Enhancements for improved CV2X scheduling and performance

Abstract

In summary, various aspects of the present disclosure relate to wireless communications. In some aspects, techniques for improving semi-persistent scheduling performance are provided, including in the context of cellular vehicle-to-everything (CV2X) communications. A method of wireless communication performed by a user device may include: determining a first period for sending a safety message; determining a second period for sending the safety message, wherein the second period is different from the first period; determining whether to continue utilizing the first period or switch to the second period based on a probabilistic determination process; generating a safety message with the first period or the second period based on the determination of continuing utilizing the first period or switching to the second period; and sending the safety message with the same period in which the safety message was generated. Numerous other aspects are provided.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. patent application No. 17 / 305,506, filed on July 8, 2021; and U.S. provisional application No. 63 / 049,961, filed on July 9, 2020, the entire contents of which are hereby incorporated by reference into this document as if fully set forth below and for all applicable purposes. Technical Field

[0003] In general, aspects of the present disclosure relate to wireless communications and to techniques for improving semi-persistent scheduling performance in terms of latency and probability of successful delivery, including in the context of cellular vehicle-to-everything (CV2X) communications and / or congestion control algorithms. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). 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, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] A wireless communication network may include multiple base stations (BSs) that can support communications for multiple user equipment (UEs). User equipment (UEs) can communicate with a base station (BS) via downlinks and uplinks. A downlink (or forward link) refers to the communication link from the BS to the UE, while an uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, gNB, access point (AP), radio head, transmit receive point (TRP), new radio (NR) BS, 5G Node B, etc.

[0006] The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user devices to communicate at the city, country, region, and even global levels. New Radio (NR) (which may also be referred to as 5G) is a set of enhancements to the LTE mobile standard released by the Third Generation Partnership Project (3GPP). NR is designed to better integrate with other open standards by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with a cyclic prefix (CP) on the downlink (DL) and CP-OFDM and / or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), thereby better supporting mobile broadband Internet access, as well as supporting beamforming, multiple input multiple output (MIMO) antenna technology, and carrier aggregation. However, as the demand for mobile broadband access continues to grow, there is a need for further improvements to LTE and NR technologies. Preferably, these improvements should be applicable to other multiple access technologies and telecommunication standards that adopt these technologies.

[0007] Aspects of the present disclosure are applicable to cellular vehicle-to-everything (CV2X) communications, including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), vehicle-to-pedestrian (V2P), and / or vehicle-to-cloud (V2C) communications. In some cases, a decentralized congestion control (DCC) algorithm can be used to adjust the communication parameters (semi-persistent scheduling (SPS) period, message rate, data rate, transmission power, etc.) of CV2X communications. For example, aspects of the present disclosure can be used to improve the scheduling, performance, and efficiency of the Society of Automotive Engineers (SAE) DCC algorithm and other DCC algorithms. In this regard, poor performance has been observed when implementing DCC algorithms. The poor performance may be the result of sidelink control information (SCI) reservations not reflecting the actual usage of the device. Therefore, in some cases, even in a congested area with a medium channel busy ratio (CBR) (e.g., 20-30%), a device attempting to reselect SPS resources may find that the map is fully utilized and resources are selected inefficiently. The enhancements and improvements of the present disclosure provide significant performance gains over existing methods. Summary of the Invention

[0008] The following summarizes some aspects of the present disclosure to provide a basic understanding of the technology discussed. This summary is not an exhaustive overview of all anticipated features of the present disclosure and is not intended to identify key or important elements of all aspects of the present disclosure, nor is it intended to delineate the scope of any or all aspects of the present disclosure. Its sole purpose is to present some concepts of one or more aspects of the present disclosure in a summarized form as a prelude to the more detailed description that will be given later.

[0009] In some aspects, a method of wireless communication performed by a user device includes: determining a first period for sending a safety message; determining a second period for sending the safety message, wherein the second period is different from the first period; determining whether to continue using the first period or switch to the second period based on a probabilistic determination process; generating the safety message with the first period or the second period based on the determination about continuing using the first period or switching to the second period; and sending the safety message with the same period as the safety message is generated.

[0010] In some aspects, a method of wireless communication performed by a user device, the method comprising: determining a first semi-persistent scheduling (SPS) period for generating a safety message; determining a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; selecting a random time offset; and generating a first safety message associated with the second SPS period based on the random time offset.

[0011] In some aspects, a user device includes: a processor, the processor being configured to: determine a first period for sending a safety message; determine a second period for sending the safety message, wherein the second period is different from the first period; determine whether to continue using the first period or switch to the second period based on a probabilistic determination process; and generate the safety message with the first period or the second period based on the determination about continuing using the first period or switching to the second period; and a modem in communication with the processor, the modem being configured to: send the safety message with the same period as the safety message is generated.

[0012] In some aspects, a user device includes: a processor configured to: determine a first semi-persistent scheduling (SPS) period for generating a safety message; determine a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; select a random time offset; and generate a first safety message associated with the second SPS period based on the random time offset.

[0013] In some aspects, a user device includes: a unit for determining a first period for sending a safety message; a unit for determining a second period for sending the safety message, wherein the second period is different from the first period; a unit for determining whether to continue using the first period or switch to the second period based on a probabilistic determination process; a unit for generating the safety message with the first period or the second period based on the determination about continuing to use the first period or switching to the second period; and a unit for sending the safety message with the same period as the safety message is generated.

[0014] In some aspects, a user device includes: a unit for determining a first semi-persistent scheduling (SPS) period for generating a safety message; a unit for determining a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; a unit for selecting a random time offset; and a unit for generating a first safety message associated with the second SPS period based on the random time offset.

[0015] In some aspects, a non-transitory computer-readable medium having program code recorded thereon for wireless communication by a user device includes: code for causing the user device to determine a first period for sending a safety message; code for causing the user device to determine a second period for sending the safety message, wherein the second period is different from the first period; code for causing the user device to determine whether to continue using the first period or switch to the second period based on a probabilistic determination process; code for causing the user device to generate the safety message with the first period or the second period based on the determination about continuing to use the first period or switching to the second period; and code for causing the user device to send the safety message with the same period as the safety message is generated.

[0016] In some aspects, a non-transitory computer-readable medium having program code recorded thereon for wireless communication by a user device includes: code for causing the user device to determine a first semi-persistent scheduling (SPS) period for generating a safety message; code for causing the user device to determine a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; code for causing the user device to select a random time offset; and code for causing the user device to generate a first safety message associated with the second SPS period based on the random time offset.

[0017] Compared to existing methods, the enhancements and improvements of the present disclosure provide significant performance gains over existing methods. In addition, many of the enhancements and improvements of the present disclosure can be applied to existing devices / systems without requiring changes to the hardware and / or existing functionality of the devices / systems to achieve the significant performance gains. In this way, many of the enhancements and improvements are backward compatible with existing devices / systems.

[0018] The foregoing has generally outlined the features and technical advantages of the examples according to the present disclosure so that the following detailed description 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 purpose of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein (both their organization and method of operation) and the associated advantages will be better understood from the description below when considered in conjunction with the accompanying drawings. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description and is not intended to be a definition of limitations to the claims.

[0019] After reviewing the following description of specific exemplary embodiments of the present invention in conjunction with the accompanying drawings, other aspects, features and embodiments of the present invention will become apparent to those skilled in the art. Although features of the present invention may be discussed below with respect to certain embodiments and the accompanying drawings, all embodiments of the present invention may include one or more of the advantageous features discussed herein. In other words, although one or more embodiments may be discussed as having certain advantageous features, one or more of these features may also be used according to the various embodiments of the present invention discussed herein. In a similar manner, although exemplary embodiments may be discussed below as device, system or method embodiments, it should be understood that these exemplary embodiments may be implemented in various devices, systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to fully understand the above-mentioned features of the present disclosure, a more detailed description of the invention briefly summarized above can be obtained by referring to various aspects (some of which are shown in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope of the present disclosure, as the description may allow for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0021] Figure 1 A wireless communication network according to some aspects of the present disclosure is shown.

[0022] Figure 2An example of a base station communicating with a user equipment (UE) in a wireless communication network according to some aspects of the present disclosure is shown.

[0023] Figure 3 An example of adjusting a basic safety message generation period according to aspects of the present disclosure is shown.

[0024] Figure 4 、 5 6A-6C illustrate examples of reducing semi-persistent scheduling (SPS) latency according to aspects of the present disclosure.

[0025] Figure 7 An example of adjusting the SPS period according to some aspects of the present disclosure is shown.

[0026] Figure 8 An example process for adjusting a safety message generation period according to aspects of the present disclosure is shown.

[0027] Figure 9 The flow of data between different components in an example apparatus according to some aspects of the present disclosure is shown.

[0028] Figure 10 A signaling diagram illustrating an SPS scheduling procedure according to some aspects of the present disclosure is shown.

[0029] Figure 11 is a flow chart of a safety message generation and dispatching process according to some aspects of the present disclosure.

[0030] Figure 12A and 12B is a graph of SPS period rounding range with a hysteresis parameter according to aspects of the present disclosure.

[0031] Figure 13A 、 13B and 13C are diagrams of secure message generation according to aspects of the present disclosure.

[0032] Figure 14-16 is a diagram of safety message generation and scheduling according to some aspects of the present disclosure.

[0033] Figure 17 is a diagram of security message generation according to some aspects of the present disclosure.

[0034] Figure 18 is a flow chart of a communication method according to some aspects of the present disclosure.

[0035] Figure 19 is a flow chart of a communication method according to some aspects of the present disclosure. DETAILED DESCRIPTION

[0036] The following describes various aspects of the present disclosure in more detail 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. More specifically, these aspects are provided so that the present disclosure will be 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 that aspect is implemented independently of any other aspect of the present disclosure or is implemented in combination with any other aspect. For example, a device can be implemented or a method can be implemented using any number of aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such devices or methods implemented using other structures, functions, or structures and functions in addition to or different from the various aspects of the present disclosure set forth herein. It should be understood that any aspect of the present disclosure disclosed herein can be embodied by one or more elements of the claims.

[0037] Several aspects of telecommunications systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements") and illustrated in the accompanying drawings. These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0038] It should be noted that although various aspects may be described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure may be applicable to communication systems based on other generations, such as 5G and beyond (including NR technology).

[0039] Figure 1is a diagram illustrating a wireless network 100 in which aspects of the present disclosure may be implemented. The wireless network 100 may be an LTE network or some other wireless network (e.g., a 5G or NR network). The wireless network 100 may include multiple BSs 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, transmit receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0040] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1 In the example shown in FIG, BS 110a may be a macro BS for macrocell 102a, BS 110b may be a pico BS for picocell 102b, and BS 110c may be a femto BS for femtocell 102c. A BS may support one or more (e.g., three) cells. The terms "eNB," "base station," "NR BS," "gNB," "TRP," "AP," "Node B," "5G NB," and "cell" may be used interchangeably herein.

[0041] In some aspects, cells may not necessarily be stationary, and the geographic area of ​​a cell may move depending on the location of the mobile BS. In some aspects, BSs may be interconnected with each other and / or with one or more other BSs or network nodes (not shown) in wireless network 100 via various types of backhaul interfaces (e.g., direct physical connections, virtual networks, and / or similar interfaces using any suitable transport network).

[0042] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and send data transmissions to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown in , a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, a relay, etc.

[0043] The wireless network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in the wireless network 100. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts).

[0044] The network controller 130 may be coupled to a set of BSs and may provide coordination and control for these BSs. The network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with each other directly or indirectly, for example, via a wireless or wired backhaul.

[0045] UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, station, etc. A UE may be a cellular phone (e.g., a smartphone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet device, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or apparatus, a biometric sensor / device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring, a smart bracelet, etc.)), an entertainment device (e.g., a music or video device, or a satellite radio unit, etc.), a vehicle component or sensor, a smart meter / sensor, industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless or wired medium.

[0046] Some UEs may be considered to be machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide a connection to or to a network (e.g., a wide area network such as the Internet or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered to be Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered to be customer premises equipment (CPE). UE 120 may be included inside a housing that houses components of UE 120 (such as a processor component, a memory component, etc.).

[0047] In general, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific RAT and can operate on one or more frequencies. RATs can also be referred to as radio technologies, air interfaces, etc. Frequencies can also be referred to as carriers, frequency channels, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0048] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) can communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for communicating with each other). For example, the UEs 120 can communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, vehicle-to-pedestrian (V2P) protocols, and / or vehicle-to-cloud (V2C) protocols, etc.), mesh networks, etc. In this case, the UEs 120 can perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by the base station 110.

[0049] As pointed out above, Figure 1 is provided as an example. Other examples may differ from those described in relation to Figure 1 Examples described.

[0050] Figure 2 A base station 110 and a UE 120 (which may be Figure 11. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general, T ≥ 1 and R ≥ 1.

[0051] At the base station 110, the transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS selected for the UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and control information (e.g., CQI requests, grants, upper layer signaling, etc.), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). A transmit (TX) multiple-input, multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and / or upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. In accordance with various aspects described in greater detail below, position coding may be utilized to generate synchronization signals to convey additional information.

[0052] At UE 120, antennas 252a through 252r may receive downlink signals from base station 110 and / or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and / or digitize) the received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), channel quality indicator (CQI), etc. In some aspects, one or more components of UE 120 may be included in a housing.

[0053] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information from a controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 (if applicable), further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antennas 234, processed by the demodulators 232, detected by the MIMO detector 236 (if applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0054] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2Any other component in the may perform one or more techniques associated with reducing semi-persistent scheduling (SPS) latency, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, and / or Figure 2 Any other component in may perform or direct e.g. Figure 8 The process 800 is respectively Figure 18 and 19 The operations of methods 1800 and 1900 and / or other processes as described herein. Memories 242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and / or memory 282 may include a non-transitory computer-readable medium storing one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of base station 110 and / or UE 120, may perform or direct, for example, Figure 8 The process 800 is respectively Figure 18 and 19 The scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink, including sidelink communications.

