Methods and apparatus for UE cell detection continuity

Abstract

A user equipment (UE) configured with early measurement reporting EMR operating in a connected mode, transmits to a first apparatus, a first message indicating a cell detection continuity capability t

Description

FIELD

[001] Various example embodiments relate generally to wireless networks and, more particularly, to user equipment (UE) cell detection continuity. BACKGROUND

[002] When a user equipment (UE) is configured with early measurement reporting (EMR), a cell may remain detectable when a UE is transitioning from a connected mode to an idle mode. EMR may be utilized during an idle mode / inactive mode of a UE to perform measurements for reporting during connection setup.

[003] In some cases, EMR may include the performance of measurements by the UE a predefined time period. Additionally, these measurements may be subject to a validity check to verify that the measurements were performed, for example, within the specified time period or by performing additional measurements. SUMMARY

[004] In an aspect of the present disclosure, a method includes transmitting, by a user equipment (UE) operating in a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the UE is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode. The UE transitions from the connected mode with a first cell to an idle mode or inactive mode. The UE determines to store connected mode cell detection information for one or more cells based upon at least one criterion, and stores m the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

[005] In an aspect of the method, the UE determines at least one cell of the one or more cells for which to store connected mode cell detection information.

[006] In an aspect of the method, the at least one criterion includes whether a cell meets LI, L2 or L3 mobility measurement criteria.

[007] In an aspect of the method, the at least one criterion includes whether a cell has been measured during connected mode.

[008] In an aspect of the method, the at least one criterion includes performing, by the UE, a comparison of a signal level of a measurement performed in connected mode to a signal level of the measurement performed in idle or inactive mode, and storing the measurement performed in connected mode upon the signal level comparison falling within a threshold.

[009] In an aspect of the method, the storing includes storing one or more identifiers identifying one or more reference signal measurements.

[0010] In an aspect of the method, the method includes receiving, by the UE, a second message from the first apparatus, the second message including an instruction to store connected mode cell detection information for one or more cells, and performing the storing based on the second message.

[0011] In an aspect of the method, the method includes transmitting, by the UE, a third message to the first apparatus, the third message including an indication of the one or more cells for which connected mode cell detection information is maintained by the UE when transitioned to the idle mode or inactive mode.

[0012] In an aspect of the method, the method includes measuring, by the UE, based on the connected mode cell detection information relating to the one or more cells, cell information in the idle mode or inactive mode.

[0013] In an aspect of the method, the UE omits cell detection of the one or more cells in the idle mode or inactive mode.

[0014] In an aspect of the method, the method includes discarding, by the UE, the stored connected mode cell detection information after a predefined period of time, wherein the predefined period of time includes a period of time after a last measurement for the one or more cells or a period of time after a cell of the one or more cells has been detected.

[0015] In an aspect of the method, storing includes storing connected mode cell detection information upon cell signal strength exceeding a threshold.

[0016] In an aspect of the method, storing includes storing connected mode cell detection information upon cell channel quality conditions exceeding a threshold.

[0017] In an aspect of the method, the method includes transitioning, by the UE, from the idle mode or inactive mode to the connected mode and using, in the transitioning, the maintained connected mode cell detection information for the one or more cells.

[0018] In an aspect of the method, the connected mode cell detection information comprises one or both of cell detection or beam index detection information for the one or more cells and, when transitioning to the connected state, the UE skips beam index detection for the one or more cells.

[0019] In an aspect of the method, the UE omits for the one or more cells, one or both of the cell detection or index detection.

[0020] In an aspect of the present disclosure, a user equipment (UE) includes at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the UE at least to perform any of the foregoing methods.

[0021] In an aspect of the present disclosure, an apparatus includes at least one processor, and at least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to perform any of the foregoing methods.

[0022] In an aspect of the present disclosure, a processor-readable medium storing instructions which, when executed by at least one processor of an apparatus, cause the apparatus at least to perform any of the foregoing methods.

[0023] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Some example embodiments will now be described with reference to the accompanying drawings.

[0025] FIG. 1 is a diagram of an example embodiment of wireless networking between a network system and a user equipment (UE), according to one illustrated aspect of the disclosure;

[0026] FIG. 2 is a diagram of example components of a network system, according to one illustrated aspect of the disclosure;

[0027] FIG. 3 is a diagram of an example transition between connected mode and idle mode, according to one illustrated aspect of the disclosure;

[0028] FIG. 4 is a diagram of an example embodiment of signals and operations among a UE, cell 1 and cell 2, according to one illustrated aspect of the disclosure; and

[0029] FIG. 5 is a diagram of an example embodiment of components of a UE or of a network apparatus, according to one illustrated aspect of the present disclosure. DETAILED DESCRIPTION

[0030] In the following description, certain specific details are set forth in order to provide a thorough understanding of disclosed aspects. However, one skilled in the relevant art will recognize that aspects may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the aspects.

[0031] Reference throughout this specification to “one aspect” or “an aspect” means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, the appearances of the phrases “in one aspect” or “in an aspect” in various places throughout this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects.

[0032] Embodiments described in the present disclosure may be implemented in wireless networking apparatuses, such as, without limitation, apparatuses utilizing Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Sendee (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, enhanced LTE (eLTE), 5G New Radio (5G NR), 5G Advance, 6G (and beyond) and 802.1 lax (Wi-Fi 6), among other wireless networking systems. The term ‘eLTE’ here denotes the LTE evolution that connects to a 5G core. LTE is also known as evolved UMTS terrestrial radio access (EUTRA) or as evolved UMTS terrestrial radio access network (EUTRAN).

[0033] The present disclosure may use the term “serving network device” to refer to a network node or network device (or a portion thereof) that services a UE. As used herein, the terms “transmit to,” “receive from,” and “cooperate with,” (and their variations) include communications that may or may not involve communications through one or more intermediate devices or nodes. The term “acquire” (and its variations) includes acquiring m the first instance or reacquiring after the first instance. The term “connection” may mean a physical connection or a logical connection.

