logged information for the report message exceeding a threshold; an amount of logged timing information exceeding a threshold; expiry of a timer; success of a second mobility procedure; failure of a second mobility procedure. . The method of any one of the preceding embodiments, wherein the synchronization procedure comprises the user equipment determining the timing advance based at least in part on transmissions by the first network node. . The method of embodiment 7, wherein the transmissions by the first network node comprise one or more of: system information transmissions; and synchronization signal transmissions. . The method of embodiment 7 or 8, wherein the user equipment further determines the timing advance based on one or more of: transmissions in a second, serving cell; and a timing advance used in the second, serving cell. The method of any one of the preceding embodiments, wherein the synchronization procedure comprises transmitting a random-access preamble to the first network node. The method of embodiment 10, wherein the timing advance is determined by a communication network to which the first network node belongs, and an indication of the timing advance is transmitted to the user equipment. The method of embodiment 11, wherein the indication of the timing advance is transmitted to the user equipment by a second, serving cell. The method of any one of the preceding embodiments, wherein the synchronization procedure is an early uplink synchronization procedure. The method of any one of the preceding embodiments, wherein the synchronization procedure is initiated responsive to an instruction from a network node. The method of embodiment 14, wherein the instruction from the network node comprises a configuration for the mobility procedure, and an indication that the user equipment is to initiate the synchronization procedure before attempt to perform the mobility procedure. The method of embodiment 15, wherein the configuration further comprises an indication that the user equipment is to determine the timing advance. The method of embodiment 14, wherein the instruction comprises a signal from the network node commanding the user equipment to initiate the synchronization procedure. The method of any one of the preceding embodiments, wherein the mobility procedure is initiated responsive to receipt of a command to initiate the mobility procedure from a second network node. The method of embodiment 18, wherein the command to initiate the mobility procedure comprises a lower-layer signal. The method of embodiment 18 or 19, wherein the command to initiate the mobility procedure comprises a medium access control, MAC, control element. The method of any one of the preceding embodiments, wherein the mobility procedure comprises one of: handover; and addition of a secondary cell. The method of any one of the preceding embodiments, wherein the mobility procedure comprises an Ll/L2-triggered mobility, LTM, procedure. The method of any one of embodiments 1 to 21, wherein the mobility procedure comprises a conditional mobility procedure. The method of any one of the preceding embodiments, further comprising receiving one or more configurations for mobility procedures to one or more candidate cells or one or more candidate network nodes, and wherein the first network node serves at least one of the one or more candidate cells, or wherein the first network node is one of the one or more candidate network nodes. The method of any one of the preceding embodiments, wherein the mobility procedure to the first network node comprises a mobility procedure to a cell, a beam, or another logical network entity served by the first network node. The method of any one of the preceding embodiments, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

27. The method of any one of the preceding embodiments, wherein the report message comprises one or more of: a self-organizing network report message; a radio link failure, RLF, report; a successful handover report, SHR.

28. The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host via the transmission to the network node.

Group B Embodiments

29. A method performed by a network node, the method comprising: configuring a user equipment for one or more mobility procedures to one or more candidate cells or one or more candidate network nodes; instructing the user equipment to initiate a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node belonging to the one or more candidate network nodes or serving one of the one or more candidate cells; and receiving, from the user equipment, in a report message, timing information related to one or more of the synchronization procedure and a mobility procedure attempted by the user equipment to the first network node using the timing advance. The method of embodiment 29, wherein the synchronization procedure comprises the user equipment determining the timing advance based at least in part on transmissions by the first network node. The method of embodiment 30, wherein the transmissions by the first network node comprise one or more of: system information transmissions; and synchronization signal transmissions. The method of embodiment 30 or 31, wherein the user equipment further determines the timing advance based on one or more of: transmissions in a second, serving cell; and a timing advance used in the second, serving cell. The method of embodiment 29, wherein the synchronization procedure comprises the user equipment transmitting a random-access preamble to the first network node. The method of any one of embodiments 29 to 33, wherein the synchronization procedure is an early uplink synchronization procedure. The method of any one of embodiments 29 to 34, wherein the configuration comprises an indication that the user equipment is to initiate the synchronization procedure before attempt to perform the mobility procedure. The method of any one of embodiments 29 to 35, wherein the configuration further comprises an indication that the user equipment is to determine the timing advance. The method of any one of embodiments 29 to 36, wherein instructing the user equipment comprises transmitting a signal to the user equipment commanding the user equipment to initiate the synchronization procedure. The method of any one of embodiments 29 to 37, further comprising transmitting a command to the user equipment to initiate the mobility procedure. The method of embodiment 38, wherein the command to initiate the mobility procedure comprises a lower-layer signal. The method of embodiment 38 or 39, wherein the command to initiate the mobility procedure comprises a medium access control, MAC, control element. The method of any one of embodiments 38 to 40, wherein the command comprises an indication of the timing advance. The method of any one of embodiments 29 to 41, wherein the mobility procedure comprises one of: handover; and addition of a secondary cell. The method of any one of embodiments 29 to 42, wherein the mobility procedure comprises an Ll/L2-triggered mobility, LTM, procedure. The method of any one of embodiments 29 to 42, wherein the mobility procedure comprises a conditional mobility procedure. The method of any one of embodiments 29 to 44, wherein the mobility procedure to the first network node comprises a mobility procedure to a cell, a beam, or another logical network entity served by the first network node. The method of any one of embodiments 29 to 45, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