[0055] In some aspects, the UE 120 may include means for adjusting a basic safety message generation period based at least in part on an SPS period for sending basic safety messages; means for generating one or more basic safety messages based at least in part on the adjusted basic safety message generation period; etc. In some aspects, the UE 120 may include means for receiving, at a processor of the UE 120 executing a safety application, from a modem of the UE 120, an indication of an anchor time, the anchor time being based at least in part on resource selection for the safety application; means for generating, using the processor, a basic safety message in the one or more basic safety messages at an offset time prior to the anchor time; means for providing the basic safety message to the modem; etc. In some aspects, the UE 120 may include means for receiving, at the modem of the UE 120, an indication of resource reselection associated with the safety application, the safety application being associated with the one or more basic safety messages; means for determining, using the modem, an updated anchor time based at least in part on the resource reselection; means for providing, from the modem, an indication of the updated anchor time to the processor of the UE executing the safety application; etc.

[0056] In some aspects, the UE 120 may include: means for receiving, at a processor of the UE executing a security application, from a modem of the UE 120, an indication of a respective transmit time for each of one or more basic safety messages, wherein the respective transmit time is based at least in part on a resource selection for the security application and an SPS period; means for generating, using the processor, the one or more basic safety messages at an offset time prior to the respective transmit time; etc. In some aspects, the UE 120 may include: means for providing, using the processor of the UE 120 executing the security application, a request for an adjusted SPS period to the modem of the UE 120; means for configuring, using the modem at a reselection opportunity, the adjusted SPS period; means for receiving, using the processor, an indication of an anchor time for transmission of the one or more basic safety messages, the anchor time being based at least in part on the adjusted SPS period; etc.

[0057] In some aspects, UE 120 may include: a unit for providing a request for an adjusted SPS period to a modem of UE 120 using a processor of UE 120 executing a security application; a unit for configuring the adjusted SPS period using the modem at a reselection opportunity; a unit for sending any packets that are not suitable for a reserved SPS transmission to a non-SPS transmission until a reselection opportunity; and the like.

[0058] In some aspects, the UE 120 may include: a unit for determining a first period for sending security messages; a unit for determining a second period for sending security messages, wherein the second period is different from the first period; a unit for determining whether to continue utilizing the first period or switch to the second period based on a probabilistic determination process; a unit for generating security messages with the first period or the second period based on the determination of whether to continue utilizing the first period or switch to the second period; and a unit for sending the security messages with the same period in which the security messages are generated.

[0059] In some aspects, UE 120 may include means for, in response to determining to switch to the second periodicity, requesting a modem of the user equipment to change to the second periodicity before sending a last safety message packet generated with the first periodicity to the modem.

[0060] In some cases, at least one of the means for determining the first period or the means for determining the second period includes means for rounding a security message generation period determined by the congestion control algorithm to the first supported SPS period or the second supported SPS period.

[0061] In some aspects, the UE 120 may include means for detecting a tracking error and / or means for generating a tracking error-based safety message separate from the plurality of supported SPS periods based on the detected tracking error.

[0062] In some aspects, the UE 120 may include means for avoiding generating a safety message during a schedule generation time period when the tracking error-based safety message is generated within a threshold amount of time of the schedule generation time period associated with the first period or the second period.

[0063] In some aspects, the UE 120 may include means for generating a safety message during a schedule generation period when the tracking error-based safety message is generated within a threshold amount of time of the schedule generation period and the schedule generation period is associated with a change in periodicity.

[0064] In some aspects, the UE 120 may include: a unit for determining a third period for sending security messages, wherein the third period is different from the first period; a unit for determining whether to continue utilizing the first period or switch to the third period based on a probabilistic determination process; and a unit for generating security messages with the first period or the third period based on the determination regarding continuing utilizing the first period or switching to the third period.

[0065] In some cases, the means for determining a first period for sending the safety message includes means for rounding the first calculation period to the first period. The means for rounding the first calculation period to the first period may include means for rounding the first calculation period to at least one of a canonical supported SPS period or a multiple of a 100 millisecond period.

[0066] In some cases, the means for determining the second period for sending the security message may include means for rounding the second calculation period to the second period. The means for rounding the second calculation period to the second period may include means for rounding the second calculation period to the second period based on a hysteresis parameter. In some aspects, the UE 120 may include means for randomly selecting a value for the hysteresis parameter from a set of available values ​​for the hysteresis parameter. In some cases, the means for rounding the second calculation period to the second period based on the hysteresis parameter may include means for determining that the second calculation period is less than (T n +T n-1 ) / 2–(T n –T n-1 )*H or greater than (T n +T n+1 ) / 2+(T n+1 –T n )*H unit, where T nis the first cycle, T n-1 is a support period less than the first period, T n+1 is the support period greater than the first period, and H is the hysteresis parameter.

[0067] In some cases, the means for determining whether to continue utilizing the first cycle or switch to the second cycle is configured to operate at a scheduled packet generation time period associated with the first cycle and prior to transmission of packets generated at the scheduled packet generation time period.

[0068] In some aspects, the UE 120 may include: a unit for determining a first semi-persistent scheduling (SPS) period for generating a safety message; a unit for determining a second SPS period for generating a safety message, the second SPS period being greater than the first SPS period; a unit for selecting a random time offset; and / or a unit for generating a first safety message associated with the second SPS period based on the random time offset.

[0069] In some cases, the means for selecting a random time offset may include means for randomly selecting a time between 0 and a second SPS period.

[0070] In some cases, the means for generating the first safety message associated with the second SPS period may include means for generating the first safety message after the random time offset from the current time if the random time offset is greater than or equal to a threshold value. In some cases, the means for generating the first safety message associated with the second SPS period may also include means for generating the first safety message after the second SPS period from the current time if the random time offset is less than the threshold value.

[0071] In some aspects, UE 120 may include means for generating a subsequent safety message associated with a second SPS period based on the second SPS period after the first safety message.

[0072] In some aspects, such a unit may include a combination of Figure 2 One or more components of UE 120 are depicted, such as controller / processor 280, transmit processor 264, TX MIMO processor 266, MOD 254, antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, and the like.

[0073] As pointed out above, Figure 2 is provided as an example. Other examples may differ from those described in relation to Figure 2 Examples described.

[0074] In a cellular V2X (C-V2X) deployment, a UE may communicate directly on a sidelink to share information (e.g., from a vehicle associated with the UE to any entity that may affect the vehicle (such as another vehicle), and vice versa). A UE's safety application may share information with a safety application on another UE by sending basic safety messages (BSMs), traffic information messages (TIMs), signal phase and timing (SPAT) messages, MAP messages for conveying geographic road information, collaborative awareness messages (CAMs), distributed environment notification messages (DENMs), in-vehicle information (IVI) messages, and the like. Basic safety messages may include information about the vehicle's location, heading, speed, safety alerts, and other information related to the vehicle's status and predicted path. Thus, a UE in a C-V2X deployment may send basic safety messages for purposes such as autonomous travel, collision detection and avoidance, and law enforcement and medical personnel message relay.

[0075] A UE's modem (e.g., a C-V2X modem or another type of modem) may unicast, broadcast, multicast, or otherwise transmit basic safety messages to one or more other UEs. A safety application executing on a processor (e.g., an application processor or another type of processor) of the UE may generate basic safety messages in a semi-persistent manner (e.g., at specific intervals or a basic safety message generation period) and may provide the basic safety messages to the modem for transmission on the sidelink. The modem may packetize, encode, modulate, and / or otherwise process the basic safety messages for transmission.

[0076] The UE's modem can schedule and / or reserve sidelink resources for transmitting basic safety messages with an SPS period. These sidelink resources can be referred to as SPS resources and can include time domain resources (e.g., symbols, time slots, subframes, etc.) and / or frequency domain resources (e.g., resource elements, subcarriers, component carriers, etc.). In this case, the SPS resources used to send the basic safety message can occur for each SPS period. In some cases, the basic safety message generation period of the processor executing the safety application and the SPS period scheduled and / or reserved by the modem may result in inefficient use of SPS resources, which may increase the information age of the basic safety message, etc. For example, the misalignment of the basic safety message generation period and the SPS period may result in an increase in the number of unused SPS sidelink resources (e.g., SPS sidelink resources skipped for basic safety message transmission). As another example, the processor may generate the basic safety message prematurely before the SPS resources used for transmission of the basic safety message, which may increase the information age of the information included in the basic safety message (the amount of time since the basic safety message was generated). As the information included in the basic safety message ages, the information becomes stale, outdated, and / or inaccurate. In some aspects, the SPS resource allocation may drift based on reserving subframes and / or allocating subframes for synchronization transmission. In this case, the SPS reservation may be every 20, 50, 100, 200, or more logical subframes that do not include such reservations, and thus the transmission time may drift from the generation time.

[0077] Some aspects described herein provide techniques and apparatus for reducing semi-persistent scheduling latency in C-V2X and other sidelink-based deployments. In some aspects, a UE may align a basic safety message generation period of a processor executing a safety application and / or other types of messages periodically sent on an SPS stream with an SPS period for sending basic safety messages, and then align the generation time of the safety message with the transmission time of resources selected for SPS transmission, thereby reducing the information age of the basic safety message and / or reducing the number of unused SPS resources.

[0078] In addition, the UE's modem can provide the processor with an anchor time or a transmit time, both of which can indicate the time at which the basic safety message is to be transmitted in the SPS resources. In this manner, the processor can generate the basic safety message at an offset from the anchor time or the transmit time in a manner that reduces the amount of time between the generation and transmission of the basic safety message. This reduces the information age of the information contained in the basic safety message, thereby preventing or reducing the likelihood that the information is stale, outdated, or inaccurate. In some aspects, the UE's processor and modem can use other techniques to reduce information age and / or SPS scheduling latency, such as generating and transmitting non-SPS basic safety messages in scenarios where the anchor time or the transmit time is updated, scheduling SPS resources within an SPS period in scenarios where the anchor or transmit time is updated, and the like.

[0079] In some aspects, the UE may be deployed in a C-V2X deployment or another type of deployment in which the UE communicates with other UEs on a sidelink. In this case, the UE may include a processor (e.g., controller / processor 280) and a memory (e.g., memory 282) that may store and execute a safety application. The processor may generate basic safety messages for the safety application and may provide the basic safety messages to the UE's modem.

[0080] The modem of the UE may be implemented by a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem component (including one or more of a receive processor, a transmit processor, a controller / processor, a memory, an integrated circuit, an application-specific integrated circuit (ASIC), etc. The modem may be capable of packetizing basic safety messages, encoding packets, modulating encoded packets, and / or performing other baseband processing of basic safety messages for transmission on the sidelink.

[0081] In some aspects, a processor executing a safety application may generate basic safety messages based at least in part on a basic safety message generation period. For example, the processor may generate basic safety messages at intervals that occur based at least in part on the basic safety message generation period. In some aspects, the basic safety message generation period may be selected based at least in part on congestion control in the wireless network (e.g., using a congestion control algorithm (e.g., an SAE DCC algorithm) and / or other techniques). The modem may reserve or schedule SPS resources on the sidelink for transmission of basic safety messages. In some aspects, the modem may reserve or schedule SPS resources such that the SPS resources occur at least in part based on the SPS period, wherein each SPS resource occurs at an interval that is based at least in part on the SPS period.

[0082] Figure 3 A diagram illustrating one or more examples 300 of adjusting a basic safety message generation period according to various aspects of the present disclosure is shown. Figure 3 As shown, example 300 may include a UE (e.g., UE 120). In some aspects, the UE may be deployed in a wireless network (such as wireless network 100).

[0083] Reference Figure 3 , the UE (e.g., a processor executing a security application) may adjust the basic safety message generation period based at least in part on the SPS period to reduce the amount of unused SPS resources scheduled by the modem, and / or align transmissions with the reservation period to reduce information age, and / or enable SPS reservations greater than 100 ms, because a generation period that is not aligned with the SPS transmission time may require a reservation period that does not exceed an allowed delay (e.g., 100 ms), because basic safety messages generated at a drifted generation time relative to the reservation will be provided to the CV2X stack within the delay budget (e.g., 100 ms) for delivery therefrom.

[0084] In some aspects, the UE may adjust the basic safety message generation period so that the basic safety message generation period is aligned with the SPS period. For example, if the SPS period indicates that the SPS resource occurs every 100 ms, the UE may adjust the basic safety message generation period so that the processor generates the basic safety message every 100 ms.

[0085] In some aspects, the UE may adjust the basic safety message generation period by rounding the basic safety message generation period (e.g., up or down or to the nearest multiple) to the SPS period. For example, if the SPS period is 100 ms (e.g., SPS resources occur once every 100 ms) and the basic safety message generation period is 230 ms (e.g., basic safety messages are generated once every 155 ms), the UE may round the basic safety message generation period (up or down) to 100 ms or 200 ms. In some aspects, the UE may round the basic safety message generation period to the nearest multiple of the SPS period.

[0086] In some aspects, if the SPS period is less than a threshold (e.g., 100 ms or another threshold), the UE may adjust the basic safety message generation period by rounding the basic safety message generation period to the nearest multiple of the SPS period. In some aspects, the UE may adjust the basic safety message generation period by rounding (e.g., up or down) the basic safety message generation period to the closest basic safety message generation period allowed for the UE (e.g., as indicated in a specification, a table, in signaling received by the UE, etc.).

[0087] In some aspects, the UE may employ a strategy of rounding to the nearest target period, rounding up to the nearest target period, or rounding down to the nearest target period. Rounding down to the nearest target period may increase load, but ensures that security messages are generated at least as frequently as with a non-rounded generator. Rounding to the nearest target period should ensure that the overall load in the system is similar to that when using a non-rounded generator. Rounding can ensure a lower load in the system at the expense of slightly longer latency.

[0088] The UE (eg, a processor executing a security application) may generate one or more basic safety messages based at least in part on the adjusted basic safety message generation period. For example, the UE may generate a basic safety message at each interval of the basic safety message generation period.

[0089] Figure 3 Examples of unadjusted basic safety message generation periods and adjusted basic safety message generation periods are shown. Other examples of unadjusted basic safety message generation periods can be adjusted to basic safety message generation periods using the techniques described herein.

[0090] like Figure 3 As shown in the upper portion of FIG, the example unadjusted basic safety message generation period can be approximately 230 ms. In the case of an example SPS period of 100 ms, a basic safety message is typically generated and sent every other SPS resource. However, in some cases, two SPS resources may not be used between basic safety message transmissions.

[0091] like Figure 3 As further shown in the lower portion of , an example adjusted basic safety message generation period may be approximately 200 ms. In this example, the unadjusted basic safety message generation period is rounded down to a multiple of the 100 ms SPS period, which eliminates the situation where two SPS resources are not used between basic safety message transmissions.

