CN114079881A

CN114079881A - Communication method and device

Info

Publication number: CN114079881A
Application number: CN202010814550.2A
Authority: CN
Inventors: 李岚涛; 刘蕾
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2020-08-13
Filing date: 2020-08-13
Publication date: 2022-02-22
Also published as: WO2022033261A1

Abstract

The application provides a communication method and device. The method comprises the following steps: the first terminal equipment sends a first request message, wherein the first request message does not contain target user information, and the first request message contains service information and is used for requesting to establish a direct link; receiving a first response message from the second terminal equipment, and establishing a first direct link with the second terminal equipment according to the first response message; the first terminal equipment receives the second response message from the third terminal equipment, can establish a plurality of direct links with different terminal equipment, does not need the first terminal equipment to send a plurality of first request messages to establish the plurality of direct links, and triggers the establishment of the plurality of direct links by the service information, so that the efficiency of establishing the plurality of direct links among the terminal equipment is improved, and the signaling overhead is saved.

Description

Communication method and device

Technical Field

The present application relates to the field of communications technologies, and in particular, to a communication method and apparatus.

Background

With the development of communication technology, the third generation partnership project (3)^rdGeneration partnership project, 3GPP) version 12, fourth Generation (4)^thgeneration, 4G) communication system can supportDevice to device communication, which may be referred to as device to device (D2D) communication. The biggest difference with conventional cellular communication technology is that D2D communication allows direct communication between terminal devices.

D2D communication can be carried out between the terminal equipment and the terminal equipment through a direct link. At present, when a terminal device at a sender initiates a request for establishing a direct link connection, a direct link can be established only with a terminal device responding to the request.

Disclosure of Invention

The application provides a communication method and a communication device, which are used for triggering the establishment of a plurality of direct links for one direct link request.

In a first aspect, an embodiment of the present application provides a communication method, where the communication method may be implemented by a terminal device, and may also be implemented by a component of the terminal device, such as a processing chip, a circuit, and the like in the terminal device. The method comprises the following steps: the method comprises the steps that a first terminal device sends a first request message, the first request message contains identification of vehicle-to-all (V2X) service, the first request message does not contain target user information, the first request message is used for requesting to establish a direct link, and the direct link is used for V2X communication; the method comprises the steps that first terminal equipment receives a first response message from second terminal equipment, and establishes a first direct link between the first terminal equipment and the second terminal equipment according to the first response message, wherein the first response message is used for indicating whether the establishment of the direct link is accepted or refused; the first terminal device receives a second response message from the third terminal device, and establishes a second direct link between the first terminal device and the third terminal device according to the second response message, wherein the second response message is used for indicating acceptance of establishment of the direct link or rejection of establishment of the direct link.

Through the design, the first terminal equipment sends a first request message, wherein the first request message does not contain target user information and is used for requesting to establish a direct link; receiving a first response message from the second terminal equipment, and establishing a first direct link with the second terminal equipment according to the first response message; the first terminal device receives the second response message from the third terminal device, can establish a plurality of direct links with different terminal devices, does not need to send a plurality of first request messages to establish the plurality of direct links, improves the efficiency of establishing the plurality of direct links between the terminal devices, and saves signaling overhead.

In one possible implementation manner, the sending, by the first terminal device, the first request message includes: the first terminal equipment uses the first source layer 2ID and the destination layer 2ID corresponding to the V2X service to send a first request message; before the first terminal device receives the first response message from the second terminal device, the method further includes: the first terminal equipment receives a second message from the second terminal equipment, wherein the second message contains user information of the second terminal equipment, and the second message is used for requesting authentication or controlling a security mode; the first terminal device sends a third message to the second terminal device using the second source layer 2ID, the third message containing user information of the second terminal device, the second source layer 2ID being different from the first source layer 2 ID.

Through the design, for the second terminal device and the third terminal device, the first terminal device uses different source layer 2 IDs to perform signaling interaction in a unicast establishing process with different terminal devices, and the situation that the first terminal device uses the same layer 2ID to establish a direct link with different terminal devices when the source layer 2 IDs of the second terminal device and the third terminal device collide is avoided.

In one possible implementation, the method further includes: the first terminal equipment starts a first timer according to the condition that the first request message does not contain target user information, wherein the starting time of the first timer is the time when the first terminal equipment sends the first request message, and the set time length of the first timer is the preset time length; when the first terminal equipment receives the response message of the first request message, the first terminal equipment does not stop the first timer; after the first timer expires, the first terminal device stops receiving or discards the response message of the first request message.

Through the design, the first timer is only stopped when the timing is finished, and the first timer cannot be stopped because the first terminal equipment receives the response message of the first request, and the first terminal equipment can process the messages of other terminal equipment before the first timer is overtime, so that the through links can be respectively established for the plurality of terminal equipment to which the received response message belongs before the first timer is overtime.

In a possible implementation manner, the method, when the first terminal device sends the third message to the target second terminal device, further includes: and the first terminal equipment starts a second timer, and the set time length of the second timer is the residual timing time length of the first timer.

Through the design, the second timer corresponds to a unicast establishment flow, the unicast establishment flow of the first terminal equipment is monitored through the second timer, the second timer finishes timing, the first terminal equipment finishes the unicast establishment flow, and resource waste caused by long-time non-response of the opposite terminal equipment is avoided. And each unicast establishing flow on the first terminal equipment is independent and does not influence each other.

In a possible implementation manner, after the first terminal device receives the second message from the second terminal device, and before the first terminal device sends the third message to the second terminal device, the method further includes: the first terminal equipment determines that the number of the established direct links on the first terminal equipment does not reach a preset threshold value.

Through the design, the first terminal equipment can refuse the direct link establishment request of the opposite terminal equipment when the unicast establishment resource is insufficient, and avoid passive acceptance and overlarge load.

In one possible implementation, the first terminal device receives a second message from a fourth terminal device; further comprising: and the first terminal equipment determines that the number of the established direct links on the first terminal equipment reaches a preset threshold value, and then the first terminal equipment sends a fourth message to fourth terminal equipment, wherein the fourth message is used for indicating that the first terminal refuses authentication or safety mode control. Optionally, the fourth message carries a first cause value, where the first cause value is lack of unicast link resources.

In one possible implementation, the first request information further includes user information of the first terminal device.

In a possible implementation manner, the third message includes user information of the second terminal device; or the third message comprises the user information of the second terminal equipment and the user information of the first terminal equipment.

In a possible implementation manner, the establishing, by the first terminal device, the first direct link between the first terminal device and the second terminal device according to the first response message includes: the first response message indicates that the establishment of the direct link is accepted, and the first terminal equipment establishes a first direct link with the second terminal equipment; the first response message indicates that the establishment of the direct link is refused, and the first terminal equipment does not establish the first direct link with the second terminal equipment.

In a possible implementation manner, the first response message is used to indicate whether to accept establishment of the direct link or to reject establishment of the direct link; the first response message of the second terminal equipment indicates to accept to establish the direct link; the method further comprises the following steps: the first terminal device uses the second source layer 2ID to communicate a direct link with the second terminal device.

Through the design, after the through link between the first terminal device and the second terminal device is established, the first terminal device and the second terminal device can still continue to perform communication of the through link by using the second source layer 2ID, the first terminal device can identify the second terminal device through the second source layer 2ID, and in addition, the problem caused by layer 2ID collision of the opposite terminal device of the through link can be avoided.

In one possible implementation manner, the sending, by the first terminal device, the first request message includes: the first terminal equipment uses the first source layer 2ID and the destination layer 2ID corresponding to the V2X service to send a first request message; before the first terminal device receives the second response message from the third terminal device, the method further includes: the first terminal equipment receives a fifth message from the third terminal equipment, wherein the fifth message contains user information of the third terminal equipment, and the fifth message is used for requesting authentication or controlling a safety mode; the first terminal device transmits a sixth message to the third terminal device using the fourth source layer 2ID, the sixth message containing user information of the third terminal device, the fourth source layer 2ID being different from the first source layer 2ID and the second source layer 2 ID.

In a possible implementation manner, the method, when the first terminal device sends the sixth message to the target third terminal device, further includes: and the first terminal equipment starts a second timer, the set time length of the second timer is the residual timing time length of the first timer, and the second timer and the third terminal equipment are in one-to-one correspondence.

In a possible implementation manner, after the first terminal device receives the fifth message from the third terminal device, and before the first terminal device sends the sixth message to the third terminal device, the method further includes: the first terminal equipment determines that the number of the established direct links on the first terminal equipment does not reach a preset threshold value.

In a possible implementation manner, the sixth message includes user information of the third terminal device; or the sixth message includes the user information of the third terminal device and the user information of the first terminal device.

In a possible implementation manner, the establishing, by the first terminal device, the first through link between the first terminal device and the third terminal device according to the second response message includes: the second response message indicates that the establishment of the direct link is accepted, and the first terminal equipment establishes a first direct link with the third terminal equipment; the second response message indicates that the establishment of the direct link is refused, and the first terminal equipment does not establish the first direct link with the third terminal equipment.

In a possible implementation manner, the second response message is used to indicate whether to accept establishment of the direct link or to reject establishment of the direct link; the second response message of the third terminal equipment indicates to accept to establish the direct link; the method further comprises the following steps: the first terminal device communicates a through link with the third terminal device using the fourth source layer 2 ID.

In a second aspect, the present application provides a communication method, where the communication method may be implemented by a terminal device, and may also be implemented by a component of the terminal device, such as a processing chip, a circuit, and the like in the terminal device. The method comprises the following steps: the first terminal equipment sends a first request message and starts a first timer; the first request message contains identification of all vehicle-to-vehicle V2X services, the first request message does not contain target user information, the first request message is used for requesting to establish a direct link, and the direct link is used for V2X communication; when the first terminal equipment receives a first response message from the second terminal equipment, keeping the first timer to keep timing until the first timer is overtime; the first response message is used for indicating acceptance of establishing the through link or rejection of establishing the through link.

In one possible implementation, the method further includes: the first response message indicates that the establishment of the direct link is accepted, and the first terminal equipment establishes a first direct link with the second terminal equipment; the first response message indicates that the establishment of the direct link is refused, and the first terminal equipment does not establish the first direct link with the second terminal equipment.

In a possible implementation manner, before the first timer expires, the first terminal device further includes: the first terminal device receives a second response message from the third terminal device, where the second response message is used to instruct the third terminal device to accept establishment of the direct link or reject establishment of the direct link.

For the beneficial effects achieved by the second aspect, please refer to the description of the first aspect, which is not repeated herein.

In a third aspect, embodiments of the present application provide a communication method, where the communication method may be implemented by a terminal device, and may also be implemented by a component of the terminal device, such as a processing chip, a circuit, and the like in the terminal device. The method comprises the following steps: the second terminal equipment receives a first request message from the first terminal equipment, wherein the first request message contains identification of all vehicle-to-vehicle V2X services and does not contain target user information, and the first request message is used for requesting to establish a direct link which is used for V2X communication; and the second terminal equipment sends a first response message to the first terminal equipment, wherein the first response message is used for indicating that the establishment of the direct link is accepted or refusing to be established.

In one possible implementation, the method further includes: the first response message indicates that the establishment of the direct link is accepted, and the second terminal equipment establishes a first direct link with the first terminal equipment; the first response message indicates that the establishment of the direct link is refused, and the second terminal equipment does not establish the first direct link with the first terminal equipment.