[0034] The present disclosure uses 5G NR as an example of a wireless network and may use smartphones and / or extended reality headsets as an example of UEs. It is intended and shall be understood that such examples are merely illustrative, and the present disclosure is applicable to other wireless networks and user equipment.

[0035] FIG. 1 is a diagram depicting an example of wireless networking between a network system 100 and a user equipment (UE) 150. The network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network equipment 130 (e.g., test equipment). The network nodes 120 will be described in more detail below. As used herein, the term “network apparatus” may refer to any component of the network system 100, such as the server 110, the network node 120, the network equipment 130, any component(s) of the foregoing, and / or any other component(s) of the network system 100. Examples of network apparatuses include, without limitation, apparatuses implementing aspects of 5G NR, among others. The present disclosure describes embodiments related to 5G NR and embodiments that involve aspects defined by 3rd Generation Partnership Project (3GPP). However, it is contemplated that embodiments relating to other wireless networking technologies are encompassed within the scope of the present disclosure.

[0036] The following description provides further details of examples of network nodes. In a 5G NR network, a gNodeB (also known as gNB) may include, e.g., a node that provides new radio (NR) user plane and control plane protocol terminations towards the UE and that is connected via a NG interface to the 5G core (5GC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2, which is hereby incorporated by reference herein.

[0037] A gNB supports various protocol layers, e.g., Layer 1 (LI) - physical layer, Layer 2 (L2), and Layer 3 (L3).

[0038] The layer 2 (L2) of NR is split into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP), where, e.g.: o The physical layer offers to the MAC sublayer transport channels; o The MAC sublayer offers to the RLC sublayer logical channels; o The RLC sublayer offers to the PDCP sublayer RLC channels; o The PDCP sublayer offers to the SDAP sublayer radio bearers; o The SDAP sublayer offers to 5GC quality of service (QoS) flows; o Control channels include broadcast control channel (BCCH) and physical control channel (PCCH).

[0039] Layer 3 (L3) includes, e.g., radio resource control (RRC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 6, which is hereby incorporated by reference herein.

[0040] A gNB central unit (gNB-CU) includes, e.g., a logical node hosting, e.g., radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB or RRC and PDCP protocols of the en-gNB, that controls the operation of one or more gNB distributed units (gNB-DUs). The gNB-CU terminates the Fl interface connected with the gNB-DU. A gNB-CU may also be referred to herein as a CU, a central unit, a centralized unit, or a control unit.

[0041] A gNB Distributed Unit (gNB-DU) includes, e.g., a logical node hosting, e.g., radio link control (RLC), media access control (MAC), and physical (PHY) layers of the gNB or en-gNB, and its operation is partly controlled by the gNB-CU. One gNB-DU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the Fl interface connected with the gNB-CU. A gNB-DU may also be referred to herein as DU or a distributed unit.

[0042] As used herein, the term “network node” may refer to any of a gNB, a gNB-CU, or a gNB-DU, or any combination of them. A RAN (radio access network) node or network node such as, e.g., a gNB, gNB-CU, or gNB-DU, or parts thereof, may be implemented using, e.g., an apparatus with at least one processor and / or at least one memory with processor-readable instructions (“program”) configured to support and / or provision and / or process CU and / or DU related functionality and / or features, and / or at least one protocol (sub-)layer of a RAN (radio access network), e.g., layer 2 and / or layer 3. Different functional splits between the central and distributed unit are possible. An example of such an apparatus and components will be described in connection with FIG. 5 below.

[0043] The gNB-CU and gNB-DU parts may, e.g., be co-located or physically separated. The gNB-DU may even be split further, e.g., into two parts, e.g., one including processing equipment and one including an antenna. A central unit (CU) may also be called baseband unit / radio equipment controller / cloud-RAN / virtual-RAN (BBU / REC / C-RAN / V-RAN), open-RAN (O-RAN), or part thereof. A. distributed unit (DU) may also be called remote radio head / remote radio unit / radio equipment / radio unit (RRH / RRU / RE / RU), or part thereof. Hereinafter, in various example embodiments of the present disclosure, a network node, which supports at least one of central unit functionality or a layer 3 protocol of a radio access network, may be, e.g., a gNB-CU. Similarly, a network node, which supports at least one of distributed unit functionality or a layer 2 protocol of the radio access network, may be, e.g., a gNB-DU.

[0044] A gNB-CU may support one or multiple gNB-DUs. A gNB-DU may support one or multiple cells and, thus, could support a serving cell for a user equipment (UE) or support a candidate cell for handover, dual connectivity, and / or carrier aggregation, among other procedures.

[0045] The user equipment (UE) 150 may be or include a wireless or mobile device, an apparatus with a radio interface to interact with a RAN (radio access network), a smartphone, an in-vehicle apparatus, an ToT device, or a M2M device, among other types of user equipment. Such UE 150 may include: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform certain operations, such as, e.g., RRC connection to the RAN. In various embodiments, the instructions may comprise computer program code. An example of components of a UE will be described m connection with FIG. 5. In embodiments, the UE 150 may be configured to generate a message (e.g., including a cell ID) to be transmitted via radio towards a RAN (e.g., to reach and communicate with a serving cell). In embodiments, the UE 150 may generate and transmit and receive RRC messages containing one or more RRC PDUs (packet data units). Persons skilled in the art will understand RRC protocol as well as other procedures a UE may perform.

[0046] With continuing reference to FIG. 1, in the example of a 5G NR network, the network system 100 provides one or more cells, which define a coverage area of the network system 100. As described above, the network system 100 may include a gNB of a 5G NR network or may include any other apparatus configured to control radio communication and manage radio resources within a cell. As used herein, the term “resource” may refer to radio resources, such as a resource block (RB), a physical resource block (PRB), a radio frame, a subframe, a time slot, a sub-band, a frequency region, a sub-carrier, a beam, etc. In embodiments, the network node 120 may be called a base station.

