Sidelink intermittent reception procedure

Abstract

This enables power saving, enhanced capabilities, and improvements for user devices (UEs) that communicate via sidelinks and operate in intermittent receive (DRX) mode. [Solution] In a wireless communication system, a UE operates in DRX mode and receives transmissions from one or more further UEs via a sidelink. When certain criteria are met, it enters an inactive mode or sleep mode. These criteria include receiving a transmission termination notice, which the UE receives from the further UE that performed the terminated transmission or from the group leader UE of the UE group to which the UE belongs. The termination of a transmission by a further UE is indicated by the further UE notifying the number of resources reserved for transmission using a Time Resource Index (TRIV) or Frequency Resource Index (FRIV), or by sidelink control information (SCI) such as a first-stage SCI or second-stage SCI.

Description

Technical Field

[0001] This application relates to the field of wireless communication systems or wireless communication networks, and more specifically, to discontinuous reception (DRX) on the sidelink (SL).

Background Art

[0002] Figure 1 is a schematic diagram of an example of a terrestrial radio network 100, including a core network 102 and one or more radio access networks RAN1, RAN2, ...RANN, as shown in Figure 1(a). Figure 1(b) is a schematic diagram of an example of a radio access network RANn, which may include one or more base stations gNB1 to gNB5. Each base station provides service to a specific area surrounding it, schematically represented by its respective cells 1061 to 1065. Base stations are provided to provide service to users within a cell. One or more base stations may provide service to users in licensed bands and / or unlicensed bands. The term base station (BS) refers to a gNB in ​​a 5G network, an eNB in ​​UMTS / LTE / LTE-A / LTE-A Pro, or simply a BS in other mobile communication standards. Users may be fixed devices or mobile devices. The wireless communication system may also be accessed by mobile or fixed IoT devices that connect to base stations or users. Mobile or fixed devices may include physical devices, ground vehicles such as robots or cars, aircraft such as manned or unmanned aerial vehicles (UAVs) (the latter also called drones), and buildings, as well as items or devices that incorporate electronics, software, sensors, or actuators, etc., and network connectivity that enables the device to collect and exchange data over existing network infrastructure. Figure 1(b) shows an exemplary diagram of five cells, but RANn may contain more or fewer such cells, and RANn may contain only one base station. Figure 1(b) shows two user UE1 and UE2, also called user devices or user equipment, located within cell 1062 and serviced by base station gNB2. Another user UE3 is shown in cell 1064, serviced by base station gNB4. Arrows 1081, 1082, and 1083 schematically represent the uplink / downlink connections for transmitting data from users UE1, UE2, and UE3 to base stations gNB2 and gNB4, or from base stations gNB2 and gNB4 to users UE1, UE2, and UE3.This can be implemented on a licensed or unlicensed band. Furthermore, Figure 1(b) shows two additional devices 1101 and 1102 within cell 1064, which may be fixed or mobile devices, e.g., IoT devices. Device 1101 accesses the wireless communication system via base station gNB4 and sends and receives data as schematically represented by arrow 1121. Device 1102 accesses the wireless communication system via user UE3, as schematically represented by arrow 1122.

[0003] Each base station gNB1 to gNB5 may be connected to the core network 102 via, for example, the S1 interface and their respective backhaul links 1141 to 1145. In Figure 1(b), the backhaul links are schematically represented by arrows pointing to the “core”. The core network 102 may be connected to one or more external networks. The external networks may be the internet, or private networks, such as an intranet or any other type of campus network, such as a private WiFi communication system or a 4G / 5G mobile communication system. Also, some or all of each base station gNB1 to gNB5 may be connected to each other via, for example, the S1 or X2 interface, or the XN interface in the NR, and their respective backhaul links 1161 to 1165, schematically represented in Figure 1(b) by arrows pointing to the “gNB”. Sidelink channels enable direct communication between UEs, also known as device-to-device (D2D) communication. The sidelink interface in 3GPP® is called PCS.

[0004] A physical resource grid may be used for data transmission. The physical resource grid may include a set of resource elements to which various physical channels and physical signals are mapped. For example, physical channels may include physical downlink, uplink, and sidelink shared channels PDSCH, PUSCH, PSSCH (also called downlink, uplink, and sidelink payload data) that carry user-specific data; physical broadcast channels PBCH that carry, for example, a master information block (MIB), one or more system information blocks (SIB), and one or more sidelink information blocks (SLIB) (if supported); physical downlink, uplink, and sidelink control channels PDCCH, PUCCH, PSSCH that carry, for example, downlink control information (DCI), uplink control information (UCI), and sidelink control information (SCI); and a physical sidelink feedback channel PSFCH that carries PCS feedback responses. The sidelink interface may support two-stage SCI. This refers to a first control region (also called the first-stage SCI) that includes a portion of the SCI, and optionally a second control region (also called the second-stage SCI) that includes a second portion of the control information.

[0005] In the case of uplinks, the physical channel may further include a physical random access channel PRACH or RACH. This is used by the UE to access the network after the UE has acquired the MIB and SIB in synchronization. The physical signal may include a reference signal or symbol RS, and a synchronization signal, etc. The resource grid may include a frame or radio frame having a specific duration in the time domain and a given bandwidth in the frequency domain. A frame may have a specific number of subframes of a given length (e.g., 1 ms). Each subframe may contain one or more slots of 12 or 14 OFDM symbols, depending on the length of the cyclic prefix CP. A frame may have fewer OFDM symbols, for example, when utilizing a shortened transmit time interval sTTI, or a mini-slot / non-slot frame structure with only a small number of OFDM symbols.

[0006] The wireless communication system may be any single-tone or multi-carrier system using frequency division multiplexing, such as an OFDM (orthogonal frequency-division multiplexing) system, an OFDMA (orthogonal frequency-division multiple access) system, or any other IFFT (Inverse Fast Fourier Transform) based signal with or without a CP (Cyclic Prefix), such as DFT-s-OFDM (Discrete Fourier Transform-spread-OFDM). Other waveforms, such as non-orthogonal waveforms for multiple access, such as FBMC (filter-bank multicarrier), GFDM (generalized frequency division multiplexing), or UFMC (universal filtered multicarrier), may also be used. The wireless communication system may operate according to, for example, the LTE-Advanced Pro standard, or the 5G or NR (New Radio) standard, or the NR-U (New Radio Unlicensed) standard.

[0007] The wireless network or communication system shown in Figure 1 may be a heterogeneous network having different overlay networks (for example, each macrocell may have a macrocell network including macro base stations such as base stations gNB1 to gNB5, and small cell base stations such as femto base stations and pico base stations, which are not shown in Figure 1). In addition to the terrestrial wireless networks described above, there are also non-terrestrial wireless communication networks (NTN), such as transceivers operating in space, like satellites, and / or transceivers operating in the air, like unmanned aerial vehicle systems. Non-terrestrial wireless communication networks or systems may operate in the same manner as the terrestrial systems described above, with reference to Figure 1, for example, according to the LTE-AdvancedPro standard or 5G or NR (new radio) standard.

[0008] In mobile communication networks, for example, in networks like those described above with reference to Figure 1, such as LTE or 5G / NR networks, there may be UEs that communicate directly with each other via one or more sidelink SL channels, for example, using a PC5 / PC3 interface or WiFi Direct. Examples of UEs that communicate directly with each other via sidelinks may include vehicles communicating directly with other vehicles (V2V communication) or vehicles communicating with other entities in the wireless communication network, such as roadside RSUs, or roadside entities such as traffic lights, road signs, or pedestrians (V2X communication). Depending on the specific network configuration, an RSU may have the functionality of a BS or UE. Other UEs may be UEs unrelated to vehicles and may include any of the above devices. Such devices may also communicate directly with each other using SL channels (D2D communication).

[0009] For example, consider two UEs communicating directly with each other via a sidelink using a PC5 / PC3 interface. One of the UEs may be connected to a BS and relay information from the BS to the other UE via the sidelink interface (and vice versa). The relay may be performed within the same frequency band (in-band relay) or using a different frequency band (out-of-band relay). In the first case, communication between the UEs and the sidelink can be separated using different time slots, as in a time-division duplex (TDD) system.

[0010] Figure 2 is a schematic diagram of an in-coverage scenario in which two UEs communicating directly with each other are connected to a base station. The base station gNB has a coverage area schematically represented by circle 200, which basically corresponds to the cells schematically represented in Figure 1. The UEs communicating directly with each other include a first vehicle 202 and a second vehicle 204, both of which reside within the coverage area 200 of the base station gNB. Both vehicles 202 and 204 are connected to the base station gNB, and furthermore, they are directly connected to each other via the PC5 interface. V2V traffic scheduling and / or interference management are assisted by the gNB through control notifications via the Uu interface, which is the radio interface between the base station and the UEs. In other words, the gNB provides the UEs with SL resource allocation settings or assistance, and the gNB also allocates the resources used for V2V communication over sidelinks. This setting is also called Mode 1 setting in NR V2X and Mode 3 setting in LTE V2X.

[0011] Figure 3 is a schematic diagram of an out-of-coverage scenario in which UEs communicating directly with each other may physically reside within a cell of the wireless communication network but are not connected to a base station, or some or all of the UEs communicating directly with each other are connected to a base station but the base station does not provide SL resource allocation settings or support. For example, three vehicles 206, 208, and 210 are shown communicating directly with each other via sidelinks using the PCS interface. V2V traffic scheduling and / or interference management are based on algorithms implemented between the vehicles. This configuration is also known as the Mode 2 configuration in NR V2X and the Mode 4 configuration in LTE V2X. As mentioned above, the out-of-coverage scenario in Figure 3 does not necessarily mean that the Mode 2 UE in NR or the Mode 4 UE in LTE are outside the base station's coverage 200, but rather that the Mode 2 UE in NR or the Mode 4 UE in LTE are not serviced by a base station, are not connected to a base station in the coverage area, or are connected to a base station but do not receive SL resource allocation settings or support from the base station. Therefore, within the coverage area 200 shown in Figure 2, in addition to UE2022 and 204 in NR mode 1 or LTE mode 3, there may also be UE206, 208, and 210 in NR mode 2 or LTE mode 4. Furthermore, Figure 3 schematically shows out-of-coverage UEs that use relays to communicate with the network. For example, UE210 can communicate with UE212 via a sidelink, and UE1 can connect to the gNB via the Uu interface. Thus, UE212 can relay information between the gNB and UE210.

[0012] While Figures 2 and 3 show vehicle UEs, please note that the in-coverage and out-of-coverage scenarios described also apply to non-vehicle UEs. In other words, any UE, such as a handheld device that communicates directly with another UE using an SL channel, can be both in-coverage and out-of-coverage. [Overview of the project]

[0013] In the wireless communication systems described above with reference to Figure 1, Figure 2, or Figure 3, the UE communicating via the sidelink may operate in intermittent receivable (DRX) mode.

[0014] Based on the conventional technologies described above, there may be a need to extend or improve UEs that communicate via sidelinks and operate in intermittent receivable (DRX) mode.

[0015] Embodiments of the present invention will be described in more detail below with reference to the drawings. [Brief explanation of the drawing]

[0016] [Figure 1] Figure 1 is a schematic diagram showing an example of a wireless communication system. [Figure 2] Figure 2 is a schematic diagram of an in-coverage scenario in which two UEs communicating directly with each other are connected to the same base station; [Figure 3] Figure 3 is a schematic diagram of an in-coverage scenario in which UEs communicate directly with each other. [Figure 4] Figure 4 shows the conventional DRX mode in a user device communicating with a base station. [Figure 5] Figure 5 is a schematic diagram of a wireless communication system including a transmitter such as a base station and one or more receivers such as user devices (UEs) that can operate according to embodiments of the present invention. [Figure 6] Figure 6 shows an embodiment of the extended ON duration after receiving a control message such as Sidelink Control Information (SCI) via the sidelink, and an early termination notification is issued after the message is received. [Figure 7] Figure 7 shows an embodiment in which the RX UE receives transmission and early termination notices from two TX UEs via a sidelink. [Figure 8]Figure 8 shows an embodiment of power saving by monitoring only the designated resources, Figure 8(a) shows an embodiment of extending the on-duration based on future resource reservations, and Figure 8(b) shows an embodiment of active time slots that are monitored based on future resource reservations. [Figure 9] Figure 9 shows an example of a computer system in which a unit or module relating to the method of the present invention and the steps of the method can operate. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described in more detail below with reference to the attached drawings. In the drawings, the same or similar elements are assigned the same reference numerals.

