WO2022240345A1

WO2022240345A1 - Methods and apparatus to control interruption for active serving cell on mulitple scell activation

Info

Publication number: WO2022240345A1
Application number: PCT/SE2022/050460
Authority: WO
Inventors: Zhixun Tang; Joakim Axmon; Muhammad Kazmi
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2021-05-11
Filing date: 2022-05-11
Publication date: 2022-11-17
Also published as: AR125833A1

Abstract

A method, system and apparatus are disclosed arrangements for control interruption for active serving cell on multiple serving cell activation. In one embodiment, a wireless device (WD) is configured to receive a serving cell activation command. The WD is configured to count a number of frequency bands having an activation status to be changed. When the number of bands is equal to one, an interruption to retune the WD is performed before a first time. When the number of bands is greater than one and an offset is a samevalue for all serving cells having changed activation status, an interruption to retune the WD is performed before a second time. When the number of bands is greater than one and when the offset is not the same for all serving cells having changed activation status, an interruption to retune the WD is performed before a third time.

Description

METHODS AND APPARATUS TO CONTROL INTERRUPTION FOR ACTIVE SERVING CELL ON MULITPLE SCELL ACTIVATION TECHNICAL FIELD The present disclosure relates to wireless communications, and in particular, to arrangements for control interruption for active serving /cell on multiple Scell activation. BACKGROUND Synchronization signals in Evolved Universal Terrestrial Radio Access (E- UTRA) FIG.1 illustrates an example Time –frequency grid of a legacy 3rd Generation Partnership (3GPP) long term evolution (LTE) frequency division duplex (FDD) cell which is wider than the smallest downlink (DL) system bandwidth of 1.4 MHz (72 subcarriers or 6 resource blocks (RBs)). Subframes 1-3 and 6-8 may be used for multi-broadcast single frequency network (MBSFN) or may be signaled to do so for other purposes, by which a wireless device (WD, also called user equipment or UE) cannot expect reference signals in more than the first orthogonal frequency division multiplexing (OFDM) symbol. Physical broadcast channel (PBCH) (carrying master information block (MIB)) and synchronization signals are transmitted at prior known OFDM symbol positions over the central 72 subcarriers. Handover to a new primary cell (PCell), configuration of a new secondary cell (SCell), and configuration and activation of a new primary secondary cell (PSCell) is usually based on measurement reports from the WD, where the WD has been configured by the network node to send measurement reports periodically, at particular events, or a combination thereof. The measurement reports contain physical cell identity, reference signal received power (RSRP) and reference signal received quality (RSRQ) of the detected cells. Cell detection, aiming at detecting and determining cell identity and cell timing of neighbor cells, is facilitated by two signals that are transmitted in each evolved universal terrestrial radio access network (EUTRAN) cell on a 5 ms basis: the primary and the secondary synchronization signal (PSS and SSS, respectively). Moreover, reference signals (RS) are transmitted in each cell in order to facilitate cell measurements and channel estimation. The PSS exists in three versions, one for each of three cell-within-group identities, and is based on Zadoff-Chu sequences that are mapped onto the central 62 subcarriers and bordered by 5 unused subcarriers on either side. There are in total 168 cell groups, and information on to which cell group a cell belongs is carried by the SSS, which is based on m-sequences. This signal also carries information on whether it is transmitted in subframe 0 or subframe 5, which is used for acquiring frame timing. For a particular cell, the SSS is further scrambled with the cell’s cell-within- group identity. Hence in total there are 2x504 versions, two for each out of 504 physical layer cell identities. Similar to PSS, SSS is mapped onto the central 62 subcarriers and bordered by 5 unused subcarriers on either side. The layout of synchronization signals in an FDD radio frame is shown in the example of FIG.2. Synchronization signals in NR The synchronization signal and PBCH block (SSB) represents the only signals that can be assumed to be present in the NR cell (unless it has been signaled that SSB is not transmitted). The SSB is used for cell detection and measurements such as SS- RSRP, SS-RSRQ, and SS-signal to interference plus noise ratio (SINR). Depending on frequency range, the SSB may also be used for so called beam management, i.e., for allowing the WD to determine which subset out of a plurality of beams transmitted in the cell is most suitable to use in the communication between base station and WD. The SSB includes Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Physical Broadcast Channel (PBCH) and Demodulation Reference Symbols (DM-RS). The individual SSB spans four adjacent OFDM symbols, as illustrated in FIG.2(a). The SSB is transmitted within a half-frame (5ms), denoted as a SSB burst. In the half-frame, multiple SSBs for different cells or different beams may be transmitted See FIG.2(b). The number of SSB locations in a burst depends on the frequency range, as well as on the NR numerology (subcarrier spacing and associated OFDM symbol length) in use. For 15Hz (numerology µ=0) and 30kHz (numerology µ=1) SSB SCS (subcarrier spacing), which are used in FR1, the number of SSB positions, also known as SSB indices, is up to 4 for carrier frequency range 0 – 3GHz, and up to 8 for carrier frequency range 3 – 6GHz. Each index may represent a different transmit (Tx) beam (transmission beam or sector) in a cell. In NR the spectrum is divided into at least two frequency ranges namely frequency range 1 (FR1) and frequency range 2 (FR2). FR1 is currently defined from 450 MHz to 7000 MHz. FR2 is currently defined from 24250MHz to 52600MHz. The FR2 range is in the millimeter wave (mmwave) frequency range and corresponding bands in FR2 are called mmwave bands. The SSB burst (hence, the individual SSBs) are transmitted according to an SSB measurement timing configuration (SMTC) cycle, which may be 5, 10, 20, 40, 80 or 160ms. See FIG.2(c). A typical network configuration for FR2 is that the SMTC period is 20ms. The WD is configured by the network node (e.g., eNB, gNB, general: “base station”) with an SMTC for each NR carrier it is to measure. The SMTC contains information on SMTC period and on SMTC offset. The SMTC offset is expressed as a number of subframes, each of length 1ms, within the range 0 to SMTC period-1, and is using the frame border of system frame number 0 of the serving cell as reference. FIG.2 illustrates an example of (a) SS block comprising four OFDM symbols, (b) SSB half-frame with SSB burst in subcarrier spacing (SCS) 15kHz numerology SSB, and (c) SSB burst periodicity with SMTC period {5,10,20,40,80,160ms}. Interruption when SCell is activated Intra-band carrier aggregation with a single radio frequency (RF) chain When an intra-band adjacent SCell is activated, the bandwidth and center frequency of an already-running RF chain needs to be modified. For example, if a WD was previously receiving a single DL component carrier (CC) with 20MHz bandwidth and carrier frequency fc, and an SCell with carrier frequency fc+20MHz is activated, this can be achieved by setting the receiver bandwidth to 40MHz and retuning the reception frequency to fc+10Mhz. Retuning the receiver center frequency is achieved by programming the local oscillator (LO) in the WD to a different operating frequency which takes a certain time duration, during which the WD is neither receiving at the old carrier frequency fc, nor receiving the CA carriers at fc and fc+20MHz. Hence the carrier at frequency fc is said to be interrupted, and requirements are specified, for example, by 3GPP RAN4 in 3GPP Technical Specification (TS) 38.133 on the maximum duration of an interruption. When the receiver bandwidth is increased, the ideal AGC (automatic gain control) setting may be different from the setting before the increase, due to the additional signal bandwidth that is admitted to the receiver. Some additional interruption time may be needed to determine the proper AGC setting to receive both signals simultaneously with one RF chain. During this time, the receiver may be interrupted, or operate with reduced performance due to the incorrect AGC setting. Inter-band contiguous carrier aggregation with separate RF chains When an interband SCell is activated, it is typically received from, (and transmitted to, for UL carrier aggregation (CA)) using a different RF chain. In this case, for power saving reasons, the RF chain may have been powered down and needs to be powered up before the SCell can be activated. Particularly if multiple RF chains are implemented in the same RF integrated circuit (RFIC), the process of powering up one RF chain can cause a transient interruption to other RF chain/chains which are implemented on the same integrated circuit (IC). Mechanisms which cause interruption include so called local oscillator pulling (LO pulling) whereby the coupling between the RF chains from LO starting temporarily pulls the other RF chain off frequency until the error can be corrected by the feedback loop in the synthesizer. Another mechanism of interruption is through power rail coupling, especially due to the need to use relatively small power supply decoupling capacitors, such that the power supply transient caused by starting an RF chain may temporarily affect the power supply to other RF chains implemented on the same integrated circuit. Interruption at NR SCell activation in 3GPP TS 38.133 Due to the mechanisms described above, the WD is permitted to make an interruption to any active serving cell when an SCell is being activated. The duration of the interruption depends on whether the active cell is on the same band as the SCell being activated (intraband case) or a different band as the SCell being activated, the numerology (slot length) of the victim cell, and the frequency range of the aggressor and victim cell. Example, requirements for standalone NR SCell operation are shown below, extracted from 3GPP Technical Standard (TS) 38.133 v16.7.0 section 8.2.2.2.2: 8.2.2.2.2 Interruptions at SCell activation/deactivation When an intra-band SCell is activated or deactivated as defined in 3GPP TS 37.340, the WD is allowed: - an interruption on any active serving cell: - of up to the duration shown in table 8.2.2.2.2-1, if the active serving cell is not in the same band as any of the SCells being activated or deactivated, or - of up to the duration shown in table 8.2.2.2.2-2, if the active serving cells are in the same band as any of the SCells being activated or deactivated provided the cell specific reference signals from the active serving cells and the SCells being activated or deactivated are available in the same slot. Table 8.2.2.2.2-1: Interruption duration for SCell activation/deactivation for inter-band carrier aggregation (CA)

Table 8.2.2.2.2-2: Interruption duration for SCell activation/deactivation for intra-band CA

