Methods, user equipment and network nodes for triggering measurement-related actions

Abstract

A method performed by a UE (140) is disclosed. The method comprises receiving (202) a first downlink reference signal (160) having a first beamforming gain from the first network node (130); receiving (206) a second downlink reference signal (190) having a second beamforming gain from a second network node (132); determining (208) a second signal power indicator value of the second downlink reference signal (190); determining (210) whether to trigger the measurement-related action, based on the first signal power indicator value and the second signal power indicator value, wherein the determined (204) first signal power indicator value of the first downlink reference signal (160) is offset with a first offset value based on information related to the first beamforming gain, and the determined (208) second signal power indicator value (190) is offset with a second offset value based on information related to the second beamforming gain.

Description

METHODS, USER EQUIPMENT AND NETWORK NODES FOR TRIGGERINGMEASUREMENT-RELATED ACTIONSTECHNICAL FIELD

[0001] The present disclosure relates generally to methods, user equipment and network nodes for triggering measurement-related actions. The present disclosure further relates to computer programs and carriers corresponding to the methods, user equipment and network nodes.BACKGROUND

[0002] Optimizing energy consumption is a requirement of mobile network design. Optimizing energy performance is often designed as minimizing the energy consumption while keeping fulfilling a set of performance requirements, e.g., user throughput, capacity, latency, etc. An energy efficient standard can only enable a low energy consuming operation by creating opportunities to deactivate hardware components for long time durations and time fractions.

[0003] One concern in the design of 5G NR that often prevents energy saving optimizations is that several functions with vastly different requirements are coupled together via a synchronization signal block (SSB) signal, e.g., a SSB signal in idle mode can be used for system information broadcasting, cell search, Random Access Channel (RACH) process and paging; a SSB signal in connected mode can be used for mobility measurements, serving cell measurements, non-serving cell measurements, synchronization, Channel State Information (CSI) report, etc. On the other hand, lean design in 6G is also considered. The concept of lean design is to minimize transmission not related to data transfers. The lean design concept has been a tremendous success, enabling much larger energy savings due to microsleep transmission than any previous generation.

[0004] The 6G lean design concept can be summarized as follows:• Enhanced lean design in time domain: This implies further reducing the timedomain footprint of idle mode signals, to align discontinuous reception on the UE side with discontinuous transmission on the network side, and vice versa, and to further enhance opportunities for micro-sleep reception in addition tomicro-sleep transmission. To some extent, this work has already started in the ongoing 3GPP Work Item on Network Energy Efficiency targeting Rel-18 and Rel-19.• Extending lean design to the node / transmission-reception point (TRP) domain: Here the idle-mode and active mode separation is key. System information (SI) transmission can occur from a sub-set of the TRPs and more than one TRP can transmit SI using Single Frequency Network (SFN) transmission. Nodes with no responsibility for SI broadcast can be activated and deactivated with no impact on the SI broadcast and other idle mode functions.• Extend lean design to the frequency domain: Improved solution in 6G further enables Sl-free carriers. Also, not all carriers need downlink mobility reference signal (RS) transmissions, and mobility RS signals on some carriers can have extended periodicity. In 6G there will therefore be different carriers that are configured differently.

[0005] In conclusion, from both the energy saving point of view and the lean design point of view, it is important to define separate signals for idle and connected mode procedures. To simplify UE implementation, it is beneficial if the signals used for idle and connected mode follow a similar structure. This can be achieved by defining multiple types of SSBs.

[0006] For example, the following types of SSB signals can be defined, according to different purposes:• Idle mode SSB (l-SSB) signal: used in idle mode. It is transmitted on the idle mode search grid. A master information block (MIB) field in the l-SSB provides information on how to receive idle-mode system information. In 5G NR terminology, this is like the cell defining SSB (CD-SSB).• Mobility SSB (M-SSB) signal: used for mobility in connected mode. It is transmitted periodically, a-periodically, in bursts, or not at all, as dynamically decided by the network. This is a downlink signal that may be used for mobility measurements, e.g., to determine if a handover is needed. The MIB in the M-SSB does not point to any system information, but preferably contains an identity associated with a specific beam or TRP in the network, aka a network node. The UE does not need to be configured with a specific list of M-SSBs to search for but can, given some information about where in the time-frequency resource space to search, “blindly” find the M-SSBs transmitted, read and report its identity.• Extended periodicity SSB (E-SSB) signal: Not detectable by idle mode UEs, but otherwise similar to the l-SSB. It is periodically transmitted with a long- extended periodicity.• Dynamic SSB or Dedicated SSB (D-SSB) signal: this signal may be used as quasi co-location (QCL) root for serving cell measurements and functions in connected mode.

[0007] Above are only examples of different types of SSB signals, more types of different signals with different names than SSB signals can be defined in a future 6G radio access technology (RAT).

[0008] Mobility measurements for connected mode mobility are performed by the UE on both the serving cell and neighbor cells. An overview of the measurement procedure is disclosed in section 9.2.4 Measurements of the NR and NG-RAN Overall Description; Stage 2, 38.300 v18.1.0. SSB signals can be used as reference signals for mobility measurements.

[0009] The UE may be configured to transmit measurement reports (MR) to the network node. Typically, event-based reporting is configured, which means that a MR is triggered when a measurement event (ME) occurs. The typical MEs can be for example: Event A1 : Reference signal power of the serving cell becomes better than a threshold; Event A2: Reference signal power of serving cell becomes worse than a threshold; Event A3: Reference signal power of the neighbor cell becomes threshold better than a special cell (SpCell); Event A4: Reference signal power of the neighbor cell becomes better than a threshold; Event A5: Reference signal power of the SpCell becomes worse than threshold 1 and reference signal power of the neighbor cellbecomes better than threshold 2; Event A6: Reference signal power of the neighbor cell becomes threshold better than a secondary cell (SCe II).

[0010] As discussed above, multiple signals, e.g., different types of SSB signals are used as reference signals for mobility measurements. Consequently, there is a need of a solution to deal with the multiple types of signals.SUMMARY

[0011] It is an object of the invention to address the problem and issues outlined above. It is an object of the invention to deal with multiple types of signals as reference signals for mobility measurements. It is possible to achieve these objects and others by using the methods and network nodes as defined in the attached claims.

[0012] According to one aspect, a method performed by a User Equipment, UE is disclosed. The UE is used for triggering a measurement-related action, the UE being wirelessly connected to a first network node, the method comprising: receiving a first downlink reference signal having a first beamforming gain from the first network node; determining a first signal power indicator value of the first downlink reference signal, wherein the determined first signal power indicator value of the first downlink reference signal is offset with a first offset value based on information related to the first beamforming gain; receiving a second downlink reference signal having a second beamforming gain from a second network node; determining a second signal power indicator value of the second downlink reference signal, wherein the determined second signal power indicator value is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; determining whether to trigger the measurement-related action, based on the determined first signal power indicator value of the first downlink reference signal and the determined second signal power indicator value of the second downlink reference signal.

[0013] According to another aspect, a method performed by a first network node is disclosed. The first network node is wirelessly connected to a User Equipment, UE, the method comprising: sending a first offset value to the UE , the first offset value isbased on information related to a first beamforming gain of a first downlink reference signal; sending the first downlink reference signal with the first beamforming gain to the UE, wherein whether to trigger a measurement-related action from the UE is determined based on a first signal power indicator value of the first downlink reference signal and the first offset value.