[0018] In wireless communication systems or networks as described above with reference to Figures 1, 2, or 3, sidelink communication between user devices, such as V2V (vehicle-to-vehicle communication), V2X (vehicle-to-anything communication), or any D2D (device-to-device communication) between any other user devices, as described above, can be implemented. However, in sidelink operations such as NR-Uu operation or PC5 operation, the UE is always on and monitors the control channel in every subframe to enable reception from the network or other UEs. Since the UE is always on even when there is no data to transmit or receive, power consumption in the UE increases. In vehicle use cases such as NR V2X, power saving may not be an issue because the vehicle UE (V-UE) is a device with sufficient power, such as the vehicle's onboard battery.

[0019] However, sidelink communication or sidelink PC5 operation is not limited to the operation of vehicle UEs, and other UEs with limited or finite power supply, such as ordinary user devices including a battery that needs to be charged regularly, may also communicate via sidelink. Such UEs may include so-called vulnerable road users (VUEs) such as pedestrian UEs (P-UEs), first responder devices for public safety, or IoT devices such as general-purpose IoT UEs and industrial IoT UEs. Since this type of UE is not always connected to a power source and depends on a battery, power saving is important.

[0020] To reduce power consumption in UEs in NR, discontinuous reception (DRX) is adopted in the Uu interface. For example, in the case of NR, further details of DRX operation are defined in 3GPP (registered trademark) TS 38.321. DRX is a mechanism in which a UE enters a sleep mode for a period and does not transmit or receive data during that time. The UE wakes up for another period during which data transmission and reception can occur. One important aspect of DRX is the synchronization between the UE and the network regarding the activation cycle and the sleep cycle, also called the DRX cycle. In the worst case, the network tries to transmit data to a UE in sleep mode, and when the UE wakes up, there is no data to receive. In the NR-Uu interface, this situation is prevented by maintaining a clearly defined agreement between the UE and the network or system regarding the sleep cycle and the activation cycle. In other words, by setting DRX for the UE by the gNB, DRX is synchronized with the gNB. The DRX cycle includes both on-time and off-time within a certain fixed time interval. In the case of the NR Uu interface, short DRX cycles and long DRX cycles are defined. The short DRX cycle spans a few symbols within a certain time slot, while the long DRX cycle may span an entire time slot or multiple time slots. The number of consecutive control messages after the successful decoding of a control message indicating a new transmission that causes the UE to become active can be specified by an inactivity timer using the following configuration. The timer is restarted when it receives a control message for a new transmission and / or other control messages directed to the UE (e.g., messages scrambled by a UE-specific RNTI or group-specific RNTI), or when it receives a corresponding signal from, for example, the group leader UE, base station, relay node, or roadside unit (RSU). When the timer expires, the UE will switch to DRX mode or off time.

[0021] Figure 4 shows the DRX mode using a non-activity timer. The DRX configuration defines a DRX cycle 250 over a specific period of time, including the on-time or period 252 at the start of the DRX cycle and the subsequent off-time or off-duration 254. In the Uu interface, the UE becomes active or starts during the on-time 252. Further, each time a transmission or a packet is received during the on-time, the timer, also called the non-activity timer, is started. In Figure 4, the reception of a data packet during the on-duration 252 of the DRX cycle starting at time t3 is shown at 256. For example, when DCI 256 is received by the UE on the PDCCH, the non-activity timer is started, adding the DRX active time 258, and the original on-duration 252 defined by the DRX configuration is extended from time t4 to t6. Thereby, the transmitter can transmit further data associated with DCI 256 on the PSCCH. If the transmitter does not intend to transmit any more data, the transmitter may send a DRX command to put the UE into the non-active mode or sleep mode. For example, at any point during the non-activity timer duration 258, the UE may receive a DRX command indicating that no further data is expected from the transmitter or that the transmitter will not transmit any more data. For example, if such a transmission end notification 260 is received at time t5 before the end point t6 of the non-activity timer duration 258, the UE can return to the sleep mode. Note that the transmission end notification 260 may also be received for transmissions that do not trigger the non-activity timer. Thereby, the normal on-duration 252 defined by the DRX communication may end before the set end point of that on-duration 252 in response to the notification 260.

[0022] Referring to Figure 4, the process described above—which, in response to the end-of-transmission notification 260, puts a UE operating in DRX mode into sleep or inactive mode, ending the on-duration 252 before the set end time, or ending the extended on-duration before the inactivity timer duration 258 ends—works well when the UE is communicating with the base station. This is because the base station is aware of all transmissions related to a particular UE, and based on this knowledge, it can make the 260 decision to inform the UE of the end of transmission if no further transmissions to the UE are scheduled. However, the situation is different when considering side-link communication.

[0023] A UE may communicate with multiple other sidelink UEs via a sidelink, and since these other UEs, when acting as transmitters, send unicast, groupcast, or broadcast messages, the UE may receive multiple transmissions from other sidelink UEs.

[0024] However, each transmitter (TX UE) cannot provide a transmit end notification or sleep command 260 as described above, with reference to Figure 4, because it is unaware of other ongoing communications on the receiving UE (RX UE). This is because putting the receiving UE into sleep mode would prevent the RX UE from receiving data or packets from other ongoing transmits from different transmitters. For example, sidelink unicast communication represents one-to-one communication between two UEs over a sidelink. Therefore, when a transmitter sends a transmit end or sleep command 260, the receiver may stop listening for further packets from this transmitter. However, since a receiver may have multiple ongoing communications, receiving a transmit end or sleep command 260 from one transmitter may not be synonymous with a sleep transition instruction, as is the case with transmissions over the Uu interface. This is because the receiver may still need to listen for ongoing transmits on other links. In the case of sidelink groupcast communication, multiple UEs within a group may transmit data, and since the UEs in the group that transmit or are transmitting data are unaware of other UEs communicating with the receiving UE, the Uu technique described with reference to Figure 4 cannot be applied. Therefore, the UE transmitting the groupcast cannot notify the receiving UE that no further data is expected and that the UE may enter sleep mode. This also applies to sidelink broadcast communication, where one transmitter provides communication to all sidelink UEs, and this transmitter, again, is unaware of whether the receiving UE has other ongoing communications on other links, and therefore may not be able to send a send-end command 260 in the manner described above with reference to Figure 4 and request the UE to return to sleep mode or sleep state.

[0025] To reduce power consumption even in UEs communicating via sidelinks using NR, DRX mode may be implemented on sidelinks as well. As described above with reference to Figures 2 and 3, UEs communicating via sidelinks may be within or outside the coverage area. If the UE is within coverage, a gNB that is aware of the DRX cycle will handle resource allocation for transmissions by the UE on the sidelink, even if it is operating via the sidelink in DRX mode. This is not possible if the UE is outside coverage, for example, if the UE is operating in mode 2. Therefore, a specific transmitter will not be able to notify a UE that is communicating with another UE via a sidelink and is operating in DRX mode to enter inactive or sleep mode.

[0026] Therefore, the known technique of the Uu interface, which involves putting the UE into sleep mode as soon as transmission is complete to improve power saving characteristics, cannot be applied to sidelink UEs, and the power saving potential of sidelink UEs operating in DRX mode may be more limited compared to UEs communicating via the Uu interface.

[0027] Embodiments of the present invention provide enhanced or improved power-saving potential or capabilities for UEs communicating via sidelinks and operating in intermittent receive (DRX) mode. Embodiments of the present invention can be implemented in a wireless communication system such as those shown in Figures 1, 2, or 3, which include a base station and a user (e.g., a mobile terminal or IoT device). Figure 5 is a schematic diagram of a wireless communication system including a transmitter 300, such as a base station, and one or more receivers 302, 304, such as user device UEs. The transmitter 300 and receivers 302, 304 can communicate via one or more wireless communication links or channels 306a, 306b, 308, such as radio links. The transmitter 300 has one or more antennas ANT TThe system may include an antenna array having the above antenna elements, a signal processor 300a, and a transceiver 300b, which are coupled to each other. Receivers 302, 304 have one or more antennas coupled to each other. UE The system includes an antenna array having the above antennas, signal processors 302a, 304a, and transceivers 302b, 304b. The base station 300 and UEs 302, 304 can communicate via their respective first radio communication links 306a and 306b (e.g., radio links using the Uu interface), while UEs 302, 304 can communicate with each other via a second radio communication link 308 (e.g., radio links using the PC5 or sidelink (SL) interface). If the UEs are not serviced by the base station or are not connected to the base station, for example, if neither is in an RRC connection state, or more generally, if SL resource allocation settings or support are not provided by the base station, the UEs can communicate with each other via the sidelink. The system or network of Figure 5, one or more UEs 302, 304 of Figure 5, and the base station 300 of Figure 5 can operate in accordance with the inventive teachings described herein.

[0028] Device [RX UE enters sleep mode / stops listening based on specific criteria.] SL RX UE The present invention provides a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, and each UE operating in intermittent receive (DRX) mode, entering an inactive or sleep mode when certain criteria are met.

[0029] According to the embodiment, the specific criteria include one or more of the following: • Receipt of transmission completion notification, • All transmissions announced by other UEs have been received. • Successful reception of a transmission for which further resources are reserved for future retransmission (e.g., early ACK) • No transmissions from other UEs are currently in progress. • No ongoing transmissions from the group leader UE or UE with a specific ID. • No ongoing transmission from base station or relay node. • Content of the received transmission, The number of times a specific transmission, such as a CAM (Cooperative Awareness Message), DENM (Decentralized Environmental Notification Message), or BSM (Basic Safety Message), was received (n times, n=2, 3, 4...). • The UE's battery status is below a set or pre-set threshold. • The UE is moving within a specific geographical location (e.g., a predefined zone or building). • The UE is moving or not moving.

[0030] According to one embodiment, the user device includes an inactive timer that specifies an inactive timer duration for which the UE remains active and monitors at least a control channel to detect transmissions. The UE starts the inactive timer when it receives a transmission from a first further UE.

[0031] According to the embodiment, the UE extends the inactive timer duration in response to receiving further transmissions by a first further UE and / or transmissions by a second further UE during the inactive timer duration, or in response to a signal from the group leader UE, or in response to a signal from a base station, relay node, or roadside unit (RSU). The UE enters inactive mode or sleep mode before reaching the end of the extended inactive timer duration if certain criteria are met, for example, in response to transmission termination notifications from both the first and second further UEs.

[0032] According to the embodiment, the UE enters an inactive mode or sleep mode in response to a transmission termination notification, and the UE receives a transmission termination notification from one or more of the following: • Further UEs to execute completed transmissions • Further UEs that have not completed the transmission, for example, the group leader UE of the UE group to which the UE belongs. • Relay node, • Roadside unit (RSU) or IoT device, • Access point for a wireless communication system (e.g., base station).

[0033] According to the embodiment, further termination of transmission notifications by the UE are indicated as follows: • Further UE termination notification (e.g., using DRX commands MAC (Medium Access Control), CE (Control Element)), or • Notification of the number of resources reserved for further transmission by the UE (e.g., using TRIV (time resource indicator value) or FRIV (frequency resource indicator value)), or • SCI (sidelink control information), for example, Stage 1 SCI or Stage 2 SCI, or ·AIM(assistance information message).

[0034] SL TX UE The present invention provides a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE transmitting one or more transmissions to one or more further UEs via a sidelink SL, each of which operates in intermittent receive DRX mode, and each UE indicating the end of one or more transmissions to the further UEs to allow them to enter an inactive or sleep mode.

