Distributed Sidelink (SL) architecture and protocol stack

Abstract

A sidelink node has a distributed processing architecture for wireless communication. The sidelink node includes a central unit configured to perform sidelink node functions. The sidelink node also includes a plurality of distributed units, the plurality of distributed units including a first distributed unit and a second distributed unit, each distributed unit coupled to and controlled by the central unit, each distributed unit configured to perform a subset of the sidelink node functions. The sidelink node includes a plurality of radio units, the plurality of radio units including a first set of radio units coupled to and controlled by the first distributed unit and a second set of radio units coupled to and controlled by the second distributed unit, each radio unit configured for sidelink transmission and reception.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. patent application No. 17 / 185,780, filed on February 25, 2021, entitled “DISTRIBUTED SIDELINK (SL) ARCHITECTURE AND PROTOCOL STACK,” which claims the benefit of U.S. Provisional Patent Application No. 62 / 983,393, filed on February 28, 2020, entitled “DISTRIBUTED SIDELINK (SL) ARCHITECTURE AND PROTOCOL STACK,” and the disclosures of both the U.S. patent application and the U.S. Provisional Patent Application are expressly incorporated herein by reference in their entirety. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications and, more particularly, to a distributed sidelink (SL) architecture and protocol stack. Background Art

[0004] Wireless communication systems are widely deployed to provide various communication services such as telephony, video, data, messaging, broadcast, etc. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in a variety of telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, or even global level. An example telecommunication standard is the fifth generation (5G) New Radio (NR). 5G NR is part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., Internet of Things (IoT)) and other requirements. 5GNR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the fourth generation (4G) Long Term Evolution (LTE) standard. There is a need for further improvements in 5G NR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0006] The wireless communication system may include or provide support for various types of communication systems, such as vehicle-related communication systems (e.g., vehicle-to-everything (V2X) communication systems). Vehicles may use vehicle-related communication systems to improve safety and help prevent vehicle collisions. Information about severe weather, nearby accidents, road conditions, and / or other information may be communicated to the driver via the vehicle-related communication system. In some cases, vehicles may communicate directly with each other or with infrastructure using device-to-device (D2D) communications over D2D wireless links.

[0007] As the demand for vehicle-related communications increases, different V2X communication systems compete for the same wireless communication resources. Therefore, there is a need to improve the sharing of wireless communication resources. Summary of the invention

[0008] In one aspect of the present disclosure, a sidelink node includes a distributed processing architecture for wireless communication. The sidelink node includes a central unit configured to perform sidelink node functions. The sidelink node also includes a plurality of distributed units, the plurality of distributed units including a first distributed unit and a second distributed unit, each distributed unit coupled to and controlled by the central unit, each distributed unit configured to perform a subset of the sidelink node functions. The sidelink node also includes a plurality of radio units, the plurality of radio units including a first set of radio units coupled to and controlled by the first distributed unit and a second set of radio units coupled to and controlled by the second distributed unit, each radio unit being configured for sidelink transmission and reception.

[0009] In another aspect of the present disclosure, a method for wireless communication via a sidelink node includes communicating a control plane message from a central unit control plane entity to another sidelink node or a sidelink user equipment (SL UE) via at least one distributed unit and at least one radio unit. The method also includes communicating a user plane message from a central unit user plane entity to the other sidelink node or the SL UE via the at least one distributed unit and the at least one radio unit.

[0010] Another aspect of the present disclosure relates to a non-transitory computer-readable medium having non-transitory program code recorded thereon. The program code is executed by a side link node and includes program code for communicating a control plane message from a central unit control plane entity to another side link node or a side link user equipment (SL UE) via at least one distributed unit and at least one radio unit. The program code also includes program code for communicating a user plane message from a central unit user plane entity to the other side link node or the SL UE via the at least one distributed unit and the at least one radio unit.

[0011] In another aspect of the disclosure, an apparatus having a distributed processing architecture for wireless communications includes components for performing sidelink node functions. The apparatus also includes components for performing a subset of the sidelink node functions, the components for performing the subset of the sidelink node functions being coupled to and controlled by the components for performing the sidelink node functions. The apparatus also includes components for sidelink transmission and reception, the components for sidelink transmission and reception being coupled to and controlled by the components for performing the subset of the sidelink node functions.

[0012] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication devices, and processing systems as generally described with reference to and illustrated by the drawings and description.

[0013] The features and technical advantages of examples according to the present disclosure have been outlined quite broadly above so that the following specific embodiments may be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples may be readily used as a basis for modifying or designing other structures for achieving the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The features of the concepts disclosed herein, i.e., their organization and methods of operation, and the associated advantages, will be better understood from the following description when considered in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for the purpose of illustration and description and not as a definition of the limitations of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description briefly summarized above may be obtained by reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the attached drawings illustrate only certain typical aspects of the present disclosure and should not be considered as limiting the scope thereof, as the description may admit of other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0015] Figure 1is a schematic diagram illustrating an example of a wireless communication system and an access network.

[0016] Figure 2A , Figure 2B , Figure 2C and Figure 2D are schematic diagrams illustrating examples of a first fifth generation (5G) new radio (NR) frame, a downlink (DL) channel within a 5G NR subframe, a second 5G NR frame, and an uplink (UL) channel within a 5G NR subframe, respectively.

[0017] Figure 3 is a schematic diagram illustrating an example of a base station and a user equipment (UE) in an access network.

[0018] Figure 4 is a schematic diagram illustrating an example of a device-to-device (D2D) communication system including vehicle-to-everything (V2X) communication according to aspects of the present disclosure.

[0019] Figure 5A and Figure 5B is a schematic diagram illustrating a use case of distributed sidelink processing according to aspects of the present disclosure.

[0020] Figure 6 is a block diagram illustrating an example of a distributed architecture according to aspects of the present disclosure.

[0021] Figure 7 is a block diagram illustrating control plane / user plane partitioning in accordance with aspects of the present disclosure.

[0022] Figure 8 is a block diagram illustrating protocol stack partitioning according to aspects of the present disclosure.

[0023] Fig. 9 is a block diagram illustrating an exemplary functional division between a central unit and distributed units according to aspects of the present disclosure.

