Patent Description:
In 3GPP Release <NUM>, Carrier Aggregation (CA) was introduced in Long Term Evolution (LTE) to enable the user equipment (UE) to transmit/receive information via multiple cells (so called Secondary Cells - SCells) from multiple carrier frequencies, to the benefit of existing non-contiguous and contiguous carriers. In CA terminology, the Primary Cell (PCell) is the cell to which the UE establishes the Radio Resource Control (RRC) connection or is handed over. In CA, cells are aggregated on the Medium Access Control (MAC) level. MAC gets grants for a certain cell and multiplexes data from different bearers to one Transport Block being sent on that cell. Also, MAC is used to control how that process is done. <FIG> illustrates an example of MAC-level control.

SCells can be "added" ("configured") for the UE using RRC signaling (e.g., RRCConnectionReconfiguration), which takes <NUM> of milliseconds. A cell that is configured for the UE becomes a "serving cell" for this UE. An SCell may also be associated with an SCell state. When configured/added via RRC, an SCell starts in a deactivated state. In LTE Rel-<NUM>, an eNB can indicate to the UE to activate-upon-configuration, or change the state, at least in RRCReconfiguration, as shown below:.

In LTE Rel-<NUM>, a new intermediate state between the deactivated and active state has been introduced for enhanced uplink operation. A MAC Control Element (MAC CE) can be used to change the SCell state between the three states as shown in <FIG>. There are also timers in MAC to move a cell between deactivated/activated/dormant. These timers are: sCellHibernationTimer (which moves the SCell from activated state to dormant state); sCellDeactivationTimer (which moves the SCell from activated state to deactivated state); and dormantSCellDeactivationTimer (which moves the SCell from dormant state to deactivated state). The MAC level SCell activation takes <NUM>-<NUM>.

Once the network understands the need to configure and/or activate CA, the question is which cells to initially configure and/or activate, if they are configured, and/or whether a cell/carrier is good enough in terms of radio quality/coverage (e.g., Reference Signal Received Power (RSRP) and Reference Signal Received Quality (RSRQ)). To understand the conditions on SCell(s) or potential SCell(s) in a given available carrier, the network may configure the UE to perform Radio Resource Management (RRM) measurements.

Typically, the network may be assisted by RRM measurements reported by a UE. The network may configure the UE with measurement IDs associated with reportConfig with event A1 (serving becomes better than threshold) in case this is a configured SCell, or A4 (neighbor becomes better than threshold) for carriers without a configured SCell. The measurement objects are associated with the carrier on which the network wants reports. If the network is aware of the exact cells it wants the UE to measure, a so-called white cell list can be configured in the measurement object so that the UE is only required to measure these cells in that carrier. <FIG> illustrates some configuration signaling.

With the introduction of Dual Connectivity (DC) in Rel-<NUM>, it was possible to add what is called a SCG (Secondary Cell Group) configuration to the UE. The main benefit would be that the UE could, in principle, add a cell from another eNodeB. Protocol-wise, that would require different MAC entities, one for each cell group. The UE will have two cell groups, one associated with the PCell (master node) and another associated with a PSCell (of the secondary eNodeB), where each group may possibly have their own associated SCells.

When it comes to adding SCells, when the UE is in single connectivity, just to exemplify, the RRCConnectionReconfiguration message may carry a cell index (so MAC identifiers are optimized, i.e., shorter), cell identifier and carrier frequency, common parameters and state information, later introduced in Rel-<NUM> (activated or dormant).

<FIG> shows a table with field descriptions for RRCConnectionReconfiguration.

The procedure to add SCells to the MCG in LTE (or to modify) is described as follows (as in 3GPP TS <NUM>):
<IMG>
<IMG>.

In LTE Rel-<NUM>, it is possible to configure the UE to report so-called early measurements upon the transition from idle to connected state. Note that the 3GPP specifications for LTE (and NR) include specific definitions for several states, including a state called "RRC_Connected. " A device operating while in the RRC_Connected state can be said to be operating in "RRC connected mode," as opposed to, for example, operating in idle mode, where the device is in an idle state as defined by the specifications. For the purposes of the present disclosure, the distinction between RRC_Connected state and RRC connected mode is not important, and these terms may generally be understood as interchangeable, unless the context indicates otherwise. When a device is described herein as entering the RRC Connected state, it should be understood that this refers to entering a defined state in which the device operates in RRC connected mode.

