CN107211404A - A kind of data transmission method and device - Google Patents

Abstract

This application discloses a kind of data transmission method and device.Wherein, data transmission method includes：Terminal device sets up device-to-device and closes on the mapping relations that service D2D ProSe protocol layers share transmission channel to D2D；The terminal device determines whether the bit number of the first Discovery message of the ProSe protocol layers generation is more than predetermined threshold value；When the bit number of the first Discovery message is more than predetermined threshold value, the first Discovery message is mapped to the D2D and shares transmission channel, the first Discovery message described in transmission channel is shared by the D2D；Or when the bit number of the first discovery message is less than or equal to the predetermined threshold value, the first Discovery message is mapped to D2D Discovery transmission channels.Such scheme, is capable of the Discovery message of the different bit numbers of flexible transmission, improves the validity of data transfer, prevents from causing the situation of packet loss because the bit number of Discovery message is more than fixed number of bits.

Description

A data transmission method and device

【Technical field】

The present application relates to the field of communication networks, in particular to a data transmission method and device.

【Background technique】

Device to Device (D2D) communication technology is a communication technology that allows user terminal equipment (User Equipment, UE) uses a wireless link for direct communication technology.

At present, based on the long-term evolution (Long Term Evolution, LTE) user terminal equipment through D2D direct communication mode includes: through the discovery channel transmission mode (commonly referred to as, D2D discovery mode), transmission mode via D2D data channel (commonly referred to as D2D direct communication mode). The LTE system will allocate D2D through broadcast messages or dedicated signaling The transmission resources of Discovery and D2D direct communication are given to the user for D2D communication in the corresponding mode.

However, currently D2D Discovery messages in LTE-based D2D communication are only allowed to pass through D2D Discovery transmission channel transmission, while D2D The Discovery transmission channel can only transmit Discovery messages with a fixed number of bits. If the number of Discovery messages exceeds the fixed number of bits, the normal transmission cannot be performed, which may cause data packet loss and reduce communication reliability.

【Content of invention】

The technical problem mainly solved by this application is to provide a data transmission method and device, which can flexibly transmit Discovery messages with different bit numbers, and improve the reliability of data transmission.

In order to solve the above problems, the first aspect of the present application provides a data transmission method, including: a terminal device establishes a device-to-device proximity service D2D The mapping relationship between the ProSe protocol layer and the D2D shared transmission channel; the terminal device determines whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold; when the number of bits of the first Discovery message is greater than a preset threshold, mapping the first Discovery message to the D2D shared transmission channel, and transmitting the first Discovery message through the D2D shared transmission channel; or when the number of bits of the first discovery message is less than or equal to the preset threshold , map the first Discovery message to D2D Discovery transport channel.

With reference to the first aspect, in the first possible implementation manner of the first aspect of the present application, the step of establishing the mapping relationship between the ProSe protocol layer and the D2D shared transport channel by the terminal device includes: Adding a Discovery dedicated radio bearer, and establishing a mapping relationship between the ProSe protocol layer and the Discovery dedicated radio bearer, wherein the Discovery dedicated radio bearer is used to carry a Discovery message, and the Discovery message carried by the Discovery dedicated radio bearer is mapped to the Discovery dedicated radio bearer. Dedicated logical channel, and identified by the Discovery dedicated logical channel identifier, the Discovery message identified by the Discovery dedicated logical channel is transmitted through the D2D shared transport channel, and the Discovery dedicated radio bearer corresponds to the Discovery dedicated logical channel. The Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.

With reference to the first aspect, in the second possible implementation manner of the first aspect of the present application, the step of establishing the mapping relationship between the ProSe protocol layer and the D2D service logical channel by the terminal device includes: The layer establishes the mapping relationship between the ProSe protocol layer and the D2D shared transmission channel.

With reference to the first or second possible implementation manner of the first aspect, in a third possible implementation manner of the first aspect of the present application, when the number of bits of the first Discovery message is greater than a preset threshold, the The first Discovery message is mapped to the D2D shared transmission channel, and the step of transmitting the first Discovery message through the D2D shared transmission channel includes: when the number of bits of the first Discovery message is greater than a preset threshold, the The terminal device transmits the first Discovery message to the packet data convergence protocol layer, maps the first Discovery message to the Discovery dedicated radio bearer; or transmits the first Discovery message to a media access control protocol layer; the terminal device maps the first Discovery message to the D2D shared transport channel, and adds a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the The Discovery message transmitted by the D2D shared transport channel.

With reference to the first aspect or the third possible implementation manner of the first aspect, in the fourth possible implementation manner of the first aspect of the present application, after the step of mapping the first Discovery message to the D2D shared transmission channel , the method further includes: the terminal device transmits the first Discovery message to the physical layer through the D2D shared transport channel, and sets a flag bit in the D2D link control information corresponding to the first Discovery message, Transmitting the first Discovery message through the transmission resource of D2D communication data, wherein the flag bit is used to indicate whether the transmission resource of D2D communication data carries a Discovery message, and the Discovery message is carried by the first Discovery dedicated radio bearer The Discovery message or the Discovery message transmitted from the ProSe protocol layer to the MAC protocol layer.

With reference to the fourth possible implementation manner of the first aspect, in the fifth possible implementation manner of the first aspect of the present application, a flag bit is set in the D2D link control information corresponding to the first Discovery message, and through D2D communication The data transmission resource transmitting the first Discovery message includes: the terminal device determining the D2D link control information corresponding to the first data packet according to scheduling information or available transmission resources, where the first Discovery message corresponds to The D2D link control information is used to indicate the transmission resource information that bears the first Discovery message; the terminal device sets a flag bit in the D2D link control information corresponding to the first Discovery message, and through the D2D link control The transmission resource indicated by the information transmits the first Discovery message.

With reference to the fourth possible implementation manner of the first aspect, in a sixth possible implementation manner of the first aspect of this application, the D2D link control information indicates the transmission resource information carrying the first Discovery message and the D2D communication Transmission resource information of common D2D communication data, the transmission resource of the D2D communication data carries the first Discovery message and the D2D communication data at the same time, and the first Discovery message and the D2D communication data are distinguished by a logical channel identifier.

With reference to the fourth possible implementation manner of the first aspect, in a seventh possible implementation manner of the first aspect of this application, the D2D link control information indicates a transmission resource of the D2D communication data carrying the first Discovery message information, the transmission resource of the D2D communication data only bears the first Discovery message, where the first Discovery message and the D2D communication data are distinguished by different transmission resources.

With reference to the third or fourth possible implementation manner of the first aspect, in an eighth possible implementation manner of the first aspect of the present application, the method further includes: the terminal device receiving the second Discovery sent by other terminal devices message; the terminal device determines whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel: when the second Discovery message comes from a D2D shared transmission channel, the terminal device processes the second Discovery message according to the mechanism for transmitting the first Discovery.

In order to solve the above problems, the second aspect of the present application provides a data transmission device, including an establishment module, a determination module, and a mapping module; the establishment module is used to establish a device-to-device proximity service D2D The mapping relationship between the ProSe protocol layer and the D2D shared transmission channel; the determining module is used to determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold; the mapping module is used when the determining module When it is determined that the number of bits of the first Discovery message is greater than a preset threshold, map the first Discovery message to the D2D shared transport channel, and transmit the first Discovery message through the D2D shared transport channel; or, when When the determination module determines that the number of bits of the first discovery message is less than or equal to the preset threshold, map the first discovery message to D2D Discovery transport channel.

With reference to the second aspect, in the first possible implementation manner of the second aspect of the present application, the establishment module is specifically configured to add a Discovery dedicated radio bearer at the packet data convergence protocol layer, and establish a ProSe protocol layer to the Discovery dedicated radio bearer mapping relationship, wherein the Discovery dedicated radio bearer is used to bear the Discovery message, the Discovery message carried by the Discovery dedicated radio bearer is mapped to the Discovery dedicated logical channel, and is identified by the Discovery dedicated logical channel identifier, and the Discovery The Discovery message identified by the dedicated logical channel is transmitted through the D2D shared transport channel, the dedicated radio bearer for Discovery corresponds to the dedicated logical channel for Discovery, and the dedicated logical channel for Discovery corresponds to the identifier for the dedicated logical channel for Discovery.

With reference to the second aspect, in a second possible implementation manner of the second aspect of the present application, the establishment module is specifically configured to establish a mapping relationship between the ProSe protocol layer and the D2D shared transport channel at the medium access control protocol layer.

