System and method for reducing interruptions in vehicle-to-vehicle communications

Abstract

A communication method and system are provided for integrating the technology of the Internet of Things (IoT) with a fifth generation (5G) communication system that supports a higher data rate than a fourth generation (4G) system. The present disclosure can be applied to smart services based on 5G communication technology and IoT-related technology, such as smart homes, smart buildings, smart cities, smart cars, connected cars, healthcare, digital education, smart retail, security and safety services. An apparatus and method for transmitting signals in a vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication system are provided. The method includes: receiving a switching command message from a base station, wherein the switching command message includes information about a first resource pool; if the switching command message also includes information about a second resource pool, selecting resources for transmitting data from the second resource pool without sensing the second resource pool; and transmitting data based on resources from the second resource pool for transmitting data.

Description

[0001] This application is a divisional application of Chinese patent application No. 201780039051.7, filed on June 20, 2017, and entitled “SYSTEM AND METHOD FOR REDUCING INTERRUPTIONS OF VEHICLE-TO-VEHICLE COMMUNICATIONS”. Technical Field

[0002] The present disclosure relates to a device-to-device (D2D) communication system. More specifically, the present disclosure relates to a vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) communication system and a method for transmission and reception. Background Art

[0003] In order to meet the demand for wireless data services that has increased since the deployment of the fourth generation (4G) communication system, efforts have been made to develop an improved fifth generation (5G) or quasi-5G communication system. Therefore, 5G or quasi-5G communication systems are also referred to as "super 4G networks" or "late long-term evolution (LTE) systems". 5G communication systems are considered to be implemented in higher frequency (mmWave) bands (e.g., 60GHz bands) to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming technology, large-scale multiple input and multiple output (MIMO) technology, full-dimensional MIMO (FD-MIMO) technology, array antenna technology, analog beamforming technology, and large-scale antenna technology are discussed in 5G communication systems. In addition, in 5G communication systems, development of system network improvements is being carried out based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, collaborative communications, collaborative multi-point (CoMP), receiving end interference elimination, etc. In 5G systems, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC) have been developed as advanced coded modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA) and sparse code multiple access (SCMA) as advanced access technologies.

[0004] The Internet is a human-centered connected network where humans generate and consume information, and the Internet is now developing towards the Internet of Things (IoT), in which distributed entities such as things exchange and process information without human intervention. The Internet of Everything (IoE) has emerged, which combines IoT technology with big data processing technology through connection with cloud servers. For IoT implementation, as technical elements, such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology" and "security technology" have been required, and sensor networks, machine-to-machine (M2M) communication, machine type communication (MTC), D2D communication, etc. have been studied recently. This IoT environment can provide smart Internet technology services that create new value for human life by collecting and analyzing data generated between connected things. IoT can be applied to various fields including smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced medical services through the integration and combination between existing information technology (IT) and various industrial applications.

[0005] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, MTC and M2M communications, and D2D communications can be implemented through beamforming, MIMO, and array antennas. The application of cloud RAN, which is the above-mentioned big data processing technology, can also be regarded as an example of the fusion between 5G technology and IoT technology.

[0006] D2D communication enables data communication services between user equipments (UEs). During D2D communication (also known as sidelink (SL) communication), a transmitting UE may transmit a data packet to a group of UEs or broadcast a data packet to all UEs, or send a unicast data packet to a specific UE. Recently, the 3rd Generation Partnership Project (3GPP) standards group has initiated work items to enhance the SL communication mechanism for vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) communications. One of the enhancements proposed for efficient transmission is to perform sensing for UE autonomous resource selection. According to existing procedures, data transmission may be significantly delayed.

[0007] The above information is presented only as background information to assist in understanding the present disclosure. No determination has been made, and no assertion has been made, as to whether any of the above content is applicable to the prior art related to the present disclosure. Summary of the invention

[0008] Technical issues

[0009] Therefore, there is a need to use sensing for UE autonomous resource selection to reduce interruptions in data transmission.

[0010] Solutions to the problem

[0011] Aspects of the present disclosure are to at least solve the above-mentioned problems and / or disadvantages and to provide at least the following advantages. Accordingly, one aspect of the present disclosure is to provide a method and apparatus for reducing interruptions in vehicle-to-vehicle (V2V) transmissions using sensing of a resource pool for UE autonomous resource selection, thereby improving system performance.

[0012] According to one aspect of the present disclosure, a method for transmitting data by a user equipment (UE) is provided. The method includes: receiving a handover command message from a base station, wherein the handover command message includes information about a first resource pool; if the handover command message also includes information about a second resource pool, selecting resources for transmitting data from the second resource pool without sensing the second resource pool; and transmitting data based on the resources for transmitting data from the second resource pool.

[0013] According to one aspect of the present disclosure, a method for transmitting information by a base station is provided. The method comprises: receiving information about at least one resource pool from another base station; and transmitting a handover command message including information about a first resource pool and information about a second resource pool based on the information about the at least one resource pool.

[0014] According to another aspect of the present disclosure, a UE for transmitting data is provided. The UE includes a transceiver and at least one processor, wherein the transceiver is used to transmit and receive signals, and the at least one processor is configured to control to receive a handover command message from a base station, wherein the handover command message includes information about a first resource pool, if the handover command message also includes information about a second resource pool, then selecting resources for transmitting data from the second resource pool without sensing the second resource pool, and transmitting data based on the resources for transmitting data from the second resource pool.

[0015] According to another aspect of the present disclosure, a base station for transmitting information is provided. The base station includes a transceiver and at least one processor, wherein the transceiver is used to transmit and receive signals, and the at least one processor is configured to control to receive information about at least one resource pool from another base station, and based on the information about the at least one resource pool, transmit a switching command message including information about a first resource pool and information about a second resource pool.

[0016] Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

[0017] Beneficial Effects

[0018] According to an embodiment of the present disclosure, V2V / V2X communication may be efficiently performed by reducing interruptions in data transmission using sensing for UE autonomous resource selection. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A timeline illustrating autonomous resource selection of a user equipment (UE) for vehicle-to-vehicle (V2V) communication according to an embodiment of the present disclosure;

[0021] Figure 2 The signaling process according to scenario 1 according to an embodiment of the present disclosure is shown;

[0022] Figure 3 An interruption of at least 1 second due to sensing according to scenario 1 according to an embodiment of the present disclosure is shown;

[0023] Figure 4 A first embodiment of scenario 1 according to an embodiment of the present disclosure is shown;

[0024] Figure 5 is a flowchart showing a first embodiment of scenario 1 according to an embodiment of the present disclosure;

[0025] Figure 6 A second embodiment of scenario 1 according to an embodiment of the present disclosure is shown;

[0026] Figure 7 is a flowchart showing a second embodiment of scenario 1 according to an embodiment of the present disclosure;

[0027] Figure 8 A third embodiment of scenario 1 according to an embodiment of the present disclosure is shown;

[0028] Fig. 9 is a flowchart showing a third embodiment of scenario 1 according to an embodiment of the present disclosure;

[0029] Fig.10 A fourth embodiment of scenario 1 according to an embodiment of the present disclosure is shown;

[0030] Fig.11 is a flowchart showing a fourth embodiment of scenario 1 according to an embodiment of the present disclosure;

[0031] Fig.12 A fifth embodiment of scenario 1 according to an embodiment of the present disclosure is shown;

[0032] Fig.13 is a flowchart showing a fifth embodiment of scenario 1 according to an embodiment of the present disclosure;

