KR102711003B1 - Apparatus and method for supporting direct communication service in wireless communication system - Google Patents

Abstract

The present disclosure relates to a communication technique and system thereof that fuses a 5G communication system for supporting a higher data transmission rate than a 4G system with IoT technology. The present disclosure can be applied to intelligent services (e.g., smart home, smart building, smart city, smart car or connected car, healthcare, digital education, retail, security and safety-related services, etc.) based on 5G communication technology and IoT-related technology. The present disclosure discloses a method and device for providing a direct communication service.

Description

{APPARATUS AND METHOD FOR SUPPORTING DIRECT COMMUNICATION SERVICE IN WIRELESS COMMUNICATION SYSTEM}

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

In order to meet the increasing demand for wireless data traffic since the commercialization of 4G communication systems, efforts are being made to develop improved 5G communication systems or pre-5G communication systems. For this reason, 5G communication systems or pre-5G communication systems are also called Beyond 4G Network communication systems or Post LTE systems.

To achieve high data rates, 5G communication systems are being considered for implementation in ultra-high frequency (mmWave) bands (e.g., 60 gigahertz (GHz) bands). To mitigate radio path loss and increase the transmission range of radio waves in ultra-high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna technologies are being discussed in 5G communication systems.

In addition, for network improvement of the system, the technologies such as evolved small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network, device to device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation are being developed in the 5G communication system. In addition, the advanced coding modulation (ACM) methods such as FQAM (Hybrid FSK and QAM Modulation) and SWSC (Sliding Window Superposition Coding), and the advanced access technologies such as FBMC (Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and SCMA (sparse code multiple access) are being developed in the 5G system.

Meanwhile, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network where information is exchanged and processed between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, is also emerging. In order to implement IoT, technological elements such as sensing technology, wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, technologies such as sensor networks for connecting objects, Machine to Machine (M2M), and Machine Type Communication (MTC) are being studied.

In the IoT environment, intelligent IT (Internet Technology) services can be provided that collect and analyze data generated from connected objects to create new values in human life. IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart home appliances, and advanced medical services through convergence and combination between existing IT (information technology) technologies and various industries.

Accordingly, various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine (M2M), and machine-type communication (MTC) are being implemented by 5G communication technologies such as beam forming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology described above can also be said to be an example of the convergence of 5G and IoT technologies.

V2X (Vehicle to Everything) is a general term that refers to all forms of communication methods applicable to road vehicles. With the advancement of wireless communication technology, various additional services are becoming possible in addition to the initial safety use cases.

The WAVE (Wireless Access in Vehicular Environments) standard based on IEEE 802.11p and IEEE P1609 has been standardized as a V2X service provision technology. However, WAVE, a type of DSRC (Dedicated Short Range Communication) technology, has the limitation that the message transmission distance between vehicles is limited.

To overcome these limitations, cellular-based V2X technology standards are being developed in 3GPP. The LTE system-based EPS (Evolved Packet System) V2X standard was completed in Release 14/Release 15, and the NR system-based 5GS (5th Generation System) V2X standard is being developed in Release 16.

According to one embodiment of the present disclosure, a method and device for providing a direct communication service in a wireless communication system can be provided.

The present invention for solving the above problems is characterized by a method for processing a control signal in a wireless communication system, comprising: a step of receiving a first control signal transmitted from a base station; a step of processing the received first control signal; and a step of transmitting a second control signal generated based on the processing to the base station.

According to one embodiment of the present disclosure, a device and method capable of effectively providing a direct communication service in a wireless communication system can be provided.

FIG. 1 illustrates a configuration of a vehicle communication system according to one embodiment of the present disclosure.
FIG. 2a illustrates a control plane protocol stack of a terminal according to one embodiment of the present disclosure.
FIG. 2b illustrates a user plane protocol stack of a terminal according to one embodiment of the present disclosure.
FIG. 3 illustrates a configuration of a direct communication link connection according to one embodiment of the present disclosure.
FIG. 4a illustrates a direct communication link connection establishment procedure according to one embodiment of the present disclosure.
FIG. 4b illustrates a data transmission procedure using a direct communication link according to one embodiment of the present disclosure.
FIG. 4c illustrates a direct communication link update procedure according to one embodiment of the present disclosure.
FIG. 4da is a diagram illustrating an example of creating a direct communication link according to one embodiment of the present disclosure.
FIG. 4db is a diagram illustrating an example of creating a direct communication link according to one embodiment of the present disclosure.
FIG. 4dc is a diagram illustrating an example of QFI (QoS flow Identifier) mapping associated with a direct communication link according to one embodiment of the present disclosure.
FIG. 4DD is a diagram illustrating an example of QFI mapping related to a direct communication link according to one embodiment of the present disclosure.
FIG. 4de is a diagram illustrating an example of sidelink radio bearer (SLRB) mapping associated with a direct communication link according to one embodiment of the present disclosure.
FIG. 4df is a diagram illustrating an example of sidelink radio bearer (SLRB) mapping associated with a direct communication link according to one embodiment of the present disclosure.
FIG. 4dg is a diagram illustrating an example of a configuration of a MAC (medium access control) PDU (protocol data unit) according to an embodiment of the present disclosure.
FIG. 4dh is a diagram illustrating an example of a subheader configuration of a SL-SCH (sidelink - shared channel) according to an embodiment of the present disclosure.
FIG. 5a is a block diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure.
FIG. 5b is a block diagram showing the configuration of a terminal according to one embodiment of the present disclosure.

Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the attached drawings. In the following description of the present disclosure, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions in the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are given the same reference numbers.

The advantages and features of the present disclosure, and the methods for achieving them, will become apparent by referring to the embodiments described in detail below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the embodiments are provided only to make the present disclosure complete and to fully inform those skilled in the art of the scope of the invention, and the present disclosure is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to a computer or other programmable data processing equipment to implement the function in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured article including an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may also be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementation examples, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

Here, the term '~ part' used in this embodiment means a software or hardware component such as an FPGA or ASIC, and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Thus, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~ parts' may be implemented to reproduce one or more CPUs in a device or a secure multimedia card. Additionally, in the embodiment, '~bu' may include one or more processors.

In the following description, terms used to identify connection nodes, terms referring to network entities, terms referring to messages, terms referring to interfaces between network entities, terms referring to various identification information, etc. are examples for convenience of explanation. Therefore, the present disclosure is not limited to the terms described below, and other terms referring to objects having equivalent technical meanings may be used.

For convenience of explanation below, this disclosure uses terms and names defined in the standards for 5G, NR (New Radio), and LTE (Long Term Evolution) systems. However, this disclosure is not limited by the terms and names, and can be equally applied to systems that comply with other standards.

In specifically explaining the embodiments of the present disclosure, the communication standards specified by 3GPP will be the main target, but the main gist of the present disclosure can be applied to other communication systems having similar technical backgrounds with slight modifications without significantly departing from the scope of the present disclosure, and this can be done at the discretion of a person skilled in the technical field of the present disclosure.

In specifically explaining the embodiments of the present disclosure, the main target will be a vehicle communication service, but the main gist of the present disclosure can be applied to other services provided in a 5G network with slight modifications without significantly departing from the scope of the present disclosure, and this can be done at the discretion of a person skilled in the art having technical knowledge in the technical field of the present disclosure.

In the 5G system, support for various services is being considered compared to the existing 4G system. For example, the most representative services may include enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), massive machine type communication (mMTC), and evolved multimedia broadcast/multicast service (eMBMS). In addition, a system that provides URLLC service may be called a URLLC system, and a system that provides eMBB service may be called an eMBB system. In addition, the terms service and system may be used interchangeably.

Among these, URLLC service is a new service that is being considered in 5G system, unlike existing 4G system, and requires ultra-high reliability (e.g. packet error rate of about 10-5) and low latency (e.g. about 0.5 msec) conditions compared to other services. In order to satisfy these strict requirements, URLLC service may need to apply shorter transmission time interval (TTI) than eMBB service, and various operation methods utilizing this are being considered.

