Multi-stage side link control information

Abstract

A method, a wireless device, a system, and a program are provided that can efficiently control sidelink (SL) wireless communication. According to the present invention, a wireless device (UE) receives first sidelink control information (204) from another wireless device (20). Based on assistance information stored in the wireless device (30) and the received first sidelink control information, the wireless device (30) determines a configuration for transmission of second sidelink control information (206). Based on the determined configuration for transmission of the second sidelink control information (206), the wireless device receives second sidelink control information (206) from the other wireless device. Based on the received second sidelink control information (206), the wireless device receives sidelink radio transmissions from the other wireless device (20).

Description

[Technical Field]

[0001] The present invention relates to a method for controlling radio transmissions and to a corresponding radio device, system and computer program. [Background technology]

[0002] In wireless communication networks, the direction of transmission from the wireless communication network to a UE (User Equipment) is typically referred to as the "downlink" (DL) direction, while the direction of transmission from the UE to the wireless communication network is typically referred to as the "uplink" (UL) direction. In addition to DL and UL wireless transmissions, it is known to support direct wireless transmissions between UEs. These direct wireless transmissions are sometimes referred to as "sidelink" (SL) wireless transmissions. For example, for the Long Term Evolution (LTE) wireless technology defined by the 3GPP (Third Generation Partnership Project), SL wireless transmissions are defined in 3GPP TS 36.201 V14.1.0 (2017-03). SL radio transmissions can be used, for example, for vehicle-to-anything (V2X) communications, including vehicle-to-vehicle (V2V) communications between vehicles, vehicle-to-pedestrian (V2P) communications between vehicles and personal devices (e.g., handheld terminals carried by pedestrians, cyclists, drivers, or passengers), vehicle-to-infrastructure (V2I) communications between vehicles and roadside units (RSUs) of traffic infrastructure (e.g., entities transmitting speed limit notifications), and vehicle-to-network (V2N) communications between vehicles and nodes of a wireless communication network. In principle, V2X communications may utilize a network infrastructure when it is available. However, at least basic V2X communication functionality shall also be possible even without a network infrastructure (e.g., outside of network coverage).

[0003] In LTE radio technology, SL radio transmissions are performed using a Physical SL Control Channel (PSCCH) and a Physical SL Shared Channel (PSSCH). The PSCCH carries SL Control Information (SCI), which may indicate, for example, scheduling information for data transmissions on the PSSCH. The SCI may indicate the radio resources allocated for PSSCH data transmission, the modulation and coding scheme (MCS) used for PSSCH data transmission, a retransmission index, the intention to reserve the same radio resources for future data transmissions, and a priority level in terms of ProSe Per-Packet Priority (PPPP). The PSCCH has a fixed size of two resource blocks (RBs) and is transmitted in the same subframe as the data transmissions on the PSSCH.

[0004] In LTE radio technology, a receiver of an SL radio transmission is typically not informed of the SL radio transmission in advance. That is, the receiver cannot reliably determine whether an SL radio transmission is likely to occur. Furthermore, the receiver typically does not know the parameters used by the transmitter of the SL radio transmission. To simplify receiver design, in LTE radio technology, SCI transmission on the PSCCH is only possible on certain radio resources using certain transmission parameters, and the same format must always be used for SCI transmission on the PSCCH. The specified RBs in which SCI transmission on the PSCCH can occur are typically referred to as the search space (SS). Using these assumptions, the complexity of an SL receiver can be limited, since it typically only needs to attempt to decode PSCCH transmissions within the search space, which is also referred to as blind decoding of the PSCCH or SCI.

[0005] However, the introduction of new services or uses of SL wireless communication in LTE wireless technology or 5G (fifth generation) wireless technology may result in diverse requirements regarding latency, reliability, and data rate that cannot be met by the above limitations on SS, SCI format, and transmission parameters, and may therefore lead to greater complexity and power consumption in SL receivers.

[0006] For these reasons, there is a demand for technology that can efficiently control SL wireless communications. Summary of the Invention

[0007] According to one embodiment, there is provided a method for controlling SL radio transmissions in a wireless communication network, wherein a wireless device receives a first SCI from another wireless device, and based on assistance information stored in the wireless device and the received first SCI, the wireless device determines a configuration for transmission of a second SCI, and based on the determined configuration for transmission of the second SCI, the wireless device receives a second SCI from the other wireless device, and based on the received second SCI, the wireless device receives an SL radio transmission from the other wireless device.

[0008] According to another embodiment, there is provided a method for controlling SL radio transmission in a wireless communication network, wherein a wireless device determines a first SCI based on aiding information stored in the wireless device. The aiding information associates the first SCI with a configuration for transmitting a second SCI. The wireless device transmits the first SCI to another wireless device. Based on the configuration, the wireless device further transmits the second SCI to the other wireless device. Based on the second SCI, the wireless device transmits an SL radio transmission to the other wireless device.

[0009] According to another embodiment, there is provided a method for controlling SL radio transmission in a wireless communication network. According to the method, assistance information is provided to a first wireless device. Further, the assistance information is provided to a second wireless device. The provision of the assistance information to the first and second wireless devices may be performed by a node of the wireless communication network. The assistance information associates a first SCI transmitted from the first wireless device to the second wireless device with a configuration for transmitting a second SCI from the first wireless device to the second wireless device.

[0010] According to another embodiment, there is provided a radio device of a wireless communication network. The radio device is configured to receive a first SCI from another radio device. The radio device is further configured to determine a configuration for transmission of a second SCI based on assistance information stored in the radio device and the received first SCI. The radio device is further configured to receive a second SCI from the other radio device based on the determined configuration for transmission of the second SCI. The radio device is further configured to receive an SL wireless transmission from the other radio device based on the received second SCI.

[0011] According to another embodiment, there is provided a radio device of a wireless communication network, the radio device comprising: at least one processor; and a memory containing instructions executable by the at least one processor operable, when executed by the at least one processor, to cause the radio device to receive a first SCI from another radio device, determine a configuration for transmission of a second SCI based on assistance information stored in the radio device and the received first SCI, receive a second SCI from the other radio device based on the determined configuration for transmission of the second SCI, and receive an SL wireless transmission from the other radio device based on the received second SCI.

[0012] According to another embodiment, a wireless device of a wireless communication network is provided. The wireless device is configured to determine a first SCI based on aiding information stored in the wireless device. The aiding information associates the first SCI with a configuration for transmission of a second SCI. The wireless device is further configured to transmit the first SCI to another wireless device. The wireless device is further configured to transmit the second SCI to the other wireless device based on the configuration. The wireless device is further configured to transmit an SL wireless transmission to the other wireless device based on the second SCI.

[0013] According to another embodiment, a radio device of a wireless communication network is provided, the radio device comprising: at least one processor; and a memory containing instructions executable by the at least one processor, the instructions operable, when executed by the at least one processor, to cause the radio device to determine a first SCI based on aiding information stored in the radio device. The aiding information associates the first SCI with a configuration for transmission of a second SCI. The instructions further operable the radio device to transmit the first SCI to another radio device, transmit the second SCI to another radio device based on the configuration, and transmit an SL wireless transmission to another radio device based on the second SCI.

[0014] According to another embodiment, a node of a wireless communication network is provided, the node being configured to provide assistance information to a first wireless device, and the node being configured to provide assistance information to a second wireless device, the assistance information associating a first SCI transmitted from the first wireless device to the second wireless device with a configuration for transmitting a second SCI from the first wireless device to the second wireless device.

[0015] According to another embodiment, a node of a wireless communication network is provided, the node comprising at least one processor and a memory containing instructions executable by the at least one processor, the memory containing instructions operable, when executed by the at least one processor, to cause the node to provide assistance information to a first wireless device and a second wireless device, the assistance information associating a first SCI transmitted from the first wireless device to the second wireless device with a configuration for transmission of a second SCI from the first wireless device to the second wireless device.

[0016] According to another embodiment, a system is provided, comprising a first wireless device and a second wireless device. The first wireless device and the second wireless device store aiding information. The first wireless device is configured to: determine a first SCI, which associates the aiding information with a setting for transmission of a second SCI, based on the aiding information stored in the first wireless device; transmit the first SCI to the second wireless device; transmit the second SCI to the second wireless device based on the setting; and transmit an SL wireless transmission to the second wireless device based on the second SCI. The second wireless device is configured to receive the first SCI from the first wireless device, determine a setting for transmission of the second SCI based on the aiding information stored in the second wireless device and the received first SCI, receive the second SCI from the first wireless device based on the determined setting for transmission of the second SCI, and receive the SL wireless transmission from the first wireless device based on the received second SCI. The system may further comprise a node of the wireless communication network configured to provide assistance information to the first wireless device and / or the second wireless device.

[0017] According to another embodiment of the present invention, there is provided a computer program or computer program product in the form of a non-transitory storage medium including program code executed by at least one processor of, for example, a wireless device of a wireless communication network. Execution of the program code causes the wireless device to receive a first SCI from another wireless device. Further, execution of the program code causes the wireless device to determine settings for transmission of a second SCI based on assistance information stored in the wireless device and the received first SCI. Further, execution of the program code causes the wireless device to receive a second SCI from the other wireless device based on the determined settings for transmission of the second SCI. Further, execution of the program code causes the wireless device to receive an SL wireless transmission from the other wireless device based on the received second SCI.

[0018] According to another embodiment of the present invention, there is provided a computer program or computer program product in the form of a non-transitory storage medium including program code executed by at least one processor of, for example, a wireless device of a wireless communication network. Execution of the program code causes the wireless device to determine a first SCI based on aiding information stored in the wireless device. The first SCI associates the aiding information with a configuration for transmission of a second SCI. Execution of the program code also causes the wireless device to transmit the first SCI to another wireless device. Execution of the program code also causes the wireless device to transmit a second SCI to another wireless device based on the configuration. Execution of the program code also causes the wireless device to transmit an SL wireless transmission to another wireless device based on the second SCI.

[0019] According to another embodiment of the present invention, there is provided a computer program or computer program product 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 of a wireless communication network, the program code causing the node to provide assistance information to a first wireless device, and the program code causing the node to provide assistance information to a second wireless device, the assistance information associating a first SCI transmitted from the first wireless device to the second wireless device with settings for transmission of a second SCI from the first wireless device to the second wireless device.

[0020] These and other details of the embodiments will be apparent from the following detailed description of the embodiments. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 illustrates an exemplary scenario illustrating wireless transmission in a wireless communication network, according to an embodiment of the present invention. [Figure 2] FIG. 1 illustrates an example process by which SL wireless transmissions between wireless devices are controlled, according to an embodiment of the present invention. [Figure 3A]FIG. 1 illustrates an example process for providing assistance information to a wireless device. [Figure 3B] FIG. 10 illustrates another example process for providing assistance information to a wireless device. [Figure 3C] FIG. 10 illustrates another example process for providing assistance information to a wireless device. [Figure 4] FIG. 10 illustrates another example process for providing assistance information to a wireless device. [Figure 5] FIG. 10 illustrates an example of assistance information used in accordance with an embodiment of the present invention for controlling SL radio transmissions. [Figure 6] 1 is a flow chart that schematically illustrates a method for controlling reception of SL radio transmissions, in accordance with an embodiment of the present invention; [Figure 7] FIG. 2 is a block diagram illustrating the functionality of a receiving wireless device according to one embodiment of the present invention. [Figure 8] 4 is a flow chart that schematically illustrates a method for controlling the sending of SL radio transmissions, according to an embodiment of the present invention; [Figure 9] 2 is a block diagram illustrating the functionality of a transmitting radio device according to one embodiment of the present invention; [Figure 10] 1 is a flow chart that schematically illustrates a method for controlling SL radio transmissions, according to an embodiment of the present invention. [Figure 11] FIG. 2 is a block diagram illustrating the functionality of a network node according to an embodiment of the present invention. [Figure 12] 1 is a diagram illustrating a schematic structure of a wireless device according to an embodiment of the present invention; [Figure 13] FIG. 2 is a schematic diagram illustrating the structure of a network node according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The concepts according to exemplary embodiments of the present invention will now be explained in more detail with reference to the accompanying drawings. The illustrated embodiment relates to the control of SL radio transmissions in a wireless communication network. In the illustrated example, it is assumed that the wireless communication network is based on LTE radio technology. However, other radio technologies that support SL radio transmissions (e.g., 5G radio technologies such as NR (New Radio) technology currently being developed by 3GPP) may be used as well. In this specification, the term "transmission" is used to include both sending and receiving.