[0024] Fig.10 is a block diagram illustrating a control plane protocol stack according to aspects of the present disclosure.

[0025] Fig.11 is a block diagram illustrating a user plane protocol stack in accordance with aspects of the present disclosure.

[0026] Fig.12 is a flow diagram illustrating an example process performed, for example, by a sidelink node in accordance with aspects of the present disclosure. DETAILED DESCRIPTION

[0027] The various aspects of the present disclosure will be described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to any specific structure or function presented throughout the present disclosure. On the contrary, these aspects are provided to make the present disclosure thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings herein, it should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether implemented independently of any other aspect of the present disclosure or implemented in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover devices or methods practiced using other structures, functions, or structures and functions other than the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure can be embodied by one or more elements of the claims.

[0028] Several aspects of telecommunication systems will now be described with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and design constraints on the overall system.

[0029] It should be noted that while various aspects may be described using terminology generally associated with 5G and later wireless technologies, various aspects of the present disclosure may be applied to other generation-based communication systems, such as and including 3G and / or 4G technologies.

[0030] In a traditional cellular communication network, wireless devices can communicate with each other via one or more network entities (such as a base station or a scheduling entity). Some networks can support device-to-device (D2D) communication, which can discover and communicate with nearby devices using a direct link between devices (e.g., without going through a base station, a relay, or another node). D2D communication can implement mesh networking and device-to-network relay functionality. Some examples of D2D technology include PC5 or direct communication mode, which is an air interface for device-to-device discovery and communication. D2D communication may also be referred to as sidelink communication.

[0031] Vehicle-to-Everything or V2X describes the communication between a vehicle and any other type of device. Information from sensors and other sources can be communicated between a vehicle and another device, such as a roadside unit (RSU). New Radio (NR) V2X is a type of 5G communication where vehicles exchange information with RSUs (roadside units) using NR V2X communication. In some cases, the RSUs can connect to a backend server / network (such as a 5G network) and provide information reported by the vehicle to the server and vice versa.

[0032] RSU is a special node deployed to assist vehicles by providing additional information. RSU can be deployed in different locations to assist vehicles. Each RSU can serve multiple V2X UEs. In this deployment, RSU looks like a base station or access point that provides vehicles with connectivity to the network.

[0033] According to aspects of the present disclosure, when many RSUs are deployed, a distributed processing architecture may be beneficial for the RSUs. That is, logical nodes may be defined for RSU functions. Some logical nodes may be deployed in a cloud environment.

[0034] For non-V2X use cases, cloud architecture / distributed processing for sidelink communications is also considered. In this case, similar to RSU, special nodes called Sidelink Assist Nodes (SLANs) can assist device-to-device communications. For example, gaming / interactive services can use SLANs to send and receive information from backend servers. According to the present disclosure, a cloud sidelink (SL) architecture refers to a special node deployed with distributed processing for any sidelink use case.

[0035] Figure 1 1 is a schematic diagram illustrating an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell 102' (a low-power cellular base station). The macro cell includes a base station. The small cell 102' includes a femto cell, a pico cell, and a micro cell.

[0036] A base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC 160 via a backhaul link 132 (e.g., an S1 interface). A base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) may interface with the core network 190 via a backhaul link 184. The base station 102 may perform one or more of the following functions, among other functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. Base stations 102 may communicate with each other directly or indirectly (eg, through EPC 160 or core network 190) via backhaul links 134 (eg, X2 interfaces). Backhaul links 134 may be wired or wireless.

[0037] Base stations 102 can communicate wirelessly with UE 104. Each base station 102 can provide communication coverage for a corresponding geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between the base station 102 and the UE 104 can include an uplink (UL) (also known as a reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also known as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 can use multiple input multiple output (MIMO) antenna technology, which includes spatial multiplexing, beamforming and / or transmit diversity. The communication link can be through one or more carriers. The base station 102 / UE 104 may use spectrum with up to Y MHz (e.g., 5, 10, 15, 20, 100, 400 MHz, etc.) bandwidth per carrier, allocating each carrier in a carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell), and the secondary component carrier may be referred to as a secondary cell (SCell).

[0038] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through various wireless D2D communication systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on IEEE 802.11 standards, LTE, or NR.

[0039] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 in the 5 GHz unlicensed spectrum via a communication link 154. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communication to determine whether the channel is available.

[0040] The small cell 102' may operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may utilize NR and use the same 5 GHz unlicensed spectrum used by the Wi-Fi AP 150. The small cell 102' utilizing NR in the unlicensed spectrum may improve the coverage of the access network and / or increase the capacity of the access network.

[0041] Whether a small cell 102' or a large cell (e.g., a macro base station), the base station 102 can include an eNB, a gNodeB (gNB), or another type of base station. Some base stations (such as gNB 180) can operate in the traditional sub-6 GHz spectrum to communicate with the UE 104 at millimeter wave (mmW) frequencies and / or near mmW frequencies. When the gNB 180 operates at mmW or near mmW frequencies, the gNB 180 can be referred to as a mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 mm and 10 mm. Radio waves in this band can be referred to as millimeter waves. Near mmW can extend down to a frequency of 3 GHz and a wavelength of 100 mm. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also known as centimeter waves. Communications using mmW / near mmW radio frequency bands (e.g., 3 GHz-300 GHz) have extremely high path losses and short distances. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range.

[0042] The base station 180 can send beamformed signals to the UE 104 in one or more transmit directions 182'. The UE 104 can receive the beamformed signals from the base station 180 in one or more receive directions 182". The UE 104 can also send beamformed signals to the base station 180 in one or more transmit directions. The base station 180 can receive beamformed signals from the UE 104 in one or more receive directions. The base station 180 / UE 104 can perform beam training to determine the best receive and transmit directions for each base station 180 / UE 104. The transmit and receive directions of the base station 180 can be the same or different. The transmit and receive directions of the UE 104 can be the same or different.

[0043] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area that broadcasts a specific service, and may be responsible for session management (start / stop) and collecting eMBMS-related billing information.