[0092] In this way, the UE can align the basic safety message generation period of the processor executing the security application with the SPS period for sending basic safety messages, thereby reducing the information age of the basic safety messages, reducing the amount of unused SPS resources, etc. In some cases, the UE can change the SPS reservation to 200ms, thereby freeing up intermediate resources for use by other devices.

[0093] As pointed out above, Figure 3 is provided as an example. Other examples may differ from those described in relation to Figure 3 Examples described.

[0094] Figure 4FIG. 4 is an example flowchart of reducing semi-persistent scheduling latency according to various aspects of the present disclosure. Figure 4 As shown, example 400 may include a UE (e.g., UE 120). In some aspects, the UE may be deployed in a wireless network (such as wireless network 100).

[0095] In some aspects, the UE may be deployed in a C-V2X deployment or another type of deployment in which the UE communicates with other UEs on a sidelink. In this case, the UE may include a processor (e.g., controller / processor 280) and a memory (e.g., memory 282) that may store and execute a safety application. The processor may generate basic safety messages for the safety application and may provide the basic safety messages to the UE's modem.

[0096] The modem of the UE may be implemented by a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem component (including one or more of a receive processor, a transmit processor, a controller / processor, a memory, an integrated circuit, an ASIC), etc. The modem may be capable of packetizing basic safety messages, encoding packets, modulating the encoded packets, and / or performing other baseband processing of basic safety messages for transmission on the sidelink.

[0097] In some aspects, a processor executing a security application may generate a basic security message based at least in part on a basic security message generation period, which may be generated using the above-described method in conjunction with Figure 3 The basic safety message generation period may be adjusted based on one or more of the techniques described herein. For example, the processor may generate basic safety messages at intervals based at least in part on a basic safety message generation period. The modem may reserve or schedule SPS resources on the sidelink for transmission of basic safety messages. In some aspects, the modem may reserve or schedule SPS resources such that the SPS resources occur based at least in part on an SPS period, wherein each SPS resource occurs at an interval based at least in part on the SPS period.

[0098] As in Figure 4 In the embodiment and as shown by reference numeral 402, to send the basic security message, the processor executing the security application can provide an SPS resource request to the modem to reserve, configure, or schedule SPS resources based on the SPS period. The modem can receive the request and can reserve, configure, or schedule SPS resources based at least in part on the SPS period.

[0099] As in Figure 4In the example and further indicated by reference numeral 404, the modem may provide to the processor an anchor time based at least in part on the SPS resource (in Figure 4 The anchor time may be the time at which the first basic safety message is sent after configuring or scheduling the SPS resource reservation. Subsequent basic safety messages may be sent at SPS periods starting from the anchor time (e.g., at time t0+1 SPS period, at time t0+2 SPS periods, etc.).

[0100] As in Figure 4 In some aspects, and as further shown by reference numeral 406, the processor may receive an indication of an anchor time, and the UE may generate and send one or more basic safety messages based at least in part on the anchor time. In some aspects, the processor executing the security application may generate the one or more basic safety messages based at least in part on an offset from the anchor time, based at least in part on an SPS period, based at least in part on a basic safety message generation period, and / or the like.

[0101] The UE may configure an offset time such that the time when the basic safety message is generated is as close as possible to the time when the basic safety message is sent, in order to reduce or minimize the information age of the basic safety message. In some aspects, the offset may be based at least in part on the processing power of the processor. For example, the offset time may be based on the amount of time the processor takes to generate the basic safety message.

[0102] like Figure 4 As shown, the processor may generate a first basic safety message at time t0-(minus) offset and may provide the first basic safety message to the modem at t0 for transmission. The processor may generate a second basic safety message at time t0+one SPS period-offset and may provide the second basic safety message to the modem at time t0+one SPS period for transmission. The processor may generate a third basic safety message at time t0+two SPS periods-offset and may provide the second basic safety message to the modem at time t0+two SPS periods for transmission. The processor may generate additional basic safety messages in a similar manner. In this manner, each basic safety message is generated and sent according to an SPS period starting from the anchor time.

[0103] In this manner, the UE's modem can provide the processor with an anchor time that can indicate a time at which a basic safety message will be sent in an SPS resource based at least in part on an SPS period. In this manner, the processor can generate the basic safety message at an offset from the anchor time in a manner that reduces the amount of time between the generation and transmission of the basic safety message. This reduces the information age of the information included in the basic safety message, thereby preventing or reducing the likelihood that the information will become stale, outdated, or inaccurate.

[0104] As pointed out above, Figure 4 is provided as an example. Other examples may differ from those described in relation to Figure 4 Examples described.

[0105] Figure 5 FIG. 5 is an example flowchart of reducing semi-persistent scheduling latency according to various aspects of the present disclosure. Figure 5 As shown, example 500 may include a UE (e.g., UE 120). In some aspects, the UE may be deployed in a wireless network (such as wireless network 100).

[0106] In some aspects, the UE may be deployed in a C-V2X deployment or another type of deployment in which the UE communicates with other UEs on a sidelink. In this case, the UE may include a processor (e.g., controller / processor 280) and a memory (e.g., memory 282) that may store and execute a safety application. The processor may generate basic safety messages for the safety application and may provide the basic safety messages to the UE's modem.

[0107] The modem of the UE may be implemented by a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem component (including one or more of a receive processor, a transmit processor, a controller / processor, a memory, an integrated circuit, an ASIC), etc. The modem may be capable of packetizing basic safety messages, encoding packets, modulating the encoded packets, and / or performing other baseband processing of basic safety messages for transmission on the sidelink.

[0108] In some aspects, a processor executing a security application may generate a basic security message based at least in part on a basic security message generation period, which may be generated using the above-described method in conjunction with Figure 3The basic safety message generation period may be adjusted based on one or more of the techniques described herein. For example, the processor may generate basic safety messages at intervals based at least in part on a basic safety message generation period. The modem may reserve or schedule SPS resources on the sidelink for transmission of basic safety messages. In some aspects, the modem may reserve or schedule SPS resources such that the SPS resources occur based at least in part on an SPS period, wherein each SPS resource occurs at an interval based at least in part on the SPS period.

[0109] As in Figure 5 In the embodiment of the present invention, and as shown by reference numeral 502, to send a basic security message, a processor executing a security application may provide an SPS resource request to the modem to reserve, configure, or schedule SPS resources based on an SPS period. The modem may receive the request and may reserve, configure, or schedule SPS resources based at least in part on the SPS period.

[0110] As in Figure 5 As further shown in FIG. 5 and by reference numerals 504-514, the modem may provide an indication to the processor of a corresponding transmit time for each basic safety message to be generated by the processor. In some aspects, the transmit time may be based at least in part on an SPS period, at least in part on a basic safety message generation period, etc. The processor may generate a basic safety message for each provided transmit time and based at least in part on the offset.

[0111] As indicated at reference numeral 504, the modem may provide to the processor a first time based at least in part on the SPS period (at Figure 5 The first transmission time may be a time after the SPS resource reservation at which the first basic safety message is configured or scheduled to be transmitted in the first SPS resource. As shown at reference numeral 506, the processor may generate the first basic safety message based at least in part on the offset relative to the first transmission time (e.g., at time t0-offset), and may provide the first basic safety message to the modem at t0 for transmission.

[0112] As indicated by reference numeral 506, the processor may generate a first basic safety message based at least in part on the offset relative to the first transmit time (eg, at time t0-offset) and may provide the first basic safety message to the modem at t0 for transmission.

[0113] As shown in reference numeral 508, the modem can provide an indication of a second time (t0+one SPS period) based at least in part on the SPS period to the processor. The second transmission time can be the time after the SPS resource reservation when the second basic safety message is configured or scheduled to be transmitted in the second SPS resource.

[0114] As indicated by reference numeral 510, the processor may generate a second basic safety message based at least in part on an offset relative to a second transmission time (e.g., at time t0+one SPS period-offset) and may provide the second basic safety message to the modem for transmission at t0+one SPS period.

[0115] As shown in reference numeral 512, the modem may provide an indication to the processor of a third time (t0+two SPS periods) based at least in part on the SPS period. The third transmission time may be a time when the third basic safety message is configured or scheduled to be transmitted in the third SPS resource two SPS periods after the SPS resource reservation.

[0116] As indicated by reference numeral 514, the processor may generate a third basic safety message based at least in part on the offset relative to the third transmission time (e.g., at time t0+two SPS periods minus the offset), and may provide the third basic safety message to the modem for transmission at t0+two SPS periods. The processor may generate subsequent basic safety messages based at least in part on the offset and the transmission time in a manner similar to that described above.

[0117] In this manner, the UE's modem can provide the processor with corresponding transmit times, each of which can indicate a time at which a basic safety message will be transmitted in an SPS resource based at least in part on an SPS period. In this manner, the processor can generate the basic safety message at an offset from the transmit time in a manner that reduces the amount of time between the generation and transmission of the basic safety message. This reduces the information age of the information included in the basic safety message, thereby preventing or reducing the likelihood that the information will become stale, outdated, or inaccurate.

[0118] As pointed out above, Figure 5 is provided as an example. Other examples may differ from those described in relation to Figure 5 Other examples may include a shift in the SPS transmission time so that the transmission time may be SPS plus or minus x ms. In some aspects, the message being transmitted may include any type of periodic message sent via the CV2X channel and / or the sidelink channel.

[0119] Figures 6A-6C6 is a diagram illustrating an example flowchart 600 for reducing semi-persistent scheduling latency according to various aspects of the present disclosure. Figures 6A-6C As shown, example 600 may include a UE (e.g., UE 120). In some aspects, the UE may be deployed in a wireless network (such as wireless network 100).

[0120] In some aspects, the UE may be deployed in a C-V2X deployment or another type of deployment in which the UE communicates with other UEs on a sidelink. In this case, the UE may include a processor (e.g., controller / processor 280) and a memory (e.g., memory 282) that may store and execute a safety application. The processor may generate basic safety messages for the safety application and may provide the basic safety messages to the UE's modem.

[0121] The modem of the UE may be implemented by a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem component (including one or more of a receive processor, a transmit processor, a controller / processor, a memory, an integrated circuit, an ASIC), etc. The modem may be capable of packetizing basic safety messages, encoding packets, modulating the encoded packets, and / or performing other baseband processing of basic safety messages for transmission on the sidelink.

[0122] In some aspects, a processor executing a safety application may generate basic safety messages based at least in part on a basic safety message generation period. For example, the processor may generate basic safety messages at intervals based at least in part on the basic safety message generation period. The modem may reserve or schedule SPS resources on the sidelink for transmission of basic safety messages. In some aspects, the modem may reserve or schedule SPS resources such that the SPS resources occur based at least in part on an SPS period, wherein each SPS resource occurs at an interval based at least in part on the SPS period.

[0123] As in Figure 6A In some cases, and as further shown by reference numeral 602, a processor executing a safety application may periodically provide an SPS resource reselection request to the modem. In some aspects, the processor may request SPS resource reselection based at least in part on an increased frequency for transmitting basic safety messages specified by the safety application, based at least in part on network congestion on the sidelink, etc.

[0124] The modem may receive an SPS resource reselection request and may perform SPS resource reselection based at least in part on receiving the request. In this case, the modem may select an updated set of SPS resources for transmission of the basic safety message and may select an updated anchor time or a new transmission time (in the case of a transmission time) based at least in part on the SPS resource reselection. Figure 6A As indicated at t1 in FIG. 6 , the modem may provide an indication of an updated anchor time or transmit time to the processor.

[0125] As in Figure 6A , and as further shown by reference numeral 606, the UE may generate and transmit one or more basic safety messages based at least in part on the updated anchor time or transmit time. For example, the processor may generate the basic safety message at an offset time relative to the updated anchor time or transmit time (e.g., at time t1-offset) and may provide the basic safety message to the modem at time t1 for transmission.

[0126] like Figure 6A As further shown, in some cases, the updated anchor time or transmission time selected by the modem may result in the basic safety message being transmitted at a time that does not meet the SPS period. In other words, the time between the transmission of the most recent basic safety message and the transmission of the basic safety message based on time t1 may be greater than the SPS period, which may result in an increased information age of the information included in the basic safety message.

[0127] In some aspects, even though transmission of the basic safety message at t1 does not satisfy the SPS periodicity, the UE is allowed to send the basic safety message at t1 due to the low and / or infrequent occurrence of the basic safety message not satisfying the SPS periodicity.

[0128] As in Figure 6B In some aspects, and as shown by reference numeral 608, the UE can mitigate the transmission of a basic safety message that does not satisfy the SPS period at time t1 by sending a non-SPS basic safety message (which may also be referred to as a single intermediate basic safety message) between the transmission of the latest basic safety message and the transmission of the basic safety message at time t1. For example, the processor may determine that the transmission of the basic safety message at time t1 will not satisfy the SPS period, and may generate a non-SPS basic safety message to satisfy the SPS period based at least in part on this determination. In this manner, the non-SPS basic safety message may be sent within the SPS period from the transmission of the latest basic safety message that satisfies the SPS period. The basic safety message may be sent at time t1 based at least in part on the SPS period, and so on.

[0129] In some aspects, the modem may instruct the processor to generate a non-SPS basic safety message such that the non-SPS basic safety message will be sent within a threshold associated with the transmission of the basic safety message at time t1. For example, the modem may instruct the processor to generate a non-SPS basic safety message such that the non-SPS basic safety message will be sent within ±50 ms from t1. In another aspect, the modem may select a resource within t1 to t2 from the time of deciding to reselect, where t1 is typically approximately 4 ms and t2 varies based on the load detected on the channel and may be less than the delay budget assumed to be 100 ms in the previous description. Therefore, by selecting a reselection time at t1–(t2-t1) / 2–t1, the modem can ensure that the transmission time will be between + / - (t2-t1) / 2 from t1.

[0130] In some aspects, using a non-SPS basic safety message may still result in the transmission of the basic safety message at time t1 not satisfying the SPS period. In other words, at time t1, the time between the transmission of the non-SPS basic safety message and the transmission of the basic safety message at time t1 may still exceed the SPS period. In these examples, the processor may generate another non-SPS basic safety message based at least in part on a determination that the transmission of the non-SPS basic safety message will result in the time between the transmission of the non-SPS message and the transmission of the basic safety message at time t1 exceeding the SPS period. In some aspects, the processor may generate additional non-SPS basic safety messages as needed to satisfy the SPS period.

