System and method for multiple discontinuous reception for a cell group

Abstract

Systems and methods for multiple discontinuous receptions for a cell group are disclosed. In one embodiment, a method performed by a wireless communication device includes receiving a first discontinuous reception (DRX) configuration corresponding to a first DRX group (e.g., a first cDRX group) that includes a first subset of cells in a cell group, and receiving a second, different DRX configuration corresponding to a second DRX group (e.g., a second cDRX group) that includes a second subset of cells in the cell group.

Description

[0001] This application is a divisional application of Chinese Patent Application No. 201980102041.2, filed on November 6, 2019, entitled “Systems and Methods for Multiple Discontinuous Reception for a Cell Group.” TECHNICAL FIELD

[0002] The present disclosure relates generally to wireless communications, and more particularly, to systems and methods for multiple discontinuous reception for a cell group. BACKGROUND

[0003] Network traffic is typically bursty, with occasional periods of transmission activity followed by longer periods of inactivity. Even when there is no traffic between the network and the UE, the UE listens for network traffic, thereby expending additional power consumption by the UE. To reduce power consumption, NR includes a mechanism for discontinuous reception. In discontinuous reception, the UE enters a sleep mode for a certain period of time and periodically wakes up to check if there is any data from the network. If there is no data, the UE returns to sleep and repeats the cycle. SUMMARY

[0004] The example embodiments disclosed herein relate to addressing one or more of the problems present in the prior art, as well as providing additional features that will become apparent when reference is made to the following detailed description in conjunction with the drawings. In accordance with various embodiments, example systems, methods, devices, and computer program products are disclosed herein. It should be understood, however, that these embodiments are presented by way of example and not limitation, and that modifications can be made by those of ordinary skill in the art to the disclosed embodiments while still maintaining within the scope of the present disclosure.

[0005] In one embodiment, a method performed by a wireless communication device includes receiving a first discontinuous reception configuration corresponding to a first DRX group comprising a first subset of cells in a cell group, and receiving a second, different DRX configuration corresponding to a second DRX group comprising a second subset of cells in the cell group.

[0006] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the first DRX configuration includes a first drx-Retransmission downlink timer and / or a first drx-Retransmission uplink timer, and the second DRX configuration includes a second drx-Retransmission downlink timer and / or a second drx-Retransmission uplink timer. In some embodiments, the wireless communication device determines to be in the active state based on identifying at least one of the first drx-Retransmission downlink timer is running or the second drx-Retransmission downlink timer is running, the first drx-Retransmission uplink timer is running or the second drx-Retransmission uplink timer is running, a pending scheduling request has been transmitted in the first set of cells, and a pending scheduling request has been transmitted in any of the first set of cells and the second set of cells.

[0007] The above and other aspects and implementations thereof are described in greater detail in the accompanying drawings, description and claims. BRIEF DESCRIPTION OF DRAWINGS

[0008] Various example embodiments of the present solution are described in detail below with reference to the following drawings or accompanying figures. The drawings are provided only for purposes of illustration and are not to be construed as limiting the present solution. It should be noted that for purposes of clarity and ease of explanation, the drawings are not necessarily drawn to scale.

[0009] Figure 1 An example cellular communication network in which the techniques and other aspects disclosed herein can be implemented is shown in accordance with embodiments of the present disclosure.

[0010] Figure 2 Block diagrams of example base station and user equipment devices in accordance with some embodiments of the present disclosure are shown.

[0011] Figure 3 A flow diagram showing a method for multiple discontinuous receptions for one cell group in accordance with some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0012] Various example embodiments of the present solution are described below with reference to the accompanying drawings, so as to enable a person of ordinary skill in the art to make and use the present solution. As will be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein can be made without departing from the scope of the present solution. Thus, the present solution is not limited to the example embodiments and applications described and illustrated herein. Additionally, the particular order or hierarchy of steps in the methods disclosed herein are merely examples. The particular order or hierarchy of steps disclosed can be rearranged, or other steps can be added, without departing from the scope of the present solution. Accordingly, those of ordinary skill in the art will appreciate that the methods and techniques disclosed herein represent various embodiments of the present solution. The methods and techniques are not limited to the exact sequence or hierarchy presented, unless explicitly stated otherwise.

[0013] A. Network Environment and Computing Environment

[0014] Figure 1 An example wireless communication network and / or system 100 in which the techniques disclosed herein can be implemented in accordance with embodiments of the present disclosure is shown. In the following discussion, the wireless communication network 100 can be any wireless network, such as a cellular network or a narrowband Internet of things (NB-IoT) network, and is referred to herein as the “network 100.” Such an example network 100 includes base stations 102 (hereinafter “BS 102”) and user equipment devices 104 (hereinafter “UE 104”) that can communicate with each other via communication links 110 (e.g., wireless communication channels), as well as a cluster of cells 126, 130, 132, 134, 136, 138, and 140 that cover a geographic area 101. In the example shown, the BS 102 and the UE 104 are contained within the respective geographic boundaries of the cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 can include at least one base station operating under its assigned bandwidth to provide sufficient wireless coverage to its intended users. Figure 1 In the example shown, the BS 102 and the UE 104 are contained within the respective geographic boundaries of the cell 126. Each of the other cells 130, 132, 134, 136, 138, and 140 can include at least one base station operating under its assigned bandwidth to provide sufficient wireless coverage to its intended users.

