Method and apparatus for handling SCell deactivation timer in a wireless communication system

Methods and apparatuses for handling a SCell deactivation timer in a wireless communication system are disclosed herein. In one method, a network node configures a UE with a first SCell. The network node configures the UE to use a first SCell deactivation timer for the first SCell. The network node configures the UE with a SPS resource on the first SCell. The network node configures the UE not to use the first SCell deactivation timer if a length of the first SCell deactivation timer is shorter than a SPS interval of the SPS resource.

FIELD

This disclosure generally relates to wireless communication networks, and more particularly, to a method and apparatus for handling a SCell deactivation timer in a wireless communication system.

BACKGROUND

SUMMARY

Methods and apparatuses for handling a SCell deactivation timer in a wireless communication system are disclosed herein. In one method, a network node configures a UE with a first SCell. The network node configures the UE to use a first SCell deactivation timer for the first SCell. The network node configures the UE with a SPS resource on the first SCell. The network node configures the UE not to use the first SCell deactivation timer if a length of the first SCell deactivation timer is shorter than a SPS interval of the SPS resource.

DETAILED DESCRIPTION

3GPP standardization activities on next generation (i.e., 5G) access technology has been launched since March 2015. The next generation access technology aims to support the following three families of usage scenarios for satisfying both the urgent market needs and the more long-term requirements set forth by the ITU-R IMT-2020: eMBB (enhanced Mobile Broadband); mMTC (massive Machine Type Communications); and URLLC (Ultra-Reliable and Low Latency Communications).

An objective of the 5G study item on the new radio access technology is to identify and develop technology components needed for new radio systems which should be able to use any spectrum band ranging at least up to 100 GHz. Supporting carrier frequencies up to 100 GHz brings a number of challenges in the area of radio propagation as path loss increases as the carrier frequency increases.

The NR (New Radio) Medium Access Control (MAC) specified transmission and reception without dynamic scheduling in 3GPP TS 38.321 V15.0.0 as disclosed as follows:

5.8 Transmission and Reception without Dynamic Scheduling

Semi-Persistent Scheduling (SPS) is configured by RRC per serving cell and per BWP. Multiple configurations can be active simultaneously only on different serving cells. Activation and deactivation of the DL SPS are independent among the Serving Cells.

For the DL SPS, a DL assignment is provided by PDCCH, and stored or cleared based on L1 signalling indicating SPS activation or deactivation.

RRC configures the following parameters when SPS is configured:

When SPS is released by upper layers, all the corresponding configurations shall be released.

After a downlink assignment is configured for SPS, the MAC entity shall consider sequentially that the Nthassignment occurs in the slot for which:
(numberOfSlotsPerFrame*SFN+slot number in the frame)=[(numberOfSlotsPerFrame*SFNstart time+slotstart time)+N*semiPersistSchedIntervalDL*numberOfSlotsPerFrame/10]modulo 1024
where SFNstart time and slotstart time are the SFN and slot, respectively, at the time the configured downlink assignment were (re-)initialised.
5.8.2 Uplink
There are two types of transmission without dynamic grant:configured grant Type 1 where an uplink grant is provided by RRC, and stored as configured uplink grant;configured grant Type 2 where an uplink grant is provided by PDCCH, and stored or cleared as configured uplink grant based on L1 signalling indicating configured grant activation or deactivation.
Type 1 and Type 2 are configured by RRC per serving cell and per BWP. Multiple configurations can be active simultaneously only on different serving cells. For Type 2, activation and deactivation are independent among the serving cells. For the same serving cell, the MAC entity is configured with either Type 1 or Type 2.
RRC configures the following parameters when the configured grant Type 1 is configured:

periodicity: periodicity of the configured grant Type 1;

timeDomainOffset: Offset of a resource with respect to SFN=0 in time domain;

numberOfConfGrant-Processes: the number of HARQ processes.

RRC configures the following parameters when the configured grant Type 2 is configured:

periodicity: periodicity of the configured grant Type 2;

numberOfConfGrant-Processes: the number of HARQ processes.