[0035] According to the embodiment, the UE indicates the end of one or more transmissions to further UEs by: • Notification to further UEs that transmission has ended (for example, using DRX commands MAC (Medium Access Control), CE (Control Element)), or - Notification of the number of resources reserved for further transmission to UEs (e.g., using TRIV (time resource indicator value) or FRIV (frequency resource indicator value)), or • SCI (sidelink control information), for example, Stage 1 SCI or Stage 2 SCI, or ·AIM(assistance information message), • Buffer status report (e.g., showing the number of transmissions or the amount of data being sent to further UEs).

[0036] [Transmission restrictions during DRX-ON duration] The present invention provides a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE transmitting a plurality of transmissions to one or more further UEs via a sidelink SL, each of which operates in intermittent receive DRX mode, each of which includes at least an initial transmission, and the UE transmits the plurality of transmissions to the further UEs such that at least one or more of the initial transmissions fall within the on-duration of the DRX cycle of one or more of the further UEs.

[0037] According to the embodiment, one or more of the multiple transmissions include at least one further transmission following an initial transmission at a later point in time.

[0038] According to the embodiment, multiple transmissions are transmissions associated with a specific criterion.

[0039] According to the embodiment, the specific criteria include one or more of the following: • The priority is above a set or pre-set threshold. • The Quality of Service (QoS) requirements are above or above the set or pre-configured threshold, • Packet quotas (e.g., specific configured or pre-configured data rate thresholds), • Number of transmissions (e.g., the set or pre-configured minimum or maximum number of transmissions (e.g., CAM or DENM messages)), • The content of the message (for example, a specific CAM or a specific DENM).

[0040] [Setting the active time for the DRX cycle] SL RX UE The present invention provides a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, each UE operating in intermittent receive (DRX) mode, and during a DRX cycle, each UE is active for a specific active time, the specific active time depending on one or more criteria.

[0041] According to the embodiment, one or more criteria include one or more of the following: • One or more characteristics of the transmitted packet, • Logical channel used for transmission, • Logical channel group used for transmission, • Quality of Service (QoS) flow, • Quality of Service (QoS) requirements related to transmission, such as priority, latency, or data rate. • Geographic location or zone, Channel busy rate, UE type, • One or more resources used by the initial transmission and / or at least one further transmission, • The current battery status of the UE.

[0042] According to the embodiment, the UE receives DRX settings that define the DRX cycle and active time, and the UE may receive DRX settings from one or more of the following: • Further UEs to perform the transmission • Further UEs that have not performed the transmission, for example, the group leader UE of the UE group to which the UE belongs. • Relay node, • Roadside Unit (RSU), or IoT device • Access point for a wireless communication system (e.g., base station).

[0043] [Criteria for determining active hours] According to the embodiment, the active time is set, pre-set, or dynamic.

[0044] According to one embodiment, the UE has multiple on-durations configured or pre-configured for a DRX cycle, and the UE determines which on-duration to use according to one or more criteria.

[0045] According to one embodiment, the UE has one or more default on-durations set or pre-configured for a DRX cycle, and the UE extends the default on-durations based on preceding transmissions to achieve the extended on-duration.

[0046] According to one embodiment, in response to the termination of the transmission that caused the extended on-duration, the UE cancels the extension and returns to the default on-duration.

[0047] [Sparse / Intermittent Active Time] According to one embodiment, a transmission includes an initial transmission and at least one further transmission at a later point in time following the initial transmission, and in response to instructions for one or more resources reserved for use by at least one further transmission, the UE extends the active time to include at least one of the indicated resources.

[0048] According to the embodiment, the UE extends the active time by the following: • Extend the on-duration of the DRX cycle until the designated reserved resource is reached, and / or • Add only the designated reserved resources that should be monitored during the active time to the on-duration of the DRX cycle.

[0049] According to the embodiment, the UE enters an inactive mode or sleep mode between the on-duration and the instructed reserved resource.

[0050] According to the embodiment, one or more further transmissions are retransmissions of the initial transmission, and in response to successfully receiving the initial transmission within the on-duration, the UE optionally sends an acknowledgment or sidelink AIM (assistance information), then enters inactive or sleep mode, skipping monitoring of the instructed reserved resource.

[0051] According to the embodiment, one or more further transmissions are retransmissions of the initial transmission, and in response to not receiving a retransmission on a reserved resource outside of the on-duration period, the UE • Maintaining activity during a specific time interval after the time slot in which retransmission was expected, for example, during an inactive timer, or • Maintain active to receive n retransmissions (n ​​≤ maximum number of notified or pre-configured retransmissions), or - Enters inactive or sleep mode and is only activated for the next on-duration of the DRX cycle, or - Sending support information (e.g., AIM) with time and / or frequency information for retransmission to the transmitter, or • Send support information (e.g., AIM) containing information about additional on-duration to the transmitter.

[0052] According to one embodiment, in addition to reserved resources, the UE receives a resource reservation period indicating that the reserved resources will be used for further transmissions during the period following the reservation period, and in response to the resource reservation period indication, the UE extends the active time to include one or more indicated resources during the period following the reservation period.

[0053] According to one embodiment, in response to a resource reservation period having a specific duration, such as zero, indicating that the transmitter has selected another resource for transmission, the UE enters an inactive or sleep mode and wakes up only during the next on-duration of the DRX cycle.

[0054] According to one embodiment, one or more resources used by at least one further transmission are indicated in a control message received by the UE, for example, a sidelink information (SCI) message.

[0055] According to the embodiment, the SCI indicates, for example, a TRIV (time resource indicator value) format or a FRIV (format or a frequency resource indicator value) format to indicate a resource to be reserved within a certain number of future time slots, and optionally, the resource reservation period indicates that the reserved resource will be used for further transmissions during the period following the reservation period.

[0056] SL TX UE The present invention provides a user device UE for a wireless communication system. The wireless communication system includes a plurality of user device UEs, each UE communicating with one or more further UEs via a sidelink SL, each UE configuring one or more of the further UEs to operate in intermittent receive (DRX) mode, and each UE determining the DRX setting of the further UEs according to one or more criteria.

[0057] According to the embodiment, one or more criteria include one or more of the following: • One or more characteristics of the transmitted packet, • Logical channel used for transmission, • Logical channel group used for transmission, • Quality of Service (QoS) flow, • Quality of Service (QoS) requirements related to transmission, such as priority, latency, or data rate. • Geographic location or zone, • Other types of UE, • One or more resources used by the initial transmission and / or at least one further transmission, • The current battery status of the UE.

[0058] [Extend / Limit Active Time] The present invention provides a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, each UE operating in intermittent receive (DRX) mode, and being active for a specific active time (e.g., on-duration) during a DRX cycle, and each UE decoding or skipping decoding transmissions according to one or more criteria.

[0059] According to the embodiment, one or more criteria include priority, and / or destination, and / or a HARQ (Hybrid Automatic Repeat Request) indicator associated with the send, and / or a cast type associated with the send (e.g., unicast send, groupcast send, or broadcast send).

[0060] According to one embodiment, if the HARQ indicator associated with the transmission indicates that the transmitter is requesting feedback for the transmission, the UE decodes the transmission and sends the feedback.

[0061] According to the embodiment, the UE checks the priority field in the first stage SCI on the physical sidelink control channel PSCCH, and if the priority field indicates a priority below a certain priority threshold, it skips decoding of the associated physical sidelink shared channel PSSCH.

[0062] According to one embodiment, the UE checks the destination field in the second stage SCI on the physical sidelink shared channel PSSCH, and if the destination field indicates that the transmission is not destined for the UE or the UE group to which the UE belongs, it skips further decoding of the PSSCH.

[0063] According to one embodiment, the UE checks the cast type within the SCI, such as the first-stage SCI or the second-stage SCI, and skips further decoding of the PSSCH if the transmission is of a specific cast type.

[0064] According to one embodiment, the UE checks the source ID field in the second stage SCI on the physical sidelink shared channel PSSCH, and if the source ID field indicates that the transmission is not from the transmitter from which the UE is trying to receive communication, or that the transmission is not on the list of source IDs to be decoded, the UE skips further decoding of the PSSCH.

[0065] According to the embodiment, If decoding of the second stage SCI fails and the priority field of the first stage SCI indicates a priority above a certain threshold, the UE will, for example, become active to receive the retransmission by extending the active time until the retransmission is received, or become active with the resources indicated or reserved in the first stage SCI for the retransmission, If the decoding of the second stage SCI fails and the transmission is at a resource location previously reserved by a transmission to the UE, the UE will extend the active time until a retransmission or another transmission is received, or If a previously reserved resource does not include an expected transmission, the UE extends the active time until a retransmission or another transmission is received.

[0066] [Actions based on feedback] The present invention provides a user device UE for a wireless communication system, the wireless communication system comprising a plurality of user device UEs, each UE communicating with one or more further UEs via a sidelink SL, each of which operates in intermittent receive (DRX) mode, and each UE sending one or more HARQ-enabled transmissions to the further UEs during the on-duration of the further UEs' DRX cycles, and if no HARQ feedback is received, the UE refrains from sending HARQ-enabled transmissions until the next on-duration of the further UEs, and then sends a HARQ-enabled transmission during the next on-duration of the further UEs.

[0067] According to the embodiment, refraining from HARQ-enabled transmission includes one or more of the following: • Do not retransmit the current transport block TB. • Do not resend until the next on-duration period. • Restart the retransmission counter during the next on-duration period. • Use of the initial redundant version RV, • Reduce the number of retransmissions based on the total duration of online activity up to that point.

[0068] According to the embodiment, even after the default on-duration has elapsed, the UE retransmits a certain number of HARQ-enabled transmissions in response to not receiving HARQ feedback, the UE refrains from transmitting HARQ-enabled transmissions until the next on-duration of the UE, and transmits HARQ-enabled transmissions during the next on-duration of the UE.

[0069] system The present invention provides a wireless communication system comprising multiple ingenious user device UEs configured for sidelink communication (for example, using resources from a set of sidelink resources of a wireless communication system).

[0070] method [RX UE enters sleep mode / stops listening based on specific criteria.] SL RX UE The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system includes a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, and each UE operating in intermittent receive (DRX) mode, the method including entering an inactive mode or sleep mode when certain criteria are met.

[0071] SL TX UE The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, and the method includes transmitting one or more transmissions to one or more further UEs via a sidelink SL, wherein one or more further UEs operate in intermittent receive DRX mode, and indicating the end of one or more transmissions to the further UEs to allow the further UEs to enter an inactive or sleep mode.

[0072] [Transmission restrictions during DRX-ON duration] The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, and the method comprises transmitting a plurality of transmissions to one or more further UEs via a sidelink SL, the one or more further UEs operating in intermittent receive DRX mode, and each of the plurality of transmissions comprises at least an initial transmission, and the plurality of transmissions are transmitted to the further UEs such that at least one or more initial transmissions fall within the on-duration of the DRX cycle of the one or more further UEs.

[0073] [Setting the active time for the DRX cycle] SL RX UE The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, and each UE operating in intermittent receive (DRX) mode, the method comprising, during a DRX cycle, the UE remaining active for a specific active time, the specific active time depending on one or more criteria.

[0074] SL TX UE The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system includes a plurality of user device UEs, the UEs communicating with one or more further UEs via a sidelink SL, and the method includes configuring one or more of the further UEs to operate in intermittent receive (DRX) mode, the DRX configuration for the further UEs being determined according to one or more criteria.

[0075] [Extend / Limit Active Time] The present invention provides a method for operating a user device UE for a wireless communication system. The wireless communication system comprises a plurality of user device UEs, each UE receiving transmissions from one or more further UEs via a sidelink SL, each UE operating in intermittent receive (DRX) mode and being active for a specific active time (e.g., on-duration) during a DRX cycle, and the method includes decoding or skipping decoding a transmission according to one or more criteria.

[0076] [Actions based on feedback] The present invention provides a method for operating a user device UE for a wireless communication system, the wireless communication system comprising a plurality of user device UEs, the UEs communicating with one or more further UEs via a sidelink SL, the one or more further UEs operating in intermittent receive (DRX) mode, the method comprising: transmitting one or more HARQ-responsive transmissions to the further UEs during the on-duration of the further UEs' DRX cycles; and, if no HARQ feedback is received, refraining from transmitting HARQ-responsive transmissions until the next on-duration of the further UEs, and transmitting HARQ-responsive transmissions during the next on-duration of the further UEs.

