Method and equipment for PDCCH (physical downlink control channel) monitoring enhancement mechanism for XR (X-ray) service

Abstract

Embodiments of the present application relate to a method and apparatus for a physical downlink control channel (PDCCH) monitoring enhancement mechanism for power saving for augmented reality (XR) traffic. In accordance with an embodiment of the present application, a network node includes a transceiver and a processor coupled to the transceiver, and the processor is configured to transmit configuration information for one or more serving cells in one or more DRX groups to a user equipment (UE) via the transceiver, wherein the configuration information comprises at least one of the following: configuration information about a search space set group (SSSG), configuration information about another SSSG, one or more sets of configuration information about discontinuous reception (DRX), or configuration information about an SSSG application associated with a DRX operation of the UE, wherein the configuration information applied by the SSSG is used to enable the UE to start monitoring physical downlink control channel (PDCCH) transmissions according to a search space set within the SSSG for the one or more serving cells within the one or more DRX groups at a point in time.

Description

Technical Field

[0001] Embodiments of the present application generally relate to wireless communication technology, and more particularly, to a method and apparatus for a physical downlink control channel (PDCCH) monitoring enhancement mechanism for power saving of extended reality (XR) services. Background Art

[0002] Extended reality (XR), including augmented reality (AR) and virtual reality (VR), as well as cloud gaming (CG) bring a new class of promising connected devices, applications and services. As a potential work area of ​​3GPP (3rd Generation Partnership Project) Rel-18, power saving of XR devices is one of the key topics. Currently, the details of the PDCCH monitoring enhancement mechanism for power saving of XR services have not been discussed. Summary of the invention

[0003] Some embodiments of the present application provide a network node. The network node includes a transceiver and a processor coupled to the transceiver, and the processor is configured to transmit first configuration information for one or more service cells in one or more DRX groups to a user equipment (UE) via the transceiver, wherein the first configuration information includes at least one of the following: configuration information about a first search space set group (SSSG), configuration information about a second SSSG, one or more sets of configuration information about discontinuous reception (DRX), or configuration information of SSSG applications associated with the DRX operation of the UE, wherein the configuration information of the SSSG application is used to enable the UE to start monitoring a physical downlink control channel (PDCCH) transmission according to a search space set within the first SSSG for the one or more service cells within the one or more DRX groups at a first point in time.

[0004] In some embodiments, the first configuration information is transmitted in a Radio Resource Control (RRC) message.

[0005] In some embodiments, each service cell within the one or more service cells is uniquely assigned to one of the one or more DRX groups, and the multiple DRX parameters of each DRX group within the one or more DRX groups include: one or more DRX parameters configured commonly for the one or more DRX groups, and one or more DRX parameters configured individually for each DRX group.

[0006] In some embodiments, each serving cell within the one or more serving cells is assigned to two or more DRX groups within the one or more DRX groups, and wherein one or more DRX parameters are separately configured for each DRX group within the two or more DRX groups.

[0007] In some embodiments, the first configuration information includes information related to a cell group bundled for SSSG switching, and wherein the service cell for the SSSG application in one DRX group within the one or more DRX groups belongs only to one cell group bundled for SSSG switching.

[0008] In some embodiments, the configuration information of the SSSG application includes at least one of the following: identification information related to the first SSSG; identification information related to the second SSSG; information used to indicate whether the SSSG application function of the UE is enabled; identification information related to the search space set associated with the on duration of the DRX cycle; a timer related to the SSSG application function of the UE; a delay value applied by the UE during the SSSG application; or one or more time offsets related to the on duration of the DRX cycle.

[0009] In some embodiments, the configuration information of the SSSG application is configured per serving cell, per cell group, per DRX group, or per bandwidth part (BWP).

[0010] In some embodiments, the first time point is at least one of: a starting time slot of an on-duration of a DRX cycle; a time slot after a time slot of a DRX active time only due to the DRX on-duration timer being running; a time slot after a time slot where a DRX inactivity timer expires; or a time slot after a last time slot of the DRX active time.

[0011] Some embodiments of the present application provide a user equipment (UE). The UE includes a transceiver and a processor coupled to the transceiver; and the processor is configured to: receive first configuration information from a network node via the transceiver, wherein the first configuration information includes at least one of the following: configuration information about a first search space set group (SSSG), configuration information about a second SSSG, one or more sets of configuration information about discontinuous reception (DRX) of one or more service cells in one or more DRX groups, or configuration information of SSSG applications associated with DRX operation of the UE; and based on the configuration information of the SSSG applications, start monitoring physical downlink control channel (PDCCH) transmission according to the search space set within the first SSSG for the one or more service cells within the one or more DRX groups at a first time point.

[0012] In some embodiments, the first configuration information is received in a Radio Resource Control (RRC) message.

[0013] In some embodiments, the configuration information of the SSSG application includes at least one of the following: identification information related to the first SSSG; identification information related to the second SSSG; information used to indicate whether the SSSG application function of the UE is enabled; identification information related to the search space set associated with the on duration of the DRX cycle; a timer related to the SSSG application function of the UE; a delay value applied by the UE during the SSSG application; or one or more time offsets related to the on duration of the DRX cycle.

[0014] In some embodiments, the configuration information of the SSSG application is configured per serving cell, per cell group, per DRX group, or per bandwidth part (BWP).

[0015] In some embodiments, the first time point is at least one of: a starting time slot of an on-duration of a DRX cycle; a time slot after a time slot of a DRX active time only due to the DRX on-duration timer being running; a time slot after a time slot where a DRX inactivity timer expires; or a time slot after a last time slot of the DRX active time.

[0016] In some embodiments, the processor of the UE is configured to evaluate whether at least one SSSG application condition is satisfied at the first time point related to the DRX operation of the UE based on configuration information of the SSSG application, and wherein in response to satisfying the at least one SSSG application condition at the first time point, monitoring the PDCCH transmission according to the search space set within the first SSSG begins at the first time point.

[0017] In some embodiments, the satisfaction of the at least one SSSG application condition includes at least one of the following: at the start time slot of the on-duration of the DRX cycle, the UE is in the DRX active time for the one or more service cells only due to the DRX on-duration timer being running; during a time period of the time offset before the start time slot of the on-duration of the DRX cycle or / until a second time point with the time offset before the start time slot of the on-duration of the DRX cycle, no indication is received on the one or more service cells to instruct the UE to start monitoring the PDCCH transmission according to the second SSSG; during the time period of the time offset before the start time slot of the on-duration of the DRX cycle or / until the second time point, no downlink control information (DCI) scrambled by a radio network temporary identifier (RNTI) is received on the one or more service cells; During the time period of the time offset before the start time slot of the on-duration of the DRX cycle or at the start time slot of the on-duration of the DRX cycle or / until the second time point, the medium access control (MAC) entity does not monitor the PDCCH transmission on the search space for beam failure recovery of the one or more service cells; during the time period of the time offset before the start time slot of the on-duration of the DRX cycle or at the start time slot of the on-duration of the DRX cycle or / until the second time point, at least one of the multiple timers including a DRX inactivity timer, a random access (RA) contention resolution timer, an msgB response timer, a downlink DRX retransmission timer and an uplink DRX retransmission timer of the one or more service cells is not running; or during the time period of the time offset before the start time slot of the on-duration of the DRX cycle or / until the second time point, the UE is in a DRX inactivity time for the one or more service cells.

[0018] In some embodiments, the satisfaction of the at least one SSSG application condition includes at least one of the following: a time slot in which the UE is in DRX active time only due to the DRX on duration timer being running, a time slot after a time slot in which the UE is in DRX active time only due to the DRX on duration timer being running, a time slot in which a DRX inactivity timer expires, a time slot after a time slot in which the DRX inactivity timer expires, a time slot in which the UE is in the last time slot of the DRX active time, or a time slot after the last time slot of the DRX active time, without DCI is detected; no SR is sent or pending in a time slot in which the UE is in DRX active time only due to the DRX on duration timer being running, in / until a time slot after a time slot in which the UE is in DRX active time only due to the DRX on duration timer being running, in a time slot in which the DRX inactivity timer expires, in / until a time slot after a time slot in which the DRX inactivity timer expires, in a last time slot in which the UE is in the DRX active time, or in / until a time slot after a last time slot in which the UE is in the DRX active time; in a time slot in which the UE is in DRX active time only due to the DRX on duration timer being running, a time slot in which the DRX On Duration timer is running and is in the DRX Active Time, a time slot after the time slot in which the UE is only due to the DRX On Duration timer running and is in the DRX Active Time, a time slot after successfully receiving a RA response, a time slot in which the DRX Inactivity Timer expires, a time slot after the time slot in which the DRX Inactivity Timer expires, a time slot in which the UE is in the last time slot of the DRX Active Time, or a time slot after the last time slot in which the UE is in the DRX Active Time, a PDCCH transmission indicating a new transmission is received; or a time slot in which the UE is only due to the DRX On Duration timer running and is in the DRX Active Time, A medium access control (MAC) entity does not monitor the PDCCH transmission on the search space for beam failure recovery of the one or more serving cells in a time slot in which the UE is in the DRX active time only due to the DRX on-duration timer being running, in / until a time slot after the time slot in which the UE is in the DRX active time due to the DRX on-duration timer being running, in a time slot in which the DRX inactivity timer expires, in / until a time slot after the time slot in which the DRX inactivity timer expires, in a last time slot in which the UE is in the DRX active time, or in / until a time slot after the last time slot in which the UE is in the DRX active time.

[0019] In some embodiments, in response to the at least one SSSG application condition being satisfied at the first point in time, the processor of the UE is configured to stop monitoring the PDCCH transmission in a search space set within the second SSSG.

[0020] In some embodiments, the processor of the UE is configured to: receive a search space group identifier list; and after receiving at least one of the configuration information of the SSSG application or the search space group identifier list, reset to monitor the PDCCH transmission according to the first SSSG.

[0021] In some embodiments, in response to commencing monitoring the PDCCH transmission according to the search space set within the first SSSG, the processor of the UE is configured to stop the search space switch timer in response to the search space switch timer being running.

[0022] In some embodiments, the processor of the UE is configured to stop monitoring the PDCCH transmission in the search space set within the first SSSG and start monitoring the PDCCH transmission according to the search space set within the second SSSG in response to at least one of the following: receiving downlink control information (DCI), wherein the DCI indicates a new transmission or a retransmission of the UE; starting a random access (RA) response timer for monitoring PDCCH transmission on the search space of the one or more serving cells; starting a DRX retransmission timer for the downlink; starting a DRX retransmission timer for the uplink; starting a RA contention resolution timer; starting a msgB response timer; or transmitting a scheduling request (SR) on a physical uplink control channel (PUCCH) transmission.