With reference to the first or second possible implementation manner of the second aspect, in a third possible implementation manner of the second aspect of the present application, the mapping module is specifically configured to determine that the first Discovery When the number of bits of the message is greater than the preset threshold, the first Discovery message is transferred to the packet data convergence protocol layer, the first Discovery message is mapped to the Discovery dedicated radio bearer, and the first Discovery A message is mapped to the D2D shared transport channel, and a Discovery dedicated logical channel identifier is added to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel; or The mapping module is specifically configured to transfer the first Discovery message to the media access control protocol layer when the determination module determines that the number of bits of the first Discovery message is greater than a preset threshold, and transfer the first Discovery message to the media access control protocol layer. The message is mapped to the D2D shared transmission channel, and a Discovery dedicated logical channel identifier is added to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel.

With reference to the second aspect or the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect of the present application, the device further includes a control module configured to use the first A Discovery message is transmitted to the physical layer through the D2D shared transmission channel, and a flag bit is set in the D2D link control information corresponding to the first Discovery message, and the first Discovery message is transmitted through the transmission resource of D2D communication data, Wherein, the flag bit is used to indicate whether the transmission resource of the D2D communication data bears a Discovery message, and the first Discovery message is a Discovery message carried by the Discovery dedicated radio bearer or transmitted from the ProSe protocol layer to the media Discovery message at the access control protocol layer.

With reference to the fourth possible implementation manner of the second aspect, in the fifth possible implementation manner of the second aspect of the present application, the control module is specifically configured to transmit the first Discovery message through the D2D shared transmission channel Go to the physical layer, determine the D2D link control information corresponding to the first Discovery message according to the scheduling information or available transmission resources, set the flag bit in the D2D link control information corresponding to the first Discovery message, and pass the D2D The transmission resource indicated by the link control information transmits the first Discovery message; wherein, the D2D link control information corresponding to the first Discovery message is used to indicate transmission resource information bearing the first Discovery message.

With reference to the fourth possible implementation manner of the second aspect, in a sixth possible implementation manner of the second aspect of this application, the D2D link control information determined by the control module indicates the The transmission resource information and the transmission resource information of the D2D communication data common to the D2D communication data, the transmission resource of the D2D communication data carries the first Discovery message and the D2D communication data at the same time, and the first Discovery message and the D2D communication data pass the logic Channel IDs are distinguished.

With reference to the fourth possible implementation manner of the second aspect, in a seventh possible implementation manner of the second aspect of this application, the D2D link control information determined by the control module indicates the The transmission resource information of the D2D communication data, the transmission resource of the D2D communication data only bears the first Discovery message, wherein the first Discovery message and the D2D communication data are distinguished by different transmission resources.

With reference to the third or fourth possible implementation manner of the second aspect, in the eighth possible implementation manner of the second aspect of the present application, the method further includes: the device further includes a receiving module; the receiving module uses is used to receive the second Discovery message sent by other terminal equipment; the determining module is also used to determine whether the second Discovery message received by the receiving module includes the Discovery dedicated logical channel identifier and/or the value of the flag bit Whether it is a preset value to determine whether the second Discovery message comes from a D2D shared transmission channel; the mapping module is also configured to, when the determining module determines that the second Discovery message comes from a D2D shared transmission channel, according to the transmission The mechanism of the first Discovery processes the second Discovery message.

In order to solve the above problems, the third aspect of the present application provides a terminal device, including a memory and a processor; the memory is used to store data; the processor is used to establish a device-to-device proximity service D2D The mapping relationship between the ProSe protocol layer and the D2D shared transport channel; the processor is used to determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold; and the number of bits used when the first Discovery message is When the number is greater than the preset threshold, map the first Discovery message to the D2D shared transmission channel, and transmit the first Discovery message through the D2D shared transmission channel; or, when the bit number of the first discovery message When it is less than or equal to the preset threshold, map the first Discovery message to D2D Discovery transport channel.

With reference to the third aspect, in the first possible implementation manner of the third aspect of the present application, the processor is specifically configured to add a Discovery dedicated radio bearer at the packet data convergence protocol layer, and establish a ProSe protocol layer to the Discovery dedicated radio bearer mapping relationship, wherein the Discovery dedicated radio bearer is used to bear the Discovery message, the Discovery message carried by the Discovery dedicated radio bearer is mapped to the Discovery dedicated logical channel, and is identified by the Discovery dedicated logical channel identifier, and the Discovery The Discovery message identified by the dedicated logical channel is transmitted through the D2D shared transport channel, the dedicated radio bearer for Discovery corresponds to the dedicated logical channel for Discovery, and the dedicated logical channel for Discovery corresponds to the identifier for the dedicated logical channel for Discovery.

With reference to the third aspect, in a second possible implementation manner of the third aspect of the present application, the processor is specifically configured to establish a mapping relationship between the ProSe protocol layer and the D2D shared transport channel at the medium access control protocol layer.

With reference to the first or second possible implementation manner of the third aspect, in a third possible implementation manner of the third aspect of the present application, the processor is configured to: when the number of bits of the first Discovery message is greater than a preset threshold, delivering the first Discovery message to the packet data convergence protocol layer, mapping the first Discovery message to the Discovery dedicated radio bearer, and mapping the first Discovery message to the D2D Share the transport channel, and add a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel; or the processor specifically uses When the number of bits of the first Discovery message is greater than a preset threshold, transfer the first Discovery message to a media access control protocol layer, map the first Discovery message to the D2D shared transport channel, and Adding a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel.

With reference to the third aspect or the third possible implementation manner of the third aspect, in a fourth possible implementation manner of the third aspect of the present application, the processor is further configured to pass the first Discovery message through the D2D The shared transmission channel is transmitted to the physical layer, and a flag bit is set in the D2D link control information corresponding to the first Discovery message, and the first Discovery message is transmitted through the transmission resource of the D2D communication data, wherein the flag bit uses In order to indicate whether the transmission resource of the D2D communication data carries a Discovery message, the first Discovery message is a Discovery message carried by the Discovery dedicated radio bearer or a Discovery message transmitted from the ProSe protocol layer to the Media Access Control protocol layer information.

With reference to the fourth possible implementation manner of the third aspect, in the fifth possible implementation manner of the third aspect of the present application, the processor is further specifically configured to transmit the first Discovery message through the D2D shared transmission channel Transfer to the physical layer, determine the D2D link control information corresponding to the first Discovery message according to the scheduling information or available transmission resources, set the flag bit in the D2D link control information corresponding to the first Discovery message, and pass the The transmission resource indicated by the D2D link control information transmits the first Discovery message; wherein, the D2D link control information corresponding to the first Discovery message is used to indicate transmission resource information carrying the first Discovery message.

With reference to the fourth possible implementation manner of the third aspect, in a sixth possible implementation manner of the third aspect of this application, the D2D link control information determined by the processor indicates an The transmission resource information and the transmission resource information of the D2D communication data common to the D2D communication data, the transmission resource of the D2D communication data carries the first Discovery message and the D2D communication data at the same time, and the first Discovery message and the D2D communication data pass the logic Channel IDs are distinguished.

With reference to the fourth possible implementation manner of the third aspect, in a seventh possible implementation manner of the third aspect of this application, the D2D link control information determined by the processor indicates the The transmission resource information of the D2D communication data, the transmission resource of the D2D communication data only bears the first Discovery message, wherein the first Discovery message and the D2D communication data are distinguished by different transmission resources.

With reference to the third or fourth possible implementation manner of the third aspect, in the eighth possible implementation manner of the third aspect of the present application, the terminal device further includes a receiver; the receiver is configured to receive the second Discovery message; the processor is configured to determine whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message Whether it comes from a D2D shared transmission channel; the processor is configured to process, by the terminal device, the second Discovery message according to the mechanism for transmitting the first Discovery when the second Discovery message comes from a D2D shared transmission channel.

In the above solution, the terminal device establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to the D2D Shared transmission channel, otherwise, map the first Discovery message to the D2D Discovery transmission channel; can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent packet loss caused by the number of bits of the Discovery message being greater than the fixed number of bits Condition.

【Description of drawings】

Fig. 1 is a flowchart of an embodiment of the data transmission method of the present application;

Fig. 2 is a flowchart of another embodiment of the data transmission method of the present application;

FIG. 3 is a schematic diagram of an embodiment of establishing a mapping relationship between a ProSe protocol layer and a D2D shared transmission channel in the present application;

FIG. 4 is a flowchart of another embodiment of the data transmission method of the present application;

FIG. 5 is a schematic diagram of another embodiment of establishing a mapping relationship between a ProSe protocol layer and a D2D shared transport channel in the present application;

FIG. 6 is a schematic diagram of channel mapping in an embodiment of mapping a Discovery message to a D2D shared transmission channel in the present application;

FIG. 7 is a schematic diagram of an embodiment of a D2D shared transport channel MAC data packet format in the present application;

FIG. 8 is a flowchart of another embodiment of the data transmission method of the present application;

FIG. 9 is a schematic diagram of channel mapping in another embodiment of mapping a Discovery message to a D2D shared transport channel in the present application;

FIG. 10 is a schematic diagram of an embodiment of the present application to distinguish between the Discovery message and the D2D communication data in FIG. 8 by using different physical resources;

Fig. 11 is a schematic structural diagram of an embodiment of the data transmission device of the present application;

Fig. 12 is a schematic structural diagram of another embodiment of the data transmission device of the present application;

FIG. 13 is a schematic structural diagram of an embodiment of a terminal device of the present application.