[0033] Fig.14 An interruption of at least 1 second due to sensing according to scenario 2 according to an embodiment of the present disclosure is shown;

[0034] Fig.15 A first embodiment of scenario 2 according to an embodiment of the present disclosure is shown;

[0035] Fig.16 is a flowchart showing a first embodiment of scenario 2 according to an embodiment of the present disclosure;

[0036] Fig.17 An interruption of at least 1 second due to sensing according to scenario 3 according to an embodiment of the present disclosure is shown;

[0037] Fig.18 A first embodiment of scenario 3 according to an embodiment of the present disclosure is shown;

[0038] Fig.19 is a flowchart showing a first embodiment of scenario 3 according to an embodiment of the present disclosure;

[0039] Fig. 20 A second embodiment of scenario 3 according to an embodiment of the present disclosure is shown;

[0040] Fig.21 is a flowchart showing a second embodiment of scenario 3 according to an embodiment of the present disclosure;

[0041] Fig. 22 A third embodiment of scenario 3 according to an embodiment of the present disclosure is shown;

[0042] Fig.23 is a flowchart showing a third embodiment of scenario 3 according to an embodiment of the present disclosure;

[0043] Fig.24 A fourth embodiment of scenario 3 according to an embodiment of the present disclosure is shown;

[0044] Fig.25 is a flowchart showing a fourth embodiment of scenario 3 according to an embodiment of the present disclosure;

[0045] Fig.26 An interruption of at least 1 second due to sensing according to scenario 4 according to an embodiment of the present disclosure is shown;

[0046] Fig. 27 is a flowchart showing a fifth embodiment of scenario 4 according to an embodiment of the present disclosure;

[0047] Fig.28 An evolved Node B (eNB) device according to an embodiment of the present disclosure is shown; and

[0048] Fig.29 A UE device according to an embodiment of the present disclosure is shown.

[0049] Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. DETAILED DESCRIPTION

[0050] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in such understanding, but these details are to be regarded as merely exemplary. Accordingly, it will be appreciated by those of ordinary skill in the art that various changes and modifications may be made to the various embodiments described herein without departing from the spirit and scope of the present disclosure. In addition, for clarity and conciseness, descriptions of well-known functions and structures may be omitted.

[0051] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0052] It should be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

[0053] In each of the drawings, the same or similar components may be denoted by the same reference numerals.

[0054] Each block of the flowchart and the combination of the flowcharts can be executed by computer program instructions. Since these computer program instructions can be installed in a processor for a general-purpose computer, a special computer or other programmable data processing device, these instructions executed by the processor for the computer or other programmable data processing device create a device that means to perform the functions described in one or more blocks of the flowchart. Since these computer program instructions can also be stored in a computer-usable or computer-readable memory of a computer or other programmable data processing device to implement the functions in a specific scheme, the computer program instructions stored in the computer-usable or computer-readable memory can also produce an article of manufacture including an instruction device that performs the functions described in one or more blocks of the flowchart. Since the computer program instructions can also be installed on a computer or other programmable data processing device, a series of operations are performed on the computer or other programmable data processing device to create a process executed by the computer to perform the computer or other programmable data processing device. The instructions can also provide steps for performing the functions described in one or more blocks of the flowchart.

[0055] In addition, each block may indicate a module, segment and / or code including one or more executable instructions for performing a specific logical function. In addition, in some alternative embodiments, the functions mentioned in the block may appear regardless of the order. For example, two blocks shown in succession may actually be performed simultaneously, or sometimes performed in reverse order according to the corresponding functions.

[0056] As used herein, the term "unit" may include software and / or hardware components, such as field programmable gate arrays (FPGAs) and / or application specific integrated circuits (ASICs). However, the meaning of "unit" is not limited to software and / or hardware. For example, a unit may be configured to be in an addressable storage medium, and may also be configured to reproduce one or more processors. Accordingly, a "unit" may include software components such as software components, object-oriented software components, category components, task components, and processors, functions, attributes, processes, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables.

[0057] The functionality provided in the components and "units" may be combined with a smaller number of components and / or "units" or may be further separated into additional components and / or "units".

[0058] Furthermore, the components and units may also be implemented as one or more central processing units (CPUs) within the reproduction device or the secure multimedia card.

[0059] The terms used in the present disclosure are provided to describe specific embodiments, and do not limit the scope of other embodiments. Unless otherwise defined, the terms and words including technical or scientific terms used in the following description and claims may have the same meaning as those generally understood by those skilled in the art. The terms usually defined in dictionaries may be interpreted as having the same or similar meaning as the context of the relevant technology. Unless otherwise defined, these terms should not be interpreted as ideal or too formal meanings. When necessary, even the terms defined in the present disclosure may not be interpreted as excluding embodiments of the present disclosure.

[0060] In this article, the base station performs resource allocation for the terminal. Examples of base stations may include eNodeB, Node B, wireless access unit, base station controller, node on the network, etc. Examples of terminals may include user equipment (UE), mobile station (MS), cellular phone, smart phone, computer, multimedia system performing communication functions, etc.

[0061] Herein, a downlink (DL) is a radio transmission path of a signal from a base station to a UE, and an uplink (UL) is a radio transmission path of a signal from a UE to a base station.

[0062] Various embodiments of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel forms.

[0063] Device-to-device (D2D) communication enables data communication services between UEs. During D2D communication (also known as sidelink (SL) communication), the transmitting UE may transmit data packets to a group of UEs or broadcast data packets to all UEs, or send unicast data packets to specific UEs. The UE performs SL communication on subframes defined within the duration of the sidelink control (SLC) cycle. A subframe is a transmission time interval with a duration of 1ms. The SLC cycle is a period in which resources allocated in a cell for SLC information (SLCI) and SL data transmission occur. During the SLC cycle, the UE sends the SLCI followed by SL data. The SLCI indicates the destination identifier and characteristics of the transmission (e.g., modulation and coding scheme (MCS), location of resources within the duration of the SLC cycle, timing alignment).

[0064] A UE supporting SL communication can operate in two modes: a mode for resource allocation, scheduled resource allocation, and a mode for UE autonomous resource selection. In the case of scheduled resource allocation, the UE needs to be RRC_CONNECTED in order to transmit data. The UE requests transmission resources from the evolved Node B (eNB). The eNB schedules transmission resources for transmitting SL control information and data. The UE sends a scheduling request (D-SR or random access) to the eNB, followed by a SL buffer status report (BSR). Based on the SLBSR, the eNB can determine that the UE has data for SL communication transmission and estimate the resources required for transmission. The eNB can use the configured SL radio network terminal identifier (SL-RNTI) to schedule transmission resources for SL communication.

[0065] In the case of UE autonomous resource selection, the UE selects resources from the resource pool and performs transport format selection to transmit SLCI and data. There are up to 8 transmission pools. Each pool may have one or more priorities associated with it. In order to transmit a media access control (MAC) protocol data unit (PDU), the UE selects a transmission pool where one of the associated priorities is equal to the priority of the logical channel with the highest priority among the logical channels identified in the MAC PDU. There is a one-to-one association between the SLC pool and the SL data pool. After selecting a resource pool, the selection is valid for the entire SLC cycle. After the SLC cycle is completed, the UE may perform resource pool selection again.

[0066] The UE interested in D2D communication transmission determines the resources to be used for D2D communication transmission as follows:

[0067] UE in Radio Resource Control (RRC) IDLE: The eNB may broadcast the SL communication transmission (TX) resource pool (i.e., commTxPoolNormalCommon) in the system information (SI) (e.g., in the SI block). If the SI includes the SL communication TX resource pool, the UE in the RRC IDLE state autonomously selects resources for SL communication transmission from these resource pools. If the SI does not include the SL communication TX resource pool, the UE in the RRC IDLE state transitions to RRC CONNECTED and then requests resources for SL communication transmission from the eNB. The ENB may provide a TX resource pool or dedicated resources.