In a possible implementation manner, after the second terminal device receives the first request message from the first terminal device, and before the second terminal device sends the first response message to the first terminal device, the method further includes: the second terminal equipment sends a second message to the first terminal equipment by using the first destination layer 2ID, wherein the second message contains user information of the second terminal equipment, and the second message is used for requesting authentication or controlling a security mode; the first destination layer 2ID is a first source layer 2ID of the first terminal device determined according to the first request message; the second terminal equipment starts a third timer, and the starting time of the third timer is the time when the second terminal equipment sends the second message; and the second terminal equipment receives a third message from the first terminal equipment, wherein the third message contains the user information of the second terminal equipment, and the second terminal equipment stops the third timer.

In a possible implementation manner, the sending, by the second terminal device, the first response message to the first terminal device includes: and the second terminal equipment sends a first response message to the first terminal equipment by using a second destination layer 2ID, wherein the second destination layer 2ID is a second source layer 2ID of the first terminal equipment determined according to the third message.

In a possible implementation manner, the first response message is used to indicate whether to accept establishment of the direct link or to reject establishment of the direct link; the first response message of the second terminal equipment indicates to accept to establish the direct link; the method further comprises the following steps: the second terminal device performs direct link communication with the first terminal device using the second destination layer 2 ID.

For the beneficial effects achieved by the third aspect, please refer to the description of the first aspect, which is not repeated herein.

In a fourth aspect, the present application provides a communication method, where the communication method may be implemented by a terminal device, or may be implemented by a component of the terminal device, such as a processing chip, a circuit, and the like in the terminal device. The method comprises the following steps: a first terminal device sends a first request message, wherein the first request message is used for requesting to establish a direct link, the first request message comprises first indication information, the first indication information is used for indicating to send a second request message, and the second request message is used for requesting to establish the direct link with the first terminal device; the first terminal equipment receives a second request message from the second terminal equipment, wherein the second request message is used for requesting to establish a direct link with the second terminal equipment; and the first terminal equipment establishes a direct link between the first terminal equipment and the second terminal equipment according to the second request message.

Through the design, the first terminal device instructs the receiving segment terminal device, such as the second terminal device, to initiate a unicast establishment request to the first terminal device by sending the first request message, and subsequently, the first terminal device may establish a direct link with the second terminal device according to the existing implementation manner.

In a possible implementation manner, the sending, by the first terminal device, the first request message further includes: and the first terminal equipment starts a third timer, the set time length of the third timer is a second preset time length, and the first timer is closed when the first terminal equipment receives the second request message.

In a fifth aspect, the present application provides a communication method, where the communication method may be implemented by a terminal device, or may be implemented by a component of the terminal device, such as a processing chip, a circuit, and the like in the terminal device. The method comprises the following steps: the method comprises the steps that a second terminal device receives a first request message from a first terminal device, wherein the first request message is used for requesting to establish a direct link, the first request message comprises first indication information, the first indication information is used for indicating to send a second request message, and the second request message is used for requesting to establish the direct link with the first terminal device; and the second terminal equipment sends a second request message to the first terminal equipment, wherein the second request message is used for requesting to establish a direct link between the first terminal equipment and the second terminal equipment.

In a possible implementation manner, the first request message further includes user information of the first terminal device; the second request message includes user information of the second terminal device and user information of the first terminal device.

The technical effects achieved by any one of the possible designs of the fifth aspect can be achieved by referring to the technical effects achieved by the fourth aspect, and detailed descriptions thereof are omitted.

In a sixth aspect, the present application provides a communication apparatus, which may be a terminal device or a chip of the terminal device. The apparatus has the function of implementing the embodiments of any of the first to fifth aspects described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

Illustratively, the apparatus includes a communication module and a processing module, wherein the communication module includes a transmitting module and a receiving module.

In one possible design, the sending module is configured to send a first request message, where the first request message includes an identifier of the V2X service and does not include target user information, and the first request message is used to request establishment of a direct link, and the direct link is used for V2X communication;

a receiving module, configured to receive a first response message from a second terminal device, where the first response message is used to indicate acceptance of establishment of a direct link or rejection of establishment of the direct link; the processing module is used for establishing a first direct link between the first terminal device and the second terminal device according to the first response message;

the receiving module is further used for receiving a second response message from the third terminal device; the second response message is used for indicating whether the establishment of the direct link is accepted or refused; and the processing module is used for establishing a second direct link between the first terminal device and the third terminal device according to the second response message.

In one possible design, the processing module is configured to control the sending module to send the first request message, and start a first timer; the first request message contains identification of all vehicle-to-vehicle V2X services, the first request message does not contain target user information, the first request message is used for requesting to establish a direct link, and the direct link is used for V2X communication; the processing module is further used for controlling the receiving module to receive a first response message from the second terminal device, and keeping the first timer to keep timing continuously until the first timer is overtime according to the fact that the first request message does not contain the target user information; the first response message is used for indicating the second terminal equipment to accept to establish the direct link or refuse to establish the direct link. A sending module, configured to send a first request message; and the receiving module is used for receiving the first response message from the second terminal equipment.

In one possible design, the receiving module is configured to receive a first request message from a first terminal device, the first request message including an identification of all car-to-car V2X services and the first request message not including target user information, the first request message being configured to request establishment of a direct link, the direct link being configured for V2X communication; a sending module, configured to send a first response message to the first terminal device, where the first response message is used to indicate acceptance of establishment of the direct link or rejection of establishment of the direct link. And the processing module is used for establishing a direct link with the first terminal equipment according to the first response message.

In one possible design, a sending module, configured to send a first request message, where the first request message is used to request to establish a direct link, and the first request message includes first indication information, where the first indication information is used to indicate sending of a second request message, and the second request message is used to request to establish a direct link with the first terminal device; a receiving module, configured to receive a second request message from a second terminal device, where the second request message is used to request establishment of a direct link with the second terminal device; and the first terminal equipment establishes a direct link between the first terminal equipment and the second terminal equipment according to the second request message.

In one possible design, a receiving module is configured to receive a first request message from a first terminal device, where the first request message is used to request a direct link to be established, and the first request message includes first indication information, where the first indication information is used to indicate that a second request message is sent, and the second request message is used to request the direct link to be established with the first terminal device; and the sending module is used for sending a second request message to the first terminal device, wherein the second request message is used for requesting to establish a direct link between the first terminal device and the second terminal device.

In a seventh aspect, the present application provides a communication apparatus, which may be an access network device and may also be a chip for the access network device. The apparatus has the function of implementing the embodiments of the second aspect described above, or the function of the embodiments of the fifth aspect described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In one possible design, the processing module is configured to determine first information, where the first information is used to determine sending time of downlink data, and the downlink data is used to be sent to the terminal device; and the sending module is used for sending the first information to the first terminal equipment.

In one possible design, the processing module is configured to determine second information, where the second information is used to indicate that the terminal device is reachable; and the sending module is used for sending the second information to the first terminal equipment.

In an eighth aspect, the present application provides a communication device comprising a processor and an interface circuit, the processor being configured to communicate with other devices via the interface circuit and to perform the method of the above aspects. The processor includes one or more.

In a ninth aspect, the present application provides a communication device comprising a processor, coupled to a memory, for invoking a program stored in the memory to perform the methods of the above aspects. The memory may be located within the device or external to the device. And the processor includes one or more.

In a tenth aspect, the present application also provides a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the processor to perform the method of the above aspects.

In an eleventh aspect, the present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the above aspects.

In a twelfth aspect, the present application also provides a chip or chip system comprising: a processor for communicating with other devices via a communication interface and for performing the methods of the above aspects.

Drawings

FIG. 1 is a system architecture diagram;

fig. 2a is a schematic flow chart of a method for establishing a direct link between terminal devices;

fig. 2b is a schematic flowchart illustrating a communication method according to an embodiment of the present disclosure;

FIG. 3 is a flowchart illustrating a process according to an embodiment of the present application;

fig. 4 is a corresponding flowchart of an embodiment provided in the present application;

fig. 5 is a schematic flow chart corresponding to a third embodiment provided in the present application;

fig. 6 is a schematic flowchart corresponding to a fourth embodiment of the present application;

fig. 7 is a flowchart illustrating another communication method according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a communication device provided in the present application;

fig. 9 is a schematic structural diagram of another communication device provided in the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

Fig. 1 is a schematic diagram of a network architecture. As shown in fig. 1, one or more terminal devices (such as terminal device 1021, terminal device 1022, and terminal device 1023) may be included in the network architecture.

The terminal device 1021 and the terminal device 1022 may be connected, and the terminal device 1021 and the terminal device 1023 may be connected through a Sidelink (SL), where the sidelink belongs to a kind of direct link between the terminal device and the terminal device. Communication between terminal device 1021 and terminal device 1022, and between terminal device 1021 and terminal device 1023, may be referred to as device-to-device (D2D) communication. For example, terminal device 1021 may send data to terminal device 1022, in this case, terminal device 1021 may be referred to as a sending terminal device (initiating UE) or a source terminal device (source user), and terminal device 1022 may be referred to as a receiving terminal device or a target terminal device (target UE); for another example, the terminal device 1022 may transmit data to the terminal device 1021, in which case, the terminal device 1022 may be referred to as a sender terminal device or a source terminal device, and the terminal device 1021 may be referred to as a receiver terminal device or a target terminal device.

Further, when the terminal device 1021 and the terminal device 1022 are within a short distance range, direct communication is possible after mutual discovery, for example, a connection can be established between the terminal device 1021 and the terminal device 1022 based on a near field communication 5 (PC 5) interface, and communication is performed through the connection, where the connection may be referred to as a PC5 connection or a PC5 link or a PC5 communication link.

It should be understood that the number of terminal devices in the network architecture is not limited, and fig. 1 illustrates a mobile phone, which is not limited. The embodiments of the present application can be applied to the network architecture shown in fig. 1.

For the convenience of understanding, terms related to the embodiments of the present application are explained, and the explanation of the terms is also included as part of the summary of the invention of the embodiments of the present application.

Terminal equipment

The terminal equipment, which may also be referred to as User Equipment (UE), includes equipment that provides voice and/or data connectivity to a user, and may include, for example, a handheld device having wireless connection capability or a processing device connected to a wireless modem. The terminal device may communicate with a core network via a Radio Access Network (RAN), exchanging voice and/or data with the RAN. The terminal device may include a wireless terminal device, a mobile terminal device, a device-to-device communication (D2D) terminal device, a vehicle-to-everything (V2X) terminal device, a machine-to-machine/machine-type communication (M2M/MTC) terminal device, an internet of things (IoT) terminal device, a subscriber unit, a subscriber station, a mobile station, a remote station, an Access Point (AP), a remote terminal, an access terminal, a user agent, or user equipment, etc. For example, mobile telephones (or so-called "cellular" telephones), computers with mobile terminal equipment, portable, pocket, hand-held, computer-included mobile devices, and the like may be included. For example, Personal Communication Service (PCS) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), and the like. Also included are constrained devices, such as devices that consume less power, or devices that have limited storage capabilities, or devices that have limited computing capabilities, etc. Examples of information sensing devices include bar codes, Radio Frequency Identification (RFID), sensors, Global Positioning Systems (GPS), laser scanners, and the like.

In this embodiment of the present application, the apparatus for implementing the function of the terminal device may be the terminal device, or may be an apparatus capable of supporting the terminal device to implement the function, such as a chip system or a combined device and a component capable of implementing the function of the terminal device, and the apparatus may be installed in the terminal device. In the embodiment of the present application, the chip system may be composed of a chip, and may also include a chip and other discrete devices. In the technical solution provided in the embodiment of the present application, a device for implementing a function of a terminal device is described as an example of the terminal device.