[0023] In some embodiments, the processor of the UE is configured to determine a starting time slot of the search space set in the first SSSG according to a starting time slot of an On-Duration of a DRX cycle for the one or more serving cells.

[0024] In some embodiments, in order to start monitoring the PDCCH transmission according to the search space set in the first SSSG, the processor of the UE is configured to be bundled to start monitoring the PDCCH transmission for all of the one or more service cells within the one or more DRX groups or a subset of the one or more service cells within the one or more DRX groups at the first time point, and wherein the subset is configured with configuration information of the SSSG application.

[0025] In some embodiments, in response to receiving both information related to a cell group bundled for SSSG switching and configuration information of the SSSG application in one of the one or more DRX groups, the processor of the UE is configured to ignore information related to the cell group for SSSG switching that includes two or more service cells having configuration information of the SSSG application.

[0026] In some embodiments, each service cell within the one or more service cells is uniquely assigned to one of the one or more DRX groups, and the multiple DRX parameters of each DRX group within the one or more DRX groups include: one or more DRX parameters configured commonly for the one or more DRX groups, and one or more DRX parameters configured individually for each DRX group.

[0027] In some embodiments, each serving cell within the one or more serving cells is assigned to two or more DRX groups within the one or more DRX groups, and wherein one or more DRX parameters are separately configured for each DRX group within the two or more DRX groups.

[0028] Some embodiments of the present application provide a method performed by a network node. The method includes: transmitting first configuration information to a user equipment (UE), wherein the first configuration information includes at least one of the following: configuration information about a first search space set group (SSSG), configuration information about a second SSSG, one or more sets of configuration information about discontinuous reception (DRX), or configuration information of an SSSG application associated with the DRX operation of the UE, wherein the configuration information of the SSSG application is used to enable the UE to start monitoring a physical downlink control channel (PDCCH) transmission according to a search space set within the first SSSG for the one or more serving cells within the one or more DRX groups at a first time point.

[0029] Some embodiments of the present application provide a method performed by a UE. The method includes: receiving first configuration information from a network node, wherein the first configuration information includes at least one of the following: configuration information about a first search space set group (SSSG), configuration information about a second SSSG, one or more sets of configuration information about discontinuous reception (DRX) of one or more service cells in one or more DRX groups, or configuration information of SSSG applications associated with the DRX operation of the UE; and based on the configuration information of the SSSG application, starting to monitor physical downlink control channel (PDCCH) transmission according to the search space set in the first SSSG for the one or more service cells in the one or more DRX groups at a first time point.

[0030] Some embodiments of the present application provide a device for wireless communication. The device includes: a non-transitory computer-readable medium having computer-executable instructions stored thereon; a receiving circuit system; a transmitting circuit system; and a processor coupled to the non-transitory computer-readable medium, the receiving circuit system, and the transmitting circuit system, wherein the computer-executable instructions cause the processor to implement the above-mentioned method performed by a UE or a network node (e.g., a base station (BS)).

[0031] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to describe the manner in which the advantages and features of the present application can be obtained, the description of the present application is presented by reference to specific embodiments of the present application illustrated in the accompanying drawings. These drawings depict only example embodiments of the present application and are therefore not to be considered limiting of its scope.

[0033] Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present application.

[0034] Figure 2 An exemplary diagram illustrating application of SSSG according to some embodiments of the present application.

[0035] Figure 3 An exemplary flow chart illustrating monitoring of PDCCH transmissions according to some embodiments of the present application.

[0036] Figure 4 An exemplary diagram illustrating application of SSSG according to some embodiments of the present application.

[0037] Figure 5 An exemplary diagram illustrating application of SSSG according to some embodiments of the present application.

[0038] Figure 6 A block diagram illustrating an exemplary apparatus according to some embodiments of the present application. DETAILED DESCRIPTION

[0039] The detailed description of the accompanying drawings is intended as a description of the preferred embodiments of the present application, and is not intended to represent the only form in which the present application can be practiced. It should be understood that the same or equivalent functions can be implemented by different embodiments, and the different embodiments are intended to be included in the spirit and scope of the present application.

[0040] Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. For ease of understanding, embodiments under specific network architectures and new service scenarios are provided, such as 3GPP 5G, 3GPP LTE version 8, etc. It is considered that with the development of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems; and in addition, the terms listed in the present application may be changed, which should not affect the principles of the present application.

[0041] Figure 1 A schematic diagram illustrating a wireless communication system according to some embodiments of the present application. Figure 1 , the wireless communication system 100 includes at least one base station (BS) 101 and at least one user equipment (UE) 102. Specifically, for illustrative purposes, the wireless communication system 100 includes one BS 101 and two UEs 102 (e.g., UE 102a and UE 102b). Figure 1 A specific number of BSs and UEs are illustrated in FIG. 1 , but it is considered that in some other embodiments of the present application, the wireless communication system 100 may include more or fewer BSs and UEs.

[0042] The wireless communication system 100 is compatible with any type of network capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with wireless communication networks, cellular telephone networks, networks based on time division multiple access (TDMA), networks based on code division multiple access (CDMA), networks based on orthogonal frequency division multiple access (OFDMA), LTE networks, networks based on 3GPP, 3GPP 5G networks, satellite communication networks, high altitude platform networks, and / or other communication networks.

[0043] BS101 may communicate with a core network (CN) node (not shown) (e.g., a mobility management entity (MME) or a serving gateway (S-GW)), a mobility management function (AMF), or a user plane function (UPF) via an interface. BSs are also referred to as access points, access terminals, base stations, macro cells, Node Bs, enhanced Node Bs (eNBs), gNBs, home Node Bs, relay nodes, or devices, or are described using other terms used in the art. In 5G NR, BSs may also be referred to as RAN nodes or network devices. Each BS may serve several UEs within a service area (e.g., a cell or a cell sector) via wireless communication links. For example, during a handover procedure of a UE, neighbor BSs may communicate with each other as needed.

[0044] UE 102 (e.g., UE 102a and UE 102b) should be understood as any type of terminal device, which may include a computing device, such as a desktop computer, a laptop computer, a personal digital assistant (PDA), a tablet computer, a smart TV (e.g., a TV connected to the Internet), a set-top box, a game console, a security system (including a security camera), a car computer, a network device (e.g., a router, a switch and a modem), or the like. According to an embodiment of the present application, UE 102 may include a portable wireless communication device, a smart phone, a cellular phone, a flip phone, a device with a subscriber identification module, a personal computer, a selective call receiver, or any other device capable of sending and receiving communication signals on a wireless network. In some embodiments, UE 102 may include a wearable device, such as a smart watch, a fitness bracelet, an optical head-mounted display, or the like. In addition, UE 102 may be referred to as a subscriber unit, a mobile device, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal or a device, or described using other terms used in the art. UE 102 may communicate directly with BS 101 via uplink (UL) communication signals.

[0045] As specified in 3GPP TS 38.213, with respect to search space set group (SSSG) switching and skipping PDCCH monitoring, the group index of the corresponding type 3 PDCCH CSS set or USS set may be provided to the UE via searchSpaceGroupIdList for PDCCH monitoring on the serving cell. The UE may determine the time slots and symbols in the time slots at which to start or stop PDCCH monitoring according to the search space set, for the serving cell for which the UE is provided with the searchSpaceGroupIdList, or for the serving cell set (if cellGroupsForSwitchList is provided), based on the minimum SCS configuration μ among all configured DL BWPs in the serving cell or in the serving cell set and based on (if any) the serving cell in which the UE receives a PDCCH and detects a corresponding DCI format 2_0 that triggers the start or stop of PDCCH monitoring according to the search space set. When the searchSpaceGroupIdList is provided to the UE, if provided by the searchSpaceGroupIdList, the UE may reset PDCCH monitoring according to the search space set with group index 0 (i.e., SSSG 0).

[0046] As specified in 3GPP TS 38.321, with respect to discontinuous reception (DRX), the MAC entity of the UE may be configured by RRC with DRX functionality, which controls the UE's PDCCH monitoring activities for the MAC entity's C-RNTI, CI-RNTI, CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI and AI-RNTI. When using DRX operation, the MAC entity of the UE shall also monitor the PDCCH as required. When in RRC_CONNECTED, if DRX is configured, then for all activated serving cells, the MAC entity of the UE may monitor the PDCCH discontinuously using DRX operation; otherwise, the MAC entity shall monitor the PDCCH.

[0047] In general, the service cells of the MAC entity can be configured by RRC in two DRX groups with separate DRX parameters. When the RRC does not configure the auxiliary DRX group, there is only one DRX group, and all service cells belong to the one DRX group. When two DRX groups are configured, each service cell is uniquely assigned to either of the two groups. The DRX parameters configured separately for each DRX group may be: drx-onDurationTimer and drx-InactivityTimer. The common DRX parameters of the DRX group may be: drx-SlotOffset, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle (optional), drx-ShortCycleTimer (optional), drx-HARQ-RTT-TimerDL and drx-HARQ-RTT-TimerUL. Regardless of whether the MAC entity monitors PDCCH on the serving cells in the DRX group, the MAC entity transmits HARQ feedback, aperiodic CSI on PUSCH, and aperiodic SRS defined in 3GPP TS 38.214 on the serving cells in the DRX group when expected. If it is not a complete PDCCH opportunity (for example, the active time starts or ends in the middle of the PDCCH opportunity), the MAC entity does not need to monitor PDCCH.

[0048] In general, XR, including AR and VR, and cloud gaming (CG) bring a new class of promising connected devices, applications and services. As a potential work area for 3GPP Rel-18, power saving of XR devices is one of the key topics. Currently, the challenge is the increased power consumption due to the long on-duration to accommodate downlink (DL) arrival jitter. DRX allows the UE to stop monitoring the PDCCH during time periods when there is no data activity, thereby saving power and without signaling overhead. However, due to the random arrival jitter range of DL XR services being approximately [-4ms, 4ms], in order to avoid delaying service transmission to the next drx-OnDuration (i.e., "DRX cycle on-duration" or "DRX on-duration"), one possibility is to configure a large drx-OnDuration to cover the jitter range as much as possible. However, this will result in limited power saving gains. Another possibility is to configure a large drx-OnDuration at the beginning of the drx-OnDuration according to a group index of 0 (e.g., such as Figure 2 0) to apply sparse PDCCH monitoring to save power, for example, Figure 2 After the data arrives, the UE may change to another SSSG (e.g. Figure 2 SSSG 1) shown in FIG. 1 is used to apply dense PDCCH monitoring.

[0049] Figure 2 An exemplary diagram illustrating application of SSSG according to some embodiments of the present application. Figure 2 Displays the “PDCCH monitoring timing in SSSG 0” and “PDCCH monitoring timing in SSSG 1”. Figure 2 In the embodiment, SSSG 0 is Figure 3 An example of SSSG #1 in the embodiment of FIG. 1 , and SSSG 1 is Figure 3 An example of SSSG#2 in an embodiment of the present invention.

