Patent Description:
<CIT> discloses discontinuous reception mechanisms for sidelink connections, in particular a SL DRX mechanism used for power savings.

3GPP document R2-<NUM> discusses the SL DRX operation in NR sidelink communication and V2X sidelink communication.

The invention is provided for Sidelink Discontinuous Reception (SL DRX) in a wireless communication system to avoid ambiguity on slot offset calculations on SL DRX. A method and a user equipment according to the invention are defined in the independent claims. The dependent claims define preferred embodiments thereof.

The invention described herein can be applied to or implemented in exemplary wireless communication systems and devices described below. In addition, the invention is described mainly in the context of the 3GPP architecture reference model. However, it is understood that with the disclosed information, one skilled in the art could easily adapt for use and implement aspects of the invention in a 3GPP2 network architecture as well as in other network architectures.

The exemplary wireless communication systems and devices described below employ a wireless communication system, supporting a broadcast service. Wireless communication systems are widely deployed to provide various types of communication such as voice, data, and so on. These systems may be based on code division multiple access (CDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), 3GPP LTE (Long Term Evolution) wireless access, 3GPP LTE-A (Long Term Evolution Advanced) wireless access, 3GPP2 UMB (Ultra Mobile Broadband), WiMax, 3GPP NR (New Radio), or some other modulation techniques.

In particular, the exemplary wireless communication systems and devices described below may be designed to support one or more standards such as the standard offered by a consortium named "3rd Generation Partnership Project" referred to herein as 3GPP, including: [<NUM>] 3GPP TS <NUM> V16. <NUM>; [<NUM>] 3GPP TS <NUM> V16. <NUM>; [<NUM>] 3GPP RAN2#<NUM>-e meeting report; [<NUM>] 3GPP RAN2#<NUM>-e meeting report; [<NUM>] Draft R2-<NUM> CR of TS <NUM> for Sidelink enhancement; [<NUM>] Draft R2-<NUM> RRC CR for NR Sidelink enhancement; and [<NUM>] 3GPP TS <NUM> V16. The standards and documents listed above are hereby expressly and fully incorporated herein by reference in their entirety.

<FIG> shows a multiple access wireless communication system according to one embodiment of the invention. An access network <NUM> (AN) includes multiple antenna groups, one including <NUM> and <NUM>, another including <NUM> and <NUM>, and an additional including <NUM> and <NUM>. In <FIG>, only two antennas are shown for each antenna group, however, more or fewer antennas may be utilized for each antenna group. Access terminal (AT) <NUM> is in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to access terminal <NUM> over forward link <NUM> and receive information from AT <NUM> over reverse link <NUM>. AT <NUM> is in communication with antennas <NUM> and <NUM>, where antennas <NUM> and <NUM> transmit information to AT <NUM> over forward link <NUM> and receive information from AT <NUM> over reverse link <NUM>. In a FDD system, communication links <NUM>, <NUM>, <NUM> and <NUM> may use different frequency for communication. For example, forward link <NUM> may use a different frequency than that used by reverse link <NUM>.

In communication over forward links <NUM> and <NUM>, the transmitting antennas of access network <NUM> may utilize beamforming in order to improve the signal-to-noise ratio of forward links for the different access terminals <NUM> and <NUM>. Also, an access network using beamforming to transmit to access terminals scattered randomly through its coverage normally causes less interference to access terminals in neighboring cells than an access network transmitting through a single antenna to all its access terminals.

The AN may be a fixed station or base station used for communicating with the terminals and may also be referred to as an access point, a Node B, a base station, an enhanced base station, an eNodeB, or some other terminology. The AT may also be called User Equipment (UE), a wireless communication device, terminal, access terminal or some other terminology.

<FIG> is a simplified block diagram of an embodiment of a transmitter system <NUM> (also known as the access network) and a receiver system <NUM> (also known as access terminal (AT) or user equipment (UE)) in a MIMO system <NUM>. At the transmitter system <NUM>, traffic data for a number of data streams is provided from a data source <NUM> to a transmit (TX) data processor <NUM>.

Preferably, each data stream is transmitted over a respective transmit antenna. TX data processor <NUM> formats, codes, and interleaves the traffic data for each data stream based on a particular coding scheme selected for that data stream to provide coded data.

The coded data for each data stream may be multiplexed with pilot data using OFDM techniques. The pilot data is typically a known data pattern that is processed in a known manner and may be used at the receiver system to estimate the channel response. The multiplexed pilot and coded data for each data stream is then modulated (e.g., symbol mapped) based on a particular modulation scheme (e.g., BPSK, QPSK, M-PSK, or M-QAM) selected for that data stream to provide modulation symbols. The data rate, coding, and modulation for each data stream may be determined by instructions performed by processor <NUM>. A memory <NUM> is coupled to processor <NUM>.

At receiver system <NUM>, the transmitted modulated signals are received by NR antennas 252a through 252r and the received signal from each antenna <NUM> is provided to a respective receiver (RCVR) 254a through 254r. Each receiver <NUM> conditions (e.g., filters, amplifies, and downconverts) a respective received signal, digitizes the conditioned signal to provide samples, and further processes the samples to provide a corresponding "received" symbol stream.

Memory <NUM> may be used to temporarily store some buffered/computational data from <NUM> or <NUM> through Processor <NUM>, store some buffed data from <NUM>, or store some specific program codes. And Memory <NUM> may be used to temporarily store some buffered/computational data from <NUM> through Processor <NUM>, store some buffed data from <NUM>, or store some specific program codes.

Turning to <FIG>, this figure shows an alternative simplified functional block diagram of a communication device according to one embodiment of the invention. As shown in <FIG>, the communication device <NUM> in a wireless communication system can be utilized for realizing the UEs (or ATs) <NUM> and <NUM> in <FIG>, and the wireless communications system is preferably the NR system. The communication device <NUM> may include an input device <NUM>, an output device <NUM>, a control circuit <NUM>, a central processing unit (CPU) <NUM>, a memory <NUM>, a program code <NUM>, and a transceiver <NUM>. The control circuit <NUM> executes the program code <NUM> in the memory <NUM> through the CPU <NUM>, thereby controlling an operation of the communications device <NUM>. The communications device <NUM> can receive signals input by a user through the input device <NUM>, such as a keyboard or keypad, and can output images and sounds through the output device <NUM>, such as a monitor or speakers. The transceiver <NUM> is used to receive and transmit wireless signals, delivering received signals to the control circuit <NUM>, and outputting signals generated by the control circuit <NUM> wirelessly.

<FIG> is a simplified block diagram of the program code <NUM> shown in <FIG> in accordance with an embodiment of the invention. In this embodiment, the program code <NUM> includes an application layer <NUM>, a Layer <NUM> portion <NUM>, and a Layer <NUM> portion <NUM>, and is coupled to a Layer <NUM> portion <NUM>. The Layer <NUM> portion <NUM> generally performs radio resource control. The Layer <NUM> portion <NUM> generally performs link control. The Layer <NUM> portion <NUM> generally performs physical connections.