[0068] UE in RRC CONNECTED: If the UE is in RRC CONNECTED state, it requests resources for SL communication transmission from the eNB. The ENB can provide a TX resource pool or dedicated resources.

[0069] Recently, the 3rd Generation Partnership Project (3GPP) standard group has initiated work items to enhance the SL communication mechanism for vehicle-to-vehicle (V2V) or vehicle-to-everything (V2X) (hereinafter, V2V / V2X) communication. One of the enhancements proposed for efficient transmission is to perform sensing for UE autonomous resource selection. The ENB provides a TX resource pool. The UE autonomously selects resources from the TX resource pool based on sensing.

[0070] Figure 1 A timeline of UE autonomous resource selection for V2V / V2X communication according to an embodiment of the present disclosure is shown.

[0071] If resource selection / reselection is triggered in UE autonomous resource selection mode at TTI 'N' 120, the UE senses at least between TTI 'N-a' 100 and TTI 'N-B' 110, where 'a' and 'b' are integers and 'a' = sensing duration + b ms. The sensing duration is 1000ms 150. The values ​​'a' and 'b' are common to V2V / V2X UEs. In UE autonomous resource selection mode, the UE transmits scheduling control information (also known as scheduling assignment (SA)) at TTI 'N+c' 130, indicating the associated data (d>=c) transmitted at TTI 'N+d' 140, where 'c' and 'd' are integers.

[0072] According to this procedure, data transmission can be delayed by '1000+b+c+d' ms. Assuming the values ​​of 'b', 'c' and 'd' are zero, the minimum delay is 1000 ms. The main observations of this procedure are as follows: First, the UE needs to perform sensing for at least 1 s before selecting resources. Second, data transmission can be delayed by at least 1 s due to sensing.

[0073] The above process causes significant delays in data transmission when the UE initiates a V2V / V2X communication transmission. In addition to the initial delay, the process also causes significant interruptions during ongoing data transmission, for example, when the UE transitions from an idle state to a connected state or when the TX resource pool changes in an RRC connected state or when the UE switches from one cell to another in an RRC connected state. A method of reducing interruptions is needed.

[0074] Scenario 1:

[0075] Figure 2 The signaling process according to scenario 1 according to an embodiment of the present disclosure is shown.

[0076] At operation S220, the UE 200 receives an SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from the eNB 210. At operation S230, the UE is in an RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in the SI). The commTxPoolNormal in the SI (if included) may be included in an entry of an inter-frequency information list (InterFreqInfoList). commTxPoolNormalCommon is a transmission resource pool of a primary cell (Pcell). If the Pcell or a frequency of the Pcell is used by the UE for SL V2V / V2X communication transmission, the UE uses commTxPoolNormalCommon for SL V2V / V2X communication transmission. commTxPoolNormal is a transmission resource pool of a frequency other than the Pcell. The UE uses commTxPoolNormal in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications.

[0077] At operation S240, the UE transitions from RRC IDLE to RRC CONNECTED state through connection setup for WAN communication. At operation S250, in the RRC CONNECTED state, the UE requests resources for SL V2V / V2X communication transmission. At operation S260, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message). In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in an entry in an inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communication. commTxPoolNormalDedicated is the transmission resource pool of the Pcell. If the Pcell or the frequency of the Pcell is used by the UE for SL V2V / V2X communication transmission, the UE uses commTxPoolNormalDedicated for SL V2V / V2X communication transmission. commTxPoolNormal is the transmission resource pool for frequencies other than the Pcell. The UE uses commTxPoolNormal in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SLV2V / V2X communication.

[0078] At operation S270, after receiving the RRCConnectionReconfiguration message, the UE stops using commTxPoolNormalCommon or commTxPoolNormal received in the SI, and at operation S280, starts using commTxPoolNormalDedicated or commTxPoolNormal received in the RRCConnectionReconfiguration message for the frequency used by the UE for SL V2V / V2X communication transmission.

[0079] Figure 3 An interruption of at least 1 s due to sensing according to scenario 1 according to an embodiment of the present disclosure is shown.

[0080] In this process, there is an interruption of at least 1 second due to sensing. When an RRCConnectionReconfiguration message 320 is received, the UE must switch resource pools. After switching the pool from commTxPoolNormalCommon or commTxPoolNormal 300 received in the SI to commTxPoolNormalDedicated or commTxPoolNormal 310 received in the RRCConnectionReconfiguration message, the UE must start sensing the resources in commTxPoolNormalDedicated or commTxPoolNormal and sense for at least as long as the sensing duration (e.g., 1 s) before selecting the resource, resulting in a delay equal to the sensing duration.

[0081] Figure 4 A first embodiment of scenario 1 according to an embodiment of the present disclosure is shown.

[0082] To reduce such interruption due to sensing, if the UE is using commTxPoolNormalCommon or commTxPoolNormal 400 received in the SI, it continues to use the commTxPoolNormalCommon or commTxPoolNormal 410 received in the SI even after receiving commTxPoolNormalDedicated or commTxPoolNormal 440 in dedicated signaling (i.e., RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration including commTxPoolNormalDedicated or commTxPoolNormal, the UE continues to use the commTxPoolNormalCommon or commTxPoolNormal 410 received in the SI while the UE senses the commTxPoolNormalDedicated or commTxPoolNormal 420 received in the RRCConnectionReconfiguration. When initial sensing (for a specified time period) is completed for commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration, the UE stops using commTxPoolNormalCommon or commTxPoolNormal received in SI. Figure 4 As shown in , there is no interruption because the use of commTxPoolNormalCommon or commTxPoolNormal received in SI is extended until the end of the initial sensing for commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration.

[0083] Figure 5 is a flowchart showing a first embodiment of scenario 1 according to an embodiment of the present disclosure.

[0084] At operation S520, the UE 500 receives an SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from the eNB 510. At operation S530, the UE is in an RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in the SI). At operation S540, the UE transitions from the RRC IDLE state to the RRC CONNECTED state through connection setup for WAN communication, and at operation S550, requests resources for SL V2V / V2X communication transmission. At operation S560, the UE receives a common TX resource pool (ie, commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (ie, RRCConnectionReconfiguration message), and at operation S570, continues to use commTxPoolNormalCommon or commTxPoolNormal received in SI until the sensing result is available. After the sensing result is available, at operation S580, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal received in dedicated signaling (ie, RRCConnectionReconfiguration message).

[0085] Figure 6 A second embodiment of scenario 1 according to an embodiment of the present disclosure is shown.

[0086] To reduce interruptions due to sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message 640), after receiving RRCConnectionReconfiguration, the UE may use the commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration without sensing 610 while it performs initial sensing (for a specified time period) 620 on commTxPoolNormalDedicated or commTxPoolNormal. Figure 6As shown in , since it is allowed to use the commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration without sensing until the end of the initial sensing for the commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration, there is no interruption. After sensing, the UE uses the commTxPoolNormalDedicated or commTxPoolNormal 630 received in RRCConnectionReconfiguration based on the sensing result.

[0087] Figure 7 is a flowchart showing a second embodiment of scenario 1 according to an embodiment of the present disclosure.