47. The method of any one of embodiments 29 to 46, wherein the report message comprises one or more of: a self-organizing network report message; a radio link failure, RLF, report; a successful handover report, SHR.

48. The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

Group C Embodiments

49. A user equipment, comprising: processing circuitry configured to cause the user equipment to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the processing circuitry.

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

51. A user equipment (UE), the 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.

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

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

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

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

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

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

58. The communication system of the previous embodiment, further comprising: the network node; and/or the UE.

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

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

61. The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.

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

63. The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.

64. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the operations of any of the Group A embodiments to receive the user data from the host. 65. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host.

66. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

67. A method implemented by a host operating in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the UE performs any of the operations of any of the Group A embodiments to receive the user data from the host.

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

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

70. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to transmit the user data to the host.

71. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.

72. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

73. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, receiving user data transmitted to the host via the network node by the UE, wherein the UE performs any of the steps of any of the Group A embodiments to transmit the user data to the host.

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

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

Claims

1. A method performed by a user equipment (500), the method comprising: initiating (204) a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node (600); attempting (206) to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance; logging (208), in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure; and transmitting (210) the report message to a network node.

2. The method of claim 1 , wherein logging timing information is responsive to detection of a first trigger event.

3. The method of claim 2, wherein the first trigger event comprises one of: failure of the mobility procedure; success of the mobility procedure; radio link failure.

4. The method of any one of the preceding claims, wherein the synchronization procedure comprises the user equipment determining the timing advance based at least in part on transmissions by the first network node.

5. The method of claim 4, wherein the transmissions by the first network node comprise one or more of: system information transmissions; and synchronization signal transmissions.

6. The method of claim 4 or 5, wherein the user equipment further determines the timing advance based on one or more of: transmissions in a second, serving cell; and atiming advance used in the second, serving cell.

7. The method of any one of the preceding claims, wherein the synchronization procedure comprises transmitting a random-access preamble to the first network node.

8. The method of claim 7, wherein the timing advance is determined by a communication network to which the first network node belongs, and an indication of the timing advance is transmitted to the user equipment.

9. The method of claim 8, wherein the indication of the timing advance is transmitted to the user equipment by a second, serving cell.

10. The method of any one of the preceding claims, wherein the synchronization procedure is an early uplink synchronization procedure.

11. The method of any one of the preceding claims, wherein the synchronization procedure is initiated responsive to an instruction from a network node.

12. The method of claim 11, wherein the instruction from the network node comprises a configuration for the mobility procedure, and an indication that the user equipment is to initiate the synchronization procedure before attempting to perform the mobility procedure.

13. The method of any one of the preceding claims, wherein the mobility procedure is initiated responsive to receipt of a command to initiate the mobility procedure from a second network node.

14. The method of any one of the preceding claims, wherein the mobility procedure comprises one of: handover; and addition of a secondary cell.

15. The method of any one of the preceding claims, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

16. A method performed by a network node (600), the method comprising: configuring (302) a user equipment (500) for one or more mobility procedures to one or more candidate cells or one or more candidate network nodes; instructing (304) the user equipment to initiate a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node belonging to the one or more candidate network nodes or serving one of the one or more candidate cells; and receiving (306), from the user equipment, in a report message, timing information related to one or more of the synchronization procedure and a mobility procedure attempted by the user equipment to the first network node using the timing advance.

17. The method of claim 16, wherein the synchronization procedure is an early uplink synchronization procedure.

18. The method of any one of claims 16 to 17, wherein the configuration comprises an indication that the user equipment is to initiate the synchronization procedure before attempting to perform the mobility procedure.