[0014] According to another aspect, a User Equipment, UE configured for triggering a measurement-related action is disclosed. The UE is operative for wirelessly connecting to a first network node, the UE comprising a communication unit, a processing circuitry and a memory, said memory containing instructions executable by said processing circuitry, whereby the UE is operative for: receiving a first downlink reference signal having a first beamforming gain from the first network node; determining a first signal power indicator value of the first downlink reference signal, wherein the determined first signal power indicator value of the first downlink reference signal is offset with a first offset value based on information related to the first beamforming gain; receiving a second downlink reference signal having a second beamforming gain from a second network node; determining a second signal power indicator value of the second downlink reference signal, wherein the determined second signal power indicator value is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; determining whether to trigger the measurement-related action, based on the determined first signal power indicator value of the first downlink reference signal and the determined second signal power indicator value of the second downlink reference signal.

[0015] According to another aspect, a first network node is disclosed. The first network node is operative for wirelessly connecting to a User Equipment, UE, the first network node comprising a communication unit, a processing circuitry and a memory, said memory containing instructions executable by said processing circuitry, whereby the first network node is operative for: sending a first offset value to the UE, the first offset value is based on information related to a first beamforming gain of a first downlink reference signal; sending the first downlink reference signal with the first beamforming gain to the UE, wherein whether to trigger a measurement-relatedaction from the UE is determined based on a first signal power indicator value of the first downlink reference signal and the first offset value.

[0016] According to other aspects, computer programs and carriers are also provided, the details of which will be described in the claims and the detailed description.

[0017] With the solutions in the application, signaling overhead for mobility measurement reporting can be reduced. The number of handover failures and / or radio link failures can also be reduced. The mobility performance and overall stability is increased, and end user experience is improved. Further possible features and benefits of this solution will become apparent from the detailed description below.BRIEF DESCRIPTION OF DRAWINGS

[0018] The solution will now be described in more detail by means of exemplary embodiments and with reference to the accompanying drawings, in which:

[0019] Fig. 1 is a schematic block diagram of a wireless communication network in which the present invention may be implemented.

[0020] Fig. 2 is a schematic block diagram of the wireless communication network, when the method of the UE is performed, according to exemplary embodiments.

[0021] Fig. 3 is a flow chart illustrating a method performed by a UE, according to exemplary embodiments.

[0022] Fig. 4 is another schematic block diagram of the wireless communication network, when the method of the UE is performed, according to exemplary embodiments.

[0023] Fig. 5 is a flow chart illustrating a method performed by a network node, according to exemplary embodiments.

[0024] Fig. 6 is a block diagram illustrating a UE in more detail, according to exemplary embodiments.

[0025] Fig. 7 is a block diagram illustrating a network node in more detail, according to exemplary embodiments.DETAILED DESCRIPTION

[0026] Fig. 1 shows a wireless communication network comprising a network node 130 that is in, or is adapted for, wireless communication with a wireless device 140, i.e. , UE. The network node 130 provides radio coverage in a cell 150, which can be interpreted as a geographical area. The wireless devices 140 shown in fig. 1 resides in the cell 150 and is served by the network node 130. The wireless communication network may be any kind of wireless communication network that can provide radio access to wireless communication devices. Example of such wireless communication networks are Global System for Mobile communication (GSM), Enhanced Data Rates for GSM Evolution (EDGE), Universal Mobile Telecommunications System (UMTS), Code Division Multiple Access 2000 (CDMA 2000), Long Term Evolution (LTE) Frequency Division Duplex (FDD) and Time Division Duplex (TDD), LTE Advanced, Wireless Local Area Networks (WLAN), Worldwide Interoperability for Microwave Access (WiMAX), WiMAX Advanced, as well as 5G wireless communication networks based on technology such as New Radio (NR).

[0027] The network node 130 may be any kind of network node that provides wireless access to the wireless device 140. The network node 130 may also be called radio network node. Examples of a network node 130 are a base station (BS), a radio BS, a base transceiver station, a BS controller, a network controller, a Node B (NB), an evolved Node B (eNB), a gNodeB (gNB), a Multi-cell / multicast Coordination Entity, a relay node, an access point (AP), a radio AP, a remote radio unit (RRU), a remote radio head (RRH), nodes in a distributed antenna system (DAS), Transmission point (TRP) and a multi-standard radio BS (MSR BS).

[0028] The wireless device 140 may be any type of device capable of wirelessly communicating with a network node 130 using radio signals. The wireless device 140 may also be called wireless communication devices or simply devices in this disclosure. For example, the wireless device 140 may be a User Equipment (UE), a machine type UE or a UE capable of machine to machine (M2M) communication, asensor, a tablet, a mobile terminal, a smart phone, a laptop embedded equipped (LEE), a laptop mounted equipment (LME), a USB dongle, a Customer Premises Equipment (CPE) etc.

[0029] The UE 140 is also within the coverage of another cell 152. The cell 152 is served by another network node 132. The network node 132 has similar property as the network node 130. The UE 140 has a potential to have radio connection to the network node 132, i.e., the cell 150 is a serving cell of the UE 140, and the cell 152 is a neighbor cell of the UE 140, i.e., a potential cell for handover. If certain requirements are fulfilled, the UE 140 can handover from the cell 150 to the cell 152.

[0030] A SSB signal is transmitted from a network node, e.g., a base station 130 to the UE 140 to provide important information such as a Physical Cell ID and Master Information Block (MIB). The structure of SSB is defined in 3GPP standard. SSB can also be used as a downlink mobility reference signal for the UE, e.g., to determine whether to trigger a handover.

[0031] For the sake of optimizing energy consumption, it is beneficial to avoid coupling different requirements together in one SSB signal, i.e., follows a design principle known as “separation of concerns”. For example in 6G, it ensures that each function can be independently optimized without any “requirement creep” and without much understanding or consideration of any other functions in the system.

[0032] In 6G distinct functions such as “idle mode SI broadcast” (e.g., existing SSB used for idle mode functions), “measurements related to target cells” (e.g., mobility RS for connected mode mobility) and “additional signals related to the serving cells” (e.g., configured synchronization signal (SS) for serving cell synchronization) should rely on different signals, thereby enabling independent optimization of each function.

[0033] From the perspective of minimizing the network energy consumption a system that allows for low idle mode consumption is desired. This can be achieved by e.g.:A design that allows for SI broadcast transmissions from a subset of the TRPs in the network. This implies that not all TRPs will have an idle mode SSB andthat not all TRPs need to participate in SI broadcast. One direct consequence of this is that the idle mode SSB cannot be used to identify all TRPs, and hence it cannot be effectively used for e.g., connected mode mobility functions.• SI transmission can be identical from two or more TRPs. The Singal to Interference Noise Ratio (SINR) gain of transmitting SI broadcast using SFN transmission can be well above 25 dB in dense deployment (inter-site- distances (ISD) less than 500 meters). This implies that the idle mode SSB cannot uniquely identify the TRPs in the network.

[0034] This has consequences for how the connected mode mobility is handled. Mobility measurements on target cells hence need to be based on a different signal than the idle mode SSB, e.g., on a new downlink mobility reference signal.

[0035] Mobility measurement can also be based on uplink transmissions (from the UEs to the TRPs), or on secondary carrier predictions, or derived from UE positioning, or any combination of these. It would be a mistake to primarily rely on a periodic downlink reference signals for mobility in 6G since a good mobility toolbox is much larger than that.

[0036] In addition, some advanced use-cases, e.g., like L1 mobility, may require a new synchronization signal also for connected mode data transmission and measurements targeting the serving cell.

[0037] As discussed in the Background part, multiple types of SSBs are defined for different UE modes for downlink mobility reference signal.