Upon configuration of a configured grant Type 1 for a serving cell by upper layers, the MAC entity shall:

1> store the uplink grant provided by upper layers as a configured uplink grant for the indicated serving cell;1> initialise (if not active) or re-initialise (if already active) the configured uplink grant to start in the symbol according to timeDomainOffset and to reoccur with periodicity.
After an uplink grant is configured for a configured grant Type 1, the MAC entity shall consider sequentially that the Nth uplink grant occurs associated with the symbol for which:
[(SFN*numberOfSlotsPerFrame*numberOfSymbolsPerSlot)+(slot number in the frame*numberOfSymbolsPerSlot)+symbol number in the slot]=(timeDomainOffset+N*periodicity)modulo 1024
After an uplink grant is configured for a configured grant Type 2, the MAC entity shall consider sequentially that the Nth uplink grant occurs associated with the symbol for which:
[(SFN*numberOfSlotsPerFrame*numberOfSymbolsPerSlot)+(slot number in the frame*numberOfSymbolsPerSlot)+symbol number in the slot]=[(SFNstart time*numberOfSlotsPerFrame*numberOfSymbolsPerSlot+slotstart time*numberOfSymbolsPerSlot+symbolstart time)N*periodicity]modulo 1024
where SFNstart time, slotstart time, and symbolstart timeare the SFN, slot, and symbol, respectively, at the time the configured uplink grant was (re-)initialised.
When a configured grant is released by upper layers, all the corresponding configurations shall be released and all corresponding uplink grants shall be cleared immediately.
The MAC entity shall:

1> if the configured grant has been triggered and not cancelled; and

1> if the MAC entity has UL resources allocated for new transmission:2> instruct the Multiplexing and Assembly procedure to generate an Configured Grant Confirmation MAC CE as defined in subclause 6.1.3.7;2> cancel the triggered configured grant confirmation.
For a configured grant Type 2, the MAC entity shall clear the configured uplink grant immediately after first transmission of Configured Grant Confirmation MAC CE triggered by the configured grant deactivation.
Retransmissions except for repetition of configured grants use uplink grants addressed to CS-RNTI.

The NR MAC Specification specified activation/deactivation of SCell (Secondary Cell) in 3GPP TS 38.321 V15.0.0 as disclosed as follows:

If the MAC entity is configured with one or more SCells, the network may activate and deactivate the configured SCells. Upon configuration of an SCell, the SCell is deactivated.

The configured SCell(s) is activated and deactivated by:

receiving the SCell Activation/Deactivation MAC CE described in subclause 6.1.3.9;configuring sCellDeactivationTimer timer per configured SCell (except the SCell configured with PUCCH, if any): the associated SCell is deactivated upon its expiry.
The MAC entity shall for each configured SCell:1> if an SCell Activation/Deactivation MAC CE is received activating the SCell:2> activate the SCell; i.e. apply normal SCell operation including:3> SRS transmissions on the SCell;3> CQI/PMI/RI/CRI reporting for the SCell;3> PDCCH monitoring on the SCell;3> PDCCH monitoring for the SCell;3> PUCCH transmissions on the SCell, if configured.2> start or restart the sCellDeactivationTimer associated with the SCell in the slot when the SCell Activation/Deactivation MAC CE was received;2> (re-)initialize any suspended configured uplink grants of configured grant Type 1 associated with this SCell according to the stored configuration, if any, and to start in the symbol according to rules in subclause 5.8.2;2> trigger PHR according to subclause 5.4.6.1> else if an SCell Activation/Deactivation MAC CE is received deactivating the SCell; or1> if the sCellDeactivationTimer associated with the activated SCell expires:2> deactivate the SCell;2> stop the sCellDeactivationTimer associated with the SCell;2> clear any configured downlink assignment and any configured uplink grant Type 2 associated with the SCell respectively;2> suspend any configured uplink grant Type 1 associated with the SCell;2> flush all HARQ buffers associated with the SCell.1> if PDCCH on the activated SCell indicates an uplink grant or downlink assignment; or1> if PDCCH on the Serving Cell scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell:2> restart the sCellDeactivationTimer associated with the SCell.1> if the SCell is deactivated:2> not transmit SRS on the SCell;2> not report CQI/PMI/RI/CRI for the SCell;2> not transmit on UL-SCH on the SCell;2> not transmit on RACH on the SCell;2> not monitor the PDCCH on the SCell;2> not monitor the PDCCH for the SCell;2> not transmit PUCCH on the SCell.
HARQ feedback for the MAC PDU containing SCell Activation/Deactivation MAC CE shall not be impacted by PCell, PSCell and PUCCH SCell interruptions due to SCell activation/deactivation in TS 38.133 [11].
When SCell is deactivated, the ongoing Random Access procedure on the SCell, if any, is aborted.

In 3GPP TS 38.331 V15.0.0, a specified SCell deactivation timer related configuration is disclosed as follows:

The IE MAC-CellGroupConfig is used to configure MAC parameters for a cell group, including DRX.