The early measurements mentioned above are measurements that the UE can perform in idle state, according to a configuration provided by the source cell, with the intention that these measurements can be sent to the source cell immediately after the UE gets connected, so that the source cell can quickly setup CA and/or other forms of DC (e.g., EN-DC, MR-DC, etc.) without the need to first provide a measurement configuration (measConfig) in RRC_CONNECTED, as shown in previous sections, and wait for hundreds of milliseconds until first samples are collected, monitored and then the first reports are triggered and transmitted to the network.

A first aspect of the existing solution, as standardized in EUTRA 3GPP TS <NUM>, is described in <NUM>. <NUM> Idle Mode Measurements. The UE can receive these idle mode measurement configurations in the system information (SIB5) in the field MeasIdleConfigSIB-r15, indicating up to <NUM> cells or ranges of cell IDs to perform measurements on. In addition, the UE can be either configured upon the transition from RRC_CONNECTED to RRC_IDLE with a dedicated measurement configuration in the RRCConnectionRelease message with the measIdleDedicated-r15 which overrides the broadcasted configurations in SIB5. The broadcasted and dedicated signaling is shown below (with bold used for emphasis):
<IMG>
<IMG>
<IMG>
<IMG>
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -.

<FIG> is a table showing MeasIdleConfig field descriptions.

The UE is provided with a list of carriers and optionally with a list of cells for which the UE shall perform measurements. The fields s-NonIntraSearch in SystemInformationBlockType3 do not affect the UE measurement procedures in IDLE mode. Upon the reception of that measurement configuration, the UE starts a timer T331 with the value provided in measldleDuration, which can go from <NUM> to <NUM> seconds. The timer stops upon receiving RRCConnectionSetup, and RRCConnectionResume indicates a transition to RRC_CONNECTED. That concept exists to limit the amount of time the UE performs measurements for the purpose of early measurements.

Another concept introduced in the LTE Rel-<NUM> solution is a validity area, which comprises a list of physical cell identities (PCIs). The intention is to limit the area where CA or DC may be setup later when the UE resumes/setups the connection, so the early measurements are somewhat useful for that purpose. If validityArea is configured, and UE reselects to a serving cell whose PCI does not match any entry in validityArea for the corresponding carrier frequency, the timer T331 is stopped. Then, the UE stops to perform IDLE measurements and releases the configuration (i.e., VarMeasIdleConfig). Notice that this does not necessarily imply that the UE releases the idle measurements that were configured in Release <NUM> and that were performed. That is, these may still be stored and possibly requested by the network. In addition, the UE may continue with IDLE mode measurements according to the broadcasted SIB5 configuration after the timer T331 has expired or stopped.

Notice also that only measurements above a certain quality threshold shall be stored as the cell candidates for CA setup. How the UE performs measurements in IDLE mode is up to UE implementation, as long as RAN4 requirements for measurement reporting defined in 3GPP TS <NUM> are met.

The UE behavior is shown in more detail below as captured in 3GPP TS <NUM>:
<IMG>
<IMG>.

Notice that it is not mandatory for the source node releasing/suspending the UE to provide a dedicated idle measurement configuration for the purpose of early measurements. If the UE is released/suspended to idle without being provided with a list of carriers to be measured, the UE obtains that from SIB2, as written below:
<IMG>.

And, in that case of the list not being provided in RRCConnectionRelease, at every cell reselection the UE performs the SIB5 acquisition to possibly update its list of carriers to measure as shown below:
<IMG>.

If the UE enters a cell within the validity area that is not broadcasting the measurement configuration in SIB5, the UE continues to perform idle measurements according to the SIUB5 acquired in the source cell (i.e. the cell the UE was suspended or released). <IMG>
<IMG>
<IMG>
<IMG>.

In LTE Rel-<NUM> euCA, the concept of idle mode measurements and early measurement reporting was introduced. The UE could be configured with measurement configurations in RRCConnectionRelease. When the UE returns to RRC_CONNECTED, if the target cell indicates idleModeMeasurements in SIB2 and the UE has available idle mode measurements (indicated in the RRC specifications to be stored in a UE variable called VarMeasIdleReport), the UE includes a flag called idleMeasAvailable in RRCConnectionSetupComplete or RRCConnectionResumeComplete. The network can then request the UE in UEInformationRequest to report the early measurements in UEInformationResponse.

The UE deletes the idle mode measurements if the UE successfully reports them in UEInformationResponse, or if the UE receives an RRCRelease message that includes a measldleConfig (i.e., new idle mode measurement configurations). Both cases are shown below:
<IMG>.