For LTE, LTE-A, or NR systems, the Layer <NUM> portion <NUM> may include a Radio Link Control (RLC) layer and a Medium Access Control (MAC) layer. The Layer <NUM> portion <NUM> may include a Radio Resource Control (RRC) layer.

Any two or more than two of the following paragraphs, (sub-)bullets, points, actions, or claims described in each invention paragraph or section may be combined logically, reasonably, and properly to form a specific method.

Any sentence, paragraph, (sub-)bullet, point, action, or claim described in each of the following invention paragraphs or sections may be implemented independently and separately to form a specific method or apparatus. Dependency, e.g., "based on", "more specifically", "example", etc., in the following invention disclosure is just one possible embodiment which would not restrict the specific method or apparatus.

In 3GPP specification <NUM>([<NUM>] 3GPP TS <NUM> V16. <NUM>), discontinuous reception (DRX), and Sidelink communication are introduced:.

Uplink grant is either received dynamically on the PDCCH, in a Random Access Response, configured semi-persistently by RRC or determined to be associated with the PUSCH resource of MSGA as specified in clause <NUM>. The MAC entity shall have an uplink grant to transmit on the UL-SCH. To perform the requested transmissions, the MAC layer receives HARQ information from lower layers. An uplink grant addressed to CS-RNTI with NDI = <NUM> is considered as a configured uplink grant. An uplink grant addressed to CS-RNTI with NDI = <NUM> is considered as a dynamic uplink grant.

If the MAC entity has a C-RNTI, a Temporary C-RNTI, or CS-RNTI, the MAC entity shall for each PDCCH occasion and for each Serving Cell belonging to a TAG that has a running timeAlignmentTimer and for each grant received for this PDCCH occasion:.

For each Serving Cell and each configured uplink grant, if configured and activated, the MAC entity shall:.

For configured uplink grants neither configured with harq-ProcID-Offset2 nor with cg-Retransmission Timer, the HARQ Process ID associated with the first symbol of a UL transmission is derived from the following equation: <MAT>.

For configured uplink grants with harq-ProcID-Offset2, the HARQ Process ID associated with the first symbol of a UL transmission is derived from the following equation: <MAT> where CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot), and numberOfSlotsPerFrame and numberOfSymbolsPerSlot refer to the number of consecutive slots per frame and the number of consecutive symbols per slot, respectively as specified in TS <NUM> [<NUM>].

For configured uplink grants configured with cg-Retransmission Timer, the UE implementation selects an HARQ Process ID among the HARQ process IDs available for the configured grant configuration. For HARQ Process ID selection, the UE shall prioritize retransmissions before initial transmissions. The UE shall toggle the NDI in the CG-UCI for new transmissions and not toggle the NDI in the CG-UCI in retransmissions.

For the MAC entity configured with lch-basedPrioritization, priority of an uplink grant is determined by the highest priority among priorities of the logical channels that are multiplexed (i.e. the MAC PDU to transmit is already stored in the HARQ buffer) or have data available that can be multiplexed (i.e. the MAC PDU to transmit is not stored in the HARQ buffer) in the MAC PDU, according to the mapping restrictions as described in clause <NUM>. The priority of an uplink grant for which no data for logical channels is multiplexed or can be multiplexed in the MAC PDU is lower than either the priority of an uplink grant for which data for any logical channels is multiplexed or can be multiplexed in the MAC PDU or the priority of the logical channel triggering an SR.

For the MAC entity configured with lch-basedPrioritization, if the corresponding PUSCH transmission of a configured uplink grant is cancelled by CI-RNTI as specified in clause <NUM>. 2A of TS <NUM> [<NUM>] or cancelled by a high PHY-priority PUCCH transmission as specified in clause <NUM> of TS <NUM> [<NUM>], this configured uplink grant is considered as a de-prioritized uplink grant. If this deprioritized uplink grant is configured with autonomousTx, the configuredGrantTimer for the corresponding HARQ process of this de-prioritized uplink grant shall be stopped if it is running.

When the MAC entity is configured with lch-basedPrioritization, for each uplink grant delivered to the HARQ entity and whose associated PUSCH can be transmitted by lower layers, the MAC entity shall:.

NOTE <NUM>: If the MAC entity is configured with lch-basedPrioritization and if there is overlapping PUSCH duration of at least two configured uplink grants whose priorities are equal, the prioritized uplink grant is determined by UE implementation.

NOTE <NUM>: If the MAC entity is not configured with lch-basedPrioritization and if there is overlapping PUSCH duration of at least two configured uplink grants, it is up to UE implementation to choose one of the configured uplink grants.

NOTE <NUM>: If the MAC entity is configured with lch-basedPrioritization, the MAC entity does not take UCI multiplexing according to the procedure specified in TS <NUM> [<NUM>] into account when determining whether the PUSCH duration of an uplink grant overlaps with the PUCCH resource for an SR transmission.

The MAC entity includes a HARQ entity for each Serving Cell with configured uplink (including the case when it is configured with supplementaryUplink), which maintains a number of parallel HARQ processes.

The number of parallel UL HARQ processes per HARQ entity is specified in TS <NUM> [<NUM>].

Each HARQ process is associated with a HARQ process identifier. For UL transmission with UL grant in RA Response or for UL transmission for MSGA payload, HARQ process identifier <NUM> is used. NOTE: When a single DCI is used to schedule multiple PUSCH, the UE is allowed to map generated TB(s) internally to different HARQ processes in case of LBT failure(s), i.e. UE may transmit a new TB on any HARQ process in the grants that have the same TBS, the same RV and the NDIs indicate new transmission.

The maximum number of transmissions of a TB within a bundle of the dynamic grant or configured grant is given by REPETITION NUMBER as follows:.

If REPETITION_NUMBER > <NUM>, after the first transmission within a bundle, at most REPETITION_NUMBER - <NUM> HARQ retransmissions follow within the bundle. For both dynamic grant and configured uplink grant, bundling operation relies on the HARQ entity for invoking the same HARQ process for each transmission that is part of the same bundle. Within a bundle, HARQ retransmissions are triggered without waiting for feedback from previous transmission according to REPETITION NUMBER for a dynamic grant or configured uplink grant unless they are terminated as specified in clause <NUM> of TS <NUM> [<NUM>]. Each transmission within a bundle is a separate uplink grant delivered to the HARQ entity.

For each transmission within a bundle of the dynamic grant, the sequence of redundancy versions is determined according to clause <NUM>. <NUM> of TS <NUM> [<NUM>]. For each transmission within a bundle of the configured uplink grant, the sequence of redundancy versions is determined according to clause <NUM>. <NUM> of TS <NUM> [<NUM>].

For each uplink grant, the HARQ entity shall:.