MAC-CellGroupConfig Information Element

In 3GPP TS 38.331 V15.0.0, a specified Semi-Persistent Scheduling (SPS) related configuration is disclosed as follows:

SPS-ConfigEditor's Note: FFS: Relation between (UL-)SPS and “ULtransmissionWithoutGrant”. Is it one feature with different configurations as the L1 parameters suggest? How is it modelled in MAC? What about DL?Editor's Note: FFS: RAN1 indicated in the L1 table: “Note: Multiple configurations is possible, how many needs to be determined”. RAN2 agreed that SPS can be used on Pcell and SCell . . . . But each UE can use it on at most one serving cell of a cell group at a time. Are the “multiple configuration” meant for one carrier? Does the UE then use several SPS-RNTIs?
The SPS-Config IE is used to configure semi-persistent transmission according to two possible schemes. The actual uplink grant may either be configured via RRC (type1) or provided via the PDCCH (addressed to SPS-RNTI) (type2).

SPS-Config Information Element

In 3GPP TS 36.331 V14.4.0, the interval of the SPS is disclosed as follows:

The IE SPS-Config is used to specify the semi-persistent scheduling configuration.

SPS-Config Information Element

SPS-Config field descriptionsfixedRV-NonAdaptiveIf this field is present and skipUplinkTxSPS is configured, non-adaptive retransmissions on configured uplink grantuses redundancy version 0, otherwise the redundancy version for each retransmission is updated based on thesequence of redundancy versions as described in TS 36.321 [6].implicitReleaseAfterNumber of empty transmissions before implicit release, see TS 36.321 [6, 5.10.2]. Value e2 corresponds to 2transmissions, e3 corresponds to 3 transmissions and so on. If skipUplinkTxSPS is configured, the UE shall ignorethis field.n1PUCCH-AN-PersistentList, n1PUCCH-AN-PersistentListP1List of parameter: nPUCCH(1, p)for antenna port P0 and for antenna port P1 respectively, see TS 36.213 [23, 10.1]. Fieldn1-PUCCH-AN-PersistentListP1 is applicable only if the twoAntennaPortActivatedPUCCH-Format1a1b in PUCCH-ConfigDedicated-v1020 is set to true. Otherwise the field is not configured.numberOfConfSPS-ProcessesThe number of configured HARQ processes for downlink Semi-Persistent Scheduling, see TS 36.321 [6].numberOfConfUISPS-ProcessesThe number of configured HARQ processes for uplink Semi-Persistent Scheduling, see TS 36.321 [6]. E-UTRANalways configures this field for asynchronous UL HARQ. Otherwise it does not configure this field.p0-NominalPUSCH-PersistentParameter: PO—NOMINAL—PUSCH(0). See TS 36.213 [23, 5.1.1.1], unit dBm step 1. This field is applicable for persistentscheduling, only. If choice setup is used and p0-Persistent is absent, apply the value of p0-NominalPUSCH for p0-NominalPUSCH-Persistent. If uplink power control subframe sets are configured by tpc-SubframeSet, this field appliesfor uplink power control subframe set 1.p0-NominalPUSCH-PersistentSubframeSet2Parameter: PO—NOMINAL—PUSCH(0). See TS 36.213 [23, 5.1.1.1], unit dBm step 1. This field is applicable for persistentscheduling, only. If p0-PersistentSubframeSet2-r12 is not configured, apply the value of p0-NominalPUSCH-SubframeSet2-r12 for p0-NominalPUSCH-PersistentSubframeSet2. E-UTRAN configures this field only if uplink powercontrol subframe sets are configured by tpc-SubframeSet, in which case this field applies for uplink power controlsubframe set 2.p0-UE-PUSCH-PersistentParameter: PO—UE—PUSCH(0). See TS 36.213 [23, 5.1.1.1], unit dB. This field is applicable for persistent scheduling,only. If choice setup is used and p0-Persistent is absent, apply the value of p0-UE-PUSCH for p0-UE-PUSCH-Persistent. If uplink power control subframe sets are configured by tpc-SubframeSet, this field applies for uplink powercontrol subframe set 1.p0-UE-PUSCH-PersistentSubframeSet2Parameter: PO—UE—PUSCH(0). See TS 36.213 [23, 5.1.1.1], unit dB. This field is applicable for persistent scheduling,only. If p0-PersistentSubframeSet2-r12 is not configured, apply the value of p0-UE-PUSCH-SubframeSet2 for p0-UE-PUSCH-PersistentSubframeSet2. E-UTRAN configures this field only if uplink power control subframe sets areconfigured by tpc-SubframeSet, in which case this field applies for uplink power control subframe set 2.semiPersistSchedC-RNTISemi-persistent Scheduling C-RNTI, see TS 36.321 [6].semiPersistSchedIntervalDLSemi-persistent scheduling interval in downlink, see TS 36.321 [6]. Value in number of sub-frames. Value sf10corresponds to 10 sub-frames, sf20 corresponds to 20 sub-frames and so on. For TDD, the UE shall round thisparameter down to the nearest integer (of 10 sub-frames), e.g. sf10 corresponds to 10 sub-frames, sf32 correspondsto 30 sub-frames, sf128 corresponds to 120 sub-frames.semiPersistSchedIntervalSLSemi-persistent scheduling interval in sidelink, see TS 36.321 [6]. Value in number of sub-frames. Value sf20corresponds to 20 sub-frames, sf50 corresponds to 50 sub-frames and so on.semiPersistSchedIntervalULSemi-persistent scheduling interval in uplink, see TS 36.321 [6]. Value in number of sub-frames. Value sf10corresponds to 10 sub-frames, sf20 corresponds to 20 sub-frames and so on. For TDD, when the configured Semi-persistent scheduling interval is greater than or equal to 10 sub-frames, the UE shall round this parameter down to thenearest integer (of 10 sub-frames), e.g. sf10 corresponds to 10 sub-frames, sf32 corresponds to 30 sub-frames, sf128corresponds to 120 sub-frames. If semiPersistSchedIntervalUL-v1430 is configured, the UE only considers thisextension (and ignores semiPersistSchedIntervalUL i.e. without suffix).sl-SPS-V-RNTISL Semi-Persistent Scheduling V-RNTI for V2X sidelink communication, see TS 36.321 [6].sps-ConfigIndexIndicates the index of one of multiple SL/UL SPS configurations.sps-ConfigSL-ToAddModListIndicates the SL SPS configurations to be added or modified, identified by SPS-ConfigIndex.sps-ConfigSL-ToReleaseListIndicates the SL SPS configurations to be released, identified by SPS-ConfigIndex.sps-ConfigUL-ToAddModListIndicates the UL SPS configurations to be added or modified, identified by SPS-ConfigIndex.sps-ConfigUL-ToReleaseListIndicates the UL SPS configurations to be released, identified by SPS-ConfigIndex.twoIntervalsConfigTrigger of two-intervals-Semi-Persistent Scheduling in uplink. See TS 36.321 [6, 5.10]. If this field is present and theconfigured Semi-persistent scheduling interval greater than or equal to 10 sub-frames, two-intervals-SPS is enabledfor uplink. Otherwise, two-intervals-SPS is disabled.ul-SPS-V-RNTIUL Semi-Persistent Scheduling V-RNTI for UEs capable of multiple uplink SPS configurations and which support V2Xcommunication, see TS 36.321 [6].