[0044] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. AMF 192 may communicate with a unified data management (UDM) 196. AMF 192 is a control node that handles signaling between UE 104 and the core network 190. Typically, AMF 192 provides quality of service (QoS) flows and session management. All user Internet Protocol (IP) packets are transmitted through UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 is connected to IP services 197. IP services 197 may include the Internet, intranet, IP multimedia subsystem (IMS), PS streaming services, and / or other IP services.

[0045] Base station 102 may also be referred to as a gNB, a Node B, an evolved Node B (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other suitable term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include a cellular phone, a smart phone, a Session Initiation Protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a medical device, an implant, a sensor / actuator, a display, or any other similar functional device. Some UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0046] Although the following description may focus on 5G NR, this document may be applicable to other similar areas such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0047] Figure 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. Figure 2C is a schematic diagram 250 illustrating an example of a second subframe within a 5G / NR frame structure. Figure 2D FIG280 is a diagram illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL, or may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , Figure 2CIn the example provided, it is assumed that the 5G NR frame structure is TDD, subframe 4 is configured with slot format 28 (mainly DL), where D is DL, U is UL, and X is flexibly used between DL / UL, and subframe 3 is configured with slot format 34 (mainly UL). Although subframes 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are DL and UL, respectively. Other slot formats 2-61 include a mixture of DL, UL and flexible codewords. The UE is configured with a slot format (dynamically configured through DL control information (DCI), or semi-statically / statically configured through radio resource control (RRC) signaling) through the received slot format indicator (SFI). Note that the following description also applies to the 5G NR frame structure, i.e., TDD.

[0048] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10ms) can be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include a mini-time slot, which may include 7, 4, or 2 symbols. Depending on the time slot configuration, each time slot may contain 7 or 14 symbols. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) OFDM (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios), or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single stream transmission). The number of time slots within a subframe is based on the time slot configuration and the number. For slot configuration 0, different numbers μ0 to 5 allow 1, 2, 4, 8, 16 and 32 slots per subframe, respectively. For slot configuration 1, different numbers 0 to 2 allow 2, 4 and 8 slots per subframe, respectively. Therefore, for slot configuration 0 and number μ, there are 14 symbols / slot and 2μ slots / subframe. The subcarrier spacing and symbol length / duration are functions of the number. The subcarrier spacing can be equal to 2^μ*15kHz, where μ is a number 0 to 5. Thus, number μ=0 has a subcarrier spacing of 15kHz and number μ=5 has a subcarrier spacing of 480kHz. The symbol length / duration is inversely proportional to the subcarrier spacing. Figure 2A-2D An example is provided for slot configuration 0 with 14 symbols per slot and a number μ = 0 with 1 slot per subframe. The subcarrier spacing is 15 kHz and the symbol duration is approximately 66.7 μs.

[0049] The resource grid may represent the frame structure. Each time slot includes a resource block (RB) (also called a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a number of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0050] like Figure 2A As shown, some REs carry reference (pilot) signals (RS) for the UE. RS may include a demodulation RS (DM-RS) (denoted as Rx for a particular configuration, where 100x is the port number, but other DM-RS configurations are also possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0051] Figure 2B Examples of various DL channels within a subframe of a frame are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. The primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The UE 104 uses the PSS to determine the subframe / symbol timing and the physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The UE uses the SSS to determine the physical layer cell identification group number and the radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the location of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) may be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block. The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN). The Physical Downlink Shared Channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH (such as System Information Blocks (SIBs)), and paging messages.

[0052] like Figure 2CAs shown, some REs carry DM-RS for channel estimation at the base station (denoted as R for one specific configuration, but other DM-RS configurations are possible). The UE can transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH). The PUSCH DM-RS can be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS can be transmitted in different configurations depending on whether short PUCCH or long PUCCH is transmitted and the specific PUCCH format used. Although not shown, the UE can transmit a sounding reference signal (SRS). The base station can use the SRS for channel quality estimation to achieve frequency-dependent scheduling on the UL.

[0053] Figure 2D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and HARQ ACK / NACK feedback. The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0054] Figure 33 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0055] The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimate may be derived from a reference signal and / or channel condition feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0056] At the UE 350, each receiver 354RX receives a signal through its corresponding antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream sent to the UE 350. If multiple spatial streams are sent to the UE 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbol and reference signal on each subcarrier are recovered and demodulated by determining the signal constellation point most likely to be sent by the base station 310. These soft decisions can be based on the channel estimate calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. These data and control signals are then provided to the controller / processor 359, which implements Layer 3 and Layer 2 functions.

[0057] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0058] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0059] Channel estimates derived by the channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a corresponding spatial stream for transmission.

[0060] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

[0061] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using an ACK and / or NACK protocol to support HARQ operations.

[0062] Figure 4 4 is a schematic diagram of a device-to-device (D2D) communication system 400 including vehicle-to-everything (V2X) communications according to various aspects of the present disclosure. For example, the D2D communication system 400 may include V2X communications (e.g., a first UE 450 communicating with a second UE 451). In some aspects, the first UE 450 and / or the second UE 451 may be configured to communicate in a licensed radio spectrum and / or a shared radio spectrum. The shared radio spectrum may be unlicensed, and thus a variety of different technologies may use the shared radio spectrum for communication, including new radio (NR), LTE, advanced LTE, licensed assisted access (LAA), dedicated short range communications (DSRC), MuLTEFire, 4G, etc. The above list of technologies is considered illustrative and is not meant to be exhaustive.

[0063] The D2D communication system 400 can use NR wireless access technology. Of course, other wireless access technologies, such as LTE wireless access technology, can be used. In D2D communication (e.g., V2X communication or vehicle-to-vehicle (V2V) communication), UE 450, 451 can be on the networks of different mobile network operators (MNOs). Each network can operate in its own radio spectrum. For example, the air interface (e.g., Uu interface) to the first UE 450 can be on one or more frequency bands different from the air interface of the second UE 451. The first UE 450 and the second UE 451 can communicate via a sidelink component carrier (e.g., via a PC5 interface). In some examples, the MNO can schedule sidelink communications between UE 450 and 451 in a licensed radio spectrum and / or a shared radio spectrum (e.g., a 5GHz radio spectrum band).

[0064] The shared radio spectrum may be unlicensed, and thus different technologies may communicate using the shared radio spectrum. In some aspects, D2D communications (eg, sidelink communications) between UEs 450, 451 are not scheduled by the MNO. The D2D communication system 400 may also include a third UE 452.