[0023] In the illustrated example, the SCI of a SL radio transmission between two radio devices (hereinafter referred to as UEs) is multi-staged, including a first SCI (hereinafter also referred to as a first-stage SCI) and a second SCI (hereinafter also referred to as a second-stage SCI). The first SCI and the second SCI may be dynamically transmitted for each SL radio transmission. The first SCI is used in conjunction with assistance information stored by the radio devices. The assistance information associates the first SCI with a configuration for transmitting the second SCI. The assistance information may be preconfigured in the UEs, e.g., based on a standard, or may be signaled to the UEs from the network, e.g., as part of system information and / or using higher layer signaling such as RRC (Radio Resource Control), or may be transferred from the first UE to the second UE, e.g., when the second UE enters the radio coverage area of ​​the first UE.

[0024] Thus, a first UE intending to transmit an SL radio transmission to a second UE may first select a suitable configuration for the transmission of the second SCI. This selection may depend on a use case. For example, this selection may depend on whether the SL radio transmission is a unicast or broadcast transmission. Furthermore, this selection may depend on the transmission mode of the SL radio transmission. For example, this selection may depend on whether the SL radio transmission uses a single-input / single-output (SISO) mode or a multiple-input / multiple-output (MIMO) mode. Furthermore, this selection may depend on the quality of service (QoS) requirements (e.g., latency, data rate, reliability, or transmission distance) of the SL radio transmission. Using the assistance information, the first UE may determine a first SCI associated with the selected configuration and transmit the first SCI to the second UE. Based on the first SCI received from the first UE and the stored assistance information, the second UE can determine a configuration for the transmission of the second SCI. Thus, the first UE can then transmit the second SCI to the second UE using the selected configuration, and the second UE can receive the second SCI from the first UE using the selected configuration. Then, based on the second SCI, the first UE can transmit an SL radio transmission to the second UE, and the second UE can receive the SL radio transmission. Thus, the assistance information and the first SCI provide high variability in the second SCI, thereby limiting blind decoding attempts required for the second SCI at the second UE, while allowing support for various use cases and requirements.

[0025] FIG. 1 illustrates an exemplary scenario involving SL radio transmissions. More specifically, FIG. 1 illustrates an access node 100 of a wireless communication network, referred to as an eNB in ​​LTE wireless technology, and various entities 11, 12, 13, 14, and 15 that may communicate using DL and / or UL radio transmissions indicated by solid arrows and SL radio transmissions indicated by dashed arrows. A service area or cell of the access node is shown schematically at 101. The service area 101 may be defined by a radio coverage area capable of DL radio transmissions from the access node 100 and UL radio transmissions to the access node 100. It should be noted that the wireless communication network may include other access nodes, each having a corresponding service area that may or may not overlap with the coverage area 101 of the access node 100.

[0026] The entities shown in FIG. 1 include vehicles 11, 12, and 13, a mobile phone 14, and a person 15 (e.g., a pedestrian, a cyclist, a vehicle driver, or a vehicle occupant). Note that in the case of vehicles 11, 12, and 13, wireless transmissions may be performed by communication modules installed in the vehicles, and in the case of person 15, wireless transmissions may be performed by wireless devices carried or worn by person 15 (e.g., wristband devices or similar wearable devices). These devices and modules may also be referred to as UEs. SL wireless transmissions may be enabled by DL wireless transmissions and / or UL wireless transmissions (e.g., control or management of SL wireless transmissions using DL wireless transmissions from access node 100). As described in more detail below, this may involve providing the aforementioned assistance information to the entities' wireless devices and / or modules. Furthermore, the entities shown in FIG. 1 are merely exemplary. SL wireless transmissions may be used to implement various types of V2X communication, including V2V, V2P, and / or V2I communication. Thus, SL radio transmissions may carry various types of V2X messages (e.g., Cooperative Awareness Messages (CAMs) or Distributed Environmental Notification Messages (DENMs)), although other types of SL radio communications may be supported as well.

[0027] In accordance with an expected use of LTE radio technology, SL radio transmissions may be based on the PC5 interface defined in 3GPP TS 23.303 V14.1.0 (2016-12). DL and UL radio transmissions may be based on the LTE Uu interface defined in 3GPP TS 23.401 V14.6.0 (2017-12). SL radio transmissions may involve data transmissions on a PSSCH, and a first SCI and a second SCI may be transmitted on a PSCCH. Each data transmission on the PSSCH may be scheduled by the first SCI and the second SCI transmitted on the PSCCH. Transmission parameters of SL radio transmissions, such as the number of used RBs, the number of retransmissions, and / or MCS, may be adaptive based on priority levels defined in terms of, for example, PPPP, the congestion level of the utilized carrier, and the mobility speed of the transmitting radio device. For example, as specified in 3GPP TS 23.303 V14.1.0, PPPP is configured on the application layer for each message transmitted over the PC5 interface.

[0028] Allocation of radio resources for SL radio transmissions may be performed centrally using DL control information (DCI) transmitted by the access node 100 to radio devices transmitting and / or receiving the SL radio transmissions. In particular, for a particular SL radio transmission, the access node 100 may transmit DCI indicating the allocated PSCCH radio resources used for transmitting the first SCI and the second SCI as well as the allocated PSCCH radio resources used for transmitting the actual data transmission.

[0029] Furthermore, allocation of radio resources for SL radio transmissions may be performed in a distributed or autonomous manner. In this case, the transmitting radio equipment autonomously determines the radio resources to be used for SL radio transmissions for both the PSCCH and the PSSCH by using a specific algorithm. The allocation of radio resources may also be based on channel sensing performed by the transmitting radio equipment, for example, to avoid conflicts, such as collisions, that may occur when multiple radio equipments attempt to use the same radio resources. The autonomously allocated radio resources may be selected from one or more resource pools. The resource pools may be pre-configured, for example, based on a standard, or may be signaled by the network, for example, using system information or higher layer signaling (e.g., RRC signaling). The sensing-based autonomous allocation of radio resources may be performed, for example, according to "Mode 4" of SL radio transmissions specified in 3GPP TS 36.213 V14.5.0 (2017-12). In Mode 4, autonomous resource allocation combines the features of semi-persistent resource allocation and sensing-based resource allocation. Semi-persistent resource allocation involves allocating radio resources over long periods of time, allowing for more or less regular reuse of radio resources. Sensing-based allocation detects the presence or absence of such regular transmissions by monitoring the radio channel by other devices. In this way, UEs can avoid collisions when autonomously selecting radio resources from a resource pool shared by multiple wireless devices.

[0030] Figure 2 shows an example of a process by which SL radio transmissions are controlled based on the principles outlined above. The process of Figure 2 involves an access node (AN) 100, a transmitting UE (SL TX) 20, and a receiving UE (SL RX) 30. Note that the transmitting UE 20 and receiving UE 30 may correspond to any pair of entities 11, 12, 13, 14, 15 shown in Figure 1.

[0031] In the example of Fig. 2, it is assumed that the access node 100 initially provides at least a portion of the assistance information to the UEs 20, 30, as indicated by messages 201 and 202. The assistance information is stored by the UEs 20, 30. The messages 201, 202 can be, for example, part of signaled system information and / or RRC messages. Other portions of the assistance information can be preconfigured in the UEs 20, 30, for example, based on a standard. In an alternative scenario, the assistance information can be completely preconfigured in the UEs 20, 30. It is noted that the illustrated concept also contemplates that the assistance information stored by the UE 20 can differ from the assistance information stored by the UE 30, for example, due to different UE types and / or supported capabilities of the UEs 20, 30. However, typically, at least a portion of the assistance information will be common to the two UEs 20, 30, and this common portion will be used to control SL radio transmissions, as will be explained in more detail below. As will be explained in more detail below, the assistance information can be provided, for example, in terms of configuration tables.

[0032] Then, as indicated by block 203, the transmitting UE 20 selects a configuration for transmission of the first-stage SCI and the second-stage SCI. The configuration for transmission of the first-stage SCI may be pre-configured and may be the same for all UEs in the wireless communication system. The configuration for transmission of the first-stage SCI may define a search space for transmission of the first-stage SCI, e.g., in terms of a location in the time and frequency domain, an MCS for transmission of the first-stage SCI, an aggregation level for transmission of the first-stage SCI, and / or an SCI format of the first-stage SCI. The aggregation level may represent the number of control channel elements (CCEs) or the amount of control channel radio resources required for transmission of the SCI.

[0033] The determination of the second-stage SCI may be more variable and may be based on the use case underlying the intended SL radio transmission or the type of intended SL radio transmission (e.g., PPPP configured by the application layer, whether the intended SL radio transmission is a unicast or broadcast transmission, and / or whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode). The configuration for the transmission of the second-stage SCI may define one or more search spaces for the transmission of the second-stage SCI, e.g., in terms of location in the time and frequency domain, one or more MCSs for the transmission of the second-stage SCI, one or more aggregation levels for the transmission of the second-stage SCI, and / or an SCI format for the second-stage SCI. The configuration for the transmission of the second-stage SCI may be selectable from multiple possible candidate configurations and is typically different from the configuration for the transmission of the first-stage SCI. For example, the configuration for the second-stage SCI transmission may define a larger search space, a different aggregation level, and / or a more complex SCI format than the configuration for the first-stage SCI transmission. Furthermore, the configuration for the second-stage SCI transmission may be configured individually for each UE and / or each SL radio transmission.

[0034] The transmitting UE 20 uses the stored assistance information to determine a first-stage SCI associated with the selected configuration. The first-stage SCI may include, for example, an index indicating the selected configuration. The first-stage SCI may also include one or more transmission parameters associated with the selected configuration (e.g., PPPP, an indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or an indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode). The first-stage SCI may be limited to information that allows identification of the selected configuration, thereby reducing the complexity of transmitting the first-stage SCI. The transmitting UE 20 then transmits the first-stage SCI to the receiving UE 30, as indicated by message 204. The transmitting UE 20 also transmits the second-stage SCI to the receiving UE 30, as indicated by message 206, based on the configuration selected in block 203.

[0035] Upon receiving the first-stage SCI, the receiving UE 30 uses the assistance information to identify a configuration associated with the first-stage SCI. Based on the identified configuration, the receiving UE 30 receives the second-stage SCI. Identifying the configuration used for transmitting the second-stage SCI can significantly reduce the complexity of receiving the second-stage SCI, for example, by limiting the range of possible search spaces, possible MCSs, possible SCI formats, and / or possible aggregation levels. In some scenarios, the first-stage SCI combined with the assistance information may identify a search space and a set of candidate SCI formats for transmitting the second-stage SCI. The receiving UE 30 may then perform blind decoding in the identified search space by using different candidate SCI formats. Also, in some scenarios, the first-stage SCI combined with the assistance information may specify a configuration for transmitting the second-stage SCI to the extent that the receiving UE 30 can decode the second-stage SCI without any blind decoding. For example, the configuration may indicate the exact radio resources, MCS, SCI format, and aggregation level used for transmitting the second stage SCI.

[0036] As further shown in FIG. 2 , the transmitting UE 20 further transmits an SL radio transmission to the receiving UE 30. This may involve the transmission of SL data 207 on a PUSSCH. Furthermore, this may involve the transmission of one or more reference symbols (RS) 208. The SL radio transmission is performed based on the information indicated in the second-stage SCI. For example, the second-stage SCI may indicate radio resources allocated to the SL radio transmission (e.g., with respect to PPPP), the MCS of the SL radio transmission, and / or a priority level of the SL radio transmission. Furthermore, the second-stage SCI may indicate retransmission parameters of the SL radio transmission (e.g., whether the SL radio transmission includes an initial transmission or a retransmission of data, the number of retransmission attempts, and / or a redundancy version of the retransmitted data). Furthermore, the second-stage SCI may indicate whether there is a reservation of radio resources for a subsequent SL radio transmission from the transmitting UE 20 to the receiving UE 30.

