Patent Publication Number: US-2022217559-A1

Title: Layer 1 (l1) signaling for fast secondary cell (scell) management

Description:
TECHNICAL FIELD 
     Wireless communication and in particular, Open Systems Interconnect (OSI) Layer 1 (L1) signaling for fast secondary cell (Scell) management (e.g., as compared to existing arrangements). 
     BACKGROUND 
     Carrier Aggregation 
     Carrier Aggregation is generally used in the 3 rd  Generation Partnership Project (3GPP) New Radio (NR) (also known as “5G”) and Long-Term Evolution (LTE) systems to improve wireless device (WD) (e.g., user equipment (UE)) transmit and receive data rates. With carrier aggregation (CA), the WD typically operates initially on a single serving cell called a primary cell (Pcell). The Pcell is operated on a component carrier in a frequency band. The WD is then configured by the network (e.g., network node) with one or more secondary serving cells (Scell(s)). Each Scell can correspond to a component carrier (CC) in the same frequency band (intra-band CA) or different frequency band (inter-band CA) from the frequency band of the CC corresponding to the Pcell. For the WD to transmit/receive data on the Scell(s) (e.g., by receiving downlink shared channel (DL-SCH) information on a physical downlink shared channel (PDSCH) or by transmitting uplink shared channel (UL-SCH) information on a physical uplink shared channel (PUSCH)), the Scell(s) should be activated by the network, e.g., the network node. The Scell(s) can also be deactivated and later reactivated as needed via activation/deactivation signaling. 
       FIG. 1  illustrates an example of Scell activation/deactivation related procedures specified for 3GPP Release 15 (Rel-15) New Radio (NR) (also known as “5G” or 5 th  Generation). As shown in  FIG. 1 , except for channel state information (CSI) reporting, the WD is allowed to start performing other ‘activation related actions’ (e.g., physical downlink control channel (PDCCH) monitoring for Scell, physical uplink control channel (PUCCH)/sounding reference signal (SRS) transmission on the Scell) within a specified range of slots, e.g., after the minimum required activation delay (such as the delay specified in 3GPP Technical Specification (TS) 38.213) and before the maximum allowed activation delay (such as the delay specified in TS 38.133). CSI reporting for the Scell starts (and stops) with a fixed slot offset after receiving the activation (deactivation) command. 
     Minimum required activation delay and maximum allowed activation delay for some example conditions are shown herein below.
         Minimum required activation delay is k1+3 ms+1 slots as specified TS 38.213 sub clause 4.3. Assuming 30 kHz numerology for Pcell, and k1=4, this would be 5.5 milliseconds (ms).   Maximum allowed activation delay may depend on conditions such as those described in TS 38.133 sub clause 8.3.2 and the value varies based on WD measurement configuration, operating frequency range and other aspects.
           Assuming T_HARQ in TS 38.133 has similar meaning as k1 in TS 38.213, and assuming ‘known Scell’ with Scell measurement cycle is equal to or smaller than [160 ms], and T_csi reporting=4 slots
               For FR1 and 30 kHz subcarrier spacing (SCS),
                   If SMTC (synchronization signal/physical broadcast channel block measurement time configuration) periodicity 5 ms, the delay cannot be larger than (T_HARQ=4 slots)+(T_act_time=5 ms+5 ms)+(T_csi_report=4 slots)=14 ms;   If SMTC periodicity 20 ms, the delay cannot be larger than (T_HARQ=4 slots)+(T_act_time=5 ms+20 ms)+(T_csi_report=4 slots)=29 ms.   
                   For FR2, assuming this is the first Scell being activated in that FR2 band,
                   SMTC periodicity 5 ms, the delay is 4 slots+5 ms+TBD*5 ms+4 slots=6 ms+X*5 ms;   SMTC periodicity 20 ms, the delay is 4 slots+5 ms+TBD*20 ms+4 slots=6 ms+X*20 ms   X&gt;1 is TBD in current Rel-15 specs.   
                   
               
               

     For other conditions, e.g. Scell is not ‘known’ and longer SMTC periodicities, the maximum allowed activation delay is much longer than the values in the above example. 
     However, the existing arrangements are inefficient. 
     SUMMARY 
     Some embodiments advantageously provide methods and apparatuses for L1 signalling for fast secondary cell (Scell) management, e.g., fast carrier aggregation (CA) Scell management. 
     In one embodiment, a method for a network node includes signalling a command, e.g., a layer 1 command, the layer 1 command activating/deactivating a secondary cell for the WD. 
     In another embodiment, a method for a wireless device (WD) includes receiving a command, e.g., a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD. 
     According to an aspect of the present disclosure, a method implemented a wireless device, WD, configured to operate on a primary cell and one or more secondary cells, Scells is provided. The method includes operating on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD on at least one secondary cell, Scell, of the one or more Scells; receiving a command via a physical downlink control channel, PDCCH, signaling on the primary cell; and responsive to receiving the command via the PDCCH signaling, performing at least one procedure for the at least one Scell of the one or more Scells, the at least one procedure including operating on one of the first BWP or a second BWP of the plurality of BWPs based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, when the WD is configured to monitor PDCCH when operating on the first BWP, performing the at least one procedure for the at least one Scell includes switching to operate on the second BWP when the first value is indicated for the at least one Scell by the command, wherein the WD is configured to not monitor PDCCH when operating on the second BWP. In some embodiments, performing the at least one procedure for the at least one Scell further includes continuing to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP, performing the at least one procedure for the at least one Scell includes continuing to operate on the first BWP when the first value is indicated for the at least one Scell by the command. In some embodiments, performing the at least one procedure for the at least one Scell further includes switching to operate on the second BWP when the second value is indicated for the at least one Scell by the command, wherein the WD is configured to monitor PDCCH when operating on the second BWP. 
     In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. In some embodiments, the method further includes receiving higher layer signaling, the higher layer signaling indicating the predefined BWP. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to a respective one of the plurality of BWPs. 
     In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD is configured to monitor PDCCH. In some embodiments, the method further includes receiving a higher layer signaling, the higher layer signaling including a BWP index indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. In some embodiments, receiving the command via the PDCCH signaling comprises receiving a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource for a Hybrid Automatic Repeat reQuest Acknowledgement, HARQ-ACK, for the command. 
     In some embodiments, receiving the command via the PDCCH signaling further comprises receiving a HARQ feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a slot for the HARQ-ACK for the command. In some embodiments, receiving the command via the PDCCH signaling comprises receiving the command as a wake-up signal. In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. In some embodiments, when a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, responsive to receiving the command via the PDCCH signaling, monitoring or not monitoring PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
     According to another aspect of the present disclosure, a method implemented a network node configured to configure a wireless device, WD, to operate on a primary cell and one or more secondary cells, Scells is provided. The method includes configuring the WD to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD on at least one secondary cell, Scell, of the one or more Scells. The method includes sending a command via a physical downlink control channel, PDCCH, signaling on the primary cell, the command indicating at least one procedure to be performed by the WD for the at least one Scell of the one or more Scells, the at least one procedure for the WD including operating on one of the first BWP or a second BWP of the plurality of BWPs based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, when the WD is configured to monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes switching, by the WD, to operate on the second BWP when the first value is indicated for the at least one Scell by the command, wherein the WD is configured to not monitor PDCCH when operating on the second BWP. In some embodiments, the at least one procedure for the at least one Scell further includes the WD continuing to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes the WD continuing to operate on the first BWP when the first value is indicated for the at least one Scell by the command. 
     In some embodiments, the at least one procedure for the at least one Scell further includes switching, by the WD, to operate on the second BWP when the second value is indicated for the at least one Scell by the command, wherein the WD is configured to monitor PDCCH when operating on the second BWP. In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. In some embodiments, the method further includes sending higher layer signaling, the higher layer signaling indicating the predefined BWP. 
     In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to a respective one of the plurality of BWPs. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD is configured to monitor PDCCH. In some embodiments, the method further includes sending a higher layer signaling, the higher layer signaling including a BWP index indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. In some embodiments, sending the command via the PDCCH signaling comprises sending a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource for a HARQ-ACK for the command. 
     In some embodiments, sending the command via the PDCCH signaling further comprises sending a Hybrid Automatic Repeat reQuest, HARQ, feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a slot for the HARQ-ACK for the command. In some embodiments, sending the command via the PDCCH signaling comprises sending the command as a wake-up signal. In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. In some embodiments, when a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, sending the command via the PDCCH signaling indicates to the WD to monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
     According to another aspect of the present disclosure, a wireless device, WD, configured to operate on a primary cell and one or more secondary cells, Scells is provided. The WD includes processing circuitry. The processing circuitry is configured to cause the WD to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD on at least one secondary cell, Scell, of the one or more Scells. The processing circuitry is configured to cause the WD to receive a command via a physical downlink control channel, PDCCH, signaling on the primary cell. The processing circuitry is configured to cause the WD to, responsive to receiving the command via the PDCCH signaling, perform at least one procedure for the at least one Scell of the one or more Scells, the at least one procedure including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, the processing circuitry is configured to cause the WD to perform the at least one procedure for the at least one Scell by being configured to cause the WD to, when the WD is configured to monitor PDCCH when operating on the first BWP, switch to operate on the second BWP when the first value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH when operating on the second BWP. In some embodiments, the processing circuitry is configured to cause the WD to perform the at least one procedure for the at least one Scell by being configured to cause the WD to continue to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, the processing circuitry is configured to cause the WD to perform the at least one procedure for the at least one Scell by being configured to cause the WD to, when the WD is configured to not monitor PDCCH when operating on the first BWP, continue to operate on the first BWP when the first value is indicated for the at least one Scell by the command. 
     In some embodiments, the processing circuitry is configured to cause the WD to perform the at least one procedure for the at least one Scell by being configured to cause the WD to switch to operate on the second BWP when the second value is indicated for the at least one Scell by the command, the WD being configured to monitor PDCCH when operating on the second BWP. In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. 
     In some embodiments, the processing circuitry is further configured to cause the WD to receive higher layer signaling, the higher layer signaling indicating the predefined BWP. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to a respective one of the plurality of BWPs. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD is configured to monitor PDCCH. In some embodiments, the processing circuitry is further configured to cause the WD to receive a higher layer signaling, the higher layer signaling including a BWP index indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. 
     In some embodiments, the processing circuitry is configured to cause the WD to receive the command via the PDCCH signaling by being configured to cause the WD to receive a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource for a Hybrid Automatic Repeat reQuest Acknowledgement, HARQ-ACK, for the command. In some embodiments, the processing circuitry is configured to cause the WD to receive the command via the PDCCH signaling by further being configured to cause the WD to receive a Hybrid Automatic Repeat reQuest, HARQ, feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a slot for the HARQ-ACK for the command. In some embodiments, the processing circuitry is configured to cause the WD to receive the command via the PDCCH signaling by being configured to cause the WD to receive the command as a wake-up signal. 
     In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. In some embodiments, the processing circuitry is configured to cause the WD to, when a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, responsive to receiving the command via the PDCCH signaling, monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
     According to another aspect of the present disclosure, a network node configured to configure a wireless device, WD, to operate on a primary cell and one or more secondary cells, Scells, is provided. The network node includes processing circuitry. The processing circuitry is configured to cause the network node to configure the WD to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD on at least one secondary cell, Scell, of the one or more Scells. The processing circuitry is configured to cause the network node to send a command via a physical downlink control channel, PDCCH, signaling on the primary cell, the command indicating at least one procedure to be performed by the WD for the at least one Scell of the one or more Scells, the at least one procedure for the WD including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, when the WD is configured to monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes switching, by the WD, to operate on the second BWP when the first value is indicated for the at least one Scell by the command, wherein the WD is configured to not monitor PDCCH when operating on the second BWP. In some embodiments, the at least one procedure for the at least one Scell further includes the WD continuing to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes the WD continuing to operate on the first BWP when the first value is indicated for the at least one Scell by the command. In some embodiments, the at least one procedure for the at least one Scell further includes switching, by the WD, to operate on the second BWP when the second value is indicated for the at least one Scell by the command, wherein the WD is configured to monitor PDCCH when operating on the second BWP. 
     In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. In some embodiments, the method further includes sending higher layer signaling, the higher layer signaling indicating the predefined BWP. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to respective one of the plurality of BWPs. 
     In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD is configured to monitor PDCCH. In some embodiments, the processing circuitry is configured to cause the network node to send a higher layer signaling, the higher layer signaling including a BWP index indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. In some embodiments, the processing circuitry is configured to cause the network node to send the command via the PDCCH signaling by being configured to cause the network node to send a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource for a Hybrid Automatic Repeat reQuest Acknowledgement, HARQ-ACK, for the command. 
     In some embodiments, the processing circuitry is further configured to cause the network node to send the command via the PDCCH signaling by being configured to cause the network node to send a Hybrid Automatic Repeat reQuest, HARQ, feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a slot for the HARQ-ACK for the command. In some embodiments, the processing circuitry is configured to cause the network node to send the command via the PDCCH signaling by being configured to cause the network node to send the command as a wake-up signal. In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. In some embodiments, when at a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, the command sent via the PDCCH signaling indicates to the WD to monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
    