[0077] [Computer program products] Embodiments of the present invention provide a computer program product that, when executed by a computer, includes instructions causing the computer to perform one or more methods according to the present invention.

[0078] [Implementation of early termination of SL communication] Embodiments of a first aspect of the present invention provide a method for improving the power-saving potential or capability of a UE by enabling a receiver, such as a sidelink UE communicating with another UE via a sidelink, to enter an inactive or sleep mode when certain criteria are met. In other words, embodiments of the present invention provide an implementation of early termination of the active time of the DRX cycle, even for communication via a sidelink.

[0079] According to the embodiment, the SL RX UE can enter inactive mode or sleep mode if one or more of the following criteria are met: • Received a notification that transmission has finished. • All transmissions announced by other UEs have been received. For example, a further UE might send a report, such as a Buffer Status Report (BSR), to an RX UE indicating that it is about to send a certain amount of data. Upon receiving that amount, the RX UE will consider or assume that no further data will be sent from this UE. • Successful reception of a transmission for which further resources are reserved for one or more retransmissions (e.g., early ACK). • There are no ongoing transmissions from other UEs on the SL. • There are no ongoing transmissions from the group leader UE or UEs with a specific ID. • There are no ongoing transmissions from the base station or relay node. • A transmission completion notification has been received, and there are no further transmissions from other UEs currently in progress on the SL. • The content of received transmissions, including communications containing specific messages such as CAM (Cooperative Awareness Message), ITS-G5 (5,9 GHz intelligent transport system) messages, DENM (Decentralized Environmental Notification Message), or BSM (Basic Safety Message). The number of times a specific communication was received. For example, after receiving the same transmission multiple times, e.g., two, three, or more generally, n times (where n is set to a value greater than 1 or a preset natural number N), the UE may decide that no further transmissions are needed and enter sleep mode until the next on-duration. This may apply, for example, to transmissions containing CAM (Cooperative Awareness Message), DENM (Decentralized Environmental Notification Message), or BSM (Basic Safety Message), where if the same message is received multiple times in different transmissions, the UE may decide that no further transmissions are needed. • The battery status of the SL RX UE is below a set or pre-set threshold. • The SL RX UE is moving within a specific geographical location (e.g., a predefined zone or building). • Is the SL RX UE moving or not?

[0080] For example, whether or not the UE is moving can be determined based on the UE's GPS position or variations in the channel impulse response. If the UE is not moving, a frequency-flat channel is provided, and the channel impulse response remains substantially unchanged.

[0081] Therefore, by allowing the SL receiver to stop sleeping or listening, the power saving capability in sidelink communication is improved by reducing the active time, similar to when communicating over the Uu interface.

[0082] Next, embodiments of the first aspect of the present invention will be described with reference to a scenario in which the SL RX UE decides whether to enter sleep mode or inactive mode in response to receiving a transmission end notification from the sidelink transmitting UE (SL TX UE), i.e., from the UE sending the transmission. The sidelink receiver SL RX UE may decide on an early termination of its on-duration in response to the transmitter SL TX UE providing a notification indicating whether and / or where one or more further transmissions following the initial transmission are expected.

[0083] Figure 6 shows an embodiment of an extended on-duration after receiving a control message such as sidelink control information SCI via the sidelink, with an early termination notification given after the message is received. The SL TX UE transmits an initial SCI1 during the SL RX UE's on-duration 252. The on-duration begins at time t1, and SCI1 is received at time t2 during the on-duration 252, followed by a first data transmission PSSCH1 from the TX UE to the RX UE via the sidelink. Upon receiving SCI1, the on-duration 252 is extended beyond the original duration ending at t4. During the original on-duration 252, or during the extended on-duration, the TX UE may transmit a further transmission associated with SCI2, which is received at time t3. In the illustrated embodiment, time t3 is before the end of the original on-duration 252 at time t3. Because the on-duration 252 is extended, the RX UE remains active for the extended duration and also receives a further data transmission PSSCH2. Furthermore, in response to the reception of SCI2, the on-duration is further extended, for example, by restarting an inactive timer. Thus, in the embodiment shown in Figure 6, the overall on-duration extension 262 extends the original on-duration 252 from time t4 to time t6.

[0084] According to the embodiment, in order to enable an RX UE communicating with a TX UE via a sidelink to improve power saving characteristics, the TX UE includes in its transmission to the RX UE an instruction that the TX UE should not expect further transmissions from the TX UE. The TX UE may indicate to the RX UE an early PSSCH termination 260. For example, the end of transmission from the TX UE can be notified by transmitting an early PSSCH termination 260 at the end of the last data transmission PSSCH2, thereby informing the RX UE that it should not expect further transmissions from the TX UE. The RX UE can terminate the extended on-duration 262 at time t5, i.e., the RX UE can become inactive after time t5. Thus, according to the embodiment, by enabling the sidelink TX UE to notify the sidelink RX UE of the end of transmission, the sidelink RX UE can terminate the extended on-duration 262, i.e., the RX UE can transition to an inactive state because it no longer needs to monitor for further transmissions that it is instructed not to occur. This allows the RX UE to reduce its active time from the period t1 to t6 to the period t1 to t5, thereby saving power.

[0085] Regarding the embodiment in Figure 6, it should be noted that the termination of transmission 260 can occur even when transmission from the TX UE occurs only during the ON duration 252. For example, transmission PSSCH1 may include an early termination 260 at the end of transmission, and as a result, the RX UE may enter an inactive state after receiving PSSCH1 in response to the termination notification. Therefore, the original ON duration 252 may be terminated before the original termination point at time t4. For example, the termination may occur at time t3 after the early termination instruction from the TX UE. In this situation, the active time is limited to the period t1-t3, so power can be saved by similarly shortening the active time.

[0086] During the active time, the RX UE monitors at least the control channel to detect further transmissions, such as a second transmission indicated by SCI2 in Figure 6. If no termination 260 is received, the RX UE continues monitoring from the end of PSSCH2 until t6, which is the end of the extended on-duration 262. If further transmissions are detected, for example by detecting a further SCI, the on-duration 262 can be further extended, for example by restarting the inactive timer. However, as mentioned above, in the example in Figure 6, if no termination 260 is received, the RX UE continues to monitor at least the control channel until time t6. This wastes power that could be saved by allowing the RX UE to terminate the extended on-duration 262 or on-duration 252 in response to a notification that the RX UE should not expect further transmissions from the TX UE. Therefore, during the active time, the TX UE may send one or more transmissions to the receiver or RX UE that trigger an extension of the active time, so that the transmitter can follow up and send further transmissions during the extended active time. Once the transmitter has completed its transmission, the receiver will not listen until the dynamically extended active time 262 has ended, because the receiver can respond to signal 260 to stop listening to the transmission from the transmitter, indicating that it has finished transmitting.

[0087] According to one embodiment, as shown in the embodiment of Figure 6, the notification 260 provided by the TX UE to the RX UE may be a transmission termination instruction, for example, by sending a MAC CE (control element) such as a DRX command that explicitly indicates at the end of the transmission that further transmissions from the TX UE should not be expected.

[0088] In one embodiment, instead of notifying a transmission termination instruction as shown in Figure 6, the TX UE may indicate that there are further transmissions when providing control information. In one embodiment, the TX UE may send a buffer status report, for example, a report indicating the number of transmissions to be sent to the RX UE or the amount of data to be sent. In another embodiment, the TX UE may indicate resources reserved for transmission when providing control information. For example, assuming the TX UE is operating in mode 2, resources reserved for transmission may be notified. Thus, instead of instructing or notifying the end of a transmission, a control message associated with a particular transmission, such as an SCI and / or AIM (assistance information message), may indicate a specific number of resources reserved for transmission as indicated in the control message (for example, in the form of actual reserved resources). This can be applied, for example, when performing a retransmission of one or more transport blocks (TBs), but can also be applied to other transmissions.

[0089] For example, as described above with reference to Figure 3, assuming operation in Mode 2, the TX UE may have slightly different operating methods for periodic or semi-persistent transmit / retransmit compared to aperiodic or dynamic transmit / retransmit. For instance, the maximum number of transmit / retransmit counts N may be limited to 32 for periodic and aperiodic transmits. One limitation on this number may be the number of available resources in the candidate resource set. Another limitation may be the number of resources that can be specified in the SCI, which may be limited to a maximum of only three resources, including the initial transmit or the resource on which the initial transmit occurs. These resources may be limited to fit within a 32ms window.

[0090] In Mode 2, the UE identifies the resources required for each possible transmission / retransmission from the available resources within the candidate resource set, and there may be limitations based on the TB's PDB (packet delay budget). Once the UE has identified the list of available candidate resources, it selects N candidate resources. The UE first randomly selects one of the N candidate resources. Assuming the first candidate resource is selected in slot ml, the UE also randomly selects a second candidate resource, but is restricted to having a gap between this candidate resource and the first selected candidate resource smaller than the 32-slot window W. This means that the second candidate resource can be located in slot m2 within the slot range [m1-31, m1+31]. This ensures that the first-stage SCI of one of the two selected candidate resources can reserve the other candidate resource. If N > 2, the UE also randomly selects a third candidate resource, but is restricted to being located in slot m3 within the range [m1–31, m1+31] or within the range [m2–31, m2+31]. This chain procedure is repeated with the aim of reserving all candidate resources for transmission / retransmission by the preceding SCI. However, if the UE can only select a subset of N candidate resources by following this procedure, the remaining resources are randomly selected within the selection window, even if the restrictions of the preceding first stage are not met.

[0091] When transmitting TBs of different sizes, the number of subchannels used for transmission may change, and the number of subchannels is selected so that the TBs and the SCIs associated with them (including first-stage and second-stage SCIs) fit within the candidate resource set. This may be limited by the maximum number of subchannels defined or allowed within the resource pool that defines the resources used for sidelink communication.

[0092] Only the UE sending the TB is aware of the PDB associated with the TB, and a selection window may be selected depending on the PDB, and all send / resend associated with the TB must be completed within the selection window. For aperiodic send, the number of send / resends may be tracked by a reselection counter. After the TB has finished sending, i.e., after the TB and all possible retransmissions of the TB have been sent, the reselection counter may be decremented by 1. Before sending the last TB that would zero out the reselection counter, the TX UE may evaluate whether a new resource should be selected for the next TB. If so, the UE can set the resource reservation period to 0ms in the first stage SCI, thereby indicating to other UEs that it has not reserved the same resource for the next TB. Otherwise, the UE may retain the same resource that is already reserved for the next TB, and the same resource reservation period is included in the first stage SCI.

[0093] For example, in the above example where resources are determined for multiple transmissions, including an initial transmission and one or more retransmissions of the initial transmission, the transmitter can notify the receiving UE of the resources reserved for a particular transmission, and as a result, the UE that receives, for example, an SCI or AIM, can know when a particular transmission will end. Resources can be indicated in the following ways, for example. For example, resources over time can be indicated in one of the following ways. • Represented by a bitmap over time, where the bitmap represents resources such as OFDM symbols, time slots, subframes, or frames, and the resource set is defined to span part or all of the length of a single BWP. • Depending on the starting resource, such as a time slot or subframe, and the duration of the resource set, • By explicit resource numbers such as time slot or subframe numbers, By puncturing resources that are explicitly mentioned, or resources that are part of another resource set or RP, • By using a starting resource and a periodic offset for subsequent occurrences, • By symbol, time slot, subframe, or frame pattern, The following formula is used to define TRIV (time resource indicator value) as defined in TS38.214: if N = 1 TRIV = 0 else if N = 2 TRIV = t1 else if (t2 - t1 - 1) ≤ 15 TRIV = 30 (t2- t1- 1) + t1+ 31 else TRIV = 30 (31 - t2+ t1) * 62 - t1 end if end if

[0094] Here, N represents the number of time slots indicated by AIM, 0 represents the time slot in which the AIM was received. 1 represents the time slot in which the AIM was received, and one other future time slot relative to the time slot in which the AIM was received. 2 means the time slot in which the AIM was received, and two other future time slots relative to the time slot in which the AIM was received. t1 indicates the first future resource time slot with respect to the time slot in which the AIM was received. t2 indicates a second future resource time slot with respect to the time slot in which the AIM was received.