When determining if NDI has been toggled compared to the value in the previous transmission the MAC entity shall ignore NDI received in all uplink grants on PDCCH for its Temporary C-RNTI.

When configuredGrantTimer or cg-RetransmissionTimer is started or restarted by a PUSCH transmission, it shall be started at the beginning of the first symbol of the PUSCH transmission.

Each HARQ process is associated with a HARQ buffer.

New transmissions are performed on the resource and with the MCS indicated on PDCCH or indicated in the Random Access Response (i.e. MAC RAR or fallbackRAR), or signalled in RRC or determined as specified in clause <NUM>. 2a for MSGA payload. Retransmissions are performed on the resource and, if provided, with the MCS indicated on PDCCH, or on the same resource and with the same MCS as was used for last made transmission attempt within a bundle, or on stored configured uplink grant resources and stored MCS when cg-Retransmission Timer is configured. If cg-RetransmissionTimer is configured, retransmissions with the same HARQ process may be performed on any configured grant configuration if the configured grant configurations have the same TBS.

When cg-RetransmissionTimer is configured and the HARQ entity obtains a MAC PDU to transmit and LBT failure indication is received from lower layer, the corresponding HARQ process is considered to be pending. For a configured uplink grant, configured with cg-Retransmission Timer, each associated HARQ process is considered as not pending when:.

If the HARQ entity requests a new transmission for a TB, the HARQ process shall:.

If the HARQ entity requests a retransmission for a TB, the HARQ process shall:.

To generate a transmission for a TB, the HARQ process shall:.

If a HARQ process receives downlink feedback information, the HARQ process shall:.

If the configuredGrantTimer expires for a HARQ process, the HARQ process shall:.

The transmission of the MAC PDU is prioritized over sidelink transmission or can be performed simultaneously with sidelink transmission if one of the following conditions is met:.

The MAC entity may be configured by RRC with a DRX functionality that controls the UE's PDCCH monitoring activity 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 shall also monitor PDCCH according to requirements found in other clauses of this specification. When in RRC _CONNECTED, if DRX is configured, for all the activated Serving Cells, the MAC entity may monitor the PDCCH discontinuously using the DRX operation specified in this clause; otherwise the MAC entity shall monitor the PDCCH as specified in TS <NUM> [<NUM>]. NOTE <NUM>: If Sidelink resource allocation mode <NUM> is configured by RRC, a DRX functionality is not configured. RRC controls DRX operation by configuring the following parameters:.

Serving Cells of a MAC entity may be configured by RRC in two DRX groups with separate DRX parameters. When RRC does not configure a secondary DRX group, there is only one DRX group and all Serving Cells belong to that one DRX group. When two DRX groups are configured, each Serving Cell is uniquely assigned to either of the two groups. The DRX parameters that are separately configured for each DRX group are: drx-onDurationTimer, drx-InactivityTimer. The DRX parameters that are common to the DRX groups are: drx-SlotOffset, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-LongCycleStartOffset, drx-ShortCycle (optional), drx-ShortCycleTimer (optional), drx-HARQ-RTT-TimerDL, and drx-HARQ-RTT-TimerUL.

When DRX is configured, the Active Time for Serving Cells in a DRX group includes the time while:.

When DRX is configured, the MAC entity shall:.

NOTE <NUM>: In case of unaligned SFN across carriers in a cell group, the SFN of the SpCell is used to calculate the DRX duration.

NOTE <NUM>: When HARQ feedback is postponed by PDSCH-to-HARQ_feedback timing indicating a non-numerical k1 value, as specified in TS <NUM> [<NUM>], the corresponding transmission opportunity to send the DL HARQ feedback is indicated in a later PDCCH requesting the HARQ-ACK feedback.

NOTE 3a: A PDCCH indicating activation of SPS or configured grant type <NUM> is considered to indicate a new transmission.

NOTE <NUM>: If a UE multiplexes a CSI configured on PUCCH with other overlapping UCI(s) according to the procedure specified in TS <NUM> [<NUM>] clause <NUM>. <NUM> and this CSI multiplexed with other UCI(s) would be reported on a PUCCH resource either outside DRX Active Time of the DRX group in which this PUCCH is configured or outside the on-duration period of the DRX group in which this PUCCH is configured if CSI masking is setup by upper layers, it is up to UE implementation whether to report this CSI multiplexed with other UCI(s).

Regardless of whether the MAC entity is monitoring PDCCH or not on the Serving Cells in a DRX group, the MAC entity transmits HARQ feedback, aperiodic CSI on PUSCH, and aperiodic SRS defined in TS <NUM> [<NUM>] on the Serving Cells in the DRX group when such is expected.

The MAC entity needs not to monitor the PDCCH if it is not a complete PDCCH occasion (e.g. the Active Time starts or ends in the middle of a PDCCH occasion).

Sidelink grant is received dynamically on the PDCCH, configured semi-persistently by RRC or autonomously selected by the MAC entity. The MAC entity shall have a sidelink grant on an active SL BWP to determine a set of PSCCH duration(s) in which transmission of SCI occurs and a set of PSSCH duration(s) in which transmission of SL-SCH associated with the SCI occurs. A sidelink grant addressed to SLCS-RNTI with NDI = <NUM> is considered as a dynamic sidelink grant.

If the MAC entity has been configured with Sidelink resource allocation mode <NUM> as indicated in TS <NUM> [<NUM>], the MAC entity shall for each PDCCH occasion and for each grant received for this PDCCH occasion:.

If the MAC entity has been configured with Sidelink resource allocation mode <NUM> to transmit using pool(s) of resources in a carrier as indicated in TS <NUM> [<NUM>] or TS <NUM> [<NUM>] based on sensing or random selection, the MAC entity shall for each Sidelink process:.

For a selected sidelink grant, the minimum time gap between any two selected resources comprises:.

NOTE: How to determine the time required for PSFCH reception and processing plus sidelink retransmission preparation is left to UE implementation.

The MAC entity shall for each PSSCH duration:.

NOTE 4a: MCS table selection is up to UE implementation if more than one MCS table is configured.

NOTE <NUM>: MCS selection is up to UE implementation if the MCS or the corresponding range is not configured by RRC.

For configured sidelink grants, the HARQ Process ID associated with the first slot of a SL transmission is derived from the following equation:.

where CURRENT_slot refers to current logical slot in the associated resource pool, and PeriodicitySL is defined in clause <NUM>.

If the TX resource (re-)selection check procedure is triggered on the selected pool of resources for a Sidelink process according to clause <NUM>. <NUM>, the MAC entity shall for the Sidelink process:.

NOTE <NUM>: If the selected sidelink grant cannot accommodate the RLC SDU, it is left for UE implementation whether to perform segmentation or sidelink resource reselection.

NOTE <NUM>: If the remaining PDB is not met, it is left for UE implementation whether to perform transmission(s) corresponding to single MAC PDU or sidelink resource reselection.