Two, through link

The direct link is used for communication between the terminal device and the terminal device, and the direct link may include a physical direct link shared channel (PSCCH) and a physical direct link control channel (PSCCH). The psch is configured to carry direct link data (SL data), and the PSCCH is configured to carry Sidelink Control Information (SCI), where the SCI may also be referred to as sidelink scheduling assignment (SL SA). The SL SA is information related to data scheduling, such as resource allocation and/or Modulation and Coding Scheme (MCS) for carrying the PSSCH.

Optionally, the direct link communication may further include: a physical downlink uplink control channel (PSUCCH). The physical through-link uplink control channel may also be referred to simply as a through-link uplink control channel. The physical direct link uplink control channel may also be referred to as a physical direct link feedback channel (PSFCH). The physical through link feedback channel may also be referred to simply as a through link feedback channel. The direct link uplink control channel or the direct link feedback channel may be used to transmit direct link feedback control information (SFCI). The direct link feedback control information may also be referred to as direct link feedback information (SL UCI) for short, or as direct link uplink control information (SL UCI). The direct link feedback control information may include at least one of Channel State Information (CSI), hybrid automatic repeat request (HARQ) information, and the like. The HARQ information may include Acknowledgement (ACK) or Negative Acknowledgement (NACK).

SL is a kind of direct link, and is applicable to a vehicle networking (V2X) scenario, where X may refer to any object. For example, the vehicle networking communication may include vehicle-to-vehicle (V2V), vehicle-to-roadside infrastructure (V2I), vehicle-to-pedestrian (V2P), and vehicle-to-network (V2N), among others. The internet of vehicles may also be referred to as a cooperative-intelligent transport system (C-ITS), and the like.

The network architecture illustrated in fig. 1 may be applied to communication systems of various Radio Access Technologies (RATs), for example, a 4G (or Long Term Evolution (LTE)) communication system, a 5G (or New Radio (NR)) communication system, or a future communication system. The network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not form a limitation on the technical solution provided in the embodiment of the present application, and as a person of ordinary skill in the art knows that along with the evolution of the communication network architecture and the appearance of a new service scenario, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

Layer 2ID pair

The Layer 2ID pair includes a source Layer 2ID (source Layer-2 ID) and a target Layer 2ID (target Layer-2 ID). For a sending UE, the source layer 2ID is the layer 2ID of the sending UE itself, and the destination layer 2ID is the layer 2ID of the destination UE.

The following describes a conventional method for establishing a direct link between terminal devices, taking the V2X scenario as an example. Referring to fig. 2a, a flow diagram corresponding to the method may include the following steps:

step 101: the UE1 (also referred to as initiating UE) sends direct link establishment request (direct link acknowledgement request) signaling, and starts a timer (e.g., T5000).

When the UE1 initiates the unicast establishment procedure, if the UE is triggered by the V2X service and does not know the user information (e.g., target user information) of the target UE, that is, the application layer does not provide the user information of the target UE, the UE1 does not carry the target user information in the unicast establishment request (e.g., direct link establishment request) sent when initiating the unicast establishment procedure, but carries the V2X service identifier to identify the corresponding V2X service. Therefore, if multiple UEs receive the direct link establishment request and are interested in the V2X service indicated by the direct link establishment request (indicated by the V2X service identifier), the multiple UEs may respectively send corresponding security-related (e.g., direct link authentication request or direct link security mode control) signaling to the UE1 to perform mutual authentication or establish security with the UE1, and after security establishment, unicast establishment is further completed.

Specifically, the UE1 has a mapping relationship between the preconfigured V2X service identifier and the destination layer 2ID, and the UE1 determines, according to the mapping relationship, the destination layer 2ID corresponding to the V2X service identifier when initiating the unicast establishment procedure. It should be appreciated that the destination layer 2ID is the source layer 2ID of the recipient terminal device with respect to UE1 that is interested in V2X traffic initiated by UE 1. The UE1 sends the direct link setup request using its own source layer 2ID and destination layer 2 ID.

Correspondingly, the UE2 receives the direct link establishment request from the UE1 by using the source layer 2ID of the UE2 (destination layer 2ID corresponding to the V2X service identifier), and then feeds back corresponding security-related signaling to the UE1 for unicast establishment.

The functions of T5000 include: stop when UE1 receives the direct link setup response message from UE2 (step 106), or T5000 stops when the timer is completed. The timing duration of the T5000 is a set duration, and before the T5000 is overtime, the UE1 waits for receiving the direct link establishment response signaling of the other UE.

Step 102: the UE2 sends a verification request to the UE 1. Correspondingly, the UE1 receives an authentication request from the UE 2.

Illustratively, the UE2 sends direct link authentication request (direct link authentication request) signaling to the UE 1. Wherein the direct link authentication request is used in a communication scenario requiring a basic Key, and the UE2 and the UE1 exchange information (Key authentication information) of Key establishment to generate a basis for communicating with the UE1Key (key, K)_NRP， new radio PC5 key)。

Specifically, when the UE2 sends the security-related signaling to the UE1, it allocates a new source layer 2ID (different from the destination layer 2ID corresponding to the V2X service identifier in step 101). The UE2 uses the source layer 2ID of UE1 as the destination layer 2ID and sends a direct link authentication request using the new source layer 2ID and the source layer 2ID of UE 1. Accordingly, the UE1 may subsequently use the new source layer 2ID of the UE2 as the destination layer 2ID of the UE1 itself for signaling interactions.

Step 103: the UE1 sends response signaling to the direct link authentication request to the UE 2. Correspondingly, the UE2 receives response signaling to the direct link authentication request from the UE 1.

The response signaling to the direct link authentication request includes a direct link authentication response or a direct link authentication rejection.

It should be noted that, in steps 102 and 103, multiple times/round may be performed. For example: if the UE1 does not accept the direct link authentication request sent by the UE1 (e.g., the verification fails), the UE1 sends a direct link authentication rejection to the UE2, and the UE1 suspends the unicast establishment procedure.

Interaction of UE1 with UE2 through direct link authentication related signaling generates basic key K_NRPThereafter, step 104 is performed.

Step 104: the UE2 sends security mode command signaling to the UE1 for triggering establishment of security between the UE2 and the UE 1. Correspondingly, the UE1 receives security mode command signaling from the UE 2.

Illustratively, the UE2 sends direct link security mode command (direct link security mode command) signaling to the UE 1.

It should be noted that the flow of establishing the direct link between the UE1 and the UE2 according to the embodiment of the present application may include steps 101 to 106. If the basic key already exists between the UE2 and the UE1 after step 101, or in a communication scenario where the basic key is not needed, the UE2 may also directly perform step 104, that is, another flow for establishing the direct link may include steps 101, 104 to 106.

It should be understood that the security mode command signaling belongs to the security-related signaling, and if step 104 is executed directly after step 101, the UE2 sends the security mode command signaling according to the manner of step 102, which is specifically described in step 102 and will not be described herein again.

Step 105: the UE1 sends security mode complete (security mode complete) signaling to the UE 2.

It should be noted that, if the UE1 does not accept the direct link security mode command sent by the UE1 (e.g., authentication failure, integrity protection failure, etc.), the UE1 sends a direct link security mode rejection to the UE2, and the UE1 suspends the unicast establishment procedure.

Step 106: the UE2 sends a direct link setup response signaling to the UE 1. Correspondingly, the UE2 receives the direct link setup response signaling from the UE1 while turning off the timer T5000.

The direct link setup response signaling is used to indicate the direct link setup result of the UE2 and the UE1, which includes the setup success and the setup failure. For example, if the establishment is successful (i.e., the UE2 accepts the direct link establishment with the UE1), the UE2 may send a direct link acknowledgement (direct link acknowledgement) message to the UE 1. If the establishment fails (i.e., the UE2 rejects establishment of the direct link with the UE1), the UE2 may send a direct link acknowledgement (direct link reject request) message to the UE 1.

As previously described, the UE1 waits to receive the direct link setup response signaling of the other UEs before the T5000 timeout. It should be appreciated that, in step 106, the UE1 receives the direct link setup response signaling from the UE2 before the T5000 timeout.

At present, when an initiating UE sends a direct link establishment request, a timer T5000 is started to start timing, T5000 stops timing when the initiating UE receives a first direct link establishment response message, and after T5000 stops timing, the initiating UE does not process messages of other UEs after the initiating UE stops timing. That is, after initiating the unicast establishment procedure, the existing initiating UE can only establish a direct link with one receiving end UE (or may fail to establish the direct link), and cannot establish the unicast establishment procedures with multiple receiving end UEs respectively. For example, in fig. 1, after receiving the unicast establishment request signaling from the UE1, a plurality of UEs may respectively feed back corresponding security-related signaling to the UE1, but the UE1 can only respond to the direct link establishment response message fed back by one of the UEs, and cannot respond to the messages fed back by the remaining UEs. The manner of establishing the direct link between the initiating UE and the multiple UEs is complicated, and the signaling overhead is large.

In view of this, an embodiment of the present application provides a communication method, where the method includes a first terminal device sending a first request message, where the first request message is used to request to establish a direct link; the first terminal device receives a first response message from the second terminal device, wherein the first response message is a response message of the first request message, the first response message is used for indicating a result of the establishment of the direct link of the second terminal device, and the first terminal device establishes the direct link with the second terminal device according to the first response message. Similarly, the first terminal device receives a second response message from the third terminal device, where the second response message is a response message of the first request message, the second response message is used to indicate a result of establishing the direct link with the third terminal device, and the first terminal device establishes the direct link with the third terminal device according to the second response message. In this embodiment of the application, after the first terminal device sends the first request message, the first terminal device may respond to a response message of one or more terminal devices, and if there are response messages of a plurality of terminal devices, the first terminal device establishes a direct link with each of the plurality of terminal devices. The flow of establishing the direct link between the first terminal device and each terminal device is independent from each other and is not affected by the flow of establishing the direct link between the first terminal device and other terminal devices, so in the embodiment of the application, after the initiating UE sends one first request message, a plurality of direct links can be established with different terminal devices, and the initiating UE does not need to send a plurality of first request messages, thereby improving the efficiency of establishing a plurality of direct links between the terminal devices and saving signaling overhead.

The first terminal device in this embodiment may be an initiating UE (UE1), and the second terminal device, the third terminal device, and the fourth terminal device are respectively a receiver terminal device of signaling 1. For convenience of description, hereinafter, the first terminal device will be referred to simply as UE1, the second terminal device will be referred to simply as UE2, the third terminal device will be referred to simply as UE3, and the fourth terminal device will be referred to simply as UE 4. That is, UE1 described later in this application may be replaced with a first terminal device, UE2 may be replaced with a second terminal device, UE3 may be replaced with a third terminal device, and UE4 may be replaced with a fourth terminal device.

For convenience of description, the direct link establishment request signaling in step 101 in fig. 2a may be abbreviated as signaling 1; the direct link authentication request signaling in step 102 may be abbreviated as signaling 2; the authentication response signaling of the direct link in step 103 can be abbreviated as signaling 3; the direct link security mode command signaling in step 104 can be abbreviated as signaling 4; the security mode completion signaling in step 105 may be abbreviated as signaling 5; the direct link setup response message in step 106 may be abbreviated as signaling 6.

Illustratively, in this embodiment of the present application, the first request message may be signaling 1, the second message may be signaling 2 and/or signaling 4, the third message may be signaling 3 and/or signaling 5, and the first response message may be signaling 6.

Before the technical solution of the present application is introduced, the concept that the embodiments of the present application are easy to confuse is explained by combining the aforementioned noun explanations:

first, layer 2ID pair

In the embodiment of the present application, multiple layer 2ID pairs are involved, and taking the interaction between the UE1 and the UE2 as an example, the multiple layer 2ID pairs include: layer 2ID pair 1 used when UE1 sends the first request message (signaling 1), layer 2ID pair 2 used when UE2 sends the second message (signaling 2 and/or signaling 4), layer 2ID pair 3 used when UE1 sends the third message (signaling 3 and/or signaling 5), and layer 2ID pair 4 used when UE2 sends the first response message (signaling 6).

