Patent Publication Number: US-2022231751-A1

Title: Beam switching time indication

Description:
TECHNICAL FIELD 
     This disclosure pertains to wireless communication technology, in particular in the context of operation in unlicensed spectrum. 
     BACKGROUND 
     There is a development to utilise increasing frequencies for wireless communication, which allow large bandwidths to be used for data transfer. In current systems like New Radio (NR), which use OFDM or SC-FDM based waveforms, also shorter (symbol) time intervals may be used, with a larger subcarrier spacing. However, this may introduce issues, in particular in comparison to legacy systems. 
     SUMMARY 
     The disclosure discusses approaches allowing improved handling of reference signaling, in particular when symbols have short symbol durations, with associated short cyclic prefixes. The approaches are particularly suitable for millimeter wave communication, in particular for radio carrier frequencies around and/or above 52.6 GHz, which may be considered high radio frequencies (high frequency) and/or millimeter waves. The carrier frequency/ies may be between 52.6 and 140 GHz, e.g. with a lower border between 52.6, 55, 60, 71 GHz and/or a higher border between 71, 72, 90, 114, 140 GHz or higher, in particular between 55 and 90 GHz, or between 60 and 72 GHz. The carrier frequency may in particular refer to a center frequency or maximum frequency of the carrier. The radio nodes and/or network described herein may operate in wideband, e.g. with a carrier bandwidth of 1 GHz or more, or 2 GHz or more, or even larger. In some cases, operation may be based on an OFDM waveform or a SC-FDM waveform (e.g., downlink and/or uplink). However, operation based on a single carrier waveform, e.g. SC-FDE, may be considered for downlink and/or uplink. In general, different waveforms may be used for different communication directions. Communicating using or utilising a carrier and/or beam may correspond to operating using or utilising the carrier and/or beam, and/or may comprise transmitting on the carrier and/or beam and/or receiving on the carrier and/or beam. 
     There is disclosed a method of operating a transmitting radio node in a wireless communication network. The method comprises transmitting reference signaling to a receiving radio node based on a beam switching time indication pertaining to the receiving radio node, and/or receiving reference signaling from a receiving radio node based on a beam switching time indication pertaining to the receiving radio node. 
     A transmitting radio node for a wireless communication network is described. The transmitting radio node is adapted for transmitting reference signaling to a receiving radio node based on a beam switching time indication pertaining to the receiving radio node, and/or for receiving reference signaling from the receiving radio node based on a beam switching time indication pertaining to the receiving radio node. 
     Moreover, a method of operating a receiving radio in a wireless communication network is proposed. The method comprises indicating, to a transmitting radio node, a beam switching time indication pertaining to the receiving radio node. Alternatively, or additionally, the method may comprise transmitting and/or receiving reference signaling based on a configuration, the configuration configured to the receiving radio node by a transmitting radio node based on the beam switching time indication. 
     A receiving radio node for a wireless communication network is also considered. The receiving radio node is adapted for indicating, to a transmitting radio node, a beam switching time indication pertaining to the receiving radio node. Alternatively, or additionally, the receiving radio node may be adapted for transmitting and/or receiving reference signaling based on a configuration, the configuration configured to the receiving radio node by a transmitting radio node based on the beam switching time indication. 
     The reference signaling may be CSI-RS or synchronisation signaling, e.g. in downlink (for example, transmitted by the transmitting radio node and received by the receiving radio node), or SRS, e.g. in uplink or sidelink (for example, transmitted by the receiving radio node and received by the transmitting radio node). Transmitting reference signaling based on the beam switching time indication may comprise transmitting reference signaling on multiple symbols (e.g., 2 or 4, or similar) in one slot, with a gap symbol being introduced based on an indicated beam switching time. The gap symbol may be introduced between two symbols, or between each pair of symbols, e.g. for long reference signaling (e.g., 4 symbols). Transmitting reference signaling based on the beam switching time indication may be based on a subcarrier spacing and/or symbol duration and/or cyclic prefix duration and/or numerology associated to the signaling used; for example, it may be performed for 480 kHz or 960 Khz of SCS or associated duration/s and/or numerologies; for lower SCS, no gap may be necessary and/or the beam switching time indication may be unconsidered. Reference signaling on multiple symbols in a slot may be transmitted with same transmission beam setting, e.g. the same beam weights and/or beam filters. Receiving reference signaling on multiple symbols in the slot may utilise different receiving beam settings for each symbol carrying reference signaling. Receiving reference signaling may be analogous, e.g. with one or more gaps. A configuration may be dynamically scheduled (e.g. with physical layer control signaling) and/or semi-statically configured (e.g. with higher layer signaling, e.g. RRC signaling or MAC signaling). A configuration may indicate when to transmit or receive reference signals, e.g. on which symbols in the same slot, and/or where to insert or expect gaps. A gaps may in general cover or consist of one or more symbols, during which no reference signaling to or from the receiving radio node may be configured. 
     The beam switching time indication may in general pertain to, and/or indicate, and/or represent a pure beam switching time, e.g. switching between filters like reception filters or transmission filters, and/or between different sets of beam weights; other processing times, e.g. for evaluating signaling, may be not considered and/or represented by the indication. The beam switching time indication may pertain to, or indicate, a beam switching time smaller than 200 ns, or smaller than 120 ns, or equal to or smaller than 100 ns. 
     The beam switching time indication may generally comprise one or more bit fields or bit patterns or parameters, which may pertain to different communication directions (e.g., RX or TX) and/or channels (e.g., PUSCH or PDSCH or PDCCH or PUCCH) and/or signals (e.g., different types of reference signals). It may be considered that the beam switching time indicated pertains to switching beams used for the same type of channel or signal. In general, the beam switching time indication may pertain to one receiving radio node, indicating a beam switching time capability of the receiving radio node. In some cases, the beam switching time indication may represent signaling indicative of one or more beam switching times of the receiving radio node. 
     The approaches described herein may be particularly beneficial in the context of beam management and/or beam selection, e.g. to identify a preferred reception beam for a given transmission beam from the communication partner. 
     It may be considered that the beam switching time indication may indicate a beam switching time of the receiving radio node for reception beam forming (and/or reception beams) and/or transmission beam forming (and/or transmission beams). Separate handling of different communication directions may be facilitated. 
     The beam switching time indication may indicate a beam switching time of the receiving node pertaining to a specific signal and/or channel. Thus, different characteristics of different types of signaling may be accommodated. 
     In general, the beam switching time indication may comprise one or more parameters. This allows flexible adaption to different transmission or reception scenarios, or one generalised approach, e.g. for low signaling overhead. 
     It may be considered that the beam switching time indication may be transmitted by the receiving radio node, e.g. with signaling indicative of the beam switching time indication. For example, the indication may be transmitted as capability signaling and/or RRC signaling; such signaling may be triggered and/or requested by the transmitting radio node. The transmitting radio node may be adapted for receiving such signaling and/or for triggering and/or requesting such. In some cases, the indication may represent a class (e.g., capability class or capacity class) of the receiving radio node, which may for example indicate that the receiving radio node is able to perform beam switching within a certain time (e.g., given by the class). 
     In some variants, the beam switching time indication may indicate a beam switching time in units of time, and/or quantified, and/or referring to a threshold. A time unit may be in nanoseconds, or tens thereof. Quantified indication may refer to a limited set of values representing ranges of times. An indication referring to a threshold may for example indicate whether the receiving radio node is able to perform beam switching in a time below (and/or in some cases up to) the threshold or not. 
     The transmitting radio node may in general comprise, and/or be adapted to utilise, processing circuitry and/or radio circuitry, in particular a transmitter and/or transceiver and/or receiver, to process (e.g., trigger and/or schedule) and/or transmit reference signaling and/or for receiving signaling indicative of the beam switching time. The transmitting radio node may in particular be a network node or base station, and/or a network radio node; it may be implemented as an IAB or relay node. However, in some cases, e.g. a sidelink scenario, it may be a wireless device. In general, the transmitting radio node may comprise and/or be adapted for transmission diversity, and/or may be connected or connectable to, and/or comprise, antenna circuitry and/or two or more independently operable or controllable antenna arrays or arrangements and/or transmitter circuitries and/or antenna circuitries, and/or may be adapted to use (e.g., simultaneously) a plurality of antenna ports (e.g., for transmitting synchronisation signaling, in particular first and second synchronisation signaling), e.g. controlling transmission using the antenna array/s. The transmitting radio node may comprise multiple components and/or transmitters and/or TRPs (and/or be connected or connectable thereto) and/or be adapted to control transmission from such. Any combination of units and/or devices able to control transmission on an air interface and/or in radio as described herein may be considered a transmitting radio node. 
     The receiving radio node may comprise, and/or be adapted to utilise, processing circuitry and/or radio circuitry, in particular a receiver and/or transmitter and/or transceiver, to receive and/or process (e.g. receive and/or demodulate and/or decode and/or perform blind detection and/or schedule or trigger such) reference signaling, and/or for transmitting signaling indicative of the beams switching time. Receiving may comprise scanning a frequency range (e.g., a carrier) for synchronisation signaling, e.g. at specific (e.g., predefined) locations in frequency domain, which may be dependent on the carrier and/or system bandwidth. The receiving radio node may in particular be a wireless device like a terminal or UE. However, in some cases, e.g. IAB or relay scenarios or multiple-RAT scenarios, it may be network node or base station, and/or a network radio node, for example an IAB or relay node. The receiving radio node may comprise one or more independently operable or controllable receiving circuitries and/or antenna circuitries and/or may be adapted to receive two or more synchronisation signalings simultaneously and/or to operate using two or more antenna ports simultaneously, and/or may be connected and/or connectable and/or comprise multiple independently operable or controllable antennas or antenna arrays or subarrays. 
     The approaches are particularly advantageously implemented in a 5th Generation (5G) telecommunication network or 5G radio access technology or network (RAT/RAN), in particular according to 3GPP (3 rd  Generation Partnership Project, a standardisation organization). A suitable RAN may in particular be a RAN according to NR, for example release 15 or later, or LTE Evolution. However, the approaches may also be used with other RAT, for example future 5.5G or 6G systems or IEEE based systems. It may be considered that the RAN is operating in an unlicensed frequency band (or carrier or part thereof) and/or based on a LBT procedure to access (for transmission) the frequency band (or carrier or part thereof), for example in a License Assisted Access (LAA) operation mode and/or in the context of NR-U (NR unlicensed). 
     A cyclic prefix (CP) may be used for orthogonal frequency-division multiplexing (OFDM) scheme in downlink and uplink and DFT spread OFDM (DFT-s-OFDM) in uplink. The CP provides a guard interval to reduce inter-symbol interference from the previous symbols, thus improving the link reliability in multipath environments. Specifically, CP is created by replicating samples from the end of each OFDM symbol to the front of the symbol. In this way, the linear convolution of a frequency-selective multipath channel can be modeled as a circular convolution and subsequently transformed to the frequency domain via a discrete Fourier transform (DFT). The CP insertion also enables using a simple channel estimation and equalization. 
     There is also described a program product comprising instructions causing processing circuitry to control and/or perform a method as described herein. Moreover, a carrier medium arrangement carrying and/or storing a program product as described herein is considered. An information system comprising, and/or connected or connectable, to a radio node and/or wireless device is also disclosed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings are provided to illustrate concepts and approaches described herein, and are not intended to limit their scope. The drawings comprise: 
         FIG. 1 , showing an exemplary scenario for reference signaling transmission; 
         FIG. 2 , showing an exemplary slot offset; 
         FIG. 3 , showing another exemplary scenario for reference signaling transmission; 
         FIG. 4 , showing an exemplary receiving radio node like a terminal or wireless device; and 
         FIG. 5 , showing another exemplary transmitting radio node like a network node or base station. 
     