NOTE <NUM>: It is left for UE implementation whether to trigger the TX resource (re-)selection due to the latency requirement of the MAC CE triggered according to clause <NUM>.

A resource(s) of the selected sidelink grant for a MAC PDU to transmit from multiplexing and assembly entity is reevaluated by physical layer at T<NUM> before the slot where the SCI indicating the resource(s) is signalled at first time as specified in clause <NUM>. <NUM> of TS <NUM> [<NUM>].

A resource(s) of the selected sidelink grant which has been indicated by a prior SCI for a MAC PDU to transmit from multiplexing and assembly entity could be checked for pre-emption by physical layer at T<NUM> before the slot where the resource(s) is located as specified in clause <NUM>. <NUM> of TS <NUM> [<NUM>].

NOTE <NUM>: It is up to UE implementation to re-evaluate or pre-empt before 'm - T<NUM>' or after 'm - T<NUM>' but before 'm'. For re-evaluation, m is the slot where the SCI indicating the resource(s) is signalled at first time as specified in clause <NUM>. <NUM> of TS <NUM>. For pre-emption, m is the slot where the resource(s) is located as specified in clause <NUM>. <NUM> of TS <NUM>.

If the MAC entity has been configured with Sidelink resource allocation mode <NUM> to transmit using pool(s) of resources in a carrier as indicated in TS <NUM> [<NUM>] or TS <NUM> [<NUM>] based on sensing or random selection the MAC entity shall for each Sidelink process:.

NOTE <NUM>: If retransmission resource(s) cannot be selected by ensuring that the resource(s) can be indicated by the time resource assignment of a prior SCI, how to select the time and frequency resources for one or more transmission opportunities from the available resources is left for UE implementation by ensuring the minimum time gap between any two selected resources in case that PSFCH is configured for this pool of resources.

NOTE <NUM>: It is left for UE implementation to reselect any pre-selected but not reserved resource(s) other than the resource(s) indicated for pre-emption or re-evaluation by the physical layer during reselection triggered by re-evaluation or pre-emption indicated by the physical layer.

NOTE <NUM>: It is up to UE implementation whether to set the resource reservation interval in the re-selected resource to replace pre-empted resource.

NOTE <NUM>: It is up to UE implementation whether to trigger resource reselection due to deprioritization as specified in clause <NUM>. <NUM> of TS <NUM> [<NUM>], clause <NUM>. <NUM> of TS <NUM> [<NUM>] and clause <NUM>.

NOTE <NUM>: For the selected sidelink grant corresponds to transmissions of multiple MAC PDU, it is up to UE implementation whether to apply re-evaluation check to the resources in non-initial reservation period that have been signalled neither in the immediate last nor in the current period.

The MAC entity includes at most one Sidelink HARQ entity for transmission on SL-SCH, which maintains a number of parallel Sidelink processes.

The maximum number of transmitting Sidelink processes associated with the Sidelink HARQ Entity is <NUM>. A sidelink process may be configured for transmissions of multiple MAC PDUs. For transmissions of multiple MAC PDUs with Sidelink resource allocation mode <NUM>, the maximum number of transmitting Sidelink processes associated with the Sidelink HARQ Entity is <NUM>.

A delivered sidelink grant and its associated Sidelink transmission information are associated with a Sidelink process. Each Sidelink process supports one TB.

For each sidelink grant, the Sidelink HARQ Entity shall:.

The Sidelink process is associated with a HARQ buffer.

New transmissions and retransmissions are performed on the resource indicated in the sidelink grant as specified in clause <NUM>. <NUM> and with the MCS selected as specified in clause <NUM>. <NUM> of TS <NUM> [<NUM>] and clause <NUM>.

If the Sidelink process is configured to perform transmissions of multiple MAC PDUs with Sidelink resource allocation mode <NUM>, the process maintains a counter SL_RESOURCE_RESELECTION_COUNTER. For other configurations of the Sidelink process, this counter is not available.

Priority of a MAC PDU is determined by the highest priority of the logical channel(s) or a MAC CE in the MAC PDU.

If the Sidelink HARQ Entity requests a new transmission, the Sidelink process shall:.

If the Sidelink HARQ Entity requests a retransmission, the Sidelink process shall:.

To generate a transmission, the Sidelink process shall:.

NOTE <NUM>: If the number of HARQ retransmissions selected by the MAC entity has been reached, or if a positive acknowledgement to a transmission of the MAC PDU has been received, or if a negative-only acknowledgement was enabled in the SCI and no negative acknowledgement was received for the transmission of the MAC PDU, the MAC entity determines this transmission corresponds to the last transmission of the MAC PDU for Sidelink resource allocation mode <NUM>. How to determine the last transmission in other cases is up to UE implementation.

The transmission of the MAC PDU is prioritized over uplink transmissions of the MAC entity or the other MAC entity if the following conditions are met:.

NOTE <NUM>: If the MAC entity is not able to perform this sidelink transmission simultaneously with all uplink transmissions as specified in clause <NUM>. <NUM> of TS <NUM> [<NUM>] at the time of the transmission, and prioritization-related information is not available prior to the time of this sidelink transmission due to processing time restriction, it is up to UE implementation whether this sidelink transmission is performed.

The MAC entity shall for each PSSCH transmission:.

If sl-PUCCH Config is configured by RRC, the MAC entity shall for a PUCCH transmission occasion:.

The HARQ-based Sidelink RLF detection procedure is used to detect Sidelink RLF based on a number of consecutive DTX on PSFCH reception occasions for a PC5-RRC connection.

RRC configures the following parameter to control HARQ-based Sidelink RLF detection:.

The following UE variable is used for HARQ-based Sidelink RLF detection.

The Sidelink HARQ Entity shall (re-)initialize numConsecutiveDTX to zero for each PC5-RRC connection which has been established by upper layers, if any, upon establishment of the PC5-RRC connection or (re)configuration of sl-maxNumConsecutiveDTX.

The Sidelink HARQ Entity shall for each PSFCH reception occasion associated to the PSSCH transmission:.

For PDU(s) associated with one SCI, MAC shall consider only logical channels with the same Source Layer-<NUM> ID-Destination Layer-<NUM> ID pair for one of unicast, groupcast and broadcast which is associated with the pair. Multiple transmissions for different Sidelink processes are allowed to be independently performed in different PSSCH durations.

The sidelink Logical Channel Prioritization procedure is applied whenever a new transmission is performed.

RRC controls the scheduling of sidelink data by signalling for each logical channel:.

RRC additionally controls the LCP procedure by configuring mapping restrictions for each logical channel:.

The following UE variable is used for the Logical channel prioritization procedure:.

The MAC entity shall initialize SBj of the logical channel to zero when the logical channel is established.

For each logical channel j, the MAC entity shall:.

NOTE: The exact moment(s) when the UE updates SBj between LCP procedures is up to UE implementation, as long as SBj is up to date at the time when a grant is processed by LCP.