[0038] The design with multiple signals (e.g., several types of SSB signals) for distinct functions enables the use of beams with a high variety of different properties in the network. For example, the type of beams of SSB signals from one cell or TRP may have very different properties. The beams used for coverage for a TRP may be transmitted with a wider beam resulting in a lower Reference Signal Received Power (RSRP), whereas a narrower beam used for traffic can have a higher RSRP. As a particular example, a D-SSB used by the UE in the serving cell may have a verynarrow beam resulting in a very high serving cell RSRP. Furthermore, to enable a lean design, the narrower beams, e.g., E-SSBs and M-SSBs in neighbor cells / TRPs, may not be always-on and therefore not always measurable by a UE.

[0039] Therefore, the detectable beams, e.g. an l-SSB may not reflect real channel property to the UE, i.e. , an l-SSB in the neighbor cell may not reflect the achievable throughput of the UE once the UE is handover to the neighbor cell / TRP when the traffic beam is turned on. Once the measurement report is sent to the network, the network can decide the appropriate action, e.g. to perform a handover, beam switch, or some other reconfiguration since the network knows the beam properties.However, if the UE is not aware of the beam properties, the measurement report may not be triggered timely, i.e. when the measurement report will not trigger any action by the network or the MR may not be triggered at all. The latter may happen e.g. when the UE measures l-SSBs from a TRP and the signal strength of the l-SSB does not reach the configured threshold which may be tailored for M-SSBs. This means that MRs triggered by the legacy events will not be triggered timely if the beam properties are not considered.

[0040] For example, when the UE detects different types of SSBs in serving cell and neighbor cells, e.g., detects a M-SSB in serving cell and detects an l-SSB in neighbor cell, the M-SSB and the l-SSB are not comparable due to their different beam properties, i.e., when the l-SSB has a lower RSRP than that of the M-SSB, the Event A3 may not occur to trigger the MR.

[0041] A cell-individual offset (CIO) refers to an offset which is configured for a particular cell, so that the CIO can be added to the downlink mobility reference signal, e.g., SSB signal. Configuring the CIO cannot accurately solve this problem since this can only be done per cells that are configured to be measured by the UE, assuming that for the 6G scenario the M-SSBs are self-detectable by the UE, and therefore no individual beams or cells / TRPs need to be configured for measurements. Also, an offset per cell or TRP does not distinguish between the different beam properties of the different beams. As a result, the unnecessary measurement reports will create signaling overhead, which will reduce the overall capacity of the network and drainthe UE battery. Alternatively, measurement report will not be sent when required resulting in e.g. failed handover, radio link failures, bad user experience, etc. in case the network is not provided with the required measurement reports needed to take appropriate actions in a timely manner.

[0042] Consequently, there is a need of a solution to reflect real channel property to the UE when a connection has not yet established between the UE and a neighbor network node in a neighbor cell. Furthermore, there is a need of a solution to compare RSRP of the serving cell and the neighbor cell when different reference signals with different beam properties are used.

[0043] As discussed above, SSB signals can be downlink mobility reference signal, i.e. , used for MEs. When the UE 140 is in different modes, different types of SSB signals can be utilized, or different reference signals with different beam properties can be used. As shown in fig. 2, the UE 140 is in connected mode with the network node 130, therefore it receives a M-SSB 160 from the network node 130 in the cell 150 as a downlink mobility reference signal. In the neighbor cell 152, since the UE 140 has not established a connection with the network node 132 yet, it receives an I- SSB 190 from the network node 132 as a downlink mobility reference signal. Please be noted that the fig. 2 only shows the beamforming gain of the l-SSB 190, not shows the coverage of the l-SSB 190. The l-SSB 190 may cover the whole cell 152, therefore UE 140 can receive the l-SSB 190 from the network node 132. The solid line and dashed line for the reference signals 160 and 190 shown in the fig. 2 are used for indicating different types of the reference signals.

[0044] As shown in fig. 2 and discussed above, M-SSB 160 and l-SSB 190 has different beam properties. For example, the M-SSB 160 has narrower and directional beams, resulting a higher RSRP, whereas the l-SSB 190 has a wider beam and a lower RSRP. Therefore, the RSRP of the M-SSB 160 is naturally always higher than the RSRP of the l-SSB 190. If the RSRP of the M-SSB 160 is compared with the RSRP of the l-SSB 190 directly for MEs, MRs cannot be triggered in time, e.g., the MR may not be triggered at all if the RSRP of the l-SSB 190 of the neighbor cell 152 cannot be threshold higher than the RSRP of the M-SSB of the serving cell 150,according to Event A3. Therefore, MR will not be triggered, resulting in e.g. failed handover, radio link failures, bad user experience, etc. Similarly, unnecessary or incorrect MRs may be triggered due to inaccurate RSRP comparison; this will create signaling overhead, which will reduce the overall capacity of the network and drain the UE battery.

[0045] In order to solve the above problem, the basic idea of the invention is to add respective offset to different types of SSB signals, or to SSB signals with different beam properties, when comparing RSRPs of SSB signals from the serving cell and the neighbor cell, i.e. , adding respective offsets to the RSRPs of the SSBs of different types or with different beamforming gains, even though the SSB signals have different beam properties. The invention may enable efficient triggering and / or filtering of measurement report by introducing offsets per reference signal type (e.g., SSB type). Therefore, a corrected measurement-related action can be triggered, e.g., a handover can be triggered. Furthermore, reduced signaling overhead is used for mobility measurement reporting; reduced number of handover failures and / or radio link failures occur. The mobility performance and overall stability is increased and end user experience is improved.

[0046] This invention proposes to configure the UE 140 with knowledge of beamtype properties for use when performing e.g. mobility measurements so that the UE 140 can do relative comparisons of the serving cell beam(s) and neighboring cell beams even when the available beams are of different type.

[0047] This is implemented by introducing offsets to be applied when performing comparisons between SSBs of different types (e.g. l-SSBs and M-SSBs or some other combination of different SSB-types) of the neighbor cells / TRPs and the serving cell (or other neighbor cells / TRPs).

[0048] The offsets can be different for different cells depending on the beam width or power offset used for the l-SSBs and M-SSBs in the cell. In one example, the offset can be deduced from the received signal itself. In other examples, the offset is given in SI per SSB type and can also include bands or frequency layers. In another option, the MIB of the M-SSB contains the offset or offsets for the beams from theTRP). In another preferred example the SSB-type offset is provided in an RRC configuration message sent to the UE.

[0049] The UE applies the configured SSB-type offset to trigger the measurement report and to filter the content of the measurement report.

[0050] As shown in fig. 3, a method performed by the UE 140 is disclosed. The method is performed by the UE 140, for triggering a measurement-related action, the UE 140 being wirelessly connected to a first network node 130, the method comprising: receiving 202 a first downlink reference signal 160 having a first beamforming gain from the first network node 130; determining 204 a first signal power indicator value of the first downlink reference signal 160, wherein the determined 204 first signal power indicator value of the first downlink reference signal 160 is offset with a first offset value based on information related to the first beamforming gain; receiving 206 a second downlink reference signal 190 having a second beamforming gain from a second network node 132; determining 208 a second signal power indicator value of the second downlink reference signal 190, wherein the determined 208 second signal power indicator value 190 is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; determining 210 whether to trigger the measurement-related action, based on the determined 204 first signal power indicator value of the first downlink reference signal 160 and the determined 208 second signal power indicator value of the second downlink reference signal 190.