For convenience of description, hereinafter, the source layer 2ID (of the UE1) in the layer 2ID pair 1 is referred to as a first source layer 2ID, and the destination layer 2ID (destination layer 2ID corresponding to the V2X service identification) is referred to as a first destination layer 2 ID. Source layer 2ID (of UE1) in layer 2ID pair 3 is denoted as second source layer 2ID, and destination layer 2ID is denoted as second destination layer 2 ID.

Source layer 2ID (of UE 2) in layer 2ID pair 2 is denoted as third source layer 2ID, where destination layer 2ID in layer 2ID pair 2 is (UE1) first source layer 2 ID. The source layer 2ID (of UE 2) in layer 2ID pair 4 is the third source layer 2ID, and the destination layer 2ID is the second source layer 2ID (of UE 1).

Second, user information (user info)

The message in the embodiment of the present application may further include user info, where the user info may include source user information (source user info) and destination user information (target user info). Similarly, for the sending end UE, source user info is user information of the sending end UE itself, and target user info is user information of the destination UE. Correspondingly, for the receiving end UE, the source user info in the received message is the user information of the sending end UE, and the target user info is the user information of the receiving end UE itself.

The messages (signaling 1 to signaling 6) in the embodiment of the present application may further include user info, where the user info includes source user information (source user info) and destination user information (target user info). Similarly, for the sending end UE, source user info is user information of the sending end UE itself, and target user info is user information of the destination UE. Correspondingly, for the receiving end UE, the source user info in the received message is the user information of the sending end UE, and the target user info is the user information of the receiving end UE itself.

For example, in the embodiment of the present application, the UE1 sends the source user info in the first request message as the user information of the UE1, and the first request message does not carry the target user info. In the second message sent by the UE2, source user info is user information of the UE2 itself, and target user info is user information of the UE1 itself. In the third message sent by UE1 to UE2, source user info is user information of UE1 itself, and target user info is user information of UE2 itself.

The technical solution of the embodiment of the present application is described as follows.

Referring to fig. 2b, a flow diagram corresponding to a communication method provided in the embodiment of the present application is shown, where the method may be applied to the system architecture shown in fig. 1, and the method includes:

step 201: the UE1 sends a first request message.

The first request message includes an identification of the V2X service (V2X service identifier) and does not include target user information (target user info). Optionally, the first request message may further include, but is not limited to, the following information: user information (source user info) of the UE1, security related parameters, etc.

Among them, the Identifier of the V2X Service is used to identify the V2X Service, for example, the Identifier of the V2X Service is a Provider Service Identifier (PSID) or an Intelligent transportation system-Application Object Identifier (ITS-AID). It should be understood that the above description is only for illustration, and the present application is not limited to the V2X service identification.

Illustratively, the first request message may be the above-mentioned direct link establishment request signaling (signaling 1) for requesting establishment of a direct link, which, as mentioned above, is used for transmitting V2X communication, and V2X communication includes data and signaling of V2X traffic.

For example, the UE1 broadcasts the first request message, in an embodiment, the UE1 may send the first request message using the first source layer 2ID and the destination layer 2ID corresponding to the V2X service, and how the UE1 determines the first source layer 2ID and the destination layer 2ID may refer to the related description above, and will not be repeated here.

Optionally, when the UE1 sends the first request message, the UE1 may further start a timer according to the first request message, for example, in step 201, if the first request message does not contain the target user information, the UE1 may start the first timer when sending the first request message.

Specifically, the first timer is configured to monitor a response message of the first request message, and when the feedback of the response message exceeds the timing time of the first timer, the response message is invalid. The starting time of the first timer is the time when the UE1 sends the first request message, the timing duration of the first timer may be a set duration, and the UE1 waits to receive the response message of one or more UEs before the first timer expires. It should be noted that the first timer is stopped only when the timing is completed, that is, the first timer is not stopped in the middle of the timing, for example, when the UE1 receives the response message of the first request message, the UE keeps the first timer to continue the timing until the first timer reaches the set time length.

Correspondingly, one or more UEs may receive the first request message, where the one or more UEs are receiving UEs of the first request message. Receiving UEs may be, for example, UEs around UE1, i.e., within a certain range from UE 1.

Step 202: the UE1 receives a first response message from the UE 2.

The first response message is used to respond to the first request message, and the first response message is used to indicate the result of the direct link setup of the UE2, where the result includes a setup success or a setup failure, and the first response message may be, for example, the signaling 6 described above, and the signaling 6 may be an accept direct link setup message (setup success) or a reject direct link setup message (setup failure).

The UE1 establishes a direct link between the UE1 and the UE2 according to the first response message. For example, the first response message indicates a rejection of establishing the direct link, i.e., failed to establish, the UE1 does not establish the direct link with the UE 2. Another example is: the first response message indicates acceptance of the establishment of the direct link, i.e., successful establishment, the UE1 establishes the direct link with the UE 2.

Optionally, before the step 202, the UE1 may further receive a second message (for example, signaling 2 and/or signaling 4) sent by the UE2, where the second message includes user information of the UE2, and the second message is used to acquire security parameters corresponding to the direct link, for example, the second message is used to request authentication (for example, identity authentication) or is used for security mode control, which is specifically described in the following detailed description of the step 302a in embodiment one, and a description thereof is not repeated here.

Subsequently, the UE1 may send a third message (e.g., signaling 3 and/or signaling 5) to the UE 2. As previously described, the UE1 may send the first request message using the first source layer 2ID, and when the UE1 sends the third message to the UE2, in an implementable manner, the UE1 sends the third message to the UE2 using a second source layer 2ID (i.e., a new source layer 2ID, different from the first source layer 2 ID), the third message including the security parameters (requested by the second message) and the user information of the UE2, and optionally, the third message may also include the user information of the UE 1. Through the above design, a series of problems caused by collision of source layer 2 IDs of multiple receiving end UEs can be avoided, which is specifically described in step 303a below and will not be described again here.

Optionally, before the UE1 sends the third message, the UE1 determines that the number of established and establishing direct links on the UE1 has not reached (is not less than, i.e., is greater than or equal to) the preset threshold. When the preset threshold is not reached, the UE1 sends a third message to the UE2, avoiding an excessive number of unicast links on the UE 1. If the predetermined threshold is reached, the UE1 may refuse to establish a direct link with the UE2, as described in relation to step 303a, and will not be repeated here.

Optionally, when the UE1 sends the third message, the second timer may be started, that is, the starting time of the second timer is the time when the UE1 sends the third message, and the set time duration of the second timer is the remaining timing duration of the first timer at this time, refer to the description of the second timer in step 303a, and the description is not repeated here. The UE1 waits to receive the first response message of the UE2 before the second timer expires, and if the UE1 receives the first response message of the UE2 before the second timer expires, the UE1 stops the second timer, it should be understood that the second timer corresponds to the UE2 one-to-one, i.e., the second timer is used for monitoring the response message of the UE2, and therefore, when the UE1 receives the first response message of the UE2, the second timer may be closed. When the feedback of the first response message of the UE2 exceeds the timing duration of the second timer, the first response message is invalid.

Step 203: the UE1 receives the second response message of the UE 3.

The first response message is used to respond to the first request message, and the second response message is used to indicate the result of the direct link setup of the UE3, where the result includes a setup success or a setup failure, and the first response message may be, for example, the signaling 6 described above, and the signaling 6 may be an accept direct link setup message (setup success) or a reject direct link setup message (setup failure).

The UE1 establishes a direct link between the UE1 and the UE3 according to the second response message.

It should be noted that there is no strict time sequence between step 203 and step 202, and step 203 may be executed first, and then step 202 may be executed, or may be executed simultaneously, which is not limited in the embodiment of the present application. For the specific execution step of step 203, refer to the specific description of step 202, which is not described herein again.

The technical solution of the present application is specifically described below with reference to specific drawings and examples.

Example one

In the first embodiment, the UE1 starts the first timer when sending the first request message, that is, the first timer stops when the counting time reaches the set time (that is, the counting is completed), that is, the first timer does not stop during the counting process, and must time out. The UE1 waits to receive a response message for the one or more UEs before the first timer expires, the response message being a response message for the one or more UEs to the first request message.

Fig. 3 is a schematic flowchart corresponding to a communication method according to an embodiment of the present application. The method can be applied to the system architecture shown in fig. 1. The method comprises the following steps:

step 301: the UE1 sends a first request message with the start of a first timer. Correspondingly, UE X (e.g., UE2, UE3) receives the first request message.

Specifically, after the UE1 sends the first request message to generate the first request message for the UE1, the first request message is delivered to an Access Stratum (AS) of the UE1 for transmission.

The first request message is already described in step 201, and is not described herein again.

The UE1 sends the first request message using its source layer 2ID and destination layer 2 ID. The manner in which the UE1 determines the source layer 2ID and the destination layer 2ID may be referred to in the related description, and will not be repeated here. Illustratively, the first request message includes a message header and a data portion, and the UE1 may encapsulate/populate the source layer 2ID and the target layer 2ID in the message header of the first request message, which will then be sent.

The timing duration of the first timer may be a set duration, the name of the first timer may be T5500, T5500 is only stopped when the timing is completed, that is, T5500 may not be stopped in the middle of the timing, and the UE1 waits for receiving a response message of one or more UEs before the time of T5500 expires. It should be understood that T5500 is only an example, the name of the first timer is not limited in the embodiments of the present application, and those skilled in the art may replace the name of the first timer with another name to perform the same function.

It should be noted that if the first request message sent by the UE1 includes the target user information, the UE1 may start a second timer, for example, T5000, when sending the first request message, and the second timer is stopped when the counting is completed or when the UE1 receives the first response message.

Correspondingly, the UEs around the UE1 receive the direct link establishment request, and assuming that there are multiple receiving UEs (denoted as UE x) that receive the first request message sent by the UE1, the UE2 is one of the one or more UEs in the UE x that are interested in the V2X service indicated by the first request message. The following procedure for establishing a direct link between UE2 and UE1 is described as follows, taking UE2 as an example:

step 302 a: the UE2 sends a second message to the UE 1. Correspondingly, the UE1 receives a second message from the UE 2.

The second message is used to obtain the security parameter corresponding to the direct link, and the second message may be, for example, signaling 2 and/or signaling 4 in the foregoing. Specifically, the second message is signaling 2, which is used for mutual authentication and generation of the basic key (K)_NRP) And the second message is signalling 4, for requesting establishment of security (of a direct link) with the UE1 (including decision of integrity protection and ciphering algorithms for the signalling and control planes, and generation of other link-related keys K_NRP-sessKeys for sessions, NRPEK (New Radio PC5 Encryption Key, New wireless PC5 Encryption Key) encrypted keys, NRPIK (New Radio PC5 Integrity Key, New wireless PC5 Integrity Key) Integrity protected keys, etc.).

Correspondingly, in step 302a, in an implementable manner, the UE2 first sends signaling 2 to the UE1, and after receiving signaling 3 of the UE1, the UE2 sends signaling 4 to the UE1, and the second message is signaling 2 and signaling 4. In another implementation, the UE2 sends signaling 4 to the UE1, and the second message is signaling 4.

Specifically, when transmitting the second message, the UE2 determines a new source Layer 2ID (third source Layer 2 ID), and transmits the second message using the third source Layer 2ID (source Layer-2 ID) and the first source Layer 2ID (target Layer-2 ID) by using the first source Layer 2ID of the UE1 determined according to the first request message as the destination Layer 2ID by the UE 2. Specifically, the first request message may include user information of the UE1, and the second request message may include user information (source user info) of the UE 2. User information (target user info) of the UE1 may also be included.