Multiple SCell activation in NR The delay within which the WD is to be able to activate the deactivated SCell with other downlink SCell being activated(s) depends upon the specified conditions. Upon receiving an SCell activation command in slot n for more than one SCell, for each of the SCell being activated, the WD should be able to transmit a valid CSI report and apply actions related to the activation command for the SCell being activated no later than in slot

where T_HARQ (in ms) is the timing between DL data transmission and acknowledgement as specified in 3GPP Technical Standard (TS) 38.213, and T_{activation_time_multiple_scells} is the target SCell activation delay in millisecond in multiple SCell activation scenario. If the SCell is known and belongs to FR1 and the SCell measurement cycle is equal to or smaller than 160ms, then Tactivation_time_multiple_scells is: ● T_{FirstSSB_MAX_multiple_scells} + T_rs + 5ms, if on the same band the WD also has at least one parallel SCell being activated which is a FR1 known Scell with the SCell measurement cycle larger than 160ms but does not have any parallel SCell being activated which is FR1 unknown SCell; ● T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells} + Trs + 5ms, if on the same band WD also has at least one parallel SCell being activated which is a FR1 unknown Scell: ● otherwise, T_{FirstSSB_MAX_multiple_scells} + 5ms. If the SCell is known and belongs to FR1 and the SCell measurement cycle is larger than 160ms, Tactivation_time_multiple_scells is: ● T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells} + T_rs + 5ms, if on the same band WD also has at least one parallel SCell being activated which is FR1 unknown Scell ● otherwise, T_{FirstSSB_MAX_multiple_scells} + T_rs + 5ms If the SCell is unknown and belongs to FR1, provided that the side condition Ês/Iot ≥ -2dB is fulfilled, Tactivation_time_multiple_scells is: ● T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells}+Trs +5ms, if the SCell is not counted in N1 ● otherwise, T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells}+T_rs*N₁ +T_rs +5ms where: N1 is the number counting for parallel FR1 unknown SCells being activated(s) except the ones which fulfilled the following conditions: ● contiguous to an active serving cell in the same band, or to a known SCell in the same band being activated by the same MAC PDU, and ● A single SSB is used in the unknown SCell; or multiple SSBs are used in the unknown SCell and TCI state indication for PDCCH is provided by the same MAC PDU used for SCell activation; and ● its ssb-PositionInBurst is same as the one of contiguous FR1 known cell or contiguous FR1 active serving cell, and ● its RTD with contiguous FR1 known cell or contiguous FR1 active serving cell is smaller than or equal to 260ns with respect to the SCell being activated’s SSB numerology and its reception power difference with contiguous FR1 known cell or contiguous FR1 active serving cell is smaller than or equal to 6dB, and ● its SMTC offset is same as the one of contiguous FR1 known cell or contiguous FR1 active serving cell However, when the following conditions are fulfilled, no activation requirement will be applied for this unknown SCell and other SCells being activated and counted in N1: ● contiguous to an active serving cell in the same band, or to a known SCell in the same band being activated by the same MAC PDU, and ● A single SSB is used in the unknown SCell; or multiple SSBs are used in the unknown SCell and TCI state indication for PDCCH is provided by the same MAC PDU used for SCell activation; and ● its ssb-PositionInBurst is same as the one of FR1 known cell or FR1 active serving cell, and ● its RTD with contiguous FR1 known cell or contiguous FR1 active serving cell is larger than 260ns with respect to the SCell being activated’s SSB numerology or its reception power difference with contiguous FR1 known cell or contiguous FR1 active serving cell is larger than 6dB, and ● its SMTC offset is same as the one of FR1 known cell or FR1 active serving cell ● T_{SMTC_MAX_multiple_scells}: o In FR1, in case of intra-band SCell activation, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity between active serving cells and SCells being activated on the same band provided the cell specific reference signals from the active serving cells and the SCells being activated or released are available in the same slot; in case of inter-band SCell activation, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity of SCells being activated on the same band. o In FR2, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity between active serving cells and SCell(s) being activated in FR2 intra-band CA. o T_{SMTC_MAX_multiple_scells} is bounded to a minimum value of 10ms. o T_{FirstSSB_MAX_multiple_scells}: is the time to the end of the first complete SSB burst indicated by the SMTC after slot n further fulfilling:

o In FR1, in case of intra-band SCell activation, the occasion when all active serving cells and SCells being activated or released are transmitting SSB bursts in the same slot; in case of inter-band SCell activation, the first occasion when the SCells being activated are transmitting SSB burst. o In FR2, the occasion when all active serving cells and SCells being activated or released are transmitting SSB bursts in the same slot. SUMMARY Some embodiments advantageously provide methods, systems, and apparatuses for arrangements for control interruption for active serving cell on multiple Scell activation. In one embodiment, a wireless device (WD) is configured to determine, as a result of initiating activation of a plurality of secondary cells (SCells), whether there is at least one currently active cell for the WD in a same frequency band as at least one Scell of the plurality of SCells being activated. The WD is also configured to identify a radio frequency (RF) retuning occasion for the at least one Scell based at least in part on the determination about the at least one currently active cell. The WD is further configured to perform RF retuning according to the identified RF retuning occasion. According to one aspect, a method in a wireless device, WD, configured to communicate with a network node includes receiving a serving cell activation command to change an activation status of a plurality of serving cells, the activation status including at least one of setup and released. The method includes, when the plurality of serving cells have at least one active serving cell in a same frequency band as the plurality of serving cells, counting a number of bands of the frequency band that have serving cells for which activation status is to be changed. The method also includes, when the number of bands is equal to one, performing an interruption to retune a radio frequency, RF, of operation of the WD before a first time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells for which activation status is to be changed. The method also includes, when the number of bands is greater than one and when a broadcast channel measurement timing configuration offset and periodicity cause an SSB/SMTC to have a temporal position that is a same value for all serving cells for which activation status is to be changed, performing an interruption to retune the RF of operation of the WD before a second time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells in a same band of the number of bands, the second time being a maximum value of a set of times for interruption operation for each band of the number of bands. The method further includes, when the number of bands is greater than one and when the measurement timing configuration offset and periodicity causes the SSB/SMTC to have a temporal position that is not the same for all serving cells for which activation status is to be changed, performing an interruption to retune the RF of operation of the WD before a third time by which to retune the RF of operation, the third time being an earliest value of a set of times for performing an interruption for each band of the number of bands. According to this aspect, in some embodiments, the frequency band is FR1. In some embodiments, the first time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n +

one of activated and deactivated in the one band and fulfilling at least one of: when the frequency band is FR1, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when the frequency band is FR2, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in the same time resource, where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the second time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being activated in a band of the number of bands and

fulfilling at least one of: when at least two active serving cells are in a same band of the number of bands, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when there are not at least two active serving cells in a same band, a condition that the serving cells for which activation status is to be changed are transmitting SSB bursts; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the method also includes performing the interruption based at least in part on synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC occasions in a first band of the number of bands followed by performing the interruption based at least in part on SMTC occasions in a second band of the number of bands. In some embodiments, a number of interruptions to retune the RF of operation depends at least in part on a number of bands having both the at least one active serving cell and the serving cells for which activation status is to be changed. In some embodiments, the method also includes determining when to retune an automatic gain control, AGC, of the WD based at least in part on a number of serving cells for which activation status is to be changed. In some embodiments, the method includes, when two serving cells for which activation status is to be changed are in different bands of the number of bands, and one of the two serving cells is not to be retuned, performing the interruption based at least in part on an earliest synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC, occasion for the serving cells for which activation status is to be changed. In some embodiments, the method also includes, when at least two bands of the number of bands have serving cells for which activation status is to be changed, determining whether there exists non-zero integers, Nm, fulfilling a condition that an SMTC offset for a serving cell, m, plus Nm times a synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC period for the serving cell is equal to an integer X. In some embodiments, when such non-zero integers, N_m, exist, performing the interruption before the second time, and when no such non-zero integers, N_m, exist, performing the interruption before the third time. In some embodiments, the time resource is any of symbol, slot and subframe. In some embodiments, a serving cell is any of a secondary cell, SCell, and special cell, SpCell. In some embodiments, changing the activation status of the serving cell includes at least one of serving cell activation, serving cell deactivation, serving cell setup, serving cell release, addition, reconfiguration of serving cell, direction serving cell activation and direction serving cell deactivation. According to another aspect, a WD is configured to communicate with a network node. The WD includes a radio interface configured to receive a serving cell activation command to change an activation status of a plurality of serving cells, the activation status including at least one of setup and released. The WD also includes processing circuitry in communication with the radio interface and configured to: when the plurality of serving cells have at least one active serving cell in a same frequency band as the plurality of serving cells, counting a number of bands of the frequency band that have serving cells with for which activation status is to be changed; when the number of bands is equal to one, perform an interruption to retune a radio frequency, RF, of operation of the WD before a first time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells for which activation status is to be changed; when the number of bands is greater than one and when a broadcast channel measurement timing configuration offset and periodicity cause an SSB/SMTC to have a temporal position that is a same value for all serving cells for which activation status is to be changed, perform an interruption to retune the RF of operation of the WD before a second time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells in a same band of the number of bands, the second time being a maximum value of a set of times for interruption operation for each band of the number of bands; and when the number of bands is greater than one and when the measurement timing configuration offset and periodicity cause an SSB/SMTC to have a temporal position that is not the same for all serving cells for which activation status is to be changed, perform an interruption to retune the RF of operation of the WD before a third time by which to retune the RF of operation, the third time being an earliest value of a set of times for performing an interruption for each band of the number of bands. According to this aspect, in some embodiments, the frequency band is FR1. In some embodiments, the first time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being

one of activated and deactivated in the one band and fulfilling at least one of: when the frequency band is FR1, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when the frequency band is FR2, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in the same time resource; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the second time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being activated in a band of the number of bands and