Meanwhile, the Internet is evolving from a human-centered connection network where humans create and consume information to an Internet of Things (IoT) network where information is exchanged and processed between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection to cloud servers, is also emerging. In order to implement IoT, technological elements such as sensing technology, wireless communication and network infrastructure, service interface technology, and security technology are required. Recently, technologies such as sensor networks for connecting objects, Machine to Machine (M2M), and Machine Type Communication (MTC) are being studied.

FIG. 1 illustrates a configuration of a vehicle communication system according to one embodiment of the present disclosure.

Referring to FIG. 1, a terminal (which may be used interchangeably with user equipment, user terminal, terminal, or vehicle UE, 110) may use direct communication (e.g., Device-to-Device, D2D, ProSe, PC5, Sidelink communication, 140) to communicate with another terminal (120) or may use network communication (150, 160) via a mobile communication system (130). In the case of direct communication, message transmission and reception between the terminal (110) and another terminal (120) may be performed via a PC5 link. In the case of network communication, a message sent by a transmitting vehicle terminal to a receiving vehicle terminal may be transmitted to a network via a Uu link and then delivered to the receiving vehicle terminal via the Uu link. The mobile communication system (130) may be an EPC system or a 5GC system defined by 3GPP or a communication system other than 3GPP. Direct communication (140) can be provided using non-3gpp RAT such as LTE RAT (Radio Access Technology) or NR RAT or WiFi.

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, but for convenience of explanation, they will be referred to as terminal (110) and terminal (120), respectively.

Referring to FIG. 2a, the control plane protocol stack of the terminal (110, 120) may be composed of a PC5 signaling protocol layer (PC5 Signaling Protocol layer, 210, 215), an RRC layer (RRC layer, 220, 225), a PDCP layer (PDCP layer, 230, 235), an RLC layer (RLC layer, 240, 245), a MAC layer (MAC layer, 250, 255), and a PHY layer (PHY layer, 260, 265). The RRC layer (220, 225), the PDCP layer (230, 235), the RLC layer (240, 245), and the MAC layer (250, 255) may be collectively referred to as an AS layer (Access Stratum layer, 200, 205). In describing the present invention below, the AS layer (200, 205) may include at least one of an RRC layer (220, 225), a PDCP layer (230, 235), an RLC layer (240, 245), and a MAC layer (250, 255).

The PC5 signaling protocol layer (210, 215) can provide link establishment and link maintenance functions for direct communication (140) between a terminal (110) and a terminal (120) through the procedures illustrated in FIGS. 4a, 4b, and 4c.

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

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

Referring to FIG. 2b, the user plane protocol stack of the terminal (110, 120) may be composed of an application layer (Application layer, 270, 275), a Service Enabling layer (SE layer, 280, 285), an SDAP layer (SDAP layer, 290, 295), a PDCP layer (PDCP layer, 230, 235), an RLC layer (RLC layer, 240, 245), a MAC layer (MAC layer, 250, 255), and a PHY layer (PHY layer, 260, 265). The SDAP layer (290, 295), the PDCP layer (230, 235), the RLC layer (240, 245), and the MAC layer (250, 255) may be collectively referred to as an Access Stratum layer (AS layer, 200, 205). In describing the present invention below, the AS layer (200, 205) may include at least one of the SDAP layer (290, 295), the PDCP layer (230, 235), the RLC layer (240, 245), and the MAC layer (250, 255).

The SE layer (280, 285) is an intermediate layer for performing the operation of the application layer (270, 275) and can provide specialized functions for each application or each service. One SE layer can support multiple application layers. In addition, a specialized SE layer can be defined for each application layer. For example, for providing V2X service, the application layer (270, 275) can be a V2X application layer. In addition, for the operation of the V2X application layer, the SE layer (280, 285) can be defined as a V2X layer. Hereinafter, for providing V2X service, the application layer (270, 275) can be used interchangeably with the V2X application layer, and the SE layer (280, 285) can be used interchangeably with the V2X layer.

The SE layer (280, 285) can provide a data transmission function on a link established for direct communication (140) between the terminal (110) and the terminal (120). The SE layer (280, 285) can include an IP protocol for message transmission, a non-IP protocol, a transport protocol (e.g., TCP or UDP), etc.

A terminal (110, 120) according to an embodiment of the present disclosure can obtain and store the following information shown in Table 1 in order to use a V2X service. The SE layer (280, 285) can use the stored information.

- When the UE is "served by E-UTRA" or "served by NR":

- PLMNs in which the UE is authorized to perform V2X communications over PC5 reference point when "served by E-UTRA" or "served by NR".
For each above PLMN:

- RAT(s) over which the UE is authorized to perform V2X communications over PC5 reference point.

- When the UE is "not served by E-UTRA" and "not served by NR":

- Indicates whether the UE is authorized to perform V2X communications over PC5 reference point when "not served by E-UTRA" and "not served by NR".

- RAT(s) over which the UE is authorized to perform V2X communications over PC5 reference point.
2) Radio parameters when the UE is "not served by E-UTRA" and "not served by NR":

- Includes the radio parameters per PC5 RAT (i.e. LTE PC5, NR PC5) with Geographical Area(s) and an indication of whether they are "operator managed" or "non-operator managed". The UE uses the radio parameters to perform V2X communications over PC5 reference point when "not served by E-UTRA" and "not served by NR" only if the UE can reliably locate itself in the corresponding Geographical Area. Otherwise, the UE is not authorized to transmit.

NOTE: Whether a frequency band is "operator managed" or "non-operator managed" in a given Geographical Area is defined by local regulations.
3) Policy/parameters per RAT for PC5 Tx Profile selection:

- The mapping of service types (e.g. PSID or ITS-AIDs) to Tx Profiles.
4) Policy/parameters related to privacy:

- The list of V2X services, e.g. PSID or ITS-AIDs of the V2X applications, with Geographical Area(s) that require privacy support.
5) Policy/parameters when NR PC5 is selected:

- The mapping of service types (e.g. PSID or ITS-AIDs) to V2X frequencies with Geographical Area(s).

- The mapping of Destination Layer-2 ID(s) and the V2X services, e.g. PSID or ITS-AIDs of the V2X application for broadcast.

- The mapping of Destination Layer-2 ID(s) and the V2X services, e.g. PSID or ITS-AIDs of the V2X application for groupcast.

- The mapping of default Destination Layer-2 ID(s) for initial signaling to establish unicast connection and the V2X services, e.g. PSID or ITS-AIDs of the V2X application.

- The list of V2X services that are allowed to use a specific PQI(s)1) Authorization policy:

- When the UE is "served by E-UTRA" or "served by NR":

- PLMNs in which the UE is authorized to perform V2X communications over PC5 reference point when "served by E-UTRA" or "served by NR".
For each above PLMN:

- RAT(s) over which the UE is authorized to perform V2X communications over PC5 reference point.

- When the UE is "not served by E-UTRA" and "not served by NR":

- Indicates whether the UE is authorized to perform V2X communications over PC5 reference point when "not served by E-UTRA" and "not served by NR".

- RAT(s) over which the UE is authorized to perform V2X communications over PC5 reference point.
2) Radio parameters when the UE is "not served by E-UTRA" and "not served by NR":

- Includes the radio parameters per PC5 RAT (ie LTE PC5, NR PC5) with Geographical Area(s) and an indication of whether they are "operator managed" or "non-operator managed". The UE uses the radio parameters to perform V2X communications over PC5 reference point when "not served by E-UTRA" and "not served by NR" only if the UE can reliably locate itself in the corresponding Geographical Area. Otherwise, the UE is not authorized to transmit.

NOTE: Whether a frequency band is “operator managed” or “non-operator managed” in a given Geographical Area is defined by local regulations.
3) Policy/parameters per RAT for PC5 Tx Profile selection:

- The mapping of service types (eg PSID or ITS-AIDs) to Tx Profiles.
4) Policy/parameters related to privacy:

- The list of V2X services, eg PSID or ITS-AIDs of the V2X applications, with Geographical Area(s) that require privacy support.
5) Policy/parameters when NR PC5 is selected:

- The mapping of service types (eg PSID or ITS-AIDs) to V2X frequencies with Geographical Area(s).

