Multiple DRX settings for D2D communication

Abstract

To provide a method, wireless communication device, node, and program for an efficient implementation of discontinuous reception (DRX) for side-link transmission and other types of device-to-device (D2D) transmission.SOLUTION: A method is for providing voice, multimedia, and data services, intelligent transportation systems, vehicle management or cooperative services, national security and public safety services, and NCIS services. A wireless communication device transmits setting information to one or more other wireless communication devices, receives setting information from one or more nodes of a wireless communication network, simultaneously maintains a first DRX setting for D2D communication and a second DRX setting for D2D communication, selects whether or not to enable the first DRX setting and / or the second DRX setting, and participates in D2D communication with one or more further wireless communication devices. This is achieved based on at least one of the first DRX setting and the second DRX setting.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a method for controlling device-to-device (D2D) communication and to a corresponding device, system and computer program. [Background technology]

[0002] Current wireless communication networks, based for example on LTE (Long Term Evolution) or NR technologies specified by 3GPP (Third Generation Partnership Project), also support D2D communication modes, sometimes referred to as sidelink communication, that enable direct communication between UEs (user equipment). Such D2D communication modes can be used, for example, for vehicular communications, including communications between vehicles, between vehicles and roadside communication infrastructure, and possibly between vehicles and cellular networks. Because communications with vehicles can broadly encompass various types of devices, another term used to refer to this class of communications is vehicle-to-everything (V2X) communications. Vehicular communications have the potential to improve road safety, reduce energy consumption, and enable new services related to intelligent transportation systems.

[0003] Due to the nature of basic road safety services, LTE V2X functionality is designed for broadcast transmissions, i.e., transmissions in which all receivers within a certain range of the transmitter, i.e., receivers that can be considered intended recipients, can receive messages from the transmitter. In practice, the transmitter may not be aware of or control the group of intended receivers. V2X functionality for NR technology is described, for example, in 3GPP TR 38.885 V16.0.0 (March 2019). NR technology also allows for more targeted V2X services by supporting groupcast, multicast, or unicast transmissions, where the intended receiver of a message consists of only a subset of receivers within a certain range of the transmitter (groupcast) or a single receiver (unicast). For example, in a platooning service for vehicles, certain messages may be of interest only to platoon members, so that they can be efficiently targeted by groupcast transmissions. In another example, a see-through function, in which one vehicle provides video data from a forward-facing camera to a following vehicle, may encompass V2X communication between only one vehicle, for which unicast transmission may be the preferred option. Moreover, NR sidelink communication supports D2D communication for UEs with and without network coverage for various degrees of interaction between the UE and the network, including the possibility of standalone, network-less operation.

[0004] Further possible use cases for D2D communications include gap analysis for NSPS (National Security and Public Safety), Network-Controlled Interactive Services (NCIS), and railways. Further enhancements to NR sidelink technology are being considered to provide wider NR sidelink coverage for such use cases. One such enhancement is power saving, which enables battery-constrained UEs to perform sidelink operations in a power-efficient manner. For example, the 3GPP work item description "NR Sidelink Enhancement," document RP-193231, TSG RAN Meeting #86 (December 2019), proposes investigating sidelink discontinuous reception (DRX) operation for broadcast, groupcast, and unicast transmission modes, aiming to define sidelink DRX configurations and procedures for implementing sidelink DRX in UEs, including mechanisms for coordinating sidelink DRX configurations between communicating UEs and mechanisms for coordinating DRX configurations for downlink (DL) and uplink (UL) communications over the Uu radio interface with sidelink DRX configurations. However, suitable mechanisms and procedures have yet to be developed.

[0005] For NR technology, DRX procedures for DL / UL communications over the Uu radio interface are specified in 3GPP TS 38.321 V16.0.0 (March 2020). Expected UE behavior with respect to receiving and processing transmissions may be controlled based on these procedures. The underlying DRX functionality is based on defining a DRX active time, sometimes referred to as an active time state or ACTIVE state, during which the UE is expected to receive and process incoming transmissions. For example, the UE is expected to decode DL control channels, process received grants, and so on. Outside of the DRX active time, sometimes referred to as DRX inactive time, the UE is not expected to receive or process transmissions. Therefore, the access node, referred to as a "gNB" in NR technology, cannot expect the UE to listen to DL transmissions. The DRX configuration may also specify transition periods between states. Typically, outside of the DRX active time, the UE turns off some of its components and enters a low-power mode, such as sleep mode. A DRX cycle is defined to ensure that the UE periodically switches to DRX active time, i.e., wakes up from sleep mode. The DRX cycle may be based on two parameters: the periodicity of the DRX cycle, which controls how often the UE switches to DRX active time, and the duration of the DRX active time, which controls how long the UE is in the DRX active state. In addition to this basic DRX cycle, the DRX procedure defines other conditions that allow the UE to switch between DRX active time and DRX inactive time. For example, if the UE expects a retransmission from the gNB, it may enter DRX inactive time, e.g., while the gNB is preparing the retransmission, and then enter DRX active time, which should coincide with the time window in which the gNB is expected to send the retransmission. Generally, the DRX active time of a DRX cycle is determined by the DRX configuration. Therefore, the DRX configuration generally allows the UE to predict when it will be in DRX active time.On the other hand, due to various timers depending on the data traffic the UE receives or sends, it may be more difficult to predict whether the UE is in the DRX active time. The DRX procedure specified in 3GPP TS 38.321 V16.0.0 applies to DL / UL communication between a UE and a wireless communication network, and may not be applicable to SL communication or other types of D2D communication.

[0006] Furthermore, SL transmissions differ from DL and UL transmissions in many aspects. For example, in DL / UL communications, an access node, e.g., a gNB, is one of the communication endpoints, and communications are typically organized in a one-to-one manner, i.e., between a specific UE and a specific access node. This simplifies the configuration of DRX in the UE. Furthermore, because access nodes are not subject to the same power constraints as UEs, DRX is performed in the UE rather than the access node. SL communications are mostly based on using a broadcast transmission mode. Even the unicast and groupcast transmission modes of NR SL technologies use broadcast communications to some extent, e.g., for discovery and connection establishment. However, existing DRX procedures for DL / UL communications are based on the assumption that communications are typically organized in a one-to-one manner, allowing access nodes to efficiently use all radio resources by balancing the load, which is not possible in the case of broadcast mode communications. Furthermore, while in DL / UL communications it is typically the access node that controls the UE's operation, for SL communications many control functions are implemented in a distributed manner, for example distributed between the transmitting (TX) and receiving (RX) UEs, and sometimes even the UE's serving access node(s). Therefore, the proper configuration of DRX for SL transmissions is even more complex than for DL / UL communications.

[0007] Therefore, there is a need for techniques that allow for efficient implementation of DRX for sidelink transmissions and other types of D2D transmissions. Summary of the Invention

[0008] According to one embodiment, there is provided a method for controlling D2D communication, wherein a wireless communication device simultaneously maintains a first DRX configuration for D2D communication and a second DRX configuration for D2D communication, and the wireless communication device participates in D2D communication with one or more further wireless communication devices based on at least one of the first DRX configuration and the second DRX configuration.

[0009] According to a further embodiment there is provided a method for controlling D2D communication, whereby a wireless communication device is configured by a node of a wireless communication network to simultaneously maintain a first DRX configuration for D2D communication with one or more further wireless communication devices and a second DRX configuration for D2D communication with the one or more further wireless communication devices.

[0010] According to a further embodiment, there is provided a wireless communication device, the wireless communication device being configured to simultaneously maintain a first DRX configuration for D2D communication and a second DRX configuration for D2D communication, and further configured to participate in D2D communication with one or more further wireless communication devices based on at least one of the first DRX configuration and the second DRX configuration.

[0011] According to a further embodiment, there is provided a wireless communication device comprising at least one processor and a memory. The memory includes instructions executable by the at least one processor that cause the wireless communication device to simultaneously maintain a first DRX configuration for D2D communication and a second DRX configuration for D2D communication. The memory also includes instructions executable by the at least one processor that cause the wireless communication device to participate in D2D communication with one or more further wireless communication devices based on at least one of the first DRX configuration and the second DRX configuration.

[0012] According to a further embodiment there is provided a node for a wireless communication network, whereby a wireless communication device is configured to simultaneously maintain a first DRX configuration for D2D communication with one or more further wireless communication devices and a second DRX configuration for D2D communication with the one or more further wireless communication devices.

[0013] According to a further embodiment, there is provided a node for a wireless communication network, the node comprising at least one processor and a memory, the memory containing instructions executable by the at least one processor causing the node to be operable to configure a wireless communication device to simultaneously maintain a first DRX configuration for D2D communication with one or more further wireless communication devices and a second DRX configuration for D2D communication with the one or more further wireless communication devices.

[0014] According to a further embodiment of the present invention, a computer program or computer program product is provided in the form of a non-transitory storage medium including program code to be executed by, for example, at least one processor of a wireless communication device. By executing the program code, the wireless communication device simultaneously maintains a first DRX configuration for D2D communication and a second DRX configuration for D2D communication. Furthermore, by executing the program code, the wireless communication device participates in D2D communication with one or more further wireless communication devices based on at least one of the first DRX configuration and the second DRX configuration.

[0015] According to a further embodiment of the present invention, a computer program or computer program product is provided in the form of a non-transitory storage medium comprising program code to be executed by at least one processor of, for example, a node for a wireless communication network, whereby execution of the program code by the node configures the wireless communication device to simultaneously maintain a first DRX configuration for D2D communication with one or more further wireless communication devices and a second DRX for D2D communication with the one or more further wireless communication devices.

[0016] Details of such and further embodiments will become apparent from the detailed description that follows. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary V2X scenario in which D2D communication may be controlled according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram illustrating an exemplary scenario in which D2D communication may be controlled according to an embodiment of the present invention; [Figure 3] 1 is a schematic diagram illustrating an exemplary NSPS communication scenario in which D2D communication may control the establishment of a direct radio link according to an embodiment of the present invention; [Figure 4A] FIG. 10 is a schematic state transition diagram illustrating the usage of received SL transmissions for enabling and disabling class-specific SL DRX configurations according to one embodiment of the present invention. [Figure 4B] FIG. 10 is a schematic state transition diagram illustrating the usage of SL transmissions sent for enabling and disabling class-specific SL DRX configurations according to one embodiment of the present invention. [Figure 5A] FIG. 1 is a schematic state transition diagram illustrating the use of SL transmissions received based on a generic SL DRX configuration for enabling and disabling class-specific SL DRX configurations according to an embodiment of the present invention. [Figure 5B] FIG. 1 is a schematic state transition diagram illustrating the use of SL transmissions sent based on a generic SL DRX configuration for enabling and disabling class-specific SL DRX configurations according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic diagram illustrating an exemplary scenario in which a generic SL DRX configuration and a class-specific SL DRX configuration operate simultaneously according to an embodiment of the present invention; [Figure 7] 1 is a schematic flow chart illustrating a method according to one embodiment of the present invention. [Figure 8]8 is an exemplary block diagram illustrating the functionality of a wireless communication device that implements functionality corresponding to the method of FIG. 7. [Figure 9] 4 is a schematic flow chart illustrating a further method according to an embodiment of the present invention; [Figure 10] 10 is an exemplary block diagram illustrating the functionality of a network node that implements functionality corresponding to the method of FIG. 9. [Figure 11] 1 is a schematic diagram illustrating the structure of a wireless communication device according to one embodiment of the present invention; [Figure 12] FIG. 2 is a schematic diagram illustrating the structure of a network node according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] In the following, concepts according to exemplary embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The illustrated embodiments relate to controlling D2D communications by wireless communication devices. These wireless communication devices may include various types of UEs or other wireless devices (WDs). As used herein, the term "wireless device" (WD) refers to a device that can be configured, arranged, and / or operable to communicate wirelessly with network nodes and / or other WDs. Unless otherwise noted, the term WD may be used interchangeably with UE in this specification. Wireless communication may encompass sending and receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for transmitting information over the air. In some embodiments, a WD may be configured to send and receive information without direct human interaction. For example, a WD may be designed to transmit information to a network on a predetermined schedule, when activated by an internal or external event, or in response to a request from the network. Examples of WDs include, but are not limited to, smartphones, mobile phones, cellular phones, voice-over-IP (VoIP) phones, wireless local loop phones, desktop computers, personal digital assistants (PDAs), wireless cameras, game consoles or devices, music storage devices, playback devices, wearable terminal devices, wireless endpoints, mobile stations, tablets, laptop computers, laptop embedded devices (LEEs), laptop mounted devices (LMEs), smart devices, wireless customer premises equipment (CPEs), vehicle-mounted wireless terminal devices, connected vehicles, etc. In some examples, in Internet of Things (IoT) scenarios, a WD may also correspond to a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another WD and / or network node. In this case, the WD may be a machine-to-machine (M2M) device, which may be referred to as a machine-type communication (MTC) device in the 3GPP context. As one specific example, the WD may be a UE implementing the 3GPP Narrowband IoT (NB-IoT) standard.Specific examples of such machines or devices include sensors, metering devices such as power meters, industrial machinery, household or personal electrical appliances (e.g., refrigerators, televisions, etc.), or personal wearables (e.g., watches, fitness trackers, etc.). In other scenarios, the WD may correspond to a vehicle or other equipment capable of monitoring and / or reporting on its operating status or other functions related to its operation. The WD may correspond to an endpoint of a wireless connection as described above, in which case the device may be referred to as a wireless terminal. Moreover, the WD described above may be mobile, in which case it may also be referred to as a mobile device or mobile terminal. The illustrated concepts particularly relate to WDs that support, for example, D2D communication by implementing 3GPP standards for sidelink communication, vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), and vehicle-to-everything (V2X). The D2D communication may be based on, for example, LTE or NR wireless technology defined by 3GPP, and may be based on, for example, the PC5 interface of the LTE or NR technology. However, it is noted that the concepts shown may also be applied to other wireless technologies, such as for example WLAN (Wireless Local Area Network) technology.