<CIT> discloses method and apparatus for efficiently controlling the carrier aggregation in a network using LTE or a next generation air interface technology.

<CIT>) discloses method and apparatus for efficiently controlling the carrier aggregation of a terminal in a network using LTE or a next generation air interface technology.

"<NPL> discloses measurements done by a UE in RRC_IDLE when it has an IDLE mode measurement.

configuration and the storage of the available measurements by a UE in both RRC_IDLE and RRC_CONNECTED.

"<NPL> discloses RRC connection management procedures.

<NPL>discloses addition of idle mode measurement testcase with measurement info from measIdleConfig.

<NPL> discloses solutions for handling IDLE state measurement while UE is moving across cells. SUMMARY If the solutions discussed above are implemented, there may be some problems. For example, if the UE is configured with idle mode measurements in one cell and then establishes/resumes the connection in another cell that does not support idle mode measurement reporting, it would not indicate the idleModeMeasurements in SIB2, and the UE would not indicate that it has any idle mode measurements to the network, so the network would not request these stored measurements.

When after that the network later releases the UE to RRC_IDLE, it would not include any idle mode measurement configurations and, since there was no discarding/cleaning up of stored idle measurements, the UE would keep the old idle mode measurements. If the UE later establishes/resumes in a cell which supports idle mode measurements, the UE would then report that it has (the old) idle mode measurement, which the network could possibly request. The network could then receive very old and outdated idle mode measurements, which may have been performed in a completely different area. This problem is illustrated in <FIG>.

Another related issue is that the idle measurement results could be large in the Rel-<NUM> context, as they can include both LTE and New Radio (NR) measurements, where the NR measurement could have detailed beam level measurements as well. As such, the UE may end up wasting valuable memory space, for a considerable time, on storing information that is not valid anyway.

Embodiments described herein are directed to a wireless device that handles stored idle measurements that are performed for early reporting. According the embodiments, a wireless device deletes stored idle mode measurement results if certain events/condition as claimed in the claims occur at the UE. One such event could be if the UE successfully reports the idle mode measurements in an RRC Resume Complete like message (e.g., RRCResumeComplete in NR). In this alternative, the network would not need these measurements in further procedures once it received an RRC Resume Complete (even if the network in theory could request again with UE Information Request). Another event for deletion may be if the UE successfully reports the idle mode measurements in an RRC Resume Request (or similar) message (e.g., RRCResumeRequest or RRCResumeRequest1 in NR). In this alternative, the network would not need these measurements in further procedures once it received an RRC Resume Request (even if the network in theory could request again with a UE Information Request or in Resume). Another behavior for deletion could include receiving an RRCConnectionRelease/RRCRelease message without idle mode measurement configurations. Another event may include receiving an RRCConnectionRelease/RRCRelease message with or without idle mode measurement configurations, only if the UE receives that while is in RRC_CONNECTED. One event may include receiving a handover message (e.g., RRCConnectionReconfiguration with MobilityControlInfo, RRCReconfiguration with reconfWithSync, MobilityFrom-EUTRACommand, MobilityFromNRCommand).

One event may include receiving a message resuming connected mode measurements (e.g., RRCConnectionResume/RRCResume message with or without a measConfig). In one instance, the UE deletes the idle mode measurements upon reception of the RRCResume/RRCConnectionResume message that resumes the connected mode measurements. In another instance, the UE deletes the idle mode measurements upon successfully obtaining connected mode measurements based on the resumed measurement configurations. In another instance, the UE deletes the idle mode measurements when this condition occurs in a cell without an indication in system information that the cell supports idle measurements for early reporting.

In one event, the UE has entered RRC_CONNECTED and experiences a failure (e.g., radio link failure, integrity check failure, reconfiguration failure, etc.). In one instance, the UE deletes the idle mode measurements upon detecting the failure. In another instance, the UE deletes the idle mode measurements upon transmitting an RRCReestablishmentRequest message. In another instance, the UE deletes the idle mode measurements upon receiving an RRCReestablishment message.

In another event, the UE resumes/sets up the connection in a cell that does not broadcast an indication in system information that the cell supports idle measurements for early reporting.

One advantage of the embodiments is that the UE is prevented from unnecessarily keeping idle mode measurements that are too old. The UE may possibly report them and confuse the network whether these are really up to date or useful measurements for various purposes. Another advantage is that memory resources at the UE are released when these measurements are known to not be needed by the network.