Correspondingly, the UE1 receives a second message from the UE 2.

It should be appreciated that each time the UE1 receives a second message from a certain UE X, it is first determined whether the second message is the first time the UE1 receives a message from that UE X. If the unicast establishment process is received for the first time, a new unicast establishment process is established with the UE X correspondingly. For example, the first signaling received by the UE1 and sent by the UE2 is signaling 2, and signaling 2 is the signaling that the UE1 receives the UE2 for the first time. For another example, the first signaling that the UE1 receives from the UE2 is signaling 4, and signaling 4 is the signaling that the UE1 receives the UE2 for the first time.

Illustratively, the UE1 may determine whether the signaling is first received from the UE according to the source Layer-2 ID and the source user info in the received second message. For example, the UE1 compares the source Layer-2 ID and the source user info in the second message received from the UE2 with the source Layer-2 ID and the source user info in the recorded history received messages, and if the source Layer-2 ID and the source user info in the second message do not exist in the history received messages, it is determined that the UE1 receives the signaling from the UE2 for the first time.

Assume in step 302a that the UE1 received the second message from UE2 as the first received message from UE 2. The UE1 responds to the second message by performing step 303 a. It should be appreciated that if the second message is not the first message received from the UE2, then the UE1 does not need to establish a new unicast establishment procedure with the UE2, i.e., does not need to perform the subsequent step 303 a.

Step 303 a: the UE1 sends a third message to the UE2 while starting the second timer. Correspondingly, the UE2 receives a third message from the UE 1.

The starting time of the second timer is the time when the UE1 sends the third message, specifically, the time when the UE1 sends the third message is the time when the AS layer of the UE1 transmits the third message. And the timing duration of the second timer is the remaining timing duration of the first timer. For example, the timing duration of the first timer is 8s, when the UE1 sends the third message, the remaining timing duration of the first timer is 6s, and the timing duration of the second timer is 6 s. The name of the second timer may be T5000, and the T5000 stops when the counting is completed, or, before the T5000 times out, the UE1 stops when receiving the first response message of the UE2, and the T5000 stops.

Because the source Layer-2 IDs of different UEs X may collide, for example, the source Layer-2 ID in the second message sent by the UE2 is the same as the source Layer-2 ID in the second message sent by the UE3, which results in that the UE1 establishes different direct links with different UEs using the same Layer 2ID pair (source Layer 2ID and destination Layer 2 ID), so that the UE1 may recognize different UEs as the same UE, and subsequently, signaling or data sent by the UE1 to the UE2 may occur and the UE3 may also receive the signaling or data; on the contrary, the UE1 cannot determine whether the signaling or data sent by the UE2 to the UE1 is sent by the UE2 or the UE 4.

To solve the above problem, the present application provides a solution that when sending the third message, the UE1 can determine a new source layer 2ID of the UE1 itself according to the second message of the UE2, and use the new source layer 2ID for subsequent message interaction with the UE 2.

There are various ways for the UE1 to determine a new source layer 2ID, as exemplified by the following:

the generation method is as follows:

the UE1 randomly generates a new layer 2ID (e.g., generates a 24bit random number) and ensures that the new layer 2ID is not duplicated for both the source layer 2ID and the destination layer 2ID on the existing UE 1.

The second generation method is as follows:

the UE1 generates a new layer 2ID (e.g., a random number of 24 bits) with the source user information included in the second message sent by the UE2 as a random factor, and ensures that the new layer 2ID is not duplicated with both the source layer 2ID and the destination layer 2ID of the existing UE 1.

The third generation mode:

the UE1 takes the source user information contained in the second message sent by the UE2 as the input of the hash algorithm (e.g., MD5), and takes the last or first 24 bits of the hash algorithm as a new layer 2ID, and ensures that the new layer 2ID is not duplicated with the source layer 2ID and the destination layer 2ID of the existing UE 1.

For convenience of description, hereinafter, source layer 2ID when the UE1 transmits the first request message is referred to as first source layer 2ID in step 301, and source layer 2ID when the UE1 transmits the third request message is referred to as second source layer 2ID in step 303 a. The source layer 2ID when the UE2 sends the second message is noted as the third source layer 2 ID.

Specifically, in transmitting the third message, the UE1 determines the third source layer 2ID of the UE2 from the second message received from the UE2, the UE1 has the third source layer 2ID of the UE2 as the destination layer 2ID, and the UE1 transmits the third message to the UE2 using the second source layer 2ID and the third source layer 2 ID. The third message includes, but is not limited to, security parameters of the direct link and user information (target user info) of the UE 2. Illustratively, the third message may be signaling 3 and/or signaling 5. If the second message received by the UE1 is signaling 2 in step 302a, the UE1 sends signaling 3 to the UE 2; if the second message received by the UE1 is signaling 4 in step 302a, the UE1 sends signaling 5 to the UE 2.

Correspondingly, the UE2 receives the third message sent by the UE 1. The UE2 determines whether the target user info in the third message is consistent with the user information of the UE2, and if so, the UE2 uses the second source layer 2ID of the UE1 determined according to the third message as a new destination layer 2ID, and the UE2 performs subsequent message interaction with the UE1 using the third source layer 2ID and the second source layer 2 ID. If not, the UE2 discards the third message.

Optionally, before step 303a, the method may further include: the UE1 determines whether the number of established and currently established direct links of the UE1 reaches (is not less than) a preset threshold, and if so, continues to perform the subsequent step 303 a; otherwise, the UE1 sends a fourth message to the UE2, where the fourth message is used to Reject the second message of the UE2, or, the fourth message is used to instruct the UE1 to Reject mutual Authentication with the UE2 or Reject establishment of Security with the UE2, and further to abort establishment of the direct link between the UE1 and the UE2, where the fourth message is, for example, Authentication Reject (Authentication Reject) or Security Mode Reject (Security Mode Reject), and optionally, the fourth message may also indicate a Reject reason, for example, the fourth message includes second indication information (cause value), the cause values have different values, each value indicates a Reject reason, for example, the cause value is 5 indicates resource limited (limited resources), the cause value is 111 indicates a protocol unknown error, and so on.

The direct link established by the UE1 refers to the direct link established by the UE1 with the peer UE (any UE) when the UE1 receives the first response message sent by the peer UE and the first response message indicates acceptance of establishment of the direct link. The direct link being established on the UE1 is a direct link to be established after the UE1 receives the second message of the other UE and enters a subsequent step of the unicast establishment procedure with the other UE in response to the second message. The predetermined threshold is the maximum number of direct links that the UE1 can establish (or maintain) at a time.

It is understood that prior to performing step 303a, the UE1 determines that the number of established and establishing direct links on the UE1 has not reached a preset threshold.

Step 304a, the UE2 sends a first response message to the UE 1. The corresponding UE1 receives the first response message from UE2, turning off the second timer.

In transmitting the first response message, the UE2 transmits the first response message to the UE1 using the third source Layer 2ID (source Layer-2 ID) and the second source Layer 2ID (target Layer-2 ID). The second source layer 2ID may be determined by the UE2 according to the third message, for example, as described above, the second source layer 2ID is encapsulated in the header of the third message, and the UE2 may determine the second source layer 2ID according to the header of the third message. The UE2 uses the second source layer 2ID as the destination layer 2 ID.

As previously described, the first response message is used to indicate a direct link establishment result of the UE2 with the UE1, which includes an establishment success or an establishment failure. Here, the first response message of the UE2 indicates acceptance of establishment of the direct link, the UE2 establishes the direct link with the UE1, and the UE1 establishes the direct link with the UE2 after the UE1 receives the first response message of the UE 2. Wherein, if the UE1 establishes a direct link with the UE2, the UE1 may continue to use the second source layer 2ID to communicate with the UE2 via the V2X of the direct link, and the V2X communication includes data interaction and signaling interaction.

Correspondingly, the UE1 receives the first response message from the UE2 while turning off the second timer, i.e., T5000. It should be appreciated that T5000 does not time out when the UE1 receives the first response message.

It should be noted that, in a possible scenario, in step 304a, if T5000 times out, the UE1 does not receive the first response message of the UE2, and in an alternative implementation, the UE1 sends the unicast establishment request to the UE2 until the number of times of retransmitting the unicast establishment request reaches the maximum set number of times of retransmission. Wherein the unicast establishment request is for requesting to establish a direct link with the UE2, the unicast establishment request includes user information (target user info) of the UE2, and the UE1 sends the unicast establishment request to the UE2 using the second source Layer 2ID (source Layer-2 ID) and the third source Layer 2ID (target Layer-2 ID).

In another alternative implementation, whether UE1 sends a unicast establishment request to UE2 depends on whether the application layer of UE1 also needs to establish a direct link with UE2, if needed, UE1 sends a unicast establishment request to UE2, otherwise, UE1 does not resend the unicast establishment request to UE 2.

In a third optional implementation manner, after the UE1 sends the first request message, when T5500 times out, the UE1 does not successfully establish any direct link, and then the UE1 sends a unicast establishment request to the UE2 until the number of times of retransmitting the unicast establishment request reaches the maximum set retransmission number.

It should be appreciated that the UE1 may also determine that the number of established and establishing direct links on the UE1 has not reached the preset threshold before the UE1 retransmits the unicast establishment request to the UE 2.

As described above, the set duration of the T5000 is the remaining timing duration of the T5500, and if the UE1 receives the first response message sent by the UE2, the T5000 does not time out, the T5500 is not timed out, that is, the T5500 is still timing, in a possible scenario, the UE1 receives the first response message of the first response message UE2 after sending the first request message, the UE1 does not close the T5500, and the T5500 continues to time until the timing time reaches the set duration. During the timing of T5500, the UE1 may also receive response messages of other UEs in the UE x except for the UE2, and the UE1 may continue to process the response messages of the other UEs before the time out of T5500. For example, the UE1 also receives the response message of the UE3, and the following briefly introduces a procedure for the UE1 to establish a direct link with the UE 3:

step 302b, the UE3 sends a second message to the UE 1. Correspondingly, the UE1 receives a second message from the UE 3.

In step 303b, the UE1 sends a third message to the UE3 and starts a new second timer. Correspondingly, the UE3 receives a third message from the UE 1.

The new second timer is a second timer started when the UE1 sends the third message to the UE2 in step 302 a. For example, in step 302a, the UE1 starts a first T5000, and in step 302b, the UE1 starts a second T5000. That is, the UE1 may establish a separate unicast establishment procedure for each UE that first receives the second message.

Similarly, the UE1 determines a new source layer 2ID, denoted as the fourth source layer 2ID, from the second message received from the UE3, the fourth source layer 2ID being different from the layer 2ID already on the UE1, i.e., the fourth source layer 2ID is different from the first source layer 2ID, the second source layer 2ID, and the third source layer 2 ID. In other words, in the unicast establishment procedure, the UE1 interacts with different UEs using different source Layer-2 IDs, thereby distinguishing the different UEs.

The manner in which the UE1 determines the fourth source layer 2ID may refer to the step of determining the second source layer 2ID in step 302a, and is not described herein again.

Step 304b, the UE3 sends a first response message to the UE 1. The corresponding UE1 receives the first response message from UE3, turning off the new second timer.