[0015] For example, the BS 102 can operate under an assigned channel transmission bandwidth to provide sufficient coverage to the UEs 104. The BS 102 and the UEs 104 can communicate through a downlink wireless frame 118 and an uplink wireless frame 124, respectively. Each wireless frame 118 / 124 can also be divided into subframes 120 / 127, which can include data symbols 122 / 128. In this disclosure, the BS 102 and the UEs 104 are described herein as non-limiting examples of“communication nodes” that can generally practice the methods disclosed herein. According to various embodiments of the present solution, such communication nodes are capable of wireless and / or wired communication.

[0016] Figure 2 A block diagram of an example wireless communication system 200 for transmitting and receiving wireless communication signals (e.g., OFDM / OFDMA signals) is shown in accordance with some embodiments of the present solution. The system 200 can include components and elements configured to support known or conventional operational features that need not be described in detail herein. In one illustrative embodiment, the system 200 can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment 100 described above. Figure 1

[0017] The system 200 generally includes a base station 202 (hereinafter“BS 202”) and a user equipment device 204 (hereinafter“UE 204”). The BS 202 includes a BS (base station) transceiver module 210, a BS antenna 212, a BS processor module 214, a BS memory module 216, and a network communication module 218, each coupled and interconnected to each other as needed through a data communication bus 220. The UE 204 includes a UE (user equipment) transceiver module 230, a UE antenna 232, a UE memory module 234, and a UE processor module 236, each coupled and interconnected to each other as needed through a data communication bus 240. The BS 202 communicates with the UE 204 through a communication channel 250, which can be any wireless channel or other medium suitable for the transmission of data described herein.

[0018] As understood by one of ordinary skill in the art, the system 200 can also include components and elements other than those shown in FIG. 2, such as a power supply, a user interface, and the like. Figure 2 ​any number of modules beyond those shown. Those skilled in the art will understand that the various illustrative blocks, modules, circuits, and processing logic described in connection with the embodiments disclosed herein can be implemented in hardware, computer-readable software, firmware, or any practical combination thereof. To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented in hardware, firmware, or software depends on the particular application and design constraints imposed on the overall system. Skilled persons familiar with the concepts described herein can implement such functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0019] According to some embodiments, the UE transceiver module 230 can be referred to herein as an "uplink" transceiver module 230, which includes a radio frequency (RF) transmitter and a RF receiver each including circuitry coupled to an antenna 232. A duplexing switch (not shown) can alternatively couple the uplink transmitter or receiver to the uplink antenna in a time duplexed manner. Similarly, according to some embodiments, the BS transceiver module 210 can be referred to herein as a "downlink" transceiver module 210, which includes a RF transmitter and a RF receiver each including circuitry coupled to an antenna 212. A downlink duplexing switch can alternatively couple the downlink transmitter or receiver to the downlink antenna 212 in a time duplexed manner. The operation of the two transceiver modules 210 and 230 can be coordinated in time such that the uplink receiver is coupled to the uplink antenna 232 for receiving transmissions over the wireless transmission link 250 at the same time that the downlink transmitter is coupled to the downlink antenna 212. In some embodiments, there is close time synchronization with minimal guard time between changes in duplex direction.

[0020] The UE transceiver module 230 and the base station transceiver module 210 are configured to communicate via the wireless data communication link 250 and in cooperation with appropriately configured RF antenna arrangements 212 / 232 capable of supporting a particular wireless communication protocol and modulation scheme. In some illustrative embodiments, the UE transceiver module 230 and the base station transceiver module 210 are configured to support industry standards such as Long Term Evolution (LET) and emerging 5G standards. It should be appreciated, however, that the present disclosure is not necessarily limited in its application to a particular standard and associated protocols. Rather, the UE transceiver module 230 and the base station transceiver module 210 can be configured to support alternative or additional wireless data communication protocols, including future standards or variants thereof.