[0050] Figure 2 The embodiment of the present invention shows multiple DRX cycles in the time domain, and each DRX cycle includes an on-duration (e.g., Figure 2 On Duration #1 or On Duration #2) and the opportunities for DRX shown in the figure. Figure 2 Display at the start time slot of On Duration #1 (i.e., Figure 21) is applied to a given SSSG (e.g., SSSG 0) shown in FIG. 1. For example, SSSG 1 is applied before the start time slot of OnDuration #1, i.e., the PCCH Monitoring Opportunity in SSSG 1 is before T1. Then, SSSG 0 is applied at the start time slot of OnDuration #1, i.e., the PCCH Monitoring Opportunity in SSSG 0 is at and after T1. In some cases, the start time slot of OnDuration #1 (i.e., T1) is aligned with the start PCCH Monitoring Opportunity in SSSG 0 (i.e., as shown in FIG. 1). Figure 2 There may be a time offset (e.g., as shown in T2) between Figure 2 Then, after data arrives, the UE may change to apply intensive PDCCH monitoring timing according to SSSG 1 again, which is Figure 2 , and specific examples are given below. Figure 5 Described in the embodiments of the present invention.

[0051] The SSSG application solution or mechanism may also be referred to as an SSSG switching solution or mechanism or the like. For the above SSSG switching solution, the following problems need to be solved: (1) if the UE expects to receive a PDCCH for critical information, then applying a search space set with a group index of 0 (e.g., SSSG 0) at the beginning of the DRX on-duration will delay transmission because the search space set monitoring pattern is not aligned with the non-uniform DRX cycle; and (2) the serving cells in the DRX group have the same DRX pattern, and the problem of how to coordinate with the traditional SSSG switching based on cellGroupsForSwitchList needs to be solved.

[0052] The embodiments of the present application are intended to solve the above-mentioned problems and design a more efficient XR service power saving mechanism. More specifically, in some embodiments of the present application, in order to balance the transmission delay and power saving of the XR device, the UE may apply a given SSSG with sparse PDCCH monitoring for the serving cell within the DRX group based on the UE's DRX operation based on drx-inactiveTimer and drx-RetransmissionTimerDL, for example: at the start time slot of the DRX on duration; and the UE may determine the start time slot of the search space set in a given SSSG based on the start time slot of the DRX on duration of the serving cell instead of the traditional PDCCH monitoring offset; or a time slot after (at least the time offset) the time slot of the DRX active time in which the UE is only due to the operation of the drx-onDurationTimer; or a time slot after (at least the time offset) the time slot in which the drx-InactivityTimer expires; or a time slot after (at least the time offset) the time slot in which the UE is in the DRX active time. In some other embodiments of the present application, if the UE receives DCI for new transmission or retransmission, etc. in the PDCCH, a given SSSG with intensive PDCCH monitoring is applied for serving cells within the DRX group.

[0053] In an embodiment of the present application, the SSSG may be replaced by a search space set defined in SearchSpace in 3GPP TS 38.331, which defines how or where to search for PDCCH candidates. Each search space may be associated with a ControlResourceSet. The IE ControlResourceSet may be used to configure a time or frequency control resource set (CORESET) in which to search for downlink control. More details will be described below in conjunction with the accompanying drawings.

[0054] Figure 3 An exemplary flow chart illustrating monitoring of PDCCH transmissions according to some embodiments of the present application. Figure 3 The exemplary method 300 in the embodiment of the present invention may be performed by a UE (e.g., Figure 1 Although described with respect to a UE, it should be understood that other devices may be configured to perform similar Figure 3 The details described in all other embodiments of this application apply to Figure 3 In addition, in Figure 3 The details described in the embodiments apply to Figure 1 , 2 and all embodiments of 4 to 6. A specific example of the exemplary method 300 is described below. Figure 4 and 5Described in the embodiments of the present invention.

[0055] In such Figure 3 In the exemplary method 300 shown in FIG. 1 , in operation 301, a UE (e.g., Figure 1 UE 102a shown in FIG. 102b) receives a request from a network node (eg, Figure 1 1) receives configuration information (denoted as configuration #1 for simplicity). In some embodiments, configuration #1 is received in an RRC message. For example, configuration #1 may include at least one of the following:

[0056] (1) Configuration information about SSSG (denoted as SSSG#1 for simplicity). For example, SSSG#1 (e.g., the search space set group with group index 0, i.e. Figure 2 , 4 SSSG 0) in and 5 has a spare PDCCH monitoring opportunity and may include one or more search space sets.

[0057] (2) Configuration information about another SSSG (denoted as SSSG#2 for simplicity). For example, SSSG#2

[0058] (For example, the search space set group with group index 1, i.e. Figure 2 and 5 SSSG 1) in has dense PDCCH monitoring opportunities and may include one or more search space sets. In an embodiment, both SSSG#1 and SSSG#2 are included in the searchSpaceGroupIdList IE.

[0059] (3) One or more groups of configuration information about DRX (denoted as DRX-config for simplicity), for example, parameters including DRX cycle, etc. DRX-config may be used to configure DRX-related parameters of the serving cells in the DRX group, for example, drx-onDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, drx-HARQ-RTT-TimerUL, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, shortDRX and drx-SlotOffset as defined in 3GPP TS 38.331, and its usage is defined in 3GPP TS 38.321.

[0060] (4) Configuration information of the SSSG application associated with the DRX operation of the UE (expressed as SSSG-DRX-config for simplicity).

[0061] In operation 302, based on configuration information of the SSSG application, the UE may start monitoring a physical downlink control channel (PDCCH) transmission according to a search space set in a first SSSG for one or more serving cells in one or more DRX groups at a first time point.

[0062] In some embodiments of operation 302, the UE may evaluate whether at least one SSSG application condition based on the SSSG-DRX-config is satisfied at a time point related to the DRX operation of the UE (denoted as time #1 for simplicity). In some embodiments, time #1 is at least one of the following:

[0063] (1) The start time slot of the on-duration of the DRX cycle, for example Figure 4 T1 shown in Figure 2.

[0064] (2) A time slot after "a time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running", e.g., T2 during which the DRX On Duration timer is running, such as Figure 4 For example, the time slot may be a time offset (eg, Y-offset) after a time slot in which the UE is in DRX active time only due to the DRX on-duration timer (eg, drx-onDurationTimer) being running.

[0065] (3) A time slot after a time slot in which a DRX inactivity timer (e.g., drx-InactivityTimer) expires, e.g., T2 during a “DRX On Duration timer is running” or T4 during a “DRX On Duration timer is not running”, such as Figure 4 For example, the time slot may be a time offset (eg, Y-offset) after the time slot in which the DRX inactivity timer (eg, drx-InactivityTimer) expires.

[0066] (4) A time slot after the last time slot in which the UE is in DRX active time, for example, T2 in which the UE stops the DRX On Duration timer before the DRX On Duration timer expires, or T4 in which the DRX On Duration timer expires, such as Figure 4 For example, the time slot may be a time offset (eg, Y-offset) after the last time slot in which the UE was in DRX active time.

[0067] (5) Where the UE is in the start time slot of the DRX active time only due to the DRX on-duration timer being running, e.g. Figure 4 T1 or T2 shown in .

[0068] In some embodiments of operation 302, in response to at least one SSSG application condition being satisfied at time #1, the UE may start monitoring PDCCH transmissions according to a search space set within SSSG #1 for one or more serving cells within one or more DRX groups at time #1, and stop monitoring PDCCH transmissions according to a search space set within SSSG #2. For example, the UE may switch from SSSG 1 to SSSG 0 at T1, such as Figure 4 Displayed in. Figure 4 SSSG 0 in is an instance of SSSG#1. Figure 4 SSSG 1 in is an instance of SSSG #2.

[0069] In some other embodiments of operation 302, in response to one or more SSSG application conditions not being satisfied at time #1, the UE may not start monitoring PDCCH transmissions according to a search space set within SSSG #1 for one or more serving cells within one or more DRX groups at time #1. For example, if the drx-InactivityTimer is running, the UE may not switch from SSSG 1 to SSSG 0 at T1, as shown in FIG. Figure 4 For example, if the UE is in DRX active time not only due to running drx-onDurationTimer, then the UE may not switch from SSSG 1 to SSSG 0 at T1, as shown in Figure 4 For example, if the UE is in DRX active time due to beam failure recovery procedures (e.g., based on dedicated (or contention-free) RACH preambles or dedicated RACH frequency resources), then the UE may not switch from SSSG 1 to SSSG 0 at T1, as shown in FIG. Figure 4 . In some embodiments, SSSG-DRX-config may be used to enable the UE to apply one SSSG at the start time slot of the DRX on duration, or to enable the UE to implicitly switch back to the one SSSG from another SSSG. For example, applying one SSSG will start monitoring PDCCH transmissions according to the search space set in the one SSSG, and stop monitoring PDCCH transmissions according to the search space set in the other SSSG. In some embodiments, SSSG-DRX-config is configured by serving cell, by cell group, by DRX group, or by BWP. In some embodiments, SSSG-DRX-config includes at least one of the following:

[0070] (1) Identification information related to SSSG#1. This field can be used to identify SSSG#1; and this information may not be configured by the network node, but is predefined in the standard specification.

[0071] (2) Identification information related to SSSG#2: This field is used to identify SSSG#2; and this information may not be configured by the network node, but is predefined in the standard specification.

[0072] (3) Information used to indicate whether the SSSG application function of the UE is enabled. This field may be called "Enabled"

[0073] or similar, and may instruct the UE to implicitly apply SSSG#1 at T1, T2, or T4, such as Figure 4 This field is displayed in . For example, this field is a Boolean value with a value of TRUE or FALSE. TRUE indicates that the UE cannot implicitly apply SSSG#1 at the start time slot of drx-onDuration. FALSE or the absence of SSSG-DRX-config indicates that the UE cannot implicitly apply SSSG#1 for the serving cell, serving cells in a cell group, serving cells in (or associated with) a DRX group, or BWP at the start time slot of drx-onDuration.

[0074] (4) Identification information related to the search space set associated with the on-duration of the DRX cycle. This field may be referred to as "searchSpace ID" or the like and may be used to identify the search space set in SSSG#1 to align with the start time slot of the drx-Onduration.

[0075] (5) Timer related to the SSSG application function of the UE. This field can be called

[0076] "searchSpaceSwitchTimer" or similar, and may be used to indicate a timer (e.g., in slots or symbols) to control the behavior of the UE to select from a search space group (e.g., Figure 2 , 4 or SSSG 1 or SSSG 0 in 5) to switch back to the search space group (e.g., Figure 2 , 4 or SSSG 0 or SSSG 1 in 5). This field can be configured separately from the traditional searchSpaceSwitchTimer. This field can be configured by BWP, by serving cell, by cell group, or by DRX group.

