CN113728722B

CN113728722B - Apparatus and method for providing direct communication service in wireless communication system

Info

Publication number: CN113728722B
Application number: CN202080030621.8A
Authority: CN
Inventors: 李淏娟; 金成勋; 郑湘烨
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2019-04-23
Filing date: 2020-04-23
Publication date: 2022-08-23
Anticipated expiration: 2040-04-23
Also published as: CN113728722A; KR20200124127A

Abstract

The present disclosure relates to a communication technology for combining a 5G communication system for supporting a data transmission rate higher than that of a 4G system with an IoT technology, and a system thereof. The present disclosure may be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or interconnected cars, healthcare, digital education, retail business, security and security-related services, etc.) based on 5 th generation (5G) communication technology and internet of things (IoT) -related technology. The present disclosure discloses a method and apparatus for providing a direct communication service.

Description

Apparatus and method for providing direct communication service in wireless communication system

Technical Field

The present disclosure relates to an apparatus and method for providing a direct communication service in a wireless communication system.

Background

In order to meet the increasing demand for wireless data traffic since the deployment of 4 th generation (4G) communication systems, efforts have been made to develop improved 5 th generation (5G) or pre-5G (pre-5G) communication systems. Accordingly, the 5G or pre-5G communication system is also referred to as a "Beyond 4G (Beyond 4G) network" or a "Long Term Evolution (LTE) system".

5G communication systems are considered to be implemented at higher frequency millimeter wave (mmWave) frequency bands (e.g., 60 gigahertz (GHz) frequency bands) in order to achieve higher data rates. In order to reduce propagation loss of radio waves and increase transmission distance, beamforming, massive Multiple Input Multiple Output (MIMO), full-dimensional MIMO (FD-MIMO), array antenna, analog beamforming, and massive antenna techniques are discussed in the 5G communication system.

Further, in the 5G communication system, development of system network improvement is underway based on advanced small cells, cloud Radio Access Network (RAN), ultra dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multipoint (CoMP), reception-side interference cancellation, and the like. In 5G systems, hybrid Frequency Shift Keying (FSK) and Quadrature Amplitude (QAM) modulation (FQAM) and Sliding Window Superposition Coding (SWSC) have also been developed as Advanced Coding Modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and Sparse Code Multiple Access (SCMA) as advanced access techniques.

The internet, as a human-centric connected network in which humans generate and consume information, is now evolving into the internet of things (IoT), where distributed entities, such as things, exchange and process information without human intervention. Internet of everything (IoE) also arose as a combination of IoT technology and big data processing technology through connection with a cloud server. As IoT implementations require technical elements such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine-to-machine (M2M) communication, machine-type communication (MTC), etc. have recently been studied.

Such an IoT environment can provide intelligent internet technology services, creating new value for human life by collecting and analyzing data generated between interconnected things. IoT may be applied to various fields including smart homes, smart buildings, smart cities, smart cars or interconnected cars, smart grids, healthcare, smart homes, and advanced medical services through fusion and combination between existing Information Technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply the 5G communication system to the IoT network. For example, technologies such as sensor networks, Machine Type Communication (MTC), and machine-to-machine (M2M) communication may be implemented through beamforming, MIMO, and array antennas. Applying a cloud Radio Access Network (RAN) as the big data processing technology described above may also be considered as an example of merging 5G technology and IoT technology.

Vehicle-to-all (V2X) is a general term referring to all types of communication methods applicable to road vehicles, and in conjunction with the development of wireless communication technology, enabling various additional services and safe use scenarios in early stages.

Wireless access in vehicular environments (WAVE) standards based on IEEE 802.11P and IEEE P1609 have been established as a technology for providing V2X service. However, WAVE, as a Dedicated Short Range Communication (DSRC) technology, has a limitation in that a message transmission distance between vehicles is limited.

To overcome the above limitation, the cellular-based V2X technology is being standardized in 3 GPP. In release 14/release 15, the Evolved Packet System (EPS) V2X standard based on the LTE system has been established, and in release 16, the establishment of the V2X standard of the 5 th generation system (5GS) based on the NR system is in progress.

The above information is presented as background information only to aid in understanding the present disclosure. No determination is made, nor is an assertion as to whether any of the above might be applicable as prior art to the present disclosure.

Disclosure of Invention

Technical problem

Aspects of the present disclosure address at least the above problems and/or disadvantages and provide at least the advantages described below.

Accordingly, an aspect of the present disclosure is to provide a method and apparatus for providing a direct communication service in a wireless communication system.

Solution to the problem

In order to solve the above problem, the present disclosure provides a method for processing a control signal in a wireless communication system, the method comprising: the method includes receiving a first control signal transmitted from a base station, processing the received first control signal, and transmitting a second control signal generated based on the processing to the base station.

According to an aspect of the present disclosure, there is provided a method performed by a first terminal in a wireless communication system. The method comprises the following steps: establishing a unicast link with a second terminal, wherein the unicast link supports one or more service types associated with a first application layer Identifier (ID) pair of the first terminal and the second terminal; determining whether to reuse the established unicast link based on a second application layer ID pair associated with the service in the event of initiating data transfer for the service; and in the event that the second application layer ID pair associated with the service is the same as the first application ID pair of the first terminal and the second terminal, modifying the established unicast link for the service to reuse the established unicast link.

According to another aspect of the present disclosure, there is provided a method performed by a second terminal in a wireless communication system. The method comprises the following steps: establishing a unicast link with a first terminal, wherein the unicast link supports one or more service types associated with a first application layer ID pair of the first terminal and a second terminal; and in an instance in which data transmission for the service is initiated, modifying the established unicast link to reuse the established unicast link, wherein the established unicast link is determined to be reused in an instance in which a second application layer ID pair associated with the service is the same as a first application ID pair of the first terminal and the second terminal.

According to another aspect of the present disclosure, a first terminal in a wireless communication system is provided. The first terminal comprises a transceiver configured to transmit and receive signals; and at least one processor coupled with the transceiver and configured to: establishing a unicast link with the second terminal, wherein the unicast link supports one or more service types associated with the first application layer ID pair of the first terminal and the second terminal; determining whether to reuse the established unicast link based on a second application layer ID pair associated with the service in the event of initiating data transfer for the service; and in the event that the second application layer ID pair associated with the service is the same as the first application ID pair of the first terminal and the second terminal, modifying the established unicast link for the service to reuse the established unicast link.

According to another aspect of the present disclosure, a second terminal in a wireless communication system is provided. The second terminal comprises a transceiver configured to transmit and receive signals; and at least one processor coupled with the transceiver and configured to: establishing a unicast link with a first terminal, wherein the unicast link supports one or more service types associated with a first application layer ID pair of the first terminal and a second terminal; and, in an instance in which data transmission for the service is initiated, modifying the established unicast link to reuse the established unicast link, wherein the reuse of the established unicast link is determined in an instance in which a second application layer ID pair associated with the service is the same as a first application ID pair of the first terminal and the second terminal.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

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.

Advantageous effects of the invention

According to the embodiments, an apparatus and method capable of effectively providing a direct communication service in a wireless communication system may be provided.

Drawings

For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, wherein like reference numbers represent like parts:

fig. 1 shows a configuration of a vehicle communication system according to an embodiment of the present disclosure;

fig. 2A illustrates a control plane protocol stack of a terminal according to an embodiment of the present disclosure;

fig. 2B illustrates a user plane protocol stack of a terminal according to an embodiment of the disclosure;

fig. 3 illustrates a configuration of a direct communication link according to an embodiment of the present disclosure;

fig. 4A illustrates a process of establishing a direct communication link according to an embodiment of the present disclosure;

FIG. 4B illustrates a process of transmitting data using a direct communication link according to an embodiment of the disclosure;

fig. 4C illustrates a process of updating a direct communication link according to an embodiment of the disclosure;

FIG. 5A is a schematic diagram illustrating generating a direct communication link according to an embodiment of the present disclosure;

FIG. 5B is a schematic diagram illustrating generating a direct communication link according to an embodiment of the present disclosure;

fig. 6A is a diagram illustrating a QoS Flow Identifier (QFI) mapping associated with a direct communication link, according to an embodiment of the present disclosure;

fig. 6B is a schematic diagram illustrating QFI mapping in relation to a direct communication link, according to an embodiment of the present disclosure;

fig. 7A is a schematic diagram illustrating a bypass radio bearer (SLRB) mapping associated with a direct communication link according to an embodiment of the present disclosure;

fig. 7B is a schematic diagram illustrating a bypass radio bearer (SLRB) mapping associated with a direct communication link, according to an embodiment of the disclosure;

fig. 8 is a schematic diagram illustrating a configuration of a Medium Access Control (MAC) Protocol Data Unit (PDU) according to an embodiment of the present disclosure;

fig. 9 is a schematic diagram illustrating a configuration of a subheader of a bypass-shared channel (SL-SCH) according to an embodiment of the present disclosure;

fig. 10 is a block diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure; and

fig. 11 is a block diagram illustrating a configuration of a terminal according to an embodiment of the present disclosure.