【detailed description】

Such as current 2G, 3G communication systems and next generation communication systems, such as Global System for Mobile Communications (the technology described in this article can be used in various communication systems, such as GSM, Global System for Mobile communications), Code Division Multiple Access (CDMA, Code Division Multiple Access) system, Time Division Multiple Access (TDMA, Time Division Multiple Access) system, Wideband Code Division Multiple Access (WCDMA, Wideband Code Division Multiple Access Wireless), Frequency Division Multiple Access (FDMA, Frequency Division Multiple Addressing) system, Orthogonal Frequency-Division Multiple Access (OFDMA, Orthogonal Frequency-Division Multiple Access) system, single carrier FDMA (SC-FDMA) system, general packet radio service (GPRS, General Packet Radio Service) system, Long Term Evolution (LTE, Long Term Evolution) system, and other such communication systems.

Various aspects are described herein in connection with wireless terminal devices and/or base stations.

A wireless terminal may be a device that provides voice and/or data connectivity to a user, a handheld device with wireless connectivity, or other processing device connected to a wireless modem. The wireless terminal can be connected via the radio access network (for example, RAN, Radio access Network) to communicate with one or more core networks, wireless terminals can be mobile terminals, such as mobile phones (or called "cellular" phones) and computers with mobile terminals, such as portable, pocket, hand-held, Mobile devices built into computers or mounted on vehicles that exchange language and/or data with the radio access network. For example, personal communication services (PCS, Personal Communication Service) phones, cordless phones, Session Initiation Protocol (SIP) phones, Wireless Local Loop (WLL, Wireless Local Loop) station, personal digital assistant (PDA, Personal Digital Assistant) and other equipment. A wireless terminal can also be called a system, a subscriber unit (Subscriber Unit), subscriber station (Subscriber Station), mobile station (Mobile Station), mobile station (Mobile), remote station (Remote Station), Access Point, Remote Terminal, Access Terminal Terminal), User Terminal (User Terminal), User Agent (User Agent), User Device (User Device), or User Equipment (User Equipment).

A base station (eg, access point) can refer to a device in an access network that communicates with wireless terminals over the air interface through one or more sectors. The base station can be used to convert received over-the-air frames to and from IP packets, acting as a router between the wireless terminal and the rest of the access network, which can include an Internet Protocol (IP) network. The base station may also coordinate attribute management for the air interface. For example, the base station can be a base station (BTS, Base Transceiver Station), can also be a base station (NodeB) in WCDMA, or an evolved base station (eNB or e-NodeB, evolutional Node) in LTE B), the application is not limited.

It should be noted that the core network node equipment provided by the present invention can be applied to different communication network systems, including but not limited to SAE (System Architecture Evolved, system architecture evolution network)/LTE (Long Term Evolved, long-term evolution network) network, UMTS (Universal Mobile Telecommunications System (Universal Mobile Communications System) network, CDMA (Code Division Multiple Access, Code Division Multiple Access), etc. The core network node equipment includes but not limited to Mobility Management Entity MME, Serving GPRS Support Node SGSN (Serving GPRS Support Node) Node) or Mobile Switching Center MSC (Mobile Switching Center), which is not limited here. For example, for an SAE/LTE network, its core network node device can be an MME, and its wireless access node device can be an eNB; for a UMTS network, its core network node device can be an SGSN or MSC, and its wireless access node device It can be RNC or nodeB. In the following, the cellular network is an SAE/LTE network as an example for illustration, and other cellular networks may be implemented with reference to the following embodiments.

Additionally, the terms "system" and "network" are often used herein interchangeably. The term "and/or" in this article is just an association relationship describing associated objects, which means that there can be three relationships, for example, A and/or B can mean: A exists alone, A and B exist simultaneously, and there exists alone B these three situations. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

The solutions of the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings.

In the following description, for purposes of illustration rather than limitation, specific details, such as specific system architectures, interfaces, and techniques, are set forth in order to provide a thorough understanding of the present application.

Referring to FIG. 1 , FIG. 1 is a flowchart of an embodiment of a data transmission method of the present application. The execution subject of this embodiment is the terminal device (User Equipment, UE), UE can be a mobile terminal device such as a mobile phone. Two UEs can communicate directly to transmit data. The data transmission method of the present embodiment includes the following steps:

S101: The terminal device establishes a mapping relationship between a device-to-device proximity service D2D ProSe protocol layer and a D2D shared transmission channel.

The terminal device establishes the device-to-device proximity service D2D ProSe protocol layer to the D2D shared transmission channel (Sidelink Shared Channel, SL-SCH) mapping relationship, so that the terminal device can map the Discovery message generated by the ProSe protocol layer to the D2D shared transmission channel. The D2D shared transmission channel is in the media access control protocol (Medium Access Control, MAC) layer.

Among them, the establishment of the mapping relationship between the ProSe protocol layer and the D2D shared transmission channel by the terminal device may be to establish a direct mapping relationship between the ProSe protocol layer and the D2D shared transmission channel at the MAC layer, or it may be established in the Packet Data Convergence Protocol (Packet Data Convergence Protocol (PDCP) layer or Radio Link Control Protocol (Radio Link A hardware or software interface is established between the Control, RLC) layer and the ProSe protocol layer, and the mapping relationship between the ProSe protocol layer and the D2D shared transmission channel of the MAC layer is established through the PDCP layer or the RLC layer, which is not limited here.

When the terminal device sends D2D communication data, it is processed according to the processing flow in the prior art.

When the terminal device sends the Discovery message generated by the ProSe protocol layer, steps S102 to S104 are performed.

S102: Determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold.

When the terminal device communicates with other terminal devices and sends the first Discovery message to the other terminal device, the terminal device determines whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. The first Discovery message is a Discovery message to be transmitted.

Wherein, the preset threshold is a preset number of bits, and the preset threshold is the D2D Discovery transmission channel (Sidelink Discovery Channel, SL-DCH) carries a fixed number of bits for the Discovery message. The preset threshold may be 232 bits, but is not limited thereto, and may also be set to other values, which are not limited here.

D2D The Discovery transmission channel can only carry Discovery messages with the number of bits less than or equal to the preset threshold. When the number of bits of the Discovery message is greater than the preset threshold, D2D The Discovery transport channel cannot carry.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is greater than the preset threshold, step S103 is performed.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is less than or equal to the preset threshold, step S104 is performed.

S103: When the number of bits of the first Discovery message is greater than a preset threshold, map the first Discovery message to the D2D shared transmission channel, and transmit the first Discovery message through the D2D shared transmission channel.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is greater than the preset threshold, the terminal device maps the first Discovery message from the ProSe protocol layer to the D2D shared transmission channel mapping relationship between the ProSe protocol layer and the MAC layer. The D2D shared transport channel of the MAC layer.

The first Discovery message is transmitted to a physical (Physical, PHY) layer through the D2D shared transmission channel, and the first Discovery message is transmitted to other terminal devices through available transmission resources of the physical layer.

S104: When the number of bits of the first discovery message is less than or equal to the preset threshold, map the first discovery message to a D2D Discovery transmission channel.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is less than or equal to the preset threshold, the terminal device maps the first Discovery message from the ProSe protocol layer to the D2D Discovery transmission channel of the MAC layer.

The terminal device transmits the first Discovery message to a physical (Physical, PHY) layer through the D2D Discovery transmission channel, and transmits the first Discovery message to other terminal devices through available transmission resources of the physical layer.

In the above solution, the terminal device establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to the D2D shared transmission channel. Transmission channel, otherwise, map the first Discovery message to the D2D Discovery transmission channel; it can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent packet loss caused by the number of bits in the Discovery message being greater than the fixed number of bits .

Please refer to FIG. 2 . FIG. 2 is a flow chart of another embodiment of the data transmission method of the present application. The execution subject of this embodiment is a terminal device, (User Equipment, UE), UE can be a mobile terminal device such as a mobile phone. Two UEs can communicate directly to transmit data. The data transmission method of the present embodiment includes the following steps:

S201: The terminal device adds a Discovery-dedicated radio bearer at the packet data convergence protocol layer, and establishes a mapping relationship between the ProSe protocol layer and the Discovery-dedicated radio bearer.