[0021] According to various embodiments, the BS 202 can be, for example, an evolved Node B (eNB), a serving BS, a target BS, a femto station, or a pico station. In some embodiments, the UE 204 can be embodied in various types of UEs, such as a mobile phone, a smartphone, a personal digital assistant (PDA), a tablet, a laptop computer, a wearable computing device, etc. The processor modules 214 and 236 can be implemented or realized with a general purpose processor, a content addressable memory, a digital signal processor, an application specific integrated circuit, a field programmable gate array, any suitable programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. In this manner, the processor can be implemented as a microprocessor, a controller, a microcontroller, a state machine, etc. The processor can also be implemented as a combination of a

[0022] Additionally, the steps of a method or algorithm described in connection with the embodiments disclosed herein can be embodied directly in hardware, in firmware, in a software module executed by processor modules 214 and 236, respectively, or in any practical combination thereof. The memory modules 216 and 234 can be implemented as RAM memory, flash memory, ROM read-only 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. In this regard, the memory modules 216 and 234 can be coupled to the processor modules 214 and 236, respectively, such that the processor modules 214 and 236 can read information from, and write information to, the memory modules 216 and 234, respectively. The memory modules 216 and 234 can also be integrated into the processor modules 214 and 236, respectively. In some embodiments, the memory modules 216 and 234 can each include a cache memory for storing temporary variables or other intermediate information during execution of instructions to be executed by the processor modules 214 and 236, respectively. The memory modules 216 and 234 can also each include a non-volatile memory for storing instructions to be executed by the processor modules 214 and 236, respectively.

[0023] The network communications module 218 generally represents the hardware, software, firmware, processing logic and / or other components that enable the base station transceiver module 210 of the BS 202 to communicate with other network components and communication nodes configured to communicate with the base station 202. For example, the network communications module 218 can be configured to support Internet or WiMAX traffic. In a typical deployment, but not limited thereto, the network communications module 218 provides an 802.3 Ethernet interface so that the base station transceiver module 210 can communicate with a conventional Ethernet-based computer network. In this manner, the network communications module 218 can include a physical interface for connection to a computer network (e.g., a Mobile Switching Center (MSC)). The terms "configured to," "configured for," and variations thereof, as used herein with respect to a particular operation or function, refer to being physically structured, programmed, formatted, and / or arranged to perform the particular operation or function.

[0024] B. Multiple discontinuous reception for a cell group

[0025] A DRX (discontinuous reception) group is one or more serving cells in a cell group that share one DRX configuration. In some embodiments, a DRX group can be configured based on a PUCCH group. In some embodiments, a DRX group includes one or more UEs (e.g., user equipment, UE 104, UE 204, user device, terminal, wireless communication device, etc.) that share one DRX configuration. In some embodiments, a cell group can include several DRX configurations. In some embodiments, a DRX group and / or configuration includes a cDRX (connected mode DRX) group and / or configuration, respectively. In some embodiments, a cDRX group includes one or more UEs that share a cDRX configuration. In some embodiments, a wireless communication device receives a first discontinuous reception (DRX) configuration corresponding to a first DRX group that includes a first subset of cells (e.g., a first cDRX group) in a cell group. In some embodiments, the wireless communication device receives a different second DRX configuration corresponding to a second DRX group that includes a second subset of cells (e.g., a second cDRX group) in the cell group. In some embodiments, the wireless communication device receives the first and / or second DRX from a wireless communication node (e.g., a base station, BS, BS 102, BS 202, gNB, network, etc.).

[0026] In some embodiments, cDRX configurations can be released / configured separately for each cDRX group. In some embodiments, cDRX configurations can be released / configured through RRC signaling. In some embodiments, cDRX configurations for each cDRX group can be activated / deactivated through a MAC CE. In some embodiments, this MAC CE includes at least one of the following information: a cDRX group identifier, a primary serving cell identifier in one cDRX group, an activation / deactivation indication.

[0027] A UE in a DRX group can be in a state such as an active state (e.g., active state, active situation) or a sleep state. In some embodiments, a UE in an active state monitors signaling (e.g., downlink control signaling, such as PDCCH physical downlink control channel). In some embodiments, a UE in a sleep state stops monitoring signaling to reduce power consumption.

[0028] A DRX cycle is a duration of a sum of an “on time” (e.g., time in active state) and an “off time” (e.g., time in sleep state). An onDurationTimer is a duration of an “on time” within a DRX cycle. A drx-InactivityTimer specifies how long a UE remains or should remain “on” after receiving a PDCCH. When a drx-InactivityTimer timer is on, a UE remains in “on state,” otherwise this can extend a UE on period to a period that is a “off” period. A drx-RetransmissionTimer specifies a maximum number of consecutive signaling subframes a UE should remain active to wait for an upcoming retransmission after a first available retransmission time. A drx-RetransmissionTimer includes a timer for downlink signaling (drx-RetransmissionTimerDL) and a timer for uplink signaling (drx-RetransmissionTimerUL).