    
    
     DETAILED DESCRIPTION 
     In the following, reference is made to a NR based system comprising a gNB and UE; the gNB may be generalised to a transmitting radio node, the UE to a receiving radio node. 
     Mobile broadband will continue to drive the demands for higher overall traffic capacity and higher achievable end-user data rates in the wireless access network. Several scenarios in the future will require data rates of up to 10 Gbps in local areas. These demands for very high system capacity and very high end-user date rates can be met by networks with distances between access nodes ranging from a few meters in indoor deployments up to roughly 50 m in outdoor deployments, i.e. with an infra-structure density considerably higher than the most dense networks of today. The wide transmission bandwidths needed to provide data rates up to 10 Gbps and above can likely only be obtained from spectrum allocations in the millimeter-wave band. High-gain beamforming, typically realized with array antennas, can be used to mitigate the increased pathloss at higher frequencies. 
     NR supports a diverse set of use cases and a diverse set of deployment scenarios. The later includes deployment at both low frequencies (100s of MHz), and very high frequencies (mm waves in the tens of GHz). Two operation frequency ranges are defined in NR Rel-15: FR1 from 410 MHz to 7125 MHz and FR2 from 24.250 GHz to 52.6 GHz. For operation in the 52.6-71 GHz band, new subcarrier spacings to support both 480 and 960 kHz, at least for data, control, and reference signals may be used; for FR1 and FR2, the largest available SCS is 120 kHZ. 
     TCI states may be used for NR systems. NR systems operating at mm-Wave frequencies make use of high-gain beamforming, typically realized with array antennas, to mitigate the increased pathloss at higher frequencies. For proper operation with such beam-forming, the network may indicate assistance information to the UE to allow it to determine what receive beam or transmit beam should be used for reception/transmission of particular signals/channels. This allows alignment of the UE receive/transmit beam direction with the gNB transmit/receive beam direction, respectively, in order to ensure robust link performance. 
     In Rel-15, the beam-forming assistance information for the downlink provided by the gNB to the UE is based on the indication of so-called “Transmission Configuration Indicator (TCI)” state(s). A UE can be configured with a list of one or more TCI states, and each TCI state provides the UE with the ID of one or two reference signals, where each reference signal can be an SS/PBCH block or a channel state information reference signal (CSI-RS). A quasi-co-location (QCL) type is associated with each of the reference signals of the TCI state, and the type can take one of 4 possible values: TypeA, TypeB, TypeC, or TypeD. A particular TCI state is indicated to the UE to aid in the reception of other signals/channels in the DL, e.g., PDSCH, PDCCH, other CSI-RS, etc. The indication of the TCI state to aid in reception of a DL signal is performed through either dynamic or semi-static signaling, i.e., via DCI, MAC-CE, or by RRC depending on the DL signal to be received. For example, for PDSCH and aperiodic CSI-RS it can be indicated by DCI. For reception of PDCCH, a TCI state is indicated by MAC-CE signaling. 
     In particular QCL TypeD may be considered, which is related to the spatial domain receiver settings in the UE, the setting of the spatial domain receive filter (receive beamforming weights). Hence, if TypeD is configured for one of the reference signals of the indicated TCI state for reception of a DL signal, e.g., PDSCH, it informs the UE that it can receive the PDSCH with the same spatial domain receiver settings as it used to receive the reference signal configured with TypeD within the TCI state. The implicit assumption is that the UE has previously performed measurements on this reference signal and “remembers” which spatial domain receiver settings it used for reception of that reference signal. In other words, the TCI state provides a means to indicate to the UE which receive beam to use for reception of the DL signal. 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 TCI-State ::= 
                 SEQUENCE { 
               
               
                  tci-StateId 
                  TCI-StateId, 
               
               
                  qcl-Type1 
                   QCL-Info, 
               
               
                  qcl-Type2 
                   QCL-Info 
               
               
                 OPTIONAL, -- Need R 
                   
               
               
                  ... 
                   
               
               
                 } 
                   
               
               
                 QCL-Info ::= 
                 SEQUENCE { 
               
               
                  cell 
                  ServCellIndex 
               
               
                 OPTIONAL, -- Need R 
                   
               
               
                  bwp-Id 
                   BWP-Id 
               
            
           
           
               
            
               
                 OPTIONAL, -- Cond CSI-RS-Indicated 
               
            
           
           
               
               
            
               
                  referenceSignal 
                   CHOICE { 
               
               
                   csi-rs 
                    NZP-CSI-RS-ResourceId, 
               
               
                   ssb 
                     SSB-Index 
               
               
                  }, 
                   
               
               
                  qcl-Type 
                   ENUMERATED {typeA, typeB, typeC, 
               
               
                 typeD}, 
                   
               
               
                  ... 
                   
               
               
                 } 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                   
               
               
                 QCL-Info field descriptions 
               
               
                   
               
             
            
               
                 bwp-Id 
               
               
                 The DL BWP which the RS is located in. 
               
               
                 cell 
               
               
                 The UE&#39;s serving cell in which the referenceSignal is configured. If the field is absent, 
               
               
                 it applies to the serving cell in which the TCI-State is configured. The RS can be 
               
               
                 located on a serving cell other than the serving cell in which the TCI-State is 
               
               
                 configured only if the qcl-Type is configured as typeC or typeD. See TS 38.214 [19] 
               
               
                 clause 5.1.5. 
               
               
                 referenceSignal 
               
               
                 Reference signal with which quasi-collocation information is provided as specified in 
               
               
                 TS 38.214 [19] subclause 5.1.5. 
               
               
                 qcl-Type 
               
               
                 QCL type as specified in TS 38.214 [19] subclause 5.1.5. 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                   
               
               
                 Conditional Presence 
                 Explanation 
               
               
                   
               
             
            
               
                 CSI-RS-Indicated 
                 This field is mandatory present if csi-rs is 
               
               
                   
                 included, absent otherwise 
               
               
                   
               
            
           
         
       
     
     Reference Signals for Beam Management may be used. NR supports periodic, semi-persistent, and aperiodic reference signals, e.g., channel-state information reference symbols (CSI-RS) in the downlink and sounding reference symbols (SRS) in the uplink that can be used for beam management, e.g., beam selection and tracking. One or more reference signal (RS) sets are configured to the UE, where an RS set contains one or more CSI-RS/SRS resources. An individual CSI-RS/SRS resource occupies N OFDM symbols within a single slot where N can for example be 1, 2, or 4 for both CSI-RS and SRS. For a CSI-RS resource, the starting symbol index within the slot for the first OFDM symbol of the resource is indicated by the RRC parameter firstOFDMSymbolInTimeDomain within CSI-RS-ResourceMapping and can take a value {0 . . 13}. For an SRS resource, the starting symbol index within the slot for the first OFDM symbol of the resource is indicated by the RRC parameter startPosition-r16 within SRS-Config and can take a value {0 . . . 13}. 
     For the case of aperiodic RS sets, the RS sets are configured by RRC and an RS set is triggered (scheduled) by a particular downlink control information (DCI) message contained in a physical downlink control channel (PDCCH) detected by the UE. In all but one special case (aperiodic SRS resources used for the purpose of channel sounding with 1T4R antenna switching), the resources within a single aperiodic RS set are contained entirely within a single slot. For the special case of an aperiodic SRSs for 1T4R antenna switching, the RS set contains 4 resources and they are configured to occupy 2 strictly adjacent slots. 
       FIG. 1  shows an example of an RS set containing 4 single symbol (N=1) aperiodic CSI-RS resources occupying OFDM symbols 5, 6, 7, and 8, respectively. These CSI-RS resources may be used, for example, for the purposes of beam management. In this example, the gNB applies different spatial domain transmit filters (beamforming weights) to each different CSI-RS resource in the form of a beam sweep. The UE can then measure the reference signal received power (RSRP) corresponding to each different CSI-RS resource within the set and report back an identity of the CSI-RS resource with the largest RSRP as well as the measured RSRP itself. The UE can also be configured to report the identities of the CSI-RS resources with the top-L largest RSRPs in the set as well as the RSRPs themselves. This enables the gNB to make decisions about what is the best beam to use to subsequently schedule the UE for future transmissions, e.g., PDSCH. In  FIG. 1 , there is shown a CSI-RS resource set contained in a single slot with 4 single symbol (N=1) CSI-RS resources configured to occupy OFDM symbols 5, 6, 7, 8. For this resource set, repetition=‘OFF,’ indicating that the UE may not assume that the gNB uses the same Tx beam for each CSI-RS resource. 
       FIG. 2  shows an example of the timing of the CSI-RS resource set in relation to the triggering DCI. The RS set configuration contains an RRC parameter that specifies a slot offset which in Rel-16 can take a value 0 . . . 16 or 24. If the UE detects a DCI message in slot N that triggers the aperiodic CSI-RS resource set, then the UE assumes that the CSI-RS resources within the set are located in slot N+K where K is the RRC configured slot offset. In  FIG. 2 , the slot offset is configured as K=4, for example. Specifically, an aperiodic CSI-RS resource set triggered by DCI is shown. The slot offset is configured by RRC as part of the resource set configuration. 
     For the case of CSI-RS resources sets, a parameter repetition that may be configured by RRC within the resource set configuration may be used. The parameter is configured if the CSI-RS resources are to be used for the purposes of L1-RSRP or L1-SINR reporting for beam management. If configured, the parameter repetition can take values ‘ON’ or ‘OFF.’ If repetition=‘OFF’ (as illustrated in In  FIG. 1 ) it means that the UE may not assume that the CSI-RS resources in resource set are transmitted by the gNB using the same downlink spatial domain transmission filter (transmit beamforming weights). In this case, the UE would typically leave its spatial domain receive filter fixed when receiving the CSI-RS resources in the set, and the gNB would vary its spatial domain transmit filter for each CSI-RS resource in the set. Based on the L1-RSRP/L1-SINR report from the UE, the gNB determines the “best” spatial domain transmit filter from the UE perspective. 
     Conversely, if repetition=‘ON,’ it means that the UE may assume that the CSI-RS resources in resource set are transmitted by the gNB using the same downlink spatial domain transmission filter (i.e., transmit beam forming weights). This allows the UE to adjust its spatial domain reception filter (i.e., receive beamforming weights) when receiving each different CSI-RS resource in the set. This is illustrated in  FIG. 3 . In this way, the UE may determine the preferred spatial domain receive filter corresponding to the particular spatial domain transmit filter used by the gNB for that CSI-RS resource set. The preferred spatial domain receive filter is typically selected to maximize a particular metric across the CSI-RS resources in the set, e.g., Layer 1 reference signal receive power (L1-RSRP) or Layer 1 signal-to-interference-plus-noise ratio (L1-SINR). Specifically,  FIG. 3  shows a CSI-RS resource set contained in a single slot with 4 single symbol (N=1) CSI-RS resources configured to occupy OFDM symbols 5, 6, 7, 8. For this resource set, repetition=‘ON’ indicating that the UE may assume that the gNB uses the same Tx beam for each CSI-RS resource. 
     SRS Resource Sets may be used for Beam Management. Similar to DL, in which CSI-RS resources are used for beam management, SRS resources can be used in the UL for beam management. The dual of the procedures described for the DL in the previous section apply to the UL such that the gNB can select a suitable receive spatial domain reception filter and the gNB can indicate to the UE what is a suitable spatial domain transmit filter for transmission of other UL signals/channels. 
     In NR Rel-15, subcarrier spacings (SCS) up to 120 kHz are supported. For NR in the 52.6 to 71 GHz band, both 480 and 960 kHz SCS at least for data, control, and reference signals may be supported. With these larger sub-carrier spacings, the OFDM symbol duration and the associated cyclic prefix (CP) duration become shorter. As shown in Table 1Table, the normal CP length decreases from 586 ns for 120 kHz SCS to 73 ns for 960 kHz. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Cyclic prefix duration as a  
               
