Patent Description:
Mobile communication has evolved significantly from early voice systems to today's highly sophisticated integrated communication platform. The next generation wireless communication system, 3GPP <NUM>th Generation (<NUM>) or New Radio (NR) will provide access to information and sharing of data anywhere, anytime by various users and applications. NR is expected to be a unified network/system that target to meet vastly different and sometime conflicting performance dimensions and services. Such diverse multi-dimensional requirements are driven by different services and applications. In general, NR will evolve based on 3GPP LTE-Advanced with additional potential new Radio Access Technologies (RATs) to enrich people lives with better, simple and seamless wireless connectivity solutions. NR will enable everything connected by wireless and deliver fast, rich contents and services.

For NR system, high frequency band communication has attracted significantly attention from the industry, since it can provide wider bandwidth to support the future integrated communication system. The beam forming is an important technology for the implementation of high frequency band system: The beam forming gain can compensate the severe path loss caused by atmospheric attenuation, improve the signal to noise ratio (SNR), and enlarge the coverage area. By aligning the transmission beam to the target UE, radiated energy is focused for higher energy efficiency, and mutual UE interference is suppressed.

<NPL>, provides some discussion regarding the relationship between IMR transmission and CSI reporting and other aspects on IMR design for NR. R1-<NUM> suggests to support UE Rx beam indication for IMR by reusing the Rx configuration of the corresponding CSI-RS, i.e. for CSI-RS resource and IMR associated with a given CSI (or CSI process), so that a UE can apply the same Rx beam derived based on CSI-RS.

<NPL> discusses options for indicating a Rx beam to the UE for transmission on the PDSCH. It is proposed that the DCI could provide a Rx beam indication for the PDSCH.

The claimed invention is defined by the independent claims.

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements.

In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of various embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the various embodiments may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of the present document, the phrase "A or B" means (A), (B), or (A and B).

In the <NUM> NR systems, beam forming will be used at both the transmission reception point (TRP) side (e.g. next generation NodeB (gNB or gNodeB)) and the UE side. The UE and the TRP should maintain the best several TRP beams and UE beams for communication and measurement. The pair of TRP transmission beam and UE reception beam changes dynamically due to the channel variation.

In order to facilitate interference measurements, the network (e.g. TRP) may configure one or more interference measurement resources (IMR) to allow interference measurements on the predetermined resources configured for the user equipment (UE). The interference measurment could be based on the periodic zero-power channel state information-reference signal (ZP CSI-RS), as used in 3GPP <NUM>th Generation (<NUM>) systems. The IMR should allow the UE to capture the interference characteristics. As will be outlined in more detail below, in 3GPP NR, the ZP CSI-RS may be used, for example, for inter-cell interference measurement (e.g. inter-TRP interference). For interference measuring, ZP CSI-RS can be transmitted from a TRP on the on the specified resource elements (REs) in an interference measurement (IM) configuration. Consequently, the UE can utilize the corresponding REs to estimate the inter-cell interference which corresponds to physical downlink shared channel (PDSCH) transmission of the neighboring transmission reception points (TRPs). The considered approach is suitable for the conventional inter-cell interference measurement and it causes relatively low overhead.

Periodic IM resource transmission using ZP CSI-RS transmitted on an IM resource for intra-cell interference measurement may be inefficient in case of Multi-User (MU)-Multiple Input Multiple Output (MIMO). For example, due to dynamic scheduling decision for MU-MIMO, the intra-cell interference realization for CSI could be dynamic. For one UE which is measuring interference on one ZP CSI-RS based resource, some other UEs without data transmission at the instance of interference measurement might send data at the instance of scheduled transmission. It leads to the interference which is not reflected on the result of interference measurement. In this case, the interference measurement based on the semi-statically configured periodic ZP CSI-RS may not be helpful enough to accurately estimate intra-cell interference from different UEs. Thus, the corresponding CSI reporting may not be able to reflect the real channel condition, which degrades the performance of link adaptation.

In order to do link adaptation, it is important to estimate the interference so that the CSI can be calculated accurately. In general, in the embodiments of the first aspect support, periodic, semi-persistent, and/or aperiodic IM resource transmission from the TRP (e.g. gNB) may be configured in an IM configuration. The IM resource (IMR) is for example based on channel state information reference signal (CSI-RS). In some embodiments, CSI-RS may be a zero power CSI-RS (ZP CSI-RS), or non-zero power CSI-RS (NZP CSI-RS). The TRP may transmit either one of the two or both kinds of CSI-RS on the configured CSI-RS based IM resource.

In embodiments of the first aspect, ZP CSI-RS could be used to obtain the inter-TRP interference. In other embodiments of the first aspect, which may be specifically useful for the MU-MIMO case, NZP CSI-RS could be used to perform interference measurement to obtain the intra-TRP interference information.

In general, the IMR configured by the network could be aperiodic, periodic or semi-persistent, as noted above. For periodic/semi-persistent CSI-RS based IMR (CSI-IM), the periodicity could be smaller than <NUM> slots, for example, <NUM> slot, especially in the scenario with burst interference. For the CSI-RS based IM configuration, the TRP (e.g. gNB) could indicate the IM resource location in both time domain and frequency domain.