Currently, based on the NR Radio Resource Control (RRC) specification as disclosed in 3GPP TS 38.331 V15.0.0, the value of the SCell deactivation timer is configured per cell group. For example, a cell group could contain a first SCell and a second SCell. The first SCell could be activated to serve an UE. The second SCell could be further activated to serve the UE together with the first SCell. The UE could start or restart a first SCell deactivation timer associated with the first SCell. The UE could start or restart a second SCell deactivation timer associated with the second SCell. Based on 3GPP TS 38.331 V15.0.0, both the first SCell deactivation timer and the second SCell deactivation timer share the same value for which the UE controls the length of the associated timer based on the value.

According to the NR MAC specification as disclosed in 3GPP TS 38.321 V15.0.0, the UE could start or restart a SCell deactivation timer associated with a SCell (which may not be configured with Physical Uplink Control Channel (PUCCH)) when dynamic scheduling (e.g., by Physical Downlink Control Channel (PDCCH) indicating a downlink assignment or an uplink grant) for the SCell or a SCell Activation/Deactivation MAC control element activating the SCell is received. Upon expiry of the SCell deactivation timer, the UE does not perform any uplink transmission (e.g. SRS, CQI/PMI/RI/CRI report, UL-SCH, PUCCH, etc.) on the SCell, not monitor (e.g. PDCCH) for the SCell and/or not monitor (e.g. PDCCH) on the SCell. However, it is not specified that a UE should restart the SCell deactivation timer when a transmission or reception based on configured resources (e.g., configured grant Type 1, configured grant Type 2, or configured DL assignment) occurs. In this situation, if a UE is configured to start or restart the SCell deactivation timer for the SCell before being configured with configured resources and then the network configures the UE with the configured resources on the SCell, the UE may deactivate the SCell (due to expiry of the SCell deactivation timer) while there is still ongoing downlink or uplink traffic waiting for reception/transmission. To avoid this, the network needs to send a dedicated signaling (e.g., SCell Activation/Deactivation MAC Control Element (CE)) to keep the UE to activate the SCell again. Furthermore, the network also needs to send a dedicated signaling (e.g., physical signaling) to the UE to (re-)activate or (re-)initialize configured resources or newly configured resources on the SCell because the old configured resources on the SCell cannot be used after deactivation of the SCell. But, this solution results in signaling overhead. Other better alternatives can be considered to solve this problem.