Throughout the drawings, it should be noted that like reference numerals are used to depict the same or similar elements, features and structures.

Detailed Description

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

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

It is to 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 (a) a component surface" includes reference to one or more of such surfaces.

Hereinafter, the operational principle of the present disclosure will be described with reference to the accompanying drawings. In the following description of the present disclosure, a detailed description of known functions or configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure relatively unclear. Terms to be described below are terms defined based on functions in the present disclosure, and may be different according to a user, a user's intention, or a habit. Therefore, the definition of the terms should be based on the contents of the entire specification.

In the drawings, some elements may be exaggerated, omitted, or schematically illustrated for the same reason. Further, the size of each element does not completely reflect the actual size. In the drawings, the same or corresponding elements have the same reference characters allotted.

Advantages and features of the present disclosure and the manner of attaining them will become apparent by reference to the following described embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments set forth below, but may be implemented in various different forms. The following examples are provided only for complete disclosure of the present disclosure and to inform those skilled in the art of the scope of the present disclosure, and the present disclosure is limited only by the scope of the appended claims. Throughout the specification, the same or similar reference numerals denote the same or similar elements.

It will be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart block or blocks. These computer program instructions may also be stored in a computer usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer usable or computer-readable memory produce an article of manufacture including instruction means that implement the function specified in the flowchart block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart block or blocks.

Further, each block of the flowchart illustrations may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the blocks may occur out of the order. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved.

As used herein, a "unit" refers to a software element or a hardware element, such as a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), which performs a predetermined function. However, the meaning of "unit" is not always limited to software or hardware. A "unit" may be constructed to be stored in an addressable storage medium or to execute one or more processors. Thus, a "unit" includes, for example, a software element, an object-oriented software element, a class element or task element, a process (process), a function, an attribute, a procedure (process), a subroutine, a program code segment, a driver, firmware, microcode, circuitry, data, a database, a data structure, a table, an array, and a parameter. The elements and functions provided by a "unit" may be combined into a smaller number of elements or "units" or divided into a larger number of elements or "units". Further, the elements and "units" may alternatively be implemented as one or more CPUs within a rendering device or secure multimedia card. Furthermore, a "unit" in an embodiment may include one or more processors.

In the following description, terms for identifying an access node, terms related to network entities, terms related to messages, terms related to interfaces between network entities, terms related to various identification information, and the like are illustratively used for convenience. Accordingly, the present disclosure is not limited by the terms used below, and other terms related to the subject matter having equivalent technical meanings may be used.

In the following description, for convenience of description, the present disclosure uses terms and names defined in 5G, New Radio (NR), and Long Term Evolution (LTE) system standards. However, the present disclosure is not limited by these terms and names, and can be applied to systems conforming to other standards in the same manner.

The detailed description of the embodiments of the present disclosure will be directed to a communication standard defined by 3 GPP. However, based on the determination of those skilled in the art, the main concept of the present disclosure may be applied to other communication systems having similar technical backgrounds through some changes and modifications without significantly departing from the scope of the present disclosure.

Although embodiments of the present disclosure will be described below primarily based on vehicle communication services, those skilled in the art can readily determine that the subject matter of the present disclosure can be applied to other services provided in a 5G network with some modifications thereto without departing from the scope of the present disclosure.

In the 5G system, it is considered to support various services more than the existing 4G system. For example, the most typical services may include enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), large-scale machine type communication (mtc), evolved multimedia broadcast/multicast service (eMBMS), and the like. Further, a system providing the URLLC service may be referred to as "URLLC system", and a system providing the eMBB service may be referred to as "eMBB system". Further, "service" may be used interchangeably with "system".

Among them, the URLLC service is newly considered in the 5G system unlike the existing 4G system, and satisfies an ultra-reliability (e.g., about 10) compared to other services ^-5 Packet error rate) and low latency (e.g., about 0.5 msec). To meet these stringent requirements, URLLC services may require the application of shorter Transmission Time Intervals (TTIs) than eMBB services, and various operating methods utilizing the same are being considered.

Meanwhile, the internet, which to date has been a human-centric connected network in which humans generate and consume information, is now evolving into the internet of things (IoT) in which distributed entities or "things" exchange and process information. Internet of everything (IoE) has come to be produced as a combination of IoT technology and big data processing technology by connecting with a cloud server. As IoT implementations require technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology, technologies for connecting things such as sensor networks, machine-to-machine (M2M) communication, Machine Type Communication (MTC), etc. have recently been studied.

Fig. 1 shows a configuration of a vehicle communication system according to an embodiment of the present disclosure.

Referring to fig. 1, a terminal 110, which may be used interchangeably with user equipment, user terminal or vehicle UE, may use direct communication 140 (e.g., device-to-device (D2D), ProSe, PC5 or bypass communication) or network communication 150 or network communication 160 through a mobile communication system 130 to communicate with another terminal 120. In the case of direct communication, the transmission and reception of messages between the terminal 110 and the other terminal 120 may be performed through a PC5 link. In the case of network communication, a message transmitted from a transmitting vehicle terminal to a receiving vehicle terminal may be transmitted to a network through a Uu link, and then may be transmitted to the receiving vehicle terminal through the Uu link. The mobile communication system 130 may be an EPC system, 5GC system or a communication system other than 3GPP defined in 3 GPP. The direct communication 140 may be provided using a non-3 gpp RAT, such as LTE Radio Access Technology (RAT), NR RAT, or wireless fidelity (Wi-Fi).

Fig. 2A illustrates a control plane protocol stack of a terminal according to an embodiment of the present disclosure, and fig. 2B illustrates a user plane protocol stack of a terminal according to an embodiment of the present disclosure. The terminal 110 may be a transmitting terminal and the terminal 120 may be a receiving terminal, wherein the transmitting terminal and the receiving terminal will be referred to as "terminal 110" and "terminal 120", respectively, for convenience of description.

Referring to fig. 2A, the control plane protocol stack of terminal 110 or terminal 120 may include a PC5 signaling protocol layer 210 or PC5 signaling protocol layer 215, a Radio Resource Control (RRC) layer 220 or RRC layer 225, a Packet Data Convergence Protocol (PDCP) layer 230 or PDCP layer 235, a Radio Link Control (RLC) layer 240 or RLC layer 245, a MAC layer 250 or MAC layer 255, and a physical layer (PHY) layer 260 or PHY layer 265. The RRC layer 220 or the RRC layer 225, the PDCP layer 230 or the PDCP layer 235, the RLC layer 240 or the RLC layer 245, and the Medium Access Control (MAC) layer 250 or the MAC layer 255 may be collectively referred to AS an Access Stratum (AS) layer 200 or the AS layer 205. Hereinafter, in describing the present disclosure, the

AS layer

200 or 205 may include at least one of the

RRC layer

220 or 225, the

PDCP layer

230 or 235, the

RLC layer

240 or 245, and the

MAC layer

250 or 255.

The PC5 signaling protocol layer 210 or the PC5 signaling protocol layer 215 may provide link establishment and link maintenance functions for the direct communication 140 between the terminal 110 and the terminal 120 through the procedures shown in fig. 4A, 4B, and 4C.

Referring to fig. 2A, a PC5 signaling (PC5-S) message of the terminal 110 or the terminal 120 may be transmitted to an opposite terminal through the PC5 signaling protocol layer 210 or the PC5 signaling protocol layer 215, the RRC layer 220 or the RRC layer 225, the PDCP layer 230 or the PDCP layer 235, the RLC layer 240 or the RLC layer 245, the MAC layer 250 or the MAC layer 255, and the PHY layer 260 or the PHY layer 265.

Alternatively, referring to fig. 2A, a PC5 signaling (PC5-S) message of the terminal 110 or the terminal 120 may be transmitted to an opposite terminal through the PC5 signaling protocol layer 210 or the PC5 signaling protocol layer 215, the PDCP layer 230 or the PDCP layer 235, the RLC layer 240 or the RLC layer 245, the MAC layer 250 or the MAC layer 255, and the PHY layer 260 or the PHY layer 265.