In principle, and in some embodiments, the CSI-IM may be frequency division multiplexed (FDMed) with synchronization signal block (SSB) or NZP CSI-RS, if the CSI-RS based IM resource and SSB/NZP CSI-RS (used for channel measurement) are quasi co-located (QCLed). This may allow reducing the reception (Rx) beam switching. Considering the DCI decoding delay and UE Rx beam switching delay, if the time offset between DCI and a CSI-RS based IM resource is smaller than a certain threshold, the UE could apply a default or pre-configured Rx beam for interference measurement (i.e. apply a default or pre-configured spatial/QCL assumption for the Rx beam).

For periodic ZP CSI-RS based IMR, the minimum periodicity in 3GPP LTE is <NUM> subframes. In a <NUM> NR based system, the <NUM> periodicity could limit the accuracy of interference measurement, especially in the scenarios with burst interference. Due to the beam forming at both the TRP (e.g. gNB) and UE side, the burst characteristics of the neighbor cell interference could be more severe. Accordingly, it is proposed to support CSI-RS based IMR transmission with smaller periodicity than <NUM>. For example, the CSI-RS based IMR could be configured every <NUM> slot. This may provide more robust and accurate interference measurement for CSI. The periodicity of <NUM> slot for CSI-RS based IMR transmission could be similar with interference measurement based on CRS which is present in every slot. The transmission periodicity of <NUM> slot could be useful for interference measurement in the scenario with burst interference. The CSI-RS based IMR transmission slot configuration is shown as in Table <NUM>, where the parameter I is configured via higher layer signaling.

In embodiments of this disclosure, the CSI-RS based IMR configuration indicates the IMR position in both time domain and frequency domain. The IMR resource configuration may be configured by the TRP (e.g. gNB) using some control signaling (e.g. RRC signaling). In the time domain, the TRP (e.g. gNB) may for example indicate over which OFDM symbol(s) the IMR is transmitted to identify the relevant OFDM symbol(s) for measurement in a given slot. In the frequency domain, the TRP (e.g. gNB) may for example indicate the frequency offset within one physical resource block (PRB). Put differently the TRP (e.g. gNB) may indicate over which subcarriers (corresponding to REs) the CSI-RS based IMR is transmitted. For RE pattern (<NUM>, <NUM>), a <NUM>-bits bitmap could be used to indicate the frequency offset. And for RE pattern (<NUM>, <NUM>), a <NUM>-bits bitmap may be required to indicate the frequency offset.

<FIG> shows an example of different CSI-IM configurations, where the RE for CSI-RS based IMR have different frequency offsets. In <FIG> there are <NUM> REs within the PRB configured for CSI-RS based IMR, but they have different offsets in the frequency domain.

Interference measurements could be applied to a sub-band or partial band only. Thus, optionally, the CSI-RS based IMR configuration may further indicate which sub-band or partial band is applied/to be used for the interference measurement by the UE. Further optionally, the frequency granularity may also be indicated by the TRP (e.g. gNB) in the CSI-RS based IMR configuration. For example, the CSI-RS based IMR may transmitted every N PRBs, where N is configurable and may be indicated in the CSI-RS based IMR configuration.

If the CSI-RS based IMR is QCLed with a SSB, then the CSI-RS and synchronization signal block (SSB) could be FDMed, so that the UE can receive the SSB and CSI-RS based IMR with the same Rx beam. This way, the UE could measure both channel and interference in single shot so that the number of beam switching at the UE side could be reduced for CSI measurement. Similarly, the CSI-RS based IMR could be FDMed with NZP CSI-RS, if the CSI-RS based IMR and NZP CSI-RS are QCLed. In this way, the UE could measure both channel and interference in single shot so that the number of beam switching at the UE side could be reduced for CSI measurement.

For interference measurement (including ZP CSI-RS and NZP CSI-RS based interference measurement), the UE assumes that the same Rx beam should be used for interference measurement as the Rx beam indicated by the TRP (e.g. gNB) for the channel measurements.

For aperiodic CSI-RS based IMR, the UE Rx beam may be indicated by the TRP (e.g. gNB) to the UE, for example, via RRC signaling. Since the IM may be triggered over DCI, there is typically some processing delay for the DCI at the UE. Also taking into account the UE Rx beam sweeping delay, the UE could apply the Rx beam for interference measurement as indicated by the DCI, if the time offset between the DCI and CSI-RS based IMR is larger than the processing and beam sweeping delay. The processing delay (sometimes also referred to as decoding delay or scheduling delay) and the beam sweeping delay could be viewed as a threshold which is up to the UE capability. If the time offset is smaller than the threshold, the UE could apply a default/pre-configured/pre-defined/rule-based spatial assumption for interference measurement.

In some embodiments that complies with the first aspect of this disclosure, for interference measurement, e.g. in an aperiodic CSI-IM configuration, the UE assumes the same Rx beam is to be used for both interference measurement and channel measurement. If the time offset between the DCI and CSI-RS based IMR is smaller than certain threshold, the UE apply a default/pre-configured/pre-defined/rule-based spatial assumption (Rx beam) for interference measurement (i.e. QCL Type-D). If the time offset is larger than certain threshold, the UE could apply the Rx beam as indicated for interference measurement. For example, as show in <FIG>, if the time offset (scheduling offset) between the last symbol of the PDCCH carrying the triggering DCI (i.e. the DCI triggering aperiodic measurement) and the first symbol of the aperiodic ZP or NZP CSI-RS) is smaller than a threshold the UE applies a default QCL assumption.