Possibly, the UE could run a SCell deactivation timer for a SCell on which configured resources could be configured on the SCell. The SCell could belong to a cell group. The UE could be configured with the SCell deactivation timer for the SCell or the cell group. The UE could be configured with Type 1 configuration or RRC configuration for SPS on the SCell (via, e.g., RRC signalling, MAC control element, or physical signalling). The UE could be configured with the configured resources (via, e.g., RRC signalling, MAC control element, or physical signaling). The SCell could be configured with PUCCH.

In one example, the UE could start or restart the SCell deactivation timer for the SCell when a transmission or reception based on the configured resources (e.g., a configured uplink grant or a configured downlink assignment) occurs.

In one example, the UE could start or restart the SCell deactivation timer with a first value for the SCell if the SCell is not configured with the configured resources. In this example, the UE could start or restart the SCell deactivation timer with a second value for the SCell if the SCell is configured with the configured resources. Alternately, the UE could control the length of the SCell deactivation timer based on the first value if the UE starts or restarts the timer with the first value. Alternately, the UE could control the length of the SCell deactivation timer based on the second value if the UE starts or restarts the timer with the second value. The UE could be configured with the first value by a base station. The UE could be configured or reconfigured with the second value by the base station. The UE could be pre-configured with the second value. The first value could be shorter/smaller than the second value. The second value could be infinite or a value resulting in the length of the SCell deactivation timer using the value being longer/larger than the length of the SPS interval so as to avoid expiry of the SCell deactivation timer during an SPS interval. The first value could be associated with the SCell. Alternately, the first value could be associated with the cell group. The second value could be associated with the SCell. Alternatively, the second value could be associated with the cell group. The UE could start or restart the SCell deactivation timer with the second value when a transmission or reception based on the configured resources occurs.

In another example, the UE could start or restart the SCell deactivation timer with a first value for the SCell if the SCell is not configured with Type 1 configuration or RRC configuration for SPS. In this example, the UE could start or restart the SCell deactivation timer with a second value for the SCell if the SCell is configured with the Type 1 configuration or RRC configuration for SPS. Alternately, the UE could control the length of the SCell deactivation timer based on the first value if the UE starts or restarts the timer with the first value. Alternately, the UE could control the length of the SCell deactivation timer based on the second value if the UE starts or restarts the timer with the second value. Alternately, the UE could be configured with the first value by a base station. Alternately, the UE could be configured or reconfigured with the second value by the base station. Alternately, the UE could be pre-configured with the second value. The first value could be shorter/smaller than the second value. Alternately, the second value could be infinite or a value resulting in the length of the SCell deactivation timer using the value being longer/larger than the length of the SPS interval. The first value could be associated with the SCell. Alternatively, the first value could be associated with the cell group. The second value could be associated with the SCell. Alternately, the second value could be associated with the cell group. The UE could start or restart the SCell deactivation timer with the second value when a transmission or reception based on the configured resources occurs.

In one example, the network could re-configure the UE to set and/or use the SCell deactivation timer with the second value for the SCell or the cell group if the network configures the configured resources on the SCell.

In one example, the network could re-configure the UE to set and/or use the SCell deactivation timer with the second value for the SCell or the cell group before/when/after the network configures the configured resources on the SCell.

In one example, the network could re-configure the UE to set and/or use the SCell deactivation timer with the second value for the SCell or the cell group if the network configures the Type 1 configuration or RRC configuration for SPS on the SCell.

In one example, the network could re-configure the UE to set and/or use the SCell deactivation timer with the second value for the SCell or the cell group before/when/after the network configures the Type 1 configuration or RRC configuration for SPS on the SCell.

In one possible example, the UE could not run a SCell deactivation timer for a SCell on which configured resources could be configured on the SCell. The SCell could belong to a cell group. The UE could be configured with the SCell deactivation timer for the SCell or the cell group. The UE could be configured with Type 1 configuration or RRC configuration for SPS on the SCell (via e.g. RRC signaling, MAC control element or physical signaling). The UE could be configured with the configured resources (via e.g. RRC signaling, MAC control element or physical signaling). The SCell could be configured with PUCCH.

In one example, the UE could not start or restart the SCell deactivation timer for the SCell when a transmission or reception based on the configured resources occurs.