It should be noted that, in the embodiment of the present application, the flow shown in fig. 2a is taken as an example, and names are performed on messages sent by different UEs to represent a specific flow for establishing a direct link between the different UEs and the UE 1. Although the message names of different UEXs sent by different UEs in this application are the same, in fact, the messages may be different, that is, the second message, the third message, and the first response message of UE1 interacting with UE2 are different from the second message, the third message, and the first response message of UE1 interacting with UE3, respectively, for example, the first response message of UE3 does not refer to the same as the first response message of UE2, the first response message of UE2 refers to the response message of UE2 to the first request message, the first response message of UE3 refers to the response message of UE3 to the first request message,

for example, the second message sent by the UE3 may be denoted as a fifth message, the third message sent by the UE1 to the UE3 may be denoted as a sixth message, and the first response message sent by the UE3 may be denoted as a second response message. For convenience of description, the following still follows the procedure shown in fig. 2a (i.e., the second message, the third message, and the first response message) to name the messages of different UEX interacting with the UE1, and similar problems will not be repeated below.

It should be noted that, steps 302a to 304a and steps 302b to 304b do not have a strict time sequence, that is, steps 302b to 304b may be executed first, and then steps 302a to 304a are executed, or steps 302a to 304a may be executed simultaneously or alternately with steps 302b to 304b, it should be understood that the simultaneous or alternate execution means that the unicast establishment procedure with the UE3 may be executed when the unicast establishment procedure with the UE2 is executed, and the embodiment of the present application is not limited thereto. The unicast establishment procedure between UE1 and UE2 should be performed in the order from step 302a to step 304a, and the unicast establishment procedure between UE1 and UE3 should be performed in the order from step 302b to step 304 b.

In one possible scenario, if the first timer T5000 is not timed up after steps 304a and 304b, the UE1 may continue to process the response messages of the remaining UEs (UEs other than UE2 and UE 3). If the first timer T5000 is finished, the UE1 stops receiving or discards the response messages of the remaining UEs.

Through the method, after sending the first request message, the UE1 can respond to the second messages of the multiple UEs, and perform unicast establishment procedures with each of the multiple UEs, respectively establish multiple unicasts with the multiple UEs, and the unicast establishment procedures do not interfere with each other.

Example two

In the second embodiment, after the UE1 sends a first request message, it may choose to establish only one unicast establishment procedure.

Referring to fig. 4, a second communication method is provided for the embodiment of the present application, and the method may be applied to the system architecture shown in fig. 1, where the method includes the following steps:

step 401: the UE1 sends the first request message using the first source layer 2ID while starting the second timer. Correspondingly, UE X (e.g., UE2, UE3) receives the first request message.

Except for the different starting timers, step 401 is the same as the rest of step 301, please refer to the above detailed description of step 301, and will not be described herein again.

As previously described, the second timer (e.g., T5000) may be stopped when the count reaches a set duration or when the UE1 receives a first response message.

Step 402: the UE2 sends a second message to the UE 1. Correspondingly, UE1 receives the second message from UE X using the first source layer 2 ID.

It should be understood that step 402 assumes that the second message first received by UE1 was sent by UE2, and that the first second message received by UE1 may also be for any other UE in UE X than UE 2. For step 402, reference may be made to the above detailed description of step 302a, which is not described herein again.

Step 403: the UE1 stops receiving messages using the first source layer 2 ID.

The UE1 stops receiving messages using the first source layer 2ID after receiving the first second message using the first source layer 2ID, or the UE1 discards other messages received using the first source layer 2 ID.

Step 404: the UE1 determines a new source layer 2ID of the UE1 itself (denoted as second source layer 2 ID) from the second message of the UE2, and uses the second source layer 2ID to handle the unicast establishment procedure with the UE2, i.e., uses the second source layer 2ID for signaling interaction with the UE 2. For example, step 405: the UE1 sends a third message to the UE1 using the second source layer 2ID, and correspondingly, the UE2 receives the third message sent by the UE 1.

For step 404 and step 405, refer to the specific execution steps of step 303a, which are not described herein again.

Step 406: the UE2 sends a first response message to the UE1, and correspondingly, the UE1 receives the first response message from the UE2 while turning off the second timer.

For step 404, reference may be made to the above detailed description of step 304a, and details are not repeated here.

By the above manner, it is clear that the UE1 can only establish one unicast establishment procedure when the first request message does not carry the target user information.

EXAMPLE III

In the third embodiment, after sending a first request message, the UE1 may choose to establish only one unicast establishment procedure, but if the direct link establishment fails, a new unicast establishment procedure may be established again until the establishment is successful or all establishment fails.

Referring to fig. 5, a fourth communication method is provided for the embodiment of the present application, and the method may be applied to the system architecture shown in fig. 1, where the method includes the following steps:

step 501: the UE1 sends a first request message with the start of a first timer. Correspondingly, UE X (e.g., including UE2, UE3, UE4) receives the first request message from UE 1.

The function of the first timer has been described above and will not be described herein.

Step 502: UE X sends the second message to UE1, and correspondingly, UE1 receives the second message sent by UE X respectively.

Illustratively, UE x is a UE, e.g., UE2 or UE3 or UE4 sends a second message to UE1, and UE1 receives the second message from UE2, or UE1 receives the second message from UE3, or UE1 receives the second message from UE 4.

Further illustratively, the UE x includes a plurality of UEs, e.g., UE2, UE3, and UE4 each send a second message to UE1, and correspondingly, UE1 receives second messages from UE2, UE3, and UE4, respectively.

Step 503: the UE1 determines a target UE and determines a new source layer 2ID (denoted as second source layer 2 ID) corresponding to the target UE according to the second message of the target UE, and the UE1 uses the second source layer 2ID to process a unicast establishment procedure with the target UE, i.e., uses the second source layer 2ID for signaling interaction with the target UE. Specifically, in step 504: the UE1 sends a third message to the target UE using the second source layer 2ID, and correspondingly, the target UE receives the third message sent by the UE1 and starts a second timer. The timing duration of the second timer is the remaining timing duration of the first timer, which is described in detail in the first embodiment above, and is not described herein again.

And if the UEX is one UE, the target UE is the UE.

If the UEX includes a plurality of UEs, the target UE may be the UE to which the first second message received by the UE1 belongs, or any UE among the plurality of UEs. For other UEs in UE X except the target UE, UE1 may cache second messages of the other UEs, and if the establishment of the direct link between UE1 and the target UE fails, UE1 may further select a new UE from the cached UEs to establish the direct link until the establishment of the direct link is successful or the establishment of the direct links with all UEs in UE X fails. It should be understood that any UE in UEX is the UE to which the second message received by UE1 belongs before the first timer expires.

For step 503 and step 504, reference may be made to the specific execution step of step 303a, which is not described herein again.

Step 505: the target UE sends a first response message to the UE1, and correspondingly, the UE1 receives the first response message from the target UE while turning off the second timer.

Specifically, if the first response message indicates that the establishment of the direct link is accepted, the UE1 establishes the direct link with the UE2 in order to establish the direct link successfully. If the UE1 establishes a direct link with the UE2, the UE1 sends a fourth message to any one of the other UEs in the UE X, where the fourth message is used to indicate a second message rejecting to accept the UE.

Additionally, the UE1 may continue to use the second source layer 2ID for through-link V2X communications with the UE2, the V2X communications including data interactions and signaling interactions.

If the first response message indicates a rejection of establishing the direct link, the UE1 does not establish the direct link with the UE2 for the establishment failure. In an implementation manner, the UE1 selects a new second message from the buffered second messages, and establishes a unicast establishment procedure with the UE to which the selected second message belongs. See steps 506 to 508, wherein the specific execution steps of the unicast establishment procedure of the UE1 may refer to steps 503 to 505, which are not described herein again.

For the specific execution step of step 505, reference may be made to the specific description of step 303a, which is not described herein again.

In one possible scenario, if the second timer expires and the UE1 does not receive the first response message from the target UE, the UE1 may also send a unicast establishment request to the target UE, attempting to re-establish the direct link with the target UE.

It is to be understood that the first source layer 2ID may be different in different embodiments and the second source layer 2ID may be different, the second source layer 2ID being meant to distinguish from the first source layer 2ID, indicating that the second source layer 2ID is different from the first source layer 2ID, and not limiting as to the specific value of the new source layer 2ID determined by the UE 1.

Through the method, after the UE1 initiates the unicast establishment request, the establishment of a plurality of direct links can be triggered, and when the establishment of one direct link is not successful, the unicast establishment request can not be initiated repeatedly, so that the signaling overhead can be saved, and the time delay can be shortened.

Example four

In the fourth embodiment, the UE1 starts a fourth timer when sending the first request message, and the function of the fourth timer is related to the first request message.

Referring to fig. 6, a second communication method is provided for the embodiment of the present application, and the method may be applied to the system architecture shown in fig. 1, where the method includes the following steps:

in step 601, the UE1 sends a first request message and starts a fourth timer. Correspondingly, UE X receives the first request message from UE 1.

The functions of the fourth timer include: if the first request message contains the target user information, the fourth timer is stopped when the UE1 receives the response message of the first request message; if the first request message does not contain the target user information, the fourth timer is stopped when the timing time reaches the set duration, namely the second timer cannot be stopped midway and is overtime certainly.

In step 602, the UE2 sends a second message to the UE1, and correspondingly, the UE1 receives the second message from the UE 2.

In step 603, the UE1 sends a third message to the UE2 while starting a second timer. Correspondingly, the UE2 receives a third message from the UE 1.

In step 604, the UE2 sends a first response message to the UE1, and correspondingly, the UE1 receives the first response message from the UE2 while turning off the second timer.

By the above method, the UE1 may start a timer by default, i.e. a fourth timer whose function can be flexibly adapted to the first request message sent by the UE 1.

EXAMPLE five

Referring to fig. 7, a fifth communication method is provided for the embodiment of the present application, and the method may be applied to the system architecture shown in fig. 1, where the method includes the following steps:

step 701: the UE1 sends the first request message with the third timer started. Correspondingly, the UE2 receives a first request message from the UE 1.

Specifically, the first request message contains an identification of the V2X service and does not contain target user information.

The manner in which the UE1 determines the first source layer 2ID and the destination layer 2ID has been described above and will not be described herein again since the UE1 transmits the first request message using the first source layer 2ID and the destination layer 2 ID.

The first request message is used for requesting the receiving-end UE to establish a direct link with the UE1, and the first request message further includes second indication information, where the second indication information is used for indicating the receiving-end UE to request the UE1 to establish the direct link between the UE1 and the receiving-end UE. In other words, the first request message is for requesting the receiving UE to initiate a unicast establishment request to UE 1.

Step 702: the UE2 sends the second request message to the UE while starting the second timer, and correspondingly, the UE1 receives the second request message from the UE2 while closing the third timer.

The UE2 is one of the one or more receiving UEs of the first request message, here taking UE2 as an example, and describes a method for establishing a direct link between UE1 and UE 2: the UE2 takes the first source layer 2ID as the destination layer 2ID and sends a second request message to the UE1 using the third source layer 2ID and the first source layer 2 ID. The second request message may include user information (source user info) of the UE2 and may also include user information (target user info) of the UE 1.

The second timer (e.g., T5000) has a function that the UE2 stops when receiving the response message of the UE1, or stops when the counted time reaches a set duration. The flow of establishing the direct link between the other receiving UE and the UE1 can be referred to as the flow of establishing the direct link between the UE2 and the UE 1.

Correspondingly, if the UE1 receives the second request message from the UE2 before the third timer (e.g., T5501) times out, the third timer is turned off.

It should be understood that, after receiving the second request message of the UE2, the UE1 first determines whether the target user info in the second request message is the user information of the UE1, and if so, responds to the second request message and closes the third timer; otherwise, the second request message of the UE2 is discarded, and the second request message of the other UE is waited to be received within the timing time of the third timer until the second request message of the other UE contains the user information of the UE1 itself, or the timing of the third timer is completed.