In the <NUM> NR system, beam forming will be used at both the TRP side and the UE side. The UE and the TRP should maintain the best several TRP beams and UE beams for communication and measurement. The pair of TRP transmission beam and UE reception beam changes dynamically due to the channel variation.

In <NUM> NR, multiple use cases should be supported in a Frequency Division Duplexing (FDD) manner in NR, e.g., enhanced Mobile Broadband (eMBB), Ultra-Reliable Low Latency Communications (URLLC), and massive machine-type communications (mMTC). Consequently, different use cases occupy different parts of the whole frequency band. Thus, it may be beneficial for <NUM> NR to adopt interference measurement restriction or subset in the frequency domain. Thus, according to the second aspect, measurement restriction(s) or measurement subset(s) is introduced in frequency domain for interference measurements. According to an embodiment of this second aspect, the measurement restriction or measurement subset indicates over which partial band or physical resource block (PRB) the UE should perform interference measurement. Thus, the UE could measure the interference in specific part(s) of the wideband (only), which is/are assigned to the UE.

When multiple subsets are configured for interference measurement, the UE may - in one embodiment - report CSI for each measurement subset. When calculating RI information, different RI value could thus be obtained for different partial band part. For example, if two measurement subsets are configured for the UE, then for the first subset the RI value may be RI<NUM>, and for the second subset, the RI value may be RI<NUM>. Note that the values for channel quality indicator (CQI) and Precoder Matrix Indicator (PMI) may be calculated by the UE based on the RI for each measurement subset and may be reported in the CSI report along with the RI of the given measurement subset.

Different RI over frequency domain could confusion to the gNB scheduling. Furthermore, a per measurement subset report will also result in an increase of the CSI reported by the UE. It would be advantageous to reduce the impact on CSI reporting, even in scenarios, where interference measurement restriction or interference measurement subset(s) are defined in the frequency domain.

Therefore, in a further embodiment of this second aspect, it is proposed that, if multiple subsets are configured for interference measurement, the rank indicator (RI) is the same among the subsets. To put it different, in this embodiment the RI is the same among the subset. The UE may for example report one RI with the CSI report which is applicable to all measurement subsets that are configured by the TRP (e.g. gNB) and which are reported on by the UE.

For example, the RI could be inherited from one subset. If different RI were calculated over different subsets in frequency domain, this may otherwise cause confusion to the gNB scheduling. <FIG> shows an example highlighting the difference between the use of RI inheritance according to an embodiment (<FIG>), and non-use of RI inheritance in case different measurement subset (<FIG>), are configured.

For example, in one embodiment, CQI/ PMI/RI are calculated by the UE for the first measurement subset. <FIG> shows a process of a UE determining the CQI/PMI/RI for different measurements subsets according to an embodiment. The UE first determines <NUM> the RI for the first measurement subset (measurement subset <NUM>). It is assumed for explanation only that the RI value for this first measurement subset is RI<NUM>. The UE may then determine <NUM> CQI and PMI for the first measurement subset. If there exists more than one measurement subset (step <NUM>, yes), the UE determines <NUM> CQI and PMI for the second subset. For the second measurement subset, the RI is inherited from the first measurement subset, e.g., the RI value for the second measurement subset is also RI<NUM>. Further, the UE could calculate the CQI/PMI for the second subset based on RI<NUM>. The determination of CQI and PMI is performed for all configured measurement subsets (if more than two) using the rank indicator on RI<NUM> of the first measurement subset in a similar fashion.

When CQI/PMI (blocks <NUM>, <NUM>) and the common RI (block <NUM>) have been determined, the UE may send <NUM> a CSI report to the TRP (e.g. gNB). Note that the CQI/PMI may not need to be determined and reported for all measurement subsets, but the TRP (e.g. gNB) may request CSI for only some of the measurement subsets.

Note that in the example process of <FIG>, the RI has been determined <NUM> by the UE for the first measurement subset (as a "common RI"), and is then used in the determination of CQI and PMI of all measurement subsets. There may also be different options on how to calculate the RI value that is to be applied to all measurement subsets. The following options may be used to determine the common RI value:.

In yet another embodiment according to the second aspect, RI/PMI/CQI for each subset can be reported to the TRP (e.g. gNB) for frequency selective precoding. Whether a common RI or multiple RIs can be reported should be pre-defined or configured by higher layer signaling or determined by the bandwidth for a subset. For example, the RI for each bandwidth part (BWP) can be reported independently.

As noted in several examples herein above, aperiodic IM can be triggered by DCI. The configuration of an aperiodic IMR could be through higher layer signaling, e.g., Radio Resource Control (RRC) signaling/messages. Optionally, a media access control (MAC) control element (CE) could be further used to select a set of candidate IMR among the resource configured by RRC. For example, through RRC signaling, the gNB could configure - for example - <NUM> CSI-RS resources for interference measurement. A MAC CE could select <NUM> of the <NUM> configured CSI-RS resources as candidate to be monitored for the UE for measurements. A DCI will trigger to activate one IM resource configuration for interference measurement.