[0037] As previously mentioned, the transmitting UE 20 may transmit one or more reference symbols 208. The transmission of the reference symbols 208 may be controlled by the second-stage SCI, allowing different configurations of the reference symbols while still allowing efficient monitoring of the reference symbols by the receiving UE 30. The reference symbols 208 may be used as the basis for performing, for example, detection-based scheduling of SL radio transmissions.

[0038] Note that while FIG. 2 illustrates the transmission of the first-stage SCI occurring before the transmission of the second-stage SCI, which in turn occurs before the SL radio transmission, this is not necessarily the case. For example, the first-stage SCI, second-stage SCI, and SL radio transmission may be transmitted substantially simultaneously, e.g., on different RBs in the same subframe. The receiving UE 30 may monitor all possible RBs in a subframe and use the first-stage SCI to reduce the complexity of blind decoding of the second-stage SCI. The decoded second-stage SCI may then be used to decode the SL data 207 and / or monitor the reference symbols 208. That is, the second-stage SCI may be transmitted using a configuration selected from a wide range of candidate configurations, but the first-stage SCI in combination with assistance information may limit the scope of blind decoding performed by the receiving UE 30 to a single configuration or at least a limited subset of candidate configurations.

[0039] Figure 3A illustrates an example process that may be used to provide assistance information to a transmitting UE 20 and a receiving UE 30. In the process of Figure 3A, it is assumed that a transmitting UE 20 enters the coverage area 101 of an access node 100, as indicated by block 301. A receiving UE 30 may be outside the coverage area 101 of the access node 100, or may have subsequently entered the coverage area 101 of the access node 100.

[0040] As further shown, the transmitting UE 20 transmits a request 302 to the access node 100 in response to entering the coverage area 101 of the access node 100. The request 302 may be transmitted, for example, in a message of a procedure used to set up a connection between the transmitting UE 20 and the access node 100. In response to the request 302, the access node 100 transmits aiding information 303 to the transmitting UE 20. The transmitting UE 20 stores the received aiding information 303. If the previously stored aiding information is available to the transmitting UE 20, the transmitting UE 20 may use the received aiding information 303 to replace or update the previously stored aiding information.

[0041] As further shown, the transmitting UE 20 may transmit assistance information 304 to the receiving UE 30. The assistance information 304 may correspond to at least a portion of the assistance information 303 received by the transmitting UE 20 and forwarded to the receiving UE 30. The transmitting UE 20 may also forward at least a portion of assistance information previously stored by the transmitting UE 20 to the receiving UE 30. The assistance information 304 may be transmitted, for example, as part of an SL discovery procedure (e.g., a ProSe discovery procedure as defined in 3GPP TS 23.303 V14.1.0). The receiving UE 30 stores the received assistance information 304. If the previously stored assistance information is available to the receiving UE 30, the receiving UE 30 may use the received assistance information 303 to replace or update the previously stored assistance information.

[0042] Figure 3B illustrates another example of a process that can be used to provide assistance information to a transmitting UE 20 and a receiving UE 30. In the process of Figure 3B, it is assumed that the receiving UE 30 enters the coverage area 101 of the access node 100, as indicated by block 305. The transmitting UE 20 may be outside the coverage area 101 of the access node 100, or may have just entered the coverage area 101 of the access node 100.

[0043] As further shown, the recipient UE 30 transmits a request 306 to the access node 100 in response to entering the service area 101 of the access node 100. The request 306 may be transmitted, for example, in a message of a procedure used to set up a connection between the recipient UE 30 and the access node 100. In response to the request 306, the access node 100 transmits aiding information 307 to the recipient UE 30. The recipient UE 30 stores the received aiding information 307. If previously stored aiding information is available at the recipient UE 30, the recipient UE 30 may use the received aiding information 307 to replace or update the previously stored aiding information.

[0044] As further shown, the receiving UE 30 may transmit aiding information 308 to the transmitting UE 20. The aiding information 308 may correspond to at least a portion of the aiding information 307 received by the receiving UE 30 and forwarded to the transmitting UE 30. The receiving UE 30 may also forward at least a portion of previously stored aiding information to the transmitting UE 20. The aiding information 308 may be transmitted, for example, as part of an SL discovery procedure (e.g., a ProSe discovery procedure as defined in 3GPP TS 23.303 V14.1.0). The transmitting UE 20 stores the received aiding information 308. If the previously stored aiding information is available to the transmitting UE 20, the transmitting UE 20 may use the received aiding information 308 to replace or update the previously stored aiding information.

[0045] Figure 3C illustrates another example process that can be used to provide assistance information to the transmitting UE 20 and the receiving UE 30. In the process of Figure 3C, the access node 100 first transmits assistance information 311 to the transmitting UE 20. The transmitting UE 20 stores the received assistance information 311. If the previously stored assistance information is available to the transmitting UE 20, the transmitting UE 20 may use the received assistance information 311 to replace or update the previously stored assistance information.

[0046] 3C, it is further assumed that the receiving UE 30 enters the radio coverage area of ​​the transmitting UE 20, as indicated by block 312. At that point, the receiving UE 30 may be outside the service area 101 of the access node 100 and therefore cannot obtain assistance information directly from the access node 100.

[0047] As further shown, the receiving UE 30 transmits a request 313 to the transmitting UE 20 in response to entering the radio coverage area of ​​the transmitting UE 20. The request 313 may be, for example, part of an SL discovery procedure (e.g., a ProSe discovery procedure as defined in 3GPP TS 23.303 V14.1.0). In response to the request 313, the transmitting UE 20 transmits aiding information 314 to the receiving UE 30. The aiding information 314 may correspond to at least a portion of the aiding information 311 received by the transmitting UE 20 and forwarded to the receiving UE 30. The transmitting UE 20 may also forward at least a portion of previously stored aiding information to the receiving UE 30. The receiving UE 30 stores the received aiding information 314. If the previously stored aiding information is available to the receiving UE 30, the receiving UE 30 may use the received aiding information 307 to replace or update the previously stored aiding information.

[0048] Figure 4 illustrates another example of a process that can be used to provide assistance information to a transmitting UE 20 and a receiving UE 30. In the process of Figure 4, it is assumed that a transmitting UE 20 enters a service area 101 of an access node 100. As indicated by block 401, the access node 100 may detect that the transmitting UE 20 has entered the service area 101 of the access node 100, for example, based on the transmitting UE 20 setting up a connection to the access node 100.

[0049] As further shown, in response to the transmitting UE 20 entering the service area 101 of the access node 100, the access node 100 transmits aiding information 402 to the transmitting UE 20. The transmitting UE 20 stores the received aiding information 402. If the previously stored aiding information is available to the transmitting UE 20, the transmitting UE 20 may use the received aiding information 402 to replace or update the previously stored aiding information.

[0050] 4, it is further assumed that at some point the receiving UE 30 enters the service area 101 of the access node 100. As indicated by block 403, the access node 100 may detect that the receiving UE 30 has entered the service area 101 of the access node 100, for example, based on the receiving UE 20 setting up a connection to the access node 100.

[0051] As further shown, in response to the receiving UE 20 entering the service area 101 of the access node 100, the access node 100 transmits aiding information 404 to the transmitting UE 20. The receiving UE 20 stores the received aiding information 404. If previously stored aiding information is available at the receiving UE 20, the transmitting UE 20 may use the received aiding information 402 to replace or update the previously stored aiding information.

[0052] 4, no explicit request is required from either the transmitting UE 20 or the receiving UE 30 to trigger the transmission of the assistance information 402, 404 by the access node 100. Furthermore, in some scenarios, the detection of the transmitting UE 20 or the receiving UE 30 entering the coverage area 101 of the access node 100 may also be omitted. For example, the access node 100 may broadcast the assistance information 402, 404, e.g., as part of the system information, such that the assistance information 402, 404

[0053] 3A, 3B, 3C, and 4 are merely exemplary, and various modifications and / or combinations may be made to provide assistance information to the transmitting UE 20 and the receiving UE 30. For example, similar to the process of FIG. 3C, the transmitting UE 20 may request assistance information from the receiving UE 30 in response to entering the radio coverage area of ​​the receiving UE 30.

[0054] FIG. 5 illustrates an example of the configuration of the support information with respect to a configuration table 500. The configuration table 500 includes multiple rows, each corresponding to a different candidate configuration for second-stage SCI transmission. As shown in the left column of the configuration table 500, each candidate configuration may be identified by an index. In the illustrated example, the first candidate configuration is identified by index 1, the second candidate configuration is identified by index 2, the third candidate configuration is identified by index 3, the fourth candidate configuration is identified by index 4, the fifth candidate configuration is identified by index 5, and the sixth candidate configuration is identified by index 6. However, the number of candidate configurations illustrated is merely an example, and the support information may specify more or fewer candidate configurations.

[0055] As shown by the center column of configuration table 500, each different candidate configuration may be associated with a particular use case. The use cases may differ, for example, with respect to reliability requirements, as represented by different PPPPs assigned to SL radio transmissions. For example, a safety-related use case may involve the transmission of emergency messages or danger alerts and may involve the assignment of a high priority level to SL radio transmissions. Meanwhile, a non-safety-related use case may involve the transmission of traffic information messages and may involve the assignment of a low priority level to SL radio transmissions. In the example of FIG. 5 , different priority levels are represented by different PPPPs. Furthermore, as further shown by the center column of configuration table 500, the use cases may differ with respect to transmission scenarios (e.g., depending on whether the SL radio transmissions are unicast or broadcast transmissions). Furthermore, as further shown by the center column of configuration table 500, the use cases may differ with respect to transmission modes (e.g., depending on whether the SL radio transmissions are performed in SISO mode or MIMO mode).

[0056] The right column of the configuration table shows configuration parameters for the transmission of the second-stage SCI. As shown, these parameters may indicate one or more search spaces for the transmission of the second-stage SCI, e.g., defined in terms of RBs and / or subframes, one or more MCSs for the transmission of the second-stage SCI, one or more aggregation levels for the transmission of the second-stage SCI, and / or an SCI format for the second-stage SCI. Furthermore, these parameters may indicate a reference symbol (RS) configuration or a sensing-based scheduling (SBS) configuration.

[0057] By having configurations according to use cases, it is possible to define a configuration for use cases requiring high reliability (e.g., transmission of emergency messages or danger alerts) that involves the use of small-sized SCI formats and / or higher aggregation levels for the second-stage SCI, thereby ensuring reliable transmission of the second-stage SCI and improving the reliability of the SL radio transmission itself. On the other hand, for use cases not requiring high reliability (e.g., transmission of traffic information), it is possible to define a configuration that involves the use of larger-sized SCI formats and / or lower aggregation levels. Similarly, one SCI format may be used for transmission in SISO mode, while another SCI format may be used for transmission in MIMO mode.

[0058] Note that while parameters for a configuration such as that shown in Figure 5 typically vary between various configurations, overlapping parameters may exist. For example, two or more of the SCI formats (SCI Format 1, SCI Format 2, SCI Format 3, SCI Format 4, SCI Format 5, SCI Format 6) may be the same. Furthermore, two or more of the different search spaces (Search Space 1, Search Space 2, Search Space 3, Search Space 4, Search Space 5, Search Space 6, Search Space 7, Search Space 8, Search Space 9) may overlap in part or in whole.

[0059] As further illustrated, at least some of the configurations may include sub-configurations. For example, such sub-configurations may correspond to configurations that define multiple candidate search spaces, as shown for the fifth and sixth configurations in the example of Figure 5. Furthermore, such sub-configurations may correspond to configurations that define multiple candidate aggregation levels, as shown for the first through fifth configurations in the example of Figure 5. Furthermore, such sub-configurations may correspond to configurations that define multiple candidate SCI formats, as shown for the third configuration in the example of Figure 5.