Referring to fig. 2B, the user plane protocol stack of the terminal 110 or the terminal 120 may include an application layer 270 or 275, a Service Enabling (SE) layer 280 or 285, a Service Data Adaptation Protocol (SDAP) layer 290 or 295, a

PDCP layer

230 or 235, an

RLC layer

240 or 245, a

MAC layer

250 or 255, and a PHY layer 260 or 265. The SDAP layer 290 or the SDAP layer 295, the PDCP layer 230 or the PDCP layer 235, the RLC layer 240 or the RLC layer 245, and the MAC layer 250 or the MAC layer 255 may be collectively referred to AS the AS layer 200 or the AS layer 205. Hereinafter, in describing the present disclosure, the

AS layer

200 or 205 may include at least one of the SDAP layer 290 or 295, the

PDCP layer

230 or 235, the

RLC layer

240 or 245, and the

MAC layer

250 or 255.

The SE layer 280 or the SE layer 285 is an intermediate layer for performing operations of the application layer 270 or the application layer 275, and may provide a dedicated function to each application or service. A single SE layer may support multiple application layers. Further, a special SE layer may be defined for each application layer. For example, the application layer 270 or the application layer 275 may be a V2X application layer for providing V2X services. Further, the SE layer 280 or the SE layer 285 may be defined as a V2X layer for operation of the V2X application layer. Hereinafter, to provide the V2X service, the application layer 270 or 275 may be used interchangeably with the V2X application layer, and the SE layer 280 or 285 may be used interchangeably with the V2X layer.

The SE layer 280 or the SE layer 285 may provide a function of transmitting data through a link for the direct communication 140 established between the terminal 110 and the terminal 120. The SE layer 280 or the SE layer 285 may include an IP protocol, a non-IP protocol, and a transport protocol (e.g., TCP or UDP) for sending messages.

The terminal 110 or the terminal 120 according to an embodiment may acquire and store the information shown in table 1 below in order to use the V2X service. The stored information may be used by the SE layer 280 or the SE layer 285.

[ Table 1]

The SDAP layer 290 or SDAP layer 295 may be used to transmit data through direct communication 140 between the terminal 110 and the terminal 120. For example, when a link for the direct communication 140 between the terminal 110 and the terminal 120 is established and then data is transmitted through the established link (e.g., PC5 unicast communication or PC5 multicast), the SDAP layer 290 or the SDAP layer 295 may be used to transmit messages. Further, for example, even when data is transmitted without establishing a link for the direct connection 140 between the terminal 110 and the terminal 120 (e.g., PC5 broadcast communication), the SDAP layer 290 or the SDAP layer 295 may be used to transmit messages.

The PC5 signaling protocol layer 210 or the PC5 signaling protocol layer 215 according to an embodiment may include functionality provided by the SE layer 280 or the SE layer 285. Alternatively, the PC5 signaling protocol layer 210 or the PC5 signaling protocol layer 215 may interact with the SE layer 280 or the SE layer 285, the RRC layer 220 or the RRC layer 225, the PDCP layer 230 or the PDCP layer 235, and/or the SDAP layer 290 or the SDAP layer 295 for link establishment and/or link maintenance.

The terminal 110 and the terminal 120 according to an embodiment may store information shown in table 2 below in order to provide a service (e.g., V2X service) using direct communication. The stored information may be used by the SE layer 280 or the SE layer 285.

[ Table 2]

Referring to table 2, the QoS parameters may include one or more QoS characteristics. The QoS characteristics may be, for example, priority level, packet delay budget, packet error rate, maximum data burst capacity, averaging window, communication range, etc. The QoS parameters may include one or more QoS characteristics and may be referred to as a "PQI (5 QI for PC 5) value.

Fig. 3 illustrates a configuration of a direct communication link between terminals according to an embodiment of the present disclosure.

Referring to fig. 3, the terminal 110 and the terminal 120 may store and drive the same application 310 and application 315. The application may be identified by an application Identification (ID) (e.g., OSAppID, etc.). Applications 310 and 315 may provide one or more services. For example, applications 310 and 315 may include service type #1(312 or 317) and service type #2(314 or 319). The respective service types may be distinguished by service type IDs (e.g., PSID, ITS-AID, etc.).

A terminal according to an embodiment may have one or more applications installed in the terminal, and the one or more applications may be simultaneously executed. The application layer user ID (e.g., terminal ID, terminal subscriber ID, user email address, etc.) associated with each application may be implemented in any of a variety of ways.

For example, one application layer user ID may be for one application. In this case, an application layer user ID may be assigned as a unique value to each user and application. Referring to fig. 3, in the case where an application #1(310), an application #2, and an application #3 are installed in a terminal 110, each of the application #1(310), the application #2, and the application #3 may be distinguished by an application layer user ID. In this case, the SE layer 280 may identify each of the application #1(310), the application #2, and the application #3 using the application layer user ID.

Alternatively, or in addition, one application layer user ID may be used for one or more applications. For example, one or more applications may share an application layer user ID.

Referring to fig. 3, in the case where an application #1(310), an application #2, and an application #3 are installed in a terminal 110, the application #1(310) and the application #2 may use one application layer user ID, and the application #3 may use another application layer user ID. In this case, the SE layer 280 may identify the application #1(310) and the application #2 using the same one application layer user ID, and may identify the application #3 using one application layer user ID.

Alternatively, or in addition, one application layer user ID may be used for all applications. For example, all applications may share an application layer user ID.

Referring to fig. 3, in the case where application #1(310), application #2, and application #3 are installed in terminal 110, all applications installed in terminal 110 may use one application layer user ID. For example, the application may not be further identified using an application layer user ID. In this case, the SE layer 280 may know that one application layer user ID is applied to all applications of the terminal 110, and may use such a case.

Hereinafter, in describing the present disclosure, the operations of the applications 310 and 315 and/or the

service types

312, 314, 317, and 319 may be understood as the operations of the application layer 270 and 275 shown in fig. 2B. One or more application and/or service types may be driven by the application layer 270 and the application layer 275.

A service type may have one or more QoS requirements. SE layer 280 or SE layer 285 may determine QoS parameters to satisfy QoS requirements provided from applications 310 and 315 and/or

service types

312, 314, 317, and 319, and may map the QoS parameters to PQI values as shown in table 2.

Terminal 110 and terminal 120 may establish direct communication link 330 using the procedures shown in fig. 4A, 4B, and 4C. The direct communication link 330 may be referred to as a "link ID". According to an embodiment of the disclosure, terminal 110 and terminal 120 may establish one direct communication link 330 for each of application 310 and application 315, and may provide one or more service types (e.g., PSID, ITS-AID, etc.) using direct communication link 330. For example, as shown in FIG. 5A, an application may have one direct communication link.

Alternatively, terminal 110 and terminal 120 may establish direct communication link 330 for each of service type 312, service type 317, service type 314, or service type 319 in accordance with embodiments of the present disclosure. One application including a plurality of service types may generate a direct communication link 330 supporting the respective service types, and each direct communication link may provide each service type (e.g., PSID, ITS-AID, etc.). For example, as shown in fig. 5B, one application may have a number of direct communication links equal to the number of service types supported.

The direct communication link 330 may include one or more QoS flows. The QoS flows may be mapped to PQI values as shown in table 2. One QoS flow may be referred to as a "QoS Flow Identifier (QFI)". For example, as shown in fig. 4, the direct communication link 330 may include four QoS flows, and each QoS flow may be referred to as "QFI # 1" (331), "QFI # 2" (332), "QFI # 3" (333), and "QFI # 4" (334). The individual QoS flows that make up the direct communication link 330 may provide different levels of QoS. The process of establishing the direct communication link 330 will be described below with reference to fig. 4A.

Terminal 110 and terminal 120 may transmit data using the procedure shown in fig. 4B. The terminal 110 and the terminal 120 may transmit data using the QoS flow included in the direct communication link 330 for transmitting data. SE layer 280 or SE layer 285 may select an appropriate QFI according to the QoS required for the data to be transmitted, and may transmit the data using the selected QFI. The process of transmitting data over direct communication link 330 will be described below with reference to fig. 4B.

Fig. 4A illustrates a process of establishing a direct communication link according to an embodiment of the present disclosure.

For the purpose of describing the present disclosure, it is assumed that the transmitting terminal 110 may initiate establishment of a direct communication link, and that the remaining

peripheral terminals

115, 120, and 125 are located near the transmitting terminal 110 and may receive a direct communication request message 425 transmitted from the transmitting terminal 110. Further, it is assumed that at least one of the peripheral terminal 115, the peripheral terminal 120, and the peripheral terminal 125 (e.g., the terminal 120) performs the direct communication 440 with the transmitting terminal 110.