[0019] In the illustrated concept, D2D communications may be performed in an energy-efficient manner by using procedures and mechanisms that enable DRX operations for D2D communications. The DRX operations apply, for example, to sidelink (SL) communications over the PC5 interface of LTE or NR technologies, denoted herein as "SL DRX." The DRX operations may involve configuring UEs participating in D2D communications with DRX active times and DRX inactive times. It should be noted that a sequence of DRX active times followed by DRX inactive times may also be denoted as an "SL DRX cycle," and that the SL DRX cycle need not repeat periodically and that the duration of the active time and / or inactive time may vary from one SL DRX cycle to the next.

[0020] In the D2D communication discussed herein, a UE may operate as a receiver, also referred to herein as an RX UE, and / or a transmitter, also referred to herein as a TX UE. For a TX UE, participating in D2D communication may involve the TX UE sending at least one D2D transmission to the RX UE during the DRX active time. For a RX UE, participating in D2D communication may involve the RX UE receiving at least one D2D transmission from the TX UE during the DRX active time. During the DRX inactive time, the RX UE may power down at least a portion of its receiver circuitry to enable energy saving. During the DRX active time, the RX UE is in a DRX active mode and is not allowed to power down a portion of its receiver circuitry. The transition between the DRX active time and the DRX inactive time is controlled by the UE's DRX configuration, e.g., using one or more timers and associated parameters. The TX UE may take the DRX inactive time into account by refraining from sending any D2D transmission to the RX UE during the DRX inactive time. Thus, the DRX configuration may be used in a RX UE to enable power savings by controlling switching between DRX active and DRX inactive times. Furthermore, the DRX configuration may be used in a TX UE to align power transmissions with the expected DRX behavior of the RX UE, or in the case of groupcast or multicast transmissions.

[0021] It should be noted that some of the following examples are described from the perspective of an RX UE and others from the perspective of a TX UE, but the roles of an RX UE and a TX UE are interchangeable. Furthermore, a UE can operate as a TX UE and an RX UE simultaneously. Furthermore, the examples described below may assume that a D2D UE and its serving access node operate using the same radio access technology (RAT), e.g., NR technology or LTE technology, but the illustrated concepts may apply to any combination of RATs between a D2D UE and its serving access node. Furthermore, in the illustrated concepts, D2D transmissions may be based on a unicast transmission mode, a groupcast transmission mode, or a broadcast transmission mode.

[0022] Figure 1 illustrates an exemplary scenario involving V2X communications. In particular, Figure 1 illustrates various UEs 10 that may participate in V2X communications or other D2D communications, as indicated by solid arrows. Additionally, Figure 1 illustrates access nodes 100 of a wireless communication network, such as eNBs in LTE technology or gNBs in NR technology, or access points in a WLAN. At least some of the UEs 10 may also communicate by using DL and / or UL radio transmissions, as indicated by dashed arrows.

[0023] The UEs 10 shown in FIG. 1 include vehicles, drones, mobile phones, and people, such as pedestrians, cyclists, vehicle drivers, or vehicle passengers. It is noted that in the case of a vehicle, radio broadcasting may be via an installed communication module, and in the case of a person, radio broadcasting may be via a portable or worn wireless device, such as a wristband device or similar wearable device. Furthermore, it is noted that the UEs shown in FIG. 1 are merely exemplary, and the illustrated concepts may similarly utilize other types of V2X or D2D communication devices, such as RSUs (roadside units) or other infrastructure-based V2X communication devices, or V2X communication devices based on aircraft such as airplanes or helicopters, spacecraft, trains or train carriages, ships, motorcycles, bicycles, scooters, or other types of mobility devices or means of transportation. V2X communication may also include utilizing the illustrated mechanisms and procedures to improve energy efficiency of V2X communication by enabling DRX operation for V2X communication between each UE 10.

[0024] FIG. 2 illustrates an exemplary D2D communication scenario. In particular, FIG. 2 illustrates multiple UEs 10 connected to each other by radio links implementing direct radio links (indicated by bidirectional arrows). Furthermore, one of the UEs 10 is connected by a radio link to an access node 100 of a wireless communication network, e.g., an eNB in ​​LTE technology or a gNB in ​​NR technology. The access node 100 is part of a RAN (Radio Access Network) of the wireless communication network, which typically also includes access nodes for providing a desired coverage of the wireless communication network. Furthermore, FIG. 2 illustrates a core network (CN) 210 of the wireless communication network. The CN 210 may provide connectivity of the UE 10 to other data networks, e.g., through a GW 220 provided in the CN 210. Furthermore, the CN 210 may include various nodes for controlling the operation of the UE 10.

[0025] A wireless link may be used for D2D communication between the UEs 10. Furthermore, a wireless link to a wireless communication network may be used to control or assist the D2D communication. Furthermore, D2D communication and / or data communication to the wireless communication network may be used to provide the UEs 10 with various types of services, such as voice services, multimedia services, data services, intelligent transportation systems (ITS) or similar vehicle management or coordination services, NSPS services, and / or NCIS services. Such services may be based on applications running on the UEs 10 and / or on devices linked to the UEs 10. Thus, in the illustrated concept, a D2D transmission may carry or correspond to a V2X message, an ITS message, or some other type of message related to the service. Furthermore, FIG. 2 illustrates an application service platform 250 in the CN 210 of the wireless communication network. Furthermore, FIG. 2 illustrates one or more application servers 300 located outside the wireless communication network. Application(s) running on the UE 10 and / or one or more other devices linked to the UE 10 may use wireless links to one or more other UEs 10, the application service platform 250, and / or the application server(s) 300, thereby enabling corresponding service(s) on the UE 10. In some scenarios, services utilized by the UE 10 may thus be hosted on the network side, for example, on the application service platform 250 or the application server(s) 300. However, some of the services may be network-independent and thus may be utilized without requiring an active data connection to the wireless communication network. This may apply, for example, to certain V2X or NSPS services. However, such services may continue to be supported from the network side while the UE 10 is within the coverage of the wireless communication network.Also, in the scenario of FIG. 2, the UE 10 may apply DRX operation to D2D communication to improve energy efficiency.

[0026] In the example of Figure 2, the UE 10 is assumed to be a mobile phone and a vehicle or vehicle-based communication device, such as, for example, an on-board or vehicle-integrated communication module or a smartphone or other user device linked to the vehicle system. However, it is noted that other types of UE may be used as well, such as, for example, a device carried by a pedestrian or an infrastructure-based device, such as, for example, the roadside unit shown in Figure 1.

[0027] FIG. 3 schematically illustrates an NSPS communication scenario. In particular, FIG. 3 illustrates multiple UEs 10 that may exchange NSPS messages associated with one or more NSPS services using D2D communication, e.g., based on LTE sidelink communication or NR sidelink communication. As further illustrated, the NSPS service may be supported by the access node 100 from the network by exchanging NSPS messages. The NSPS service may include, for example, group communication of rescue vehicles, emergency personnel, or other equipment or personnel of a public safety-related organization. Such communication may also involve utilizing the illustrated mechanisms and procedures to enable DRX operation for D2D communication between each UE 10, thereby improving energy efficiency of the D2D communication.

[0028] As mentioned above, in some scenarios, D2D communication to which DRX operation is applied may be based on NR technology or LTE technology SL mode using a PC5 air interface. In such cases, SL communication may be based on multiple physical channels, including a physical sidelink control channel (PSCCH), a physical sidelink shared channel (PSSCH), a physical sidelink feedback channel (PSFCH), and a physical sidelink broadcast channel (PSBCH), defined at the physical (PHY) layer of the air interface between the TX UE and the RX UE. The decoded data from the PHY layer may then be further processed by a media access control (MAC) entity of the RX UE.

[0029] The PSCCH carries only control information, usually referred to as first stage SCI (sidelink control information). The first stage SCI is transmitted using a predefined format on a given radio resource, allowing the RX UE to use blind decoding. That is, the RX UE attempts to decode the PSCCH in a predefined format on a given radio resource without knowing in advance whether the PSCCH was actually transmitted or not. If the decoding operation is successful, the RX UE assumes that the PSCCH was transmitted. Otherwise, the RX UE assumes that the PSCCH was not transmitted. The PSCCH carries the information necessary to decode the PSCCH.

[0030] The PSSCH carries both control information and a data payload. The control information is usually referred to as the second stage SCI. The control information is transmitted using the radio resource allocation and transmission format indicated in the PSCCH. The control information also includes information necessary to decode the data payload carried by the PSSCH.

[0031] The PSFCH carries only feedback information. The content of the PSFCH depends on the mode of HARQ operation. In some cases, both positive acknowledgements (also denoted ACK) and negative acknowledgements (also denoted NACK) are transmitted. In other cases, only NACKs are transmitted. PSFCH transmissions are made on given radio resources and using a predefined format.

[0032] The PSBCH carries basic system configuration information such as bandwidth, TDD (Time Division Duplex) configuration, and the like. Additionally, the PSBCH carries synchronization signals.

[0033] A typical operation for SL communication may be that a first UE performs SL transmission on the PSCCH and PSSCH. A second UE receives the SL transmission. Receiving the SL transmission may involve the second UE detecting the PSCCH using blind decoding and decoding the first stage SCI carried by the PSCCH. If the blind decoding is successful, the second UE decodes the second stage SCI carried by the PSSCH using the decoded content of the PSCCH. The second UE decodes the second stage SCI and then decodes the payload data carried by the PSSCH using the first stage SCI and the second stage SCI. If the second UE successfully decodes the payload data, it transmits hybrid automatic repeat request (HARQ) feedback on the PSFCH. Various schemes may be utilized to provide the HARQ feedback. The first UE expects to receive HARQ feedback from the second UE and may use the presence and content of the PSFCH to determine further action, such as whether to perform a retransmission. Therefore, the PSDCH can be used to trigger actions related to HARQ operation for SL transmissions. In some cases, the use of HARQ feedback may also be omitted. For example, in broadcast mode, HARQ feedback is generally not used for SL transmissions. The TX UE (e.g., the first UE in the considered example) may indicate in the SCI whether the TX UE expects the RX UE (e.g., the second UE in the considered example) to transmit a PSFCH in the HARQ feedback.

[0034] In the illustrated concept, DRX operation for SL transmissions is based on configuring multiple SL DRX configurations for the UE. In particular, the UE simultaneously maintains two or more SL DRX configurations and selectively applies one or more of these SL DRX configurations when receiving or sending SL transmissions. The UE may selectively enable or disable certain SL DRX configurations for this purpose.

[0035] In some scenarios, one or more of the SL DRX configurations may be class-specific, i.e., each may be associated with a particular class of SL traffic. When the UE receives or transmits data packets of a particular class, it may use these data packets to control DRX operation associated with the corresponding SL DRX configuration, e.g., by starting, stopping, or resetting a timer such that the UE switches between a DRX active time and a DRX inactive time. Because DRX operation is controlled per SL DRX configuration, there may be a separate DRX active time and a separate DRX inactive time for each SL DRX configuration. However, it should be noted that the separate DRX active times and separate DRX inactive times typically combine into an overall pattern, and the UE will either have an overall DRX active time or an overall DRX inactive time accordingly. In some aspects of the present disclosure, for example, which SL DRX cycle triggered a switch to the current DRX active time may be utilized when determining whether or which SL traffic class data packets should be transmitted.

[0036] In some scenarios, the multiple SL DRX configurations may include specific SL DRX configurations associated with specific classes of SL traffic, or may include multiple specific SL DRX configurations, each associated with a specific class of SL traffic, and a common SL DRX configuration that is generic to multiple or all classes of SL traffic. Thus, the common SL DRX configuration may be used, for example, for classes of SL traffic that do not have an associated specific SL DRX configuration. Furthermore, the common SL DRX configuration may also be used as a fallback or for bootstrapping specific SL DRX configurations.