    
     
       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 Scell activation/deactivation in 3GPP NR Rel-15; 
         FIG. 2  is a schematic diagram of an exemplary network architecture illustrating a communication system connected via an intermediate network to a host computer according to the principles in the present disclosure; 
         FIG. 3  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. 4  is a flowchart illustrating exemplary 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. 5  is a flowchart illustrating exemplary 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. 6  is a flowchart illustrating exemplary 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. 7  is a flowchart illustrating exemplary 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. 8  is a flowchart of an exemplary process in a network node for Scell management unit according to some embodiments of the present disclosure; 
         FIG. 9  is a flowchart of an exemplary process in a wireless device for operational unit according to some embodiments of the present disclosure; 
         FIG. 10  illustrates an example of a first embodiment of the present disclosure; 
         FIG. 11  illustrates an example of a second embodiment of the present disclosure; and 
         FIG. 12  illustrates an example of a third embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     In 3GPP Rel-15, a CA activation command may be sent in a Medium Access Control (MAC) control element (CE). The minimum required activation delay is ˜5 ms for a typical case. This is quite slow as compared to other NR procedures. Also, the maximum allowed activation delays are quite long as compared to other NR procedures. Due to such long delays, it is riskier for the network (e.g., network node) to frequently deactivate the Scell, since bringing the WD back to Scell activated state can take a minimum of ˜5 ms to a maximum allowed value of tens or hundreds of milliseconds depending on specific scenarios and WD implementation. Yet, if the Scell operations are not stopped whenever possible, WD power consumption is unnecessarily increased. 
     Thus, some embodiments of the present disclosure provide mechanisms for faster Scell operation when compared to existing LTE or NR CA approaches. This can be accomplished by introducing new OSI Layer 1 (L1), i.e., physical layer, commands in addition to the existing MAC CE based higher layer signaling. The MAC CE based Scell activation/deactivation commands may control a first set of WD procedures/actions associated with the Scell [e.g., a) CSI reporting for Scell, b) PDCCH monitoring for SCell, c) PUCCH/SRS transmissions on the SCell]. The L1 commands may control a second set of WD procedures/actions [e.g., a) PDCCH monitoring for SCell, b) PUCCH/SRS transmissions on the SCell, c) bandwidth part (BWP) switching on Scell]. While the WD can receive both MAC CE based activation/deactivation commands and L1 based commands, the time for the WD to apply the second set of actions (associated with L1 commands) may be smaller than the time needed for applying the first set of actions (associated with the MAC CE based signaling). 
     In some embodiments, the proposed mechanisms may enable the network to control Scell procedures more dynamically by sending frequent L1 commands while continuing to use the MAC CE based activation/deactivation mechanism relatively infrequently. From the WD perspective, additional power savings can be achieved with this mechanism when compared with the current approach of only using MAC CE based activation/deactivation commands. 
     In some embodiments, for a WD configured with CA, the WD receives an L1 command in PDCCH downlink control information (DCI) with bit(s) corresponding to one or more SCell(s). For a first Scell of the one or more SCell(s) which is configured with only one BWP, the WD may use the bit(s) corresponding to the first Scell to turn on/turn off PDCCH monitoring for that SCell. For a second Scell of the one of more SCell(s) which is configured with multiple BWPs, the WD may use the bit(s) corresponding to the second Scell to determine a BWP (of the multiple BWPs) to use for operation on the second SCell. The WD may be configured with zero PDCCH candidates on one of the multiple BWPs configured for the second SCell. 
     Some embodiments of proposed L1 command structures can provide different options with varying trade-offs between flexibility and overhead to control Scell management actions for Scells with one or more configured BWPs. 
     Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to L1 signaling for fast (e.g., as compared to existing arrangements) CA Scell management. 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). 
     As used herein, the term “command” used in “layer 1/L1 command” is intended broadly to encompass instructions, indicators, bits, a field in a control information message, etc. and is not intended to be limiting. 
     As used herein, the phrase “activating/deactivating” is intended broadly to encompass either activating an Scell, de-activating an Scell, activating/starting one or more procedures to be performed on the Scell, de-activating/stopping one or more procedures to be performed on the Scell and/or continuing a procedure that is already being performed on the Scell. 
     As used herein, the terms “operation,” “procedure” and “action” are used interchangeably. Any two or more embodiments described in this disclosure may be combined in any way with each other. 
     Although the description herein may be explained in the context of a particular channel and a particular command, such as a PDCCH channel comprising an L1 command, it should be understood that the principles may also be applicable to other channels and other commands. 
     In some embodiments, control information on one or more resources may be considered to be transmitted in a message having a specific format. A message may comprise or represent bits representing payload information and coding bits, e.g., for error coding. 
     Receiving (or obtaining) control information may comprise receiving one or more control information messages (e.g., L1 command). It may be considered that receiving control signaling comprises demodulating and/or decoding and/or detecting, e.g. blind detection of, one or more messages, in particular a message carried by the control signaling, e.g. based on an assumed set of resources, which may be searched and/or listened for the control information. It may be assumed that both sides of the communication are aware of the configurations, and may determine the set of resources, e.g. based on the reference size. 
     Signaling may generally comprise one or more symbols and/or signals and/or messages. A signal may comprise or represent one or more bits. An indication may represent signaling, and/or be implemented as a signal, or as a plurality of signals. One or more signals may be included in and/or represented by a message. Signaling, in particular control signaling, may comprise a plurality of signals and/or messages, which may be transmitted on different carriers and/or be associated to different signaling processes, e.g. representing and/or pertaining to one or more such processes and/or corresponding information. An indication may comprise signaling, and/or a plurality of signals and/or messages and/or may be comprised therein, which may be transmitted on different carriers and/or be associated to different acknowledgement signaling processes, e.g. representing and/or pertaining to one or more such processes. Signaling associated to a channel may be transmitted such that represents signaling and/or information for that channel, and/or that the signaling is interpreted by the transmitter and/or receiver to belong to that channel. Such signaling may generally comply with transmission parameters and/or format/s for the channel. 
     An indication (e.g., bit map, field in DCI, etc.) generally may explicitly and/or implicitly indicate the information it represents and/or indicates. Implicit indication may for example be based on position and/or resource used for transmission. Explicit indication may for example be based on a parametrization with one or more parameters, and/or one or more index or indices corresponding to a table, and/or one or more bit patterns representing the information. 
     Configuring a radio node, in particular a terminal or WD, may refer to the radio node being adapted or caused or set and/or instructed to operate according to the configuration (e.g., to monitor an x-RNTI or a binary sequence for C-RNTI to determine which table to be used to interpret an indication or signal). Configuring may be done by another device, e.g., a network node (for example, a base station or gNB) or network, in which case it may comprise transmitting configuration data to the radio node to be configured. Such configuration data may represent the configuration to be configured and/or comprise one or more instruction pertaining to a configuration, e.g. a configuration for transmitting and/or receiving on allocated resources, in particular frequency resources. A radio node may configure itself, e.g., based on configuration data received from a network or network node. A network node may utilize, and/or be adapted to utilize, its circuitry/ies for configuring. Allocation information may be considered a form of configuration data. Configuration data may comprise and/or be represented by configuration information, and/or one or more corresponding indications and/or message/s. 
     A channel may generally be a logical or physical channel. A channel may comprise and/or be arranged on one or more carriers, in particular a plurality of subcarriers. A wireless communication network may comprise at least one network node, in particular a network node as described herein. A terminal (e.g., WD) connected or communicating with a network may be considered to be connected or communicating with at least one network node, in particular any one of the network nodes described herein. 
     Generally, configuring may include determining configuration data representing the configuration and providing, e.g. transmitting, it to one or more other nodes (parallel and/or sequentially), which may transmit it further to the radio node (or another node, which may be repeated until it reaches the wireless device). Alternatively, or additionally, configuring a radio node, e.g., by a network node or other device, may include receiving configuration data and/or data pertaining to configuration data, e.g., from another node like a network node, which may be a higher-level node of the network, and/or transmitting received configuration data to the radio node. Accordingly, determining a configuration and transmitting the configuration data to the radio node may be performed by different network nodes or entities, which may be able to communicate via a suitable interface, e.g., an X2 interface in the case of LTE or a corresponding interface for NR. Configuring a terminal (e.g. WD) may comprise scheduling downlink and/or uplink transmissions for the terminal, e.g. downlink data and/or downlink control signaling and/or DCI and/or uplink control or data or communication signaling, in particular acknowledgement signaling, and/or configuring resources and/or a resource pool therefor. 
     A cell may be generally a communication cell, e.g., of a cellular or mobile communication network, provided by a node. A serving cell may be a cell on or via which a network node (the node providing or associated to the cell, e.g., base station or eNodeB) transmits and/or may transmit data (which may be data other than broadcast data) to a user equipment, in particular control and/or user or payload data, and/or via or on which a user equipment transmits and/or may transmit data to the node; a serving cell may be a cell for or on which the user equipment is configured and/or to which it is synchronized and/or has performed an access procedure, e.g., a random access procedure, and/or in relation to which it is in a RRC connected or RRC idle state, e.g., in case the node and/or user equipment and/or network follow the a standard. One or more carriers (e.g., uplink and/or downlink carrier/s and/or a carrier for both uplink and downlink) may be associated to a cell. 
     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. 
     Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in  FIG. 2  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  16   a ,  16   b ,  16   c  (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  18   a ,  18   b ,  18   c  (referred to collectively as coverage areas  18 ). Each network node  16   a ,  16   b ,  16   c  is connectable to the core network  14  over a wired or wireless connection  20 . A first wireless device (WD)  22   a  located in coverage area  18   a  is configured to wirelessly connect to, or be paged by, the corresponding network node  16   a . A second WD  22   b  in coverage area  18   b  is wirelessly connectable to the corresponding network node  16   b . While a plurality of WDs  22   a ,  22   b  (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. 2  as a whole enables connectivity between one of the connected WDs  22   a ,  22   b  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  22   a ,  22   b  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  22   a . Similarly, the network node  16  need not be aware of the future routing of an outgoing uplink communication originating from the WD  22   a  towards the host computer  24 . 
     A network node  16  is configured to include a Scell management unit  32 , the network node  16  and/or the Scell management unit  32  being configured to configure the WD  22  to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD  22  on at least one secondary cell, Scell, of the one or more Scells and to send a command via a physical downlink control channel, PDCCH, signaling on a primary cell, the command indicating at least one procedure to be performed by the WD for the at least one Scell of the one or more Scells, the at least one procedure for the WD including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. In some embodiments, the network node  16  is configured to include the Scell management unit  32  which is configured to cause a radio interface to signal a layer 1 command, the layer 1 command activating/deactivating a secondary cell for the WD  22 . 
     A wireless device  22  is configured to include an operational unit  34 , the wireless device  22  and/or the operational unit  34  being configured to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD  22  on at least one secondary cell, Scell, of the one or more Scells and to receive a command via a physical downlink control channel, PDCCH, signaling on a primary cell; and responsive to receiving the command via the PDCCH signaling, perform at least one procedure for the at least one Scell of the one or more Scells, the at least one procedure including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. In some embodiments, the wireless device  22  is configured to include the operational unit  34  which is configured to receive (and/or decode) a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD. 
     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. 3 . 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 include Scell management unit  32  configured to cause the radio interface  62  to signal a layer 1 command, the layer 1 command activating/deactivating a secondary cell for the WD  22 . 
     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 operational unit  34  configured to receive a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD  22 . 
     In some embodiments, the inner workings of the network node  16 , WD  22 , and host computer  24  may be as shown in  FIG. 3  and independently, the surrounding network topology may be that of  FIG. 2 . 
     In  FIG. 3 , 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&#39;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&#39;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. 2 and 3  show various “units” such as Scell management unit  32 , and operational 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. 4  is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of  FIGS. 2 and 3 , 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. 3 . In a first step of the method, the host computer  24  provides user data (Block S 100 ). 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 S 102 ). In a second step, the host computer  24  initiates a transmission carrying the user data to the WD  22  (Block S 104 ). 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 S 106 ). 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 S 108 ). 
