Resource reservation for sidelink communications

Abstract

The first wireless device determines a second reservation period in a slot unit based on the first reservation period in a millisecond (ms) unit and a number of sidelink slots in a fixed period. The number of sidelink slots is configured based on a resource pool. A transport block is transmitted via one or more transmission resources based on the second reservation period.

Description

[0001] Divisional application

[0002] This application is a divisional application of the Chinese invention patent application with the parent application number 2021800281130. The name of the invention of the parent application is "Resource Reservation for Side Link Communications" and the application date is February 16, 2021.

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 977,085, filed on February 14, 2020, the entire contents of which are hereby incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Examples of several of the various embodiments of the present disclosure are described herein with reference to the accompanying drawings.

[0006] Figure 1A and Figure 1B An exemplary mobile communication network is shown in which embodiments of the present disclosure may be implemented.

[0007] Figure 2A and Figure 2B New Radio (NR) user plane and control plane protocol stacks are shown separately.

[0008] Figure 3 Shown in Figure 2A Examples of services provided between the protocol layers of the NR user plane protocol stack.

[0009] Figure 4A Shows the flow Figure 2A Figure 2 shows an exemplary downlink data flow of the NR user plane protocol stack.

[0010] Figure 4B An exemplary format of a MAC subheader in a MAC PDU is shown.

[0011] Figure 5A and Figure 5B The mapping between logical channels, transport channels and physical channels for downlink and uplink are shown respectively.

[0012] Figure 6 is an example diagram showing RRC state transition of a UE.

[0013] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown.

[0014] Figure 8 An exemplary configuration of time slots in the time and frequency domain of an NR carrier is shown.

[0015] Fig. 9 An example of bandwidth adaptation using three configured BWPs for NR carriers is shown.

[0016] Fig. 10A Three carrier aggregation configurations with two component carriers are shown.

[0017] Fig. 10B An example of how aggregated cells may be configured into one or more PUCCH groups is shown.

[0018] Fig.11A An example of SS / PBCH block structure and location is shown.

[0019] Fig. 11B An example of CSI-RS mapped in the time and frequency domains is shown.

[0020] Fig. 12A and Fig. 12B Three examples of downlink and uplink beam management procedures are shown respectively.

[0021] Fig.13A , Fig. 13B and Fig. 13C A four-step contention-based random access procedure, a two-step contention-free random access procedure and another two-step random access procedure are shown respectively.

[0022] Fig.14A An example of a CORESET configuration for the bandwidth portion is shown.

[0023] Fig. 14B An example of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing is shown.

[0024] Fig.15 An example of a wireless device communicating with a base station is shown.

[0025] Fig.16A , Fig. 16B , Fig. 16C and Fig.16D Exemplary structures for uplink and downlink transmissions are shown.

[0026] Fig.17 are illustrative diagrams of aspects of embodiments of the present disclosure.

[0027] Fig.18 are illustrative diagrams of aspects of embodiments of the present disclosure.

[0028] Fig.19A and Fig.19B are illustrative diagrams of aspects of embodiments of the present disclosure.

[0029] Fig. 20A and Fig. 20B are illustrative diagrams of aspects of embodiments of the present disclosure.

[0030] Fig.21 are illustrative diagrams of aspects of embodiments of the present disclosure.

[0031] Fig.22A and Fig. 22B are illustrative diagrams of aspects of embodiments of the present disclosure.

[0032] Fig.23 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0033] Fig.24 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0034] Fig.25 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0035] Fig.26 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0036] Fig. 27 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0037] Fig.28 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0038] Fig.29 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0039] Fig.30 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0040] Fig.31 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0041] Fig.32 is a flow chart of aspects of exemplary embodiments of the present disclosure.

[0042] Fig.33 is a flow chart of aspects of exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0043] In the present disclosure, various embodiments are presented in the form of examples of how the disclosed technology can be implemented and / or how the disclosed technology can be practiced in environments and scenarios. It will be apparent to those skilled in the relevant art that various changes in form and detail can be made therein without departing from the scope of the present invention. In fact, after reading the specification, it will be apparent to those skilled in the relevant art how to implement alternative embodiments. The embodiments of the present invention should not be limited by any described exemplary embodiments. The embodiments of the present disclosure will be described with reference to the accompanying drawings. Restrictions, features and / or elements from the disclosed exemplary embodiments can be combined to create additional embodiments within the scope of the present disclosure. Any figure highlighting functionality and advantages is provided only for illustrative purposes. The disclosed architecture is flexible and configurable enough so that it can be utilized in a manner different from that shown. For example, the actions listed in any flow chart can be reordered or only optionally used in certain embodiments.

[0044] Embodiments may be configured to operate as desired. When certain criteria are met, such as in a wireless device, a base station, a radio environment, a network, a combination of the above, etc., the disclosed mechanism may be executed. Exemplary criteria may be based at least in part on, for example, wireless device or network node configuration, traffic load, initial system settings, packet size, traffic characteristics, a combination of the above, etc. When one or more criteria are met, various exemplary embodiments may be applied. Therefore, exemplary embodiments that selectively implement the disclosed protocol may be implemented.

[0045] A base station may communicate with a mixture of wireless devices. A wireless device and / or base station may support multiple technologies and / or multiple versions of the same technology. A wireless device may have certain specific capabilities, depending on the wireless device category and / or capabilities. When the present disclosure refers to a base station communicating with multiple wireless devices, the present disclosure may refer to a subset of the total wireless devices in the coverage area. For example, the present disclosure may refer to multiple wireless devices of a given LTE or 5G version with a given capability and in a given sector of a base station. The multiple wireless devices in the present disclosure may refer to a selected plurality of wireless devices, and / or a subset of the total wireless devices in the coverage area that perform according to the disclosed method, etc. There may be multiple base stations or multiple wireless devices in the coverage area that may not comply with the disclosed method, for example, these wireless devices or base stations may perform based on older versions of LTE or 5G technology.

[0046] In the present disclosure, "a" and "an" and similar phrases will be interpreted as "at least one" and "one or more". Similarly, any term ending with the suffix "(s)" will be interpreted as "at least one" and "one or more". In the present disclosure, the term "may" is interpreted as "may, for example". In other words, the term "may" indicates that the phrase after the term "may" is an example of a suitable possibility among multiple suitable possibilities that may or may not be used for one or more embodiments in various embodiments. As used herein, the terms "comprising" and "consisting of..." list one or more components of the element being described. The terms "comprising" and "including" are interchangeable and do not exclude that unlisted components are included in the element being described. In contrast, "consisting of..." provides a complete listing of the one or more components of the element being described. As used herein, the term "based on" should be interpreted as "based at least in part on" rather than, for example, "based only on". As used herein, the term "and / or" represents any possible combination of the listed elements. For example, “A, B and / or C” can mean A; B; C; A and B; A and C; B and C; or A, B and C.

[0047] If A and B are sets, and every element of A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, the possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase "based on" (or equivalently "at least based on") indicates that the phrase after the term "based on" is an example of one of multiple suitable possibilities that may or may not be used for one or more different embodiments. The phrase "in response to" (or equivalently "at least in response to") indicates that the phrase after the phrase "in response to" is an example of one of multiple suitable possibilities that may or may not be used for one or more different embodiments. The phrase "depends on" (or equivalently "at least depends on") indicates that the phrase after the phrase "depends on" is an example of one of multiple suitable possibilities that may or may not be used for one or more different embodiments. The phrase "adopting / using" (or equivalently "at least adopting / using") indicates that the phrase after the phrase "adopting / using" is an example of one of multiple suitable possibilities that may or may not be used for one or more different embodiments.

[0048] The term configured may relate to the capabilities of a device, whether the device is in an operational state or a non-operational state. "Configured" may also mean a specific setting in a device that affects the operational characteristics of the device, whether the device is in an operational state or a non-operational state. In other words, hardware, software, firmware, registers, memory values, etc. may be "configured" within a device to provide specific characteristics to the device, whether the device is in an operational state or a non-operational state. Terms such as "a control message caused in a device" may mean that the control message has parameters that can be used to configure specific characteristics in the device or parameters that can be used to implement certain actions in the device, whether the device is in an operational state or a non-operational state.

[0049] In the present disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE) N includes parameter (IE) M, and parameter (IE) M includes parameter (IE) K, and parameter (IE) K includes parameter (information element) J. Then, for example, N includes K, and N includes J. In an exemplary embodiment, when one or more messages include multiple parameters, it means that a parameter of the multiple parameters is in at least one of the one or more messages, but not necessarily in each of the one or more messages.

[0050] Many of the features set forth are described as optional, either by the use of "may" or by the use of parentheses. For the sake of brevity and readability, the present disclosure does not explicitly recite every permutation that can be obtained by selecting from the set of optional features. The present disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven different ways, i.e., having only one of the three possible features, having any two of the three possible features, or having three of the three possible features.

[0051] Many elements described in the disclosed embodiments can be implemented as modules. Modules are defined here as elements that perform defined functions and have defined interfaces to other elements. The modules described in this disclosure can be implemented with hardware, software, firmware, wetware (e.g., hardware with biological elements) in combination with hardware, or a combination thereof, all of which can be equivalent in behavior. For example, a module can be implemented as a software routine written in a computer language, which is configured to be executed by a hardware machine (such as, C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as, Simulink, Stateflow, GNU Octave, or LabVIEWMathScript). It is possible to implement a module using physical hardware that incorporates discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include: computers, microcontrollers, microprocessors, application specific integrated circuits (ASICs); field programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, C++, etc. FPGAs, ASICs and CPLDs are often programmed using hardware description languages ​​(HDLs), such as VHSIC Hardware Description Language (VHDL) or Verilog, which configure the connections between internal hardware modules with less functionality on the programmable devices. The mentioned techniques are often used in combination to achieve the results of the functional modules.

[0052] Figure 1A 1 shows an example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented. The mobile communication network 100 may be, for example, a public land mobile network (PLMN) operated by a network operator. Figure 1A As shown in , the mobile communication network 100 includes a core network (CN) 102 , a radio access network (RAN) 104 , and wireless devices 106 .

[0053] CN 102 may provide an interface to one or more data networks (DNs), such as a public DN (e.g., the Internet), a private DN, and / or an intra-carrier DN, for wireless device 106. As part of the interface functionality, CN 102 may set up an end-to-end connection between wireless device 106 and one or more DNs, authenticate wireless device 106, and provide charging functionality.

[0054] The RAN 104 may connect the CN 102 to the wireless device 106 via radio communications over an air interface. As part of the radio communications, the RAN 104 may provide scheduling, radio resource management, and retransmission protocols. The direction of communication from the RAN 104 to the wireless device 106 over the air interface is referred to as downlink, while the direction of communication from the wireless device 106 to the RAN 104 over the air interface is referred to as uplink. Downlink transmissions may be separated from uplink transmissions using frequency division duplexing (FDD), time division duplexing (TDD), and / or some combination of the two duplexing techniques.

[0055] The term "wireless device" may be used throughout this disclosure to mean and encompass any mobile or fixed (non-mobile) device that requires or can use wireless communication. For example, a wireless device may be a phone, a smartphone, a tablet, a computer, a laptop, a sensor, a meter, a wearable device, an Internet of Things (IoT) device, a vehicle roadside unit (RSU), a relay node, a car, and / or any combination thereof. The term "wireless device" encompasses other terms including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, handset, wireless transmit and receive unit (WTRU), and / or wireless communication device.

[0056] The RAN 104 may include one or more base stations (not shown). The term "base station" may be used throughout this disclosure to mean and encompass: a Node B (associated with UMTS and / or 3G standards); an evolved Node B (eNB, associated with E-UTRA and / or 4G standards); a remote radio head (RRH); a baseband processing unit coupled to one or more RRHs; a repeater node or relay node used to extend the coverage area of ​​a donor node; a next generation evolved Node B (ng-eNB); a generation Node B (gNB, associated with NR and / or 5G standards); an access point (AP, associated with, for example, WiFi or any other suitable wireless communication standard); and / or any combination thereof. A base station may include at least one gNB central unit (gNB-CU) and at least one gNB distributed unit (gNB-DU).

[0057] The base stations included in the RAN 104 may include one or more sets of antennas for communicating with the wireless devices 106 over the air interface. For example, one or more of the base stations may include three sets of antennas to control three cells (or sectors) respectively. The size of a cell may be determined by the range at which a receiver (e.g., a base station receiver) can successfully receive transmissions from a transmitter (e.g., a wireless device transmitter) operating in the cell. The cells of the base stations may together provide radio coverage to the wireless devices 106 over a wide geographic area to support wireless device mobility.

[0058] In addition to three-sector sites, other implementations of the base station are possible. For example, one or more of the base stations in the RAN 104 may be implemented as a sectorized site with more or less than three sectors. One or more of the base stations in the RAN 104 may be implemented as an access point, a baseband processing unit coupled to several remote radio heads (RRHs), and / or a repeater or relay node for extending the coverage area of ​​a donor node. The baseband processing unit coupled to the RRH may be part of a centralized or cloud RAN architecture, where the baseband processing unit may be centralized in a baseband processing unit pool or virtualized. The repeater node may amplify and rebroadcast the radio signal received from the donor node. The relay node may perform the same / similar functions as the repeater node, but may decode the radio signal received from the donor node to eliminate noise before amplifying and rebroadcasting the radio signal.

[0059] The RAN 104 may be deployed as a homogeneous network of macrocell base stations with similar antenna types and similar high levels of transmit power. The RAN 104 may be deployed as a heterogeneous network. In a heterogeneous network, a small cell base station may be used to provide a small coverage area, such as a coverage area that overlaps with a relatively large coverage area provided by a macrocell base station. Small coverage areas may be provided in areas with high data traffic (or so-called "hot spots") or in areas where macrocell coverage is weak. Examples of small cell base stations include, in descending order of coverage area: microcell base stations, picocell base stations, and femtocell base stations or home base stations.

[0060] The Third Generation Partnership Project (3GPP) was established in 1998 to Figure 1A 3GPP provides global specification standardization for mobile communication networks similar to the mobile communication network 100 in the mobile communication network 100. To date, 3GPP has developed specifications for three generations of mobile networks: the third generation (3G) network known as the Universal Mobile Telecommunications System (UMTS), the fourth generation (4G) network known as the Long Term Evolution (LTE), and the fifth generation (5G) network known as the 5G System (5GS). Embodiments of the present disclosure are described with reference to the RAN of the 3GPP 5G network known as the Next Generation RAN (NG-RAN). These embodiments may be applicable to the RAN of other mobile communication networks, such as Figure 1A The RAN 104 in 5G networks, the RAN of early 3G and 4G networks, and those of yet-to-be-specified future networks (e.g., 3GPP 6G networks). The NG-RAN implements the 5G radio access technology known as New Radio (NR) and may be configured to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies.

[0061] Figure 1BAnother exemplary mobile communication network 150 in which embodiments of the present disclosure may be implemented is shown. The mobile communication network 150 may be, for example, a PLMN operated by a network operator. Figure 1B As shown in FIG. 1 , the mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively referred to as UE 156). Figure 1A The corresponding components described are implemented and operate in the same or similar manner.

[0062] 5G-CN 152 provides an interface to one or more DNs, such as a public DN (e.g., the Internet), a private DN, and / or an operator's internal DN, to UE 156. As part of the interface function, 5G-CN 152 may set up an end-to-end connection between UE 156 and the one or more DNs, authenticate UE 156, and provide charging functions. Compared to the CN of the 3GPP 4G network, the basis of 5G-CN152 may be a service-based architecture. This means that the architecture of the nodes constituting 5G-CN 152 may be defined as network functions that provide services to other network functions via interfaces. The network functions of 5G-CN 152 may be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0063] like Figure 1B As shown in FIG. 1 , 5G-CN 152 includes an access and mobility management function (AMF) 158A and a user plane function (UPF) 158B. For ease of explanation, Figure 1B They are shown as one component AMF / UPF 158 in FIG. UPF 158B can act as a gateway between NG-RAN 154 and the one or more DNs. UPF 158B can perform functions such as: packet routing and forwarding, packet inspection and user plane policy rule enforcement, service usage reporting, uplink classification to support routing of service flows to the one or more DNs, user plane quality of service (QoS) processing (e.g., packet filtering, gating, uplink / downlink rate enforcement and uplink service verification), downlink packet buffering and downlink data notification triggering. UPF 158B can act as an anchor point for intra / inter-radio access technology (RAT) mobility, an external protocol (or packet) data unit (PDU) session point interconnected with the one or more DNs, and / or a fulcrum for supporting multi-host PDU sessions. UE 156 can be configured to receive services through a PDU session, which is a logical connection between the UE and the DN.

[0064] The AMF 158A may perform functions such as: non-access stratum (NAS) signaling termination, NAS signaling security, access stratum (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmissions), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including roaming rights verification, mobility management control (subscription and policy), network slicing support and / or session management function (SMF) selection. NAS may refer to functions operating between the CN and the UE, and AS may refer to functions operating between the UE and the RAN.

[0065] 5G-CN 152 may include Figure 1B . For example, 5G-CN 152 may include one or more of the following: session management function (SMF), NR repository function (NRF), policy control function (PCF), network exposure function (NEF), unified data management (UDM), application function (AF) and / or authentication server function (AUSF).

[0066] The NG-RAN 154 may connect the 5G-CN 152 to the UE 156 via radio communications over an air interface. The NG-RAN 154 may include: one or more gNBs, such as gNB 160A and gNB 160B (collectively referred to as gNB 160); and / or one or more ng-eNBs, such as ng-eNB 162A and ng-eNB 162B (collectively referred to as ng-eNB 162). The gNB 160 and ng-eNB 162 may be more generally referred to as base stations. The gNB 160 and ng-eNB 162 may include one or more groups of antennas for communicating with the UE 156 over an air interface. For example, one or more gNBs in the gNB 160 and / or one or more ng-eNBs in the ng-eNB 162 may include three groups of antennas to control three cells (or sectors) respectively. The cells of gNB 160 and ng-eNB 162 may together provide radio coverage to UE 156 over a wide geographic area to support UE mobility.

[0067] like Figure 1BAs shown in FIG. 1 , gNB 160 and / or ng-eNB 162 may be connected to 5G-CN 152 via an NG interface and to other base stations via an Xn interface. The NG and Xn interfaces may be established using a direct physical connection and / or an indirect connection through an underlying transport network such as an Internet Protocol (IP) transport network. gNB 160 and / or ng-eNB 162 may be connected to UE 156 via a Uu interface. For example, Figure 1B As shown in FIG. 1 , gNB 160A may be connected to UE 156A via a Uu interface. NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stack associated with the interface may be composed of Figure 1B The network elements in a network are used to exchange data and signaling messages and may include two planes: a user plane and a control plane. The user plane may process data that the user is interested in. The control plane may process signaling messages that the network elements are interested in.

[0068] The gNB 160 and / or ng-eNB 162 may be connected to one or more AMF / UPF functions of the 5G-CN 152, such as the AMF / UPF 158, by means of one or more NG interfaces. For example, the gNB 160A may be connected to the UPF 158B of the AMF / UPF 158 by means of a NG user plane (NG-U) interface. The NG-U interface may provide delivery of user plane PDUs (e.g., non-guaranteed delivery) between the gNB 160A and the UPF 158B. The gNB 160A may be connected to the AMF 158A by means of a NG control plane (NG-C) interface. The NG-C interface may provide, for example, NG interface management, UE context management, UE mobility management, delivery of NAS messages, paging, PDU session management, and configuration delivery and / or warning message transmission.

[0069] The gNB 160 may provide NR user plane and control plane protocol terminations to the UE 156 via a Uu interface. For example, the gNB 160A may provide NR user plane and control plane protocol terminations to the UE 156A via a Uu interface associated with the first protocol stack. The ng-eNB 162 may provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol terminations to the UE 156 via a Uu interface, where E-UTRA refers to a 3GPP 4G radio access technology. For example, the ng-eNB 162B may provide E-UTRA user plane and control plane protocol terminations to the UE 156B via a Uu interface associated with the second protocol stack.

[0070] 5G-CN 152 is described as being configured to handle both NR and 4G radio access. One of ordinary skill in the art will appreciate that it is possible for NR to be connected to a 4G core network in a mode known as "non-standalone operation". In non-standalone operation, the 4G core network is used to provide (or at least support) control plane functions (e.g., initial access, mobility, and paging). Although Figure 1B Only one AMF / UPF 158 is shown in the figure, but a gNB or ng-eNB can be connected to multiple AMF / UPF nodes to provide redundancy and / or load sharing across the multiple AMF / UPF nodes.