[0047] FIG. 1 provides an example and is merely illustrative of a network system 100 and a UE 150. Persons skilled in the art will understand that the network system 100 includes components not illustrated in FIG. 1 and will understand that other user equipment may be in communication with the network system 100.

[0048] FIG. 2 is a block diagram of example components of the network system 100 of FIG. 1. A 5G NR network may be described as an example of the network system 100, and it is intended that aspects of the following description shall be applicable to other types of network systems, as well. The network system may operate in accordance with the signals and connections shown in FIG. 1 such that the UE 150 is in communication with the network system 100 through the radio access network 225. Additionally, the network system may be divided into user plane components and functions and control plane components and functions, as shown and described herein. Unless indicated otherwise, the terms “component”, “function”, and “service” may be used interchangeably herein, and they may refer to and be implemented by instructions executed by one or more processors.

[0049] Example functions of the components are described below. The example functions are merely illustrative, and it shall be understood that additional operations and functions may be performed by the components described herein. Additionally, the connections between components may be virtual connections over service-based interfaces such that any component may communicate with any other component. In this manner, any component may act as a service “producer,” for any other component that is a service “consumer,” to provide services for network functions.

[0050] For example, a core network 210 is described in the control plane of the network system. The core network 210 may include an authentication server function (AUSF) 211, an access and mobility function (AMF) 212, and a session management function (SMF) 213. The core network 210 may also include a network slice selection function (NSSF) 214, a network exposure function (NEF) 215, a network repository function (NRF) 216, and a unified data management function (UDM) 217, which may include a uniform data repository (UDR) 224.

[0051] Additional components and functions of the core network 210 may include an application function 218, policy control function (PCF) 219, network data analytics function (NWDAF) 220, analytics data repository function (ADRF) 221, management data analytics function (MDAF) 222, and operations and management function (0AM) 223.

[0052] The user plane includes the UE 150, a radio access network (RAN) 225, a user plane function (UPF) 226, and a data network (DN) 227. The RAN 225 may include one or more components described in connection with FIG. 1, such as one or more network nodes. However, the RAN 225 may not be limited to such components. The UPF 226 provides connection for data, being transmitted over the RAN 225. The DN 226 identifies services from service providers, Internet access, and third party services, for example.

[0053] The AMF 212 processes connection and mobility tasks. The AUSF 211 receives authentication requests from the AMF 212 and interacts with UDM 217 to authenticate and validate network responses for determination of successful authentication. The SMF 213 conducts packet data unit (PDU) session management, as well as manages session context with the UPF 226.

[0054] The NSSF 214 may select a network slicing instance (NSI) and determine the allowed network slice selection assistance information (NSSAI). This selection and determination is utilized to set the AMF 212 to provide service to the UE 150. The NEF 215 secures access to network services for third parties to create specialized network services. The NRF 216 acts as a repository to store network functions to allow the functions to register with and discover each other.

[0055] The UDM 217 generates authentication vectors for use by the AUSF 211 and ADM 212 and provides user identification handling. The UDM 217 may be connected to the UDR 224 which stores data associated with authentication, applications, or the like. The AF 218 provides application services to a user (e.g., streaming services, etc.). The PCF 219 provides policy control functionality. For example, the PCF 219 may assist in network slicing and mobility management, as well as provide quality of service (QoS) and charging functionality.

[0056] The NWDAF 220 collects data (e.g., from the UE 150 and the network system) to perform network analytics and provide insight to functions that utilize the analytics in the providing of services. The ADRF 221 allows the storage, retrieval, and removal of data and analytics by consumers. The MDAF 222 provides additional data analytics services for network functions. The 0AM 223 provides provisioning and management processing functions to manage elements in or connected to the network (e.g., UE 150, network nodes, etc. ).

[0057] FIG. 2 is merely an example of components of a network system, and variations are contemplated to be within the scope of the present disclosure. In embodiments, the network system may include other components not illustrated in FIG. 2. In embodiments, the network system may not include every component illustrated in FIG. 2. In embodiments, the components and connections may be implemented with different connections than those illustrated in FIG. 2. Such and other embodiments are contemplated to be within the scope of the present disclosure.

[0058] Although further detail will be provided below, when UE is configured with early measurement reporting (EMR), a cell may remain detectable when a UE is transitioning from a connected mode to an idle mode. EMR may be utilized during an idle mode / inactive mode of a UE to perform measurements for reporting during connection setup.

[0059] As mentioned above, in some cases, EMR may include the a performance indicator of measurements performed by the UE during a predefined time period. An example of the performance indicator is accuracy or an accuracy estimate of the measurements. Additionally, these measurements may be subject to a validity check to verify that the measurements were performed, for example, within the specified time period.

[0060] For example, in Release 16 of the 3GPP specifications, early measurement reporting means that the UE is configured to perform measurements in idle / inactive mode to be reported at connection setup to assist in enabling configuration of carrier aggregation / dual connectivity (CA / DC) once the connection is established. Hence, to enable faster carrier aggregation or dual connectivity SCell / PSCell setup once the UE has entered RRC Connected mode. The required measurement time, during which the UE is required to perform the EMR measurements, may be restricted by a timer (e.g., T331) that starts once the UE enters idle / mactive mode. In various embodiments, the UE measurement accuracy requirements may apply only during timer T331. After T331 expires, in release 16 EMR it is up to UE implementation whether it continues to perform measurements.

[0061] In various embodiments, the UE may continue the related measurements and indicate their availability to the network after the timer has expired. However, in such scenario the UE measurement accuracy requirements do not apply and no accuracy requirements can be guaranteed for the reported measurements. In Release 18 of the 3GPP specifications, a validity check of the measurements by the UE performed in idle / inactive mode may be performed before reporting these results to the network. The validity check may include that, at RRC connection setup, the UE verifies that the idle / inactive mode measurements it has available are performed within a specified time period X before a first message (msgl / paging message) of the RRC connection setup independent of the timer. The first message (msgl) may be the first message of a random access procedure performed on a random access channel (RACH). Additionally, the measurement result may include or indicate the accuracy requirements at the time of measurement. In various embodiments, the time duration X may be a network-configurable value.