       FIG. 5  is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of  FIG. 2 , 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. 2 and 3 . In a first step of the method, the host computer  24  provides user data (Block S 110 ). 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 S 112 ). 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 S 114 ). 
       FIG. 6  is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of  FIG. 2 , 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. 2 and 3 . In an optional first step of the method, the WD  22  receives input data provided by the host computer  24  (Block S 116 ). 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 S 118 ). Additionally or alternatively, in an optional second step, the WD  22  provides user data (Block S 120 ). 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 S 122 ). 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 S 124 ). 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 S 126 ). 
       FIG. 7  is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of  FIG. 2 , 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. 2 and 3 . 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 S 128 ). In an optional second step, the network node  16  initiates transmission of the received user data to the host computer  24  (Block S 130 ). In a third step, the host computer  24  receives the user data carried in the transmission initiated by the network node  16  (Block S 132 ). 
       FIG. 8  is a flowchart of an exemplary process in a network node  16  for CA Scell management according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the network node  16  may be performed by one or more elements of network node  16  such as by Scell management unit  32  in processing circuitry  68 , processor  70 , communication interface  60 , radio interface  62 , etc. according to the example method. The example method, implemented in a network node  16  configured to configure a wireless device, WD  22 , to operate on a primary cell and one or more secondary cells, Scells, includes configuring (Block S 134 ), such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , the WD  22  to operate on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD  22  on at least one secondary cell, Scell, of the one or more Scells. The method includes sending (Block S 136 ), such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , a command via a physical downlink control channel, PDCCH, signaling on the primary cell, the command indicating at least one procedure to be performed by the WD  22  for the at least one Scell of the one or more Scells, the at least one procedure for the WD  22  including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD  22  being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, when the WD  22  is configured to monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes the WD  22  switching to operate on the second BWP when the first value is indicated for the at least one Scell by the command, the WD  22  being configured to not monitor PDCCH when operating on the second BWP. In this case the network node  16  may, in some embodiments, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , cause the WD  22  to switch to operate on the second BWP when the first value is indicated for the at least one Scell by the command, the WD  22  being configured to not monitor PDCCH when operating on the second BWP. In some embodiments, the at least one procedure for the at least one Scell further includes the WD  22  continuing to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In this case the network node  16  may, in some embodiments, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , cause the WD  22  to continue to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, when the WD  22  is configured to not monitor PDCCH when operating on the first BWP, the at least one procedure for the at least one Scell includes the WD  22  continuing to operate on the first BWP when the first value is indicated for the at least one Scell by the command. In this case the network node  16  may, in some embodiments, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , cause the WD  22  to continue to operate on the first BWP when the first value is indicated for the at least one Scell by the command. 
     In some embodiments, the at least one procedure for the at least one Scell further includes the WD  22  switching to operate on the second BWP when the second value is indicated for the at least one Scell by the command, the WD  22  being configured to monitor PDCCH when operating on the second BWP. In this case the network node  16  may, in some embodiments, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , cause the WD  22  to switch to operate on the second BWP when the second value is indicated for the at least one Scell by the command, the WD  22  being configured to monitor PDCCH when operating on the second BWP. In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. For example, the second BWP may be configured with a specific BWP index by or via the higher layers. The specific BWP index may in some embodiments be a firstActiveDownlinkBWP-Id, see example further down below. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. In some embodiments, the method includes sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , higher layer signaling, the higher layer signaling indicating the predefined BWP. 
     In some embodiments, when the WD  22  is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to a respective one of the plurality of BWPs. In some embodiments, when the WD  22  is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD  22  is configured to monitor PDCCH. In some embodiments, the method further includes sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , a higher layer signaling, the higher layer signaling including an index, such as a BWP index, indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. In some embodiments, sending the command via the PDCCH signaling comprises sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource, such as a PUCCH resource, for a Hybrid Automatic Repeat reQuest Acknowledgement, HARQ-ACK, for the command. 
     In some embodiments, sending the command via the PDCCH signaling further includes, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , sending a Hybrid Automatic Repeat reQuest, HARQ, feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a resource, such as a slot, for a HARQ-ACK for the command. In some embodiments, sending the command via the PDCCH signaling includes sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , the command as a wake-up signal. In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD  22  is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD  22  is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. Each of the N bits may indicate the first or the second value for the respective one of the N Scells. In some embodiments, when at least a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , the command via the PDCCH signaling may indicate to the WD  22  to monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. For example, when the WD  22  is configured with a single BWP for a second Scell of the one or more Scells, sending, such as via Scell management unit  32 , processing circuitry  68 , processor  70 , communication interface  60  and/or radio interface  62 , the command via the PDCCH signaling may indicate to the WD  22  to monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
     In some embodiments, the method includes signalling, such as via a Scell management unit  32 , processing circuitry  68 , processor  70 , and/or radio interface  62 , a layer 1 command, the layer 1 command activating/deactivating a secondary cell for a wireless device (WD)  22 . 
     In some embodiments, the layer 1 command corresponds to a first delay time period before the WD  22  can perform a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command. In some embodiments, the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. In some embodiments, the layer 1 command is included in a downlink control information (DCI) message sent via a physical downlink control channel (PDCCH). In some embodiments, the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD  22 . In some embodiments, the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD in the Scell. In some embodiments, the first set of procedures comprises PDCCH monitoring on the Scell, performing uplink transmissions on the SCell and bandwidth part (BWP) switching in the Scell. In some embodiments, the layer 1 command indicates to the WD  22  to switch BWPs based at least in part on which BWP is configured with PDCCH monitoring candidates. In some embodiments, the layer 1 command indicates a BWP index value of a BWP to which the WD  22  is to switch in the Scell. In some embodiments, the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell. In some embodiments, the method further includes transmitting, such as via a Scell management unit  32 , processing circuitry  68 , processor  70 , and/or radio interface  62 , a higher layer signaling indicating a number of bits for the layer 1 command. In some embodiments, a duration of the first delay time period is based at least in part on an offset value included, such as via a Scell management unit  32 , processing circuitry  68 , processor  70 , and/or radio interface  62 , in one of the DCI and higher layer signaling. 
       FIG. 9  is a flowchart of an exemplary process in a wireless device  22  for CA Scell management 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 operational unit  34  in processing circuitry  84 , processor  86 , radio interface  82 , etc. The example method, in the WD  22  configured to operate on a primary cell and one or more secondary cells, Scells, includes operating (Block S 138 ), such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , on a first bandwidth part, BWP, of a plurality of bandwidth parts, BWPs, the plurality of BWPs being configured for the WD  22  on at least one secondary cell, Scell, of the one or more Scells. The method includes receiving (Block S 140 ), such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , a command via a physical downlink control channel, PDCCH, signaling on the primary cell. The method includes responsive to receiving the command via the PDCCH signaling, performing (Block S 142 ), such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , at least one procedure for the at least one Scell of the one or more Scells, the at least one procedure including operating on one of the first BWP and a second BWP of the plurality of bandwidth parts based on whether a first value or a second value is indicated for the at least one Scell by the command, the WD  22  being configured to not monitor PDCCH for at least one of the first BWP and the second BWP. 
     In some embodiments, when the WD  22  is configured to monitor PDCCH when operating on the first BWP, performing the at least one procedure for the at least one Scell includes switching, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , to operate on the second BWP when the first value is indicated for the at least one Scell by the command, the WD  22  being configured to not monitor PDCCH when operating on the second BWP. In some embodiments, performing the at least one procedure for the at least one Scell further includes continuing, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , to operate on the first BWP when the second value is indicated for the at least one Scell by the command. In some embodiments, when the WD  22  is configured to not monitor PDCCH when operating on the first BWP, performing the at least one procedure for the at least one Scell includes continuing, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , to operate on the first BWP when the first value is indicated for the at least one Scell by the command. In some embodiments, performing the at least one procedure for the at least one Scell further includes switching, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , to operate on the second BWP when the second value is indicated for the at least one Scell by the command, wherein the WD  22  is configured to monitor PDCCH when operating on the second BWP. 
     In some embodiments, a bandwidth part, BWP, index, for the second BWP is configured by higher layers. For example, the second BWP may be configured with a specific BWP index, e.g., a firstActiveDownlinkBWP-Id, by or via the higher layers. In some embodiments, the first value is 0 and the second value is 1. In some embodiments, at least one of the first BWP and the second BWP is configured with one or more PDCCH candidates. In some embodiments, the BWP for which the WD  22  is configured to not monitor PDCCH is a predefined BWP, the predefined BWP being configured with no PDCCH candidates. In some embodiments, the method further includes receiving, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , higher layer signaling, the higher layer signaling indicating the predefined BWP. In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is a BWP with a lowest BWP index among a plurality of indices, each BWP index corresponding to respective one of the plurality of BWPs. 
     In some embodiments, when the WD is configured to not monitor PDCCH when operating on the first BWP and the second value is indicated for the at least one Scell by the command, the second BWP is based at least in part on a most recent active BWP for which the WD is configured to monitor PDCCH. In some embodiments, the method further includes receiving, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , a higher layer signaling, the higher layer signaling including an index, such as a BWP index, indicating one of the first BWP and the second BWP. In some embodiments, the higher layer signaling is one of a radio resource control, RRC, signaling and a medium access control, MAC, control element, CE, signaling. In some embodiments, receiving the command via the PDCCH signaling comprises receiving, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , a physical uplink control channel, PUCCH, resource indicator in a downlink control information, DCI, the PUCCH resource indicator indicating a resource, such as a PUCCH resource, for a Hybrid Automatic Repeat reQuest Acknowledgement, HARQ-ACK, for the command. 
     In some embodiments, receiving the command via the PDCCH signaling further comprises receiving, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , a Hybrid Automatic Repeat reQuest, HARQ, feedback timing indicator in the DCI, the HARQ feedback timing indicator indicating a resource, such as a slot, for a HARQ-ACK for the command. In some embodiments, receiving the command via the PDCCH signaling comprises receiving, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , the command as a wake-up signal. In some embodiments, the command is included in a physical downlink control channel, PDCCH, downlink control information, DCI, along with a set of bits for power savings when the WD  22  is configured to receive a PDCCH DCI format configured for power savings. In some embodiments, the WD  22  is configured with N Scells and the command includes N bits, each bit of the N bits corresponding to a respective one of the N Scells. Each of the N bits may indicate the first or the second value for the respective one of the N Scells. In some embodiments, when at least a second Scell of the one or more Scells is configured with a single bandwidth part, BWP, the WD  22  may, responsive to receiving the command via the PDCCH signaling, be configured to monitor or not monitor, such as by operational unit  34 , processing circuitry  84 , processor  86  and/or radio interface  82 , PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. For example, when the WD  22  is configured with a single BWP for a second Scell of the one or more Scells, the WD  22  may be configured to, responsive to receiving the command via the PDCCH signaling, monitor or not monitor PDCCH on the single BWP of the second Scell based on whether the first value or the second value is indicated for the second Scell by the command. 
     In some embodiments, the method includes receiving, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD  22 . 
     In some embodiments, responsive to the layer 1 command, one of:
         after a first delay time period, performing, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , at least one of a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command;   continuing to perform, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , the at least one of the first set of procedures; and   stopping performance, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , of the at least one of the first set of procedures.       