According to some embodiments, a method, in a UE adapted to perform idle mode measurements, includes performing and storing one or more radio signal measurements while in an idle mode or inactive state. The method includes deleting the stored radio signal measurements in response to any one of the following events: receiving an RRC release message that does not include an idle mode measurement configuration; receiving an RRC release message while in RRC Connected state; receiving a handover message; successfully obtaining one or more connected mode measurements; receiving a message instructing the UE to resume one or more connected mode measurements; entering RRC Connected state and subsequently experiencing a radio link failure, integrity check failure, or reconfiguration failure; and resuming or establishing a connection in a cell that does not broadcast an indication that the cell support supports early reporting of idle mode measurements.

The method may include receiving an idle mode measurement configuration from a source cell when entering the idle mode or inactive state, wherein said performing one or more radio signal measurements is according to the received idle mode measurement configuration. The method may also include, prior to deleting the stored radio signal measurements, entering a connected state without being requested to report the idle mode measurements.

Further aspects of the present invention are directed to an apparatus, wireless device, UE, network node, base station, relay node, network devices, computer program products or computer readable storage medium corresponding to the methods summarized above and functional implementations of the above-summarized wireless relay node.

Advantages of the embodiments also include the UE avoiding the indefinite keeping of idle mode measurement results and, consequently, avoiding the report of them much later. If that reporting would have happened, the network could receive outdated idle measurements and possibly make decisions based on these outdated measurements. These decisions may include decisions about handover, release and redirect, setup of dual connectivity, setup of carrier aggregation, etc. For example, the UE could be handed over to a cell based on these measurements that is reportedly a good cell (e.g., with strong RSRP and RSRQ), while in reality is no longer a good cell, hence creating interference and/or leading to a handover failure/re-establishment. In other example, the UE could be added to an SCG based on these measurements that is reportedly a good cell (e.g., with strong RSRP and RSRQ), while in reality is no longer a good cell, hence creating interference and/or leading to an SCG failure.

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

Exemplary embodiments of the present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which examples of embodiments of inventive concepts are shown. Components from one embodiment can be tacitly assumed to be present/used in another embodiment. Any two or more embodiments described in this document may be combined with each other. The embodiments are described with respect to LTE or NR, but can be adapted to other radio access technologies where the techniques or selections may be relevant. It should be understood that the specific names used herein for various messages may change, in subsequent versions of a particular standard, or may differ, in other standards, and that the techniques described herein may be implemented using similar messages, regardless of the names used for those messages.

References herein to 3GPP TS <NUM>. xxx, 3GPP TS <NUM>. xxx, TS <NUM>. xxx, or TS <NUM>. xxx should be understood as referring to the specifications developed and maintained by the 3rd-Generation Partnership Project (3GPP). Where no version is specified, it should be assumed that these references refer to the most current version as of <NUM> June <NUM>.

Particular embodiments described herein may be based on the existing LTE idle mode procedures in 3GPP TS <NUM> v15. It has been agreed that idle mode measurements will be introduced in LTE inactive, as well as NR idle and inactive, but the precise procedures have not been specified yet. The changes proposed for LTE are equally applicable to NR. In various embodiments, the intra-RAT (radio access technology) case is used as an example, but the method is applicable for inter-RAT procedures where the UE is being suspended in a first RAT (e.g., NR) and has a stored idle measurement for early report, and the UE performs inter-RAT cell reselection (and further procedures such as resume/setup attempt). The term "power saving state" may be used for Inactive state and IDLE. However, the term is applicable to any other power saving state where the UE is configured to perform measurements for early reporting.

In one embodiment, a method at a UE or wireless terminal for handling idle mode measurement results includes receiving and storing idle mode measurement configurations from a source cell when entering a power saving state (e.g., RRC_IDLE, RRC_IDLE with suspended RRC connection, RRC_INACTIVE) and performing idle mode measurements according to the configurations. The method further includes leaving the power saving state and entering a connected state (e.g., RRC_CONNECTED) without being requested to report the idle mode measurement results. The method includes deleting the idle mode measurement results upon reporting the idle mode measurements in an RRC Resume Complete (or similar) message (e.g., RRCResumeComplete in NR). In this alternative, the network would not need these measurements in further procedures once it got an RRC Resume Complete (even if the network in theory could request again with UE Information Request). The deletion may occur as part of the procedure upon receiving an RRC Resume (or similar) message containing the indication to report idle measurements in Resume Complete. And, the results are deleted only after an acknowledgement that the message with the measurements was successfully delivered.