[0065] For example, the third UE 452 may operate on the first network 410 (e.g., of the first MNO) or another network. The third UE 452 may perform D2D communication with the first UE 450 and / or the second UE 451. The first roadside unit (RSU) 420 may communicate with the third UE 452 via the sidelink carriers 432, 442. The first network 410 operates in the first spectrum and includes the first RSU 420 (e.g., communicating with at least the first UE 450, e.g., Figure 1-3 ). The first RSU 420 may communicate with the first UE 450 via the sidelink carriers 430, 440.

[0066] In some aspects, the second UE 451 can be on a different network than the first UE 450. In some aspects, the second UE 451 can be on a second network 411 (e.g., of a second MNO). The second network 411 can operate in a second spectrum (e.g., a second spectrum different from the first spectrum) and can include a second RSU 421 that communicates with the second UE 451, such as Figure 1-3 As shown. The second RSU 421 can communicate with the second UE 451 via the sidelink carriers 431, 441. The RSUs 420, 421 can be combined with traffic infrastructure (e.g., traffic lights, light poles, etc.). For example, the RSUs 420, 421 can be traffic lights located on the roadside. Additionally or alternatively, the RSUs 420, 421 can be independent units.

[0067] D2D communication (e.g., V2X communication and / or V2V communication) may also be implemented via one or more sidelink carriers 470, 480. The sidelink carriers 470, 480 may include one or more channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). In some examples, the sidelink carriers 470, 480 may operate using a PC5 interface. The first UE 450 may transmit to one or more (e.g., multiple) devices, including transmitting to the second UE 451 and the RSU 420 via the sidelink carriers (e.g., 470, 480). The second UE 451 may transmit to one or more (e.g., multiple) devices, including transmitting to the first UE 450 or the RSU 421 via the sidelink carriers (e.g., 470, 480). The RSU 420, 421 may forward the data received from the transmitter UE 450, 451 to the cellular network (e.g., gNB of the 5G network) (not shown) via UL transmission. The 5G network (e.g., gNB) may transmit the data received from the RSU 420, 421 to other UEs 450, 451 via DL transmission.

[0068] In some aspects, the UL sidelink carrier 440 and the first sidelink carrier 470 can be aggregated to increase bandwidth. In some aspects, the first sidelink carrier 470 and / or the second sidelink carrier 480 can share a first spectrum (with the first network 410) and / or share a second spectrum (with the second network 411). In some aspects, the sidelink carriers 470, 480 can operate in an unlicensed / shared radio spectrum.

[0069] In some aspects, the sidelink communication on the sidelink carrier may occur between the first UE 450 and the second UE 451. In one aspect, the first UE 450 may perform sidelink communication with one or more (e.g., multiple) devices including the second UE 451 via the first sidelink carrier 470. For example, the first UE 450 may send a broadcast transmission to multiple devices (e.g., the second and third UEs 451, 452) via the first sidelink carrier 470. The second UE 451 (e.g., and other UEs) may receive such a broadcast transmission. Additionally or alternatively, the first UE 450 may send a multicast transmission to multiple devices (e.g., the second and third UEs 451, 452) via the first sidelink carrier 470. The second UE 451 and / or the third UE 452 (e.g., and other UEs) may receive such a multicast transmission. The multicast transmission may be connectionless or connection-oriented. The multicast transmission may also be referred to as a groupcast transmission.

[0070] In addition, the first UE 450 may send a unicast transmission to a device (such as the second UE 451) via the first sidelink carrier 470. The second UE 451 (e.g., and other UEs) may receive such unicast transmissions. Additionally or alternatively, the second UE 451 may perform sidelink communications with one or more (e.g., multiple) devices including the first UE 450 via the second sidelink carrier 480. For example, the second UE 451 may send a broadcast transmission to multiple devices via the second sidelink carrier 480. The first UE 450 (e.g., and other UEs) may receive such broadcast transmissions.

[0071] In another example, the second UE 451 may send a multicast transmission to multiple devices (e.g., the first and third UEs 450, 452) via the second sidelink carrier 480. The first UE 450 and / or the third UE 452 (e.g., and other UEs) may receive such a multicast transmission. In addition, the second UE 451 may send a unicast transmission to a device (such as the first UE 450) via the second sidelink carrier 480. The first UE 450 (e.g., and other UEs) may receive such a unicast transmission. The third UE 452 may communicate in a similar manner.

[0072] For example, in some aspects, such sidelink communication on the sidelink carrier may occur without the MNO allocating resources for such communication (e.g., one or more portions of resource blocks (RBs), time slots, frequency bands, and / or channels associated with the sidelink carriers 470, 480) and / or without scheduling such communication. The sidelink communication may include traffic communication (e.g., data communication, control communication, paging communication, and / or system information communication). In addition, the sidelink communication may include sidelink feedback communication associated with the traffic communication (e.g., transmission of feedback information for previously received traffic communication). The sidelink communication may employ at least one sidelink communication structure having at least one feedback symbol. The feedback symbol of the sidelink communication structure may allocate any sidelink feedback information that may be communicated between devices (e.g., the first RSU 420, the second RSU 421, the first UE 450, the second UE 451, and / or the third UE 452) in the device-to-device (D2D) communication system 400.

[0073] In some aspects, the RSU 420, 421 or another device may include components for communicating, components for establishing, components for executing, components for sidelink transmission and reception, components for selecting, and components for managing. Such components may include components in conjunction with Figure 3 One or more components of a UE 350 or base station 310 are depicted.

[0074] In certain aspects, devices such as RSUs 420, 421 may have a distributed processing architecture. The sidelink architecture may be enhanced to support a cloud-like environment. Figure 5A and Figure 5B is a schematic diagram illustrating a use case of distributed sidelink processing according to aspects of the present disclosure. Figure 5A As shown, an enterprise or factory can deploy a side link auxiliary node (SLAN) that supports PC5 (licensed or unlicensed spectrum of PC5). Each SLAN can be connected between the data network 510 and the UE 450, 452 or the factory / enterprise component 512, 514, 516. The interface between the SLANs can be a PC5 link, and the interface between the factory component 512, 514, 516 and the UE 450, 452 can also be a PC5 link.