- The mapping of Destination Layer-2 ID(s) and the V2X services, eg PSID or ITS-AIDs of the V2X application for broadcast.

- The mapping of Destination Layer-2 ID(s) and the V2X services, eg PSID or ITS-AIDs of the V2X application for groupcast.

- The mapping of default Destination Layer-2 ID(s) for initial signaling to establish unicast connection and the V2X services, eg PSID or ITS-AIDs of the V2X application.

- The list of V2X services that are allowed to use a specific PQI(s)

The SDAP layer (290, 295) can be used when transmitting data through direct communication (140) between terminals (110) and (120). For example, when transmitting data through the established link after establishing a direct communication (140) link connection between terminals (110) and (120) (for example, PC5 unicast communication or PC5 groupcast), the SDAP layer (290, 295) can be used for message transmission. In addition, for example, when transmitting data without establishing a direct communication (140) link connection between terminals (110) and (120) (for example, PC5 broadcast communication), the SDAP layer (290, 295) can be used for message transmission.

The PC5 signaling protocol layer (210, 215) according to an embodiment of the present disclosure may include functions provided by the SE layer (280, 285). Alternatively, the PC5 signaling protocol layer (210, 215) may interact with the SE layer (280, 285) and/or the RRC layer (220, 225) and/or the PDCP layer (230, 235) and/or the SDAP layer (290, 295) for link connection establishment and/or link connection management.

A terminal (110, 120) according to an embodiment of the present disclosure may store the following information as shown in Table 2 in order to provide a service (e.g., V2X service) using direct communication. The SE layer (280, 285) may use the stored information.

PQI
Value Resource Type Default Priority Level Packet Delay Budget Packet Error
Rate Default Maximum Data Burst Volume
Default
Averaging Window Example Services 1
GBR 3 20 ms
10 ^-4 N/A 2000 ms Platooning between UEs - Higher degree of automation;
Platooning between UE and RSU - Higher degree of automation;
2
(NOTE 1) 4 50 ms 10 ^-2 N/A 2000 ms Sensor sharing - higher degree of automation 3 3 100 ms 10 ^-4 N/A 2000 ms Information sharing for automated driving - between UEs or UE and RSU - higher degree of automation;
55 Non-GBR 3 10 ms 10 ^-4 N/A N/A Cooperative lane change - higher degree of automation; 56 6 20 ms 10 ^-1 N/A N/A Platooning informative exchange - low degree of automation;
Platooning - information sharing with RSU; 57 5 25 ms 10 ^-1 N/A N/A Cooperative lane change - lower degree of automation; 58 4 100 ms 10 ^-2 N/A N/A Sensor information sharing - lower degree of automation 59 6 500 ms 10 ^-1 N/A N/A Platooning - reporting to an RSU;
82 Delay Critical GBR 3 10 ms
10 ^-4 2000 bytes 2000 ms cooperative collision avoidance;
Sensor sharing - Higher degree of automation;
Video sharing - higher degree of automation;
83 (NOTE 1) 2 3 ms 10 ^-5 2000 bytes 2000 ms Emergency trajectory alignment;
Sensor sharing - Higher degree of automation
NOTE 1: GBR and Delay Critical GBR PQIs can only be used for unicast PC5 communications.
Editor's Note: It is FFS if GBR and Delay Critical GBR can also be used for broadcast and groupcast.
NOTE 2: The MBDV value for Non-GBR PQIs is an informative indication of typical packet size.

Referring to Table 2, a QoS parameter can be composed of one or more QoS characteristics. The QoS characteristics can be, for example, Priority Level, Packet Delay Budget, Packet Error Rate, Maximum Data Burst Volume, Averaging Window, and Communication Range. A QoS parameter can be composed of one or more QoS characteristics and can be referred to as a PQI (5QI for PC5) value.

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

Referring to FIG. 3, terminals (110) and terminals (120) can store and run the same application (310, 315). Applications can be distinguished by application IDs (e.g., OSAppID, etc.). The applications (310, 315) can provide one or more services. That is, for example, the applications (310, 315) can include service type #1 (312, 317) and service type #2 (314, 319). Each service type can be distinguished by a service type ID (e.g., PSID, ITS-AID, etc.).

A terminal according to an embodiment of the present invention has one or more applications installed, and one or more applications can be run simultaneously. The application layer user ID (e.g., terminal ID, terminal subscriber ID, user email address, etc.) associated with each application can be used in various ways as follows.

For example, one application layer user ID can be used in one application. At this time, the application layer user ID can be assigned as a unique value for each user and application. Referring to FIG. 3, if Application#1 (310), Application#2, and Application#3 are installed in the terminal (110), each application Application#1 (310), Application#2, and Application#3 can be distinguished by the application layer user ID. In this case, the SE layer (280) can distinguish each application (Application#1 (310), Application#2, and Application#3) by the application layer user ID.

Alternatively, one application layer user ID may be used by more than one application. That is, one or more applications may share one application layer user ID. Referring to FIG. 3, if Application#1 (310), Application#2, and Application#3 are installed in the terminal (110), Application#1 (310) and Application#2 may use one application layer user ID, and Application#3 may use another application layer user ID. In this case, the SE layer (280) may distinguish Application#1 (310) and Application#2 with the same one application layer user ID, and may distinguish Application#3 with one application layer user ID.

Alternatively, one application layer user ID may be used in all applications. That is, all applications may share one application layer user ID. Referring to FIG. 3, if Application#1 (310), Application#2, and Application#3 are installed in the terminal (110), all applications installed in the terminal (110) may use one application layer user ID. That is, each application may not be additionally distinguished by using the application layer user ID. In this case, the SE layer (280) may know and use that one application layer user ID is applied to all applications of the terminal (110).

In explaining the present invention below, the operation of the application (310, 315) and/or service type (312, 314, 317, 319) can be understood as the operation of the application layer (270, 275) illustrated in Fig. 2b. One or more applications and/or service types can be driven in the application layer (270, 275).

A service type may have one or more QoS requirements. The SE layer (280, 285) may determine QoS parameters to satisfy the QoS requirements provided by the application (310, 315) and/or the service type (312, 314, 317, 319) and map them to the PQI values shown in Table 2.

The terminal (110) and the terminal (120) can establish a direct communication link (330) using the procedures illustrated in FIGS. 4a, 4c, and 4d. The direct communication link (330) may be referred to as a link ID. According to an embodiment of the present invention, the terminal (110) and the terminal (120) can establish one direct communication link (330) per application (310, 315) and provide one or more service types (e.g., PSID, ITS-AID, etc.) on the direct communication link (330). That is, as in FIG. 4d, one application can have one direct communication link.

Alternatively, according to an embodiment of the present invention, the terminal (110) and the terminal (120) can establish a direct communication link (330) for each service type (312, 317, 314, 319). One application including multiple service types can create a direct communication link (330) supporting each service type, and provide each service type (e.g., PSID, ITS-AID, etc.) on each direct communication link. That is, as in FIG. 4db, one application can have as many direct communication links as the number of service types it supports.

The above direct communication link (330) may include one or more QoS Flows. The QoS Flows may be mapped to the PQI values 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). Each QoS Flow constituting the direct communication link (330) may provide different levels of QoS. The direct communication link (330) connection procedure is described in detail in FIG. 4a.

The terminals (110, 120) can transmit data using the procedure illustrated in FIG. 4b. The terminals (110, 120) can transmit data using QoS Flow included in the direct communication link (330) for data transmission. The SE layer (280, 285) can select an appropriate QFI according to the QoS required by the data to be transmitted and transmit the data using the selected QFI. The data transmission procedure via the direct communication link (330) is described in detail in FIG. 4b.