The triggering of aperiodic IM could be optionally combined with the uplink grant for CSI reporting. For example, the TRP (e.g. gNB) could signal DCI (on PDCCH) that contains an uplink resource assignment for the aperiodic CSI report. The DCI may include a field that triggers or activates an aperiodic CSI report based on selected ones of the configured CSI-RS resources for IM. Due to the latency of control information processing, time offset should be considered between the DCI and when the IMR is present.

If the IMR indicates that the UE should use a different Rx beam with the current one, there should be more delay to be take into account due to the UE Rx beam switching. The offset could be preconfigured or up to UE capability.

In some embodiments, besides the resource information of the IMR configuration, the IMR configuration could also indicate the measurement restriction/subset information. The measurement restriction/subset information may indicate whether the interference measurement should be applied to subset in frequency domain.

Generally, interference measurements can be performed using ZP and NZP CSI-RS, for example for a given IMR configuration, or NZP CSI-RS could also be used (in the alternative or in addition to CSI-IM) for interference measurement. For NZP CSI-RS based interference measurement, there could be two ways for interference measurement, one is using colliding NZP CSI-RS (e.g. the TRP(s) transmit NZP CSI-RSs to different UEs on the same resources), and the other one is interference emulation.

In an embodiment, interference emulation is used. The UE may feedback interference information as many CQI combinations as possible. However, the signaling overhead may an issue. Therefore, in another embodiment, the UE reports a single CQI covering all the configured NZP CSI-RS. For example, if the gNB configures <NUM> NZP CSI-RS resources, the UE will measure interference from all the NZP CSI-RS.

Another possibility is that the UE performs blind detection. If the interference from another user is negligible, it will be ignored. Only the interference of other users which is higher than certain threshold will be considered for CQI calculation. When reporting the CQI, the UE should also indicate to the gNB about the combination (UE pairing) considered for CQI calculation.

Depending on the Rx beam at the UE, the interference characteristics experienced by UE receiver could be different. Therefore, in one embodiment, it is indicated which Rx beam the UE should use for interference measurement. Since SSB could be used for beam management, the UE Rx beam indication for interference measurement could be QCLed with CSI-RS or SSB. In the scenario of carrier aggregation, if different sub-band subsets (component carriers) are configured belonging to different TRPs, the IMR configuration could indicate which Rx beam can be used for different sub-band subsets.

In an embodiment, the UE Rx beam should be indicated for interference measurement. The UE Rx beam indication may be for example indicated to the UE be together with IMR. The indication could be QCLed with CSI-RS or SSB. Hence, some ZP CSI-RS or NZP CSI-RS for interference measurement can be QCLed with CSI-RS or SSB, which can be pre-defined or configured by higher layer signaling or DCI. In the scenario of carrier aggregation, if different sub-band subsets (component carrier) are configured belonging to different TRPs, the IMR configuration could indicate which Rx beam can be used for different sub-band subsets.

<FIG> illustrates an architecture of a system <NUM> of a network in accordance with some embodiments. The system <NUM> is shown to include a user equipment (UE) <NUM> and a UE <NUM>. The UEs <NUM> and <NUM> are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface.

In some embodiments, any of the UEs <NUM> and <NUM> can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

The UEs <NUM> and <NUM> may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) <NUM> - the RAN <NUM> may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs <NUM> and <NUM> utilize connections <NUM> and <NUM>, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections <NUM> and <NUM> are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation (<NUM>) protocol, a New Radio (NR) protocol, and the like.

Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced the control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations.

The RAN <NUM> is shown to be communicatively coupled to a core network (CN) <NUM> -via an S1 interface <NUM>. In embodiments, the CN <NUM> may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment the S1 interface <NUM> is split into two parts: the S1-U interface <NUM>, which carries traffic data between the RAN nodes <NUM> and <NUM> and the serving gateway (S-GW) <NUM>, and the S1-mobility management entity (MME) interface <NUM>, which is a signaling interface between the RAN nodes <NUM> and <NUM> and MMEs <NUM>.

<FIG> illustrates an architecture of a system <NUM> of a network in accordance with some embodiments. The system <NUM> is shown to include a UE <NUM>, which may be the same or similar to UEs <NUM> and <NUM> discussed previously; a RAN node <NUM>, which may be the same or similar to RAN nodes <NUM> and <NUM> discussed previously; a User Plane Function (UPF) <NUM>; a Data network (DN) <NUM>, which may be, for example, operator services, Internet access or 3rd party services; and a <NUM> Core Network (5GC or CN) <NUM>.

The CN <NUM> may include an Authentication Server Function (AUSF) <NUM>; a Core Access and Mobility Management Function (AMF) <NUM>; a Session Management Function (SMF) <NUM>; a Network Exposure Function (NEF) <NUM>; a Policy Control function (PCF) <NUM>; a Network Function (NF) Repository Function (NRF) <NUM>; a Unified Data Management (UDM) <NUM>; and an Application Function (AF) <NUM>. The CN <NUM> may also include other elements that are not shown, such as a Structured Data Storage network function (SDSF), an Unstructured Data Storage network function (UDSF), and the like.