[0088] At operation S720, the UE 700 receives an SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from the eNB 710. At operation S730, the UE is in an RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in the SI). At operation S740, the UE transitions from the RRC IDLE state to the RRC CONNECTED state for WAN communication through connection setup. At operation S750, in the RRC CONNECTED state, the UE requests resources for SL V2V / V2X communication transmission. At operation S760, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., an RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration message, at operation S770, the UE stops using commTxPoolNormalCommon or commTxPoolNormal received in the SI, and at operation S780, starts using commTxPoolNormalDedicated or commTxPoolNormal received in the dedicated signaling until the sensing result is available. Resources are randomly selected from commTxPoolNormalDedicated or commTxPoolNormal received in the dedicated signaling. After the sensing result is available, at operation S790, the UE performs SL V2V / V2X communication using commTxPoolNormalDedicated or commTxPoolNormal received in the dedicated signaling. Resources are selected from commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result.

[0089] Figure 8 A third embodiment of scenario 1 according to an embodiment of the present disclosure is shown.

[0090] To reduce such interruptions due to sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message 830), the UE performs sensing for commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration for a short duration (e.g., 250 ms), the sensing time being a defined time period T 810. T>=duration of normal sensing, i.e., 1000 ms. After the short sensing duration, the UE may use commTxPoolNormalDedicated or commTxPoolNormal received in RRCConnectionReconfiguration 820.

[0091] Fig. 9 is a flowchart showing a third embodiment of scenario 1 according to an embodiment of the present disclosure.

[0092] At operation S920, the UE 900 receives an SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from the eNB 910. At operation S930, the UE is in an RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in the SI). At operation S940, the UE transitions from the RRC IDLE state to the RRC CONNECTED state for WAN communication through connection setup. At operation S950, in the RRC CONNECTED state, the UE requests resources for SL V2V / V2X communication transmission. At operation S960, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., an RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration message, at operation S970, the UE stops using commTxPoolNormalCommon or commTxPoolNormal received in the SI. The UE performs short duration sensing on commTxPoolNormalDedicated or commTxPoolNormal received in the RRCConnectionReconfiguration message. When the short sensing period expires, at operation S980, the UE starts using commTxPoolNormalDedicated or commTxPoolNormal based on the short sensing result until the sensing result of normal sensing is available. After the sensing result of normal sensing is available, at operation S990, the UE uses commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result of normal sensing.

[0093] Fig.10 A fourth embodiment of scenario 1 according to an embodiment of the present disclosure is shown.

[0094] To reduce such interruption due to sensing, the eNB may signal two sets of TX resource pools, commTxPoolNormalDedicated1 or commTxPoolNormal1 and commTxPoolNormalDedicated2 or commTxPoolNormal2, in dedicated signaling (i.e., RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration, the UE starts sensing commTxPoolNormalDedicated2 or commTxPoolNormal2 1020 and uses commTxPoolNormalDedicated1 or commTxPoolNormal1 1010 during the UE sensing commTxPoolNormalDedicated2 or commTxPoolNormal2. After receiving the RRCConnectionReconfiguration message 1040, the UE stops using the commTxPoolNormalCommon or commTxPoolNormal 1000 received in the SI. After initial sensing (for a specified time period) for commTxPoolNormalDedicated2 or commTxPoolNormal2, the UE stops using commTxPoolNormalDedicated1 or commTxPoolNormal1 received in RRCConnectionReconfiguration and starts using commTxPoolNormalDedicated2 or commTxPoolNormal2 1030 based on the sensing result.

[0095] Fig.11 is a flowchart showing a fourth embodiment of scenario 1 according to an embodiment of the present disclosure.

[0096] At operation S1120, UE 1100 receives SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from eNB 1110. At operation S1130, the UE is in RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in SI). At operation S1140, the UE transitions from RRC IDLE to RRC CONNECTED state through connection setup for WAN communication. At operation S1150, in the RRC CONNECTED state, the UE requests resources for SL V2V / V2X communication transmission. At operation S1160, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated1, commTxPoolNormalDedicated2 or commTxPoolNormal1, commTxPoolNormal2) in dedicated signaling (i.e., RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration message, at operation S1170, the UE stops using commTxPoolNormalCommon or commTxPoolNormal, and at operation S1180, starts using commTxPoolNormalDedicated1 or commTxPoolNormal1 until the sensing result for commTxPoolNormalDedicated2 or commTxPoolNormal2 is available. Resources are randomly selected from commTxPoolNormalDedicated1 or commTxPoolNormal1. After the sensing result of commTxPoolNormalDedicated2 or commTxPoolNormal2 is available, at operation S1190, the UE starts to perform SL V2V / V2X communication using commTxPoolNormalDedicated2 or commTxPoolNormal2 based on the sensing result. Resources are selected from commTxPoolNormalDedicated2 or commTxPoolNormal2 based on the sensing result.

[0097] Fig.12 A fifth embodiment of scenario 1 according to an embodiment of the present disclosure is shown.

[0098] To reduce such interruptions due to sensing, the eNB may signal a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (RRCConnectionReconfiguration message)) and a special transmission resource pool (i.e., commTxPoolExceptional) in broadcast signaling SI. commTxPoolExceptional may also be included in the dedicated signaling (RRCConnectionReconfiguration message). In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, commTxPoolExceptional (if included) for non-serving frequencies may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, the commTxPoolExceptional (if included) for the serving frequency (i.e., the frequency of the Pcell) may be included as part of the common configuration. In the RRCConnectionReconfiguration message, the commTxPoolExceptional (if included) may be included in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. After receiving the RRCConnectionReconfiguration message including a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal 1240), the UE uses commTxPoolExceptional (if signaled in the broadcast or dedicated signaling of the relevant frequency) without sensing (i.e., randomly selecting resources from the resource pool), while the UE performs sensing on the resources included in commTxPoolNormalDedicated 1210. After receiving the RRCConnectionReconfiguration message 1200, the UE stops using commTxPoolNormalCommon.After completing initial sensing of resources included in commTxPoolNormalDedicated or commTxPoolNormal1220, the UE stops using commTxPoolExceptional. No sensing is performed on the use of commTxPoolExceptional (or, selected resources). Optionally, sensing may be performed on commTxPoolExceptional during the period when the UE uses commTxPoolNormalCommon. Optionally, sensing may be started on commTxPoolExceptionalCommon after the connection is started. The sensing period of commTxPoolExceptional may be (predefined or signaled) less than the normal sensing duration.

[0099] Fig.13 is a flowchart showing a fifth embodiment of scenario 1 according to an embodiment of the present disclosure.

[0100] At operation S1320, UE 1300 receives SI including a common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal) from eNB 1310. At operation S1330, UE is in RRC IDLE state and performs SL V2V / V2X communication transmission using the common transmission resource pool (i.e., commTxPoolNormalCommon or commTxPoolNormal received in SI). At operation S1340, UE transitions from RRC IDLE to RRC CONNECTED state through connection setup for WAN communication. At operation S1350, in RRC CONNECTED state, UE requests resources for SL V2V / V2X communication transmission. At operation S1360, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., an RRCConnectionReconfiguration message). After receiving the RRCConnectionReconfiguration message, at operation S1370, the UE stops using commTxPoolNormalCommon or commTxPoolNormal. At operation S1380, the UE starts using commTxPoolExceptional without sensing until the sensing result is available for commTxPoolNormalDedicated or commTxPoolNormal. Resources are randomly selected from commTxPoolExceptional. After the sensing result is available, at operation S1390, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal. Resources are selected based on the sensing result.