FIG. 4a illustrates a connection establishment procedure of a direct communication link (ProSe link establishment) according to one embodiment of the present disclosure.

For the purpose of explaining the present invention, it is assumed that the transmitting terminal (110) is a terminal that initiates a direct communication link connection, and the remaining peripheral terminals (115, 120, 125) are terminals that are located within a close distance of the transmitting terminal (110) and can receive a direct communication request message (Direct Communication Request, 425) transmitted by the transmitting terminal (110). In addition, it is assumed that at least one of the peripheral terminals (115, 120, 125), for example, the terminal (120), is a terminal that establishes direct communication (440) with the transmitting terminal (110).

Referring to FIG. 4a, the peripheral terminals (115, 120, 125) can determine the destination layer-2 ID for receiving the direct communication request (409) message at step 400 based on the V2X service policy parameters of [Table 1] (e.g., corresponding to 'The mapping of default Destination Layer-2 ID(s) for initial signaling to establish unicast connection and the V2X services, e.g. PSID or ITS-AIDs of the V2X application' of [Table 1]). The destination layer-2 ID for receiving the direct communication request message can be determined to a different value depending on the application layer or the application supported by the application layer or the service type supported by the application layer (e.g., PSID, ITS-AID, etc.). Alternatively, the destination layer-2 ID for receiving the direct communication request message can be determined to the same default value regardless of the application layer or the application supported by the application layer or the service type supported by the application layer.

The application layer (270) of the terminal (110) that wants to perform an application operation can provide at least one of the 'application data' (hereinafter, 'service data' or 'data' may be used interchangeably) generated by the application layer (270) in step 403, the 'service type' indicating the type of data, the 'communication mode' indicating the communication method of the data (for example, broadcast, groupcast, unicast, etc.), the 'application layer user identifier' of the transmitting terminal (110), the 'application layer user identifier' of the receiving terminal (120), and the 'QoS requirements' to the SE layer (280). In the case of vehicle communication, the service type may be PSID, ITS-AID, etc. The service type that the application layer (270) provides to the SE layer (280) may be one or more service types. In addition, the QoS requirement that the application layer (270) provides to the SE layer (280) may be one or more QoS requirements. In addition, the application layer (270) may provide the SE layer (280) with a service type and one or more QoS requirement mapping information mapped thereto. Below is an example of information that the application layer (270) provides to the SE layer (280) at step 403.

- Application data,

- Application ID (e.g. 310 in Figure 3)

- One or more service types (e.g., 312, 314 in Fig. 3)

- One or more QoS requirements mapped to each service type,

- Communication mode,

- Application layer user IDs of the transmitting and receiving terminals (110, 120).

The SE layer (280) of the terminal (110) can determine whether to perform a link connection setup procedure at step 406 based on information (e.g., application data, communication mode, service type, etc.) received from the application layer (270) at step 403. For example, if the communication mode received from the application layer (270) is PC5 unicast, the SE layer (280) can determine that a link connection is necessary. If it determines whether a previously established direct communication link can be reused, and if it cannot be reused, it determines to perform a setup procedure, and can perform the following operations. If the previously established direct communication link can be reused, the procedure illustrated in FIG. 4b can be performed.

For example, if there is a 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) from the application layer (270) at step 403, the SE layer (280) can know that the terminal (110) has a direct communication link preset with the terminal (120). Accordingly, the SE layer (280) can determine not to connect a new direct communication link, but to reuse the existing direct communication link, and can perform the procedure illustrated in FIG. 4b. According to an embodiment of the present invention, if one application layer user ID is used in one application, the terminal (110) can establish one direct communication link with the terminal (120) per application. That is, one direct communication link is created for one application, and signaling and data for one application can be transmitted over one direct communication link. Alternatively, when one application layer user ID is used in more than one application, the terminal (110) may establish one direct communication link with the terminal (120) for the applications sharing the application layer user ID. That is, the applications sharing one application layer user ID may share one direct communication link and transmit signaling and data for the applications over the one direct communication link. Alternatively, when one application layer user ID is used in all applications, one direct communication link may be established between the terminals (110) and (120), and signaling and data for all applications supported by the terminals (110) and (120) may be transmitted over the one 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 can perform the following procedure.

The SE layer (280) of the terminal (110) can assign a link ID (Link Identifier) to designate a direct communication link (330) to be created through the process from step 409 to step 418. The link ID can be assigned as a unique value within the terminal (110). The SE layer (280) can create a link profile for the direct communication link (330) designated by the link ID assigned by the SE layer (280). The link profile can include application layer user IDs of the transmitting and receiving terminals (110, 120) received by the SE layer (280) from the application layer (270) in step 403.

In addition, the SE layer (280) can convert the QoS requirement received from the application layer (270) in step 403 into a PQI (PC5 5QI) value that can be used in the AS layer (200). One service type can request multiple QoS requirements, and accordingly, one service type can be mapped to multiple PQI values. In addition, the SE layer (280) can assign QFI to each PQI value. According to an embodiment of the present invention, if the service types are different for the same PQI value (e.g., PQI#3), different QFI values (e.g., QFI#3 and QFI#4) can be assigned. This example is illustrated in FIG. 4dc.

Alternatively, according to an embodiment of the present invention, the same QFI value (e.g., QFI#3) may be assigned even if the service types are different for the same PQI value (e.g., PQI#3). An example of this is illustrated in FIG. 4dd.

The link profile generated and managed by the SE layer (280) can store one or more of a PQI value associated with a direct communication link, a QFI value corresponding to each PQI value, a service type corresponding to each PQI value, and a service type corresponding to each QFI value.

The SE layer (280) can determine and assign its own layer-2 ID of the terminal (110) to be used for direct communication. The SE layer (280) can store the terminal's own layer-2 ID in a link profile that the SE layer (280) creates and manages. Below is an example of information stored in a link profile created by the SE layer (280) in step 406. The corresponding link profile can be referred to as a link ID.

- Application layer user ID of the terminal (110) (information received from the application layer (270) at step 415),

- Application layer user ID of terminal (120) (information received from application layer (270) at step 415),

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

- Application ID supported by the direct communication link (e.g., 310 in Figure 3)

- One or more service types supported by the direct communication link (e.g., 312, 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) can generate a Direct Communication Request message for unicast link setup. The Direct Communication Request message can include at least one of the 'application message', 'application ID', 'service type', 'application layer user identifier' of the transmitting terminal (110), 'application layer user identifier' of the receiving terminal (120), 'link ID' indicating the direct communication link, 'QoS requirements' that the direct communication link should provide, 'PQI', 'QFI', and 'layer-2 ID' of the transmitting terminal (110) received from the application layer (270) in step 403. Below is an example of information included in the direct communication request message.

- Application data

- Application layer user ID of terminal (110)

- Application layer user ID of terminal (120)

- Link ID, which refers to a direct communication link

- Application ID supported by the direct communication link (e.g., 310 in Figure 3)

- One or more service types supported by the direct communication link (e.g., 312, 314 in Fig. 3)

- 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.

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

The SE layer (280) can determine the source layer-2 ID and the destination layer-2 ID to be included in the MAC header in order to transmit the generated Direct Communication Request message. The SE layer (280) can use the layer-2 ID that the terminal (110) has allocated itself as the source layer-2 ID. The source layer-2 ID can be identical to the layer-2 ID value of the terminal (110) stored in the link profile. In addition, the SE layer (280) can refer to the V2X service policy parameters of [Table 1] stored by the terminal in order to determine the destination layer-2 ID. For example, the destination layer-2 ID can be determined based on 'The mapping of default Destination Layer-2 ID(s) for initial signaling to establish unicast connection and the V2X services, e.g. PSID or ITS-AIDs of the V2X application' of [Table 1]. The above destination layer-2 ID may be the same value as the destination layer-2 ID determined by the surrounding terminals (115, 120, 125) in step 400.

