Communication device and communication method for operation in low-power state

Abstract

The present invention provides a communication device and communication method for operation in a low-power state. [Solution] The communication device UE comprises a circuit that determines a first power-saving state which is included in a plurality of power-saving states when in operation, and a transmitting / receiving unit which transmits and / or receives at least one type of sidelink signal corresponding to the determination of the first power-saving state when in operation. The method includes steps 1402 to set the UE to operate in a default power-saving state / initial power-saving state, step 1404 to determine other power-saving states to operate in and further set to switch to such power-saving states, step 1406 to start a timer, step 1408 to determine if the timer has expired, and step 1410 to decrease the timer by one unit if the timer has not expired. When the timer has expired, the UE is set to operate in its default power-saving state.

Description

Technical Field

[0001] The following disclosure relates to a communication device and a communication method for operating in a power-saving state, and more specifically, to a sidelink user equipment (UE).

Background Art

[0002] V2X (vehicle-to-everything) communication enables interaction between vehicles and the public road and other road users, and is thus considered an important element in realizing autonomous vehicles.

[0003] To accelerate the progress of realizing autonomous vehicles, the 3rd Generation Partnership Project (3GPP) has discussed V2X communication based on the new radio access technology (NR) of 5G (also referred to as NR N2X communication and mutually interchangeable) for the identification of technical solutions for advanced V2X services. Through V2X communication, a vehicle (i.e., also referred to as a communication device or user equipment (UE) that supports V2X applications and mutually interchangeable) can exchange its status information with other nearby vehicles, infrastructure nodes, and / or pedestrians via sidelink (SL). The status information includes information such as position, speed, and orientation.

[0004] According to the V2X Work Item Description (WID) (Non-Patent Literature 1) of Release 17 (Rel-17), power saving allows battery-constrained UEs to perform side-link operation with high power efficiency. The NR side-link in Rel-16 is designed based on the assumption of an "always-on" operation where the UE operates the side-link, focusing, for example, only on UEs installed in vehicles with sufficient battery capacity. Solutions for power saving in Rel-17 are needed for vulnerable road users (VRUs) in V2X use cases, and for UEs in public safety and commercial use cases where power consumption in the UE needs to be minimized.

[0005] Furthermore, at the RAN1#103-e meeting, two types of UE receivers (i.e., a type with receiving capability and a type without) were determined regarding the evaluation and power-saving characteristics of Rel-17. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] RP-202846 [Non-Patent Document 2] 3GPP TS 38.300 v16.3.0 [Non-Patent Document 3] 3GPP TS 38.211 v16.3.0 [Non-Patent Document 4] TS 23.502 [Non-Patent Document 5] ITU-R M.2083 [Non-Patent Document 6] TR 38.913 [Non-Patent Document 7] TS 23.287 v16.4.0 [Non-Patent Document 8] European Telecommunication Standards Institute (ETSI) technical report (TR) 103 300 [Overview of the project] [Problems that the invention aims to solve]

[0007] Specifically, there are no clear regulations yet regarding how SL UE should be power-efficient, or how SL UE should balance its power efficiency with performance requirements.

[0008] Therefore, there is a need to develop new communication devices and communication methods that address one or more of the above challenges and operate in a low-power state. Furthermore, other desirable features and characteristics will become apparent from the following detailed description and the appended claims, in conjunction with the accompanying drawings and the background art of this disclosure. [Means for solving the problem]

[0009] One non-limiting, exemplary embodiment contributes to providing a communication device and communication method for utilizing SL-RSRP in V2X resource sensing and V2X resource selection.

[0010] In a first aspect, the disclosure provides a communication device comprising: a circuit that, when in operation, determines one of a plurality of power-saving states to operate in; and a transceiver that, when in operation, transmits and / or receives at least one type of sidelink signal corresponding to the determination of one of the plurality of power-saving states.

[0011] In a second aspect, the Disclosure provides a communication method for determining one of a plurality of power-saving states to operate in, and transmitting and / or receiving at least one type of sidelink signal corresponding to the determination of one of the plurality of power-saving states.

[0012] Note that general or specific embodiments can be implemented as a system, method, integrated circuit, computer program, storage medium, or any optional combination thereof.

[0013] Further benefits and advantages of the disclosed embodiments will become apparent from the specification and the drawings. These benefits and / or advantages can be obtained individually by various embodiments and features of the specification and the drawings, and it is not necessary to provide all embodiments and features for the purpose of obtaining one or more of such benefits and / or advantages.

Brief Description of Drawings

[0014] The embodiments of the present disclosure are merely examples, but will be better understood and readily apparent to those skilled in the art from the following description and in association with the drawings. [Figure 1] Diagram showing an exemplary 3GPP NR-RAN architecture [Figure 2] Schematic diagram showing the functional split between NG-RAN and 5GC [Figure 3] Sequence diagram of the setup / reset procedure for a radio resource control (RRC) connection [Figure 4] Schematic diagram showing the usage scenarios of enhanced Mobile BroadBand (eMBB), massive Machine Type Communications (mMTC), and Ultra Reliable and Low Latency Communications (URLLC) [Figure 5] Block diagram showing an exemplary 5G system architecture for V2X communication in a non-roaming scenario [Figure 6] Schematic diagram of an example of a communication device according to various embodiments (the communication device can be implemented as a UE or a gNB / base station, and according to various embodiments of the present disclosure, vulnerable road users can be set to transmit a first signal at periodic transmission time intervals.) [Figure 7] Flowchart showing a communication method for a vulnerable road user to transmit a first signal at periodic transmission time intervals according to various embodiments of the present disclosure [Figure 8] Flowchart showing four power saving state settings for SL signal reception according to an embodiment of the present disclosure [Figure 9] Flowchart showing the use of a notification signal to configure a UE to operate in one of a plurality of power saving states according to various embodiments of the present disclosure [Figure 10] Flowchart showing the use of a notification signal to configure a UE to operate in one of a plurality of power saving states according to various embodiments of the present disclosure [Figure 11] Flowchart showing the use of a notification signal to configure a UE to operate in one of a plurality of power saving states according to various embodiments of the present disclosure [Figure 12] Flowchart showing a process of switching from a current power saving state to a preferred power saving state according to an embodiment of the present disclosure [Figure 13] Flowchart showing a process of switching from a power saving state currently operating by a communication device to another power saving state by another communication device according to an embodiment of the present disclosure [Figure 14] Flowchart showing a process of operating in a default power saving state according to an embodiment of the present disclosure

[0015] Those skilled in the art can understand that the elements in the figure are clearly and simply explained and are not necessarily drawn to a certain scale. For example, in order to better understand this embodiment, the dimensions of some of the elements in the figure, block diagram, or flowchart may be exaggerated with respect to other elements.