[0029] Some embodiments define an active state for when multiple cDRX groups are configured to a UE. In some embodiments, a UE in a cDRX group is in an active state in response to at least one of the following conditions. A first condition is that a drx-onDurationTimer is running, where the drx-onDurationTimer is configured for the cDRX group. A second condition is that a drx-onInactivityTimer is running, where the drx-onInactivitynTimer is configured for the cDRX group. A third condition is that a drx-RetransmissionTimerDL is running, where the drx-RetransmissionTimerDL is configured for the cDRX group or another cDRX group. A fourth condition is that a drx-RetransmissionTimerUL is running, where the drx-RetransmissionTimerUL is configured for the cDRX group or another cDRX group. A fifth condition is that a scheduling request is sent on a PUCCH (Physical Uplink Control Channel) in the same cDRX group or any cDRX group and is pending.

[0030] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the first DRX configuration includes a first drx-retransmission downlink timer and / or a first drx-retransmission uplink timer, and the second DRX configuration includes a second drx-retransmission downlink timer and / or a second drx-retransmission uplink timer. In some embodiments, the wireless communication device determines to be in an active state based on at least one of the following conditions. A first condition is that it is identified that the first drx-retransmission downlink timer is running or the second drx-retransmission downlink timer is running. A second condition is that it is identified that the first drx-retransmission uplink timer is running or the second drx-retransmission uplink timer is running. A third condition is that it is identified that a pending scheduling request has been sent in the first subset of cells. A fourth condition is that it is identified that a pending scheduling request has been sent in either of the first subset of cells and the second subset of cells.

[0031] After receiving a random access response (RAR) message from the first cDRX group, the UE determines that the contention-free random access channel (RACH) is complete. In some embodiments, the UE needs to remain awake to monitor the PDCCH in the first cDRX group until a PDCCH is received that matches the UE's cell-radio network temporary identifier (C-RNTI). In some embodiments, the UE needs to remain awake to monitor the PDCCH in any cDRX group until a PDCCH is received that matches the UE's C-RNTI.

[0032] In some embodiments, the wireless communication device receives a random access response message from a wireless communication node in the first subset of cells to determine to be in an active state. In some embodiments, the wireless communication device remains in the active state until a physical downlink control channel (PDCCH) is received on the first subset of cells by a corresponding cell-radio network temporary identifier (C-RNTI). In some embodiments, the wireless communication device remains in the active state until a PDCCH is received on any of the first subset of cells and the second subset of cells by the C-RNTI. In some embodiments, the wireless communication device remains in the active state until a PDCCH is received on the first subset of cells by the C-RNTI and on any of the second subset of cells by the C-RNTI. In some embodiments, the wireless communication device remains in the active state until a physical downlink control channel (PDCCH) is received on the aPcDRX group (active primary cDRX group) by a corresponding cell-radio network temporary identifier (C-RNTI). In some embodiments, the PcDRX group is a cDRX group that includes a PCell (primary cell).

[0033] Some embodiments define the behavior of drx-inactivityTimer for multiple cDRX groups. In some embodiments, the drx-inactivityTimer is started and stopped based on various triggering mechanisms. In some embodiments, the drx-inactivityTimer is started in response to at least one of the following conditions. A first condition is receiving a DCI (downlink control information) on PDCCH indicating a new UL / DL transmission from the same cDRX group as the drx-inactivityTimer. A second condition is receiving a DCI on PDCCH indicating a new UL / DL transmission from any cDRX group. In some embodiments, the drx-inactivityTimer is stopped in response to at least one of the following conditions. A first condition is receiving a long DRX command MAC (medium access control) CE (control element) or a short DRX MAC CE from the same cDRX group as the drx-inactivityTimer. A second condition is receiving a long DRX command MAC CE or a short DRX command MAC CE from any cDRX group.

[0034] In some embodiments, the wireless communication device is currently using a first DRX configuration associated with a first cDRX group. In some embodiments, the first DRX configuration includes a drx-inactivity timer. In some embodiments, the wireless communication device starts the drx-inactivity timer in response to at least one of the following conditions. A first condition is receiving a physical downlink control channel (PDCCH) in the first cell subset indicating a new DL or UL transmission. A second condition is receiving a physical downlink control channel (PDCCH) in either of the first cell subset and the second cell subset indicating a new DL or UL transmission. In some embodiments, the wireless communication device stops the drx-inactivity timer in response to at least one of the following conditions. A first condition is receiving a DRX command MAC control element (CE) (e.g., a long DRX command MAC CE or a short DRX command MAC CE) corresponding to the first cell subset. A second condition is receiving a DRX command MAC control element (CE) (e.g., a long DRX command MAC CE or a short DRX command MAC CE) corresponding to either of the first cell subset and the second cell subset.

[0035] A DRX cycle can include a short DRX cycle (e.g., shortDRX-cycle). In some embodiments, the shortDRX-cycle can be implemented within the "off" period of a long DRX cycle. In some embodiments, the drx-ShortCycleTimer is a consecutive number of subframes that the UE follows the shortDRX-cycle after the drx-inactivityTimer has expired. In some embodiments, the drx-ShortCycleTimer is started, restarted, or stopped based on various triggering mechanisms.