[0077] (6) The delay value applied by the UE during SSSG application. This field may be referred to as

[0078] "searchSpaceSwitchDelay" or similar, and can be used to indicate the delay value to be applied by the UE for SSSG switching. This field can be configured separately from the legacy searchSpaceSwitchDelay. This field can be configured per BWP, per serving cell, per cell group, or per DRX group.

[0079] (7) One or more time offsets related to the on-duration of the DRX cycle. For example, the SSSG-DRX-config contains a field "X-offset" which is used to indicate the time offset value before the start time slot of the (most recent or next) drx-onDuration, for example, to determine T0, such as Figure 4 SSSG-DRX-config includes a field "Y-offset" which is used to indicate a time offset value to determine T2 or T4. X-offset and Y-offset may not be configured by the network node, but are predefined in the standard specification. In some embodiments, the value of the traditional searchSpaceSwitchDelay is used as the time offset.

[0080] In some embodiments, SSSG-DRX-config further includes information related to the DRX group. This field may be referred to as "Drx-Group information" and may be used to identify one or more sets of configuration information about DRX (i.e., it may be referred to as multiple DRX-config sets or the like) to implicitly apply SSSG#1 at T1, T2, or T4, such as Figure 4. Multiple DRX-config groups (or sets) may be active in one cell, which may result in multiple active DRX cycles with different start times and / or lengths of drx-onduration. For example, each DRX-config set may have a separate DRX parameter, including at least one of the following: an identifier of a set of DRX configurations, drx-onDurationTimer, drx-InactivityTimer, drx-HARQ-RTT-TimerDL, drx-HARQ-RTT-TimerUL, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-Cycle, drx-StartOffset, shortDRX, and drx-SlotOffset. For a certain DRX-config, it is not necessary to use the SSSG application function for the short DRX on duration. Therefore, the network node may control which set of DRX configurations the UE uses for this SSSG application function to avoid complexity. For example, the value {first, second, third, ...} may be enumerated, where the first corresponds to DRX config-1, the second corresponds to DRX config-2, and the third corresponds to DRX config-3. For example, the value may be a list of identifiers of DRX-config.

[0081] In an embodiment, the SSSG-DRX-config is configured for a cell group associated with only one set of DRX-configs, for example, the SSSG-DRX-config is used to enable SSSG applications for serving cells in the cell group based on a set of DRX-configs at T1, T2 or T4. In an example, the SSSG-DRX-config may be configured as follows.

[0082]

[0083]

[0084] In an embodiment, the SSSG-DRX-config is configured for a cell group associated with one of a plurality of DRX groups. For example, when a serving cell in a cell group is assigned to more than one set of DRX-configs, the SSSG-DRX-config is used to indicate which set of DRX-configs the SSSG is applied to the serving cells in the cell group at T1, T2, or T4. In another example, the SSSG-DRX-config may be configured as follows.

[0085]

[0086] In another embodiment, SSSG-DRX-config is configured for the serving cell. If the serving cell is assigned to only one set of DRX-config, SSSG-DRX-config contains a value Enabled to indicate which set of DRX-config is applied for the serving cell at T1, T2, or T4. If the serving cell is assigned to more than one set of DRX-config, SSSG-DRX-config is used to indicate which set of DRX-config is applied for the serving cell associated with one of the multiple DRX groups at T1, T2, or T4. For example, it can be configured as follows.

[0087]

[0088] In another embodiment, the SSSG-DRX-config is configured for one BWP. For example, the SSSG-DRX-config is associated with one BWP. In an example, the SSSG-DRX-config may be configured as follows.

[0089]

[0090]

[0091] Return to reference Figure 3 In operation 302, in some embodiments, satisfying at least one SSSG application condition includes at least one of the following situations. In other words, the UE may evaluate whether at least one of the following situations occurs, and once at least one of the following situations occurs, the UE may determine that at least one SSSG application condition is satisfied. Specific examples are described below Figure 4 The operation 412 in the first embodiment is described.

[0092] (1) The UE is in DRX active time for one or more serving cells in the starting time slot of the OnDuration of the DRX cycle simply due to the DRX OnDuration timer being running.

[0093] (2) “during a time period of a time offset (e.g., X offset) before the start time slot of the on-duration of the DRX cycle (e.g., the time period ending at T1)” or “at / until another time point of a time offset (e.g., X offset) before the start time slot of the on-duration of the DRX cycle (e.g., T1) (expressed as time #2, e.g., T0 for simplicity)”, no indication (e.g., a field in the DCI) is received to instruct the UE to start monitoring PDCCH transmission for one or more serving cells according to SSSG #2.

[0094] (3) “During a time period of a time offset (e.g., X offset) before the start time slot of the on-duration of the DRX cycle (e.g., the time period ending at T1)” or “at / until time #2 (e.g., T0)”, no DCI scrambled by RNTI (e.g., C-RNTI or CS-RNTI or MCS-C-RNTI) is received on one or more serving cells.

[0095] (4) "During the time period of a time offset (e.g., X offset) before or at the start time slot of the on-duration of the DRX cycle" or "at / until time #2", the MAC entity does not monitor PDCCH transmissions on the search space for beam failure recovery of one or more serving cells (e.g., indicated by recoverySearchSpaceId).

[0096] (5) “During a time period of a time offset (e.g., X-Offset) before the start time slot of the OnDuration of the DRX cycle or at the start time slot of the OnDuration of the DRX cycle” or “at / until time #2”, at least one of “a plurality of timers including a DRX inactivity timer, a RA contention resolution timer, a msgB response timer, a DRX retransmission timer for downlink, and a DRX retransmission timer for uplink of one or more serving cells” is not running. For example, the plurality of timers may include drx-InactivityTimer, ra-ContentionResolutionTimer, msgB-ResponseWindow, drx-RetransmissionTimerDL, or drx-RetransmissionTimerUL.

[0097] (6) “During a time period of a time offset (eg, X offset) before the start time slot of the OnDuration of the DRX cycle” or “at / until time #2”, the UE is in DRX inactivity time for one or more serving cells.

[0098] In some embodiments, satisfying at least one SSSG application condition includes at least one of the following situations. Figure 4 The operation 422 in Example 2 is described.

[0099] (1) A time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running, "a time slot after / until a time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running (e.g., T2)", "a time slot in which the DRX Inactivity timer expires", "a time slot after / until a time slot in which the DRX Inactivity timer expires (e.g., T2 or T4)", "a last time slot in which the UE is in DRX active time", or "a time slot after / until the last time slot in which the UE is in DRX active time (e.g., T2 or T4)", for example, no DCI is detected at T2 during the "DRX On Duration timer is running" or at T4 during the "DRX On Duration timer is not running".

[0100] (2) A time slot in which the UE is in DRX Active Time only due to the DRX On Duration timer being running, "a time slot after / until a time slot in which the UE is in DRX Active Time only due to the DRX On Duration timer being running", "a time slot in which the DRX Inactivity timer expires", "a time slot after / until a time slot in which the DRX Inactivity timer expires", "a time slot in which the UE is in DRX Active Time", or "a time slot after / until the last time slot in which the UE is in DRX Active Time", e.g., at T2 during the "DRX On Duration timer being running" or at T4 during the "DRX On Duration timer not being running", no SR is sent or pending.

[0101] (3) A PDCCH transmission indicating a new transmission is received in a time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running, "a time slot after / until a time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running", "a time slot after successfully receiving a RA response", "a time slot in which the DRX Inactivity timer expires", "a time slot after / until a time slot in which the DRX Inactivity timer expires", "a last time slot in which the UE is in DRX active time", or "a time slot after / until the last time slot in which the UE is in DRX active time", for example, at T2 during the "DRX On Duration timer being running" or at T4 during the "DRX On Duration timer not being running".

[0102] (4) a time slot in which the UE is in DRX active time only due to the DRX OnDuration timer being running, “a time slot after / until a time slot in which the UE is in DRX active time only due to the DRX OnDuration timer being running”, “a time slot in which the DRX Inactivity timer expires, before / after a time slot in which the UE is in DRX active time only due to the DRX OnDuration timer being running”

[0103] Until a time slot after the time slot in which the DRX inactivity timer expires", "until the last time slot in which the UE is in DRX active time", or "at / until a time slot after the last time slot in which the UE is in DRX active time", for example, at T2 during the "DRX on duration timer is running" or at T4 during the "DRX on duration timer is not running", the MAC entity does not monitor PDCCH transmission on the search space for beam failure recovery of one or more serving cells.

[0104] In some embodiments, the UE may receive a search space group identifier list (e.g., searchSpaceGroupIdList), and upon receiving at least one of the SSSG-DRX-config or the search space group identifier list, reset to monitor PDCCH transmission according to SSSG#1. For example, in operation 301, the UE may receive SSSG-DRX-config and / or searchSpaceGroupIdList. Then, the UE may optionally reset PDCCH monitoring according to the search space set with SSSG#1.

[0105] In some embodiments, in response to at least one SSSG application condition being satisfied at time #1, the UE may stop monitoring PDCCH transmissions in the search space set within SSSG #2. For example, the UE may switch from SSSG #2 to SSSG #1.

[0106] In some other embodiments, in response to one or more SSSG application conditions not being met at time #1, the UE may not stop monitoring PDCCH transmissions in the search space set within SSSG #2. For example, the UE may not switch from SSSG #2 to SSSG #1.

[0107] In some embodiments, in response to starting to monitor PDCCH transmissions according to the search space set within SSSG #1, the UE may stop the search space switch timer in response to the search space switch timer being running. For example, the UE may stop the searchSpaceSwitchTimer.

[0108] In some embodiments, in response to at least one of the following situations, the UE may stop monitoring PDCCH transmissions in the search space set within SSSG#1 and start monitoring PDCCH transmissions according to the search space set within SSSG#2. Specific examples are described below Figure 5 Operation 503 of an embodiment of the present invention is described, where the UE may switch from SSSG#1 to SSSG#2 at T5 (eg, during the period when the “DRX on-duration timer is running”).

[0109] (1) DCI is received. The DCI indicates a new transmission or retransmission for the UE. For example, the DCI indicates a new transmission or retransmission of data on a specified DRB or logical channel, which may be pre-configured by the network node.

[0110] (2) Start a RA response timer (eg, ra-ResponseWindow) for monitoring PDCCH transmissions on the search space of one or more serving cells. For example, the DCI indicates a designated preamble that can be preconfigured by the network node.

[0111] (3) Start the DRX retransmission timer for the downlink, for example, drx-RetransmissionTimerDL. For example, the DCI indicates data retransmission on a specified DRB or logical channel, which may be pre-configured by the network node.