The MAC entity shall for each SCI corresponding to a new transmission:.

NOTE <NUM>: If multiple Destinations have the logical channels satisfying all conditions above with the same highest priority or if multiple Destinations have either the MAC CE and/or the logical channels satisfying all conditions above with the same priority as the MAC CE, which Destination is selected among them is up to UE implementation.

NOTE <NUM>: sl-HARQ-FeedbackEnabled is set to disabled for the transmission of a MAC PDU only carrying CSI reporting MAC CE.

The UE shall also follow the rules below during the SL scheduling procedures above:.

The MAC entity shall not generate a MAC PDU for the HARQ entity if the following conditions are satisfied:.

Logical channels shall be prioritised in accordance with the following order (highest priority listed first):.

The MAC entity shall multiplex a MAC CE and MAC SDUs in a MAC PDU according to clauses <NUM>. <NUM> and <NUM>.

SCI indicate if there is a transmission on SL-SCH and provide the relevant HARQ information. A SCI consists of two parts: the <NUM>st stage SCI on PSCCH and the <NUM>nd stage SCI on PSSCH as specified in clause <NUM> of TS <NUM> [<NUM>].

There is at most one Sidelink HARQ Entity at the MAC entity for reception of the SL-SCH, which maintains a number of parallel Sidelink processes.

Each Sidelink process is associated with SCI in which the MAC entity is interested. This interest is determined by the Sidelink identification information of the SCI. The Sidelink HARQ Entity directs Sidelink transmission information and associated TBs received on the SL-SCH to the corresponding Sidelink processes.

The number of Receiving Sidelink processes associated with the Sidelink HARQ Entity is defined in TS <NUM> [<NUM>].

For each PSSCH duration, the Sidelink HARQ Entity shall:.

NOTE <NUM>: When a new TB arrives, the Sidelink HARQ Entity allocates the TB to any unoccupied Sidelink process. If there is no unoccupied Sidelink process in the Sidelink HARQ entity, how to manage receiving Sidelink processes is up to UE implementation.

NOTE 1a: If the NDI has not been toggled compared to the value of the previous received transmission corresponding to the Sidelink identification information and the Sidelink process ID of the SCI, and if there is no Sidelink process associated with the Sidelink identification information and the Sidelink process ID of the SCI, it is up to UE implementation to handle the corresponding TB.

NOTE <NUM>: A single sidelink process can only be (re-)associated to a single combination of Sidelink identification information and Sidelink process ID at a time and a single combination of Sidelink identification information and Sidelink process ID can only be (re-)associated to a single sidelink process at a time.

For each PSSCH duration where a transmission takes place for the Sidelink process, one TB and the associated HARQ information is received from the Sidelink HARQ Entity.

For each received TB and associated Sidelink transmission information, the Sidelink process shall:.

In 3GPP <NUM>([<NUM>] 3GPP TS <NUM> V16. <NUM>), slot offset for Uu DRX is introduced.

The IE DRX-Config is used to configure DRX related parameters. <IMG>
<IMG>.

In 3GPP RAN2#<NUM> meeting ([<NUM>] 3GPP RAN2#<NUM>-e meeting report), calculation for slot offset and start offset is discussed:.

In RAN2#<NUM>-e meeting ([<NUM>] 3GPP RAN2#<NUM>-e meeting report), start offset calculation is agreed:.

In MAC CR for introducing SL DRX ([<NUM>] Draft R2-<NUM> CR of TS <NUM> for Sidelink enhancement), slot offset and start offset for broadcast and group cast is calculated:.

When SL DRX is configured, the Active Time includes the time while:.

When one or multiple SL DRX is configured, the MAC entity shall:.

When the cast type is groupcast or broadcast as indicated by upper layer, the sl-drx-StartOffset and sl-drx-SlotOffset are derived from the following equations:.

NOTE : The sl-drx-HARQ-RTT-Timer is derived from the retransmission resource timing (i.e., immediately next retransmission resource indicated in a SCI) when a SCI indicates a retransmission resource. The UE uses the sl-drx-HARQ-RTT-Timer is configured as specified in TS <NUM> [<NUM>] when a SCI doesn't indicate a retransmission resource.

In RRC CR of SL DRX ([<NUM>] Draft R2-<NUM> RRC CR for NR Sidelink enhancement), Sidelink DRX configuration is introduced:.

The IE SL-DRX-Config-GC-BC is used to configure DRX related parameters for NR sidelink groupcast and broadcast communication. <IMG>
<IMG>.

In [<NUM>] 3GPP TS <NUM> V16. <NUM>, paragraphs related to a number of slots within one subframe or <NUM> milliseconds are quoted below.

Throughout this specification, unless otherwise noted, the size of various fields in the time domain is expressed in time units Tc = <NUM>/(Δfmax · Nf) where Δfmax = <NUM> · <NUM><NUM> Hz and Nf = <NUM>. The constant κ = Ts/Tc = <NUM> where Ts = <NUM>/(Δfref · Nf,ref), Δfref = <NUM>·<NUM><NUM> Hz and Nf,ref = <NUM>.

Throughout this specification, unless otherwise noted, statements using the term "UE" in clauses <NUM>, <NUM>, <NUM>, or <NUM> are equally applicable to the IAB-MT part of an IAB-node.

Multiple OFDM numerologies are supported as given by Table <NUM>-<NUM> where µ and the cyclic prefix for a downlink or uplink bandwidth part are obtained from the higher-layer parameters subcarrierSpacing and cyclicPrefix, respectively.

Downlink, uplink, and sidelink transmissions are organized into frames with Tf = (ΔfmaxNf/<NUM>)·Tc = <NUM> duration, each consisting of ten subframes of Tsf = (ΔfmaxNf/<NUM>)·Tc = <NUM> duration. The number of consecutive OFDM symbols per subframe is <MAT>. Each frame is divided into two equally-sized half-frames of five subframes each with half-frame <NUM> consisting of subframes <NUM> - <NUM> and half-frame <NUM> consisting of subframes <NUM> - <NUM>.

There is one set of frames in the uplink and one set of frames in the downlink on a carrier.

Uplink frame number i for transmission from the UE shall start TTA = (NTA + NTA,offset)Tc before the start of the corresponding downlink frame at the UE where NTA,offset is given by [<NUM>, TS <NUM>], except for msgA transmission on PUSCH where NTA = <NUM> shall be used.

For subcarrier spacing configuration µ, slots are numbered <MAT> in increasing order within a subframe and <MAT> in increasing order within a frame. There are <MAT> consecutive OFDM symbols in a slot where <MAT> depends on the cyclic prefix as given by Tables <NUM>. <NUM>-<NUM> and <NUM>. <NUM>-<NUM>. The start of slot <MAT> in a subframe is aligned in time with the start of OFDM symbol <MAT> in the same subframe.