[0036] Some embodiments define the behavior of the drx-ShortCycleTimer for multiple cDRX groups. In some embodiments, the drx-ShortCycleTimer timer is started or restarted in response to at least one of the following conditions. A first condition is receiving a short DRX command MAC CE from the same cDRX group. A second condition is receiving a short DRX command MAC CE from any cDRX group. A third condition is the expiration of the drx-inactivityTimer configured to the same cDRX group. A fourth condition is the expiration of the drx-inactivityTimer configured to any cDRX group. In some embodiments, the drx-ShortCycleTimer is stopped in response to at least one of the following conditions. A first condition is receiving a long DRX command MAC CE from the same cDRX group. A second condition is receiving a long DRX command MAC CE from any cDRX group.

[0037] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the first DRX configuration includes a drx-ShortCycle timer. In some embodiments, the wireless communication device starts or restarts the drx-ShortCycle timer in response to at least one of the following conditions. A first condition is receiving a DRX command MAC control element (CE) (e.g., a long DRX command MAC CE or a short DRX command MAC CE) corresponding to a first subset of cells. A second condition is receiving a DRX command MAC control element (CE) (e.g., a long DRX command MAC CE or a short DRX command MAC CE) corresponding to any one of the first subset of cells and a second subset of cells.

[0038] In some embodiments, the wireless communication device starts the drx-ShortCycle timer configured in the first cDRX group in response to identifying expiration of the drx-inactivity timer of the first cDRX group. In some embodiments, the second DRX configuration includes a second drx-inactivity timer. In some embodiments, the wireless communication device starts the drx-ShortCycle timer configured in the first cDRX group in response to identifying expiration of any of the first drx-inactivity timer and the second drx-inactivity timer. In some embodiments, the wireless communication device stops the drx-ShortCycle timer configured in the first cDRX group in response to receiving a long drx command MAC control element (CE) from the first subset of cells and a long DRX command MAC control element (CE) from any of the first subset of cells and the second subset of cells.

[0039] In the current release, the long DRX command MAC CE is a subheader (similar to a MAC CE). Some embodiments implement a long DRX command MAC CE for each cDRX group. In some embodiments, for the first cDRX group, the UE only applies the long DRX command MAC CE received in the first cDRX group. In some embodiments, for the first cDRX group, the UE supports applying the long DRX command MAC CE received from different cDRX groups. In some embodiments, the UE applies the long DRX command MAC CE to all configured cDRX groups. In some embodiments, the long DRX command MAC CE reuses the format of the similar subheader (e.g., when applying the long DRX command MAC CE to the cDRX group that receives the long DRX command MAC CE and / or applying the long DRX command MAC CE to all configured cDRX groups). In some embodiments, the long DRX command MAC CE is modified to add a payload to indicate which cDRX group will apply the MAC CE (e.g., when supporting applying the long DRX command MAC CE received in different cDRX groups). This payload includes a cDRX group identifier or a cDRX group indicator.

[0040] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the first DRX configuration (e.g., a configuration of a first cDRX group) includes a DRX command MAC control element (CE) (e.g., a long DRX command MAC CE or a short DRX command MAC CE). In some embodiments, the wireless communication device applies the DRX command MAC CE to the first subset of cells. In some embodiments, the wireless communication device applies the DRX command MAC CE to the second subset of cells, where the DRX command MAC CE includes a payload indicating the second subset of cells. In some embodiments, the wireless communication device applies the DRX command MAC CE to both the first subset of cells and the second subset of cells.

[0041] In some embodiments, CSI (channel state information) reporting is a two-step process including measurement and reporting. Currently, when a UE is configured for DRX, the UE needs to determine whether to perform CSI reporting based on an active status at a time point of the CSI reporting. In some embodiments, a BS configures a UE to identify a subset of cells where measurement and reporting are to be performed. However, if a PUCCH SCell (secondary cell) where CSI reporting is performed is in a different cDRX group than a corresponding SCell where CSI measurement is performed, the current version does not define UE behavior regarding whether to report CSI in such a scenario.

[0042] Some embodiments implement CSI reporting for multiple cDRX groups. In some embodiments, a UE identifies that reporting of CSI is to be performed on a cell (e.g., a cell, a group of cells, a DRX group, and / or a cDRX group). In some embodiments, whether to perform CSI reporting is determined based on whether the UE is in an active state on the cell where CSI reporting is performed. In some embodiments, whether to perform CSI reporting is determined based on whether the UE is in an active state on the cell where CSI measurement is performed. In some embodiments, whether to perform CSI reporting is determined based on whether the UE is in an active state on any cell where CSI measurement or CSI reporting is performed.