[0075] Figure 5B is a schematic diagram illustrating an in-vehicle networking use case according to aspects of the present disclosure. With in-vehicle networking (eg, V2X), a distributed PC5 implementation is deployed in a vehicle for logical distribution of in-vehicle processing. Figure 5B As shown, the central unit (CU), distributed units (DU) and radio units (RU) support PC5 with other information sources (e.g., sensors, electronic units, etc.) to provide coordinated multi-point (CoMP)-like coverage within the vehicle.

[0076] Figure 6 6 is a block diagram illustrating an example of a distributed architecture according to aspects of the present disclosure. RSU / SLAN 602 is shown in communication with data network 604. RSU / SLAN 602 functions may be divided into logical nodes. For example, central unit (CU) 606 is a logical node that includes all RSU / SLAN functions except for functions specifically assigned to distributed units (DU) 608. Central unit 606 controls the operation of DU 608.

[0077] Each distributed unit (DU) 608 is a logical node that includes a subset of RSU / SLAN functions according to the functional partitioning option (discussed below). Each DU 608 is connected to only one central unit 606. For the control plane, the SLF1-C (Side Link F1-Control) interface is supported to communicate between the DU 608 and the central unit 606. For the user plane, the SLF1-U (Side Link F1-User) interface may be supported to communicate between the DU 608 and the central unit 606.

[0078] The radio unit (RU) 610 includes a radio transceiver unit for sidelink transmission and reception. Multiple RUs 610 can be controlled by one distributed unit 608. Each RU 610 is controlled by only one distributed unit 608. A sidelink fronthaul interface (SLFI) can be used to communicate between the distributed unit 608 and the RU 610. The RU 610 can be deployed closer to the sidelink UE. The distributed unit 608 and the central unit 606 can be deployed in the cloud.

[0079] Each RSU / SLAN 602 communicates with other RSU / SLAN 602 for mobility processing of remote UEs. Mobility processing includes the situation where the UE moves from the coverage of one RSU / SLAN 602 to another RSU / SLAN 602. For inter-node communication, there are at least two options. Option one adopts enhancements to PC5 (e.g., PC5-S or PC5-RRC) to support remote UE mobility processing and data forwarding during mobility. Option two includes a new sidelink to everything (SLXn) interface to support communication between RSUs. SLXn-AP (application protocol), SLXn-UP (user plane) procedures can be defined to support mobility processing of remote UEs. In an exemplary configuration, in option two, the underlying physical transport can remain as PC5, where a new protocol layer is defined on PC5.

[0080] Figure 7 704. The RSU / SLAN 702 is shown in communication with a data network 704. The RSU / SLAN architecture 702 in the central unit can be logically divided into a control plane and multiple user plane processing entities. For example, a central unit control plane (CU-CP) entity 706 can be connected to a distributed unit (DU) 708 via an SLF1-C (side link F1-control) interface. One distributed unit 708 is connected to only one CU-CP 706. Each central unit user plane (CU-UP) 712 may only support user plane functions for certain types of services and bearers. The CU-CP 706 selects an appropriate CU-UP 712 for the service requested by the UE.

[0081] The central unit user plane (CU-UP) 712 is used for data forwarding, data routing, encryption, security processing and other user plane functions. For example, the CU-UP 712 communicates with the CU-CP 706 via the SLE1 interface. The communication defines a context for the user, including any control signaling exchange through the SLE1 interface to establish a user plane context for user plane function management (e.g., bearer management). For example, the CU-UP 712 is connected to the distributed unit 708 via the SLF1-U (side link F1-user) interface. Each CU-UP 712 is connected to only one CU-CP 706.

[0082] Each distributed unit 708 can be connected to multiple CU-UPs 712 under the control of the same CU-CP 706. One CU-UP 712 can be connected to multiple distributed units 708 under the control of the same CU-CP 706. Depending on where the CU-CP 706 manages the context, the CU-CP 706 can transmit to one distributed unit 708 or multiple distributed units 708. In other words, the connection between the CU-UP 712 and the distributed unit 708 is established by the CU-CP 706 using the bearer context management function. For example, each distributed unit 708 communicates with at least one radio unit 710 via SLFI (side link forward interface).

[0083] Figure 8 is a block diagram illustrating the partitioning of a protocol stack according to aspects of the present disclosure. Figure 8 , an exemplary PC5 protocol stack partitioning will be discussed. The PC5 stack and functions of the RSU / SLAN 802 can be distributed into logical nodes including a central unit (e.g., CU-CP 806 and CU-UP 812), a distributed unit 808, and a radio unit 810. According to this aspect of the present disclosure, the radio unit 810 handles PC5 lower physical layer functions. For example, the radio unit 810 communicates with the distributed unit 808 via an SLF1 interface. The distributed unit 808 manages the radio link control (PC5-RLC) channel of the PC5 link, the media access control (PC5-MAC) layer, and the upper physical layer functions.

[0084] CU-CP 806 is responsible for the control plane processing of the PC5 link between the RSU / SLAN 802 and the sidelink UE. CU-CP806 handles PC5-S signaling for connection establishment (PC5-S), radio resource control (PC5-RRC) for access layer configuration and capability exchange, and packet data convergence protocol (PC5-PDCP) functions to support the control plane services of the sidelink UE. CU-UP 812 manages the user plane connection between the RSU / SLAN 802 and the sidelink UE. CU-UP 812 handles the service data adaptation protocol (PC5-SDAP) and packet data convergence protocol (PC5-PDCP) functions to support the user plane services of the sidelink UE.

[0085] Fig. 9 is a block diagram illustrating an exemplary functional division between a central unit and distributed units according to aspects of the present disclosure. Although a particular protocol stack division has been described, the RSU / SLAN may be deployed with other protocol stack division options between distributed units and a central unit, such as in e.g. Fig. 9 As seen in and described in 3GPP TR 38.801, section 11 “RAN logical architecture for NR”, the disclosure of 3GPP TR 38.801, section 11 is incorporated herein by reference in its entirety.