               
                 function of sub-carrier spacing 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                 SCS [kHz] 
                 120 
                 240 
                 480 
                 960 
               
               
                   
                   
               
               
                   
                 CP duration [ns] 
                 585.9 
                 293.0 
                 146.5 
                 73.2 
               
               
                   
                   
               
            
           
         
       
     
     As shown in  FIG. 3  for the downlink, the UE performs a receive beam sweep whereby a different receive beam is tested in each OFDM symbol, corresponding to each different CSI-RS resource. Based on signal strength measurements on the CSI-RS resources, the best receive beam for future reception of other signals/channels (e.g., PDSCH) can be determined. 
     Conversely, for the uplink, the dual procedure is performed whereby the UE performs a transmit beam sweep in which a different transmit beam is tested in each OFDM symbol, corresponding to each different SRS resource and the gNB determines a preferred SRS resource based on signal strength measurements. Based on future indications or a preferred SRS resources from the gNB, the UE uses the indication to select the appropriate transmit beam for transmission of other signals/channels in the uplink (e.g., PUSCH). 
     In both cases (downlink or uplink) the UE is required to switch either receive or transmit beams in order to perform a CSI-RS measurement (downlink) or transmit an SRS (uplink). However, beam switches take time, and it is preferable that the beam switch is completed prior to reception of a CSI-RS or transmission of an SRS to allow accurate beam strength measurements. To achieve this, typically the UE implements beam switching such that it occurs during the cyclic prefix (CP) duration prior to each OFDM symbol. For the maximum subcarrier spacing supported in Rel-15/16 (120 kHz), the cyclic prefix duration is roughly 586 ns. This provides sufficient margin for beam switching, since according the worst-case beam switching time is assumed to be based on the analogue implementation and is estimated as &lt;100 ns. 
     For the new large subcarrier spacings (480 and 960 kHz) for NR operating in the 52.6-71 GHz band, the CP duration during which a UE typically switches its receive beam can be less than the time to perform a beam switch. For example, for 960 kHz, the CP duration is 73 ns, whereas beam switch time can be on the order of 100 ns. In addition, there are other sources of errors and RF imperfections that eat into the CP, e.g., delay spread, timing errors, etc. Factoring in these sources of error as well as the beam switch time, the CP duration can be exceeded significantly, even for 480 kHz SCS. 
     While 100 ns may be an upper limit on the beam switch time, not all UEs have the same implementation. Some UEs may have longer switching times than others, e.g., due to the choice between analog, digital, or hybrid beamforming implementation. 
     To avoid degrading signal strength measurements on CSI-RS and SRS resources when the CP duration is too short compared to beam switch time plus other impairments, the gNB can configure a gap between successive CSI-RS or SRS resources within a CSI-RS/SRS resource set. For example, in Specifically, Figure, a one symbol gap could be configured in between each CSI-RS resource to allow the UE enough time to perform beam switching. However, it would be preferable not to introduce such gaps for UEs that have a capability for shorter switching times that do not exceed the CP duration. 
     There are provided approaches for the UE to signal a capability parameter that is based on the time required to switch between Rx beams (downlink) and/or between Tx beams (uplink). The capability signaling allows the network to configure RS resources (e.g., CSI-RS, SRS) with a gap of one or more OFDM symbols between successive CSI-RS/SRS resources in a resource set. For UEs that are less capable (longer switching times) a gap can be configured, and for UEs that are more capable (shorter switching times) RS resources in consecutive symbols can be configured. 
     The proposed solution allows the network to efficiently configure RS resources (e.g., CSI-RS, SRS) taking into account different capabilities between UEs on the time it takes to switch between one Rx beam and another or between one Tx beam and another. UEs can be configured with gaps between CSI-RS resources or SRS resources for UEs with long beam switch time requirements, thus improving accuracy of signal strength measurements based on the RS resources. 
     The UE may indicate to the network a parameter based on the time required to switch between two different UE spatial domain receive filters (Rx beams) for reception of two particular signals/channels in the downlink. The two signals/channels can be of the same or different types. Each signal type can be one of PDSCH, PDCCH, CSI-RS, PRS, or SS/PBCH-block. 
     Alternatively, or additionally, the UE may indicate to the network a parameter based on the time required to switch between two different UE spatial domain transmit filters (Tx beams) for transmission of two particular signals/channels in the uplink. The two signals/channels can be of the same or different types. Each signal type can be one of PUSCH, PUCCH, PRACH, or SRS. 
     Alternatively, or additionally, separate parameters may be indicated for one or more different pairs of signal/channel types and/or communication directions. 
     In any of the above variants, a parameter may indicate the absolute beam switch time (in ns) or a quantized version thereof. In one non-limiting example, the quantized version of the beam switch time can be a number of OFDM symbols. In another non-limiting example, the parameter can indicate whether or not a gap of a pre-determined number of OFDM symbols is needed between a pair of signal/channel types to allow for beam switch time. 
     In a variation of this variant, the parameter may indicate whether or not a gap of a pre-determined number of OFDM symbols is needed between reference signal (RS) resources within an RS resource set. In one non-limiting example, the RS resource set can be a CSI-RS resource set or an SRS resource set. 
     In a variation of this variant, the parameter may be indicating that no gap, or a gap of x times a predetermined number of OFDM symbols is needed between a pair of signal/channel types to allow for beam switch time. 
     In any of the above variants, a separate parameter may be indicated for one or more different pairs of signal/channel types. 
     In any of the above variants, the parameter may be based on the maximum beam switch time amongst different pairs of signal/channel types in the downlink. 
     In any of the above variants, the parameter may be based on the maximum beam switch time amongst different pairs of signal/channel types in the uplink. 
     In any of the above variants, the parameter may be based on the maximum beam switch time amongst different pairs of signal/channel types in the uplink and downlink. 
     In any of the above variants, the parameter may be indicated to the network as part of UE capability exchange. 
     In any of the above variants, the parameter may be a function of the sub-carrier spacing and/or the operating frequency band and/or carrier. 
     In any of the above variants, the parameter may be a function of a cell-common parameter signaled from the network. 
     In any of the above variants, the parameter may be a function of both the sub-carrier spacing of the symbol before the switch and the sub-carrier spacing after the switch. As one nonlimiting example, the parameter can have one value if the sub-carrier spacing is the same before and after the switch and another value if the sub-carrier spacing after the switch is different from before the switch. 
     In any of the above variants, rather than the UE signaling the parameter to the network, the parameter may be hard coded as a UE requirement in specifications. 
     In a variation, different values of the parameter may be it associated with different UE capability classes, where the UE capability class may be separately indicated to the network. 
       FIG. 4  schematically shows a radio node, in particular a wireless device or terminal  10  or a UE (User Equipment). Radio node  10  comprises processing circuitry (which may also be referred to as control circuitry)  20 , which may comprise a controller connected to a memory. Any module of the radio node  10 , e.g. a communicating module or determining module, may be implemented in and/or executable by, the processing circuitry  20 , in particular as module in the controller. Radio node  10  also comprises radio circuitry  22  providing receiving and transmitting or transceiving functionality (e.g., one or more transmitters and/or receivers and/or transceivers), the radio circuitry  22  being connected or connectable to the processing circuitry. An antenna circuitry  24  of the radio node  10  is connected or connectable to the radio circuitry  22  to collect or send and/or amplify signals. Radio circuitry  22  and the processing circuitry  20  controlling it are configured for cellular communication with a network, e.g. a RAN as described herein, and/or for sidelink communication. Radio node  10  may generally be adapted to carry out any of the methods of operating a radio node or wireless device like terminal or UE disclosed herein; in particular, it may comprise corresponding circuitry, e.g. processing circuitry and/or radio circuitry and/or antenna circuitry, and/or modules, e.g. software modules. It may be considered that the radio node  10  comprises, and/or is connected or connectable, to a power supply. 
       FIG. 5  schematically shows a radio node  100 , which may in particular be implemented as a network node  100 , for example an eNB or gNB or similar for NR. Radio node  100  comprises processing circuitry (which may also be referred to as control circuitry)  120 , which may comprise a controller connected to a memory. Any module, e.g. transmitting module and/or receiving module and/or configuring module of the node  100  may be implemented in and/or executable by the processing circuitry  120 . The processing circuitry  120  is connected to control radio circuitry  122  of the node  100 , which provides receiver and transmitter and/or transceiver functionality (e.g., comprising one or more transmitters and/or receivers and/or transceivers). An antenna circuitry  124  may be connected or connectable to radio circuitry  122  for signal reception or transmittance and/or amplification. Node  100  may be adapted to carry out any of the methods for operating a radio node or network node disclosed herein; in particular, it may comprise corresponding circuitry, e.g. processing circuitry, and/or modules. The antenna circuitry  124  may be connected to and/or comprise an antenna array. The node  100 , respectively its circuitry, may be adapted to perform any of the methods of operating a network node or a radio node as described herein; in particular, it may comprise corresponding circuitry, e.g. processing circuitry, and/or modules. The radio node  100  may generally comprise communication circuitry, e.g. for communication with another network node, like a radio node, and/or with a core network and/or an internet or local net, in particular with an information system, which may provide information and/or data to be transmitted to a user equipment. 
     Data signaling may be on a data channel, for example on a PDSCH or PSSCH, or on a dedicated data channel, e.g. for low latency and/or high reliability, e.g. a URLLC channel. Control signaling may be on a control channel, for example on a common control channel or a PDCCH or PSCCH, and/or comprise one or more DCI messages or SCI messages. Reference signaling may be associated to control signaling and/or data signaling, e.g. DM-RS and/or PT-RS. 
     Reference signaling, for example, may comprise DM-RS and/or pilot signaling and/or discovery signaling and/or synchronisation signaling and/or sounding signaling and/or phase tracking signaling and/or cell-specific reference signaling and/or user-specific signaling, in particular CSI-RS. Reference signaling in general may be signaling with one or more signaling characteristics, in particular transmission power and/or sequence of modulation symbols and/or resource distribution and/or phase distribution known to the receiver. Thus, the receiver can use the reference signaling as a reference and/or for training and/or for compensation. The receiver can be informed about the reference signaling by the transmitter, e.g. being configured and/or signaling with control signaling, in particular physical layer signaling and/or higher layer signaling (e.g., DCI and/or RRC signaling), and/or may determine the corresponding information itself, e.g. a network node configuring a UE to transmit reference signaling. Reference signaling may be signaling comprising one or more reference symbols and/or structures. Reference signaling may be adapted for gauging and/or estimating and/or representing transmission conditions, e.g. channel conditions and/or transmission path conditions and/or channel (or signal or transmission) quality. It may be considered that the transmission characteristics (e.g., signal strength and/or form and/or modulation and/or timing) of reference signaling are available for both transmitter and receiver of the signaling (e.g., due to being predefined and/or configured or configurable and/or being communicated). Different types of reference signaling may be considered, e.g. pertaining to uplink, downlink or sidelink, cell-specific (in particular, cell-wide, e.g., CRS) or device or user specific (addressed to a specific target or user equipment, e.g., CSI-RS), demodulation-related (e.g., DMRS) and/or signal strength related, e.g. power-related or energy-related or amplitude-related (e.g., SRS or pilot signaling) and/or phase-related, etc. 
     References to specific resource structures like transmission timing structure and/or symbol and/or slot and/or mini-slot and/or subcarrier and/or carrier may pertain to a specific numerology, which may be predefined and/or configured or configurable. A transmission timing structure may represent a time interval, which may cover one or more symbols. Some examples of a transmission timing structure are transmission time interval (TTI), subframe, slot and mini-slot. A slot may comprise a predetermined, e.g. predefined and/or configured or configurable, number of symbols, e.g. 6 or 7, or 12 or 14. A mini-slot may comprise a number of symbols (which may in particular be configurable or configured) smaller than the number of symbols of a slot, in particular 1, 2, 3 or 4, or more symbols, e.g. less symbols than symbols in a slot. A transmission timing structure may cover a time interval of a specific length, which may be dependent on symbol time length and/or cyclic prefix used. A transmission timing structure may pertain to, and/or cover, a specific time interval in a time stream, e.g. synchronized for communication. Timing structures used and/or scheduled for transmission, e.g. slot and/or mini-slots, may be scheduled in relation to, and/or synchronized to, a timing structure provided and/or defined by other transmission timing structures. Such transmission timing structures may define a timing grid, e.g., with symbol time intervals within individual structures representing the smallest timing units. Such a timing grid may for example be defined by slots or subframes (wherein in some cases, subframes may be considered specific variants of slots). A transmission timing structure may have a duration (length in time) determined based on the durations of its symbols, possibly in addition to cyclic prefix/es used. The symbols of a transmission timing structure may have the same duration, or may in some variants have different duration. The number of symbols in a transmission timing structure may be predefined and/or configured or configurable, and/or be dependent on numerology. The timing of a mini-slot may generally be configured or configurable, in particular by the network and/or a network node. The timing may be configurable to start and/or end at any symbol of the transmission timing structure, in particular one or more slots. 