fulfilling at least one of: when at least two active serving cells are in a same band of the number of bands, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when there are not at least two active serving cells in a same band, a condition that the serving cells for which activation status is to be changed are transmitting SSB bursts; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the processing circuitry is further configured to perform the interruption based at least in part on synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC occasions in a first band of the number of bands followed by retuning the RF of operation based at least in part on SMTC occasions in a second band of the number of bands. In some embodiments, a number of interruptions due to retuning the RF of operation depends at least in part on a number of bands having both the at least one active serving cell and the serving cells for which activation status is to be changed. In some embodiments, the processing circuitry is further configured to determine when to retune an automatic gain control, AGC, of the WD based at least in part on a number of serving cells for which activation status is to be changed. In some embodiments, when two serving cells for which activation status is to be changed are in different bands of the number of bands, and one of the two serving cells is not to be retuned, performing the interruption based at least in part on an earliest SMTC occasion for the serving cells for which activation status is to be changed. In some embodiments, the processing circuitry is further configured to, when at least two bands of the number of bands have serving cells for which activation status is to be changed, determining whether there exists non-zero integers, Nm, fulfilling a condition that an SMTC offset for a serving cell, m, plus Nm times a synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC period for the serving cell is equal to an integer X. In some embodiments, when such non-zero integers, Nm, exist, retuning the RF of operation of the WD before the second time, and when no such non-zero integers, N_m, exist, processing circuitry is further configured to perform the interruption before the third time. In some embodiments, the time resource is any of symbol, slot and subframe. In some embodiments, a serving cell is any of a secondary cell, SCell, and special cell, SpCell. In some embodiments, changing the activation status of the serving cell includes at least one of serving cell activation, serving cell deactivation, serving cell setup, serving cell release, addition, reconfiguration of serving cell, direction serving cell activation and direction serving cell deactivation. BRIEF DESCRIPTION OF THE DRAWINGS A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: FIG.1 illustrates an example of Time –frequency grid of a legacy LTE FDD cell which is wider than the smallest DL system bandwidth of 1.4 MHz (72 subcarriers or 6 RBs); FIG.2 illustrates an example of: (a) SS block comprising four OFDM symbols, (b) SSB half-frame with SSB burst in SCS 15kHz numerology SSB, and (c) SSB burst periodicity with SMTC period {5,10,20,40,80,160ms}; FIG.3 illustrates an example of activation of two SCells with a single MAC CE command when one SCell (or spCell) is active (already activated) FIG.4 is a schematic diagram of an example network architecture illustrating a communication system connected via an intermediate network to a host computer according to the principles in the present disclosure; FIG.5 is a block diagram of a host computer communicating via a network node with a wireless device over an at least partially wireless connection according to some embodiments of the present disclosure; FIG.6 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for executing a client application at a wireless device according to some embodiments of the present disclosure; FIG.7 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a wireless device according to some embodiments of the present disclosure; FIG.8 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data from the wireless device at a host computer according to some embodiments of the present disclosure; FIG.9 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a host computer according to some embodiments of the present disclosure; FIG.10 is a flowchart of an example process in a wireless device according to some embodiments of the present disclosure; FIG.11 is a flowchart of another example process in a wireless device according to some embodiments of the present disclosure; FIG.12 illustrates an example flow chart according to some embodiments of the present disclosure; FIG.13 illustrates an example of RF tuning based on the earliest SMTC occasion for SCells being activated according to some embodiments of the present disclosure; FIG.14 illustrates an example of RF tuning based on only one of bands having SCell being activated and the active serving cell in the same band according to some embodiments of the present disclosure; FIG.15 illustrates an example of RF tuning when the SMTC offset is the same for all SCells being activated even in different bands, e.g., SCell1 in Band #0 and SCell 2 in Band # 1 have the same SMTC offset according to some embodiments of the present disclosure; FIG.16 illustrates an example of RF tuning when the SMTC offset is different for SCells being activated in different bands, e.g., SCell1 in Band #0 and SCell 2 in Band # 1 have different SMTC offsets according to some embodiments of the present disclosure; FIG.17 illustrates as same SMTC offset between cells being activated; FIG.18 illustrates cell activation with different SMTC offsets between cells being activated; and FIG.19 illustrates a common SMTC occasion for cells being activated with different SMTC configurations. DETAILED DESCRIPTION Multiple SCell activation delay for activation of multiple SCells is to be specified in the 3GPP Release 16 (3GPP Rel-16) scope of NR. The standardization work so far has focused on studying the relation and impact between the victim and aggressor SCells, but the further impact on active serving cells has not been fully considered. In early discussions, out of concern for the impact to active serving cells, only one interruption occasion was specified for the case when one single medium access control (MAC) control element (CE) command is received for activation of multiple SCells in the specification. When two SCells (SCell #0 and SCell #1 in FIG.3) are activated with a single MAC CE command, the RF re-tuning for the two SCells should be completed before the first complete SSB burst indicated by the SMTC of SCell0. Otherwise, the WD cannot meet the activation delay requirement for SCell0. However, the SCell 1 must wait for the AGC retuning occasion where active serving cell and SCell #1 are transmitting SSB bursts in the same slot. Thus, the active serving cell will have performance degradation due to poor AGC retuning up until the AGC retuning occasion. Here, the active serving cell can be an active SCell or SPcell. FIG.3 illustrates an example of activation of two SCells with a single MAC CE command when one SCell (or SPCell) is active (already activated). In some embodiments of the present disclosure, when multiple SCells are activated by the same MAC CE command, the WD will determine the RF retuning time based on the SMTC occasion T_{FirstSSB_MAX_multiple_scells}, where T_{FirstSSB_MAX_multiple_scells}: is the time ● only one of SCells being activated has active serving cell(s) _^

i = 1, 2, …, maxBands, when the SMTC offset is the same for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band; ●

_ maxBands, when: o all SCells being activated are on FR2; or o no additional AGC retuning is needed for all SCells being activated; or o no active serving cell(s) in the same band with the SCells being activated which need AGC retuning; or o SMTC offset is different for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band When the SCell of more than one band being activated have active serving cell(s) in the same band and SMTC offset is different, performance degradation can be expected for active serving cell(s) with SCell(s) being activated in the same band #i after min{T_{FirstSSB_MAX}, band #i} to the T_{FirstSSB_MAX}, band #i. The number maxBands is the maximum number of WD supported bands which have SCells being activated. The time T_{FirstSSB_MAX, band #k} is the T_{FirstSSB_MAX, band #i} time for the band #k which has active serving cell(s) and SCell being activated(s). T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n + for the SCell(s) being activated in band #i, further fulfilling:

● In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot; otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst. ● In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. Alternatively, the definition for T_{FirstSSB_MAX_multiple_scells} can be: T_{FirstSSB_MAX_multiple_scells}: is the time: ● T_{FirstSSB_MAX, band #k}, when only one of SCells being activated has active serving cell(s) in the same band; ● max {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when common SMTC occasion exists for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band; where, the common SMTC occasion can be defined as: ● there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: o SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. ● min {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when: o all SCells being activated are on FR2; or o no additional AGC retuning is needed for all SCells being activated; or o no active serving cell(s) in the same band with the SCells being activated which need AGC retuning; or o SMTC offset is different for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band When the SCell(s) of more than one band being activated have active serving cell(s) in the same band and SMTC offset is different, performance degradation can be expected for active serving cell(s) with SCell(s) being activated in the same band #i after min{T_{FirstSSB_MAX, band #i}} to the T_{FirstSSB_MAX, band #i}. where: ● maxBands is the maximum number of WD supported bands which have SCells being activated. ● T_{FirstSSB_MAX, band #k} is the T_{FirstSSB_MAX, band #i} time for the band #k which has active serving cell(s) and to-be-activated SCell(s). ● T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n + for the SCell(s) being