[0037] In the following, the presented concepts are explained in more detail, taking into account in particular procedures and mechanisms for operating multiple SL DRX configurations simultaneously, and procedures and mechanisms resulting in SL DRX configurations that can be maintained and operated simultaneously, where it is noted that the latter procedures and mechanisms can be used independently from the former procedures for operating multiple SL DRX configurations simultaneously.

[0038] As used herein, the SL DRX configuration can be enabled (which may also be referred to as "activated" or "true") or disabled (which may also be referred to as "deactivated" or "false"). Here, an enabled SL configuration is used to control switching between the DRX active time and the DRX inactive time. A disabled SL configuration is configured in the UE, i.e., the parameters are defined and stored in the UE, but are not currently used to control switching between the DRX active time and the DRX inactive time. In some parts of this invention, reference is made to enabled or disabled DRX configurations.

[0039] As mentioned above, in some scenarios, a UE may be configured with one or more class-specific SL DRX configurations. Such class-specific SL configurations may also be referred to herein as S-DRX configurations. Each S-DRX configuration is associated with one particular class of SL traffic, e.g., data packets of a particular class conveyed by an SL transmission. In general, for each data packet conveyed by an SL transmission, it can be determined whether the data packet belongs to a particular class of SL traffic. Therefore, various types of information associated with a data packet may be used to define a particular class. Such information may include an identifier (ID) of the UE sending the data packet, e.g., a Layer 1 (L1) ID used on the PHY layer or a Layer 2 (L2) ID used on the MAC layer. Additionally or alternatively, such information may include, for example, a source address or a destination address carried by the data packet, e.g., an L1 address or an L2 address. Additionally or alternatively, such information may include, for example, a combination of an L1 ID or an L2 ID. For example, a combination of an L1 ID or an L2 ID may be used to identify an SL unicast link. Additionally or alternatively, for example, such information may include a link identifier, such as an identifier of an SL unicast link. Additionally or alternatively, such information may include, for example, a transmission mode of the data packet, indicating whether the data packet is transmitted by unicast, groupcast, or broadcast. For groupcast, multiple subtypes may be identified. Additionally or alternatively, for example, such information may include a service identifier, for example, identifying whether the data packet is associated with a traffic safety service, a public safety service, or the like. Additionally or alternatively, for example, such information may include location information, such as an area identifier. Additionally or alternatively, such information may include, for example, identifying a QoS (Quality of Service) flow, a QoS level, a QoS class, or a priority of the data packet.

[0040] The S-DRX configuration defines a DRX active state and a DRX inactive state, which correspond to the aforementioned DRX active time and DRX inactive time, respectively. With respect to the S-DRX configuration, these states are also referred to herein as the S-ACTIVE state (S-ACT) and the S-INACTIVE state (S-INACT), respectively. Furthermore, the S-DRX configuration defines the transition between the S-ACTIVE state and the S-INACTIVE state.

[0041] The S-DRX configuration may be used to enable power-efficient transmission of data packets of a particular class. To this end, if an RX UE is configured with the S-DRX configuration, it may operate to monitor SL radio resources for SL transmissions containing data packets of a particular class whenever it is in the S-ACTIVE state. The RX UE may ignore or discard any received data packets of a particular class while in the S-INACTIVE state, and may even power down part of its receiver circuitry so as not to receive any SL transmissions. This behavior may be configured or pre-configured in the UE. A TX UE (at least potentially) having RX UE(s) with the S-DRX configuration configured may operate in a corresponding manner by transmitting data packets of a particular class only while the RX UE(s) are in the S-ACTIVE state.

[0042] In some scenarios, the class of a data packet may be indicated using L1 or L2 control signaling, for example in the SCI or MAC CE (Control Element). Alternatively or additionally, the class of a data packet may be indicated in the packet's header. For example, an identifier and / or address and / or transmission mode may be indicated in the SCI of the SL transmission carrying the data packet. If a given data packet may be allocated to different classes, the class indicated by the L1 or L2 control signaling may be selected to correspond to the one associated with a given SL transmission, for example depending on the identifiers of the TX UE and RX UE and / or the SL radio bearer utilized.

[0043] In some scenarios, the S-DRX configuration may take effect once configured or reconfigured. The configuration or reconfiguration of the S-DRX configuration may be performed, for example, as part of an SL connection establishment procedure, an SL radio bearer configuration procedure, or an SL radio bearer reconfiguration procedure. For unicast, the S-DRX configuration may be configured or reconfigured using RRC (Radio Resource Control), for example, a PC5 RRC message. For example, when configuring or reconfiguring the S-DRX configuration for each SL unicast connection, the initiating UE may send a dedicated PC5-RRC message to the peer UE, including the S-DRX configuration for the established SL unicast connection. This may be achieved after the PC5-S message exchange to establish and configure security for the SL unicast connection. In another example, when configuring or reconfiguring the S-DRX configuration for each SL radio bearer, the initiating UE may include the S-DRX configuration in a PC5-RRC RRCReconfigurationSidelink message sent to the peer UE.

[0044] In some scenarios, the S-DRX configuration may also have a configurable initial state, for example, defined by the S-DRX AS (Access Stratum) configuration. This initial state may be set to enabled or disabled. Thus, the initial state after configuring the S-DRX configuration may be defined according to current requirements. Furthermore, this state may be changed by reconfiguration.

[0045] For example, if the S-DRX configuration is initially set to "disabled," the S-DRX configuration can be enabled by another control message, i.e., a control message separate from the control message that results in the S-DRX configuration. For example, the TX UE can enable the S-DRX configuration in the RX UE by sending a control message to the RX UE. Furthermore, the RX UE determines the enablement of the S-DRX configuration and notifies the TX UE by sending a control message to the TX UE. In each case, the control message may correspond to Layer-1 signaling, such as an instruction carried by a dedicated PC5-RRC message, a MAC CE, or an SCI.

[0046] In some scenarios, the S-DRX configuration may be implicitly enabled by an SL transmission that does not necessarily include a control message. For example, the S-DRX configuration may be enabled in a UE when the UE sends or receives an SL transmission with a data packet of a particular class. In this case, the UE may also start a timer when receiving or sending an SL transmission and keep the S-DRX configuration enabled until the timer expires. The timer may be set together with the S-DRX configuration or by a separate control message, for example, a dedicated PC5-RRC message, a MAC CE, or Layer-1 signaling such as an instruction carried by the SCI.

[0047] In some scenarios, the S-DRX configuration may be enabled by a control message indicating an activation time, e.g., with respect to a timeslot in which the S-DRX configuration is to be enabled. For example, the TX UE may instruct the RX UE to enable the S-DRX configuration by sending a control message indicating a given timeslot, and the RX UE enables the S-DRX configuration from this timeslot. Furthermore, the TX UE may instruct the RX UE to enable the S-DRX configuration by sending a control message indicating an offset number of timeslots, and the RX UE enables the S-DRX configuration after this offset number.

[0048] In some scenarios, the UE may enable the S-DRX configuration based on upcoming data traffic. For example, when the TX UE intends to send a data packet belonging to a particular class, the S-DRX configuration may be enabled in the TX UE. Similarly, when the RX UE expects to receive a data packet belonging to a particular class, the S-DRX configuration may be enabled in the RX UE.

[0049] Which of the above variables can be used to enable the S-DRX configuration may also be configurable, for example as part of the S-DRX configuration.

[0050] The S-DRX configuration may be disabled in various ways. In some scenarios, the S-DRX configuration is disabled during termination of an SL connection or an SL radio bearer. In some cases, the S-DRX configuration may be autonomously released by the RX UE and / or the TX UE. For example, when an SL unicast connection is terminated, the S-DRX configuration for this SL unicast connection may be disabled.

[0051] In some scenarios, the S-DRX configuration may be disabled by a control message. For example, the TX UE may disable the S-DRX configuration in the RX UE by sending a control message to the RX UE. Furthermore, the RX UE may disable the S-DRX configuration and notify the TX UE by sending a control message. In each case, the control message may be L1 signaling, such as a dedicated PC5-RRC message, a MAC CE, or an instruction carried by the SCI.

[0052] In some scenarios, the S-DRX configuration may be disabled when a timer expires. For example, a timer may be reset each time the UE sends or receives a data packet of a particular class. If no data packets of a particular class are sent or received for a certain period of time, the time expires and the S-DRX configuration is disabled. This timer-based disabling of the S-DRX configuration may be applied to the TX UE and / or the RX UE. The timer setting for controlling the disabling of the S-DRX configuration may be common to multiple or all S-DRX configurations, or may be configured individually for each S-DRX configuration, e.g., as part of the S-DRX configuration.

[0053] In some scenarios, the UE may enable the S-DRX configuration based on upcoming data traffic. For example, when the TX UE has no data packets of a particular class to send, the S-DRX configuration may be disabled in the TX UE. When the RX UE no longer expects to receive data packets of a particular class, the S-DRX configuration may be disabled in the RX UE.

[0054] FIG. 4A shows a state transition diagram for illustrating an example in which the S-DRX configuration is enabled by receiving a data packet of a specific class and disabled in response to the expiration of a timer. In the example of FIG. 4A, if the S-DRX configuration is in a disabled state, the S-DRX configuration is enabled when the UE receives a data packet of the specific class. Each time the UE receives an additional packet of the specific class, the timer is reset. When the timer expires, the S-DRX configuration is disabled. The procedure of the example of FIG. 4A may be applied to a RX UE and / or a TX UE. Furthermore, it is noted that the UE may be configured such that receiving data packets that do not belong to a specific class does not affect the state of the S-DRX configuration associated with the specific class.

[0055] FIG. 4B shows a state transition diagram for illustrating an example where the S-DRX configuration is enabled by sending a data packet of a specific class and disabled in response to expiration of a timer. In the example of FIG. 4B, if the S-DRX configuration is in a disabled state, the S-DRX configuration is enabled when the UE sends a data packet of the specific class. Each time the UE sends another packet of the specific class, the timer is reset. When the timer expires, the S-DRX configuration is disabled. The procedure of the example of FIG. 4B may be applied to a TX UE and / or a RX UE. Furthermore, it is noted that the UE may be configured such that sending data packets that do not belong to a specific class does not affect the state of the S-DRX configuration associated with the specific class.

[0056] As mentioned above, the use of one or more S-DRX configurations may also be combined into a common SL DRX configuration, also referred to herein as a C-DRX configuration, that is generic for multiple or all classes of SL traffic. Thus, the C-DRX configuration may be applicable to classes of SL traffic that are different from any of the specific classes considered. The C-DRX configuration defines DRX active and DRX inactive states, which correspond to the aforementioned DRX active and DRX inactive times, respectively. With respect to the C-DRX configuration, these states are also referred to herein as the C-ACTIVE state (C-ACT) and the C-INACTIVE state (C-INACT), respectively. Furthermore, the C-DRX configuration defines the transition between the C-ACTIVE and C-INACTIVE states.

[0057] The C-DRX configuration can be used for multiple purposes. For example, the C-DRX configuration can enable power-efficient reception of data packets regardless of whether they belong to any particular class. For example, the C-DRX configuration can be used by a TX UE to transmit data packets when the TX UE does not have enough information to determine which S-DRX configuration to use. Furthermore, the C-DRX configuration can be used to bootstrap an S-DRX configuration, i.e., to enable information exchange between a RX UE and a TX UE for the purpose of establishing an S-DRX configuration. For example, two UEs can use the C-DRX configuration to establish a unicast SL connection and one or more associated S-DRX configuration(s). The C-DRX configuration can also be used to dynamically enable and / or disable an S-DRX configuration. For example, if the S-DRX configuration associated with a particular class of SL traffic is disabled, the sending and receiving of SL transmissions using data packets of this particular class can be achieved based on the C-DRX configuration. Figures 5A and 5B show corresponding examples.

[0058] FIG. 5A shows a state transition diagram for explaining an example in which the S-DRX configuration is enabled by receiving a data packet of a specific class based on the C-DRX configuration and disabled in response to the expiration of a timer. In the example of FIG. 5A, when the S-DRX configuration is disabled, the S-DRX configuration is enabled when the UE receives a data packet of a specific class. The UE receives this data packet based on the C-DRX configuration. Thus, power efficiency can be improved even before the S-DRX configuration is enabled. Each time the UE receives another packet of a specific class, the timer is reset. When the timer expires, the S-DRX configuration is disabled. The procedure of the example of FIG. 5A can be applied to RX UEs and / or TX UEs. Furthermore, it is noted that the UE can be configured such that receiving data packets not belonging to a specific class does not affect the state of the S-DRX configuration associated with the specific class.