     In some embodiments, the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. In some embodiments, the layer 1 command is included in a downlink control information (DCI) message via a physical downlink control channel (PDCCH). In some embodiments, the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD  22 . In some embodiments, the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD  22  in the Scell. In some embodiments, the first set of procedures comprises PDCCH monitoring, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , on the Scell, performing uplink transmissions, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , on the SCell and bandwidth part (BWP) switching, such as via operational unit  34 , processing circuitry  84 , processor  86 , radio interface  82 , in the Scell. In some embodiments, the processing circuitry  84  is further configured to switch BWPs based on the layer 1 command and which BWP is configured with PDCCH monitoring candidates. In some embodiments, the layer 1 command indicates a BWP index value of a BWP to which the WD  22  is to switch in the Scell. In some embodiments, the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell. In some embodiments, the processing circuitry  84  is configured to receive a higher layer signaling indicating a number of bits for the layer 1 command. In some embodiments, a duration of the first delay time period is based at least in part on an offset value included in one of the DCI and higher layer signaling. 
     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, and which may be implemented by the network node  16 , wireless device  22  and/or host computer  24 , the sections below provide details and examples of arrangements for L1 signaling for fast CA Scell management, as compared to existing arrangements. 
     In some embodiments, a WD  22  communicates with the network (e.g., network node  16 ) using a primary serving cell (Pcell). The WD  22  may also configured with one or more secondary serving cells (Scell(s)). The WD  22  receives a higher layer Scell activation/deactivation command. Upon reception of the higher layer activation/deactivation command (e.g., transmitted by the network node  16 ), the WD  22  starts/stops performing a first set of actions. The first set of actions may include periodic CSI reporting for the Scell (e.g., if the WD  22  is configured for periodic CSI reporting). The first set of actions can also include PDCCH monitoring on the Scell. If the WD  22  is configured with multiple BWPs for the Scell, the PDCCH monitoring can be on a preconfigured/default BWP of the Scell. If the WD  22  receives the higher layer activation command in time slot n, the WD  22  may apply the first set of actions starting with slot n+D1 (i.e., after an activation delay of D1 slots). 
     The WD  22  may also receive a physical layer command (e.g., an L1 command) (e.g., transmitted by the network node  16 ). Upon reception of the L1 command, the WD  22  starts/stops performing a second set of actions. The second set of actions can be PDCCH monitoring or BWP switching as discussed in the examples below. The second set of actions for an Scell can be different based on whether the WD  22  is configured with one BWP for the Scell or whether it is configured with multiple BWPs for the Scell. If the WD  22  receives the L1 command in time slot n1, the WD  22  may apply the second set of actions starting with slot n1+D2 (i.e., after a delay of D2 slots). The delay D2 is smaller than D1. 
     The higher layer Scell activation/deactivation command (e.g., transmitted by the network node  16 ) can be received by the WD  22  in a MAC CE (MAC control element). The first set of actions can also include transmitting PUCCH/periodic SRS on the Scell. The L1 command (e.g., transmitted by the network node  16 ) can be received by the WD  22  using a PDCCH. For example, the L1 command can be part of PDCCH DCI (downlink control information). The PDCCH DCI corresponding to the L1 command can include the bits corresponding to the Scell(s) configured for the WD  22  based on which the WD  22  performs the second set of actions. The bits can be according to the examples discussed herein. 
     In the following, some options/embodiments are described below as examples. It is understood that any one or more of the features described in the various example options/embodiments can be combined with another in any manner. 
     Option/Embodiment 1 In one example (option 1), the WD  22  is configured with N SCell(s). The PDCCH DCI corresponding to the L1 command can include N bits (b 0 , b 1 , . . . bN—1): b 0  can correspond to Scell 0  e.g., an Scell with lowest cell index among the configured Scell(s), b 1  can correspond to Scell 1 , e.g., Scell with next lowest cell index among the configured Scell(s) and so on. If b 0  is set for a first state (e.g., 1) the WD  22  can start PDCCH monitoring on the Scell 0  and if b 0  is set to a second state (e.g., 0) the WD  22  can stop PDCCH monitoring on the Scell 0 . If the WD  22  is already monitoring PDCCH on Scell 0  prior to receiving b 0  set to first state, the WD  22  continues PDCCH monitoring on that Scell. If the WD  22  is configured (e.g., by the network node  16 ) with multiple BWPs for Scell 0 , and if the WD  22  receives (e.g., via radio interface  82 ) L1 command with b 0  set to a second state, the WD  22  can stop monitoring PDCCH on the current active BWP of Scell 0  or alternately on all BWPs of SCell 0 . If the WD  22  is configured (e.g., by the network node  16 ) with multiple BWPs for Scell 0 , and if the WD  22  receives (e.g., via radio interface  82 ) L1 command with b 0  set to first state, and the WD  22  is not monitoring PDCCH on Scell 0  prior to receiving the L1 command, the WD  22  can start PDCCH monitoring on one of the multiple BWPs configured for Scell 0 . The BWP on which the WD  22  can start PDCCH monitoring can be preconfigured by higher layer (e.g., radio resource control (RRC)) signaling (e.g., by network node  16 ). In one alternative, the WD  22  can start PDCCH monitoring on a BWP with specific BWP-index (e.g., firstActiveDownlinkBWP-Id) configured by higher layers. In another alternative, the WD  22  can start PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) on a default DL BWP configured by higher layers. In another alternative, the WD  22  can start PDCCH monitoring on a BWP with lowest index among the DL BWPs configured for SCell 0 . If the WD  22  is already monitoring PDCCH on Scell 0  prior to receiving b 0  set to first state, WD  22  can continue PDCCH monitoring on its current active BWP of Scell 0 . Similar procedure may be used for other Scells configured for the WD  22 . 
       FIG. 10  shows an example with option 1. In  FIG. 10 , WD  22  is configured with Scell 0  (with one BWP), SCell 1  (with two BWPs) and Scell 2  (with 4 BWPs). All three Scells are in activated state (e.g., using a MAC CE based Scell activation command). Before reception of an L1 command C1, the WD  22  is not monitoring PDCCH on Scell 0 , Scell 1  but monitoring PDCCH on BWP 1  of Scell 2  (as shown in the first column shown in  FIG. 10  with shading on Scell 2  BWP 1 ). Upon reception of an L1 command C1 with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {1,1,0} respectively, the WD  22  starts PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) on Scell 0  (as indicated by the shading in Scell 0  BWP 0 ), Scell 1  (e.g., on BWP 0  of Scell 1  which can be default/preconfigured BWP for this Scell), and stops PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) on Scell 2  (since the bit associated with Scell 2  was set to the second state/0). Upon reception of an L1 command C2 (e.g., via radio interface  82 ) with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {0,1,1} respectively, the WD  22  stops PDCCH monitoring on Scell 0 , continues PDCCH monitoring on its current active BWP (i.e., BWP 0 ) and starts PDCCH monitoring on Scell 2  (e.g. on BWP 0  of Scell 2  which can be default/preconfigured BWP for this Scell). 
     Option/Embodiment 2 
     In another example (option 2), the WD  22  is configured with N SCell(s). The PDCCH DCI corresponding to the L1 command can include N bits (b 0 , b 1 , . . . bN—1). For some or all of the N SCells, the WD  22  can be configured (e.g., by network node  16 ) with more than one BWP. If the WD  22  is configured with only one BWP for SCellx of the N Scells, the WD  22  can start/stop PDCCH monitoring on Scellx based on the state indicated by bit bx corresponding to Scellx (i.e., similar procedure as described for option 1 above where if bx is set for a first state (e.g., 1) the WD  22  can start/continue PDCCH monitoring on the Scellx and if bx is set to a second state (e.g., 0) the WD  22  can stop PDCCH monitoring on the Scellx). If the WD  22  is configured with multiple BWPs (e.g., by network node  16 ) for Scelly of the N Scells, and if bit ‘by’ corresponding to Scelly indicates a first state (e.g., 0), the WD  22  can perform a BWP switch operation (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) by switching from its current active BWP (BWPc) to a predefined BWP (BWPd). BWPd can be a BWP for which the WD  22  is not configured to monitor PDCCH (e.g., zero PDCCH monitoring candidates are configured for all search spaces and for aggregation levels configured for BWPd). If bit ‘by’ corresponding to Scelly indicates a second state (e.g., 1), the WD  22  can perform a BWP switch operation (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) by switching to a BWP (BWPe) for which the WD  22  is configured to monitor PDCCH. In one alternative, BWPe can be a BWP with specific BWP-index (e.g. firstActiveDownlinkBWP-Id) configured by higher layers (e.g., by network node  16 ). In another alternative, BWPe can be a default DL BWP configured by higher layers (e.g., by network node  16 ). In another alternative, BWPe can be a BWP with lowest index among the DL BWPs configured for SCelly. 