[0095] Resources across frequencies can be shown in one of the following ways: • Represented by a bitmap, the bitmap shows multiple resources across a single BWP, for example, a resource block. • Depending on the starting resource (e.g., a resource block) and the number of resources in the resource set, • If the resource set is frequency-discontinuous, multiple starting resources (e.g., resource blocks) and multiple ending resources will be used. ·Explicit resource indexes such as resource block indexes, By puncturing resources that are explicitly mentioned, or resources that are part of another resource set or RP, • By using a starting resource and a periodic offset for subsequent occurrences, Depending on the pattern of resource blocks or subchannels, The following formula is used to define FRIV (frequency resource indicator value) as defined in TS38.214:

number

[0096] Therefore, using the above format, resources reserved for transmission by the TX UE may be notified, for example, in SCI1 in Figure 6. Upon receiving instructions for reserved resources, the RX UE can determine when further transmissions from the TX UE are not expected. SCI1 may contain assistance information, or the RX UE may receive additional AIM (assistance information message) informing the RX UE about resources reserved for transmission from the TX UE. This allows the RX UE to know that it should not expect further transmissions from the TX UE after transmission PSSCH2, and thus can enter an inactive state at t5. Similarly, if SCI1 only indicates resources for PSSCH1, the RX UE does not expect further transmissions from the TX UE after PSSCH1 and can enter an inactive state at t3.

[0097] According to a further embodiment, when an RX UE receives an instruction that a transmission from one TX UE has ended, if there is only one ongoing transmission from one TX UE to the RX UE via a sidelink, it may enter an inactive state as described above. However, the RX UE may also communicate with one or more further sidelink TX UEs and may receive transmissions from other TX UEs. Therefore, according to the embodiment, an RX UE communicating with multiple TX UEs via a sidelink may enter an inactive state in response to an early termination 260 notification of a transmission from one TX UE only if the RX UE has confirmed that there are no other ongoing transmissions with other TX UEs. In other words, in response to an instruction that a transmission from one TX UE has ended, the RX UE may transition to a sleep mode or an inactive state if it is not active due to a transmission from another TX UE.

[0098] Figure 7 shows an embodiment of the present invention in which the RX UE receives transmissions from the first TX UE A and the second TX UE B via a sidelink. During the ON period 252 t1-t4, the RX UE receives SCI associated with one or more transmissions from TX UE A via the sidelink. * Receive. SCI * Upon receiving the signal, the on-duration 252 is extended from time t4 to time t7. At time t3, the RX UE receives additional SCIBs associated with one or more transmissions by further TX UE B, thereby further extending the on-duration or active time from time t7 to time t8. According to the embodiment shown in Figure 7, TX UE B may notify the RX UE of a PSSCH MAC_CEB indicating that the RX UE should not expect further transmissions from TX UE B. This may be received at time t5, and in response to this notification, the RX UE may enter inactive mode, i.e., terminate the extended on-duration. However, since the RX UE has not yet received an instruction from TX UE A that it should not expect further transmissions from TX UE A, according to the embodiment of the present invention, due to ongoing transmissions by TX UE A, the RX UE takes no action at t5 in response to the first early termination 260A, i.e., remains in the active state and continues to monitor the control channel for further transmissions. At time t6, TX UE A sends PSSCH MAC.CEA indicating that no further transmissions from TX UE A are expected, and as a result, RX UE initiates early termination 260A at time t7, allowing it to enter inactive mode before the actual end of the extended on-duration at time t8. This allows for power savings. At time t6, as all other transmissions, including those from TX UE B, have already ended as notified by TX UE B, RX UE knows that only transmissions from TX UE A are ongoing. Therefore, upon receiving the early termination signal from TX UE A, RX UE may enter sleep or inactive mode at time t7.

[0099] Therefore, by providing an instruction from each TX UE that no further transmission from the TX UE is expected, the receiver can reliably detect when to actually transition to sleep mode or inactive mode, or when to stop listening to the control channel for further transmission. This reduces power consumption because the RX UE does not need to be active for the entire extended on-duration, as illustrated with reference to Figures 6 and 7.

[0100] The present invention is not limited to the above embodiment in which the transmission termination notice is provided by the SL TX UE sending the transmission. According to other embodiments, the transmission termination notice may be provided by one or more of the following entities of the wireless communication network. • Further UEs that have not completed the transmission, for example, the group leader of the UE group to which the UE belongs. • Relay node. ·Roadside unit (RSU). IoT devices. • Access points such as base stations for wireless communication systems (for example, when SL TX UE is a Mode 1 UE).

[0101] [Transmission limit on on-duration by TX UE] A second embodiment of the present invention provides a method for enabling an RX UE communicating with a transmitter via a sidelink to save power by avoiding unused ON durations. More specifically, considering a scenario as shown in Figure 6, if a TX UE transmits at any point, for example, outside of the RX UE's ON period 252, the transmission by the TX UE will not be received. The TX UE can then transmit a retransmission, which, if configured to do so, can eventually be detected by the RX UE during the next ON period. However, this means the RX UE will initially monitor the ON duration during which no transmission occurs, and power may not be saved during this time.

[0102] According to an embodiment of the second aspect, such a situation can be avoided and power can be saved by ensuring that the RX UE reliably receives the start of transmission during the ON period 252 (see Figure 6). Thus, embodiments of the present invention provide a TX UE that initiates transmission during the time the RX UE is active, i.e., during the ON period. The transmission operation may be performed within the MAC scheduler, and as similarly as described above, the PHY layer reports a set of candidate resources to the MAC scheduler. When deciding which candidate resources to use for transmission or data packets, or when deciding which data packet to transmit next, the MAC scheduler makes its decision taking into account one or more corresponding ON durations of DRX cycles used by the RX UE and any potential extensions obtained by the inactive timer.

[0103] In some embodiments, this technique may be applied to transmissions associated with a priority that has a specific set or pre-configured threshold or level, also known as high-priority transmissions. To increase the certainty of such high-priority transmissions, the RX UE reliably detects the transmission. If the RX UE does not receive a high-priority transmission during the ON period, the RX UE enters sleep mode or inactive mode. To ensure that such transmissions are reliably detected, and to gain additional active time by extending the ON duration for potential retransmissions as needed, the TX UE places the initial transmission within the RX UE's ON duration. This reduces the likelihood that the RX UE will miss all of the transmitter's transmissions. Thus, while ensuring that the transmission is received by the RX UE, it is also guaranteed that the transmission is received during the initial ON duration, thus avoiding the wasted power of only retransmitting without transmitting the initial transmission during the ON duration.

[0104] According to a further embodiment of the second aspect, the method may be applied as follows: • For transmissions where the Quality of Service (QoS) requirement is above a set or pre-configured threshold, · For transmissions with a specific packet quota (e.g., a specific configured or pre-configured data rate threshold), or • Depends on the number of transmissions set or pre-configured, for example, the minimum or maximum number of transmissions (e.g., CAM, DENM, or BSM), It depends on the content of the message (for example, a specific CAM or a specific DENM). Setting Active Hours via TX UE In the above embodiment, the active time is defined by either the on-duration 252 or the extended on-duration 262. According to an embodiment of a third aspect of the present invention, the active time may be determined according to one or more of the following: • Characteristics or features of the transmitted data packet, for example, one or more characteristics of the transmitted packet. · Destination RX UE (for example, UE type), • Logical channel used for transmission, • Quality of Service (QoS) flow, • Quality of Service (QoS) requirements related to transmission, such as priority, latency, or data rate. • Logical channel group used for transmission, UE battery status, • The UE is moving within a specific geographical location (e.g., a predefined zone or building). Channel busy rate, UE type, • One or more resources used by the initial transmission and / or at least one further transmission.

[0105] Therefore, the active time of a DRX cycle may vary depending on one or more of the above criteria. For example, an RX UE may be configured or pre-configured with several different ON durations that may be periodic, and a TX UE may be aware of the configured / pre-configured ON durations available to the RX UE. Thus, depending on the service or communication link, the TX UE may indicate the active time or ON duration that the RX UE should apply, along with the control information associated with the transmission. For example, an in-SCI notification, such as a first-stage SCI or a second-stage SCI, may cause the RX UE to select an ON duration from several configured or pre-configured ON durations that it is instructed to use for transmissions received from the TX UE.

[0106] For example, an RX UE can receive DRX settings that define the DRX cycle and active time. An RX UE may receive one or more of the following DRX settings: • Further UEs to perform the transmission • Further UEs that have not performed the transmission, for example, the group leader UE of the UE group to which the UE belongs. • Relay node, • RSU or IoT device, • Access point for a wireless communication system (e.g., base station).

[0107] For example, a TX UE can configure one or more RX UEs to operate in intermittent receive (DRX) mode, and can select or determine the DRX settings to configure the RX UEs according to one or more of the above criteria.

[0108] In other embodiments, the active time can be dynamically controlled, for example, based on preceding transmissions. This allows the on-duration (e.g., inactive timer) to be extended by received packets, for example, as described above with reference to Figures 6 and 7, thereby enabling the TX UE to transmit new packets. In other words, in such embodiments, an initially configured or pre-configured on-duration 252 (e.g., by DRX configuration information) can be extended in response to the transmission or reception of data packets, thereby creating an extended on-duration 262 that replaces the on-duration 252 that was initially configured for the DRX operation. For example, the actual length of the on-duration 252 for a DRX cycle may be extended for each subsequent DRX cycle, i.e., an extended on-duration 262 is used instead of the periodic initial on-duration 252 after the reception of a packet.

[0109] In a further embodiment, the extension may be canceled when the TX UE indicates the end of transmission. That is, after notification of the termination notification 260 described above with reference to Figures 6 and 7, the DRX cycle may cease using the extended on-duration 262 and revert to the initial on-duration 252, also known as the default on-duration.

[0110] According to the preceding embodiment, a set or pre-set active time is used by the RX UE to determine the on-duration or extended on-duration during the DRX cycle. According to other embodiments, rather than defining a specific period during which resources should be monitored, a specific characteristic of SL transmissions, namely resources designated or reserved for SL transmissions and potential future transmissions, may be used. Embodiments utilize this characteristic to enable power consumption reduction by monitoring only resources actually designated or reserved for sidelink transmissions. Parameters used to indicate such future resources may be time and frequency resource allocation parameters. Such parameters may be defined using SCI format 1-a, the first stage SCI. This indicates resources reserved within the next 32 time slots, for example, using the TRIV format and FRIV format described above, respectively, or using any of the above formats for notifying reserved resources. Information regarding reserved resources may be included in an AIM (assistance information message), which may be part of an SCI message, the first and / or second stage SCI, or separate from an SCI message (e.g., transmitted in data or PSSCH).

[0111] Based on information about the actual resources used for further transmissions by the TX UE, the RX UE may monitor resources indicated by the TX UE for one or more transmissions, in addition to monitoring resources during the on-duration. Therefore, the power-saving characteristics of the RX UE can be improved by limiting additional monitoring of resources other than those during the on-duration to only those resources indicated for transmission.

[0112] According to the embodiment, power savings relating to monitoring only the designated resources can be achieved by extending the on-duration based on future resource reservations, or by listening only to the designated resources for future transmissions. In the first case, there is no fixed extension of the on-duration, and the extension is only up to the last resource notified by the TX UE, so the RX UE can stop monitoring other resources after the last designated resource without needing to receive a transmission completion notification.

[0113] Only resources that transmit after the on-duration period are monitored, and resources that do not transmit between the on-duration period and the extended period do not need to be monitored, so that during such a period the UE can enter sleep mode or inactive mode.

[0114] Figure 8 shows an embodiment of power saving by monitoring only the designated resources. Figure 8(a) shows an embodiment of extending the on-duration based on future resource reservations, and Figure 8(b) shows an embodiment of active time slots being monitored based on future resource reservations.