Embodiments for Carrying Out the Invention

[0016] Some embodiments of this disclosure will be described, by example, with reference to the drawings. Similar reference numerals and letters in the drawings refer to similar or equivalent elements.

[0017] 3GPP is continuing work towards the next release of fifth-generation mobile phone technology (also simply called "5G"), including the development of new radio access technologies (NR) operating in the frequency range up to 100 GHz. The first version of the 5G standard was completed at the end of 2017, which enabled the prototyping and commercial deployment of smartphones compliant with the 5G NR standard. The second version of the 5G standard was completed in June 2020, further expanding the reach of 5G to new services, spectrums, and deployments such as Unlicensed Spectrum (NR-U), Non-Public Networks (NPN), Time-Sensitive Networking (TSN), and Cellular V2X.

[0018] In particular, the system architecture as a whole assumes an NG-RAN (Next Generation - Radio Access Network) equipped with gNBs. The gNBs provide the UE-side termination for the user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols of the NG radio access. The gNBs are connected to each other by Xn interfaces. Furthermore, the gNBs are connected to the NGC (Next Generation Core) by Next Generation (NG) interfaces, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing AMF) by NG-C interfaces, and to the UPF (User Plane Function) (e.g., a specific core entity performing UPF) by NG-U interfaces. The NG-RAN architecture is shown in Figure 1 (see, for example, Non-Patent Document 2).

[0019] The NR user plane protocol stack (see, for example, Section 4.4.1 of Non-Patent Document 2) includes the PDCP (Packet Data Convergence Protocol (see Section 6.4 of Non-Patent Document 2)) sublayer, RLC (Radio Link Control (see Section 6.3 of Non-Patent Document 2)) sublayer, and MAC (Medium Access Control (see Section 6.2 of Non-Patent Document 2)) sublayer, which are terminated on the network side in gNB. Additionally, a new access layer (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, Section 6.5 of Non-Patent Document 2). Furthermore, a control plane protocol stack is defined for NR (see, for example, Section 4.4.2 of Non-Patent Document 2). An overview of the Layer 2 functionality is described in Section 6 of Non-Patent Document 2. The functions of the PDCP, RLC, and MAC sublayers are enumerated in Sections 6.4, 6.3, and 6.2 of Non-Patent Document 2, respectively. The functions of the RRC layer are listed in Section 7 of Non-Patent Document 2.

[0020] For example, the Medium-Access-Control layer handles logical channel multiplexing and scheduling and scheduling-related functions, including handling various neural networks.

[0021] For example, the physical layer (PHY) is responsible for coding, processing hybrid automatic repeat requests (HARQ), modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The physical layer also handles the mapping of transport channels to physical channels. The physical layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include the Physical Random Access Channel (PRACH), Physical Uplink Shared Channel (PUSCH), and Physical Uplink Control Channel (PUCCH) for uplinks; the Physical Downlink Shared Channel (PDSCH), Physical Downlink Control Channel (PDCCH), and Physical Broadcast Channel (PBCH) for downlinks; and the Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Feedback Channel (PSFCH) for sidelinks (SL).

[0022] SL supports direct inter-UE communication using SL resource allocation modes, physical layer signals / physical layer channels, and physical layer procedures. Two SL resource allocation modes are supported: (a) Mode 1, where SL resource allocation is provided by the network, and (b) Mode 2, where the UE determines the SL transmit resources in the resource pool.

[0023] PSCCH indicates the resources and other transmission parameters used by the UE for PSSCH. A PSCCH transmission is associated with a Demodulation Reference Signal (DM-RS). A PSSCH transmits the Transport Block (TB) of the data itself, along with control information such as HARQ procedures and Channel State Information (CSI) feedback triggers. At least six Orthogonal Frequency Division Multiplex (OFDM) symbols in the slot are used for PSSCH transmissions. A PSSCH transmission is associated with a DM-RS and may also be associated with a Phase-Tracking Reference Signal (PT-RS).

[0024] PSFCH carries HARQ feedback via SL from the UE that is the intended recipient of the PSSCH transmission to the UE that performed the transmission. The PSFCH sequence is transmitted in one PRB that is repeated across two OFDM symbols near the end of the SL resource in the slot.

[0025] The SL synchronization signal consists of the SL Primary Synchronization Signal (S-PSS) and the SL Secondary Synchronization Signal (S-SSS), occupying 2 symbols and 127 subcarriers, respectively. The Physical Sidelink Broadcast Channel (PSBCH) occupies 9 symbols and 5 symbols in the case of a normal cyclic prefix and an extended cyclic prefix, respectively, and includes the associated demodulation reference signal (DM-RS).

[0026] Regarding the physical layer procedure for HARQ feedback in sidelinks, SL HARQ feedback uses PSFCH and can be performed in one of two options. In one option, which can be set to unicast and groupcast, the PSFCH sends either an ACK or a NACK using a resource dedicated to the single UE sending the PSFCH. In the other option, which can be set to groupcast, the PSFCH sends either a NACK on a resource that can be shared by multiple UEs sending the PSFCH, or no PSFCH signal is sent.

[0027] In SL resource allocation mode 1, a UE that receives a PSFCH can report SL HARQ feedback to the gNB via PUCCH or PUSCH.

[0028] Regarding physical layer procedures for power control in sidelinks, in the case of in-coverage operation, the power spectral density of SL transmissions may be adjusted based on path loss from the gNB, while in the case of unicast, the power spectral density of several SL transmissions may be adjusted based on path loss between the two communicating UEs.

[0029] Regarding the physical layer procedure in CSI reporting, in the case of unicast, the Channel Status Information Reference Signal (CSI-RS) is supported for CSI measurement and CSI reporting in the sidelink. The CSI report is carried in the SL MAC CE.

[0030] For measurements in sidelinks, the following UE measurements are supported. • PSBCH Reference Signal Received Power (PSBCH RSRP) • PSSCH reference signal received power (PSSCH-RSRP) • PSCCH reference signal received power (PSCCH-RSRP) Sidelink Received Signal Strength Indicator (SL RSSI); Sidelink Channel Occupancy Ratio (SL CR); • Sidelink Channel Busy Ratio (SL CBR)

[0031] NR use cases / deployment scenarios can include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC), each with diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps on the downlink and 10 Gbps on the uplink) and effective (user-experienced) data rates approximately three times that of IMT-Advanced. URLLC, on the other hand, has more stringent requirements, including ultra-low latency (0.5 ms for both UL and DL for user plane latency) and high reliability (1-10 ms within 1 ms).-5 ) is required. Finally, mMTC preferably has a high connectivity density (1,000,000 devices / km in urban environments). 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices may be required.