The SE layer (280) may transmit information to the AS layer (200) in order to transmit a direct communication request message. The information transmitted to the AS layer (200) may include at least one of the direct communication request message, the source layer-2 ID of the message, the destination layer-2 ID of the message, the link ID, the PQI value, the QFI value, the mapping information between PQI and QFI, the communication mode (e.g., PC5 broadcast), and the message type (e.g., signal (control) message). The following illustrates an example of information transmitted by the SE layer (280) to the AS layer (200).

- Direct Communication Request message

- Source Layer-2 ID of the message

- Destination layer-2 ID of the message

- Link ID, which refers to 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.

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

- Communication mode

- Message type

The AS layer (200) can store information received from the SE layer (280) and manage a radio bearer (SideLink Radio Bearer, SLRB) for direct communication. According to an embodiment of the present invention, one QFI value may be assigned to one PQI value, and one QFI value may be mapped to one SLRB (for example, QFI#5 and SLRB#3). Or, when the service types are different, different QFI values may be assigned to the same PQI value, and multiple QFI values may be mapped to one SLRB (for example, QFI#3, QFI4#, and SLRB#2). Or, one QFI value may be assigned to one PQI value, and multiple QFI values may be mapped to one SLRB (for example, QFI#1, QFI#2, and SLRB#1). Such an example is illustrated in FIG. 4de.

Alternatively, according to an embodiment of the present invention, 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). Alternatively, one QFI value may be assigned to the same PQI value even if the service types are different, 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 multiple QFI values may be mapped to one SLRB (e.g., QFI#1, QFI#2, and SLRB#1). Such an example is illustrated in FIG. 4df.

The AS layer (200) can configure a MAC header based on the information received from the SE layer (280). An example of MAC PDU configuration is illustrated in FIG. 4dg. The MAC PDU can include a MAC header. The MAC header can include an SL-SCH subheader and an R/R/E/LCID/F/L subheader. The SL-SCH subheader can be commonly applied to the entire MAC payload. The R/R/E/LCID/F/L subheader can sequentially correspond to one MAC SDU among the MAC payload.

Fig. 4dh shows an example of the SL-SCH subheader configuration illustrated in Fig. 4dg. The SL-SCH subheader may include a source layer-2 ID (corresponding to SRC in Table 4) and a destination layer-2 ID (corresponding to DST in Table 4). The source layer-2 ID and the destination layer-2 ID may have a range of 3 octets or 2 octets, respectively. The AS layer (200) may set the source layer-2 ID received from the SE layer (280) to the source layer-2 ID of the SL-SCH subheader (corresponding to SRC in Table 4). In addition, the AS layer (200) may set the destination layer-2 ID received from the SE layer (280) to the destination layer-2 ID of the SL-SCH subheader (corresponding to DST in Table 4).

The R/R/E/LCID/F/L subheader may include a Logical Channel ID (LCID) that indicates the message type of the MAC SDU to which the subheader refers. Table 3 shows examples of LCID. The AS layer (200) may determine the LCID based on the message type received from the SE layer (280). For example, if the message type may indicate a signaling message, the LCID may be set to 11100 or 11101 or 11110.

Index LCID values 00000 Reserved 00001-01010 Identity of the logical channel 01011-10100 Identity of the logical channel which is used for duplication 10101-11011 Reserved 11100 PC5-S messages that are not protected 11101 PC5-S messages "Direct Security Mode Command" and "Direct Security Mode Complete" 11110 Other PC5-S messages that are protected 11111 Padding

The AS layer (200) can configure a MAC header as described above and transmit a direct communication request message received from the SE layer (280) to a peripheral terminal (115, 120, 125) through the physical layer (260) by including the MAC payload (step 409).

The peripheral terminals (115, 120, 125) of the transmitting terminal (110) can receive the direct communication request message transmitted by the transmitting terminal (110) (step 412). The peripheral terminals (115, 120, 125) can forward the received direct communication request message to the SE layer through the PHY layer and AS layer of the terminals (115, 120, 125). The SE layer that has received the direct communication request message can determine a method of processing the message by checking the destination address of the message. If the destination address of the message is the destination layer-2 ID address determined by the terminal in step 400, the SE layer can determine that the received message is a direct communication request message among the PC5-S signaling messages. The SE layer can select an application layer to which to deliver the received message based on at least one of the destination layer-2 ID address of the received message, the 'service type' included in the received message, the 'application layer user identifier' of the terminal included in the received message, or the 'application ID' information included in the received message, and can deliver the received message to the selected application layer.

The application layer (275) of the terminal (120) that has received the direct communication request message may decide to reply to the received direct communication request message based on the information such as 'application data', 'service type', 'application layer user identifier' of the transmitting terminal (110), and 'application layer user identifier' of the receiving terminal (120) included in the received request message.

The application layer (275) of the terminal (120) that wishes to accept the received direct communication request may provide at least one of the 'application data' (hereinafter, 'service data' or 'data' may be used interchangeably), the 'service type' indicating the type of data, the 'communication mode' indicating the communication method of the data (for example, broadcast, groupcast, unicast, etc.), the 'application layer user identifier' of the transmitting terminal (110), the 'application layer user identifier' of the receiving terminal (120), and the 'QoS requirements' to the SE layer (285). In the case of vehicular communication, the service type may be PSID, ITS-AID, etc. The service type that the application layer (275) provides to the SE layer (285) may be one or more service types. In addition, the QoS requirement that the application layer (275) provides to the SE layer (285) may be one or more QoS requirements. In addition, the application layer (275) may provide the SE layer (285) with a service type and one or more QoS requirement mapping information mapped thereto. Below is an example of information that the application layer (275) provides to the SE layer (285) at step 412.

- Application data,

- Application ID (e.g. 315 in Figure 3)

- One or more service types (e.g., 317, 319 in Fig. 3)

- One or more QoS requirements mapped to each service type,

- Communication mode,

- Application layer user IDs of the transmitting and receiving terminals (110, 120).

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

The SE layer (285) of the terminal (120) can assign a link ID (Link Identifier) to designate a direct communication link (330) to be created through the process from step 415 to step 418. Alternatively, the SE layer (285) can use a link ID received from the transmitting terminal (110) in step 409. The link ID can be assigned as a unique value within the terminal (120). The SE layer (285) can create a link profile for the direct communication link (330) designated by the link ID. The link profile can include application layer user IDs of the transmitting and receiving terminals received in steps 412 to 409.

Additionally, the SE layer (285) may convert the QoS requirements received in steps 412 to 409 into PQI (PC5 5QI) values that can be used in the AS layer (205) to determine the PQI to be supported in direct communication. Alternatively, the SE layer (285) may utilize the PQI value received in step 409.

The SE layer (285) can determine the QFI mapped to the PQI to be supported in direct communication. Alternatively, the SE layer (285) can determine the QFI using the mapping information of the PQI value and the QFI received in step 409.

The relationship between service types and QoS requirements, PQI, and QFI can be applied similarly to the method described in step 406.

The link profile generated and managed by the SE layer (285) can store one or more of a PQI value associated with a direct communication link, a QFI value corresponding to each PQI value, a service type corresponding to each PQI value, and a service type corresponding to each QFI value.

The SE layer (285) can determine and assign its own layer-2 ID of the terminal (120) to be used for direct communication. The SE layer (285) can store the terminal's own layer-2 ID in a link profile that the SE layer (285) creates and manages. Below is an example of information stored in a link profile created by the SE layer (285) in step 415. The corresponding link profile can be referred to as a link ID.

- Application layer user ID of the terminal (110) (information received in steps 409 to 415),

- Application layer user ID of the terminal (120) (information received in steps 409 to 415),

- Layer-2 ID of terminal (110) (information received at step 409)

- Layer-2 ID of terminal (120) (Layer-2 ID assigned by the terminal itself in step 415)

- Application ID supported by the direct communication link (e.g., 315 in Figure 3)

- One or more service types supported by the direct communication link (e.g., corresponding 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.