[0060] As further shown, when a configuration specifies subsets, the configuration may also specify a priority for the subsets. For example, in the case of the fifth and sixth configurations, which specify subsets corresponding to different candidate search spaces, the configuration also specifies a search space priority (SS priority). For the fifth configuration, search space 6 is specified to have the highest priority, followed by search space 5, and then search space 7. Thus, the receiving UE 30 will first perform blind decoding in search space 6, then in search space 5 if sufficient blind decoding capacity remains, and then in search space 7 if sufficient blind decoding capacity remains. For the sixth configuration, search space 8 is specified to have the highest priority, followed by search space 9. Thus, the receiving UE 30 will perform blind decoding in search space 8, then in search space 9 if sufficient blind decoding capacity remains. In some scenarios, the decision to attempt blind decoding in a particular search space may also depend on the speed of the receiving UE 30. For example, if the receiving UE 30 is moving at high speed and transmission performance in the lower priority search spaces is degraded, the receiving UE 30 may decide to refrain from attempting blind decoding in one of the lower priority search spaces.

[0061] In some scenarios, the configuration may specify different search spaces, aggregation levels, and / or SCI formats for transmitting different types of SCIs. For example, the wireless communication system may support functions such as (A) scheduling (including transmission of a first type of SCI required for decoding a data transmission), (B) resource reservation (including transmission of a second type of SCI indicating the transmitting UE 20's intention to use a specific radio resource at a later time), (C) resource reservation release (including transmission of a third type of SCI indicating the transmitting UE 20's intention to release a reserved radio resource), and (D) resource substitution (including transmission of a fourth type of SCI indicating the receiving UE 30's intention to refrain from using a reserved radio resource). For each of the aforementioned types of SCIs, different configurations for transmitting the second-stage SCIs may be specified, e.g., different search spaces, aggregation levels, and / or SCI formats. For example, for the first and second types of SCIs, the configuration for transmitting the second-stage SCI may be defined using a first search space corresponding to, for example, the first OFDM (Orthogonal Frequency Division Multiplexing) symbol in an OFDM symbol group or slot. Meanwhile, for the third and fourth types of SCIs, the configuration for transmitting the second-stage SCI may be defined using a second search space corresponding to, for example, the use of a subsequent OFDM symbol in the group or slot. The receiving UE 30 may support different functions to different degrees. For example, the receiving UE 30 may support only scheduling and resource reservation. In this case, the receiving UE 30 may attempt to decode the second-stage SCI only in the first search space. Meanwhile, if the receiving UE 30 fully supports the above-described functions (A) to (D), it may attempt to decode the second-stage SCI in both the first and second search spaces.

[0062] It should be noted that the various functions described above are merely examples, and similar different types of SCI may be defined for other functions.

[0063] In some scenarios, the SCI format used in the second-stage SCI may be designed to promote backward compatibility. This is achieved by defining one or more information fields common to all SCI formats, which may be supplemented by one or more additional information fields to define future SCI formats. The common information field may be located in the first bit of the SCI format, and the additional information field may be located in the subsequent bits of the SCI format. The common information field indicates information such as allocated radio resources, resource reservation, and priority level. The receiving UE 30 may use the information indicated by the common information field to control the selection of radio resources for currently received SL radio transmissions and / or subsequent SL radio transmissions, e.g., in terms of radio resource allocation, radio resource reservation, radio resource reselection, or radio resource substitution.

[0064] Therefore, in some scenarios, the illustrated concept of multi-stage SCI may be used to promote backward compatibility. For example, legacy UEs and more advanced UEs may coexist in a wireless communication network. In this case, the first-stage SCI may use an SCI format supported by both the legacy UEs and the more advanced UEs. Similarly, the second-stage SCI may use one or more SCI formats supported by both the legacy UEs and the more advanced UEs. However, the second-stage SCI may use one or more SCI formats that are not fully supported by the legacy UEs. These SCI formats may specify one or more common information fields supported by the legacy UEs and one or more additional information fields supported only by the more advanced UEs. In this way, the common information fields support all the functions of the legacy UEs and ensure backward compatibility. The additional information fields may be introduced to support enhanced functions of the more advanced UEs. If the transmitting UE 20 corresponds to a more advanced UE, it can transmit the second stage SCI with the common information field and the additional information field, while if the receiving UE 30 corresponds to a legacy UE, it can receive the common information field of the second stage SCI and ignore the additional information field of the second stage SCI.

[0065] As mentioned above, the second-stage SCI may indicate information regarding the allocation of radio resources for SL radio transmissions. The radio resources may be centrally scheduled, i.e., selected based on scheduling information in the DCI from the access node 100. However, in other scenarios, the radio resources for SL radio transmissions may be autonomously allocated by the transmitting UE 20. This may involve channel sensing by the transmitting UE 20, i.e., based on a sensing-based scheduling mechanism. Therefore, the second-stage SCI may also indicate information for performing sensing-based scheduling. However, in some cases, all information required for performing sensing-based scheduling (e.g., allocated radio resources and / or priority levels) may be included in the first-stage SCI.

[0066] The SCI used in the illustrated concept may be protected by an error detection code (e.g., a CRC (cyclic redundancy check) code or similar redundancy check code that verifies the integrity of the transmitted SCI). In this case, for example, separate error detection codes are used for each SCI stage, so that a first error detection code can protect the first-stage SCI and a second error detection code can protect the second-stage SCI. However, for resource efficiency reasons, a common error detection code can be used for both the first-stage SCI and the second-stage SCI. In this case, the common error detection code can be carried by the first-stage SCI, the second-stage SCI, or both the first-stage SCI and the second-stage SCI. If a common error detection code is transmitted by both the first stage SCI and the second stage SCI, it is also possible to transmit a first part of the error detection code in the first stage SCI and a second part of the error detection code in the second stage SCI, and concatenate the first and second parts of the error detection code by the receiving UE 30.

[0067] Figure 6 is a flow chart illustrating a method for controlling SL radio transmissions that can be used to implement the illustrated concepts. The method of Figure 6 may be adapted to implement the illustrated concepts in a radio device receiving SL radio transmissions from another radio device. For example, the radio device may correspond to the receiving UE 30 described above, and the other radio device may correspond to the transmitting UE 20 described above. The SL radio transmissions may include transmissions on a data channel, such as the transmission of SL data 207 described above. Alternatively or additionally, the SL radio transmissions may include transmissions of one or more reference signals, such as the transmission of reference symbols 208 described above.

[0068] If a processor-based implementation of the wireless device is used, at least some of the steps of the method of Figure 6 may be performed and / or controlled by one or more processors of the wireless device, and such a wireless device may also include memory storing program code that implements at least some of the described functions or steps of the method of Figure 6.

[0069] At step 610, the wireless device may receive assistance information. The wireless device may receive at least a portion of the assistance information from a node of a wireless communication network, such as access node 100 described above. This may be accomplished in response to the wireless device entering the node's coverage area, as described with respect to the process of FIG. 3B or 4, for example. Alternatively or additionally, the wireless device may receive at least a portion of the assistance information from another wireless device, as described with respect to the process of FIG. 3A or 3C. In the latter case, the wireless device may receive at least a portion of the assistance information in response to the wireless device entering the wireless coverage area of ​​the other wireless device, as described with respect to the process of FIG. 3C. The wireless device may request the assistance information from a node and / or another wireless device. That is, the wireless device may receive at least a portion of the assistance information in response to a request from the other wireless device, as described with respect to the process of FIG. 3B or 3C. The wireless device may then store the received assistance information for later use.

[0070] In step 620, the wireless device receives a first SCI from another wireless device, such as the aforementioned first stage SCI 204. In some scenarios, the first SCI may also include information regarding sensing-based allocation of radio resources for SL radio transmissions (e.g., information defining a resource pool in which radio resources can be found by the sensing-based allocation mechanism and / or information defining one or more radio channels that the sensing-based allocation mechanism will monitor).

[0071] In step 630, the wireless device determines settings for transmission of a second SCI, such as the aforementioned second-stage SCI 206. This determination is accomplished based on aiding information stored in the wireless device, which may correspond, at least in part, to the aiding information received in step 610. Furthermore, the determination of step 630 is based on the first SCI received in step 620.

[0072] In some scenarios, a first part of the configuration for transmitting the second SCI information may be defined by the first SCI, and a second part of the configuration for transmitting the second SCI may be defined by the assistance information. For example, the assistance information may include one or more parameters that define the configuration, from which other parameters of the configuration may be implicitly derived. Examples of such parameters are the aforementioned PPPP, the aforementioned indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or the aforementioned indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters as shown in the center column of the configuration table in FIG. 5).

[0073] The assistance information may define multiple candidate configurations for transmission of the second SCI. In this case, the first SCI may identify a configuration for transmission of the second SCI among the candidate configurations. For example, the first SCI may include an index that identifies a configuration for transmission of the second SCI among the candidate configurations, such as the configuration index described with respect to FIG. 5. However, the first SCI may also include other information that can be used to implicitly identify a configuration, such as PPPP, an indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or an indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters such as those shown in the center column of the configuration table in FIG. 5).

[0074] The configuration for transmission of the second SCI may specify radio resources that form a search space for transmission of the second SCI. In some scenarios, the configuration for transmission of the second SCI may specify radio resources that form multiple search spaces for transmission of the SCI. In this case, the configuration may specify a priority order for the multiple search spaces.

[0075] The configuration for the transmission of the second SCI may also specify one or more formats for the transmission of the second SCI, such as the SCI format described above. If multiple formats are specified, the configuration may also specify a priority order for the multiple formats. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more aggregation levels for the transmission of the second SCI. If multiple aggregation levels are specified, the configuration may also specify a priority order for the multiple aggregation levels. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more modulation and / or coding schemes for the transmission of the second SCI. If multiple modulation and / or coding schemes are specified, the configuration may also specify a priority order for the multiple modulation and / or coding schemes.

[0076] In step 640, the wireless device receives a second SCI from another wireless device, which is accomplished based on the settings determined in step 630.

[0077] The second SCI may include information indicating at least one of the following: radio resources used for the SL radio transmission, a modulation and / or coding scheme used for the SL radio transmission, one or more retransmission parameters for the SL radio transmission, and a priority level for the SL radio transmission. The radio resources may be indicated in terms of time / frequency location and / or in terms of resource reservation.

[0078] In some scenarios, at least one of the first SCI and the second SCI includes a common error detection code that verifies the integrity of both the first SCI and the second SCI, and based on the common error detection code, the wireless device may perform a single integrity check to determine whether the first SCI and the second SCI were received correctly.

[0079] In step 650, the wireless device receives a SL wireless transmission from another wireless device. This is accomplished based on the second SCI received in step 640.

[0080] FIG. 7 is a functional block diagram of a wireless device 700 operating in accordance with the method of FIG. 6. The wireless device 700 may correspond, for example, to the receiving UE 30 described above. As shown, the wireless device 700 may optionally be provided with a module 710 configured to receive assistance information, as described with respect to step 610. Additionally, the wireless device 700 may be provided with a module 720 configured to receive a first SCI, as described with respect to step 620. Additionally, the wireless device 700 may be provided with a module 730 configured to determine settings for transmission of a second SCI, as described with respect to step 630. Additionally, the wireless device 700 may be provided with a module 740 configured to receive a second SCI, as described with respect to step 640. Additionally, the wireless device 700 may be provided with a module 750 configured to receive an SL radio transmission, as described with respect to step 650.

[0081] It should be noted that wireless device 700 may include other modules implementing other functions, such as known functions of a UE supporting V2X or other types of SL communications. Furthermore, the modules of wireless device 700 do not necessarily represent the hardware structure of wireless device 700, but may correspond, for example, to functional elements implemented in hardware, software, or a combination thereof.

[0082] 8 is a flowchart illustrating a method for controlling SL radio transmissions that can be used to implement the illustrated concepts. The method of FIG. 8 may be adapted to implement the illustrated concepts in a radio device that transmits SL radio transmissions to another radio device. For example, the radio device may correspond to the aforementioned transmitting UE 20, and the other radio device may correspond to the aforementioned receiving UE 30. The SL radio transmissions may include transmissions on a data channel, such as the aforementioned transmission of SL data 207. Alternatively or additionally, the SL radio transmissions may include transmissions of one or more reference signals, such as the aforementioned transmission of reference symbols 208.