In one example, the UE could not start or restart the SCell deactivation timer for the SCell if the SCell is configured with the configured resources. In this example, the UE could start or restart the SCell deactivation timer with a value for the SCell if the SCell is not configured with the configured resources. The UE could control the length of the SCell deactivation timer based on the value if the UE starts or restarts the timer with the value. The UE could be configured with the value by a base station. The value could be associated with the SCell. The value could be associated with the cell group. The UE does not start or restart the SCell deactivation timer for the SCell when a transmission or reception based on the configured resources on the SCell occurs. The SCell deactivation timer could be running before the UE is configured with the configured resource on the SCell. In that situation, the UE could stop the SCell deactivation timer for the SCell when it is configured to activate, reactivate, initiate, or reinitiate the configured resources (via e.g. RRC signaling, MAC control element or physical signaling) for the SCell. The UE could start or restart the SCell deactivation timer for the SCell when it is configured to deactivate or release the configured resources (via e.g. RRC signaling, MAC control element or physical signaling) for the SCell.

In one example, the UE could not start or restart the SCell deactivation timer for the SCell if the SCell is configured with Type 1 configuration or RRC configuration for SPS. In this example, the UE could start or restart the SCell deactivation timer with a value for the SCell if the SCell is not configured with the Type 1 configuration or a RRC configuration for SPS. The UE could control the length of the SCell deactivation timer based on the value if the UE starts or restarts the timer with the value. The UE could be configured with the value by a base station. The value could be associated with the SCell. Alternately, the value could be associated with the cell group. The SCell deactivation timer could be running before the UE is configured with the Type 1 configuration or RRC configuration for SPS on the SCell. In that situation, the UE could stop the SCell deactivation timer for the SCell when it is configured with the Type 1 configuration or RRC configuration for SPS (via e.g. RRC signaling, MAC control element or physical signaling) for the SCell. The UE could start or restart the SCell deactivation timer for the SCell when it is configured to release the Type 1 configuration or RRC configuration for SPS (via e.g. RRC signaling, MAC control element or physical signaling) for the SCell.

In one example, the network could de-configure the UE to use the SCell deactivation timer for the SCell or the cell group if the network configures the configured resources on the SCell. In other words, the SCell deactivation timer is disabled.

In one example, the network could de-configure the UE to use the SCell deactivation timer for the SCell or the cell group before/when/after the network configures the configured resources on the SCell.

In one example, the network could de-configure the UE to use the SCell deactivation timer for the SCell or the cell group if the network configures the Type 1 configuration or RRC configuration for the SPS on the SCell.

In one example, the network could de-configure the UE to use the SCell deactivation timer for the SCell or the cell group before/when/after the network configures the Type 1 configuration or RRC configuration for the SPS on the SCell.

In one possible example, the network could configure the UE with configured resources only on a PUCCH SCell. Furthermore, the network could configure the UE with Type 1 configuration or RRC configuration for SPS only on the PUCCH SCell. The UE would not use the SCell deactivation timer for the PUCCH SCell. Thus, the UE would not deactivate the PUCCH SCell due to expiry of the SCell deactivation timer while it is transmitting or receiving based on the configured resources. A PUCCH SCell could mean a SCell configured with PUCCH.

In another alternative to solve the issue mentioned above could be that a UE determines whether to deactivate a SCell when a SCell deactivation timer for the SCell expires based on whether there is any configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. The UE could not deactivate the SCell if there is any configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. The UE may not deactivate the SCell when the SCell deactivation timer for the SCell expires if there is any configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. For example, the UE could not deactivate the SCell if it is configured with Type 1 configuration or RRC configuration for the SPS on the SCell. For another example, the UE could not deactivate the SCell if configured resources (e.g. Type 1 resources or SPS resources) is not initialized, reinitialized, activated, or reactivated (via e.g. RRC signaling, MAC control element or physical signaling) on the SCell. In addition, the UE could start or restart a SCell deactivation timer for the SCell. When the SCell deactivation timer expires, the UE could not deactivate the SCell if the Type 1 configuration or the RRC configuration for the SPS on the SCell and/or the configured resources are initialized, reinitialized, activated, or reactivated on the SCell. More specifically, the UE could start or restart the SCell deactivation timer upon the expiry of the SCell deactivation timer if the Type 1 configuration or the RRC configuration for the SPS on the SCell and/or the configured resources are initialized, reinitialized, activated, or reactivated on the SCell.

The UE may deactivate a SCell when a SCell deactivation timer for the SCell expires if there is no configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. The UE may deactivate the SCell when the SCell deactivation timer expires if there is no configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. The UE may deactivate the SCell when the SCell deactivation timer expires if there is no configured downlink assignment or configured grant (Type 1 or Type 2) on the SCell for the UE. The SPS may be configured grant type 1. The SPS may be configured grant type 2.