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

The SE layer (285) can generate a Direct Communication Response message for unicast link setup. The Direct Communication Response message can include at least one of the received 'application message' received in step 412, the 'application ID' received in steps 412 to 409, the 'service type', the 'application layer user identifier' of the terminal (110), the 'application layer user identifier' of the terminal (120), the 'link ID' indicating the direct communication link, the 'QoS requirements' that the direct communication link should provide, the 'PQI', the 'QFI', the 'layer-2 ID' of the terminal (110), and the 'layer-2 ID' of the terminal (120). Below is an example of information included in the direct communication request message.

- Application data

- Application layer user ID of terminal (110)

- Application layer user ID of terminal (120)

- Link ID, which refers to a direct communication link

- Application ID supported by the direct communication link (e.g., 315 in Figure 3)

- One or more service types supported by the direct communication link (e.g., corresponding to 317 and 319 in Fig. 3)

- 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.

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

The SE layer (285) can determine the source layer-2 ID and the destination layer-2 ID to be included in the MAC header in order to transmit the generated Direct Communication Response message. The SE layer (285) can use the layer-2 ID assigned by the terminal (120) as the source layer-2 ID. The source layer-2 ID can be identical to the layer-2 ID value of the terminal (120) stored in the link profile. In addition, the SE layer (285) can use the source layer-2 ID of the direct communication request message received in step 409 as the destination layer-2 ID. The destination layer-2 ID can be identical to the layer-2 ID value of the terminal (110) stored in the link profile.

The SE layer (285) may transmit information to the AS layer (205) in order to transmit a direct communication response message. The information transmitted to the AS layer (205) may include at least one of the direct communication response message, the source layer-2 ID of the message, the destination layer-2 ID of the message, the link ID, the PQI value, the QFI value, the mapping information between the PQI and QFI, the communication mode (e.g., PC5 unicast), and the message type (e.g., a signal (control) message). The following illustrates an example of information transmitted by the SE layer (285) to the AS layer (205).

- Direct Communication Response message

- Source Layer-2 ID of the message

- Destination layer-2 ID of the message

- Link ID, which refers to 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.

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

- Communication mode

- Message type

The AS layer (205) can store information received from the SE layer (285) and manage a radio bearer (SideLink Radio Bearer, SLRB) for direct communication. The SLRB management and the relationship between the SLRB and QFI and PQI can be similarly applied to the method described in step 406.

The AS layer (205) can configure a MAC header based on information received from the SE layer (285). The method for configuring the MAC header can be applied similarly to the method described in step 406.

The AS layer (205) can configure a MAC header as described above and transmit a direct communication response message received from the SE layer (285) to the terminal (110) through the physical layer (265) including the MAC payload (step 418).

The SE layer (280) of the terminal (110) that has received the direct communication response message can determine that the received message is a PC5-S signaling message based on at least one of the destination layer-2 ID address or the Logical Channel ID (LCID) of the received message or the information transmitted from the AS layer (for example, an indicator indicating a PC5-S signaling message), and process the received message as follows. The SE layer (280) can confirm that the received message is a direct communication response message and can notify the application layer (270) that the direct communication link connection has been established. At this time, the SE layer (280) of the terminal (110) can also notify the application layer (270) of information related to the connected direct communication link (for example, link ID, QFI, etc.). Below is an example of information that the SE layer (285) transmits to the application layer (270).

- Direct communication connection setup completed indication

- Link ID indicating direct communication

- QFIs supported by direct communication

- Mapping information for QFI and QoS requirements

- Application data (if there is data received in step 418)

- Application layer user ID of terminal (110)

- Application layer user ID of terminal (120)

In addition, the SE layer (280) can notify the AS layer (200) of direct communication link information (e.g., link ID, QFI information) for which connection setup is complete. Below is an example of information that the SE layer (280) transmits to the AS layer (200). The AS layer (200) can store the received information and use it for future direct communication.

- Direct communication connection setup completed indication

- Link ID indicating direct communication

- QFIs supported by direct communication

- Mapping information of QFI and PQI

- Layer-2 ID of terminal (110)

- Layer-2 ID of terminal (120)

The SE layer (280) can update the link profile information generated in step 406 based on the received direct communication response message information. For example, the destination layer-2 ID of the direct communication response message received in step 418 can be stored as the 'layer-2 ID' of the terminal (120). In addition, if the information included in the direct communication response message received in step 418 (for example, the 'application layer user identifier' of the terminal (120), 'QoS requirements', 'PQI', 'QFI' information, etc.) does not match the link profile information generated in step 406, the link profile information can be updated with the information received in step 418.

FIG. 4b illustrates a data transmission procedure using a direct communication link according to one embodiment of the present disclosure.

Referring to FIG. 4b, terminals (110) and terminals (120) can complete direct communication link connection setup through the procedure described above in FIG. 4a. Terminals (110, 120) can create a link profile during the direct communication link connection setup process and store layer-2 ID information of terminals (110, 120) to be used for the direct communication link.

The terminal (120) can determine a destination layer-2 ID (Destination Layer-2 ID) for receiving data and signaling messages transmitted on the direct communication link generated through the procedure of FIG. 4a in step 421. For example, the destination layer-2 ID can be determined as a layer-2 ID of the terminal (120) included in the corresponding link profile.

The application layer (270) of the terminal (110) can transmit at least one of the following to the SE layer (280): 'application data' generated by the application layer (270) in step 424, 'link ID' indicating a direct communication link through which data will be transmitted, 'service type' indicating a type of data, 'communication mode' indicating a method of data communication (e.g., broadcast, groupcast, unicast, etc.), 'application layer user identifier' of the transmitting terminal (110), 'application layer user identifier' of the receiving terminal (120), 'QoS requirements' required for data transmission, 'PQI' required for data transmission, and 'QFI' required for data transmission.

The SE layer (280) can check the link profile information associated with the link ID received in step 424. The SE layer (280) can determine the source layer-2 ID and the destination layer-2 ID for transmitting the 'application data' received in step 424. For example, the source layer-2 ID can be determined as the layer-2 ID of the terminal (110) stored in the link profile associated with the link ID. The destination layer-2 ID can be determined as the layer-2 ID of the terminal (120) stored in the link profile associated with the link ID (step 427).

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

The SE layer (280) can transmit at least one of the following information to the AS layer (200): 'application data' received in step 424, 'source layer-2 ID' and 'destination layer-2 ID' determined in step 427, 'QFI', 'link ID' related to the corresponding direct communication link, communication mode (e.g., PC5 unicast), and message type (e.g., data (User Plane) message). Below is an example of information transmitted by the SE layer (280) to the AS layer (200).

- Application data

- Link ID indicating direct communication

- QFI required for direct communication

- PQI required for direct communication

- Mapping information of QFI and PQI required for direct communication

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

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

- Communication mode

- Message type

The AS layer (200) can configure a MAC header based on information received from the SE layer (280). The method for configuring the MAC header can be applied similarly to the method described in step 406.

The source layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (110) received in step 427. Alternatively, the source layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (110) mapped to the link ID stored by the AS layer (200) in the procedure of FIG. 4a by referring to the link ID received in step 427.

The destination layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (120) received in step 427. Alternatively, the destination layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (120) mapped to the link ID stored by the AS layer (200) in the procedure of FIG. 4a by referring to the link ID received in step 427.

The AS layer (200) can determine the QFI to which the application data received in step 427 should be transmitted. The QFI can be determined by a combination of information received in step 427 (e.g., QFI) or information received in step 427 (e.g., link ID) and information stored by the AS layer (200) in the procedure of FIG. 4a.

The AS layer (200) can determine the LCID based on the type of message (e.g., data) received in step 427. The logical channel ID value used for the data message may be different from the logical channel ID value used for the signaling message. Additionally, 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 that can indicate the QFI to transmit the message and a value that can indicate a link ID.

The AS layer (200) can configure a MAC header as described above and transmit application data received from the SE layer (280) to the terminal (120) through the physical layer (260) including the MAC payload (step 430).