[0032] Therefore, an OFDM neurology (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) suitable for one use case may not be effective for other use cases. For example, low-latency services may preferably require a shorter symbol length (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with shorter delay spreads. The subcarrier spacing should be optimized on a case-by-case basis so that similar CP overhead is maintained. NR may support one or more subcarrier spacing values. Therefore, currently, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc., are being considered. Symbol length T u And the subcarrier spacing Δf is given by the equation Δf = 1 / T u It is directly related by [the same principle]. Similar to the LTE system, the term “resource element” can be used to mean the smallest resource unit composed of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0033] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each neurology and each carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see Non-Patent Literature 3).

[0034] Figure 2 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0035] In particular, gNB and ng-eNB host the following main functions: - Radio resource management functions such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to UEs on both uplink and downlink; - Compression, encryption, and integrity protection of the IP header of the data; - Selection of the AMF when the UE attaches if routing to the AMF cannot be determined from the information provided by the UE; - Routing user plane data toward UPF; - Routing of control plane information to AMF; - Setting up and disconnecting connections; - Scheduling and sending paging messages; - Scheduling and transmission of system notification information (originating from AMF or Operation, Admission, Maintenance functions (OAM)); - Setting up measurements and reporting for mobility and scheduling; - Transport-level packet marking on the uplink; - Session management; - Support for network slicing; - Mapping for QoS flow management and data radio bearers; - Support for UEs in the RRC_INACTIVE state; - Non-Access Stratum (NAS) message delivery function; - Sharing of wireless access network; - Dual connectivity; - Close cooperation between NR and E-UTRA.

[0036] The Access and Mobility Management Function (AMF) hosts the following main functions: - A function to terminate signaling in the Non-Access Stratum (NAS); - Security of NAS signaling; - Security control of Access Stratum (AS); - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of the UE in idle mode (including control and execution of paging retransmissions); - Management of registration areas; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming permission checks; - Mobility management and control (enrollment and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0037] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Routing and forwarding of packets; - Packet inspection and enforcement of policy rules in the user plane. - Reporting traffic usage; - Uplink classifier that supports routing of traffic flow to data networks; - Branching point for supporting multi-homed PDU sessions; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of upstream link traffic (mapping to SDF QoS flow); - Buffering of downlink packets and triggering of downlink data notifications.

[0038] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - Assignment and management of IP addresses for UEs; - UPF selection and control; - A traffic steering configuration feature in User Plane Functions (UPF) for routing traffic to the appropriate destination; - Policy enforcement and QoS for the control unit; - Notification of downlink data.

[0039] Figure 3 shows some of the interactions between the UE, gNB, and AMF (5GC entity) during the transition of the UE from RRC_IDLE to RRC_CONNECTED in the NAS portion (see Non-Patent Document 2). The transition steps are as follows: 1. The UE requests that a new connection be set up from the RRC_IDLE state. 2 / 2a.gNB completes the RRC setup procedure. Note: The following describes scenarios in which gNB rejects a request. 3. In RRCSetupComplete, the first NAS message from the UE, sent via piggyback, is sent to the AMF. 4 / 4a / 5 / 5a. Additional NAS messages may be exchanged between the UE and the AMF (see Non-Patent Document 4). 6. The AMF prepares the UE context data (including PDU session context, security key, UE radio capability, and UE security capability, etc.) and sends it to the gNB. 7 / 7a.gNB activates AS security with the UE. 8 / 8a.gNB performs a reconfiguration to set up SRB2 and DRB. 9. The gNB notifies the AMF that the setup procedure is complete.

[0040] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. Specifically, this transition requires AMF to prepare UE context data (which includes, for example, PDU session context, security key, UE Radio Capability, UE Security Capabilities, etc.) and send it to the gNB along with an Initial Context Setup Request. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, and the UE responding to the gNB with a SecurityModeComplete message. Subsequently, the gNB sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures itself to set up the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, gNB notifies AMF that the setup procedure is complete with an Initial Context Setup Response.

[0041] Figure 4 shows some use cases for 5G NR. The 3rd generation partnership project new radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specification development for enhanced mobile-broadband (eMBB) has been completed. Current and future work will include expanding support for eMBB, as well as standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 4 shows some examples of anticipated use scenarios for IMT beyond 2020 (see, for example, Figure 2 in Non-Patent Document 5).

[0042] URLLC use cases have stringent performance requirements such as throughput, latency, and availability, and URLLC use cases are envisioned as one of the necessary tools to enable future applications such as wireless control of industrial production or manufacturing processes, telemedicine surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set out in Non-Patent Document 6. In NR URLLC in Release 15, a key requirement is that the target user plane latency is 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). A typical URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size when the user plane latency is 1 ms.

[0043] From a physical layer perspective, reliability can be improved in many ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, and PDCCH repetition. However, this room for improvement may expand towards achieving ultra-high reliability as NR becomes more stable and developed (in terms of critical requirements for NR URLLC). Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0044] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level repetition on data channels, and preemption on downlink. Preemption means that a transmission for which a resource has already been allocated is stopped, and that allocated resource is used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, transmissions that were already permitted are replaced by later transmissions. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (eMBB, etc.). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for the 1E-5 target BLER.

[0045] A key characteristic of mMTC (massive machine type communication) use cases is the extremely large number of connected devices that typically transmit relatively small amounts of data that are less susceptible to latency. These devices are required to be low-cost and have very long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one solution that saves power from the user interface (UE) and extends battery life.

[0046] As mentioned above, the scope of reliability improvements in NR is expected to broaden. High or very high reliability is a critical requirement in all cases, and especially for URLLC and mMTC. Several mechanisms can improve reliability from both a radio and network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvements regardless of the specific communication scenario.

[0047] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include high reliability (10 -6 Features include reliability up to a certain level, high availability, packet size up to 256 bytes, and time synchronization down to a few microseconds (depending on the use case, the value can be set to 1 microsecond or a few microseconds depending on the frequency range and short latency of approximately 0.5 ms to 1 ms (especially 0.5 ms latency on the target user plane)).

[0048] Furthermore, several technical enhancements are possible for NR URLLC from a physical layer perspective. These enhancements include enhancements to the PDCCH (Physical Downlink Control Channel) for compact DCI, increased PDCCH repetition, and increased PDCCH monitoring. Enhancements to the UCI (Uplink Control Information) relate to enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Enhancements to PUSCH related to mini-slot level hopping, and enhanced retransmission / repetition are also possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) containing fewer symbols than a slot (a slot contains 14 symbols).