[0051] As shown in figs. 2 and 3, in the step 202, the UE 140 receives a first downlink reference signal 160 from the network node 130. The first downlink reference signal 160 can be e.g., a M-SSB signal, which is used for UE mobility determination. In this situation, the UE 140 is in a connected mode with the network node 130. The M-SSB 160 has a narrow beam but a high beamforming gain.

[0052] In the step 204, the UE determines a first signal power indicator value of the first downlink reference signal 160, e.g., RSRP, Received Signal Strength Indicator (RSSI), Signal-to-Noise Ratio (SNR), Reference Signal Received Quality (RSRQ),Signal to Interference & Noise Ratio (SINR) of the first downlink reference signal 160, etc.

[0053] The first power indicator value may not be used for comparison directly, but added with an offset. The offset may be a positive value, a negative value, or zero. The first power indicator value may be added with a first offset value for comparison, and the first offset value is based on information related to a first beamforming gain of the first downlink reference signal 160. More details will be discussed below.

[0054] In the step 206, the UE 140 receives a second downlink reference signal 190 from the second network node 132. In an example, the UE 140 has not established a connection with the network node 132 yet, therefore no M-SSB can be received from the second network node 132 currently, or the M-SSB may not always be measurable by the UE. Instead, the UE 140 can detect an available downlink reference signal 190 from the second network node 132, e.g., there is a l-SSB signal which is available and covers the whole second cell 152. Therefore, the UE 140 can receive this l-SSB signal 190 as the second downlink reference signal. The l-SSB signal 190 may have a broad beam but a low beamforming gain. In another example, M-SSB from the second network node 132 is currently not measurable. Similarly, the UE 140 receives l-SSB signal 190 as the second downlink reference signal. In another example, M-SSB is received and measurable for the UE 140. Therefore, M- SSB is used as the second downlink reference signal for the UE 140.

[0055] In the step 208, the UE 140 determines a second signal power indicator value of the second downlink reference signal 190. The second signal power indicator can also be e.g., RSRP, RSSI, SNR, RSRQ, SINR, etc. The second signal power indicator should be the same type as the first signal power indicator, so that the two signal power indicator values are comparable. Similar with the first power indicator value, the second power indicator value may be added with a second offset value for comparison. The second offset value is based on information related to a second beamforming gain of the second downlink reference signal 190. More details will be discussed below. The second offset may be a positive value, a negative value, or zero.

[0056] In the step 210, the UE 140 determines whether to trigger a measurement- related action, based on the first signal power indicator value and the second power indicator value with their respective offset values. The measurement-related action can be, e.g., UE 140 transmitting MRs to the network node 130, or a conditional handover. In some embodiments, the first offset value and the second offset value may be an SSB-type specific offset (STO) that depends on the SSB-types.

[0057] The determination in the step 210 is based on comparison of the first and the second power indicator values, i.e. , to determine if any ME happens. The first and the second power indicator values are offset with respective offset value. The offset values for different types of reference signals in a cell may be configured according to the relative beamforming gains of the different types of reference signals, e.g., SSB. The offset value here describes the differences between the SSB types. For the example shown in fig. 4, if the M-SSB 160 has a beamforming gain that is X dB larger than that of the l-SSB 170 in cell 150, considering the relative beamforming gain X dB between M-SSB 160 and l-SSB 170, then the offset value for the M-SSB 160 can be set to 0 dB and the offset value for the l-SSB 170 can be set to X dB. As another example, the offset values for the different types of downlink reference signals may be inversely proportional to the beamforming gains of the first and second downlink reference signals, or the offset value of the l-SSB 170 is X times as big as the offset value of the M-SSB 160. In cell 152, the offset values for M-SSB 180 and l-SSB 190 can be configured in the same way. For example, if the M-SSB 180 has a beamforming gain that is X dB larger than that of the l-SSB 190 in cell 152, considering the relative beamforming gain X dB between M-SSB 180 and l-SSB 190, then the offset value for the M-SSB 180 can be set to 0 dB and the offset value for the l-SSB 190 can be set to X dB. Please note that the solid line and dashed line for the reference signals 160, 170, 180 and 190 shown in the fig. 4 are used for indicating different types of the reference signals.

[0058] In the example shown in fig. 2, M-SSB 160 is used by the first network node 130 as the first downlink reference signal and l-SSB 190 is used by the second network node 132 as the second downlink reference signal. Alternatively, the first network node 130 and the second network node 132 can use the same type ofdownlink reference signals, e.g., both use l-SSBs, but the two downlink reference signals have different beamforming gains. This embodiment is also applicable in this situation.

[0059] According to another example shown in fig. 4, the first cell 150 has e.g. 1 I- SSB beam 170 and 4 M-SSBs beams 160 with overlapping coverage then the UE 140 may be configured with the first offset value for the l-SSB 170 in the first cell 150 to be 6 dB and the first offset value for the M-SSB of the first cell 150 to be 0 dB. In this example it is assumed that the M-SSB 160 of the first cell 150 is typically received with 6 dB larger power due to the additional beamforming gain of the 4 M- SSBs relative to the l-SSB.

[0060] The second cell 152 has 1 l-SSB 190 and 8 M-SSBs 180 with overlapping coverage. The second cell 152 is configured with a second offset value 9 dB for the l-SSB 190 and a second offset value 0 dB for the M-SSB 180. In this example it is assumed that the M-SSB 180 of the second cell 152 is typically received with 9 dB larger power due to the additional beamforming gain of the M-SSB relative to the I- SSB. In this embodiment, it is the beam type with the largest beamforming gain that was used as reference in both cases and that is different for the first and second cells above.

[0061] It may be more logical to compare the expected target M-SSB with the serving M-SSB, rather than comparing the l-SSBs between different cells. In a preferred embodiment, if the SSB-type with the smallest beamforming gain is used instead as reference and negative offset values (e.g., STO-values) are used for SSB types with additional relative beamforming gains, then the measurement will become comparable again, even if they relate to SSB measurements from different cells. More details are disclosed below. By such an embodiment, the signal power indicator values of the first and second downlink reference signals are comparable taking respective beamforming gains into account, the determination of the measurement- related action is more accurate, and the efficiency of the handover related operations are increased.

[0062] According to another embodiment, the first downlink reference signal 160 is of a first type, and the second downlink reference signal 190 is of a second type. The first type and the second type can be different types or the same type.

[0063] In this embodiment, it is defined that the first downlink reference signal 160 and the second downlink reference signal 190 have certain signal type(s); for example, as discussed above, 160 is a M-SSB signal and 190 is an l-SSB signal. Other signal types are also available.

[0064] According to another embodiment, the first type is one of Idle Mode Synchronization Signal Block, l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB; the second type is one of l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB.

[0065] In this embodiment, both the first type and second type of downlink reference signals can be chosen from a list comprising l-SSB, M-SSB, E-SSB and D- SSB. These different types of SSB signals have different beamforming gains.

[0066] According to another embodiment, the determined 204 first signal power indicator value of the first downlink reference signal 160 is further offset with a third offset value, the third offset value is based on identifier of a first cell 150 served by the first network node 130. The third offset value may be a cell individual offset (CIO) than depends on the cell identities. As an example, when considering both STO and CIO, a comparable measurement may be calculated as: Comparable measurement = RSRP_measurement + CIO + STO, where the RSRP_measurement is the received reference signal power of the SSB, the CIO depends on the cell identifier, and the STO depends on the SSB type. The cell identifier sometimes is also called cell identity.