[0083] If a processor-based implementation of the wireless device is used, at least some of the steps of the method of Figure 8 may be performed and / or controlled by one or more processors of the wireless device, and such a wireless device may also include a memory storing program code that implements at least some of the described functions or steps of the method of Figure 8.

[0084] At step 810, the wireless device may receive assistance information. The wireless device may receive at least a portion of the assistance information from a node of a wireless communication network, such as access node 100 described above. This may be accomplished in response to the wireless device entering the node's coverage area, e.g., as described with respect to the process of FIG. 3A or FIG. 4. Alternatively or additionally, the wireless device may receive at least a portion of the assistance information from another wireless device, as described with respect to the process of FIG. 3B. In the latter case, the wireless device may receive at least a portion of the assistance information in response to the wireless device entering the wireless coverage area of ​​the other wireless device. The wireless device may request the assistance information from a node and / or another wireless device. That is, the wireless device may receive at least a portion of the assistance information in response to a request from the other wireless device, as described with respect to the process of FIG. 3A. The wireless device may then store the received assistance information for later use.

[0085] In step 820, the wireless device determines a first SCI, such as the first-stage SCI 204 described above. The aiding information associates the first SCI with a configuration for transmitting a second SCI (such as the second-stage SCI 206 described above). This determination is achieved based on aiding information stored in the wireless device, which may correspond at least in part to the aiding information received in step 810. The determination of step 820 may involve the wireless device initially determining a configuration, for example, depending on the use case involving the transmission of the SL wireless transmission or the type of SL wireless transmission. Thereafter, the wireless device may select a second SCI such that the configuration can be identified based on the stored aiding information.

[0086] In some scenarios, a first part of the configuration for the transmission of the second SCI may be defined by the first SCI, and a second part of the configuration for the transmission of the second SCI may be defined by the assistance information. For example, the assistance information may include one or more parameters that define the configuration, from which other parameters of the configuration may be implicitly derived. Examples of such parameters are the aforementioned PPPP, the aforementioned indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or the aforementioned indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters as shown in the center column of the configuration table in FIG. 5).

[0087] The assistance information may define multiple candidate configurations for transmission of the second SCI. In this case, the first SCI may identify a configuration for transmission of the second SCI among the candidate configurations. For example, the first SCI may include an index that identifies a configuration for transmission of the second SCI among the candidate configurations, such as the configuration index described with respect to FIG. 5. However, the first SCI may also include other information that can be used to implicitly identify a configuration, such as PPPP, an indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or an indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters such as those shown in the center column of the configuration table in FIG. 5).

[0088] The configuration for transmission of the SCI may specify radio resources that form a search space for transmission of the second SCI. In some scenarios, the configuration for transmission of the second SCI may specify radio resources that form multiple search spaces for transmission of the SCI. In this case, the configuration may specify a priority order for the multiple search spaces.

[0089] The configuration for the transmission of the second SCI may also specify one or more formats for the transmission of the second SCI, such as the SCI format described above. If multiple formats are specified, the configuration may also specify a priority order for the multiple formats. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more aggregation levels for the transmission of the second SCI. If multiple aggregation levels are specified, the configuration may also specify a priority order for the multiple aggregation levels. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more modulation and / or coding schemes for the transmission of the second SCI. If multiple modulation and / or coding schemes are specified, the configuration may also specify a priority order for the multiple modulation and / or coding schemes.

[0090] In step 830, the wireless device transmits the first SCI to another wireless device. In some scenarios, the first SCI may also include information regarding sensing-based allocation of radio resources for SL radio transmissions (e.g., information defining a resource pool in which radio resources can be found by the sensing-based allocation mechanism and / or information defining one or more radio channels that the sensing-based allocation mechanism monitors).

[0091] In step 840, the wireless device transmits the second SCI to another wireless device based on the settings associated with the first SCI determined in step 820.

[0092] The second SCI may include information indicating at least one of the following: radio resources used for the SL radio transmission, a modulation and / or coding scheme used for the SL radio transmission, one or more retransmission parameters for the SL radio transmission, and a priority level for the SL radio transmission. The radio resources may be indicated in terms of time / frequency location and / or resource reservation.

[0093] In some scenarios, at least one of the first SCI and the second SCI includes a common error detection code that verifies the integrity of both the first SCI and the second SCI, and based on the common error detection code, the wireless device may perform a single integrity check to determine whether the first SCI and the second SCI were received correctly.

[0094] In step 850, the wireless device sends an SL wireless transmission to another wireless device, based on the second SCI sent in step 840.

[0095] FIG. 9 is a functional block diagram of a wireless device 900 operating in accordance with the method of FIG. 8. The wireless device 900 may correspond, for example, to the transmitting UE 20 described above. As shown, the wireless device 900 may optionally be provided with a module 910 configured to receive assistance information, as described with respect to step 810. Additionally, the wireless device 900 may be provided with a module 920 configured to determine a first SCI, as described with respect to step 820. Additionally, the wireless device 900 may be provided with a module 930 configured to transmit the first SCI, as described with respect to step 830. Additionally, the wireless device 900 may be provided with a module 940 configured to transmit a second SCI, as described with respect to step 840. Additionally, the wireless device 900 may be provided with a module 950 configured to transmit an SL radio transmission, as described with respect to step 850.

[0096] It should be noted that wireless device 900 may include other modules implementing other functions, such as known functions of a UE supporting V2X or other types of SL communications. Furthermore, the modules of wireless device 900 do not necessarily represent the hardware structure of wireless device 900, but may correspond, for example, to functional elements implemented in hardware, software, or a combination thereof.

[0097] FIG. 10 is a flowchart illustrating a method for controlling SL radio transmissions that can be used to implement the illustrated concepts. The method of FIG. 10 may be used to implement the illustrated concepts in a node of a wireless communication network that controls at least one of a first radio device and a second radio device. Thus, at least some steps of the method may be performed by the node. The node may correspond to the aforementioned access node 100, the first radio device may correspond to the aforementioned transmitting UE 20, and the second radio device may correspond to the aforementioned receiving UE 30. The first radio device may transmit SL radio transmissions to the second radio device. The SL radio transmissions may include transmissions on a data channel, such as the aforementioned transmission of SL data 207. Alternatively or additionally, the SL radio transmissions may include transmissions of one or more reference signals, such as the aforementioned transmission of reference symbols 208.

[0098] If a processor-based implementation of the node is used, one or more processors of the node may perform and / or control at least some of the steps of the method of Figure 10. Such wireless device may also include a memory storing program code that implements at least some of the described functions or steps of the method of Figure 10.

[0099] In step 1010, assistance information is provided to the first wireless device. For example, the node may transmit the assistance information in response to the first wireless device entering the node's coverage area, as described with respect to the process of Figure 3A or Figure 4. The node may transmit the assistance information to the first wireless device via the second wireless device, as described with respect to the process of Figure 3B.

[0100] The support information associates a first SCI transmitted from a first wireless device to a second wireless device, such as the aforementioned first stage SCI 204, with settings for transmitting a second SCI from the first wireless device to the second wireless device, such as the aforementioned second stage SCI 206.

[0101] In step 1020, the assistance information is provided to the second wireless device. This may be accomplished in response to the second wireless device entering the node's coverage area, for example, as described with respect to the processes of Figures 3B or 4. The node may transmit the assistance information to the second wireless device via the first wireless device, as described with respect to the processes of Figures 3A and 3C.

[0102] The first and second wireless devices may then store the received assistance information for later use.

[0103] In some scenarios, a first part of the configuration for the transmission of the second SCI may be defined by the first SCI, and a second part of the configuration for the transmission of the second SCI may be defined by the assistance information. For example, the assistance information may include one or more parameters that define the configuration, from which other parameters of the configuration may be implicitly derived. Examples of such parameters are the aforementioned PPPP, the aforementioned indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or the aforementioned indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters as shown in the center column of the configuration table in FIG. 5).

[0104] The assistance information may define multiple candidate configurations for transmission of the second SCI. In this case, the first SCI may identify a configuration for transmission of the second SCI among the candidate configurations. For example, the first SCI may include an index that identifies a configuration for transmission of the second SCI among the candidate configurations, such as the configuration index described with respect to FIG. 5. However, the first SCI may also include other information that can be used to implicitly identify a configuration, such as PPPP, an indicator of whether the intended SL radio transmission is a unicast or broadcast transmission, and / or an indicator of whether the SL radio transmission is intended to be performed in SISO mode or MIMO mode (e.g., parameters such as those shown in the center column of the configuration table in FIG. 5).

[0105] The configuration for transmission of the SCI may specify radio resources that form a search space for transmission of the second SCI. In some scenarios, the configuration for transmission of the second SCI may specify radio resources that form multiple search spaces for transmission of the SCI. In this case, the configuration may specify a priority order for the multiple search spaces.

[0106] The configuration for the transmission of the second SCI may also specify one or more formats for the transmission of the second SCI, such as the SCI format described above. If multiple formats are specified, the configuration may also specify a priority order for the multiple formats. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more aggregation levels for the transmission of the second SCI. If multiple aggregation levels are specified, the configuration may also specify a priority order for the multiple aggregation levels. Additionally or alternatively, the configuration for the transmission of the second SCI may also specify one or more modulation and / or coding schemes for the transmission of the second SCI. If multiple modulation and / or coding schemes are specified, the configuration may also specify a priority order for the multiple modulation and / or coding schemes.

[0107] In some scenarios, the first SCI may also include information regarding sensing-based allocation of radio resources for SL radio transmissions (e.g., information defining a resource pool in which radio resources can be found by the sensing-based allocation mechanism and / or information defining one or more radio channels that the sensing-based allocation mechanism monitors).

[0108] The second SCI may include information indicating at least one of the following: radio resources used for the SL radio transmission, a modulation and / or coding scheme used for the SL radio transmission, one or more retransmission parameters for the SL radio transmission, and a priority level for the SL radio transmission. The radio resources may be indicated in terms of time / frequency location and / or resource reservation.

[0109] In some scenarios, at least one of the first SCI and the second SCI includes a common error detection code that verifies the integrity of both the first SCI and the second SCI, and based on the common error detection code, the wireless device may perform a single integrity check to determine whether the first SCI and the second SCI were received correctly.

[0110] Figure 11 is a functional block diagram of a node 1100 operating in accordance with the method of Figure 10. Node 1100 may correspond, for example, to access node 100 described above. As shown, node 1100 may be provided with a module 1110 configured to provide assistance information to a first wireless device, as described with respect to step 1010. Additionally, node 1100 may be provided with a module 1120 configured to provide assistance information to a second wireless device, as described with respect to step 1020.

[0111] It should be noted that wireless device 1100 may include other modules that implement other functions, such as known functions of an eNB in ​​LTE wireless technology, a gNB in ​​NR technology, or similar access node.

[0112] It should be noted that the functionality described with respect to Figures 6 and 8, and optionally with respect to Figure 10, may be combined in a system including a first wireless device operating according to the method of Figure 6, a second wireless device operating according to the method of Figure 8, and optionally a network node operating according to the method of Figure 10. In such a system, the first wireless device may determine a first SCI based on assistance information stored in the first wireless device. The assistance information associates the first SCI with settings related to transmission of a second SCI. The first wireless device further transmits the first SCI to the second wireless device. Based on the settings associated with the first SCI, the first wireless device also transmits the second SCI to the second wireless device. Based on the second SCI, the first wireless device transmits an SL wireless transmission to the second wireless device. The second wireless device receives the first SCI from the first wireless device. Furthermore, the second wireless device determines a configuration for transmission of the second SCI based on the assistance information stored in the second wireless device and the received first SCI. Furthermore, the second wireless device receives the second SCI from the first wireless device based on the determined configuration. Furthermore, the second wireless device receives an SL wireless transmission from the first wireless device based on the received second SCI. A node operating according to the method of FIG. 10 may provide assistance information to the first wireless device and / or the second wireless device.