[0049] The 5G Quality of Service (QoS) model is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR (Granteed Bit Rate) QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity of QoS within a PDU session. QoS flows are identified within a PDU session by a QoS Flow ID (QFI) carried in the encapsulation header via the NG-U interface.

[0050] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearers (DRB) in accordance with the PDU session, as shown above, for example, in Figure 3. Additional DRBs for the QoS flow of that PDU session can be configured later (when this is done is up to the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0051] Figure 5 shows the non-roaming reference architecture for 5G NR (see Section 4.2.1.1 of Non-Patent Document 7). An Application Function (AF) (for example, an external application server hosting 5G services, as illustrated in Figure 4) interacts with the 3GPP core network to provide services, such as influencing traffic routing, accessing the Network Exposure Function (NEF), or interacting with the policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on operator deployment, Application Functions considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions not authorized by the operator to directly access the Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0052] Figure 5 further illustrates the functional units of the 5G architecture for V2X communication, namely the Unified Data Management (UDM), Policy Control Function (PCF), Network Exposure Function (NEF), Application Function (AF), Unified Data Repository (UDR), Access and Mobility Management Function (AMF), Session Management Function (SMF), and User Plane Function (UPF) in 5GC, as well as the V2X Application Server (V2AS) and Data Network (DN; e.g., operator-provided services, internet access, or third-party services). All or part of the core network functions and application services may be deployed and operated in a cloud computing environment.

[0053] According to Non-Patent Document 8, the flow summarized from a V2X use case for vulnerable road users (VRUs) includes the following: 1. Detection of the presence of VRU. The options are as follows: Self-positioning by the VRU, which has sensors that enable it to determine its own characteristics, including its position and velocity, and may also have other sources. • Detection and tracking of VRUs by other road users (e.g., V-ITS-S). • Detection and tracking of VRUs by roadside units connected to R-ITS-S or Central ITS-S. 2. An assessment of whether the VRU is exposed to potential risks from other road users, along with the VRU's location and dynamic status, should be transmitted. Either party may transmit information about the VRU that they know. Information about the VRU should be filtered and transmitted only according to message trigger conditions. Potential risks from other road users depend, among other things, on the following conditions: Road layout, • Dynamic status of VRU and other road users, as well as • Traffic signal status and compliance with traffic signals for both the VRU and (where applicable) the vehicle. 3. Evaluation of a secure messaging environment to determine whether the VRU's own ITS-S should send a message (specifically, evaluation of whether the VRU is part of a cluster). 4. Sending information about VRUs at risk. The options are as follows: • VRU sends ego-status information. The VRU cluster leader sends cluster information. • V-ITS-S, R-ITS-S, C-ITS-S, or other road users transmit information about VRUs in potentially risky situations. 5. Risk assessment. This includes the following phases (receiving side): • Fusion of sensor data and observational information transmitted by other road users to build local dynamic maps, with information about the road user's location, speed, and, if possible, other data (e.g., intent), and • Risk assessment based on estimated trajectories and speeds of various road users. 6. Warnings or measures to protect the VRU, including the following: • Warnings from device carriers (VRU or other road users) • Sending collision warnings to other road users, and • Measures to be taken in the case of autonomous vehicles. It includes.

[0054] As mentioned above, the most basic step in addressing VRU safety concerns is detecting the presence of the VRU. It is unclear when a VRU-UE should transmit SL broadcast signals and safety messages to indicate its presence. Furthermore, it should be noted that DRX is used for power saving purposes on LTE and NR uplink and downlink (Uu) connections. A VRU-UE should monitor potential PDCCHs and activate DRX on-duration for potential transmissions. Based on this, UEs with SL capabilities should utilize the DRX function as much as possible to minimize activation time for power saving purposes.

[0055] In the various embodiments described below, the following types of road users are considered vulnerable road users (VRUs) according to the classification in Non-Patent Document 8 and Annex 1 of Regulation (EU) 168 / 2013[i.8]. • Pedestrians (including children, the elderly, and joggers). • Emergency responders, safety workers, road workers. • Animals such as horses, dogs, and related wild animals (see notes below). Wheelchair users, strollers. • Skaters, skateboarders, and Segways that may be equipped with electric engines. • Bicycles and electric-assist bicycles (e-bikes) with a speed limit of 25 km / h (electric-assist bicycles, Class L1e-A [i.8]). • High-speed e-bike (Class L1e-B[i.8]) with a top speed of 25 km / h or more. • Electric two-wheeled vehicles (PTW: Powered Two Wheeler), mopeds (scooters) (Class L1e [i.8]). • PTW, motorcycle (Class L3e[i.8]); • PTW (Pedestrian-Traffic Wheelchair) with a 45 km / h speed limit; three-wheeled vehicles (Class L2e, L4e, L5e[i.8]); • PTW with a 45 km / h speed limit, four-wheeled vehicle (Class L5e and L6e[i.8]). Note: The relevant wildlife is limited to animals that pose a safety risk to other road users (VRUs, vehicles).

[0056] In the various embodiments described below, the communication device may refer to a sidelink UE. The sidelink UE may transmit and / or receive sidelink signals such as the physical sidelink control channel (PSCCH), physical sidelink shared channel (PSSCH), sidelink synchronization block (S-SSB), physical sidelink feedback channel (PSFCH), first and second stage sidelink control information (SCI), downlink control notification signals, radio resource control signals, media access control (MAC) control element (CE), radio resource control (RRC) signals, physical downlink control channel (PDCCH), sidelink synchronization signal (SLSS), physical sidelink broadcast channel (PSBCH), and physical sidelink feedback channel (PSFCH).

[0057] According to this disclosure, a communication device may be configured to operate in a power-saving state, or to decide to operate in a power-saving state. The power-saving state may be one of several power-saving states in which the communication device can operate. Each of the several power-saving states corresponds to a variety of features / capabilities characterized by different levels of power saving during operation.

[0058] In various embodiments in which a communication device may refer to a sidelink (SL) user device (UE), other communication devices may communicate with the sidelink UE by transmitting and / or receiving sidelink signals. These other communication devices are (i) a base station (gNodeB or gNB) or one of the cellular networks (in which case the sidelink UE is within the network coverage of the base station or cellular network), and (ii) other sidelink UEs, regardless of whether both the sidelink UE and the other sidelink UE are within the network coverage of the base station.