[0062] When the UE is configured with EMR cell, the cell remains detectable according to the cell detection requirements (e.g., as defined for idle!nactiveNR-MeasReport-rl6 in 3GPP specification TS 38.133). The cell remains detectable when transitioning from connected to idle mode. In one example, the cell remains detectable means, that the UE will keep the UE timing (and measurements) and would for example store / maintain use the previously acquired cell identification information acquired by reading PSS / SSS and performing index identification. Since the UE maintains the information on the PSS and / or SSS, or more generally a synchronization signal block, there is no need to identify the cells PSS and / or SSS. Hence, in one example it means UE does not need to perform PSS and / or SSS detection. This means that the UE does not need to spend extra time for PSS and / or SSS detection. In an additional example, the cell remains detectable, can also include that the UE does not need to re-acquire the SSB Index.

[0063] However, when UE does not support EMR (or is not configured with EMR), the UE is not required to maintain the cell detectable, which results that the measurement time for the cell in idle / inactive mode is significantly increased as it includes the time for cell detection (possibly including Index identification). In some cases, the UE may not have enough time to perform cell detection together with measurements e.g. for frequency range 1 or frequency range 2 (FR1 or FR2, or FR2-1 or any other FR) based upon a configured value for X.

[0064] Described herein in more detail below, in various embodiments, a method an an apparatus for UE cell detection continuity' for EMR (e.g., enhanced EMR). The method may be performed by a UE, i.e the apparatus, to carry' over (e.g., store / maintain) measurements performed in a connected mode upon the UE transitioning to the idle mode or inactive mode.

[0065] In various embodiments, continuity’ may be applied when a UE measures a cell in connected mode and the cell remains detectable during and after transitioning to idle mode, and vice versa (from idle / inactive to connected) for any cell.

[0066] In various embodiments, a UE indicating this continuity capability is capable of transitioning from, connected mode to idle or inactive state with the cell detection status and measurement information over to idle mode or inactive mode, and transitioning from idle mode or inactive mode to connected mode, hence reducing or removing the time that it takes for cell detection, measurements and beam reading (Index reading), for example. In various embodiments, different sets of requirements may be defined to apply for different cases. In various embodiments, the measurement information may be m a format of cell detection details including cell IDs or it may be SSB Index information, and / or measurements carried over to the connected idle or inactive mode.

[0067] In an embodiment, the UE maintains the connected mode cell detection information of all cells that are detected at the time of transitioning to the idle / inactive mode. In another embodiment, the UE maintains the connected mode cell detection information for a subset of these detected cells. The reduction in the maintained connected mode cell detection information may be based on UE capability. The capability may be per-band, e.g., only for a certain frequency range (FR 1, FR2, or FR2-1 of 3GPP specifications), and / or the capability may define a maximum number of detected cells UE can maintain in the idle / inactive mode. In various embodiments, the UE may store / maintain the connected mode cell detection information cells only for up to Y number of cells, where the cells in Y can be configured by the network, based on UE capacity, defined in the 3GPP specifications or where the one or more cells can be selected based on any criteria, (e.g. signal quality or mobility based criteria). In an embodiment, the UE may independently select to either store or discard the connected mode cell detection information when transitioning to the idle / inactive mode, and the configuration and requirements may define how to indicate the stored / maintained detected cells to the network.

[0068] When a state transition occurs, cell detection related information, such as information derived from PSS and SSS reading and decoding and identifiers identifying a particular cell and or a particular reference signal measurement is stored and / or maintained in the UE, and when a UE state transition occurs, in various embodiments, this information remains usable in the UE. For example, the UE may store / maintain (e.g., carry over, transition measurements, and / or measurement related identifier information) over the state transitions. In the instance of cell detection, the requirements which the network uses to derive UE measurement times may be significantly reduced, potentially improving system performance. The state transition may be either from connected mode to idle / inactive mode or from idle / inactive to connected mode, or any future state transition.

[0069] In various embodiments, the UE may determine whether to store or maintain connected mode cell detection information for one or more cells based upon at least one criterion. For example, in various embodiments, the at least one criterion may include whether a cell meets LI, L2 or L3 mobility measurement criteria, and / or whether a cell has been measured during connected mode. In various embodiments, the at least one criterion may include performing, by the UE, a comparison of a signal level of a measurement performed in connected mode to a signal level of the measurement performed in idle or inactive mode, and storing the measurement performed in connected mode upon the signal level comparison falling within a threshold.

[0070] As used herein, a communication with a radio access network (RAN) may refer to and mean a communication with a portion of a RAN, such as with a network node (e.g., a DU and / or a CU), or another portion of a RAN. As used herein, a communication with a core network may refer to and mean a communication with one or more services / applications of the core network, such as AMF or another service of a core network.

[0071] As used herein, the terms “first” and “second”, or the like, may refer to a first or second instance of a message being transmitted / received by a component (e.g., UE, apparatus, etc.), or a first or second component in a sequence of described components. As such, the terms are used in a non-limiting manner, and can refer to any message, operation, device, component, or the like.

[0072] In accordance with the brief description, FIG. 3 is a diagram of an example transition between connected mode and idle mode 300, according to one illustrated aspect of the disclosure of an example transition between connected mode and idle mode, according to one illustrated aspect of the disclosure. As shown in FIG. 3, a UE may be connected to a cell (e.g., cell x) and in connected mode operating in accordance with connected mode and perform measurement according to connected mode measurement requirements. As the UE transitions from the connected mode to the idle mode (or inactive mode), the UE performs idle mode measurement according to idle mode measurement requirements that do not include cell detection and possibly not index identification.

[0073] In various embodiments, the cell (e.g., cell x) remains detectable from the connected mode to the idle mode. The UE may maintain or store measurements performed by the UE during connected mode for the cell (e.g., cell x) when entering idle / inactive mode, reducing / omitting the need to perform cell detection, index reading and / or measurements during idle / inactive mode. At some point, the UE may transition from the idle mode back to connected mode, requiring connected mode measurement requirements. Cell x may remain detectable during the transition from idle mode to connected mode.

