Patent Description:
Network traffic is often bursty, with occasional periods of transmission activity followed by long periods of inactivity. Even while there is no traffic between a network and a UE, the UE listens for network traffic, costing the UE additional power consumption. To reduce power consumption, NR includes mechanisms for discontinuous reception. In discontinuous reception, the UE goes to sleep mode for a certain period of time and wakes up periodically to check if there is any data coming from the network. If there is no data, the UE goes back to sleep and repeats the cycle.

3GPP Draft R2-<NUM> is a related prior art document.

The example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments can be made while remaining within the scope of this disclosure.

" Such an example network <NUM> includes a base station <NUM> (hereinafter "BS <NUM>") and a user equipment device <NUM> (hereinafter "UE <NUM>") that can communicate with each other via a communication link <NUM> (e.g., a wireless communication channel), and a cluster of cells <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM> overlaying a geographical area <NUM>.

<FIG> illustrates a block diagram of an example wireless communication system <NUM> for transmitting and receiving wireless communication signals, e.g., OFDM/OFDMA signals, in accordance with some embodiments of the present solution. The system <NUM> may include components and elements configured to support known or conventional operating features that need not be described in detail herein. In one illustrative embodiment, system <NUM> can be used to communicate (e.g., transmit and receive) data symbols in a wireless communication environment such as the wireless communication environment <NUM> of <FIG>, as described above.

The operations of the two transceiver modules <NUM> and <NUM> can be coordinated in time such that the uplink receiver circuitry is coupled to the uplink antenna <NUM> for reception of transmissions over the wireless transmission link <NUM> at the same time that the downlink transmitter is coupled to the downlink antenna <NUM>.

A DRX (discontinuous reception) group is one or multiple serving cells in a cell group sharing one DRX configuration. In some embodiments, the DRX group can be configured based on a PUCCH group. In some embodiments, the DRX group includes one or more UEs (e.g., a user equipment, the UE <NUM>, the UE <NUM>, a user device, a terminal, a wireless communication device, etc.) sharing the one DRX configuration. In some embodiments, a cell group may 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 sharing a cDRX configuration. In some embodiments, a wireless communication device receives a first discontinuous reception (DRX) configuration corresponding to a first DRX group including a first subset of cells (e.g., a first cDRX group) in a cell group. In some embodiments, the wireless communication device receives a second, different DRX configuration corresponding to a second DRX group including a second subset of cells (e.g., a second cDRX group) in the cell group. In some embodiments, the wireless communication devices receives the first DRX and/or the second DRX from a wireless communication node (e.g., a base station, a BS, the BS <NUM>, the BS <NUM>, a gNB, a network, etc.).

In some embodiments, the cDRX configuration can be released/configured separately for each cDRX group. In some embodiments, the cDRX configuration can be released/configured by RRC signaling. In some embodiments, the cDRX configuration for each cDRX group can be activated/deactivated via a MAC CE. In some embodiments, this MAC CE includes at least one of the following information: a cDRX group identifier, a main serving cell identifier in one cDRX group, activation/deactivation indication.

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

A DRX cycle is a duration of a sum of one 'ON time' (e.g., time in active state) and one 'OFF time' (e.g., time in sleep state). The onDurationTimer is a duration of 'ON time' within one DRX cycle. A drx-InactivityTimer specifies how long the UE remains, or should remain, 'ON' after reception of a PDCCH. When the drx-InactivityTimer timer is on, the UE remains in 'ON state,' which may extend the UE ON period into the period which is 'OFF' period otherwise. A drx-RetransmissionTimer specifies a maximum number of consecutive subframes of signaling the UE should remain active to wait an incoming retransmission after the first available retransmission time. The drx-RetransmissionTimer includes a timer for downlink signaling (drx-RetransmissionTimerDL) and a timer for uplink signaling (drx-RetransmissionTimerUL).