[0071] As discussed, Figure 1B The interfaces between network elements in a network (e.g., Uu, Xn, and NG interfaces) may be associated with a protocol stack used by the network elements to exchange data and signaling messages. The protocol stack may include two planes: a user plane and a control plane. The user plane may process data of interest to the user, while the control plane may process signaling messages of interest to the network elements.

[0072] Figure 2A and Figure 2B Examples of NR user plane and NR control plane protocol stacks for the Uu interface between UE 210 and gNB 220 are shown, respectively. Figure 2A and Figure 2B The protocol stack shown in can be used with e.g. Figure 1B The protocol stacks of the Uu interface between UE156A and gNB 160A shown in are the same or similar.

[0073] Figure 2A An NR user plane protocol stack including five layers implemented in a UE 210 and a gNB 220 is shown. At the bottom of the protocol stack, the physical layer (PHY) 211 and 221 may provide transport services to higher layers of the protocol stack and may correspond to layer 1 of the open system interconnection (OSI) model. The next four protocols above the PHY 211 and 221 include a medium access control layer (MAC) 212 and 222, a radio link control layer (RLC) 213 and 223, a packet data convergence protocol layer (PDCP) 214 and 224, and a service data application protocol layer (SDAP) 215 and 225. Together, these four protocols may constitute layer 2 or the data link layer of the OSI model.

[0074] Figure 3 An example of services provided between protocol layers of the NR user plane protocol stack is shown. Figure 2A and Figure 3Starting from the top of , SDAPs 215 and 225 can perform QoS flow processing. UE 210 can receive services through a PDU session, which can be a logical connection between UE 210 and a DN. A PDU session can have one or more QoS flows. The UPF of the CN (e.g., UPF 158B) can map IP packets to the one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of delay, data rate, and / or error rate). SDAPs 215 and 225 can perform mapping / demapping between the one or more QoS flows and one or more data radio bearers. The mapping / demapping between the QoS flows and the data radio bearers can be determined by the SDAP 225 at the gNB 220. The SDAP 215 at the UE 210 can learn the mapping between the QoS flows and the data radio bearers through reflective mapping or control signaling received from the gNB 220. For reflective mapping, the SDAP 225 at the gNB 220 may mark downlink packets with a QoS flow indicator (QFI), which may be observed by the SDAP 215 at the UE 210 to determine the mapping / demapping between QoS flows and data radio bearers.

[0075] The PDCP 214 and 224 may perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, may perform encryption / decryption to prevent unauthorized decoding of data transmitted over the air interface, and may perform integrity protection to ensure that control messages originate from the intended source. The PDCP 214 and 224 may perform retransmission of undelivered packets, in-sequence delivery and reordering of packets, and removal of duplicate received packets due to, for example, intra-gNB handovers. The PDCP 214 and 224 may perform packet repetition to increase the likelihood that a packet is received, and remove any duplicate packets at the receiver. Packet repetition may be applicable to services that require high reliability.

[0076] although Figure 3 Not shown, but PDCP 214 and 224 can perform mapping / de-mapping between split radio bearers and RLC channels in a dual connectivity scenario. Dual connectivity is a technology that allows a UE to connect to two cells or more generally to two cell groups: a primary cell group (MCG) and a secondary cell group (SCG). A split bearer is a split bearer when a single radio bearer (such as one of the radio bearers provided by PDCP 214 and 224 as a service to SDAP 215 and 225) is handled by a cell group in dual connectivity. PDCP 214 and 224 can map / demapped split radio bearers between RLC channels belonging to a cell group.

[0077] RLC 213 and 223 can perform segmentation, retransmission through automatic repeat request (ARQ), and removal of duplicate data units received from MAC 212 and 222, respectively. RLC 213 and 223 can support three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). Based on the transmission mode in which the RLC is operating, the RLC can perform one or more of the functions described. RLC configuration can be based on each logical channel, independent of parameter sets and / or transmission time interval (TTI) duration. As shown in FIG. Figure 3 As shown in FIG. 1 , RLC 213 and 223 may provide RLC channels as services to PDCP 214 and 224, respectively.

[0078] The MAC 212 and 222 may perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. The multiplexing / demultiplexing may include multiplexing / demultiplexing data units belonging to the one or more logical channels into / from a transport block (TB) delivered to / from the PHY 211 and 221. The MAC 222 may be configured to perform scheduling, scheduling information reporting, and priority handling between UEs with the aid of dynamic scheduling. Scheduling may be performed in the gNB 220 (at the MAC 222) for downlink and uplink. The MAC 212 and 222 may be configured to perform error correction by hybrid automatic repeat request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA)), priority handling between logical channels of the UE 210 with the aid of logical channel prioritization, and / or padding. The MAC 212 and 222 may support one or more parameter sets and / or transmission timing. In an example, mapping restrictions in logical channel prioritization may control which parameter sets and / or transmission timings a logical channel may use. Figure 3 As shown, MAC 212 and 222 may provide logical channels as services to RLC 213 and 223 .

[0079] PHY 211 and 221 can perform mapping of transport channels to physical channels and digital and analog signal processing functions for sending and receiving information over the air interface. These digital and analog signal processing functions may include, for example, encoding / decoding and modulation / demodulation. PHY 211 and 221 can perform multi-antenna mapping. Figure 3 As shown in , PHY 211 and 221 may provide one or more transport channels as a service to MAC 212 and 222 .

[0080] Figure 4A An exemplary downlink data flow through the NR user plane protocol stack is shown. Figure 4AThe downlink data flow of three IP packets (n, n+1, and m) flowing through the NR user plane protocol stack to generate two TBs at the gNB 220 is shown. The uplink data flow flowing through the NR user plane protocol stack can be the same as Figure 4A The downlink data flow is similar to that depicted in .

[0081] Figure 4A The downlink data flow of starts when SDAP 225 receives three IP packets from one or more QoS flows and maps the three packets to radio bearers. Figure 4A In the SDAP header (in Figure 4A The data unit from / to a higher protocol layer is called a service data unit (SDU) of the lower protocol layer, and the data unit to / from a lower protocol layer is called a protocol data unit (PDU) of the higher protocol layer. Figure 4A As shown in , the data unit from SDAP 225 is the SDU of the lower protocol layer PDCP 224 and is the PDU of SDAP 225.

[0082] Figure 4A The remaining protocol layers in can perform their associated functions (e.g., Figure 3 ), add the corresponding headers, and forward their corresponding outputs to the next lower layer. For example, PDCP 224 may perform IP header compression and encryption, and forward its output to RLC 223. RLC 223 may optionally perform segmentation (e.g., Figure 4A 222) and forwards its output to MAC 222. MAC 222 may multiplex many RLC PDUs and may attach MAC subheaders to the RLC PDUs to form a transport block. In NR, MAC subheaders may be distributed throughout the MAC PDU, as shown in FIG. Figure 4A In LTE, the MAC subheader can be located entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and associated latency because the MAC PDU subheader can be calculated before assembling the complete MAC PDU.

[0083] Figure 4BAn exemplary format of a MAC subheader in a MAC PDU is shown. The MAC subheader includes: an SDU length field for indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a logical channel identifier (LCID) field for identifying the logical channel from which the MAC SDU originates to assist in the demultiplexing process; a flag (F) for indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0084] Figure 4B Further shown is a MAC Control Element (CE) inserted into the MAC PDU by a MAC (such as MAC 223 or MAC 222). For example, Figure 4B Two MAC CEs are shown inserted into the MAC PDU. Figure 4B ) and inserting a MAC CE at the end of a MAC PDU for uplink transmission. MAC CE may be used for in-band control signaling. Exemplary MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those used for PDCP duplicate detection, channel state information (CSI) reporting, sounding reference signal (SRS) transmission, and activation / deactivation of previously configured components; discontinuous reception (DRX)-related MAC CEs; timing advance MAC CEs; and random access-related MAC CEs. A MAC subheader having a format similar to that described for a MAC SDU may be present before the MAC CE, and the MAC CE may be identified with a reserved value in the LCID field that indicates the type of control information included in the MAC CE.

[0085] Before describing the NR control plane protocol stack, the mapping between logical channels, transport channels, and physical channels and channel types is first described. One or more of these channels can be used to perform functions associated with the NR control plane protocol stack described later below.

[0086] Figure 5A and Figure 5BThe mapping between logical channels, transport channels and physical channels is shown for downlink and uplink respectively. Information is passed through channels between RLC, MAC and PHY of the NR protocol stack. Logical channels can be used between RLC and MAC and can be classified as control channels that carry control and configuration information in the NR control plane, or as traffic channels that carry data in the NR user plane. Logical channels can be classified as dedicated logical channels dedicated to a specific UE, or as common logical channels that can be used by more than one UE. Logical channels can also be defined by the type of information they carry. The set of logical channels defined by NR includes, for example:

[0087] - Paging Control Channel (PCCH), which is used to carry paging messages used to page UEs whose location is unknown to the network at the cell level;

[0088] - Broadcast Control Channel (BCCH), which is used to carry system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIBs), which can be used by UEs to obtain information about how a cell is configured and how it operates within the cell;

[0089] - Common Control Channel (CCCH), which is used to carry control messages and random access;

[0090] - a dedicated control channel (DCCH) used to carry control messages to / from a specific UE to configure the UE; and

[0091] - Dedicated Traffic Channel (DTCH), which is used to carry user data to / from a specific UE.

[0092] Transport channels are used between the MAC layer and the PHY layer and can be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example:

[0093] - Paging Channel (PCH), which is used to carry paging messages originating from PCCH;

[0094] - Broadcast Channel (BCH), which is used to carry the MIB from the BCCH;

[0095] - Downlink Shared Channel (DL-SCH), which is used to carry downlink data and signaling messages, including SIBs from BCCH;

[0096] - Uplink Shared Channel (UL-SCH), which is used to carry uplink data and signaling messages; and

[0097] - Random Access Channel (RACH), which is used to allow a UE to contact the network without any previous scheduling.

[0098] The PHY may use physical channels to pass information between processing levels of the PHY. A physical channel may have a set of associated time-frequency resources for carrying information of one or more transport channels. The PHY may generate control information to support low-level operation of the PHY and provide control information to lower levels of the PHY via physical control channels (referred to as L1 / L2 control channels). The set of physical channels and physical control channels defined by NR includes, for example:

[0099] - Physical Broadcast Channel (PBCH), which is used to carry the MIB from the BCH;

[0100] - Physical Downlink Shared Channel (PDSCH), which is used to carry downlink data and signaling messages from DL-SCH and paging messages from PCH;

[0101] - Physical Downlink Control Channel (PDCCH), which is used to carry downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling grants, and uplink power control commands;

[0102] - Physical Uplink Shared Channel (PUSCH), which is used to carry uplink data and signaling messages from the UL-SCH, and in some cases uplink control information (UCI) as described below;

[0103] - Physical Uplink Control Channel (PUCCH), which is used to carry UCI, which may include HARQ acknowledgment, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI) and scheduling request (SR); and - Physical Random Access Channel (PRACH), which is used for random access.

[0104] Similar to the physical control channel, the physical layer generates physical signals to support the lower-level operations of the physical layer. Figure 5A and Figure 5B As shown in , the physical layer signals defined by NR include: primary synchronization signal (PSS), secondary synchronization signal (SSS), channel state information reference signal (CSI-RS), demodulation reference signal (DMRS), sounding reference signal (SRS) and phase tracking reference signal (PT-RS). These physical layer signals will be described in more detail below.

[0105] Figure 2B An exemplary NR control plane protocol stack is shown. Figure 2BAs shown in , the NR control plane protocol stack may use the same / similar first four protocol layers as the exemplary NR user plane protocol stack. These four protocol layers include PHY 211 and 221, MAC 212 and 222, RLC 213 and 223, and PDCP 214 and 224. Instead of having SDAP 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane protocol stack instead has radio resource control (RRC) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0106] The NAS protocols 217 and 237 may provide control plane functions between the UE 210 and the AMF 230 (e.g., AMF 158A) or more generally between the UE 210 and the CN. The NAS protocols 217 and 237 may provide control plane functions between the UE 210 and the AMF 230 via signaling messages referred to as NAS messages. There is no direct path between the UE 210 and the AMF 230 through which NAS messages may be transmitted. NAS messages may be transmitted using the AS of the Uu and NG interfaces. The NAS protocols 217 and 237 may provide control plane functions such as authentication, security, connection setup, mobility management, and session management.

[0107] The RRCs 216 and 226 may provide control plane functions between the UE 210 and the gNB 220, or more generally between the UE 210 and the RAN. The RRCs 216 and 226 may provide control plane functions between the UE 210 and the gNB 220 via signaling messages referred to as RRC messages. The RRC messages may be transported between the UE 210 and the RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. The MAC may multiplex control plane and user plane data into the same transport block (TB). The RRC 216 and 226 may provide control plane functions such as: broadcast of system information related to AS and NAS; paging initiated by CN or RAN; establishment, maintenance, and release of an RRC connection between UE 210 and RAN; security functions including key management; establishment, configuration, maintenance, and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; UE measurement reporting and control of the reporting; detection of radio link failure (RLF) and recovery from radio link failure; and / or NAS messaging. As part of establishing an RRC connection, the RRC 216 and 226 may establish an RRC context, which may involve configuring parameters for communication between the UE 210 and the RAN.

[0108] Figure 6 is an example diagram showing the RRC state transition of the UE. The UE can Figure 1A The wireless device 106 depicted in Figure 2A and Figure 2B The UE 210 depicted in FIG. 1 and any other wireless device described in the present disclosure may be the same or similar. Figure 6 As shown in , the UE may be in at least one of three RRC states: RRC connected 602 (eg, RRC_CONNECTED), RRC idle 604 (eg, RRC_IDLE), and RRC inactive 606 (eg, RRC_INACTIVE).

[0109] In RRC connection 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the following: Figure 1A The one or more base stations included in the RAN 104 depicted in FIG. Figure 1B One of the gNB 160 or ng-eNB 162 depicted in FIG. Figure 2A and Figure 2B gNB220 depicted in ; or any other base station described in the present disclosure. A base station connected to a UE may have an RRC context for the UE. The RRC context, referred to as the UE context, may include parameters for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., involving data radio bearers, signaling radio bearers, logical channels, QoS flows and / or PDU sessions); security information; and / or PHY, MAC, RLC, PDCP and / or SDAP layer configuration information. When in RRC connection 602, the mobility of the UE may be managed by the RAN (e.g., RAN 104 or NG-RAN 154). The UE may measure signal levels (e.g., reference signal levels) from a serving cell and neighboring cells, and report these measurements to the base station currently serving the UE. The UE's serving base station may request handover to a cell of one of the neighboring base stations based on the reported measurements. The RRC state may transition from RRC connected 602 to RRC idle 604 via a connection release procedure 608 , or to RRC inactive 606 via a connection deactivation procedure 610 .

[0110] In RRC idle 604, an RRC context may not be established for the UE. In RRC idle 604, the UE may not have an RRC connection with a base station. When in RRC idle 604, the UE may be in a sleep state for most of the time (e.g., to save battery power). The UE may wake up periodically (e.g., once in each discontinuous reception cycle) to monitor paging messages from the RAN. The mobility of the UE may be managed by the UE through a procedure known as cell reselection. The RRC state may transition from RRC idle 604 to RRC connected 602 through a connection establishment procedure 612, which may involve a random access procedure, as discussed in more detail below.

[0111] In RRC Inactive 606, the previously established RRC context is maintained in the UE and the base station. This allows a quick transition to RRC Connected 602 with reduced signaling overhead compared to the transition from RRC Idle 604 to RRC Connected 602. While in RRC Inactive 606, the UE may be in a sleep state, and the mobility of the UE may be managed by the UE through cell reselection. The RRC state may transition from RRC Inactive 606 to RRC Connected 602 through a Connection Resumption Procedure 614, or to RRC Idle 604 through a Connection Release Procedure 616, which may be the same or similar to the Connection Release Procedure 608.

[0112] The RRC state may be associated with a mobility management mechanism. In RRC idle 604 and RRC inactive 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC idle 604 and RRC inactive 606 is to allow the network to notify the UE of an event via a paging message without broadcasting the paging message over the entire mobile communication network. The mobility management mechanism used in RRC idle 604 and RRC inactive 606 may allow the network to track the UE at a cell group level, so that the paging message may be broadcast over a cell in the cell group in which the UE currently resides instead of over the entire mobile communication network. The mobility management mechanism used for RRC idle 604 and RRC inactive 606 tracks the UE at a cell group level. These mobility management mechanisms may do so using groups of different granularities. For example, there may be three levels of cell grouping granularity: a single cell; a cell within a RAN area identified by a RAN area identifier (RAI); and a cell within a group of RAN areas referred to as tracking areas and identified by a tracking area identifier (TAI).

[0113] Tracking areas may be used to track UEs at the CN level. A CN (e.g., CN 102 or 5G-CN 152) may provide a list of TAIs associated with UE registration areas to a UE. If a UE moves through cell reselection to a cell associated with a TAI that is not included in the list of TAIs associated with a UE registration area, the UE may perform a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0114] The RAN area may be used to track the UE at the RAN level. For a UE in the RRC inactive 606 state, a RAN notification area may be assigned to the UE. The RAN notification area may include one or more cell identities, a list of RAIs, or a list of TAIs. In an example, a base station may belong to one or more RAN notification areas. In an example, a cell may belong to one or more RAN notification areas. If the UE moves to a cell not included in the RAN notification area assigned to the UE through cell reselection, the UE may perform a notification area update on the RAN to update the RAN notification area of ​​the UE.

[0115] The base station storing the RRC context for the UE or the last serving base station of the UE may be referred to as the anchor base station. The anchor base station may maintain the RRC context for the UE at least during the period of time that the UE remains in the RAN notification area of ​​the anchor base station and / or during the period of time that the UE remains in RRC inactivity 606.

[0116] gNBs, such as Figure 1B The gNB 160 in the embodiment of the present invention can be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DU). The gNB-CU can be coupled to one or more gNB-DUs using the F1 interface. The gNB-CU can include RRC, PDCP, and SDAP. The gNB-DU can include RLC, MAC, and PHY.

[0117] In NR, physical signals and physical channels (about Figure 5A and Figure 5BDiscussed) can be mapped onto orthogonal frequency division multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data through F orthogonal subcarriers (or tones). Before transmission, the data can be mapped to a series of complex symbols called source symbols (e.g., M-quadrature amplitude modulation (M-QAM) symbols or M-phase shift keying (M-PSK) symbols) and divided into F parallel symbol streams. The F parallel symbol streams can be treated as if they are in the frequency domain and used as input to the inverse fast Fourier transform (IFFT) block that transforms them into the time domain. The IFFT block can take F source symbols at a time (one source symbol from each of the F parallel symbol streams), and use each source symbol to modulate the amplitude and phase of one of the F sinusoidal basis functions corresponding to the F orthogonal subcarriers. The output of the IFFT block can be F time domain samples representing the sum of the F orthogonal subcarriers. The F time domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and up-conversion, the OFDM symbols provided by the IFFT block can be transmitted over the air interface at the carrier frequency. The F parallel symbol streams can be mixed using the FFT block before being processed by the IFFT block. This operation produces a discrete Fourier transform (DFT) precoded OFDM symbol and can be used by the UE in the uplink to reduce the peak to average power ratio (PAPR). The FFT block can be used to perform inverse processing on the OFDM symbol at the receiver to restore the data mapped to the source symbol.

[0118] Figure 7 An exemplary configuration of an NR frame into which OFDM symbols are grouped is shown. An NR frame may be identified by a system frame number (SFN). The SFN may repeat for a period of 1024 frames. As shown, a NR frame may have a duration of 10 milliseconds (ms) and may include 10 subframes of duration 1 ms. A subframe may be divided into time slots that include, for example, 14 OFDM symbols per time slot.