[0131] In some aspects, the modem may autonomously generate and send non-SPS basic safety messages (eg, without input from a processor), making the process of sending the non-SPS basic safety messages transparent to the processor.

[0132] As in Figure 6C In some aspects, the UE can mitigate transmission of a basic safety message at time t1 that does not satisfy the SPS period by adjusting selection of SPS resources for the basic safety message and illustrated by reference numeral 610. In these examples, the modem can adjust selection of SPS resources such that time t1 occurs earlier in time and within the SPS period from the most recent basic safety message transmission such that the SPS period is satisfied.

[0133] like Figure 6CAs further shown, a subsequent basic safety message may be generated and sent at an SPS period relative to the adjusted time t1. For example, the processor may generate the subsequent basic safety message at an offset value relative to the adjusted time t1+one SPS period and may provide the subsequent basic safety message to the modem for transmission at the adjusted time t1+one SPS period.

[0134] In this way, the UE's processor and modem can use one or more of the above-mentioned techniques to reduce information age and / or SPS scheduling latency, for example, generating and sending non-SPS basic safety messages in scenarios where the anchor time or transmission time is updated, scheduling SPS resources within the SPS period in scenarios where the anchor time or transmission time is updated, and so on.

[0135] As pointed out above, Figures 6A-6C is provided as an example. Other examples may differ from those described in relation to Figures 6A-6C Examples described.

[0136] Figure 7 7 is a state diagram illustrating an example 700 of reducing semi-persistent scheduling latency according to various aspects of the present disclosure. Figure 7 As shown, example 700 may include a UE (e.g., UE 120). In some aspects, the UE may be deployed in a wireless network (such as wireless network 100).

[0137] In some aspects, the UE may be deployed in a C-V2X deployment or another type of deployment in which the UE communicates with other UEs on a sidelink. In this case, the UE may include a processor (e.g., controller / processor 280) and a memory (e.g., memory 282) that may store and execute a safety application. The processor may generate basic safety messages for the safety application and may provide the basic safety messages to the UE's modem.

[0138] The modem of the UE may be implemented by a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem component (including one or more of a receive processor, a transmit processor, a controller / processor, a memory, an integrated circuit, an ASIC), etc. The modem may be capable of packetizing basic safety messages, encoding packets, modulating the encoded packets, and / or performing other baseband processing of basic safety messages for transmission on the sidelink.

[0139] In some aspects, a processor executing a security application may generate a basic security message based at least in part on a basic security message generation period, which may be generated using the above-described method in conjunction with Figure 3 The basic safety message generation period may be adjusted based on one or more of the techniques described herein. For example, the processor may generate basic safety messages at intervals based at least in part on a basic safety message generation period. The modem may reserve or schedule SPS resources on the sidelink for transmission of basic safety messages. In some aspects, the modem may reserve or schedule SPS resources such that the SPS resources occur based at least in part on an SPS period, wherein each SPS resource occurs at an interval based at least in part on the SPS period.

[0140] In some aspects, the modem and / or processor may adjust the SPS period (e.g., based at least in part on an expected change in the base safety message generation period for the safety application, based at least in part on sidelink and / or network congestion, etc.). For example, the processor may request an SPS period that is greater than the reserved SPS period for the safety application. As another example, the processor may request an SPS period that is less than the reserved SPS period for the safety application. The modem may receive a request to adjust the SPS period and may adjust the SPS period at the next reselection opportunity, which may occur at a specific time or at a specific interval in the wireless network. Figure 7 Example 700 may illustrate various operating states and state transitions for adjusting the SPS period.

[0141] like Figure 7 As shown, state 702 corresponds to a state of the UE where the SPS period reserved by the modem is set to or equal to the SPS period requested by the processor executing the security application. In state 702, the processor may generate a basic safety message according to the reserved SPS period.

[0142] like Figure 7 As further shown, state 704 corresponds to a state of the UE in which the SPS period requested by the processor is greater than the SPS period reserved by the modem. In some aspects, the UE can transition from state 702 or state 706 to state 704 based at least in part on the processor providing a request to the modem for an adjusted SPS period greater than the SPS period reserved by the modem.

[0143] In state 704, the processor may generate basic safety messages at the reserved SPS period or less frequently until the modem provides an indication to the processor that the reserved SPS period has been adjusted to match the requested SPS period (in which case the UE may transition to state 702), until the processor provides a request to the modem for an adjusted SPS period that matches the reserved SPS period (in which case the UE may transition to state 702), or until the processor provides a request to the modem for an adjusted SPS period that is less than the reserved SPS period (in which case the UE may transition to state 702). In some aspects, when the reserved SPS period is adjusted to a larger period, the modem may change selection when the latest basic safety message arrives to avoid out-of-phase transmissions.

[0144] like Figure 7 As further shown, state 706 corresponds to a state of the UE where the SPS period requested by the processor is less than the SPS period reserved by the modem. In some aspects, the UE can transition from state 702 or state 704 to state 706 based at least in part on the processor providing a request to the modem for an adjusted SPS period that is less than the SPS period reserved by the modem.

[0145] In state 706, the processor may generate basic safety messages with the requested SPS period until the processor provides an indication to the modem that the reserved SPS period has been adjusted to match the requested SPS period (in which case the UE may transition to state 702), until the processor provides a request to the modem for an adjusted SPS period that matches the reserved SPS period (in which case the UE may transition to state 702), or until the processor provides a request to the modem for an adjusted SPS period that is greater than the reserved SPS period (in which case the UE may transition to state 704).

[0146] In addition, when the UE is in state 706, the modem can send a non-SPS basic safety message as needed so that the UE sends the basic safety message with the requested SPS period.In these examples, the modem can generate and send the non-SPS basic safety message without input from the processor.

[0147] In this way, the processor and modem of the UE can adjust the SPS period for sending basic safety messages, can adjust the generation of basic safety messages to adapt to the SPS period adjustment, and so on.

[0148] As pointed out above, Figure 7is provided as an example. Other examples may differ from those described in relation to Figure 7 Examples described.

[0149] In some aspects, for example, the processor may reserve an SPS stream cycle all the time, and use the same cycle to generate a packet. Congestion control algorithms (such as, the congestion control algorithm specified by the Society of Automotive Engineers (SAE) and / or another type of congestion control algorithm) can be used by the processor to determine and update the cycle. However, when the request changes the stream cycle, the modem can delay the change of the SPS reservation, and can keep the reservation until the next reselection. Before the next reselection, there will be a mismatch between the actual safety message generation cycle at the safety application and the actual SPS cycle reserved for transmission. Before the modem SPS reservation is updated to match the requested SPS reservation (which equals the safety application message generation cycle), any packet received for transmission that does not arrive in the delay budget from the next transmission opportunity is sent as non-SPS or a single transmission.

[0150] In some aspects, as a variation of the above alternative, the modem may determine to delay changing the period until the next reservation if the period is decreasing, but change the reservation immediately, or after a short delay, if the period is decreasing.

[0151] Figure 8 is a diagram illustrating an example process 800 performed, for example, by a UE, according to various aspects of the present disclosure. The example process 800 is a diagram in which a UE (e.g., in conjunction with Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4 , 5, 6A-6C and / or 7 show and describe examples of a UE) performing operations associated with reducing semi-persistent scheduling delay.

[0152] like Figure 8 As shown, in some aspects, process 800 may include adjusting a basic safety message generation period based at least in part on an SPS period used to send basic safety messages (block 810). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller / processor 280, memory 282, etc.) may adjust the basic safety message generation period based at least in part on the SPS period used to send basic safety messages, as described above.

[0153] like Figure 8As further shown, in some aspects, process 800 may include generating one or more basic safety messages based at least in part on the adjusted basic safety message generation period (block 820). For example, the UE (e.g., using receive processor 258, transmit processor 264, controller / processor 280, memory 282, etc.) may generate one or more basic safety messages based at least in part on the adjusted basic safety message generation period, as described above.

[0154] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0155] Although Figure 8 Example blocks of process 800 are shown, but in some aspects process 800 may include Figure 8 The blocks may include additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in process 800. Additionally or alternatively, two or more blocks of the blocks of process 800 may be executed in parallel.

[0156] Figure 9 is a data flow diagram 900 illustrating the data flow between different components in an example apparatus 902. The apparatus 902 may be a UE (e.g., in conjunction with Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4 , 5, 6A-6C, 7, 8, and / or 10). In some aspects, apparatus 902 includes a determining / adjusting component 904, a basic safety message generating component 906, an anchoring / transmission time determining component 908, and a sending component 910.

[0157] In some aspects, the determining / adjusting component 904 may be configured to: Figure 3-8 11-19. In some aspects, basic safety message generation component 906 can generate one or more basic safety messages 912 based at least in part on the basic safety message generation period determined / adjusted by determination / adjustment component 904. In some aspects, basic safety message generation component 906 can provide one or more basic safety messages 912 to sending component 910, and sending component 910 can send one or more basic safety messages 912.

[0158] In some aspects, anchor / transmission time determination component 908 can determine an anchor time and can provide an indication of the anchor time to basic safety message generation component 906. In some aspects, the anchor time can be selected based at least in part on resources used for a safety application associated with device 902. In some aspects, basic safety message generation component 906 can receive the indication of the anchor time and can generate a basic safety message 912 at an offset time prior to the anchor time.

[0159] In some aspects, anchor / transmission time determination component 908 can receive an indication of resource reselection associated with a safety application associated with one or more basic safety messages 912, can determine an updated anchor time based at least in part on the resource reselection, and can provide an indication of the updated anchor time to basic safety message generation component 906. In some aspects, basic safety message generation component 906 can generate a basic safety message in the one or more basic safety messages at an offset time prior to the updated anchor time. In some aspects, basic safety message generation component 906 can generate a non-SPS basic safety message 914 based at least in part on a determination that transmission of a basic safety message 912 at the updated anchor time would cause the amount of time between the updated anchor time and the time at which a most recently generated basic safety message 912 generated by basic safety message generation component 906 would be sent to exceed an SPS period.

[0160] In some aspects, sending component 910 can use resources before the updated anchor time for transmission of basic safety message 912 based at least in part on a determination that transmission of basic safety message 912 at the updated anchor time would cause an amount of time between the updated anchor time and the time at which a basic safety message 912 most recently generated by basic safety message generating component 906 would be sent to exceed an SPS period.

[0161] In some aspects, anchor / transmission time determination component 908 can determine a respective transmit time for each of one or more basic safety messages 912 and can provide an indication of the respective transmit time to basic safety message generation component 906. In some aspects, basic safety message generation component 906 can generate one or more basic safety messages 912 at an offset time prior to the respective transmit time.

[0162] In some aspects, basic safety message generation component 906 can provide a request for an adjusted SPS period to determination / adjustment component 904. Determination / adjustment component 904 can receive the request, can configure the determined / adjusted SPS period at a reselection opportunity, and can provide an indication of an anchor time for transmission of one or more basic safety messages 912 to basic safety message generation component 906, the anchor time being based at least in part on the determined / adjusted SPS period. In some aspects, basic safety message generation component 906 can generate one or more basic safety messages 912 based at least in part on the SPS period before basic safety message generation component 906 receives the adjusted SPS period.

[0163] In some aspects, determining / adjusting component 904 may include a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem of apparatus 902 (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, and / or memory), etc. In some aspects, basic safety message generating component 906 may include a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem of apparatus 902 (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, and / or memory), etc. In some aspects, the anchor / transmit time determining component 908 may include a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem of the apparatus 902 (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, and / or memory), etc. In some aspects, the transmit component 910 may include a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem of the apparatus 902 (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, and / or memory), etc.

[0164] The device 902 may include executing Figure 3-8 and additional components of aspects of 11-19, etc. Can be performed by components or combinations of components Figure 3-8Each block of the algorithm or other aspects of 11-19 and 11-19, and the device 902 may include one or more of those components. The component can be one or more hardware components specifically configured to perform the process / algorithm, implemented by a processor configured to perform the process / algorithm, stored in a computer-readable medium for implementation by a processor, or some combination thereof.

[0165] exist Figure 9 The number and arrangement of components shown in the diagram are provided as examples. Figure 9 There may be additional components, fewer components, different components, or components arranged differently than those shown in FIG. Figure 9 Two or more components shown in may be implemented within a single component, or in Figure 9 A single component shown in may be implemented as multiple distributed components. Additionally or alternatively, Figure 9 A set of components (e.g., one or more components) shown in FIG may perform the operations described by Figure 9 One or more functions performed by another group of components shown in FIG.

[0166] Figure 10 1 is a signaling diagram of an SPS scheduling process 1000 according to various aspects of the present disclosure. As shown, various aspects of the SPS scheduling process 1000 may be performed by a UE (e.g., in conjunction with Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4 , 5, 6A-6C, 7 and 9). In this regard, the UE may utilize one or more components (a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, memory and / or antenna)) to perform various aspects of the SPS scheduling process 1000. In this regard, although specific components or groups of components of the UE may be described as performing various aspects of the SPS scheduling process 1000, it should be understood that in some cases, alternative components and / or groups of components may be used to perform the same or similar aspects of the SPS scheduling process 1000.

[0167] At block 1002, the processor of the UE determines a period for sending a safety message. The period may be a plurality of support semi-persistent scheduling (SPS) periods (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 ms or other suitable values). In this regard, the plurality of support SPS periods may be defined by a specification (3gpp, SAE, etc.), a UE definition, or otherwise. For example, in some cases, the plurality of support SPS periods include an SPS period associated with a sidelink PC5 or LTE-V2X. In some cases, the processor, modem, and / or other components of the UE may be programmed to facilitate the UE to use a plurality of support SPS periods (or a subset thereof) to generate and / or send a safety message.

[0168] In some cases, at block 1002, the processor determines the period by rounding the calculated period to a multiple of a canonical supported SPS period and / or a 100 millisecond period. In some cases, at block 1002, the processor rounds the safety message generation period determined by the congestion control algorithm to a supported SPS period among a plurality of supported SPS periods. In this regard, the congestion control algorithm may be an SAE Distributed Congestion Control (DCC) algorithm, and the safety message generation period may be a maximum inter-transmission time (MAX_ITT). In some cases, MAX_ITT is calculated as MAX_ITT=min(600ms, max(100ms, N / B*100ms)), where 600ms is the maximum allowed MAX_ITT, 100ms is the minimum allowed MAX_ITT, N is the number of devices within a 100m radius, and B is a density factor having a default value of 25. In other cases, different maximum, minimum, and density values ​​may be utilized. In other aspects, the congestion control algorithm can be a distributed congestion control (DCC) algorithm that generates generation cycles based on measured load, device speed, and / or other parameters.