activated in band #i, further fulfilling: o In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot; otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst; and/or o In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. After optimizing the RF retuning occasion, the performance degradation duration and scenarios for active serving cells may be minimized as much as possible. Some embodiments are described for SCell activation but the embodiments are applicable also for SCell deactivation since the same command may be used for multiple SCell activation and/or deactivation. Hence, the term “SCell activation” can be read herein as “SCell activation and/or deactivation” or even more generally “SCell setup or release” or even more generally “serving cell setup or release” or even more generally “cell setup or release”. For example “SCell or cell or serving cell setup or release” may further comprise any one or combination of the following procedures: addition, release, activation, Direct Activation, or deactivation, configuration, reconfiguration of a cell, where ‘cell’ can be for example an SCell, PSCell, etc. Some embodiments are described for SCell activation but the embodiments are applicable also for direct SCell activation of multiple downlink SCells at SCell addition since the same multiple activation procedure may be used. Some embodiments are applicable for SCells operating in any frequency range (FR) or any combinations of FRs, e.g., all SCells belonging to FR# 1 (FR1), all SCells belonging to FR#2 (FR2), some SCells belonging to FR1 while others to FR2 etc. The frequencies in FR1 are lower than those belonging to FR2. For example, FR1 may include frequencies between 400 MHz to 7 GHz; and FR2 may include frequencies between 24 GHz to 52.6 GHz etc. In some embodiments, operations to reconfigure RF in response to multiple SCell activation commands are performed on the condition that SCells being activated will retune AGC gain with the active serving cells in the same band based on an SMTC occasion other than the earliest SMTC occasion for SCells being activated, thereby minimizing the performance degradation for active serving cells. Some embodiments may advantageously provide that the WD will avoid longer inappropriate AGC settings for active serving cells when performing multiple SCell activation. There may also be a reduced missed ACK/NACK rate caused by the inappropriate AGC setting. This may result in higher system and end-user throughputs with less impact to outer loop link adaptation and serving cell performance, in general. Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to arrangements for control interruption for active serving cell on multiple Scell activation. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description. As used herein, relational terms, such as “first” and “second,” “top” and “bottom,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication. In some embodiments described herein, the term “coupled,” “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections. The term “network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term “radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node. In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein can be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device, etc. Also, in some embodiments the generic term “radio network node” is used. It can be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH). Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure. Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Some embodiments provide arrangements for control interruption for active serving cell on multiple Scell activation. Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG.4 a schematic diagram of a communication system 10, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network 12, such as a radio access network, and a core network 14. The access network 12 comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes 16), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices 22) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node 16. Note that although only two WDs 22 and three network nodes 16 are shown for convenience, the communication system may include many more WDs 22 and network nodes 16. Also, it is contemplated that a WD 22 can be in simultaneous communication and/or configured to separately communicate with more than one network node 16 and more than one type of network node 16. For example, a WD 22 can have dual connectivity with a network node 16 that supports LTE and the same or a different network node 16 that supports NR. As an example, WD 22 can be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN. The communication system 10 may itself be connected to a host computer 24, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 24 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 26, 28 between the communication system 10 and the host computer 24 may extend directly from the core network 14 to the host computer 24 or may extend via an optional intermediate network 30. The intermediate network 30 may be one of, or a combination of more than one of, a public, private or hosted network. The intermediate network 30, if any, may be a backbone network or the Internet. In some embodiments, the intermediate network 30 may comprise two or more sub-networks (not shown). The communication system of FIG.4 as a whole enables connectivity between one of the connected WDs 22a, 22b and the host computer 24. The connectivity may be described as an over-the-top (OTT) connection. The host computer 24 and the connected WDs 22a, 22b are configured to communicate data and/or signaling via the OTT connection, using the access network 12, the core network 14, any intermediate network 30 and possible further infrastructure (not shown) as intermediaries. The OTT connection may be transparent in the sense that at least some of the participating communication devices through which the OTT connection passes are unaware of routing of uplink and downlink communications. For example, a network node 16 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 24 to be forwarded (e.g., handed over) to a connected WD 22a. Similarly, the network node 16 need not be aware of the future routing of an outgoing uplink communication originating from the WD 22a towards the host computer 24. A network node 16 is configured to include a configuration unit 32 which is configured to cause the network node 16 to send a command to the WD 22 to activate the plurality of Scells. A wireless device 22 is configured to include an interruption unit 34 which is configured to perform an interruption to retune an RF frequency of the WD before a certain time based on serving cells to be activated in multiple frequency bands. Example implementations, in accordance with an embodiment, of the WD 22, network node 16 and host computer 24 discussed in the preceding paragraphs will now be described with reference to FIG.5. In a communication system 10, a host computer 24 comprises hardware (HW) 38 including a communication interface 40 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 10. The host computer 24 further comprises processing circuitry 42, which may have storage and/or processing capabilities. The processing circuitry 42 may include a processor 44 and memory 46. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 42 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 44 may be configured to access (e.g., write to and/or read from) memory 46, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read- Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Processing circuitry 42 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by host computer 24. Processor 44 corresponds to one or more processors 44 for performing host computer 24 functions described herein. The host computer 24 includes memory 46 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 48 and/or the host application 50 may include instructions that, when executed by the processor 44 and/or processing circuitry 42, causes the processor 44 and/or processing circuitry 42 to perform the processes described herein with respect to host computer 24. The instructions may be software associated with the host computer 24. The software 48 may be executable by the processing circuitry 42. The software 48 includes a host application 50. The host application 50 may be operable to provide a service to a remote user, such as a WD 22 connecting via an OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the remote user, the host application 50 may provide user data which is transmitted using the OTT connection 52. The “user data” may be data and information described herein as implementing the described functionality. In one embodiment, the host computer 24 may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry 42 of the host computer 24 may enable the host computer 24 to observe, monitor, control, transmit to and/or receive from the network node 16 and/or the wireless device 22. The processing circuitry 42 of the host computer 24 may include a monitor unit 54 configured to enable the service provider to observe, monitor, control, transmit to and/or receive from the network node 16 and/or the wireless device 22. The communication system 10 further includes a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the host computer 24 and with the WD 22. The hardware 58 may include a communication interface 60 for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system 10, as well as a radio interface 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 62 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The communication interface 60 may be configured to facilitate a connection 66 to the host computer 24. The connection 66 may be direct or it may pass through a core network 14 of the communication system 10 and/or through one or more intermediate networks 30 outside the communication system 10. In the embodiment shown, the hardware 58 of the network node 16 further includes processing circuitry 68. The processing circuitry 68 may include a processor 70 and a memory 72. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 68 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 70 may be configured to access (e.g., write to and/or read from) the memory 72, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Thus, the network node 16 further has software 74 stored internally in, for example, memory 72, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node 16 via an external connection. The software 74 may be executable by the processing circuitry 68. The processing circuitry 68 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node 16. Processor 70 corresponds to one or more processors 70 for performing network node 16 functions described herein. The memory 72 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16. For example, processing circuitry 68 of the network node 16 may be configured to perform network node methods discussed herein. The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 82 may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The hardware 80 of the WD 22 further includes processing circuitry 84. The processing circuitry 84 may include a processor 86 and memory 88. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 84 may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor 86 may be configured to access (e.g., write to and/or read from) memory 88, which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). Thus, the WD 22 may further comprise software 90, which is stored in, for example, memory 88 at the WD 22, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD 22. The software 90 may be executable by the processing circuitry 84. The software 90 may include a client application 92. The client application 92 may be operable to provide a service to a human or non-human user via the WD 22, with the support of the host computer 24. In the host computer 24, an executing host application 50 may communicate with the executing client application 92 via the OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the user, the client application 92 may receive request data from the host application 50 and provide user data in response to the request data. The OTT connection 52 may transfer both the request data and the user data. The client application 92 may interact with the user to generate the user data that it provides. The processing circuitry 84 may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD 22. The processor 86 corresponds to one or more processors 86 for performing WD 22 functions described herein. The WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22. For example, the processing circuitry 84 of the wireless device 22 may include an interruption unit 34 configured to perform WD methods discussed herein, such as the methods discussed with reference to FIG.10 as well as other figures. In some embodiments, the inner workings of the network node 16, WD 22, and host computer 24 may be as shown in FIG.5 and independently, the surrounding network topology may be that of FIG.4. In FIG.5, the OTT connection 52 has been drawn abstractly to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from the service provider operating the host computer 24, or both. While the OTT connection 52 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network). The wireless connection 64 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the WD 22 using the OTT connection 52, in which the wireless connection 64 may form the last segment. More precisely, the teachings of some of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 52 between the host computer 24 and WD 22, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 52 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 48, 90 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 52 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary WD signaling facilitating the host computer’s 24 measurements of throughput, propagation times, latency and the like. In some embodiments, the measurements may be implemented in that the software 48, 90 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 52 while it monitors propagation times, errors etc. Thus, in some embodiments, the host computer 24 includes processing circuitry 42 configured to provide user data and a communication interface 40 that is configured to forward the user data to a cellular network for transmission to the WD 22. In some embodiments, the cellular network also includes the network node 16 with a radio interface 62. In some embodiments, the network node 16 is configured to, and/or the network node’s 16 processing circuitry 68 is configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the WD 22, and/or preparing/terminating/ maintaining/supporting/ending in receipt of a transmission from the WD 22. In some embodiments, the host computer 24 includes processing circuitry 42 and a communication interface 40 that is configured to a communication interface 40 configured to receive user data originating from a transmission from a WD 22 to a network node 16. In some embodiments, the WD 22 is configured to, and/or comprises a radio interface 82 and/or processing circuitry 84 configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/ supporting/ending a transmission to the network node 16, and/or preparing/ terminating/maintaining/supporting/ending in receipt of a transmission from the network node 16. Although FIGS.4 and 5 show various “units” such as configuration unit 32, and determination unit 34 as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry. FIG.6 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIGS.4 and 5, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIG.5. In a first step of the method, the host computer 24 provides user data (Block S100). In an optional substep of the first step, the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50 (Block S102). In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S104). In an optional third step, the network node 16 transmits to the WD 22 the user data which was carried in the transmission that the host computer 24 initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block S106). In an optional fourth step, the WD 22 executes a client application, such as, for example, the client application 92, associated with the host application 50 executed by the host computer 24 (Block S108). FIG.7 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.4 and 5. In a first step of the method, the host computer 24 provides user data (Block S110). In an optional substep (not shown) the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50. In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block S112). The transmission may pass via the network node 16, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step, the WD 22 receives the user data carried in the transmission (Block S114). FIG.8 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.4 and 5. In an optional first step of the method, the WD 22 receives input data provided by the host computer 24 (Block S116). In an optional substep of the first step, the WD 22 executes the client application 92, which provides the user data in reaction to the received input data provided by the host computer 24 (Block S118). Additionally or alternatively, in an optional second step, the WD 22 provides user data (Block S120). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application 92 (Block S122). In providing the user data, the executed client application 92 may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD 22 may initiate, in an optional third substep, transmission of the user data to the host computer 24 (Block S124). In a fourth step of the method, the host computer 24 receives the user data transmitted from the WD 22, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126). FIG.9 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG.4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS.4 and 5. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 16 receives user data from the WD 22 (Block S128). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (Block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (Block S132). FIG.10 is a flowchart of an example process in a wireless device 22 according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by WD 22 may be performed by one or more elements of WD 22 such as by interruption unit 34 in processing circuitry 84, processor 86, radio interface 82, etc. The example method includes as a result of initiating activation of a plurality of secondary cells (SCells), determining (Block S134), such as via determination unit 34, processing circuitry 84, processor 86 and/or radio interface 82, whether there is at least one currently active cell for the WD in a same frequency band as at least one Scell of the plurality of Scells being activated. The method includes identifying (Block S136), such as via determination unit 34, processing circuitry 84, processor 86 and/or radio interface 82, a radio frequency (RF) retuning occasion for the at least one Scell based at least in part on the determination about the at least one currently active cell. The method includes performing (Block S138), such as via determination unit 34, processing circuitry 84, processor 86 and/or radio interface 82, RF retuning according to the identified RF retuning occasion (S138). FIG.11 is a flowchart of an example process in a wireless device 22 according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by WD 22 may be performed by one or more elements of WD 22 such as by determination unit 34 in processing circuitry 84, processor 86, radio interface 82, etc. The example method includes: receiving a serving cell activation command to change an activation status of a plurality of serving cells, the activation status including at least one of setup and released (Block S140). The method includes, when the plurality of serving cells have at least one active serving cell in a same frequency band as the plurality of serving cells, counting a number of bands of the frequency band that have serving cells for which activation status is to be changed (Block S142). The method also includes, when the number of bands is equal to one, performing an interruption to retune a radio frequency, RF, of operation of the WD before a first time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells for which activation status is to be changed (Block S144). The method also includes, when the number of bands is greater than one and when a broadcast channel measurement timing configuration offset and periodicity cause an SSB/SMTC to have a temporal position that is a same value for all serving cells for which activation status is to be changed, performing an interruption to retune the RF of operation of the WD before a second time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells in a same band of the number of bands, the second time being a maximum value of a set of times for interruption operation for each band of the number of bands (Block S146). The method further includes, when the number of bands is greater than one and when the measurement timing configuration offset and periodicity cause the SSB/SMTC to have a temporal position that is not the same for all serving cells for which activation status is to be changed, performing an interruption to retune the RF of operation of the WD before a third time by which to retune the RF of operation, the third time being an earliest value of a set of times for performing an interruption for each band of the number of bands (Block S148). In some embodiments, the frequency band is FR1. In some embodiments, the first time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being one of activated and

deactivated in the one band and fulfilling at least one of: when the frequency band is FR1, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when the frequency band is FR2, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in the same time resource, where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the second time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + ^ being activated in a band of the number of bands and fulfilling at least

one of: when at least two active serving cells are in a same band of the number of bands, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when there are not at least two active serving cells in a same band, a condition that the serving cells for which activation status is to be changed are transmitting SSB bursts; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology. In some embodiments, the method also includes performing the interruption based at least in part on synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC occasions in a first band of the number of bands followed by performing the interruption based at least in part on SMTC occasions in a second band of the number of bands. In some embodiments, a number of interruptions to retune the RF of operation depends at least in part on a number of bands having both the at least one active serving cell and the serving cells for which activation status is to be changed. In some embodiments, the method also includes determining when to retune an automatic gain control, AGC, of the WD based at least in part on a number of serving cells for which activation status is to be changed. In some embodiments, the method includes, when two serving cells for which activation status is to be changed are in different bands of the number of bands, and one of the two serving cells is not to be retuned, performing the interruption based at least in part on an earliest synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC, occasion for the serving cells for which activation status is to be changed. In some embodiments, the method also includes, when at least two bands of the number of bands have serving cells for which activation status is to be changed, determining whether there exists non-zero integers, N_m, fulfilling a condition that an SMTC offset for a serving cell, m, plus N_m times a synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC period for the serving cell is equal to an integer X. In some embodiments, when such non-zero integers, Nm, exist, performing the interruption before the second time, and when no such non-zero integers, N_m, exist, performing the interruption before the third time. In some embodiments, the time resource is any of symbol, slot and subframe. In some embodiments, a serving cell is any of a secondary cell, SCell, and special cell, SpCell. In some embodiments, changing the activation status of the serving cell includes at least one of serving cell activation, serving cell deactivation, serving cell setup, serving cell release, addition, reconfiguration of serving cell, direction serving cell activation and direction serving cell deactivation. In some embodiments, initiation of the activation of the plurality of Scells is responsive to the WD receiving a MAC CE message to activate the plurality of Scells. In some embodiments, identification of the RF retuning occasion is based at least in part on one of (i) an earliest SMTC occasion amongst SMTC occasions for the plurality of Scells being activated; and (ii) other than the earliest SMTC occasion, the one of the earliest SMTC occasion and the other than the earliest SMTC occasion being based at least one part on the determination about the at least one currently active cell. In some embodiments, the one of the earliest SMTC occasion and the other than the earliest SMTC occasion and/or the identification of the RF retuning occasion being further based on at least one of: how many bands have active serving cells and Scells being activated and whether an SMTC offset is the same for each of the plurality of Scells being activated. In some embodiments, performance of the RF retuning comprises RF retuning the at least one Scell in the same frequency band as the currently active cell during the determined RF retuning occasion. In some embodiments, performance of the RF retuning further comprises retuning all the plurality of Scells during the determined RF retuning occasion. In some embodiments, performance of the RF retuning further comprises RF retuning Scells not on the same frequency band as any currently active cell during a different RF retuning occasion. In some embodiments, the method may include communicating (i.e., transmitting and/or receiving signaling) on the at least one Scell after the RF retuning and the activation. Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for control interruption for active serving cell on multiple Scell activation, which may be implemented by the network node 16, wireless device 22 and/or host computer 24. An example process is described with reference to the flowchart of FIG.12 as follows: Step 1 Upon receiving the SCell activation command (e.g., MAC-CE, reconfiguration message, etc.), the WD 22 checks one or more of the following conditions: If either of the following is fulfilled: -step 1-1: if none of the SCells being activated require AGC retuning, i.e., gain search and gain setting based on signal strength measurements on the downlink; or - step 1-2: if one or more of the SCells being activated require AGC retuning, but neither of those SCells are in the same band as an active serving cell, then the process proceeds to: step 1-3: the WD 22 carries out RF retuning before the earliest SMTC occasion over the set of SCells being activated. Otherwise, the WD 22 continues to Step 2 below. An example is provided in FIG.13, where there are two SCells being activated (SCell #0, SCell #1) in different bands (band #0, band #1). If SCell #1 does not need AGC retuning (gain search and gain setting by means of signal strength measurements on downlink), or if only SCell #0 needs AGC retuning, the WD 22 will retune the RF based on the earliest SMTC occasion for SCells being activated. Step 2 If SCells being activated have active serving cells in the same band, the WD 22 will count how many bands have both SCells being activated and the active serving cells. If there is only one band which has an SCell being activated and the active serving cell(s) in the same band, go to step 3; If two or more bands have SCells being activated and the active serving cells in the same band, go to step 4. Step 3 When the WD 22 immediately retunes the RF after the MAC CE command to meet the requirement for SCells being activated (such as SCell #0) which has the shortest TFirstSSB_MAX, the performance degradation for active serving cell in band #1 will be expected (see FIG.14). To minimize the impact to the active serving cell, the RF retuning time may be based on the SCell being activated which has the active serving cell in the same band. Thus, the existing definition of T_{FirstSSB_MAX_multiple_scells} for multiple SCell activation currently used in the standard may be updated as follows. Introduce T_{FirstSSB_MAX, band #i} , where T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n for t