     There is generally considered a program product comprising instructions adapted for causing processing and/or control circuitry to carry out and/or control any method described herein, in particular when executed on the processing and/or control circuitry. Also, there is considered a carrier medium arrangement carrying and/or storing a program product as described herein. 
     A carrier medium arrangement may comprise one or more carrier media. Generally, a carrier medium may be accessible and/or readable and/or receivable by processing or control circuitry. Storing data and/or a program product and/or code may be seen as part of carrying data and/or a program product and/or code. A carrier medium generally may comprise a guiding/transporting medium and/or a storage medium. A guiding/transporting medium may be adapted to carry and/or carry and/or store signals, in particular electromagnetic signals and/or electrical signals and/or magnetic signals and/or optical signals. A carrier medium, in particular a guiding/transporting medium, may be adapted to guide such signals to carry them. A carrier medium, in particular a guiding/transporting medium, may comprise the electromagnetic field, e.g. radio waves or microwaves, and/or optically transmissive material, e.g. glass fiber, and/or cable. A storage medium may comprise at least one of a memory, which may be volatile or non-volatile, a buffer, a cache, an optical disc, magnetic memory, flash memory, etc. 
     A system comprising one or more radio nodes or wireless devices as described herein, in particular a network node and a user equipment, is described. The system may be a wireless communication system, and/or provide and/or represent a radio access network. 
     Moreover, there may be generally considered a method of operating an information system, the method comprising providing information. Alternatively, or additionally, an information system adapted for providing information may be considered. Providing information may comprise providing information for, and/or to, a target system, which may comprise and/or be implemented as radio access network and/or a radio node, in particular a network node or user equipment or terminal. Providing information may comprise transferring and/or streaming and/or sending and/or passing on the information, and/or offering the information for such and/or for download, and/or triggering such providing, e.g. by triggering a different system or node to stream and/or transfer and/or send and/or pass on the information. The information system may comprise, and/or be connected or connectable to, a target, for example via one or more intermediate systems, e.g. a core network and/or internet and/or private or local network. Information may be provided utilising and/or via such intermediate system/s. 
     Providing information may be for radio transmission and/or for transmission via an air interface and/or utilising a RAN or radio node as described herein. Connecting the information system to a target, and/or providing information, may be based on a target indication, and/or adaptive to a target indication. A target indication may indicate the target, and/or one or more parameters of transmission pertaining to the target and/or the paths or connections over which the information is provided to the target. Such parameter/s may in particular pertain to the air interface and/or radio access network and/or radio node and/or network node. Example parameters may indicate for example type and/or nature of the target, and/or transmission capacity (e.g., data rate) and/or latency and/or reliability and/or cost, respectively one or more estimates thereof. The target indication may be provided by the target, or determined by the information system, e.g. based on information received from the target and/or historical information, and/or be provided by a user, for example a user operating the target or a device in communication with the target, e.g. via the RAN and/or air interface. For example, a user may indicate on a user equipment communicating with the information system that information is to be provided via a RAN, e.g. by selecting from a selection provided by the information system, for example on a user application or user interface, which may be a web interface. An information system may comprise one or more information nodes. An information node may generally comprise processing circuitry and/or communication circuitry. In particular, an information system and/or an information node may be implemented as a computer and/or a computer arrangement, e.g. a host computer or host computer arrangement and/or server or server arrangement. In some variants, an interaction server (e.g., web server) of the information system may provide a user interface, and based on user input may trigger transmitting and/or streaming information provision to the user (and/or the target) from another server, which may be connected or connectable to the interaction server and/or be part of the information system or be connected or connectable thereto. The information may be any kind of data, in particular data intended for a user of for use at a terminal, e.g. video data and/or audio data and/or location data and/or interactive data and/or game-related data and/or environmental data and/or technical data and/or traffic data and/or vehicular data and/or circumstantial data and/or operational data. The information provided by the information system may be mapped to, and/or mappable to, and/or be intended for mapping to, communication or data signaling and/or one or more data channels as described herein (which may be signaling or channel/s of an air interface and/or used within a RAN and/or for radio transmission). It may be considered that the information is formatted based on the target indication and/or target, e.g. regarding data amount and/or data rate and/or data structure and/or timing, which in particular may be pertaining to a mapping to communication or data signaling and/or a data channel. Mapping information to data signaling and/or data channel/s may be considered to refer to using the signaling/channel/s to carry the data, e.g. on higher layers of communication, with the signaling/channel/s underlying the transmission. A target indication generally may comprise different components, which may have different sources, and/or which may indicate different characteristics of the target and/or communication path/s thereto. A format of information may be specifically selected, e.g. from a set of different formats, for information to be transmitted on an air interface and/or by a RAN as described herein. This may be particularly pertinent since an air interface may be limited in terms of capacity and/or of predictability, and/or potentially be cost sensitive. The format may be selected to be adapted to the transmission indication, which may in particular indicate that a RAN or radio node as described herein is in the path (which may be the indicated and/or planned and/or expected path) of information between the target and the information system. A (communication) path of information may represent the interface/s (e.g., air and/or cable interfaces) and/or the intermediate system/s (if any), between the information system and/or the node providing or transferring the information, and the target, over which the information is, or is to be, passed on. A path may be (at least partly) undetermined when a target indication is provided, and/or the information is provided/transferred by the information system, e.g. if an internet is involved, which may comprise multiple, dynamically chosen paths. Information and/or a format used for information may be packet-based, and/or be mapped, and/or be mappable and/or be intended for mapping, to packets. Alternatively, or additionally, there may be considered a method for operating a target device comprising providing a target indicating to an information system. More alternatively, or additionally, a target device may be considered, the target device being adapted for providing a target indication to an information system. In another approach, there may be considered a target indication tool adapted for, and/or comprising an indication module for, providing a target indication to an information system. The target device may generally be a target as described above. A target indication tool may comprise, and/or be implemented as, software and/or application or app, and/or web interface or user interface, and/or may comprise one or more modules for implementing actions performed and/or controlled by the tool. The tool and/or target device may be adapted for, and/or the method may comprise, receiving a user input, based on which a target indicating may be determined and/or provided. Alternatively, or additionally, the tool and/or target device may be adapted for, and/or the method may comprise, receiving information and/or communication signaling carrying information, and/or operating on, and/or presenting (e.g., on a screen and/or as audio or as other form of indication), information. The information may be based on received information and/or communication signaling carrying information. Presenting information may comprise processing received information, e.g. decoding and/or transforming, in particular between different formats, and/or for hardware used for presenting. Operating on information may be independent of or without presenting, and/or proceed or succeed presenting, and/or may be without user interaction or even user reception, for example for automatic processes, or target devices without (e.g., regular) user interaction like MTC devices, of for automotive or transport or industrial use. The information or communication signaling may be expected and/or received based on the target indication. Presenting and/or operating on information may generally comprise one or more processing steps, in particular decoding and/or executing and/or interpreting and/or transforming information. Operating on information may generally comprise relaying and/or transmitting the information, e.g. on an air interface, which may include mapping the information onto signaling (such mapping may generally pertain to one or more layers, e.g. one or more layers of an air interface, e.g. RLC (Radio Link Control) layer and/or MAC layer and/or physical layer/s). The information may be imprinted (or mapped) on communication signaling based on the target indication, which may make it particularly suitable for use in a RAN (e.g., for a target device like a network node or in particular a UE or terminal). The tool may generally be adapted for use on a target device, like a UE or terminal. Generally, the tool may provide multiple functionalities, e.g. for providing and/or selecting the target indication, and/or presenting, e.g. video and/or audio, and/or operating on and/or storing received information. Providing a target indication may comprise transmitting or transferring the indication as signaling, and/or carried on signaling, in a RAN, for example if the target device is a UE, or the tool for a UE. It should be noted that such provided information may be transferred to the information system via one or more additionally communication interfaces and/or paths and/or connections. The target indication may be a higher-layer indication and/or the information provided by the information system may be higher-layer information, e.g. application layer or user-layer, in particular above radio layers like transport layer and physical layer. The target indication may be mapped on physical layer radio signaling, e.g. related to or on the user-plane, and/or the information may be mapped on physical layer radio communication signaling, e.g. related to or on the user-plane (in particular, in reverse communication directions). The described approaches allow a target indication to be provided, facilitating information to be provided in a specific format particularly suitable and/or adapted to efficiently use an air interface. A user input may for example represent a selection from a plurality of possible transmission modes or formats, and/or paths, e.g. in terms of data rate and/or packaging and/or size of information to be provided by the information system. 
     In general, a numerology and/or subcarrier spacing may indicate the bandwidth (in frequency domain) of a subcarrier of a carrier, and/or the number of subcarriers in a carrier and/or the numbering of the subcarriers in a carrier, and/or the symbol time length. Different numerologies may in particular be different in the bandwidth of a subcarrier. In some variants, all the subcarriers in a carrier have the same bandwidth associated to them. The numerology and/or subcarrier spacing may be different between carriers in particular regarding the subcarrier bandwidth. A symbol time length, and/or a time length of a timing structure pertaining to a carrier may be dependent on the carrier frequency, and/or the subcarrier spacing and/or the numerology. In particular, different numerologies may have different symbol time lengths, even on the same carrier. A larger subcarrier spacing may correspond to a smaller duration of a symbol. 
     Signaling may generally comprise one or more (e.g., modulation) symbols and/or signals and/or messages. A signal may comprise or represent one or more bits. An indication may represent signaling, and/or be implemented as a signal, or as a plurality of signals. One or more signals may be included in and/or represented by a message. Signaling, in particular control signaling, may comprise a plurality of signals and/or messages, which may be transmitted on different carriers and/or be associated to different signaling processes, e.g. representing and/or pertaining to one or more such processes and/or corresponding information. An indication may comprise signaling, and/or a plurality of signals and/or messages and/or may be comprised therein, which may be transmitted on different carriers and/or be associated to different acknowledgement signaling processes, e.g. representing and/or pertaining to one or more such processes. Signaling associated to a channel may be transmitted such that represents signaling and/or information for that channel, and/or that the signaling is interpreted by the transmitter and/or receiver to belong to that channel. Such signaling may generally comply with transmission parameters and/or format/s for the channel. 