If the third timer expires and the UE1 does not receive the second request message containing the user information of the UE1, the first request message may be retransmitted in the above retransmission manner.

Step 703: UE1 sends a second message to UE2 and, correspondingly, UE2 receives the second message from UE 1.

Step 704: the UE2 sends a third message to the UE1 while starting the second timer. Correspondingly, the UE1 receives a third message from the UE 2.

Step 705: the UE1 sends a first response message to the UE 2. Correspondingly, the UE2 receives the first response message from the UE1 while turning off the second timer.

If the UE1 also receives the second request message of other UEs in the process of steps 702 to 705, the UE1 may determine whether to reject the second request message of the UE according to whether the number of established and currently established direct links of the UE1 reaches a set threshold. See the above description for details, which are not repeated herein.

By the method, the UE1 instructs the receiving end UE to initiate a unicast establishment request to the UE1 by sending the first request message, and subsequently, the UE1 may establish a direct link with the UE according to the existing implementation manner, in which the implementation manner of establishing multiple direct links after the UE1 sends one first request message is simpler.

Note that the names of the first timer (T5500), the second timer (T5000), and the third timer (T5501) are not limited in the embodiment of the present application, and those skilled in the art may replace the names of the timers with other names to perform the same function. The functions of any of the above timers may be integrated into an existing timer, and for example, T5000 may also have the function of a fourth timer.

The embodiments provided in the present application can be used alone or in combination with each other. For example, in the second to fourth embodiments, before the UE1 sends the third message to the UE2, it may be further determined whether the number of established and currently established direct links on the UE1 reaches a set threshold, and if not, the fourth message may be sent to the UE 2. For details, refer to the description in the first embodiment, and are not described herein again.

As shown in fig. 8, which is a possible exemplary block diagram of a communication device according to the present application, the device 800 may be in the form of software or hardware. The apparatus 800 may include: a processing unit 802 and a communication unit 803. As an implementation manner, the communication unit 803 may include a receiving unit and a transmitting unit. The processing unit 802 is used for controlling and managing the operation of the apparatus 800. The communication unit 803 is used to support communication of the apparatus 800 with other network entities. The apparatus 800 may further comprise a storage unit 801 for storing program codes and data of the apparatus 800.

The processing unit 802 may be a processor or a controller, and may be, for example, a general-purpose Central Processing Unit (CPU), a general-purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The storage unit 801 may be a memory. The communication unit 803 is an interface circuit of the apparatus for receiving signals from other apparatuses. For example, when the device is implemented in the form of a chip, the communication unit 803 is an interface circuit for the chip to receive a signal from another chip or device, or an interface circuit for the chip to transmit a signal to another chip or device.

The apparatus 800 may be a terminal device (e.g., a first terminal device, a second terminal device) in any of the above embodiments, and may also be a chip for the terminal device. For example, when the apparatus 800 is a terminal device, the processing unit 802 may be a processor, and the communication unit 803 may be a transceiver, for example. Optionally, the transceiver may comprise radio frequency circuitry and the storage unit may be, for example, a memory. For example, when the apparatus 800 is a chip for a terminal device, the processing unit 802 may be a processor, for example, and the communication unit 803 may be an input/output interface, a pin, a circuit, or the like, for example. The processing unit 802 can execute a computer execution instruction stored in a storage unit, optionally, the storage unit is a storage unit in the chip, such as a register, a cache, and the like, and the storage unit can also be a storage unit located outside the chip in the terminal device, such as a read-only memory (ROM) or another type of static storage device that can store static information and instructions, a Random Access Memory (RAM), and the like.

In the first embodiment, the apparatus 800 is the first terminal device in the above example, and the communication unit 803 of the first terminal device includes a transmitting unit and a receiving unit. A sending unit, configured to send a first request message, where the first request message includes an identifier of a V2X service, and the first request message does not include target user information, and the first request message is used to request to establish a direct link, and the direct link is used for V2X communication;

a receiving unit, configured to receive a first response message from a second terminal device, where the first response message is used to indicate whether to accept establishment of a direct link or to reject establishment of the direct link; a processing unit 802, configured to establish a first direct link between a first terminal device and a second terminal device according to the first response message;

a receiving unit configured to receive a second response message from a third terminal device; the second response message is used for indicating whether the establishment of the direct link is accepted or refused; a processing unit 802, configured to establish a second direct link between the first terminal device and the third terminal device according to the second response message.

In a possible implementation method, the processing unit 802 is specifically configured to send the first request message by using a first source layer 2ID and a destination layer 2ID corresponding to the V2X service; a receiving unit, further configured to receive a second message from the second terminal device, where the second message includes user information of the second terminal device, and the second message is used to request authentication or is used for security mode control; a sending unit, further configured to send a third message to the second terminal device using a second source layer 2ID, where the third message includes user information of the second terminal device, and the second source layer 2ID is different from the first source layer 2 ID.

In a possible implementation method, the processing unit 802 is further configured to start a first timer according to that the first request message does not include target user information, where a starting time of the first timer is a time when the first terminal device sends the first request message, a set time of the first timer is a preset time, and the receiving unit does not stop the first timer when receiving a response message of the first request message; after the first timer expires, controlling a receiving unit to stop receiving or discarding a response message of the first request message.

In a possible implementation method, the processing unit 802 is further configured to start a second timer, where a set duration of the second timer is a remaining timing duration of the first timer.

In a possible implementation method, the processing unit 802 is further configured to determine that the number of established direct links on the first terminal device does not reach a preset threshold.

In a possible implementation method, the receiving unit receives a second message from a fourth terminal device; the processing unit 802 is further configured to determine that the number of established direct links on the first terminal device reaches a preset threshold, control the sending unit to send a fourth message to the fourth terminal device, where the fourth message is used to instruct the first terminal to reject authentication or reject security mode control. Optionally, the fourth message carries a first cause value, where the first cause value is lack of unicast link resources.

In a possible implementation method, the first request information further includes user information of the first terminal device.

In a possible implementation method, the third message includes user information of the second terminal device; or the third message includes the user information of the second terminal device and the user information of the first terminal device.

In a possible implementation method, the first response message indicates acceptance of establishment of a direct link, and the processing unit 802 is configured to establish the first direct link with the second terminal device; the first response message indicates that the establishment of a direct link is rejected, and the processing unit 802 is configured to not establish the first direct link with the second terminal device.

In a possible implementation method, the first response message is used to indicate whether to accept establishment of the direct link or to reject establishment of the direct link; the first response message of the second terminal equipment indicates to accept to establish a direct link; a processing unit 802, further configured to perform communication of the direct link with the second terminal device using the second source layer 2 ID.

In the second embodiment, the processing unit 802 is configured to control the sending unit to send the first request message, and start a first timer; the first request message contains identification of all vehicle-to-vehicle V2X services, the first request message does not contain target user information, the first request message is used for requesting to establish a direct link, and the direct link is used for V2X communication; the processing unit 802 is further configured to control the receiving unit, and when receiving the first response message from the second terminal device, keep the first timer to continue timing until the timing time of the first timer reaches a preset time length; the first response message is used for indicating acceptance of establishing the through link or rejection of establishing the through link. A transmitting unit configured to transmit a first request message; a receiving unit, configured to receive a first response message from a second terminal device.

In a possible implementation method, the receiving unit is configured to receive a second response message from a third terminal device, where the second response message is used to indicate whether to accept or reject to establish the direct link.

In a third embodiment, a sending unit, configured to send a first request message, where the first request message is used to request to establish a direct link, and the first request message includes first indication information, where the first indication information is used to indicate sending of a second request message, and the second request message is used to request to establish a direct link with the first terminal device; a receiving unit, configured to receive a second request message from a second terminal device, where the second request message is used to request establishment of a direct link with the second terminal device; the processing unit 802 is configured to establish a direct link between the first terminal device and the second terminal device according to the second request message.

In a possible implementation method, the processing unit 802 is configured to start a third timer, where a set duration of the third timer is a second preset duration, and the first timer stops the third timer when the first terminal device receives the second request message.

In the fourth embodiment, the apparatus 800 is the second terminal device in the above example, and the communication unit 803 of the second terminal device includes a transmitting unit and a receiving unit. A receiving unit, configured to receive a first request message from a first terminal device, where the first request message includes an identifier of all car-to-car V2X services, and the first request message does not include target user information, and the first request message is used to request establishment of a direct link, and the direct link is used for V2X communication; a sending unit, configured to send a first response message to the first terminal device, where the first response message is used to indicate acceptance of establishment of the direct link or rejection of establishment of the direct link. A processing unit 802, configured to establish a direct link with the first terminal device according to the first response message.

In a possible implementation method, the processing unit 802 is configured to send a second message to the first terminal device using a first destination layer 2ID, where the second message includes user information of the second terminal device, and the second message is used to request authentication or is used for security mode control; the first destination layer 2ID is a first source layer 2ID of the first terminal device determined from the first request message; starting a third timer, wherein the starting time of the third timer is the time when the second terminal equipment sends the second message; a receiving unit, configured to receive a third message from the first terminal device, where the third message includes user information of the second terminal device, and the second terminal device stops the third timer.

In a possible implementation method, the processing unit 802 is further configured to send the first response message to the first terminal device by using a second destination layer 2ID, where the second destination layer 2ID is a second source layer 2ID of the first terminal device determined according to the third message.

In a possible implementation method, the first response message is used to indicate whether to accept establishment of the direct link or to reject establishment of the direct link; the first response message of the second terminal equipment indicates to accept to establish a direct link; a processing unit 802, further configured to perform communication of the direct link with the first terminal device using the second destination layer 2 ID.

In a fifth embodiment, a receiving unit, configured to receive a first request message from a first terminal device, where the first request message is used to request to establish a direct link, where the first request message includes first indication information, where the first indication information is used to indicate that a second request message is sent, and the second request message is used to request to establish a direct link with the first terminal device; a sending unit, configured to send a second request message to the first terminal device, where the second request message is used to request to establish a direct link between the first terminal device and the second terminal device.

In a possible implementation method, the first request message further includes user information of the first terminal device; the second request message includes user information of the second terminal device and user information of the first terminal device.

Referring to fig. 9, a schematic diagram of an apparatus provided by the present application, where the apparatus may be the terminal device in the above embodiment (the first terminal device and the second terminal device in the above example). The apparatus 900 includes: a processor 902 and a communication interface 903. Optionally, the apparatus 900 may further comprise a memory 901 and/or a communication line 904. Wherein the communication interface 903, the processor 902, and the memory 901 may be connected to each other through a communication line 904; the communication line 904 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The communication lines 904 may be divided into address buses, data buses, control buses, and the like. For ease of illustration, only one thick line is shown in FIG. 9, but this does not indicate only one bus or one type of bus.

The processor 902 may be a CPU, microprocessor, ASIC, or one or more integrated circuits configured to control the execution of programs in accordance with the teachings of the present application.

The communication interface 903 may be any device, such as a transceiver, for communicating with other devices or communication networks, such as an ethernet, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), a wired access network, and the like.

The memory 901 may be, but is not limited to, a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be separate and coupled to the processor via a communication line 904. The memory may also be integral to the processor.

The memory 901 is used for storing computer-executable instructions for executing the scheme of the present application, and is controlled by the processor 902 to execute. The processor 902 is configured to execute computer-executable instructions stored in the memory 901, so as to implement the communication method provided by the above embodiments of the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable media. The readable medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the readable medium would include the following: an electrical connection having one or more wires, a portable disk, a hard disk, a random access device (RAM), a read-only device (ROM), an erasable programmable read-only device (EPROM or flash memory), an optical fiber, a portable compact disc read-only device (CD-ROM), an optical device, a magnetic device, or any suitable combination of the foregoing.