e SCell(s) being activated in band #i, and further fulfilling:

● In FR1, in case of an active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same time resource (e.g., symbols, slot, subframe etc.); otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst; ● -In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. FIG.14 illustrates an example of RF tuning based on only one of bands having SCell being activated and the active serving cell in the same band. When only one of the SCells being activated has an active serving cell in the same band, T_{FirstSSB_MAX_multiple_scells} may be updated to be the T_{FirstSSB_MAX, band #k}, where, T_{FirstSSB_MAX, band #k} is the time for the SCell being activated in band #k which has the active serving cells in the same band. Returning to FIG.12: Step 4 When two or more bands have SCells being activated and active serving cells in the same band, the WD 22 may further check whether the SMTC offset is the same for all SCells being activated even across different bands. If yes, go to step 5; If no, go to step 6. Alternatively, the WD 22 may check that for the K SCells being activated, there exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the mth cell in the set of K SCells to be activated. If such set and such integer value X exist, there will be a common time period over which the SMTCs on the different carriers coincide. Hence here it is not required that SMTC offsets are the same on all carriers. It is however a necessary but not sufficient condition that the following is fulfilled: modulo(SMTC offset#m, minimum_SMTC_period) = Y, for m=1,...,K, where minimum_SMTC_period = min(SMTC period#1, SMTC_period#2, ..., SMTC period #K) If such set of non-zero integers and such integer value X exist, go to step 5; Otherwise, go to step 6. Returning to FIG.12: Step 5 If the WD 22 immediately retunes the RF based on the earliest T_{FirstSSB_MAX}, the active serving cells which are in the same band with the latter SCells being activated will potentially experience a performance degradation. To avoid the performance degradation for the active serving cells, the RF retuning occasion may be based on the longest T_{FirstSSB_MAX} because more than one of SCells being activated have active serving cells in their bands. When SMTC offset are the same for all SCells being activated and at least one of the SCell being activated has active serving cell in the same band, the T_{FirstSSB_MAX_multiple_scells} may be updated to be max{T_{FirstSSB_MAX, band #i}}, i=0,1,…, where, T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n in t

same band for SCell being activated in band #i, further fulfilling: ● -in case of active serving cells in the same band, the occasion when all active serving cells and SCells being activated or released are transmitting SSB bursts in the same time resource (e.g., symbols, slot, subframe etc.); and ● -otherwise, the first occasion when the SCells being activated are transmitting SSB bursts. Based on this update, the active serving cell won’t be disturbed by the AGC retuning in the same band. FIG.15 illustrates an example of RF tuning when the SMTC offset is the same for all SCells being activated even in different bands, e.g., SCell1 in Band #0 and SCell 2 in Band # 1 have the same SMTC offset. Returning to FIG.12: Step 6. If WD 22 is just permitted only one RF retuning occasion, the performance degradation (e.g., interruption of signals in some time resources such as symbols, slots, subframes etc.) for some active serving cells can be expected based on current 3GPP specifications, because more than one of the SCells being activated have active serving cells in the same band. From the network’s perspective, it may be important to let the network know the accurate possible performance degradation duration for some active serving cells once the clear requirement is defined. This enables the network (e.g., serving base station) to adapt the scheduling of signals to the WD 22. For example, during the interrupted time resources the network node may refrain from scheduling the WD 22. FIG.16 illustrates an example of RF tuning when the SMTC offset is different for SCells being activated in different bands, e.g., SCell1 in Band #0 and SCell 2 in Band # 1 have different SMTC offset. A further enhancement for this scenario is to permit multiple RF retuning times. The WD 22 may first retune the RF based on SMTC occasions T_{FirstSSB_MAX, band} , but not retune the RF for band #1. After that, the WD 22 may c nd #0 hoose the 2 RF retuning occasions based on T_{FirstSSB_MAX}, band #1. Multiple interruptions may be expected. The number of interruptions (e.g., number of time resources where signals are interrupted) may depend on the number of bands having both SCells being activated and the active serving cells in the same band. Applicable to Direct SCell activation Although some embodiments are described above in the context of SCell activation of configured but deactivated SCells, the described embodiments can also be applied for so called Direct SCell activation, whereby multiple SCells are directly activated upon SCell addition (via radio resource control (RRC) reconfiguration) or upon handover or PSCell change (via RRC reconfiguration). In Direct SCell activation, the WD 22 may not wait for a MAC SCell activation command when the SCell is added in activated state. In Direct SCell activation, the SCell activation as described above may be started when the WD 22 has finished the RRC processing for the SCell addition, or when the WD 22 has completed the handover or PSCell change procedure (random access towards PCell or PSCell). Some embodiments may include one or more of the following: Embodiment A1. A wireless device (WD) configured to communicate with a network node, the WD configured to, and/or comprising a radio interface and/or processing circuitry configured to: as a result of initiating activation of a plurality of secondary cells (SCells), determine whether there is at least one currently active cell for the WD in a same frequency band as at least one Scell of the plurality of SCells being activated; identify a radio frequency (RF) retuning occasion for the at least one Scell based at least in part on the determination about the at least one currently active cell; and perform RF retuning according to the identified RF retuning occasion. Embodiment A2. The WD of Embodiment A1, wherein initiation of the activation of the plurality of Scells is responsive to the WD receiving a MAC CE message to activate the plurality of Scells. Embodiment A3. The WD of any one of Embodiments A1 and A2, wherein identification of the RF retuning occasion is based at least in part on one of (i) an earliest SMTC occasion amongst SMTC occasions for the plurality of Scells being activated; and (ii) other than the earliest SMTC occasion, the one of the earliest SMTC occasion and the other than the earliest SMTC occasion being based at least one part on the determination about the at least one currently active cell. Embodiment A4. The WD of any one of Embodiments A1-A3, wherein the one of the earliest SMTC occasion and the other than the earliest SMTC occasion and/or the identification of the RF returning occasion being further based on at least one of: how many bands have active serving cells and Scells being activated and whether an SMTC offset is a same for each of the plurality of Scells being activated. Embodiment B1. A method implemented in a wireless device (WD), the method comprising: as a result of initiating activation of a plurality of secondary cells (SCells), determining whether there is at least one currently active cell for the WD in a same frequency band as at least one Scell of the plurality of Scells being activated; identifying a radio frequency (RF) retuning occasion for the at least one Scell based at least in part on the determination about the at least one currently active cell; and performing RF retuning according to the identified RF retuning occasion. Embodiment B2. The method of Embodiment B1, wherein initiation of the activation of the plurality of Scells is responsive to the WD receiving a MAC CE message to activate the plurality of Scells. Embodiment B3. The method of any one of Embodiments B1 and B2, wherein identification of the RF retuning occasion is based at least in part on one of (i) an earliest SMTC occasion amongst SMTC occasions for the plurality of Scells being activated; and (ii) other than the earliest SMTC occasion, the one of the earliest SMTC occasion and the other than the earliest SMTC occasion being based at least one part on the determination about the at least one currently active cell. Embodiment B4. The method of any one of Embodiments B1-B3, wherein the one of the earliest SMTC occasion and the other than the earliest SMTC occasion and/or the identification of the RF returning occasion being further based on at least one of: how many bands have active serving cells and Scells being activated and whether an SMTC offset is a same for each of the plurality of Scells being activated. The following provides information that may be relevant to the embodiments disclosed herein: Example A: 1 INTRODUCTION In RAN4 #98-e meeting, a WF for multiple SCell activation was approved [1]. In RAN4 #98-bis-e meeting, RAN4 still hadn’t achieved the agreements on one of the remaining issue as follow.

In this contribution, we will further discussion on this remaining issue. 2 BACKGROUND In current TS38.133, the interruption due to SCell activation had been defined as follow. The interruption length includes both RF retuning and the first AGC retuning time for intra-band SCell activation.