[0119] The duration of a time slot may depend on the parameter set of the OFDM symbol used for the time slot. In NR, flexible parameter sets are supported to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz, up to cells with carrier frequencies in the mm-wave range). Parameter sets may be defined in terms of subcarrier spacing and cyclic prefix duration. For parameter sets in NR, the subcarrier spacing may be scaled up by powers of two from a baseline subcarrier spacing of 15 kHz, and the cyclic prefix duration may be scaled down by powers of two from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines parameter sets with the following subcarrier spacing / cyclic prefix duration combinations: 15 kHz / 4.7 μs; 30 kHz / 2.3 μs; 60 kHz / 1.2 μs; 120 kHz / 0.59 μs; and 240 kHz / 0.29 μs.

[0120] A slot may have a fixed number of OFDM symbols (eg, 14 OFDM symbols). Parameter sets with higher subcarrier spacing have shorter slot durations and correspondingly more slots per subframe. Figure 7 The transmission structure of the time slot duration and each subframe time slot associated with the parameter set is shown (for ease of explanation, Figure 7 Parameter sets with subcarrier spacing of 240kHz are not shown in Figure 1). Subframes in NR can be used as a time reference independent of the parameter set, while slots can be used as the unit for scheduling uplink and downlink transmissions. To support low latency, scheduling in NR can be decoupled from the slot duration and start at any OFDM symbol and continue to transmit as many symbols as needed. These partial slot transmissions can be called mini-slots or sub-slot transmissions.

[0121] Figure 8 An exemplary configuration of a time slot in the time and frequency domain of an NR carrier is shown. The time slot includes a resource element (RE) and a resource block (RB). RE is the smallest physical resource in NR. RE spans one OFDM symbol in the time domain through one subcarrier in the frequency domain, such as Figure 8 As shown. RB spans twelve consecutive REs in the frequency domain, as Figure 8 As shown. The NR carrier can be limited to a width of 275RB or 275×12=3300 subcarriers. If this restriction is used, the NR carrier can be limited to 50MHz, 100MHz, 200MHz and 400MHz for subcarrier spacings of 15, 30, 60 and 120kHz, respectively, where the 400MHz bandwidth can be set based on the 400MHz bandwidth limit per carrier.

[0122] Figure 8A single parameter set is shown used across the entire bandwidth of the NR carrier. In other example configurations, multiple parameter sets may be supported on the same carrier.

[0123] NR may support wide carrier bandwidths (e.g., up to 400 MHz for a subcarrier spacing of 120 kHz). Not all UEs may be able to receive the full carrier bandwidth (e.g., due to hardware limitations). Moreover, receiving the full carrier bandwidth may be prohibitive in terms of UE power consumption. In an example, to reduce power consumption and / or for other purposes, the UE may adapt the size of the UE's receive bandwidth based on the amount of traffic the UE plans to receive. This is referred to as bandwidth adaptation.

[0124] NR defines bandwidth parts (BWPs) to support UEs that cannot receive the full carrier bandwidth and supports bandwidth adaptation. In an example, a BWP may be defined by a subset of contiguous RBs on a carrier. The UE may be configured (e.g., via the RRC layer) with one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the configured BWPs for the serving cell may be active. The one or more BWPs may be referred to as the active BWP of the serving cell. When a serving cell is configured with a secondary uplink carrier, the serving cell may have one or more first active BWPs in the uplink carrier and one or more second active BWPs in the secondary uplink carrier.

[0125] For unpaired spectrum, a downlink BWP from a set of configured downlink BWPs may be linked with an uplink BWP from a set of configured uplink BWPs if the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP. For unpaired spectrum, the UE may expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0126] For a downlink BWP in a set of configured downlink BWPs on a primary cell (PCell), the base station may configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domain where a UE can look for control information. A search space may be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, a base station may configure a common search space for a UE on a PCell or a primary secondary cell (PSCell) in an active downlink BWP.

[0127] For an uplink BWP in the set of configured uplink BWPs, the BS may configure one or more resource sets for one or more PUCCH transmissions for the UE. The UE may receive downlink receptions (e.g., PDCCH or PDSCH) in the downlink BWP according to the configured parameter set (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE may transmit uplink transmissions (e.g., PUCCH or PUSCH) in the uplink BWP according to the configured parameter set (e.g., subcarrier spacing and cyclic prefix length of the uplink BWP).

[0128] One or more BWP indicator fields may be provided in downlink control information (DCI). The value of the BWP indicator field may indicate which BWP in a set of configured BWPs is the active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields may indicate the active uplink BWP for one or more uplink transmissions.

[0129] The base station may semi-statically configure a default downlink BWP for the UE within the set of configured downlink BWPs associated with the PCell. If the base station does not provide a default downlink BWP to the UE, the default downlink BWP may be the initial active downlink BWP. The UE may determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0130] The base station may configure the BWP inactivity timer value for the PCell for the UE. The UE may start or restart the BWP inactivity timer at any appropriate time. For example, the UE may start or restart the BWP inactivity timer in the following circumstances: (a) when the UE detects a DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation; or (b) when the UE detects a DCI indicating an active downlink BWP or an active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation. If the UE does not detect the DCI within a time interval (e.g., 1 ms or 0.5 ms), the UE may run the BWP inactivity timer towards expiration (e.g., an increment from zero to the BWP inactivity timer value, or a decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE may switch from the active downlink BWP to the default downlink BWP.

[0131] In an example, the base station may semi-statically configure the UE with one or more BWPs. The UE may switch the active BWP from the first BWP to the second BWP in response to receiving a DCI indicating that the second BWP is the active BWP and / or in response to expiration of a BWP inactivity timer (e.g., when the second BWP is the default BWP).

[0132] Downlink and uplink BWP switching can be performed independently in paired spectrum (where BWP switching refers to switching from a currently active BWP to a non-currently active BWP). In unpaired spectrum, downlink and uplink BWP switching can be performed simultaneously. Switching between configured BWPs can occur based on RRC signaling, DCI, expiration of a BWP inactivity timer, and / or initiation of random access.

[0133] Fig. 9 An example of bandwidth adaptation using three configured BWPs of an NR carrier is shown. A UE configured with the three BWPs may switch from one BWP to another at a switching point. Fig. 9 In the example shown in , the BWPs include: BWP 902, with a bandwidth of 40 MHz and a subcarrier spacing of 15 kHz; BWP 904, with a bandwidth of 10 MHz and a subcarrier spacing of 15 kHz; and BWP 906, with a bandwidth of 20 MHz and a subcarrier spacing of 60 kHz. BWP 902 may be the initial active BWP, and BWP 904 may be the default BWP. The UE may switch between BWPs at a switching point. Fig. 9 In the example of , the UE may switch from BWP 902 to BWP 904 at switch point 908. The switch at switch point 908 may occur for any suitable reason, such as in response to expiration of a BWP inactivity timer (indicating a switch to a default BWP) and / or in response to receiving a DCI indicating that BWP 904 is an active BWP. The UE may switch from active BWP 904 to BWP 906 at switch point 910 in response to receiving a DCI indicating that BWP 906 is an active BWP. The UE may switch from active BWP 906 to BWP 904 at switch point 912 in response to expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating that BWP 904 is an active BWP. The UE may switch from active BWP 904 to BWP 902 at switch point 914 in response to receiving a DCI indicating that BWP 902 is an active BWP.

[0134] If the UE is configured for a secondary cell with a default downlink BWP and timer values ​​from the set of configured downlink BWPs, the UE procedures for switching the BWP on the secondary cell may be the same / similar to those on the primary cell. For example, the UE may use the timer values ​​and default downlink BWP for the secondary cell in the same / similar manner as the UE would use these values ​​for the primary cell.

[0135] To provide higher data rates, two or more carriers may be aggregated and transmitted to / from the same UE simultaneously using carrier aggregation (CA). The aggregated carriers in CA may be referred to as component carriers (CC). When CA is used, there are many serving cells for the UE, one serving cell per CC. CCs may have three configurations in the frequency domain.

[0136] Fig. 10A Three CA configurations with two CCs are shown. In the intra-band contiguous configuration 1002, the two CCs are aggregated in the same frequency band (Band A) and are located directly adjacent to each other in the frequency band. In the intra-band non-contiguous configuration 1004, the two CCs are aggregated in the frequency band (Band A) and are separated by a gap in the frequency band. In the inter-band configuration 1006, the two CCs are located in the frequency bands (Band A and Band B).

[0137] In an example, up to 32 CCs may be aggregated. Aggregated CCs may have the same or different bandwidths, subcarrier spacings, and / or duplex schemes (TDD or FDD). A serving cell for a UE using CA may have a downlink CC. For FDD, one or more uplink CCs may optionally be configured for the serving cell. For example, the ability to aggregate more downlink carriers than uplink carriers may be useful when the UE has more data traffic in the downlink than in the uplink.

[0138] When CA is used, one of the aggregated cells for the UE may be referred to as a primary cell (PCell). The PCell may be a serving cell to which the UE initially connects at RRC connection establishment, reestablishment and / or handover. The PCell may provide NAS mobility information and security input to the UE. The UE may have different PCells. In the downlink, the carrier corresponding to the PCell may be referred to as a downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell may be referred to as an uplink primary CC (UL PCC). Other aggregated cells for the UE may be referred to as secondary cells (SCells). In an example, the SCell may be configured after the PCell is configured for the UE. For example, the SCell may be configured via an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the SCell may be referred to as a downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell may be referred to as an uplink secondary CC (UL SCC).

[0139] The configured SCell for a UE can be activated and deactivated based on, for example, traffic and channel conditions. Deactivation of an SCell can mean stopping PDCCH and PDSCH reception on the SCell, and stopping PUSCH, SRS, and CQI transmission on the SCell. Figure 4B The MAC CE may be used to activate and deactivate the configured SCells. For example, the MAC CE may use a bitmap (e.g., one bit per SCell) to indicate which SCells (e.g., in a subset of configured SCells) are activated or deactivated for the UE. The configured SCells may be deactivated in response to the expiration of an SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0140] The downlink control information of a cell (such as scheduling assignments and scheduling grants) can be transmitted on the cell corresponding to the assignment and grant, which is called self-scheduling. The DCI of a cell can be transmitted on another cell, which is called cross-carrier scheduling. Uplink control information for aggregated cells (e.g., HARQ confirmation and channel state feedback, such as CQI, PMI and / or RI) can be transmitted on the PUCCH of the PCell. For a large number of aggregated downlink CCs, the PUCCH of the PCell may become overloaded. The cell can be divided into multiple PUCCH groups.

[0141] Fig. 10B An example of how aggregated cells can be configured into one or more PUCCH groups is shown. PUCCH group 1010 and PUCCH group 1050 may include one or more downlink CCs, respectively. Fig. 10B In the example of , PUCCH group 1010 includes three downlink CCs: PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 in this example includes three downlink CCs: PCell 1051, SCell 1052, and SCell 1053. One or more uplink CCs may be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs may be configured as primary Scell ​​(PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1010 (shown as UCI 1031, UCI 1032, and UCI 1033) may be transmitted in the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1050 (shown as UCI 1071, UCI 1072, and UCI 1073) may be transmitted in the uplink of PSCell 1061. In the example, if Fig. 10B If the aggregated cell depicted in FIG. 1 is not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell transmits UCI associated with a downlink CC, and the PCell may become overloaded. By dividing the transmission of UCI between PCell 1021 and PSCell 1061, overload can be prevented.

[0142] A physical cell ID and a cell index may be assigned to a cell comprising a downlink carrier and an optional uplink carrier. The physical cell ID or cell index may identify a downlink carrier and / or an uplink carrier of a cell, for example, depending on the context in which the physical cell ID is used. The physical cell ID may be determined using a synchronization signal transmitted on a downlink component carrier. The cell index may be determined using an RRC message. In the present disclosure, the physical cell ID may be referred to as a carrier ID, and the cell index may be referred to as a carrier index. For example, when the present disclosure relates to a first physical cell ID of a first downlink carrier, the present disclosure may mean that the first physical cell ID is used for a cell comprising the first downlink carrier. The same / similar concepts may apply, for example, to carrier activation. When the present disclosure indicates that a first carrier is activated, the present specification may mean that a cell comprising the first carrier is activated.

[0143] In CA, the multi-carrier nature of the PHY may be exposed to the MAC. In an example, the HARQ entity may operate on a serving cell. A transport block may be generated based on the assignment / grant of each serving cell. A transport block and potential HARQ retransmissions of the transport block may be mapped to a serving cell.

[0144] In the downlink, the base station may transmit (e.g., unicast, multicast and / or broadcast) one or more reference signals (RS) to the UE (e.g., PSS, SSS, CSI-RS, DMRS and / or PT-RS, such as Figure 5A In the uplink, the UE may transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, as shown in FIG. Figure 5B ). The PSS and SSS may be transmitted by a base station and used by a UE to synchronize the UE with the base station. The PSS and SSS may be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes the PSS, SSS, and PBCH. The base station may periodically transmit bursts of SS / PBCH blocks.

[0145] Fig.11A An example of the structure and location of SS / PBCH blocks is shown. A burst of SS / PBCH blocks may include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, such as Fig.11A As shown). Bursts may be transmitted periodically (e.g., every 2 frames or 20 ms). Bursts may be limited to half a frame (e.g., the first half frame with a duration of 5 ms). It should be understood that Fig.11A are examples, and these parameters (number of SS / PBCH blocks per burst, periodicity of bursts, burst position within a frame) may be configured based on, for example: the carrier frequency of the cell in which the SS / PBCH blocks are transmitted; a parameter set or subcarrier spacing for the cell; configuration by the network (e.g., using RRC signaling); or any other suitable factor. In an example, the UE may assume the subcarrier spacing of the SS / PBCH blocks based on the carrier frequency being monitored unless the radio network configures the UE to assume a different subcarrier spacing.

[0146] The SS / PBCH block may span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, such as Fig.11A) and may span one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). The PSS, SSS, and PBCH may have a common center frequency. The PSS may be transmitted first and may span, for example, 1 OFDM symbol and 127 subcarriers. The SSS may be transmitted after the PSS (e.g., two symbols later) and may span 1 OFDM symbol and 127 subcarriers. The PBCH may be transmitted after the PSS (e.g., spanning the next 3 OFDM symbols) and may span 240 subcarriers.

[0147] The UE may not know the location of the SS / PBCH blocks in the time and frequency domain (for example, when the UE is searching for cells). In order to find and select a cell, the UE may monitor the carrier of the PSS. For example, the UE may monitor the frequency position within the carrier. If the PSS is not found after a certain duration (for example, 20ms), the UE may search for the PSS at different frequency positions within the carrier, as indicated by the synchronization raster. If the PSS is found at a certain position in the time and frequency domain, the UE may determine the location of the SSS and PBCH based on the known structure of the SS / PBCH block, respectively. The SS / PBCH block may be a cell definition SS block (CD-SSB). In an example, a primary cell may be associated with a CD-SSB. The CD-SSB may be located on a synchronization raster. In an example, cell selection / search and / or reselection may be based on the CD-SSB.

[0148] The SS / PBCH block may be used by the UE to determine one or more parameters of the cell. For example, the UE may determine the physical cell identifier (PCI) of the cell based on the sequence of the PSS and SSS, respectively. The UE may determine the location of the frame boundary of the cell based on the location of the SS / PBCH block. For example, the SS / PBCH block may indicate that it has been transmitted according to a transmission pattern in which the SS / PBCH block in the transmission pattern is a known distance from the frame boundary.

[0149] The PBCH may use QPSK modulation and may use forward error correction (FEC). FEC may use polarity coding. One or more symbols spanned by the PBCH may carry one or more DMRS for demodulating the PBCH. The PBCH may include an indication of the current system frame number (SFN) of the cell and / or an SS / PBCH block timing index. These parameters may contribute to the time synchronization of the UE with the base station. The PBCH may include a master information block (MIB) for providing one or more parameters to the UE. The MIB may be used by the UE to locate the remaining minimum system information (RMSI) associated with the cell. The RMSI may include a system information block type 1 (SIB1). SIB1 may contain information required for the UE to access the cell. The UE may use one or more parameters of the MIB to monitor the PDCCH that may be used to schedule the PDSCH. The PDSCH may include SIB1. SIB1 may be decoded using the parameters provided in the MIB. The PBCH may indicate that SIB1 does not exist. Based on the PBCH indicating that SIB1 does not exist, the UE may point to a frequency. The UE may search for SS / PBCH blocks at the frequency to which the UE is pointing.

[0150] The UE may assume that one or more SS / PBCH blocks transmitted with the same SS / PBCH block index are quasi-co-located (QCLed) (e.g., having the same / similar Doppler spread, Doppler shift, average gain, average delay and / or spatial Rx parameters). The UE may not assume QCL for SS / PBCH block transmissions with different SS / PBCH block indices.

[0151] SS / PBCH blocks (e.g., those within a half-frame) may be transmitted in spatial directions (e.g., using different beams across the coverage area of ​​a cell). In an example, a first SS / PBCH block may be transmitted in a first spatial direction using a first beam, and a second SS / PBCH block may be transmitted in a second spatial direction using a second beam.

[0152] In an example, within a frequency range of a carrier, a base station may transmit multiple SS / PBCH blocks. In an example, a first PCI of a first SS / PBCH block of the multiple SS / PBCH blocks may be different from a second PCI of a second SS / PBCH block of the multiple SS / PBCH blocks. PCIs of SS / PBCH blocks transmitted in different frequency positions may be different or the same.

[0153] The CSI-RS may be transmitted by a base station and used by a UE to obtain channel state information (CSI). The base station may configure the UE with one or more CSI-RS for channel estimation or any other suitable purpose. The base station may configure the UE with one or more CSI-RSs of the same / similar CSI-RS. The UE may measure the one or more CSI-RSs. The UE may estimate the downlink channel state and / or generate a CSI report based on the measurement of the one or more downlink CSI-RSs. The UE may provide the CSI report to the base station. The base station may use the feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0154] The base station may semi-statically configure the UE with one or more CSI-RS resource sets. The CSI-RS resources may be associated with a position and periodicity in the time and frequency domains. The base station may selectively activate and / or deactivate CSI-RS resources. The base station may indicate to the UE that the CSI-RS resources in the CSI-RS resource set are activated and / or deactivated.

[0155] The base station may configure the UE to report CSI measurement values. The base station may configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE may be configured with timing and / or periodicity of multiple CSI reports. For aperiodic CSI reporting, the base station may request a CSI report. For example, the base station may command the UE to measure the configured CSI-RS resources and provide a CSI report related to the measurement values. For semi-persistent CSI reporting, the base station may configure the UE to transmit periodically and selectively activate or deactivate periodic reporting. The base station may configure the UE with a CSI-RS resource set and CSI reporting using RRC signaling.

[0156] The CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE may be configured to employ the same OFDM symbol for downlink CSI-RS and control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the physical resource blocks (PRBs) configured for the CORESET. The UE may be configured to employ the same OFDM symbol for downlink CSI-RS and SS / PBCH blocks when the downlink CSI-RS and SS / PBCH blocks are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the PRBs configured for the SS / PBCH blocks.

[0157] Downlink DMRS can be transmitted by the base station and used by the UE for channel estimation. For example, the downlink DMRS can be used for consistent demodulation of one or more downlink physical channels (e.g., PDSCH). The NR network can support one or more variable and / or configurable DMRS modes for data demodulation. At least one downlink DMRS configuration can support a frontload DMRS mode. The frontload DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station can semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for PDSCH. The DMRS configuration can support one or more DMRS ports. For example, for single-user MIMO, the DMRS configuration can support up to eight orthogonal downlink DMRS ports per UE. For multi-user MIMO, the DMRS configuration can support up to 4 orthogonal downlink DMRS ports per UE. The radio network may (e.g., at least for CP-OFDM) support a common DMRS structure for downlink and uplink, where the DMRS position, DMRS pattern and / or scrambling sequence may be the same or different. The base station may transmit the downlink DMRS and the corresponding PDSCH using the same precoding matrix. The UE may use the one or more downlink DMRS to perform consistent demodulation / channel estimation on the PDSCH.

[0158] In an example, a transmitter (e.g., a base station) may use a precoder matrix for a portion of a transmission bandwidth. For example, the transmitter may use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first precoder matrix and the second precoder matrix may be different based on the first bandwidth being different from the second bandwidth. The UE may assume that the same precoding matrix is ​​used throughout a set of PRBs. The set of PRBs may be represented as a precoding resource block group (PRG).

[0159] The PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS is present on a layer in the one or more layers of the PDSCH. The higher layers may configure up to 3 DMRS for the PDSCH.