[0059] FIG. 5B shows a state transition diagram for explaining an example in which the S-DRX configuration is enabled by sending a data packet of a specific class based on the C-DRX configuration and is disabled in response to the expiration of a timer. In the example of FIG. 5B, if the S-DRX configuration is disabled, the S-DRX configuration is enabled when the UE sends a data packet of a specific class. The UE sends this data packet based on the C-DRX configuration. Thus, power efficiency can be improved even before the S-DRX configuration is enabled. Each time the UE sends another packet of a specific class, the timer is reset. When the timer expires, the S-DRX configuration is disabled. The procedure in the example of FIG. 5B can be applied to RX UEs and / or TX UEs. Furthermore, it is noted that the UE can be configured so that sending data packets that do not belong to a specific class does not affect the state of the S-DRX configuration associated with the specific class.

[0060] The combination of a C-DRX configuration with one or more S-DRX configurations may provide several benefits. For example, the fallback configuration provided by the C-DRX configuration may be used, for example, after a connection failure. Furthermore, the C-DRX configuration may be used efficiently to bootstrap the S-DRX configuration(s). Furthermore, the C-DRX configuration may tolerate long outage periods during which the UE may be in a power saving mode, while the S-DRX configuration(s) may be optimized in terms of fast message exchange between each UE and may be enabled only on demand.

[0061] When using multiple SL DRX configurations, e.g., one or more S-DRX and C.DRX configurations, an overall DRX active state and an overall DRX inactive state are used by taking into account the states of the individual SL DRX configurations in the combination. For example, the overall DRX active time may correspond to the time when any of the individual SL DRX configurations is in the DRX active time. Otherwise, the UE is in the overall DRX inactive time.

[0062] FIG. 6 shows an example for explaining enabling of the S-DRX configuration based on the transmission and reception of SL transmissions of a particular class and disabling of the S-DRX configuration based on a timer. In particular, FIG. 6 shows the enabling and disabling of the S-DRX configuration, as well as the changes over time in the state of the C-DRX configuration and the state of the S-DRX configuration. In the example of FIG. 6, reception of data packets of a particular class associated with the S-DRX configuration is indicated by a solid vertical arrow, and reception of data packets of some other class is indicated by a dashed vertical arrow. As can be seen, reception of data packets of a particular class enables or keeps the S-DRX configuration enabled. Reception of data packets of some other class does not enable or affect the enabled state of the S-DRX configuration.

[0063] The TX UE may be configured with the following operations depending on the state of the C-DRX configuration and / or the S-DRX configuration. In some variants, a TX UE may transmit data packets of a certain class only during the DRX active time of the associated S-DRX configuration, in particular only while its own S-DRX configuration and / or the S-DRX configuration(s) of the RX UE(s) are in S-ACTIVE state. In some variations, a TX UE may transmit multiple N data packets of a particular class during the DRX active time of the C-DRX configuration, in particular while its own C-DRX configuration and / or the C-DRX configuration of the RX UE(s) are in the C-ACTIVE state. These N data packets may be used, for example, to enable the associated S-DRX configuration in the RX UE(s). In some cases, the number N may be N=1. In some variants, a TX UE may transmit data packets of a particular class during the DRX active time of the associated S-DRX setting, during the DRX active time of the C-DRX setting or during the DRX active time of some other DRX setting, e.g. an S-DRX setting related to another class, in particular during the S-DRX setting of the TX UE itself and / or when the RX UE(s) are in S-ACTIVE state, or during the C-DRX setting of the TX UE itself and / or when the C-DRX setting of the RX UE(s) is in C-ACTIVE state, or while some other DRX setting at the TX UE and / or RX UE is in DRX active state. In some variants, a TX UE may transmit data packets of a specific class if any of its own DRX configurations is in DRX active state, and similarly for S-DRX configurations related to classes other than the specific class. In some variants, during the DRX active time of an S-DRC configuration related to a particular class, the transmission of data packets of a particular class is given higher priority than the transmission of data packets of other classes. In some variants, a TX UE may transmit data packets of a particular class during the DRX active time of the C-DRX configuration or during the DRX active time of some other DRX configuration, e.g. an S-DRX configuration associated with another class, only if the congestion level in the DRX active is below a certain threshold. In some variations, when multiple DRX active times for different DRX configurations are valid, the TX UE may select a DRX active to be used for transmitting packets of a particular class. This selection may be achieved depending on the congestion level at the considered DRX active time. For example, the TX UE may decide to transmit at a given DRX active time only if the congestion level at this DRX active time is below a certain threshold. In some variants, the TX UE may transmit data packets that do not belong to any particular class with an associated configured S-DRX configuration only during the DRX active time of the C-DRX configuration, in particular only during the TX UE's own C-DRX configuration and / or only when the C-DRX configuration at the RX UE(s) is in the C-ACTIVE state. For example, for SL unicast transmission of data packets, the TX UE may transmit SL-SRB messages, e.g., PC5-S or PC5-RRC messages, only while the C-DRX configuration is in the C-ACTIVE state. According to a further example, the TX UE may transmit SL transmissions using standalone SL CSI (Channel State Information) reports, i.e., transport blocks containing only SL CSI reports, for SL unicast packet transmissions only during the DRX active time of the C-DRX configuration, in particular only during the TX UE's own C-DRX configuration and / or only when the C-DRX configuration at the RX UE(s) is in the C-ACTIVE state. According to a further example, a TX UE may transmit data packets for SL groupcast and SL broadcast transmission of data packets only during the DRX active time of the C-DRX configuration, in particular during the C-DRX configuration of the TX UE itself and / or when the C-DRX configuration in the RX UE(s) is in the C-ACTIVE state. In some variants, the TX UE may transmit data packets not belonging to a particular class during the DRX active time of the S-DRX setting related to the particular class, during the DRX active time of the C-DRX setting or during the DRX active time of some other DRX setting, e.g. the S-DRX setting related to some other class, in particular while the S-DRX setting related to the particular class of the TX UE itself and / or the S-DRX setting related to the particular class of the RX UE(s) are in the S-ACTIVE state or while the C-DRX setting of the TX UE itself and / or the C-DRX setting in the RX UE(s) are in the C-ACTIVE state or while other DRX settings of the TX UE and / or RX UE(s) are in the DRX active state. In some variations, the selection between at least some of the above operations of the TX UE may be negotiated and agreed upon between the TX UE and the RX UE(s) during connection establishment. Furthermore, the selection between at least some of the above operations of the TX UE may be configured by a node of the wireless communication network or may be part of a pre-configuration based on, for example, a standard, a manufacturer setting, or a network operator setting. In some variants, the transmission of data packets of a certain class in a C-ACTIVE or S-ACTIVE state of an S-DRX configuration associated with another class may or may not affect this C-ACTIVE or S-ACTIVE state, e.g., based on a configuration or pre-configuration of the TX UE. For example, in this case, it may be configured or pre-configured in the UE whether the DRX active time of the C-DRX configuration or the DRX active time of an S-DRX configuration associated with another class should be extended, e.g., by starting or resetting a timer.

[0064] The RX UE may be configured with the following operations depending on the state of the C-DRX configuration and / or the S-DRX configuration. In some variants, the RX UE is expected to process, e.g. receive, data packets of a certain class only during the DRX active time of the S-DRX configuration related to the certain class, in particular during the S-DRX configuration of the RX UE itself and / or when the TX UE is in S-ACTIVE state. Otherwise, the RX UE is not expected to process, e.g. ignore or discard, data packets of the certain class. In some variants, the RX UE is expected to process, e.g. receive, data packets of a certain class during the DRX active time of the associated S-DRX configuration, during the DRX active time of the C-DRX configuration or during the DRX active time of some other DRX configuration, e.g. an S-DRX configuration related to another class, in particular during the S-DRX configuration of the RX UE itself and / or when the S-DRX configuration of the TX UE is in the S-ACTIVE state, during the C-DRX configuration of the RX UE itself and / or when the C-DRX configuration of the TX UE is in the C-ACTIVE state or while some other DRX configuration of the RX UE and / or the TX UE is in the DRX active state. Otherwise, the RX UE is not expected to process, e.g. ignore or discard, data packets of the certain class. In some variants, the RX UE is expected to process, e.g. receive, data packets that do not belong to any particular class with an associated configured S-DRX configuration only during the DRX active time of the C-DRX configuration, in particular only during the RX UE's own C-DRX configuration and / or when the TX UE's C-DRX configuration is in C-ACTIVE state. Otherwise, the RX UE is not expected to process these data packets, but will, e.g., ignore or discard them. In some variants, the RX UE is expected to process, e.g. receive, data packets that do not belong to a particular class during the DRX active time of the S-DRX setting related to the particular class, during the DRX active time of the C-DRX setting, or during the DRX active time of some other DRX setting, e.g. an S-DRX setting related to some other class, in particular while the S-DRX setting related to the particular class of the RX UE itself and / or the S-DRX setting related to the particular class of the TX UE(s) is / are in the S-ACTIVE state, or during the C-DRX setting of the RX UE itself and / or the C-DRX setting of the TX UE is / are in the C-ACTIVE state, or while the DRX settings of the other TX UEs and / or TX UEs are in the DRX active state. Otherwise, the RX UE is not expected to process these data packets, but will, for example, ignore or discard them. In some variants, the selection between at least some of the above operations of the RX UE may be negotiated and agreed upon between the TX UE and the RX UE(s) during connection establishment. Furthermore, the selection between at least some of the above operations of the RX UE may be configured by a node of the wireless communication network or may be part of a pre-configuration, for example based on a standard, a manufacturer setting, or a network operator setting. In some variants, the reception of data packets of a particular class in a C-ACTIVE or S-ACTIVE state of an S-DRX configuration associated with another class may or may not affect this C-ACTIVE or S-ACTIVE state, for example based on a configuration or pre-configuration of the RX UE. For example, in this case, it may be configured or pre-configured in the UE whether to extend the DRX active time of the C-DRX configuration or the DRX active time of an S-DRX configuration associated with another class, for example by starting or resetting a timer.

[0065] In some scenarios, enabling the S-DRX configuration may cancel the effect of data packets of a particular class on the C-DRX configuration. For example, when the S-DRX configuration is disabled, reception of packets of a particular class may affect the C-DRX configuration-based DRX operation, e.g., by resetting timers, initiating state transitions, or the like. Then, when the S-DRX configuration related to a particular class is enabled, transmission or reception of data packets of a particular class should no longer affect the DRX procedure based on the C-DRX configuration, e.g., by not resetting timers or initiating state transitions of the C-DRX configuration. In other words, from the perspective of the DRX procedure based on the C-DRX configuration, no data packets are transmitted or received.

[0066] Procedures and mechanisms for providing a DRX configuration to a UE are described in more detail below. These procedures may be used, among other things, to provide the aforementioned S-DRX configuration(s) and / or C-DRX configuration.

[0067] In some scenarios, a UE may be equipped with one or more DRX configurations. As mentioned above, such DRX configurations may be defined by parameters that control the DRX procedure, especially with regard to the transition between DRX active and DRX inactive times. These parameters may include, for example, the settings of one or more timers. Providing a UE with a DRX configuration may be based on a configuration or pre-configuration, such as, for example, a standard, a manufacturer setting, or a network operator setting. The configuration or pre-configuration may be UE-specific or may be part of a resource pool configuration, a bandwidth portion configuration, or a carrier configuration.

[0068] In some scenarios, the DRX configuration may include one or more of the aforementioned C-DRX configuration and / or the aforementioned S-DRX configuration, each of which may be part of the configuration of a corresponding SL radio bearer.

[0069] In some scenarios, a UE may randomly select a DRX configuration among multiple configured or pre-configured DRX configurations used for communication with another UE.

[0070] In some scenarios, the UE may select between multiple configured or pre-configured DRX configurations or may otherwise determine the DRX configuration based on a congestion metric. For example, the UE measures congestion in resources corresponding to the DRX active time of each of multiple configured or pre-configured DRX configurations and selects the DRX configuration with the lowest congestion metric or the DRX configuration with the congestion metric below a threshold.

[0071] In some scenarios, a UE may inform other UEs about its selected DRX configuration. For example, the UE may indicate the index of the selected DRX configuration in a message it sends to other UEs, e.g., as part of a control message. This may be used by multiple UEs for equivalent activation of a particular DRX configuration, e.g., as described above.

[0072] In some scenarios, the UE may inform one or more other UEs about the DRX configuration to be used. In such cases, other DRX configurations configured in the UE but not used may be disabled. The indication of the DRX configuration to be used may be provided by L1 signaling, MAC CE, or RRC signaling. In some cases, the indication may be provided in the form of a bitmap, with each bit in the bitmap corresponding to one of multiple DRX configurations to be enabled or disabled. Furthermore, the indication may include one or more identifiers of the DRX configurations, each identifier indicating a particular DRX configuration to be enabled or disabled. Such identifiers may be specified, for example, as part of the DRX configuration.

[0073] In some scenarios, a UE may take into account DRX configurations used by other UEs when selecting or determining its own DRX configuration, for example, a UE may avoid selecting a DRX configuration that is the same as or has been used by other UEs for SL communications that are not covered by the UE itself.