[0169] At block 1004 , the processor of the UE sends an SPS reservation request to the modem based on the period determined at block 1002 .

[0170] At block 1006, the modem obtains an SPS reservation based on the request received from the processor.

[0171] At block 1008 , the processor of the UE generates data (eg, a security message) at the period determined at block 1002 .

[0172] At block 1010, the UE's processor transmits a data / security message to the modem.

[0173] At block 1012 , the modem selects resources (eg, time and / or frequency resources) for sending data / safety messages at the SPS period obtained at block 1006 .

[0174] At block 1014, the modem sends the data / safety message using the resources selected at 1012 and based on the obtained SPS period.

[0175] At block 1016, the UE's processor determines whether the period of the data / security message should remain the same or be updated. If the processor determines that the period should remain the same, the UE will continue the loop of blocks 1008-1016 with the current period until the processor determines at block 1016 that the period should be updated.

[0176] At box 1016, when the processor determines that a cycle different from the current cycle should be used, the processor can determine that the cycle should be updated. In some cases, the cycle updated is also a support SPS cycle (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000ms or other suitable values) in a plurality of support SPS cycles. In some cases, the processor determines the cycle updated by rounding the calculated cycle to a multiple of the support SPS cycle and / or 100 millisecond cycle of the specification. In some cases, the processor rounds the safety message generation cycle determined by the congestion control algorithm to a support SPS cycle in a plurality of support SPS cycles. In this regard, the congestion control algorithm can be an SAE distributed congestion control (DCC) algorithm, and the safety message generation cycle can be a maximum inter-transmission time (MAX_ITT). In some cases, MAX_ITT is calculated as MAX_ITT = min(600ms, max(100ms, N / B*100ms)), where 600ms is the maximum allowed MAX_ITT, 100ms is the minimum allowed MAX_ITT, N is the number of devices within a 100m radius, and B is a density factor that defaults to 25. In other cases, different maximum, minimum, and density values ​​may be utilized.

[0177] In some cases, the processor generates a signal based on a hysteresis parameter (e.g., as referenced Figure 12A and 12B The hysteresis parameter described above (e.g., the hysteresis parameter described above) rounds the calculated period to the second period to determine the updated period. In this regard, the hysteresis parameter can increase the range of the calculated period, which will cause the processor to round to the current period (e.g., the first period) and thus maintain the current period. This can prevent the UE from attempting to repeatedly switch back and forth between two adjacent periods when the calculated period value is close to the rounding boundary of an adjacent period and small changes in the environment and / or communication may potentially result in different period determinations.

[0178] In some cases, the hysteresis parameter is a percentage of the gap between the current period and the adjacent supported period. For example, if the current period is 300 ms and the adjacent supported period is 400 ms (or 200 ms), the gap is 100 ms. In some cases, the percentage is between 0% and 50%, including between 5% and 15%. In some cases, the processor randomly selects the value of the hysteresis parameter from a set of available values ​​for the hysteresis parameter. In this regard, by having each UE randomly select the hysteresis parameter, the possibility of a large number of UEs changing the period at the same time is reduced because the UEs will have different rounding ranges due to the hysteresis parameter having a value different from the randomly selected value.

[0179] In some cases, at box 1016, the processor rounds the calculated period to a support period based on determining whether the calculated period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, where Tn is the current period, Tn-1 is the support period less than the current period, Tn+1 is the support period greater than the current period, and H is a lag parameter.

[0180] If the period calculated at block 1016 is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H, the processor rounds the calculated period to a period lower than the current period (e.g., Tn-1). If the period calculated at block 1016 is greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, the processor rounds the calculated period to a period value higher than the current period (e.g., Tn+1). If the period calculated at block 1016 is between (Tn+Tn-1) / 2–(Tn–Tn-1)*H and (Tn+Tn+1) / 2+(Tn+1–Tn)*H, the processor rounds the calculated period to the current period, and therefore, the period is not changed.

[0181] In some cases, at block 1016, the processor determines whether to continue utilizing the first cycle or switch to the second cycle based on a probability determination process. That is, even if the processor determines that a cycle change can be guaranteed (e.g., based on a MAX_ITT calculation), the processor may utilize a probability determination process to determine whether to actually change the cycle or continue utilizing the current cycle. The probability determination process may include weighted coin flips, probabilistic Boolean operations, or other suitable techniques. In some cases, the probability determination process is weighted toward the current cycle. That is, the probability determination process is biased toward maintaining the current cycle rather than switching to a different cycle. In this regard, in some cases, the probability determination process is weighted toward the first cycle between 2:1 and 100:1, such as 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 50:1, or other suitable values. In some cases, the processor executes block 1016 and determines whether to continue utilizing the current cycle or switch to an updated cycle at the scheduled packet generation time period associated with the current cycle and before sending the packet generated at the scheduled packet generation time period.

[0182] At block 1018 , the UE's processor sends an updated SPS reservation request to the modem based on the updated period determined at block 1016 .

[0183] At block 1020, the modem obtains an updated SPS reservation based on the request received from the processor at block 1018. In some cases, the modem requests and / or obtains an updated reservation upon receiving an SPS reservation request from the processor (e.g., see Figure 14 In some cases, the modem delays requesting and / or obtaining an updated SPS reservation after receiving an SPS reservation request from the processor (see, e.g., Figure 15 and 16 ).

[0184] At block 1022 , the processor of the UE generates data (eg, a security message) at the period determined at block 1016 .

[0185] At block 1024 , the UE's processor transmits the data / security message generated at block 1022 to the modem.

[0186] At block 1026 , the modem selects resources (eg, time and / or frequency resources) for transmitting the data / safety message received at block 1024 at the SPS period obtained at block 1020 .

[0187] At block 1028 , the modem sends the data / safety message using the resources selected at block 1026 and based on the SPS period obtained at 1020 .

[0188] At block 1030, the UE's processor determines whether the period of the data / security messages should remain the same or be updated (in the same or similar manner as block 1016), and the process continues in an iterative loop through blocks similar or identical to blocks 1016-1028.

[0189] Figure 11 is a signaling diagram of a safety message generation and scheduling process 1100 according to various aspects of the present disclosure. As shown, various aspects of the safety message generation and scheduling process 1100 may be performed by a UE (e.g., in conjunction with a Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4 , 5, 6A-6C, 7, 9 and 10). In this regard, the UE may utilize one or more components (a receive processor (e.g., receive processor 258), a transmit processor (e.g., transmit processor 264), a controller / processor (e.g., controller / processor 280), a memory (e.g., memory 282), a modem (e.g., implemented by one or more of the receive processor, transmit processor, controller / processor, memory and / or antenna)) to perform various aspects of the safety message generation and scheduling process 1100. In this regard, although specific components or groups of components of the UE may be described as performing various aspects of the safety message generation and scheduling process 1100, it should be understood that in some cases, alternative components and / or groups of components may be used to perform the same or similar aspects of the safety message generation and scheduling process 1100.

[0190] The Intelligent Transportation System (ITS) stack process begins at block 1102. The ITS stack may be a security program (eg, the SAE ITS stack) or another program executed by a processor of the UE.

[0191] At block 1104, the UE determines the maximum inter-frame transmission time (MAX_ITT) and rounds the MAX_ITT to the supported SPS period. In some cases, the UE rounds the calculated MAX_ITT to a multiple of the canonical supported SPS period and / or a 100 millisecond period. In some cases, the MAX_ITT is calculated as MAX_ITT = min(600ms, max(100ms, N / B*100ms)), where 600ms is the maximum allowed MAX_ITT, 100ms is the minimum allowed MAX_ITT, N is the number of devices within a 100m radius, and B is a density factor with a default value of 25. In other cases, different maximum, minimum, and density values ​​may be utilized.

[0192] At block 1106 , the UE makes an SPS reservation based on the period determined at block 1104 .

[0193] At block 1108 , the processor of the UE generates a basic safety message and delivers the generated basic safety message to the modem of the UE at the period determined at block 1104 .

[0194] At block 1110 , the UE's processor waits for the period determined at block 1104 .

[0195] At block 1112, the processor of the UE determines a candidate MAX_ITT after rounding with hysteresis. In some cases, the processor determines the candidate MAX_ITT by rounding the calculated MAX_ITT to a supported SPS period based on a hysteresis parameter (see, e.g., Figure 12A and 12B In this regard, the hysteresis parameter can increase the range of the calculated MAX_ITT value, which will cause the processor to round to the current cycle and therefore maintain the current cycle. This can prevent the UE from attempting to repeatedly switch back and forth between two adjacent cycles when the calculated MAX_ITT value is close to the rounding boundary of an adjacent cycle and small changes in the environment and / or communication can potentially lead to different cycle determinations.

[0196] In some cases, the hysteresis parameter is a percentage of the gap between the current period and the adjacent supported period. For example, if the current period is 300 ms and the adjacent supported period is 400 ms (or 200 ms), the gap is 100 ms. In some cases, the percentage is between 0% and 50%, including between 5% and 15%. In some cases, the processor randomly selects the value of the hysteresis parameter from a set of available values ​​for the hysteresis parameter. In this regard, by having each UE randomly select the hysteresis parameter, the possibility of a large number of UEs changing the period at the same time is reduced because the UEs will have different rounding ranges due to the hysteresis parameter having a value different from the randomly selected value.

[0197] In some cases, at block 1112, the processor rounds the calculated candidate MAX_ITT to a supported period based on determining whether the calculated MAX_ITT is less than (Tn+Tn-1) / 2-(Tn-Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1-Tn)*H, where Tn is the current period, Tn-1 is a supported period less than the current period, Tn+1 is a supported period greater than the current period, and H is a hysteresis parameter. In this regard, if the candidate MAX_ITT calculated at block 1112 is less than (Tn+Tn-1) / 2-(Tn-Tn-1)*H, the processor rounds the candidate MAX_ITT calculated at block 1112 to a period lower than the current period (e.g., Tn-1). Similarly, if the candidate MAX_ITT calculated at block 1112 is greater than (Tn+Tn+1) / 2+(Tn+1−Tn)*H, the processor rounds the candidate MAX_ITT calculated at block 1112 to a period higher than the current period (e.g., Tn+1). If the period calculated at block 1112 is between (Tn+Tn-1) / 2−(Tn−Tn-1)*H and (Tn+Tn+1) / 2+(Tn+1−Tn)*H, the processor rounds the candidate MAX_ITT calculated at block 1112 to the current period, and therefore, the period is not changed.

[0198] At block 1114, the processor determines whether the period / MAX_ITT determined at block 1112 is different from the current period / MAX_ITT. For example, the processor may determine whether the period / MAX_ITT (from block 1114) is greater than or less than the current period / MAX_ITT (from block 1104). If not, the secure message generation and scheduling process 1100 continues to block 1116 without changing the period / MAX_ITT.

[0199] If the processor determines at block 1114 that the period / MAX_ITT determined at block 1112 is different from the current period / MAX_ITT, the security message generation and scheduling process 1100 proceeds to block 1118, where the UE's processor determines, based on a probabilistic determination process, whether the period should remain the same or be updated to the period / MAX_ITT determined at block 1112. The probabilistic determination process may include weighted coin flips, probabilistic Boolean operations, or other suitable techniques. In some cases, the probabilistic determination process is weighted toward the current period. That is, the probabilistic determination process is biased toward maintaining the current period rather than switching to the period / MAX_ITT determined at block 1112. In this regard, in some cases, the probabilistic determination process is weighted toward a first period between 2:1 and 100:1, such as 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 50:1, or other suitable values. In some cases, the processor executes block 1118 and determines whether to continue utilizing the current period or to switch to the period / MAX_ITT determined at block 1112 at a scheduled packet generation time period associated with the current period (e.g., due to a delay at block 1110) and before sending packets generated at the scheduled packet generation time period.

[0200] If the processor determines at block 1118 that the current period / MAX_ITT should not be updated, the safety message generation and scheduling process 1100 proceeds to block 1116 and does not change the period / MAX_ITT. If the processor determines at block 1118 that the current period / MAX_ITT should be updated and is changed to the period / MAX_ITT determined at block 1112, the safety message generation and scheduling process 1100 proceeds to block 1120. At block 1120, the period is updated to the period / MAX_ITT determined at block 1112, and the UE makes an SPS reservation based on the updated period. The safety message generation and scheduling process 1100 then proceeds to block 1108, as shown.

[0201] In some cases, the UE generates safety messages at a computation period that is independent of tracking errors at the underlying device receiving the transmission.

[0202] In some cases, the UE detects a tracking error and generates a tracking error-based safety message in response to the detected tracking error at block 1122. At block 1124, the UE may deliver the tracking error-based safety message to the UE's modem as an event transmission separate from the SPS-scheduled safety message generation and transmission. Thus, the generated tracking error-based safety message may be generated and / or sent separately from multiple supported SPS periods (see, e.g., Figure 13B and 13C ).

[0203] In some cases, when a safety message based on a tracking error is generated within a threshold amount of time of the schedule generation period, the UE avoids generating a safety message during the schedule generation period associated with the SPS cycle (see, e.g. Figure 13C ). In some cases, the threshold amount of time is based on a packet delay budget (e.g., 50, 100, 200 ms, or other suitable value) or other parameters. For example, at block 1126, the UE's processor may determine whether the time elapsed since the last tracking error-based safety message is greater than the packet delay budget. If so, the safety message generation and scheduling process 1100 proceeds to block 1108 and generates and delivers the next scheduled safety message to the modem. However, if the time elapsed since the last tracking error-based safety message is less than the packet delay budget, the next scheduled safety message is skipped and the safety message generation and scheduling process 1100 may proceed to block 1110. However, in some cases, the UE continues to generate safety messages during the scheduled generation period even when the tracking error-based safety message is generated within the threshold amount of time before the scheduled generation period. For example, if the scheduled generation period is associated with a change in period (e.g., from a first period to a second period), the UE may proceed to block 1108 and generate and deliver the next scheduled safety message to the modem.