The terminal device adds a Discovery dedicated radio bearer to the PDCP layer of the packet data convergence protocol layer, and establishes a mapping relationship between the ProSe protocol layer and the Discovery dedicated radio bearer, thereby establishing a mapping relationship between the ProSe protocol layer and the D2D shared transmission channel. The terminal device also configures a Discovery dedicated logical channel for the Discovery dedicated radio bearer.

Wherein, the Discovery dedicated radio bearer is used to bear the Discovery message. The Discovery message carried by the Discovery dedicated radio bearer is mapped to the Discovery dedicated logical channel, and is identified by the Discovery dedicated logical channel identifier, and the Discovery message identified by the Discovery dedicated logical channel is transmitted through the D2D shared transport channel. The Discovery dedicated radio bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.

For example, please refer to FIG. 3 together. FIG. 3 is a schematic diagram of an embodiment of establishing a mapping relationship between a ProSe protocol layer and a D2D shared transport channel in this application.

The terminal device adds a Discovery dedicated radio bearer to the PDCP layer of the protocol stack in the D2D direct communication mode, and establishes a mapping relationship between the ProSe protocol layer and the Discovery dedicated radio bearer, so that the terminal device can map the Discovery message from the ProSe protocol layer to the Discovery of the PDCP layer. Dedicated radio bearers, so as to establish a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel in the MAC layer through the PDCP layer and the RLC layer.

Among them, the Discovery dedicated radio bearer is used to carry the Discovery message. The Discovery message carried by the Discovery dedicated radio bearer can be mapped to the Discovery dedicated logical channel and identified by the Discovery dedicated logical channel identifier. The Discovery message identified by the Discovery dedicated logical channel can be shared through D2D. transmission channel for transmission.

When the terminal device sends D2D communication data, it is processed according to the processing flow in the prior art. Among them, the D2D communication data generated at the application layer is processed sequentially through the TCP/UDP layer, IP layer, Packet Data Convergence Protocol PDCP layer, Radio Link Control Protocol RLC layer, MAC layer, and PHY layer.

When the terminal device sends the Discovery message generated by the ProSe protocol layer, steps S202 to S206 are performed.

When the terminal device receives data sent by other terminal devices, steps S207-S209 are performed.

S202: Determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold.

When the terminal device communicates with other terminal devices and sends the first Discovery message to the other terminal device, the terminal device determines whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. The first Discovery message is a Discovery message to be transmitted.

Wherein, the preset threshold is a preset number of bits, and the preset threshold is the D2D Discovery transmission channel (Sidelink The fixed number of bits of the Discovery message carried by the Discovery Channel (SL-DCH).

The preset threshold may be less than or equal to the maximum number of bits that the SL-DCH can carry. The preset threshold may be 232 bits, but it is not limited thereto, and may also be set to other values, which are not limited here. The maximum number of bits that can be carried by the SL-DCH is determined by the D2D direct communication resources available to the sending UE.

D2D The Discovery transmission channel can carry a Discovery message with a number of bits less than or equal to the preset threshold. When the number of bits of the Discovery message is greater than the preset threshold, D2D The Discovery transport channel cannot carry.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is greater than the preset threshold, step S203 is performed.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is less than or equal to the preset threshold, step S206 is performed.

S203: When the number of bits of the first Discovery message is greater than a preset threshold, the terminal device transfers the first Discovery message to the packet data convergence protocol layer, and maps the first Discovery message to the Discovery dedicated radio bearer.

When the terminal device determines that the number of bits of the first discovery message is greater than the preset threshold, the first discovery message is transferred from the ProSe protocol layer to the PDCP layer, and the discovery message is transferred from the ProSe protocol Layer is mapped to the Discovery dedicated radio bearer of the PDCP layer.

The PDCP layer processes the first Discovery message according to the processing method of D2D communication data, and submits it to the RLC layer for further processing, then submits the first Discovery message to the MAC layer, and maps it to a D2D service logic channel dedicated to Discovery Wherein, the dedicated logical channel corresponds to the above-mentioned Discovery dedicated radio bearer, and the Discovery dedicated D2D service logical channel has a one-to-one correspondence with the Discovery dedicated logical channel identifier.

Wherein, after the first Discovery message is mapped to the Discovery dedicated radio bearer, the processing flow at the PDCP layer and the RLC layer is the same as the processing flow of the D2D communication data at the PDCP layer and the RLC layer in the prior art, and details are not described here.

S204: The terminal device maps the first Discovery message to the D2D shared transport channel, and adds a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the The Discovery message transmitted by the D2D shared transport channel.

After submitting the first Discovery message from the RLC layer to the MAC layer, the terminal device maps the first Discovery message to the D2D shared transport channel according to the mapping relationship between the D2D service logical channel STCH and the D2D shared transport channel SL-SCH in the MAC layer.

After the terminal device maps the first Discovery message to the D2D shared transmission channel, it adds a data packet header to the first Discovery message in the D2D shared transmission channel, and adds a Discovery dedicated logical channel identifier (Logical Channel Identity, LCID). The Discovery dedicated logical channel identifier corresponds to the Discovery dedicated radio bearer, and the Discovery dedicated logical channel identifier is used to identify the Discovery message from the Discovery dedicated radio bearer transmitted through the D2D shared transport channel.

The Discovery-dedicated logical channel identifier corresponding to the Discovery-dedicated radio bearer is used to enable other terminal devices to recognize that the first Discovery message contains the Discovery message from the Discovery-dedicated radio bearer through the Discovery-dedicated logical channel identifier after receiving the first Discovery message , for further processing.

Since the value of the logical channel identifier of D2D communication data is usually 1~10, the value of the Discovery dedicated logical channel identifier corresponding to the Discovery dedicated radio bearer can be any logical channel except the identifier value 1~10 in the logical channel value. For example, the value of the logical channel identifier used to identify the Discovery message is 11, but it is not limited thereto.

S205: The terminal device transmits the first Discovery message to the physical layer through the D2D shared transmission channel, and sets a flag bit in the D2D link control information corresponding to the first Discovery message, and passes the D2D communication data The transmission resource transmits the first Discovery message.

After adding the Discovery dedicated logical channel identifier to the first Discovery message, the terminal device transmits the first Discovery message added with the Discovery dedicated logical channel identifier from the MAC layer to the physical layer through the D2D shared transport channel.

Afterwards, the terminal device sends the D2D link control information (Sidelink Control Information, SCI), the flag bit is set, and the first Discovery message is transmitted through the transmission resource of the D2D communication data.

Wherein, the flag bit is used to indicate whether the transmission resource of the D2D communication data bears a Discovery message, and the first Discovery message is a Discovery message carried by a Discovery-dedicated radio bearer.

Wherein, a flag bit is set in the D2D link control information corresponding to the first Discovery message, and the step of transmitting the first Discovery message through the transmission resources of the D2D communication data includes: the terminal device determines according to the scheduling information or the available transmission resources The D2D link control information corresponding to the first Discovery message, wherein the D2D link control information corresponding to the first Discovery message is used to indicate the transmission resource information carrying the first Discovery message; A flag bit is set in the D2D link control information corresponding to the Discovery message, so as to transmit the first Discovery message through the transmission resources indicated by the D2D link control information.

The D2D link control information is used to indicate the information of the transmission resource carrying the data to be transmitted, and the information of the transmission resource includes information such as frequency and time of the transmission resource. At this time, the D2D link control information is used to indicate the transmission resource information bearing the first Discovery message. The flag bit in the D2D link control information may occupy 1 bit (bit) in the SC, and the flag bit is used to indicate whether the first Discovery message includes the Discovery message carried by the Discovery dedicated radio bearer.

For example, if the value of the 1-bit flag of the SCI is set to "1", the first Discovery message carried by the transmission resource indicated by the SCI includes the Discovery message carried by the Discovery dedicated radio bearer; otherwise, the first Discovery message carried by the transmission resource indicated by the SCI; The data packet carried by the transmission resource only includes other D2D communication data, and does not include the Discovery message carried by the Discovery dedicated radio bearer.

The terminal device is controlled through the D2D link (Sidelink Control, SC) resources to transmit the SCI of the first Discovery message, and transmit the first Discovery message through available D2D communication data resources according to the SCI, so as to send the first Discovery message to other terminal devices.