19. The method of any one of claims 16 to 18, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and atempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and atempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of atempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of atempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

20. A user equipment (500) comprising processing circuitry (502) configured to cause the user equipment to: initiate (204) a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node (600); atempt (206) to perform a mobility procedure to the first network node, in which the user equipment transmits to the first network node using the timing advance; log (208), in a report message, timing information related to one or more of the synchronization procedure and the mobility procedure; and transmit (210) the report message to a network node.

21. The user equipment of claim 20, wherein the timing information is logged responsive to detection of a first trigger event.

22. The user equipment of claim 21, wherein the first trigger event comprises one of: failure of the mobility procedure; success of the mobility procedure; radio link failure.

23. The user equipment of any one of claims 20 to 22, wherein the synchronization procedure comprises the user equipment determining the timing advance based at least in part on transmissions by the first network node.

24. The user equipment of claim 23, wherein the transmissions by the first network node comprise one or more of: system information transmissions; and synchronization signal transmissions.

25. The user equipment of claim 23 or 24, wherein the user equipment further determines the timing advance based on one or more of: transmissions in a second, serving cell; and a timing advance used in the second, serving cell.

26. The user equipment of any one of claims 20 to 25, wherein the synchronization procedure comprises transmitting a random-access preamble to the first network node.

27. The user equipment of claim 26, wherein the timing advance is determined by a communication network to which the first network node belongs, and an indication of the timing advance is transmitted to the user equipment.

28. The user equipment of claim 27, wherein the indication of the timing advance is transmitted to the user equipment by a second, serving cell.

29. The user equipment of any one of claims 20 to 28, wherein the synchronization procedure is an early uplink synchronization procedure.

30. The user equipment of any one of claims 20 to 29, wherein the synchronization procedure is initiated responsive to an instruction from a network node.

31. The user equipment of claim 30, wherein the instruction from the network node comprises a configuration for the mobility procedure, and an indication that the user equipment is to initiate the synchronization procedure before attempting to perform the mobility procedure.

32. The user equipment of any one of claims 20 to 31, wherein the mobility procedure is initiated responsive to receipt of a command to initiate the mobility procedure from a second network node.

33. The user equipment of any one of claims 20 to 32, wherein the mobility procedure comprises one of: handover; and addition of a secondary cell.

34. The user equipment of any one of claims 20 to 33, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

35. A user equipment adapted to perform the method according to any one of claims 1 to 19.

36. A network node (600) comprising processing circuitry (602) configured to cause the network node to: configure (302) a user equipment (500) for one or more mobility procedures to one or more candidate cells or one or more candidate network nodes; instruct (304) the user equipment to initiate a synchronization procedure for the determination of a timing advance for uplink transmissions to a first network node belonging to the one or more candidate network nodes or serving one of the one or more candidate cells; and receive (306), from the user equipment, in a report message, timing information related to one or more of the synchronization procedure and a mobility procedure attempted by the user equipment to the first network node using the timing advance.

37. The network node of claim 36, wherein the synchronization procedure is an early uplink synchronization procedure.

38. The network node of any one of claims 36 to 37, wherein the configuration comprises an indication that the user equipment is to initiate the synchronization procedure before attempting to perform the mobility procedure.

39. The network node of any one of claims 36 to 38, wherein the timing information comprises one or more of: an indication of an elapsed time between initiating the synchronization procedure and attempting the mobility procedure; an indication of an elapsed time between initiating a synchronization to a second network node and attempting the mobility procedure to the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and initiating the synchronization procedure towards the first network node; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and determining the timing advance towards the first network node; an indication of an elapsed time between determining a first value of the timing advance and determining a second, subsequent value of the timing advance; an indication of an elapsed time between receiving an instruction to initiate a synchronization procedure towards the first network node and becoming synchronized to the first network node; an indication of an elapsed time between becoming synchronized to the first network node and losing synchronization to the first network node; an indication of whether the user equipment already had a value for the timing advance at a time of receiving an indication of the timing advance from a network node; an indication of whether the user equipment had a valid value for the timing advance at a time of attempting the mobility procedure; an indication of whether the user equipment already had a value for the timing advance to one or more other network nodes at a time of attempting the mobility procedure to the first network node; an indication of whether a time advance command is received from the first network node after executing the mobility procedure.

40. A network node (600) configured to perform the method of any of claims 16 to 19.