[0074] The UE may have maintained or stored measurements performed by the UE during connected mode for the cell (e.g., cell x) which can eliminate, or reduce the need to perform cell detection, index reading and / or measurements during a transition from the idle mode / inactive mode to the connected mode. Accordingly, the UE and network may operate more quickly during the transition. In various embodiments, this may include the UE not performing cell detection for the cell (e.g., cell x), index reading for the cell and / or measurements for the cell, since the UE has already performed measurements when the UE was in connected mode to cell x prior to entering the idle mode or inactive mode.

[0075] Accordingly, in various embodiments, the UE that is configured with the cell detection continuity may perform cell detection continuity to reduce measurement times to set up a carrier aggregation or dual connectivity when in connected for a CA / DC cell.

[0076] In various embodiments, for a UE in which the capability is supported by the UE, the UE is expected to carry over cell detection information on state transitions. In the case of a UE capability being supported without configuration, the UE may either be required to transition information about all the detected cells to the next transition. If the UE capability is supported with configuration, the UE carries over cell detected related information for the cells which are configured to support cell detection continuity.

[0077] Based on an indication that the UE supports cell detection continuity, the network can expect the UE does not need to perform cell detection, index identification and / or measurements of the cells, and may take into account a shorter measurement time for setting up the cell for example to be used in CA. The advantages in the reduction of the measurement time may scale up when the UE supports the cell detection continuity for a plurality of cells in a CA / DC scenario. In various embodiments, the network may take this capability into account when deciding whether to establish CA / DC connection by employing the cell detection continuity capability.

[0078] In various embodiments, the cell detection continuity capability may be used with dynamic threshold indicating radio conditions (e.g. SINR threshold), for example, the UE retains the cell detected when switching into idle mode if cell signals / quality are better than a minimum threshold.

[0079] In various embodiments, the cell detection continuity capability may be used with the UE mobility status (low, medium, high mobility). Depending on the mobility state, the UE may carry over cell(s) (e.g., maintain the cell as detectable by storing the cell measurements). If the mobility status is, for example high, no cells are transitioned to idle-mode, and if the mobility status is low, the UE may transition cell(s). If the mobility is medium, the UE may transition some cells, and the selection of the cells may be based on the measurements. For example, a cell indicating an increasing measured signal quality may be transitioned because the UE is probably moving towards that cell.

[0080] In various embodiments, a time based condition (e.g., since the last measurement), and / or a network based condition (e.g., a cell remains detectable during the transition) maybe used with the cell detection continuity capability. For example, since the last measurement or since the cell was detected, the UE retains the cell detected for a defined period of time after last measurement or after cell has been detected.

[0081] In various embodiments, the UE may transmit a dynamic indication / selection information on which cells the cell continuity applies. The dynamic indication / selection information may be embedded in, for example, measurement reporting (e.g., L1 / L2 / L3 reporting), in-band signaling (e.g., a media access control-control element (MAC-CE)), and / or radio resource control (RRC) signaling (e.g., a flag or a list including association with a cell identifier such as the PCI or candidateCelllD).

[0082] In accordance with the brief description, FIG. 4 is a diagram of an example embodiment of signals and operations among a UE, cell 1 and cell 2, according to one illustrated aspect of the disclosure. In various embodiments, the components depicted in FIG. 5 may correspond to similar components described above in FIGS. 1 and 2. The following paragraphs will describe various signals and operations. It will be understood that a described signal may have associated operations and a described operation may have associated signals. In various embodiments, the signals and operation shown in FIG. 4 may be utilized by a regulatory location service.

[0083] At operation 401, the UE is operating in the RRCconnected mode. At operation 402, the UE transmits measurement report (e.g., LI, L3, MAC, or potentially L2) to cell 1 and cell 1 receives the measurement report. Persons of skill in the art will appreciate the measurement report of operation 402.

[0084] At operation 403, the network (e.g., via cell 1) has information on what cells have been detected and possibly measured. Accordingly, the network knows now which cells it can configure for detection continuity. In various embodiments, the network may do a blind configuration as well. In various embodiments, detected cells are serving+neighboring cells with a signal strength above a minimum threshold. In various embodiments, operations 402-403 may be considered a first option (opt# 1), relating to acquiring detected cell information.

[0085] After operation 403, several example alternative configuration embodiments may be employed. In a first alternative configuration option (alt# 1), and RRCReconfiguration alternative may be utilized.

[0086] Accordingly, at operation 404, cell 1 transmits an RRCReconfiguration message with idlelnactiveNR-CellDetectionContinuity-rlx configuration to the UE and the UE receives the RRCReconfiguration message. In various embodiments, the RRCReconfiguration message includes the configuration associated with the IdlelnactiveNR-CellDetectionContinuity, Cellid I candidateld, and / or RS index information to map the detected cell information across states (e.g., connected mode and / or idle / inactive mode).

[0087] At operation 405, the UE transmits an RRCReconfiguration complete message to cell 1 and cell 1 receives the RRCReconfiguration complete message. In various embodiments, the UE may transmit information about measured or detected cells.

[0088] In a second alternative configuration option (alt#2), an RRCRelease may be utilized.

[0089] Accordingly, at operation 406, cell 1 transmits an RRCRelease message with idlelnactiveNR-CellDetectionContinuity-rlx configuration to the UE and the UE receives the RRCRelease message. In various embodiments, the RRCRelease message may indicate which cells to carry over in a state transition from connected to idle / inactive mode.

[0090] At operation 407, the UE stores the necessary information to carry cell information to IDLE / inactive-mode. In various embodiments, the information may include Cell id, RS reference such as SSB index information, and / or available measurement results. In various embodiments, the UE may also carry some UE specific information such as UE location information, measurement time, etc.