It can be understood that due to the packet cutting function of RLC, the first Discovery message may be divided into multiple fragments and transmitted separately; therefore, the first Discovery message may be a single MAC data packet, or may be divided into multiple MAC data packets . When the first Discovery message is divided into multiple data packets, they can be transmitted multiple times respectively; the physical resources occupied by the data packets transmitted multiple times can be the same or different, which is not limited here. S206: When the number of bits of the first discovery message is less than or equal to the preset threshold, map the first discovery message to D2D Discovery transport channel.

When the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is less than or equal to the preset threshold, the terminal device transmits the first Discovery message from the ProSe protocol layer to the MAC layer, and according to the D2D in the ProSe protocol layer and the MAC layer The mapping relationship of the Discovery transmission channel is to map the first Discovery message to the D2D Discovery transmission channel of the MAC layer.

S207: The terminal device receives a second Discovery message sent by other terminal devices.

When other terminal devices send the second Discovery message to the terminal device, the terminal device receives the second Discovery message sent by the other terminal device.

S208: The terminal device determines whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel.

The terminal device determines whether the received second Discovery message contains the Discovery dedicated logical channel identifier corresponding to the Discovery dedicated radio bearer and/or whether the value of the flag bit of the D2D link control information is a preset value, so as to determine whether the received second Discovery message Whether the Discovery message comes from the D2D shared transport channel.

Wherein, the preset value of the flag bit of the D2D link control information corresponds to the preset value in step S205. When the terminal device determines that the second Discovery message contains the Discovery dedicated logical channel identifier corresponding to the Discovery dedicated radio bearer, or the value of the flag bit of the D2D link control information is a preset value, it determines that the received second Discovery message is from the D2D sharing The transport channel, where the second Discovery message includes the Discovery message carried by the Discovery dedicated radio bearer.

When the received second Discovery message is from the D2D shared transmission channel, perform step S209; otherwise, perform processing according to the method in the prior art.

S209: When the second Discovery message comes from the D2D shared transport channel, deliver the second Discovery message from the medium access control protocol layer to the packet data convergence protocol layer through the D2D shared transport channel, and Submit from the packet data convergence protocol layer to the ProSe protocol layer for processing.

Since the terminal device sends the Discovery message and receives the Discovery message are two inverse processes, therefore, when the terminal device receives the second Discovery message, it performs processing referring to the flow of the first Discovery message.

Specifically: when the terminal device confirms that the received second Discovery message comes from the D2D shared transport channel, it submits the received second Discovery message from the MAC layer to the RLC layer through the D2D shared transport channel, and then further submits it to the PDCP layer, and according to The mapping relationship between the Discovery dedicated radio bearer at the PDCP layer and the ProSe protocol layer, and the received information is submitted from the PDCP layer to the ProSe protocol layer for processing. For details, please refer to the description of steps S201-S205, which will not be repeated here.

In the above solution, the terminal device adds a dedicated radio bearer for Discovery at the packet data convergence protocol layer, and establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel. When the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold , the first Discovery message is mapped to the D2D shared transmission channel; otherwise, the first Discovery message is mapped to the D2D Discovery transmission channel; it is possible to flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent If the number is greater than the fixed number of bits, it will cause packet loss.

Please refer to FIG. 4 . FIG. 4 is a flow chart of another embodiment of the data transmission method of the present application. The execution subject of this embodiment is the terminal device (User Equipment, UE), UE can be a mobile terminal device such as a mobile phone. Two UEs can communicate directly to transmit data.

The difference between this embodiment and the previous embodiment lies in steps S301, S303~S305, and S307~S309. The data transmission method of the present embodiment includes the following steps:

S301: The terminal device establishes a mapping relationship between a ProSe protocol layer and a D2D shared transmission channel at a media access control protocol layer.

Please refer to FIG. 5 together. FIG. 5 is a schematic diagram of another embodiment of establishing a mapping relationship between a ProSe protocol layer and a D2D shared transport channel in this application. Among them, Figure 5-1 is a schematic diagram of the protocol stack for establishing the mapping relationship between the ProSe protocol layer and the D2D shared transmission channel in this application, and Figure 5-2 is a channel mapping diagram for establishing the mapping relationship between the ProSe protocol layer and the D2D shared transmission channel in this application. In the schematic diagram, the mapping path 2 represents the mapping relationship from the ProSe protocol layer to the D2D shared transmission channel.

The terminal device establishes a mapping relationship between the ProSe protocol layer and the D2D shared transmission channel at the MAC layer of the media access control protocol layer, so that the terminal device can map the Discovery message generated by the ProSe protocol layer to the D2D shared transmission channel in the MAC layer.

When the terminal device sends D2D communication data, it is processed according to the processing flow in the prior art.

When the terminal device sends the Discovery message generated by the ProSe protocol layer, steps S302 to S306 are executed.

When the terminal device receives data sent by other terminal devices, steps S307-S309 are performed.

S302: Determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold.

Step S302 is the same as step S202 in the previous embodiment. For details, please refer to the detailed description of step S202 in the previous embodiment, which will not be repeated here.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is greater than the preset threshold, step S303 is executed.

When the number of bits of the first Discovery message generated by the ProSe protocol layer of the terminal device is less than or equal to the preset threshold, step S306 is performed.

S303: When the number of bits of the first Discovery message is greater than a preset threshold, deliver the first Discovery message to a medium access control protocol layer.

When the terminal device determines that the number of bits in the first Discovery message is greater than the preset threshold, it transmits the first Discovery message from the ProSe protocol layer to the MAC layer.

S304: The terminal device maps the first Discovery message to the D2D shared transport channel, and adds a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the The Discovery message transmitted by the D2D shared transport channel.

After submitting the first Discovery message to the MAC layer, the terminal device maps the first Discovery message to the D2D shared transport channel in the MAC layer according to the mapping relationship between the ProSe protocol layer and the D2D shared transport channel in the MAC layer.

After the terminal device maps the first Discovery message to the D2D shared transmission channel, it adds a data packet header to the first Discovery message in the D2D shared transmission channel, and adds a Discovery dedicated logical channel identifier (Logical Channel Identity, LCID).

The Discovery dedicated logical channel identifier is used to identify that the first Discovery message is a Discovery message transmitted through a D2D shared transmission channel. The Discovery message identified by the Discovery dedicated logical channel is delivered by the ProSe protocol layer to the Media Access Control protocol layer, and can be transmitted through the D2D shared transmission channel.

The Discovery dedicated logical channel identifier is used to enable other terminal devices to recognize that the first Discovery message is submitted by the ProSe protocol layer to the media access control protocol layer through the Discovery dedicated logical channel identifier after receiving the first Discovery message, and Transmission over the D2D shared transport channel for further processing. Please refer to FIG. 6 together. FIG. 6 is a channel mapping diagram of an embodiment of mapping a Discovery message to a D2D shared transmission channel in this application.

As shown in Figure 6, since the value of the logical channel identifier of D2D communication data is usually 1~10, therefore, the value of the Discovery dedicated logical channel identifier corresponding to the Discovery dedicated radio bearer can be 1~10 except the identifier value in the logical channel The value of any logical channel other than . For example, the value of the logical channel identifier used to identify the Discovery message is 11, but it is not limited thereto.

Wherein, as shown in FIG. 7 , FIG. 7 is a schematic diagram of an embodiment of a D2D shared transport channel MAC data packet format in the present application.

When the terminal device confirms that the available D2D communication data transmission resources have extra transmission resources to transmit D2D communication data after carrying the first data packet, the terminal device sets the Discovery dedicated logical channel identifier and A logical channel identifier corresponding to the D2D communication data to be transmitted, so that the terminal device can simultaneously transmit the first Discovery message and the D2D communication data to be transmitted through the same D2D communication data transmission resource.

When the terminal device confirms that the available D2D communication data transmission resources have no redundant transmission resources to transmit D2D communication data after carrying the first Discovery message, the terminal device sets the Discovery dedicated logical channel identifier and the to-be-transmitted The logical channel identifier corresponding to the D2D communication data, so that the terminal device can simultaneously transmit the first Discovery message and the D2D communication data to be transmitted through different D2D communication data transmission resources. Wherein, the first Discovery message and the D2D communication data are distinguished through different transmission resources.

S305: The terminal device transmits the first Discovery message to the physical layer through the D2D shared transmission channel, and sets a flag bit in the D2D link control information corresponding to the first Discovery message, and passes the D2D communication data The transmission resource transmits the first Discovery message, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the Discovery message is transmitted from the ProSe protocol layer to the media access control Discovery message of the protocol layer.

After adding the Discovery dedicated logical channel identifier to the first Discovery message, the terminal device transmits the first Discovery message added with the Discovery dedicated logical channel identifier to the physical layer through the D2D shared transmission channel.