[0160] The downlink PT-RS may be transmitted by a base station and used by a UE for phase noise compensation. Whether a downlink PT-RS exists may depend on an RRC configuration. The presence and / or type of a downlink PT-RS may be configured based on a UE-specific configuration using a combination of RRC signaling and / or an association with one or more parameters for other purposes (e.g., a modulation and coding scheme (MCS)) that may be indicated by a DCI. When configured, the dynamic presence of a downlink PT-RS may be associated with one or more DCI parameters including at least an MCS. The NR network may support multiple PT-RS densities defined in the time / frequency domain. When present, the frequency domain density may be associated with at least one configuration of the scheduled bandwidth. The UE may use the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports may be less than the number of DMRS ports in the scheduled resources. The downlink PT-RS may be limited to the scheduled time / frequency duration of the UE. The downlink PT-RS may be transmitted on a symbol to facilitate phase tracking at the receiver.

[0161] The UE may transmit an uplink DMRS to a base station for channel estimation. For example, the base station may use the uplink DMRS to consistently demodulate one or more uplink physical channels. For example, the UE may transmit an uplink DMRS with a PUSCH and / or a PUCCH. The uplink DM-RS may span a frequency range similar to the frequency range associated with the corresponding physical channel. The base station may configure the UE with one or more uplink DMRS configurations. At least one DMRS configuration may support a front-load DMRS mode. The front-load DMRS may be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS may be configured to be transmitted at one or more symbols of the PUSCH and / or PUCCH. The base station may semi-statically configure the UE with the number (e.g., maximum number) of front-load DMRS symbols for the PUSCH and / or PUCCH, and the UE may use the front-load DMRS symbol to schedule a single-symbol DMRS and / or a dual-symbol DMRS. NR networks may support a common DMRS structure for downlink and uplink (e.g., for cyclic prefix orthogonal frequency division multiplexing (CP-OFDM)), where the DMRS positions, DMRS patterns, and / or scrambling sequences of the DMRS may be the same or different.

[0162] The PUSCH may include one or more layers, and the UE may transmit at least one symbol having a DMRS present on a layer in the one or more layers of the PUSCH. In an example, a higher layer may configure up to three DMRSs for the PUSCH.

[0163] Depending on the RRC configuration of the UE, an uplink PT-RS (which can be used by the base station for phase tracking and / or phase noise compensation) may or may not exist. The presence and / or type of the uplink PT-RS can be configured based on UE-specific configuration through a combination of RRC signaling and / or one or more parameters for other purposes (e.g., modulation and coding scheme (MCS)) indicated by the DCI. When configured, the dynamic presence of the uplink PT-RS can be associated with one or more DCI parameters including at least the MCS. The radio network can support multiple uplink PT-RS densities defined in the time / frequency domain. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can use the same precoding for DMRS ports and PT-RS ports. The number of PT-RS ports can be less than the number of DMRS ports in the scheduled resources. For example, the uplink PT-RS can be limited to the scheduled time / frequency duration of the UE.

[0164] The UE may transmit an SRS to a base station for channel state estimation to support uplink channel-dependent scheduling and / or link adaptation. The SRS transmitted by the UE may allow the base station to estimate the uplink channel state at one or more frequencies. The scheduler at the base station may use the estimated uplink channel state to assign one or more resource blocks for uplink PUSCH transmission from the UE. The base station may semi-statically configure the UE with one or more SRS resource sets. For an SRS resource set, the base station may configure the UE with one or more SRS resources. The applicability of the SRS resource set may be configured by a higher layer (e.g., RRC) parameter. For example, when a higher layer parameter indicates beam management, the SRS resources in the SRS resource set in the one or more SRS resource sets (e.g., having the same / similar time domain behavior, periodic, aperiodic, etc.) may be transmitted at a certain time (e.g., at the same time). The UE may transmit one or more SRS resources in the SRS resource set. The NR network may support aperiodic, periodic, and / or semi-persistent SRS transmission. The UE may transmit SRS resources based on one or more trigger types, wherein the one or more trigger types may include higher layer signaling (e.g., RRC) and / or one or more DCI formats. In an example, at least one DCI format may be used for the UE to select at least one configured SRS resource set from one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In an example, when PUSCH and SRS are transmitted in the same time slot, the UE may be configured to transmit SRS after transmission of PUSCH and corresponding uplink DMRS.

[0165] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the following: an SRS resource configuration identifier; the number of SRS ports; the time domain behavior of the SRS resource configuration (e.g., an indication of periodic, semi-persistent, or non-periodic SRS); time slot, mini-slot, and / or subframe level periodicity; time slots of periodic and / or non-periodic SRS resources; the number of OFDM symbols in the SRS resources; the start OFDM symbol of the SRS resources; SRS bandwidth; frequency hopping bandwidth; cyclic shift; and / or SRS sequence ID.

[0166] The antenna ports are defined such that the channel through which a symbol on the antenna port is communicated can be inferred from the channel through which another symbol on the same antenna port is communicated. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer the channel (e.g., fading gain, multipath delay, etc.) used to communicate the second symbol on the antenna port from the channel used to communicate the first symbol on the antenna port. If one or more large-scale properties of the channel through which the first symbol on the first antenna port is communicated can be inferred from the channel through which the second symbol on the second antenna port is communicated, the first antenna port and the second antenna port can be referred to as quasi-co-located (QCLed). The one or more large-scale properties may include at least one of the following: delay spread; Doppler spread; Doppler shift; average gain; average delay; and / or spatial receive (Rx) parameters.

[0167] Channels using beamforming require beam management. Beam management may include beam measurement, beam selection, and beam indication. A beam may be associated with one or more reference signals. For example, a beam may be identified by one or more beamforming reference signals. The UE may perform downlink beam measurements and generate beam measurement reports based on downlink reference signals (e.g., channel state information reference signals (CSI-RS)). After setting up an RRC connection with a base station, the UE may perform a downlink beam measurement procedure.

[0168] Fig. 11B An example of a channel state information reference signal (CSI-RS) mapped in the time and frequency domain is shown. Fig. 11BThe squares shown in the figure may represent resource blocks (RBs) within the bandwidth of the cell. The base station may transmit one or more RRC messages including CSI-RS resource configuration parameters indicating one or more CSI-RS. One or more of the following parameters may be configured for the CSI-RS resource configuration through higher layer signaling (e.g., RRC and / or MAC signaling): CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and resource element (RE) positions in a subframe), CSI-RS subframe configuration (e.g., subframe position, offset and periodicity in a radio frame), CSI-RS power parameters, CSI-RS sequence parameters, code division multiplexing (CDM) type parameters, frequency density, transmission comb, quasi co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid) and / or other radio resource parameters.

[0169] Fig. 11B The three beams shown may be configured for a UE in a UE-specific configuration. Fig. 11B Three beams (beam #1, beam #2, and beam #3) are shown in the figure, and more or fewer beams can be configured. CSI-RS1101 can be allocated to beam #1, which can be transmitted in one or more subcarriers in the RB of the first symbol. CSI-RS1102 can be allocated to beam #2, which can be transmitted in one or more subcarriers in the RB of the second symbol. CSI-RS1103 can be allocated to beam #3, which can be transmitted in one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), the base station can use other subcarriers in the same RB (for example, those subcarriers not used to transmit CSI-RS1101) to transmit another CSI-RS associated with the beam of another UE. By using time domain multiplexing (TDM), the beam for the UE can be configured so that the beam for the UE uses symbols from the beams of other UEs.

[0170] CSI-RS, such as Fig. 11BThose shown in (e.g., CSI-RS1101, 1102, 1103) may be transmitted by a base station and used by a UE for one or more measurement values. For example, a UE may measure a reference signal received power (RSRP) of a configured CSI-RS resource. The base station may configure the UE with a reporting configuration, and the UE may report the RSRP measurement value to the network (e.g., via one or more base stations) based on the reporting configuration. In the example, the base station may determine one or more transmission configuration indication (TCI) states including multiple reference signals based on the reported measurement results. In the example, the base station may indicate one or more TCI states to the UE (e.g., via RRC signaling, MAC CE, and / or DCI). The UE may receive a downlink transmission having a receive (Rx) beam determined based on the one or more TCI states. In the example, the UE may or may not have beam correspondence capability. If the UE has beam correspondence capability, the UE may determine the spatial domain filter of the transmission (Tx) beam based on the spatial domain filter of the corresponding Rx beam. If the UE does not have beam-corresponding capability, the UE may perform an uplink beam selection procedure to determine the spatial domain filter of the Tx beam. The UE may perform an uplink beam selection procedure based on one or more sounding reference signal (SRS) resources configured to the UE by the base station. The base station may select and indicate the uplink beam of the UE based on measurements of one or more SRS resources transmitted by the UE.

[0171] In the beam management procedure, the UE may assess (e.g., measure) the channel quality of one or more beam pair links, beam pair links including a transmit beam transmitted by a base station, and a receive beam received by the UE. Based on the assessment, the UE may transmit a beam measurement report indicating one or more beam pair quality parameters, the one or more beam pair quality parameters including, for example, one or more beam identifiers (e.g., beam index, reference signal index, etc.), RSRP, precoding matrix indicator (PMI), channel quality indicator (CQI) and / or rank indicator (RI).

[0172] Fig. 12AExamples of three downlink beam management procedures are shown: P1, P2, and P3. Procedure P1 can enable UE measurements of transmit (Tx) beams of a transmit reception point (TRP) (or multiple TRPs), for example to support selection of one or more base station Tx beams and / or UE Rx beams (shown as ovals in the top and bottom rows of P1, respectively). Beamforming at the TRP can include Tx beam sweeping for a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of P1 and P2). Beamforming at the UE can include Rx beam sweeping for a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of P1 and P3). Procedure P2 can be used to enable UE measurements of Tx beams of a TRP (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top row of P2). The UE and / or the base station may perform procedure P2 using a smaller beam set than the beam set used in procedure P1, or using a narrower beam than the beam used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beam at the UE.

[0173] Fig. 12B Examples of three uplink beam management procedures are shown: U1, U2, and U3. Procedure U1 can be used to enable a base station to perform measurements on a UE's Tx beams, for example, to support selection of one or more UE Tx beams and / or base station Rx beams (shown as ovals in the top and bottom rows of U1, respectively). Beamforming at the UE can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a clockwise direction indicated by dashed arrows in the bottom rows of U1 and U3). Beamforming at the base station can include, for example, Rx beam sweeping from a set of beams (shown as ovals rotating in a counterclockwise direction indicated by dashed arrows in the top rows of U1 and U2). Procedure U2 can be used to enable a base station to adjust its Rx beam when the UE uses a fixed Tx beam. The UE and / or base station can perform procedure U2 using a smaller beam set than the beam set used in procedure P1, or using a narrower beam than the beam used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure U3 to adjust its Tx beam when the base station uses a fixed Rx beam.

[0174] The UE may initiate a beam failure recovery (BFR) procedure based on detecting a beam failure. The UE may transmit a BFR request (e.g., preamble, UCI, SR, MAC CE, etc.) based on the initiation of the BFR procedure. The UE may detect a beam failure based on a determination that the quality of the beam-pair link of the associated control channel is unsatisfactory (e.g., having an error rate above an error rate threshold, a received signal power below a received signal power threshold, expiration of a timer, etc.).

[0175] The UE may measure the quality of a beam-to-link using one or more reference signals (RS), the one or more reference signals including one or more SS / PBCH blocks, one or more CSI-RS resources, and / or one or more demodulation reference signals (DMRS). The quality of a beam-to-link may be based on one or more of the following: a block error rate (BLER), an RSRP value, a signal-to-interference-plus-noise ratio (SINR) value, a reference signal received quality (RSRQ) value, and / or a CSI value measured on an RS resource. The base station may indicate that the RS resource is quasi-co-located (QCLed) with one or more DM-RS of a channel (e.g., a control channel, a shared data channel, etc.). When the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameters, fading, etc.) from a transmission to the UE via the RS resource are similar or identical to the channel characteristics from a transmission to the UE via the channel, the RS resource and the one or more DMRS of the channel may be QCLed.

[0176] The network (e.g., gNB and / or ng-eNB of the network) and / or the UE may initiate a random access procedure. A UE in RRC_IDLE state and / or RRC_INACTIVE state may initiate a random access procedure to request connection setup to the network. The UE may initiate a random access procedure from the RRC_CONNECTED state. The UE may initiate a random access procedure to request uplink resources (e.g., uplink transmission for SR when there are no available PUCCH resources) and / or to obtain uplink timing (e.g., when the uplink synchronization state is not synchronized). The UE may initiate a random access procedure to request one or more system information blocks (SIBs) (e.g., other system information, such as SIB2, SIB3, etc.). The UE may initiate a random access procedure for a beam failure recovery request. The network may initiate a random access procedure for handover and / or for establishing a time alignment for SCell addition.

[0177] Fig.13A A four-step contention-based random access procedure is shown.Before initiating the procedure, the base station may transmit a configuration message 1310 to the UE. Fig.13AThe procedure shown includes the transmission of four messages: Msg 1 1311, Msg 2 1312, Msg3 1313, and Msg 4 1314. Msg 1 1311 may include and / or be referred to as a preamble (or random access preamble). Msg2 1312 may include and / or be referred to as a random access response (RAR).

[0178] The configuration message 1310 may be transmitted, for example, using one or more RRC messages. The one or more RRC messages may indicate one or more random access channel (RACH) parameters to the UE. The one or more RACH parameters may include at least one of the following: general parameters for one or more random access procedures (e.g., RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon); and / or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast the one or more RRC messages to one or more UEs. The one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to the UE in the RRC_CONNECTED state and / or the RRC_INACTIVE state). The UE may determine the time-frequency resources and / or uplink transmission power for transmitting Msg 1 1311 and / or Msg 3 1313 based on the one or more RACH parameters. Based on the one or more RACH parameters, the UE may determine the reception timing and downlink channel for receiving Msg 2 1312 and Msg 4 1314.

[0179] The one or more RACH parameters provided in the configuration message 1310 may indicate one or more physical RACH (PRACH) opportunities that can be used to transmit Msg 11311. The one or more PRACH opportunities may be predefined. The one or more RACH parameters may indicate one or more available sets of one or more PRACH opportunities (e.g., prach-ConfigIndex). The one or more RACH parameters may indicate an association between: (a) one or more PRACH opportunities, and (b) one or more reference signals. The one or more RACH parameters may indicate an association between: (a) one or more preambles, and (b) one or more reference signals. The one or more reference signals may be SS / PBCH blocks and / or CSI-RS. For example, the one or more RACH parameters may indicate the number of SS / PBCH blocks mapped to the PRACH opportunity and / or the number of preambles mapped to the SS / PBCH block.

[0180] The one or more RACH parameters provided in the configuration message 1310 may be used to determine the uplink transmission power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters may indicate a reference power for preamble transmission (e.g., a received target power and / or an initial power for preamble transmission). There may be one or more power offsets indicated by the one or more RACH parameters. For example, the one or more RACH parameters may indicate: a power ramp step size; a power offset between SSB and CSI-RS; a power offset between transmissions of Msg 1 1311 and Msg 3 1313; and / or a power offset value between preamble groups. The one or more RACH parameters may indicate one or more thresholds based on which the UE may determine at least one reference signal (e.g., SSB and / or CSI-RS) and / or uplink carrier (e.g., a normal uplink (NUL) carrier and / or a supplementary uplink (SUL) carrier).

[0181] Msg 1 1311 may include one or more preamble transmissions (e.g., a preamble transmission and one or more preamble retransmissions). The RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). The preamble group may include one or more preambles. The UE may determine the preamble group based on the path loss measurement value and / or the size of Msg 3 1313. The UE may measure the RSRP of one or more reference signals (e.g., SSB and / or CSI-RS) and determine at least one reference signal having an RSRP above an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). For example, if the association between the one or more preambles and the at least one reference signal is configured by the RRC message, the UE may select at least one preamble associated with the one or more reference signals and / or the selected preamble group.

[0182] The UE may determine the preamble based on the one or more RACH parameters provided in the configuration message 1310. For example, the UE may determine the preamble based on a path loss measurement, an RSRP measurement, and / or the size of Msg 3 1313. As another example, the one or more RACH parameters may indicate: a preamble format; a maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). The base station may use the one or more RACH parameters to configure the association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS) for the UE. If the association is configured, the UE may determine the preamble included in Msg 1 1311 based on the association. Msg 1 1311 may be transmitted to the base station via one or more PRACH opportunities. The UE may use one or more reference signals (e.g., SSB and / or CSI-RS) for selecting a preamble and for determining a PRACH opportunity. One or more RACH parameters (eg, ra-ssb-OccasionMskIndex and / or ra-OccasionList) may indicate an association between a PRACH opportunity and the one or more reference signals.

[0183] If no response is received after the preamble transmission, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power for the preamble retransmission. The UE may select the initial preamble transmission power based on the path loss measurement and / or the target received preamble power configured by the network. The UE may determine to retransmit the preamble and may ramp up the uplink transmission power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating the ramp-up step size for the preamble retransmission. The ramp-up step size may be the amount of incremental increase in the uplink transmission power for retransmission. If the UE determines the same reference signal (e.g., SSB and / or CSI-RS) as the previous preamble transmission, the UE may ramp up the uplink transmission power. The UE may count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). For example, if the number of preamble transmissions exceeds a threshold (eg, preambleTransMax) configured by the one or more RACH parameters, the UE may determine that the random access procedure is not successfully completed.

[0184] Msg 2 1312 received by the UE may include a RAR. In some scenarios, Msg 2 1312 may include multiple RARs corresponding to multiple UEs. Msg 2 1312 may be received after or in response to the transmission of Msg 1 1311. Msg 2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a random access RNTI (RA-RNTI). Msg 2 1312 may indicate that Msg 1 1311 is received by the base station. Msg 2 1312 may include a time alignment command that may be used by the UE to adjust the transmission timing of the UE, a scheduling grant for transmitting Msg 3 1313, and / or a temporary cell RNTI (TC-RNTI). After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of Msg 2 1312. The UE may determine when to start the time window based on the PRACH opportunity used by the UE to transmit the preamble. For example, the UE may start a time window of one or more symbols after the last symbol of the preamble (e.g., at the first PDCCH opportunity starting from the end of the preamble transmission). The one or more symbols may be determined based on a parameter set. The PDCCH may be in a common search space (e.g., Type1-PDCCH common search space) configured by an RRC message. The UE may identify the RAR based on a radio network temporary identifier (RNTI). The RNTI may be used depending on one or more events that initiate a random access procedure. The UE may use a random access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH opportunity in which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on: an OFDM symbol index; a time slot index; a frequency domain index; and / or a UL carrier indicator of a PRACH opportunity. Examples of RA-RNTIs may be as follows:

[0185] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0186] Wherein s_id may be the index of the first OFDM symbol of the PRACH opportunity (e.g., 0≤s_id<14), t_id may be the index of the first time slot of the PRACH opportunity in the system frame (e.g., 0≤t_id<80), f_id may be the index of the PRACH opportunity in the frequency domain (e.g., 0≤f_id<8), and ul_carrier_id may be the UL carrier used for preamble transmission (e.g., 0 for a NUL carrier and 1 for a SUL carrier).

[0187] The UE may transmit Msg 3 1313 in response to successfully receiving Msg 2 1312 (e.g., using the resources identified in Msg 2 1312). Msg 3 1313 may be used, for example, Fig.13A Contention resolution in a contention-based random access procedure as shown in . In some scenarios, multiple UEs may transmit the same preamble to a base station, and the base station may provide a RAR corresponding to the UE. If the multiple UEs interpret the RAR as corresponding to themselves, a conflict may occur. Contention resolution (e.g., using Msg 3 1313 and Msg 4 1314) may be used to increase the likelihood that a UE does not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier in Msg 3 1313 (e.g., if a C-RNTI is assigned, the TC-RNTI included in Msg 2 1312 and / or any other suitable identifier).

[0188] Msg 4 1314 may be received after or in response to the transmission of Msg 3 1313. If a C-RNTI is included in Msg 3 1313, the base station will address the UE on the PDCCH using the C-RNTI. If a unique C-RNTI of the UE is detected on the PDCCH, it is determined that the random access procedure is successfully completed. If a TC-RNTI is included in Msg 3 1313 (e.g., if the UE is in an RRC_IDLE state or is not otherwise connected to the base station), Msg 4 1314 will be received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU includes a UE contention resolution identity MAC CE that matches or otherwise corresponds to the CCCH SDU sent (e.g., transmitted) in Msg 3 1313, the UE may determine that contention resolution is successful and / or the UE may determine that the random access procedure is successfully completed.