According to one method, the 3GPP TS 38.321 may be modified such that the MAC entity shall for each configured SCell:1> if PDCCH on the activated SCell indicates an uplink grant or downlink assignment; or1> if PDCCH on the Serving Cell scheduling the activated SCell indicates an uplink grant or a downlink assignment for the activated SCell; or1> if a downlink assignment for SPS or an uplink grant is configured in the slot for the activated S Cell:2> restart the sCellDeactivationTimer associated with the SCell.

According to one method, the 3GPP TS 38.321 may be modified such that if the MAC entity is configured with one or more SCells, the network may activate and deactivate the configured SCells. Upon configuration of an SCell, the SCell is deactivated. The configured SCell(s) is activated and deactivated by:receiving the SCell Activation/Deactivation MAC CE described in subclause 6.1.3.9;configuring sCellDeactivationTimer timer per configured SCell (except the SCell configured with PUCCH, downlink assignment for SPS, or configured grant, if any): the associated SCell is deactivated upon its expiry.

According to one method, a network node could configure a UE with a first SCell. The network node could configure the UE to use a first SCell deactivation timer for the first SCell. The network node could configure the UE with a SPS resource on the first SCell. The network node could configure the UE not to use the first SCell deactivation timer for the first SCell.

In one or more of the above-disclosed methods, a first dedicated signalling used to configure the UE to use the first SCell deactivation timer for the first SCell could be sent to the UE.

In one or more of the above-disclosed methods, a second dedicated signalling used to configure the SPS configuration could be sent to the UE.

In one or more of the above-disclosed methods, a third dedicated signalling used to configure the UE not to use the first SCell deactivation timer for the first SCell could be sent to the UE.

In one or more of the above-disclosed methods, the second dedicated signalling could be the same as the third dedicated signalling.

In one or more of the above-disclosed methods, de-configuration of the first SCell deactivation timer could be included in the third dedicated signalling.

In one or more of the above-disclosed methods, the network could further configure the UE with a second SCell.

In one or more of the above-disclosed methods, the second SCell is not configured with the SPS resource.

In one or more of the above-disclosed methods, the first SCell and the second SCell could belong to same cell group.

In one or more of the above-disclosed methods, the network node could further configure the UE to use the first SCell deactivation timer for the second SCell.

In one or more of the above-disclosed methods, the network node could configure the UE to use a second SCell deactivation timer for the second SCell.

In one or more of the above-disclosed methods, the network node could configure the UE not to use the first SCell deactivation timer for the first SCell before releasing the SPS resource.

In another method, the network node could configure a UE with a first SCell. The network node could configure the UE to set and/or use a first SCell deactivation timer with a first value for the first SCell. The network node could configure the UE with SPS resource on the first SCell. The network node could configure the UE to set and/or use the first SCell deactivation timer with a second value for the first SCell.

In one or more of the above-disclosed methods, a first dedicated signalling used to configure the UE to set and/or use the first SCell deactivation timer with the first value for the first SCell could be sent to the UE.

In one or more of the above-disclosed methods, a first dedicated signalling used to configure the UE to set and/or use the first SCell deactivation timer with the first value for the first SCell could be sent to the UE.

In one or more of the above-disclosed methods, a second dedicated signalling used to configure the SPS configuration could be sent to the UE.

In one or more of the above-disclosed methods, a third dedicated signalling used to configure the UE to set and/or use the first SCell deactivation timer with the second value for the first SCell could be sent to the UE.

In one or more of the above-disclosed methods, the second dedicated signalling could be the same as the third dedicated signalling.

In one or more of the above-disclosed methods, the network could further configure the UE with a second SCell.

In one or more of the above-disclosed methods, the second SCell could not be configured with the SPS resource.

In one or more of the above-disclosed methods, the first SCell and the second SCell could belong to same cell group.

In one or more of the above-disclosed methods, the network node could further configure the UE to set and/or use the first SCell deactivation timer with the first value for the second SCell.

In one or more of the above-disclosed methods, the network node could further configure the UE to set and/or use a second SCell deactivation timer with the first value for the second SCell.

In one or more of the above-disclosed methods, the network node could further configure the UE to set and/or use the first SCell deactivation timer with the second value for the first SCell before releasing the SPS resource.

In another method, the UE could be configured with a first SCell. The UE could be configured to set and/or use a first SCell deactivation timer with a first value for the first SCell. The UE could be configured with a SPS resource on the first SCell. The UE could start or restart the first SCell deactivation timer with the first value if a transmission or reception based on the SPS resource occurs.

In one or more of the above-disclosed methods, the transmission or reception based on the SPS resource could mean that the transmission or reception is performed due to a configured uplink grant or a configured downlink assignment.