An example of how that could be implemented in the NR RRC specifications (3GPP TS <NUM>) is shown below (with bold used as emphasis):
<IMG>
<IMG>
<IMG>.

In another embodiment, deletion of stored idle mode measurements may occur upon reporting the idle mode measurements in RRC Resume Request (or similar) message (e.g., RRCResumeRequest or RRCResumeRequest1 in NR). In this alternative, the network would not need these measurements in further procedures once it received an RRC Resume Request (even if the network in theory could request again with UE Information Request or in Resume). Deletion may also occur upon receiving RRCConnectionRelease/RRCRelease message without idle mode measurement configurations.

In the existing 3GPP specification, the UE would delete the VarMeasIdleReport (i.e., the idle mode measurement results) if it received an RRCConnectionRelease comprising the measldleConfig. However, if the UE has stored idle mode measurements when it connects to a cell that does not support idle mode measurements, it will not be requested to report them and would not delete the results. If the UE later is released to RRC_IDLE or RRC_INACTIVE, it would receive an RRCConnectionRelease message. Since the cell does not support idle mode measurements, it would not include the measldleConfig, and the UE would keep the old idle mode measurements. If the UE deletes the idle mode measurements regardless of whether the RRCConnectionRelease/RRCRelease message contains the measldleConfig, the UE would not store and report outdated measurements.

An example of the embodiment is shown below for LTE (in 3GPP TS <NUM> v15. Similar implementations could be introduced for NR idle mode measurements (for RRC_IDLE and/or RRC_INACTIVE). <IMG>
<IMG>.

In another embodiment, the deletion may occur upon receiving an RRCConnectionRelease/RRCRelease message only if the UE receives that while it is in RRC_CONNECTED. The difference compared to the previous embodiment (where the UE always deletes the measurements upon reception of RRC Release (or similar) message) is that the UE keeps the idle mode measurement results if it receives the RRCConnectionRelease/RRCRelease message while the UE is in RRC_IDLE or RRC_INACTIVE. This may be as a response to an RRC Resume Request like message (e.g., RRCResumeRequest or RRCResumeRequest1). This may, for instance, happen if the UE tries to establish/resume in a cell that is overloaded (or request a service that is not supported in that cell), and the cell release and redirects the UE to another cell or when a resume procedure is triggered by a RAN area update. In that case, the UE would be able to report the idle mode measurement results in the new target cell.

An example of the embodiment is shown below for LTE (in 3GPP TS <NUM> v15. <NUM>), where the UE first checks whether it received the RRCConnectionRelease message in response to an RRCConnectionResumeRequest or RRCConnectionSetupRequest message. In one instance, the UE may check whether it is in RRC _CONNECTED if it should delete/clear the idle mode measurements (VarMeasIdleReport). Similar implementations could be introduced for NR idle mode measurements (for RRC_IDLE and/or RRC_INACTIVE). <IMG>
<IMG>.

In one embodiment, deletion occurs upon receiving a handover message (e.g., RRCConnectionReconfiguration with mobilityControlInfo, RRCReconfiguration with reconfWithSync, MobilityFromEUTRACommand, MobilityFromNRCommand.

In another embodiment, the UE keeps the idle mode measurements after it has entered RRC _CONNECTED (unless requested to report them in RRCResumeComplete or UEInformationResponse) until the UE receives a message handing over the UE to another cell. In LTE, this would be indicated by receiving the RRCConnectionReconfiguration message with the field mobilityControlInfo included (for intra-LTE handover) or by receiving the MobilityFromEUTRACommand (for inter-RAT handover). In either case, the network has indicated that it cannot serve the UE anymore and since it has not requested the idle mode measurements, it is not interested in receiving them.

In NR, the corresponding handover message would be the RRCReconfiguration message with the ReconjWithSync (for intra-NR handover) or the MobiltiyFromNRCommand (for inter-RAT handover). In one instance, the UE only deletes the idle mode measurements if the handover command indicates a handover to another cell and/or node, i.e., the UE keeps the idle mode measurements for intra-cell, and/or intra-node handover (including intra-gNB-CU handover). In another instance, the UE deletes the idle mode measurements upon the reception of the handover command (RRCConnectionReconfiguration with mobilityControlInfo/RRCReconfiguration with reconfWithSync/MobilityFromEUTRACommand/MobilityFrom NRCommand). In another instance, the UE deletes the idle mode measurements upon completing the handover (e.g., successfully connected to the target, transmitted the complete message, etc.). In another variant, an intra-cell handover may be used by the network as a way to delete these measurements.