     In another alternative BWPe can be the most recent current active BWP for the WD  22  on which it was monitoring PDCCH. If bit ‘by’ corresponding to Scelly indicates the second state (e.g., 1), the WD  22  can perform a BWP switch operation (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) by switching to a BWP (BWPe) for which the WD  22  is configured to monitor PDCCH only if prior to receiving the L1 command with bit ‘by’, the WD  22  is operating on a BWP for which the WD  22  is not configured to monitor PDCCH (e.g. BWPd). If the WD  22  is operating on a BWP with PDCCH monitoring prior to receiving the L1 command with bit ‘by’ indicating second state, the WD  22  can continue operating on that BWP (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) and not perform any BWP switch operation. 
       FIG. 11  shows an example with option 2. In  FIG. 11 , WD  22  is configured with Scell 0  (with one BWP), SCell 1  (with two BWPs) and Scell 2  (with 4 BWPs) e.g., by network node  16 . All three Scells are in activated state (e.g., using a MAC CE based Scell activation command). Furthermore, BWP 1  of Scell 1  and BWP 3  of SCell 2  are not configured with any PDCCH monitoring candidates (e.g. denoted by BWP 1 * and BWP 3 * for convenience in  FIG. 11 ). Before reception of an L1 command C1, the WD  22  is not monitoring PDCCH on Scell 0 ; on Scell 1 , the WD  22  is operating on BWP 1  (which has no PDCCH monitoring candidates); and on Scell 2  the WD  22  is operating on BWP 1  (which has PDCCH monitoring candidates). Upon reception of an L1 command C1 with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {1,1,0} respectively, the WD  22  starts PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) on Scell 0 ; on Scell 1  WD  22  switches to BWP 0  (i.e., the BWP with PDCCH monitoring candidates); on Scell 2  WD  22  switches to BWP 3  (i.e., the BWP which has no PDCCH monitoring candidates since zero is indicated for this Scell). Upon reception of an L1 command C2 with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {0,1,1} respectively, the WD  22  stops PDCCH monitoring on Scell 0  (since DCI bit set to 0); on Scell 1  WD  22  continues operating on BWP 0 ; and on Scell 2  WD  22  switches to BWP 0  (which has PDCCH monitoring candidates and which can also be e.g. default/preconfigured BWP for this Scell). 
     Option/Embodiment 3 
     In another example (option 3), the WD  22  can be configured with N SCell(s) and for some or all of the N SCells the WD  22  can be configured (such as by network node  16 ) with more than one BWP. For this example, if the WD  22  is configured with NBx BWPs for Scellx of the N SCells, where NBx&gt;1, the PDCCH DCI corresponding to the L1 command can include ceil(log 2(NBx)) bits (where log 2( ) is logarithm with base  2 ) corresponding to Scellx. If Scellx is configured with only one BWP the DCI includes 1 bit for Scellx and similar procedure as described for option 1 above is applied where if the one bit bx corresponding to Scellx is set for a first state (e.g. 1) the WD  22  can start/continue PDCCH monitoring on the Scellx and if bx is set to second state (e.g. 0) the WD  22  can stop PDCCH monitoring on the Scellx. If Scellx is configured with NBx&gt;1 BWPs (e.g., by network node  16 ), the ceil(log 2(NBx)) bits indicate the BWP index to which the WD  22  should switch upon reception of the L1 command. i.e., if NBx=2, there is one bit for Scellx and WD  22  switches to either first BWP of Scellx or second BWP of SCellx based on the one bit. If NBx=3, there are 2 bits for Scellx and WD  22  switches (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) to one of first, second or third BWPs given by 3 of the 4 states indicated by the two bits. The fourth state indicated by these bits can be reserved. If NBx=4, there are 2 bits for Scellx and WD  22  switches to one of first, second, third or fourth BWPs given by the 4 states indicated by the two bits. If NBx&gt;1 BWPs are configured for Scellx, one of the BWPs can be a BWP for which the WD  22  is not configured to monitor PDCCH (e.g., zero PDCCH monitoring candidates are configured for all search spaces and for aggregation levels configured for that BWP). While option 3 may be more flexible than options 1 or 2 discussed above, it may also have more overhead compared to these options. A single DCI can be used for joint indication of BWP switching on some of the Scells and to start/stop PDCCH monitoring on a single BWP for some other of the Scells e.g., on Scells that correspond to single BWP. 
       FIG. 12  shows an example with option 3. In  FIG. 12 , WD  22  is configured with Scell 0  (with one BWP), SCell 1  (with two BWPs) and Scell 2  (with 4 BWPs). All three Scells are in activated state (e.g., using a MAC CE based Scell activation command). Furthermore, BWP 1  of Scell 1  and BWP 3  of SCell 2  are not configured with any PDCCH monitoring candidates (e.g. denoted by BWP 1 * and BWP 3 * for convenience in Figure). Before reception of an L1 command C1, the WD  22  is not monitoring PDCCH on Scell 0 ; on Scell 1 , the WD  22  is operating on BWP 1  (which has no PDCCH monitoring candidates); and on Scell 2  the WD  22  is operating on BWP 1  (which has PDCCH monitoring candidates). Upon reception of an L1 command C1 (e.g., via radio interface  82 ) with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {1,0,11} respectively (i.e., here 1 bit for Scell 0  since it has only one BWP, ceil(log 2(2))=1 bit for Scell 1 , and ceil(log 2(4))=2 bits for Scell 2 ), the WD  22  starts PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) on Scell 0 ; on Scell 1 , since DCI bit indicates 0, WD  22  switches to BWP 0  which has index  0 ; on Scell 2 , since the DCI bits indicate 11, WD  22  switches to BWP 3  which has index 3  (i.e., in this example, bit states 00 maps to BWP 0 , 01 maps to BWP 1 , 10 maps to BWP 2 , 11 maps to BWP 3 ). Upon reception of an L1 command C2 (e.g., via radio interface  82 ) with DCI bits corresponding to {SCell 0 ,SCell 1 ,Scell 2 } set to {0,1,01} respectively, the WD  22  stops PDCCH monitoring on Scell 0 ; on Scell 1 , the WD  22  switches to BWP 1  which has index 1 ; and on Scell 2  the WD  22  switches to BWP 1  which has index  1  which is mapped to DCI bit state 01. 
     Option/Embodiment 4 
     As another example (option 4), the WD  22  can be configured with N SCell(s) and for some or all of the N SCells the WD  22  can be configured with more than one BWP (e.g., by network node  16 ). For this example, if the WD  22  is configured with NBx BWPs for Scellx of the N SCells, the PDCCH DCI corresponding to the L1 command can include a bitmap of NBx bits with first bit of the bitmap corresponding to first BWP of NBx BWPs, second bit corresponding to a second BWP of NBx BWPs and so on. Thus, the DCI can include N such bitmaps for N Scells. For Scellx, the WD  22  starts/continues monitoring PDCCH (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) for those BWPs whose bits are set to 1 and stops PDCCH monitoring (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) for those BWPs whose bits are set to 0. Similar to above examples, if the WD  22  is configured with only one BWP for Scellx, the bit indicates whether WD  22  can start/stop monitoring PDCCH for that SCell. Option 4 has more overhead than options 1,2,3 but can provide extra flexibility e.g., for cases where WD  22  can operate with more than one active BWP in a given serving cell at a given time. 
     The PDCCH DCI (e.g., from network node  16 ) corresponding to the L1 command can include a PUCCH resource indicator (e.g., 3 bits). In response to detecting or successfully decoding (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) the PDCCH DCI corresponding to L1 command, the WD  22  can send (e.g., via radio interface  82 ) a HARQ-ACK in the PUCCH resource given by the PUCCH resource indicator. 
     The PDCCH DCI (e.g., from network node  16 ) corresponding to the L1 command can include a HARQ feedback timing indicator (e.g., 3 bits). In response to detecting or successfully decoding the PDCCH DCI corresponding to L1 command in slot n, the WD  22  can transmit a HARQ-ACK in the PUCCH resource (given by the PUCCH resource indicator) where the slot in which the HARQ-ACK is transmitted is given by the HARQ feedback timing indicator. 
     The PDCCH DCI (e.g., from network node  16 ) corresponding to the L1 command can include additional format bits indicating the format in which the bits corresponding to the Scell(s) are sent. For example, the format bits can indicate whether the bits corresponding to Scells are according to a first option (e.g. option 1) or a second option (e.g. option 2) of the options discussed above. 