     An antenna arrangement may comprise one or more antenna elements (radiating elements), which may be combined in antenna arrays. An antenna array or subarray may comprise one antenna element, or a plurality of antenna elements, which may be arranged e.g. two dimensionally (for example, a panel) or three dimensionally. It may be considered that each antenna array or subarray or element is separately controllable, respectively that different antenna arrays are controllable separately from each other. A single antenna element/radiator may be considered the smallest example of a subarray. Examples of antenna arrays comprise one or more multi-antenna panels or one or more individually controllable antenna elements. An antenna arrangement may comprise a plurality of antenna arrays. It may be considered that an antenna arrangement is associated to a (specific and/or single) radio node, e.g. a configuring or informing or scheduling radio node, e.g. to be controlled or controllable by the radio node. An antenna arrangement associated to a UE or terminal may be smaller (e.g., in size and/or number of antenna elements or arrays) than the antenna arrangement associated to a network node. Antenna elements of an antenna arrangement may be configurable for different arrays, e.g. to change the beamforming characteristics. In particular, antenna arrays may be formed by combining one or more independently or separately controllable antenna elements or subarrays. The beams may be provided by analog beamforming, or in some variants by digital beamforming, or by hybrid beamforming combing analog and digital beamforming. The informing radio nodes may be configured with the manner of beam transmission, e.g. by transmitting a corresponding indicator or indication, for example as beam identify indication. However, there may be considered cases in which the informing radio node/s are not configured with such information, and/or operate transparently, not knowing the way of beamforming used. An antenna arrangement may be considered separately controllable in regard to the phase and/or amplitude/power and/or gain of a signal feed to it for transmission, and/or separately controllable antenna arrangements may comprise an independent or separate transmit and/or receive unit and/or ADC (Analog-Digital-Converter, alternatively an ADC chain) or DCA (Digital-to-Analog Converter, alternatively a DCA chain) to convert digital control information into an analog antenna feed for the whole antenna arrangement (the ADC/DCA may be considered part of, and/or connected or connectable to, antenna circuitry) or vice versa. A scenario in which an ADC or DCA is controlled directly for beamforming may be considered an analog beamforming scenario; such controlling may be performed after encoding/decoding and/or after modulation symbols have been mapped to resource elements. This may be on the level of antenna arrangements using the same ADC/DCA, e.g. one antenna element or a group of antenna elements associated to the same ADC/DCA. Digital beamforming may correspond to a scenario in which processing for beamforming is provided before feeding signaling to the ADC/DCA, e.g. by using one or more precoder/s and/or by precoding information, for example before and/or when mapping modulation symbols to resource elements. Such a precoder for beamforming may provide weights, e.g. for amplitude and/or phase, and/or may be based on a (precoder) codebook, e.g. selected from a codebook. A precoder may pertain to one beam or more beams, e.g. defining the beam or beams. The codebook may be configured or configurable, and/or be predefined. DFT beamforming may be considered a form of digital beamforming, wherein a DFT procedure is used to form one or more beams. Hybrid forms of beamforming may be considered. 
     A beam may be defined by a spatial and/or angular and/or spatial angular distribution of radiation and/or a spatial angle (also referred to as solid angle) or spatial (solid) angle distribution into which radiation is transmitted (for transmission beamforming) or from which it is received (for reception beamforming). Reception beamforming may comprise only accepting signals coming in from a reception beam (e.g., using analog beamforming to not receive outside reception beam/s), and/or sorting out signals that do not come in in a reception beam, e.g. in digital postprocessing, e.g. digital beamforming. A beam may have a solid angle equal to or smaller than 4*pi sr (4*pi correspond to a beam covering all directions), in particular smaller than 2* pi, or pi, or pi/2, or pi/4 or pi/8 or pi/16. In particular for high frequencies, smaller beams may be used. Different beams may have different directions and/or sizes (e.g., solid angle and/or reach). A beam may have a main direction, which may be defined by a main lobe (e.g., center of the main lobe, e.g. pertaining to signal strength and/or solid angle, which may be averaged and/or weighted to determine the direction), and may have one or more sidelobes. A lobe may generally be defined to have a continuous or contiguous distribution of energy and/or power transmitted and/or received, e.g. bounded by one or more contiguous or contiguous regions of zero energy (or practically zero energy). A main lobe may comprise the lobe with the largest signal strength and/or energy and/or power content. However, sidelobes usually appear due to limitations of beamforming, some of which may carry signals with significant strength, and may cause multi-path effects. A sidelobe may generally have a different direction than a main lobe and/or other side lobes, however, due to reflections a sidelobe still may contribute to transmitted and/or received energy or power. A beam may be swept and/or switched over time, e.g., such that its (main) direction is changed, but its shape (angular/solid angle distribution) around the main direction is not changed, e.g. from the transmitter&#39;s views for a transmission beam, or the receiver&#39;s view for a reception beam, respectively. Sweeping may correspond to continuous or near continuous change of main direction (e.g., such that after each change, the main lobe from before the change covers at least partly the main lobe after the change, e.g. at least to 50 or 75 or 90 percent). Switching may correspond to switching direction non-continuously, e.g. such that after each change, the main lobe from before the change does not cover the main lobe after the change, e.g. at most to 50 or 25 or 10 percent. 
     Signal strength may be a representation of signal power and/or signal energy, e.g. as seen from a transmitting node or a receiving node. A beam with larger strength at transmission (e.g., according to the beamforming used) than another beam does may not necessarily have larger strength at the receiver, and vice versa, for example due to interference and/or obstruction and/or dispersion and/or absorption and/or reflection and/or attrition or other effects influencing a beam or the signaling it carries. Signal quality may in general be a representation of how well a signal may be received over noise and/or interference. A beam with better signal quality than another beam does not necessarily have a larger beam strength than the other beam. Signal quality may be represented for example by SIR, SNR, SINR, BER, BLER, Energy per resource element over noise/interference or another corresponding quality measure. Signal quality and/or signal strength may pertain to, and/or may be measured with respect to, a beam, and/or specific signaling carried by the beam, e.g. reference signaling and/or a specific channel, e.g. a data channel or control channel. Signal strength may be represented by received signal strength, and/or relative signal strength, e.g. in comparison to a reference signal (strength). 
     Uplink or sidelink signaling may be OFDMA (Orthogonal Frequency Division Multiple Access) or SC-FDMA (Single Carrier Frequency Division Multiple Access) signaling. Downlink signaling may in particular be OFDMA signaling. However, signaling is not limited thereto (Filter-Bank based signaling and/or Single-Carrier based signaling, e.g. SC-FDE signaling, may be considered alternatives). 
     A radio node may generally be considered a device or node adapted for wireless and/or radio (and/or millimeter wave) frequency communication, and/or for communication utilising an air interface, e.g. according to a communication standard. 
     A radio node may be a network node, or a user equipment or terminal. A network node may be any radio node of a wireless communication network, e.g. a base station and/or gNodeB (gNB) and/or eNodeB (eNB) and/or relay node and/or micro/nano/pico/femto node and/or transmission point (TP) and/or access point (AP) and/or other node, in particular for a RAN or other wireless communication network as described herein. 
     The terms user equipment (UE) and terminal may be considered to be interchangeable in the context of this disclosure. A wireless device, user equipment or terminal may represent an end device for communication utilising the wireless communication network, and/or be implemented as a user equipment according to a standard. Examples of user equipments may comprise a phone like a smartphone, a personal communication device, a mobile phone or terminal, a computer, in particular laptop, a sensor or machine with radio capability (and/or adapted for the air interface), in particular for MTC (Machine-Type-Communication, sometimes also referred to M2M, Machine-To-Machine), or a vehicle adapted for wireless communication. A user equipment or terminal may be mobile or stationary. A wireless device generally may comprise, and/or be implemented as, processing circuitry and/or radio circuitry, which may comprise one or more chips or sets of chips. The circuitry and/or circuitries may be packaged, e.g. in a chip housing, and/or may have one or more physical interfaces to interact with other circuitry and/or for power supply. Such a wireless device may be intended for use in a user equipment or terminal. 
     A radio node may generally comprise processing circuitry and/or radio circuitry. A radio node, in particular a network node, may in some cases comprise cable circuitry and/or communication circuitry, with which it may be connected or connectable to another radio node and/or a core network. 
     Circuitry may comprise integrated circuitry. Processing circuitry may comprise one or more processors and/or controllers (e.g., microcontrollers), and/or ASICs (Application Specific Integrated Circuitry) and/or FPGAs (Field Programmable Gate Array), or similar. It may be considered that processing circuitry comprises, and/or is (operatively) connected or connectable to one or more memories or memory arrangements. A memory arrangement may comprise one or more memories. A memory may be adapted to store digital information. Examples for memories comprise volatile and non-volatile memory, and/or Random Access Memory (RAM), and/or Read-Only-Memory (ROM), and/or magnetic and/or optical memory, and/or flash memory, and/or hard disk memory, and/or EPROM or EEPROM (Erasable Programmable ROM or Electrically Erasable Programmable ROM). 
     Radio circuitry may comprise one or more transmitters and/or receivers and/or transceivers (a transceiver may operate or be operable as transmitter and receiver, and/or may comprise joint or separated circuitry for receiving and transmitting, e.g. in one package or housing), and/or may comprise one or more amplifiers and/or oscillators and/or filters, and/or may comprise, and/or be connected or connectable to antenna circuitry and/or one or more antennas and/or antenna arrays. An antenna array may comprise one or more antennas, which may be arranged in a dimensional array, e.g. 2D or 3D array, and/or antenna panels. A remote radio head (RRH) may be considered as an example of an antenna array. However, in some variants, an RRH may be also be implemented as a network node, depending on the kind of circuitry and/or functionality implemented therein. 
     Communication circuitry may comprise radio circuitry and/or cable circuitry. Communication circuitry generally may comprise one or more interfaces, which may be air interface/s and/or cable interface/s and/or optical interface/s, e.g. laser-based. Interface/s may be in particular packet-based. Cable circuitry and/or a cable interfaces may comprise, and/or be connected or connectable to, one or more cables (e.g., optical fiber-based and/or wire-based), which may be directly or indirectly (e.g., via one or more intermediate systems and/or interfaces) be connected or connectable to a target, e.g. controlled by communication circuitry and/or processing circuitry. 
     Any one or all of the modules disclosed herein may be implemented in software and/or firmware and/or hardware. Different modules may be associated to different components of a radio node, e.g. different circuitries or different parts of a circuitry. It may be considered that a module is distributed over different components and/or circuitries. A program product as described herein may comprise the modules related to a device on which the program product is intended (e.g., a user equipment or network node) to be executed (the execution may be performed on, and/or controlled by the associated circuitry). 
     A wireless communication network may be or comprise a radio access network and/or a backhaul network (e.g. a relay or backhaul network or an IAB network), and/or a Radio Access Network (RAN) in particular according to a communication standard. A communication standard may in particular a standard according to 3GPP and/or 5G, e.g. according to NR or LTE, in particular LTE Evolution. 
     A wireless communication network may be and/or comprise a Radio Access Network (RAN), which may be and/or comprise any kind of cellular and/or wireless radio network, which may be connected or connectable to a core network. The approaches described herein are particularly suitable for a 5G network, e.g. LTE Evolution and/or NR (New Radio), respectively successors thereof. A RAN may comprise one or more network nodes, and/or one or more terminals, and/or one or more radio nodes. A network node may in particular be a radio node adapted for radio and/or wireless and/or cellular communication with one or more terminals. A terminal may be any device adapted for radio and/or wireless and/or cellular communication with or within a RAN, e.g. a user equipment (UE) or mobile phone or smartphone or computing device or vehicular communication device or device for machine-type-communication (MTC), etc. A terminal may be mobile, or in some cases stationary. A RAN or a wireless communication network may comprise at least one network node and a UE, or at least two radio nodes. There may be generally considered a wireless communication network or system, e.g. a RAN or RAN system, comprising at least one radio node, and/or at least one network node and at least one terminal. 
     Transmitting in downlink may pertain to transmission from the network or network node to the terminal. Transmitting in uplink may pertain to transmission from the terminal to the network or network node. Transmitting in sidelink may pertain to (direct) transmission from one terminal to another. Uplink, downlink and sidelink (e.g., sidelink transmission and reception) may be considered communication directions. In some variants, uplink and downlink may also be used to described wireless communication between network nodes, e.g. for wireless backhaul and/or relay communication and/or (wireless) network communication for example between base stations or similar network nodes, in particular communication terminating at such. It may be considered that backhaul and/or relay communication and/or network communication is implemented as a form of sidelink or uplink communication or similar thereto. 
     Control information or a control information message or corresponding signaling (control signaling) may be transmitted on a control channel, e.g. a physical control channel, which may be a downlink channel or (or a sidelink channel in some cases, e.g. one UE scheduling another UE). For example, control information/allocation information may be signaled by a network node on PDCCH (Physical Downlink Control Channel) and/or a PDSCH (Physical Downlink Shared Channel) and/or a HARQ-specific channel. Acknowledgement signaling, e.g. as a form of control information or signaling like uplink control information/signaling, may be transmitted by a terminal on a PUCCH (Physical Uplink Control Channel) and/or PUSCH (Physical Uplink Shared Channel) and/or a HARQ-specific channel. Multiple channels may apply for multi-component/multi-carrier indication or signaling. 