Referring to fig. 4A, in operation 400, the peripheral terminal 115, the peripheral terminal 120, and the peripheral terminal 125 may determine a destination layer-2ID for receiving the direct communication request message 409 based on the V2X service policy parameters in table 1 (e.g., which correspond to the "mapping of default destination layer-2 ID(s) (layer 2 ID) and V2X service (e.g., PSID or ITS-AID applied by V2X") for initial signaling to establish a unicast connection). The destination layer-2ID for receiving the direct communication request message may be determined as different values for respective application layers, respective applications supported by the application layers, or respective service types (e.g., PSID, ITS-AID, etc.) supported by the application layers. Alternatively, the destination layer-2ID for receiving the direct communication request message may be determined to be the same default value regardless of the application layer, the applications supported by the application layer, or the types of services supported by the application layer.

The application layer 270 of the terminal 110 for performing the application operation may provide the SE layer 280 with at least one of "application data" (hereinafter, this will be used interchangeably with "service data" or "data") generated by the application layer 270 in operation 403, "service type" indicating the type of data, "communication mode" indicating the communication method (e.g., broadcast, multicast, unicast, etc.) of the data, "application layer user ID" (application layer user identifier) of the transmitting terminal 110, "application layer user ID" (application layer user identifier) of the receiving terminal 120, and "QoS requirement". In the case of vehicle communication, PSID, ITS-AID, or the like may be used as the service type. The application layer 270 may provide one or more service types to the SE layer 280. Further, application layer 270 may provide one or more QoS requirements to SE layer 280. Further, application layer 270 may provide SE layer 280 with a service type and mapping information between one or more QoS requirements and the service type. An example of the information provided by the application layer 270 to the SE layer 280 in operation 403 is as follows.

-application data

Application ID (e.g. 310 in FIG. 3)

At least one service type (e.g. corresponding to 312 and 314 in fig. 3)

-one or more QoS requirements mapped to respective service types

-communication mode

Application layer user IDs of the sending terminal 110 and the receiving terminal 120

In operation 406, the SE layer 280 of the terminal 110 may determine whether to perform a link establishment procedure based on information (e.g., application data, communication mode, service type, etc.) received from the application layer 270 in operation 403. For example, if the communication mode received from the application layer 270 is PC5 unicast, the SE layer 280 may determine that a link needs to be established. If it is determined whether the pre-established direct communication link is reused (recycle), and if it is determined that the pre-established direct communication link cannot be reused, the SE layer 280 may determine to perform an establishment procedure, thereby performing the following operation. If the pre-established direct communication link can be reused, the SE layer 280 may perform the process shown in FIG. 4B.

For example, if there is a link profile (profile) storing the application layer user ID of the transmitting terminal 110 and/or the application layer user ID of the receiving terminal 120 from the application layer 270 in operation 403, the SE layer 280 may recognize that the terminal 110 and the terminal 120 have a pre-established direct communication link. Thus, the SE layer 280 may determine to reuse a pre-established direct communication link instead of establishing a new direct communication link, and may perform the process shown in fig. 4B. According to an embodiment of the present disclosure, in case of using one application layer user ID in each application, the terminal 110 may establish one direct communication link with the terminal 120 for each application. For example, one direct communication link may be created for each application, and signaling and data for one application may be sent over one direct communication link. Alternatively, where an application layer user ID is used in one or more applications, terminal 110 may establish a direct communication link with terminal 120 for applications sharing the application layer user ID. For example, applications sharing an application layer user ID may share a direct communication link, and signaling and data for the applications may be sent over the direct communication link. Alternatively, in case one application layer user ID is used in all applications, a single direct communication link may be established between the terminal 110 and the terminal 120, so that signaling and data for all applications supported by the terminal 110 and the terminal 120 are transmitted through the single direct communication link.

If there is no link profile storing the application layer user ID of the transmitting terminal 110 and/or the application layer user ID of the receiving terminal 120, the SE layer may perform the following procedure.

The SE layer 280 of the terminal 110 may assign a link Identifier (ID) indicating the direct communication link 330 to be established through the procedure of operation 409 through operation 418. The link ID may be assigned as a unique value in the terminal 110. SE layer 280 may generate a link profile for direct communication link 330 indicated as the link ID assigned by SE layer 280. The link profile may include the application layer user IDs of the transmitting terminal 110 and the receiving terminal 120 received by the SE layer 280 from the application layer 270 in operation 403.

Further, SE layer 280 may translate the QoS requirements received from application layer 270 in operation 403 into PQI (PC 55 QI) values available to AS layer 200. One service type may request messages for multiple QoS requirements, and thus, one service type may be mapped to multiple PQI values. Further, SE layer 280 may assign QFI to each PQI value. According to an embodiment of the present disclosure, if the service type is different with respect to the same PQI value (e.g., PQI #3), different QFI values (e.g., QFI #3 and QFI #4) may be assigned to the service type. This example is shown in fig. 6A.

Alternatively, according to an embodiment of the present disclosure, even if the service type is different with respect to the same PQI value (e.g., PQI #3), the same QFI value (e.g., QFI #3) may be assigned to the service type. This example is shown in fig. 6B.

The link profile generated and managed by SE layer 280 may include and store at least one of PQI values associated with the direct communication link, QFI values corresponding to the respective PQI values, service types corresponding to the respective PQI values, and service types corresponding to the respective QFI values.

The SE layer 280 may determine the SE layer 280 of the terminal 110 to be used for direct communication to have its own layer-2ID, and may assign the layer-2ID to itself. The SE layer 280 may store the SE layer 280's own layer-2ID of the terminal 110 in a link profile generated and managed by the SE layer 280. An example of the information stored in the link configuration file generated by the SE layer 280 in operation 406 is as follows. The link profile may be referred to as a "link ID".

Application layer user ID of terminal 110 (information received from application layer 270 in operation 403)

Application layer user ID of terminal 120 (information received from application layer 270 in operation 403)

Layer-2ID of terminal 110 (layer-2 ID assigned by the terminal itself)

Application IDs supported by direct communication links (corresponding to, e.g., 310 in FIG. 3)

One or more service types supported by the direct communication link (corresponding to, for example, 312 and 314 in fig. 3)

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

Mapping information between service types, PQIs and QFIs supported by direct communication links

The SE layer 280 may generate a direct communication request message for establishing a unicast link. The direct communication request message may include at least one of an "application message", "application ID", "service type", an "application layer user ID" (application layer user identifier) of the transmitting terminal 110, an "application layer user ID" (application layer user identifier) of the receiving terminal 120, a "link ID" indicating a direct communication link, "QoS requirements that must be provided by the direct communication link," PQI "," QFI ", and" layer-2ID "of the transmitting terminal 110, which are received from the application layer 270 in operation 403. Examples of the information included in the direct communication request message are as follows.

-application data

Application layer user ID of terminal 110

Application layer user ID of terminal 120

-link ID indicating the direct communication link

-one or more QoS requirements supported by the direct communication link

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

The SE layer 280 may determine a source layer-2ID and a destination layer-2ID to be included in a MAC header in order to transmit the generated direct communication request message. The SE layer 280 may use the layer-2ID allocated by the terminal 110 itself as the source layer-2 ID. The source layer-2ID may be the same as the layer-2ID value of the terminal 110 stored in the link profile. In addition, SE layer 280 may reference the V2X service policy parameters in table 1 stored by the terminal in order to determine the destination layer-2 ID. For example, the destination layer-2ID may be determined based on the "mapping of default destination layer-2 ID(s) and V2X services (e.g., PSID or ITS-AID of V2X application) used for initial signaling to establish the unicast connection" in table 1. The destination layer-2ID may have the same value as the destination layer-2ID determined by the peripheral terminal 115, the peripheral terminal 120, and the peripheral terminal 125 in operation 400.

The SE layer 280 may deliver information to the AS layer 200 for sending direct communication request messages. The information delivered to the AS layer 200 may include at least one of a direct communication request message, a source layer-2ID of the message, a destination layer-2ID of the message, a link ID, a PQI value, a QFI value, mapping information between PQI and QFI, a communication mode (e.g., PC5 broadcast), and a type of message (e.g., a signal (control) message). Examples of information that the SE layer 280 delivers to the AS layer 200 are AS follows.