[0204] Figure 12A and 12B is a graph of SPS period rounding ranges with hysteresis parameters according to various aspects of the present disclosure. In this regard, Figure 12A 12. The diagram 1200 is shown in which the hysteresis parameter is set to zero so that the rounding ranges are equal between adjacent supported SPS periods. That is, in the diagram 1200, the rounding ranges have a uniform distribution between adjacent periods (e.g., similar to having no hysteresis parameter). For example, a range 1202 extending from 250 to 350 defines a value that the UE will round to a period of 300 ms. That is, for calculated period values ​​between 250 and 350 (e.g., MAX_ITT), the UE may round the calculated period to 300 ms (which is Figure 12A One of the supported SPS periods) as well as 20, 50, 100, 200, 300, 400, 500, and 600ms.

[0205] Figure 12BGraph 1250 is shown in which a hysteresis parameter increases the rounding range of the current period. In this manner, the hysteresis parameter can increase the range of the calculated period, which will cause the UE to round to the current period and, therefore, maintain the current period. Using the hysteresis parameter in this manner can prevent the UE from attempting to repeatedly switch back and forth between two adjacent periods when the calculated period value is close to the rounding boundary of an adjacent period and small changes in the environment and / or communication may result in different period determinations.

[0206] In some cases, the hysteresis parameter is the percentage of the gap between the first period and the adjacent support period. Figure 12B As shown, if the current cycle is 300ms and the adjacent supported cycles are 200ms and 400ms, the gap between the two adjacent cycles is 100ms. However, if the adjacent supported cycles are 200ms and 350ms, the gap will be 100ms with respect to the 200ms cycle and 50ms with respect to the 350ms cycle. In some cases, the percentage is between 0% and 50%, including between 5% and 15%. Figure 12B An example of a hysteresis percentage of 5% for a current cycle of 300ms is shown. As shown, a range 1502 extending from 245 to 355 defines the values ​​that the UE will round to for a cycle of 300ms due to the 5% hysteresis parameter and the 100ms gap between adjacent supported cycles.

[0207] In some cases, the UE randomly selects a value for the hysteresis parameter from a set of available values ​​for the hysteresis parameter. In this regard, by having each UE randomly select the hysteresis parameter, the likelihood of a large number of UEs changing the period simultaneously is reduced because the UEs will have different rounding ranges due to the hysteresis parameter having a value different from the randomly selected value.

[0208] In some cases, the UE rounds the calculated period or MAX_ITT to a supported period based on determining whether the calculated period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, where Tn is the current period, Tn-1 is a supported period less than the current period, Tn+1 is a supported period greater than the current period, and H is a hysteresis parameter. In this regard, if the calculated period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H, the UE rounds the calculated period to a period lower than the current period (e.g., Tn-1). Similarly, if the calculated period is greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, the UE rounds the calculated period to a period higher than the current period (e.g., Tn+1). If the calculated period is between (Tn+Tn-1) / 2−(Tn−Tn-1)*H and (Tn+Tn+1) / 2+(Tn+1−Tn)*H, the UE rounds the calculated period to the current period, and thus, the period does not change.

[0209] Figure 13A 、 13B and 13C are diagrams of secure message generation according to various aspects of the present disclosure.

[0210] Figure 13A Safety message generation 1300 is shown, which shows multiple safety messages 1302a generated with a period 1304 and multiple safety messages 1302b generated with a period 1306 different from period 1304. In the example shown, period 1306 is greater than period 1304, but in other cases, period 1306 is less than period 1304. Periods 1304 and 1306 can be supported SPS periods (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 ms or other suitable values). In this regard, the supported SPS period can be defined by a specification (3gpp, SAE, etc.), a UE definition, or otherwise. For example, in some cases, the supported SPS period includes an SPS period associated with sidelink PC5 or LTE-V2X. In some cases, the processor, modem, and / or other components of the UE may be programmed to facilitate the UE generating and / or sending safety messages using multiple supported SPS periods (or a subset thereof).

[0211] Figure 13B 13. The secure message generation 1340 is shown. The secure message generation 1340 is similar in many respects to the Figure 13A, including illustrating a plurality of safety messages 1302a generated with a period 1304 and a plurality of safety messages 1302b generated with a period 1306 different from the period 1304. The safety message generation 1340 also includes a tracking error based safety message, which may be generated (and sent) as an event transmission separate from the SPS scheduled safety messages 1302a and 1302b. In some cases, when the tracking error based safety message 1342 is generated within a threshold amount of time of the scheduled generation time period associated with the SPS period, the UE avoids generating safety messages during the scheduled generation time period associated with the SPS period. Figure 13B , the time period 1350 is greater than a threshold (eg, packet delay budget), and therefore, the UE proceeds to generate the next scheduled packet associated with the SPS period, as shown.

[0212] However, Figure 13C Safety message generation 1380 is shown, where a safety message 1342 based on a tracking error is generated within a threshold amount of time of a scheduled generation time period associated with an SPS period. Figure 13C As shown, the time period 1390 is less than a threshold (e.g., a packet delay budget), and therefore, the UE skips the next scheduled packet generation associated with the SPS period (as indicated by an "X"). In some cases, if the scheduled generation period is associated with a change in period, the UE continues to generate safety messages 1302b at the scheduled generation period even if the time period 1390 is less than the threshold amount of time before the scheduled generation period.

[0213] Figure 14-16 is a diagram of security message generation and scheduling in accordance with various aspects of the present disclosure.

[0214] Figure 14 A diagram illustrating security message generation and scheduling 1400 in accordance with various aspects of the present disclosure is shown. The diagram illustrates security packet generation at an ITS stack 1400a (e.g., at a processor of a UE) and a lower layer reservation 1400b (e.g., at a modem of a UE) in accordance with various aspects of the present disclosure.

[0215] The safety packet generation ITS stack 1400a shows a plurality of safety message packet generation time periods 1402a with a period 1404 and a plurality of safety message packet generation time periods 1402b with a period 1406 different from the period 1404. In the example shown, the period 1406 is greater than the period 1404, but in other cases, the period 1406 is less than the period 1404. The periods 1404 and 1406 can be supported SPS periods (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 ms or other suitable values). In this regard, the supported SPS periods can be defined by a specification (3gpp, SAE, etc.), a UE definition, or otherwise. For example, in some cases, the supported SPS periods include SPS periods associated with the sidelink PC5 or LTE-V2X. In some cases, the processor, modem, and / or other components of the UE may be programmed to facilitate the UE generating and / or sending safety messages using multiple supported SPS periods (or a subset thereof).

[0216] During each security message packet generation period 1402a, the ITS stack / processor may generate a security message packet 1420a, which is transmitted to the UE's lower layers / modem. Similarly, during each security message packet generation period 1402b, the ITS stack / processor may generate a security message packet 1420b, which is transmitted to the UE's lower layers / modem. The UE's lower layers / modem may then transmit the security message packets 1420a and 1420b.

[0217] Figure 14 An example is shown where at time period 1410, the UE determines that an updated period has been calculated or determined (see, e.g., Figure 11 , block 1114 ("Yes")), but the probability determination indicates that the current cycle is maintained (see, e.g. Figure 11 , block 1118 ("No")). However, at time period 1412, the UE again determines that the updated period has been calculated or determined (see, for example, Figure 11 , block 1114 ("Yes")), and the probability determination indicates that the current cycle is updated to the new cycle (see, e.g. Figure 11 , block 1118 ("Yes")). Therefore, the UE's ITS stack / processor transmits an updated SPS reservation request to the UE's lower layers / modem (see, e.g. Figure 10, block 1018), the updated SPS reservation request is received by the UE's lower layers / modem at time period 1414. As shown, the UE's lower layers / modem may receive the updated SPS reservation request before receiving the last safety message packet 1420a generated with the current SPS period 1404. Thus, in some cases, the UE's ITS stack / processor transmits the updated SPS reservation request to the modem before generating the first data packet 1402b with the updated SPS period 1406. Upon receiving the updated SPS reservation request at time period 1414, the UE's lower layers / modem may obtain the updated SPS (see, e.g., Figure 10 , block 1020). Figure 14 , the UE's lower layers / modem requests and / or obtains an updated SPS reservation upon receiving the SPS reservation request from the processor, as indicated by time period 1416. In some cases, the modem delays requesting and / or obtaining an updated SPS reservation after receiving the SPS reservation request from the processor (see, e.g., Figure 15 and 16 ).

[0218] Figure 15 A diagram illustrating security message generation and scheduling 1500 in accordance with various aspects of the present disclosure is shown. The diagram illustrates security packet generation at an ITS stack 1500a (e.g., at a processor of a UE) and a lower layer reservation 1500b (e.g., at a modem of a UE) in accordance with various aspects of the present disclosure.

[0219] The ITS stack 1500a for security packet generation illustrates multiple security message packet generation periods 1502a with a period 1504 and multiple security message packet generation periods 1502b with a period 1506 different from period 1504. During each security message packet generation period 1502a, the ITS stack / processor may generate a security message packet 1520a, which is transmitted to the lower layers / modem of the UE. Similarly, during each security message packet generation period 1502b, the ITS stack / processor may generate a security message packet 1520b, which is transmitted to the lower layers / modem of the UE. The lower layers / modem of the UE may then transmit the security message packets 1520a and 1520b.

[0220] Figure 15 An example is shown where at time period 1512, the UE determines that an updated period has been calculated or determined (see, e.g., Figure 11 , block 1114 ("Yes")), and the probability determination indicates that the current cycle is updated to the new cycle (see, e.g. Figure 11, block 1118 ("Yes")). Therefore, the UE's ITS stack / processor transmits an updated SPS reservation request to the UE's lower layers / modem (see, e.g. Figure 10 , block 1018), the updated SPS reservation request is received by the UE's lower layers / modem at time period 1514. As shown, the UE's lower layers / modem may receive the updated SPS reservation request before receiving the last safety message packet 1520a generated with the current SPS period 1504. Thus, in some cases, the UE's ITS stack / processor transmits the updated SPS reservation request to the modem before generating the first data packet 1502b with the updated SPS period 1506.

[0221] Upon receiving the updated SPS reservation request at time period 1514, the UE's lower layers / modem may obtain the updated SPS (see, e.g., Figure 10 , block 1020). Figure 15 , the UE's lower layers / modem delay requesting and / or obtaining an updated SPS reservation after receiving the updated SPS reservation request from the processor until time period 1516. However, the UE's lower layers / modem may implement the updated SPS period upon receiving the updated SPS reservation request by omitting the scheduled safety message packets under the current period 1504, as indicated by an "X" through safety message packet 1520c. Figure 15 An example is shown where the UE's lower layers / modem delay requesting and / or obtaining updated SPS reservations with increasing periodicity. Figure 16 Another example of a UE's lower layers / modem delaying requesting and / or obtaining updated SPS reservations as the period decreases is shown.

[0222] Figure 16 A diagram illustrating security message generation and scheduling 1600 in accordance with various aspects of the present disclosure is shown. The diagram illustrates security packet generation at an ITS stack 1600a (e.g., at a processor of a UE) and a lower layer reservation 1600b (e.g., at a modem of a UE) in accordance with various aspects of the present disclosure.

[0223] Security Packet Generation ITS Stack 1600a illustrates multiple security message packet generation periods 1602a with a period 1604 and multiple security message packet generation periods 1602b with a period 1606 that is different from period 1604. In the illustrated example, period 1606 is less than period 1604. During each security message packet generation period 1602a, the ITS stack / processor may generate a security message packet 1620a, which is transmitted to the lower layers / modem of the UE. Similarly, during each security message packet generation period 1602b, the ITS stack / processor may generate a security message packet 1620b, which is transmitted to the lower layers / modem of the UE. The lower layers / modem of the UE may then transmit the security message packets 1620a and 1620b.

[0224] Figure 16 An example is shown where at time period 1612, the UE determines that an updated period has been calculated or determined (see, e.g., Figure 11 , block 1114 ("Yes")), and the probability determination indicates that the current cycle is updated to the new cycle (see, e.g. Figure 11 , block 1118 ("Yes")). Therefore, the UE's ITS stack / processor transmits an updated SPS reservation request to the UE's lower layers / modem (see, e.g. Figure 10 , block 1018), the updated SPS reservation request is received by the UE's lower layers / modem at time period 1614. As shown, the UE's lower layers / modem may receive the updated SPS reservation request before receiving the last safety message packet 1620a generated with the current SPS period 1604. Thus, in some cases, the UE's ITS stack / processor transmits the updated SPS reservation request to the modem before generating the first data packet 1602b with the updated SPS period 1606.

[0225] Upon receiving the updated SPS reservation request at time period 1614, the UE's lower layers / modem may obtain the updated SPS (see, e.g., Figure 10 , block 1020). Figure 16In the embodiment of the present invention, the lower layers / modem of the UE delay requesting and / or obtaining the updated SPS reservation after receiving the updated SPS reservation request from the processor until time period 1616. However, when receiving the updated SPS reservation request, the lower layers / modem of the UE can realize the updated SPS period by adding a safety message packet 1630 (e.g., similar to a safety message packet based on tracking errors, a one-time or event-based safety message packet) to the safety message packet 1620a scheduled under the current period 1604. As shown, the safety message packet 1630 fills the gap between the current period and the updated period to provide transmission of safety messages according to the updated SPS period before the modem reserves the updated SPS period. Therefore, although the example shown shows an extra safety message packet 1630 between each scheduled safety message packet 1620a, in other cases, two, three, four or more extra safety message packets 1630 can be used between each scheduled safety message packet 1610a.

[0226] Figure 17 1700 is shown for security packet generation at an ITS stack 1700a (e.g., at a processor of a UE) in accordance with various aspects of the present disclosure. The ITS stack 1700a illustrates multiple security message packet generation periods 1702a with a period 1704 and multiple security message packet generation periods 1702b with a period 1706 that is different from the period 1504. In the example shown, the period 1706 is smaller than the period 1704. At each security message packet generation period 1702a, 1702b, the ITS stack / processor may generate a security message packet, which may be transmitted to the lower layers / modem of the UE. The lower layers / modem of the UE may send the security message packets according to the associated SPS period.

[0227] Figure 17 An example is shown where at time period 1712, the UE determines that an updated period has been calculated or determined (see, e.g., Figure 11 , block 1114 ("Yes")), and the probability determination indicates that the current cycle is updated to the new cycle (see, e.g. Figure 11, block 1118 ("Yes")). In response to determining that the period should be updated, the UE selects a random time offset 1714. In some cases, the UE selects the time offset 1714 from a range or set of available time offsets. For example, in some cases, the UE randomly selects the time offset 1714 from between 0 and the updated SPS period 1706. The UE then generates an initial security message 1702b associated with the updated SPS period 1706 based on the selected time offset. In some cases, the UE generates the initial security message 1702b associated with the updated SPS period 1706 after the random time offset 1714 from the current time (e.g., time period 1712). For example, if the random time offset 1714 is greater than or equal to a threshold value, the UE may generate a first security message after the random time offset 1714 from the current time, such as Figure 17 shown.