[0112] (4) Start the uplink DRX retransmission timer, for example, drx-RetransmissionTimerUL. For example, the DCI indicates data retransmission on a specified DRB or logical channel, which may be pre-configured by the network node.

[0113] (5) Start the RA contention resolution timer, for example, ra-ContentionResolutionTimer.

[0114] (6) Start the msgB response timer, for example, msgB-ResponseWindow.

[0115] (7) Transmitting SR on PUCCH transmission For example, DCI indicates the SR configuration associated with a specified logical channel, which may be pre-configured by the network node.

[0116] In some embodiments, the UE may determine the starting time slot of the search space set in SSSG#1 based on the starting time slot of the on-duration of the DRX cycle for one or more serving cells. In this embodiment, the UE aligns the starting time slot of the PDCCH monitoring for the search space set in SSSG#1 with the drx-Onduration.

[0117] For example, in operation 301, SSSG-DRX-config optionally indicates a search space searchSpace ID=s, which identifies a search space set in SSSG#1 aligned with drx-Onduration. In operation 302, if the UE implicitly starts monitoring PDCCH according to SSSG#1 and stops monitoring PDCCH according to SSSG#2 for the serving cell, the UE may determine the starting time slot of the search space set "s" in SSSG#1 according to the starting time slot of the DRX on duration of the serving cell.

[0118] For example, for a given continuous active period of PDCCH monitoring on the BWP of the serving cell, for the search space set "s", if n_f is according to the following formula, then the UE can determine the number of frames numbered n_f in the frame numbered n_f. There is a PDCCH monitoring opportunity in the time slot:

[0119]

[0120] - where O s =o DRX , the search space set "s" is associated with the DRX group, for example, "s" is "(4) identification information associated with the search space set associated with the on-duration of the DRX cycle" specified by the network node. Parameter o DRX is the most recent start time of the drx-onDurationTimer in the time slot, i.e., o DRX Pass

[0121] This is updated every time drx-onDurationTimer starts using the following formula:

[0122]

[0123] -The SFN and subframe number are the latest SFN and subframe number that meet the conditions for starting drx-onDurationTimer.

[0124] - where k s PDCCH monitoring periodicity and s The PDCCH monitoring offset of the time slot is determined by TS

[0125] monitoringSlotPeriodicityAndOffset definition in 38.331.

[0126] In some embodiments, in order to start monitoring PDCCH transmissions according to the search space set in SSSG#1 in operation 302, the UE may be bundled to start monitoring PDCCH transmissions at time #1 for all one or more serving cells within one or more DRX groups or for a subset of one or more serving cells within one or more DRX groups. The subset may be configured using SSSG-DRX-config. For example, the serving cells in the DRX group are bundled for the above-mentioned search space group switching purpose. The following options may exist in different embodiments, namely option 1, option 2, option 3 and option 4.

[0127] (1) Option 1: If a cellGroupsForSwitchList indicating one or more groups of serving cells is provided to the UE, and if only one of the above SSSG application conditions is met in one serving cell, then the above Figure 3 The SSSG switching procedure in the embodiment is applicable to all service cells in each group. The service cells configured with SSSG-DRX-config in the DRX group should belong to only one cell group in cellGroupsForSwitchList. For example, if service cell 1 and service cell 2 are configured with SSSG-DRX-config in the DRX group, they should be unique in the same cell group in cellGroupsForSwitchList. Or, if there is one service cell configured with SSSG-DRX-config in the DRX group, all service cells in the DRX group should belong to only one cell group in cellGroupsForSwitchList. For example, if service cell 1 and service cell 2 are in the DRX group and only service cell 1 is configured with SSSG-DRX-config, they should be unique in the same cell group in cellGroupsForSwitchList.

[0128] (2) Option 2: If SSSG-DRX-config is provided to the UE but the traditional cellGroupsForSwitchList is not provided, then the above Figure 3 The SSSG switching procedure in the embodiment is applicable to all service cells configured with SSSG-DRX-config in the DRX group, or if there is a service cell configured with SSSG-DRX-config in the DRX group, then it is applicable to all service cells in the DRX group. Otherwise, the above procedure is only applicable to the service cell for which the UE is provided with searchSpaceGroupIdList.

[0129] (3) Option 3: If the SSSG-DRX-config and the legacy cellGroupsForSwitchList are provided to the UE, then a cell group including a serving cell configured with the SSSG-DRX-config in the cellGroupsForSwitchList may be ignored. For example, if a serving cell configured with the SSSG-DRX-config is included in a cell group in the cellGroupsForSwitchList, then the UE may ignore the cell group. Figure 3 The SSSG switching procedure in the embodiment is applicable to all service cells configured with SSSG-DRX-config in the DRX group.

[0130] (4) Option 4: If SSSG-DRX-config for serving cells in a DRX group is not provided to the UE, cellGroupsForSwitchList optionally exists. That is, in Option 4, only when SSSG-DRX-config for serving cells in a DRX group is not provided to the UE, it is possible to configure a cellGroupsForSwitch containing serving cells in the DRX group in cellGroupsForSwitchList. If SSSG-DRX-config is provided to the UE, cellGroupsForSwitchList should not be configured.

[0131] In an embodiment, in response to receiving both "information related to cell groups bundled for SSSG switching (e.g., cellGroupsForSwitchList)" and "SSSG-DRX-config in a DRX group within one or more DRX groups" in operation 301, the UE may ignore the information related to the cell group for SSSG switching including the service cell with SSSG-DRX-config in the DRX group or all service cells in the DRX group (if one service cell is configured with SSSG-DRX-config).

[0132] In some embodiments, each serving cell within one or more serving cells in the one or more DRX groups is uniquely assigned to one of the one or more DRX groups, and the plurality of DRX parameters for each DRX group within the one or more DRX groups comprises:

[0133] (1) One or more DRX parameters commonly configured for one or more DRX groups. For example, the commonly configured DRX parameters include at least one of the following: drx-SlotOffset, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle, drx-ShortCycleTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerUL.

[0134] (2) One or more DRX parameters configured separately for each DRX group.

[0135] In some embodiments, each service cell in one or more service cells in one or more DRX groups is assigned to two or more DRX groups in the one or more DRX groups, and one or more DRX parameters are configured separately for each DRX group in the two or more DRX groups. For example, the DRX parameters configured separately for each DRX group include at least one of the following: an identifier of a set of DRX configurations, drx-onDurationTimer, drx-InactivityTimer, drx-SlotOffset, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle, drx-ShortCycleTimer, drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerUL.

[0136] Some other embodiments of the present application provide a method for a network node (eg, Figure 1 Although described with respect to a network node, it should be understood that other devices may be configured to perform similar methods. In this exemplary procedure, the network node may transmit configuration information (denoted as configuration #1 for simplicity) for one or more serving cells in one or more DRX groups to a UE (e.g., Figure 1 In some embodiments, configuration #1 is transmitted in an RRC message. For example, configuration #1 may include at least one of the following:

[0137] (1) Configuration information about SSSG (denoted as SSSG#1 for simplicity);

[0138] (2) configuration information about another SSSG (denoted as SSSG#2 for simplicity);

[0139] (3) one or more sets of configuration information about DRX (denoted as DRX-config for simplicity); or

[0140] (4) Configuration information of SSSG application associated with DRX operation of UE (denoted as SSSG-DRX-config for simplicity). In some embodiments, SSSG-DRX-config may be used to enable UE to start monitoring PDCCH transmission according to a search space set in SSSG#1 for one or more serving cells in one or more DRX groups at a time point (denoted as time #1 for simplicity). In some embodiments, time #1 is at least one of the following:

[0141] a) The start time slot of the on-duration of the DRX cycle, e.g. Figure 4 T1 shown in;

[0142] b) A time slot after a time slot in which the UE is in DRX active time only due to the DRX On Duration timer being running, e.g. T2 during the "DRX On Duration timer being running", e.g. Figure 4 In display;

[0143] c) A timeslot after the timeslot in which the DRX Inactivity Timer expires, e.g., T2 during the "DRX On Duration Timer is running" or T3 during the "DRX On Duration Timer is not running"

[0144] During T4, such as Figure 4 or

[0145] d) A time slot after the last time slot in which the UE is in DRX active time, for example, T2 where the UE stops the DRX On Duration timer before the DRX On Duration timer expires or T4 where the DRX On Duration timer expires, such as Figure 4 Displayed in.

[0146] e) where the UE is in the start time slot of DRX active time only due to the DRX On Duration timer being running, e.g. Figure 4 T1 or T2 shown in .

[0147] In some embodiments, each serving cell within the one or more serving cells is uniquely assigned to one of the one or more DRX groups, and the plurality of DRX parameters for each DRX group within the one or more DRX groups comprises:

[0148] (1) one or more DRX parameters commonly configured for one or more DRX groups; and

[0149] (2) One or more DRX parameters configured separately for each DRX group.

[0150] In some embodiments, each serving cell within the one or more serving cells is assigned to two or more DRX groups within the one or more DRX groups, and one or more DRX parameters are separately configured for each DRX group within the two or more DRX groups.

[0151] In some embodiments, configuration #1 includes information related to the cell group bundled for SSSG switching (e.g., cellGroupsForSwitch in cellGroupsForSwitchList), and the service cell for SSSG application in one DRX group within one or more DRX groups belongs only to one cell group bundled for SSSG switching. In other words, if configuration #1 includes cellGroupsForSwitchList, it means that two or more service cells for SSSG application in one DRX group belong to the same cell group bundled for SSSG switching, and the two or more service cells will switch SSSG at the same time.

[0152] In some embodiments, the SSSG-DRX-config is configured by serving cell, by cell group, by DRX group or by BWP. In some embodiments, the SSSG-DRX-config includes at least one of the following:

[0153] (1) Identification information related to SSSG#1;

[0154] (2) Identification information related to SSSG#2;

[0155] (3) Information indicating whether the SSSG application function of the UE is enabled, for example, "Enabled";

[0156] (4) identification information related to the search space set associated with the on-duration of the DRX cycle, for example, searchSpace ID;

[0157] (5) Timers related to the UE's SSSG application functions, for example, searchSpaceSwitchTimer;

[0158] (6) the delay value applied by the UE during SSSG application, e.g., searchSpaceSwitchDelay; or

[0159] (7) One or more time offsets related to the on-duration of the DRX cycle, e.g., X-offset and / or

[0160] or Y-offset.

[0161] Figure 4 An exemplary diagram illustrating the application of SSSG according to some embodiments of the present application. Figure 4 In the embodiment of the present invention, the following time points are defined as follows.

[0162] (1) T1: at the start (or initial or first) time slot (start) of the (most recent or next) drx-onDuration of the DRX cycle.

[0163] (2) T0: The time slot at least X offset slots / symbols / ms (eg, the value of searchSpaceSwitchDelay or X-offset in SSSG-DRX-config) before the start time slot of the (most recent or next) drx-onDuration of the DRX cycle.