In one or more of the above-disclosed methods, the UE could initialize the configured uplink grant or the configured downlink assignment if a PDCCH addressed to a CS-RNTI for the first SCell is received.

In one or more of the above-disclosed methods, the UE could further start or restart the first SCell deactivation timer if a PDCCH indicating an uplink grant or a downlink assignment on the first SCell is received.

In one or more of the above-disclosed methods, the UE could further deactivate the first SCell if the first SCell deactivation timer expires.

As those skilled in the art will appreciate, the various disclosed embodiments may be combined to form new embodiments and/or methods.

FIG. 5is a flow chart500according to one exemplary embodiment from the perspective of a network node. In step505, the network node configures a UE with a first SCell. In step510, the network node configures the UE to use a first SCell deactivation timer for the first SCell. In step515, the network node configures the UE with a SPS resource on the first SCell. In step520, the network node configures the UE not to use the first SCell deactivation timer if a length of the first SCell deactivation timer is shorter than a SPS interval of the SPS resource.

In another method, the network node could not configure the UE not to use the first SCell deactivation timer if the length of the first SCell deactivation timer is longer than or equal to the SPS interval of the SPS resource.

In another method, the network node could configure the SPS interval and configure the UE not to use the first SCell deactivation timer via different dedicated signalling or the same dedicated signalling.

In another method, the dedicated signalling could be a RRC signalling.

In another method, the first SCell deactivation timer could be started or restarted if a downlink control information for the first SCell is transmitted to the UE, a packet is transmitted on the first SCell to the UE, and/or a packet is received on the first SCell from the UE.

In another method, the first SCell could be deactivated when the first SCell deactivation timer expires.

In another method, the UE could use the first SCell deactivation timer when receiving a dedicated signalling for configuring the UE with the SPS resource.

In another method, the SPS resource could be a resource on which the UE periodically performs an uplink transmission or a downlink reception.

In another method, the SPS interval could be an interval between two uplink transmissions or two downlink receptions performed by the UE based on the SPS resource.

FIG. 6is a flow chart600according to one exemplary embodiment from the perspective of a network node. In step605, the network node configures a UE with a first SCell. In step610, the network node configures the UE to set and/or use a first SCell deactivation timer with a first value for the first SCell. In step615, the network node configures the UE with a SPS resource on the first SCell. In step620, the network node configures the UE to set and/or use the first SCell deactivation timer with a second value if the first value is shorter than a SPS interval of the SPS resource, wherein the second value is larger than or equal to the SPS interval of the SPS resource.

In another method, the network node could not configure the UE to set and/or use the first SCell deactivation timer with the second value if the first value is longer than or equal to the SPS interval of the SPS resource.

In another method, the network node could configure the SPS interval and configure the UE to set and/or use the first SCell deactivation timer with the second value via different dedicated signalling or the same dedicated signalling.

In another method, the dedicated signalling could be a RRC signalling.

In another method, the first SCell deactivation timer could be started or restarted if a downlink control information for the first SCell is transmitted to the UE, a packet is transmitted on the first SCell to the UE, and/or a packet is received on the first SCell from the UE.

In another method, the first SCell could be deactivated when the first SCell deactivation timer expires.

In another method, the UE could use the first SCell deactivation timer when receiving a dedicated signalling for configuring the UE with the SPS resource.

In another method, the SPS resource could be a resource on which the UE periodically performs uplink transmission or downlink reception.

In another method, the SPS interval could be an interval between two uplink transmissions or two downlink receptions performed by the UE based on the SPS resource.

Referring back toFIGS. 3 and 4, in one embodiment, the device300includes a program code312stored in memory310. The CPU308could execute program code312(i) to configure a UE with a first SCell; (ii) to configure the UE to use a first SCell deactivation timer for the first SCell; (iii) to configure the UE with a SPS resource on the first SCell; and (iv) to configure the UE not to use the first SCell deactivation timer if a length of the first SCell deactivation timer is shorter than a SPS interval of the SPS resource.

In another aspect, the CPU308could execute program code312to (i) to configure a UE with a first SCell; (ii) to configure the UE to set and/or use a first SCell deactivation timer with a first value for the first SCell; (iii) to configure the UE with a SPS resource on the first SCell; and (iv) to configure the UE to set and/or use the first SCell deactivation timer with a second value if the first value is shorter than a SPS interval of the SPS resource, wherein the second value is larger than or equal to the SPS interval of the SPS resource.

Furthermore, the CPU308can execute the program code312to perform all of the above-described actions and steps or others methods described herein.

The above-disclosed methods could reduce signaling overhead for activating or reactivating a SCell and for initiating or reinitiating a SPS resource on the SCell.