     Signaling may generally be considered to represent an electromagnetic wave structure (e.g., over a time interval and frequency interval), which is intended to convey information to at least one specific or generic (e.g., anyone who might pick up the signaling) target. A process of signaling may comprise transmitting the signaling. Transmitting signaling, in particular control signaling or communication signaling, e.g. comprising or representing acknowledgement signaling and/or resource requesting information, may comprise encoding and/or modulating. Encoding and/or modulating may comprise error detection coding and/or forward error correction encoding and/or scrambling. Receiving control signaling may comprise corresponding decoding and/or demodulation. Error detection coding may comprise, and/or be based on, parity or checksum approaches, e.g. CRC (Cyclic Redundancy Check). Forward error correction coding may comprise and/or be based on for example turbo coding and/or Reed-Muller coding, and/or polar coding and/or LDPC coding (Low Density Parity Check). The type of coding used may be based on the channel (e.g., physical channel) the coded signal is associated to. A code rate may represent the ratio of the number of information bits before encoding to the number of encoded bits after encoding, considering that encoding adds coding bits for error detection coding and forward error correction. Coded bits may refer to information bits (also called systematic bits) plus coding bits. 
     Communication signaling may comprise, and/or represent, and/or be implemented as, data signaling, and/or user plane signaling, and/or may carry user data or payload data; in some cases, alternatively or additionally, communication signaling may comprise control signaling and/or carry control information. Communication signaling may be associated to a data channel, e.g. a physical downlink channel or physical uplink channel or physical sidelink channel, in particular a PDSCH (Physical Downlink Shared Channel) or PSSCH (Physical Sidelink Shared Channel). Generally, a data channel may be a shared channel or a dedicated channel. Data signaling may be signaling associated to and/or on a data channel. 
     An indication generally may explicitly and/or implicitly indicate the information it represents and/or indicates. Implicit indication may for example be based on position and/or resource used for transmission. Explicit indication may for example be based on a parametrisation with one or more parameters, and/or one or more index or indices, and/or one or more bit patterns representing the information. It may in particular be considered that control signaling as described herein, based on the utilised resource sequence, implicitly indicates the control signaling type. 
     A resource element may generally describe the smallest individually usable and/or encodable and/or decodable and/or modulatable and/or demodulatable time-frequency resource, and/or may describe a time-frequency resource covering a symbol time length in time and a subcarrier in frequency. A signal may be allocatable and/or allocated to a resource element. A subcarrier may be a subband of a carrier, e.g. as defined by a standard. A carrier may define a frequency and/or frequency band for transmission and/or reception. In some variants, a signal (jointly encoded/modulated) may cover more than one resource elements. A resource element may generally be as defined by a corresponding standard, e.g. NR or LTE. As symbol time length and/or subcarrier spacing (and/or numerology) may be different between different symbols and/or subcarriers, different resource elements may have different extension (length/width) in time and/or frequency domain, in particular resource elements pertaining to different carriers. 
     A resource generally may represent a time-frequency and/or code resource, on which signaling, e.g. according to a specific format, may be communicated, for example transmitted and/or received, and/or be intended for transmission and/or reception. 
     A border symbol may generally represent a starting symbol or an ending symbol for transmitting and/or receiving. A starting symbol may in particular be a starting symbol of uplink or sidelink signaling, for example control signaling or data signaling. Such signaling may be on a data channel or control channel, e.g. a physical channel, in particular a physical uplink shared channel (like PUSCH) or a sidelink data or shared channel, or a physical uplink control channel (like PUCCH) or a sidelink control channel. If the starting symbol is associated to control signaling (e.g., on a control channel), the control signaling may be in response to received signaling (in sidelink or downlink), e.g. representing acknowledgement signaling associated thereto, which may be HARQ or ARQ signaling. An ending symbol may represent an ending symbol (in time) of downlink or sidelink transmission or signaling, which may be intended or scheduled for the radio node or user equipment. Such downlink signaling may in particular be data signaling, e.g. on a physical downlink channel like a shared channel, e.g. a PDSCH (Physical Downlink Shared Channel). A starting symbol may be determined based on, and/or in relation to, such an ending symbol. 
     Configuring a radio node, in particular a terminal or user equipment, may refer to the radio node being adapted or caused or set and/or instructed to operate according to the configuration. Configuring may be done by another device, e.g., a network node (for example, a radio node of the network like a base station or eNodeB) or network, in which case it may comprise transmitting configuration data to the radio node to be configured. Such configuration data may represent the configuration to be configured and/or comprise one or more instruction pertaining to a configuration, e.g. a configuration for transmitting and/or receiving on allocated resources, in particular frequency resources. A radio node may configure itself, e.g., based on configuration data received from a network or network node. A network node may utilise, and/or be adapted to utilise, its circuitry/ies for configuring. Allocation information may be considered a form of configuration data. Configuration data may comprise and/or be represented by configuration information, and/or one or more corresponding indications and/or message/s 
     Generally, configuring may include determining configuration data representing the configuration and providing, e.g. transmitting, it to one or more other nodes (parallel and/or sequentially), which may transmit it further to the radio node (or another node, which may be repeated until it reaches the wireless device). Alternatively, or additionally, configuring a radio node, e.g., by a network node or other device, may include receiving configuration data and/or data pertaining to configuration data, e.g., from another node like a network node, which may be a higher-level node of the network, and/or transmitting received configuration data to the radio node. Accordingly, determining a configuration and transmitting the configuration data to the radio node may be performed by different network nodes or entities, which may be able to communicate via a suitable interface, e.g., an X2 interface in the case of LTE or a corresponding interface for NR. Configuring a terminal may comprise scheduling downlink and/or uplink transmissions for the terminal, e.g. downlink data and/or downlink control signaling and/or DCI and/or uplink control or data or communication signaling, in particular acknowledgement signaling, and/or configuring resources and/or a resource pool therefor. 
     A resource structure may be considered to be neighbored in frequency domain by another resource structure, if they share a common border frequency, e.g. one as an upper frequency border and the other as a lower frequency border. Such a border may for example be represented by the upper end of a bandwidth assigned to a subcarrier n, which also represents the lower end of a bandwidth assigned to a subcarrier n+1. A resource structure may be considered to be neighbored in time domain by another resource structure, if they share a common border time, e.g. one as an upper (or right in the figures) border and the other as a lower (or left in the figures) border. Such a border may for example be represented by the end of the symbol time interval assigned to a symbol n, which also represents the beginning of a symbol time interval assigned to a symbol n+1. 
     Generally, a resource structure being neighbored by another resource structure in a domain may also be referred to as abutting and/or bordering the other resource structure in the domain. 
     A resource structure may general represent a structure in time and/or frequency domain, in particular representing a time interval and a frequency interval. A resource structure may comprise and/or be comprised of resource elements, and/or the time interval of a resource structure may comprise and/or be comprised of symbol time interval/s, and/or the frequency interval of a resource structure may comprise and/or be comprised of subcarrier/s. A resource element may be considered an example for a resource structure, a slot or mini-slot or a Physical Resource Block (PRB) or parts thereof may be considered others. A resource structure may be associated to a specific channel, e.g. a PUSCH or PUCCH, in particular resource structure smaller than a slot or PRB. 
     Examples of a resource structure in frequency domain comprise a bandwidth or band, or a bandwidth part. A bandwidth part may be a part of a bandwidth available for a radio node for communicating, e.g. due to circuitry and/or configuration and/or regulations and/or a standard. A bandwidth part may be configured or configurable to a radio node. In some variants, a bandwidth part may be the part of a bandwidth used for communicating, e.g. transmitting and/or receiving, by a radio node. The bandwidth part may be smaller than the bandwidth (which may be a device bandwidth defined by the circuitry/configuration of a device, and/or a system bandwidth, e.g. available for a RAN). It may be considered that a bandwidth part comprises one or more resource blocks or resource block groups, in particular one or more PRBs or PRB groups. A bandwidth part may pertain to, and/or comprise, one or more carriers. 
     A carrier may generally represent a frequency range or band and/or pertain to a central frequency and an associated frequency interval. It may be considered that a carrier comprises a plurality of subcarriers. A carrier may have assigned to it a central frequency or center frequency interval, e.g. represented by one or more subcarriers (to each subcarrier there may be generally assigned a frequency bandwidth or interval). Different carriers may be non-overlapping, and/or may be neighboring in frequency domain. 
     It should be noted that the term “radio” in this disclosure may be considered to pertain to wireless communication in general, and may also include wireless communication utilising millimeter waves, in particular above one of the thresholds 10 GHz or 20 GHz or 50 GHz or 52 GHz or 52.6 GHz or 60 GHz or 72 GHz or 100 GHz or 114 GHz. Such communication may utilise one or more carriers, e.g. in FDD and/or carrier aggregation. Upper frequency boundaries may correspond to 300 GHz or 200 GHz or 120 GHz or any of the thresholds larger than the one representing the lower frequency boundary. 
     A radio node, in particular a network node or a terminal, may generally be any device adapted for transmitting and/or receiving radio and/or wireless signals and/or data, in particular communication data, in particular on at least one carrier. The at least one carrier may comprise a carrier accessed based on an LBT procedure (which may be called LBT carrier), e.g., an unlicensed carrier. It may be considered that the carrier is part of a carrier aggregate. 
     Receiving or transmitting on a cell or carrier may refer to receiving or transmitting utilizing a frequency (band) or spectrum associated to the cell or carrier. A cell may generally comprise and/or be defined by or for one or more carriers, in particular at least one carrier for UL communication/transmission (called UL carrier) and at least one carrier for DL communication/transmission (called DL carrier). It may be considered that a cell comprises different numbers of UL carriers and DL carriers. Alternatively, or additionally, a cell may comprise at least one carrier for UL communication/transmission and DL communication/transmission, e.g., in TDD-based approaches. 
     A channel may generally be a logical, transport or physical channel. A channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers. A channel carrying and/or for carrying control signaling/control information may be considered a control channel, in particular if it is a physical layer channel and/or if it carries control plane information. Analogously, a channel carrying and/or for carrying data signaling/user information may be considered a data channel, in particular if it is a physical layer channel and/or if it carries user plane information. A channel may be defined for a specific communication direction, or for two complementary communication directions (e.g., UL and DL, or sidelink in two directions), in which case it may be considered to have two component channels, one for each direction. Examples of channels comprise a channel for low latency and/or high reliability transmission, in particular a channel for Ultra-Reliable Low Latency Communication (URLLC), which may be for control and/or data. 
     In general, a symbol may represent and/or be associated to a symbol time length, which may be dependent on the carrier and/or subcarrier spacing and/or numerology of the associated carrier. Accordingly, a symbol may be considered to indicate a time interval having a symbol time length in relation to frequency domain. A symbol time length may be dependent on a carrier frequency and/or bandwidth and/or numerology and/or subcarrier spacing of, or associated to, a symbol. Accordingly, different symbols may have different symbol time lengths. In particular, numerologies with different subcarrier spacings may have different symbol time length. Generally, a symbol time length may be based on, and/or include, a guard time interval or cyclic extension, e.g. prefix or postfix. 
     A sidelink may generally represent a communication channel (or channel structure) between two UEs and/or terminals, in which data is transmitted between the participants (UEs and/or terminals) via the communication channel, e.g. directly and/or without being relayed via a network node. A sidelink may be established only and/or directly via air interface/s of the participant, which may be directly linked via the sidelink communication channel. In some variants, sidelink communication may be performed without interaction by a network node, e.g. on fixedly defined resources and/or on resources negotiated between the participants. Alternatively, or additionally, it may be considered that a network node provides some control functionality, e.g. by configuring resources, in particular one or more resource pool/s, for sidelink communication, and/or monitoring a sidelink, e.g. for charging purposes. 
     Sidelink communication may also be referred to as device-to-device (D2D) communication, and/or in some cases as ProSe (Proximity Services) communication, e.g. in the context of LTE. A sidelink may be implemented in the context of V2x communication (Vehicular communication), e.g. V2V (Vehicle-to-Vehicle), V2I (Vehicle-to-Infrastructure) and/or V2P (Vehicle-to-Person). Any device adapted for sidelink communication may be considered a user equipment or terminal. 