     Higher layers can explicitly indicate (e.g., via higher layer signaling from network node&#39;s  16  radio interface  62 ) the number of bits per SCell within the DCI for L1 command. For example, if the WD  22  is configured with multiple SCells with different number of BWPs per Scell, for simpler DCI formatting, higher layer can configure a fixed 2 bits per SCell regardless of the number of BWPs per Scell. If a WD  22  needs fewer states for an Scell, then additional states can be reserved. 
     The PDCCH DCI (e.g., from network node  16 ) corresponding to the L1 command can include zero padding bits to size match the size of the PDCCH DCI to the size of PDCCH for another DCI format (e.g. DCI format 0-0 or 1-0). The PDCCH DCI corresponding to the L1 command can be configured to be monitored in common search space, in WD  22  search space or in both. 
     The PDCCH DCI corresponding to the L1 command can include a cyclic redundancy check (CRC) (e.g. 24 bits), the CRC can be scrambled by an RNTI (radio network temporary identifier) that is specific to L1 commands. The RNTI can be different from C-RNTI/RA-RNTI/P-RNTI/SI-RNTI/SP-CSI/MCS-C-RNTI (cell-RNTI/random access-RNTI/paging-RNTI/system information-RNTI/semi-persistent-channel state information/modulation and coding scheme-cell-RNTI) configured for the WD  22 . The RNTI can be a PDCCH monitoring RNTI or a PM-RNTI or Scell monitoring RNTI or SM-RNTI. The WD  22  may be configured (e.g., by network node  16 ) with more than one RNTI to receive the PDCCH DCI corresponding L1 commands. For example, the WD  22  may be configured with a first RNTI which corresponds to PDCCH DCI with the L1 command having bits for a first set of Scells and a second RNTI which corresponds to PDCCH DCI with the L1 command having bits for a second set of Scells. Such a configuration is useful for cases where WD  22  has to receive Scell management bits for a large number of Scells and the size of PDCCH DCI exceeds the size of another DCI format to which it has to be size matched. 
     Upon reception of PDCCH DCI corresponding to the L1 command, the WD  22  can apply the corresponding actions (e.g. start/stop of PDCCH monitoring, BWP switching), after a time offset t_offset. The time offset can be from the slot in which the L1 command is received by the WD  22 . Alternately, the time offset can be from the slot in which the WD  22  transmits HARQ-ACK in response to successful decoding (or detecting) of the PDCCH DCI corresponding to the L1 command. 
     The time offset can be used indicated to the WD  22  by separate bits in the PDCCH DCI. Alternately, the time offset can be a predefined value or a preconfigured value via higher layers. The possible time offset value(s) can also be indicated by the WD  22  to the network node  16  via WD  22  capability signaling. The time offset can depend on the numerology of the PDCCH and/or the numerology of the HARQ-ACK transmission. If the WD  22  is configured with multiple BWPs for an Scell, the time offset used by the WD  22  can depend on the BWP on which the WD  22  is operating on the Scell when an L1 command corresponding to that Scell is received by the WD  22 . For example, when switching from a BWP with no PDCCH monitoring candidates to a BWP with PDCCH monitoring candidates, the WD  22  may apply a first time offset; and when switching from a BWP with PDCCH monitoring candidates to a BWP with no PDCCH monitoring candidates, the WD  22  may apply a second time offset. The second time offset can be smaller than the first time offset. 
     In some cases, if the L1 command indicates the WD  22  to start PDCCH monitoring on Scellx, the WD  22  can start PDCCH monitoring on that Scell after a small time offset starting from the slot in which the PDCCH DCI is detected or successfully decoded or detected (e.g. after t 1 =2 ms from slot n where L1 command is received). However, if the L1 command indicates the WD  22  to stop PDCCH monitoring on Scellx, the WD  22  can perform this action (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) after a time offset starting from the slot in which it transmits a HARQ-ACK in response to detecting the PDCCH DCI with the L1 command (e.g. after t 2 =2 ms from slot n+k1 where L1 command is received in slot n and corresponding HARQ-ACK is sent in slot n+k1). 
     The PDCCH DCI corresponding to the L1 command can include an offset k_offset (e.g. a certain number of slots). If the WD  22  receives the L1 command in slot n1, the WD  22  applies the second set of actions (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) starting from slot n1+k_offset. For example, if the WD  22  receives an L1 command indicating ‘off’, and k_offset=X for an Scell, the WD  22  stops PDCCH monitoring on the Scell in response to receiving this command. Later, when the WD  22  receives another L1 command indicating ‘on’ for the Scell on slot n2, the WD  22  is expected to start PDCCH monitoring for the Scell from slot n2+X. Knowing X in advance (i.e., before the L1 ‘on’ command is received) may allow the WD  22  to put its PDCCH decoding hardware in an appropriate sleep state based on X. Larger X value could allow the WD  22  to put its hardware in a state with higher power saving (i.e., by turning off most receiver (rx) components), while a smaller X would allow a state with relatively smaller power savings. However, as a trade-off, a smaller X would allow faster Scell management. In another alternative, k_offset can be configured for the WD  22  via higher layers (i.e., it can be indicated via RRC signalling or MAC CE signalling). The WD  22  may have different k_offset values for different serving cells. In another example, the L1 command can be included (e.g., by network node  16 ) in a PDCCH DCI scheduling PDSCH/PUSCH for the WD  22  for the corresponding Scell. For example, the bits corresponding ‘TPC command for scheduled PUCCH’ field in DCI format 1-0 or 1-1, can be used for indicating ‘off’ L1 command and optionally k_offset. 
     The PDCCH DCI corresponding to the L1 command can include timer value T timer  (e.g., a certain number of slots). If the WD  22  receives the L1 command in slot n1, the WD  22  applies the second set of actions (e.g., via processing circuitry  84 , operational unit  34  and/or radio interface  82 ) starting from slot n1+k_offset and for an amount of time given by the timer value after which the WD  22  stops applying the second set of actions is stopped. 
     The L1 command can be received by the WD  22  as a wake-up signal or a reference signal (e.g., CSI-RS) with a predefined resource/scrambling pattern. The PDCCH corresponding to the L1 command can be received by the WD  22  on the Pcell/PScell. If the L1 command includes DCI bits corresponding to a set of Scells, the PDCCH corresponding to the L1 command can be received by the WD  22  on a serving cell that is different from the set of Scells. 
     In some cases, if the WD  22  receives an L1 command and the DCI bits corresponding to Scellx in the L1 command indicating to the WD  22  to switch from a BWP 1  to BWP 2 , and if BWP 1  has no PDCCH monitoring candidates and BWP 2  has PDCCH monitoring candidates, the WD  22  can stop transmitting/receiving on a set of Scells (e.g., Scells in same frequency band as Scellx) for a short duration (e.g., x=2 ms) to retune its radio frequency (RF) to be able to turn on PDCCH reception on BWP 2 . This duration can occur starting from next slot in which DCI is received or alternate next slot after which a HARQ-ACK corresponding to the L1 command is transmitted by the WD  22 . If the DCI bits indicate that the WD  22  is to switch from a BWP 2  to BWP 1 , there may be no need for WD  22  to stop transmitting/receiving on the set of Scells in response to the L1 command. If any radio frequency (RF) retuning is to be performed, the WD  22  can perform this at a later stage (e.g., during discontinuous reception (DRX) or measurement gap). 
     If the WD  22  is configured to receive a PDCCH DCI format configured for power savings, the DCI bits discussed in options 1, 2, 3, 4 above can be included (e.g., by network node  16 ) in the PDCCH DCI configured for power savings along with any other bits included for WD  22  power savings. 
     The PDCCH DCI corresponding to the L1 command can be sent by the network to the WD  22  via a gNB or other network node  16 . 
     One example of DCI content for L1 command is shown below:
         DCI format A_B is used for the transmission of L1 commands for SCell PDCCH monitoring and associated BWP operation.   The following information is transmitted by means of the DCI format A_B with cyclic redundancy check (CRC) scrambled by SM-RNTI:
           1.—block number  1 , block number  2 , . . . , block number N   
           The parameter Scell-in-SM-DCI provided by higher layers determines the index to the block number for the information of an Scell i, with the following fields defined for each block:
           2.—L1 On/off—0 or 1 bit
               if the corresponding Scell i is configured with one BWP, L1 On/off indicator is 1 bit, otherwise there is no L1 On/Off indicator in the block   
               3. Bandwidth part indicator—0, 1 or 2 bits as determined by the number of DL BWPs n BWP,RRC  configured by higher layers for Scell i, excluding the initial downlink (DL) bandwidth part. The bitwidth for this field is determined as ┌ log 2 (n BWP )┐ bits, where
               a. n BWP =n BWP, RRC +1 if n BWP,RRC ≤3, in which case the bandwidth part indicator is equivalent to the ascending order of the higher layer parameter BWP-Id; and   b. otherwise n BWP =n BWPRRC , in which case the bandwidth part indicator may be defined in a table.   
               