Afterwards, the terminal device sends the D2D link control information (Sidelink Control Information, SCI), the flag bit is set, and the first Discovery message is transmitted through the transmission resource of the D2D communication data.

The flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the first Discovery message is a Discovery message transmitted from the ProSe protocol layer to the MAC protocol layer.

Wherein, a flag bit is set in the D2D link control information corresponding to the first Discovery message, and the step of transmitting the first Discovery message through the transmission resources of the D2D communication data includes: the terminal device determines according to scheduling information or available transmission resources The D2D link control information corresponding to the first Discovery message, wherein the D2D link control information corresponding to the first Discovery message is used to indicate the transmission resource information carrying the first Discovery message; the terminal device in the D2D link corresponding to the first Discovery message The flag bit is set in the link control information, so as to transmit the first Discovery message through the transmission resource indicated by the D2D link control information. For example, after the terminal device submits the first data packet from the MAC layer to the physical layer through the D2D shared transmission channel, it determines the D2D link control information corresponding to the first Discovery message according to the scheduling information or available transmission resources, and in the first Discovery message The value of the flag bit is set in the corresponding D2D link control information, so as to transmit the first Discovery message through the transmission resource indicated by the D2D link control information. Wherein, the D2D link control information corresponding to the first Discovery message is used to indicate the transmission resource information bearing the first Discovery message.

Specifically, the terminal device obtains the D2D link control information corresponding to the first Discovery message from the scheduling information sent by the base station, or determines the D2D link control information corresponding to the first Discovery message according to the transmission resources allocated by the first Discovery message.

Afterwards, in the D2D link control information (Sidelink Control Information, SCI) to set the value of the flag bit. Wherein, the D2D link control information corresponding to the first Discovery message indicates the transmission resource information bearing the first Discovery message and the common transmission resource information of the D2D communication data. Wherein, the D2D link control information is used to indicate the information of the transmission resource carrying the data to be transmitted, and the information of the transmission resource includes information such as frequency and time of the transmission resource.

At this time, the D2D link control information is used to indicate the transmission resource information carrying the first Discovery message, or the transmission resource information common to the first Discovery message and the D2D communication data. Wherein, the first Discovery message is distinguished from the D2D communication data by a logical channel identifier.

The first Discovery message and the D2D communication data are distinguished by flag bits in the D2D link control information and different transmission resources. It can be understood that the first Discovery message may be a data packet, and only one transmission is sufficient.

The flag bit in the D2D link control information may occupy 1 bit in the SC, and the flag bit is used to indicate whether the first Discovery message includes the Discovery message transmitted from the ProSe protocol layer to the MAC layer.

For example, if the value of the 1-bit flag of the SCI is set to "1", the first Discovery message carried by the transmission resource indicated by the SCI includes the Discovery message delivered from the ProSe protocol layer to the MAC layer; The data packet carried by the indicated transmission resource only includes other D2D communication data, and does not include the Discovery message passed from the ProSe protocol layer to the MAC layer.

S306: When the number of bits of the first discovery message is less than or equal to the preset threshold, map the first discovery message to a D2D Discovery transmission channel.

Step S306 is the same as step S206 in the previous embodiment. For details, please refer to the detailed description of step S206 in the previous embodiment, which will not be repeated here.

S307: The terminal device receives a second Discovery message sent by other terminal devices.

Step S307 is the same as step S207 in the previous embodiment. For details, please refer to the specific description of step S207 in the previous embodiment, which will not be repeated here.

S308: The terminal device determines whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from D2D shared transmission channel.

The terminal device determines whether the received second Discovery message contains the Discovery dedicated logical channel identifier and/or whether the value of the flag bit of the D2D link control information is a preset value, thereby determining whether the received second Discovery message comes from a D2D shared transmission channel. Wherein, the preset value of the flag bit of the D2D link control information corresponds to the preset value in step S305.

When the terminal device determines that the second Discovery message includes the Discovery dedicated logical channel identifier, or the value of the flag bit of the D2D link control information is a preset value, it determines that the received second Discovery message is from the D2D shared transport channel.

When the received second Discovery message is from the D2D shared transmission channel, perform step S309; otherwise, perform processing according to the method in the prior art.

S309: When the second Discovery message comes from the D2D shared transmission channel, through the D2D The Discovery transport channel transfers the second Discovery message from the MAC protocol layer to the ProSe protocol layer for processing.

Since the terminal device sends the Discovery message and receives the Discovery message are two inverse processes, therefore, when the terminal device receives the second Discovery message, it performs processing referring to the flow of the first Discovery message.

Specifically: when the terminal device confirms that the received second Discovery message is from the D2D shared transmission channel, it transmits the second Discovery message from the MAC layer to the ProSe protocol layer through the D2D shared transmission channel for processing. For details, please refer to the description of steps S301-S305, which will not be repeated here.

In the above solution, the terminal device establishes a direct mapping relationship between the ProSe protocol layer and the D2D shared transmission channel at the MAC layer, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to to the D2D shared transmission channel, otherwise, the first Discovery message is mapped to the D2D Discovery transmission channel; it can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent the occurrence of problems caused by the number of bits of the Discovery message being greater than the fixed number of bits. The case of packet loss.

Please refer to FIG. 8 . FIG. 8 is a flow chart of another embodiment of the data transmission method of the present application. The execution subject of this embodiment is the terminal device (User Equipment, UE), where the UE may be a mobile terminal device such as a mobile phone. Two UEs can communicate directly to transmit data.

Steps S401-S403 in this embodiment are respectively the same as S301-S303 in the previous embodiment, and steps S406 and S407 in this embodiment are respectively the same as steps S306 and S307 in the previous embodiment. The data transmission method of the present embodiment includes the following steps:

S401: The terminal device establishes a mapping relationship between a ProSe protocol layer and a D2D shared transmission channel at a media access control protocol layer.

Step S401 is the same as step S301 in the previous embodiment. For details, please refer to the detailed description of step S301 in the previous embodiment, which will not be repeated here.

S402: Determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold.

Step S402 is the same as step S302 in the previous embodiment. For details, please refer to the detailed description of step S302 in the previous embodiment, which will not be repeated here.

S403: When the number of bits of the first Discovery message is greater than a preset threshold, submit the first Discovery message to a medium access control protocol layer.

Step S403 is the same as step S303 in the previous embodiment. For details, please refer to the specific description of step S303 in the previous embodiment, which will not be repeated here.

S404: The terminal device maps the first Discovery message to the D2D shared transmission channel.

After submitting the first Discovery message to the MAC layer, the terminal device maps the first Discovery message to the D2D shared transport channel in the MAC layer according to the direct mapping relationship between the ProSe protocol layer and the D2D shared transport channel in the MAC layer.

Wherein, a schematic diagram of mapping the first data packet to the D2D shared transmission channel is shown in FIG. 9 . FIG. 9 is a schematic diagram of channel mapping in another embodiment of mapping a Discovery message to a D2D shared transmission channel in the present application.

In this embodiment, the first Discovery message mapped to the D2D shared transport channel and the D2D communication data use the same logical channel identifier. As shown in FIG. 9 , the values of the first Discovery message and the logical channel identifier of the D2D communication data are usually 1-10.

S405: The terminal device transmits the first Discovery message to the physical layer through the D2D shared transmission channel, and sets a flag bit in the D2D link control information corresponding to the first Discovery message, and passes the D2D communication data The transmission resource transmits the first Discovery message, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the Discovery message is transmitted from the ProSe protocol layer to the media access control protocol Discovery message of the layer.

After the terminal device maps the first Discovery message to the D2D shared transmission channel, it transmits the first Discovery message from the MAC layer to the physical layer through the D2D shared transmission channel, and determines the D2D information corresponding to the first Discovery message according to the scheduling information or available transmission resources. For the link control information, the value of the flag bit is set in the D2D link control information corresponding to the first Discovery message, so as to transmit the first Discovery message through the transmission resources indicated in the D2D link control information. Wherein, the D2D link control information corresponding to the first Discovery message is used to indicate the transmission resource information bearing the first Discovery message.

After that, in the D2D link control information (Sidelink Control Information, SCI) to set the flag bit.

Wherein, the D2D link control information is used to indicate the information of the transmission resource carrying the data to be transmitted, and the information of the transmission resource includes information such as frequency and time of the transmission resource.

At this time, the D2D link control information corresponding to the first Discovery message is only used to indicate the transmission resource information bearing the first Discovery message. The transmission resource information bearing the D2D communication data is indicated by the D2D link control information corresponding to the D2D communication data. The first Discovery message and the D2D communication data are distinguished by different transmission resources and transmitted respectively. The flag bit in the D2D link control information may occupy 1 bit (bit) in the SC, and the flag bit is used to indicate whether the first Discovery message includes the second Discovery message carried by the D2D shared transport channel.