[0115] Figure 8 shows a DRX cycle 250 of the RX UE. The DRX cycle 250 includes a periodic on-duration 252 which, according to the embodiment, can be extended in accordance with future resources reserved for transmission by the TX UE. In the embodiment of Figure 8, it is assumed that an initial transmission is received from the TX UE in time slot (1) during the on-duration 252, as shown in the center of the figure. The initial transmission is associated with control information that also indicates the resources reserved for further transmissions by the TX UE that transmitted the initial transmission. Such further transmissions may be retransmissions of the initial transmission in time slots (2) and (3), or, according to the other embodiment, may include other initial transmissions by the TX UE. In the embodiment shown in Figure 8(a), two retransmissions are assumed, and the initial transmission in time slot (1) indicates to the RX UE, for example using support information, that retransmissions will occur in time slots (2) and (3). The RX UE recognizes that the first retransmission in time slot (2) is still within the on-duration 252, but the second retransmission in time slot (3) is outside the on-duration 252. The RX UE extends the on-duration 252 by extending the active time until the time slot (3) in which the last retransmission takes place, creating an extended on-duration 262 depending on the actual resources to be monitored. Thus, according to the embodiment of Figure 8(a), packets received during the active time or on-duration 252 (e.g., an initial transmission in time slot CD) extend the on-duration 252 by a duration (illustrated by two time slots in this embodiment) that depends on the indicated future time slot reservations for further transmissions. Thus, in the embodiment of Figure 8(a), if one further transmission in time slot (3) outside the default on-duration 252 is notified by the TX UE, the RX UE extends its active time until the end of the reserved packets in time slot (3).

[0116] Figure 8(b) shows an embodiment in which the RX UE listens only for additional resources outside of the on-duration or default on-duration 252 instructed by the TX UE. The situation in Figure 8(b) is similar to the situation in Figure 8(a), except that the RX UE monitors only the time slot (3) instructed for a second retransmission outside of the default on-duration 252, except that the two time slots between the end of the default on-duration 252 and the extended active time slot (3) are not monitored by the RX UE.

[0117] Therefore, as shown in Figure 8(a), the power-saving characteristics of the RX UE are enhanced because the actual extension of the default ON period is only until the last reserved resource for transmission (e.g., time slot (3)), but as shown in Figure 8(b), the power-saving characteristics can be further enhanced by not listening to or monitoring the time slot between the default ON duration and the actual duration, and the retransmission in time slot (3). Thus, to save power in the RX UE, it is ensured that the RX UE receives a transmit or transport block within the ON period 252, but once the ON period 252 ends, the RX UE listens only to the time slots indicated (e.g., by the TRIV format), otherwise the RX UE enters an inactive or sleep mode between the indicated resources. This improves power saving capabilities.

[0118] In a further embodiment, as described above, the transmission of a TX UE to an RX UE via a sidelink may include an initial transmission and a retransmission of the initial transmission, as shown in Figure 8. In a further embodiment, when an initial transmission and a retransmission are transmitted, after receiving the first transmission within the on-duration 252, the RX UE may enter sleep mode or inactive mode once the transmission is successfully received. That is, since the transmission has already been successfully decoded, the RX UE stops listening for future retransmissions of its transport block. Thus, assuming Figure 8, if the initial transmission in time slot (1) is successfully received by the RX UE, the RX UE may enter sleep or inactive mode after time slot (1), as there is no need to further monitor time slots (2) and (3). In an embodiment, if the TX UE transmission is a HARQ-enabled transmission, the transition to inactive / sleep mode may be postponed for one or more time slots after the initial transmission has been successfully received. In this way, in response to the successful initial transmission in time slot CD, the RX UE sends an acknowledgment (ACK) or sidelink assistance information (AIM) and enters sleep mode. Even if the initial transmission is not received successfully, the same process may apply if the first retransmission received in time slot (2) is successfully decoded.

[0119] According to a further embodiment, the TX UE may reserve resources for further or second transmissions or transport blocks by performing periodic transmissions as defined in Rel-16. For example, the above format, such as a TRIV parameter, may be used to indicate resources for further transmissions. In such a case, the control information may include, in addition to notification of the actual reserved resources, a so-called resource reservation period as an additional parameter, for example, contained in SCI format 1-a. During this period, after the indicated reservation period, the same resources may be used for further transmissions. According to such an embodiment, the TX UE may need to change the resources used for transmitting a second or further transport block, and in such a situation, the TX UE may transmit a reservation period of a certain duration, for example, a reservation period with zero indicated as the duration. This notifies the RX UE that no further transmissions are expected or have been received from the TX UE, so the RX EU can stop monitoring the resources for the mentioned transmissions and enter sleep or inactive mode.

[0120] In a further embodiment, an RX UE monitoring a time slot indicating a reserved resource (e.g., a time slot after the on-duration or the actual time slot for a retransmission (e.g., time slot (3) in Figure 8(b))) may not receive a transmit or retransmission in that time slot. In such a situation, according to the embodiment, if a transmit or retransmission is not received in the reserved resource (3) outside of the on-duration 252, the RX UE may remain active for a short period by, for example, starting an inactive timer after the time slot (3) in which a transmit was expected. The absence of a retransmission in time slot (3) may be due to a re-evaluation of the resource used by the TX UE, so the initially notified resource (3) may have been determined to be unavailable for transmit by the TX UE for some reason. The UE, which remains active for a short period after the indicated resource (3), may detect the missing retransmission on the re-evaluated resource selected by the TX UE. A retransmission may also not be received if the retransmission cannot be decoded by the RX UE.

[0121] According to another embodiment, the RX UE can remain active for n retransmissions, where n is less than or equal to the maximum number of retransmissions notified or preset. According to another embodiment, the RX UE can directly enter sleep or inactive mode and be activated only during the next on-duration. According to yet another embodiment, the RX UE can transmit support information such as AIM (including information about one or more on-durations of the RX UE), including the time and / or frequency information of the RX UE being active and able to receive retransmissions or support information such as AIM, to the TX UE.

[0122] [Extending / limiting active time via TX UE] According to an embodiment of a fourth aspect of the present invention, the power-saving characteristics of an RX UE communicating with another UE via a sidelink can be further enhanced by determining whether or not a particular transmission from a TX UE should actually be processed by the RX UE.

[0123] For example, if an RX UE determines that a received transmission is of a specific type, has certain characteristics, or meets certain criteria, the RX UE may, in order to conserve power, monitor only messages or transmissions that meet the requirements for transmissions to be processed by the RX UE, and discard other transmissions or messages. For instance, the UE may decide whether to decode a transmission or skip decoding a transmission based on one or more criteria. This reduces power consumption because the necessary decoding of certain messages or transmissions is not performed.

[0124] For example, whether a transmission is of interest to the RX UE may be determined based on the destination ID (e.g., whether the transmission is a unicast or groupcast transmission), and / or depending on the priority associated with the transmission, and / or whether a HARQ (Hybrid Automatic Repeat Request) indicator is associated with the transmission, and / or based on the cast type associated with the transmission (e.g., unicast transmission, groupcast transmission, or broadcast transmission).

[0125] For example, the destination ID and priority may be indicated within the SCI associated with a transmission and may be received within the monitored control channel during the on-duration. For example, when considering application priority, a field in the first-stage SCI transmitted over the PSCCH may be evaluated. By evaluating the priority field of the first-stage SCI, the RX UE can skip PSCCH decoding if the specified priority does not reach a certain level. For example, a low-power RX UE may only monitor transmissions or messages above a certain priority and discard or not decode PSCCH messages or transmissions of lower priority.

[0126] When considering the destination, the RX UE can evaluate the destination field contained in the second-stage SCI transmitted over the PSSCH. For example, based on the indicated destination ID, the RX UE can determine whether a particular transmission actually specifies an RX ID address and therefore needs to be decrypted. Furthermore, the RX UE can determine whether a transmission is a transmission to a group or a unicast transmission, for example, based on the group ID and unicast ID indicated in the destination field. For example, the RX UE might decide that a unicast transmission should be decrypted, while a groupcast transmission does not.

[0127] If the HARQ indicator associated with a transmit indicates that the transmitter is requesting feedback on the transmit, the RX UE decodes the transmit and sends feedback. Otherwise, i.e., if the HARQ indicator indicates that the transmitter is not requesting feedback, the UE may skip decoding to conserve power. In a further embodiment, the UE may skip decoding even if feedback is requested. This may be useful, for example, in groupcast communications where members of a power-saving group skip lower-priority messages. However, if feedback is not sent to a transmitter that is expecting feedback from all group members, the transmitter will retransmit the message. In this case, to avoid the above behavior, an ACK may be sent even if the message was not successfully decoded, thereby avoiding unnecessary retransmission.

[0128] In other embodiments, the RX UE may skip certain cast types, which may be configured by the TX UE or base station, or pre-configured on the resource pool. The RX UE checks the cast type within an SCI, such as a first-stage SCI or a second-stage SCI, and skips further decoding of the PSSCH if the transmission is of a specific cast type.

[0129] According to a further embodiment, the RX UE may skip further PSSCH decoding if the second-stage SCI indicates a source ID different from the list of communication partners of interest to the UE. For example, the RX UE checks the source ID field in the second-stage SCI on the physical sidelink shared channel PSSCH and skips further decoding of the PSSCH if the source ID field indicates that the transmission is not from a transmitter from which the RX UE is trying to receive communication, or that the transmission is not on the list of source IDs to be decoded.

[0130] Further embodiments address a situation where the RX UE decides to decode the second stage SCI on the PSSCH based on information from the first stage SCI, but the decodement fails. In such a situation or scenario, if the priority indicated in the first stage SCI is high priority, i.e., at a specific priority level, the RX UE may remain active for a specific period of time to receive packet retransmissions, for example by triggering an inactive timer. The RX UE may remain active for a specific period of time by extending the active time, or by checking the reserved field in the first stage SCI that indicates when and where retransmissions are expected, so that the UE remains active until it reaches the resource indicated in the reserved field (Figure 8(a)), or becomes active again when it reaches the resource where retransmissions occur (Figure 8(b)).

[0131] In other embodiments, the RX UE recognizes, for example, thanks to reserved resource indications, that a transmission at the location where decryption failed was actually previously reserved for transmission from the TX UE to the RX UE. If decryption fails, a collision or preemption of the transmission destined for the RX UE may have occurred. In this case as well, the extended active time during which the RX UE monitors the resource after the ON period allows for the detection and reception of the next transmission in the case of a collision, or an alternative transmission in the case of preemption. This also applies if the reserved resource did not contain any expected transmissions, i.e., if decryption failed because there were no transmissions.

[0132] [Actions taken by TX UE based on HARQ feedback] According to an embodiment of a fifth aspect of the present invention, a TX UE communicating with another UE via a sidelink may send one or more transmit or data packets during the ON duration of an RX UE and request feedback. For example, the TX UE may send a HARQ-enabled transmit. If the RX UE does not report the necessary HARQ feedback for any of the received packets or transmits, the TX UE assumes that the RX UE may not have sent or received the packet, or that this is due to another issue, such as a half-duplex issue. In such a case, the TX UE may assume that the RX UE missed the transmit or packet and therefore did not extend its active time. In other words, the TX UE does not consider immediate retransmission and waits until the next ON period of the RX UE's DRX cycle, as it assumes that the default ON period of the DRX cycle applies. In other words, the TX UE may hold a HARQ-enabled transmit, and the hold may include one or more of the following: • Do not resend until the next on-duration period. • Do not retransmit the current transport block TB. Instead of waiting until the next on-duration, retransmission for this TB will be stopped immediately. • Restart the retransmission counter during the next on-duration period. • Use the initial redundant version RV.

[0133] For example, if the initial transmission is missed, the UE will not have a copy of the initial RV. However, if the UE misses the initial RV, the code is designed to degrade the decoding performance.

[0134] Therefore, since the initial RV alone offers the best performance for successful decoding, the initial RV is sent again. • Reduce the number of retransmissions based on the total duration of online activity up to that point. In other embodiments, the TX UE may assume that the RX UE has extended its default on-duration, for example by activating an inactive timer, because it is considered likely that the RX UE is likely to receive transmissions from two or more other transmitters via a sidelink. Alternatively, the TX UE may assume that the RX UE did not respond due to a half-duplex issue. In either case, despite the default on-duration having elapsed, the TX UE may, based on these assumptions, retransmit the same transmission or packet a set or pre-configured number of times due to the extended on-duration period assumed to have been triggered by the RX UE. If the RX UE still does not respond to these retransmissions, the TX UE may hold the packet or transmission until the next default on-duration.