The UPF <NUM> may act as an anchor point for intra-RAT and inter-RAT mobility, an external PDU session point of interconnect to DN <NUM>, and a branching point to support multi-homed PDU session. The UPF <NUM> may also perform packet routing and forwarding, packet inspection, enforce user plane part of policy rules, lawfully intercept packets (UP collection); traffic usage reporting, perform QoS handling for user plane (e.g., packet filtering, gating, UL/DL rate enforcement), perform Uplink Traffic verification (e.g., SDF to QoS flow mapping), transport level packet marking in the uplink and downlink, and downlink packet buffering and downlink data notification triggering. UPF <NUM> may include an uplink classifier to support routing traffic flows to a data network. The DN <NUM> may represent various network operator services, Internet access, or third party services. NY <NUM> may include, or be similar to application server <NUM> discussed previously.

The AUSF <NUM> may store data for authentication of UE <NUM> and handle authentication related functionality. The AUSF <NUM> may facilitate a common authentication framework for various access types.

The AMF <NUM> may be responsible for registration management (e.g., for registering UE <NUM>, etc.), connection management, reachability management, mobility management, and lawful interception of AMF-related events, and access authentication and authorization. AMF <NUM> may provide transport for SM messages between and SMF <NUM>, and act as a transparent proxy for routing SM messages. AMF <NUM> may also provide transport for short message service (SMS) messages between UE <NUM> and an SMS function (SMSF) (not shown by <FIG>). AMF <NUM> may act as Security Anchor Function (SEA), which may include interaction with the AUSF <NUM> and the UE <NUM>, receipt of an intermediate key that was established as a result of the UE <NUM> authentication process. Where USIM based authentication is used, the AMF <NUM> may retrieve the security material from the AUSF <NUM>. AMF <NUM> may also include a Security Context Management (SCM) function, which receives a key from the SEA that it uses to derive access-network specific keys. Furthermore, AMF <NUM> may be a termination point of RAN CP interface (N2 reference point), a termination point of NAS (N1) signalling, and perform NAS ciphering and integrity protection.

AMF <NUM> may also support NAS signalling with a UE <NUM> over an N3 interworking-function (IWF) interface. The N3IWF may be used to provide access to untrusted entities. N33IWF may be a termination point for the N2 and N3 interfaces for control plane and user plane, respectively, and as such, may handle N2 signalling from SMF and AMF for PDU sessions and QoS, encapsulate/de-encapsulate packets for IPSec and N3 tunnelling, mark N3 user-plane packets in the uplink, and enforce QoS corresponding to N3 packet marking taking into account QoS requirements associated to such marking received over N2. N3IWF may also relay uplink and downlink control-plane NAS (N1) signalling between the UE <NUM> and AMF <NUM>, and relay uplink and downlink user-plane packets between the UE <NUM> and UPF <NUM>. The N3IWF also provides mechanisms for IPsec tunnel establishment with the UE <NUM>.

The SMF <NUM> may be responsible for session management (e.g., session establishment, modify and release, including tunnel maintain between UPF and AN node); UE IP address allocation & management (including optional Authorization); Selection and control of UP function; Configures traffic steering at UPF to route traffic to proper destination; termination of interfaces towards Policy control functions; control part of policy enforcement and QoS; lawful intercept (for SM events and interface to LI System); termination of SM parts of NAS messages; downlink Data Notification; initiator of AN specific SM information, sent via AMF over N2 to AN; determine SSC mode of a session. The SMF <NUM> may include the following roaming functionality: handle local enforcement to apply QoS SLAs (VPLMN); charging data collection and charging interface (VPLMN); lawful intercept (in VPLMN for SM events and interface to LI System); support for interaction with external DN for transport of signalling for PDU session authorization/authentication by external DN.

The NEF <NUM> may provide means for securely exposing the services and capabilities provided by 3GPP network functions for third party, internal exposure/re-exposure, Application Functions (e.g., AF <NUM>), edge computing or fog computing systems, etc. In such embodiments, the NEF <NUM> may authenticate, authorize, and/or throttle the AFs. NEF <NUM> may also translate information exchanged with the AF 628and information exchanged with internal network functions. For example, the NEF <NUM> may translate between an AF-Service-Identifier and an internal 5GC information. NEF <NUM> may also receive information from other network functions (NFs) based on exposed capabilities of other network functions. This information may be stored at the NEF <NUM> as structured data, or at a data storage NF using a standardized interfaces. The stored information can then be re-exposed by the NEF <NUM> to other NFs and AFs, and/or used for other purposes such as analytics.

The NRF <NUM> may support service discovery functions, receive NF Discovery Requests from NF instances, and provide the information of the discovered NF instances to the NF instances. NRF <NUM> also maintains information of available NF instances and their supported services.

The PCF <NUM> may provide policy rules to control plane function(s) to enforce them, and may also support unified policy framework to govern network behaviour. The PCF <NUM> may also implement a front end (FE) to access subscription information relevant for policy decisions in a UDR of UDM <NUM>.