The example below shows when the UE deletes the idle mode measurements upon receiving the handover command in LTE (intra-LTE or inter-RAT). Similar implementations could be introduced for NR idle mode measurements.

In another example, the idle mode measurements are deleted upon the completion of the inter-RAT handover, as seen below.

In one embodiment, deletion of idle mode measurements occurs upon receiving a reconfiguration message configuring SCG and/or SCell. For example, the UE may delete the idle mode measurements upon reception of the RRCConnectionReconfiguration /RRCReconfiguration containing, for example, mrdc-SecondaryCellGroupConfig or endc-Config. In another embodiment, the UE deletes the idle mode measurements upon reception of the RRCConnectionReconfiguration IRRCReconfiguration comprising SCell addition/ modification (e.g., sCellToAddModList). In one embodiment, the UE deletes the idle mode measurements upon reception of an indication for SCell activation/deactivation. In one instance, this is in the RRCConnection Reconfiguration/RRCReconfiguration comprising, for example, the field sCellState. In another instance, this is a MAC control element, such as the SCell Activation/Deactivation MAC CE. In one instance, this is an L1 signal, such as a DCI signal activating/deactivating an SCell. An example of this addition to 3GPP TS <NUM> includes:
<IMG>
<IMG>
<IMG>.

In another embodiment, deletion of idle mode measurements occurs when the UE receives a message configuring new connected mode measurements (e.g., RRCConnection Reconfiguration/RRCReconfiguration with measConfig).

If the UE has entered RRC _CONNECTED without being requested to report the idle mode measurements in either RRCResumeComplete, or in UEInformationResponse, the UE may receive a reconfiguration message configuring new connected mode measurements. Since the network has not requested that the UE report the idle mode measurements, this would indicate to the UE that the network is not interested in receiving them.

In one embodiment, the UE deletes the idle mode measurements upon the reception of the message configuring the new connected mode measurements as shown below for LTE. A similar procedure could be introduced for NR.

In one instance, the UE deletes the idle mode measurements upon successfully obtaining new connected mode measurements either for any measurement object, or for a measurement object corresponding to the cell/frequency/beam for which there is an idle mode measurement. <IMG>
<IMG>
<IMG>
<IMG>
<IMG>.

In an embodiment, deletion of idle mode measurements may occur when the UE receives a message resuming connected mode measurements (e.g., RRCConnectionResume/ RRCResume with or without measConfig). For example, the UE deletes the idle mode measurements upon reception of the RRCResume/RRCConnectionResume message, which resumes the connected mode measurements.

In one embodiment, the UE deletes the idle mode measurements upon successfully obtaining connected mode measurements based on the resumed measurement configurations. In another embodiment, the UE deletes the idle mode measurements when this condition occurs in a cell without an indication in system information that the cell supports idle measurements for early reporting. An example implementation of this is shown below, and similar procedures can be introduced for NR and LTE/5GC from RRC INACTIVE. <IMG>
<IMG>
<IMG>.

In one embodiment, deletion occurs when the UE experiences a failure in RRC_CONNECTED (e.g., radio link failure, integrity check failure, reconfiguration failure, etc.) For example, the UE may delete the idle mode measurements upon detecting a radio link failure.

Similar embodiments can be seen for the other failure cases.

In another embodiment, the UE deletes the idle mode measurements upon transmitting an RRCReestablishmentRequest message.

In another embodiment, the UE deletes the idle mode measurements upon receiving an RRCReestablishment message.

In an embodiment, deletion of idle mode measurements may occur upon a defined time period having elapsed since the UE entered RRC_CONNECTED (e.g., a timer started when the UE entered RRC_CONNECTED). That part of the method relies on a timer T3xx that may have at least one of the starting conditions: Timer T3xx starts upon the UE entering Connected state; or Timer T3xx starts upon the stop or expiry of timer T331 (i.e., any timer that, while running, the UE is required to perform early measurements). The reasoning here is that there is some time that the UE is required to store the idle measurements after the UE stops to perform idle measurements.