[0074] In some scenarios, a particular class of SL communication may determine the DRX configuration used by the UE. For example, an identifier or index may be associated with each class of SL communication, or with data packets of a particular class conveyed by the SL communication, and may be used to select a DRX configuration to be used for SL communication packets of a particular class among multiple configured or pre-configured DRX configurations. As an example, a UE may be equipped with N DRX configurations indexed {0, 1, ..., N-1}. Each particular class of SL communication or data packet of a particular class may have an identifier or index. The UE may then select a DRX configuration with an index given by P modulo N for a particular class with index P.

[0075] In some scenarios, the C-DRX configuration may be part of a configuration provided by a network node or part of a pre-configuration. The C-DRC configuration may be always enabled. In contrast, each S-DRX configuration may be enabled as needed, for example, while the UE is participating in an ongoing SL communication of a particular class, or while participating in, for example, a class-specific unicast communication, a class-specific groupcast communication, or a class-specific broadcast communication. The S-DRX configuration may be configured by the network node based on a pre-configuration, or may be negotiated or agreed upon between the UEs participating in the SL communication.

[0076] In some scenarios, the C-DRX configuration may be shared by UEs configured to operate using a specific carrier, a specific resource pool, a specific bandwidth portion, or any combination of a specific carrier, a specific resource pool, and a specific bandwidth portion.

[0077] In some scenarios, an S-DRX configuration related to a particular class may be shared by UEs that are interested in data packets of a particular class, e.g., UEs that send or are expected to transmit data packets of a particular class. For example, such an association may be determined from a particular service that the UE uses that is based on data packets of a particular class, or may be determined from the location of the UE, e.g., depending on whether the UE is located in a particular geographical area.

[0078] In some scenarios, C-DRX may be used to configure, e.g., select, adjust, or enable, the S-DRX configuration of a pair of UEs or multiple UEs, e.g., to coordinate the S-DRX configurations used by these UEs. This includes, for example, using the C-DRX configuration to inform other UE(s) of the S-DRX configuration being used or to change the S-DRX configuration being used. As mentioned above, the C-DRX configuration may also be used by two or more UEs to coordinate the enabling and / or disabling of a particular S-DRX configuration, e.g., by informing other UE(s) about the enabling or disabling of the S-DRX configuration.

[0079] It is noted that the principles of using multiple SL DRX configurations and / or one or more class-specific SL DRX configurations described above are not limited to SL communication but may also be applied to other types of D2D communication.

[0080] 7 shows a flow chart illustrating a method that may be utilized to implement the illustrated concepts. The method of FIG. 7 may be used to implement the illustrated concepts in a wireless communication device, for example, corresponding to any of the UEs described above. In some scenarios, the wireless communication device may be a vehicle or an in-vehicle device, although other types of WDs, for example, as mentioned above, may be used as well.

[0081] If a processor-based implementation of a wireless communication device is used, at least some of the steps of the method of Figure 7 may be performed and / or controlled by one or more processors of the wireless communication device. Such a wireless communication device may also include a memory storing program code for implementing at least some of the functions or steps of the method of Figure 7 described below.

[0082] At step 710, the wireless communication device may receive and / or send configuration information. For example, the wireless communication device may receive configuration information from one or more other wireless communication devices. Additionally, the wireless communication device may send configuration information to one or more other wireless communication devices. Additionally, the wireless communication device may receive configuration information from one or more nodes of a wireless communication network, such as the aforementioned access node 100. Additionally, the wireless communication device may send configuration information to one or more nodes of a wireless communication network, such as the aforementioned access node 100.

[0083] In step 720, the wireless communication device simultaneously maintains a first DRX configuration for D2D communication and a second DRX configuration for D2D communication. Each of the first DRX configuration and the second DRX configuration has a purpose to be used for D2D communication between the wireless communication device and one or more further wireless communication devices. For example, the D2D communication may correspond to SL communication, e.g., via a PC5 interface of LTE technology or a PC5 interface of NR technology. Thus, the first DRX configuration and the second DRX configuration may correspond to SL DRX configurations. Each of the first DRX configuration and the second DRX configuration may be based on one or more timers for controlling transitions between a respective DRX active time and a respective DRX inactive time.

[0084] In some scenarios, the wireless communication device may determine at least one of the first DRX setting and the second DRX setting based on setting information received from at least one of the one or more further wireless communication devices, such as received in step 710.

[0085] In some scenarios, the wireless communication device may determine at least one of the first DRX setting and the second DRX setting based on setting information received from a node of the wireless communication network, such as received in step 710.

[0086] In some scenarios, the wireless communication device may determine at least one of the first DRX configuration and the second DRX configuration based on congestion of radio resources used for D2D communication, for example, by using a congestion metric as a basis for selecting between multiple predefined DRX configurations.

[0087] In some scenarios, the wireless communication device may determine at least one of the first DRX configuration and the second DRX configuration based on DRX configurations used by other wireless communication devices, and information regarding such DRX configurations used by other wireless communication devices may be indicated by the configuration information received in step 710.

[0088] In some scenarios, the wireless communication device may determine at least one of the first DRX configuration and the second DRX configuration based on a selection between a plurality of predefined DRX configurations, and the selection between the plurality of predefined DRX configurations may be based at least in part on a random selection.

[0089] In some scenarios, the wireless communication device may determine configuration information regarding at least one of the first DRX configuration and the second DRX configuration and indicate the determined configuration information to at least one of the one or more further wireless communication devices.

[0090] In some scenarios, the first DRX configuration may be compatible with multiple D2D communication classes, while the second DRX configuration may be compatible only with a specific D2D communication class. The multiple D2D communication classes may or may not include a specific D2D communication class. The C-DRX configuration described above is an example of a first DRX configuration. The S-DRC configuration described above is an example of a second DRX configuration. The D2D communication class may correspond, for example, to the class of SL communication described above or the class of data packets conveyed by the SL transmission.

[0091] The D2D communication class may be defined based on identifiers of wireless communication devices participating in the D2D communication, such as L1 identifiers or L2 identifiers, and / or addresses of wireless communication devices participating in the D2D communication, such as L1 addresses or L2 addresses. Alternatively or additionally, the D2D communication class may be defined based on identifiers of D2D communication links used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a unicast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a groupcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a broadcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on one or more service types using the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on locations of wireless communication devices participating in the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on one or more quality of service attributes used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on data traffic characteristics of the D2D communication, for example taking into account periodicity or other patterns of data packet arrival.

[0092] In some scenarios, the wireless communication device may simultaneously maintain a first DRX configuration for D2D communication and multiple second DRX configurations for D2D communication, each of the second DRX configurations adapted to a different specific D2D communication class. For example, the wireless communication device may simultaneously maintain the aforementioned C-DRC configuration and the aforementioned multiple S-DRX configurations.

[0093] In step 730, the wireless communication device may select whether to enable the first DRX configuration and / or the second DRX configuration. The selection in step 730 may be based, at least in part, on D2D communication with one or more further wireless communication devices. Alternatively, or in addition, the selection in step 730 may be based, at least in part, on congestion of radio resources used for D2D communication, e.g., on a congestion metric. Alternatively, or in addition, the selection in step 730 may be based, at least in part, on random selection. Alternatively, or in addition, the selection in step 730 may be based, at least in part, on information received from at least one of the one or more further wireless communication devices, e.g., on the configuration information received in step 710. Alternatively, or in addition, the selection in step 730 may be based, at least in part, on information received from a node of the wireless communication network, e.g., on the configuration information received in step 710.

[0094] In some scenarios, the wireless communication device may indicate to at least one of the one or more further wireless communication devices a selected at least one of the first DRX setting and / or the second DRX setting, for example by setting information sent in step 710.

[0095] As mentioned above, in some scenarios, the first DRX configuration is compatible with multiple D2D communication classes and the second DRX configuration is compatible with a specific D2D communication class. In some cases, the multiple D2D communication classes may include the specific D2D communication class.

[0096] In such a case, step 730 may include the wireless communication device enabling the second DRX configuration in response to the first D2D transmission. The first D2D transmission may belong to a specific D2D communication class. Alternatively, or in addition, the first D2D transmission may include an instruction to enable the second DRX configuration. For example, the first D2D transmission may carry a corresponding control message or corresponding control signaling. In some cases, the wireless communication device may start a timer for controlling the enablement of the second DRX configuration in response to enabling the second DRX configuration.

[0097] Further, step 730 may include the wireless communication device disabling the second DRX configuration in response to the second D2D transmission. The second D2D transmission may include an instruction to disable the second DRX configuration. For example, the second D2D transmission may convey a corresponding control message or corresponding control signaling. In some cases, the wireless communication device may disable the second DRX configuration in response to expiration of a timer. As described above, the wireless communication device may start the timer in response to enabling the second DRX configuration. Furthermore, the wireless communication device may reset the timer in response to a D2D transmission for a specific D2D communication class. In some cases, the wireless communication device may also disable the second DRX configuration in response to release of a D2D communication link used for a specific class of D2D communication. In some cases, the wireless communication device may also disable the second DRX configuration in response to cessation of a specific class of D2D communication.

[0098] In step 740, the wireless communication device participates in D2D communication with one or more additional wireless communication devices. This is achieved based on at least one of a first DRX configuration and a second DRX configuration. Participating in D2D communication may involve the wireless communication device receiving at least one D2D transmission from at least one of the one or more additional wireless communication devices during a DRX active time. Thus, the wireless communication device may correspond as an RX UE, operating, for example, as described above. Furthermore, participating in D2D communication may involve the wireless communication device sending at least one D2D transmission to at least one of the one or more additional wireless communication devices during a DRX active time. Thus, the wireless communication device may correspond as a TX UE, operating, for example, as described above.

[0099] In some scenarios, step 740 may involve the wireless communication device's processing of one or more D2D transmissions depending on a first DRX active time activated by the first DRX configuration and / or a second DRX active time activated by a second DRX configuration associated with a particular D2D communication class. The processing may be associated with sending or receiving D2D transmissions. In some cases, the wireless communication device may process D2D transmissions of a particular D2D communication class during the first DRX active time or the second DRX active time. In some cases, the wireless communication device may process D2D transmissions of a particular D2D communication class only during the second DRX active time. In some cases, the wireless communication device may process only a limited number of D2D transmissions of a particular D2D communication class during the first DRX active time. In some cases, the wireless communication device may determine whether to process D2D transmissions of a particular D2D communication class in the first DRX active time depending on a congestion level in the first DRX active time. In some cases, the wireless communication device may determine whether to process D2D transmissions of a D2D communication class different from the specific D2D communication class during the first DRX active time based on a congestion level during the second DRX active time. In some cases, the wireless communication device may process D2D transmissions of a specific D2D communication class with a higher priority than D2D transmissions of another D2D communication class during the second DRX active time.

[0100] 8 shows a functional block diagram of a wireless communication device 900 operating according to the method of FIG. 7. The wireless communication device 800 may correspond to, for example, any of the UEs mentioned above. As shown, the wireless communication device 800 may comprise a module 810 configured to receive and / or send configuration information, such as that described in connection with step 710. Furthermore, the wireless communication device 800 may comprise a module 820 configured to simultaneously maintain multiple DRX configurations, such as that described in connection with step 720. Furthermore, the wireless communication device 800 may optionally comprise a module 830 configured to select enabling / disabling of at least one of the DRX configurations, such as that described in connection with step 730. Furthermore, the wireless communication device 800 may comprise a module 840 configured to participate in D2D communication, such as that described in connection with step 740.

[0101] It is noted that the wireless communication device 800 may include additional modules for performing other functions, such as known functions of a UE in LTE and / or NR radio technologies. Furthermore, it is noted that the modules of the wireless communication device 800 do not necessarily correspond to the hardware structure of the wireless communication device 800, but may correspond to functional elements implemented, for example, by hardware, software, or a combination thereof.

[0102] Figure 9 shows a flow diagram illustrating a method that may be used to implement the concepts shown in Figure 9. The method of Figure 9 may be used to implement the concepts shown in a node of a wireless communication network, for example, corresponding to the access node 100 described above.

[0103] If a processor-based implementation of the node is used, at least some of the steps of the method of Figure 9 may be performed and / or controlled by one or more processors of the node. Such a node may also include memory storing program code for implementing at least some of the functions or steps of the method of Figure 9 described below.

[0104] At step 910, the node may receive and / or send configuration information. For example, the node may receive configuration information from one or more wireless communication devices. Further, the node may send configuration information to one or more wireless communication devices. Further, the node may receive configuration information from one or more other nodes of the wireless communication network, such as another access node or control node. Further, the node may send configuration information to one or more other nodes of the wireless communication network, such as another access node or control node.