[0189] The UE may be configured with a supplementary uplink (SUL) carrier and a normal uplink (NUL) carrier. Initial access (e.g., a random access procedure) may be supported in an uplink carrier. For example, a base station may configure two separate RACH configurations for the UE: one for the SUL carrier and the other for the NUL carrier. For random access in a cell configured with a SUL carrier, the network may indicate which carrier (NUL or SUL) to use. For example, if the measured quality of one or more reference signals is below a broadcast threshold, the UE may determine the SUL carrier. The uplink transmissions (e.g., Msg1 1311 and / or Msg 3 1313) of the random access procedure may remain on the selected carrier. In one or more cases, the UE may switch uplink carriers during the random access procedure (e.g., between Msg 1 1311 and Msg 3 1313). For example, the UE may determine and / or switch an uplink carrier for Msg 1 1311 and / or Msg 3 1313 based on channel clarity assessment (eg, listen before talk).

[0190] Fig. 13B The two-step contention-free random access procedure is shown. Fig.13A Similar to the four-step contention-based random access procedure shown, the base station may transmit a configuration message 1320 to the UE before the procedure is initiated. The configuration message 1320 may be similar to the configuration message 1310 in some aspects. Fig. 13B The procedure shown includes the transmission of two messages: Msg 1 1321 and Msg 2 1322. Msg 1 1321 and Msg 2 1322 may be similar in some respects to Fig.13A As shown in Msg 1 1311 and Msg 2 1312. Fig.13A and Fig. 13B It will be appreciated that the contention-free random access procedure may not include messages similar to Msg 3 1313 and / or Msg 4 1314.

[0191] Can be initiated for beam failure recovery, other SI requests, SCell addition and / or handover Fig. 13B For example, the base station may indicate or assign a preamble to be used for Msg 1 1321 to the UE. The UE may receive an indication of the preamble (eg, ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0192] After transmitting the preamble, the UE may start a time window (e.g., ra-ResponseWindow) to monitor the PDCCH for the RAR. In the case of a beam failure recovery request, the base station may configure the UE with a separate time window and / or a separate PDCCH in the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE may monitor PDCCH transmissions addressed to the Cell RNTI (C-RNTI) on the search space. Fig. 13B In the contention-free random access procedure shown, the UE may determine that the random access procedure is successfully completed after or in response to the transmission of Msg 1 1321 and the reception of the corresponding Msg 2 1322. For example, if the PDCCH transmission is addressed to the C-RNTI, the UE may determine that the random access procedure is successfully completed. For example, if the UE receives a RAR including a preamble identifier corresponding to a preamble transmitted by the UE and / or the RAR includes a MAC sub-PDU with a preamble identifier, the UE may determine that the random access procedure is successfully completed. The UE may determine that the response is an indication of a confirmation of the SI request.

[0193] Fig. 13C Another two-step random access procedure is shown. Fig.13A and Fig. 13B Similar to the random access procedure shown, the base station may transmit a configuration message 1330 to the UE before the procedure is initiated. Configuration message 1330 may be similar to configuration message 1310 and / or configuration message 1320 in some aspects. Fig. 13C The procedure shown includes the transmission of two messages: Msg A 1331 and Msg B 1332.

[0194] Msg A 1331 may be transmitted by the UE in an uplink transmission. Msg A 1331 may include one or more transmissions of a preamble 1341 and / or one or more transmissions of a transport block 1342. Transport block 1342 may include Fig.13A The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Msg B 1332 may include the same content as that of Msg 3 1313 as shown in FIG. 1314 . Transmission block 1342 may include UCI (e.g., SR, HARQ ACK / NACK, etc.). The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Fig.13A and Fig. 13B Msg 2 1312 (eg, RAR) and / or Fig.13A The content of Msg4 1314 shown is similar and / or identical.

[0195] The UE can initiate a call for licensed spectrum and / or unlicensed spectrum. Fig. 13C The UE may determine whether to initiate a two-step random access procedure based on one or more factors. The one or more factors may be: the radio access technology being used (e.g., LTE, NR, etc.); whether the UE has a valid TA; the cell size; the RRC state of the UE; the type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0196] The UE may determine the radio resources and / or uplink transmission power of the preamble 1341 and / or the transport block 1342 included in the Msg A 1331 based on the two-step RACH parameters included in the configuration message 1330. The RACH parameters may indicate the modulation and coding scheme (MCS), time-frequency resources, and / or power control of the preamble 1341 and / or the transport block 1342. The time-frequency resources (e.g., PRACH) used for transmission of the preamble 1341 and the time-frequency resources (e.g., PUSCH) used for transmission of the transport block 1342 may be multiplexed using FDM, TDM, and / or CDM. The RACH parameters may enable the UE to determine the reception timing and downlink channel for monitoring and / or receiving the Msg B 1332.

[0197] The transmission block 1342 may include data (e.g., delay-sensitive data), an identifier of the UE, security information, and / or device information (e.g., an International Mobile Subscriber Identity (IMSI)). The base station may transmit Msg B 1332 as a response to Msg A 1331. Msg B 1332 may include at least one of the following: a preamble identifier; a timing high-level command; a power control command; an uplink grant (e.g., a radio resource assignment and / or MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE may determine that the two-step random access procedure is successfully completed if the following conditions exist: the preamble identifier in Msg B 1332 matches the preamble transmitted by the UE; and / or the identifier of the UE in Msg B 1332 matches the identifier of the UE in Msg A 1331 (e.g., transmission block 1342).

[0198] The UE and the base station may exchange control signaling. The control signaling may be referred to as L1 / L2 control signaling and may originate from the PHY layer (e.g., layer 1) and / or the MAC layer (e.g., layer 2). The control signaling may include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0199] Downlink control signaling may include: downlink scheduling assignment; uplink scheduling grant indicating uplink radio resources and / or transport format; time slot format information; preemption indication; power control command; and / or any other suitable signaling. The UE may receive downlink control signaling in a payload transmitted by the base station on a physical downlink control channel (PDCCH). The payload transmitted on the PDCCH may be referred to as downlink control information (DCI). In some scenarios, the PDCCH may be a group common PDCCH (GC-PDCCH) common to a group of UEs.

[0200] The base station may attach one or more cyclic redundancy check (CRC) parity bits to the DCI to facilitate detection of transmission errors. When the DCI is intended for a UE (or a group of UEs), the base station may scramble the CRC parity bits with an identifier of the UE (or an identifier of the group of UEs). Scrambling the CRC parity bits with the identifier may include a Modulo-2 addition (or an exclusive OR operation) of the identifier value and the CRC parity bits. The identifier may include a 16-bit value of a radio network temporary identifier (RNTI).

[0201] DCI can be used for different purposes. The purpose can be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled with a paging RNTI (P-RNTI) can indicate paging information and / or system information change notification. The P-RNTI can be predefined as hexadecimal "FFFE". A DCI with CRC parity bits scrambled with a system information RNTI (SI-RNTI) can indicate a broadcast transmission of system information. The SI-RNTI can be predefined as hexadecimal "FFFF". A DCI with CRC parity bits scrambled with a random access RNTI (RA-RNTI) can indicate a random access response (RAR). A DCI with CRC parity bits scrambled with a cell RNTI (C-RNTI) can indicate a dynamically scheduled unicast transmission and / or the triggering of a PDCCH ordered random access. A DCI with CRC parity bits scrambled with a temporary cell RNTI (TC-RNTI) can indicate contention resolution (e.g., similar to Fig.13AThe other RNTIs configured by the base station to the UE may include: a configured scheduling RNTI (CS-RNTI), a transmission power control PUCCH RNTI (TPC-PUCCH-RNTI), a transmission power control PUSCH RNTI (TPC-PUSCH-RNTI), a transmission power control SRS RNTI (TPC-SRS-RNTI), an interruption RNTI (INT-RNTI), a slot format indication RNTI (SFI-RNTI), a semi-persistent CSI RNTI (SP-CSI-RNTI), a modulation and coding scheme cell RNTI (MCS-C-RNTI), etc.

[0202] Depending on the purpose and / or content of the DCI, the base station may transmit DCI with one or more DCI formats. For example, DCI format 0_0 may be used for scheduling of PUSCH in a cell. DCI format 0_0 may be a fallback DCI format (e.g., with a compact DCI payload). DCI format 0_1 ​​may be used for scheduling of PUSCH in a cell (e.g., with a larger DCI payload than DCI format 0_0). DCI format 1_0 may be used for scheduling of PDSCH in a cell. DCI format 1_0 may be a fallback DCI format (e.g., with a compact DCI payload). DCI format 1_1 may be used for scheduling of PDSCH in a cell (e.g., with a larger DCI payload than DCI format 1_0). DCI format 2_0 may be used to provide a slot format indication to a UE group. DCI format 2_1 may be used to notify a UE group of physical resource blocks and / or OFDM symbols, where the UE may assume that no transmission to the UE is expected. DCI format 2_2 may be used to transmit a transmission power control (TPC) command for PUCCH or PUSCH. DCI formats 2_3 may be used to transmit a set of TPC commands for SRS transmission by one or more UEs. DCI formats for new functions may be defined in future releases. DCI formats may have different DCI sizes, or may share the same DCI size.

[0203] After scrambling the DCI with the RNTI, the base station may process the DCI with channel coding (e.g., polarity coding), rate matching, scrambling, and / or QPSK modulation. The base station may map the coded and modulated DCI on resource elements used for and / or configured for PDCCH. Based on the payload size of the DCI and / or the coverage of the base station, the base station may transmit the DCI via a PDCCH occupying multiple consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as the aggregation level) may be 1, 2, 4, 8, 16, and / or any other suitable number. CCE may include the number of resource element groups (REGs) (e.g., 6). REG may include a resource block in an OFDM symbol. The mapping of the coded and modulated DCI on the resource elements may be based on the mapping of CCEs and REGs (e.g., CCE to REG mapping).

[0204] Fig.14A An example of a CORESET configuration for a bandwidth portion is shown. A base station may transmit DCI via a PDCCH on one or more control resource sets (CORESETs). A CORESET may include time-frequency resources in which a UE attempts to decode DCI using one or more search spaces. A base station may configure a CORESET in the time-frequency domain. Fig.14A In the example of FIG. 1401 , the first CORESET 1401 and the second CORESET 1402 appear at the first symbol in the time slot. The first CORESET 1401 overlaps the second CORESET 1402 in the frequency domain. The third CORESET 1403 appears at the third symbol in the time slot. The fourth CORESET 1404 appears at the seventh symbol in the time slot. The CORESETs may have different numbers of resource blocks in the frequency domain.

[0205] Fig. 14B An example of CCE to REG mapping for DCI transmission on CORESET and PDCCH processing is shown. The CCE to REG mapping can be an interlaced mapping (e.g., for the purpose of providing frequency diversity) or a non-interlaced mapping (e.g., for the purpose of facilitating interference coordination and / or frequency selective transmission of control channels). The base station can perform different or the same CCE to REG mapping for different CORESETs. A CORESET can be associated with the CCE to REG mapping through RRC configuration. A CORESET can be configured with antenna port quasi-co-location (QCL) parameters. The antenna port QCL parameters can indicate the QCL information of the demodulation reference signal (DMRS) for PDCCH reception in the CORESET.

[0206] The base station may transmit an RRC message including configuration parameters of one or more CORESETs and one or more search space sets to the UE. The configuration parameters may indicate an association between a search space set and a CORESET. The search space set may include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters may indicate: the number of PDCCH candidates to be monitored for each aggregation level; the PDCCH monitoring period and the PDCCH monitoring type; one or more DCI formats to be monitored by the UE; and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set may be predefined and known to the UE. The set of CCEs in the UE-specific search space set may be configured based on the identity of the UE (e.g., C-RNTI).

[0207] like Fig. 14B As shown, the UE may determine the time-frequency resources of the CORESET based on the RRC message. The UE may determine the CCE to REG mapping of the CORESET based on the configuration parameters of the CORESET (e.g., interlaced or non-interlaced and / or mapping parameters). The UE may determine the number of search space sets configured on the CORESET based on the RRC message (e.g., up to 10). The UE may monitor a set of PDCCH candidates according to the configuration parameters of the search space set. The UE may monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may include decoding one or more PDCCH candidates in the set of PDCCH candidates according to the monitored DCI format. Monitoring may include decoding the DCI content of one or more PDCCH candidates, which have possible (or configured) PDCCH positions, possible (or configured) PDCCH formats (e.g., the number of CCEs, the number of PDCCH candidates in the common search space, and / or the number of PDCCH candidates in the UE-specific search space) and possible (or configured) DCI formats. Decoding may be referred to as blind decoding. The UE may determine that the DCI is valid for the UE in response to a CRC check (e.g., scrambled bits of the CRC parity bits of the DCI matching the RNTI value). The UE may process the information contained in the DCI (e.g., scheduling assignments, uplink grants, power control, timeslot format indications, downlink preemption, etc.).

[0208] The UE may transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. The uplink control signaling transmission may include a hybrid automatic repeat request (HARQ) confirmation for the received DL-SCH transport block. The UE may transmit the HARQ confirmation after receiving the DL-SCH transport block. The uplink control signaling may include channel state information (CSI) indicating the channel quality of the physical downlink channel. The UE may transmit the CSI to the base station. Based on the received CSI, the base station may determine the transmission format parameters (e.g., including multiple antennas and beamforming schemes) for downlink transmission. The uplink control signaling may include a scheduling request (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit UCI (e.g., HARQ confirmation (HARQ-ACK), CSI report, SR, etc.) via a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH). The UE may transmit uplink control signaling via PUCCH using one of several PUCCH formats.

[0209] There may be five PUCCH formats, and the UE may determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols for UCI transmission and the number of UCI bits). PUCCH format 0 may have a length of one or two OFDM symbols and may include two or fewer bits. If the transmission exceeds one or two symbols and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two, the wireless device may use PUCCH format 0 to transmit the UCI in the PUCCH resource. PUCCH format 1 may occupy between four and fourteen OFDM symbols and may include two or fewer bits. If four or more symbols are transmitted and the number of HARQ-ACK / SR bits is one or two, the UE may use PUCCH format 1. PUCCH format 2 may occupy one or two OFDM symbols and may include more than two bits. If the transmission exceeds one or two symbols and the number of UCI bits is two or more, the UE may use PUCCH format 2. PUCCH format 3 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources do not include orthogonal cover codes, the UE may use PUCCH format 3. PUCCH format 4 may occupy between four and fourteen OFDM symbols and may include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resources include orthogonal cover codes, the UE may use PUCCH format 4.

[0210] The base station may transmit configuration parameters of multiple PUCCH resource sets to the UE using, for example, an RRC message. The multiple PUCCH resource sets (e.g., up to four sets) may be configured on the uplink BWP of the cell. The PUCCH resource set may be configured with: a PUCCH resource set index; multiple PUCCH resources having PUCCH resources identified by a PUCCH resource identifier (e.g., pucch-Resourceid); and / or multiple (e.g., maximum number) UCI ​​information bits that the UE may transmit using one of the multiple PUCCH resources in the PUCCH resource set. When multiple PUCCH resource sets are configured, the UE may select one of the multiple PUCCH resource sets (e.g., HARQ-ACK, SR, and / or CSI) based on the total bit length of the UCI information bits. If the total bit length of the UCI information bits is two or less, the UE may select the first PUCCH resource set with a PUCCH resource set index equal to "0". If the total bit length of the UCI information bits is greater than two and less than or equal to the first configured value, the UE may select a second PUCCH resource set having a PUCCH resource set index equal to "1". If the total bit length of the UCI information bits is greater than the first configured value and less than or equal to the second configured value, the UE may select a third PUCCH resource set having a PUCCH resource set index equal to "2". If the total bit length of the UCI information bits is greater than the second configured value and less than or equal to a third value (e.g., 1406), the UE may select a fourth PUCCH resource set having a PUCCH resource set index equal to "3".

[0211] After determining a PUCCH resource set from a plurality of PUCCH resource sets, the UE may determine PUCCH resources for UCI (HARQ-ACK, CSI, and / or SR) transmission from the PUCCH resource set. The UE may determine the PUCCH resources based on a PUCCH resource indicator in a DCI (e.g., a DCI format 1_0 or a DCI for 1_1) received on the PDCCH. The three-bit PUCCH resource indicator in the DCI may indicate one PUCCH resource in eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE may use the PUCCH resources indicated by the PUCCH resource indicator in the DCI to transmit UCI (HARQ-ACK, CSI, and / or SR).

[0212] Fig.15 An example of a wireless device 1502 communicating with a base station 1504 according to an embodiment of the present disclosure is shown. The wireless device 1502 and the base station 1504 may be part of a mobile communication network, such as Figure 1A The mobile communication network 100 shown, Figure 1B The mobile communication network 150 shown or any other communication network. Fig.15 Only one wireless device 1502 and one base station 1504 are shown in FIG. 1 , but it should be understood that the mobile communication network may include more than one UE and / or more than one base station, which have the same Fig.15 Configurations the same or similar to those shown.

[0213] The base station 1504 may connect the wireless device 1502 to a core network (not shown) by radio communication via an air interface (or radio interface) 1506. The direction of communication from the base station 1504 to the wireless device 1502 over the air interface 1506 is referred to as downlink, while the direction of communication from the wireless device 1502 to the base station 1504 over the air interface is referred to as uplink. Downlink transmissions may be separated from uplink transmissions using FDD, TDD, and / or some combination of the two duplexing techniques.

[0214] In the downlink, data to be sent from base station 1504 to wireless device 1502 may be provided to processing system 1508 of base station 1504. The data may be provided to processing system 1508 via, for example, a core network. In the uplink, data to be sent from wireless device 1502 to base station 1504 may be provided to processing system 1518 of wireless device 1502. Processing system 1508 and processing system 1518 may implement layer 3 and layer 2 OSI functions to process data for transmission. Layer 2 may include, for example, information about Figure 2A , Figure 2B , Figure 3 and Figure 4A The 3 layers may include the following: Figure 2B RRC layer.

[0215] After processing by processing system 1508, data to be transmitted to wireless device 1502 may be provided to transmission processing system 1510 of base station 1504. Similarly, after processing by processing system 1518, data to be transmitted to base station 1504 may be provided to transmission processing system 1520 of wireless device 1502. Transmission processing system 1510 and transmission processing system 1520 may implement layer 1 OSI functions. Layer 1 may include information about Figure 2A , Figure 2B , Figure 3 and Figure 4A For transmission processing, the PHY layer may perform, for example, forward error correction coding of transport channels, interleaving, rate matching, mapping of transport channels to physical channels, modulation of physical channels, multiple-input multiple-output (MIMO) or multi-antenna processing, etc.

[0216] At base station 1504, receive processing system 1512 may receive uplink transmissions from wireless device 1502. At wireless device 1502, receive processing system 1522 may receive downlink transmissions from base station 1504. Receive processing system 1512 and receive processing system 1522 may implement layer 1 OSI functions. Layer 1 may include information about Figure 2A , Figure 2B , Figure 3 and Figure 4A For reception processing, the PHY layer may perform, for example, error detection, forward error correction decoding, deinterleaving, demapping of transport channels to physical channels, demodulation of physical channels, MIMO or multi-antenna processing, etc.

[0217] like Fig.15 As shown, wireless device 1502 and base station 1504 may include multiple antennas. The multiple antennas may be used to perform one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, wireless device 1502 and / or base station 1504 may have a single antenna.

[0218] Processing system 1508 and processing system 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer-readable media) may store computer program instructions or codes that may be executed by processing system 1508 and / or processing system 1518 to perform one or more of the functions discussed herein. Fig.15 Not shown, transmit processing system 1510, transmit processing system 1520, receive processing system 1512, and / or receive processing system 1522 may be coupled to a memory (e.g., one or more non-transitory computer-readable media) storing computer program instructions or code that may be executed to perform one or more of their respective functions.