               

     Another example of DCI content for L1 command is shown below where the higher layers configure (e.g., by network node  16  signaling) the number of bits per Scell within the L1 command DCI:
         DCI format A_B is used for the transmission of L1 commands for SCell PDCCH monitoring and associated BWP operation.   The following information is transmitted by means of the DCI format A_B with CRC scrambled by SM-RNTI:
           1.—block number  1 , block number  2 , . . . , block number N   The parameter Scell-in-SM-DCI provided by higher layers determines the index to the block number for the information of an Scell i, and the parameter length-of-Block-in-SM-DCI indicates the number of bits X for each block:   2.—L1 On/off and BWP indicator—X bits   For example, if X=2,
               if Scell 1  has one BWP and is associated with block number  1 , then in block number  1  if bits are set to 00=&gt; stop PDCCH monitoring, 01=&gt; start PDCCH monitoring, and {10,11} can be reserved.   if Scell  2  has two BWP and is associated with block number  2 , then in block number  2  if bits are set to 00=&gt; switch to BWP 0 , 01=&gt; switch to BWP 1 , and {10,11} can be reserved.
                   In another alternative, then in block number  2  if bits are set to 00=&gt; switch to BWP 0  and start PDCCH monitoring, 01=&gt; switch to BWP 1  and start PDCCH monitoring, and 10=&gt; switch to BWP 0  and stop PDCCH monitoring, 01=&gt; switch to BWP 1  and stop PDCCH monitoring; and   
                   if Scell  3  has two BWPs and is associated with block number  3 , then in block number  3  if bits are set to 00=&gt; switch to BWP 0 , 01=&gt; switch to BWP 1 , and 10=&gt; switch to BWP 2  and {11} can be reserved.   
               