[0164] (3) T2: a time slot during the drx-onDuration window, including at least one of the following time points:

[0165] The start slot after the start slot of the DRX On Duration of the DRX cycle (by at least Y offset slots / symbols / ms, e.g. the value of searchSpaceSwitchDelay or Y-offset in SSSG-DRX-config);

[0166] Start after the slot in which drx-InactivityTimer expires (at least Y offset slots / symbols / ms)

[0167] Time slot;

[0168] The first time in which the UE is in DRX active time only due to running drx-onDurationTimer

[0169] or the starting slot after the last slot (at least Y offset slots / symbols / ms);

[0170] The starting slot after the last slot in which the UE was in DRX active time (by at least Y offset slots / symbols / ms);

[0171] For example, if a DRX command MAC CE or a long DRX command MAC CE is received, the UE stops the drx-onDurationTimer and the drx-InactivityTimer;

[0172] For example, upon receiving the end indicator of a burst, the UE stops the drx-onDurationTimer and the drx-InactivityTimer;

[0173] The last time slot of the measurement gap during which drx-onDurationTimer is running;

[0174] After the last time slot of the measurement gap during which drx-onDurationTimer is running (at least Y offset time

[0175] slot / symbol / ms);

[0176] The starting slot after the slot in which ra-ContentionResolutionTimer expires (at least Y offset slots / symbols / ms);

[0177] The starting slot after the slot in which the msgB-ResponseWindow expires (at least Y offset slots / symbols / ms);

[0178] The starting slot after the slot in which drx-RetransmissionTimerDL expires (at least Y offset slots / symbols / ms);

[0179] The starting slot after the slot in which drx-RetransmissionTimerUL expires (at least Y offset slots / symbols / ms);

[0180] (4) T3: The start time slot of the (most recent or next) drx-onDurationTimer expiration.

[0181] (5) T4: The time slot during which drx-onDurationTimer is not running, including at least one of the following time points:

[0182] The start slot after T3 (at least Y offset slots / symbols / ms) (e.g., the value of searchSpaceSwitchDelay)

[0183] Start after the slot in which drx-InactivityTimer expires (at least Y offset slots / symbols / ms)

[0184] Time slot

[0185] • The starting slot after the slot in which the drx-RetransmissionTimerDL expires (at least Y offset slots / symbols / ms).

[0186] • The starting slot after the slot in which the drx-RetransmissionTimerUL expires (by at least Y offset slots / symbols / ms).

[0187] The starting slot after the slot in which ra-ContentionResolutionTimer expires (at least Y offset slots / symbols / ms);

[0188] The starting slot after the slot in which the msgB-ResponseWindow expires (at least Y offset slots / symbols / ms);

[0189] • Starts after the last slot in which the UE was in DRX active time (at least Y offset slots / symbols / ms).

[0190] Figure 4 Shows "PDCCH monitoring timing in SSSG 0". Figure 4 In the embodiment, SSSG 0 is Figure 3 , and SSSG 1 ( Figure 4 Not shown) Figure 3 In different scenarios, there may be Figure 4 The following three sub-embodiments of the embodiment, namely, embodiment 1, embodiment 2 and embodiment 3.

[0191] Example 1

[0192] Embodiment 1 relates to an example of an SSSG applied according to a DRX operation at T1. In embodiment 1, in order to avoid transmission delay, the UE may implicitly apply an SSSG for a PDCCH monitoring mode on a serving cell at a start time slot of a DRX on duration or a DRX cycle according to the DRX operation of the UE. The following operations 411 and 412 may be performed in embodiment 1.

[0193] In operation 411 of embodiment 1, the BS may send information about SSSG#1 (for example, Figure 4 0), configuration information about SSSG#2 (e.g., Figure 4 The configuration information of SSSG 1) not shown in FIG. 4 is sent to the UE. For example, in operation 411, the UE may receive SSSG-DRX-config and / or searchSpaceGroupIdList. Then, the UE may optionally reset PDCCH monitoring according to the search space set with SSSG#1.

[0194] In operation 412 of embodiment 1, the UE starts searching for service cells in the DRX group configured with SSSG-DRX-config and searchSpaceGroupIdList according to the search space set SSSG#1 (for example, Figure 40) shown in , and stops monitoring PDCCH according to SSSG#2 (e.g., Figure 4 The UE may monitor the PDCCH in the search space set in SSSG 1) not shown in TS 38.321. For example, the UE may determine the start time slot of drx-onduation according to the conventional DRX formula in TS 38.321. If the searchSpaceSwitchTimer runs at the start time slot of on-duration #1 (i.e., T1), the UE may optionally stop the searchSpaceSwitchTimer.

[0195] For example, if at least one of the following conditions is met, the UE may optionally perform operation 412 of embodiment 1:

[0196] If during a time period of / until T0 or T1 or a time offset (e.g., X offset) before T0 or T1, a field in a DCI indicating that the UE starts monitoring the PDCCH according to the second SSSG is not received on a serving cell in the DRX group;

[0197] ● if during a time period of / until T0 or T1 or a time offset (e.g., X offset) before T0 or T1, no DCI scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI or SFI-RNTI or AI-RNTI in PDDCH is received on a serving cell in the DRX group;

[0198] ● if during a time period at / until T0 or T1 or a time offset (e.g., X-offset) before T0 or T1, the MAC entity does not monitor PDCCH transmissions on the search space indicated by recoverySearchSpaceId of the serving cell (e.g., SpCell within a DRX group) identified by C-RNTI (while ra-ResponseWindow is running);

[0199] If at / until T0 or T1 or at a time offset (e.g., X offset) before T0 or T1

[0200] During this period, the drx-InactivityTimer configured for the DRX group does not run;

[0201] ● If at / until T0 or T1 or at a time offset (eg, X offset) before T0 or T1

[0202] During this period, the ra-ContentionResolutionTimer on the serving cell in the DRX group does not run;

[0203] If at / until T0 or T1 or at a time offset (e.g., X offset) before T0 or T1

[0204] During this period, the msgB-ResponseWindow on the serving cell in the DRX group does not run;

[0205] If at / until T0 or T1 or at a time offset (e.g., X offset) before T0 or T1

[0206] During this period, the drx-RetransmissionTimerDL on the serving cell in the DRX group does not run;

[0207] ● If at / until T0 or T1 or at a time offset (eg, X offset) before T0 or T1

[0208] During this period, the drx-RetransmissionTimerUL on the serving cell in the DRX group does not run;

[0209] If at / until T0 or T1 or at a time offset (e.g., X offset) before T0 or T1

[0210] During this period, the drx-HARQ-RTT-TimerUL on the serving cell in the DRX group does not run;

[0211] If during the time period of / until T0 or T1 or a time offset (e.g., X offset) before T0 or T1, the drx-HARQ-RTT-TimerDL on the serving cell in the DRX group is not running, or the downlink HARQ feedback is ACK;

[0212] • If during a time period at / until T0 or T1 or a time offset (eg, X offset) before T0 or T1, the UE is in DRX inactivity time for a serving cell in the DRX group.

[0213] - For example, if a DRX Command MAC CE or a Long DRX Command MAC CE is received.

[0214] - For example, an end of burst indicator is received.

[0215] If at / until T0 or T1 or at a time offset (e.g., X offset) before T0 or T1

[0216] During the period, the start time slot of the DRX on duration does not appear during the measurement gap;

[0217] ● If at / until T0 or T1 or at a time offset (eg, X offset) before T0 or T1

[0218] During this period, no SR is sent or pending on the serving cells in the DRX group;

[0219] If, after successfully receiving a random access response for a random access preamble that is not selected by the MAC entity among contention-based random access preambles, a PDCCH indicating a new transmission of the C-RNTI of the MAC entity addressed to the serving cell in the DRX group is not received during / until a time period of T0 or T1 or a time offset (e.g., X offset) before T0 or T1. In other words, the UE expects a PDCCH indicating a new transmission of the serving cell.

[0220] In an embodiment, the UE may perform operation 412 of embodiment 1 as follows:

[0221] If the UE is not provided with a SearchSpaceSwitchTrigger for the serving cell,

[0222] - If the UE detects the DCI format by monitoring the PDCCH according to the search space set with group index 0, the UE starts monitoring the PDCCH according to the search space set with group index 1 for the serving cell and stops monitoring the PDCCH according to the search space set with group index 0

[0223] - When μ∈{0,1,2,3}, at least P after the last symbol of the PDCCH with DCI format switch When the start time slot of a symbol begins,

[0224] - When μ∈{5,6}, at least P after the last symbol of the PDCCH with DCI format switch A set of symbols X s The start of a time slot.

[0225] If the UE detects a DCI format by monitoring PDCCH in any search space set, the UE sets the timer value to the value provided by searchSpaceSwitchTimer.

[0226] - If the UE monitors PDCCH according to the search space set with group index 1 for the serving cell, the UE starts monitoring PDCCH according to the search space set with group index 0 for the serving cell and stops monitoring PDCCH according to the search space set with group index 1 for the serving cell

[0227] - At least P after the time slot in which the timer expires switchsymbols, or if a search space set is provided to the UE for monitoring the PDCCH to detect DCI format 2_0, then when μ∈{0,1,2,3}, after the last symbol of the remaining channel occupancy duration of the serving cell (if indicated by DCI format 2_0), or

[0228] - if the UE is provided with SSSG-DRX-config for a serving cell within the DRX group and if the UE is not in DRX active time at / until the slot that is X offset symbols before the slot where DRX-onDurationTimer starts, then at the start of the slot where DRX-onDurationTimer starts, or

[0229] - if the UE is provided with SSSG-DRX-config for a serving cell within the DRX group and if the DRX-inactivityTimer is not running in the timeslot in which the DRX-onDurationTimer is started, then at the start of the timeslot in which the DRX-onDurationTimer is started, or

[0230] - If the UE is provided with SSSG-DRX-config for the serving cell within the DRX group and if the DRX-inactivityTimer is not running in the slot that is X offset symbols before the slot in which the DRX-onDurationTimer is started, then at the start of the slot in which the DRX-onDurationTimer is started.

[0231] In another embodiment, the UE may perform operation 412 of embodiment 1 as follows:

[0232] 1> If SSSG-DRX-config information is configured for the DRX group,

[0233] 2> Possibility 1: and if during / until the start slot of the X offset symbol before the start slot of the DRX cycle or during the time period of the time offset (e.g., X offset) before the start slot of the DRX cycle, no SSSG switching indication is received from the lower layer indicating the start of PDCCH monitoring according to a search space set other than group index 0; or

[0234] 2> Possibility 2: and if the timing instance is not in active time during the start timeslot of X offset before the start timeslot of drx-onDurationTimer of the DRX group or the time period of the time offset (e.g., X offset) before the start timeslot of the DRX cycle; or

[0235] 2> Possibility 3: If at the start time slot of the drx-onDurationTimer of the DRX group, the timing instance is in active time only due to the drx-onDurationTimer; or

[0236] 2> Possibility 4: If the drx-inactivity timer does not run at the start time slot of drx-onDurationTimer;

[0237] 3> At the start time slot of the drx-onDurationTimer of the DRX group, the UE starts monitoring the PDCCH for the serving cell according to SSSG#1.