[0101] In an alternative embodiment of the present disclosure, in response to the SL communication request, the eNB may signal (e.g., using one bit indication) in the RRCConnectionReconfiguration message to use the commTxPoolNormalCommon broadcasted in the SIB instead of signaling commTxPoolNormalDedicated. As a result, the UE does not have to switch from commTxPoolNormalCommon to commTxPoolNormalDedicated and therefore does not interrupt.

[0102] In an alternative embodiment of the present disclosure, the eNB may indicate in broadcast signaling (e.g., a one-bit indicator) that the UE may continue to use the commTxPoolNormalCommon broadcasted in the SIB in the RRC connected state. The UE does not need to request resources when in the RRC connected state or when the UE transitions from RRC idle to RRC connected. As a result, the UE does not request new resources and does not have to switch from commTxPoolNormalCommon to commTxPoolNormalDedicated, and therefore does not interrupt.

[0103] In an alternative embodiment of the present disclosure, the eNB may signal commTxPoolNormalDedicated, and also signal (e.g., using one bit indication) that commTxPoolNormalDedicated is the same as or a subset of commTxPoolNormalCommon in the RRCConnectionReconfiguration message. As a result, the UE does not have to start sensing again because the UE is already performing sensing.

[0104] Scenario 2:

[0105] The UE is in RRC IDLE. The common TX resource pool (i.e., commTxPoolNormalCommon) is not broadcast in the SI. The UE transitions from RRC IDLE to RRC CONNECTED to request resources for SL V2V / V2X communication transmissions. After initiating the connection, the UE uses the commTxPoolExceptional received in the SI to perform sidelink communication transmissions. In the SI, the commTxPoolExceptional for non-serving frequencies (if included) may be included in the entry of the inter-frequency information list (InterFreqInfoList) for the frequencies on which the UE wants to transmit sidelink V2V / V2X communications. In the SI, the commTxPoolExceptional for the serving frequency (i.e., the frequency of the Pcell) (if included) may be included as part of the common configuration.

[0106] The UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message). The UE stops using commTxPoolExceptional and starts using commTxPoolNormalDedicated or commTxPoolNormal. In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communication. commTxPoolNormalDedicated is the transmission resource pool of Pcell. If Pcell or the frequency of Pcell is used by the UE for SL V2V / V2X communication transmission, the UE uses commTxPoolNormalDedicated for SL V2V / V2X communication transmission. commTxPoolNormal is the transmission resource pool for frequencies other than Pcell. The UE uses commTxPoolNormal in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications.

[0107] Fig.14 An interruption of at least 1 s due to sensing according to scenario 2 according to an embodiment of the present disclosure is shown.

[0108] In this process, there is an interruption of at least 1 second due to sensing. After switching the pool from commTxPoolExceptional 140 to commTxPoolNormalDedicated or commTxPoolNormal 1410, the UE must start sensing commTxPoolNormalDedicated or commTxPoolNormal, resulting in a delay of at least 1 second.

[0109] There is no benefit of using the exceptional pool if the time X between connection start and receiving commTxPoolNormalDedicated or commTxPoolNormal in RRCConnectionReconfiguration is less than '1000+b+c+d' ms and the UE switches from commTxPoolExceptional to commTxPoolNormalDedicated or commTxPoolNormal after receiving commTxPoolNormalDedicated in RRCConnectionReconfiguration 1420. There will be a delay of at least 1000+X ms in SL communication transmission.

[0110] Fig.15 A first embodiment of scenario 2 according to an embodiment of the present disclosure is shown.

[0111] To reduce such interruptions due to sensing, if the UE is using commTxPoolExceptional 1500, it continues to use commTxPoolExceptional 1510 even after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message). After receiving RRCConnectionReconfiguration 1540 including commTxPoolNormalDedicated or commTxPoolNormal, the UE continues to use commTxPoolExceptional while the UE senses commTxPoolNormalDedicated or commTxPoolNormal 1520. When initial sensing (for a specified period) is completed for commTxPoolNormalDedicated or commTxPoolNormal, the UE stops using commTxPoolExceptional. Fig.15As shown in , because the use of commTxPoolExceptional is extended until the end of the initial sensing for commTxPoolNormalDedicated or commTxPoolNormal, there is no interruption after receiving RRCConnectionReconfiguration. commTxPoolExceptional may also be included in dedicated signaling (RRCConnectionReconfiguration message). In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, commTxPoolExceptional for non-serving frequencies (if included) may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, commTxPoolExceptional for serving frequencies (i.e., the frequency of the Pcell) (if included) may be included as part of the common configuration.

[0112] The interruption between connection initiation and receiving commTxPoolNormalDedicated or commTxPoolNormal in RRCConnectionReconfiguration can be reduced by relaxing the sensing time for commTxPoolExceptional. The UE can select resources from commTxPoolExceptional without sensing. Optionally, the UE can select resources from commTxPoolExceptional after a shorter sensing duration. The sensing duration for commTxPoolExceptional can be much smaller than that for the normal Tx pool.

[0113] Fig.16 is a flowchart showing a first embodiment of scenario 2 according to an embodiment of the present disclosure.

[0114] At operation S1620, UE 1600 receives SI including a special transmission resource pool (i.e., commTxPoolExceptional) from eNB 1610. At operation S1630, the UE performs SL V2V / V2X communication transmission using the commTxPoolExceptional received in the SI from the moment of transmitting the RRC connection request. Resources are randomly selected from commTxPoolExceptional. At operation S1640, the UE transitions from RRC IDLE to RRC CONNECTED state for WAN communication through connection setup, and at operation S1650, requests resources for SL V2V / V2X communication transmission. At operation S1660, the UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message). At operation S1670, the UE continues to use commTxPoolExceptional until the sensing result for commTxPoolNormalDedicated or commTxPoolNormal is available. Resources are randomly selected from commTxPoolExceptional. After the sensing result is available, at operation S1680, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message). Resources are selected from commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result.

[0115] In the second embodiment of scenario 2, in order to reduce such interruption caused by sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message), after receiving RRCConnectionReconfiguration, the UE may use commTxPoolNormalDedicated or commTxPoolNormal without sensing, while it performs sensing on commTxPoolNormalDedicated or commTxPoolNormal. After sensing commTxPoolNormalDedicated or commTxPoolNormal, based on the sensing result, the UE may use commTxPoolNormalDedicated or commTxPoolNormal. The interruption between connection startup and receiving commTxPoolNormalDedicated or commTxPoolNormal in RRCConnectionReconfiguration can be reduced by allowing the use of commTxPoolExceptional with relaxed sensing time. The UE can select resources from commTxPoolExceptional without sensing. Optionally, the UE can select resources from commTxPoolExceptional after a shorter sensing duration. The sensing duration for commTxPoolExceptional can be much smaller than that for the normal Tx pool. After receiving the RRCConnectionReconfiguration message, the UE stops using commTxPoolException.

[0116] In a third embodiment of the present disclosure for scenario 2, in order to reduce such interruption due to sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message), the UE may use commTxPoolNormalDedicated or commTxPoolNormal for a limited time period T after receiving RRCConnectionReconfiguration with a short sensing duration (e.g., 250ms). T>=duration of normal sensing, i.e., 1000ms. The interruption between connection initiation and receiving commTxPoolNormalDedicated or commTxPoolNormal in RRCConnectionReconfiguration may be reduced by allowing the use of commTxPoolExceptional with a short sensing time. The UE may select resources from commTxPoolExceptional without sensing. Alternatively, the UE may select resources from commTxPoolExceptional after a shorter sensing duration. The sensing duration for commTxPoolExceptional can be much smaller than that for normal Tx pool.After receiving the RRCConnectionReconfiguration message, the UE stops using commTxPoolException.