[0091] At operation 408, cell 1 transmits an RRCRelease message to the UE and the UE receives the RRC release message. Upon receipt of the RRCRelease message at operation 408, UE is released to IDLE / INACTIVE mode. In various embodiments, operation 408 may be utilized with alternative #1 and / or alternative #2.

[0092] At operation 409, the UE carries over the cell information (e.g., stores measurement information relating to one or more cells detected in the connected mode) for use in idle mode. In various embodiments, the UE carries over the information from connected mode to the idle / inactive mode and keeps the cell detectable. For example, the UE may maintain and store measurements for connected cells as mentioned above. As the cell information is carried over, it is now usable in idle / inactive mode for measurements.

[0093] At operation 410, cell 2 transmits a reference signal (e.g., synchronization signal block (SSB)) to the UE and the UE receives the reference signal. At operation 411, cell 1 transmits a reference signal (e.g., SSB) to the UE and the UE receives the reference signal.

[0094] At operation 412, the UE performs measurements in idle / inactive mode without instituting cell detection. In various embodiments, the UE may perform measurements without associated cell detection requirements, since UE knows already where to receive cell reference signals (e.g. system information blocks (SIBs)). Accordingly, less time may be needed for measurements.

[0095] At operation 413, cell 1 transmits an SIB to the UE and the UE receives the SIB. In various embodiments, the SIB may include, for example, dynamic information such as whether to perform cell continuity for the serving cell (e.g., cell 1), or a neighbor cell (eg., cell 2), and / or thresholds to associate with cell detection continuity. The SIB may also dynamically indicate to the UE which cell has to be kept detectable (serving cell, neighbor cell, etc.).

[0096] At operation 414, cell 1 transmits an RRCSetup message to the UE and the UE receives the RRC setup message. In various embodiments, the RRCSetup message may include an indication as to whether the UE is to maintain, or carry over, detected cell information.

[0097] At operation 415, the UE transmits an RRCSetupComplete message to cell 1 and cell 1 receives the RRCSetupComplete message. In various embodiments, the UE may inform the network which cells to carry over, send reports for the indicated cells, and / or re-use the measurement configuration of idle mode in connected mode.

[0098] At operation 416, the UE enters an RRC Connected mode. In various embodiments, the UE may connect to a same cell as previously detected, or connect to a new cell for which the UE has stored measurement information

[0099] At operation 417, the UE performs measurements without performing cell detection. In various embodiments, the UE performs measurements and the network knows the UE is using measurement requirements where cell detection is reduced due to the use of the UE’s cell detection continuity capability.

[00100] At operation 418, cell 1 transmits a measurement configuration message to the UE and the UE receives the measurement configuration message. In various embodiments, the measurement configuration message may indicate a CellContinuityConfiguration (e.g., which parameters to enable measurements without cell detection by using the detected cell information from the previous state).

[00101] At operation 419, the UE performs measurements without the cell detection after receiving the measurement configuration message in accordance with the parameters specified in the measurement configuration message.

[00102] The operations of FIG. 4 are merely illustrative, and variations are contemplated to be within the scope of the present disclosure. In embodiments, the operations may include other operations not illustrated in FIG. 4. In embodiments, the operations may not include every operation illustrated in FIG. 4. In embodiments, the operations may be implemented in a different order than that illustrated in FIG. 4. Such and other embodiments are contemplated to be within the scope of the present disclosure. Persons of skill in the art will appreciate that, although various example components are described as perform various functions, other components may perform those functions described in FIG. 4.

[00103] The following describes operations from the perspective of a UE. From such a perspective, a method may include transmitting, by a user equipment (UE) operating in a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the UE is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode. The UE transitions from the connected mode with a first cell to an idle mode or inactive mode. The UE determines to store connected mode cell detection information for one or more cells based upon at least one criterion, and stores in the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

[00104] Referring now to FIG. 5, there is shown a block diagram of example components of a UE or a network apparatus (e.g., of a RAN or a core network). The apparatus includes an electronic storage 510, a processor 520, a network interface 540, and a memory 550. The various components may be communicatively coupled with each other. The processor 520 may be and may include any type of processor, such as a single-core central processing unit (CPU), a multicore CPU, a microprocessor, a digital signal processor (DSP), a System-on-Chip (SoC), or any other type of processor. The memory 550 may be a volatile type of memory, e.g., RAM, or a non-volatile type of memory, e.g., NAND flash memory. The memory 950 includes processor-readable instructions that are executable by the processor 520 to cause the apparatus to perform various operations, including those mentioned herein, such as the operations of FIGS. 3-4.

[00105] The electronic storage 510 may be and include any type of electronic storage used for storing data, such as hard disk drive, solid state drive, optical disc, and / or other non-transitory computer-readable mediums, among other types of electronic storage. The electronic storage 510 stores processor-readable instructions for causing or configured for causing the apparatus to perform its operations and also stores data associated with such operations, such as storing data relating to 5G NR standards, among other data. The network interface 540 may implement wireless networking technologies such as 5G NR and / or other wireless networking technologies.

[00106] The components shown in FIG. 5 are merely examples, and persons skilled in the art will understand that an apparatus includes other components not illustrated and may include multiples of any of the illustrated components. Such and other embodiments are contemplated to be within the scope of the present disclosure. For example, a transmitter and a receiver may be included as components for transmitting and receiving signals.

[00107] Further embodiments of the present disclosure include the following examples.

[00108] Example 1.1. A UE, comprising: means for transmitting, operating in a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the UE is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode; means for transitioning from the connected mode with a first cell to an idle mode or inactive mode; means for determining to store connected mode cell detection information for one or more cells based upon at least one criterion; and means for storing, in the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

[00109] Example 1.2. The UE of example 1.1, wherein the UE determines at least one cell of the one or more cells for which to store connected mode cell detection information.

[00110] Example 1.3. The UE of example 1.1 or 1.2, wherein the at least one criterion includes whether a cell meets LI, L2 or L3 mobility measurement criteria.