               

     In some embodiments, higher layers (e.g., sent by network node  16 ) can explicitly configure the (BWP index, PDCCH start/stop) pair for each state in each block. 
     For size matching with 1_0 in common search space, the following may be applied. The number of information bits in format A_B may be equal to or less than the payload size of format 1_0 monitored in common search space in the same serving cell. If the number of information bits in format A_B is less than the payload size of format 1_0 monitored in common search space in the same serving cell, zeros may be appended to format A_B until the payload size equals that of format 1_0 monitored in common search space in the same serving cell. 
     For size matching with a DCI format X_Y (e.g. 1_0/0_1/1_1, etc.) in WD-specific search space, the following may be applied. The number of information bits in format A_B may be equal to or less than the payload size of format X_Y monitored in WD-specific search space in the same serving cell. If the number of information bits in format A_B is less than the payload size of format X_Ymonitored in WD-specific search space in the same serving cell, zeros may be appended to format A_B until the payload size equals that of format X_Y monitored in WD-specific search space in the same serving cell. 
     Accordingly, for a WD  22  configured with e.g., CA, dual-connectivity (DC), etc., the WD  22  can advantageously receive an L1 command in PDCCH DCI with bit(s) corresponding to one or more SCell(s). For a first Scell of the one of more SCell(s) which is configured with only one BWP, the WD  22  can use the bit(s) corresponding to the first Scell to turn on/turn off PDCCH monitoring on/for that SCell. For a second Scell of the one of more SCell(s) which is configured with multiple BWPs, the WD  22  can use the bit(s) corresponding to the second Scell to determine a BWP (of the multiple BWPs) to use for operation on the second SCell. The WD  22  may be configured with zero PDCCH candidates on one of the multiple BWPs configured for the second SCell. 
     Some examples may include one or more of: 
     Example A1. A network node configured to communicate with a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: 
     signal a layer 1 command, the layer 1 command activating/deactivating a secondary cell for the WD. 
     Example A2. The network node of Example A1, wherein the layer 1 command corresponds to a first delay time period before the WD can perform a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command. 
     Example A3. The network node of any one of Examples A1 and A2, wherein the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. 
     Example A4. The network node of any one of Examples A1-A3, wherein one or more of: 
     the layer 1 command is included in a downlink control information (DCI) message via a physical downlink control channel (PDCCH); 
     the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD; 
     the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD in the Scell; 
     the first set of procedures comprises PDCCH monitoring on the Scell, performing uplink transmissions on the SCell and bandwidth part (BWP) switching in the Scell; 
     the layer 1 command indicates to the WD to switch BWPs based at least in part on which BWP is configured with PDCCH monitoring candidates; 
     the layer 1 command indicates a BWP index value of a BWP to which the WD is to switch in the Scell; 
     the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell; 
     the processing circuitry is configured to cause the radio interface to transmit a higher layer signaling indicating a number of bits for the layer 1 command; and 
     a duration of the first delay time period is based at least in part on an offset value included in one of the DCI and higher layer signaling. 
     Example B1. A method implemented in a network node, the method comprising: 
     signalling a layer 1 command, the layer 1 command activating/deactivating a secondary cell for a wireless device (WD). 
     Example B2. The method of Example B1, wherein the layer 1 command corresponds to a first delay time period before the WD can perform a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command. 
     Example B3. The method of any one of Examples B1 and B2, wherein the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. 
     Example B4. The method of any one of Examples B1-B3, wherein one or more of: 
     the layer 1 command is included in a downlink control information (DCI) message via a physical downlink control channel (PDCCH); 
     the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD; 
     the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD in the Scell; 
     the first set of procedures comprises PDCCH monitoring on the Scell, performing uplink transmissions on the SCell and bandwidth part (BWP) switching in the Scell; 
     the layer 1 command indicates to the WD to switch BWPs based at least in part on which BWP is configured with PDCCH monitoring candidates; 
     the layer 1 command indicates a BWP index value of a BWP to which the WD is to switch in the Scell; 
     the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell; 
     further comprising transmitting a higher layer signaling indicating a number of bits for the layer 1 command; and 
     a duration of the first delay time period is based at least in part on an offset value included in one of the DCI and higher layer signaling. 
     Example C1. 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: 
     receive a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD. 
     Example C2. The WD of Example C1, wherein the processing circuitry is further configured to: 
     responsive to the layer 1 command, one of:
         after a first delay time period, perform at least one of a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command;   continue to perform the at least one of the first set of procedures; and   stop performance of the at least one of the first set of procedures.       

     Example C3. The WD of any one of Examples C1 and C2, wherein the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. 
     Example C4. The WD of any one of Examples C1-C3, wherein one or more of: 
     the layer 1 command is included in a downlink control information (DCI) message via a physical downlink control channel (PDCCH); 
     the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD; 
     the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD in the Scell; 
     the first set of procedures comprises PDCCH monitoring on the Scell, performing uplink transmissions on the SCell and bandwidth part (BWP) switching in the Scell; 
     the processing circuitry is further configured to switch BWPs based on the layer 1 command and which BWP is configured with PDCCH monitoring candidates; 
     the layer 1 command indicates a BWP index value of a BWP to which the WD is to switch in the Scell; 
     the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell; 
     the processing circuitry is configured to receive a higher layer signaling indicating a number of bits for the layer 1 command; and 
     a duration of the first delay time period is based at least in part on an offset value included in one of the DCI and higher layer signaling. 
     Example D1. A method implemented in a wireless device (WD), the method comprising: 
     receiving a layer 1 command, the layer 1 command activating/deactivating a secondary cell (Scell) for the WD. 
     Example D2. The method of Example D1, further comprising: 
     responsive to the layer 1 command, one of:
         after a first delay time period, performing at least one of a first set of procedures, the first set of procedures being different from a second set of procedures associated with a higher layer Scell activation/deactivation command;   continuing to perform the at least one of the first set of procedures; and   stopping performance of the at least one of the first set of procedures.       

     Example D3. The method of any one of Examples D1 and D2, wherein the first delay time period is less than a second delay time period associated with the higher layer Scell activation/deactivation command. 
     Example D4. The method of any one of Examples D1-D3, wherein one or more of: 
     the layer 1 command is included in a downlink control information (DCI) message via a physical downlink control channel (PDCCH); 
     the layer 1 command includes a bit map, each bit in the bit map activating/deactivating one of a plurality of Scells configured for the WD; 
     the layer 1 command includes a bit map, each bit in the bit map starting/stopping/continuing the at least one of the first set of procedures configured for the WD in the Scell; 
     the first set of procedures comprises PDCCH monitoring on the Scell, performing uplink transmissions on the SCell and bandwidth part (BWP) switching in the Scell; 
     switching BWPs based on the layer 1 command and which BWP is configured with PDCCH monitoring candidates; 
     the layer 1 command indicates a BWP index value of a BWP to which the WD is to switch in the Scell; 
     the layer 1 command includes a bit map, the bit map mapping to BWPs in the Scell; 
     the processing circuitry is configured to receive a higher layer signaling indicating a number of bits for the layer 1 command; and 
     a duration of the first delay time period is based at least in part on an offset value included in one of the DCI and higher layer signaling. 
     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&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;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&#39;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 
               
               
                   
                   
               
             
            
               
                   
                 BWP 
                 Bandwidth 
               
               
                   
                 CDM 
                 Code Division Multiplex 
               
               
                   
                 CQI 
                 Channel Quality Information 
               
               
                   
                 CRC 
                 Cyclic Redundancy Check 
               
               
                   
                 CSI-RS 
                 Channel State Information Reference Signal 
               
               
                   
                 DC 
                 Dual-connectivity 
               
               
                   
                 DCI 
                 Downlink Control Information 
               
               
                   
                 DFT 
                 Discrete Fourier Transform 
               
               
                   
                 DM-RS 
                 Demodulation Reference Signal 
               
               
                   
                 EIRP 
                 Effective Isotropic Radiated Power 
               
               
                   
                 FDM 
                 Frequency Division Multiplex 
               
               
                   
                 HARQ 
                 Hybrid Automatic Repeat Request 
               
               
                   
                 OFDM 
                 Orthogonal Frequency Division Multiplex 
               
               
                   
                 PAPR 
                 Peak to Average Power Ratio 
               
               
                   
                 PBCH 
                 Primary Broadcast Channel 
               
               
                   
                 PUCCH 
                 Physical Uplink Control Channel 
               
               
                   
                 PUSCH 
                 Physical Uplink Shared Channel 
               
               
                   
                 SRS 
                 Sounding Reference Signal 
               
               
                   
                 PRACH 
                 Physical Random Access Channel 
               
               
                   
                 PRB 
                 Physical Resource Block 
               
               
                   
                 RRC 
                 Radio Resource Control 
               
               
                   
                 SS-block 
                 Synchronisation Signal Block 
               
               
                   
                 UCI 
                 Uplink Control Information 
               
               
                   
                   
               
            
           
         
       
     
     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.