-direct communication request message

Source layer-2ID of message

-destination layer-2ID of message

-a link ID indicating a direct communication link

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

-communication mode

Type of message

The AS layer 200 may store information delivered from the SE layer 280 and may manage a bypass radio bearer (SLRB) for direct communication. According to an embodiment of the present disclosure, one QFI value may be assigned to one PQI value, and one QFI value may be mapped to one SLRB (e.g., QFI #5 and SLRB # 3). Alternatively, if the service types are different, different QFI values may be assigned to the same PQI value, and a plurality of QFI values may be mapped to one SLRB (e.g., QFI #3, QFI #4, and SLRB # 2). Alternatively, one QFI value may be assigned to one PQI value, and a plurality of QFI values may be mapped to one SLRB (e.g., QFI #1, QFI #2, and SLRB # 1). This example is shown in fig. 7A.

Alternatively, according to an embodiment of the present disclosure, one QFI value may be assigned to one PQI value, and one QFI value may be mapped to one SLRB (e.g., QFI #4 and SLRB # 3). Or, even if the service types are different, one QFI value may be assigned to the same PQI value and one QFI value may be mapped to one SLRB (e.g., QFI #3 and SLRB # 2). Alternatively, one QFI value may be assigned to one PQI value, and a plurality of QFI values may be mapped to one SLRB (e.g., QFI #1, QFI #2, and SLRB # 1). This example is shown in fig. 7B.

The AS layer 200 may configure the MAC header based on information delivered from the SE layer 280. An example of configuring the MAC PDU is shown in fig. 8. The MAC PDU may include a MAC header 810. The MAC header may include SL-SCH subheader 811 and R/R/E/LCID/F/L subheader 812. The SL-SCH subheader 811 may be applied in common to the entire MAC payload 820. The R/E/LCID/F/L subheader 812 may correspond in order to one MAC SDU 830 of the MAC payload.

Fig. 9 is a schematic diagram illustrating a configuration of the SL-SCH subheader illustrated in fig. 8 according to an embodiment of the present disclosure. The SL-SCH subheader 811 may include a source layer-2ID 910 (corresponding to the SRC in Table 4) and a destination layer-2ID 920 (corresponding to the DST in Table 4). The source layer-2ID 910 and destination layer-2ID 920 may each have a range of 3 octet values or 2 octet values. The AS layer 200 may configure the source layer-2ID delivered from the SE layer 280 AS the source layer-2ID 910 of the SL-SCH subheader (corresponding to the SRC in Table 4). In addition, the AS layer 200 may configure the destination layer-2ID delivered from the SE layer 280 AS the destination layer-2ID 920 of the SL-SCH subheader (corresponding to the DST in Table 4).

The R/E/LCID/F/L subheader 812 may include a Logical Channel Id (LCID) indicating the type of message of the MAC SDU 830 indicated by the subheader. Table 3 shows an example of LCID. The AS layer 200 may determine the LCID based on the type of message delivered from the SE layer 280. For example, if the type of message indicates a signaling message, the LCID may be set to 11100, 11101, or 11110.

[ Table 3]

The AS layer 200 may configure the MAC header 810 AS described above and may include the direct communication request message received from the SE layer 280 in the MAC payload 820, thereby transmitting the direct communication request message to the peripheral terminal 115, the peripheral terminal 120, and the peripheral terminal 125 through the physical layer 260 (operation 409).

The peripheral terminal 115 of the transmitting terminal 110, the peripheral terminal 120, and the peripheral terminal 125 may receive the direct communication request message transmitted from the transmitting terminal 110 (operation 412). The

peripheral terminals

115, 120 and 125 may deliver the received direct communication request message to the SE layer through the PHY layer and the AS layer of the

terminals

115, 120 and 125. After receiving the direct communication request message, the SE layer may identify a destination address of the message, thereby determining a method of processing the message. If the destination address of the message is the destination layer-2ID address determined by the terminal in operation 400, the SE layer may determine that the received message is a direct communication request message among PC5-S signaling messages. The SE layer may select an application layer to which the received message is to be delivered based on at least one of a "destination layer-2ID address" of the received message, a "service type" included in the received message, an "application layer user ID (application layer user identifier)" of the terminal included in the received message, or an "application ID" included in the received message, and may deliver the received message to the selected application layer.

The application layer 275 of the terminal 120 that receives the direct communication request message may determine to respond to the received direct communication request message based on "application data", "service type", an "application layer user ID" (application layer user identifier) of the transmitting terminal 110, an "application layer user ID" (application layer user identifier) of the receiving terminal 120, and the like, included in the received direct communication request message.

The application layer 275 of the terminal 120 that wishes to accept the received direct communication request may provide the SE layer 285 with at least one of "application data" (hereinafter, this will be used interchangeably with "service data" or "data") generated by the application layer 275 in operation 412, "service type" indicating the type of data, "communication mode" (e.g., broadcast, multicast, unicast, etc.) indicating the communication method of the data, "application layer user ID" (application layer user identifier) of the transmitting terminal 110, "application layer user ID" (application layer user identifier) of the receiving terminal 120, and "QoS requirements. In the case of vehicle communication, PSID, ITS-AID, or the like may be used as the service type. The application layer 275 may provide one or more service types to the SE layer 285. Further, application layer 275 may provide one or more QoS requirements to SE layer 285. Further, application layer 275 may provide SE layer 285 with the service type and mapping information between one or more QoS requirements and the service type. An example of information provided by the application layer 275 to the SE layer 285 in operation 412 is as follows.

-application data

Application ID (e.g. 315 in FIG. 3)

One or more service types (corresponding for example to 317 and 319 in figure 3)

-one or more QoS requirements mapped to respective service types

-communication mode

The SE layer 280 of the terminal 120 may determine whether to perform the link establishment procedure in operation 415 based on information (e.g., application data, communication mode, service type, etc.) received from the application layer 275 in operation 412. For example, if application data received from the application layer 275 requires a direct communication link to be established, the SE layer 285 may determine to perform a link establishment procedure. The SE layer 285 may perform the following operation (operation 415) based on the information received from the application layer 275 in operation 412 and the information received from the transmitting terminal 110 in operation 409.

The SE layer 285 of the terminal 120 may assign a link Identifier (ID) indicating that the direct communication link 330 is to be established through the process of operations 415 through 418. Alternatively, the SE layer 285 may use the link ID received from the transmitting terminal 110 in operation 409. The link ID may be assigned as a unique value in the terminal 120. SE layer 285 may generate a link profile for direct communication link 330 indicated using the link ID assigned by SE layer 285. The link profile may include the application layer user IDs of the transmitting terminal and the receiving terminal received in operation 412 or operation 409.

Further, SE layer 285 may convert the QoS requirement received in operation 412 or operation 409 into a PQI (PC 55 QI) value available to AS layer 205 in order to determine the PQI to be supported in direct communication. Alternatively, SE layer 285 may use the PQI value received in operation 409.

SE layer 285 may determine the QFI that map to the PQI to be supported in direct communication. Alternatively, the SE layer 285 may determine QFI using mapping information between the PQI value and QFI received in operation 409.

The method described in operation 406 may be applied to the relationship between service type, QoS requirements, PQI and QFI in a similar manner.

The link profile generated and managed by SE layer 285 may include and store at least one of PQI values associated with the direct communication link, QFI values corresponding to the PQI values, service types corresponding to the PQI values, and service types corresponding to the QFI values.

The SE layer 285 may determine the SE layer 285's own layer-2ID of the terminal 120 to be used for direct communication, and may assign the layer-2ID to itself. The SE layer 285 may store its own layer-2ID of the terminal 120 in a link profile generated and managed by the SE layer 285. An example of information stored in the link configuration file generated by SE layer 285 in operation 415 is as follows. The link profile may be referred to as a "link ID".

Application layer user ID of terminal 110 (information received in operations 409 to 415)

Application layer user ID of terminal 120 (information received in operations 409 through 415)

Layer-2ID of terminal 110 (information received in operation 409)

Layer-2ID of terminal 120 (layer-2 ID assigned by terminal itself in operation 415)

Application IDs supported by direct communication links (corresponding to 315 in FIG. 3, for example)

One or more service types supported by the direct communication link (corresponding for example to 317 and 319 in fig. 3)

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

SE layer 285 may generate a direct communication response message for establishing a unicast link. The direct communication response message may include at least one of the "application message" received in operation 412, the "application ID", "service type" received in operation 412 or operation 409, the "application layer user ID" (application layer user identifier) of the transmitting terminal 110, the "application layer user ID" (application layer user identifier) of the receiving terminal 120, a "link ID" indicating a direct communication link, a "QoS requirement", "PQI", "QFI" that must be provided by the direct communication link, the "layer-2 ID" of the transmitting terminal 110, and the "layer-2 ID" of the receiving terminal 120. Examples of the information included in the direct communication response message are as follows.