[0117] In a fourth embodiment of the present disclosure for scenario 2, in order to reduce such interruptions due to sensing, the eNB may signal two sets of TX resource pools, commTxPoolNormalDedicated1 and commTxPoolNormalDedicated2, in dedicated signaling (i.e., RRCConnectionReconfiguration message). After receiving RRCConnectionReconfiguration, the UE starts sensing commTxPoolNormalDedicated2 and uses commTxPoolNormalDedicated1 during the UE's sensing of commTxPoolNormalDedicated2. After receiving the RRCConnectionReconfiguration message, the UE stops using commTxPoolException. After initial sensing for commTxPoolNormalDedicated2, the UE stops using commTxPoolNormalDedicated1.

[0118] Scenario 3:

[0119] Fig.17 An interruption of at least 1 s due to sensing according to scenario 3 according to an embodiment of the present disclosure is shown.

[0120] The UE is in RRC CONNECTED. The UE is interested in SL V2V / V2X communication transmission and requests SL common transmission resources 1720. The UE receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message 1710). In this process, because the UE can select resources 1700 from commTxPoolNormalDedicated or commTxPoolNormal only after sensing, there is an interruption of at least 1s due to sensing. The same interruption will also occur when commTxPoolNormalDedicated or commTxPoolNormal configured by the RRCConnectionReconfiguration message is reconfigured by another RRCConnectionReconfiguration message. In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in the entry of the InterFreqInfoList for the frequencies at which the UE wants to transmit SL V2V / V2X communications. commTxPoolNormalDedicated is the transmission resource pool for Pcell. commTxPoolNormal is the transmission resource pool for frequencies other than Pcell.

[0121] Fig.18 A first embodiment of scenario 3 according to an embodiment of the present disclosure is shown.

[0122] In order to reduce such interruption due to sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message 1820), after receiving RRCConnectionReconfiguration, the UE uses the received commTxPoolNormalDedicated or commTxPoolNormal 1800 without sensing while it performs initial sensing (for a specified period) on commTxPoolNormalDedicated or commTxPoolNormal 1830. After the sensing result is available, the UE may use the received commTxPoolNormalDedicated or commTxPoolNormal 1810 based on the sensing result. If commTxPoolNormalDedicated or commTxPoolNormal was previously configured before receiving the RRCConnectionReconfiguration message, the UE stops using the commTxPoolNormalDedicated or commTxPoolNormal after receiving the RRCConnectionReconfiguration message.

[0123] Fig.19 is a flowchart showing a first embodiment of scenario 3 according to an embodiment of the present disclosure.

[0124] At operation S1920, UE 1900 receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message) from eNB 1910. At operation S1930, the UE uses commTxPoolNormalDedicated or commTxPoolNormal until the sensing result is available for commTxPoolNormalDedicated or commTxPoolNormal. Resources are randomly selected from commTxPoolNormalDedicated or commTxPoolNormal. After the sensing result is available, at operation S1940, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal. The resource is selected from commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result.

[0125] Fig. 20 A second embodiment of scenario 3 according to an embodiment of the present disclosure is shown.

[0126] In order to reduce such interruptions due to sensing, after receiving commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message 2020), after receiving RRCConnectionReconfiguration with a short sensing duration (e.g., 250ms), the UE may use the received commTxPoolNormalDedicated or commTxPoolNormal for a limited time period T 2000. T>=duration of normal sensing, i.e., 1000ms. If commTxPoolNormalDedicated or commTxPoolNormal was previously configured before receiving the RRCConnectionReconfiguration message, the UE stops using the commTxPoolNormalDedicated or commTxPoolNormal after receiving the RRCConnectionReconfiguration message.

[0127] Fig.21is a flowchart showing a second embodiment of scenario 3 according to an embodiment of the present disclosure.

[0128] At operation S2120, UE 2100 receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message) from eNB 2110. At operation S2130, when a short sensing result for commTxPoolNormalDedicated or commTxPoolNormal is available, the UE uses commTxPoolNormalDedicated or commTxPoolNormal. Resources are selected from commTxPoolNormalDedicated or commTxPoolNormal based on the short sensing result. After the normal sensing result is available, at operation S2140, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal. The resource is selected from commTxPoolNormalDedicated or commTxPoolNormal based on normal sensing results.

[0129] Fig. 22 A third embodiment of scenario 3 according to an embodiment of the present disclosure is shown.

[0130] To reduce such interruptions due to sensing, the eNB may signal two sets of TX resource pools, commTxPoolNormalDedicated1 and commTxPoolNormalDedicated2, in dedicated signaling (i.e., RRCConnectionReconfiguration message 2220). After receiving RRCConnectionReconfiguration, the UE starts sensing commTxPoolNormalDedicated2 and uses commTxPoolNormalDedicated1 2200 during the UE sensing commTxPoolNormalDedicated2 2230. After initial sensing for commTxPoolNormalDedicated2 2210, the UE stops using commTxPoolNormalDedicated1. If commTxPoolNormalDedicated or commTxPoolNormal was previously configured before receiving the RRCConnectionReconfiguration message, the UE stops using the commTxPoolNormalDedicated or commTxPoolNormal after receiving the RRCConnectionReconfiguration message.

[0131] Fig.23 is a flowchart showing a third embodiment of scenario 3 according to an embodiment of the present disclosure.

[0132] At operation S2320, UE 2300 receives a common TX resource pool (i.e., commTxPoolNormalDedicated1 and commTxPoolNormalDedicated2 or commTxPoolNormal1 and commTxPoolNormal2) in dedicated signaling (i.e., RRCConnectionReconfiguration message) from eNB 2310. At operation S2330, when the sensing result for commTxPoolNormalDedicated2 or commTxPoolNormal2 is available, the UE uses commTxPoolNormalDedicated1 or commTxPoolNormal1. Resources are randomly selected from commTxPoolNormalDedicated1 or commTxPoolNormal1. After the sensing result is available, at operation S2340, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated2 or commTxPoolNormal2. Resources are selected from commTxPoolNormalDedicated2 or commTxPoolNormal2 based on the normal sensing result.

[0133] Fig.24 A fourth embodiment of scenario 3 according to an embodiment of the present disclosure is shown.

[0134] To reduce such interruptions due to sensing, the eNB may signal the transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal in dedicated signaling (i.e., RRCConnectionReconfiguration message 2420)) and the special transmission resource pool (i.e., commTxPoolExceptional) in broadcast signaling SI.

[0135] commTxPoolExceptional may also be included in dedicated signaling (RRCConnectionReconfiguration message). In the RRCConnectionReconfiguration message, commTxPoolNormal (if included) may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, commTxPoolExceptional (if included) for non-serving frequencies may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. In the SI, commTxPoolExceptional (if included) for the serving frequency (i.e., the frequency of the Pcell) may be included as part of the common configuration. In the RRCConnectionReconfiguration message, commTxPoolExceptional (if included) may be included in an entry in the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications.