[0059] In various embodiments, the default power-saving state or initial power-saving state may be one of several power-saving states that the communication device has (pre-configured) for operation. Such a default / initial power-saving state may be the most power-saving state, the most power-consuming state, or a preferred / appropriate power-saving state. The default / initial power-saving state is determined by the communication device or by other communication devices (e.g., gNB, other SL UE) based on current operating conditions and parameters, or any other state. Such a default power-saving state may also be (pre-configured) or (pre-defined) by a specification (e.g., a 3GPP specification), a government regulatory authority, or a UE vendor.

[0060] In various embodiments, the term "state" of a power-saving state can be used interchangeably with "mode," "method," "type," and "level."

[0061] In various embodiments, parameters relating to the communication device may refer to relevant factors considered and used in determining the operating power-saving state, such as the transmission and reception priority of the communication device, the speed at which the communication device moves, the type of communication device, the type of vehicle (e.g., train, bus, van, sedan, bicycle), the location of the communication device 600 by the Global Navigation Satellite System (GNSS), the congestion level of network traffic and road traffic around the communication device 600, and a zone identifier (ID) indicating the geographic zone in which the communication device 600 is located.

[0062] As mentioned above, it is unclear how SL UE should be in a power-saving state or how it should operate in a power-saving state, and how SL UE balances its own power saving and performance requirements, for example, to transmit or receive certain types of sidelink signals. Therefore, it is necessary to develop new communication devices and communication methods to address one or more of the above challenges and to operate in a power-saving state.

[0063] According to this disclosure, multiple power-saving states are defined for an SL UE, and the SL UE determines one of these power-saving states and is configured to operate in one of these power-saving states. Each of the multiple power-saving states is associated with a different feature / capability that is characterized by a different level of power saving. The power-saving states can be set or changed by any of the following: RRC setting parameters, MAC CE, a new SCI field / format by PSCCH signaling, or a new DCI field / format by PDCCH signaling.

[0064] As shown in Figure 6, the communication device 600 may include a circuit 614, at least one wireless transmitter 602, at least one wireless receiver 604, and at least one antenna 612 (for simplicity, only one antenna is shown in Figure 6 for illustrative purposes). The circuit 614 may include at least one control unit 1506. The control unit 606 is used to perform tasks designed to be performed by at least one control unit 606, with the assistance of software and hardware. Tasks include controlling communication with one or more other communication devices in a wireless network. The circuit 614 may further include at least one transmit signal generator 608 and at least one receive signal processing unit 610. At least one control unit 606 can control, under the control of at least one control unit 606, at least one transmit signal generation unit 608 for generating signals (e.g., sidelink / uplink / downlink signals) to be transmitted via at least one radio transmitter 602 to one or more other communication devices (e.g., base station communication devices), and at least one receive signal processing unit 610 for processing signals (e.g., sidelink / uplink / downlink signals) received from one or more other communication devices via at least one radio receiver 604 under the control of at least one control unit 606. The at least one transmit signal generation unit 608 and the at least one receive signal processing unit 610 may be standalone modules of a communication device 600 that communicate with the at least one control unit 606 for the functions described above, as shown in Figure 6. Alternatively, the at least one transmit signal generation unit 608 and the at least one receive signal processing unit 610 may be included in the at least one control unit 606. In various embodiments, during operation, at least one wireless transmitter 602, at least one wireless receiver 604, and at least one antenna 612 may be controlled by at least one control unit 606.

[0065] At least one wireless transmitter 602 and at least one wireless receiver 604 may be included in a standalone module of the communication device 600, each performing both the functions of transmitting and receiving signals with other communication devices. Such modules may be referred to as transceivers in various embodiments of the present disclosure.

[0066] It will be apparent to those skilled in the art that the arrangement of these functional modules is flexible and may change according to actual needs and / or requirements. Data processing, virtual memory, and other related control devices can be provided on a suitable circuit board and / or within a chipset.

[0067] The communication device 600 provides functions necessary for operation in a power-saving state when in operation. For example, the communication device 600 may be a sidelink UE or a VRU-UE. Circuit 614 (at least one control unit 606 of circuit 614) may, when in operation, determine one of a plurality of power-saving states for operation, and the transmitting / receiving unit (including at least one wireless transmitting unit 602 and at least one wireless receiving unit 604) may, when in operation, transmit and / or receive at least one type of sidelink signal corresponding to the determination of one of the plurality of power-saving states. In the embodiment, at least one transmitting signal generation unit 608 and at least one receiving signal processing unit 610 may, respectively, be configured to transmit and / or receive at least one type of sidelink signal so that at least one wireless transmitting unit 602 and at least one wireless receiving unit 604, or the transmitting / receiving unit (including at least one wireless transmitting unit 602 and at least one wireless receiving unit 604), transmits and / or receives at least one type of sidelink signal when in operation.

[0068] In one embodiment, the transmitting / receiving unit may receive a notification signal from another communication device relating to one of a plurality of power-saving states, the notification signal may include a request to operate in one of the plurality of power-saving states, and the circuit 614 (at least one control unit 606 of the circuit 614) decides to operate in one of the plurality of power-saving states in response to the receipt of the notification signal.

[0069] In other embodiments, when determining which power-saving state to operate in, the circuit 614 (at least one control unit 606 of the circuit 614) may acquire parameters relating to the communication device 600, and the circuit 614 (at least one control unit 606 of the circuit 614) may decide to operate in one of a plurality of power-saving states based on the acquired parameters.

[0070] In yet another embodiment, with respect to one of a plurality of power-saving states from the other communication device (for example, a suitable power-saving state that balances power saving with performance requirements determined based on parameters), the transceiver may transmit support information to the other communication device, including the parameters described above regarding the communication device 600, before receiving a notification signal from the other communication device informing the communication device to operate in the power-saving state. The circuit 614 (at least one control unit 606 of the circuit 614) then decides to operate in one of the plurality of power-saving states in response to the receipt of the notification signal.

[0071] In other embodiments, the circuit 614 of the communication device 600 may identify one of a plurality of power-saving states based on parameters relating to the communication device 600, and may, for example, operate in a preferred power-saving state (or switch to a preferred power-saving state). The transmitting / receiving unit may further transmit a request signal to the other communication device indicating a request to operate in one of the plurality of power-saving states (or switch to one of the plurality of power-saving states). The transmitting / receiving unit may then receive a response signal from the other communication device that accepts the request and enables the communication device 600 to operate in the power-saving state identified by the communication device.