[0135] [General matters] Although embodiments of the present invention have been described in detail above, each embodiment and aspect may be implemented individually or in combination of two or more.

[0136] According to the embodiment, the wireless communication system may include a terrestrial network, a non-terrestrial network, or a network or part of a network that uses an aircraft or space vehicle as a receiver, or a combination thereof.

[0137] According to embodiments, the user device UE described herein may be a handheld UE called a VRU (Vulnerable Road User) or P-UE (Pedestrian UE), such as a UE with limited power or a UE used by pedestrians, or a wearable or handheld UE called a PS-UE (Public safety UE), used by public safety officers and first responders, or an IoT UE (e.g., a sensor, actuator, or UE located within a campus network to perform repetitive tasks and requiring periodic input from a gateway node), or a mobile terminal, or a fixed terminal, or a cellular IoT-UE, or a vehicle UE, or a vehicle group leader (GL) UE, or an IoT or narrowband IoT (NB-IoT) device, or a WiFi non-access point station (non-AP). It could be one or more of the following: STA) (e.g., 802.11ax or 802.11be), or ground vehicles, or aircraft, or drones, or mobile base stations, or roadside units (RSUs), or buildings, or any other item or device (e.g., a sensor or actuator) having a network connection that enables the item / device to communicate using a wireless communication network, or any other item / device (e.g., a sensor or actuator) having a network connection that enables communication using a sidelink, or any sidelink-enabled network entity.

[0138] The base station BS described herein may be implemented as a mobile or non-mobile base station and may be one or more of the following: a macrocell base station, or a small cell base station, or a central unit of a base station, or a distributed unit of a base station, or an IAB (Integrated Access and Backhaul) node, or a roadside unit, or a UE, or a group leader GL, or a relay, or an RRH (Remote Radio Head), or an AMF, or an MME, or an SMF, or a core network entity, or a mobile edge computing entity, or a network slice such as one in an NR or 5G core context, or a WiFi AP STA (e.g., 802.11ax or 802.11be), or any transmit / receive point TRP that enables an item or device to communicate using a wireless communication network, and the item or device has network connectivity for communicating using a wireless communication network.

[0139] While some aspects of the above concept are described in the context of apparatus, it is clear that these aspects also represent descriptions of corresponding methods, where a block or device corresponds to a method step or a feature of a method step. Similarly, aspects described in the context of a method step also represent descriptions of corresponding blocks, items, or features of the corresponding apparatus.

[0140] Various elements and features of the present invention may be implemented as hardware using analog and / or digital circuits, as software through the execution of instructions by one or more general-purpose or dedicated processors, or as a combination of hardware and software. For example, embodiments of the present invention may be implemented in the environment of a computer system or another processing system. Figure 9 shows an example of a computer system 600. The steps of a unit or module, and the method performed by these units, may be performed on one or more computer systems 600. The computer system 600 includes one or more processors 602, such as dedicated or general-purpose digital signal processors. The processors 602 are connected to a communication infrastructure 604, such as a bus or network. The computer system 600 includes main memory 606, e.g., random access memory RAM, and secondary memory 608, e.g., a hard disk drive and / or removable storage drive. The secondary memory 608 may allow computer programs or other instructions to be loaded into the computer system 600.

[0141] The computer system 600 may further include a communication interface 610 that enables the transfer of software and data between the computer system 600 and external devices. The communication may be in the form of electronic signals, electromagnetic signals, optical signals, or other signals that can be processed by the communication interface. The communication may use wires or cables, optical fibers, telephone lines, cell phone links, RF links, and other communication channels 612.

[0142] The terms “computer program medium” and “computer-readable medium” are generally used to refer to tangible storage media such as hard disks installed on removable storage units or hard disk drives. These computer program products are means for providing software to the computer system 600. The computer program, also called computer control logic, is stored in main memory 606 and / or secondary memory 608. The computer program may also be received via the communication interface 610. When executed, the computer program enables the computer system 600 to implement the present invention. In particular, when executed, the computer program enables the processor 602 to implement a process of the present invention, such as any of the methods described herein. Thus, such a computer program may represent a controller of the computer system 600. If the present disclosure is implemented using software, the software may be stored in a computer program product and loaded into the computer system 600 using an interface such as a removable storage drive or the communication interface 610.

[0143] Hardware or software implementations may be carried out using a digital storage medium, such as cloud storage, floppy disks, DVDs, Blu-rays, CDs, ROMs, PROMs, EPROMs, EEPROMs®, or FLASH® memory, which store electronically readable control signals that can be programmed to perform the respective methods. Thus, the digital storage medium may be computer-readable.

[0144] Some embodiments of the present invention include a data carrier having an electronically readable control signal that can cooperate with a programmable computer system so that one of the methods described herein can be performed.

[0145] Generally, embodiments of the present invention may be implemented as a computer program product having program code, the program code operable to perform one of the methods when the computer program product is executed on a computer. The program code may be stored, for example, on a machine-readable carrier.

[0146] Other embodiments include a computer program stored on a machine-readable carrier for performing one of the methods described herein. In other words, one embodiment of the method of the present invention is a computer program having program code for performing one of the methods described herein when executed on a computer.

[0147] Therefore, a further embodiment of the method of the present invention is a data carrier, digital storage medium, or computer-readable medium on which a computer program for performing one of the methods of the present invention is recorded. Therefore, a further embodiment of the method of the present invention is a data stream or sequence of signals representing a computer program for performing one of the methods of the present invention. The data stream or sequence of signals may be configured to be transmitted over a data communication connection, such as the Internet. A further embodiment includes processing means, such as a computer or programmable logic device, configured or adapted to perform one of the methods of the present invention. A further embodiment includes a computer on which a computer program for performing one of the methods of the present invention is installed.

[0148] In some embodiments, some or all of the functions of the method herein may be carried out using a programmable logic device such as a field-programmable gate array. In some embodiments, a field-programmable gate array can cooperate with a microprocessor to carry out one of the methods herein. Generally, the method is preferably carried out by any hardware device.

[0149] The embodiments described above are merely illustrative of the principles of the present invention. Modifications and changes to the arrangements and details described herein will be obvious to those skilled in the art. Therefore, the invention is intended to be limited only by the current claims and not by the specific details presented in the descriptions and explanations of the embodiments herein.

Claims

1. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device receives transmissions from one or more further user devices via a side link. The user device operates in intermittent reception mode. The user device is a user device that enters an inactive mode or sleep mode when certain criteria are met.

2. The aforementioned specific criteria are, - I have received the transmission completion notification. - All transmissions announced from further user devices have been received. - Successful reception of the aforementioned transmission, for which further resources are reserved for future retransmissions such as early ACK. - There are no ongoing transmissions from the aforementioned user devices. - There are no ongoing transmissions from the group leader user device or user devices with a specific ID. - There are no ongoing transmissions from base stations or relay nodes. - Content of the received transmission, - Receiving a specific transmission n times (n = 2, 3, 4...) such as a transmission containing CAM (Cooperative Awareness Message), DENM (Decentralized Environmental Notification Message), or BSM (Basic Safety Message), - The battery status of the user device is below the set or pre-set threshold. - The user device is moving within a specific geographical location, such as a predefined zone or building. - Whether the user device is moving or not, A user device according to claim 1, comprising one or more of the following:

3. The user device includes an inactive timer that specifies the duration of the inactive timer, during which the user device remains active and monitors at least the control channel to detect transmissions. The user device according to claim 1 or 2, wherein the user device starts the inactive timer in response to receiving a transmission from a first further user device.

4. The user device extends the inactive timer duration in response to receiving further transmissions from the first further user device and / or transmissions from the second further user device during the inactive timer duration, or in response to a signal from the group leader user device, or in response to a signal from a base station, relay node, or roadside unit. The user device according to claim 3, wherein the user device enters the inactive mode or sleep mode before reaching the end of the extended inactive timer duration in response to the fulfillment of certain criteria, such as a transmission termination notification from both the first further user device and the second further user device.

5. The user device enters the inactive mode or sleep mode in response to the transmission completion notification. The user device is - Further user devices that perform the completed transmission, - Further user devices that have not completed the aforementioned transmission, such as the group leader user device of the user device group to which the aforementioned user device belongs, Relay node, ・Roadside unit or IoT device, • Access points for wireless communication systems such as base stations, A user device according to any one of claims 2 to 4, which receives a transmission completion notification from one or more of the following.

6. Further user device notifications of transmission termination are: - Notification of the end of transmission by the aforementioned user device using DRX command MAC (Medium Access Control), CE (Control Element), etc. - Notification of the number of resources reserved for transmission by the further user device, using TRIV (time resource indicator value) or FRIV (frequency resource indicator value), or - SCI such as Stage 1 SCI (Sidelink Control Information) or Stage 2 SCI, or ・AIM (assistance information message), The user device according to claim 5, as shown by [representation].

7. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device sends one or more transmissions to one or more further user devices via a side link, and the one or more further user devices operate in intermittent receive mode. The user device indicates to the further user device the end of the one or more transmissions so that the further user device may enter an inactive mode or sleep mode.

8. The user device is - Sending a notification to the aforementioned user device that transmission has ended using intermittent receiving commands such as MAC (Medium Access Control) and CE (Control Element), or - Notification of the number of resources reserved for the transmission to the further user devices, using TRIV (time resource indicator value) or FRIV (frequency resource indicator value), or - SCI such as Stage 1 SCI (Sidelink Control Information) or Stage 2 SCI, or ・AIM (assistance information message), - A buffer status report showing the number of transmissions or the amount of data transmitted to the aforementioned further user devices, The user device according to claim 7, which indicates the termination of one or more transmissions to the further user device.

9. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device sends multiple transmissions to one or more further user devices via a side link, and the one or more further user devices operate in intermittent receiving mode, and each of the multiple transmissions includes at least one initial transmission. The user device transmits the plurality of transmissions to the further user devices such that at least one of the initial transmissions falls within the on-duration of the intermittent receive cycle of the one or more further user devices.

10. The user device according to claim 9, wherein one or more of the plurality of transmissions include at least one further transmission following the initial transmission at a later point in time.

11. The user device according to claim 9 or 10, wherein the plurality of transmissions are transmissions associated with a specific criterion.

12. The aforementioned specific criteria are, - The priority is above the set or pre-set threshold. - The service quality requirements are above the set or pre-configured threshold. - Packet quotas such as specific settings or pre-configured data rate thresholds, - Number of transmissions, such as the minimum or maximum number of transmissions set or pre-configured. - The content of specific messages such as CAM (Cooperative Awareness Message) or DENM (Decentralized Environmental Notification Message), A user device according to claim 11, comprising one or more of the following.

13. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device receives transmissions from one or more further user devices via a side link. The user device operates in intermittent reception mode. During an intermittent reception cycle, the user device is active for a specific active period, and the specific active period depends on one or more criteria.

14. The one or more of the above criteria are, - One or more characteristics of the transmitted packet, • Logical channel used for transmission, • Logical channel group used for transmission, • Service quality flow, - Service quality requirements related to transmission, such as priority, delay, or data rate. • Geographic location or zone, Channel busy rate, • User device type, - One or more resources used by the initial transmission and / or at least one further transmission, - Current battery status of the user device, A user device according to claim 13, comprising one or more of the following.

15. The user device receives the intermittent reception settings that define the intermittent reception cycle and the active time, and the user device - Further user devices that perform the aforementioned transmission, - Further user devices that have not performed the aforementioned transmission, such as the group leader user device of the user device group to which the user device belongs. Relay node, ・Roadside unit or IoT device, • Access points for wireless communication systems such as base stations, The user device according to claim 13 or 14, which can receive the intermittent reception setting from one or more of the following.

16. The user device according to any one of claims 13 to 15, wherein the active time is set, pre-set, or dynamic.

17. The user device according to claim 16, wherein the user device has a set or pre-set number of on-durations for the intermittent reception cycle, and the user device determines the on-duration to be used according to one or more criteria.