The AS layer (205) of the terminal (120) that has received the 'application data' can 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 MAC header of the received message. The AS layer (205) can forward the received message to the SE layer (285). The SE layer (285) can determine whether the received message is a message for a direct communication link generated by the above-described procedure based on the link ID and/or destination layer-2 ID and/or QFI information of the received message.

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

In addition, the SE layer (285) of the terminal (120) can determine the service type or application ID of the received message based on the link ID and/or destination layer-2 ID and/or QFI information of the received message. Based on this, the SE layer (285) can transfer the received 'application data' to the application (315) of the corresponding application layer (275) or the service type (317 to 319) included in the application. In addition, the SE layer (285) can transfer 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 an update procedure of a direct communication link according to an embodiment of the present disclosure.

Referring to FIG. 4c, terminals (110) and terminals (120) can complete direct communication link connection setup through the procedure described above in FIG. 4a. Terminals (110, 120) can create a link profile during the direct communication link connection setup process and store layer-2 ID information of terminals (110, 120) to be used for the direct communication link.

The terminal (120) can determine a destination layer-2 ID (Destination Layer-2 ID) for receiving data and signaling messages transmitted on the direct communication link generated through the procedure of FIG. 4a in step 421. For example, the destination layer-2 ID can be determined as a layer-2 ID of the terminal (120) included in the corresponding link profile.

The application layer (270) of the terminal (110) can transmit at least one of the 'application data' generated by the application layer (270) in step 433, the 'link ID' indicating a direct communication link through which the data will be transmitted, the 'service type' indicating the type of data, the 'communication mode' indicating a method of data communication (e.g., broadcast, groupcast, unicast, etc.), the 'application layer user identifier' of the transmitting terminal (110), the 'application layer user identifier' of the receiving terminal (120), the 'QoS requirements' required for data transmission, the 'PQI' required for data transmission, and the 'QFI' required for data transmission to the SE layer (280).

If there is a 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) received from the application layer (270) at step 433, the SE layer (280) can know that the terminal (110) has a direct communication link preset with the terminal (120). Accordingly, the SE layer (280) can decide not to connect a new direct communication link, but to reuse the existing direct communication link, and can decide to perform the link update procedure illustrated in FIG. 4B (step 436). According to an embodiment of the present invention, if one application layer user ID is used in one application, the terminal (110) can establish one direct communication link with the terminal (120) per application. That is, one direct communication link is created for one application, and signaling and data for one application can be transmitted over one direct communication link. Alternatively, when one application layer user ID is used in more than one application, the terminal (110) may establish one direct communication link with the terminal (120) for the applications sharing the application layer user ID. That is, the applications sharing one application layer user ID may share one direct communication link and transmit signaling and data for the applications over the one direct communication link. Alternatively, when one application layer user ID is used in all applications, one direct communication link may be established between the terminals (110) and (120), and signaling and data for all applications supported by the terminals (110) and (120) may be transmitted over the one direct communication link.

Alternatively, the SE layer (480) may decide to perform a link update procedure (step 436) if the service type received in step 433 does not exist in the link profile associated with the link ID and/or if the PQI and/or QFI mapped to the QoS requirement do not exist in the link profile associated with the link ID.

The SE layer (280) can determine a new PQI and/or a new QFI that satisfies the QoS requirements received at step 433, similar to the method described in FIG. 4a.

The SE layer (280) may generate a Link Update Request message. The Link Update Request message may include at least one of a link ID, a new PQI determined by the SE layer (280), a new QFI, and mapping information between the PQI and QFI.

The SE layer (280) can determine a source layer-2 ID and a destination layer-2 ID similar to the method described in FIG. 2b to transmit a link update request message.

The SE layer (280) can transmit at least one of the following information to the AS layer (200): a 'link update request message', a 'source layer-2 ID' and a 'destination layer-2 ID' determined in step 436, a 'link ID' related to the corresponding direct communication link, a communication mode (e.g., PC5 unicast), and a message type (e.g., PC5-S signaling message). Below is an example of information that the SE layer (280) transmits to the AS layer (200).

- Link update request message

- Link ID indicating direct communication

- Additional application ID required for direct communication

- Additional QFI required for direct communication

- Additional PQI required for direct communication

- Mapping information for additional QFI and additional PQI required for direct communication

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

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

- Communication mode

- Message type

The AS layer (200) can configure a MAC header based on information received from the SE layer (280). The method for configuring the MAC header can be applied similarly to the method described in step 406.

The source layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (110) received in step 436. Alternatively, the source layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (110) mapped to the link ID stored by the AS layer (200) in the procedure of FIG. 4a by referring to the link ID received in step 427.

The destination layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (120) received in step 436. Alternatively, the destination layer-2 ID of the MAC header may be set to the layer-2 ID of the terminal (120) mapped to the link ID stored by the AS layer (200) in the procedure of FIG. 4a by referring to the link ID received in step 436.

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

The AS layer (200) can configure a MAC header as described above and transmit a link update request message received from the SE layer (280) to the terminal (120) through the physical layer (260) by including the MAC payload (step 439).

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

Additionally, the SE layer (285) of the terminal (120) can determine that the received message is a signaling message based on the LCID of the message.

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

The SE layer (285) can transmit changed QoS information to the application layer (275).

Additionally, the SE layer (285) can transmit the link ID of the direct communication link and the changed QoS information related to the direct communication link to the AS layer (205). The AS layer (205) can store the received link ID and update the QoS information (e.g., new PQI and corresponding QFI information) and use it for future direct communications.

FIG. 5a is a block diagram illustrating a configuration of a network entity according to an embodiment of the present disclosure.

A network entity according to one embodiment of the present disclosure may include a mobile communication system (130).

Referring to FIG. 5A, the network entity may be composed of a transceiver (500), a control unit (510), and a storage unit (520). The transceiver (500), the control unit (510), and the storage unit (520) of the network entity may operate according to the communication method of the network entity described above. However, the components of the network entity are not limited to the examples described above. For example, the network entity may include more or fewer components than the components described above. In addition, the transceiver (500), the control unit (510), and the storage unit (520) may be implemented in the form of a single chip. In addition, the control unit (510) may include at least one processor.

The transceiver (500) is a general term for the receiver (506) of the network entity and the transmitter (503) of the network entity, and can transmit and receive signals. The transmitted and received signals can include control information and data. To this end, the transceiver (500) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and frequency-down-converts a received signal. However, this is only one embodiment of the transceiver (500), and the components of the transceiver (500) are not limited to the RF transmitter and the RF receiver.

In addition, the transceiver (500) can receive a signal through a wireless channel and output it to the control unit (510), and transmit the signal output from the control unit (510) through the wireless channel.

The storage unit (520) can store programs and data required for the operation of the network entity. In addition, the storage unit (520) can store control information or data included in a signal obtained from the network entity. The control unit (520) can be configured as a storage medium or a combination of storage media such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD.

The control unit (510) can control a series of processes so that the network entity can operate according to the embodiment of the present disclosure described above. For example, the control unit (510) can receive a control signal and a data signal through the transceiver unit (500), and process the received control signal and the data signal. In addition, the control unit (510) can transmit the processed control signal and the data signal through the transceiver unit (500).

FIG. 5b is a block diagram showing the configuration of a terminal according to one embodiment of the present disclosure.

Specifically, FIG. 5b may be a block diagram illustrating the internal structure of a terminal (110, 115, 120, 125) according to one embodiment of the present disclosure. The terminal may include a transceiver (550), a control unit (560), and a storage unit (570).

According to the communication method of the terminal described above, the transceiver (550), the control unit (560), and the storage unit (570) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver (550), the control unit (560), and the storage unit (570) may be implemented in the form of a single chip. In addition, the control unit (560) may include at least one processor.

The transceiver (550) is a general term for the terminal's receiver (556) and the terminal's transmitter (553), and can transmit and receive signals with the base station. The signals transmitted and received with the base station can include control information and data. To this end, the transceiver (550) can be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver (550), and the components of the transceiver (550) are not limited to the RF transmitter and RF receiver.