[0067] In this embodiment, the determined first signal power indicator value of the first downlink reference signal 160 can be further added with a third offset value. The third offset value depends on the identity / identifier of the cell 150, so that the determined first signal power indicator value is more accurate, considering the cell property of the serving cell 150. Thus, a determined first signal power indicator valuemay be calculated as: determined first signal power indicator value = measured first signal power indicator value + first offset value + third offset value.

[0068] According to another embodiment, the determined 208 second signal power indicator value of the second downlink reference signal 190 is further offset with a fourth offset value, the fourth offset value is based on identity / identif ier of a second cell 152 served by the second network node 132. The fourth offset value may be a cell individual offset (CIO) that depends on the cell identities.

[0069] In this embodiment, the determined second signal power indicator value of the second downlink reference signal 190 can be further added with a fourth offset value. The fourth offset value depends on the identifier / identity of the cell 152, so that the determined second signal power indicator value is more accurate, considering the cell property of the cell 152. Alternatively, the fourth offset value can only be configured for the cells which the UE 140 is configured to measure. If the cell 152 is not a listed cell, i.e. a neighbor cell that the UE 140 discovers autonomously, the cell 152 cannot be configured with a fourth offset value, and the second signal power indicator value of the second downlink reference signal 190 cannot be further offset with the fourth offset value. Thus, a determined second signal power indicator value may be calculated as: determined second signal power indicator value = measured second signal power indicator value + second offset value + fourth offset value.

[0070] According to a preferred embodiment, referring to fig. 4, multiple types of the first downlink reference signals 160, 170 exist in the first cell 150, each type of the first downlink reference signal 160, 170 is related to a respective first offset value; among the multiple types of the first downlink reference signals 160, 170, the first offset value of the first downlink reference signal 170 which has least beamforming gain is OdB, and the first offset value of the first downlink reference signal 160 is -6dB; and / or multiple types of the second downlink reference signals 180, 190 exist in the second cell 152, each type of the second downlink reference signal 180, 190 is related to a respective second offset value; among the multiple types of the second downlink reference signals 180, 190, the second offset value ofthe second downlink reference signal 190 which has least beamforming gain is OdB, and the second offset value of the second downlink reference signal 180 is -9dB.

[0071] In the example shown in fig. 4, 1 l-SSB beam 170 and 4 M-SSBs beams 160 with overlapping coverage exist in the first cell 150. The beamforming gain of the M-SSB 160 is 6 dB larger than the beamforming gain of the l-SSB 170. 1 l-SSB beam 190 and 8 M-SSB beams 180 with overlapping coverage exist in the second cell 152. The beamforming gain of the M-SSB 180 is 9 dB larger than the beamforming gain of the l-SSB 190.

[0072] In the first cell 150, the l-SSB 170 has the least beamforming gain, therefore the first offset value relates to the l-SSB 170 is configured to be 0 dB; accordingly, the first offset value relates to the M-SSB 160 is -6 dB. In the second cell 152, the l-SSB 190 has the least beamforming gain, therefore the second offset value relates to the l-SSB 190 is configured to be 0 dB; accordingly, the second offset value relates to the M-SSB 180 is configured to be -9 dB. Therefore, comparable signal power indication values of the first and second downlink reference signals can be obtained. When the UE 140 receives a first downlink reference signal, it can either be the l-SSB 170 or the M-SSB 160, depends on the mode of the UE 140. In some preferred embodiments, when making the comparison, the expected target M-SSB of the neighbor cell is compared with the serving M-SSB of the serving cell, given that the signal strength that is actually obtained in the serving cell is the signal strength of the M-SSB.

[0073] As for the second cell 152, since UE 140 has not established a connection with the second network node 132, the UE 140 receives the l-SSB 190 as the second downlink reference signal in normal situations, due to the coverage of the I- SSB 190. In some special situations, e.g., there is a second UE which is near the UE 140, and the second UE is in a connected mode connecting to the second network node 132, the second UE can receive a M-SSB 180 as a downlink reference signal. If the UE 140 is also in the coverage of the M-SSB 180 which is for the second UE, the UE 140 can also use the M-SSB 180 as its own second downlink reference signal.

[0074] This example is applicable e.g., when a comparison between two M-SSBs from different cells is desired. For example, the signal power indicator of M-SSB 160 of the first cell 150 is measured, and the signal power indicator of l-SSB 190 of the second cell 152 is measured. The signal power indicator of l-SSB 190 from the target second cell 152 is added with 9 dB, so that an estimated signal power indicator of M-SSB 180 is obtained. Therefore, the signal power indicator of M-SSB 160 can be compared correctly with the estimated signal power indicator of M-SSB 180.

[0075] According to another embodiment, the method further comprises receiving 212 the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the first downlink reference signal, and / or receiving 212 the second offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the second downlink reference signal.

[0076] In one embodiment, specific offsets are configured between l-SSBs, M- SSBs, E-SSBs. In one example, the offsets are configured to the UE by dedicated RRC signaling. In another example, the offsets are configured by System Information (SI).

[0077] For example, the offset value can be added to SIB1 and different offset values for different SSB types can be contained. In this case, the UE 140 may read SIB1 corresponding to the cell to determine the offset values for the cell. In one option, SIB can carry offset values for several cells, e.g. all cells served by the network node or the entire RAN based Notification Area (RNA). In this case, it is sufficient that the UE 140 obtains the offsets for the cells or TRPs belonging to the network node or RNA once, i.e. when it enters a cell belonging to the network node or RNA for the first time. In this case, the SIB could be an on-demand SSB which is only transmitted when requested by the UE 140.

[0078] In another example, the offset value can be carried in a RRC message or RRC Information Element carried on a Broadcast Channel, e.g. in a similar way as the MIB of the SSB. In one option, it contains only the offset value of the specific SSB type of this cell / TRP. In another option, it contains the offset values of all SSB types of the cell / TRP.

[0079] In another example, a specific offset value is configured for the serving D- SSB. This offset value may change rather frequently and can be updated by dedicated RRC signaling, MAC-CE or DCI. In the case MAC CE and DCI is used, the update may be an index pointing to a certain value in a pre-configured list that the UE has been configured by RRC signaling.

[0080] In another example, the offset value can be deduced from corresponding downlink reference signal, i.e. , the first offset value can be deduced from the first downlink reference signal, the second offset value can be deduced from the second downlink reference signal.

[0081] According to another embodiment, the method further comprises obtaining 214 the first offset value from an identifier of the first cell 150 served by the first network node 130 and / or obtaining the second offset value from an identifier of the second cell 152 served by the network node 132.

[0082] In this embodiment, the specific offset value of l-SSBs, M-SSBs or E- SSBs of a specific cell or TRP can be derived from the cell or TRP identifier, e.g., Physical Cell Identity (PCI). For example, a modulus operation of the identifier can give the offset. This can be implemented as:Identifier mod k = offset group, where the offset group determines the offset value. For example, offset group 0 corresponds to offset value of mo, offset group 1 corresponds to offset value of rm and so on. This means that the offset value is tied to the identifier of the cell, e.g. the PCI. In one example, the offset groups can specify offset values for l-SSBs, M- SSBs and E-SSBs. This option may require several groups. The mapping from offsetgroup to offset value may be hard coded in the specification, configured by system information or by dedicated RRC signaling.

[0083] According to another embodiment, respective first and second offset values are configured for different frequency bands. In one embodiment, a specific SSB-type offset may be configured between different bands or frequencies. This offset can be used e.g. to trigger inter-frequency measurement reports from the UE.

[0084] By this embodiment, different frequency bands can be configured with respective first and second offset value, giving more flexibility to this method.