[0043] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the wireless communication device identifies that reporting of channel state information (CSI) is to be performed in a first subset of cells. In some embodiments, the wireless communication device determines whether to report the CSI based on at least one of the following conditions. A first condition is whether the wireless communication device is in an active state in the first subset of cells. A second condition is whether the wireless communication device is in an active state in the first subset of cells or a second subset of cells where measurement of the CSI is to be performed. A third condition is whether the wireless communication device is in an active state in the first subset of cells or the second subset of cells where reporting of the CSI or measurement of the CSI is to be performed.

[0044] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the wireless communication device needs to transmit a SRS (sounding reference signal) for a serving cell in a second cDRX group in a first cDRX group. The wireless communication device determines whether to report the SRS based on at least one of the following conditions. A first condition is whether the wireless communication device is in an active state in the first cell subset. A second condition is whether the wireless communication device is in an active state in the first cell subset or the second cell subset for which the SRS is transmitted. A third condition is whether the wireless communication device is in an active state in the first cell subset or the second cell subset for which the SRS is transmitted or will be performed. A fourth condition is whether the wireless communication device is in an active state in the cDRX group related to the PUCCH group for which the SRS is transmitted.

[0045] In rel-16, WUS (wake-up signal) is associated with cDRX to save power consumption. The WUS signal is used to indicate the UE to wake up to monitor PDCCH in the following one or more on duration time. However, in rel-16, only one cDRX configuration is configured per MAC. In some embodiments where multiple cDRX groups are configured, to improve power efficiency, one WUS is associated to one cDRX group, instead of the whole CG (cell group).

[0046] Some embodiments include a WUS mechanism adapted to scenarios of multiple cDRX groups in one given CG. In some embodiments, the WUS includes a cDRX group identifier. In some embodiments, the UE receives (e.g., receives, transmits, or uses) a particular WUS to indicate a cDRX group. In some embodiments, the UE determines whether to wake up to monitor PDCCH from a cDRX group based on an indication included in the WUS. In some embodiments, the UE determines whether to wake up to monitor PDCCH from a cDRX group based on an indication of a corresponding WUS.

[0047] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the wireless communication device receives at least one of a global wake-up signal (WUS) including an identifier corresponding to the first cell subset or the second cell subset or a specific wake-up signal (WUS) corresponding to the first cell subset or the second cell subset.

[0048] Since the SCells configured to the UE can not be SFN (System Frame Number) aligned, to save power for monitoring PDCCH, in some embodiments, the UE active state on all serving cells of one group remains aligned. Some embodiments calculate the starting point (e.g., start time or drx-StartOffset) of the onDuration timer for each cDRX group. In some embodiments, for short DRX cycle, [(SFN + SFN_OFFSET) x 10 + subframe number] modulo (drx-ShortCycle) = (drx-StartOffset) modulo (drx-ShortCycle) = drx-StartOffset. In some embodiments, for long DRX cycle, [(SFN + SFN_OFFSET) x 10 + subframe number] modulo (drx-LongCycle) = drx-StartOffset. In some embodiments, SFN represents the SFN number of the cDRX group. In some embodiments, SFN_OFFSET represents the SFN gap between this cDRX group and the PCell. In some embodiments, the SFN number of the cDRX group can be derived from a specific serving cell in this cDRX group. In some embodiments, SFN represents the SFN number of the primary cell (Pcell). In some embodiments, SFN_OFFSET represents the SFN gap between the cDRX group and the PCell.

[0049] In some embodiments, the first DRX configuration includes a first onDuration timer and the second DRX configuration includes a second onDuration timer. In some embodiments, a start timing of the first onDuration timer is related to a system frame number (SFN) offset between the first subset of cells and a SFN of a primary cell, and a start timing of the second onDuration timer is related to a SFN offset between the second subset of cells and the SFN of the primary cell.

[0050] Some embodiments include interaction between a master node (MN) and a secondary node (SN) for cDRX group configuration. In some embodiments, a cell group information message from the MN to the SN includes all configured cDRX configurations in the MN. In some embodiments, a cell group information message from the SN to the MN includes all configured cDRX configurations in the SN. In some embodiments, a CU (Central Unit) informs a DU (distributed Unit) to release one or more cDRX groups.

[0051] In some embodiments, a wireless communication device (UE) sends assistance information to another wireless communication device (NW). In some embodiments, the assistance information is used to inform the NW of a cDRX configuration (e.g., a favorite cDRX configuration of the UE). In some embodiments, this cDRX configuration is assistance information per cDRX group or PUCCH group. In some embodiments, the cDRX configuration in the assistance information includes at least one of the following parameters: a serving cell ID / a list of serving cell IDs, a PUCCH group identifier, a drx_ondurationTimer, a drx_inactivityTimer, a drx-HARQ-RTT-TimerDL, a drx-HARQ-RTT-TimerUL, a drx-RetransmissionTimerDL, or a drx-RetransmissionTimerUL.