Please refer to FIG. 10 together. FIG. 10 is a schematic diagram of an embodiment of using different physical resources to distinguish Discovery messages and D2D communication data in this application.

As shown in FIG. 10 , the terminal device uses different transmission resources to distinguish the first Discovery message from other D2D communication data, and uses different SCI resource transmissions to transmit corresponding SCIs respectively. Among them, 1 of the above SCI The bit identification bit is used to indicate whether the resource indicated by the corresponding SCI bears the first Discovery message.

For example, if the value of the 1-bit flag of the above SCI is set to "1", the resource indicated by the SCI is the transmission resource corresponding to the first Discovery message; otherwise, the resource indicated by the SCI is other D2D communication data The corresponding transmission resources.

The terminal device is also controlled through the D2D link (Sidelink Control, SC) resources transmit the SCI of the D2D communication data, and instruct the terminal device to transmit the D2D communication data through the available D2D communication data resources according to the SCI of the D2D communication data, so as to send the D2D communication data to other terminal devices.

In addition, after the terminal device submits the first Discovery message from the MAC layer to the physical layer through the D2D shared transmission channel, the terminal device can obtain the first Discovery message and the transmission resource of the D2D communication data and the corresponding SC through the scheduling information sent by the base station. Resources: the terminal device may also obtain transmission resources for the first Discovery message, D2D communication data, and respective corresponding SC resources in the D2D direct communication contention resource pool corresponding to the terminal device. Wherein, the resource pool is a set of time-frequency resources. The D2D direct communication contention resource pool is configured through LTE system broadcast or dedicated signaling, which will not be described here.

In the above base station scheduling information, a 1-bit identification bit may be added to distinguish whether the SC resource and the transmission resource allocated by the SCI correspond to the transmission of the first Discovery message or the transmission of D2D communication data.

It can be understood that the first Discovery message may be a data packet, and only one transmission is sufficient.

In this embodiment, the terminal device sets a flag bit in the D2D link control information corresponding to the first Discovery message to distinguish the first Discovery message from the D2D communication data, and transmits the first Discovery message and the D2D communication data through different transmission resources. communication data.

S406: When the number of bits of the first discovery message is not greater than the preset threshold, map the first discovery message to D2D Discovery transport channel.

Step S406 is the same as step S306 in the previous embodiment. For details, please refer to the specific description of step S306 in the previous embodiment, which will not be repeated here.

S407: The terminal device receives a second Discovery message sent by another terminal device.

Step S407 is the same as step S307 in the previous embodiment. For details, please refer to the specific description of step S307 in the previous embodiment, which will not be repeated here.

S408: The terminal device determines whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel.

The terminal device determines whether the value of the flag bit of the D2D link control information included in the received second Discovery message is a preset value, thereby determining whether the received second Discovery message comes from a D2D shared transmission channel. Wherein, the preset value of the flag bit of the D2D link control information corresponds to the preset value in step S406.

When the terminal device determines that the value of the flag bit of the D2D link control information contained in the second Discovery message is a preset value, it determines that the received second Discovery message is from the D2D shared transmission channel.

When the received second Discovery message is from the D2D shared transmission channel, perform step S409; otherwise, perform processing according to the method in the prior art.

S409: When the information includes the second Discovery message, through the D2D The Discovery transport channel delivers the second Discovery message from the MAC protocol layer to the ProSe protocol layer for processing.

Since the terminal device sends the Discovery message and receives the Discovery message are two inverse processes, therefore, when the terminal device receives the second Discovery message, it performs processing referring to the flow of the first Discovery message.

Specifically, when the terminal device confirms that the received second Discovery message is from the D2D shared transmission channel, it submits the second Discovery message from the MAC layer to the ProSe protocol layer through the D2D shared transmission channel for processing. For details, please refer to the description of steps S401-S405, which will not be repeated here.

In this embodiment, the SCI flag is set to distinguish the Discovery message and the D2D communication data through different transmission resources, so that the terminal device that receives the information can identify the current transmission resource corresponding to the current transmission resource through the SCI flag. Is it a Discovery message or D2D communication data.

In the above solution, the terminal device establishes a direct mapping relationship between the ProSe protocol layer and the D2D shared transmission channel at the MAC layer, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to to the D2D shared transmission channel, otherwise, the first Discovery message is mapped to the D2D Discovery transmission channel; it can flexibly transmit Discovery messages with different numbers of bits, improve the reliability of data transmission, and prevent the occurrence of problems caused by the number of bits in the Discovery message being greater than the fixed number of bits. The case of packet loss.

Please refer to FIG. 11 . FIG. 11 is a schematic structural diagram of an embodiment of a data transmission device of the present application. The modules included in the data transmission device of this embodiment are used to execute the steps in the embodiment corresponding to FIG. 1 . For details, please refer to FIG. 1 and related descriptions of the embodiment corresponding to FIG. 1 , and details are not repeated here. The data transmission device of this embodiment includes an establishment module 1110 , a determination module 1120 and a mapping module 1130 .

The establishing module 1110 is used for establishing the device-to-device proximity service D2D The mapping relationship between the ProSe protocol layer and the D2D shared transmission channel. For example, the establishment module 1110 establishes the device-to-device proximity service D2D The mapping relationship between the ProSe protocol layer and the D2D shared transmission channel. After the establishment module 1110 establishes the mapping relationship between the ProSe protocol layer and the D2D shared transport channel, it sends notification information to the determination module 1120 .

The determining module 1120 is configured to receive the notification information sent by the determining module 1120, and determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. For example, the determining module 1120 determines whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. The determination module 1120 sends the determination result to the mapping module 1130 .

The mapping module 1130 is configured to receive the determination result sent by the determination module 1120, and when the determination module 1120 determines that the number of bits of the first Discovery message is greater than a preset threshold, map the first Discovery message to the D2D shared transmission channel, Transmit the first Discovery message through the D2D shared transmission channel; or, when the determining module 1120 determines that the number of bits of the first Discovery message is less than or equal to the preset threshold, map the first Discovery message to D2D Discovery transport channel.

For example, the mapping module 1130 receives the determination result sent by the determination module 1120, and when the determination module 1120 determines that the number of bits of the first Discovery message is greater than a preset threshold, maps the first Discovery message to the D2D shared transmission channel, Transmit the first Discovery message through the D2D shared transmission channel; or, when the determining module 1120 determines that the number of bits of the first Discovery message is less than or equal to the preset threshold, map the first Discovery message to D2D Discovery transport channel.

In the above scheme, the data transmission device establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to the D2D Shared transmission channel, otherwise, map the first Discovery message to the D2D Discovery transmission channel; can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent packet loss caused by the number of bits of the Discovery message being greater than the fixed number of bits Condition.

Please refer to FIG. 12 . FIG. 12 is a schematic structural diagram of another embodiment of the data transmission device of the present application. The modules included in the data transmission device of this embodiment are used to execute the steps in the embodiments corresponding to Fig. 2, Fig. 4, and Fig. 8. For details, please refer to Fig. 2, Fig. 4, Fig. 8 and the corresponding embodiments Relevant descriptions are not repeated here. The data transmission device of this embodiment includes an establishment module 1210 , a determination module 1220 , a mapping module 1230 , a control module 1240 and a receiving module 1250 .

The establishing module 1210 is specifically configured to add a Discovery-dedicated radio bearer at the packet data convergence protocol layer, and establish a mapping relationship from the ProSe protocol layer to the Discovery-dedicated radio bearer, wherein the Discovery-dedicated radio bearer is used to carry a Discovery message, and the Discovery The Discovery message carried by a dedicated radio bearer is mapped to a Discovery dedicated logical channel, and is identified by a Discovery dedicated logical channel identifier, and the Discovery message identified by the Discovery dedicated logical channel is transmitted through the D2D shared transport channel, and the Discovery dedicated logical channel The radio bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.

For example, the establishment module 1210 adds a Discovery-dedicated radio bearer at the packet data convergence protocol layer, and establishes a mapping relationship from the ProSe protocol layer to the Discovery-dedicated radio bearer, wherein the Discovery-dedicated radio bearer is used to bear Discovery messages, and the Discovery-dedicated The Discovery message carried by the radio bearer is mapped to a Discovery dedicated logical channel, and is identified by a Discovery dedicated logical channel identifier, and the Discovery message identified by the Discovery dedicated logical channel is transmitted through the D2D shared transport channel, and the Discovery dedicated wireless The bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.