[0085] According to another embodiment, the first network node 130 is a serving network node for the UE 140 and the second network node 132 is a network node in a neighbor cell.

[0086] According to another embodiment, the triggers for MRs from the UE 140 are defined taking the configured offset values into account. This means that a MR is triggered if the event (A1 -A6), e.g. A3 or A6, is fulfilled taking the configured offset values into account. Typically, both the serving cell 150 and the neighbor cell 152 have offsets. Consider for example the event A3 where Neighbor cell becomes threshold better than SpCell and assume that the first downlink reference signal of the cell 150 (e.g., serving beam of SpCell) is one of the M-SSBs 160 in Figure 4 with the offset OdB, and the second downlink reference signal of the cell 152 is the l-SSB 190. In this embodiment, the second offset value of the l-SSB 190 is 9 dB. In the prior art which does not take the offset values into account, the event A3 would be:RSRP of l-SSB 190 of cell 152 - RSRP of M-SSB 160 of cell 150 > threshold.While according to this embodiment, the event A3 would be:(RSRP of l-SSB 190 of cell 152 + 9dB) - RSRP of M-SSB 160 of cell 150 > threshold.

[0087] In the above condition, what the expected signal strength in the neighbor cell (i.e., RSRP of l-SSB 190 of neighbor cell 152 + 9dB is the expected RSRP of M-SSB in neighbor cell 152) should be at least threshold higher than the observed or measured signal strength in the serving cell 150 (i.e., obtained M-SSB 160 RSRP in cell 150). RSRP of / -SSB 190 of cell 152 + 9 dB calculates an estimated signal strength RSRP of the M-SSB 180 of the neighbor cell 152. RSRP of M-SSB 160 of cell 150 is the observed or actually obtained signal strength in the serving cell 150. Therefore, by comparing RSRP of the estimated M-SSB 180 in cell 152 and the observed M-SSB 160 in cell 150, the condition of event A3 can be detected.

[0088] In one embodiment, the MR triggered by a neighbor cell l-SSB has different thresholds depending on if the corresponding M-SSBs of the neighbor cell are transmitted or not. According to another embodiment, the neighbor cell l-SSB 190 has different offset values depending on if the corresponding M-SSBs of the neighbor cell are transmitted or not. In an example, it could be so that the offset 9dB of the l-SSB 109 is used only when the M-SSBs 180 of the cell 152 are not transmitted. When the M-SSBs 180 are transmitted, the l-SSB 190 would use no or a different offset value. The reason for this is that if the M-SSBs 180 are transmitted, they could be measured directly as the second downlink reference signal and trigger a MR. There is no need to measure and offset the RSRP of the I- SSB 190.

[0089] According to another embodiment, a conditional hand over (CHO) can be triggered based on measurements of beams (e.g. downlink reference signals) taking offset values into account. In this case, the offset of an l-SSB to a M-SSB which is not transmitted (and thereby not measured) can trigger a CHO to the l-SSB, whereafter the M-SSB is turned on and the UE uses the M-SSB as the serving beam, e.g., downlink reference signal.

[0090] Referring to fig. 5, a method performed by a first network node 130 is disclosed. The first network node 130 is wirelessly connected to a User Equipment, UE 140, the method comprising: configuring 302 a first offset value to the UE 140, the first offset value is based on information related to a first beamforming gain of a first downlink reference signal 160; sending 304 the first downlink reference signal 160 with the first beamforming gain to the UE 140, wherein whether to trigger ameasurement-related action from the UE 140 is determined based on a first signal power indicator value of the first downlink reference signal 160 and the first offset value.

[0091] According to another embodiment, the method further comprises configuring 306 multiple offsets value to the UE 140, each offset value being respectively based on information relates to a beamforming gain of each type of multiple types of downlink reference signals, the multiple types of downlink reference signals having different beamforming gains. Multiple offset values may be configured for respective types of the downlink reference signals (e.g., different SSB types) to enable efficient triggering and / or filtering of measurement reports.

[0092] According to another embodiment, the configuring 302 of the first offset value to the UE 140 further comprises: configuring 302 the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message to the UE 140, the first downlink reference signal.

[0093] According to another embodiment, the first network node 130 is a serving network node for the UE 140.

[0094] According to another embodiment, the reception of a MR triggers a network node to transmit M-SSBs, e.g., triggers the second network node 132 to transmit M-SSBs 180. In this case, the thresholds for MR triggering by l-SSBs or E- SSBs are configured so that an MR is triggered when it is likely that a handover to a M-SSB could happen in the near future and transmissions of M-SSB from the network node of the cell or TRP would be beneficial.

[0095] Fig. 6 discloses a block diagram of a UE 140. A UE 140 is configured for triggering a measurement-related action, the UE 140 being operative for wirelessly connecting to a first network node 130, the UE 140 comprising a communication unit 602, a processing circuitry 603 and a memory 604, said memory 604 containing instructions executable by said processing circuitry 603, whereby the UE 140 is operative for: receiving a first downlink reference signal 160 having a firstbeamforming gain from the first network node 130; determining a first signal power indicator value of the first downlink reference signal 160, wherein the determined first signal power indicator value of the first downlink reference signal 160 is offset with a first offset value based on information related to the first beamforming gain; receiving a second downlink reference signal 190 having a second beamforming gain from a second network node 132; determining a second signal power indicator value of the second downlink reference signal 190, wherein the determined second signal power indicator value 190 is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; determining whether to trigger the measurement-related action, based on the determined first signal power indicator value of the first downlink reference signal 160 and the determined second signal power indicator value of the second downlink reference signal 190.

[0096] According to another embodiment, the first downlink reference signal 160 is of a first type, and the second downlink reference signal 190 is of a second type.

[0097] According to another embodiment, the first type is one of Idle Mode Synchronization Signal Block, l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB; the second type is one of l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB.

[0098] According to another embodiment, the determined first signal power indicator value of the first downlink reference signal 160 is further offset with a third offset value, the third offset value is based on identifier of a first cell 150 served by the first network node 130.