-application data

Application layer user ID of terminal 110

Application layer user ID of terminal 120

-link ID indicating the direct communication link

-one or more QoS requirements supported by the direct communication link

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

The SE layer 285 may determine a source layer-2ID and a destination layer-2ID to be included in the MAC header in order to transmit the generated direct communication response message. The SE layer 285 may use a layer-2ID allocated by the terminal 120 itself as a source layer-2 ID. The source layer-2ID may be the same as the layer-2ID value of the terminal 120 stored in the link profile. In addition, the SE layer 285 may use the source layer-2ID of the direct communication request message received in operation 409 as the destination layer-2 ID. The destination layer-2ID may be the same as the layer-2ID value of the terminal 110 stored in the link profile.

The SE layer 285 may deliver information to the AS layer 205 for sending direct communication response messages. The information delivered to the AS layer 205 may include at least one of a direct communication response message, a source layer-2ID of the message, a destination layer-2ID of the message, a link ID, a PQI value, a QFI value, mapping information between PQI and QFI, a communication mode (e.g., PC5 broadcast), and a type of message (e.g., a signal (control) message). Examples of information that SE layer 285 delivers to AS layer 205 are AS follows.

-direct communication response message

Source layer-2ID of message

-destination layer-2ID of message

-a link ID indicating a direct communication link

-one or more PQI values supported by the direct communication link

-one or more QFI values supported by the direct communication link

-communication mode

Type of message

The AS layer 205 may store information received from the SE layer 285 and may manage a bypass radio bearer (SLRB) for direct communication. The method described in operation 406 may be applied to the relationship between SLRB management, SLRB, QFI, and PQI in a similar manner.

The AS layer 205 may configure the MAC header based on information received from the SE layer 285. The method described in operation 406 may be applied to the method of configuring the MAC header in a similar manner.

The AS layer 205 may configure the MAC header AS described above and may include the direct communication response message received from the SE layer 285 in the MAC payload, thereby transmitting the direct communication response message to the terminal 110 through the physical layer 265 (operation 418).

The SE layer 280 of the terminal 110 receiving the direct communication response message may determine that the received message is a PC5-S signaling message based on at least one of a destination layer-2ID address of the received message, a logical channel ID (lcid), or information received from the AS layer (e.g., an indicator indicating a PC5-S signaling message), and may process the received message AS follows. The SE layer 280 may identify that the received message is a direct communication response message and notify the application layer 270 that a direct communication link has been established. At this time, the SE layer 280 of the terminal 110 may further inform the application layer 270 of information (e.g., link ID, QFI, etc.) related to the established direct communication link. An example of information that the SE layer 280 delivers to the application layer 270 is as follows.

-direct communication link setup complete indication

-link ID indicating direct communication

QFI supported by direct communication

Mapping information between QFI and QoS requirements

Application data (in case data is received in operation 418)

Application layer user ID of terminal 110

Application layer user ID of terminal 120

Further, the SE layer 280 may inform the AS layer 200 of information about the established direct communication link (e.g., link ID, QFI information, etc.). Examples of information that the SE layer 280 delivers to the AS layer 200 are shown below. The AS layer 200 may store the received information and may use the received information for direct communication in the future.

-direct communication link setup complete indication

-link ID indicating direct communication

QFI supported by direct communication

-mapping information between QFI and PQI

Layer-2ID of terminal 110

Layer-2ID of terminal 120

The SE layer 280 may update the link profile information generated in operation 406 based on the information about the received direct communication response message. For example, the destination layer-2ID of the direct communication response message received in operation 418 may be stored as the "layer-2 ID" of the terminal 120. Further, if the information included in the direct communication response message received in operation 418 (e.g., "application layer user ID" (application layer user identifier), "QoS requirement," "PQI," "QFI," etc. of the terminal 120) does not match the link profile information generated in operation 406, the link profile information may be updated using the information received in operation 418.

Fig. 4B illustrates a process for transmitting data using a direct communication link according to an embodiment of the present disclosure.

Referring to fig. 4B, the terminal 110 and the terminal 120 may complete the establishment of the direct communication link through the procedure described with reference to fig. 4A. The terminal 110 and the terminal 120 may generate a link profile in the course of establishing the direct communication link and may store layer-2ID information on the terminal 110 and the terminal 120 for use in the direct communication link.

In operation 421, the terminal 120 may determine a destination layer-2ID for receiving data and signaling messages transmitted through the direct communication link generated through the process shown in fig. 4A. For example, the destination layer-2ID may be determined as the layer-2ID of the terminal 120 included in the corresponding link profile.

The application layer 270 of the terminal 110 may deliver to the SE layer 280 at least one of "application data" generated by the application layer 270 in operation 424, "link ID" indicating a direct communication link through which data is transmitted, "service type" indicating a type of data, "communication mode" indicating a communication method of data (e.g., broadcast, multicast, unicast, etc.), "application layer user ID" of the transmitting terminal 110 (application layer user identifier), "application layer user ID" of the receiving terminal 120 (application layer user identifier), "QoS requirements required to transmit data," PQI "required to transmit data, and" QFI "required to transmit data.

SE layer 280 may identify link profile information associated with the link ID received in operation 424. The SE layer 280 may determine a source layer-2ID and a destination layer-2ID for transmitting the "application data" received in operation 424. For example, the source layer-2ID may be determined using the layer-2ID of the terminal 110 stored in the link profile associated with the link ID. The destination layer-2ID may be determined using the layer-2ID of the terminal 120 stored in the link profile associated with the link ID (operation 427).

The SE layer 280 may determine the QFI for transmitting the application data received in operation 424 (operation 427). For example, SE layer 280 may use the QFI received in operation 424. Alternatively, SE layer 280 may determine a QFI corresponding to the PQI received in operation 424. To determine the QFI corresponding to the PQI, the SE layer 280 may use information preset in the terminal or mapping information between the PQI and the QFI stored in a link profile associated with the link ID. Alternatively, SE layer 280 may determine the QFI corresponding to the QoS requirements received in operation 424. To determine the QFI corresponding to the QoS requirement, the SE layer 280 may use information preset in the terminal or mapping information between the QoS requirement and the QFI stored in a link profile associated with the link ID.

The SE layer 280 may send at least one of the "application data" received in operation 424, the "source layer-2 ID" and the "destination layer-2 ID" determined in operation 427, a "link ID" associated with the corresponding direct communication link, a communication mode (e.g., PC5 unicast), and a type of message (e.g., a data (user plane) message) to the AS layer 200. Examples of information that the SE layer 280 delivers to the AS layer 200 are AS follows.

-application data

-link ID indicating direct communication

QFI required for direct communication

PQI required for direct communication

Mapping information between QFI and PQI required for direct communication

Source layer-2ID (i.e. layer-2ID of terminal 110)

Destination layer-2ID (i.e. layer-2ID of terminal 120)

-communication mode

-type of message

The AS layer 200 may configure the MAC header based on information delivered from the SE layer 280. The method described in operation 406 may be applied to the method of configuring the MAC header in a similar manner.

The source layer-2ID of the MAC header may be set to the layer-2ID of the terminal 110 received in operation 427. Alternatively, based on the link ID received in operation 427, the source layer-2ID of the MAC header may be set to the layer-2ID of the terminal 110 mapped to the link ID stored by the AS layer 200 in the procedure of fig. 4A.

The destination layer-2ID of the MAC header may be set to the layer-2ID of the terminal 120 received in operation 427. Alternatively, based on the link ID received in operation 427, the destination layer-2ID of the MAC header may be set to the layer-2ID of the terminal 120 mapped to the link ID stored by the AS layer 200 in the procedure of fig. 4A.

The AS layer 200 may determine the QFI used to transmit the application data received in operation 427. The QFI may be determined by the information received in operation 427 (e.g., QFI) or a combination of the information received in operation 427 (e.g., link ID) and the information stored by the AS layer 200 in the process of fig. 4A.

The AS layer 200 may determine the LCID based on the type of message (e.g., data) received in operation 427. The logical channel ID value used in the data message may be different from the logical channel ID value used in the signaling message. Further, the LCID may be set to a value indicating the QFI through which the message is transmitted.

The SDAP header and/or the MAC header may include at least one of a value indicating a QFI used to transmit the message and a value indicating a link ID.