1.1.1.1.1 8.2.2.2.2 Interruptions at SCell activation/deactivation When an intra-band SCell is activated or deactivated as defined in TS 37.340 [17], the UE is allowed - an interruption on any active serving cell: - of up to X2 slot, if the active serving cell and the SCell being activated or deactivated are in a FR1 band pair or in a FR1+FR2 band pair. - of up to X2 slot, if the active serving cell and the SCell being activated or deactivated are in a FR2 band pair and UE is capable of independent beam management on this FR2 band pair. Where X2 is specified in Table 8.2.2.2.2-1. or - of up to the duration shown in table 8.2.2.2.2-2, if the active serving cells are in the same band as any of the SCells being activated or deactivated provided the cell specific reference signals from the active serving cells and the SCells being activated or deactivated are available in the same slot. Table 8.2.2.2.2-1: Interruption length X2 for SCell activation/deactivation for inter-band CA

When RAN4 discussed the requirements for multiple SCell activation, single RF retuning is expected when single MAC CE command is configured[2]. • Agreement in RAN4 #95e: – Single interruption due to RF tuning/retuning shall be assumed when one single MAC CE command is received for multiple SCell activation. In last meeting, some companies raised one issue to illustrate the negative impact for SMTC offset misalignment. When two SCells (SCell #0 and SCell #1) are activated with a single MAC CE, and the SMTC offset for them are misaligned, the RF re-tuning for these two SCells needs to be done before the first complete SSB burst indicated by the SMTC of SCell0, as otherwise UE cannot meet the activation delay requirement for SCell0. However, the SCell 1 had to wait the AGC retuning occasion until active serving cell and SCell #1 are transmitting SSB bursts in the same slot. Thus, the active serving cell will have performance degradation due to poor AGC retuning during this waiting time. Thus, to avoid this issue, some companies suggest RAN4 shall define applicability rule for only apply the multiple SCell activation requirement when SMTC offset is same for all SCells being activated by the same MAC CE. When we further studied this issue, we found it still cannot solve the performance degradation issue for active serving cells even when RAN4 applies the multiple SCell requirements for same SMTC offset among the SCells being activated by the same MAC CE. For example, when SCell #0, SCell #1 and active serving cell have the same SMTC offset, but active serving cell has a larger periodicity than SCell being activated, the AGC retuning occasion shall be the T_{FirstSSB_MAX} where the occasion is all active serving cells and SCells being activated transmitting SSB bursts in the same slot. Thus, if the same activation delay requirement for SCell #0 is applied, SCell #1 cannot adjust the AGC immediately after RF retuning. The active serving cell will face the same performance degradation due to poor AGC retuning during the waiting time. FIG.17 shows a same SMTC offset between SCells being activated. Observation 1: Aligning SMTC offset cannot solve the performance degradation on active serving cells when active serving cells have the different SMTC periodicity with SCells being activated in the same band. During Rel-16 multiple SCell activation discussion, RAN4 just studied the relation and impact between the victim and aggressor SCells, but RAN4 hadn’t discussed the further impact due to active serving cells. Thus, RAN4 shall define a unified framework to solve this remaining issue on multiple SCell activation. 3. Scenarios Based on current multiple SCell activation applicability rule, any to-be- activated unknown SCell shall have active serving cell(s) or known SCell being activated(s) on the same band. The issue is SCell being activated needs additional AGC retuning which is based on the SSB transmission occasion for all the active serving cells and SCells being activated. Firstly, we list the scenarios which has no performance degradation issue as follow. ● FR2 In FR2, when to-be-activated unknown SCells have active serving cell(s) or known SCell being activated(s) on the same band, no additional AGC retuning is needed. ● All SCells being activated don’t need AGC retuning In this scenario, no additional AGC retuning is needed for the SCell being activated. ● No active serving cell in the same band with the SCell being activated which needs AGC retuning In this scenarios, AGC retuning doesn’t need to wait the SSB for active serving cell in the same band and no additional interruption due to intra-band AGC retuning is needed. Thus, no requirement update is needed for above scenarios. Proposal 1: There is no performance degradation issue for active serving cells due to AGC retuning for SCell being activated when ● unknown SCells being activated have active serving cell(s) or known SCell being activated(s) on the same band in FR2, or ● all SCells being activated don’t need AGC retuning, or ● no active serving cell in the same band with the SCell being activated which needs AGC retuning Furthermore, we will consider the scenarios with additional interruption due to AGC retuning in FR1. To simplify the analysis, we firstly consider the scenario with only one band has both SCells being activated and active serving cells. Case 1: Only one band’s SCell(s) being activated has active serving cells in the same band When UE immediately retunes the RF after MAC CE command to meet the requirement for SCells being activated(such as SCell #0) which has the shortest T_{FirstSSB_MAX}, the performance degradation for active serving cell in band #1 will be expected(left figure in Error! Reference source not found.). To minimize the impact to active serving cell, the RF retuning time shall be based on the SCell being activated which has the active serving cell in the same band. On the contrary, in right figure for Error! Reference source not found., the SCell #1 which has active serving cell in the same band shall immediately retunes the RF after the MAC CE command. Proposal 2: To avoid the performance degradation for active serving cell, RF retuning occasion shall base on the SCell(s) which has active serving cells in the same band other than any SCell which has the earliest SMTC occasion after T_HARQ+3ms. FIG.18 shows SCell activation when different SMTC offset between SCells are being activated (Case 1). Case 2: Two or More bands have the SCells being activated and active serving cells in the same band We further consider the scenarios when two or more bands have the SCells being activated and active serving cells in the same band. Firstly, we want to introduce a definition for ‘common SMTC occasion’ as follow, where UE can detect the SMTCs for all SCells being activated at a common occasion. there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. For example, if one SCell SMTC configuration is {periodicity = 80ms, offset = 40ms}, another SCell configuration is {periodicity = 40ms, offset = 0ms}, we can still find a SMTC occasion where UE can detect both SCells’ SMTC. FIG.19 shows a common SMTC occasion for SCells being activated with different SMTC configuration. Proposal 3: Define ‘common SMTC occasion’ when two or more bands have the SCells being activated and active serving cells in the same band as follow. there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. ● Case 2-1: common SMTC occasion exists among SCells being activated If the UE immediately retunes the RF based on the earliest T_{FirstSSB_MAX}, the active serving cells which are in the same band with the latter SCells being activated will potentially experience a performance degradation. To avoid the performance degradation for the active serving cells, the RF retuning occasion shall be based on the longest T_{FirstSSB_MAX} because more than one of SCells being activated have active serving cells in their bands. When common SMTC occasion exists for all SCells being activated and more than one band has at least one of the SCell being activated and the active serving cell(s) in the same band, the RF retuning occasion shall base on the common SMTC occasion for all SCells being activated. Based on this update, all the active serving cells’ scheduling won’t be disturbed by the AGC retuning in the same band. Proposal 4: When common SMTC occasion exists for all SCells being activated and more than one band has the SCell being activated and the active serving cell(s) in the same band, the RF retuning occasion shall base on the common SMTC occasion for all SCells being activated. ● Case 2-2: SMTC offset misalignment among SCells being activated In this scenario, if RAN4 just permit only one RF retuning occasion, the performance degradation for some active serving cells can be expected based on current specification because more than one of the SCells being activated have active serving cells in the same band. From network’s perspective, it’s important to let network know the accurate performance degradation duration for active serving cells. Thus, a clear requirement shall also be defined in this scenario. The further enhancement for this scenario can be considered in next release. Proposal 5: When common SMTC occasion non-exists for SCells being activated and more than band has the SCell(s) being activated and active serving cell(s) in the same band, the performance degradation for active serving cells which are in the same band with latter SCells being activated is expected. RAN4 should further enhance this scenario in the latter release. Thus, T_{FirstSSB_MAX_multiple_scells} definition for multiple SCell activation shall be updated. Proposal 6: The T_{FirstSSB_MAX_multiple_scells} definition for multiple SCell activation requirement shall be updated as follows. T_{FirstSSB_MAX_multiple_scells}: is the time - T_{FirstSSB_MAX, band #k}, when only one band’s SCell(s) being activated has active serving cell(s) in the same band; - max {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when common SMTC occasion exists for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band; Where, the common SMTC occasion can be defined as there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. - min {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when -all SCells being activated are on FR2, or -no additional AGC retuning is needed for all SCells being activated, or -no active serving cell(s) in the same band with the SCells being activated which need AGC retuning, or -SMTC offset is different for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band When more than one bands’ SCell(s) being activated have active serving cell(s) in the same band and SMTC offset is different, performance degradation can be expected for active serving cell(s) with SCell(s) being activated in the same band #i after min{ T_{FirstSSB_MAX, band #i}} to the T_{FirstSSB_MAX}, b_{and #i}. Where, maxBands is the maximum number of UE supported bands which have SCells being activated. T_{FirstSSB_MAX, band #k} is the T_{FirstSSB_MAX, band #i} time for the band #k which has active serving cell(s) and to-be-activated SCell(s). T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot for the SCell(s)

being activated in band #i, further fulfilling: - In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot; otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst. - In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. 3. CONCLUSION In the contribution, we discuss the remaining issues for multiple SCell activation. We have the following proposals: Observation 1: Aligning SMTC offset cannot solve the performance degradation on active serving cells when active serving cells have the different SMTC periodicity with SCells being activated in the same band. Proposal 1: There is no performance degradation issue for active serving cells due to AGC retuning for SCell being activated when ● to-be-activated unknown SCells have active serving cell(s) or known SCell being activated(s) on the same band in FR2, or ● all SCells being activated don’t need AGC retuning, or ● no active serving cell in the same band with the SCell being activated which needs AGC retuning Proposal 2: To avoid the performance degradation for active serving cell, RF retuning occasion shall base on the SCell(s) which has active serving cells in the same band other than any SCell which has the earliest SMTC occasion after THARQ+3ms. Proposal 3: Define ‘common SMTC occasion’ when two or more bands have the SCells being activated and active serving cells in the same band as follow. there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. Proposal 4: When common SMTC occasion exists for all SCells being activated and more than one band has the SCell being activated and the active serving cell(s) in the same band, the RF retuning occasion shall base on the common SMTC occasion for all SCells being activated. Proposal 5: When common SMTC occasion non-exists for SCells being activated and more than band has the SCell(s) being activated and active serving cell(s) in the same band, the performance degradation for active serving cells which are in the same band with latter SCells being activated is expected. RAN4 should further enhance this scenario in the latter release. Proposal 6: The T_{FirstSSB_MAX_multiple_scells} definition for multiple SCell activation requirement shall be updated as follows. T_{FirstSSB_MAX_multiple_scells}: is the time - T_{FirstSSB_MAX, band #k}, when only one band’s SCell(s) being activated has active serving cell(s) in the same band; - max {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when common SMTC occasion exists for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band; Where, the common SMTC occasion can be defined as there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. - min {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when -all SCells being activated are on FR2, or -no additional AGC retuning is needed for all SCells being activated, or -no active serving cell(s) in the same band with the SCells being activated which need AGC retuning, or -SMTC offset is different for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band When more than one bands’ SCell(s) being activated have active serving cell(s) in the same band and SMTC offset is different, performance degradation can be expected for active serving cell(s) with SCell(s) being activated in the same band #i after min{T_{FirstSSB_MAX, band #i}} to the T_{FirstSSB_MAX,} band #i. Where, maxBands is the maximum number of UE supported bands which have SCells being activated. T_{FirstSSB_MAX, band #k} is the T_{FirstSSB_MAX, band #i} time for the band #k which has active serving cell(s) and to-be-activated SCell(s). T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n for the SCell(s)