[0052] Figure 3 A flowchart illustrating a method 300 for multiple discontinuous receptions for one cell group is shown in accordance with some embodiments of the present disclosure. Reference is made to FIG. 1 for purposes of explanation of the method 300. Figures 1 to 2 In some embodiments, the method 300 is performed by the UE 104 and / or the UE 204. Additional, fewer, or different operations can be performed in the method 300 depending on the embodiments.

[0053] A wireless communication device receives a first discontinuous reception (DRX) configuration corresponding to a first DRX group (e.g., a first cDRX group) that includes a first subset of cells in a cell group (302). The wireless communication device receives a different second DRX configuration corresponding to a second DRX group (e.g., a second cDRX group) that includes a second subset of cells in the cell group (304). In some embodiments, the wireless communication device receives the first and / or second DRX from a wireless communication node.

[0054] In some embodiments, the wireless communication device is currently using a first DRX configuration. In some embodiments, the first DRX configuration includes a first drx-retransmission downlink timer and / or a first drx-retransmission uplink timer, and the second DRX configuration includes a second drx-retransmission downlink timer and / or a second drx-retransmission uplink timer. In some embodiments, the wireless communication device determines to be in the active state based on at least one of the following conditions. A first condition is identifying that the first drx-retransmission downlink timer is running or the second drx-retransmission downlink timer is running. A second condition is identifying that the first drx-retransmission uplink timer is running or the second drx-retransmission uplink timer is running. A third condition is identifying that a pending scheduling request has been transmitted in the first subset of cells. A fourth condition is identifying that a pending scheduling request has been transmitted in any of the first subset of cells and the second subset of cells.

[0055] While various embodiments of the present solution have been described above, it should be understood that they have been presented by way of example only, and not limitation. Likewise, the various figures can depict example architectures or configurations, which could employ various technologies not yet developed but anticipated to be useful in the future. As such, some embodiments can be directed to implementations functionally equivalent to the ones disclosed herein. Accordingly, the breadth and scope of the present solution should not be limited by any of the above-described example embodiments, but should be defined only in accordance with the following claims and their equivalents.

[0056] It should also be understood that any reference to an element in the present disclosure using a designation such as "first," "second," and so forth does not limit the quantity or order of those elements. Rather, these designations are used as a convenient method of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements can be employed, or that the first element must precede the second element.

[0057] Additionally, one of ordinary skill in the art will recognize that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, and symbols can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0058] Those of ordinary skill in the art will further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., a number of logic devices, an analog implementation, or a combination of both), firmware, various forms of program or design code incorporating instructions (which can be referred to herein, for convenience, as "software" or a "software module"), or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software or any combination thereof, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0059] In addition, those of ordinary skill in the art will appreciate that the various illustrative logical blocks, modules, devices, components and circuits described herein can be implemented within or performed by an integrated circuit (IC), which can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or a combination of these components. The logical blocks, modules, and circuits can also include antennas and / or transceivers to communicate with various components within a network or within a device. The general purpose processor can be a microprocessor, but in the alternative, the processor can be any conventional processor, controller, or state machine. The processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other such configuration.

[0060] If implemented in software, the functions can be stored or transmitted over as one or more instructions or code on a computer-readable medium. Therefore, the steps of a method or algorithm disclosed herein can be implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program or code from one place to another. Storage media can be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.

[0061] In this document, the term "module" as used herein, refers to software, firmware, hardware, and any combination of these elements that is used to perform the associated functions described herein. Additionally, for purposes of discussion, the various modules are described as discrete modules; however, as will be apparent to one of ordinary skill in the art, two or more modules can be combined to form a single module that performs the associated functions of the combined modules.

[0062] Additionally, in embodiments of the present solution, memory or other storage devices and communication components can be employed. It will be appreciated that, for clarity, the above description has described embodiments of the solution with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains can be used without detracting from the solution. For example, functionality illustrated to be performed by separate processing logic elements or controllers can be performed by the same processing logic element or controller. Hence, references to specific functional units are only to be seen as references to suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization.

[0063] Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the scope of the disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein and made apparent to others skilled in the art by the teachings herein.

Claims

1. A method of wireless communication, comprising: receiving, by a wireless communication device, a first discontinuous reception (DRX) configuration corresponding to a first DRX group comprising a first subset of cells in a group of cells, wherein the first DRX configuration comprises a first drx-Inactivity timer and a drx-ShortCycle timer, wherein the drx-ShortCycle timer included in the first DRX configuration is configured for both the first DRX group and a second DRX group; receiving, by the wireless communication device, a second DRX configuration different from the first DRX configuration, the second DRX configuration corresponding to the second DRX group comprising a second subset of cells in the group of cells, wherein the second DRX configuration comprises a second drx-Inactivity timer; starting or restarting, by the wireless communication device, the drx-ShortCycle timer for both the first DRX group and the second DRX group in response to receiving a DRX command MAC control element (CE) corresponding to any one of the first subset of cells in the first DRX group and the second subset of cells in the second DRX group; and starting, by the wireless communication device, the first drx-Inactivity timer in response to receiving a physical downlink control channel (PDCCH) in the first subset of cells for scheduling a new uplink (UL) or downlink (DL) transmission.