Some embodiments define the active state for when multiple cDRX groups are configured to the UE. In some embodiments, a UE in a cDRX group is in the active state responsive to at least one of the following conditions. The first condition is that a drx-onDurationTimer is running, wherein the drx-onDurationTimer is configured for the cDRX group. The second condition is that a drx-onlnactivityTimer is running, wherein the drx-onInactivitynTimer is configured for the cDRX group. The third condition is that a drx-RetransmissionTimerDL is running, wherein the drx-RetransmissionTimerDL is configured for the cDRX group or other cDRX groups. The fourth condition is that a drx-RetransmissionTimerUL is running, wherein the drx-RetransmissionTimerUL is configured for the cDRX group or other cDRX groups. The fifth condition is that a scheduling request is sent on PUCCH (physical uplink control channel) in a same cDRX group, or in any cDRX groups, and is pending.

In some embodiments, the wireless communication device is currently using the 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. The first condition is identifying that either the first drx-Retransmission downlink timer is running or the second drx-Retransmission downlink timer is running. The second condition is identifying that either the first drx-Retransmission uplink timer is running or the second drx-Retransmission uplink timer is running. The third condition is identifying that a scheduling request, that is pending, has been sent in the first subset of cells. The fourth condition is identifying that a scheduling request, that is pending, has been sent in any of the first subset of cells and the second subset of cells.

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 done. In some embodiments, the UE needs to stay awake to monitor the PDCCH in the first cDRX group until receiving a PDCCH that matches the UE's cell-radio network temporary identifier (C-RNTI). In some embodiments, the UE needs to stay awake to monitor the PDCCH in any cDRX group until receiving a PDCCH that matches the UE's C-RNTI.

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

Some embodiments define a behavior of drx-inactivityTimer for multiple cDRX groups. In some embodiments, the drx-inactivityTimer starts and stops based on various triggers. In some embodiments, the drx-inactivityTimer starts responsive to at least one of the following conditions. The first condition is that a DCI (downlink control information) addressing new UL/DL transmission being received on a PDCCH is from a same cDRX group as the drx-inactivityTimer. The second condition is that a DCI addressing new UL/DL transmission being received on a PDCCH is from any cDRX groups. In some embodiments, the drx-inactivityTimer stops responsive to at least one of the following conditions. The first condition is a reception of long DRX command MAC (medium access control) CE (control element) or a short DRX MAC CE from the same cDRX group with drx-inactivityTimer. The second condition is a reception of a long DRX command MAC CE or a short DRX command MAC CE from the any cDRX groups.

In some embodiments, the wireless communication device is currently using the first DRX configuration associated with the 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. The first condition is receiving a physical downlink control channel (PDCCH) addressing new DL or UL transmission in the first subset of cells. The second condition is receiving a physical downlink control channel (PDCCH) addressing new DL or UL transmission in any of the first subset of cells and the second subset of cells. In some embodiments, the wireless communication device stops the drx-Inactivity timer in response to at least one of the following conditions. The 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 subset of cells. The 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 of the first subset of cells and the second subset of cells.

A DRX cycle can include a short DRX cycle (e.g., shortDRX-cycle). In some embodiments, the shortDRX-cycle that can be implemented within the 'OFF' period of a long DRX Cycle. In some embodiments, the drx-ShortCycleTimer is the consecutive number of subframes the UE follows the shortDRX-cycle after the drx-inactivityTimer has expired. In some embodiments, the drx-ShortCycleTimer starts, restarts, or stops based on various triggers.

Some embodiments define a behavior of drx-ShortCycleTimer for multiple cDRX groups. In some embodiments, the drx-ShortCycleTimer starts or restarts responsive to at least one of the following conditions. The first condition is a reception of a short DRX command MAC CE from a same cDRX group. The second condition is a reception of a short DRX command MAC CE from any cDRX group. The third condition is an expiration of the drx-inactivityTimer that is configured to the same cDRX group. The fourth condition is an expiration of the drx-inactivityTimer that is configured to the any cDRX group. In some embodiments, the drx-ShortCycleTimer stops responsive to at least one of the following conditions. The first condition is a reception of a long DRX command MAC CE from the same cDRX group. The second condition is a reception of a long DRX command MAC CE from any cDRX group.