OFDM symbols in a slot in a downlink or uplink frame can be classified as 'downlink', 'flexible', or 'uplink'. Signaling of slot formats is described in clause <NUM> of [<NUM>, TS <NUM>].

In a slot in a downlink frame, the UE shall assume that downlink transmissions only occur in 'downlink' or 'flexible' symbols.

In a slot in an uplink frame, the UE shall only transmit in 'uplink' or 'flexible' symbols.

A UE not capable of full-duplex communication and not supporting simultaneous transmission and reception as defined by parameter simultaneousRxTxInterBandENDC, simultaneousRxTxInterBandCA or simultaneousRxTxSUL [<NUM>, TS <NUM>] among all cells within a group of cells is not expected to transmit in the uplink in one cell within the group of cells earlier than NRx-TxTc after the end of the last received downlink symbol in the same or different cell within the group of cells where NRx-Tx is given by Table <NUM>. <NUM>-<NUM>.

A UE not capable of full-duplex communication and not supporting simultaneous transmission and reception as defined by parameter simultaneousRxTxInterBandENDC, simultaneousRxTxInterBandCA or simultaneousRxTxSUL [<NUM>, TS <NUM>] among all cells within a group of cells is not expected to receive in the downlink in one cell within the group of cells earlier than NTx-RxTc after the end of the last transmitted uplink symbol in the same or different cell within the group of cells where NTx-Rx is given by Table <NUM>. <NUM>-<NUM>.

For DAPS handover operation, a UE not capable of full-duplex communication is not expected to transmit in the uplink to a cell earlier than NRx-TxTc after the end of the last received downlink symbol in the different cell where NRx-Tx is given by Table <NUM>. <NUM>-<NUM>.

For DAPS handover operation, a UE not capable of full-duplex communication is not expected to receive in the downlink from a cell earlier than NTx-RxTc after the end of the last transmitted uplink symbol in the different cell where NTx-Rx is given by Table <NUM>. <NUM>-<NUM>.

A UE not capable of full-duplex communication is not expected to transmit in the uplink earlier than NRx-TxTc after the end of the last received downlink symbol in the same cell where NRx-Tx is given by Table <NUM>. <NUM>-<NUM>.

A UE not capable of full-duplex communication is not expected to receive in the downlink earlier than NTx-RxTc after the end of the last transmitted uplink symbol in the same cell where NTx-Rx is given by Table <NUM>. <NUM>-<NUM>.

In New Radio (NR), a Sidelink (SL) User Equipment (UE) could perform SL communication (e.g., unicast, groupcast, and/or broadcast) with one or more other UEs. In Release <NUM> NR, SL Discontinuous reception (DRX) is introduced. A receiver (Rx) UE could monitor Physical Sidelink Control Channel (PSCCH) and/or Sidelink Control Information (SCI) discontinuously based on sidelink DRX configuration. The sidelink DRX configuration could be configured by a network or provided/configured by a transmitter (Tx) UE. In groupcast and broadcast, the drx start offset and drx slot offset is calculated by the Rx UE via at least destination Identity (ID) (e.g., Destination Layer-<NUM> ID associated with the groupcast group or the broadcast/groupcast transmission). According to MAC CR (e.g., [<NUM>] Draft R2-<NUM> CR of TS <NUM> for Sidelink enhancement), the start offset is calculated via: <MAT>.

And the slot offset is calculated via: <MAT>.

Wherein the slot offset (e.g., sl-drx-SlotOffset) is derived from modulus of destination ID divided by on-duration timer (length) (in the unit of milliseconds). Based on the calculation, one issue could occur when the derived slot offset, based on modulus of destination ID divided by on-duration timer (length), may not align to the slot boundary. One example is shown in <FIG>. For a sidelink bandwidth part (BWP) or carrier configured with <NUM> slots in one millisecond/subframe (e.g., subcarrier spacing configuration u=<NUM>, or subcarrier spacing is configured as <NUM>), when sl-drx-onDurationTimer is <NUM> (in unit of <NUM>/<NUM>) and destination layer-<NUM> ID is <NUM>, the derived slot offset is <NUM> (in unit of <NUM>/<NUM>) and does not align with the slot boundary, which could lead to ambiguity on UE behaviour regarding which slot to start DRX timers. For the sidelink BWP or carrier configured with <NUM> slots in one millisecond/subframe, slot offset to align with the slot boundary may be <NUM>, <NUM>, <NUM>, <NUM> (in unit of <NUM>/<NUM>). Another issue could occur when the derived slot offset is larger than <NUM>. For example, when sl-drx-onDurationTimer is <NUM> and Destination Layer-<NUM> ID is <NUM>, the derived slot offset is <NUM>, which is beyond the millisecond boundary and defies the function of slot offset. The UE may not start the DRX timers without waiting for a long period of time, which could lead to poor performance of DRX operation on sidelink.

One concept of the invention is that a UE could determine or derive a slot offset for a SL communication based on a destination ID (e.g., Destination Layer-<NUM> ID) of the SL communication and number of slots in one millisecond/subframe. For example, the slot offset could be modulus of the destination ID divided by the number of slots in one millisecond/subframe or in one frame (e.g., numberOfSlotsPerFrame). The number of slots could be number of consecutive slots per frame/subframe. <MAT> <MAT> <MAT>.

Preferably, the number of slots in one millisecond/subframe may be determined or derived based on following table in TS <NUM>, wherein u is based on subcarrier spacing configuration.

Additionally and/or alternatively, the slot offset could be derived based on modulus of the destination ID divided by a predefined number (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>,. The pre-defined number could be specified, (pre-)configured, or provided by a network or Tx UE.

Additionally and/or alternatively, the slot offset could be derived based on modulus of the destination ID divided by a predefined number (e.g., <NUM>) or on-duration timer (length). The slot offset could be the modulus rounded up or down to (the closet) slot boundary or to a specific slot boundary. An example is shown in <FIG>. The carrier or the bandwidth part is configured with <NUM> slots in one millisecond. When the on-duration timer (length) is <NUM> (<NUM>/<NUM>), and destination Layer-<NUM> ID is <NUM>, the modulus of the destination Layer-<NUM> ID divided by the on-duration timer is <NUM> (<NUM>/<NUM>). The UE could derive slot offset by rounding down (e.g., floor function) to the nearest slot boundary less than or equal to the modulus, wherein in this example, the starting boundary of the <NUM>nd slot (e.g., <NUM>/<NUM>). Alternatively, the UE could derive slot offset by rounding up (e.g., ceiling function) to the nearest slot boundary larger than or equal to the modulus, wherein in this example, the starting boundary of the <NUM>rd slot (e.g., <NUM>/<NUM>). Alternatively, if the modulus of slot offset is not aligned to slot boundary, the UE could derive slot offset as the first slot after modulus of slot offset, wherein in this example, the <NUM>rd slot boundary. <MAT> <MAT>.