[0086] Fig.10 is a block diagram illustrating a control plane protocol stack according to aspects of the present disclosure. Fig.10 , now discuss the communication between the sidelink UE (SL UE) 1002 and the RSU / SLAN control plane 1004 with a distributed processing architecture. The PC5-S layer, PC5-RRC layer and PC5-PDCP layer of the sidelink UE communicate with the corresponding layers in the central unit of the RSU / SLAN 1004. Control information within the sidelink UE 1002 is also passed from the PC5-RLC (radio link control) layer to the PC5-MAC (media access control) layer, and then to the PC5-PHY (physical) layer. The control information is then passed to the radio unit PC5-lower PHY layer. The radio unit communicates the information to the PC5-upper PHY layer in the distributed unit, which then processes the information upward to, for example, the SLF1 application protocol (SLF1-AP) through the PC5-MAC layer and PC5-RLC layer. The SLF1 application protocol, which performs UE context management, generates messages for transmission to the central unit. For example, these messages may be transmitted through a wired network via SCTP (Stream Control Transmission Protocol), IP, L2 (Layer 2), and L1 (Layer 1). These SCTP messages are not managed by PC5.

[0087] Fig.11 is a block diagram illustrating a user plane protocol stack in accordance with aspects of the present disclosure. Fig.11 User plane communication between a side link UE (SL UE) 1102 and a RSU / SLAN control plane 1104 with a distributed processing architecture is shown. After the control plane signaling is completed, the user plane signaling can route the data. For example, the side link UE 1102 processes the user application data downward to the PC5-PHY layer through the PC5 stack. The data is then sent to the radio unit PC5-lower PHY layer, which passes the data to the distributed unit PC5-upper PHY layer. The distributed unit processes the data upward to the PC5-RLC layer, which communicates with GTP-U (General Packet Radio Service (GPRS) Tunneling Protocol-User Plane) for tunneling the user plane packets to the central unit.

[0088] As mentioned above, Figure 4-Figure 11 are provided as examples. Other examples may be related to reference Figure 4-11 The content described is different.

[0089] Fig.12 is a flow chart illustrating an example method of wireless communication performed by a sidelink node according to aspects of the present invention.Process 1200 is an example of communicating with a distributed sidelink (SL) architecture and protocol stack.

[0090] like Fig.12 As shown, in some aspects, process 1200 may include communicating a control plane message from a central unit control plane entity to another side link node or side link user equipment (SL UE) via at least one distributed unit and at least one radio unit (block 1210). For example, a UE (e.g., using antenna 352, RX / TX 354, TX processor 368, RX processor 356, controller / processor 359, memory 360, etc.) or a base station (e.g., using antenna 320, RX / TX 318, TX processor 316, RX processor 370, controller / processor 375, memory 376, etc.) may communicate the control plane message.

[0091] like Fig.12As shown, in some aspects, process 1200 may include communicating a user plane message from a central unit user plane entity to another side link node or SL UE via at least one distributed unit and at least one radio unit (block 1220). For example, a UE (e.g., using antenna 352, RX / TX 354, TX processor 368, RX processor 356, controller / processor 359, memory 360, etc.) or a base station (e.g., using antenna 320, RX / TX 318, TX processor 316, RX processor 370, controller / processor 375, memory 376, etc.) may communicate the user plane message.

[0092] The following numbered clauses describe implementation examples.

[0093] 1. A sidelink node having a distributed processing architecture for wireless communications, the sidelink node comprising:

[0094] a central unit configured to perform a sidelink node function;

[0095] a plurality of distributed units, the plurality of distributed units comprising a first distributed unit and a second distributed unit, each distributed unit coupled to and controlled by the central unit, each distributed unit configured to perform a subset of the sidelink node functions; and

[0096] A plurality of radio units, the plurality of radio units comprising a first set of radio units coupled to and controlled by the first distributed unit and a second set of radio units coupled to and controlled by the second distributed unit, each radio unit being configured for sidelink transmission and reception.

[0097] 2. A sidelink node according to clause 1, wherein the sidelink node comprises a roadside unit (RSU), a sidelink (SL) user equipment (UE) and / or a sidelink auxiliary node (SLAN).

[0098] 3. A sidelink node according to clause 1 or 2, wherein at least one of the plurality of radio units is configured to communicate with another sidelink node or a sidelink (SL) user equipment (UE).

[0099] 4. A sidelink node according to any of the preceding clauses, wherein the central unit comprises:

[0100] a control plane coupled to each distributed unit and configured to select at least one of a plurality of user planes for a requested service, wherein each distributed unit is coupled to the control plane; and

[0101] The multiple user planes, each user plane is coupled to the control plane, wherein each distributed unit is coupled to the multiple user planes under the control of the control plane, and each user plane is coupled to the multiple distributed units under the control of the control plane.

[0102] 5. A sidelink node according to any of the preceding clauses, wherein the central unit comprises a first part of a PC5 stack, each distributed unit comprises a second part of the PC5 stack, and each radio unit comprises a third part of the PC5 stack.

[0103] 6. A side link node according to any of the preceding clauses, wherein a central unit control plane (CU-CP) is configured to manage the control plane of a PC5 link between the side link node and another side link node or a side link user equipment (SL UE), the control plane of the central unit comprising a PC5-radio resource control (RRC) function, a PC5-S function and a PC5-PDCP (Packet Data Convergence Protocol) function.

[0104] 7. A side link node according to any of the preceding clauses, wherein each of the multiple user planes of the central unit is configured to manage a user plane connection between the side link node and another side link node or a side link user equipment (SL UE), and each user plane of the central unit includes a PC5-PDCP (Packet Data Convergence Protocol) function and a PC5-SDAP (Service Data Adaptation Protocol) function.

[0105] 8. A side link node according to any of the preceding clauses, wherein each distributed unit is configured to manage the RLC (Radio Link Control), MAC (Media Access Control) and upper layer PHY (Physical) functions of the PC5 link between the side link node and another side link node or a side link user equipment (SL UE), and each distributed unit includes an application protocol for managing the control plane context between each distributed unit and the central unit.

[0106] 9. A sidelink node according to any of the preceding clauses, wherein each radio unit is configured to manage lower layer PHY (physical) functions of a PC5 link between the sidelink node and another sidelink node or a sidelink user equipment (SL UE).