[0072] Figure 7 shows a flowchart illustrating a communication method 700 for operating in a power-saving state according to various embodiments of the present disclosure. Step 702 is a step of determining one of a plurality of power-saving states. Step 704 is a step of transmitting and / or receiving at least one type of sidelink signal corresponding to the determination of one of the plurality of power-saving states. According to the present disclosure, the power-saving states are characterized by different levels of power saving during operation, by being (pre-defined) for the UE for various SL receiving capabilities. Figure 8 shows a flowchart 800 illustrating four power-saving state settings (states D1 to D4) for SL signal reception according to one embodiment of the present disclosure. The power-saving states (states D1 to D4) and their corresponding settings may be (pre-defined) as follows: • State D1:UE supports the reception of all types of SL signals and the characteristics of those SL signals. • State D2:UE supports PSCCH and PSSCH reception, and only supports PSCCH and PSSCH features such as PSCCH sensing, PSSCH reception and decoding, and does not support additional features such as receiving SLSS / PSBCH when not required for power saving. • State D3: UE supports PSCCH reception, and only supports PSCCH features such as PSCCH reception for sensing only. PSCCH reception is not permitted if the UE is performing sensing only for resource selection. • State D4:UE performs only transmission operations and does not receive any kind of sidelink signal.

[0073] A power-saving state for the UE (e.g., one of states D1-D4) may be determined by the UE itself, the network, or other SL UEs for power-saving purposes and / or system efficiency to ensure performance requirements. Additionally or alternatively, power-saving states for either SL reception or SL transmission may be defined separately to include / exclude other SL capabilities / features such as full sensing / partial sensing, reserve / preemption, SLSS / PSBCH, PSFCH for monitoring / transmission. Power-saving states can be set / switched, for example, by using notification signals as alerts. Such notification signals may be one or a combination thereof. • RRC settings from higher layers (e.g., by the UE itself or from the network). Such signaling can be achieved by a new RRC parameter, SwitchPowerSavingState, which can be defined as a SEQUENCE for a state index or as ENUMERATED for all states. • MAC CE, for example, a new MAC CE with a new index to indicate the desired power saving state. • A first-stage SCI via PSCCH signaling in a standalone PSCCH, or a PSCCH having a dummy PSCCH. Such PSCCH signaling may be implemented by a field of one or more SCI bits (either a specific field or a reused field) or a new SCI format to indicate a new power-saving state to be changed. • The second stage of SCI using PSSCH. • PDCCH signaling (either Mode 1 or Mode 2) when the UE is within gNB coverage. Such signaling can be achieved by DCI bits or fields in a new DCI format.

[0074] Figure 9 shows a flowchart 900 illustrating the use of an RRC setting from a higher layer to configure a UE to operate in one of several power-saving states, according to one embodiment of the present disclosure. In this embodiment, a new RRC parameter, SwitchPowerSavingState, is used, and four different values ​​of this new RRC parameter each represent one of four power-saving state settings (states D1 to D4). For simplicity, only the new RRC parameter SwitchPowerSavingState is shown for the use of the RRC setting. It will be understood that other RRC parameters may be used as notifications, additionally or alternatively, to achieve power-saving state setting signaling.

[0075] Figure 10 shows a flowchart 1000 illustrating the use of a PSCCH to configure a UE to operate in one of a plurality of power-saving states according to another embodiment of the present disclosure. In this embodiment, a PSCCH having two SCI bits, “00”, “01”, “10”, and “11”, is used to represent four power-saving state settings (states D1, D2, D3, and D4), respectively.

[0076] Similarly, Figure 11 shows a flowchart 1100 illustrating the use of a PDCCH to configure a UE to operate in one of a plurality of power-saving states according to yet another embodiment of the present disclosure. In this embodiment, a PDCCH having two DCI bits, “00”, “01”, “10”, and “11”, is used to indicate each of four power-saving state settings (states D1, D2, D3, and D4).

[0077] According to this disclosure, a UE can switch from one power-saving state to another power-saving state via an event trigger. Such a trigger event may be from the UE itself, another UE, a gNB, or a network. In one embodiment, a higher layer of the UE determines the preference for switching its power-saving state to another power-saving state, for example, to reduce power consumption or to have better performance (increased capability). The preference for operating in such another power-saving state may be determined based on parameters and related factors relating to the UE.

[0078] If the UE is under network coverage, the UE informs the network of its preferred / desired power-saving state. If the network agrees, it notifies the UE of the power-saving state switch; if it does not agree, the switch does not occur. On the other hand, if the UE is not under network coverage, or if the network does not control the UE's power-saving state switch, the UE is configured to switch to its preferred / desired power-saving state.

[0079] Figure 12 shows a flowchart 1200 illustrating a process for switching from the current power-saving state to a preferred power-saving state of the UE according to one embodiment of the present disclosure. In step 1202, the UE is configured to determine a preferred power-saving state. In step 1204, the UE determines whether it is within network (or gNB) coverage. If the UE is within network coverage, step 1206 is performed; otherwise, step 1212 is performed. In step 1206, the UE is configured to determine whether the network controls the switching of the UE's power-saving state. If the network controls the switching, step 1208 is performed; otherwise, step 1212 is performed. In one embodiment, the UE is then further configured to send a request signal to indicate its preferred power-saving state and a request to switch to the preferred power-saving state to the network. In step 1208, the UE is configured to determine whether the network agrees to switch to the UE's preferred power-saving state, for example, by determining whether the UE receives a response signal that accepts the request. If the network does not agree, step 1210 is performed, and the UE does not switch to its preferred power-saving state, but remains in its current power-saving state. If the network agrees, step 1212 is performed. In step 1212, the UE is configured to operate in (or switch to) its preferred power-saving state.

[0080] In addition to, or instead of, a request signal indicating a request to switch to a preferred power-saving state, the UE may transmit support information to the network (or gNB) including parameters (with relevant coefficients) relating to the UE.

[0081] Figure 13 shows a flowchart 1300 illustrating a process for switching from a power-saving state currently operated by one communication device to another power-saving state operated by another communication device, according to one embodiment of the present disclosure. For simplicity, the process is illustrated using a network. It will be understood that, instead of a network, any other communication device, such as a gNB and other sidelink UEs, may be used in the process to notify the UE to switch from the current power-saving state to another power-saving state.

[0082] In step 1302, the UE is configured to report its parameters and related factors to the network. In one embodiment, such parameters and related factors are included in the UE support information sent to the network. In step 1304, the network is configured to evaluate the parameters and related factors. In step 1306, the network is configured to determine whether the UE needs to switch its power saving state. If the network determines that the UE needs to switch its power saving state (for example, if the network determines that a certain power saving state is more suitable for the UE to operate in compared to the current power saving state in which the UE operates (balancing power saving and performance requirements)), step 1308 is performed, and the network is then configured to notify the UE to switch to another power saving state, for example by sending the aforementioned notification signals indicating the other power saving state to the UE; if no switch is needed, step 1310 is performed. In step 1310, for example, it is determined that the UE does not need to switch, for example, that there is no more suitable power saving state than the current power saving state and the UE remains operating in the current power saving state.