Additionally and/or alternatively, the UE may not round up/down the modulus to the nearest slot boundary for deriving the slot offset. The UE may not monitor Sidelink Control Information / Physical Sidelink Control Channel (SCI/PSCCH) if it is not a complete PSCCH occasion. For example, the UE may not monitor a PSCCH occasion in a (sidelink) slot if or when the slot offset is in the middle of the (sidelink) slot. The UE may not monitor SCI/PSCCH in one sidelink slot if the one sidelink slot is not completely in sidelink active time (e.g., the sidelink active time starts or ends in the middle of the one sidelink slot).

Additionally and/or alternatively, the slot offset could be derived based on modulus of the destination ID divided by on-duration timer (length) and also by a predefined number (e.g., <NUM>). It can induce that slot offset is smaller than <NUM> millisecond. Furthermore, the slot offset could be the modulus rounded up or down to (the closet) slot or subframe boundary or to a specific slot boundary. Alternatively, the UE may not round up/down the modulus to the nearest slot boundary for deriving the slot offset.

An example is shown in <FIG>. The sl-drx-onDurationTimer is <NUM> and the Destination ID is <NUM>. The modulus of destination ID divided by sl-drx-onDurationTimer is <NUM>, which is beyond subframe boundary. The UE could derive a slot offset based on a second modulus of the modulus divided by <NUM>, which gives <NUM>/<NUM> in the unit of <NUM>/<NUM>.

Preferably, transformation from "slot" to "milliseconds" may be as follows: <MAT> <MAT> <MAT>.

Preferably, number of slots in one millisecond, or numberOfSlotsPerSubframe could be determined or derived based on subcarrier spacing or numerology of a SL BWP.

An example is shown in <FIG>. The number of slots per subframe (of a SL BWP) is <NUM>. For each Destination ID (for groupcast or broadcast), the UE could derive sl-drx-SlotOffset based on a remainder of the Destination ID divided by the number of slots per subframe (<NUM> in this example), wherein the slot offset is the remainder divided by the number of slots per subframe (e.g., remainder = <NUM>, slot offset = <NUM>/<NUM>; remainder =<NUM>, slot offset = <NUM>/<NUM>).

Another example is shown in <FIG>. The number of slots per subframe (of a SL BWP) is <NUM>. For each Destination ID (for groupcast or broadcast), the UE could derive sl-drx-SlotOffset based on a remainder of the Destination ID divided by the number of slots per subframe (<NUM> in this example), wherein the slot offset is the remainder divided by the number of slots per subframe (e.g., remainder = <NUM>, slot offset = <NUM>/<NUM>; remainder =<NUM>, slot offset = <NUM>/<NUM>, remainder = <NUM>, slot offset = <NUM>/<NUM>, remainder = <NUM>, slot offset = <NUM>/<NUM>).

Preferably, for subcarrier spacing being as <NUM>*<NUM>µ kHz, number of slots in one millisecond is <NUM>µ.

Preferably,
µ = <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> according to numerology or subcarrier spacing of SL BWP.

Preferably, slot boundary is based on <MAT>, wherein i=<NUM>, <NUM>,. <NUM>µ - <NUM>.

Preferably, sl-drx-SlotOffset (ms) = { round down [Destination Layer-<NUM> ID modulo <NUM>] in unit of <MAT> (ms).

Preferably, sl-drx-SlotOffset (ms) = { round up [Destination Layer-<NUM> ID modulo <NUM>] in unit of <MAT> (ms).

For example, for SCS=<NUM>, and there are <NUM> slots in one subframe, if destination Layer-<NUM> ID=<NUM> (in unit of decimal value), sl-drx-SlotOffset (ms) = {<NUM> round down in unit of <MAT>. In this example, sl-drx-SlotOffset <MAT> (ms).

Preferably, for a sidelink group, a UE determines starting timing of on-duration timer based on a derived sl-drx-SlotOffset.

Preferably, the UE starts on-duration timer for monitoring (groupcast) sidelink transmission at least for the group based on at least a derived sl-drx-SlotOffset.

Preferably, for unicast sidelink DRX configuration, starting timing of on-duration timer is based on higher layer configuration (instead of derived based on destination ID).

Preferably, sl-drx-SlotOffset (ms) which is derived for a starting timing of on-duration timer shall be aligned with slot boundary (in unit of ms).

Preferably, sl-drx-SlotOffset (<NUM>/<NUM>) which is derived for a starting timing of on-duration timer shall be aligned with slot boundary (<NUM>/<NUM>).

Preferably, for unicast sidelink DRX configuration, candidate value of sl-drx-SlotOffset in higher layer configuration (e.g., via vehicle-to-everything (V2X) layer, network or Tx UE configuration) could be <NUM>, <NUM>, <NUM>, <NUM>,. <NUM> (in unit of <NUM>/<NUM>).

Preferably, for groupcast sidelink DRX, candidate value of sl-drx-SlotOffset shall be <MAT>, wherein i=<NUM>, <NUM>,. (<NUM>µ - <NUM>) (in unit of <NUM>/<NUM>).

Preferably, for groupcast sidelink DRX, for value(s) other than <MAT> in a set of value {<NUM>,<NUM>,. <NUM>}, wherein i=<NUM>, <NUM>,. (<NUM>µ - <NUM>), is not allowed to use or apply for sl-drx-SlotOffset.

For all concepts, embodiments, and examples above and herein:.

All concepts, embodiments and examples above can be merged into new concepts and/or new concept combinations.

Referring to <FIG>, with this and other concepts, systems, and methods of the present invention, a method <NUM> for a UE in a wireless communication system comprises performing a SL communication associated with a destination ID (step <NUM>) and deriving a slot offset associated with the SL groupcast communication based on the destination ID and number of slots in a subframe (step <NUM>).

Preferably, the slot offset is derived via a modulus of the destination ID divided by the number of slots in a subframe.

Preferably, the number of slots in a subframe is configured by a network.

Preferably, the number of slots in a subframe is associated with a SL BWP.

Preferably, the slot offset is sl-drx-slotoffset.

Referring back to <FIG> and <FIG>, in one or more embodiments from the perspective of a UE, the device <NUM> includes a program code <NUM> stored in memory <NUM> of the transmitter. The CPU <NUM> could execute program code <NUM> to: (i) perform a SL communication associated with a destination ID; and (ii) derive a slot offset associated with the SL groupcast communication based on the destination ID and number of slots in a subframe. Moreover, the CPU <NUM> can execute the program code <NUM> to perform all of the described actions, steps, and methods described above, below, or otherwise herein.

Referring to <FIG>, with this and other concepts, systems, and methods of the present invention, a method <NUM> for a UE in a wireless communication system comprises performing a SL communication associated with a destination ID (step <NUM>) and deriving a slot offset associated with the SL groupcast communication based on the destination ID and a fixed number (step <NUM>).