     A sidelink communication channel (or structure) may comprise one or more (e.g., physical or logical) channels, e.g. a PSCCH (Physical Sidelink Control CHannel, which may for example carry control information like an acknowledgement position indication, and/or a PSSCH (Physical Sidelink Shared CHannel, which for example may carry data and/or acknowledgement signaling). It may be considered that a sidelink communication channel (or structure) pertains to and/or used one or more carrier/s and/or frequency range/s associated to, and/or being used by, cellular communication, e.g. according to a specific license and/or standard. Participants may share a (physical) channel and/or resources, in particular in frequency domain and/or related to a frequency resource like a carrier) of a sidelink, such that two or more participants transmit thereon, e.g. simultaneously, and/or time-shifted, and/or there may be associated specific channels and/or resources to specific participants, so that for example only one participant transmits on a specific channel or on a specific resource or specific resources, e.g., in frequency domain and/or related to one or more carriers or subcarriers. 
     A sidelink may comply with, and/or be implemented according to, a specific standard, e.g. an LTE-based standard and/or NR. A sidelink may utilise TDD (Time Division Duplex) and/or FDD (Frequency Division Duplex) technology, e.g. as configured by a network node, and/or preconfigured and/or negotiated between the participants. A user equipment may be considered to be adapted for sidelink communication if it, and/or its radio circuitry and/or processing circuitry, is adapted for utilising a sidelink, e.g. on one or more frequency ranges and/or carriers and/or in one or more formats, in particular according to a specific standard. It may be generally considered that a Radio Access Network is defined by two participants of a sidelink communication. Alternatively, or additionally, a Radio Access Network may be represented, and/or defined with, and/or be related to a network node and/or communication with such a node. 
     Communication or communicating may generally comprise transmitting and/or receiving signaling. Communication on a sidelink (or sidelink signaling) may comprise utilising the sidelink for communication (respectively, for signaling). Sidelink transmission and/or transmitting on a sidelink may be considered to comprise transmission utilising the sidelink, e.g. associated resources and/or transmission formats and/or circuitry and/or the air interface. Sidelink reception and/or receiving on a sidelink may be considered to comprise reception utilising the sidelink, e.g. associated resources and/or transmission formats and/or circuitry and/or the air interface. Sidelink control information (e.g., SCI) may generally be considered to comprise control information transmitted utilising a sidelink. 
     Generally, carrier aggregation (CA) may refer to the concept of a radio connection and/or communication link between a wireless and/or cellular communication network and/or network node and a terminal or on a sidelink comprising a plurality of carriers for at least one direction of transmission (e.g. DL and/or UL), as well as to the aggregate of carriers. A corresponding communication link may be referred to as carrier aggregated communication link or CA communication link; carriers in a carrier aggregate may be referred to as component carriers (CC). In such a link, data may be transmitted over more than one of the carriers and/or all the carriers of the carrier aggregation (the aggregate of carriers). A carrier aggregation may comprise one (or more) dedicated control carriers and/or primary carriers (which may e.g. be referred to as primary component carrier or PCC), over which control information may be transmitted, wherein the control information may refer to the primary carrier and other carriers, which may be referred to as secondary carriers (or secondary component carrier, SCC). However, in some approaches, control information may be sent over more than one carrier of an aggregate, e.g. one or more PCCs and one PCC and one or more SCCs. 
     A transmission may generally pertain to a specific channel and/or specific resources, in particular with a starting symbol and ending symbol in time, covering the interval therebetween. A scheduled transmission may be a transmission scheduled and/or expected and/or for which resources are scheduled or provided or reserved. However, not every scheduled transmission has to be realized. For example, a scheduled downlink transmission may not be received, or a scheduled uplink transmission may not be transmitted due to power limitations, or other influences (e.g., a channel on an unlicensed carrier being occupied). A transmission may be scheduled for a transmission timing substructure (e.g., a mini-slot, and/or covering only a part of a transmission timing structure) within a transmission timing structure like a slot. A border symbol may be indicative of a symbol in the transmission timing structure at which the transmission starts or ends. 
     Predefined in the context of this disclosure may refer to the related information being defined for example in a standard, and/or being available without specific configuration from a network or network node, e.g. stored in memory, for example independent of being configured. Configured or configurable may be considered to pertain to the corresponding information being set/configured, e.g. by the network or a network node. 
     A configuration or schedule, like a mini-slot configuration and/or structure configuration, may schedule transmissions, e.g. for the time/transmissions it is valid, and/or transmissions may be scheduled by separate signaling or separate configuration, e.g. separate RRC signaling and/or downlink control information signaling. The transmission/s scheduled may represent signaling to be transmitted by the device for which it is scheduled, or signaling to be received by the device for which it is scheduled, depending on which side of a communication the device is. It should be noted that downlink control information or specifically DCI signaling may be considered physical layer signaling, in contrast to higher layer signaling like MAC (Medium Access Control) signaling or RRC layer signaling. The higher the layer of signaling is, the less frequent/the more time/resource consuming it may be considered, at least partially due to the information contained in such signaling having to be passed on through several layers, each layer requiring processing and handling. 
     A scheduled transmission, and/or transmission timing structure like a mini-slot or slot, may pertain to a specific channel, in particular a physical uplink shared channel, a physical uplink control channel, or a physical downlink shared channel, e.g. PUSCH, PUCCH or PDSCH, and/or may pertain to a specific cell and/or carrier aggregation. A corresponding configuration, e.g. scheduling configuration or symbol configuration may pertain to such channel, cell and/or carrier aggregation. It may be considered that the scheduled transmission represents transmission on a physical channel, in particular a shared physical channel, for example a physical uplink shared channel or physical downlink shared channel. For such channels, semi-persistent configuring may be particularly suitable. 
     Generally, a configuration may be a configuration indicating timing, and/or be represented or configured with corresponding configuration data. A configuration may be embedded in, and/or comprised in, a message or configuration or corresponding data, which may indicate and/or schedule resources, in particular semi-persistently and/or semi-statically. 
     A control region of a transmission timing structure may be an interval in time and/or frequency domain for intended or scheduled or reserved for control signaling, in particular downlink control signaling, and/or for a specific control channel, e.g. a physical downlink control channel like PDCCH. The interval may comprise, and/or consist of, a number of symbols in time, which may be configured or configurable, e.g. by (UE-specific) dedicated signaling (which may be single-cast, for example addressed to or intended for a specific UE), e.g. on a PDCCH, or RRC signaling, or on a multicast or broadcast channel. In general, the transmission timing structure may comprise a control region covering a configurable number of symbols. It may be considered that in general the border symbol is configured to be after the control region in time. A control region may be associated, e.g. via configuration and/or determination, to one or more specific UEs and/or formats of PDCCH and/or DCI and/or identifiers, e.g. UE identifiers and/or RNTIs or carrier/cell identifiers, and/or be represented and/or associated to a CORESET and/or a search space. 
     The duration of a symbol (symbol time length or interval) of the transmission timing structure may generally be dependent on a numerology and/or carrier, wherein the numerology and/or carrier may be configurable. The numerology may be the numerology to be used for the scheduled transmission. 
     A transmission timing structure may comprise a plurality of symbols, and/or define an interval comprising several symbols (respectively their associated time intervals). In the context of this disclosure, it should be noted that a reference to a symbol for ease of reference may be interpreted to refer to the time domain projection or time interval or time component or duration or length in time of the symbol, unless it is clear from the context that the frequency domain component also has to be considered. Examples of transmission timing structures include slot, subframe, mini-slot (which also may be considered a substructure of a slot), slot aggregation (which may comprise a plurality of slots and may be considered a superstructure of a slot), respectively their time domain component. A transmission timing structure may generally comprise a plurality of symbols defining the time domain extension (e.g., interval or length or duration) of the transmission timing structure, and arranged neighboring to each other in a numbered sequence. A timing structure (which may also be considered or implemented as synchronisation structure) may be defined by a succession of such transmission timing structures, which may for example define a timing grid with symbols representing the smallest grid structures. A transmission timing structure, and/or a border symbol or a scheduled transmission may be determined or scheduled in relation to such a timing grid. A transmission timing structure of reception may be the transmission timing structure in which the scheduling control signaling is received, e.g. in relation to the timing grid. A transmission timing structure may in particular be a slot or subframe or in some cases, a mini-slot. 
     Feedback signaling may be considered a form or control signaling, e.g. uplink or sidelink control signaling, like UCI (Uplink Control Information) signaling or SCI (Sidelink Control Information) signaling. Feedback signaling may in particular comprise and/or represent acknowledgement signaling and/or acknowledgement information and/or measurement reporting. 
     Signaling utilising, and/or on and/or associated to, resources or a resource structure may be signaling covering the resources or structure, signaling on the associated frequency/ies and/or in the associated time interval/s. It may be considered that a signaling resource structure comprises and/or encompasses one or more substructures, which may be associated to one or more different channels and/or types of signaling and/or comprise one or more holes (resource element/s not scheduled for transmissions or reception of transmissions). A resource substructure, e.g. a feedback resource structure, may generally be continuous in time and/or frequency, within the associated intervals. It may be considered that a substructure, in particular a feedback resource structure, represents a rectangle filled with one or more resource elements in time/frequency space. However, in some cases, a resource structure or substructure, in particular a frequency resource range, may represent a non-continuous pattern of resources in one or more domains, e.g. time and/or frequency. The resource elements of a substructure may be scheduled for associated signaling. 
     Example types of signaling comprise signaling of a specific communication direction, in particular, uplink signaling, downlink signaling, sidelink signaling, as well as reference signaling (e.g., SRS or CRS or CSI-RS), communication signaling, control signaling, and/or signaling associated to a specific channel like PUSCH, PDSCH, PUCCH, PDCCH, PSCCH, PSSCH, etc.). 
     In the context of this disclosure, there may be distinguished between dynamically scheduled or aperiodic transmission and/or configuration, and semi-static or semi-persistent or periodic transmission and/or configuration. The term “dynamic” or similar terms may generally pertain to configuration/transmission valid and/or scheduled and/or configured for (relatively) short timescales and/or a (e.g., predefined and/or configured and/or limited and/or definite) number of occurrences and/or transmission timing structures, e.g. one or more transmission timing structures like slots or slot aggregations, and/or for one or more (e.g., specific number) of transmission/occurrences. Dynamic configuration may be based on low-level signaling, e.g. control signaling on the physical layer and/or MAC layer, in particular in the form of DCI or SCI. Periodic/semi-static may pertain to longer timescales, e.g. several slots and/or more than one frame, and/or a non-defined number of occurrences, e.g., until a dynamic configuration contradicts, or until a new periodic configuration arrives. A periodic or semi-static configuration may be based on, and/or be configured with, higher-layer signaling, in particular RCL layer signaling and/or RRC signaling and/or MAC signaling. 
     In this disclosure, for purposes of explanation and not limitation, specific details are set forth (such as particular network functions, processes and signaling steps) in order to provide a thorough understanding of the technique presented herein. It will be apparent to one skilled in the art that the present concepts and aspects may be practiced in other variants and variants that depart from these specific details. 
     For example, the concepts and variants are partially described in the context of Long Term Evolution (LTE) or LTE-Advanced (LTE-A) or New Radio mobile or wireless communications technologies; however, this does not rule out the use of the present concepts and aspects in connection with additional or alternative mobile communication technologies such as the Global System for Mobile Communications (GSM) or IEEE standards as IEEE 802.11ad or IEEE 802.11 ay. While described variants may pertain to certain Technical Specifications (TSs) of the Third Generation Partnership Project (3GPP), it will be appreciated that the present approaches, concepts and aspects could also be realized in connection with different Performance Management (PM) specifications. 
     Moreover, those skilled in the art will appreciate that the services, functions and steps explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, or using an Application Specific Integrated Circuit (ASIC), a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA) or general purpose computer. It will also be appreciated that while the variants described herein are elucidated in the context of methods and devices, the concepts and aspects presented herein may also be embodied in a program product as well as in a system comprising control circuitry, e.g. a computer processor and a memory coupled to the processor, wherein the memory is encoded with one or more programs or program products that execute the services, functions and steps disclosed herein. 
     It is believed that the advantages of the aspects and variants presented herein will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, constructions and arrangement of the exemplary aspects thereof without departing from the scope of the concepts and aspects described herein or without sacrificing all of its advantageous effects. The aspects presented herein can be varied in many ways. 
     Some useful abbreviations comprise 
     