being activated in band #i, further fulfilling: - In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot; otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst. - In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. 3 REFERENCE [1]. R4-2103620, WF on R16 RRM enhancement part 3 – Multiple SCell activation, inter-frequency measurement without MG, FR2 inter-band CA, UE specific CBW change, Apple [2]. R4-2008994, WF on NR RRM enhancements – multiple SCell activation, Apple Example B 1.1.2 8.3.7 SCell Activation Delay Requirement for Deactivated SCell with Multiple Downlink SCells The requirements in this clause shall apply for the UE configured with more than one SCells. In EN-DC, NE-DC, standalone NR, or in one CG of NR-DC, the requirements in this clause shall apply when the following conditions are met: - UE only receives one single MAC command for multiple SCell activation within the activation period defined in this clause - in each single CG, there are no other SCell activation, deactivation, addition or release before activation is completed for all the SCells activated by the single MAC CE in this clause, and - in EN-DC and NE-DC, there are no E-UTRAN SCell activation, deactivation, addition or release before multiple SCell activation is completed in this clause, and - any to-be-activated unknown SCell has active serving cell(s) or known to-be-activated SCell(s) on the same band In two CGs of NR-DC, the requirements in this clause shall apply when the following conditions are met: - UE receives one MAC command per CG for multiple SCell activation within the activation period defined in this clause, and - UE supports per-FR measurement gap capability, and - any to-be-activated unknown SCell has active serving cell(s) or known to-be-activated SCell(s) on the same band The delay within which the UE shall be able to activate the deactivated SCell with other downlink to-be-activated SCell(s) depends upon the specified conditions. Upon receiving SCell activation command in slot n for more than one SCell, for each of the to-be-activated SCell, the UE shall be capable to transmit valid CSI report and apply actions related to the activation command for the SCell being activated no later than in slot n where:

T_HARQ (in ms) is the timing between DL data transmission and acknowledgement as specified in TS 38.213 [3] Tactivation_time_multiple_scells is the target SCell activation delay in millisecond in multiple SCell activation scenario. If the SCell is known and belongs to FR1 and the SCell measurement cycle is equal to or smaller than 160ms, Tactivation_time_multiple_scells is: - T_{FirstSSB_MAX_multiple_scells} + T_rs + 5ms, if on the same band UE also has at least one parallel to-be-activated SCell which is FR1 known Scell with the SCell measurement cycle larger than 160ms but does not have any parallel to-be-activated SCell which is FR1 unknown SCell. - T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells} + Trs + 5ms, if on the same band UE also has at least one parallel to-be-activated SCell which is FR1 unknown Scell - otherwise, T_{FirstSSB_MAX_multiple_scells} + 5ms. If the SCell is known and belongs to FR1 and the SCell measurement cycle is larger than 160ms, T_{activation_time_multiple_scells} is: - T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells} + T_rs + 5ms, if on the same band UE also has at least one parallel to-be-activated SCell which is FR1 unknown Scell - otherwise, T_{FirstSSB_MAX_multiple_scells} + Trs + 5ms If the SCell is unknown and belongs to FR1, provided that the side condition Ês/Iot ≥ -2dB is fulfilled, T_{activation_time_multiple_scells} is: - T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells}+T_rs +5ms, if the SCell is not counted in N1 - otherwise, T_{FirstSSB_MAX_multiple_scells} + T_{SMTC_MAX_multiple_scells}+T_rs*N₁ +T_rs +5ms If the SCell being activated belongs to FR2 and if there is at least one active serving cell on that FR2 band, then Tactivation_time_multiple_scells is same as single SCell activation delay requirement as defined in clause 8.3.2. If the SCell being activated belongs to FR2 and if there is at least one active serving cell on that FR2 band, if the UE is not provided with any SMTC for the target SCell, T_{activation_time_multiple_scells} is same as single SCell activation delay requirement as defined in clause 8.3.2 If the SCell being activated belongs to FR2 and if there is no active serving cell on that FR2 band provided that PCell or PSCell is FR1: If the target SCell is known to UE and semi-persistent CSI-RS is used for CSI reporting, then Tactivation_time_multiple_scells is same as single SCell activation delay requirement as defined in clause 8.3.2. If the target SCell is known to UE and periodic CSI-RS is used for CSI reporting, then Tactivation_time_multiple_scells is same as single SCell activation delay requirement as defined in clause 8.3.2. If the target SCell is unknown to UE and semi-persistent CSI- RS is used for CSI reporting, provided that the side condition Ês/Iot ≥ -2dB is fulfilled, then Tactivation_time_multiple_scells is: - 3 ms + max(T_{uncertainty_MAC_multiple_scells} +T_FineTiming + 2ms, T_{uncertainty_SP_multiple_scells}), if on the same band UE also has at least one parallel to-be-activated SCell which is FR2 known Scell. T_{uncertainty_MAC_multiple_scells} =0 and T_{uncertainty_SP_multiple_scells} =0 if UE receives the SCell activation command, semi-persistent CSI-RS activation command and TCI state activation commands at the same time. If the target SCell is unknown to UE and periodic CSI-RS is used for CSI reporting, provided that the side condition Ês/Iot ≥ -2dB is fulfilled, then Tactivation_time_multiple_scells is: - max(T_{uncertainty_MAC_multiple_scells} + 5ms + T_FineTiming, T_{uncertainty_RRC_multiple_scells} + T_{RRC_delay}-T_HARQ), if on the same band UE also has at least one parallel to-be-activated SCell which is FR2 known Scell . T_{uncertainty_MAC_multiple_scells} =0 if UE receives the SCell activation command and TCI state activation commands at the same time. The requirements for FR2 unknown SCells apply provided that the parameter ssb-PositionsInBurst is same for the SCell and the known serving cell on the same FR2 band. Where, N1 is the number counting for parallel FR1 unknown to-be- activated SCell(s) only except the ones which fulfilled the following conditions: - contiguous to an active serving cell in the same band, or to a known SCell in the same band being activated by the same MAC PDU, and - A single SSB is used in the unknown SCell; or multiple SSBs are used in the unknown SCell and TCI state indication for PDCCH is provided by the same MAC PDU used for SCell activation; and - its ssb-PositionInBurst is same as the one of contiguous FR1 known cell or contiguous FR1 active serving cell, and - its RTD with contiguous FR1 known cell or contiguous FR1 active serving cell is smaller than or equal to 260ns with respect to the to-be-activated SCell’s SSB numerology and its reception power difference with contiguous FR1 known cell or contiguous FR1 active serving cell is smaller than or equal to 6dB, and - its SMTC offset is same as the one of contiguous FR1 known cell or contiguous FR1 active serving cell However, when the following conditions are fulfilled, no activation requirement will be applied for this unknown SCell and other SCells being activated and counted in N1: - contiguous to an active serving cell in the same band, or to a known SCell in the same band being activated by the same MAC PDU, and - A single SSB is used in the unknown SCell; or multiple SSBs are used in the unknown SCell and TCI state indication for PDCCH is provided by the same MAC PDU used for SCell activation; and - its ssb-PositionInBurst is same as the one of FR1 known cell or FR1 active serving cell, and - its RTD with contiguous FR1 known cell or contiguous FR1 active serving cell is larger than 260ns with respect to the to-be- activated SCell’s SSB numerology or its reception power difference with contiguous FR1 known cell or contiguous FR1 active serving cell is larger than 6dB, and - its SMTC offset is same as the one of FR1 known cell or FR1 active serving cell T_{SMTC_MAX_multiple_scells}: - In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity between active serving cell(s) and SCell(s) being activated on the same band provided the cell specific reference signals from the active serving cell(s) and the SCell(s) being activated or released are available in the same slot; otherwise, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity of SCells being activated on the same band. - In FR2, T_{SMTC_MAX_multiple_scells} is the longest SMTC periodicity between active serving cell(s) and SCell(s) being activated in FR2 intra- band CA. - T_{SMTC_MAX_multiple_scells} is bounded to a minimum value of 10ms. T_{FirstSSB_MAX_multiple_scells}: is the time - T_{FirstSSB_MAX}, band #k, when only one band’s SCell(s) being activated has active serving cell(s) in the same band; - max {T_{FirstSSB_MAX, band #i}} i = 1, 2, …, maxBands, when common SMTC occasion exists for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band; Where, the common SMTC occasion can be defined as there for K SCells being activated exists a set of non-zero integers N1, ..., NK and a value X fulfilling the following: - SMTC offset#m + Nm×SMTC period#m = X, for m=1,...,K, where SMTC offset#m and SMTC period#m are SMTC offset and SMTC period, respectively, for the m-th Scell in the set of K SCells to be activated. - min {T_{FirstSSB_MAX}, band #i} i = 1, 2, …, maxBands, when - all SCells being activated are on FR2, or - no additional AGC retuning is needed for all SCells being activated, or - no active serving cell(s) in the same band with the SCells being activated which need AGC retuning, or - SMTC offset is different for all SCells being activated and more than one band’s SCell(s) being activated have active serving cell(s) in the same band When more than one bands’ SCell(s) being activated have active serving cell(s) in the same band and SMTC offset is different, performance degradation can be expected for active serving cell(s) with SCell(s) being activated in the same band #i after min{T_{FirstSSB_MAX, band #i}} to the T_{FirstSSB_MAX, band #i}. Where, maxBands is the maximum number of UE supported bands which have SCells being activated. T_{FirstSSB_MAX, band #k} is the T_{FirstSSB_MAX, band #i} time for the band #k which has active serving cell(s) and to-be-activated SCell(s). T_{FirstSSB_MAX, band #i} is the time to the end of the first complete SSB burst indicated by the SMTC after slot n +