Preferably, the slot offset is derived via a modulus of the destination ID divided by the fixed number.

Preferably, the fixed number is configured by a network.

Preferably, the fixed number is <NUM>, <NUM>, <NUM>,<NUM>, or <NUM>.

Preferably, the SL communication is a groupcast or broadcast.

Referring back to <FIG> and <FIG>, in one or more embodiments from the perspective of a UE, the device <NUM> includes a program code <NUM> stored in memory <NUM> of the transmitter. The CPU <NUM> could execute program code <NUM> to: (i) perform a SL communication associated with a destination ID; and (ii) derive a slot offset associated with the SL groupcast communication based on the destination ID and a fixed number. Moreover, the CPU <NUM> can execute the program code <NUM> to perform all of the described actions, steps, and methods described above, below, or otherwise herein.

Referring to <FIG>, with this and other concepts, systems, and methods of the present invention, a method <NUM> for a UE in a wireless communication system comprises performing a SL communication associated with a destination ID (step <NUM>), having or being configured with a SL DRX configuration associated with the SL communication, wherein the SL DRX configuration comprises at least an on-duration timer and a DRX cycle (step <NUM>), deriving a first offset associated with the SL communication based on the destination ID and the DRX cycle (step <NUM>), deriving a second offset associated with the SL communication based on the destination ID and a number of slots per subframe (step <NUM>), starting the on-duration timer after a time period determined based on the second offset from the beginning of a subframe, wherein the subframe is determined based on at least the first offset (step <NUM>), and monitoring SCI when the on-duration timer is running (step <NUM>).

Preferably, the second offset is derived by a first value divided by the number of slots per subframe, wherein the first value is a remainder of the destination ID divided by the number of slots per subframe.

Preferably, the first offset is a start offset or sl-drx-StartOffset.

Preferably, the second offset is a slot offset or sl-drx-SlotOffset.

Preferably, the SL DRX configuration comprises at least the on-duration timer means the SL DRX configuration comprising a time duration length of the on-duration timer, and/or the SL DRX configuration comprising at least the DRX cycle means the SL DRX configuration comprising a time duration length of the DRX cycle.

Preferably, the SL communication is groupcast communication or broadcast communication.

Preferably, the second offset is in units of milliseconds.

Preferably, the subframe satisfies a remainder of a number associated with the subframe divided by the DRX cycle equals the first offset, and/or the number associated with the subframe is equal to ((frame number of the subframe × <NUM>) + (a subframe number of the subframe)).

Preferably, the second offset is set to (the destination ID modulo the number of slots per subframe)/(the number of slots per subframe).

Preferably, the number of slots per subframe is a number of slots per subframe in a SL BWP, wherein the UE performs the SL communication in the SL BWP, and/or the number of slots per subframe is associated with a numerology or a subcarrier spacing of the SL BWP, and/or the number of slots per subframe is one of <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM>, based on the numerology or the subcarrier spacing of the SL BWP.

Referring back to <FIG> and <FIG>, in one or more embodiments from the perspective of a UE, the device <NUM> includes a program code <NUM> stored in memory <NUM> of the transmitter. The CPU <NUM> could execute program code <NUM> to: (i) perform a SL communication associated with a destination ID; (ii) be configured with or having a SL DRX configuration associated with the SL communication, wherein the SL DRX configuration comprises at least an on-duration timer and a DRX cycle; (iii) derive a first offset associated with the SL communication based on the destination ID and the DRX cycle; (iv) derive a second offset associated with the SL communication based on the destination ID and a number of slots per subframe; (v) start the on-duration timer after a time period determined based on the second offset from the beginning of a subframe, wherein the subframe is determined based on at least the first offset; and (vi) monitor SCI when the on-duration timer is running. Moreover, the CPU <NUM> can execute the program code <NUM> to perform all of the described actions, steps, and methods described above, below, or otherwise herein.

Any combination of the above concepts or teachings can be jointly combined or formed to a new embodiment. The disclosed details and embodiments can be used to solve at least (but not limited to) the issues mentioned above and herein.

It is noted that any of the methods, alternatives, steps, examples, and embodiments proposed herein may be applied independently, individually, and/or with multiple methods, alternatives, steps, examples, and embodiments combined together.

Various aspects of the disclosure have been described above. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative. Based on the teachings herein one skilled in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. As an example of some of the above concepts, in some aspects, concurrent channels may be established based on pulse repetition frequencies. In some aspects, concurrent channels may be established based on pulse position or offsets. In some aspects, concurrent channels may be established based on time hopping sequences. In some aspects, concurrent channels may be established based on pulse repetition frequencies, pulse positions or offsets, and time hopping sequences.

Those of ordinary skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques.

Those of ordinary skill in the art would further appreciate that the various illustrative logical blocks, modules, processors, means, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two, which may be designed using source coding or some other technique), various forms of program or design code incorporating instructions (which may be referred to herein, for convenience, as "software" or a "software module"), or combinations of both.

The steps of a method or algorithm described in connection 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. A software module (e.g., including executable instructions and related data) and other data may reside in a data memory such as 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 computer-readable storage medium known in the art. A sample storage medium may be coupled to a machine such as, for example, a computer/processor (which may be referred to herein, for convenience, as a "processor") such the processor can read information (e.g., code) from and write information to the storage medium. A sample storage medium may be integral to the processor. The ASIC may reside in user equipment. In the alternative, the processor and the storage medium may reside as discrete components in user equipment. Moreover, in some aspects, any suitable computer-program product may comprise a computer-readable medium comprising codes relating to one or more of the aspects of the disclosure. In some aspects, a computer program product may comprise packaging materials.

Claim 1:
A method for a User Equipment, in the following also referred to as UE, comprising:
performing a Sidelink, in the following also referred to as SL, communication associated with a destination Identity, in the following also referred to as ID, (<NUM>, <NUM>);
having, or being configured with, a SL Discontinuous Reception, in the following also referred to as DRX, configuration associated with the SL communication, wherein the SL DRX configuration comprises parameters for setting at least an on-duration timer and a DRX cycle (<NUM>);
deriving a first offset associated with the SL communication based on the destination ID and the DRX cycle (<NUM>);
deriving a second offset associated with the SL communication based on the destination ID and a number of slots per subframe (<NUM>, <NUM>);
starting the on-duration timer after a time period determined based on the second offset from the beginning of a subframe, wherein the subframe is determined based on at least the first offset (<NUM>); and
monitoring Sidelink Control Information, in the following also referred to as SCI, when the on-duration timer is running (<NUM>),
characterized in that:
the second offset is set to (the destination ID modulo the number of slots per subframe)/(the number of slots per subframe), or
the second offset is derived via a modulus of the destination ID divided by the number of slots per subframe, or
the second offset is derived by a first value divided by the number of slots per subframe, wherein the first value is a remainder of the destination ID divided by the number of slots per subframe.