[0113] Furthermore, the methods of Figures 6 and 8 may also be implemented within the same wireless device acting as both a receiver and a transmitter of SL wireless transmissions, for example when performing bidirectional SL communication with another wireless device.

[0114] Figure 12 illustrates a processor-based implementation of a wireless device 1200 that can be used to implement the concepts described above. For example, the structure illustrated in Figure 12 may be adapted to implement the concepts in the transmitting UE 20 or receiving UE 30 described above.

[0115] As shown, wireless device 1200 includes one or more radio interfaces 1210. Radio interface 1210 may support a radio access technology that supports SL radio transmissions, such as, for example, an LTE radio technology or an NR radio technology. Additionally, radio interface 1210 may support DL and UL radio transmissions with a wireless communication network.

[0116] Additionally, wireless device 1200 may include one or more processors 1250 coupled to wireless interface 1210 and memory 1260 coupled to processor 1250. By way of example, wireless interface 1210, processor 1250, and memory 1260 may be coupled by one or more internal bus systems of wireless device 1200. Memory 1260 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., hard disk or solid-state disk), etc. As shown, memory 1260 may include software 1270, firmware 1280, and / or control parameters 1290. Memory 1260 may include program code suitable for execution by processor 1250 to implement the above-described functions of the wireless device or apparatus for controlling the wireless device, as described with respect to FIG. 6 and / or FIG. 8.

[0117] 12 is merely schematic, and that wireless device 1200 may actually include other components, such as other interfaces or processors, that are not shown for clarity. It is also understood that memory 1260 may include other program code for implementing known functions of a UE supporting SL radio transmissions, such as implementing V2X communications. Furthermore, in some embodiments, a computer program for implementing the functions of wireless device 1200 may be provided, for example, in the form of a physical medium carrying the program code and / or other data stored in memory 1260, or via download or streaming of the program code.

[0118] Figure 13 shows a processor-based implementation of a network node 1300 that can be used to implement the concepts described above. For example, the structure shown in Figure 13 may be adapted to implement the concepts in transmission described above.

[0119] As shown, the network node 1300 includes an access interface 1310. The access interface 1310 may be used for communication with and control of one or more wireless devices via DL and UL radio transmissions. If the network node corresponds to an access node, the access interface 1310 may be a radio interface. However, in some scenarios, the network node 1300 may correspond to a more centralized node (e.g., a core network node). In this case, the access interface 1300 may also correspond to an interface for communication with an access node serving the wireless devices. The aforementioned transmitting UE 20 and receiving UE 30 are examples of such wireless devices. As further shown, the access node may include a network interface 1320 that can be used for communication with other network nodes.

[0120] Additionally, network node 1300 may include one or more processors 1350 coupled to access interface 1310 and memory 1360 coupled to processor 1350. By way of example, access interface 1310, processor 1350, and memory 1360 may be coupled by one or more internal bus systems of network node 1300. Memory 1360 may include ROM (e.g., flash ROM), RAM (DRAM or SRAM), mass storage (e.g., hard disk or solid-state disk), etc. As shown, memory 1360 may include software 1370, firmware 1380, and / or control parameters 1390. Memory 1360 may include program code suitably configured for execution by processor 1350 to implement the above-described functionality of the network node, as described with respect to FIG. 10 .

[0121] 13 is merely schematic, and it will be appreciated that the network node 1300 may actually include other components, such as other interfaces or processors, that are not shown for clarity. It will also be appreciated that the memory 1360 may include other program code that implements known functions of an eNB of LTE radio technology, a gNB of NR radio technology, or a similar network node. Also, according to some embodiments, a computer program that implements the functions of the network node 1300 may be provided, for example, in the form of a physical medium that stores the program code and / or other data stored in the memory 1360, or by providing the program code for download or streaming.

[0122] As can be seen, the above concepts may be adapted for efficient control of SL radio transmissions. In particular, it is possible to increase the variability of the SCI used to control SL radio transmissions without excessively increasing the required complexity of the SL radio transmission receiver. In particular, it is possible to suppress or completely avoid blind decoding by the SL radio transmission receiver. In this way, it is possible to efficiently support various use cases with different requirements for SL radio transmissions. Furthermore, it is possible to configure the transmission of the SCI to facilitate backward compatibility.

[0123] It is understood that the above-described examples and embodiments are merely illustrative and susceptible to various modifications. For example, the illustrated concepts are applicable in connection with various types of wireless technologies, not limited to the aforementioned examples of LTE or NR wireless technologies. Furthermore, these concepts are not limited to suppressing SCIs in two stages, but can also be applied to accommodate any larger number of stages, where the setting of each stage is implicitly determined from the SCI transmitted in the previous stage. Furthermore, it is understood that the above concepts can be implemented using correspondingly designed software executed by one or more processors of existing devices or equipment, or dedicated device hardware. Furthermore, it should be noted that each illustrated device or equipment can be implemented as a single device or a system consisting of multiple interacting devices or modules.

[0124] In light of the above, embodiments provided by the present disclosure include the following.

[0125] Embodiment 1: A method for controlling sidelink radio transmission in a wireless communication network, comprising: receiving, by a wireless device (30), first sidelink control information (204) from another wireless device (20); determining, by the wireless device (30), based on assistance information stored in the wireless device (30) and the received first sidelink control information (204), a configuration for transmission of second sidelink control information (206); receiving, by the wireless device (30) from another wireless device (20) second sidelink control information (206) based on the determined configuration for transmission of the second sidelink control information (206); receiving, by the wireless device (30), a sidelink radio transmission (207, 208) from another wireless device (20) based on the received second sidelink control information (206); A method comprising:

[0126] Embodiment 2: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 2. The method of embodiment 1, wherein the first sidelink control information (204) identifies a configuration for transmission of the second sidelink control information (206) among candidate configurations.

[0127]

[0023] Embodiment 3: The method of embodiment 2, wherein the first sidelink control information (204) includes an index that identifies a configuration, among candidate configurations, for transmission of the second sidelink control information (206).

[0128] Embodiment 4: The method according to any one of embodiments 1 to 3, wherein the first sidelink control information (204) includes information regarding sensing-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0129] Embodiment 5: The method according to any one of embodiments 1 to 4, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources to be used for the sidelink radio transmissions (207, 208), a modulation and / or coding scheme to be used for the sidelink radio transmissions (207, 208), one or more retransmission parameters of the sidelink radio transmissions (207, 208), and a priority level of the sidelink radio transmissions (207, 208).

[0130] Embodiment 6: The method according to any one of embodiments 1 to 5, wherein a first part of the configuration for the transmission of the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration for the transmission of the second sidelink control information (206) is specified by the assistance information.

[0131] Embodiment 7: The method according to any one of embodiments 1 to 6, wherein the configuration for the transmission of the second sidelink control information (206) defines radio resources that constitute a search space for the transmission of the second sidelink control information (206).

[0132]

[0023] Embodiment 8: The method of embodiment 7, wherein the configuration for the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and a priority of the multiple search spaces.

[0133]

[0023] Embodiment 9: The method according to any one of embodiments 1 to 8, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0134]

[0023] Embodiment 10: The method according to any one of embodiments 1 to 9, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0135]

[0023] Embodiment 11: The method according to any one of embodiments 1 to 10, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0136]

[0033] Embodiment 12: The method according to any one of embodiments 1 to 11, wherein at least one of the first sidelink control information (204) and the second sidelink control information (206) includes a common error detection code that verifies the integrity of both the first sidelink control information (204) and the second sidelink control information (206).

[0137] Embodiment 13: A method for implementing the present invention, comprising: receiving, by a wireless device (30), at least a portion of assistance information from a node (100) of a wireless communication network; storing the received assistance information by the wireless device; 13. The method of any one of embodiments 1 to 12, comprising:

[0138]

[0033] Embodiment 14: The method of embodiment 13, comprising receiving at least a portion of the assistance information in response to the wireless device (30) entering a service area of ​​the node (100).

[0139] Embodiment 15: The method of any one of embodiments 1 to 14, comprising the wireless device (30) receiving at least a portion of the assistance information from another wireless device (20).

[0140]

[0033] Embodiment 16: The method of embodiment 15, comprising receiving at least a portion of the assistance information in response to the wireless device (30) entering a wireless coverage area of ​​another wireless device (20).

[0141] Embodiment 17: The method of any one of embodiments 13 to 16, comprising receiving at least a portion of the assistance information by the wireless device (30) in response to a request (306, 313) from the wireless device (30).

[0142] Embodiment 18: The method according to any one of embodiments 1 to 17, wherein the sidelink wireless transmission (207, 208) includes a transmission on a data channel.

[0143] Embodiment 19: The method according to any one of embodiments 1 to 18, wherein the sidelink radio transmission (207, 208) includes transmission of one or more reference signals.

[0144] Embodiment 20: A method for controlling sidelink radio transmission in a wireless communication network, comprising: determining, by the wireless device (20), first sidelink control information (204) based on assistance information stored in the wireless device (20), the assistance information associating the first sidelink control information (204) with a configuration for transmission of second sidelink control information (206); a wireless device (20) transmitting first sidelink control information (204) to another wireless device (30); transmitting, based on the configuration, second sidelink control information from the wireless device to another wireless device; transmitting, by the wireless device (20) a sidelink radio transmission (207, 208) to another wireless device (30) based on the second sidelink control information (206); A method comprising:

[0145] Embodiment 21: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 21. The method of embodiment 20, wherein the first sidelink control information (204) identifies a configuration for transmission of the second sidelink control information (206) among candidate configurations.

[0146]

[0073] Embodiment 22: The method of embodiment 21, wherein the first sidelink control information (204) includes an index that identifies a configuration, among the candidate configurations, for transmission of the second sidelink control information (206).

[0147] Embodiment 23: The method according to any one of embodiments 20 to 22, wherein the first sidelink control information (204) includes information regarding sensing-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0148] Embodiment 24: The method according to any one of embodiments 20 to 23, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources to be used for the sidelink radio transmissions (207, 208), a modulation and / or coding scheme to be used for the sidelink radio transmissions (207, 208), one or more retransmission parameters of the sidelink radio transmissions (207, 208), and a priority level of the sidelink radio transmissions (207, 208).

[0149] Embodiment 25: The method according to any one of embodiments 20 to 24, wherein a first part of the configuration for transmitting the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration for transmitting the second sidelink control information (206) is specified by the assistance information.

[0150]

[0071] Embodiment 26: The method according to any one of embodiments 20 to 25, wherein the configuration for the transmission of the second sidelink control information (206) defines radio resources that constitute a search space for the transmission of the second sidelink control information (206).

[0151]

[0082] Embodiment 27: The method of embodiment 26, wherein the configuration for the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and a priority of the multiple search spaces.

[0152]

[0082] Embodiment 28: The method according to any one of embodiments 20 to 27, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0153]

[0072] Embodiment 29: The method according to any one of embodiments 20 to 28, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0154]

[0082] Embodiment 30: The method according to any one of embodiments 20 to 29, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0155]

[0033] Embodiment 31: The method according to any one of embodiments 20 to 30, wherein at least one of the first sidelink control information (204) and the second sidelink control information (206) includes a common error detection code that verifies the integrity of both the first sidelink control information (204) and the second sidelink control information (206).

[0156]

[0047] Embodiment 32: A method for implementing a wireless communication system, comprising: receiving, by a wireless device (20), at least a portion of assistance information from a node (100) of a wireless communication network; storing the received assistance information by the wireless device; 32. The method of any one of embodiments 20 to 31, comprising:

[0157]

[0071] Embodiment 33: The method of embodiment 32, comprising receiving at least a portion of the assistance information in response to the wireless device (20) entering the service area of ​​the node (100).

[0158] Embodiment 34: The method of any one of embodiments 20 to 33, comprising the wireless device (20) receiving at least a portion of the assistance information from another wireless device (30).

[0159] Embodiment 35: The method of embodiment 34, comprising receiving at least a portion of the assistance information in response to the wireless device (20) entering a wireless coverage area of ​​another wireless device (30).