for the SCell(s) being activated in band #i, further fulfilling: - In FR1, in case of active serving cell(s) in the same band with SCell(s) being activated, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot; otherwise, the first SMTC occasion when the SCell(s) being activated are transmitting SSB burst. - In FR2, the occasion when all active serving cell(s) and SCell(s) being activated or released are transmitting SSB bursts in the same slot. Tuncertainty_MAC_multiple_scells is the time period between reception of the activation command for PDCCH TCI, PDSCH TCI (when applicable) and SCell activation command of this unknown SCell. Tuncertainty_SP_multiple_scells is the time period between reception of the activation command for semi-persistent CSI-RS resource set for CQI reporting and SCell activation command of this unknown SCell. T_{uncertainty_RRC_multiple_scells} is the time period between reception of the RRC configuration message for TCI of periodic CSI-RS for CQI reporting (when applicable) and SCell activation command of this unknown SCell. Trs, TFineTiming, and TRRC_delay is defined in clause 8.3.2. Longer delays for RRM measurement requirements, and in case of FR2 also SSB based RLM/BFD/CBD/L1-RSRP measurement requirements, can be expected during the cell detection time for unknown SCell activation. The condition of known SCell in FR1 or FR2 is defined in clause 8.3.2. If the UE has been provided with higher layer in TS 38.331 [2] signaling of smtc2 prior to the activation command, T_{SMTC_Scell} follows smtc1 or smtc2 according to the physical cell ID of the target cell being activated. TSMTC_MAX_multiple_scell follows smtc1 or smtc2 according to the physical cell IDs of the target cells being activated and the active serving cells. The starting point and the end-point of an interruption window on PCell or any activated SCell in MCG for NR standalone mode, or on PSCell or any activated SCell in SCG for EN-DC mode is same as single SCell activation requirement in clause 8.3.2. Starting from the slot specified in clause 4.3 of TS 38.213 [3] (timing for secondary Cell activation/deactivation) and until the UE has completed the SCell activation, the UE shall report out of range if the UE has available uplink resources to report CQI for the SCell. Starting from the slot specified in clause 4.3 of TS 38.213 [3] (timing for secondary Cell activation/deactivation) and until the UE has completed a first L1- RSRP measurement, the UE shall report lowest valid L1 SS-RSRP range if the UE has available uplink resources to report L1-RSRP for the SCell. As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices. Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the "C" programming language. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user's computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. Abbreviations that may be used in the preceding description include: Abbreviation Explanation ACK Acknowledgement AFC Automatic frequency correction AGC Automatic gain control ATC Automatic timing correction (tracking) CC Component carrier CP Cyclic prefix CQI Channel quality indicator CRS Cell specific reference signals CSI Channel state information CSI-RS Channel state information reference signals DL Downlink E-UTRA Evolved universal terrestrial radio access (4G) FDD Frequency division duplex FFT Fast Fourier transform FR1 Frequency range 1 (0-6GHz) FR2 Frequency range 2 (24GHz-) HO Handover IC Integrated circuit L1-RSRP Layer 1 RSRP LO Local oscillator MAC Medium access control MAC-CE MAC control element MRTD Maximum receive time difference NR New Radio (5G) OFDM Orthogonal frequency division multiplex P(S)Cell Primary or Primary Secondary cell PBCH Physical broadcast channel PCell Primary cell PDCCH Physical downlink control channel PDP Power delay profile PDSCH Physical downlink shared channel PSCell Primary Secondary cell PSS Primary synchronization signal RF Radio frequency RFIC Radio frequency integrated circuit RRC Radio resource control RS Reference signal RSRP Reference signal received power RSRQ Reference signal received quality SS-RSRP Synchronization signal-based RSRP SS-RSRQ Synchronization signal-based RSRQ SCell Secondary cell SCS Subcarrier spacing SINR Signal to interference and noise ratio SMTC SSB measurement time configuration spCell Special cell (PCell or PSCell) SSB Synchronization signal and PBCH block SSS Secondary synchronization signal SS-SINR Synchronization signal-based SINR TCI Transmission configuration indicator TDD Time division duplex TRP Transmission point UE User equipment UL Uplink It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.

Claims

What is claimed is:

1. A method in a wireless device, WD (22), configured to communicate with a network node (16), the method comprising: receiving (SI 40) a serving cell activation command to change an activation status of a plurality of serving cells, the activation status including at least one of setup and release; when the plurality of serving cells have at least one active serving cell in a same frequency band as the plurality of serving cells, counting (S142) a number of bands of the frequency band that have serving cells for which activation status is to be changed; when the number of bands is equal to one, performing (SI 44) an interruption to retune a radio frequency, RF, of operation of the WD (22) before a first time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells for which activation status is to be changed; and when the number of bands is greater than one and when a broadcast channel measurement timing configuration offset and periodicity cause a synchronization signal and physical broadcast channel, PBCH, block, SSB, measurement timing configuration, SMTC, to have a temporal position that is a same value for all serving cells for which activation status is to be changed, performing (S146) an interruption to retune the RF of operation of the WD (22) before a second time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells in a same band of the number of bands, the second time being a maximum value of a set of times for interruption operation for each band of the number of bands; and when the number of bands is greater than one and when the measurement timing configuration periodicity and offset cause the SSB/SMTC to have a temporal position that is not the same for all serving cells for which activation status is to be changed, performing (S148) an interruption to retune the RF of operation of the WD (22) before a third time by which to retune the RF of operation, the third time being an earliest value of a set of times for performing an interruption for each band of the number of bands.

2. The method of Claim 1, wherein the frequency band is FR1.

3. The method of any of Claims 1 and 2, wherein the first time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being one of activated and deactivated in the one band and fulfilling at least

one of: when the frequency band is FR1, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when the frequency band is FR2, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in the same time resource ; wherein T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology.

4. The method of any of Claims 1-3, wherein the second time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n

being activated in a band of the number of bands and fulfilling at least one of: when at least two active serving cells are in a same band of the number of bands, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when there are not at least two active serving cells in a same band, a condition that the serving cells for which activation status is to be changed are transmitting SSB bursts; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology.

5. The method of any of Claims 1-4, further comprising retuning the RF of operation based at least in part on synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC occasions in a first band of the number of bands followed by performing an interruption based at least in part on SMTC occasions in a second band of the number of bands.

6. The method of any of Claims 1-5, wherein a number of interruptions depends at least in part on a number of bands having both the at least one active serving cell and the serving cells for which activation status is to be changed.

7. The method of any of Claims 1-6, further comprising determining when to retune an automatic gain control, AGC, of the WD (22) based at least in part on a number of serving cells for which activation status is to be changed.

8. The method of Claim 7, further comprising, when two serving cells for which activation status is to be changed are in different bands of the number of bands, and one of the two serving cells is not to be retuned, retuning the RF of operation based at least in part on an earliest synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC, occasion for the serving cells for which activation status is to be changed.

9. The method of any of Claims 1-8, further comprising, when at least two bands of the number of bands have serving cells for which activation status is to be changed, determining whether there exists non-zero integers, N_m, fulfilling a condition that an SMTC offset for a serving cell, m, plus N_m times a synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC period for the serving cell is equal to an integer X.

10. The method of Claim 9, wherein, when such non-zero integers, N_m, exist, performing an interruption before the second time, and when no such non-zero integers, N_m, exist, retuning the RF of operation of the WD (22) before the third time.

11. The method of any of Claims 1-10, wherein the time resource is any of symbol, slot and subframe.

12. The method of any of any of Claims 1-11, wherein a serving cell is any of a secondary cell, SCell, and special cell, SpCell.

13. The method of any of any of Claims 1-12, wherein changing the activation status of the serving cell includes at least one of serving cell activation, serving cell deactivation, serving cell setup, serving cell release, addition, reconfiguration of serving cell, direction serving cell activation and direction serving cell deactivation.

14. A wireless device, WD (22), configured to communicate with a network node (16), the WD (22) comprising: a radio interface (82) configured to receive a serving cell activation command to change an activation status of a plurality of serving cells, the activation status including at least one of setup and released; and processing circuitry (84) in communication with the radio interface (82) and configured to: when the plurality of serving cells have at least one active serving cell in a same frequency band as the plurality of serving cells, count a number of bands of the frequency band that have serving cells with for which activation status is to be changed; when the number of bands is equal to one, perform an interruption to retune a radio frequency, RF, of operation of the WD (22) before a first time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells for which activation status is to be changed; and when the number of bands is greater than one and when a broadcast channel measurement timing configuration offset and periodicity causes a synchronization signal and physical broadcast channel, PBCH, block, SSB, measurement timing configuration, SMTC, to have a temporal position that is a same value for all serving cells for which activation status is to be changed, perform an interruption to retune the RF of operation of the WD (22) before a second time by which to retune the RF of operation, the interruption being based at least in part on a number of serving cells in a same band of the number of bands, the second time being a maximum value of a set of times for interruption operation for each band of the number of bands; and when the number of bands is greater than one and when the measurement timing configuration offset and periodicity cause the SSB/SMTC to have a temporal position that is not the same for all serving cells for which activation status is to be changed, perform an interruption to retune the RF of operation of the WD (22) before a third time by which to retune the RF of operation, the third time being an earliest value of a set of times for performing an interruption for each band of the number of bands.

15. The WD (22) of Claim 14, wherein the frequency band is FR1.

16. The WD (22) of any of Claims 14 and 15, wherein the first time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being one of activated and deactivated in the one band and fulfilling at least

17. The WD (22) of any of Claims 14-16, wherein the second time is a time to the end of a first complete synchronization signal and physical broadcast channel block, SSB, burst indicated by an SSB measurement timing configuration, SMTC, after slot n + being activated in a band of the number of bands and fulfilling at least one of:

when at least two active serving cells are in a same band of the number of bands, a condition that all of the at least one active serving cell and the serving cells for which activation status is to be changed are transmitting SSB bursts in a same time resource; and when there are not at least two active serving cells in a same band, a condition that the serving cells for which activation status is to be changed are transmitting SSB bursts; where T_HARQ is a time of hybrid automatic repeat request acknowledgement and NR slot length depends on a numerology.

18. The WD (22) of any of Claims 14-17, wherein the processing circuitry is further configured to perform an interruption based at least in part on synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC occasions in a first band of the number of bands followed by retuning the RF of operation based at least in part on SMTC occasions in a second band of the number of bands.

19. The WD (22) of any of Claims 14-18, wherein a number of interruptions depends at least in part on a number of bands having both the at least one active serving cell and the serving cells for which activation status is to be changed.

20. The WD (22) of any of Claims 14-19, wherein the processing circuitry is further configured to determine when to retune an automatic gain control, AGC, of the WD (22) based at least in part on a number of serving cells for which activation status is to be changed.

21. The WD (22) of Claim 20, wherein the processing circuitry is further configured to, when two serving cells for which activation status is to be changed are in different bands of the number of bands, and one of the two serving cells is not to be retuned, retune the RF of operation based at least in part on an earliest synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC, occasion for the serving cells for which activation status is to be changed.

22. The WD (22) of any of Claims 14-21, wherein the processing circuitry is further configured to, when at least two bands of the number of bands have serving cells for which activation status is to be changed, determine whether there exists non-zero integers, N_m, fulfilling a condition that an SMTC offset for a serving cell, m, plus N_m times a synchronization signal and physical broadcast channel block, SSB, measurement timing configuration, SMTC period for the serving cell is equal to an integer X.

23. The WD (22) of Claim 22, wherein, when such non-zero integers, N_m, exist, retuning the RF of operation of the WD (22) before the second time, and when no such nonzero integers, N_m, exist, performing the interruption before the third time.

24. The WD (22) of any of Claims 14-23, wherein the time resource is any of symbol, slot and subframe.

25. The WD (22) of any of any of Claims 14-24, wherein a serving cell is any of a secondary cell, SCell, and special cell, SpCell.

26. The WD (22) of any of any of Claims 14-25, wherein changing the activation status of the serving cell includes at least one of serving cell activation, serving cell deactivation, serving cell setup, serving cell release, addition, reconfiguration of serving cell, direction serving cell activation and direction serving cell deactivation.