The AS layer 200 may configure the MAC header AS described above and may include the application data received from the SE layer 280 in the MAC payload, thereby transmitting the application data to the terminal 120 through the physical layer 260 (operation 430).

The AS layer 205 of the terminal 120 receiving the "application data" may determine that the received message is a data message based on information (e.g., logical channel ID, etc.) included in the SDAP header and/or the MAC header of the received message. The AS layer 205 may deliver the received message to the SE layer 285. The SE layer 285 may determine whether the received message is a message for a direct communication link generated according to the above-described procedure based on the link ID, the destination layer-2ID, and/or the QFI information of the received message.

Further, SE layer 285 of terminal 120 may determine that the received message is a data message based on information (e.g., an SDAP header, a MAC header, etc.) received from AS layer 205.

Further, the SE layer 285 of the terminal 120 may determine a service type or an application ID of the received message based on the link ID, the destination layer-2ID, and/or QFI information of the received message. Based on this, the SE layer 285 may deliver the received "application data" to the application 315 of the corresponding application layer 275 or a service type included in the application (317 or 319). Alternatively, the SE layer 285 may deliver direct communication link information (e.g., link ID, service type, application ID, etc.) associated with the "application data" to the application layer 275.

Fig. 4C illustrates a process of updating a direct communication link according to an embodiment of the present disclosure.

Referring to fig. 4C, the terminal 110 and the terminal 120 may complete the establishment of the direct communication link through the procedure described with reference to fig. 4A. The terminal 110 and the terminal 120 may generate a link profile in the course of establishing the direct communication link and may store layer-2ID information on the terminal 110 and the terminal 120 for use in the direct communication link.

In operation 421, the terminal 120 may determine a destination layer-2ID for receiving data and signaling messages transmitted through the direct communication link generated through the process shown in fig. 4A. For example, the destination layer-2ID may be set to the layer-2ID of the terminal 120 included in the corresponding link profile.

The application layer 270 of the terminal 110 may deliver to the SE layer 280 at least one of "application data" generated by the application layer 270 in operation 433, "link ID" indicating a direct communication link through which data is transmitted, "service type" indicating a type of data, "communication mode" indicating a communication method of data (e.g., broadcast, multicast, unicast, etc.), "application layer user ID" of the transmitting terminal 110 "(application layer user identifier)," application layer user ID "of the receiving terminal 120" (application layer user identifier), "QoS requirement" required to transmit data, "PQI" required to transmit data, and "QFI" required to transmit data.

If there is a link profile including the application layer user ID of the transmitting terminal 110 and/or the application layer user ID of the receiving terminal 120 received from the application layer 270 in operation 433, the SE layer 280 may recognize that the terminal 110 and the terminal 120 have a pre-established direct communication link. Accordingly, the SE layer 280 may determine to reuse a pre-established direct communication link instead of establishing a new direct communication link, and may determine to perform the link update procedure shown in fig. 4B (operation 436). According to an embodiment of the present disclosure, in case of using one application layer user ID in one application, the terminal 110 may establish one direct communication link with the terminal 120 for each application. For example, one direct communication link may be generated for each application, and signaling and data for each application may be transmitted through one direct communication link. Alternatively, where an application layer user ID is used in one or more applications, terminal 110 may establish a direct communication link with terminal 120 for applications sharing the application layer user ID. For example, applications sharing an application layer user ID may share a direct communication link, and signaling and data for the applications may be sent over the direct communication link. Alternatively, in case one application layer user ID is used in all applications, one direct communication link may be established between the terminal 110 and the terminal 120, so that signaling and data for all applications supported by the terminal 110 and the terminal 120 are transmitted through one direct communication link.

SE layer 280 may determine to perform a link update procedure (operation 436) if there is no service type received in operation 433 in the link profile associated with the link ID and/or if there is no PQI and/or QFI mapped to the QoS requirements in the link profile associated with the link ID.

SE layer 280 may determine a new PQI and/or a new QFI that satisfy the QoS requirements received in operation 433 in a manner similar to the method described with reference to fig. 4A.

SE layer 280 may generate a link update request message. The link update request message may include at least one of a link ID, new PQI and QFI determined by SE layer 280, and mapping information between PQI and QFI.

To send the link update request message, SE layer 280 may determine the source layer-2ID and the destination layer-2ID similar to the method described with reference to fig. 2B.

The SE layer 280 may send at least one of a "link update request message," the "source layer-2 ID" and the "destination layer-2 ID" determined in operation 436, a "link ID" associated with the corresponding direct communication link, a communication mode (e.g., PC5 unicast), and a type of message (e.g., PC5-S signaling message) to the AS layer 200. An example of the information that the SE layer 280 delivers to the AS layer 200 is AS follows.

-a link update request message

-link ID indicating direct communication

Additional application IDs required for direct communication

Additional QFI required for direct communication

Additional PQIs required for direct communication

Mapping information between additional QFIs and additional PQIs required for direct communication

Source layer-2ID (i.e. layer-2ID of terminal 110)

Destination layer-2ID (i.e. layer-2ID of terminal 120)

-a communication mode.

Type of message

The source layer-2ID of the MAC header may be set to the layer-2ID of the terminal 110 received in operation 436. Alternatively, with reference to the link ID received in operation 436, the source layer-2ID of the MAC header may be set to the layer-2ID of the terminal 110 mapped to the link ID stored by the AS layer 200 in the procedure of fig. 4A.

The destination layer-2ID of the MAC header may be set to the layer-2ID of the terminal 120 received in operation 436. Alternatively, with reference to the link ID received in operation 436, the destination layer-2ID of the MAC header may be set to the layer-2ID of the terminal 120 mapped to the link ID stored by the AS layer 200 in the procedure of fig. 4A.

The AS layer 200 may determine the LCID based on the type of message (e.g., signaling) received in operation 436. The logical channel ID value used in the signaling message may be different from the logical channel ID value used in the data message.

The AS layer 200 may configure the MAC header AS described above and may include the link update request message received from the SE layer 280 in the MAC payload, thereby transmitting the link update request message to the terminal 120 through the physical layer 260 (operation 439).

The terminal 120 receiving the link update request message may perform a link update corresponding to the link update request message (operation 442).

The AS layer 205 of the terminal 120 receiving the link update request message may determine that the received message is a signaling message based on a logical channel ID of a MAC header of the received message. The AS layer 205 may deliver the received message to the SE layer 285. The SE layer 285 may determine whether the received message is a signaling message for a direct communication link generated according to the above-described procedure based on the link ID, the destination layer-2ID, and/or QFI information of the received message.

Further, the SE layer 285 of the terminal 120 may determine that the received message is a signaling message based on the LCID of the message.

SE layer 285 of terminal 120 may store the new QoS information (e.g., QoS requirements, PQI, QFI, etc.) included in the received message in a link profile associated with the link ID.

The SE layer 285 may deliver the changed QoS information to the application layer 275.

Further, SE layer 285 may deliver the link ID of the direct communication link and the changed QoS information related to the corresponding direct communication link to AS layer 205. The AS layer 205 may store the received link ID, may update QoS information (e.g., the new PQI and the QFI corresponding to the new PQI), and may use the QoS information for direct communication in the future.

The AS layer (205) may transmit a link update response message including the changed QoS information received from the SE layer (285) to the terminal (110) (operation 445). The method described in operation 418 may be applied in a similar manner to operation 445.

Fig. 5A is a schematic diagram illustrating generating a direct communication link according to an embodiment of the present disclosure.

Fig. 5B is a schematic diagram illustrating generating a direct communication link according to an embodiment of the present disclosure.

Fig. 6A is a schematic diagram illustrating QoS Flow Identifier (QFI) mapping in relation to a direct communication link, according to an embodiment of the present disclosure.

Fig. 6B is a schematic diagram illustrating QFI mapping in relation to a direct communication link according to an embodiment of the present disclosure.

Fig. 7A is a schematic diagram illustrating a bypass radio bearer (SLRB) mapping in relation to a direct communication link, according to an embodiment of the present disclosure.

Fig. 7B is a schematic diagram illustrating a bypass radio bearer (SLRB) mapping associated with a direct communication link according to an embodiment of the present disclosure.

Fig. 8 is a schematic diagram illustrating a configuration of a Medium Access Control (MAC) Protocol Data Unit (PDU) according to an embodiment of the present disclosure.

Fig. 9 is a schematic diagram illustrating a configuration of a subheader of a bypass shared channel (SL-SCH) according to an embodiment of the present disclosure.

Fig. 10 is a block diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure.