[0160] Embodiment 36: The method of any one of embodiments 32 to 35, comprising receiving at least a portion of the assistance information by the wireless device (20) in response to a request (302) from the wireless device (20).

[0161] Embodiment 37: The method according to any one of embodiments 20 to 36, wherein the sidelink wireless transmission (207, 208) includes a transmission on a data channel.

[0162] Embodiment 38: The method according to any one of embodiments 20 to 37, wherein the sidelink radio transmission (207, 208) includes transmission of one or more reference signals.

[0163] Embodiment 39: A method for controlling sidelink radio transmissions in a wireless communication network, comprising: providing assistance information to the first wireless device (20); providing assistance information to the second wireless device (30), the assistance information associating the first sidelink control information (204) transmitted from the first wireless device (20) to the second wireless device (30) with a configuration for transmission of second sidelink control information (206) from the first wireless device (20) to the second wireless device (30); A method comprising:

[0164] Embodiment 40: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 40. The method of embodiment 39, wherein the first sidelink control information (204) identifies a configuration for transmission of the second sidelink control information (206) among the candidate configurations.

[0165]

[0081] Embodiment 41: The method of embodiment 40, wherein the first sidelink control information (204) includes an index that identifies a configuration, among the candidate configurations, for transmitting the second sidelink control information (206).

[0166] Embodiment 42: The method according to any one of embodiments 39 to 41, wherein the first sidelink control information (204) includes information regarding sensing-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0167] Embodiment 43: The method according to any one of embodiments 39 to 42, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources to be used for the sidelink radio transmissions (207, 208), a modulation and / or coding scheme to be used for the sidelink radio transmissions (207, 208), one or more retransmission parameters of the sidelink radio transmissions (207, 208), and a priority level of the sidelink radio transmissions (207, 208).

[0168] Embodiment 44: The method according to any one of embodiments 39 to 43, wherein a first part of the configuration for transmitting the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration for transmitting the second sidelink control information (206) is specified by the assistance information.

[0169]

[0082] Embodiment 45: The method according to any one of embodiments 39 to 44, wherein the configuration for the transmission of the second sidelink control information (206) defines radio resources that constitute a search space for the transmission of the second sidelink control information (206).

[0170]

[0081] Embodiment 46: The method of embodiment 45, wherein the configuration for the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and a priority of the multiple search spaces.

[0171]

[0082] Embodiment 47: The method according to any one of embodiments 39 to 46, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0172]

[0082] Embodiment 48: The method according to any one of embodiments 39 to 47, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0173]

[0081] Embodiment 49: The method according to any one of embodiments 39 to 48, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0174] Embodiment 50: A method according to any one of embodiments 39 to 49, comprising a node (100) of a wireless communication network transmitting assistance information in response to a first wireless device (20) and / or a second wireless device (30) entering the service area (101) of the node (100).

[0175] Embodiment 51: A method according to any one of embodiments 39 to 50, comprising a node (100) of a wireless communication network transmitting assistance information in response to a request (302, 306) from a first wireless device (20) and / or a request from a second wireless device (30).

[0176] Embodiment 52: The method of any one of embodiments 39 to 51, comprising a node (100) of a wireless communication network transmitting assistance information to a second wireless device (30) via a first wireless device (20).

[0177] Embodiment 53: The method of any one of embodiments 39 to 52, comprising a node (100) of a wireless communication network transmitting assistance information to a first wireless device (20) via a second wireless device (30).

[0178] Embodiment 54: A method according to any one of embodiments 39 to 53, wherein the sidelink radio transmission (207, 208) includes a transmission on a data channel.

[0179] Embodiment 55: The method according to any one of embodiments 39 to 54, wherein the sidelink radio transmission (207, 208) includes transmission of one or more reference signals.

[0180] Embodiment 56: A wireless device (30) of a wireless communication network, comprising: receiving first sidelink control information (204) from another wireless device (20); determining a configuration for transmission of a second sidelink control information (206) based on assistance information stored in the wireless device (30) and the received first sidelink control information (204); receiving second sidelink control information from another wireless device based on the determined configuration for transmission of the second sidelink control information; receiving a sidelink radio transmission (207, 208) from another wireless device (20) based on the received second sidelink control information (206); A wireless device (30) configured to perform the following:

[0181] Embodiment 57: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 57. The wireless device (30) of embodiment 56, wherein the first sidelink control information (204) identifies a configuration for transmitting the second sidelink control information (206) among the candidate configurations.

[0182] Embodiment 58: A wireless device (30) as described in embodiment 57, wherein the first sidelink control information (204) includes an index that identifies a configuration for transmitting the second sidelink control information (206) among the candidate configurations.

[0183] Embodiment 59: A wireless device (30) described in any one of embodiments 56 to 58, wherein the first sidelink control information (204) includes information regarding detection-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0184] Embodiment 60: A wireless device (30) described in any one of embodiments 56 to 59, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources used for the sidelink radio transmissions (207, 208), modulation and / or coding schemes used for the sidelink radio transmissions (207, 208), one or more retransmission parameters for the sidelink radio transmissions (207, 208), and a priority level for the sidelink radio transmissions (207, 208).

[0185] Embodiment 61: A wireless device (30) described in any one of embodiments 56 to 60, wherein a first part of the configuration regarding the transmission of the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration regarding the transmission of the second sidelink control information (206) is specified by assistance information.

[0186] Embodiment 62: A wireless device (30) described in any one of embodiments 56 to 61, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources that constitute a search space for the transmission of the second sidelink control information (206).

[0187] Embodiment 63: A wireless device (30) as described in embodiment 62, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and the priority of the multiple search spaces.

[0188] Embodiment 64: A wireless device (30) described in any one of embodiments 56 to 63, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0189] Embodiment 65: A wireless device (30) described in any one of embodiments 56 to 64, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0190] Embodiment 66: A wireless device (30) described in any one of embodiments 56 to 65, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0191] Embodiment 67: A wireless device (30) described in any one of embodiments 56 to 66, wherein at least one of the first sidelink control information (204) and the second sidelink control information (206) includes a common error detection code that verifies the integrity of both the first sidelink control information (204) and the second sidelink control information (206).

[0192]

[0082] Embodiment 68: Receiving at least a portion of assistance information from a node (100) of a wireless communication network; storing the received assistance information; 68. A wireless device (30) as described in any one of embodiments 56 to 67, configured to perform the following.

[0193] Embodiment 69: A wireless device (30) as described in embodiment 13, configured to receive at least a portion of the assistance information in response to the wireless device (30) entering the service area of ​​the node (100).

[0194] Embodiment 70: A wireless device (30) according to any one of embodiments 56 to 69, configured to receive at least a portion of the assistance information from another wireless device (20).

[0195] Embodiment 71: A wireless device (30) as described in embodiment 70, configured to receive at least a portion of the assistance information in response to the wireless device (30) entering the wireless coverage area of ​​another wireless device (20).

[0196] Embodiment 72: A wireless device (30) described in any one of embodiments 68 to 71, configured to receive at least a portion of the assistance information in response to a request (306, 313) from the wireless device (30).

[0197] Embodiment 73: A wireless device (30) described in any one of embodiments 56 to 72, wherein the sidelink wireless transmission (207, 208) includes a transmission on a data channel.

[0198] Embodiment 74: A wireless device (30) described in any one of embodiments 56 to 73, wherein the sidelink wireless transmission (207, 208) includes transmission of one or more reference signals.

[0199] Embodiment 75: A wireless device (30) as described in embodiment 56, configured to perform the steps of the method as described in any one of embodiments 1 to 19.

[0200] Embodiment 76: A wireless device (30) described in any one of embodiments 56 to 75, comprising at least one processor and a memory containing instructions executable by the at least one processor, the instructions being operable, when executed by the at least one processor, to cause the wireless device (30) to perform a method described in any one of embodiments 1 to 19.

[0201] Embodiment 77: A wireless device (20) of a wireless communication network, comprising: determining a first sidelink control information (204) based on assistance information stored in the wireless device (20), the assistance information associating the first sidelink control information (204) with a configuration for transmission of a second sidelink control information (206); transmitting first sidelink control information (204) to another wireless device (30); transmitting second sidelink control information (206) to another wireless device (30) based on the configuration; transmitting a sidelink radio transmission (207, 208) to another wireless device (30) based on the second sidelink control information (206); A wireless device (20) configured to perform the above.

[0202] Embodiment 78: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 78. The wireless device (20) of embodiment 77, wherein the first sidelink control information (204) identifies a configuration for transmitting the second sidelink control information (206) among the candidate configurations.

[0203] Embodiment 79: A wireless device (20) as described in embodiment 78, wherein the first sidelink control information (204) includes an index that identifies a configuration for transmitting the second sidelink control information (206) among the candidate configurations.

[0204] Embodiment 80: A wireless device (20) described in any one of embodiments 77 to 79, wherein the first sidelink control information (204) includes information regarding detection-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0205] Embodiment 81: A wireless device (20) described in any one of embodiments 77 to 80, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources used for the sidelink radio transmissions (207, 208), modulation and / or coding schemes used for the sidelink radio transmissions (207, 208), one or more retransmission parameters for the sidelink radio transmissions (207, 208), and a priority level for the sidelink radio transmissions (207, 208).

[0206] Embodiment 82: A wireless device (20) described in any one of embodiments 77 to 81, wherein a first part of the configuration regarding the transmission of the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration regarding the transmission of the second sidelink control information (206) is specified by assistance information.

[0207] Embodiment 83: A wireless device (20) described in any one of embodiments 77 to 82, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources that constitute a search space for the transmission of the second sidelink control information (206).

[0208] Embodiment 84: A wireless device (20) as described in embodiment 83, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and the priority of the multiple search spaces.

[0209] Embodiment 85: A wireless device (20) described in any one of embodiments 77 to 84, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0210] Embodiment 86: A wireless device (20) described in any one of embodiments 77 to 85, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0211] Embodiment 87: A wireless device (20) described in any one of embodiments 77 to 86, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0212] Embodiment 88: A wireless device (20) described in any one of embodiments 77 to 87, wherein at least one of the first sidelink control information (204) and the second sidelink control information (206) includes a common error detection code that verifies the integrity of both the first sidelink control information (204) and the second sidelink control information (206).

[0213] Embodiment 89: The wireless device (20) receiving at least a portion of the assistance information from a node (100) of the wireless communication network; storing the received assistance information; 89. A wireless device (20) as described in any one of embodiments 77 to 88, configured to perform the following.

[0214] Embodiment 90: A wireless device (20) as described in embodiment 89, configured to receive at least a portion of the assistance information in response to the wireless device (20) entering the service area of ​​the node (100).

[0215] Embodiment 91: A wireless device (20) according to any one of embodiments 77 to 90, configured to receive at least a portion of the assistance information from another wireless device (30).

[0216] Embodiment 92: A wireless device (20) as described in embodiment 91, configured to receive at least a portion of the assistance information in response to the wireless device (20) entering the wireless coverage area of ​​another wireless device (30).

[0217] Embodiment 93: A wireless device (20) described in any one of embodiments 77 to 92, configured to receive at least a portion of the assistance information in response to a request (302) from the wireless device (20).

[0218] Embodiment 94: A wireless device (20) described in any one of embodiments 77 to 93, wherein the sidelink wireless transmission (207, 208) includes a transmission on a data channel.

[0219] Embodiment 95: A wireless device (20) described in any one of embodiments 77 to 94, wherein the sidelink wireless transmission (207, 208) includes transmission of one or more reference signals.

[0220] Embodiment 96: A wireless device (20) as described in embodiment 77, configured to perform the steps of the method as described in any one of embodiments 20 to 38.

[0221] Embodiment 97: A wireless device (20) described in any one of embodiments 77 to 96, comprising at least one processor and a memory containing instructions executable by the at least one processor, the instructions being operable, when executed by the at least one processor, to cause the wireless device (20) to perform a method described in any one of embodiments 20 to 38.