[0099] According to another embodiment, the determined second signal power indicator value of the second downlink reference signal 190 is further offset with a fourth offset value, the fourth offset value is based on identifier of a second cell 152 served by the second network node 132.[000100] According to another embodiment, multiple types of the first downlink reference signals 160, 170 exist in the first cell 150, each type of the first downlinkreference signal 160, 170 is related to a respective first offset value; among the multiple types of the first downlink reference signals 160, 170, the first offset value of the first downlink reference signal 170 which has least beamforming gain is OdB; and / or multiple types of the second downlink reference signals 180, 190 exist in the second cell 152, each type of the second downlink reference signal 180, 190 is related to a respective second offset value; among the multiple types of the second downlink reference signals 180, 190, the second offset value of the second downlink reference signal 190 which has least beamforming gain is OdB.[000101] According to another embodiment, UE 140 is further operative for: receiving the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the first downlink reference signal, and / or receiving the second offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the second downlink reference signal.[000102] According to another embodiment, UE is further operative for: obtaining the first offset value from an identifier of the first cell 150 served by the first network node 130 and / or obtaining the second offset value from an identifier of the second cell 152 served by the network node 132.[000103] According to another embodiment, respective first and second offset values are configured for different frequency bands.[000104] According to another embodiment, the first network node 130 is a serving network node for the UE 140, and the second network node 132 is a network node in a neighbor cell.[000105] Fig. 7 discloses a block diagram of a first network node 130. The first network node 130 is operative for wirelessly connecting to a User Equipment, UE 140, the first network node 130 comprising a communication unit 702, a processing circuitry 703 and a memory 704, said memory 704 containing instructions executable by said processing circuitry 703, whereby the first network node 130 is operative for:configuring a first offset value to the UE 140, the first offset value is based on information related to a first beamforming gain of a first downlink reference signal 160; sending the first downlink reference signal 160 with the first beamforming gain to the UE 140, wherein whether to trigger a measurement-related action from the UE 140 is determined based on a first signal power indicator value of the first downlink reference signal 160 and the first offset value.[000106] According to another embodiment, the first network node is further operative for: configuring multiple offsets value to the UE 140, each offset value respectively relates to a beamforming gain of each of multiple downlink reference signals, the multiple downlink reference signal having different beamforming gains.[000107] According to another embodiment, the configuring of the first offset value to the UE 140 further comprises: configuring the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message to the UE 140, the first downlink reference signal.[000108] According to another embodiment, the first network node 130 is a serving network node for the UE 140.[000109] According to another embodiment in fig. 6, the UE 140 may further comprise a communication unit 602, which may be considered to comprise conventional means for wireless communication with the network node 130, such as a transceiver for wireless transmission and reception of signals. The instructions executable by said processing circuitry 603 may be arranged as a computer program 605 stored e.g., in said memory 604. The processing circuitry 603 and the memory 604 may be arranged in a sub-arrangement 601 . The sub-arrangement 601 may be a micro-processor and adequate software and storage therefore, a Programmable Logic Device, PLD, or other electronic component(s) / processing circuit(s) configured to perform the method mentioned above. The processing circuitry 603 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these adapted to execute instructions.[000110] The computer program 605 may be arranged such that when its instructions are run in the processing circuitry, they cause the UE 140 to perform the steps described in any of the described exemplary embodiments of the UE 140 and its method. The computer program 605 may be carried by a computer program product connectable to the processing circuitry 603. The computer program product may be the memory 604, or at least arranged in the memory. The memory 604 may be realized as for example a RAM (Random -access memory), ROM (Read-Only Memory) or an EEPROM (Electrical Erasable Programmable ROM). In some embodiments, a carrier may contain the computer program 605. The carrier may be one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or computer readable storage medium. The computer-readable storage medium may be e.g., a CD, DVD or flash memory, from which the program could be downloaded into the memory 604. Alternatively, the computer program may be stored on a server or any other entity to which the UE 140 has access via the communication unit 602. The computer program 605 may then be downloaded from the server into the memory 604.[000111 ] According to another embodiment in fig. 7, the network node 130 may further comprise a communication unit 702, which may be considered to comprise conventional means for wireless communication with the UE 140, such as a transceiver for wireless transmission and reception of signals. The instructions executable by said processing circuitry 703 may be arranged as a computer program 705 stored e.g., in said memory 704. The processing circuitry 703 and the memory 704 may be arranged in a sub-arrangement 701 . The sub-arrangement 701 may be a micro-processor and adequate software and storage therefore, a Programmable Logic Device, PLD, or other electronic component(s) / processing circuit(s) configured to perform the method mentioned above. The processing circuitry 703 may comprise one or more programmable processors, application-specific integrated circuits, field programmable gate arrays or combinations of these adapted to execute instructions.[000112] The computer program 705 may be arranged such that when its instructions are run in the processing circuitry, they cause the UE 140 to perform the steps described in any of the described exemplary embodiments of the network node 130and its method. The computer program 705 may be carried by a computer program product connectable to the processing circuitry 703. The computer program product may be the memory 704, or at least arranged in the memory. The memory 704 may be realized as for example a RAM (Random-access memory), ROM (Read-Only Memory) or an EEPROM (Electrical Erasable Programmable ROM). In some embodiments, a carrier may contain the computer program 705. The carrier may be one of an electronic signal, an optical signal, an electromagnetic signal, a magnetic signal, an electric signal, a radio signal, a microwave signal, or computer readable storage medium. The computer-readable storage medium may be e.g., a CD, DVD or flash memory, from which the program could be downloaded into the memory 704. Alternatively, the computer program may be stored on a server or any other entity to which the network node 130 has access via the communication unit 702. The computer program 705 may then be downloaded from the server into the memory 704.[000113] Although the description above contains a plurality of specificities, these should not be construed as limiting the scope of the concept described herein but as merely providing illustrations of some exemplifying embodiments of the described concept. It will be appreciated that the scope of the presently described concept fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the presently described concept is accordingly not to be limited. Reference to an element in the singular is not intended to mean "one and only one" unless explicitly so stated, but rather "one or more." Further, the term “a number of”, such as in “a number of wireless devices” signifies one or more devices. All structural and functional equivalents to the elements of the above-described embodiments that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed hereby. Moreover, it is not necessary for an apparatus or method to address each and every problem sought to be solved by the presently described concept, for it to be encompassed hereby. In the exemplary figures, a broken line generally signifies that the feature within the broken line is optional.

Claims

CLAIMS1 . A method performed by a User Equipment, UE (140), for triggering a measurement-related action, the UE (140) being wirelessly connected to a first network node (130), the method comprising: receiving (202) a first downlink reference signal (160) having a first beamforming gain from the first network node (130); determining (204) a first signal power indicator value of the first downlink reference signal (160), wherein the determined (204) first signal power indicator value of the first downlink reference signal (160) is offset with a first offset value based on information related to the first beamforming gain; receiving (206) a second downlink reference signal (190) having a second beamforming gain from a second network node (132); determining (208) a second signal power indicator value of the second downlink reference signal (190), wherein the determined (208) second signal power indicator value (190) is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; and determining (210) whether to trigger the measurement-related action, based on the determined (204) first signal power indicator value of the first downlink reference signal (160) and the determined (208) second signal power indicator value of the second downlink reference signal (190).

2. The method as claimed in claim 1 , wherein the first downlink reference signal (160) is of a first type, and the second downlink reference signal (190) is of a second type.

3. The method as claimed in claim 2, wherein the first type is one of Idle Mode Synchronization Signal Block, l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB; the second type is one of l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB.

4. The method as claimed in any one of claims 1-3, the determined (204) first signal power indicator value of the first downlink reference signal (160) is further offset with a third offset value, the third offset value is based on identifier of a first cell (150) served by the first network node (130).

5. The method as claimed in any one of the claims 1 -4, the determined (208) second signal power indicator value of the second downlink reference signal (190) is further offset with a fourth offset value, the fourth offset value is based on identifier of a second cell (152) served by the second network node (132).

6. The method as claimed in any one of the claims 1 -5, wherein multiple types of the first downlink reference signals (160, 170) exist in the first cell (150), each type of the first downlink reference signal (160, 170) is related to a respective first offset value; among the multiple types of the first downlink reference signals (160, 170), the first offset value of the first downlink reference signal (170) which has least beamforming gain is OdB; and / or multiple types of the second downlink reference signals (180, 190) exist in the second cell (152), each type of the second downlink reference signal (180, 190) is related to a respective second offset value; among the multiple types of the second downlink reference signals (180, 190), the second offset value of the second downlink reference signal (190) which has least beamforming gain is OdB.

7. The method as claimed in any one of the claims 1 -6, the method comprises: receiving (212) the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the first downlink reference signal; and / or receiving (212) the second offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the second downlink reference signal.

8. The method as claimed in any one of the claims 1 -6, the method comprises: obtaining (214) the first offset value from an identifier of a first cell (150) served by the first network node (130) and / or obtaining the second offset value from an identifier of a second cell (152) served by the second network node (132).