[0107] 10. A side-link node as described in any of the preceding clauses, configured to communicate with another side-link node via an enhanced PC5 interface or an SLXn interface.

[0108] 11. A method for wireless communication by a sidelink node, comprising:

[0109] communicating a control plane message from the central unit control plane entity to another sidelink node or sidelink user equipment (SL UE) via at least one distributed unit and at least one radio unit; and

[0110] A user plane message is communicated from a central unit user plane entity to the other sidelink node or the SL UE via the at least one distributed unit and the at least one radio unit.

[0111] 12. The method of clause 11, wherein the control plane messages are communicated via a PC5 interface and the user plane messages are communicated via the PC5 interface.

[0112] 13. A method according to clause 11 or 12, wherein the control plane messages are communicated via an SLXn interface and the user plane messages are communicated via the SLXn interface.

[0113] 14. A method according to any of clauses 11-13, wherein the control plane messages are communicated via a PC5 interface and a tunnelling protocol, and the user plane messages are communicated via the PC5 interface and the tunnelling protocol.

[0114] 15. A method according to any of clauses 11-14, further comprising establishing a connection between the at least one distributed unit and the central unit control plane entity using a bearer context management function.

[0115] 16. The method according to any one of clauses 11 to 15, further comprising:

[0116] The central unit control plane entity manages the control plane functions of the PC5 link to the other side link node or the SL UE;

[0117] The user plane function of the PC5 link to the other side link node or the SL UE is managed by the central unit user plane entity;

[0118] managing, by the at least one distributed unit, RLC (Radio Link Control) layer functions, MAC (Media Access Control) layer functions, and upper physical layer functions of the PC5 link to the other side link node or the SL UE; and

[0119] The lower physical layer functions of the PC5 link to the other sidelink node or the SL UE are managed by the at least one radio unit.

[0120] 17. A non-transitory computer-readable medium having program code recorded thereon, the program code being executed by a sidelink node, and comprising:

[0121] Program code for communicating control plane messages from a central unit control plane entity to another sidelink node or sidelink user equipment (SL UE) via at least one distributed unit and at least one radio unit; and

[0122] Program code for communicating a user plane message from a central unit user plane entity to the other sidelink node or the SL UE via the at least one distributed unit and the at least one radio unit.

[0123] 18. The computer-readable medium of clause 17, wherein the program code that communicates the control plane messages communicates via a PC5 interface and the program code that communicates the user plane messages communicates via the PC5 interface.

[0124] 19. The computer-readable medium of clause 17 or 18, wherein the program code to communicate the control plane message communicates via an SLXn interface and the program code to communicate the user plane message communicates via the SLXn interface.

[0125] 20. The computer-readable medium of any of clauses 17-19, wherein the program code to communicate the control plane messages communicates via a PC5 interface and a tunneling protocol, and the program code to communicate the user plane messages communicates via the PC5 interface and the tunneling protocol.

[0126] 21. The computer-readable medium of any of clauses 17-20, further comprising program code for establishing a connection between the at least one distributed unit and the central unit control plane entity using a bearer context management function.

[0127] 22. The computer-readable medium of any of clauses 17-21, further comprising:

[0128] Program code for managing the control plane of the PC5 link with the central unit control plane entity;

[0129] program code for managing a user plane connection of said PC5 link with said central unit user plane entity;

[0130] program code to manage RLC (Radio Link Control) layer functions, MAC (Media Access Control) layer functions and upper physical layer functions of said PC5 link with said at least one distributed unit; and

[0131] Program code to manage underlying physical layer functions of said PC5 link with said at least one radio unit.

[0132] 23. An apparatus having a distributed processing architecture for wireless communications, comprising:

[0133] Components for performing side link node functions;

[0134] means for performing a subset of the sidelink node functions, the means for performing the subset of the sidelink node functions being coupled to and controlled by the means for performing the sidelink node functions; and

[0135] Means for sidelink transmission and reception are coupled to and controlled by the means for performing the subset of sidelink node functions.

[0136] 24. Apparatus according to clause 23, comprising a road side unit (RSU), a side link (SL) user equipment (UE) and / or a side link auxiliary node (SLAN).

[0137] 25. An apparatus according to clause 23 or 24, wherein the means for sidelink transmission and reception comprises means for communicating with a sidelink node or a sidelink (SL) user equipment (UE).

[0138] 26. An apparatus as described in any of clauses 23-25, wherein the means for performing a sidelink function comprises means for selecting at least one of a plurality of user planes for the requested service.

[0139] 27. An apparatus according to any one of clauses 23-26, wherein the component for performing sidelink functions comprises a first part of a PC5 stack, the component for performing the subset of sidelink functions comprises a second part of the PC5 stack, and the component for sidelink transmission and reception comprises a third part of the PC5 stack.

[0140] 28. An apparatus according to any of clauses 23-27, wherein the components for performing sidelink node functions include components for managing a control plane of a PC5 link with another sidelink node or a sidelink user equipment (SL UE), the control plane including a PC5-Radio Resource Control (RRC) function, a PC5-S function and a PC5-PDCP (Packet Data Convergence Protocol) function.

[0141] 29. An apparatus according to any of clauses 23-28, wherein the components for performing side link node functions include components for managing user plane connections with another side link node or side link user equipment (SL UE), each user plane connection including PC5-PDCP (Packet Data Convergence Protocol) functions and PC5-SDAP (Service Data Adaptation Protocol) functions.

[0142] 30. An apparatus according to any of clauses 23-29, further comprising means for communicating with a sidelink node via an enhanced PC5 interface or an SLXn interface.

[0143] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit these aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of these aspects.

[0144] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and / or a combination of hardware and software.

[0145] Some aspects are described herein in conjunction with thresholds. As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0146] Obviously, the systems and / or methods described herein and in Appendix A can be implemented in various forms of hardware, firmware, and / or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited in these respects. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code - it should be understood that software and hardware can be designed to implement the systems and / or methods based at least in part on the description herein.

[0147] Although specific combinations of features are described in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features can be combined in a manner that is not specifically described in the claims and / or not specifically disclosed in the specification. Although each dependent claim listed below may be directly subordinate to only one claim, the disclosure of various aspects includes each dependent claim combined with each other claim in the claim set. The phrase "at least one" mentioned in the list of items refers to any combination of those items, including single members. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, as well as any combination with multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc, or any other ordering of a, b and c).