In some embodiments, the wireless communication device is currently using the first DRX configuration. In some embodiments, the first DRX configuration includes a drx-ShortCycle timer. In some embodiments, the wireless communication device either starts or restarts the drx-ShortCycle timer in response to at least one of the following conditions. The 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 subset of cells. The 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 of the first subset of cells and the second subset of cells.

In some embodiments, the wireless communication device starts the drx-ShortCycle timer configured in the first cDRX group in response to identifying that the drx-Inactivity timer of the first cDRX group is expired. 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 that any of the first drx-Inactivity timer and second drx-Inactivity timer is expired. 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 receiving a long DRX command MAC control element (CE) from any of the first subset of cells and the second subset of cells.

In the current release, the long DRX command MAC CE is a subheader (similar to a MAC CE). Some embodiments implement the long DRX command MAC CE for each cDRX group. In some embodiments, for the first cDRX group, the UE only applies a long DRX command MAC CE received in the first cDRX group. In some embodiments, for the first cDRX group, the UE supports applying a long DRX command MAC CE received from a different cDRX group. In some embodiments, the UE applies a long DRX command MAC CE to all configured cDRX groups. In some embodiments, a subheader-like format of long DRX command MAC CE is reused (e.g., when applying the long DRX command MAC CE to the cDRX group where the long DRX command MAC CE is received 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 the different cDRX group). This payload include a cDRX group identifier or a cDRX group indicator.

In some embodiments, the wireless communication device is currently using the first DRX configuration. In some embodiments, the first DRX configuration (e.g., the configuration of the 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, wherein 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 of the first subset of cells and the second subset of cells.

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

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

In some embodiments, the wireless communication device is currently using the first DRX configuration. In some embodiments, the wireless communication device identifies that reporting of channel state information (CSI) is to be performed in the 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. The first condition is whether the wireless communication device is in an active state in the first subset of cells. The second condition is whether the wireless communication device is in an active state in either the first subset of cells or the second subset of cells where measuring of the CSI is to be performed. The third condition is whether the wireless communication device is in an active state in either the first subset of cells or the second subset of cells where either the reporting of the CSI or the measuring of the CSI is to be performed.

In some embodiments, the wireless communication device is currently using the first DRX configuration. In some embodiments, the wireless communication device needs to send SRS (sounding reference signal) in the first cDRX group for the serving cell, which is in the second cDRX group. The wireless communication device determines whether to report the SRS based on at least one of the following conditions. The first condition is whether the wireless communication device is in an active state in the first subset of cells. The second condition is whether the wireless communication device is in an active state in either the first subset of cells or the second subset of cells where SRS is sending for. The third condition is whether the wireless communication device is in an active state in either the first subset of cells or the second subset of cells where either the sending SRS or for which sending SRS is to be performed. The fourth condition is whether the wireless communication device in an active state in cDRX group that is related to the PUCCH group that is used for sending SRS.

In rel-<NUM>, a WUS (wake-up signal) is linked to cDRX in order to save power consumption. The WUS signal is used for indicating to the UE to wake up to monitor the PDCCH for the next one or multiple onduration times. However, in rel-<NUM>, only one cDRX configuration is configured per MAC. In some embodiments where multiple cDRX groups are configured, in order to improve power efficiency, one WUS is linked to one cDRX group instead of a whole CG (cell group).

Some embodiments include a mechanism of WUS for adapting to the scenario 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) one specific WUS to indicate a cDRX group. In some embodiments, the UE determines whether to wake up to monitor the PDCCH from one cDRX group based on the indication included in WUS. In some embodiments, the UE determines whether to wake up to monitor the PDCCH from one cDRX group based on the indication of a corresponding WUS.