[0219] The processing system 1508 and / or the processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may include, for example, a general purpose processor, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) and / or other programmable logic device, discrete gate and / or transistor logic, discrete hardware components, on-board units, or any combination thereof. The processing system 1508 and / or the processing system 1518 may perform at least one of the following: signal encoding / processing, data processing, power control, input / output processing, and / or any other functions that may enable the wireless device 1502 and the base station 1504 to operate in a wireless environment.

[0220] The processing system 1508 and / or the processing system 1518 may be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and the one or more peripheral devices 1526 may include software and / or hardware that provides features and / or functions, such as a speaker, a microphone, a keyboard, a display, a touch pad, a power supply, a satellite transceiver, a universal serial bus (USB) port, a hands-free headset, a frequency modulation (FM) radio unit, a media player, an Internet browser, an electronic control unit (e.g., for a motor vehicle) and / or one or more sensors (e.g., an accelerometer, a gyroscope, a temperature sensor, a radar sensor, a lidar sensor, an ultrasonic sensor, a light sensor, a camera, etc.). The processing system 1508 and / or the processing system 1518 may receive user input data from the one or more peripheral devices 1516 and / or the one or more peripheral devices 1526 and / or provide user output data to the one or more peripheral devices. The processing system 1518 in the wireless device 1502 can receive power from the power source and / or can be configured to distribute power to other components in the wireless device 1502. The power source can include one or more power sources, such as batteries, solar cells, fuel cells, or any combination thereof. The processing system 1508 and / or the processing system 1518 can be connected to the GPS chipset 1517 and the GPS chipset 1527, respectively. The GPS chipset 1517 and the GPS chipset 1527 can be configured to provide geographic location information of the wireless device 1502 and the base station 1504, respectively.

[0221] Fig.16AAn exemplary structure for uplink transmission is shown. The baseband signal representing the physical uplink shared channel can perform one or more functions. The one or more functions may include at least one of the following: scrambling; modulating scrambled bits to generate complex-valued symbols; mapping complex-valued modulated symbols to one or several transmission layers; transform precoding to generate complex-valued symbols; precoding of complex-valued symbols; mapping of precoded complex-valued symbols to resource elements; generating a complex-valued time-domain single carrier frequency division multiple access (SC-FDMA) or CP-OFDM signal for an antenna port; and the like. In the example, when transform precoding is enabled, an SC-FDMA signal for uplink transmission can be generated. In the example, when transform precoding is not enabled, the uplink transmission can be performed by Fig.16A Generate a CP-OFDM signal for uplink transmission. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0222] Fig. 16B An exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal may be a complex-valued SC-FDMA or CP-OFDM baseband signal and / or a complex-valued physical random access channel (PRACH) baseband signal for an antenna port. Filtering may be employed prior to transmission.

[0223] Fig. 16C An exemplary structure for downlink transmission is shown. A baseband signal representing a physical downlink channel may perform one or more functions. The one or more functions may include: scrambling coded bits in a codeword to be transmitted on a physical channel; modulating the scrambled bits to generate complex-valued modulation symbols; mapping the complex-valued modulation symbols onto one or several transmission layers; precoding of complex-valued modulation symbols on layers for transmission on antenna ports; mapping complex-valued modulation symbols for antenna ports to resource elements; generating complex-valued time-domain OFDM signals for antenna ports; and the like. These functions are shown as examples, and it is contemplated that other mechanisms may be implemented in various embodiments.

[0224] Fig.16D Another exemplary structure for modulation and up-conversion of a baseband signal to a carrier frequency is shown. The baseband signal may be a complex valued OFDM baseband signal at an antenna port. Filtering may be employed prior to transmission.

[0225] The wireless device may receive one or more messages (e.g., RRC messages) including configuration parameters of multiple cells (e.g., primary cells, secondary cells) from a base station. The wireless device may communicate with at least one base station (e.g., two or more base stations in dual connectivity) via the multiple cells. The one or more messages (e.g., as part of the configuration parameters) may include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, and RRC layer. For example, the configuration parameters may include parameters for configuring physical layer and MAC layer channels, bearers, and the like. For example, the configuration parameters may include parameters indicating the values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0226] Once started, a timer can start running and continue running until it stops or until it expires. If the timer is not running, it can be started, or if it is running, it can be restarted. A timer can be associated with a value (e.g., a timer can start or restart from a certain value, or can start from zero and expire once it reaches the value). The duration of a timer may not be updated until the timer stops or expires (e.g., due to BWP switching). A timer can be used for a time period / window of a measurement process. When the specification refers to implementations and procedures related to one or more timers, it should be understood that there are multiple ways to implement the one or more timers. For example, it should be understood that one or more of the multiple ways of implementing the timer can be used for a time period / window of a measurement procedure. For example, a random access response window timer can be used to measure a time window for receiving a random access response. In an example, instead of the start and expiration of the random access response window timer, the time difference between two timestamps can be used. When the timer is restarted, the measurement process of the time window can be restarted. Other exemplary embodiments can be provided to restart the measurement of the time window.

[0227] Fig.17 An example of device-to-device (D2D) communication is shown, where there is direct communication between wireless devices. In the example, D2D communication can be performed via a side link (SL). The wireless devices can exchange side link communications via a side link interface (e.g., a PC5 interface). The side link is different from an uplink (where the wireless device communicates to a base station) and a downlink (where the base station communicates to the wireless device). The wireless device and the base station can exchange uplink and / or downlink communications via a user plane interface (e.g., a Uu interface).

[0228] As shown in the figure, wireless device #1 and wireless device #2 can be in the coverage area of ​​base station #1. For example, both wireless device #1 and wireless device #2 can communicate with base station #1 via the Uu interface. Wireless device #3 can be in the coverage area of ​​base station #2. Base station #1 and base station #2 can share a network and can jointly provide a network coverage area. Wireless device #4 and wireless device #5 can be outside the network coverage area.

[0229] In-coverage D2D communication can be performed when two wireless devices share a network coverage area. Both wireless device #1 and wireless device #2 are in the coverage area of ​​base station #1. Therefore, they can perform in-coverage intra-cell D2D communication marked as side link A. Wireless device #2 and wireless device #3 are in the coverage areas of different base stations, but share the same network coverage area. Therefore, they can perform in-coverage inter-cell D2D communication marked as side link B. Partial coverage D2D communication can be performed when one wireless device is in the network coverage area and the other wireless device is outside the network coverage area. Wireless device #3 and wireless device #4 can perform partial coverage D2D communication marked as side link C. When both wireless devices are outside the network coverage area, out-of-coverage D2D communication can be performed. Wireless device #4 and wireless device #5 can perform out-of-coverage D2D communication marked as side link D.

[0230] Sidelink communications may be configured using physical channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink feedback channel (PSFCH), a physical sidelink discovery channel (PSDCH), a physical sidelink control channel (PSCCH), and / or a physical sidelink shared channel (PSSCH). The first wireless device may use the PSBCH to send broadcast information to the second wireless device. The PSBCH may be similar to the PBCH in some aspects. The broadcast information may include, for example, a slot format indication, resource pool information, a sidelink system frame number, or any other suitable broadcast information. The first wireless device may use the PSFCH to send feedback information to the second wireless device. The feedback information may include, for example, HARQ feedback information. The first wireless device may use the PSDCH to send discovery information to the second wireless device. The wireless device may use the discovery information to signal its presence and / or service availability to other wireless devices in the area. The first wireless device may use the PSCCH to send sidelink control information (SCI) to the second wireless device. The PSCCH may be similar to the PDCCH and / or PUCCH in some aspects. The control information may include, for example, time / frequency resource allocation information (RB size, number of retransmissions, etc.), demodulation related information (DMRS, MCS, RV, etc.), identification information for transmitting wireless devices and / or receiving wireless devices, process identifiers (HARQ, etc.), or any other suitable control information. PSCCH can be used to allocate, prioritize and / or reserve side link resources for side link transmission. The first wireless device can use PSSCH to send and / or relay data and / or network information to the second wireless device. PSSCH may be similar to PDSCH and / or PUSCH in some aspects. Each side link channel may be associated with one or more demodulation reference signals. Side link operation may use a side link synchronization signal to establish the timing of the side link operation. A wireless device configured for side link operation may, for example, use PSBCH to send a side link synchronization signal. The side link synchronization signal may include a primary side link synchronization signal (PSSS) and a secondary side link synchronization signal (SSSS).

[0231] The sidelink resources may be configured to the wireless device in any suitable manner. The wireless device may be pre-configured for the sidelink, e.g., pre-configured with sidelink resource information. Additionally or alternatively, the network may broadcast system information related to a resource pool for the sidelink. Additionally or alternatively, the network may configure a particular wireless device to have a dedicated sidelink configuration. The configuration may identify the sidelink resources to be used for sidelink operation (e.g., configure a sidelink band combination).

[0232] The wireless device may operate in different modes, for example, an assisted mode (which may be referred to as mode 1) or an autonomous mode (which may be referred to as mode 2). The mode selection may be based on the coverage status of the wireless device, the radio resource control status of the wireless device, information and / or instructions from the network, and / or any other suitable factors. For example, if the wireless device is in an idle or inactive state, or if the wireless device is out of network coverage, the wireless device may choose to operate in the autonomous mode. For example, if the wireless device is in a connected mode (e.g., connected to a base station), the wireless device may choose to operate in the assisted mode (or operate at the direction of the base station). For example, the network (e.g., a base station) may instruct a connected wireless device to operate in a particular mode.

[0233] In assisted mode, the wireless device may request scheduling from the network. For example, the wireless device may send a scheduling request to the network, and the network may allocate sidelink resources to the wireless device. Assisted mode may be referred to as network assisted mode, gNB assisted mode, or base station assisted mode. In autonomous mode, the wireless device may select sidelink resources based on measurements within one or more resource pools (e.g., pre-configured or network-assigned resource pools), sidelink resource selections made by other wireless devices, and / or sidelink resource usage by other wireless devices.

[0234] To select a sidelink resource, the wireless device may observe a sensing window and a selection window. During the sensing window, the wireless device may use a sidelink resource pool to observe SCIs transmitted by other wireless devices. The SCI may identify resources that may be used and / or reserved for sidelink transmissions. Based on the resources identified in the SCI, the wireless device may select resources within the selection window (e.g., resources different from the resources identified in the SCI). The wireless device may transmit using the selected sidelink resource.

[0235] Fig.18 An example of a resource pool for sidelink operation is shown. A wireless device may operate using one or more sidelink cells. A sidelink cell may include one or more resource pools. Each resource pool may be configured to operate according to a specific mode (e.g., assisted or autonomous). The resource pool may be divided into resource units. In the frequency domain, each resource unit may include, for example, one or more resource blocks that may be referred to as subchannels. In the time domain, each resource unit may include, for example, one or more time slots, one or more subframes, and / or one or more OFDM symbols. The resource pool may be continuous or non-continuous (e.g., including continuous resource units or non-continuous resource units) in the frequency domain and / or time domain. The resource pool may be divided into repeated resource pool portions. The resource pool may be shared between one or more wireless devices. For example, each wireless device may attempt to use different resource units for transmission to avoid conflicts.

[0236] The sidelink resource pools may be arranged in any suitable manner. In the figure, the exemplary resource pools are non-contiguous in the time domain and limited to a single sidelink BWP. In the exemplary resource pools, the frequency resources are divided into Nf resource units per time unit, numbered from zero to Nf-1. The exemplary resource pool may include multiple parts (non-contiguous in this example) that repeat every k time units. In the figure, the time resources are numbered n, n+1...n+k, n+k+1...etc.

[0237] The wireless device may select one or more resource units from the resource pool for transmission. In an exemplary resource pool, the wireless device selects resource unit (n, 0) for sidelink transmission. The wireless device may also select periodic resource units in a later portion of the resource pool, such as resource unit (n+k, 0), resource unit (n+2k, 0), resource unit (n+3k, 0), etc. The selection may be based on, for example, a determination that a transmission using resource unit (n, 0) will not (or is unlikely to) conflict with a sidelink transmission of a wireless device sharing the sidelink resource pool. The determination may be based on, for example, the behavior of other wireless devices sharing the resource pool. For example, if no sidelink transmission is detected in resource unit (nk, 0), the wireless device may select resource unit (n, 0), resource (n+k, 0), etc. For example, if a sidelink transmission from another wireless device is detected in resource unit (nk, 1), the wireless device may avoid selecting resource unit (n, 1), resource (n+k, 1), etc.

[0238] Different sidelink physical channels may use different resource pools. For example, PSCCH may use a first resource pool, and PSSCH may use a second resource pool. Different resource priorities may be associated with different resource pools. For example, data associated with a first QoS, service, priority, and / or other characteristic may use a first resource pool, and data associated with a second QoS, service, priority, and / or other characteristic may use a second resource pool. For example, the network (e.g., a base station) may configure a priority level for each resource pool, supported services for each resource pool, and the like. For example, the network (e.g., a base station) may configure a first resource pool for use by unicast UEs, a second resource pool for use by multicast UEs, and the like. For example, the network (e.g., a base station) may configure a first resource pool for transmitting sidelink data, a second resource pool for transmitting discovery messages, and the like.

[0239] In the prior art, a wireless device may be configured with a first retention period in milliseconds indicated from a higher layer or another wireless device. The first retention period may need to be converted into a logical unit in which a side link operation can be performed. In a cellular network, some radio resources may be allocated for cellular Uu operations. For example, in a TDD configuration, several time resources may be allocated for downlink operations. The wireless device may determine a second retention period based on the number of uplink unit resources (e.g., subframes or time slots) in the TDD configuration and the first retention period. For example, if the TDD configuration includes 6 uplink subframes in every 10 subframes, the wireless device may obtain a second retention period of 60 subframes based on the first retention period of 100ms and the number of uplink unit resources in the TDD configuration.

[0240] The prior art may not be accurate when not all of some uplink resources are configured for sidelink resources. For example, if 50% of the UL resources are configured for SL resources in the same TDD configuration, the first reservation of 100ms can be converted into a second reservation period of 120 subframes. The second reservation period of 120 subframes can span 200ms, which is a double delay.

[0241] When the TDD configuration periodicity is not fixed, the prior art may determine an inaccurate second retention period. The prior art may determine the second retention period based on the number of uplink unit resources (e.g., time slots) in the TDD configuration. For example, the first TDD configuration has a periodicity of 10ms, and in the first TDD configuration, the number of uplink time slots is 5. The second TDD configuration has a periodicity of 0.5ms, and the number of uplink time slots in the second TDD configuration is 1. The second TDD configuration may have 20 uplink time slots with a periodicity of 10ms, but the prior art may determine the second retention period based on the number of uplink time slots in the second TDD configuration.

[0242] The exemplary embodiments of the present disclosure define a method for determining a second retention period in units of basic time resources (e.g., time slots) based on resource pool configuration and / or TDD (or time slot format) configuration. In an exemplary embodiment, the wireless device can determine the second retention period in units of time slots based on the number of side link time slots in the first retention period and the fixed period. The number of side link time slots can be determined using the resource pool configuration. The number of side link time slots can be determined using the time slot format configuration. For example, the resource pool configuration can indicate a resource pool bitmap. Some of the bitmaps can indicate the location of the side link time slots. The wireless device can count the number of side link time slots in a fixed time period. When some uplink resources are not configured for side link resources, the exemplary embodiment can lead to accurate determination of the second retention period in units of time slots.

[0243] In an exemplary embodiment, the wireless device can determine a second reservation period in units of time slots based on the number of side link time slots within the first reservation period and the fixed period. The number of side link time slots can be determined using a time slot format configuration. For example, the time slot format configuration can indicate the number of side link time slots. For example, in the time slot format configuration, side link resources can be allocated in uplink time slots. When some uplink resources are not configured for side link resources, the exemplary embodiment can result in accurate determination of the second reservation period in units of time slots.

[0244] In an exemplary embodiment, the wireless device may determine the number of side link time slots within a fixed time period. The fixed number of side link time slot periods may be based on the TDD configuration. For example, assuming there are two different TDD configuration periodicities, if the wireless device determines the second retention period based on the number of side link time slots in the fixed period that is typically used for the two different TDD configuration periodicities, the wireless device may even determine the exact second retention period for the different TDD configurations. Regardless of the TDD configuration, the fixed duration may be 20 milliseconds.

[0245] Based on the exemplary embodiments of the present disclosure, the wireless device may determine the second retention period of the resource pool configuration, the slot format configuration, and the parameter set without additional delay.

[0246] In existing systems, the sidelink resource pool is configured only in a portion of the uplink resources. In an example, in an FDD cell, the sidelink resource pool can be configured in the uplink frequency band, and in a TDD cell, the sidelink resources can be configured in the uplink subframe. The sidelink resource pool can be configured for one or more UL resources from the available UL resources, where the one or more UL resources can be a subset of the available UL resources. For example, a portion of the available UL resources can be configured for the sidelink resource pool, and the remaining portion of the available UL resources can be used for Uu operations (e.g., communication between a base station and a wireless device, uplink control information transmission, or UL shared channel transmission).

[0247] In the existing sidelink operation, by multiplying the scaling factor by the first retention period, a first retention period indicated in milliseconds (ms) from a higher layer or by another wireless device via a sidelink control channel can be converted into a second retention period in subframes (or units of basic time resources, such as time slots or subframes). The scaling factor can be a one-to-one association with a TDD configuration. Fig.19A shows a TDD configuration, and Fig.19BA table for determining Pstep is shown. Pstep is divided by 100 to derive a scaling factor, and the scaling factor is multiplied by the first retention period indicated in ms to the second retention period in subframes. The method can convert an absolute time period into a logical unit for performing actual sidelink operations. The transmitter wireless device can indicate the resource retention period via a sidelink control channel or sidelink control information. The resource retention period can be indicated in ms, and the receiver wireless device receiving the sidelink control channel or the sidelink control information can convert the first retention period into the second retention period in subframes.

[0248] In the existing sidelink operation, in a TDD cell, since there may be no sidelink resources in each time resource (e.g., subframe), excessive delay may occur in a resource reservation operation in which some future resources are reserved for transmitting another transport block. In order to alleviate the excessive delay, a scaling value of the reservation period is introduced according to the TDD configuration. For example, Fig. 20A and Fig. 20B As shown, different scaling values ​​can be used depending on the TDD configuration. In the example, in TDD configuration 0, there are six time resources (e.g., subframes) in a radio frame (e.g., 10ms). This means that the resources after 100ms in milliseconds represent resources that appear after 60 subframes. Therefore, even if the future resources are indicated as 100ms, this means that the actual transmission occurs after 60 UL subframes. However, this solution does not solve the problem of excessive delay when not all UL subframes are configured for sidelink subframes. For example, if Fig.21 As shown in FIG. 1 , assuming that only 50% of the UL subframes are configured as SL resources in TDD configuration 0, the existing method of using different scaling values ​​according to the TDD configuration will result in double delay. In this figure, the wireless device may indicate a 50ms retention period, but the actual delay may be 100ms because only 50% of the resources are configured for sidelink resources.

[0249] Furthermore, the method of converting the reservation period into logical units may not be applicable when the subcarrier spacing changes. For example, at 30kHz subcarrier spacing, one logical unit (subframe or time slot) is reduced to 0.5ms instead of 1ms. If the value of the reservation period is actually directly converted to the number of logical units, the reservation occurs when the wireless device does not expect it, or this may cause the reservation to be performed too quickly. Fig.22A and Fig. 22B shows different behaviors for different subcarrier spacings. For 15kHz, 10 slots are reserved equal to Fig.22A The 10ms reservation shown is, however, for 30kHz, the 10 slot reservation is reduced to Fig. 22BTherefore, when the SCS changes, the existing methods may not have accurate resource reservation behavior.

[0250] In addition, when the TDD configuration or resource pool is dynamically changed in the existing side link operation, the method of determining the reservation period based only on the TDD configuration may lead to inaccurate resource reservation operation. For example, in a TDD cell, when the base station dynamically changes the TDD configuration, the prior art may lead to inaccurate resource reservation operation.