A program product for configuring parameters according to an embodiment of the present invention may employ a portable compact disc-read only memory (CD-ROM) and include program code, and may be run on a server device. However, the program product of the present invention is not limited in this respect, and in this document, a readable medium may be any tangible medium that can contain, or embody a program for use by or in connection with an information delivery, apparatus, or device.

A readable signal medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable signal medium may also be any readable medium that is not a readable medium and that can communicate, propagate, or transport a program for use by or in connection with a periodic network action system, apparatus, or device.

Program code embodied on a readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device.

The embodiment of the application also provides a readable medium of the computing equipment aiming at the information synchronization method, namely, the content is not lost after the power is off. The medium includes a software program comprising a program code, which when executed on a computing device, when read and executed by one or more processors, implements any of the above aspects of the embodiments of the present application.

The present application is described above with reference to block diagrams and/or flowchart illustrations of methods, apparatus (systems) and/or computer program products according to embodiments of the application. It will be understood that one block of the block diagrams and/or flowchart illustrations, and combinations of blocks in the block diagrams and/or flowchart illustrations, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, and/or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer and/or other programmable data processing apparatus, create means for implementing the functions/acts specified in the block diagrams and/or flowchart block or blocks.

Accordingly, the subject application may also be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). Furthermore, the application may take the form of a computer program product on a computer-usable or computer-readable medium having computer-usable or computer-readable program code embodied in the medium for use by or in connection with an instruction execution system. In the context of this application, a computer-usable or computer-readable medium may be any medium that can contain, have, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include such modifications and variations.

Claims

1. A method of communication, comprising:

a first terminal device sends a first request message, wherein the first request message contains identification of all vehicle-to-all V2X services and does not contain target user information, and the first request message is used for requesting to establish a direct link which is used for V2X communication;

the first terminal device receives a first response message from a second terminal device, and establishes a first direct link between the first terminal device and the second terminal device according to the first response message, wherein the first response message is used for indicating acceptance of establishment of the direct link or rejection of establishment of the direct link;

the first terminal device receives a second response message from a third terminal device, and establishes a second direct link between the first terminal device and the third terminal device according to the second response message, wherein the second response message is used for indicating acceptance of establishment of the direct link or rejection of establishment of the direct link.

2. The method of claim 1, wherein the first terminal device sending a first request message comprises:

the first terminal equipment sends the first request message by using a first source layer 2ID and a destination layer 2ID corresponding to the V2X service;

before the first terminal device receives the first response message from the second terminal device, the method further includes:

the first terminal equipment receives a second message from the second terminal equipment, wherein the second message contains user information of the second terminal equipment, and the second message is used for requesting authentication or controlling a security mode;

the first terminal device sends a third message to the second terminal device using a second source layer 2ID, the third message including user information of the second terminal device, the second source layer 2ID being different from the first source layer 2 ID.

3. The method of claim 1 or 2, wherein the method further comprises:

the first terminal device starts a first timer according to the first request message, the starting time of the first timer is the time when the first terminal device sends the first request message, and the set time length of the first timer is a preset time length;

when the first terminal equipment receives the response message of the first request message, the first terminal equipment does not stop the first timer;

after the first timer expires, the first terminal device stops receiving or discarding the response message of the first request message.

4. The method of claim 3, wherein the method further comprises:

and when the first terminal equipment sends the third message to the second terminal equipment, the first terminal equipment starts a second timer, and the set time length of the second timer is the residual timing time length of the first timer.

5. The method of claim 2, wherein after the first terminal device receives the second message from the second terminal device and before the first terminal device sends a third message to the second terminal device, the method further comprises:

the first terminal equipment determines that the number of the established direct links on the first terminal equipment does not reach a preset threshold value.

6. The method of any of claims 1-5, wherein the first request information further comprises user information of the first terminal device.

7. The method of any of claims 2-6, wherein the third message comprises user information of the second terminal device; or the third message includes the user information of the second terminal device and the user information of the first terminal device.

8. The method of any of claims 1-7, wherein the first terminal device establishing the first direct link between the first terminal device and the second terminal device according to the first response message comprises:

the first response message indicates that the establishment of a direct link is accepted, and the first terminal equipment establishes the first direct link with the second terminal equipment;

the first response message indicates that the establishment of a direct link is refused, and the first terminal equipment does not establish the first direct link with the second terminal equipment.

9. The method of claim 2, wherein the first response message is to indicate acceptance of establishment of a pass-through link or rejection of establishment of a pass-through link; the first response message of the second terminal equipment indicates to accept to establish a direct link; the method further comprises the following steps:

and the first terminal equipment uses the second source layer 2ID to communicate with the second terminal equipment through the direct link.

10. The method of any one of claims 1-9, further comprising:

the first terminal equipment receives a second message from a fourth terminal equipment;

the first terminal equipment determines that the number of the established direct links on the first terminal equipment reaches a preset threshold value;

and the first terminal equipment sends a fourth message to the fourth terminal equipment, wherein the fourth message is used for indicating that the first terminal equipment rejects authentication or rejects security mode control.

11. A method of communication, comprising:

the first terminal equipment sends a first request message and starts a first timer; wherein the first request message contains an identification of all vehicle-to-vehicle V2X traffic and does not contain target user information, the first request message being for requesting establishment of a direct link for V2X communications;

when the first terminal equipment receives a first response message from second terminal equipment, the first terminal equipment keeps the first timer to keep timing until the first timer is overtime; wherein the first response message is used for indicating acceptance of establishing the through link or rejection of establishing the through link.

12. The method of claim 11, further comprising:

13. The method of claim 11, wherein the first terminal device, prior to the first timer expiring, further comprises:

and the first terminal equipment receives a second response message from third terminal equipment, wherein the second response message is used for indicating that the establishment of the direct link is accepted or refused.

14. A method of communication, comprising:

the second terminal device receives a first request message from a first terminal device, wherein the first request message contains identification of all vehicle-to-vehicle V2X services and does not contain target user information, and the first request message is used for requesting to establish a direct link which is used for V2X communication;

and the second terminal equipment sends a first response message to the first terminal equipment, wherein the first response message is used for indicating that the establishment of the direct link is accepted or refused.

15. The method of claim 14, further comprising:

the first response message indicates that the establishment of a direct link is accepted, and the second terminal equipment establishes the first direct link with the first terminal equipment;

the first response message indicates that the establishment of the direct link is refused, and the second terminal equipment does not establish the first direct link with the first terminal equipment.

16. The method of claim 14, wherein after the second terminal device receives the first request message from the first terminal device and before sending the first response message to the first terminal device, the method further comprises:

the second terminal device sends a second message to the first terminal device by using a first destination layer 2ID, wherein the second message contains user information of the second terminal device, and the second message is used for requesting authentication or controlling a security mode;

when the second terminal equipment sends the second message, the second terminal equipment starts a third timer;

the second terminal equipment receives a third message from the first terminal equipment, wherein the third message comprises user information of the second terminal equipment;

and the second terminal equipment stops the third timer according to the third message.

17. The method of claim 16, wherein the second terminal device sending a first response message to the first terminal device, comprising:

and the second terminal equipment uses a second destination layer 2ID to send the first response message to the first terminal equipment.

18. The method of claim 17, wherein the first response message of the second terminal device indicates acceptance of establishment of the direct link; the method further comprises the following steps:

and the second terminal equipment uses the second destination layer 2ID to communicate with the first terminal equipment through the direct link.

19. A method of communication, comprising:

a first terminal device sends a first request message, wherein the first request message is used for requesting to establish a direct link, the first request message comprises first indication information, the first indication information is used for indicating to send a second request message, and the second request message is used for requesting to establish the direct link with the first terminal device;

the first terminal device receives the second request message from a second terminal device;

and the first terminal equipment establishes a direct link between the first terminal equipment and the second terminal equipment according to the second request message.

20. The method of claim 19, wherein the method further comprises:

the first terminal equipment starts a third timer, and the set time length of the third timer is a second preset time length;

and stopping the third timer when the first terminal equipment receives the second request message.

21. A method of communication, comprising:

the method comprises the steps that a second terminal device receives a first request message from a first terminal device, wherein the first request message comprises first indication information, the first request message is used for requesting to establish a direct link, the first indication information is used for indicating to send a second request message, and the second request message is used for requesting to establish the direct link with the first terminal device;

and the second terminal equipment sends the second request message to the first terminal equipment according to the first request message.

22. The method of claim 21, wherein the first request message further includes user information of the first terminal device; the second request message includes user information of the second terminal device and user information of the first terminal device.

23. A communications apparatus, the apparatus comprising:

a communication unit, configured to send a first request message, where the first request message includes an identifier of a V2X service, and the first request message does not include target user information, and the first request message is used to request to establish a direct link, and the direct link is used for V2X communication;

the communication unit is further used for receiving a first response message from the second terminal device, wherein the first response message is used for indicating that the establishment of the direct link is accepted or refused; the processing unit is used for establishing a first direct link between the first terminal device and the second terminal device according to the first response message;

a communication unit, further configured to receive a second response message from a third terminal device; the second response message is used for indicating whether the establishment of the direct link is accepted or refused; and the processing unit is used for establishing a second direct link between the first terminal device and the third terminal device according to the second response message.

24. A communications apparatus, the apparatus comprising:

a communication unit for transmitting a first request message; the first request message contains identification of all vehicle-to-vehicle V2X services, the first request message does not contain target user information, the first request message is used for requesting to establish a direct link, and the direct link is used for V2X communication; the processing unit is used for starting a first timer when the communication unit sends the first request message;

a communication unit, further configured to receive a first response message from the second terminal device; the first response message is used for indicating the second terminal equipment to accept to establish the direct link or refuse to establish the direct link. And the processing unit is further used for keeping the first timer to keep timing continuously according to the condition that the first request message does not contain the target user information until the timing time of the first timer reaches the preset time length.

25. A communications apparatus, the apparatus comprising:

a communication unit, configured to receive a first request message from a first terminal device, where the first request message includes an identification of all vehicle-to-all V2X services and does not include target user information, and the first request message is used to request establishment of a direct link used for V2X communication; sending a first response message to the first terminal device, wherein the first response message is used for indicating acceptance of establishment of a direct link or rejection of establishment of the direct link;

and the processing unit is used for establishing a direct link with the first terminal equipment according to the first response message.

26. A communications apparatus, the apparatus comprising:

a communication unit, configured to send a first request message, where the first request message is used to request to establish a direct link, and the first request message includes first indication information, where the first indication information is used to indicate sending of a second request message, and the second request message is used to request to establish a direct link with the first terminal device; receiving a second request message from the second terminal device, wherein the second request message is used for requesting to establish a direct link with the second terminal device;

and the processing unit is used for establishing a direct link between the first terminal device and the second terminal device according to the second request message.

27. A communications apparatus, the apparatus comprising:

a communication unit, configured to receive a first request message from a first terminal device, where the first request message is used to request to establish a direct link, where the first request message includes first indication information, the first indication information is used to indicate that a second request message is sent, and the second request message is used to request to establish the direct link with the first terminal device; and sending a second request message to the first terminal device, where the second request message is used to request establishment of a direct link between the first terminal device and the second terminal device.

28. A communications apparatus, comprising a processor and a memory, the processor to execute instructions stored on the memory which, when executed, cause the apparatus to perform the method of any of claims 1 to 10, or the method of any of claims 11 to 13, or the method of any of claims 14 to 18, or the method of any of claims 19 to 22.

29. A computer-readable storage medium comprising instructions that, when executed, implement the method of any of claims 1 to 22.