2. The method of wireless communication of claim 1, further comprising: receiving, by the wireless communication device, the PDCCH in the first subset of cells in the first DRX group.

3. The method of wireless communication of claim 1, further comprising: receiving, by the wireless communication device, a long DRX command MAC control element (CE) from any one of the first subset of cells in the first DRX group and the second subset of cells in the second DRX group; and stopping, by the wireless communication device, the drx-ShortCycle timer configured in the first DRX configuration in response to receiving the long DRX command MAC CE.

4. The method of wireless communication of claim 1, further comprising: determining, by the wireless communication device, that a report of channel state information (CSI) is to be performed in the first subset of cells in the first DRX group; and determining, by the wireless communication device, whether to report CSI based on whether the wireless communication device is in an active state in the first subset of cells in the first DRX group.

5. The method of wireless communication of claim 1, further comprising: determining, by the wireless communication device, that a sounding reference signal (SRS) is to be transmitted in the first subset of cells in the first DRX group; and determining, by the wireless communication device, whether to transmit the SRS based on whether the wireless communication device is in an active state in the first subset of cells in the first DRX group. ​ ​ ​ 6. The wireless communication method of claim 1, wherein: a system frame number (SFN) of a primary cell (Pcell) is used to calculate at least one of a start time of an onDurationTimer of the first DRX group or a start time of an onDurationTimer of the second DRX group.

7. The wireless communication method of any one of claims 1-6, wherein: the wireless communication device stops the drx-Inactivity timer in response to receiving a DRX command MAC CE corresponding to the first subset of cells, the DRX command MAC CE comprising a long DRX command MAC CE or a short DRX command MAC CE.

8. A wireless communication device comprising: at least one processor configured to: receive, via a receiver, a first discontinuous reception (DRX) configuration corresponding to a first DRX group comprising a first subset of cells in a group of cells, wherein the first DRX configuration comprises a first drx-Inactivity timer and a drx-ShortCycle timer, wherein the drx-ShortCycle timer comprised in the first DRX configuration is configured for both the first DRX group and a second DRX group; receive, via the receiver, a second DRX configuration different from the first DRX configuration, the second DRX configuration corresponding to the second DRX group comprising a second subset of cells in the group of cells, wherein the second DRX configuration comprises a second drx-Inactivity timer; start or restart the drx-ShortCycle timer for both the first DRX group and the second DRX group in response to receiving a DRX command MAC control element (CE) corresponding to any one of the first subset of cells in the first DRX group and the second subset of cells in the second DRX group; and start the first drx-Inactivity timer in response to receiving a physical downlink control channel (PDCCH) in the first subset of cells for scheduling a new uplink (UL) or downlink (DL) transmission.

9. The wireless communication device of claim 8, wherein the at least one processor is further configured to: receive, via the receiver, the PDCCH in the first subset of cells in the first DRX group.

10. The wireless communication device of claim 8, wherein the at least one processor is further configured to: receive, via the receiver, a long DRX command MAC control element (CE) from any one of the first subset of cells in the first DRX group and the second subset of cells in the second DRX group; and stop the drx-ShortCycle timer configured in the first DRX configuration in response to receiving the long DRX command MAC CE.

11. The wireless communication device of claim 8, wherein the at least one processor is further configured to: determine that reporting of channel state information (CSI) is to be performed in the first subset of cells in the first DRX group; and determine whether to report CSI based on whether the wireless communication device is in an active state in the first subset of cells in the first DRX group.

12. The wireless communication device of claim 8, wherein the at least one processor is further configured to: determine that sounding reference signals (SRS) are to be transmitted in the first subset of cells in the first DRX group; and determine whether to transmit SRS based on whether the wireless communication device is in an active state in the first subset of cells in the first DRX group.

13. The wireless communication device of claim 8, wherein: a system frame number (SFN) of a primary cell (Pcell) is used to calculate at least one of: a start time of an onDurationTimer of the first DRX group, or a start time of an onDurationTimer of the second DRX group.

14. The wireless communication device of any of claims 8-13, wherein: the wireless communication device stops the drx-Inactivity timer in response to receiving a DRX command MAC CE corresponding to the first subset of cells, the DRX command MAC CE comprising a long DRX command MAC CE or a short DRX command MAC CE.

15. A non-transitory computer-readable medium storing instructions that, when executed by at least one processor of a wireless communication device, cause the at least one processor to perform the method of any of claims 1-7.

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