18. The user device according to claim 16 or 17, wherein the user device has one or more default on-durations set or pre-set for the intermittent receive cycle, and the user device extends the default on-durations to an extended on-duration based on a preceding transmission.

19. The user device according to claim 18, wherein in response to the termination of the transmission that caused the extended on-duration, the user device cancels the extension and returns to the default on-duration.

20. A transmission includes an initial transmission and at least one further transmission following the initial transmission at a later point in time. The user device according to any one of claims 13 to 15, in response to instructions for one or more resources reserved for use by at least one further transmission, the user device extends the active time to include at least one of the instructed resources.

21. The user device is - Extend the on-duration of the intermittent receive cycle to the specified reserved resource, and / or - Add only the designated reserved resources to be monitored during the active time to the on-duration of the intermittent receive cycle. The user device according to claim 20, which extends the active time by the means of doing so.

22. The user device according to claim 21, wherein the user device enters the inactive mode or sleep mode between the on-duration and the instructed reserved resource.

23. The one or more further transmissions are retransmissions of the initial transmission. The user device according to claim 21 or 22, wherein, in response to successfully receiving the initial transmission within the ON duration, the user device optionally sends an acknowledgment or sidelink AIM (assistance information), then enters the inactive or sleep mode and skips monitoring the instructed reserved resource.

24. The one or more further transmissions are retransmissions of the initial transmission. In response to the fact that a retransmission is not received on a reserved resource outside of the aforementioned on-duration period, the user device: - Maintaining activity during a specific time interval after the time slot in which retransmission was expected, such as during an inactive timer, or - Maintain active to receive n retransmissions (n ​​≤ maximum number of notified or pre-configured retransmissions), or - Enter the inactive mode or sleep mode and activate only for the next on-duration of the intermittent reception cycle, or - Sending support information to the transmitter that includes time and / or frequency information for retransmission, such as AIM (assistance information), or - The user device according to claim 21 or 22, which transmits support information having information regarding additional on-duration time such as AIM to the transmitter.

25. In addition to the reserved resources, the user device receives a resource reservation period, which indicates that the reserved resources will be used for further transmissions during the period following the reservation period. The user device according to any one of claims 20 to 24, which, in response to an instruction for the resource reservation period, extends the active time to include one or more of the instructed resources during the period following the reservation period.

26. The user device according to claim 25, in response to a resource reservation period having a specific duration, such as zero, indicating that the transmitter has selected another resource for the transmission, the user device enters the inactive or sleep mode and is activated only during the next on-duration of the intermittent receive cycle.

27. The user device according to any one of claims 20 to 26, wherein the one or more resources used by the at least one further transmission are indicated in a control message received by the user device, such as a sidelink information SCI message.

28. The user device according to claim 27, wherein the SCI indicates the resource reserved within a specific number of future time slots using the TRIV (time resource indicator value) format or the FRIV (format or a frequency resource indicator value) format, and optionally the resource reservation period indicates that the reserved resource will be used for further transmissions during the period following the reservation period.

29. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device communicates with one or more further user devices via a side link. The user device configures one or more of the further user devices to operate in intermittent reception mode. The user device determines the intermittent reception settings of the further user device according to one or more criteria.

30. The one or more of the above criteria are, - One or more characteristics of the transmitted packet, • Logical channel used for transmission, • Logical channel group used for transmission, • Service quality flow, - Service quality requirements related to transmission, such as priority, delay, or data rate. • Geographic location or zone, • Other user device types, - One or more resources used by the initial transmission and / or at least one further transmission, - Current battery status of the user device, The user device according to claim 29, comprising one or more of the following:

31. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device receives transmissions from one or more further user devices via a side link. The user device operates in intermittent reception mode and is active for a specific active period during the intermittent reception cycle, for example, the on-duration period. The user device is a user device that decodes a transmission or skips decoding a transmission according to one or more criteria.

32. The user device according to claim 31, wherein the one or more criteria include priority, and / or destination, and / or a HARQ (Hybrid Automatic Repeat Request) indicator associated with the transmission, and / or a cast type associated with the transmission, such as a unicast transmission, a groupcast transmission, or a broadcast transmission.

33. The user device according to claim 32, wherein if a HARQ indicator associated with the transmission indicates that the transmitter is requesting feedback for the transmission, the user device decodes the transmission and transmits the feedback.

34. The user device according to claim 32, wherein the user device checks a priority field in the first stage SCI on the physical sidelink control channel, and if the priority field indicates a priority below a specific priority threshold, it skips decoding the associated physical sidelink shared channel.

35. The user device according to claim 34 or 34, wherein the user device checks the destination field in the second stage SCI on the physical sidelink shared channel, and if the destination field indicates that the transmission is not destined for the user device or the user device group to which the user device belongs, it skips further decoding of the PSSCH.

36. The user device according to claim 34 or 35, wherein the user device checks the cast type within the SCI, such as a first-stage SCI or a second-stage SCI, and skips further decoding of the physical sidelink shared channel if the transmission is of a specific cast type.

37. The user device according to claim 34 or 36, wherein the user device checks the source ID field in the second stage SCI on the physical sidelink shared channel, and if the source ID field indicates that the transmission is not from a transmitter from which the user device is about to receive communications, or that the transmission is not on the list of source IDs to be decoded, the user device skips further decoding of the physical sidelink shared channel.

38. If decoding of the second-stage SCI fails and the priority field of the first-stage SCI indicates a priority above a certain threshold, the user device may, for example, become active to receive the retransmission by extending the active time until the retransmission is received, or become active with the resources indicated or reserved in the first-stage SCI for the retransmission, If the decoding of the two-stage SCI fails and the transmission is at a resource location previously reserved by the transmission to the user device, the user device extends the active time until the retransmission or another transmission is received, or The user device according to any one of claims 35 to 37, wherein if a previously reserved resource does not include an expected transmission, the user device extends the active time until the retransmission or another transmission is received.

39. A user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices. The user device communicates with one or more further user devices via a side link, and the one or more further user devices operate in intermittent receive mode. The user device transmits one or more HARQ-enabled transmissions to the further user device during the on-duration of the intermittent receiving cycle of the further user device. In response to not receiving HARQ feedback, the user device refrains from sending HARQ-enabled transmissions until the next on-duration of the further user device, and sends the HARQ-enabled transmissions during the next on-duration of the further user device.

40. Refraining from the aforementioned HARQ-compatible transmission means - Do not retransmit the current transport block any further. - Do not retransmit until the next on-duration period. - Restart the retransmission counter during the next ON duration. - Use of initial redundant version, - Reduce the number of retransmissions based on the total amount of time the device has been on continuously. The user device according to claim 39, comprising one or more of the above.

41. The user device according to claim 39, wherein even after the default on-duration has elapsed, the user device retransmits the HARQ-responsive transmission a certain number of times, and in response to not receiving HARQ feedback, the user device refrains from transmitting the HARQ-responsive transmission until the next on-duration of the further user device, and transmits the HARQ-responsive transmission during the next on-duration of the further user device.

42. The user device operates in an out-of-coverage mode, and in the out-of-coverage mode, the user device - The user device is not connected to the base station of the wireless communication system, and for example, the user device is operating in mode 2 or is not in an RRC connection state, and / or the user device does not receive sidelink resource allocation settings or assistance from the base station. - Connected to a base station of the wireless communication system that is unable to provide sidelink resource allocation settings or assistance for the user device for one or more reasons, and / or A user device according to any one of claims 1 to 41, connected to a base station of the wireless communication system that does not support sidelink services such as NR V2X services, such as a GSM, UMTS, or LTE base station.

43. The user devices include handheld user devices called VRU (Vulnerable Road User) or P-UE (Pedestrian UE), such as user devices with limited power or user devices used by pedestrians, or wearable or handheld user devices called PS-UE (Public Safety UE), used by public safety officers and first responders, or IoT user devices such as sensors, actuators, or user devices that are installed in the campus network to perform repetitive tasks and require periodic input from gateway nodes, or mobile terminals or fixed terminals or cellular IoT-user devices, or vehicle user devices or vehicle group leader user devices (GL-UE), or IoT or NB-IoT (narrowband A user device according to any one of claims 1 to 42, comprising one or more of the following: an IoT device, or a ground vehicle, or an aircraft, or a drone, or a mobile base station, or a roadside RSU, or a building, or any other item or device having a network connection that enables communication using a wireless communication network such as a sensor or actuator, or any other item / device having a network connection that enables communication using a sidelink such as a sensor or actuator, or any sidelink-enabled network entity.

44. A wireless communication system comprising a user device according to any one of claims 1 to 43, wherein the wireless communication system is configured for sidelink communication, for example, sidelink communication using resources from a set of sidelink resources of the wireless communication system.

45. The wireless communication system according to claim 44, wherein the wireless communication system comprises one or more base stations, the base stations comprising one or more of the following: a macrocell base station or a small cell base station or a central unit of a base station or a distributed unit of a base station or an IAB (Integrated Access and Backhaul) node or a roadside unit or a user device or a group leader user device (GL-UE) or a relay or an RRH (Remote Radio Head) or an AMF or MME or SMF or a core network entity or a mobile edge computing entity or a network slice such as one in an NR or 5G core context, or any transmit / receive point that enables an item or device to communicate using the wireless communication network, the item or device having network connectivity for communicating using the wireless communication network.

46. A method for operating a user device for a wireless communication system, wherein the wireless communication system includes a plurality of user devices, the user devices receive transmissions from one or more further user devices via a side link, the user devices operate in intermittent reception mode, and the method is A method that includes a step of entering an inactive mode or sleep mode when certain criteria are met.

47. A method for operating a user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices, and the method is A step of sending one or more transmissions to one or more further user devices via a sidelink SL, wherein the one or more further user devices operate in intermittent receiving mode; A method comprising the step of indicating to the further user device the end of the one or more transmissions so that the further user device may enter an inactive mode or sleep mode.

48. A method for operating a user device for a wireless communication network, wherein the wireless communication network includes a plurality of user devices, and the method is A step of sending multiple transmissions to one or more further user devices via a side link, wherein the one or more further user devices operate in intermittent receiving mode, and each of the multiple transmissions includes at least one initial transmission. A method comprising the step of sending the plurality of transmissions to the further user devices such that at least one of the initial transmissions falls within the on-duration of the intermittent reception cycle of the one or more further user devices.

49. A method for operating a user device for a wireless communication system, wherein the wireless communication system includes a plurality of user devices, the user devices receive transmissions from one or more further user devices via a sidelink SL, the user devices operate in intermittent reception mode, and the method is A method comprising the step of maintaining an active state for a specific active period during an intermittent reception cycle, wherein the specific active period depends on one or more criteria.

50. A method for operating a user device for a wireless communication system, wherein the wireless communication system includes a plurality of user devices, the user devices communicate with one or more further user devices via a side link SL, and the method is The step includes configuring one or more of the aforementioned further user devices to operate in intermittent reception mode, The method by which the intermittent reception settings of the further user device are determined based on one or more criteria.

51. A method for operating a user device for a wireless communication system, wherein the wireless communication system includes a plurality of user devices, the user devices receive transmissions from one or more further user devices via a sidelink SL, the user devices operate in intermittent receive mode, and are active for a specific active time, such as an on-duration, during an intermittent receive cycle, and the method is A method comprising the step of decrypting a transmission or skipping the decryption of a transmission according to one or more criteria.

52. A method for operating a user device for a wireless communication system, wherein the wireless communication system includes a plurality of user devices, the user devices communicate with one or more further user devices via a side link, the one or more further user devices operate in intermittent reception mode, and the method is The steps include sending one or more HARQ-enabled transmissions to a further user device during the on-duration of an intermittent reception cycle of that further user device, A method comprising the steps of: responding to the failure to receive HARQ feedback, refraining from sending a HARQ-enabled transmission until the next on-duration of the further user device, and sending the HARQ-enabled transmission during the next on-duration of the further user device.

53. A computer-readable medium that, when executed on a computer, stores instructions for performing the method according to any one of claims 46 to 52.

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