The communication system 130 may comprise a network entity according to an embodiment.

Referring to fig. 10, the network entity may include a transceiver 1010, a controller 1020, and a storage unit 1030. The transceiver 1010, the controller 1020, and the storage unit 1030 of the network entity may operate according to the above-described communication method of the network entity. However, the configuration of the network entity is not limited to the above example. For example, a network entity may include more or fewer components than those described above. Further, the transceiver 1010, the controller 1020, and the storage unit 1030 may be implemented in a single chip. Further, the controller 1020 may include at least one processor.

The receiver 1016 of the network entity and the transmitter 1013 of the network entity may be collectively referred to as a "transceiver 1010" that may transmit and receive signals. The transmitted and received signals may include control information and data. To this end, the transceiver 1010 may include an RF transmitter for up-converting and amplifying a frequency of a transmission signal and an RF receiver for low-noise amplifying a reception signal and down-converting a frequency thereof. However, this is merely an example of the transceiver 1010, and the components of the transceiver 1010 are not limited to RF transmitters and RF receivers.

Further, the transceiver 1010 may receive a signal through a wireless channel to output the signal to the controller 1020, and may transmit the signal output from the controller 1020 through the wireless channel.

The storage unit 1030 may store programs and data required for the operation of the network entity. In addition, the storage unit 1030 may store control information or data included in a signal obtained from a network entity. The controller 1020 may include a storage medium such as Read Only Memory (ROM), Random Access Memory (RAM), a hard disk, a compact disk-ROM (CD-ROM), and a Digital Versatile Disk (DVD), or a combination of storage media.

The controller 1020 may control a series of processes so that the network entity may operate according to the above-described embodiments. For example, the controller 1020 may receive control signals and data signals through the transceiver 1010 and may process the received control signals and data signals. In addition, the controller 1020 may transmit the processed control signals and data signals through the transceiver 1010.

Fig. 11 is a block diagram illustrating a configuration of a terminal according to an embodiment of the present disclosure

Referring to fig. 11, a block diagram of an internal structure of the terminal 110, the terminal 115, the terminal 120, or the terminal 125 is shown. The terminal may include a transceiver 1110, a controller 1120, and a storage unit 1130.

The transceiver 1110, the controller 1120, and the storage unit 1130 of the terminal may operate according to the above-described communication method of the terminal. However, the configuration of the terminal is not limited to the above example. For example, a terminal may include more or fewer components than those described above. Further, the transceiver 1110, the controller 1120, and the storage unit 1130 may be implemented in a single chip. Further, the controller 1120 may include at least one processor.

The receiver 1116 of the terminal and the transmitter 1113 of the terminal may be collectively referred to as a "transceiver 1110" that may transmit and receive signals to and from a base station. The signals transmitted to and received from the base station may include control information and data. To this end, the transceiver 1110 may include an RF transmitter for up-converting and amplifying a frequency of a transmission signal and an RF receiver for low-noise amplifying a reception signal and down-converting a frequency thereof. However, this is merely an example of the transceiver 1110, and the components of the transceiver 1110 are not limited to an RF transmitter and an RF receiver.

In addition, the transceiver 1110 may receive a signal through a wireless channel to output the signal to the controller 1120, and may transmit the signal output from the controller 1120 through a wireless channel.

The storage unit 1130 may store programs and data required for the operation of the terminal. In addition, the storage unit 1130 may store control information or data included in a signal obtained from the terminal. The controller 1120 may include a storage medium (such as ROM, RAM, hard disk, CD-ROM, and DVD) or a combination of storage media.

The controller 1120 may control a series of processes so that the terminal can operate according to the above-described embodiments. For example, the controller 1120 may receive control signals and data signals through the transceiver 1110 and may process the received control signals and data signals. In addition, the controller 1120 may transmit the processed control signals and data signals through the transceiver 1110.

While the 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 therein without departing from the spirit and scope of the disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a first terminal in a wireless communication system, the method comprising:

establishing a unicast link with a second terminal for a first service of a first service type, wherein the unicast link supports a plurality of service types associated with a same application layer ID of the first terminal having one or more application layer identifier IDs, and the first service type is associated with a first application layer ID pair between the application layer ID of the first terminal and the application layer ID of the second terminal;

in the event of initiating data transfer for a second service of a second service type, determining whether a second application layer ID pair associated with the second service type is the same as a first application layer ID pair of the first terminal and the second terminal;

determining to reuse the established unicast link if the second application layer ID pair associated with the second service type is the same as the first application layer ID pair for the first and second terminals; and

modifying the established unicast link by adding the second service type to a unicast link established with the second terminal.

2. The method of claim 1, further comprising:

in the case where the unicast link is established, allocating a link identifier for the unicast link,

wherein the unicast link is associated with a unicast link profile, wherein the unicast link profile comprises the plurality of service types, the application Layer IDs of the first and second terminals, the Layer-2 IDs of the first and second terminals, and the quality of service QoS flow identifier QFI for each of the plurality of service types.

3. The method of claim 2, further comprising:

delivering, by a service-enabled SE Layer, the link identifier and information about the unicast link to an Access Stratum (AS) Layer, wherein the information about the unicast link comprises Layer-2ID information of a first terminal and a second terminal;

maintaining, by an AS layer, the link identifier and the information about the unicast link to reuse the unicast link; and

performing data communication with a second terminal via the unicast link using the Layer-2ID information.

4. The method of claim 3, wherein the modifying the established unicast link comprises:

a link modification request message is sent to the second terminal,

wherein the link modification request message includes information on the second service type and information on a QoS flow for the second service type,

wherein the unicast link profile is updated based on the link modification request message, and

wherein the second service type is added to the unicast link based on the link modification request message.

5. A method performed by a second terminal in a wireless communication system, the method comprising:

establishing a unicast link with a first terminal for a first service of a first service type, wherein the unicast link supports a plurality of service types associated with a same application layer ID of a second terminal having one or more application layer identifier IDs, and the first service type is associated with a first application layer ID pair between the application layer ID of the first terminal and the application layer ID of the second terminal; and

modifying the established unicast link, in case of initiating a data transfer for the service, to reuse the established unicast link for a second service of a second service type,

wherein, in case a second application layer ID pair associated with the second service type is the same as a first application layer ID pair for a first terminal and a second terminal, it is determined to reuse the established unicast link for the second service, and

wherein the established unicast link is modified by adding the second service type to the unicast link established with the first terminal.

6. The method of claim 5, wherein the first and second light sources are selected from the group consisting of,

wherein in case of establishing the unicast link, a link identifier is allocated for the unicast link, and

7. The method of claim 6, further comprising:

performing data communication with the first terminal via the unicast link using the Layer-2ID information.

8. A first terminal in a wireless communication system, the first terminal comprising:

a transceiver configured to transmit and receive signals; and

a controller coupled with the transceiver and configured to:

establishing a unicast link with a second terminal for a first service of a first service type, wherein the unicast link supports a plurality of service types associated with a same application layer ID of the first terminal having one or more application layer identifier IDs, and the first service type is associated with a first application layer ID pair between the application layer ID of the first terminal and the application layer ID of the second terminal,

in the event of initiating data transfer for a second service of a second service type, determining whether a second application layer ID pair associated with the second service type is the same as a first application layer ID pair for the first terminal and the second terminal;

modifying the established unicast link by adding the second service type to the unicast link established with the second terminal.

9. The first terminal of claim 8,

wherein the controller is further configured to, in case the unicast link is established, assign a link identifier for the unicast link, and

10. The first terminal of claim 9, wherein the controller is further configured to:

delivering, by a service-enabled SE Layer, the link identifier and information about the unicast link to an Access Stratum (AS) Layer, wherein the information about the unicast link includes Layer-2ID information of a first terminal and a second terminal,

maintaining, by an AS layer, the link identifier and the information about the unicast link to reuse the unicast link, an

Performing data communication with the second terminal via the unicast link using the Layer-2ID information.

11. The first terminal of claim 10,

wherein the controller is further configured to transmit a link modification request message to the second terminal,

12. A second terminal in a wireless communication system, the second terminal comprising:

a transceiver configured to transmit and receive a signal; and

a controller coupled with the transceiver and configured to:

wherein, in case a second application layer ID pair associated with the second service type is the same as a first application layer ID pair of a first terminal and a second terminal, it is determined that the unicast link established for the second service reuse, and

13. The second terminal according to claim 12,

14. The second terminal of claim 13, wherein the controller is further configured to:

15. The second terminal according to claim 14,

wherein the controller is further configured to receive a link modification request message from the first terminal,