[0083] In various embodiments, the UE may be configured to decide to operate (or switch to) a particular power-saving state, or a power-saving state that supports or does not support a particular feature / function. Similarly, notification signals (e.g., RRC, PSCCH, and PDCCH signals as shown in Figures 10-12) or response signals to requests from the UE may include notifications that directly inform the UE that the UE will operate (or switch to) a particular power-saving state, or notifications that inform the UE that the UE will operate (or switch to) a power-saving state that supports or does not support a particular feature / function.

[0084] For example, the UE may receive a signal to switch to a preferred power-saving state D2, and if the UE is currently operating in power-saving state D3, it will switch to operating in power-saving state D2. Alternatively, the UE may receive a signal to operate in a state that supports PSSCH. Thus, the UE may decide to operate in (or switch to) such a power-saving state. For example, if the UE is operating in state D3, upon receiving the signal, the UE will switch to state D1 or D2. On the other hand, the UE may receive a signal to operate in a state that does not support PSSCH, and thus the UE can decide to operate in (or switch to) such a power-saving state. For example, if the UE is operating in state D1, upon receiving the above signal, the UE will switch to state D3 or D4.

[0085] As mentioned earlier, an SL UE may have a default / initial power-saving state pre-configured from among several power-saving states that the SL UE can operate in. If the SL UE switches to a power-saving state other than its default / initial power-saving state, a fallback timer, for example, a timer-based fallback parameter may be activated. The fallback timer may be used to switch back to the default / initial power-saving state once it expires. Such timer-based fallback parameters may be configured using RRC signaling or one of the MAC / PSCCH signaling signals, similar to discontinuous reception (DRX), as a pattern / timer.

[0086] Figure 14 shows a flowchart 1400 illustrating a process operating in a default power-saving state according to one embodiment of the present disclosure. In step 1402, the UE may be configured to operate in a default power-saving state / initial power-saving state. In step 1404, the UE may be further configured to determine and therefore switch to another power-saving state in which it operates. In step 1406, the timer is started. In step 1408, it is determined whether the timer has expired. If the timer has not expired, step 1410 is performed and the timer is decremented by one unit. If the timer has expired, the UE is configured to operate in its default power-saving state.

[0087] Such default power-saving states may be (pre)set or (pre)defined by either a specification (e.g., 3GPP), a government regulatory authority, or the UE vendor. It should be noted that the behavior of various power-saving states should be defined in 3GPP (e.g., RRC settings, UE capabilities). Higher-level behavior, such as which states are implemented and what use cases are implemented for specific states, should be subject to national / regional regulations or UE implementation and decisions.

[0088] In one embodiment of the present disclosure, as shown in state D3 of Figure 8, if the UE supports only PSCCH reception and features such as PSCCH reception for sensing only, the UE needs to be active only when it receives the first stage SCI (e.g., the first 2 symbols or first 3 symbols in the SL slot) in order to monitor the second stage SCI or PSCCH without PSSCH. Specifically, only PSCCH sensing opportunities may be defined for the UE, and no PSSCH reception slots / subframes are defined. The UE may be in (micro / write / deep) sleep mode for the rest of the PSCCH symbols / slots. Alternatively, the PSSCH reception slots / subframes may be defined identically to the reception state that supports PSSCH reception, and the UE monitors the PSCCH symbols in the PSSCH reception slots / subframes.

[0089] Furthermore, if there are other SL UEs attempting to send SL messages carried by PSSCH to an SL UE that performs only PSCCH sensing, those other SL UEs may need to transmit a standalone PSCCH to notify the SL UE to switch to another power-saving state in which PSSCH reception is possible. The standalone PSCCH may carry one or more bits in the SCI to notify to switch to a particular power-saving state or a state that supports a function (e.g., PSSCH reception). In the following paragraphs, several exemplary embodiments will be described with reference to this disclosure, including terminology related to 5G core networks, as well as communication devices and methods for sidelink broadcasting.

[0090] <Control signal> In this disclosure, the downlink control signal (information) relating to this disclosure may be a signal (information) transmitted via the PDCCH of the physical layer, or a signal (information) transmitted via the MAC Control Element (CE) of the upper layer or RRC. The downlink control signal may be a predefined signal (information). The uplink control signal (information) relating to this disclosure may be a signal (information) transmitted via the PUCCH of the physical layer, or a signal (information) transmitted via the MAC CE of the upper layer or RRC. The uplink control signal may also be a predefined signal (information). The uplink control signal may be Uplink Control Information (UCI), First Stage Sidelink Control Information (SCI), or Second Stage SCI.

[0091] <Base station> In this disclosure, a base station may be, for example, a transmission reception point (TRP), a cluster head, an access point, a remote radio head (RRH), an eNodeB (eNB), a gNodeB (gNB), a base station (BS), a base transceiver station (BTS), a base unit, or a gateway. In side-link communication, a terminal may be used instead of a base station. A base station may be a relay device that relays communication between a higher-level node and a terminal. A base station may be a roadside unit.

[0092] <Uplink / Downlink / Sidelink> This disclosure may be applied to uplink, downlink, and sidelink channels. This disclosure may be applied, for example, to uplink channels such as PUSCH, PUCCH, and PRACH; downlink channels such as PDSCH, PDCCH, and PBCH; and sidelink channels such as Physical Sidelink Shared Channel (PSSCH), Physical Sidelink Control Channel (PSCCH), and Physical Sidelink Broadcast Channel (PSBCH). PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channel, downlink data channel, uplink data channel, and uplink control channel, respectively. PSCCH and PSSCH are examples of sidelink control channel and sidelink data channel, respectively. PBCH and PSBCH are examples of broadcast channels, respectively, and PRACH is an example of a random access channel.

[0093] <Data Channel / Control Channel> This disclosure may apply to either a data channel or a control channel. The channels in this disclosure may be replaced with data channels including PDSCH, PUSCH, and PSSCH, and / or control channels including PDCCH, PUCCH, PBCH, PSCCH, and PSBCH.

[0094] <Reference signal> In this disclosure, a reference signal is a signal known to both the base station and the mobile station, and each reference signal may be referred to as a reference signal (RS) or pilot signal. A reference signal may be any of the following: DMRS, Channel State Information - Reference Signal (CSI-RS), Tracking Reference Signal (TRS), Phase Tracking Reference Signal (PTRS), Cell-specific Reference Signal (CRS), and Sounding Reference Signal (SRS).