[0251] In the prior art of sidelink operation, a wireless device may utilize a resource reservation function, wherein the wireless device may reserve one or more periodic resources based on a reservation period. Resource reservation may be beneficial for sidelink applications such as cooperative sensing messages. For resource reservation, the wireless device may receive a reservation period from its application layer or a higher layer, wherein the reservation period may be indicated in time units (e.g., milliseconds, seconds). Based on the reservation period in time units, the wireless device may need to derive a resource reservation period, wherein the resource reservation period may be based on a time domain unit of a physical resource (e.g., a subframe and / or a time slot and / or a frame and / or X time slots and / or X OFDM symbols). In the prior art, a time unit (e.g., 1 ms) is mapped to a time domain unit (e.g., a subframe) of a physical resource. Since sidelink resources may be configured to one or more uplink subframes, the prior art may derive a resource reservation period based on a TDD configuration and mapping. For example, a TDD configuration includes 6 uplink subframes in every 10 subframes, using a scaling factor of 60 in 100 ms. A retention period of 100 ms can be exported to 60 resource retention periods.

[0252] Existing mechanisms may be deficient in certain circumstances. For example, when a resource pool includes side link resources with a large gap (e.g., >2 ms) between two consecutive side link resources, existing operations may result in excessive delays. For example, existing operations may not work effectively in the case of one or more subcarrier spacings, where a time slot (e.g., a basic time unit of a physical resource) may not correspond to a time unit (e.g., 1 ms). For example, existing operations may not address situations where uplink resources are dynamically adapted (e.g., via a time slot format) or where a resource pool configuration is changed. In view of various parameter sets and dynamic resource adaptation mechanisms, there is a need to enhance the prior art.

[0253] An embodiment of the present disclosure defines a method for converting a first retention period in ms into a second retention period in basic time units (e.g., time slots or subframes) based on subcarrier spacing and / or resource pool configuration and / or TDD (or time slot formation) configuration and / or base station indication parameters.

[0254] Even when TDD configuration or time slot format or resource pool or parameter set changes, the embodiments of the present disclosure will not cause excessive delay by adaptively adjusting the reservation period. In addition, even if the resource pool or TDD configuration or time slot format configuration is changed, accurate resource reservation can be performed.

[0255] In some aspects of the implementation scheme, the slot format configuration or TDD configuration or TDD UL-DL or DL-UL configuration may refer to configuration signaling for configuring downlink, uplink and / or flexible time slots within a specific time interval. The slot format or TDD configuration or TDD UL-DL configuration may be one or more control signalings that configure which time slot and / or symbol is used for downlink, uplink, and is flexible within a specific time interval. The base station may configure the slot format configuration or TDD configuration to the wireless device via a physical layer (e.g., DCI) or a higher layer signal (e.g., SIB or RRC). For external coverage, the slot format or TDD configuration may be pre-configured or stored in a memory of the wireless device.

[0256] In an exemplary embodiment, the wireless device may receive a side link subcarrier spacing (SCS) and / or a side link resource pool configuration and / or a time slot format configuration from a base station as a physical layer (e.g., DCI) or a higher layer signal (e.g., MAC CE or SIB or RRC). For external coverage, the side link SCS, the side link resource pool configuration and / or the time slot format configuration may be pre-configured for the wireless device, or configured from another wireless device via a physical side link broadcast channel (PSBCH), which may transmit some system information for side link operation. The wireless device may be indicated by a first retention period in milliseconds. The wireless device may determine a second retention period based on the side link SCS, the side link resource pool configuration and / or the side link time slot format configuration. For example, the wireless device may convert a first retention period indicated in ms to a second retention period in time slots based on the side link SCS, the side link resource pool configuration and / or the side link time slot format configuration. After the conversion, the first wireless device may select one or more transmission resources based on the second retention period. The wireless device may transmit a transport block via the selected one or more resources. Fig.23 A flow chart of this embodiment is shown.

[0257] In an example, when the wireless device performs resource reservation, the wireless device may configure a first reservation period in ms from a higher layer. The wireless device may then determine a second reservation period in time slots based on the first reservation period, the sidelink SCS, and the resource pool configuration. Specifically, the wireless device may receive a configuration of a sidelink SCS as a sidelink bandwidth part (BWP) of a physical layer (e.g., DCI) or a higher layer signal (e.g., RRC or SIB) from a base station, or the sidelink SCS may be configured by another wireless device or a preconfigured parameter stored in a USIM or a memory of the wireless device. The sidelink SCS may be partially configured as a sidelink BWP configuration. Depending on the sidelink SCS, the time interval of a time slot may change. For example, the time interval length of a time slot is 1ms in a 15kHz SCS, 0.5ms in a 30kHz SCS, 0.25ms in a 60kHz, and 0.125ms in a 120kHz. Each SCS may be expressed as 15kHz*2 u , where u may be an integer corresponding to the sidelink SCS determination. The wireless device may determine a portion of an active sidelink timeslot for a period of the configured resource pool, where the period may be predetermined or configured by the base station, or may be fixed. The portion of an active sidelink timeslot may be defined by the number of sidelink timeslots (denoted by N) divided by the total number of timeslots (e.g., 20*2 u , where u is determined by SCS).

[0258] For example, the period that determines the portion of the valid side link timeslot may be the same as the timeslot configuration period configured by the base station, such as "dl-UL-TransmissionPeriodicity", or may be fixed to a number, such as 20ms. The wireless device may use the number of side link timeslots configured in the resource pool configuration to determine that the portion of the valid side link timeslot lasts for a fixed duration of 20ms. The fixed duration may be independent of the TDD configuration periodicity or dl-UL-TransmissionPeriodicity. The total number of timeslots of 20ms may be used to determine the second retention period. The portion of the valid side link timeslot is the number of valid side link timeslots divided by the total number of timeslots. The first retention period in ms is multiplied by 2 u , the second retention period can be converted into the number of side link time slots. If the portion of the side link time slots within a certain time interval is not 100%, the first reservation used to derive the second retention period can be scaled by the portion R, where R represents the portion of valid side link time slots within a predetermined or configurable time interval. As a result, the second retention period can be determined as 2 u The product of R and the first retention period is expressed as the formula P second-reservation-period =P first-reservation-period *2u *R, its P first-reservation-period is the first retention period, and P second-reservation-period It refers to the second retention period. Since R = N / (20*2 u ), so the formula can be rewritten as P second-reservation-period =P first-reservation-period *2 u *R=P first-reservation-period *N / 20.

[0259] In some examples of the implementation scheme, the first reservation period indicated in ms can be adaptively converted into the number of logical time slots according to the configuration of the side link SCS or resource pool without unnecessary delay or inaccurate resource reservation. In addition, even between the transmitting and receiving wireless devices, the reservation period in ms units indicated by the upper layer can be signaled to each other, and the conversion operation can be effectively performed in the time slot domain, so that the information bits in the control channel can be consistently designed regardless of the resource pool configuration and / or the side link SCS configuration.

[0260] In an exemplary embodiment, the wireless device may receive a slot format configuration and / or a sidelink SCS from a base station, or may pre-configure the slot format configuration and / or the sidelink SCS configuration. The sidelink SCS may be partially configured as a sidelink bandwidth portion configuration. The wireless device may convert a first retention period indicated in ms to a second retention period in slots based on the slot format configuration and the SCS. The first retention period may be configured from a higher layer, or indicated by another wireless device via a control signal (e.g., PSCCH) or control information (e.g., SCI). The sidelink resource pool can only be configured in a limited manner in the UL resources of the slot format configuration. By using this, the second retention period may be determined using a portion of the UL resources of the slot format. For example, if the portion of the resources of the UL in the slot format configuration is 50%, the second retention period may be determined by multiplying 0.5 by the first retention period and 2 u (which is a factor related to SCS). This can be expressed as the following equation:

[0261] P second-reservation-period =P first-reservation-period *2 u *The portion of the UL time slot and / or UL symbol in the time slot format configuration, where it can be assumed that the time slot format configuration is configured in seconds.

[0262] The number of sidelink time slots within a fixed period is determined by the resource pool configuration and the time slot format configuration. The first set of resources in the time slot format configuration can be indicated as UL time slots or symbols. The second set of resources in the first set of resources is configured by the sidelink resource pool. The sidelink resource pool bitmap can be applied to UL time slots or symbols. If the number of UL symbols in a time slot is greater than the lower limit, the time slot can be configured for a valid sidelink time slot.

[0263] For example, the portion of the UL resources may be determined by parameters such as nrofUplinkSlots and / or nrofUplinkSymbols signaled at a higher layer (e.g., RRC or SIB or DCI). nrofUplinkSlots and / or nrofUplinkSymbols may be configured as part of a slot format configuration or a TDD configuration and may be determined by the portion of the UL resources in the slot configuration period. In an example, the portion of the UL resources is determined by (nrofUplinkSlots*1ms(=0.001) / 2 u +nrofUplinkSymbols*1ms / 2 u / 14) / (time slot configuration period) or (nrofUplinkSlots*1ms / 2^u) / (time slot configuration period). The latter is an example in which a time slot in which only some symbols are configured as UL is not counted as part of the UL resources. If the side link time slot is part of the time slot format configuration, or the side link time slot is directly indicated or pre-configured by the base station, or the side link time slot is independent of UL, DL and flexibly set, the part of the SL time slot can be used to determine the second retention period instead of the part of the UL time slot. For example, if the number of SL time slots in the time slot configuration period (which can be indicated by the base station or pre-configured) is N, and the SCS is indicated by u, the part of the side link resources can be determined as follows, part of the SL resources = N*1ms / 2 u / Time slot configuration period.

[0264] At the same time, the situation of changing TDD or time slot format configuration in the cell can be considered. Under high carrier frequency, due to the large path loss of high carrier frequency, the size of the cell may be small, and because the number of wireless devices in the cell may be small, the ratio of DL and UL services may vary greatly. If the TDD or time slot format configuration is maintained in a specific configuration, unnecessary resource waste or increased waiting time may occur. Therefore, adaptively changing the TDD configuration or time slot format configuration may be a method to reduce resource efficiency and packet delay. If the TDD or time slot format configuration is dynamically changed, the side link resource pool configuration and resource reservation operation may also be changed. For example, when the TDD or time slot format configuration changes, the side link resource pool bitmap mapping on the TDD configuration may also change. If the TDD or time slot format configuration or the side link resource pool configuration is changed, the method for determining the part of the side link or uplink resource presented in some embodiments becomes unclear. For example, if the first time slot format configuration is configured, the resource reservation period is indicated by the first wireless device, but the second time slot format configuration is received before the indicated reservation period passes. It becomes ambiguous whether the slot format configuration used to calculate a portion of the sidelink or UL resources is the first slot format or the second slot format. The following embodiments and examples may resolve this issue.

[0265] In one embodiment, the base station may configure a reference slot format configuration or a TDD configuration (e.g., a tdd-UL-DL-configuration) and / or a sidelink SCS to the wireless device via a physical layer signal (e.g., DCI) or a higher layer signal (e.g., SIB or RRC). The reference slot format configuration or TDD configuration may be different from the actual slot format configuration. The wireless device may determine a portion of the uplink or sidelink resources based on the reference tdd-UL-DL-configuration and / or the sidelink SCS. The wireless device may convert a first reservation period indicated in ms to a second reservation period in slots based on the sidelink SCS and / or a portion of the uplink or sidelink resources, which may be determined based on the reference slot format configuration. In an example, when the wireless device performs resource reservation, the wireless device may configure a first reservation period in ms from a higher layer. The wireless device may then convert the first reservation period to a second reservation period in slots based on the sidelink SCS and / or the reference slot format configuration. It can be expressed as the following equation, P second-reservation-period =P first-reservation-period *2 u* Portion of UL slots and / or UL symbols in a reference slot format configuration. In this example, even if the actual TDD or slot format configuration changes, from an average point of view, it is assumed that the portion of the sidelink or uplink resources is constant. Regardless of the actual TDD or slot format configuration, only the reference TDD or slot format configuration is used to convert the first retention period (in ms) into the second retention period (in slots).

[0266] In an example, the base station may configure a scaling value and / or a side link SCS to the wireless device via a physical layer signal (e.g., DCI) or a higher layer signal (e.g., SIB or RRC) to convert a first retention period in ms to a second retention period in time slots. The scaling value may be configured by resource pool or by BWP or by carrier or by UE. The wireless device may convert the first retention period to the second retention period based on the scaling value and / or the side link SCS. Here, the scaling value may be a value corresponding to a portion of the UL resources or side link resources in an average sense in a time slot format or TDD configuration. In this embodiment, as another alternative to configuring the method of the reference TDD configuration in some embodiments, the base station may indicate / configure a scaling value (or a ratio of effective UL resources or side link resources) for converting the retention period directly to the wireless device. For external network coverage, the scaling value may be pre-configured or fixed. In an example, the base station may configure a side link resource pool configuration, or may pre-configure a side link resource pool configuration (for external coverage) for the wireless device, and may define a scaling value table based on the side link resource pool configuration. Based on the resource pool configuration, the wireless device can determine the scaling value based on the scaling value table. For example, a portion of the side link resource is configured in the resource pool within 10msec (or Xmsec), and the scaling value table, where for a portion of the side link resource is 20%: the scaling value is 20; for a portion of the side link resource between 20-40: the scaling value is 30; for a portion of the side link resource between 40-60: the scaling value is 50; for a portion of the side link resource between 60-80: the scaling value is 70, and so on. Finer or coarser granularity can be considered. Fig.24 A table of this example is depicted. This example may avoid the signaling overhead for explicitly signaling the scaling value.

[0267] In an example, the base station may configure a first scaling value and / or a sidelink SCS to the wireless device via a physical layer signal (e.g., DCI) or a higher layer signal (e.g., SIB or RRC) to convert a first retention period in ms to a second retention period in slots. The first scaling value may be configured per resource pool or per BWP or per carrier or per UE. The wireless device may calculate the second scaling value as the first scaling value * (the number of available UL slots within Xmsec or the number of sidelink slots within Xmsec), where X may be predetermined or configured by the base station. Assuming that the resource pool may be configured to be applied only across semi-static UL, the resource pool may configure the "sparseness" of the resource pool, and the actual UL availability may be defined based on the actual slot format configuration.

[0268] In an embodiment, depending on the value of the first retention period, the wireless device may have different retention period conversion behaviors. For example, if the first retention period is less than or equal to a threshold value (e.g., 100 ms), the first retention period in ms indicated by a higher layer or another wireless device may be converted to a second retention period based only on the SCS, but if the first retention period is greater than the threshold value, the first retention period may be converted to the second retention period based on the SCS and the time slot format or resource pool configuration. As a specific example, when the first retention period is less than or equal to 100 ms, the second retention period is determined by simply multiplying the retention period by 2u. When the first retention period is greater than or equal to 100 ms, the wireless device may convert the first retention period by multiplying the first retention period by 2u. u and a portion of the UL or side link resources to determine a second reservation period in units of time slots.

[0269] In an embodiment, the wireless device may perform a reservation operation on resources and time slots after a first reservation period in ms. If the time slot is not a side link time slot after the first reservation period, the wireless device may perform actual transmission in the side link time slot that occurs first among the time slots after the first reservation period.

[0270] Meanwhile, in some embodiments or examples, when the second retention period is a non-integer value, a rule for converting the value into an integer by applying a lower or upper limit function may be used. For example, the wireless device may determine the second retention period as an upper limit function that multiplies 2^u and a portion of the uplink or side link resources by the value of the first retention period. This is because the second retention period must be an integer.

[0271] The sidelink resource pool can only be configured in static UL resources to minimize the variability of UL and DL resources. For example, the wireless device can receive a tdd-UL-DL-ConfigurationCommon signal from the base station. The tdd-UL-DL-ConfigurationCommon provides

[0272] - Reference SCS configuration μ ref As referenceSubcarrierSpacing

[0273] -Mode 1.

[0274] Mode 1 provides

[0275] -P msec slot configuration period as dl-UL-TransmissionPeriodicity

[0276] -Time slot d with downlink symbols only slots The number of nrofDownlinkSlots

[0277] - Downlink symbol d sym The number of nrofDownlinkSymbols

[0278] - Time slot u with uplink symbols only slots The number of nrofUplinkSlots

[0279] - Uplink symbol u sym The number of nrofUplinkSymbols

[0280] The value P = 0.625 msec is only for μ ref = 3 is valid. Value P = 1.25msec is only valid for μ ref =2 or μ ref = 3 is valid. The value P = 2.5msec is only valid for μ ref =1, or μ ref =2, or μ ref =3 is valid. The time slot configuration period of P msec includes the SCS configuration μ ref of From the S time slot, the first d slots The time slot contains only downlink symbols, and the last u slots A time slot includes only uplink symbols. slots d after the time slot sym The symbol is a downlink symbol. The last u slots u before the time slot sym Symbols are uplink symbols. The remaining is a flexible symbol. The first symbol of each 20 / P period is the first symbol in an even frame.

[0281] If tdd-UL-DL-ConfigurationCommon provides Mode 1 and Mode 2, the wireless device sets the slot format of each slot over the first number of slots indicated by Mode 1, and the wireless device sets the slot format of each slot over the second number of slots indicated by Mode 2. Mode 2 provides

[0282] -P2 msec slot configuration period as dl-UL-TransmissionPeriodicity

[0283] -Time slot d with downlink symbols only slots,2 The number of nrofDownlinkSlots

[0284] - Downlink symbol d sym The number of nrofDownlinkSymbols

[0285] - Time slot u with uplink symbols only s l o t s, 2 The number of nrofUplinkSlots

[0286] - Uplink symbol u sym, 2 The number of nrofUplinkSymbols

[0287] The applicable value of P2 is the same as the applicable value of P. The time slot configuration period of P+P2 msec includes the first Time slot and second From the S2 time slot, the first d slots,2 The time slot contains only downlink symbols, and the last u slots,2 Only uplink symbols are included. slots,2 d after the time slot sym,2 The symbol is a downlink symbol. The last u slots,2 u before the time slot sym,2 Symbols are uplink symbols. The remaining is a flexible symbol. The wireless device expects P+P2 to be divided by 20 msec. The first symbol of each 20 / (P+P2) period is the first symbol in an even frame.

[0288] As a way to configure the side link resource pool, it is possible to consider configuring the side link resources only in the UL time slots and / or UL symbols in the time slot format or TDD configuration (such as tdd-UL-DL-ConfigurationCommon). For this operation, the base station can configure the side link resource pool bitmap to the wireless device via the physical layer (e.g., DCI) or a higher layer signal (e.g., SIB, RRC), where the size of the side link resource pool bitmap can be equal to the number of uplink time slots or the number of uplink time slots + tdd-UL-DL-ConfigurationCommon 1. The former (side link resource pool bitmap size = the number of UL time slots in tdd-UL-DL-ConfigurationCommon) assumes that some UL time slots are not allocated as side link resources, while the latter (side link resource pool bitmap size = the number of UL time slots in tdd-UL-DL-ConfigurationCommon + 1) assumes that the side link resource pool bitmap can be allocated to some UL time slots. If the base station configures mode 1 and mode 2 in tdd-UL-DL-ConfigurationCommon, two sidelink resource pool bitmaps may be (pre-)configured, where the first bitmap may be used for UL resources of mode 1 and the second bitmap may be used for UL resources of mode 2. If mode 1 and mode 2 are configured in the slot format configuration, but only one bitmap exists in the sidelink resource pool configuration, the wireless device may know whether the corresponding bitmap is for mode 1 or mode 2 based on the bitmap size. However, when the UL resource size of mode 1 and the UL resource size of mode 2 are the same, the wireless device may be ambiguous about which mode the sidelink resource pool bitmap applies to. Therefore, if only one sidelink resource pool bitmap is configured, it may be assumed to apply to mode 1. Alternatively, the sidelink resource pool bitmap is applied to mode 1 and mode 2 in sequence. If the number of UL resources of mode 1 and the size of the sidelink resource pool bitmap do not match, repetition (the size of the sidelink resource pool bitmap may be smaller than the number of UL resources) or truncation (when the size of the sidelink resource pool bitmap is larger than the UL resources) may be considered. In addition, the side link resource pool bitmap can have the same periodicity of the time slot format or TDD configuration. For example, the side link resource pool bitmap periodicity can be the same as the time slot configuration period in tdd-UL-DL-ConfigurationCommon. If mode 1 and mode 2 are configured in tdd-UL-DL-ConfigurationCommon, the side link resource pool configuration may have two bitmaps and two periodicities. This method configures the side link resource pool only in the UL resources common to the wireless devices to prevent the side link resource pool from changing dynamically and align the side link resource pool between the wireless devices.