[0105] In step 920, the node may determine one or more DRX configurations for D2D communication. Each DRX configuration has a purpose to be used for D2D communication between the wireless communication device and one or more further wireless communication devices. In particular, the node may determine a first DRX configuration for D2D communication of the wireless communication device with one or more further wireless communication devices and a second DRX configuration for D2D communication of the wireless communication device with one or more further wireless communication devices. For example, the D2D communication may correspond to SL communication, e.g., over a PC5 interface of LTE technology or a PC5 interface of NR technology. Thus, the DRX configuration may correspond to an SL DRX configuration. Each of the DRX configurations may be based on one or more timers for controlling transitions between a respective DRX active time and a respective DRX inactive time.

[0106] In some scenarios, the node may determine at least one of the DRX settings based on setting information received from one or more wireless communication devices, such as received in step 910.

[0107] In some scenarios, the node may determine at least one of the DRX settings based on setting information received from another node in the wireless communication network, such as received in step 910.

[0108] In some scenarios, the node may determine at least one of the DRX configurations based on congestion of the radio resources used for D2D communication, for example by using a congestion metric as a basis for selecting between multiple predefined DRX configurations.

[0109] In some scenarios, the node may determine at least one of the DRX configurations based on DRX configurations used by other wireless communication devices, which information regarding such DRX configurations used by other wireless communication devices may be indicated by the configuration information as received in step 910.

[0110] In some scenarios, the node may determine at least one of the DRX configurations based on a selection between multiple predefined DRX configurations, which selection between multiple predefined DRX configurations may be based at least in part on random selection.

[0111] In some scenarios, the node may determine configuration information for the determined DRX configuration(s) and indicate the determined configuration information to the wireless communication device.

[0112] In some scenarios, the DRX configurations determined in step 920 may include a first DRX configuration compatible with multiple D2D communication classes and a second DRX configuration compatible with a specific D2D communication class. The multiple D2D communication classes may or may not include the specific D2D communication class. The aforementioned C-DRX configuration is an example of a first DRX configuration. The aforementioned S-DRC configuration is an example of a second DRX configuration. The D2D communication class corresponds, for example, to the aforementioned class of SL communication or the class of data packets conveyed by the SL transmission.

[0113] The D2D communication class may be defined based on identifiers of wireless communication devices participating in the D2D communication, such as L1 identifiers or L2 identifiers, and / or addresses of wireless communication devices participating in the D2D communication, such as L1 addresses or L2 addresses. Alternatively or additionally, the D2D communication class may be defined based on identifiers of D2D communication links used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a unicast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a groupcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a broadcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on one or more service types using the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on locations of wireless communication devices participating in the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on one or more quality of service attributes used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on data traffic characteristics of the D2D communication, for example taking into account periodicity or other patterns of data packet arrival.

[0114] In step 930, the node configures the wireless communication device to simultaneously maintain a first DRX configuration for D2D communication and a second DRX configuration for D2D communication. Each of the first DRX configuration and the second DRX configuration has a purpose of being used for D2D communication between the wireless communication device and one or more further wireless communication devices. For example, the D2D communication may correspond to SL communication, e.g., via a PC5 interface of LTE technology or a PC5 interface of NR technology. Thus, the first DRX configuration and the second DRX configuration may correspond to SL DRX configurations. Each of the first DRX configuration and the second DRX configuration may be based on one or more timers for controlling transitions between respective DRX active times and respective DRX inactive times. The first DRX configuration and the second DRX configuration may correspond to the first DRX configuration and the second DRX configuration that may have been determined in step 920.

[0115] The first DRX configuration may be compatible with multiple D2D communication classes, and the second DRX configuration may be compatible with a specific D2D communication class. The multiple D2D communication classes may or may not include a specific D2D communication class. The C-DRX configuration described above is an example of a first DRX configuration. The S-DRC configuration described above is an example of a second DRX configuration. The D2D communication class corresponds, for example, to the class of SL communication described above or the class of data packets conveyed by the SL transmission.

[0116] The D2D communication class may be defined based on identifiers of wireless communication devices participating in the D2D communication, such as L1 identifiers or L2 identifiers, and / or addresses of wireless communication devices participating in the D2D communication, such as L1 addresses or L2 addresses. Alternatively or additionally, the D2D communication class may be defined based on identifiers of D2D communication links used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a unicast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a groupcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on whether the D2D communication is based on a broadcast transmission mode. Alternatively or additionally, the D2D communication class may be defined based on one or more service types using the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on locations of wireless communication devices participating in the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on one or more quality of service attributes used for the D2D communication. Alternatively or additionally, the D2D communication class may be defined based on data traffic characteristics of the D2D communication, for example taking into account periodicity or other patterns of data packet arrival.

[0117] Further, the node may configure the wireless communication device with respect to selecting whether to enable the first DRX configuration and / or the second DRX configuration. The node may configure the wireless communication device to perform the selection based at least in part on D2D communication with one or more further wireless communication devices. Alternatively, or in addition, the node may configure the wireless communication device to perform the selection based at least in part on congestion of radio resources used for D2D communication, for example based on a congestion metric. Alternatively, or in addition, the node may configure the wireless communication device to perform the selection based at least in part on a random selection. Alternatively, or in addition, the node may configure the wireless communication device to perform the selection based at least in part on information received from at least one of the one or more further wireless communication devices. Alternatively, or in addition, the node may configure the wireless communication device to perform the selection based at least in part on information received from a node of the wireless communication network.

[0118] As mentioned above, in some scenarios, the first DRX configuration is compatible with multiple D2D communication classes and the second DRX configuration is compatible with a specific D2D communication class. In some cases, the multiple D2D communication classes may include the specific D2D communication class.

[0119] In some scenarios, the node may configure the wireless communication device to simultaneously maintain a first DRX configuration for D2D communication and multiple second DRX configurations for D2D communication, each of the second DRX configurations adapted to a different specific D2D communication class. For example, the wireless communication device may simultaneously maintain the aforementioned C-DRC configuration and the aforementioned multiple S-DRX configurations.

[0120] In such a case, the node may configure the wireless communication device to enable the second DRX configuration. The first D2D transmission may belong to a specific D2D communication class. Alternatively, or in addition, the first D2D transmission may include an instruction to enable the second DRX configuration. For example, the first D2D transmission may carry a corresponding control message or corresponding control signaling. In some cases, the node may configure the wireless communication device to start a timer for controlling the enablement of the second DRX configuration in response to the enablement of the second DRX configuration.

[0121] Further, the node may configure the wireless communication device to disable the second DRX setting in response to a second D2D transmission. The second D2D transmission may include an instruction to disable the second DRX setting. For example, the second D2D transmission may convey a corresponding control message or corresponding control signaling. In some cases, the node may configure the wireless communication device to disable the second DRX setting in response to expiration of a timer. As described above, the wireless communication device may be configured to start a timer in response to enabling the second DRX setting. Furthermore, the node may configure the wireless communication device to reset the timer in response to a D2D transmission of a particular D2D communication class. In some cases, the node may configure the wireless communication device to disable the second DRX setting in response to release of a D2D communication link used for a particular class of D2D communication. In some cases, the node may configure the wireless communication device to disable the second DRX setting in response to cessation of a particular class of D2D communication.

[0122] In some scenarios, a node may configure a wireless communication device to rely on a first DRX active time initiated by a first DRX configuration and / or a second DRX active time initiated by a second DRX configuration associated with a particular D2D communication class for processing of one or more D2D transmissions by the wireless communication device. This processing may be associated with sending or receiving D2D transmissions. In some cases, the node may configure the wireless communication device to process D2D transmissions of a particular D2D communication class during the first DRX active time or the second DRX active time. In some cases, the node may configure the wireless communication device to process D2D transmissions of a particular D2D communication class only during the second DRX active time. In some cases, the node may configure the wireless communication device to process only a limited number of D2D transmissions of a particular D2D communication class during the first DRX active time. In some cases, the node may configure the wireless communication device to determine whether to process a D2D transmission of a specific D2D communication class during a first DRX active time depending on a congestion level during the first DRX active time. In some cases, the node may configure the wireless communication device to determine whether to process a D2D transmission of a D2D communication class different from the specific D2D communication class during the first DRX active time depending on a congestion level during a second DRX active time. In some cases, the node may configure the wireless communication device to process a D2D transmission of a specific D2D communication class that has a higher priority than a D2D transmission of another D2D communication class during the second DRX active time.

[0123] 10 shows a functional block diagram of a node 1000 for a wireless communication network operating in accordance with the method of FIG. 9. The node 1000 may correspond to, for example, any of the access nodes described above. As shown, the node 1000 may comprise a module 1010 configured to receive configuration information such as that described in connection with step 910. Further, the node 1000 may comprise a module 1020 configured to determine a DRX configuration for D2D communication such as that described in connection with step 920. Further, the node 1000 may comprise a module 930 configured to configure the wireless communication device to simultaneously maintain multiple DRX configurations for D2D communication such as that described in connection with step 930.

[0124] It is noted that node 1000 may include further modules for performing other functions, such as known functions of an eNB in ​​LTE technology and / or a gNB in ​​NR technology. It is further noted that the modules of node 1000 do not necessarily correspond to the hardware structure of node 1000, but may correspond to functional elements implemented, for example, by hardware, software, or a combination thereof.

[0125] It should also be understood that the functionality described in connection with Figures 7-10 may be combined in various ways, for example, in a system including two or more wireless communication devices operating according to the method of Figure 7, or in a system including one or more wireless communication devices operating according to the method of Figure 7 and a node operating according to the method of Figure 9. Furthermore, the same wireless communication device may perform functionality corresponding to an RX UE and functionality corresponding to a TX UE.

[0126] 11 illustrates a processor-based implementation of a wireless communication device 1100 that may be used to implement the concepts described above. For example, the structure shown in FIG. 11 may be used to implement the concepts in any of the UEs described above.

[0127] As shown, the wireless communication device 1100 includes one or more air interfaces 1110. The air interface(s) 1110 may be based on, for example, NR or LTE technology. The air interface(s) 1110 may support D2D communication using SL communication defined for, for example, NR or LTE technology.

[0128] Further, the wireless communication device 1100 may include one or more processors 1150 coupled to the wireless interface(s) 1110 and a memory 1160 coupled to the processor(s) 1150. By way of example, the wireless interface(s) 1110, the processor(s) 1150, and the memory 1160 may be coupled by one or more internal bus systems of the wireless communication device 1100. The memory 1160 may include read-only memory (ROM), e.g., flash ROM; random access memory (RAM), e.g., dynamic RAM (DRAM) or static RAM (SRAM); mass storage, e.g., a hard disk or solid-state disk; or the like. As shown, the memory 1160 may include software 1170 and / or firmware 1180. The memory 1160 may include suitably configured program code executed by the processor(s) 1150 to perform the aforementioned functions for controlling D2D communications, such as those described in connection with FIG. 7 or FIG. 8.

[0129] 11 is only a schematic diagram, and that additional components, such as additional interfaces, e.g., a dedicated management interface, or additional processors, that may actually be included in the wireless communication device 1100 are not shown for clarity. It should also be understood that the memory 1160 may include additional program code for implementing known functions of the UE. According to some embodiments, computer programs for implementing functions of the wireless communication device 1100 may also be provided, for example, in the form of a physical medium storing program code and / or other data stored in the memory 1160, or by making the program code downloadable or by streaming.

[0130] 12 illustrates a processor-based implementation of a node 1200 for a wireless communication network that may be used to implement the concepts described above. For example, the structure shown in FIG. 12 may be used to implement the concepts in any of the access nodes described above.

[0131] As shown, the node 1200 may include one or more radio interfaces 1210. The radio interface(s) 1210 may be based on, for example, NR or LTE technology. The radio interface(s) 1210 may be used to control wireless communication devices, such as any of the UEs described above. Additionally, the node 1200 may include one or more network interfaces 1220. The network interface(s) 1220 may be used to communicate with, for example, one or more other nodes of a wireless communication network. The network interface(s) 1220 may also be used to control wireless communication devices, such as any of the UEs described above.

[0132] Further, node 1200 may include one or more processors 1250 coupled to interface(s) 1210(s), 1220(s), and memory 1260 coupled to processor(s). By way of example, interface(s) 1210(s), processor(s) 1250(s), and memory 1260 may be coupled by one or more internal bus systems of node 1200. Memory 1260 may include ROM, such as, for example, flash ROM; RAM, such as, for example, DRAM or SRAM; mass storage, such as, for example, a hard disk or solid-state disk; or the like. As shown, memory 1260 may include software 1270 and / or firmware 1280. Memory 1260 may include suitably configured program code executed by processor(s) 1250 to implement the aforementioned functions for controlling D2D communications, such as those described in connection with FIGS. 9 and 10 .

[0133] 12 is only a schematic diagram, and that in practice additional components, such as additional interfaces, e.g., a dedicated management interface, or additional processors, that may be included in wireless communication device 1200 are not shown for clarity. It should also be understood that memory 1260 may include additional program code for implementing known functions of an eNB or gNB. According to some embodiments, computer programs for implementing functions of node 1200 may also be provided, for example, in the form of a physical medium storing program code and / or other data stored in memory 1260, or by making the program code downloadable or by streaming.