[00111] Example 1.4. The UE of example 1.1 or 1.2, wherein the at least one criterion includes whether a cell has been measured during connected mode.

[00112] Example 1.5. The UE of example 1.1 or 1.2, wherein the at least one criterion includes performing, by the UE, a comparison of a signal level of a measurement performed in connected mode to a signal level of the measurement performed in idle or inactive mode, and storing the measurement performed in connected mode upon the signal level comparison falling within a threshold.

[00113] Example 1.6. The UE of example 1.1, wherein the storing includes storing one or more identifiers identifying one or more reference signal measurements.

[00114] Example 1.7. The UE of any one of examples 1.1 to 1.6, further comprising: means for receiving, by the UE, a second message from the first apparatus, the second message including an instruction to store connected mode cell detection information for one or more cells; and means for performing the storing based on the second message.

[00115] Example 1.8. The UE of any one of examples 1.1 to 1.7, further comprising means for transmitting, by the UE, a third message to the first apparatus, the third message including an indication of the one or more cells for which connected mode cell detection information is maintained by the UE when transitioned to the idle mode or inactive mode.

[00116] Example 1.9. The UE of example 1.1, further comprising means for measuring, by the UE, based on the connected mode cell detection information relating to the one or more cells, cell information in the idle mode or inactive mode.

[00117] Example 1.10. The UE of example 1.8 or 1.9, wherein the UE omits cell detection of the one or more cells in the idle mode or inactive mode.

[00118] Example 1.11. The UE of any one of examples 1.1 to 1.10, further comprising means for discarding, by the UE, the stored connected mode cell detection information after a predefined period of time, wherein the predefined period of time includes a period of time after a last measurement for the one or more cells or a period of time after a cell of the one or more cells has been detected.

[00119] Example 1.12. The UE of any one of examples 1.1 to 1.11, wherein storing includes storing connected mode cell detection information upon cell signal strength exceeding a threshold.

[00120] Example 1.13. The UE of any one of examples 1.1 to 1.2, wherein storing includes storing connected mode cell detection information upon cell channel quality conditions exceeding a threshold.

[00121] Example 1.14. The UE of any one of examples 1.1 to 1.13, further comprising means for transitioning, by the UE, from the idle mode or inactive mode to the connected mode and using, in the transitioning, the maintained connected mode cell detection information for the one or more cells.

[00122] Example 1.15. The UE of example 1.14, wherein the connected mode cell detection information comprises one or both of cell detection or beam index detection information for the one or more cells and, when transitioning to the connected state, the UE skips beam index detection for the one or more cells.

[00123] Example 1.16. The UE of example 1.14 or 1.15, wherein the UE omits for the one or more cells, one or both of the cell detection or index detection.

[00124] Example 2.1. An apparatus comprising: means for transmitting, operating in a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the UE is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode; means for transitioning from the connected mode with a first cell to an idle mode or inactive mode; means for determining to store connected mode cell detection information for one or more cells based upon at least one criterion; and means for storing, in the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

[00125] Example 2.2. The apparatus of example 2.1, wherein the apparatus determines at least one cell of the one or more cells for which to store connected mode cell detection information.

[00126] Example 2.3. The apparatus of example 2.1 or 2.2, wherein the at least one criterion includes whether a cell meets LI, L2 or L3 mobility measurement criteria.

[00127] Example 2.4. The apparatus of example 2.1 or 2.2, wherein the at least one criterion includes whether a cell has been measured during connected mode.

[00128] Example 2.5. The apparatus of example 2.1 or 2.2, wherein the at least one criterion includes performing, by the apparatus, a comparison of a signal level of a measurement performed in connected mode to a signal level of the measurement performed in idle or inactive mode, and storing the measurement performed in connected mode upon the signal level comparison falling within a threshold.

[00129] Example 2.6. The apparatus of example 2.1, wherein the storing includes storing one or more identifiers identifying one or more reference signal measurements.

[00130] Example 2.7. The apparatus of any one of examples 2.1 to 2.6, further comprising: means for receiving, by the apparatus, a second message from the first apparatus, the second message including an instruction to store connected mode cell detection information for one or more cells; and means for performing the storing based on the second message.

[00131] Example 2.8. The apparatus of any one of examples 2.1 to 2.7, further comprising means for transmitting, by the apparatus, a third message to the first apparatus, the third message including an indication of the one or more cells for which connected mode cell detection information is maintained by the apparatus when transitioned to the idle mode or inactive mode.

[00132] Example 2.9. The apparatus of example 2.1, further comprising means for measuring, by the apparatus, based on the connected mode cell detection information relating to the one or more cells, cell information m the idle mode or inactive mode.

[00133] Example 2.10. The apparatus of example 2.8 or 2.9, wherein the UE omits cell detection of the one or more cells in the idle mode or inactive mode.

[00134] Example 2.11. The apparatus of any one of examples 2.1 to 2.10, further comprising means for discarding, by the apparatus, the stored connected mode cell detection information after a predefined period of time, wherein the predefined period of time includes a period of time after a last measurement for the one or more cells or a period of time after a cell of the one or more cells has been detected.

[00135] Example 2.12. The apparatus of any one of examples 2.1 to 1.11, wherein storing includes storing connected mode cell detection information upon cell signal strength exceeding a threshold.

[00136] Example 2.13. The apparatus of any one of examples 2.1 to 2.2, wherein storing includes storing connected mode cell detection information upon cell channel quality conditions exceeding a threshold.

[00137] Example 2.14. The apparatus of any one of examples 2.1 to 2.13, further comprising means for transitioning, by the apparatus, from the idle mode or inactive mode to the connected mode and using, in the transitioning, the maintained connected mode cell detection information for the one or more cells.

[00138] Example 2.15. The apparatus of example 2.14, wherein the connected mode cell detection information comprises one or both of cell detection or beam index detection information for the one or more cells and, when transitioning to the connected state, the UE skips beam index detection for the one or more cells.