       
         
           
               
               
             
               
                   
               
               
                 Abbreviation 
                 Explanation 
               
               
                   
               
             
            
               
                 ACK/NACK 
                 Acknowledgment/Negative Acknowledgement 
               
               
                 ARQ 
                 Automatic Repeat reQuest 
               
               
                 BER 
                 Bit Error Rate 
               
               
                 BLER 
                 Block Error Rate 
               
               
                 BPSK 
                 Binary Phase Shift Keying 
               
               
                 BWP 
                 BandWidth Part 
               
               
                 CAZAC 
                 Constant Amplitude Zero Cross Correlation 
               
               
                 CB 
                 Code Block 
               
               
                 CBG 
                 Code Block Group 
               
               
                 CCA 
                 Clear Channel Assessment 
               
               
                 CDM 
                 Code Division Multiplex 
               
               
                 CM 
                 Cubic Metric 
               
               
                 CORESET 
                 Control Resource Set 
               
               
                 CQI 
                 Channel Quality Information 
               
               
                 CRC 
                 Cyclic Redundancy Check 
               
               
                 CRS 
                 Common reference signal 
               
               
                 CSI 
                 Channel State Information 
               
               
                 CSI-RS 
                 Channel state information reference signal 
               
               
                 DAI 
                 Downlink Assignment Indicator 
               
               
                 DCI 
                 Downlink Control Information 
               
               
                 DFT 
                 Discrete Fourier Transform 
               
               
                 DFTS-FDM 
                 DFT-spread-FDM 
               
               
                 DM(-)RS 
                 Demodulation reference signal(ing) 
               
               
                 eMBB 
                 enhanced Mobile BroadBand 
               
               
                 FBE 
                 Frame Based Equipment 
               
               
                 FDD 
                 Frequency Division Duplex 
               
               
                 FDE 
                 Frequency Domain Equalisation 
               
               
                 FDF 
                 Frequency Domain Filtering 
               
               
                 FDM 
                 Frequency Division Multiplex 
               
               
                 HARQ 
                 Hybrid Automatic Repeat Request 
               
               
                 IAB 
                 Integrated Access and Backhaul 
               
               
                 IFFT 
                 Inverse Fast Fourier Transform 
               
               
                 IR 
                 Impulse Response 
               
               
                 ISI 
                 Inter Symbol Interference 
               
               
                 LBT 
                 Listen-Before-Talk 
               
               
                 MBB 
                 Mobile Broadband 
               
               
                 MCS 
                 Modulation and Coding Scheme 
               
               
                 MIMO 
                 Multiple-input-multiple-output 
               
               
                 MRC 
                 Maximum-ratio combining 
               
               
                 MRT 
                 Maximum-ratio transmission 
               
               
                 MU-MIMO 
                 Multiuser multiple-input-multiple-output 
               
               
                 OFDM/A 
                 Orthogonal Frequency Division Multiplex/Multiple Access 
               
               
                 PAPR 
                 Peak to Average Power Ratio 
               
               
                 PDCCH 
                 Physical Downlink Control Channel 
               
               
                 PDSCH 
                 Physical Downlink Shared Channel 
               
               
                 PRACH 
                 Physical Random Access CHannel 
               
               
                 PRB 
                 Physical Resource Block 
               
               
                 PUCCH 
                 Physical Uplink Control Channel 
               
               
                 PUSCH 
                 Physical Uplink Shared Channel 
               
               
                 (P)SCCH 
                 (Physical) Sidelink Control Channel 
               
               
                 PSS 
                 Primary Synchronisation Signal(ing) 
               
               
                 (P)SSCH 
                 (Physical) Sidelink Shared Channel 
               
               
                 QAM 
                 Quadrature Amplitude Modulation 
               
               
                 OCC 
                 Orthogonal Cover Code 
               
               
                 QPSK 
                 Quadrature Phase Shift Keying 
               
               
                 PSD 
                 Power Spectral Density 
               
               
                 RAN 
                 Radio Access Network 
               
               
                 RAT 
                 Radio Access Technology 
               
               
                 RB 
                 Resource Block 
               
               
                 RNTI 
                 Radio Network Temporary Identifier 
               
               
                 RRC 
                 Radio Resource Control 
               
               
                 RX 
                 Receiver, Reception, Reception-related/side 
               
               
                 SA 
                 Scheduling Assignment 
               
               
                 SC-FDE 
                 Single Carrier Frequency Domain Equalisation 
               
               
                 SC-FDM/A 
                 Single Carrier Frequency Division Multiplex/Multiple  
               
               
                   
                 Access 
               
               
                 SCI 
                 Sidelink Control Information 
               
               
                 SCS 
                 Subcarrier Spacing 
               
               
                 SI 
                 System Information 
               
               
                 SINR 
                 Signal-to-interference-plus-noise ratio 
               
               
                 SIR 
                 Signal-to-interference ratio 
               
               
                 SNR 
                 Signal-to-noise-ratio 
               
               
                 SR 
                 Scheduling Request 
               
               
                 SRS 
                 Sounding Reference Signal(ing) 
               
               
                 SSS 
                 Secondary Synchronisation Signal(ing) 
               
               
                 SVD 
                 Singular-value decomposition 
               
               
                 TB 
                 Transport Block 
               
               
                 TDD 
                 Time Division Duplex 
               
               
                 TDM 
                 Time Division Multiplex 
               
               
                 TX 
                 Transmitter, Transmission, Transmission-related/side 
               
               
                 UCI 
                 Uplink Control Information 
               
               
                 UE 
                 User Equipment 
               
               
                 URLLC 
                 Ultra Low Latency High Reliability Communication 
               
               
                 VL-MIMO 
                 Very-large multiple-input-multiple-output 
               
               
                 ZF 
                 Zero Forcing 
               
               
                 ZP 
                 Zero-Power, e.g. muted CSI-RS symbol 
               
               
                   
               
            
           
         
       
     
     Abbreviations may be considered to follow 3G PP usage if applicable.