[0134] As can be seen, the concept described above can be used to perform D2D communication in an energy-efficient manner. In particular, this concept can be used to apply DRX to SL communication or other types of D2D communication without requiring any hierarchical structure of involved devices. Furthermore, this concept can be used to enable DRX for D2D communication not only in unicast mode but also in groupcast mode or broadcast mode, or in any combination of unicast mode, groupcast mode, and broadcast mode. Furthermore, different SL DRX configurations can be provided depending on the requirements of each UE.

[0135] It should be understood that the examples and embodiments described above are merely illustrative and subject to various modifications. For example, the illustrated concepts may be applied, without limitation, to LTE or NR technology in the SL mode in connection with various types of radio technologies and D2D communications, such as WLAN or other wireless ad-hoc network technologies. Furthermore, the concepts may be applied, without limitation, to vehicle-based UEs in connection with various types of UEs. Furthermore, the concepts may be applied, without limitation, to V2X, NSPS, or NCIS in connection with various services supported by D2D communications. Furthermore, aspects of the illustrated concepts related to determining and providing a DRX configuration for D2D communications could also be used independently from aspects related to simultaneously configuring multiple DRX configurations for D2D communications. Furthermore, it is noted that in some scenarios, one or more of the class-specific DRX configurations may be used independently from a general-purpose DRX configuration. For example, a UE may be configured with one or more of the S-DRX configurations but without a C-DRX configuration. It should also be understood that the above concepts may be implemented using dedicated device hardware or correspondingly designed software to be executed by one or more processors of an existing device or apparatus. Furthermore, it should be noted that the illustrated apparatus or each of the devices may be implemented as a single device or as a system of multiple interacting devices or modules.

[0136] In view of the above, the present disclosure provides the following embodiments.

[0137] Embodiment 1: 1. A method for controlling device-to-device (D2D) communication, comprising: a wireless communication device (10, 800, 1100) simultaneously maintaining a first discontinuous reception (DRX) configuration for D2D communication and a second DRX configuration for D2D communication; a wireless communication device (10, 800, 1100) participating in D2D communication with one or more further wireless communication devices (10, 800, 1100) based on at least one of a first DRX configuration and a second DRX configuration; A method comprising:

[0138] Embodiment 2: The wireless communication device (10, 800, 1100) selects whether to enable the first DRX setting and / or the second DRX setting; 2. The method of embodiment 1, comprising:

[0139] Embodiment 3: the selection of whether to enable the first DRX configuration and / or the second DRX configuration is based at least in part on D2D communication with one or more further wireless communication devices (10, 800, 1100); 3. The method of embodiment 2.

[0140] Embodiment 4: the selection of whether to enable a first DRX configuration and / or a second DRX configuration is based at least in part on congestion of radio resources used for D2D communication; 4. The method of embodiment 2 or 3.

[0141] Embodiment 5: the selection of whether to enable the first DRX configuration and / or the second DRX configuration is based at least in part on a random selection. 5. The method of any one of embodiments 2 to 4.

[0142] Embodiment 6: the selection of whether to enable the first DRX configuration and / or the second DRX configuration is based at least in part on information received from at least one of one or more further wireless communication devices (10, 800, 1100); 6. The method of any one of embodiments 2 to 5.

[0143] Embodiment 7: the selection of whether to enable the first DRX configuration and / or the second DRX configuration is based at least in part on information received from a node (100, 1000, 1200) of the wireless communication network; 7. The method of any one of embodiments 2 to 6.

[0144] Embodiment 8: the wireless communication device (10, 800, 1100) instructing at least one of the one or more further wireless communication devices (10, 800, 1100) of a selected at least one of the first DRX setting and / or the second DRX setting; 8. The method of any one of embodiments 2 to 7, comprising:

[0145] Embodiment 9: the first DRX configuration is adapted to a plurality of D2D communication classes and the second DRX configuration is adapted to a specific D2D communication class; 9. The method of any one of embodiments 1 to 8.

[0146] Embodiment 10: The plurality of D2D communication classes includes a specific D2D communication class; 10. The method of embodiment 9.

[0147] Embodiment 11: the wireless communication device enabling a second DRX configuration in response to the first D2D transmission; 11. The method of embodiment 9 or 10, comprising:

[0148] Embodiment 12: the first D2D transmission belongs to a particular D2D communication class; 12. The method of embodiment 11.

[0149] Embodiment 13: the first D2D transmission includes an instruction to enable the second DRX configuration; 13. The method of embodiment 11 or 12.

[0150] Embodiment 14: the wireless communication device (10, 800, 1100) starts a timer for controlling the activation of the second DRX setting in response to the activation of the second DRX setting; 14. The method of any one of embodiments 9 to 13, comprising:

[0151] Embodiment 15: the wireless communication device (10, 800, 1100) disabling the second DRX configuration in response to the second D2D transmission; 15. The method of any one of embodiments 9 to 14, comprising:

[0152] Embodiment 16: the second D2D transmission includes an instruction to disable the second DRX configuration; 16. The method of embodiment 15.

[0153] Embodiment 17: the wireless communication device (10, 800, 1100) disables the second DRX setting in response to expiration of the timer; 17. The method of any one of embodiments 9 to 16, comprising:

[0154] Embodiment 18: the wireless communication device (10, 800, 1100) starts a timer in response to enabling the second DRX configuration; 18. The method of embodiment 17, comprising:

[0155] Embodiment 19: the wireless communication device (10, 800, 1100) resetting a timer in response to a D2D transmission of a particular D2D communication class; 19. The method of embodiment 17 or 18, comprising:

[0156] Embodiment 20: the wireless communication device (10, 800, 1100) disables the second DRX configuration in response to the release of the D2D communication link used for the particular class of D2D communication; 20. The method of any one of embodiments 9 to 19, comprising:

[0157] Embodiment 21: the wireless communication device (10, 800, 1100) disabling the second DRX configuration in response to the stopping of the specific class of D2D communication; 21. The method of any one of embodiments 9 to 20, comprising:

[0158] Embodiment 22: The D2D communication class is defined based on an identifier of a wireless communication device (10, 800, 1100) participating in the D2D communication and / or an address of a wireless communication device (10, 800, 1100) participating in the D2D communication; 22. The method of any one of embodiments 9 to 21.

[0159] Embodiment 23: a D2D communication class is defined based on an identifier of a D2D communication link used for the D2D communication; 23. The method of any one of embodiments 9 to 22.

[0160] Embodiment 24: The D2D communication class is defined based on whether the D2D communication is based on a unicast transmission mode; 24. The method of any one of embodiments 9 to 23.

[0161] Embodiment 25: The D2D communication class is defined based on whether the D2D communication is based on a groupcast transmission mode; 25. The method of any one of embodiments 9 to 24.

[0162] Embodiment 26: The D2D communication class is defined based on whether the D2D communication is based on a broadcast transmission mode; 26. The method of any one of embodiments 9 to 25.

[0163] Embodiment 27: The D2D communication class is defined based on one or more service types using the D2D communication; 27. The method of any one of embodiments 9 to 26.

[0164] Embodiment 28: The D2D communication class is defined based on the locations of the wireless communication devices participating in the D2D communication; 28. The method of any one of embodiments 9 to 27.

[0165] Embodiment 29: a D2D communication class is defined based on one or more quality of service attributes used for the D2D communication; 29. The method of any one of embodiments 9 to 28.

[0166] Embodiment 30: The D2D communication class is defined based on the data traffic characteristics of the D2D communication; 30. The method of any one of embodiments 9 to 29.

[0167] Embodiment 31: a wireless communication device (10, 800, 1100) simultaneously maintaining a first DRX configuration for D2D communication and a plurality of second DRX configurations for D2D communication; This includes: each of the second DRX configurations is adapted to a different specific D2D communication class; 31. The method of any one of embodiments 9 to 30.

[0168] Embodiment 32: The processing of one or more D2D transmissions by the wireless communication device (10, 800, 1100) is dependent on a first DRX active time activated by a first DRX configuration and / or a second DRX active time activated by a second DRX configuration associated with a particular D2D communication class; 32. The method of any one of embodiments 9 to 31.

[0169] Embodiment 33: a wireless communication device (10, 800, 1100) processes D2D transmissions of a particular D2D communication class during a first DRX active time or a second DRX active time; 33. The method of embodiment 32, comprising:

[0170] Embodiment 34: the wireless communication device (10, 800, 1100) processes D2D transmissions of the specific D2D communication class only during the second DRX active time; 33. The method of embodiment 32, comprising:

[0171] Embodiment 35: the wireless communication device (10, 800, 1100) processes only a limited number of D2D transmissions of a particular D2D communication class during the first DRX active time; 34. The method of embodiment 32 or 33, comprising:

[0172] Embodiment 36: the wireless communication device (10, 800, 1100) determines whether to process D2D transmissions of a particular D2D communication class during the first DRX active time, depending on a congestion level during the first DRX active time; 36. The method of embodiment 32, 33 or 35, comprising:

[0173] Embodiment 37: the wireless communication device (10, 800, 1100) determines whether to process a D2D transmission of a D2D communication class different from the particular D2D communication class of the first DRX active time depending on the congestion level of the second DRX active time; 37. The method of any one of embodiments 32 to 36, comprising:

[0174] Embodiment 38: the wireless communication device processes a D2D transmission of a particular D2D communication class with a higher priority than a D2D transmission of another D2D communication class during the second DRX active time; 38. The method of any one of embodiments 32 to 37, comprising:

[0175] Embodiment 38: The participation in D2D communication is during the DRX active time, the wireless communication device (10, 800, 1100) receives at least one D2D transmission from at least one of the one or more further wireless communication devices (10, 800, 1100); 38. The method of any one of embodiments 1 to 37.

[0176] Embodiment 39: The participation in D2D communication is during the DRX active time, the wireless communication device (10, 800, 1100) sends at least one D2D transmission to at least one of the one or more further wireless communication devices (10, 800, 1100); 39. The method of any one of embodiments 1 to 38.

[0177] Embodiment 40: the wireless communication device (10, 800, 1100) determines at least one of the first DRX configuration and the second DRX configuration based on configuration information received from at least one of the one or more further wireless communication devices (10, 800, 1100); 40. The method of any one of embodiments 1 to 39, comprising:

[0178] Embodiment 41: a wireless communication device (10, 800, 1100) determining at least one of a first DRX configuration and a second DRX configuration based on configuration information received from a node (100, 1000, 1200) of the wireless communication network; 41. The method of any one of embodiments 1 to 40, comprising:

[0179] Embodiment 42: a wireless communication device (10, 800, 1100) determining at least one of a first DRX configuration and a second DRX configuration based on congestion of radio resources used for D2D communication; 42. The method of any one of embodiments 1 to 41, comprising:

[0180] Embodiment 43: The wireless communication device (10, 800, 1100) determines at least one of a first DRX setting and a second DRX setting based on a DRX setting used by another wireless communication device (10, 800, 1100); 43. The method of any one of embodiments 1 to 42, comprising:

[0181] Embodiment 44: a wireless communication device (10, 800, 1100) determining at least one of a first DRX setting and a second DRX setting based on a selection between a plurality of predefined DRX settings; 44. The method of any one of embodiments 1 to 43, comprising:

[0182] Embodiment 45: The selection between the predefined DRX configurations is based at least in part on random selection. 45. The method of embodiment 44.

[0183] Embodiment 46: determining, by a wireless communication device (10, 800, 1100), configuration information regarding at least one of a first DRX configuration and a second DRX configuration; the wireless communication device (10, 800, 1100) indicating the determined configuration information to at least one of the one or more further wireless communication devices; 46. ​​The method of any one of embodiments 1 to 45, comprising:

[0184] Embodiment 47: A method for controlling D2D communication in a wireless communication network, comprising: a node (100, 1000, 1200) of a wireless communication network configuring a wireless communication device (10, 800, 1100) to simultaneously maintain a first discontinuous reception (DRX) configuration for D2D communication with one or more further wireless communication devices (10, 800, 1100) and a second DRX configuration for D2D communication with one or more further wireless communication devices (10, 800, 1100); The method includes:

[0185] Embodiment 48: the first DRX configuration is adapted to a plurality of D2D communication classes and the second DRX configuration is adapted to a specific D2D communication class; 48. The method of embodiment 47.

[0186] Embodiment 49: The plurality of D2D communication classes includes a specific D2D communication class; 49. The method of embodiment 48.

[0187] Embodiment 50: the node (100, 1000, 1200) configuring the wireless communication device (10, 800, 1100) to enable a second DRX configuration in response to the first D2D transmission; 50. The method of embodiment 48 or 49, comprising:

[0188] Embodiment 51: the first D2D transmission belongs to a particular D2D communication class; The method of embodiment 50.

[0189] Embodiment 52: the first D2D transmission includes an instruction to enable the second DRX configuration; 52. The method of embodiment 50 or 51.