In some embodiments, the wireless communication device is currently using the first DRX configuration. In some embodiments, the wireless communication device receives at least one of a global wake-up signal (WUS) that includes an identifier corresponding to either the first subset of cells or the second subset of cells or a specific wake-up signal (WUS) that corresponds to either the first subset of cells or the second subset of cells.

Since SCells configured to UE may not be SFN (system frame number) aligned, for saving the power of monitoring PDCCH, in some embodiments, the UE active status on all serving cells of one group is kept aligned. Some embodiments calculate the start point(e.g., start time, or drx-StartOffset) of an onDuration timer for each cDRX group. In some embodiments, for short DRX cycle, [(SFN+SFN_OFFSET )× <NUM> + subframe number] modulo (drx-ShortCycle) = (drx-StartOffset) modulo (drx-ShortCycle) = drx-StartOffset. In some embodiments, for long DRX cycle, [(SFN+SFN_OFFSET) × <NUM>+ subframe number] modulo (drx-LongCycle) = drx-StartOffset. In some embodiments, the SFN represents the SFN number of the cDRX group. In some embodiments, SFN_OFFSET represents the SFN gap between this cDRX group and PCell. In some embodiments, the SFN number of the cDRX group can be derived from one specific serving cell in this cDRX group. In some embodiments, the 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.

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 starting timing of the first onDuration timer is related to a system frame number (SFN) offset between an SFN of the first subset of cells and a primary cell and a starting timing of the second onDuration timer is related to an SFN offset between an SFN of the second subset of cells and the primary cell.

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

In some embodiments, the wireless communication device (UE) sends an assistance information to another wireless communication device (NW). In some embodiments, the assistance information is to inform the NW with a cDRX configuration (e.g., the UE's favorite cDRX configuration). In some embodiments , this cDRX configuration is assistance information is for each cDRX group or PUCCH group. In some embodiments, the cDRX configuration in assistance information includes at least one of the following parameters: serving cell ID/serving cell ID list, PUCCH group Identifier, drx_ondurationTimer, drx_inactivityTimer, drx-HARX-RTT-TimerDL, drx-HARQ-RTT-TimerUL, drx-RetransmissionTimerDL, or drx-RetransmissionTimerUL.

<FIG> illustrates a flowchart diagram illustrating a method <NUM> of multiple discontinuous receptions for one cell group, in accordance with some embodiments of the present disclosure. Referring to <FIG>, the method <NUM> is performed by the UE <NUM> and/or the UE <NUM>, in some embodiments. Additional, fewer, or different operations may be performed in the method <NUM> depending on the embodiment.

A wireless communication device receives a first discontinuous reception (DRX) configuration corresponding to a first DRX group including a first subset of cells (e.g., a first cDRX group) in a cell group (<NUM>). The wireless communication device receives a second, different DRX configuration corresponding to a second DRX group including a second subset of cells (e.g., a second cDRX group) in the cell group (<NUM>). In some embodiments, the wireless communication devices receives the first DRX and/or the second DRX from a wireless communication node.

In some embodiments, the wireless communication device is currently using the 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. The first condition is identifying that either the first drx-Retransmission downlink timer is running or the second drx-Retransmission downlink timer is running. The second condition is identifying that either the first drx-Retransmission uplink timer is running or the second drx-Retransmission uplink timer is running. The third condition is identifying that a scheduling request, which is pending, has been sent in the first subset of cells. The fourth condition is identifying that a scheduling request, which is pending, has been sent in any of the first subset of cells and the second subset of cells.

Claim 1:
A wireless communication method, comprising:
receiving, by a wireless communication device, a first discontinuous reception, DRX, configuration corresponding to a first DRX group including a first subset of cells in a cell group, wherein the first DRX configuration includes 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 including a second subset of cells in the cell group, wherein the second DRX configuration includes a second drx-Inactivity timer; and
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 of the first subset of cells in the first DRX group and the second subset of cells in the second DRX group.