The UDM <NUM> may handle subscription-related information to support the network entities' handling of communication sessions, and may store subscription data of UE <NUM>. The UDM <NUM> may include two parts, an application FE and a User Data Repository (UDR). The UDM may include a UDM FE, which is in charge of processing of credentials, location management, subscription management and so on. Several different front ends may serve the same user in different transactions. The UDM-FE accesses subscription information stored in the UDR and performs authentication credential processing; user identification handling; access authorization; registration/mobility management; and subscription management. The UDR may interact with PCF <NUM>. UDM <NUM> may also support SMS management, wherein an SMS-FE implements the similar application logic as discussed previously.

The AF <NUM> may provide application influence on traffic routing, access to the Network Capability Exposure (NCE), and interact with the policy framework for policy control. The NCE may be a mechanism that allows the 5GC and AF <NUM> to provide information to each other via NEF <NUM>, which may be used for edge computing implementations. In such implementations, the network operator and third party services may be hosted close to the UE <NUM> access point of attachment to achieve an efficient service delivery through the reduced end-to-end latency and load on the transport network. For edge computing implementations, the 5GC may select a UPF <NUM> close to the UE <NUM> and execute traffic steering from the UPF <NUM> to DN <NUM> via the N6 interface. This may be based on the UE subscription data, UE location, and information provided by the AF <NUM>. In this way, the AF <NUM> may influence UPF (re)selection and traffic routing. Based on operator deployment, when AF <NUM> is considered to be a trusted entity, the network operator may permit AF <NUM> to interact directly with relevant NFs.

As discussed previously, the CN <NUM> may include an SMSF, which may be responsible for SMS subscription checking and verification, and relaying SM messages to/from the UE <NUM> to/from other entities, such as an SMS-GMSC/IWMSC/SMS-router. The SMS may also interact with AMF <NUM> and UDM <NUM> for notification procedure that the UE <NUM> is available for SMS transfer (e.g., set a UE not reachable flag, and notifying UDM <NUM> when UE <NUM> is available for SMS).

The system <NUM> may include the following service-based interfaces: Namf: Service-based interface exhibited by AMF; Nsmf: Service-based interface exhibited by SMF; Nnef: Service-based interface exhibited by NEF; Npcf: Service-based interface exhibited by PCF; Nudm: Service-based interface exhibited by UDM; Naf: Service-based interface exhibited by AF; Nnrf: Service-based interface exhibited by NRF; and Nausf: Service-based interface exhibited by AUSF.

The system <NUM> may include the following reference points: N1: Reference point between the UE and the AMF; N2: Reference point between the (R)AN and the AMF; N3: Reference point between the (R)AN and the UPF; N4: Reference point between the SMF and the UPF; and N6: Reference point between the UPF and a Data Network. There may be many more reference points and/or service-based interfaces between the NF services in the NFs, however, these interfaces and reference points have been omitted for clarity. For example, an N5 reference point may be between the PCF and the AF; an N7 reference point may be between the PCF and the SMF; an N11 reference point between the AMF and SMF; etc. In some embodiments, the CN <NUM> may include an Nx interface, which is an inter-CN interface between the MME (e.g., MME <NUM>) and the AMF <NUM> in order to enable interworking between CN <NUM> and CN <NUM>.

Although not shown by <FIG>, system <NUM> may include multiple RAN nodes <NUM> wherein an Xn interface is defined between two or more RAN nodes <NUM> (e.g., gNBs and the like) that connecting to 5GC <NUM>, between a RAN node <NUM> (e.g., gNB) connecting to 5GC <NUM> and an eNB (e.g., a RAN node <NUM> of <FIG>), and/or between two eNBs connecting to 5GC <NUM>.

In some implementations, the Xn interface may include an Xn user plane (Xn-U) interface and an Xn control plane (Xn-C) interface. The Xn-U may provide non-guaranteed delivery of user plane PDUs and support/provide data forwarding and flow control functionality. The Xn-C may provide management and error handling functionality, functionality to manage the Xn-C interface; mobility support for UE <NUM> in a connected mode (e.g., CM-CONNECTED) including functionality to manage the UE mobility for connected mode between one or more RAN nodes <NUM>. The mobility support may include context transfer from an old (source) serving RAN node <NUM> to new (target) serving RAN node <NUM>; and control of user plane tunnels between old (source) serving RAN node <NUM> to new (target) serving RAN node <NUM>.

A protocol stack of the Xn-U may include a transport network layer built on Internet Protocol (IP) transport layer, and a GTP-U layer on top of a UDP and/or IP layer(s) to carry user plane PDUs. The Xn-C protocol stack may include an application layer signaling protocol (referred to as Xn Application Protocol (Xn-AP)) and a transport network layer that is built on an SCTP layer. The SCTP layer may be on top of an IP layer. The SCTP layer provides the guaranteed delivery of application layer messages. In the transport IP layer point-to-point transmission is used to deliver the signaling PDUs. In other implementations, the Xn-U protocol stack and/or the Xn-C protocol stack may be same or similar to the user plane and/or control plane protocol stack(s) shown and described herein.