[0148] Unless clearly described, any element, action or instruction used herein should not be interpreted as critical or necessary. In addition, as used herein, the articles "a" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more projects (e.g., related projects, unrelated projects, combinations of related and unrelated projects, etc.), and can be used interchangeably with "one or more". If only one project is referred to, phrase "only one" or similar language is used. In addition, as used herein, the terms "has", "have", "having" etc. are open terms. In addition, the phrase "based on" is intended to represent "based at least in part", unless otherwise explicitly stated.

Claims

1. A sidelink node having a distributed processing architecture for wireless communications, the sidelink node comprising: a central unit configured to perform a sidelink node function; a plurality of distributed units, the plurality of distributed units comprising a first distributed unit and a second distributed unit, each distributed unit being coupled to and controlled by the central unit, each distributed unit being configured to perform a subset of the sidelink node functions; as well as a plurality of radio units, the plurality of radio units comprising a first set of radio units coupled to and controlled by the first distributed unit and a second set of radio units coupled to and controlled by the second distributed unit, each radio unit being configured for sidelink transmission and reception; The side link node comprises a road side unit RSU and / or a side link auxiliary node SLAN, Wherein the central unit comprises: a control plane coupled to each distributed unit and configured to select at least one of a plurality of user planes for a requested service, wherein each distributed unit is coupled to the control plane; as well as The multiple user planes, each user plane is coupled to the control plane, wherein each distributed unit is coupled to the multiple user planes under the control of the control plane, and each user plane is coupled to the multiple distributed units under the control of the control plane.

2. The sidelink node according to claim 1, wherein the sidelink node comprises a sidelink SL user equipment UE.

3. The sidelink node according to claim 1, wherein at least one of the plurality of radio units is configured to communicate with another sidelink node or a sidelink SL user equipment UE.

4. The sidelink node of claim 1, wherein the central unit comprises a first portion of a PC5 stack, each distributed unit comprises a second portion of the PC5 stack, and each radio unit comprises a third portion of the PC5 stack.

5. The sidelink node according to claim 1, wherein a central unit control plane CU-CP is configured to manage a control plane of a PC5 link between the sidelink node and another sidelink node or a sidelink user equipment SL UE, and the control plane of the central unit includes a PC5-radio resource control RRC function, a PC5-S function and a PC5-packet data convergence protocol PDCP function.

6. The side link node according to claim 1, wherein each of the multiple user planes of the central unit is configured to manage the user plane connection between the side link node and another side link node or a side link user equipment SL UE, and each user plane of the central unit includes a PC5-Packet Data Convergence Protocol PDCP function and a PC5-Service Data Adaptation Protocol SDAP function.

7. A side link node according to claim 1, wherein each distributed unit is configured to manage the radio link control RLC, media access control MAC and upper layer physical PHY functions of the PC5 link between the side link node and another side link node or a side link user equipment SL UE, and each distributed unit includes an application protocol for managing the control plane context between each distributed unit and the central unit.

8. The sidelink node according to claim 1, wherein each radio unit is configured to manage lower layer physical (PHY) functions of a PC5 link between the sidelink node and another sidelink node or a sidelink user equipment (SL UE).

9. The side-link node of claim 1, configured to communicate with another side-link node via an enhanced PC5 interface or an SLXn interface.

10. An apparatus having a distributed processing architecture for wireless communication, comprising: Components for performing side link node functions; a plurality of components for performing a subset of the side-link node functions, the plurality of components for performing the subset of the side-link node functions comprising a first component for performing the subset of the side-link node functions and a second component for performing the subset of the side-link node functions, each component for performing the subset of the side-link node functions being coupled to and controlled by the component for performing the side-link node functions; as well as a plurality of components for sidelink transmission and reception, including a first component for sidelink transmission and reception and a second component for sidelink transmission and reception, the first component for sidelink transmission and reception being coupled to and controlled by the first component for performing a subset of the sidelink node functions, and the second component for sidelink transmission and reception being coupled to and controlled by the second component for performing a subset of the sidelink node functions; The device comprises a road side unit RSU and / or a side link auxiliary node SLAN, Wherein the components for performing the side link node function include: means for selecting at least one of a plurality of user planes for the requested service, coupled to each means for performing a subset of the sidelink node functions, and each means for performing a subset of the sidelink node functions is coupled to the means for selecting at least one of a plurality of user planes for the requested service; as well as A plurality of components for managing user plane connections with another side link node or a side link user equipment SL UE, each component for managing user plane connections with another side link node or SL UE is coupled to the component for selecting at least one of a plurality of user planes for a requested service, wherein each component for performing a subset of the side link node functions is coupled to the plurality of components for managing user plane connections with another side link node or SL UE under the control of the component for selecting at least one of a plurality of user planes for the requested service, and each component for managing user plane connections with another side link node or SL UE is coupled to the plurality of components for performing a subset of the side link node functions under the control of the component for selecting at least one of a plurality of user planes for the requested service. The apparatus according to claim 10 , comprising a SL UE.

12. The apparatus of claim 10, wherein at least one of the plurality of means for sidelink transmission and reception comprises means for communicating with a sidelink node or a SL UE.

13. An apparatus according to claim 10, wherein the component for performing the side link node function comprises a first part of the PC5 stack, each component for performing a subset of the side link node function comprises a second part of the PC5 stack, and each component for side link transmission and reception comprises a third part of the PC5 stack.

14. The apparatus according to claim 10, wherein the component for performing the sidelink node function includes a component for managing a control plane of a PC5 link with another sidelink node or a sidelink user equipment SL UE, the control plane including a PC5-radio resource control RRC function, a PC5-S function, and a PC5-packet data convergence protocol PDCP function.

15. The apparatus of claim 10, wherein each of the plurality of user planes comprises a PC5-Packet Data Convergence Protocol (PDCP) function and a PC5-Service Data Adaptation Protocol (SDAP) function.

16. The apparatus of claim 10, further comprising means for communicating with a sidelink node via an enhanced PC5 interface or an SLXn interface.

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