[0238] Example 2

[0239] Embodiment 2 relates to an example of SSSG applied according to DRX operation at T2. In embodiment 2, in order to balance transmission delay and power consumption for PDCCH monitoring, the UE implicitly applies SSSG to the serving cell for PDCCH monitoring according to UE operation at a time point after the DRX on duration or the start time slot of the DRX cycle during drx-onDuration. The following operations 421 and 422 may be performed in embodiment 2.

[0240] In operation 421 of embodiment 2, the BS may send information about SSSG#1 (for example, Figure 4 0), configuration information about SSSG#2 (e.g., Figure 4 The configuration information of SSSG 1) not shown, SSSG-DRX-config and DRX-config are sent to the UE.

[0241] In operation 422 of the second embodiment, the UE may start searching the DRX group configured with SSSG-DRX-config and searchSpaceGroupIdList according to SSSG#1 (for example, Figure 4 0) in the search space set shown in SSSG #0), and stop monitoring the PDCCH according to SSSG #2 (e.g., Figure 4 The search space set in SSSG 1) not shown in FIG. 1 monitors PDCCH.

[0242] For example, if at least one of the following conditions is met, the UE may optionally perform operation 422 of embodiment 2:

[0243] If during a time period of a time offset (e.g., X offset) before the start time slot of T2 or / until T2 (start time slot of at least Y offset time slots / symbols / ms before T2), no DCI is detected; for example, if during a time period of a time offset (e.g., X offset) before the start time slot of T2 or / until the start time slot of at least Y offset time slots / symbols / ms before T2, no DCI is detected for indicating that the UE starts monitoring the PDCCH according to the second SSSG; for example, if during a time period of a time offset (e.g., X offset) before the start time slot of T2 or / until the start time slot of at least Y offset time slots / symbols / ms before T2, no DCI with a CRC scrambled by C-RNTI / CS-RNTI / MCS-C-RNTI / SFI-RNTI is received in a time slot in the PDCCH;

[0244] If during the time period of time offset (eg X offset) before the start slot of T2 or at / until T2 (start slot of at least Y offset slots / symbols / ms before T2), no SR is sent or pending.

[0245] if, after successfully receiving a random access response for a random access preamble that was not selected by the MAC entity among the contention-based random access preambles, a PDCCH indicating a new transmission of the C-RNTI addressed to the MAC entity has been received during a time period of a time offset (e.g., X offset) before the start slot of T2 or at / until T2 (a start slot of at least Y offset slots / symbols / ms before T2);

[0246] If during a time period of a time offset (e.g., X offset) before the start slot of T2 or at / until T2 (start slot of at least Y offset slots / symbols / ms before T2), the MAC entity does not monitor PDCCH transmissions on the search space indicated by the recoverySearchSpaceId of the serving cell (e.g., Pcell or PScell) identified by the C-RNTI (while the ra-ResponseWindow is running).

[0247] • If the start slot is at least Y offset slots / symbols / ms before T2, the drx-inactivity timer is not running and the drx-onDurationTimer is running.

[0248] An example of operation 422 of Embodiment 2 is as follows:

[0249] 1> If SSSG-DRX-config information is configured for the DRX group,

[0250] 2> Possibility 1: and if during a time period of a time offset (e.g., X offset) after the start time slot (e.g., Y offset) of the timing instance in which the drx-inactivity timer expires or stops, no SSSG switching indication is received from a lower layer indicating the start of PDCCH monitoring according to a search space set other than group index 0; or

[0251] 3> At a time slot of a time offset (e.g., Y offset) after the time slot, the UE starts monitoring PDCCH for the serving cell according to SSSG#1 (if drx-onDurationTimer is running).

[0252] 2> Possibility 2: and if the timing instance is the last time slot in which the UE is not in active time; or

[0253] 3> At a time slot of a time offset (e.g., Y offset) after the time slot, the UE starts monitoring PDCCH for the serving cell according to SSSG#1 (if drx-onDurationTimer is running).

[0254] 2> Possibility 3: If the timing instance is the start slot in which the UE is in active time only due to drx-onDurationTimer; or

[0255] 3> At a time offset (eg, Y offset) after the time slot, the UE starts monitoring the PDCCH for the serving cell according to SSSG#1.

[0256] 2> Possibility 4: If the timing instance is in a time slot where the drx-inactivity timer expires or stops and the drx-onDurationTimer is running;

[0257] 3> At a time offset (eg, Y offset) after the time slot, the UE starts monitoring the PDCCH for the serving cell according to SSSG#1.

[0258] Example 3

[0259] Embodiment 3 relates to an example of SSSG applied according to DRX operation at T4. In embodiment 3, in order to avoid transmission delay, the UE may implicitly apply SSSG#1 to the serving cell for PDCCH monitoring according to the operation of the UE at a time point after the DRX on duration or the start time slot of the DRX cycle when drx-onDurationTimer is not running. The following operations 431 and 432 may be performed in embodiment 3.

[0260] In operation 431 of embodiment 3, the BS may send information about SSSG#1 (for example, Figure 4 0), configuration information about SSSG#2 (e.g., Figure 4 The configuration information of SSSG 1) not shown, SSSG-DRX-config and DRX-config are sent to the UE.

[0261] In operation 432 of embodiment 3, the UE may start searching the DRX group configured with SSSG-DRX-config and searchSpaceGroupIdList according to SSSG#1 (for example, Figure 4 0) in the search space set shown in SSSG #0), and stop monitoring the PDCCH according to SSSG #2 (e.g., Figure 4 The search space set in SSSG 1) not shown in FIG. 1 monitors PDCCH.

[0262] For example, if at least one of the following conditions is met, the UE may optionally perform operation 432 of Embodiment 3:

[0263] ·If no DCI is detected during a time period of a time offset (e.g., Y offset) before the start slot of T4 or until the start slot before T4 (at least Y offset slots / symbols / ms); for example, if during a time period of a time offset (e.g., Y offset) before the start slot of T4 or until the start slot before T4 (at least Y offset slots / symbols / ms), no DCI is detected for indicating that the UE starts monitoring PDCCH according to SSSG#2 and the drx-onDurationTimer does not run; for example, if during a time period of a time offset (e.g., Y offset) before the start slot of T4 or until the start slot before T4 (at least Y offset slots / symbols / ms), no DCI with a CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI or SFI-RNTI is received in the time slot.

[0264] If during the time period of time offset (e.g., Y offset) before the start slot of T4 or at / until T4 (start slot of at least Y offset slots / symbols / ms before T4), no SR is sent or pending, and drx-onDurationTimer does not run.

[0265] ●If, after a random access response is successfully received for a random access preamble that is not selected by the MAC entity among the contention-based random access preambles, a PDCCH indicating a new transmission of the C-RNTI addressed to the MAC entity has been received during a time period of a time offset (e.g., Y offset) before the start slot of T4 or until the start slot of / before T4 (at least Y offset slots / symbols / ms), and the drx-onDurationTimer is not running.

[0266] If during a time period of a time offset (e.g., Y offset) before the start slot of T4 or at / until the start slot before T4 (at least Y offset slots / symbols / ms), the MAC entity does not monitor PDCCH transmissions on the search space indicated by the recoverySearchSpaceId of the serving cell identified by C-RNTI (e.g., SpCell within the DRX group) (and ra-ResponseWindow is running), and drx-onDurationTimer is not running.

[0267] If during a time period that is time offset (eg, Y offset) before the start slot of T4 or a start slot before T4 (at least Y offset slots / symbols / ms), the drx-inactivity timer is not running and the drx-onDurationTimer is not running.

[0268] Figure 5 An exemplary diagram illustrating the application of SSSG according to some embodiments of the present application. Figure 5 In the embodiment, T1 and T2 are Figure 4 The T1 and T2 defined in the embodiment are the same. Figure 5 In the embodiment of , the time point T5 is further defined as follows:

[0269] (1) T5: After the last slot or last symbol of the PDCCH with DCI (at least Y offset slots / symbols / ms) (e.g., searchSpaceSwitchDelay value, which is called P switch )'s start time slot.

[0270] Figure 5 Displays the “PDCCH monitoring timing in SSSG 0” and “PDCCH monitoring timing in SSSG 1”. Figure 5 In the embodiment, SSSG 0 is Figure 3 An example of SSSG #1 in the embodiment of FIG. 1 , and SSSG 1 is Figure 3 An example of SSSG#2 in an embodiment of the present invention. Figure 5The embodiment of the present invention relates to an instance of applying another SSSG (e.g., SSSG#2) at T5 according to a detected DCI from a network node (e.g., BS). The following operations 501 to 503 may be performed at Figure 5 is performed in the embodiment of the present invention.

[0271] In operation 501, the BS may send information about SSSG#1 (for example, Figure 5 0), configuration information about SSSG#2 (e.g., Figure 5 1), SSSG-DRX-config and DRX-config are sent to the UE. For example, in operation 501, the UE may receive SSSG-DRX-config and / or searchSpaceGroupIdList. Then, the UE may optionally reset PDCCH monitoring according to the search space set with SSSG#1.

[0272] In operation 502, the UE may start monitoring the PDCCH according to the search space set SSSG#1 (e.g., SSSG 0) for the service cells in the DRX group configured with SSSG-DRX-config and searchSpaceGroupIdList at the starting time slot (i.e., T1) of the on-duration #1 of the DRX cycle, and stop monitoring the PDCCH according to the search space set in SSSG#2 (e.g., SSSG 1).

[0273] In operation 503, if the SSSG-DRX-config for the serving cell is provided to the UE, and if the UE detects the DCI (e.g., as shown in FIG. 5 ) by monitoring the PDCCH in the serving cell according to SSSG #1 (e.g., SSSG 0), Figure 5 0 at T5”), the UE may perform the following operations:

[0274] After the last slot or last symbol of the PDCCH with DCI (at least Y offset slots / symbols / ms) (e.g., searchSpaceSwitchDelay value, which is called P switch), at the start time slot of the starting time slot of SSSG#2 (e.g., SSSG 1) (e.g., T5), the UE starts monitoring PDCCH according to SSSG#2 (e.g., SSSG 1) for the serving cell, and stops monitoring PDCCH according to SSSG#1 (e.g., SSSG 0), where DCI can be used to indicate new transmission or retransmission, etc., and DCI (which is used to indicate that the UE starts monitoring PDCCH according to SSSG#2 (e.g., SSSG 1)) can be detected. In addition, the DCI in the PDCCH may have a CRC scrambled by C-RNTI or CS-RNTI or MCS-C-RNTI or SFI-RNTI. And then, the UE may start the searchSpaceSwitchTimer in SSSG-DRX-config (if configured) or start the traditional searchSpaceSwitchTimer (of BWP) of the serving cell; or the UE does not start the searchSpaceSwitchTimer.