[0136] After receiving an RRCConnectionReconfiguration including a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal), the UE uses commTxPoolExceptional (if signaled in broadcast or dedicated signaling on the relevant frequency) without sensing 2400 (i.e., randomly selecting resources from the resource pool), while the UE performs sensing 2430 on the resources included in commTxPoolNormalDedicated. After completing initial sensing on the resources included in commTxPoolNormalDedicated or commTxPoolNormal 2410, the UE stops using commTxPoolExceptional. No sensing is performed on the use of commTxPoolExceptional. Optionally, sensing may be performed for commTxPoolExceptional, wherein the sensing period for commTxPoolExceptional may be less than the normal sensing duration (predefined or signaled). If commTxPoolNormalDedicated or commTxPoolNormal was previously configured before receiving the RRCConnectionReconfiguration message, the UE stops using the commTxPoolNormalDedicated or commTxPoolNormal after receiving the RRCConnectionReconfiguration message.

[0137] Fig.25 is a flowchart showing a fourth embodiment of scenario 3 according to an embodiment of the present disclosure.

[0138] At operation S2520, UE 2500 receives a common TX resource pool (i.e., commTxPoolNormalDedicated or commTxPoolNormal) in dedicated signaling (i.e., RRCConnectionReconfiguration message) from eNB 2510. At operation S2530, the UE uses commTxPoolExceptional until the sensing result for commTxPoolNormalDedicated or commTxPoolNormal is available. Resources are randomly selected from commTxPoolExceptional. The UE may receive commTxPoolExceptional via broadcast signaling or dedicated signaling. After the sensing result is available, at operation S2540, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal. Resources are selected from commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result.

[0139] Scene 4 (Switch):

[0140] Fig.26 An interruption of at least 1 s due to sensing according to scenario 4 according to an embodiment of the present disclosure is shown.

[0141] The UE is in RRC CONNECTED. The UE performs SL V2V / V2X communication transmission in the source cell 2600. The UE switches from the source cell to the target cell. In the handover command (or, RRCConnectionReconfiguration with mobilityControl IE), the UE receives a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal 2620). In the handover command (or, RRCConnectionReconfiguration), commTxPoolNormal may be included in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communication. The handover command is received by the UE from the source cell. In this process, because the UE can select resources 2610 from the received commTxPoolNormalDedicated or commTxPoolNormal of the target cell only after sensing, there is an interruption of at least 1s due to sensing.

[0142] In the first embodiment of the present disclosure for scenario 4, in order to reduce such interruption due to sensing, after receiving a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal in a handover command (or, RRCConnectionReconfiguration)), the UE may use, i.e., select resources from commTxPoolNormalDedicated or commTxPoolNormal without performing sensing (i.e., randomly selecting resources from the resource pool), while it performs sensing on commTxPoolNormalDedicated or commTxPoolNormal. Once the initial sensing is completed, the UE does not randomly select resources from commTxPoolNormalDedicated or commTxPoolNormal, but selects resources based on the sensing results. In an example, the duration of normal sensing may be 1000ms. In the handover command (or, RRCConnectionReconfiguration), commTxPoolNormal may be included in the inter-frequency information list (InterFreqInfoList). The UE uses commTxPoolNormal in the entry of the InterFreqInfoList for the frequency at which the UE wants to transmit SL V2V / V2X communication.

[0143] In a second embodiment of the present disclosure for scenario 4, in order to reduce such interruption due to sensing, after receiving a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal in a handover command), the UE may select resources from commTxPoolNormalDedicated or commTxPoolNormal with a short sensing duration (e.g., 250 ms) and use the resources for a limited time period T. T<duration of normal sensing. In an example, the duration of normal sensing may be 1000 ms. In a handover command (or, RRCConnectionReconfiguration), commTxPoolNormal may be included in an inter-frequency information list (InterFreqInfoList). The UE uses commTxPoolNormal in an entry of the InterFreqInfoList for the frequency at which the UE wants to transmit SL V2V / V2X communication.

[0144] In a third embodiment of the present disclosure for scenario 4, in order to reduce such interruption due to sensing, two sets of TX resource pools in the switching command may be signaled, commTxPoolNormalDedicated1 or commTxPoolNormal1 and commTxPoolNormal2 or commTxPoolNormal2. During the period when the UE senses commTxPoolNormalDedicated2 or commTxPoolNormal2, the UE uses commTxPoolNormalDedicated1 or commTxPoolNormal1 without sensing (i.e., randomly selecting resources from the resource pool). After initial sensing for commTxPoolNormalDedicated2 or commTxPoolNormal2, the UE stops using commTxPoolNormalDedicated1 or commTxPoolNormal1. In an example, the duration of the initial sensing may be 1000ms. In the handover command (or, RRCConnectionReconfiguration), commTxPoolNormal1 and commTxPoolNormal2 may be included in the inter-frequency information list (InterFreqInfoList). The UE uses commTxPoolNormal1 and commTxPoolNormal2 in the entry of the InterFreqInfoList for the frequency at which the UE wants to transmit SL V2V / V2X communication.

[0145] In a fourth embodiment of the present disclosure for scenario 4, a transmission resource pool configuration (i.e., commTxPoolNormalDedicated or commTxPoolNormal) for autonomous resource selection is signaled in a handover command (or, an RRCConnectionReconfiguration message). In the handover command (or, an RRCConnectionReconfiguration message), commTxPoolNormal may be included in an entry in the InterFreqInfoList for the frequency at which the UE wants to transmit SLV2V / V2X communications. The source cell may signal a special transmission resource pool (i.e., commTxPoolExceptional in broadcast signaling (i.e., SI) or dedicated signaling (i.e., RRCConnectionReconfiguration message)). By receiving the handover command, the UE uses the source cell provided with commTxPoolExceptional without sensing (i.e., randomly selecting resources from the resource pool). Optionally, sensing may be performed for commTxPoolExceptional, where the sensing period for commTxPoolExceptional may be (predefined or signaled) less than the normal sensing duration. The UE may initiate sensing for commTxPoolExceptional when the source cell signal quality is below a threshold, or when TTT starts, or when the target cell quality exceeds the source quality by a threshold, or when the target cell quality is above a threshold. The UE continues to use commTxPoolExceptional until initial sensing is completed for commTxPoolNormalDedicated or commTxPoolNormal received in the handover command (or, RRCConnectionReconfiguration message). In the case where scheduled resource allocation is indicated in the handover command, the UE continues to use commTxPoolExceptional until the handover is completed, i.e., until the timer associated with the handover runs.

[0146] In the fifth embodiment of the present disclosure for scenario 4, in order to reduce such interruptions due to sensing, in addition to the transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal of the target cell) in the handover command (or, RRCConnectionReconfiguration message), a special transmission resource pool (i.e., commTxPoolExceptional) may also be signaled. In the handover command (or, RRCConnectionReconfiguration message), commTxPoolNormal may be included in an entry of the InterFreqInfoList for the frequency at which the UE wants to transmit SLV2V / V2X communications. In the handover command (or, RRCConnectionReconfiguration message), commTxPoolNormal may be included in an entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. If commTxPoolExceptional is received in a handover command (or, RRCConnectionReconfiguration message), the UE uses commTxPoolExceptional without sensing (i.e., randomly selecting resources from the resource pool) by receiving the handover command. Optionally, sensing may be performed for commTxPoolExceptional, where the sensing period for commTxPoolExceptional may be (predefined or signaled) less than the normal sensing duration. The UE continues to use commTxPoolExceptional until initial sensing is completed for commTxPoolNormalDedicated or commTxPoolNormal received in the handover command (or, RRCConnectionReconfiguration message).

[0147] Fig. 27 is a flowchart showing a fifth embodiment of scenario 4 according to an embodiment of the present disclosure.