9. The method as claimed in any one of the claims 1-8, respective first and second offset values are configured for different frequency bands.

10. The method as claimed in any one of the claims 1 -9, the first network node (130) is a serving network node for the UE (140), and the second network node (132) is a network node in a neighbor cell.

11. A method performed by a first network node (130), the first network node (130) being wirelessly connected to a User Equipment, UE (140), the method comprising: configuring (302) a first offset value to the UE (140), the first offset value is based on information related to a first beamforming gain of a first downlink reference signal (160); sending (304) the first downlink reference signal (160) with the first beamforming gain to the UE (140), wherein whether to trigger a measurement-related action from the UE (140) is determined based on a first signal power indicator value of the first downlink reference signal (160) and the first offset value.

12. The method as claimed in claim 11 , the method further comprises configuring (306) multiple offsets value to the UE (140), each offset value respectively relates to a beamforming gain of each of multiple downlink reference signals, the multiple downlink reference signal having different beamforming gains.

13. The method as claimed in claim 11 or 12, the configuring (302) of the first offset value to the UE (140) comprises: configuring (302) the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE andDownlink Control Information, DCI, message to the UE (140), the first downlink reference signal.

14. The method as claimed in any one of claims 11-13, the first network node (130) is a serving network node for the UE (140).

15. A User Equipment, UE (140) configured for triggering a measurement- related action, the UE (140) being operative for wirelessly connecting to a first network node (130), the UE (140) comprising a communication unit (602), a processing circuitry (603) and a memory (604), said memory (604) containing instructions executable by said processing circuitry (603), whereby the UE (140) is operative to: receive a first downlink reference signal (160) having a first beamforming gain from the first network node (130); determine a first signal power indicator value of the first downlink reference signal (160), wherein the determined first signal power indicator value of the first downlink reference signal (160) is offset with a first offset value based on information related to the first beamforming gain; receive a second downlink reference signal (190) having a second beamforming gain from a second network node (132); determine a second signal power indicator value of the second downlink reference signal (190), the determined second signal power indicator value (190) is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; and determine whether to trigger the measurement-related action, based on the determined first signal power indicator value of the first downlink reference signal (160) and the determined second signal power indicator value of the second downlink reference signal (190).

16. The UE as claimed in claim 15, the first downlink reference signal (160) is of a first type, and the second downlink reference signal (190) is of a second type.

17. The UE as claimed in claim 16, the first type is one of Idle Mode Synchronization Signal Block, l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB; the second type is one of l-SSB, Mobility SSB, Extended periodicity SSB and Dynamic SSB.

18. The UE as claimed in any one of claims 15-17, the determined first signal power indicator value of the first downlink reference signal (160) is further offset with a third offset value, the third offset value is based on identifier of a first cell (150) served by the first network node (130).

19. The UE as claimed in any one of the claims 15-18, the determined second signal power indicator value of the second downlink reference signal (190) is further offset with a fourth offset value, the fourth offset value is based on identifier of a second cell (152) served by the second network node (132).

20. The UE as claimed in any one of the claims 15-19, wherein multiple types of the first downlink reference signals (160, 170) exist in the first cell (150), each type of the first downlink reference signal (160, 170) is related to a respective first offset value; among the multiple types of the first downlink reference signals (160, 170), the first offset value of the first downlink reference signal (170) which has least beamforming gain is OdB; and / or multiple types of the second downlink reference signals (180, 190) exist in the second cell (152), each type of the second downlink reference signal (180, 190) is related to a respective second offset value; among the multiple types of the second downlink reference signals (180, 190), the second offset value of the second downlink reference signal (190) which has least beamforming gain is OdB.21 . The UE as claimed in any one of the claims 15-20, the UE is operative to receive the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the first downlink reference signal, and / or receive the second offset value in at least one of Radio Resource Control, RRC, SystemInformation, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message, the second downlink reference signal.

22. The UE as claimed in any one of the claims 15-20, the UE is operative to obtaining the first offset value from an identifier of a first cell (150) served by the first network node (130) and / or obtaining the second offset value from an identifier of a second cell (152) served by the second network node (132).

23. The UE as claimed in any one of the claims 15-22, respective first and second offset values are configured for different frequency bands.

24. The UE as claimed in any one of the claims 15-23, the first network node (130) is a serving network node for the UE (140), and the second network node (132) is a network node in a neighbor cell.

25. A first network node (130), the first network node (130) being operative for wirelessly connecting to a User Equipment, UE (140), the first network node (130) comprising a communication unit (702), a processing circuitry (703) and a memory (704), said memory (704) containing instructions executable by said processing circuitry (703), whereby the first network node (130) is operative to: configure a first offset value to the UE (140), the first offset value is based on information related to a first beamforming gain of a first downlink reference signal (160); send the first downlink reference signal (160) with the first beamforming gain to the UE (140), wherein whether to trigger a measurement-related action from the UE (140) is determined based on a first signal power indicator value of the first downlink reference signal (160) and the first offset value.

26. The first network node as claimed in claim 25, the first network node is operative to configure multiple offsets value to the UE (140), each offset value respectively relates to a beamforming gain of each of multiple downlink reference signals, the multiple downlink reference signal having different beamforming gains.

27. The first network node as claimed in claim 25 or 26, the configuring of the first offset value to the UE (140) further comprises: configuring the first offset value in at least one of Radio Resource Control, RRC, System Information, SI, Media Access Control Control Element, MAC CE and Downlink Control Information, DCI, message to the UE (140), the first downlink reference signal.

28. The first network node as claimed in any one of claims 25-27, the first network node (130) is a serving network node for the UE (140).

29. A computer program (605) comprising instructions, which, when executed by at least one processing circuitry (603) of a UE (140), configured for triggering a measurement-related action, the UE (140) being wirelessly connected to a first network node (130), causes the UE (140) to perform the following steps: receiving (202) a first downlink reference signal (160) having a first beamforming gain from the first network node (130); determining (204) a first signal power indicator value of the first downlink reference signal (160), wherein the determined first signal power indicator value of the first downlink reference signal (160) is offset with a first offset value based on information related to the first beamforming gain; receiving (206) a second downlink reference signal (190) having a second beamforming gain from a second network node (132); determining (208) a second signal power indicator value of the second downlink reference signal (190), wherein the determined second signal power indicator value (190) is offset with a second offset value based on information related to the second beamforming gain, and at least one of the first and the second offset value is different from zero; and determining (210) whether to trigger the measurement-related action, based on the determined (204) first signal power indicator value of the first downlink reference signal (160) and the determined (208) second signal power indicator value of the second downlink reference signal (190).

30. A carrier containing the computer program (605) according to claim 29, wherein the carrier is one of an electronic signal, an optical signal, a radio signal, an electric signal, or a computer readable storage medium.31 . A computer program (705) comprising instructions, which, when executed by at least one processing circuitry (703) of a first network node (130), configured for triggering a measurement-related action, the first network node (130) being wirelessly connected to a User Equipment, UE (140), causes the first network node (130) to perform the following steps: configuring (302) a first offset value to the UE (140), the first offset value is based on information related to a first beamforming gain of a first downlink reference signal (160); sending (304) the first downlink reference signal (160) with the first beamforming gain to the UE (140), wherein whether to trigger a measurement-related action from the UE (140) is determined based on a first signal power indicator value of the first downlink reference signal (160) and the first offset value.

32. A carrier containing the computer program (705) according to claim 31 , wherein the carrier is one of an electronic signal, an optical signal, a radio signal, an electric signal, or a computer readable storage medium.

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