[0222] Embodiment 98: A node (100) of a wireless communication network, comprising: providing assistance information to the first wireless device (20); providing assistance information to the second wireless device (30), the assistance information associating the first sidelink control information (204) transmitted from the first wireless device (20) to the second wireless device (30) with a configuration for transmission of second sidelink control information (206) from the first wireless device (20) to the second wireless device (30); A wireless device (100) configured to:

[0223] Embodiment 99: The assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206); 99. The node (100) of embodiment 98, wherein the first sidelink control information (204) identifies a configuration for transmitting the second sidelink control information (206) among candidate configurations.

[0224] Embodiment 100: A node (100) as described in embodiment 99, wherein the first sidelink control information (204) includes an index that identifies a configuration for transmitting the second sidelink control information (206) among the candidate configurations.

[0225] Embodiment 101: A node (100) described in any one of embodiments 98 to 100, wherein the first sidelink control information (204) includes information regarding detection-based allocation of radio resources for sidelink radio transmissions (207, 208).

[0226] Embodiment 102: A node (100) described in any one of embodiments 98 to 101, wherein the second sidelink control information (206) includes information indicating at least one of the following: radio resources used for the sidelink radio transmissions (207, 208), a modulation and / or coding scheme used for the sidelink radio transmissions (207, 208), one or more retransmission parameters for the sidelink radio transmissions (207, 208), and a priority level for the sidelink radio transmissions (207, 208).

[0227] Embodiment 103: A node (100) described in any one of embodiments 98 to 102, wherein a first part of the configuration regarding the transmission of the second sidelink control information (206) is specified by the first sidelink control information (204), and a second part of the configuration regarding the transmission of the second sidelink control information (206) is specified by assistance information.

[0228] Embodiment 104: A node (100) described in any one of embodiments 98 to 103, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources that form a search space for the transmission of the second sidelink control information (206).

[0229] Embodiment 105: A node (100) as described in embodiment 104, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies radio resources constituting multiple search spaces for the transmission of the second sidelink control information (206) and a priority of the multiple search spaces.

[0230] Embodiment 106: A node (100) described in any one of embodiments 98 to 105, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a format regarding the transmission of the second sidelink control information (206).

[0231] Embodiment 107: A node (100) described in any one of embodiments 98 to 106, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies an aggregation level regarding the transmission of the second sidelink control information (206).

[0232] Embodiment 108: A node (100) described in any one of embodiments 98 to 107, wherein the configuration regarding the transmission of the second sidelink control information (206) specifies a modulation and / or coding scheme regarding the transmission of the second sidelink control information (206).

[0233] Embodiment 109: A node (100) described in any one of embodiments 98 to 108, configured to transmit assistance information in response to a first wireless device (20) and / or a second wireless device (30) entering the service area (101) of the node (100).

[0234] Embodiment 110: A node (100) described in any one of embodiments 98 to 109, configured to transmit assistance information in response to a request (302, 306) from a first wireless device (20) and / or a request from a second wireless device (30).

[0235] Embodiment 111: A node (100) described in any one of embodiments 98 to 110, configured to transmit assistance information to a second wireless device (30) via a first wireless device (20).

[0236] Embodiment 112: A node (100) described in any one of embodiments 98 to 111, configured to transmit assistance information to a first wireless device (20) via a second wireless device (30).

[0237] Embodiment 113: A node (100) described in any one of embodiments 98 to 112, wherein the sidelink wireless transmission (207, 208) includes a transmission on a data channel.

[0238] Embodiment 114: A node (100) described in any one of embodiments 98 to 113, wherein the sidelink radio transmissions (207, 208) include transmission of one or more reference signals.

[0239] Embodiment 115: A node (100) described in embodiment 98 configured to perform the steps of the method described in any one of embodiments 39 to 55.

[0240] Embodiment 116: A node (100) described in any one of embodiments 98 to 115, comprising at least one processor and a memory containing instructions executable by the at least one processor, the instructions being operable, when executed by the at least one processor, to cause the node (100) to perform a method described in any one of embodiments 39 to 55.

[0241] Embodiment 117: A system comprising a first wireless device (20) and a second wireless device (30) storing assistance information, A first wireless device (20) determining a first sidelink control information (204) based on assistance information stored in the first wireless device (20), the assistance information associating the first sidelink control information (204) with a configuration for transmission of a second sidelink control information (206); transmitting first sidelink control information (204) to a second wireless device (30); transmitting second sidelink control information (206) to a second wireless device (30) based on the configuration; transmitting a sidelink radio transmission (207, 208) to a second wireless device (30) based on the second sidelink control information (206); configured to: A second wireless device (30) receiving first sidelink control information (204) from a first wireless device (20); determining a configuration for transmission of a second sidelink control information (206) based on assistance information stored in the second radio device (30) and the received first sidelink control information (204); receiving second sidelink control information from the first wireless device based on the determined configuration for transmission of the second sidelink control information; receiving a sidelink radio transmission (207, 208) from the first wireless device (20) based on the received second sidelink control information (206); A system configured to:

[0242] Embodiment 118: The system described in embodiment 117, further comprising a node (100) of a wireless communication network, configured to provide assistance information to a first wireless device (20) and / or a second wireless device (30).

[0243] Embodiment 119: A computer program comprising program code executed by at least one processor of a wireless device (30, 20), wherein execution of the program code causes the wireless device (30, 20) to perform a method according to any one of embodiments 1 to 38.

[0244] Embodiment 120: A computer program product comprising program code executed by at least one processor of a wireless device (30, 20), wherein execution of the program code causes the wireless device (30, 20) to perform a method according to any one of embodiments 1 to 38.

[0245] Embodiment 121: A computer program comprising program code executed by at least one processor of a node (100) of a wireless communication network, wherein execution of the program code causes the node (100) to perform a method described in any one of embodiments 39 to 55.

[0246] Embodiment 122: A computer program product comprising program code executed by at least one processor of a node (100) of a wireless communication network, wherein execution of the program code causes the node (100) to perform a method described in any one of embodiments 39 to 55.

Claims

1. 1. A method for controlling sidelink radio transmissions in a wireless communication network, comprising: receiving, by a wireless device (30), first sidelink control information (204) from another wireless device (20); determining, by the wireless device (30), a configuration for transmission of second sidelink control information (206) based on assistance information stored in the wireless device (30) and the received first sidelink control information (204); and receiving, by the wireless device (30) from the other wireless device (20) based on the determined configuration regarding transmission of the second sidelink control information (206); and receiving, by the wireless device (30), a sidelink radio transmission (207, 208) from the other wireless device (20) based on the received second sidelink control information (206); Including, the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). method.

2. 1. A method for controlling sidelink radio transmissions in a wireless communication network, comprising: determining, by the wireless device (20), first SL control information (204) based on assistance information stored in the wireless device (20), the assistance information associating the first SL control information (204) with a configuration for transmission of second SL control information (206); transmitting, by the wireless device (20), the first sidelink control information (204) to another wireless device (30); transmitting, by the wireless device (20) based on the configuration, the second sidelink control information (206) to the other wireless device (30); transmitting, by the wireless device (20) a sidelink radio transmission (207, 208) to the other wireless device (30) based on the second sidelink control information (206); Including, the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). method.

3. 3. The method of claim 1, wherein the first sidelink control information (204) comprises information regarding sensing-based allocation of radio resources for the sidelink radio transmissions (207, 208).

4. The method of claim 1, wherein the first sidelink control information (204) identifies, among the candidate configurations, the configuration for transmitting the second sidelink control information (206).

4. The method according to any one of claims 1 to 3.

5. 4. The method of claim 1, wherein the first sidelink control information (204) comprises an index identifying the configuration for transmission of the second sidelink control information (206) among the candidate configurations.

6. 4. The method of claim 1, wherein the second sidelink control information comprises information indicating at least one of: radio resources to be used for the sidelink radio transmission; a modulation and / or coding scheme to be used for the sidelink radio transmission; one or more retransmission parameters of the sidelink radio transmission; and a priority level of the sidelink radio transmission.

7. 4. The method of claim 1, wherein a first part of the configuration for transmission of the second sidelink control information is specified by the first sidelink control information and a second part of the configuration for transmission of the second sidelink control information is specified by the assistance information.

8. 4. The method of claim 1, wherein the configuration for the transmission of the second sidelink control information specifies one or more of: radio resources constituting a search space for the transmission of the second sidelink control information; radio resources constituting multiple search spaces for the transmission of the second sidelink control information and a priority of the multiple search spaces; a format for the transmission of the second sidelink control information; an aggregation level for the transmission of the second sidelink control information; a modulation and / or coding scheme for the transmission of the second sidelink control information.

9. said wireless device (20) receiving at least a portion of said assistance information from a node (100) of said wireless communication network; storing the received assistance information by the wireless device; 4. The method of claim 1, comprising:

10. 4. The method of claim 1, wherein the sidelink radio transmissions (207, 208) comprise one or more transmissions of a data channel and one or more reference signal transmissions.

11. 1. A method for controlling sidelink radio transmissions in a wireless communication network, comprising: a node (100) of said wireless communication network providing assistance information to a first wireless device (20); the node (100) of the wireless communication network providing the assistance information to a second wireless device (30); the assistance information associates first sidelink control information (204) transmitted from the first radio device (20) to the second radio device (30) with a configuration for transmission of second sidelink control information (206) from the first radio device (20) to the second radio device (30); the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). method.

12. 12. The method of claim 11, wherein the first sidelink control information (204) comprises information regarding sensing-based allocation of radio resources for sidelink radio transmissions (207, 208) from the first wireless device (20) to the second wireless device (30).

13. a node (100) of the wireless communication network transmitting the assistance information in response to the first wireless device (20) and / or the second wireless device (30) entering a service area (101) of the node (100); a node (100) of the wireless communication network transmitting said assistance information in response to a request (302, 306) from said first wireless device (20) and / or a request from said second wireless device (30); a node (100) of the wireless communication network transmitting said assistance information to said second wireless device (30) via said first wireless device (20); The method according to claim 11 or 12, comprising one or more of: a node (100) of the wireless communication network transmitting the assistance information to the first wireless device (20) via the second wireless device (30).

14. A wireless device (30) of a wireless communication network, comprising: receiving first sidelink control information from another wireless device; determining a configuration for transmission of second sidelink control information (206) based on assistance information stored in the wireless device (30) and the received first sidelink control information (204); and receiving the second sidelink control information from the other wireless device based on the determined configuration for transmission of the second sidelink control information; receiving a sidelink radio transmission (207, 208) from the other wireless device (20) based on the received second sidelink control information (206); and configured to: the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). Wireless equipment (30).

15. A wireless device (30) according to claim 14, configured to perform the steps of the method according to any one of claims 3 to 10.

16. A wireless device (20) of a wireless communication network, comprising: determining first SLCI information (204) based on assistance information stored in the wireless device (20), the assistance information associating the first SLCI information (204) with a configuration for transmission of second SLCI information (206); transmitting the first sidelink control information (204) to another wireless device (30); transmitting the second sidelink control information (206) to the other wireless device (30) based on the configuration; and transmitting a sidelink radio transmission (207, 208) to the other wireless device (30) based on the second sidelink control information (206); and configured to: the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). Wireless equipment (20).

17. A wireless device (20) according to claim 16, configured to perform the steps of the method according to any one of claims 3 to 10.

18. A node (100) of a wireless communication network, comprising: providing assistance information to a first wireless device (20); providing said assistance information to a second wireless device (30); configured to: the assistance information associates first sidelink control information (204) transmitted from the first radio device (20) to the second radio device (30) with a configuration for transmission of second sidelink control information (206) from the first radio device (20) to the second radio device (30); the assistance information defines a plurality of candidate configurations for transmission of the second sidelink control information (206). A node (100) of a wireless communication network.

19. Node (100) according to claim 18, configured to perform the steps of the method according to claim 12 or 13.

20. 11. A computer program comprising program code executed by at least one processor of a wireless device (30, 20), the execution of which causes the wireless device (30, 20) to perform a method according to any one of claims 1 to 10.

21. 14. A computer program comprising program code executed by at least one processor of a node (100) of a wireless communication network, the execution of said program code causing said node (100) to perform the method of any one of claims 11 to 13.

Images