[0148] At operation S2730, the target cell 2720 transmits a transmission resource pool configuration for autonomous resource selection (i.e., commTxPoolNormalDedicated or commTxPoolNormal of the target cell in the target configuration) to the source cell 2710. The transmission resource pool configuration also includes commTxPoolExceptional. At operation S2740, the source cell transmits a handover command to the UE 2700. The handover command (or, RRCConnectionReconfiguration message) may include commTxPoolNormalDedicated or commTxPoolNormal and commTxPoolExceptional. At operation S2750, if commTxPoolExceptional is received in the handover command (or, RRCConnectionReconfiguration message), the UE may perform SL V2V / V2X communication transmission using commTxPoolExceptional until a sensing result for commTxPoolNormalDedicated or commTxPoolNormal is available. The resource is randomly selected from commTxPoolExceptional. After the sensing result is available, at operation S2760, the UE performs SL V2V / V2X communication transmission using commTxPoolNormalDedicated or commTxPoolNormal. The resource is selected from commTxPoolNormalDedicated or commTxPoolNormal based on the sensing result.

[0149] In the sixth embodiment of the present disclosure for scenario 4, in order to reduce such interruptions due to sensing, in addition to the resource pool configuration of the target cell for scheduled resource allocation in the handover command (or, RRCConnectionReconfiguration message), a special transmission resource pool (i.e., commTxPoolExceptional) is also signaled. In the handover command (or, RRCConnectionReconfiguration), commTxPoolNormal may be included in the entry of the inter-frequency information list (InterFreqInfoList) for the frequency at which the UE wants to transmit SL V2V / V2X communications. If commTxPoolExceptional is received in the handover command (or, RRCConnectionReconfiguration message), the UE uses commTxPoolExceptional without sensing (i.e., randomly selecting resources from the resource pool) through the reception of the handover command. Optionally, sensing may be performed for commTxPoolExceptional, wherein the sensing period for commTxPoolExceptional may be (predefined or signaled) less than the normal sensing duration. The UE continues to use commTxPoolExceptional until the handover is completed, i.e., until the timer associated with the handover (i.e., T304, T304 started by the UE when a handover command is received from the source cell, and T304, T304 stopped when the handover to the target cell is successfully completed) runs. In other words, if T304 runs, the UE uses commTxPoolExceptional without sensing (i.e., random selection).

[0150] Fig.28 An eNB device according to an embodiment of the present disclosure is shown.

[0151] Reference Fig.28 , the eNB 2800 includes a transceiver 2810, a processor 2820, and a memory 2830. Optionally, the transceiver may be implemented as a transmitter and a receiver, and each component may be implemented by one or more processors. The transceiver may transmit the transmission resource pool information to the UE, and the memory may store the transmission resource pool information. According to various embodiments of the present disclosure, the processor is configured to determine the transmission resource pool of the UE and control the transceiver and the memory. The processor 2820 may include multiple processors.

[0152] Fig.29 A UE device according to an embodiment of the present disclosure is shown.

[0153] Reference Fig.29, UE 2900 includes a transceiver 2910, a processor 2920, and a memory 2930. Optionally, the transceiver may be implemented as a transmitter and a receiver, and each component may be implemented by one or more processors. The transceiver may receive transmission resource pool information from the eNB, and use resources in the transmission resource pool to transmit scheduling information and data for V2V / V2X communication. The memory may store the transmission resource pool information. According to various embodiments of the present disclosure, the processor is configured to randomly determine resources in the transmission resource pool or perform sensing on the transmission resource pool and determine resources in the transmission resource pool based on the sensing result and control the transceiver and the memory. The processor 2920 may include multiple processors.

[0154] The above various embodiments and drawings of the present disclosure have been provided only as specific examples to help understand the present disclosure, and do not limit the scope of the present disclosure. Accordingly, those skilled in the art to which the present disclosure belongs will understand that other variations can be made based on the technical concept of the present disclosure without departing from the scope of the present disclosure.

[0155] While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present disclosure as defined by the following claims and their equivalents.

Claims

1. A method performed by a terminal in a communication system, the method include: receiving a radio resource control (RRC) reconfiguration message from a base station, wherein the RRC reconfiguration message includes information about a regular transmission resource pool; Based on receiving the information about the special transmission resource pool and not obtaining the sensing result of the regular transmission resource pool, performing resource allocation based on random selection using resources in the special transmission resource pool; and Based on the resources selected from the special transmission resource pool, a first scheduling allocation SA and first data corresponding to the first SA are transmitted.

2. The method according to claim 1, further comprising: include: Based on obtaining a sensing result for the regular transmission resource pool, performing resource allocation based on the sensing result using resources in the regular transmission resource pool; as well as Based on the resources selected from the regular transmission resource pool, a second SA and second data corresponding to the second SA are transmitted.

3. The method according to claim 1, in, The special transmission resource pool is used to transmit the first SA and the first data until the sensing of the regular transmission resource pool is completed.

4. The method according to claim 1, in, The information about the special transmission resource pool is received via a system information block SIB.

5. The method according to claim 1, in, The information about the special transmission resource pool is received by the RRC reconfiguration message.

6. The method according to claim 1, in, The terminal is configured in an autonomous resource selection mode.

7. A method performed by a base station in a communication system, the method include: transmitting a radio resource control (RRC) reconfiguration message to the terminal, wherein the RRC reconfiguration message includes information about a normal transmission resource pool; and Get information about a particular transport resource pool, wherein the randomly selected resources from the special transmission resource pool are used to transmit the scheduling allocation SA and data corresponding to the SA to another terminal until the sensing result of the regular transmission resource pool is obtained, and The information about the special transmission resource pool is transmitted to the terminal through the RRC reconfiguration message or the system information block SIB.

8. The method according to claim 7, in, The terminal is configured in an autonomous resource selection mode.

9. A terminal in a communication system, the terminal include: Transceiver; as well as At least one processor configured to: receiving a radio resource control (RRC) reconfiguration message from a base station, wherein the RRC reconfiguration message includes information about a regular transmission resource pool; Based on receiving the information about the special transmission resource pool and not obtaining the sensing result of the regular transmission resource pool, performing resource allocation based on random selection using resources in the special transmission resource pool; and Based on the resources selected from the special transmission resource pool, a first scheduling allocation SA and first data corresponding to the first SA are transmitted.

10. The terminal according to claim 9, in, The at least one processor is further configured to: Based on obtaining a sensing result for the regular transmission resource pool, performing resource allocation based on the sensing result using resources in the regular transmission resource pool; and Based on the resources selected from the regular transmission resource pool, a second SA and second data corresponding to the second SA are transmitted.

11. The terminal according to claim 9, in, The special transmission resource pool is used to transmit the first SA and the first data until the sensing of the regular transmission resource pool is completed.

12. The terminal according to claim 9, in, The information about the special transmission resource pool is received via a system information block SIB.

13. The terminal according to claim 9, in, The information about the special transmission resource pool is received by the RRC reconfiguration message.

14. The terminal according to claim 9, in, The terminal is configured in an autonomous resource selection mode.

15. A base station in a communication system, the base station include: Transceiver; as well as At least one processor configured to: transmitting a radio resource control (RRC) reconfiguration message to the terminal, wherein the RRC reconfiguration message includes information about a normal transmission resource pool; and Get information about a particular transport resource pool, wherein the randomly selected resources from the special transmission resource pool are used to transmit the scheduling allocation SA and data corresponding to the SA to another terminal until the sensing result of the regular transmission resource pool is obtained, and The information about the special transmission resource pool is transmitted to the terminal through the RRC reconfiguration message or the system information block SIB.

16. The base station according to claim 15, in, The terminal is configured in an autonomous resource selection mode.

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