[0190] Embodiment 53: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to start a timer for controlling activation of the second DRX setting in response to activation of the second DRX setting; 53. The method of any one of embodiments 48 to 52, comprising:

[0191] Embodiment 54: the node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to disable the second DRX configuration in response to the second D2D transmission; 54. The method of any one of embodiments 48 to 53, comprising:

[0192] Embodiment 55: the second D2D transmission includes an instruction to disable the second DRX configuration; 55. The method of embodiment 54.

[0193] Embodiment 56: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to disable the second DRX setting in response to expiration of the timer; 56. The method of any one of embodiments 48 to 55, comprising:

[0194] Embodiment 57: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to start a timer in response to enabling the second DRX configuration; 57. The method of embodiment 56, comprising:

[0195] Embodiment 58: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to reset a timer in response to a D2D transmission of a particular D2D communication class; 58. The method of embodiment 56 or 57, comprising:

[0196] Embodiment 59: a node (100, 1000, 1200) configuring a wireless communication device (10, 800, 1100) to disable a second DRX configuration in response to release of a D2D communication link used for a particular class of D2D communication; 59. The method of any one of embodiments 48 to 58, comprising:

[0197] Embodiment 60: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to disable the second DRX configuration in response to the stopping of the D2D communication of the specific class; 60. The method of any one of embodiments 48 to 59, comprising:

[0198] Embodiment 61: The D2D communication class is defined based on an identifier of a wireless communication device (10, 800, 1100) participating in the D2D communication and / or an address of a wireless communication device (10, 800, 1100) participating in the D2D communication; 61. The method of any one of embodiments 48 to 60.

[0199] Embodiment 62: a D2D communication class is defined based on an identifier of a D2D communication link used for the D2D communication; 62. The method of any one of embodiments 48 to 61.

[0200] Embodiment 63: The D2D communication class is defined based on whether the D2D communication is based on a unicast transmission mode; 63. The method of any one of embodiments 48 to 62.

[0201] Embodiment 64: The D2D communication class is defined based on whether the D2D communication is based on a groupcast transmission mode; 64. The method of any one of embodiments 48 to 63.

[0202] Embodiment 65: The D2D communication class is defined based on whether the D2D communication is based on a broadcast transmission mode; 65. The method of any one of embodiments 48 to 64.

[0203] Embodiment 66: The D2D communication class is defined based on one or more service types using the D2D communication; 66. The method of any one of embodiments 48 to 65.

[0204] Embodiment 67: The D2D communication class is defined based on the locations of the wireless communication devices participating in the D2D communication; 67. The method of any one of embodiments 48 to 66.

[0205] Embodiment 68: a D2D communication class is defined based on one or more quality of service attributes used for the D2D communication; 68. The method of any one of embodiments 48 to 67.

[0206] Embodiment 69: A D2D communication class is defined based on data traffic characteristics of the D2D communication; 69. The method of any one of embodiments 48 to 68.

[0207] Embodiment 70: a node (100, 1000, 1200) configuring a wireless communication device (10, 800, 1100) to simultaneously maintain a first DRX configuration for D2D communication and a plurality of second DRX configurations for D2D communication; wherein each of the second DRX configurations is adapted to a different specific D2D communication class. 70. The method of any one of embodiments 48 to 69.

[0208] Embodiment 71: The processing of one or more D2D transmissions by the wireless communication device (10, 800, 1100) is dependent on a first DRX active time activated by a first DRX configuration and / or a second DRX active time activated by a second DRX configuration associated with a particular D2D communication class; 71. The method of any one of embodiments 48 to 70.

[0209] Embodiment 72: A node (100, 1000, 1200) configures a wireless communication device (10, 800, 1100) to process D2D transmissions of a specific D2D communication class during a first DRX active time or a second DRX active time; 72. The method of embodiment 71, comprising:

[0210] Embodiment 73: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to process D2D transmissions of a specific D2D communication class only during the second DRX active time; 72. The method of embodiment 71, comprising:

[0211] Embodiment 74: a node (100, 1000, 1200) configuring a wireless communication device (10, 800, 1100) to process only a limited number of D2D transmissions of a particular D2D communication class during a first DRX active time; 73. The method of embodiment 71 or 72, comprising:

[0212] Embodiment 75: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to determine whether to process D2D transmissions of a specific D2D communication class during the first DRX active time based on a congestion level during the first DRX active time. 75. The method of embodiment 71, 72 or 74, comprising:

[0213] Embodiment 76: The node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to determine whether to process a D2D transmission of a D2D communication class different from the specific D2D communication class during the first DRX active time, based on a congestion level during the second DRX active time. 76. The method of any one of embodiments 71 to 75, comprising:

[0214] Embodiment 77: the node (100, 1000, 1200) configures the wireless communication device (10, 800, 1100) to process D2D transmissions of a particular D2D communication class with higher priority than D2D transmissions of another D2D communication class during the second DRX active time; 77. The method of any one of embodiments 71 to 76, comprising:

[0215] Embodiment 78: the node (100, 1000, 1200) determining at least one of the first DRX configuration and the second DRX configuration based on configuration information received from at least one of the one or more further wireless communication devices; 78. The method of any one of embodiments 47 to 77, comprising:

[0216] Embodiment 79: The node (100, 1000, 1200) determines at least one of the first DRX configuration and the second DRX configuration based on congestion of radio resources used for D2D communication; 79. The method of any one of embodiments 47 to 78, comprising:

[0217] Embodiment 80: The node (100, 1000, 1200) determines at least one of the first DRX configuration and the second DRX configuration based on a DRX configuration used by another wireless communication device; 80. The method of any one of embodiments 47 to 79, comprising:

[0218] Embodiment 81: the node (100, 1000, 1200) determines at least one of the first DRX configuration and the second DRX configuration based on a selection between a plurality of predefined DRX configurations; 81. The method of any one of embodiments 47 to 80, comprising:

[0219] Embodiment 82: The selection between the predefined DRX configurations is based at least in part on random selection. 82. The method of embodiment 81.

[0220] Embodiment 83: A wireless communication device (10, 800, 1100), comprising: simultaneously maintaining a first discontinuous reception (DRX) configuration for D2D communication and a second DRX configuration for D2D communication, and participating in D2D communication with one or more further wireless communication devices based on at least one of the first DRX configuration and the second DRX configuration; The wireless communication device is configured as follows: (10, 800, 1100).

[0221] Embodiment 84: 47. A method according to any one of claims 2 to 46, A wireless communication device (10, 800, 1100) as described in embodiment 83.

[0222] Embodiment 85: At least one processor (1150); a memory (1160) containing program code executable by at least one processor (1150); Execution of the program code by at least one processor (1150) causes the wireless communication device (10, 800, 1100) to perform the method of any one of embodiments 1 to 46. 85. A wireless communication device (10, 800, 1100) as described in embodiment 83 or 84.

[0223] Embodiment 86: A node (100, 1000, 1200) for a wireless communication network, comprising: A node (100, 1000, 1200) configured to configure a wireless communication device (10, 800, 1100) to simultaneously maintain a first discontinuous reception (DRX) setting for D2D communication with one or more further wireless communication devices (10, 800, 1100) and a second DRX setting for D2D communication with one or more further wireless communication devices (10, 800, 1100).

[0224] Embodiment 87: The node (100, 1000, 1200) is configured to perform the method according to any one of embodiments 48 to 82. A node as described in embodiment 86.

[0225] Embodiment 88: At least one processor (1250) and a memory (1260) containing program code executable by at least one processor (1250); Execution of the program code by at least one processor (1250) causes the node (100, 1000, 1200) to perform the method according to any one of embodiments 47 to 82; A node (100, 1000, 1200) as described in embodiment 86 or 87.

[0226] Embodiment 89: A computer program or computer program product including program code, the program code being executed by at least one processor (1150) of a wireless communication device (10, 800, 1100), and causing the wireless communication device (10, 800, 1100) to perform a method according to any one of embodiments 1 to 46.

[0227] Embodiment 90: A computer program or computer program product comprising program code, the program code being executed by at least one processor of a node (100, 1000, 1200) for a wireless communication network, the execution of the program code causing the node (100, 1000, 1200) to perform a method according to any one of embodiments 47 to 82.

Claims

1. 1. A method for controlling sidelink communications, comprising: a user equipment (10, 800, 1100) simultaneously maintaining a first discontinuous reception (DRX) configuration for sidelink communications and a second DRX configuration for sidelink communications, the first DRX configuration being compatible with multiple sidelink communication classes and the second DRX configuration being compatible with one specific sidelink communication class; the user equipment (10, 800, 1100) participating in sidelink communications with one or more further user equipments (10, 800, 1100) based on at least one of the first DRX configuration and the second DRX configuration; A method comprising:

2. the user equipment (10, 800, 1100) simultaneously maintains the first DRX configuration for sidelink communications and a plurality of second DRX configurations for sidelink communications; 2. The method of claim 1, wherein each of the plurality of second DRX configurations is adapted to a different specific sidelink communication class.

3. selecting whether the user equipment (10, 800, 1100) should enable the first DRX setting and / or the second DRX setting; This includes: The selection of whether to enable the first DRX setting and / or the second DRX setting includes: the sidelink communication with the one or more further user equipments (10, 800, 1100); information received from at least one of said one or more further user equipments (10, 800, 1100); and Information received from a node (100, 1000, 1200) of a wireless network based at least in part on one or more of The method according to claim 1 or 2.

4. selecting whether the user equipment (10, 800, 1100) should enable the first DRX setting and / or the second DRX setting; the user equipment (10, 800, 1100) indicating the selected at least one of the first DRX setting and / or the second DRX setting to at least one of the one or more further user equipments (10, 800, 1100); 3. The method of claim 1 or 2, comprising:

5. 1. A method for controlling sidelink communications in a wireless communication network, comprising: a node (100, 1000, 1200) of the wireless communication network configuring a user equipment (10, 800, 1100) to simultaneously maintain a first discontinuous reception (DRX) configuration for sidelink communication with one or more further user equipments (10, 800, 1100) and a second DRX configuration for sidelink communication with one or more further user equipments (10, 800, 1100), the first DRX configuration is adapted to multiple sidelink communication classes and the second DRX configuration is adapted to one specific sidelink communication class. The method includes:

6. the plurality of sidelink communication classes does not include the specific sidelink communication class; 6. The method according to any one of claims 1 to 5.

7. 7. The method according to claim 1, wherein the sidelink communication class is determined based on identifiers of user equipments (10, 800, 1100) participating in the sidelink communication and / or addresses of user equipments (10, 800, 1100) participating in the sidelink communication.

8. 8. The method of claim 1, wherein the sidelink communication class is defined based on one or more quality of service attributes used for the sidelink communication.

9. The method of claim 8 , wherein the one or more quality of service attributes include one or more of a quality of service flow, a quality of service level, a quality of service class, and a quality of service priority level.

10. The method according to claim 1 , wherein the first DRX setting is a common DRX setting and the second DRX setting is a specific DRX setting.

11. The method of claim 1 , wherein the user equipment is one of a vehicle, a vehicle-mounted wireless terminal device, and a connected vehicle.

12. A user equipment (10, 800, 1100), simultaneously maintaining a first discontinuous reception (DRX) configuration for sidelink communications and a second DRX configuration for sidelink communications, the first DRX configuration being compatible with multiple sidelink communication classes and the second DRX configuration being compatible with one specific sidelink communication class; participating in sidelink communications with one or more further user equipments based on at least one of the first DRX configuration and the second DRX configuration. The user equipment (10, 800, 1100) is configured as follows:

13. The user equipment (10, 800, 1100) is configured to execute the method according to any one of claims 2 to 4 and claims 6 to 11 when claim 1 is recited, 13. A user equipment (10, 800, 1100) according to claim 12.

14. A computer program comprising program code, the program code being executed by at least one processor (1150) of a user equipment (10, 800, 1100), and causing the user equipment (10, 800, 1100) to perform a method according to any one of claims 1 to 4 and, when claim 1 is recited, claims 6 to 11.

15. A node (100, 1000, 1200) for a wireless communication network, comprising:

1. A node (100, 1000, 1200) configured to simultaneously maintain a first discontinuous reception (DRX) configuration for sidelink communication with one or more further user equipments (10, 800, 1100) and a second DRX configuration for sidelink communication with one or more further user equipments (10, 800, 1100), wherein the first DRX configuration is adapted to a plurality of sidelink communication classes and the second DRX configuration is adapted to one particular sidelink communication class.

16. The node (100, 1000, 1200) is configured to execute the method according to any one of claims 6 to 11 when claim 5 is relied upon, The node of claim 15.

17. A computer program comprising program code, the program code being executed by at least one processor of a node (100, 1000, 1200) for a wireless communication network, the execution of the program code causing the node (100, 1000, 1200) to A computer program causing the computer to carry out the method according to claim 5 or any one of claims 6 to 11 when claim 5 is relied upon.

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