[0095] <Time interval> In this disclosure, a time resource unit is not limited to one or a combination of slots and symbols, but may be a frame, superframe, subframe, slot, subslot of a time slot, minislot, or a symbol, an orthogonal frequency division multiplexing (OFDM) symbol, a single-carrier frequency division multiplexing access (SC-FDMA) symbol, or any other time resource unit. The number of symbols contained in a slot is not limited to the number of symbols exemplified in the embodiments described above, but may be any other number of symbols.

[0096] <Frequency Band> This disclosure may apply to either the licensed band or the unlicensed band.

[0097] <Communication> This disclosure may be applied to base station-to-terminal communication (Uu-link communication), terminal-to-terminal communication (side-link communication), and V2X (Vehicle to Everything) communication. The channels in this disclosure may also be referred to as PSCCH, PSSCH, Physical Side-Link Feedback Channel (PSFCH), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, and PBCH. Furthermore, this disclosure can be applied to either terrestrial networks or non-terrestrial networks (NTN) using satellites or high-altitude pseudo-satellite (HAPS) satellites. In addition, this disclosure may be applied to networks with large cell sizes or terrestrial networks with large latency relative to symbol length or slot length, such as ultra-wideband transmit networks.

[0098] <Antenna port> An antenna port refers to a logical antenna (antenna group) formed from one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna, but can also refer to an array antenna consisting of multiple antennas. For example, the number of physical antennas constituting an antenna port is not defined; instead, an antenna port is defined as the smallest unit on which a terminal is permitted to transmit a reference signal. An antenna port can also be defined as the smallest unit for multiplication of pre-coded vector weights.

[0099] This disclosure can be implemented as software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments can be implemented partially or entirely as an integrated circuit (LSI), and each process described in the above embodiments can be controlled partially or entirely by a single LSI or a combination of LSIs. An LSI can be configured from individual chips, or from a single chip to include some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs. The method of integration is not limited to LSIs, and may be implemented with dedicated circuits, general-purpose processors, or dedicated processors. Alternatively, a Field Programmable Gate Array (FPGA) that can be programmed after LSI manufacturing, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI, may be used. This disclosure can be implemented as digital or analog processing. Furthermore, if advancements in semiconductor technology or derivative technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, these technologies can be used to integrate functional blocks. The application of biotechnology, for example, is a possibility.

[0100] This disclosure is applicable to all types of devices, systems, and equipment with communication capabilities (collectively referred to as communication equipment).

[0101] The communication device may include a wireless transceiver and a processing / control circuit. The wireless transceiver may include a receiver and a transmitter, or both as functions. The wireless transceiver (transmitter and receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or something similar.

[0102] Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0103] Communication devices are not limited to portable or mobile devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0104] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0105] Furthermore, the communication device also includes devices such as control units and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this may include control units and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0106] Furthermore, communication equipment includes infrastructure facilities, such as base stations, access points, and any other devices, devices, and systems, that communicate with or control the above-mentioned, non-limiting devices. Those skilled in the art will understand that numerous variations and / or modifications can be made to this disclosure, as shown in the specific embodiments, without departing from the broadly described spirit or scope of this disclosure. Therefore, these embodiments should be considered illustrative and not limiting in all respects.

Claims

1. During operation, a circuit determines the first power-saving state which is included in multiple power-saving states, During operation, the system includes a transceiver that transmits and / or receives at least one type of sidelink signal corresponding to the determination of the first power-saving state, The circuit is further configured with a default power-saving state and a fallback timer. The default power saving state is a second power saving state that is included in the plurality of power saving states which is different from the first power saving state. The fallback timer is triggered during operation in the first power-saving state. The circuit switches from the first power-saving state to the default power-saving state after the fallback timer has expired. Communication device.

2. The circuit is configured to determine the first power-saving state based on the identification of the transmission priority and / or reception priority for at least one type of sidelink signal. The communication device according to claim 1.

3. The first power-saving state relates to one of the following: (a) reception of all types of sidelink signals, (b) reception of only the Physical Sidelink Control Channel (PSCCH) and the Physical Sidelink Shared Channel (PSSCH), (c) reception of only the PSCCH, (d) reception of the Sidelink Synchronization Block (S-SSB) and / or the Physical Sidelink Feedback Channel (PSFCH), or (e) reception of only the PSCCH and the second stage Sidelink Control Information (SCI). The communication device according to claim 1 or 2.

4. If the first power-saving state relates solely to the reception of PSCCH, the communication device is configured to be active when receiving the first stage SCI. The communication device according to claim 3.

5. The circuit is configured to determine the first power-saving state based on parameters relating to the communication device. The communication device according to claim 1.

6. The parameters include at least one of the following: the speed of the communication device, the type of the communication device, the vehicle type, the position according to the Global Navigation Satellite System (GNSS), the congestion level, and the zone ID. The communication device according to claim 5.

7. The transmitting and receiving unit further transmits support information including the parameters to other communication devices. The communication device according to claim 5 or 6.

8. The transmitting and receiving unit further transmits a request signal to another communication device indicating a request to operate in the first power-saving state. The communication device according to claim 1.

9. The transmitting and receiving unit further receives a response signal that accepts the request, and the circuit is configured to determine the first power-saving state based on the response signal. The communication device according to claim 8.

10. The transmitting / receiving unit receives a notification signal regarding the first power saving state from another communication device, and the circuit is configured to determine the first power saving state based on the notification signal. The communication device according to claim 1.

11. The notification signal relates to at least one of the following: sidelink control information (SCI) signaling, downlink control information (DCI) signaling, media access control (MAC) control element (CE) signaling, and radio resource control (RRC) signaling. The communication device according to claim 10.

12. The SCI signaling is carried by one of the following: a first-stage SCI of a standalone physical sidelink control channel (PSCCH), a PSCCH having a dummy physical sidelink shared channel (PSSCH), and a second-stage SCI; the DCI signaling is carried by a physical downlink control channel (PDCCH). The communication device according to claim 11.

13. The aforementioned at least one type of sidelink signal includes at least one of the following: physical sidelink control channel (PSCCH), physical sidelink shared channel (PSSCH), sidelink synchronization signal (SLSS), physical sidelink broadcast channel (PSBCH), and physical sidelink feedback channel (PSFCH). The communication device according to claim 1.

14. The fallback timer is configured using one of the following: RRC signaling, MAC signaling, and PSCCH signaling. The communication device according to claim 1.

15. It operates in a first power-saving state, which is one of several power-saving states, each corresponding to a side-link capability. Based on the sidelink capability corresponding to the first power-saving state, transmit and / or receive at least one type of sidelink signal. Communication method.

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