[0275] In operation 503, in some embodiments, if the UE detects DCI "for all one or more serving cells within one or more DRX groups" or "for a subset of one or more serving cells within one or more DRX groups", then the UE may be bundled to start monitoring PDCCH transmissions. The subset may be configured with SSSG-DRX-config. For example, the serving cells in the DRX group are bundled for the above-mentioned search space group switching purpose. The options in the different embodiments described above are applicable to Figure 5 An embodiment of Figure 3 Option 1, option 2, option 3 and option 4 in the embodiments.

[0276] In some other embodiments, if the UE is provided with the SSSG-DRX-config for the serving cell, the UE starts monitoring the PDCCH according to SSSG#2 and stops monitoring the PDCCH according to SSSG#1 for the serving cell at one of the following time points (if the drx-onDurationTimer is running):

[0277] a) At the start of the time slot in which the UE starts the ra-ResponseWindow for monitoring the PDCCH transmission on the search space indicated by the recoverySearchSpaceId of the serving cell (e.g., primary cell (PCell) or primary and secondary cell (PSCell)) identified by the C-RNTI (at least Y offset time slots / symbols / ms thereafter). For example, the recoverySearchSpaceId belongs to SSSG#2, contains the recoverySearchSpaceId, and the recoverySearchSpaceId does not belong to SSSG#1.

[0278] b) At the start of the slot in which the UE starts the drx-RetransmissionTimerDL (at least Y offset slots / symbols / ms after). For example, if a MAC PDU is received in a configured downlink assignment and a HARQ-NACK for the MAC PDU is transmitted.

[0279] c) At the start of the slot in which the UE starts the drx-RetransmissionTimerUL (at least Y offset slots / symbols / ms later). For example, if a MAC PDU is transmitted in a configured uplink grant.

[0280] d) At the start of the slot in which the ra-ContentionResolutionTimer or msgB-ResponseWindow starts (at least Y offset slots / symbols / ms later).

[0281] e) the time slot in which the scheduling request (SR) is sent on the PUCCH (at least Y offset time slots after /

[0282] symbol / ms) starts at the beginning of the time slot.

[0283] Figure 6 6 is a block diagram illustrating an exemplary apparatus 600 according to some embodiments of the present application. Figure 6 6, the apparatus 600 may include at least one processor 606 and at least one transceiver 602 coupled to the processor 606. Although in this figure, elements such as at least one transceiver 602 and the processor 606 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present application, the transceiver 602 may be divided into two devices, such as a receiving circuit system and a transmitting circuit system. In some embodiments of the present application, the apparatus 600 may further include an input device, a memory, and / or other components.

[0284] In some embodiments of the present application, the device 600 may be a UE or a network node (eg, a BS). The transceiver 602 and the processor 606 may interact with each other to execute the above, for example, Figures 1 to 5 The operations of the UE or the network node described in any one of the foregoing.

[0285] In some embodiments of the present application, the device 600 may further include at least one non-transitory computer-readable medium. For example, in some embodiments of the present disclosure, the non-transitory computer-readable medium may store thereon computer-executable instructions to enable the processor 606 to implement the method described above with respect to the UE or the network node (e.g., BS). For example, when the computer-executable instructions are executed, the processor 606 interacts with the transceiver 602 to perform Figures 1 to 5 The operations of the UE or network node described in.

[0286] Those skilled in the art will appreciate that the operations or steps of the methods described in conjunction with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations or steps of the methods may reside as one or any combination or set of codes and / or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.

[0287] In this document, the term "include", "comprise" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment containing the element list not only includes those elements, but also may include other elements that are not explicitly listed or inherent to this process, method, article or equipment. The element starting with "one", "one" or the like does not exclude the existence of additional identical elements in the process, method, article or equipment containing the element without more restrictions. In addition, the term "another" is defined as at least the second or more. The term "having" and the like as used herein are defined as "comprising". For example, the expression of "A and / or B" or "at least one of A and B" may include any and all combinations of words enumerated together with the expression. For example, the expression "A and / or B" or "at least one of A and B" may include A, B or both A and B. The wording "first", "second" or the like is only used to clearly illustrate the embodiments of the application, and is not used to limit the essence of the application.

Claims

1. A network node, comprising: Transceiver; and a processor coupled to the transceiver and configured to transmit, via the transceiver, first configuration information for one or more serving cells in one or more DRX groups to a user equipment (UE), wherein the first configuration information comprises at least one of: Configuration information about the first search space set group SSSG, Regarding the configuration information of the second SSSG, One or more sets of configuration information about discontinuous reception (DRX), or Configuration information of the SSSG application associated with the DRX operation of the UE, wherein the configuration information of the SSSG application is used to enable the UE to start monitoring the physical downlink control channel PDCCH transmission according to the search space set within the first SSSG for the one or more service cells within the one or more DRX groups at a first point in time.

2. The network node according to claim 1, wherein each service cell within the one or more service cells is assigned to two or more DRX groups within the one or more DRX groups, and wherein one or more DRX parameters are separately configured for each DRX group within the two or more DRX groups.

3. A network node according to claim 1, wherein the first configuration information includes information related to a cell group bundled for SSSG switching, and wherein the service cell used for the SSSG application in a DRX group within the one or more DRX groups belongs only to one cell group bundled for SSSG switching.

4. The network node according to claim 1, wherein the configuration information of the SSSG application is configured by serving cell, by cell group, by DRX group or by bandwidth part (BWP).

5. The network node according to claim 1, wherein the first time point is at least one of the following: The start time slot of the on-duration of the DRX cycle; wherein the UE is in a time slot subsequent to a time slot of DRX active time only due to the DRX on-duration timer being running; a time slot following the time slot in which the DRX inactivity timer expires; or The UE is in a time slot after the last time slot of the DRX active time.

6. A user equipment UE, comprising: Transceiver; and a processor coupled to the transceiver, wherein the processor is configured to: receiving, via the transceiver, first configuration information from a network node, wherein the first configuration information comprises at least one of the following: configuration information about a first search space set group SSSG, configuration information about a second SSSG, one or more groups of configuration information about discontinuous reception (DRX) of one or more serving cells in one or more DRX groups, or configuration information of an SSSG application associated with a DRX operation of the UE; and Based on the configuration information of the SSSG application, at a first time point, the one or more serving cells in the one or more DRX groups begin to monitor Physical Downlink Control Channel (PDCCH) transmission according to a search space set in the first SSSG.

7. The UE according to claim 6, wherein the configuration information of the SSSG application is configured by serving cell, by cell group, by DRX group or by bandwidth part (BWP).

8. The UE according to claim 6, wherein the first time point is at least one of the following: The start time slot of the on-duration of the DRX cycle; wherein the UE is in a time slot subsequent to a time slot of DRX active time only due to the DRX on-duration timer being running; a time slot following the time slot in which the DRX inactivity timer expires; or The UE is in a time slot after the last time slot of the DRX active time.

9. A UE according to claim 6, wherein the processor of the UE is configured to evaluate whether at least one SSSG application condition is satisfied at the first time point related to the DRX operation of the UE based on configuration information of the SSSG application, and wherein in response to satisfying the at least one SSSG application condition at the first time point, monitoring the PDCCH transmission according to the search space set within the first SSSG begins at the first time point.

10. The UE of claim 9, wherein the satisfaction of the at least one SSSG application condition comprises at least one of the following: In a starting time slot of the OnDuration of the DRX cycle, the UE is in DRX active time for the one or more serving cells only due to the DRX OnDuration timer being running; an indication for the UE to start monitoring the PDCCH transmission according to the second SSSG is not received on the one or more serving cells during a time period of a time offset before a start time slot of the on-duration of the DRX cycle or until a second time point of the time offset before the start time slot of the on-duration of the DRX cycle; During the time period of the time offset before the start time slot of the on-duration of the DRX cycle or until the second time point, no downlink control information DCI scrambled by a radio network temporary identifier RNTI is received on the one or more serving cells; During the time period of the time offset before the start time slot of the on-duration of the DRX cycle or at the start time slot of the on-duration of the DRX cycle or until the second time point, a medium access control MAC entity does not monitor the PDCCH transmission on the search space for beam failure recovery of the one or more serving cells; During the time period of the time offset before the start time slot of the on-duration of the DRX cycle or at the start time slot of the on-duration of the DRX cycle or until the second time point, at least one of a plurality of timers including a DRX inactivity timer, a random access RA contention resolution timer, a msgB response timer, a downlink DRX retransmission timer, and an uplink DRX retransmission timer of the one or more serving cells is not running; or During the time period of the time offset before the start time slot of the On-Duration of the DRX cycle or until the second time point, the UE is in a DRX inactive time for the one or more serving cells.

11. The UE of claim 6, wherein the processor of the UE is configured to determine a starting time slot of the search space set in the first SSSG according to a starting time slot of an on-duration of a DRX cycle of the one or more serving cells.

12. The UE according to claim 6, wherein in order to start monitoring the PDCCH transmission according to the search space set in the first SSSG, the processor of the UE is configured to be bundled to start monitoring the PDCCH transmission for all of the one or more service cells within the one or more DRX groups or a subset of the one or more service cells within the one or more DRX groups at the first time point, and wherein the subset is configured with configuration information of the SSSG application.

13. A UE according to claim 6 or claim 12, wherein in response to receiving both information related to a cell group bundled for SSSG switching and configuration information of the SSSG application in one DRX group within the one or more DRX groups, the processor of the UE is configured to ignore information related to the cell group for SSSG switching that includes two or more service cells with configuration information of the SSSG application.

14. The UE according to claim 6, wherein each service cell within the one or more service cells is assigned to two or more DRX groups within the one or more DRX groups, and wherein one or more DRX parameters are separately configured for each DRX group within the two or more DRX groups.

15. A method performed by a user equipment UE, comprising: receiving first configuration information from a network node, wherein the first configuration information comprises at least one of the following: configuration information about a first search space set group SSSG, configuration information about a second SSSG, one or more groups of configuration information about discontinuous reception (DRX) of one or more serving cells in one or more DRX groups, or configuration information of an SSSG application associated with a DRX operation of the UE; and Based on the configuration information of the SSSG application, at a first time point, the one or more serving cells in the one or more DRX groups begin to monitor Physical Downlink Control Channel (PDCCH) transmission according to a search space set in the first SSSG.

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