[0228] In some cases, the UE generates an initial safety message 1702b associated with the updated SPS period 1706 after the updated SPS period from the current time. For example, if the random time offset 1714 is less than a threshold value, the UE can generate a first safety message after the updated SPS period 1706 from the current time. In some cases, the threshold value is between 50ms and 200ms, including 100ms. In some cases, the threshold value is the minimum allowed SPS period. After the initial safety message 1702b associated with the updated SPS period 1706, the UE uses the updated SPS period 1706 to generate a subsequent safety message 1702b associated with the second SPS period, as shown in the figure.

[0229] By having the UE select a random time offset 1714 and generate its updated initial security message 1702b of period 1706 based on the random time offset 1714, the likelihood of UEs clumping SPS scheduling within a small time window when the UE group experiences congestion (and therefore, many UEs may change periods) is greatly reduced and / or eliminated, resulting in more efficient use of network resources, improved latency and a better user experience.

[0230] Figure 18 1800 is a flow chart of a communication method 1800 according to various aspects of the present disclosure. Aspects of the method 1800 may be performed by a computing device (e.g., a processor, a processing circuit, and / or other appropriate components) or other appropriate means for performing the various aspects of the apparatus. For example, a UE (e.g., in conjunction with Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4, 5, 6A-6C, 7, 9 and / or 10) can utilize one or more components (receive processor (e.g., receive processor 258), transmit processor (e.g., transmit processor 264), controller / processor (e.g., controller / processor 280), memory (e.g., memory 282), modem (e.g., implemented by one or more of receive processor, transmit processor, controller / processor, memory and / or antenna), etc.) to perform various aspects of method 1800. As shown, method 1800 includes multiple enumerated aspects, but method 1800 can include additional aspects before, after, and between the enumerated aspects. For example, method 1800 can adopt the same method as described above with respect to Figure 3-17 And below about Figure 19 Similar mechanisms and aspects described herein. In some cases, one or more of the enumerated aspects may be omitted or performed in a different order.

[0231] At box 1810, the UE determines a first period for sending a safety message. The first period may be a plurality of support semi-persistent scheduling (SPS) periods (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 ms or other suitable values) of a supported SPS period. In this regard, a plurality of supported SPS periods may be defined by a specification (3gpp, SAE, etc.), a UE definition, or otherwise defined. For example, in some cases, a plurality of supported SPS periods include an SPS period associated with a sidelink PC5 or LTE-V2X. In some cases, the processor, modem, and / or other components of the UE may be programmed to facilitate the UE to use a plurality of supported SPS periods (or a subset thereof) to generate and / or send a safety message.

[0232] At block 1820, the UE determines a second period for sending the safety message. The second period is different from the first period determined at block 1810. The second period may be a second supported SPS period among a plurality of supported SPS periods (e.g., 20, 50, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 ms, or other suitable values).

[0233] In some cases, the UE determines the first period and / or the second period by rounding the calculated period to the first or second period. For example, the UE may round the calculated period to at least one of a standardized supported SPS period or a multiple of a 100 millisecond period. In some cases, the processor rounds the safety message generation period determined by the congestion control algorithm to a supported SPS period among multiple supported SPS periods. In this regard, the congestion control algorithm may be an SAE distributed congestion control (DCC) algorithm, and the safety message generation period may be a maximum inter-transmission time (MAX_ITT). In some cases, MAX_ITT is calculated as MAX_ITT=min(600ms, max(100ms, N / B*100ms)), where 600ms is the maximum allowed MAX_ITT, 100ms is the minimum allowed MAX_ITT, N is the number of devices within a radius of 100m, and B is a density factor having a default value of 25. In other cases, different maximum, minimum, and density values ​​may be utilized.

[0234] In some cases, the UE can be configured to detect the presence of a hysteresis parameter (e.g. Figure 12A and 12B ) rounds the calculated period to the second period to determine the second period. In this regard, the hysteresis parameter can increase the range of the calculated period, which will cause the UE to round to the current period (e.g., the first period) and thus maintain the current period. This can prevent the UE from attempting to repeatedly switch back and forth between two adjacent periods when the calculated period value is close to the rounding boundary of an adjacent period and small changes in the environment and / or communication may result in different period determinations.

[0235] In some cases, the hysteresis parameter is a percentage of the gap between the first period and the adjacent supported period. For example, if the first period is 300 ms and the adjacent supported period is 400 ms (or 200 ms), the gap is 100 ms. In some cases, the percentage is between 0% and 50%, including between 5% and 15%. In some cases, the UE randomly selects the value of the hysteresis parameter from a set of available values ​​for the hysteresis parameter. In this regard, by having each UE randomly select the hysteresis parameter, the possibility of a large number of UEs changing the period at the same time is reduced because the UEs will have different rounding ranges due to the hysteresis parameter having a different value than the randomly selected value.

[0236] In some cases, the UE rounds the second calculated period to a second period based on determining whether the second calculated period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, where Tn is the current period, Tn-1 is a supported period that is less than the current period, Tn+1 is a supported period that is greater than the current period, and H is a hysteresis parameter. In this regard, if the second calculated period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H, the UE rounds the second calculated period to a period lower than the current period (e.g., Tn-1). Similarly, if the second calculated period is greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, the UE rounds the second calculated period to a period higher than the current period (e.g., Tn+1). If the second calculated period is between (Tn+Tn-1) / 2-(Tn-Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1-Tn)*H, the UE rounds the second calculated period to the current period, and thus the period does not change.

[0237] At block 1830, the UE determines whether to continue utilizing the first cycle or switch to the second cycle. In some cases, the UE determines whether to continue utilizing the first cycle or switch to the second cycle based on a probability determination process. The probability determination process may include weighted coin flips, probabilistic Boolean operations, or other suitable techniques. In some cases, the probability determination process is weighted toward the first cycle. That is, the probability determination process is biased toward maintaining the current cycle rather than switching to a different cycle. In this regard, in some cases, the probability determination process is weighted toward the first cycle between 2:1 and 100:1, such as 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 15:1, 20:1, 25:1, 50:1, or other suitable values. In some cases, the UE determines whether to continue utilizing the first cycle or switch to the second cycle at a scheduled packet generation time period associated with the first cycle and before sending packets generated at the scheduled packet generation time period.

[0238] At block 1840 , the UE generates a security message with the first period or the second period based on the determination at block 1830 to continue utilizing the first period or to switch to the second period.

[0239] At block 1850, the UE sends security messages at the same periodicity as the security messages generated at block 1840. In some cases, the modem of the UE sends security messages at the same periodicity as the periodicity at which the UE's security program (e.g., ITS stack) generates security messages. Thus, if the UE determines at block 1830 to continue utilizing the first periodicity and generates security messages at the first periodicity at block 1840, then at block 1850, the modem may send security messages at the first periodicity. Similarly, if the UE determines at block 1830 to switch to the second periodicity and generates security messages at the second periodicity at block 1840, then at block 1850, the modem may send security messages at the second periodicity.

[0240] In some examples of method 1800, the UE Figure 3-6C , 10 and / or 13A-17 to generate and / or send a security message in a manner similar to the examples shown.

[0241] In some examples of method 1800, in response to determining to switch to the second periodicity at block 1830, the UE requests the UE's modem to change to the second periodicity before sending the last safety message packet generated with the first periodicity to the modem. Thus, in some cases, the UE requests the modem to update the SPS periodicity before sending the first data packet generated with the updated SPS periodicity (e.g., the second SPS periodicity).

[0242] In some examples of method 1800, the UE detects a tracking error and generates a tracking error-based safety message separate from the SPS scheduling safety message based on the detected tracking error. Thus, the tracking error-based safety message may be generated and / or sent separately from the plurality of supported SPS periods (see, e.g., Figure 13B and 13C In some cases, when a safety message based on a tracking error is generated within a threshold amount of time of the schedule generation time period, the UE avoids generating a safety message during the schedule generation time period associated with the first cycle or the second cycle (see, e.g. Figure 13C In some cases, the threshold amount of time is based on a packet delay budget (e.g., 50, 100, 200 ms, or other suitable value) or other parameters. In some cases, if the schedule generation period is associated with a change in periodicity (e.g., from a first period to a second period), the UE continues to generate safety messages during the schedule generation period even when a tracking error-based safety message is generated within the threshold amount of time of the schedule generation period.

[0243] In some examples of method 1800, if the UE determines at block 1830 to continue utilizing the first cycle, the UE may determine a third cycle for transmitting security messages, where the third cycle is different from the first cycle. The UE may determine whether to continue utilizing the first cycle or switch to the third cycle based on a probabilistic determination process, and generate security messages using the first cycle or the third cycle based on the determination to continue utilizing the first cycle or switch to the third cycle. In this regard, the third cycle may be the same cycle as the second cycle to which the UE did not initially switch when the UE determined at block 1830 to continue utilizing the first cycle.

[0244] Figure 19 1900 is a flow chart of a communication method 1900 according to various aspects of the present disclosure. Aspects of the method 1900 may be performed by a computing device (e.g., a processor, a processing circuit, and / or other appropriate components) or other appropriate means for performing the various aspects of the apparatus. For example, a UE (e.g., in conjunction with Figure 1 and 2 The UE 120 shown and described in conjunction with Figure 3 、 4 , 5, 6A-6C, 7, 9 and / or 10) can utilize one or more components (receive processor (e.g., receive processor 258), transmit processor (e.g., transmit processor 264), controller / processor (e.g., controller / processor 280), memory (e.g., memory 282), modem (e.g., implemented by one or more of receive processor, transmit processor, controller / processor, memory and / or antenna), etc.) to perform various aspects of method 1900. As shown, method 1900 includes multiple enumerated aspects, but method 1900 can include additional aspects before, after, and between the enumerated aspects. For example, method 1900 can adopt the same method as described above with respect to Figure 3-18 Similar mechanisms and aspects described herein. In some cases, one or more of the enumerated aspects may be omitted or performed in a different order.

[0245] At block 1910, the UE determines a first semi-persistent scheduling (SPS) period for generating a safety message. In some cases, at block 1910, the UE employs the same or similar aspects as block 1810 of method 1800 described above.

[0246] At block 1920, the UE determines a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period. In some cases, at block 1920, the UE employs the same or similar aspects as block 1820 of method 1800 described above.

[0247] At block 1930, the UE selects a random time offset. In some cases, the UE selects a time offset from a range or set of available time offsets. For example, in some cases, the UE randomly selects a time offset between 0 and the second SPS period.

[0248] At block 1940, the UE generates a first safety message associated with a second SPS period based on the random time offset (see, e.g., Figure 17 ). In some cases, the UE generates the first security message after a random time offset from the current time. For example, if the random time offset is greater than or equal to a threshold value, the UE may generate the first security message after the random time offset from the current time. In some cases, the UE generates the first security message after the second SPS period starting from the current time. For example, if the random time offset is less than a threshold value, the UE may generate the first security message after the second SPS period starting from the current time. In some cases, the threshold value is between 50ms and 200ms, including 100ms. In some cases, the threshold value is the minimum allowed SPS period. In some instances of method 1900, the UE generates a subsequent security message associated with the second SPS period based on the second SPS period after the first security message (see, for example Figure 17 ).

[0249] By having the UE select a random time offset and generate its updated periodic first security message based on the random time offset, the likelihood of UEs aggregating SPS scheduling within a small time window when the UE group experiences congestion (and therefore, many UEs may change periods) is greatly reduced and / or eliminated, resulting in more efficient use of network resources, improved latency and a better user experience.

[0250] By way of non-limiting example, the present disclosure includes the following aspects.

[0251] Aspect 1 includes a method of wireless communication performed by a user equipment (UE), the method comprising: determining a first cycle for sending a safety message; determining a second cycle for sending the safety message, wherein the second cycle is different from the first cycle; determining whether to continue using the first cycle or switch to the second cycle based on a probability determination process; generating the safety message with the first cycle or the second cycle based on the determination about continuing to use the first cycle or switching to the second cycle; and sending the safety message with the same cycle as the safety message is generated.

[0252] Aspect 2 includes the method according to aspect 1, further comprising: in response to determining to switch to the second cycle, before sending the last safety message packet generated in the first cycle to the modem of the user equipment, requesting the modem to change to the second cycle.

[0253] Aspect 3 includes a method according to any one of Aspects 1-2, wherein the first period is the first supported semi-persistent scheduling (SPS) period among a plurality of supported SPS periods; and the second period is the second supported SPS period among the plurality of supported SPS periods.

[0254] Aspect 4 includes a method according to any one of aspects 1-3, wherein the plurality of supported SPS periods includes an SPS period associated with sidelink PC5.

[0255] Aspect 5 includes a method according to any one of Aspects 1-4, wherein at least one of determining the first period or determining the second period includes: rounding the security message generation period determined by the congestion control algorithm to the first supported SPS period or the second supported SPS period.

[0256] Aspect 6 includes the method according to any one of aspects 1-5, wherein the congestion control algorithm is an SAE distributed congestion control algorithm, and the safety message generation period is a maximum inter-transmission time (MAX_ITT).

[0257] Aspect 7 includes the method of any one of aspects 1-6, further comprising: detecting a tracking error; and generating a tracking error-based safety message separate from the plurality of supported SPS periods based on the detected tracking error.

[0258] Aspect 8 includes a method according to any one of Aspects 1-7, further comprising: when the tracking error-based safety message is generated within a threshold time amount of the scheduled generation time period associated with the first period or the second period, avoiding generating a safety message during the scheduled generation time period.

[0259] Aspect 9 includes the method of any of aspects 1-8, wherein the threshold amount of time is based on a packet delay budget.

[0260] Aspect 10 includes a method according to any one of aspects 1-9, further comprising: generating a safety message during the scheduled generation time period when the tracking error-based safety message is generated within a threshold time amount of the scheduled generation time period and the scheduled generation time period is associated with a change in period.

[0261] Aspect 11 includes the method of any of aspects 1-10, wherein the probability determination process is weighted toward the first period.

[0262] Aspect 12 includes a method according to any one of Aspects 1-11, wherein determining whether to continue using the first cycle or switch to the second cycle includes: determining to continue using the first cycle; and generating the security message with the first cycle or the second cycle includes: generating the security message with the first cycle.