In addition, the transceiver (550) can receive a signal through a wireless channel and output it to the control unit (560), and transmit the signal output from the control unit (560) through the wireless channel.

The storage unit (570) can store programs and data required for the operation of the terminal. In addition, the storage unit (570) can store control information or data included in a signal obtained from the terminal. The storage unit (570) can be composed of a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

The control unit (560) can control a series of processes so that the terminal can operate according to the embodiment of the present disclosure described above. For example, the control unit (560) can receive a control signal and a data signal through the transceiver unit (550), and process the received control signal and data signal. In addition, the control unit (560) can transmit the processed control signal and data signal through the transceiver unit (550).

The embodiments disclosed in the specification and drawings above are merely specific examples presented to easily explain and aid understanding of the contents of the present invention, and are not intended to limit the scope of the present invention. Therefore, the scope of the present invention should be interpreted as including all changes or modified forms derived based on the technical idea of the present invention in addition to the embodiments disclosed herein.

Claims (16)

In a method performed by a first terminal in a wireless communication system,
A step for establishing a direct communication link for unicast communication with a second terminal for the first service of the first service type;
Each of the first terminal and the second terminal has one or more application layer IDs (identifiers),
The above direct communication link is associated with a first pair of an application layer ID of the first terminal and an application layer ID of the second terminal, and
The direct communication link associated with the first pair supports multiple service types;
For a second service of a second service type, a step of checking whether a second pair of an application layer ID of the first terminal and an application layer ID of the second terminal is identical to the first pair;
a step of determining to reuse the direct communication link when the first pair and the second pair are identical; and
A method comprising the step of modifying said direct communication link.
In the first paragraph,
Further comprising the step of assigning a link ID (identifier) to the above direct communication link,
A method, characterized in that the link profile associated with the direct communication link includes information about the plurality of service types, application layer IDs of the first terminal and the second terminal, layer-2 IDs of the first terminal and the second terminal, and a quality of service (QoS) flow identifier (QFI) for each service type of the plurality of service types.
In the second paragraph,
The SE (Service Enabler) layer further includes a step of transmitting information about the link ID and direct communication link to the AS (Access Stratum) layer,
Information about the above direct communication link includes the layer-2 ID of the first terminal and the layer-2 ID of the second terminal,
Information about the above link ID and the above direct communication link is maintained in the AS layer, and
A method characterized in that data communication with the second terminal is performed through the direct communication link using the layer-2 ID of the first terminal and the layer-2 ID of the second terminal.
In the third paragraph, the step of modifying the direct communication link is:
Comprising a step of transmitting a link modification request message to the second terminal,
The above link modification request message includes information about the QoS flow associated with the second service type,
A method characterized in that the above link profile is updated based on the link modification request message.
In paragraph 1,
a step of establishing a new direct communication link when the second pair of application layer IDs for the second service type is different from the first pair; and
A method characterized by further comprising the step of performing data communication for the second service via the new direct communication link.
In a method performed by a second terminal in a wireless communication system,
A step for establishing a direct communication link for unicast communication with a first terminal for a first service of a first service type;
Each of the first terminal and the second terminal has one or more application layer IDs (identifiers),
The above direct communication link is associated with a first pair of an application layer ID of the first terminal and an application layer ID of the second terminal, and
The direct communication link associated with the first pair supports multiple service types; and
Including a step of modifying said direct communication link to reuse said direct communication link for a second service of a second service type,
A method in which the direct communication link is reused for the second service when the second pair of the application layer ID of the first terminal and the application layer ID of the second terminal is identical to the first pair.
In Article 6,
When the above direct communication link is established, a link ID (identifier) for the above direct communication link is assigned, and
A method, characterized in that the link profile associated with the direct communication link includes information about the plurality of service types, application layer IDs of the first terminal and the second terminal, layer-2 IDs of the first terminal and the second terminal, and a quality of service (QoS) flow identifier (QFI) for each service type of the plurality of service types.
In Article 7,
The SE (Service Enabler) layer further includes a step of transmitting information about the link ID and direct communication link to the AS (Access Stratum) layer,
Information about the above direct communication link includes the layer-2 ID of the first terminal and the layer-2 ID of the second terminal,
Information about the above link ID and the above direct communication link is maintained in the AS layer, and
A method characterized in that data communication with the first terminal is performed through the direct communication link using the layer-2 ID of the first terminal and the layer-2 ID of the second terminal.
In a first terminal in a wireless communication system,
A transceiver configured to transmit and receive signals; and
A control unit functionally connected to the above transmitter and receiver,
The above control unit,
Establishing a direct communication link for unicast communication with a second terminal for a first service of a first service type, wherein each of the first terminal and the second terminal has one or more application layer IDs (identifiers), and the direct communication link is associated with a first pair of an application layer ID of the first terminal and an application layer ID of the second terminal, and the direct communication link associated with the first pair supports a plurality of service types,
For the second service of the second service type, it is checked whether the second pair of the application layer ID of the first terminal and the application layer ID of the second terminal is identical to the first pair,
If the first pair and the second pair are identical, it is decided to reuse the direct communication link, and
A first terminal configured to modify the above direct communication link.
In Article 9,
The above control unit is further configured to assign a link ID (identifier) to the direct communication link,
A first terminal, characterized in that the link profile associated with the direct communication link includes information about the plurality of service types, application layer IDs of the first terminal and the second terminal, layer-2 IDs of the first terminal and the second terminal, and a quality of service (QoS) flow identifier (QFI) for each service type of the plurality of service types.
In Article 10,
The above control unit is set so that the SE (Service Enabler) layer transmits information about the link ID and direct communication link to the AS (Access Stratum) layer,
Information about the above direct communication link includes the layer-2 ID of the first terminal and the layer-2 ID of the second terminal,
Information about the above link ID and the above direct communication link is maintained in the AS layer, and
A first terminal, characterized in that data communication with the second terminal is performed via the direct communication link using the layer-2 ID of the first terminal and the layer-2 ID of the second terminal.
In Article 11,
The above control unit is set to transmit a link modification request message to the second terminal to modify the direct communication link,
The above link modification request message includes information about the QoS flow associated with the second service type, and
A first terminal, characterized in that the link profile is updated based on the link modification request message.
In Article 9,
A first terminal, characterized in that the control unit is configured to establish a new direct communication link when a second pair of application layer IDs for the second service type is different from the first pair, and to perform data communication for the second service through the new direct communication link.
In a second terminal in a wireless communication system,
A transceiver configured to transmit and receive signals; and
A control unit functionally connected to the above transmitter and receiver,
The above control unit,
Establishing a direct communication link for unicast communication with a first terminal for a first service of a first service type, wherein each of the first terminal and the second terminal has one or more application layer IDs (identifiers), and the direct communication link is associated with a first pair of an application layer ID of the first terminal and an application layer ID of the second terminal, and the direct communication link associated with the first pair supports a plurality of service types, and
is set to modify said direct communication link to reuse said direct communication link for a second service of the second service type;
A second terminal, in which the direct communication link is reused for the second service, when the second pair of the application layer ID of the first terminal and the application layer ID of the second terminal is identical to the first pair.
In Article 14,
When the above direct communication link is established, a link ID (identifier) for the above direct communication link is assigned, and
A second terminal, characterized in that the link profile associated with the direct communication link includes information about the plurality of service types, application layer IDs of the first terminal and the second terminal, layer-2 IDs of the first terminal and the second terminal, and a quality of service (QoS) flow identifier (QFI) for each service type of the plurality of service types.
In Article 15,
The above control unit is set so that the SE (Service Enabler) layer transmits information about the link ID and direct communication link to the AS (Access Stratum) layer,
Information about the above direct communication link includes the layer-2 ID of the first terminal and the layer-2 ID of the second terminal,
Information about the above link ID and the above direct communication link is maintained in the AS layer, and
A second terminal, characterized in that data communication with the first terminal is performed via the direct communication link using the layer-2 ID of the first terminal and the layer-2 ID of the second terminal.