[0289] In an embodiment, the wireless device may determine that only a time slot with a certain number (i.e., a lower limit) or more symbols constituting a time slot is a valid side link time slot. In this case, the lower limit of the number of symbols constituting the time slot may be predetermined, or the base station may configure the lower limit to the wireless device via a physical layer (e.g., DCI) or a higher layer signal (e.g., SIB or RRC). For example, the lower limit may be determined by adding the minimum number of symbols constituting the PSCCH / PSSCH (control and data channels) and / or the minimum number of symbols constituting the PSFCH (feedback channel). For example, the number of symbols of the PSCCH / PSSCH may be six. This is because when the number of symbols is less than a threshold, the DMRS configuration and / or the control channel data channel multiplexing options may not be defined. In addition, due to the lack of data transmission resource elements, a side link time slot configured to be less than a specific number of symbols may not have a low coding rate, which may reduce reliability.

[0290] In the prior art, after a wireless device selects a resource, the wireless device may maintain the resource semi-persistently. For example, the wireless device may maintain the selected resource an integer number of times with a reservation period. Maintaining the selected resource an integer number of times may be referred to as a resource reselection counter. For each transmission, the counter value is decremented by 1. If multiple wireless devices have the same counter value, there may be a half-duplex problem. For example, different wireless devices may accidentally start transmitting on the same time resource and continue to transmit on the same time resource. This may prevent the wireless device from receiving packets.

[0291] To solve this problem, the prior art selects a counter value between 5 and 15. The range of the counter value may be related to the CR measurement window size. Since the wireless device has an average value of 10 counters, and assuming that the wireless device has a retention period of 100 ms, the wireless device may maintain transmission for about 1000 ms on average. Therefore, if the CR measurement window size is 1000 ms, the wireless device may accurately measure the CR on average.

[0292] If the base station flexibly configures the CR measurement window size, the accuracy of the CR measurement may be reduced, or / and unnecessary long resource reservations may be performed. For example, if the base station configures the wireless device with a CR measurement window size of 250 ms, and the reservation period is 100 ms, the wireless device may maintain transmission for 1000 ms on average.

[0293] The exemplary embodiments of the present disclosure define a method for determining the range of a side link resource reselection counter for transmitting one or more transport blocks via a side link. In an exemplary embodiment, the wireless device can determine the range of the side link resource reselection counter based on the CR measurement window size. For example, for a CR measurement window size of 1000ms, the wireless device can determine that the range of the side link resource reselection counter is between 5 and 15. For a CR measurement window size of 200ms, the wireless device can determine that the range of the side link resource reselection counter is between 1 and 3. When the CR measurement value is small, the wireless device can reduce the side link resource reselection counter value. The wireless device can transmit one or more transport blocks via the side link based on the range of the side link resource reselection counter. Based on the exemplary embodiment, the wireless device can obtain accurate CR measurements and avoid unnecessary long resource reservations.

[0294] In the prior art, a wireless device selects a resource once in a semi-persistent resource selection operation and maintains it for a certain integer number of times. The number of times or integer value of maintaining the selected resource may be referred to as a counter. The wireless device may determine the counter value before reselecting the resource and maintain the selected resource as many times as the counter. The counter value is reduced by 1 each time a transmission occurs. If multiple wireless devices have the same counter value, there may be a half-duplex problem, where different wireless devices accidentally start transmitting on the same time resource and continue to transmit on the same time resource, and packets may not be received. To solve this problem, a conventional operation of selecting a counter value between 5 and 15 has been introduced. The range of the counter value may also be related to the sensing window size. Since the wireless device has an average value of 10 counters, and it can be assumed that the wireless device has a retention period of 100ms, the wireless device can maintain transmission for about 1000ms on average. Therefore, if the size of the sensing window is 1000ms, the wireless device can monitor the interval of maintaining transmission on average, so that the sensing accuracy can be improved. In the NR sidelink, all or part of the SCS, channel busy rate (CBR) measurement window size, sensing window size, channel occupancy rate (CR) measurement window size, time slot format and resource pool configuration can be (pre-)configured. For example, according to the (pre-)configuration, the CR window size can be 1000ms or 1000 time slots, and according to the (pre-)configuration, the CBR measurement time window size can be 100ms and 100 time slots. The sensing window size can be pre-configured between 1000+100ms and 100ms. Fig.25The timing relationship between the sensing window and the selection is shown. In this figure, the sensing window size refers to T0. In this case, if the counter value is randomly selected only between 5 and 15, the accuracy of the sensing or the accuracy of the CR and CBR measurements may be reduced. For example, if the base station configures the sensing window size T0 to 1000+100ms, the SCS is 60kHz, and the retention period is 100ms, the wireless device maintains transmission for an average of 250ms. This may lead to increased inaccuracy in the sensing results within the 1000+100ms sensing window.

[0295] In an embodiment, the counter range may be determined based on at least one or more of the SCS, retention period, CBR measurement window, CR measurement window, sensing window, time slot format (or TDD configuration), and resource pool configuration. A counter range scaling function may be introduced. For example, when the retention period Prsvp is less than or equal to 100ms, the counter range is a lower limit function or an upper limit function of 100 / Prsvp*

[515] . For example, the counter range may be determined based on the SCS, for example, for 2u*15kHzSCS, the counter range is proportionally increased to (u+1)*[5 15]. The counter range may be determined so that the average counter number*retention period is greater than or equal to the CBR measurement window. The counter range may be determined based on the CR measurement window size. For example, for a 1000 time slot CR window and a 30kHz SCS, the counter range is [10 30]. For example, when the CR measurement window size is 1000ms, the counter range may be 5 to 15. For example, when the CR measurement window size is 500ms, the counter range may be 3 to 8. For example, when the CR measurement window size is 250 ms, the counter range may be 2 to 4. For example, when the CR measurement window size is 125 ms, the counter range may be 1 to 2.

[0296] In an example, the counter range of the sidelink resource reselection counter value may be determined based on the SCS. For example, when the SCS is 15 kHz, the counter range may be 5 to 15.

[0297] In an example, the counter range may be determined based on the sensing window size. For example, when the sensing window size is 1000 ms, the counter range may be 5 to 15. For example, when the sensing window size is 500 ms, the counter range may be 3 to 8. The counter range scaling value for each retention period may be (pre)configured. For example, the counter range scaling value may be (pre)configured inversely proportional to the retention period. Fig.26 An exemplary flow chart of this embodiment is shown.

[0298] In the prior art, a wireless device may discard a reserved resource due to an indication from a high priority packet. This operation may be referred to as a preemption operation. For example, a first wireless device may reserve three resources. The sidelink control information on the first transmission resource may indicate two additional resources including a second transmission resource and a third transmission resource. If the preempting wireless device indicates that the second transmission resource is for preemption, the first wireless device may discard the second transmission resource and perform resource reselection.

[0299] The prior art may not consider previously selected resources for resource reselection. For example, any resource that overlaps in time with the previously selected third transmission resource may not be excluded from candidate resources for resource reselection.

[0300] If the first wireless device selects any resource that overlaps in time with the third transmission resource, the transmission power may be divided, in-band emissions may be increased, and coverage may be reduced.

[0301] An exemplary embodiment of the present disclosure determines a procedure for resource reselection. In an exemplary embodiment, the wireless device may determine a transmission time resource reserved by the wireless device for transmitting a transport block via a side link. The wireless device may determine one or more first resources to be excluded from candidate resources for transmitting the transport block based on the transmission time resource. For example, the one or more first resources may be any resource that overlaps with a previously reserved resource in time. The wireless device may select a second resource for transmission from candidate resources other than the one or more first resources.

[0302] Based on the exemplary embodiments, the wireless device can avoid the problems of power allocation, in-band emission and coverage reduction.

[0303] In an example, the wireless device can be considered to be operating in which a high priority packet must give up resource usage after reserving resources through a sensing operation. This operation can be referred to as a preemptive operation. Fig. 27 In the embodiment of the present invention, a first wireless device has reserved three resources, and the first transmission indicates the location of two additional resources through control signaling. However, if a preemption indication signal is received from a second wireless device with a high priority packet after the first transmission, and the preemption indication signal overlaps with the second transmission resource, the second transmission resource may be discarded and the resource needs to be reselected. Resources included in the time resources, such as the previously selected third resource, can be excluded from resource reselection. If resources, such as the third transmission resource, are selected in the time resources, the transmission power is divided, the in-band emission can be increased, and the coverage can be reduced. To alleviate this problem, the wireless device can exclude the resources that have been selected for transmission and any resources that overlap with the already selected resources in the time domain when reselecting resources.

[0304] In an embodiment, the wireless device may identify the transmission time resources reserved by the wireless device, and may determine the first resource to be excluded based on the identified transmission time resources to select the second resource for the side link transmission. The wireless device may select the second resource for the side link transmission from resources other than the first resource, and may transmit the side link signal on the second resource. The wireless device may transmit the transmission time resource information via the side link control channel. The wireless device performs resource (re) selection after identifying the transmission time resource. The resource (re) selection may be triggered by a new packet arrival or preemption indication. The resource to be excluded may be any resource that overlaps with the transmission time resource in time. Fig.28 An example of a flow chart of this embodiment is shown.

[0305] In an example, the wireless device may receive one or more messages from a base station, the message including a sidelink SCS, a timeslot format configuration, and a sidelink resource pool configuration. The wireless device may convert a first retention period in milliseconds into a second retention period in timeslots based on the sidelink SCS, the timeslot format configuration, and / or the sidelink resource pool configuration, and may select one or more transmission resources based on the second retention period, and may transmit a transport block via the selected one or more resources. In this example, the first retention period may be given by a higher layer in milliseconds, and the SCS is as follows: 15kHz corresponds to μ=0, 30kHz corresponds to μ=1, 60kHz corresponds to μ=2, 120kHz corresponds to μ=4, 240kHz corresponds to μ=8, and so on. The wireless device may determine a portion of valid sidelink resources within a certain period of time based on the timeslot format configuration and / or the sidelink resource pool configuration, wherein the period is predetermined or configured by the base station. The second retention period may be obtained by converting 2 μ And this portion is multiplied by the first retention period to obtain.

[0306] In an example, a first wireless device may receive one or more messages from a base station, the messages including: a sidelink subcarrier spacing (SCS); a time slot format configuration; and / or a backup link resource pool configuration. The first wireless device may receive a PSCCH from a second wireless device, the PSCCH including: a first reservation period in milliseconds; and one or more frequency resources within a sidelink resource pool, and the first wireless device may determine a second reservation period in time slots based on the first reservation period, the sidelink SCS, the time slot format configuration, and / or the sidelink resource pool configuration, and may determine the excluded resources based on the second reservation period and the one or more frequency resources. The first wireless device may then select one or more transmission resources based on the excluded resources; and may transmit a transport block via the selected resources.

[0307] In an example, a wireless device may receive one or more messages from a base station, the message including: a subcarrier spacing (SCS), a channel busy rate (CBR) measurement window, a channel occupancy rate (CR) measurement window, a sensing window, a time slot format configuration, and a resource pool configuration. The wireless device may determine an integer value range of a resource reservation number for one or more transport blocks via a side link based on at least one of the SCS, the CBR measurement window, the CR measurement window, the sensing window, the time slot format, and the resource pool configuration. The wireless device may select a reserved number within the integer value range and select one or more frequency resources with the selected reserved number. The wireless device may then transmit the side link transport block on the selected one or more frequency resources with the selected reserved number.

[0308] In an example, a wireless device may identify a transmission time resource reserved by the wireless device, and may determine a first resource to be excluded based on the identified transmission time resource to select a second resource for sidelink transmission. The wireless device may select a second resource for sidelink transmission from a resource other than the first resource, and may transmit a sidelink signal on the second resource. The wireless device may transmit transmission time resource information via a sidelink control channel. The wireless device may trigger resource (re)selection after identifying the transmission time resource. Resource (re)selection may be triggered by a new packet arrival or preemption indication, and the resource to be excluded is any resource that overlaps in time with the transmission time resource.

[0309] According to various embodiments, a device (such as, for example, a wireless device, an off-grid wireless device, a base station, etc.) may include one or more processors and a memory. The memory may store instructions that, when executed by one or more processors, cause the device to perform a series of actions. Embodiments of exemplary actions are illustrated in the drawings and the specification. Features from various embodiments may be combined to create additional embodiments.

[0310] Fig.29 29 is a flow chart illustrating aspects of an exemplary embodiment of the present disclosure. At 2910, the wireless device may determine a second reservation period in time slots based on the first reservation period in milliseconds and the number of side link time slots within the fixed period. For example, the number of side link time slots may be based on a resource pool configuration. At 2920, the wireless device may transmit a transport block via one or more transmission resources based on the second reservation period.

[0311] Fig.3029 is a flow chart illustrating aspects of an exemplary embodiment of the present disclosure. At 2910, the wireless device may determine a second reservation period in time slots based on the first reservation period in milliseconds and the number of side link time slots within the fixed period. For example, the number of side link time slots may be based on a resource pool configuration. At 2920, the wireless device may transmit a transport block via one or more transmission resources based on the second reservation period.

[0312] Fig.31 31 is a flow chart illustrating aspects of an exemplary embodiment of the present disclosure. At 3110, the wireless device may determine a range of a sidelink resource reselection counter for transmitting one or more transport blocks via a sidelink based on a CR measurement window size. At 3120, the wireless device may transmit one or more transport blocks via a sidelink based on the range.

[0313] Fig.32 is a flow chart illustrating aspects of an exemplary embodiment of the present disclosure.At 3210, the wireless device may transmit one or more transport blocks via the sidelink based on a range of sidelink resource reselection counter values, wherein the range corresponds to a CR measurement window size.

[0314] Fig.33 3310, the wireless device may select a second resource from candidate resources other than one or more first resources based on the transmission time resources reserved by the wireless device. At 3320, the wireless device may transmit a transport block via the second resource of the side link.

[0315] According to an exemplary embodiment, the first wireless device may receive one or more messages indicating a time slot format configuration and a resource pool configuration from a base station. The first wireless device may receive physical side link control information (SCI) indicating a first retention period in milliseconds (ms) from a second wireless device. The first wireless device may determine a second retention period in time slots based on the first retention period and the number of side link time slots within a fixed period. For example, the number of side link time slots may be based on the resource pool configuration and the time slot format configuration. The first wireless device may select one or more transmission resources based on the second retention period. The first wireless device may transmit a transport block via one or more transmission resources.

[0316] According to an exemplary embodiment, at least one of the one or more messages may be a radio resource control message.At least one of the one or more messages may be a system information block.

[0317] According to an exemplary embodiment, the first wireless device may receive side link control information indicating a first retention period in milliseconds (ms) from the second wireless device. The first wireless device may determine a second retention period in time slots based on the first retention period and the number of side link time slots within the fixed period. For example, the number of side link time slots may be based on a resource pool configuration and a time slot format configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second retention period. The first wireless device may select one or more transmission resources based on the second retention period.

[0318] According to an exemplary embodiment, the first wireless device may receive side link control information indicating a first retention period in milliseconds (ms) from the second wireless device. The first wireless device may determine a second retention period in time slots based on the number of side link time slots within the first retention period and the fixed period. The number of side link time slots may be based on a time slot format configuration. The time slot format configuration may be a reference time slot format configuration. The time slot format configuration may be the same as or different from the actual time slot format configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second retention period. The number of side link time slots may be further based on a resource pool configuration.

[0319] According to an exemplary embodiment, the first wireless device may receive sidelink control information indicating a first retention period in milliseconds (ms) from the second wireless device. The first wireless device may determine a second retention period in time slots based on the first retention period and the number of sidelink time slots within the fixed period, wherein the number of sidelink time slots is based on a resource pool configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second retention period. The number of sidelink time slots may be further based on a time slot format configuration.

[0320] According to an exemplary embodiment, the first wireless device may determine a second reservation period in time slots based on a first reservation period in milliseconds (ms) and a number of side link time slots within a fixed period. The number of side link time slots may be based on a resource pool configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second reservation period.

[0321] According to an exemplary embodiment, the first wireless device may receive a first reservation period from a higher layer of the first wireless device. The first reservation period may be received from the second wireless device via the SCI. In an example, the number of side link time slots may be further configured based on the time slot format. In an example, the resource pool configuration indicates one or more side link time slots within a fixed period.

[0322] According to an exemplary embodiment, a first wireless device may determine a second reservation period in units of time slots based on a first reservation period in units of milliseconds (ms) and a number of side link time slots within a fixed period, wherein the number of side link time slots is based on a time slot format configuration. The first wireless device may transmit a transport block via one or more transmission resources based on the second reservation period. The first reservation period may be received from a higher layer of the first wireless device. The higher layer may be an application layer. In an example, the first reservation period may be received from a second wireless device via an SCI. The number of side link time slots may be further based on a resource pool configuration. In an example, the time slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration (TDD UL-DL configuration). The time slot format configuration may indicate one or more side link time slots within a fixed period. The fixed period may be 20ms. The fixed period may not depend on the periodicity of the TDD UL-DL configuration. The fixed period may not depend on the periodicity of the time slot format configuration. The first wireless device may convert a first reservation period in units of milliseconds into a second reservation period in units of time slots based on the number of side link time slots within the fixed period.

Claims

1. A method comprising: determining, by the first wireless device, a number of sidelink time slots configured in a sidelink resource pool; Determining a second reservation period in time slots based on the first reservation period in milliseconds (ms) and the number of sidelink time slots; as well as The transport block is transmitted via one or more transmission resources selected based on the second retention period.

2. The method of claim 1, further comprising determining the number of the side link time slots based on a bitmap of the side link resource pool.

3. The method according to claim 1, wherein: The first retention period is received from a higher layer of the first wireless device. 4 . The method of claim 1 , further comprising receiving sidelink control information (SCI) indicating the first retention period from a second wireless device.

5. The method of claim 1, wherein determining the second retention period in time slots is further based on the number of the sidelink time slots within a fixed duration.

6. The method of claim 1 , wherein determining the second retention period in units of time slots comprises: The first retention period in milliseconds is converted into the second retention period in time slots based on the number of the side link time slots within a fixed duration.

7. The method according to claim 1, wherein: The number of sidelink time slots is further based on the number of valid sidelink time slots; and An active sidelink time slot among the active sidelink time slots has a number of uplink symbols greater than a threshold.

8. The method of claim 7, further comprising receiving an indication of the threshold from a base station.

9. The method of claim 1, wherein the number of sidelink time slots is configured based on a time slot format.

10. The method according to claim 9, wherein: The slot format configuration is a cell-specific time division duplex (TDD) uplink (UL) and downlink (DL) configuration.

11. A first wireless device, comprising: one or more processors; and a memory storing instructions that, when executed by the one or more processors, cause the first wireless device to: determining a number of side link time slots configured in a side link resource pool; Determining a second reservation period in time slots based on the first reservation period in milliseconds (ms) and the number of sidelink time slots; as well as The transport block is transmitted via one or more transmission resources selected based on the second retention period.

12. The first wireless device according to claim 11, wherein: The instructions also cause the first wireless device to determine the number of the sidelink time slots based on a bitmap of the sidelink resource pool.

13. The first wireless device according to claim 11, wherein: The first retention period is received from a higher layer of the first wireless device.

14. The first wireless device according to claim 11, wherein: The instructions also cause the first wireless device to receive sidelink control information (SCI) from a second wireless device indicating the first retention period.

15. The first wireless device according to claim 11, wherein: The instructions also cause the first wireless device to determine the second reservation period in units of time slots further based on the number of the sidelink time slots within a fixed duration.

16. The first wireless device according to claim 11, wherein: The instructions also cause the first wireless device to convert the first retention period in milliseconds to the second retention period in slots based on a number of the sidelink slots within a fixed duration.

17. The first wireless device of claim 11, wherein: The number of sidelink time slots is further based on the number of valid sidelink time slots; and An active sidelink time slot among the active sidelink time slots has a number of uplink symbols greater than a threshold.

18. The first wireless device according to claim 17, wherein: The instructions also cause the first wireless device to receive an indication of the threshold from a base station.

19. The first wireless device according to claim 11, wherein: The number of side link time slots is configured based on a time slot format.

20. A non-transitory computer-readable medium comprising instructions that, when executed by one or more processors of a first wireless device, cause the first wireless device to: determining a number of side link time slots configured in a side link resource pool; Determining a second reservation period in time slots based on the first reservation period in milliseconds (ms) and the number of sidelink time slots; as well as The transport block is transmitted via one or more transmission resources selected based on the second retention period.

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