[0263] Aspect 13 includes a method according to any one of Aspects 1-12, further comprising: determining a third cycle for sending the security message, wherein the third cycle is different from the first cycle; determining whether to continue using the first cycle or switch to the third cycle based on the probability determination process; and generating the security message with the first cycle or the third cycle based on the determination about continuing to use the first cycle or switching to the third cycle.

[0264] Aspect 14 includes a method according to any one of Aspects 1-13, wherein the determining whether to continue using the first cycle or switch to the second cycle includes: determining to switch to the second cycle; and the using the first cycle or the second cycle to generate the safety message includes: transmitting the safety message in the second cycle.

[0265] Aspect 15 includes the method according to any one of aspects 1-14, wherein determining the first period for sending the safety message includes rounding a first calculation period to the first period.

[0266] Aspect 16 includes the method of any one of aspects 1-15, wherein rounding the first computation period to the first period comprises rounding the first computation period to at least one of a canonical supported SPS period or a multiple of a 100 millisecond period.

[0267] Aspect 17 includes the method according to any one of aspects 1-16, wherein determining the second period for sending the safety message includes rounding a second calculation period to the second period.

[0268] Aspect 18 includes the method of any one of aspects 1-17, wherein rounding the second calculation period to the second period comprises rounding the second calculation period to the second period based on a hysteresis parameter.

[0269] Aspect 19 includes the method according to any one of aspects 1-18, further comprising randomly selecting the value of the hysteresis parameter from a set of available values ​​of the hysteresis parameter.

[0270] Aspect 20 includes the method of any one of aspects 1-19, wherein the hysteresis parameter is a percentage of a gap between the first period and an adjacent support period.

[0271] Aspect 21 includes a method according to any one of Aspects 1-20, wherein rounding the second calculation period to the second period based on a lag parameter includes: determining that the second calculation period is less than (Tn+Tn-1) / 2–(Tn–Tn-1)*H or greater than (Tn+Tn+1) / 2+(Tn+1–Tn)*H, wherein Tn is the first period, Tn-1 is a support period less than the first period, Tn+1 is a support period greater than the first period, and H is the lag parameter.

[0272] Aspect 22 includes a method according to any one of Aspects 1-21, wherein the determination of whether to continue using the first cycle or switch to the second cycle occurs at a scheduling packet generation time period associated with the first cycle and occurs before transmitting a packet generated at the scheduling packet generation time period.

[0273] Aspect 23 includes the method of any of aspects 1-22, wherein the probability determination process is weighted toward the first period between 5:1 and 10:1.

[0274] Aspect 24 includes the method of any of aspects 1-23, wherein the percentage is between 5% and 15%.

[0275] Aspect 25 includes a method of wireless communication performed by a user device, the method comprising: determining a first semi-persistent scheduling (SPS) period for generating a safety message; determining a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; selecting a random time offset; and generating a first safety message associated with the second SPS period based on the random time offset.

[0276] Aspect 26 includes the method of aspect 25, wherein selecting the random time offset comprises randomly selecting a time between 0 and the second SPS period.

[0277] Aspect 27 includes a method according to any one of aspects 25-26, wherein the generating the first safety message associated with the second SPS period includes: if the random time offset is greater than or equal to a threshold value, then generating the first safety message after the random time offset from the current time.

[0278] Aspect 28 includes a method according to any one of aspects 25-27, wherein the generating of the first safety message associated with the second SPS period includes: if the random time offset is less than the threshold value, the generating of the first safety message after the second SPS period from the current time.

[0279] Aspect 29 includes the method according to any of aspects 25-28, further comprising: generating a subsequent safety message associated with the second SPS period based on the second SPS period after the first safety message.

[0280] Aspect 30 includes the method according to any one of aspects 25-29, wherein the threshold value is 100 ms.

[0281] Aspect 31 includes a user equipment (UE) comprising: a transceiver, a memory, and a processor coupled to the transceiver and the memory, the UE being configured to: determine a first period for sending a safety message; determine a second period for sending the safety message, wherein the second period is different from the first period; determine whether to continue using the first period or switch to the second period based on a probability determination process; and generate the safety message with the first period or the second period based on the determination about continuing to use the first period or switching to the second period; and a modem in communication with the processor, the modem being configured to: send the safety message with the same period as the safety message is generated.

[0282] Aspect 32 includes a user equipment (UE) according to aspect 31, wherein the first period is a first supported semi-persistent scheduling (SPS) period among a plurality of supported SPS periods; the plurality of supported SPS periods include an SPS period associated with a side link PC5; the second period is a second supported SPS period among the plurality of supported SPS periods; and the processor is further configured to: detect a tracking error; generate a tracking error-based safety message separate from the plurality of supported SPS periods based on the detected tracking error; in response to determining to switch to the second period, request the modem to change to the second period before sending the last safety message packet generated with the first period to the modem; and determine at least one of the first period or the second period by rounding the safety message generation period determined by the congestion control algorithm executed by the processor to the first supported SPS period or the second supported SPS period.

[0283] Aspect 33 includes a user equipment (UE) comprising: a transceiver, a memory, and a processor coupled to the transceiver and the memory, the UE being configured to: determine a first semi-persistent scheduling (SPS) period for generating a safety message; determine a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; select a random time offset; and generate a first safety message associated with the second SPS period based on the random time offset.

[0284] Aspect 34 includes a base station (BS) comprising: a transceiver, a memory, and a processor coupled to the transceiver and the memory, the BS configured to perform any one of aspects 1-33.

[0285] Aspect 35 includes a non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions including one or more instructions that, when executed by one or more processors of a user device, cause the one or more processors to perform any of Aspects 1-25.

[0286] Aspect 36 includes a non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions including one or more instructions that, when executed by one or more processors of a user device, cause the one or more processors to perform any of aspects 25-30.

[0287] Aspect 37 includes a non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions including one or more instructions that, when executed by one or more processors of a base station, cause the one or more processors to perform any of aspects 1-33.

[0288] Aspect 38 includes a user equipment (UE) comprising means for performing any of aspects 1-25.

[0289] Aspect 39 includes a user equipment (UE) comprising means for performing any of aspects 25-30.

[0290] Aspect 40 includes a base station (BS) comprising means for performing any of aspects 1-33.

[0291] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the various aspects.

[0292] 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 using hardware, firmware, and / or a combination of hardware and software.

[0293] 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.

[0294] It will be apparent that the systems and / or methods described herein can be implemented using various forms of hardware, firmware, and / or combinations of hardware and software. The actual specialized control hardware or software code used to implement these systems and / or methods is not limiting in any way. Thus, the operation and behavior of the systems and / or methods are described herein without reference to specific software code, with the understanding that software and hardware can be designed to implement the systems and / or methods based, at least in part, on the description herein.

[0295] Even if the specific combination of features is recorded in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of each aspect. In fact, many of these features can be combined in a manner not specifically recorded in the claims and / or specifically disclosed in the specification. Although each dependent claim listed below can only directly depend on one claim, the disclosure of each aspect includes the combination of each dependent claim and each other claim in the claim set. The phrase "at least one of" the item list 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, and any combination with multiples of the same element (for example, aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc and ccc or any other sorting of a, b and c).

[0296] None of the elements, actions or instructions used herein should be interpreted as key or necessary, unless clearly described as such. 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 projects and unrelated projects, etc.), and can be used interchangeably with "one or more". In the case of only one project being expected, the phrase "only one" or similar language is used. In addition, as used herein, the terms "has", "have", "having" and / or similar terms are intended to be open terms. In addition, unless otherwise expressly stated, the phrase "based on" is intended to mean "at least partially based on".

Claims

1. A method of wireless communication performed by a user equipment, the method comprising: determining a first period for sending a security message based on at least a distributed congestion control algorithm; determining a second period for sending the security message based at least on the distributed congestion control algorithm, wherein the second period is different from the first period; determining whether to continue utilizing the first cycle or switch to the second cycle based on a probability determination process; generating the safety message in the first cycle or the second cycle based on the determination as to continue utilizing the first cycle or switching to the second cycle; and The safety message is sent at the same period as the safety message is generated.

2. The method according to claim 1, further comprising: In response to determining to switch to the second cycle, before sending a last safety message packet generated in the first cycle to the modem of the user equipment, requesting the modem to change to the second cycle.

3. The method according to claim 1, wherein: The first period is a first SPS supported period among a plurality of SPS supported periods; and The second period is a second SPS supported period among the plurality of SPS supported periods.

4. The method according to claim 3, wherein: The plurality of supported SPS periods includes an SPS period associated with the sidelink PC5.

5. The method according to claim 3, wherein At least one of determining the first period or determining the second period includes rounding a security message generation period determined by the distributed congestion control algorithm to the first supported SPS period or the second supported SPS period.

6. The method according to claim 5, wherein: The distributed congestion control algorithm is an SAE distributed congestion control algorithm, and the safety message generation period is a maximum inter-transmission time (MAX_ITT).

7. The method according to claim 3, further comprising: Detect tracking errors; as well as A tracking error based safety message is generated based on the detected tracking error, separate from the plurality of SPS supported periods.

8. The method according to claim 7, further comprising: When the tracking error-based safety message is generated within a threshold amount of time of a schedule generation time period associated with the first cycle or the second cycle, generating a safety message during the schedule generation time period is avoided.

9. The method according to claim 8, wherein The threshold amount of time is based on a packet delay budget.

10. The method according to claim 7, further comprising: A safety message is generated during a schedule generation time period when the tracking error-based safety message is generated within a threshold amount of time of a schedule generation time period and the schedule generation time period is associated with a change in the first period or a change in the second period.

11. The method according to claim 1, wherein The probability determination process is weighted towards the first period.

12. The method of claim 1, wherein: Determining whether to continue using the first cycle or switch to the second cycle includes: determining to continue using the first cycle; and Generating the safety message in the first cycle or the second cycle includes: generating the safety message in the first cycle.

13. The method according to claim 12, further comprising: determining a third period for sending the security message, wherein the third period is different from the first period; determining whether to continue utilizing the first cycle or switch to the third cycle based on the probability determination process; and The safety message is generated in the first cycle or the third cycle based on the determination as to continue utilizing the first cycle or switching to the third cycle.

14. The method of claim 1, wherein: The determining whether to continue to utilize the first cycle or switch to the second cycle includes: determining to switch to the second cycle; and The using the first cycle or the second cycle to generate the safety message includes: transmitting the safety message in the second cycle.

15. The method according to claim 1, wherein Determining the first cycle for sending the security message includes: The first calculation period is rounded to the first period.

16. The method according to claim 15, wherein Rounding the first calculation period to the first period includes rounding the first calculation period to at least one of a canonical supported SPS period or a multiple of a 100 millisecond period.

17. The method according to claim 15, wherein: The determining the second period for sending the safety message includes: The second calculation cycle is rounded to the second cycle.

18. The method according to claim 17, wherein Rounding the second calculation period to the second period includes rounding the second calculation period to the second period based on a hysteresis parameter.

19. The method according to claim 18, further comprising: A value for the hysteresis parameter is randomly selected from a set of available values ​​for the hysteresis parameter.

20. The method according to claim 18, wherein The hysteresis parameter is a percentage of the gap between the first period and an adjacent support period.

21. The method according to claim 18, wherein Rounding the second calculation period to the second period based on a hysteresis parameter includes: Determine the second calculation cycle is Less than (T n +T n-1 ) / 2–(T n –T n-1 )*H or Greater than (T n +T n+1 ) / 2+(T n+1 –T n )*H, Among them, T n is the first period, T n-1 is less than the support period of the first period, T n+1 is a support period greater than the first period, and H is the hysteresis parameter.

22. The method according to claim 1, wherein The determining whether to continue utilizing the first cycle or switch to the second cycle occurs at a scheduled packet generation time period associated with the first cycle and prior to transmitting packets generated at the scheduled packet generation time period.

23. A method of wireless communication performed by a user equipment, the method comprising: determining a first half persistent scheduling (SPS) period for generating safety messages based on at least a distributed congestion control algorithm; determining, based at least on the distributed congestion control algorithm, a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; Select a random time offset; as well as A first safety message associated with the second SPS period is generated based on the random time offset.

24. The method according to claim 23, wherein Selecting the random time offset comprises: Randomly select a time between 0 and the second SPS period.

25. The method according to claim 24, wherein The generating the first safety message associated with the second SPS period includes: Based on the random time offset being greater than or equal to a threshold value, the first security message is generated after the random time offset from the current time.

26. The method according to claim 25, wherein The generating the first safety message associated with the second SPS period includes: Based on the random time offset being less than the threshold value, the first safety message is generated after the second SPS period from the current time.

27. The method according to claim 26, further comprising: After the first safety message, a subsequent safety message associated with the second SPS period is generated based on the second SPS period.

28. A user equipment (UE), comprising: A processor configured to: determining a first period for sending a security message based on at least a distributed congestion control algorithm; determining a second period for sending the security message based at least on the distributed congestion control algorithm, wherein the second period is different from the first period; determining whether to continue utilizing the first cycle or switch to the second cycle based on a probability determination process; and generating the safety message in the first cycle or the second cycle based on the determination as to continue utilizing the first cycle or switching to the second cycle; and a modem in communication with the processor, the modem being configured to: The safety message is sent at the same period as the safety message is generated.

29. The UE according to claim 28, wherein: The first period is a first supported semi-persistent scheduling (SPS) period in a plurality of supported SPS periods; the plurality of supported SPS periods includes an SPS period associated with a side link PC5; The second period is a second supported SPS period among the plurality of supported SPS periods; and The processor is further configured to: Detect tracking errors; generating, based on the detected tracking error, a tracking error-based safety message separate from the plurality of supported SPS periods; In response to determining to switch to the second cycle, before sending a last safety message packet generated in the first cycle to the modem, requesting the modem to change to the second cycle; as well as At least one of the first period or the second period is determined by rounding a safety message generation period determined by the distributed congestion control algorithm executed by the processor to the first supported SPS period or the second supported SPS period.

30. A user equipment comprising: A processor configured to: determining a first half persistent scheduling (SPS) period for generating safety messages based on at least a distributed congestion control algorithm; determining, based at least on the distributed congestion control algorithm, a second SPS period for generating the safety message, the second SPS period being greater than the first SPS period; Select a random time offset; as well as A first safety message associated with the second SPS period is generated based on the random time offset.

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