The timer T3xx may have at least one of the stopping conditions: the UE successfully reports the idle measurements; or the UE discards the measurement due to some other conditions, for example, upon reception of a message, as one of the cases described in the method. Upon the expiry or stop of timer T3xx, the UE deletes the idle measurements. Another aspect is that the timer T3xx may be configured.

An example of the RRCConnectionSetup message may be as follows:
<IMG>
<IMG>.

An example of an RRCConnectionResume message may be as follows:
<IMG>
<IMG>
<IMG>.

The example values in the message could be any specified value. In another embodiment, only a single timer value is specified, which does not have to be signaled in the RRCConnectionSetup/RRCConnectionResume message.

In an embodiment, deletion of idle mode measurements occurs upon receiving an RRCConnectionRelease/RRCRelease message with an explicit configuration that the UE shall delete stored idle mode measurements. The UE may receive an explicit configuration within the RRCConnectionRelease/RRCRelease message that instructs the UE whether it shall delete or maintain the stored idle mode measurements. The configuration may then include information about whether the UE shall delete or maintain stored measurements (or different parts of them), dependent on further criteria, such as how old the measurements are, the level of the measurements (e.g., carrier, cell or beam level); and/or what objects the measurements are for (e.g., what specific RAT, carrier or cell they concern).

An example of the RRCConnectionRelease message is:
<IMG>
<IMG>
<IMG>.

In an embodiment, the UE resumes/sets up the connection in a cell that does not broadcast an indication in system information that the cell supports idle measurements for early reporting.

In one example, if a UE with stored idle mode measurements initiates a resume or establishment procedure in a cell that does not indicate support for idle mode measurements (e.g., with the idleModeMeasurements indication in SIB2 for LTE), the UE would delete the idle mode measurement. An example of this procedure is shown below for LTE:
<IMG>.

A similar procedure in NR (3GPP TS <NUM> v15. <NUM>) could be, for example:
<IMG>
<IMG>.

Embodiments described herein introduce methods to delete idle mode measurement results that the network has not requested, even after the UE has entered RRC_CONNECTED. This helps the UE to avoid keeping idle mode measurements indefinitely.

<FIG> shows illustrates an example wireless device <NUM> (e.g., UE) that is configured to perform the techniques described herein for the UE. The wireless device <NUM> may also be considered to represent any wireless devices that may operate in a network and that are capable of communicating with a network node or another wireless device over radio signals. The wireless device <NUM> may also be referred to, in various contexts, as a radio communication device, a target device, a device-to-device (D2D) UE, a machine-type UE or UE capable of machine to machine (M2M) communication, a sensor-equipped UE, a PDA (personal digital assistant), a wireless tablet, a mobile terminal, a smart phone, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), a wireless USB dongle, a Customer Premises Equipment (CPE), etc..

The wireless device <NUM> communicates with one or more radio nodes or base stations, such as one or more network nodes <NUM>, via antennas <NUM> and a transceiver circuit <NUM>. The transceiver circuit <NUM> may include transmitter circuits, receiver circuits, and associated control circuits that are collectively configured to transmit and receive signals according to a radio access technology, for the purposes of providing cellular communication services.

The wireless device <NUM> also includes one or more processing circuits <NUM> that are operatively associated with and control the radio transceiver circuit <NUM>. The processing circuit <NUM> comprises one or more digital processing circuits <NUM>, e.g., one or more microprocessors, microcontrollers, Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), Complex Programmable Logic Devices (CPLDs), Application Specific Integrated Circuits (ASICs), or any mix thereof. More generally, the processing circuit <NUM> may comprise fixed circuitry, or programmable circuitry that is specially adapted via the execution of program instructions implementing the functionality taught herein, or may comprise some mix of fixed and programmed circuitry. The processing circuit <NUM> may be multi-core.

The processing circuit <NUM> also includes a memory <NUM>. The memory <NUM>, in some embodiments, stores one or more computer programs <NUM> and, optionally, configuration data <NUM>. The memory <NUM> provides non-transitory storage for the computer program <NUM> and it may comprise one or more types of computer-readable media, such as disk storage, solid-state memory storage, or any mix thereof. By way of non-limiting example, the memory <NUM> comprises any one or more of SRAM, DRAM, EEPROM, and FLASH memory, which may be in the processing circuit <NUM> and/or separate from processing circuit <NUM>. In general, the memory <NUM> comprises one or more types of computer-readable storage media providing non-transitory storage of the computer program <NUM> and any configuration data <NUM> used by the wireless device <NUM>.