<FIG> illustrates example components of a device <NUM> in accordance with some embodiments. In some embodiments, the device <NUM> may include application circuitry <NUM>, baseband circuitry <NUM>, Radio Frequency (RF) circuitry <NUM>, front-end module (FEM) circuitry <NUM>, one or more antennas <NUM>, and power management circuitry (PMC) <NUM> coupled together at least as shown. The components of the illustrated device <NUM> may be included in a UE or a RAN node. In some embodiments, the device <NUM> may include less elements (e.g., a RAN node may not utilize application circuitry <NUM>, and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device <NUM> may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

The baseband circuitry <NUM> may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry <NUM> and to generate baseband signals for a transmit signal path of the RF circuitry <NUM>. Baseband processing circuity <NUM> may interface with the application circuitry <NUM> for generation and processing of the baseband signals and for controlling operations of the RF circuitry <NUM>. For example, in some embodiments, the baseband circuitry <NUM> may include a third generation (<NUM>) baseband processor 704A, a fourth generation (<NUM>) baseband processor 704B, a fifth generation (<NUM>) baseband processor 704C, or other baseband processor(s) 704D for other existing generations, generations in development or to be developed in the future (e.g., second generation (<NUM>), sixth generation (<NUM>), etc.). The baseband circuitry <NUM> (e.g., one or more of baseband processors 704A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry <NUM>. In other embodiments, some or all of the functionality of baseband processors 704A-D may be included in modules stored in the memory <NUM> and executed via a Central Processing Unit (CPU) 704E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry <NUM> may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry <NUM> may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry <NUM> may include one or more audio digital signal processor(s) (DSP) 704F. The audio DSP(s) 704F may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry <NUM> and the application circuitry <NUM> may be implemented together such as, for example, on a system on a chip (SOC).

RF circuitry <NUM> may enable communication with wireless networks
using modulated electromagnetic radiation through a non-solid medium.

In some embodiments, the receive signal path of the RF circuitry <NUM> may include mixer circuitry 706a, amplifier circuitry 706b and filter circuitry 706c. In some embodiments, the transmit signal path of the RF circuitry <NUM> may include filter circuitry 706c and mixer circuitry 706a. RF circuitry <NUM> may also include synthesizer circuitry 706d for synthesizing a frequency for use by the mixer circuitry 706a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 706a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry <NUM> based on the synthesized frequency provided by synthesizer circuitry 706d. The amplifier circuitry 706b may be configured to amplify the down-converted signals and the filter circuitry 706c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry <NUM> for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 706a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 706a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 706d to generate RF output signals for the FEM circuitry <NUM>. The baseband signals may be provided by the baseband circuitry <NUM> and may be filtered by filter circuitry 706c.

In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 706a of the receive signal path and the mixer circuitry 706a of the transmit signal path may be configured for super-heterodyne operation.

In some embodiments, the synthesizer circuitry 706d may be a fractional-N synthesizer or a fractional N/N+<NUM> synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 706d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer circuitry 706d may be configured to synthesize an output frequency for use by the mixer circuitry 706a of the RF circuitry <NUM> based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 706d may be a fractional N/N+<NUM> synthesizer.

Synthesizer circuitry 706d of the RF circuitry <NUM> may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+<NUM> (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

In some embodiments, synthesizer circuitry 706d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry <NUM> may include an IQ/polar converter.

While <FIG> shows the PMC <NUM> coupled only with the baseband circuitry <NUM>. However, in other embodiments, the PMC <NUM><NUM> may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry <NUM>, RF circuitry <NUM>, or FEM <NUM>.

If there is no data traffic activity for an extended period of time, then the device <NUM> may transition off to an RRC_Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device <NUM> goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device <NUM> may not receive data in this state, in order to receive data, it must transition back to RRC_Connected state.

<FIG> illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry <NUM> of <FIG> may comprise processors 704A-704E and a memory <NUM> utilized by said processors. Each of the processors 704A-704E may include a memory interface, 804A-804E, respectively, to send/receive data to/from the memory <NUM>.

<FIG> is an illustration of a control plane protocol stack in accordance with some embodiments. In this embodiment, a control plane <NUM> is shown as a communications protocol stack between the UE <NUM> (or alternatively, the UE <NUM>), the RAN node <NUM> (or alternatively, the RAN node <NUM>), and the MME <NUM>.

The PHY layer <NUM> may transmit or receive information used by the MAC layer <NUM> over one or more air interfaces. The PHY layer <NUM> may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC layer <NUM>. The PHY layer <NUM> may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and Multiple Input Multiple Output (MIMO) antenna processing.

The MAC layer <NUM> may perform mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) from one or more logical channels onto transport blocks (TB) to be delivered to PHY via transport channels, de-multiplexing MAC SDUs to one or more logical channels from transport blocks (TB) delivered from the PHY via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), and logical channel prioritization.

The RLC layer <NUM> may operate in a plurality of modes of operation, including: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer <NUM> may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC layer <NUM> may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment.

The PDCP layer <NUM> may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

The main services and functions of the RRC layer <NUM> may include broadcast of system information (e.g., included in Master Information Blocks (MIBs) or System Information Blocks (SIBs) related to the non-access stratum (NAS)), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting. Said MIBs and SIBs may comprise one or more information elements (IEs), which may each comprise individual data fields or data structures.