[00139] Example 2.16. The apparatus of example 2.14 or 2.15, wherein the apparatus omits for the one or more cells, one or both of the cell detection or index detection.

[00140] The embodiments and aspects disclosed herein are examples of the present disclosure and may be embodied in various forms. For instance, although certain embodiments herein are described as separate embodiments, each of the embodiments herein may be combined with one or more of the other embodiments herein. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Like reference numerals may refer to similar or identical elements throughout the description of the figures.

[00141] The phrases “in an aspect,” “in aspects,” “in various aspects,” “in some aspects,” or “in other aspects” may each refer to one or more of the same or different aspects in accordance with this present disclosure. The phrase “a plurality of’ may refer to two or more.

[00142] In various embodiments, the terms “first message” and “second message”, as well as any subsequent messages may refer to any messages that are transmitted or received in an order and are not necessarily limited to any particular message.

[00143] The phrases “in an embodiment,” “in embodiments,” “in various embodiments,” “in some embodiments,” or “in other embodiments” may each refer to one or more of the same or different embodiments in accordance with the present disclosure. A phrase in the form “A or B” means “(A), (B), or (A and B).” A phrase in the form “at least one of A, B, or C” means “(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C) ”

[00144] Any of the herein described methods, programs, algorithms or codes may be converted to, or expressed in, a programming language or computer program. The terms “programming language” and “computer program,” as used herein, each include any language used to specify instructions to a computer, and include (but is not limited to) the following languages and their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command languages, Pascal, Perl, PL1, Python, scripting languages, Visual Basic, metalanguages which themselves specify programs, and all first, second, third, fourth, fifth, or further generation computer languages. Also included are database and other data schemas, and any other meta-languages. No distinction is made between languages which are interpreted, compiled, or use both compiled and interpreted approaches. No distinction is made between compiled and source versions of a program. Thus, reference to a program, where the programming language could exist in more than one state (such as source, compiled, object, or linked) is a reference to any and all such states. Reference to a program may encompass the actual instructions and / or the intent of those instructions.

[00145] While aspects of the present disclosure have been shown in the drawings, it is not intended that the present disclosure be limited thereto, as it is intended that the present disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particular aspects. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. An apparatus, comprising:at least one processor; andat least one memory storing instructions which, when executed by the at least one processor, causes the apparatus at least to perform:transmitting, operating in a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the apparatus is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode;transitioning from the connected mode with a first cell to an idle mode or inactive mode;determining to store connected mode cell detection information for one or more cells based upon at least one criterion; andstoring, in the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

2. The apparatus of claim 1, wherein the apparatus is a user equipment.

3. A method, comprising:transmitting, by a user equipment -UE- operating m a connected mode, to a first apparatus, a first message indicating a cell detection continuity capability that the UE is capable of transitioning connected mode cell detection information from the connected mode to an idle mode or inactive mode;transitioning, by the UE, from the connected mode with a first cell to an idle mode or inactive mode;determining, by the UE, to store connected mode cell detection information for one or more cells based upon at least one criterion; andstoring, by the UE, in the idle mode or inactive mode, the connected mode cell detection information for one or more cells.

4. The method of claim 3, wherein the UE determines at least one cell of the one or more cells for which to store connected mode cell detection information.

5. The method of claim 3 or 4, wherein the at least one criterion includeswhether a cell meets LI, L2 or L3 mobility measurement criteria.

6. The method of claim 3 or 4, wherein the at least one criterion includeswhether a cell has been measured during connected mode.

7. The method of claim 3 or 4, wherein the at least one criterion includes performing, by the UE, a comparison of a signal level of a measurement performed in connected mode to a signal level of the measurement performed in idle or inactive mode, and storing the measurement performed in connected mode upon the signal level comparison falling within a threshold.

8. The method of claim 3, wherein the storing includes storing one or more identifiers identifying one or more reference signal measurements.

9. The method of claim 3 or 4, further comprising:receiving, by the UE, a second message from the first apparatus, the second message including an instruction to store connected mode cell detection information for one or more cells; andperforming, by the UE, the storing based on the second message.

10. The method of any one of claims 3 to 9, further comprising transmitting, by the UE, a third message to the first apparatus, the third message including an indication of the one or more cells for which connected mode cell detection information is maintained by the UE when transitioned to the idle mode or inactive mode.

11. The method of claim 3, further comprising measuring, by the UE, based on the connected mode cell detection information relating to the one or more cells, cell information m the idle mode or inactive mode.

12. The method of claim 10 or 11, wherein the UE omits cell detection of the one or more cells in the idle mode or inactive mode.

13. The method of any of claims 3 to 11, further comprising discarding, by the UE, the stored connected mode cell detection information after a predefined period of time, wherein the predefined period of time includes a period of time after a last measurement for the one or more cells or a period of time after a cell of the one or more cells has been detected.

14. The method of any of claims 3 to 13, wherein storing includes storing connected mode cell detection information upon cell signal strength exceeding a threshold.

15. The method of any of claims 3 to 14, wherein storing includes storing connected mode cell detection information upon cell channel quality conditions exceeding a threshold.

16. The method of any of claims 3 to 15, further comprising transitioning, by the UE, from the idle mode or inactive mode to the connected mode and using, in the transitioning, the maintained connected mode cell detection information for the one or more cells.

17. The method of claim 16, wherein the connected mode cell detection information comprises one or both of cell detection or beam index detection information for the one or more cells and, in response to transitioning to the connected state, the UE skips beam index detection for the one or more cells.

18. The method of claim 16 or 17, wherein the UE omits for the one or more cells, one or both of the cell detection or index detection.

19. A user equipment -UE-, comprising:at least one processor; andat least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to perform a method as in any of claims 3-18.5 20. A processor-readable medium storing instructions which, when executed by atleast one processor of an apparatus, cause the apparatus at least to perform a method as in any one of claims 3-18.

21. An apparatus, comprising:10 at least one processor; andat least one memory storing instructions which, when executed by the at least one processor, cause the apparatus at least to perform a method as in any of claims 3-18.

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