Accordingly, in some embodiments, the processing circuit <NUM> of the wireless device <NUM> is configured to perform idle mode measurements. The processing circuit <NUM> is configured to perform and store one or more radio signal measurements while in an idle mode or inactive state, and delete the stored radio signal measurements in response to any one of a number of events. The events include: receiving a RRC release message that does not include an idle mode measurement configuration; receiving an RRC release message while in RRC Connected state; receiving a handover message; receiving a reconfiguration message adding a secondary cell for carrier aggregation; receiving a reconfiguration message modifying a secondary cell for carrier aggregation; receiving a reconfiguration message activating or deactivating a secondary cell for carrier aggregation; receiving a message configuring one or more new connected mode measurements; successfully obtaining one or more connected mode measurements; receiving a message instructing the UE to resume one or more connected mode measurements; entering RRC Connected state and subsequently experiencing a radio link failure, integrity check failure, or reconfiguration failure; entering RRC Connected state and failing to receive a request for reporting of idle mode measurements before expiry of a timer for maintaining idle mode measurements; and resuming or establishing a connection in a cell that does not broadcast an indication that the cell support supports early reporting of idle mode measurements.

Processing circuitry <NUM> is also configured to perform method <NUM>, according to some embodiments. Method <NUM>, shown in <FIG>, includes performing and storing one or more radio signal measurements while in an idle mode or inactive state (block <NUM>) and deleting the stored radio signal measurements in response to any one of the events listed above (block <NUM>). The method may include receiving an idle mode measurement configuration from a source cell when entering the idle mode or inactive state, where the performing one or more radio signal measurements is according to the received idle mode measurement configuration. The method may include, prior to deleting the stored radio signal measurements, entering a connected state without being requested to report the idle mode measurements.

<FIG>, according to some embodiments, illustrates a communication system that includes a telecommunication network <NUM>, such as a 3GPP-type cellular network, which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of base stations 912a, 912b, 912c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 913a, 913b, 913c. Each base station 912a, 912b, 912c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first UE <NUM> located in coverage area 913c is configured to wirelessly connect to, or be paged by, the corresponding base station 912c. A second UE <NUM> in coverage area 913a is wirelessly connectable to the corresponding base station 912a.

It is noted that the host computer <NUM>, base station <NUM> and UE <NUM> illustrated in <FIG> may be identical to the host computer <NUM>, one of the base stations 1012a, 1012b, 1012c and one of the UEs <NUM>, <NUM> of <FIG>, respectively.

The wireless connection <NUM> between the UE <NUM> and the base station <NUM> is in accordance with the teachings of the embodiments described throughout this disclosure, such as provided by nodes such as a wireless device and relay node <NUM>, along with the corresponding method <NUM>. The embodiments described herein provide the deletion of idle mode measurements so that they are not stored indefinitely. The teachings of these embodiments may improve the reliability, connections, data rate, capacity, latency and/or power consumption for the network and UE <NUM> using the OTT connection <NUM>.

Additionally, or alternatively, in an optional second step <NUM>, the UE provides user data.

As discussed in detail above, the techniques described herein, e.g., as illustrated in the process flow diagram of <FIG>, may be implemented, in whole or in part, using computer program instructions executed by one or more processors. It will be appreciated that a functional implementation of these techniques may be represented in terms of functional modules, where each functional module corresponds to a functional unit of software executing in an appropriate processor or to a functional digital hardware circuit, or some combination of both.

<FIG> illustrates an example functional module or circuit architecture for a wireless device <NUM>. The functional implementation includes a performing module <NUM> for performing and storing one or more radio signal measurements while in an idle mode or inactive state.

Claim 1:
A method, in a user equipment, UE, adapted to perform idle mode measurements, the method comprising:
performing and storing one or more radio signal measurements while in an idle mode or inactive state; and
deleting the stored radio signal measurements in response to any one of the following events:
entering Radio Resource Control, RRC, Connected state and reporting the stored radio signal measurements in an RRC Resume Complete message;
receiving an RRC release message that does not include an idle mode measurement configuration;
receiving an RRC release message while in RRC Connected state;
receiving a handover message;
successfully obtaining one or more connected mode measurements;
receiving a message instructing the UE to resume one or more connected mode measurements;
entering RRC Connected state and subsequently experiencing a radio link failure, integrity check failure, or reconfiguration failure;
and
resuming or establishing a connection in a cell that does not broadcast an indication that the cell support supports early reporting of idle mode measurements.