The UE <NUM> and the RAN node <NUM> may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack comprising the PHY layer <NUM>, the MAC layer <NUM>, the RLC layer <NUM>, the PDCP layer <NUM>, and the RRC layer <NUM>.

The non-access stratum (NAS) protocols <NUM> form the highest stratum of the control plane between the UE <NUM> and the MME <NUM>. The NAS protocols <NUM> support the mobility of the UE <NUM> and the session management procedures to establish and maintain IP connectivity between the UE <NUM> and the P-GW <NUM>.

The S1 Application Protocol (S1-AP) layer <NUM> may support the functions of the S1 interface and comprise Elementary Procedures (EPs). An EP is a unit of interaction between the RAN node <NUM> and the CN <NUM>. The S1-AP layer services may comprise two groups: UE-associated services and non UE-associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer.

The Stream Control Transmission Protocol (SCTP) layer (alternatively referred to as the SCTP/IP layer) <NUM> may ensure reliable delivery of signaling messages between the RAN node <NUM> and the MME <NUM> based, in part, on the IP protocol, supported by the IP layer <NUM>. The L2 layer <NUM> and the L1 layer <NUM> may refer to communication links (e.g., wired or wireless) used by the RAN node and the MME to exchange information.

The RAN node <NUM> and the MME <NUM> may utilize an S1-MME interface to exchange control plane data via a protocol stack comprising the L1 layer <NUM>, the L2 layer <NUM>, the IP layer <NUM>, the SCTP layer <NUM>, and the S1-AP layer <NUM>.

<FIG> is an illustration of a user plane protocol stack in accordance with some embodiments. In this embodiment, a user plane <NUM> is shown as a communications protocol stack between the UE <NUM> (or alternatively, the UE <NUM>), the RAN node <NUM> (or alternatively, the RAN node <NUM>), the S-GW <NUM>, and the P-GW <NUM>. The user plane <NUM> may utilize at least some of the same protocol layers as the control plane <NUM>. For example, the UE <NUM> and the RAN node <NUM> may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange user plane data via a protocol stack comprising the PHY layer <NUM>, the MAC layer <NUM>, the RLC layer <NUM>, the PDCP layer <NUM>.

The General Packet Radio Service (GPRS) Tunneling Protocol for the user plane (GTP-U) layer <NUM> may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. The UDP and IP security (UDP/IP) layer <NUM> may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication on the selected data flows. The RAN node <NUM> and the S-GW <NUM> may utilize an S1-U interface to exchange user plane data via a protocol stack comprising the L1 layer <NUM>, the L2 layer <NUM>, the UDP/IP layer <NUM>, and the GTP-U layer <NUM>. The S-GW <NUM> and the P-GW <NUM> may utilize an S5/S8a interface to exchange user plane data via a protocol stack comprising the L1 layer <NUM>, the L2 layer <NUM>, the UDP/IP layer <NUM>, and the GTP-U layer <NUM>. As discussed above with respect to <FIG>, NAS protocols support the mobility of the UE <NUM> and the session management procedures to establish and maintain IP connectivity between the UE <NUM> and the P-GW <NUM>.

<FIG> is a block diagram illustrating components, according to some example embodiments, able to read instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, <FIG> shows a diagrammatic representation of hardware resources <NUM> including one or more processors (or processor cores) <NUM>, one or more memory/storage devices <NUM>, and one or more communication resources <NUM>, each of which may be communicatively coupled via a bus <NUM>. For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor <NUM> may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources <NUM>.

For example, the communication resources <NUM> may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, Bluetooth components (e.g., Bluetooth Low Energy), Wi-Fi components, and other communication components.

Instructions <NUM> may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors <NUM> to perform any one or more of the methodologies discussed herein. The instructions <NUM> may reside, completely or partially, within at least one of the processors <NUM> (e.g., within the processor's cache memory), the memory/storage devices <NUM>, or any suitable combination thereof. Furthermore, any portion of the instructions <NUM> may be transferred to the hardware resources <NUM> from any combination of the peripheral devices <NUM> or the databases <NUM>. Accordingly, the memory of processors <NUM>, the memory/storage devices <NUM>, the peripheral devices <NUM>, and the databases <NUM> are examples of computer-readable and machine-readable media.

Claim 1:
A method comprising:
configuring an aperiodic interference measurement, IM, resource of a user equipment, UE (<NUM>, <NUM>), wherein the aperiodic IM resource is based on channel state information, CSI,-reference signal, RS, CSI-RS, wherein the CSI-RS is a zero power CSI-RS, ZP CSI-RS, or a non-zero power CSI-RS, NZP CSI-RS,
wherein the UE (<NUM>, <NUM>) assumes the same Rx beam to be used for both, interference measurement and channel measurement, and
characterized in that
if a time offset between a downlink control information, DCI, triggering the CSI-RS, and the CSI-RS based aperiodic IM resource is smaller than a threshold, the UE (<NUM>, <NUM>) applies a default spatial assumption for interference measurement, and if said time offset is larger than certain threshold, the UE (<NUM>, <NUM>) applies the Rx beam as indicated for interference measurement.