The establishment module 1210 is specifically configured to establish a mapping relationship between the ProSe protocol layer and the D2D shared transport channel at the medium access control protocol layer. For example, the establishment module 1210 establishes a mapping relationship between the ProSe protocol layer and the D2D shared transport channel at the medium access control protocol layer.

The establishing module 1210 sends notification information to the determining module 1220 after establishing the mapping relationship between the ProSe protocol layer and the D2D shared transport channel.

The determining module 1220 is configured to receive the notification information sent by the determining module 1220, and determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. For example, the determining module 1220 determines whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold. The determination module 1220 sends the determination result to the mapping module 1230 .

The mapping module 1230 is specifically configured to receive the determination result sent by the determination module 1220, and when the determination module 1220 determines that the number of bits of the first Discovery message is greater than a preset threshold, transfer the first Discovery message to the packet data convergence protocol layer, mapping the first Discovery message to the Discovery dedicated radio bearer, and mapping the first Discovery message to the D2D shared transport channel, and adding a Discovery dedicated logical channel identifier to the first Discovery message, Wherein, the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel;

Or the mapping module 1230 is specifically configured to transfer the first Discovery message to the media access control protocol layer when the determining module 1220 determines that the number of bits of the first Discovery message is greater than a preset threshold, and transfer the first Discovery message to the media access control protocol layer. Mapping to the D2D shared transport channel, and adding a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel.

For example, the mapping module 1230 receives the determination result sent by the determination module 1220, and when the determination module 1220 determines that the number of bits of the first Discovery message is greater than a preset threshold, transfers the first Discovery message to the packet data convergence protocol layer , mapping the first Discovery message to the Discovery dedicated radio bearer, and mapping the first Discovery message to the D2D shared transport channel, and adding a Discovery dedicated logical channel identifier to the first Discovery message, wherein , the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel;

Or when the determining module 1220 determines that the number of bits of the first Discovery message is greater than the preset threshold, the mapping module 1230 transfers the first Discovery message to the medium access control protocol layer, and maps the first Discovery message to The D2D shared transport channel, and adding a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel.

The mapping module 1230 is further configured to map the first Discovery message to D2D when the determining module 1220 determines that the number of bits of the first Discovery message is less than or equal to the preset threshold Discovery transport channel.

For example, when the determination module 1220 determines that the number of bits of the first discovery message is less than or equal to the preset threshold, the mapping module 1230 maps the first discovery message to the D2D Discovery transport channel. After the mapping module 1230 completes the mapping, it sends notification information to the control module 1240 .

The control module 1240 is configured to receive the notification information sent by the mapping module 1230, transfer the first Discovery message to the physical layer through the D2D shared transport channel, and set A flag bit, for transmitting the first Discovery message through the transmission resource of the D2D communication data, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the Discovery message is the Discovery dedicated radio bearer The Discovery message carried or the Discovery message transmitted from the ProSe protocol layer to the Media Access Control protocol layer.

For example, the control module 1240 receives the notification information sent by the mapping module 1230, transmits the first Discovery message to the physical layer through the D2D shared transport channel, and sets in the D2D link control information corresponding to the first Discovery message A flag bit, for transmitting the first Discovery message through the transmission resource of D2D communication data, wherein the flag bit is used to indicate whether the transmission resource of D2D communication data carries a Discovery message, and the first Discovery message is dedicated to the Discovery The Discovery message carried by the radio bearer or the Discovery message transmitted from the ProSe protocol layer to the MAC protocol layer.

The control module 1240 is specifically configured to transmit the first Discovery message to the physical layer through the D2D shared transmission channel, determine the D2D link control information corresponding to the first Discovery message according to scheduling information or available transmission resources, and in the Set a flag bit in the D2D link control information corresponding to the first Discovery message, and transmit the first Discovery message through the transmission resources indicated by the D2D link control information; wherein, the D2D link corresponding to the first Discovery message The control information is used to indicate transmission resource information bearing the first Discovery message.

Wherein, the D2D link control information determined by the control module 1240 indicates the transmission resource information carrying the transmission resource information of the first Discovery message and the common D2D communication data transmission resource information of the D2D communication data, and the transmission resource of the D2D communication data simultaneously carries the The first Discovery message and the D2D communication data are distinguished by a logical channel identifier.

Wherein, the D2D link control information determined by the control module 1240 indicates the transmission resource information of the D2D communication data carrying the first Discovery message, and the transmission resource of the D2D communication data only carries the first Discovery message, wherein the The first Discovery message and the D2D communication data are distinguished by different transmission resources.

For example, the control module 1240 transmits the first Discovery message to the physical layer through the D2D shared transmission channel, determines the D2D link control information corresponding to the first Discovery message according to scheduling information or available transmission resources, and in the A flag bit is set in the D2D link control information corresponding to the first Discovery message, and the first Discovery message is transmitted through the transmission resources indicated by the D2D link control information; wherein, the D2D link control information corresponding to the first Discovery message The information is used to indicate transmission resource information bearing the first Discovery message.

Wherein, the D2D link control information determined by the control module 1240 indicates the transmission resource information carrying the transmission resource information of the first Discovery message and the common D2D communication data transmission resource information of the D2D communication data, and the transmission resource of the D2D communication data simultaneously carries the The first Discovery message and the D2D communication data are distinguished by a logical channel identifier.

Wherein, the D2D link control information determined by the control module 1240 indicates the transmission resource information of the D2D communication data carrying the first Discovery message, and the transmission resource of the D2D communication data only carries the first Discovery message, wherein the The first Discovery message and the D2D communication data are distinguished by different transmission resources.

The receiving module 1250 is configured to receive the second Discovery message sent by other terminal devices. For example, the receiving module 1250 receives the second Discovery message sent by other terminal devices. The receiving module 1250 sends the received second Discovery message to the determining module 1220 .

The determining module 1220 is further configured to receive the second Discovery message sent by the receiving module 1250, and determine whether the second Discovery message received by the receiving module 1250 includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value. Set a value to determine whether the second Discovery message is from a D2D shared transport channel. The determination module 1220 sends the determination result to the mapping module 1230 .

The mapping module 1230 is configured to process the second Discovery message according to the mechanism for transmitting the first Discovery when the determining module 1220 determines that the second Discovery message is from the D2D shared transmission channel.

In the above scheme, the data transmission device establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to the D2D Shared transmission channel, otherwise, map the first Discovery message to the D2D Discovery transmission channel; can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent packet loss caused by the number of bits of the Discovery message being greater than the fixed number of bits Condition.

Referring to FIG. 13 , FIG. 13 is a schematic structural diagram of an embodiment of a terminal device according to the present application. The terminal device may be a mobile terminal device such as a mobile phone. The terminal device in this embodiment includes: a receiver 1310 , a processor 1320 , a transmitter 1330 , a read only memory 1340 , a random access memory 1350 and a bus 1360 .

Receiver 1310 is used to receive information.

The processor 1320 controls the operation of the terminal device, and the processor 1320 may also be called a CPU (Central Processing Unit, central processing unit). The processor 1320 may be an integrated circuit chip with signal processing capabilities. The processor 1320 can also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components . A general-purpose processor may be a microprocessor, or the processor may be any conventional processor, or the like.

The transmitter 1330 is used to send information.

Memories may include read only memory 1340 and random access memory 1350 , and provide instructions and data to processor 1320 . A portion of the memory may also include non-volatile random access memory (NVRAM).

Various components of the terminal device are coupled together through a bus 1360, wherein the bus 1360 may include a power bus, a control bus, and a status signal bus, etc. in addition to a data bus. However, for clarity of illustration, the various buses are labeled as bus 1360 in the figure.

The memory stores the following elements, executable modules or data structures, or subsets thereof, or extensions thereof:

Operation instructions: include various operation instructions for realizing various operations.

Operating system: includes various system programs for implementing various basic services and processing hardware-based tasks.

In the embodiment of the present invention, the processor 1320 performs the following operations by calling the operation instruction stored in the memory (the operation instruction can be stored in the operating system):

The processor 1320 is configured to establish a mapping relationship between the device-to-device proximity service D2D ProSe protocol layer and the D2D shared transmission channel;

The processor 1320 is configured to determine whether the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than a preset threshold; The Discovery message is mapped to the D2D shared transmission channel, and the first Discovery message is transmitted through the D2D shared transmission channel; or, when the number of bits of the first discovery message is less than or equal to the preset threshold, the The first Discovery message is mapped to D2D Discovery transport channel.

Optionally, the processor 1320 is specifically configured to add a Discovery dedicated radio bearer at the packet data convergence protocol layer, and establish a mapping relationship from the ProSe protocol layer to the Discovery dedicated radio bearer, where the Discovery dedicated radio bearer is used to bear the Discovery message The Discovery message carried by the Discovery-dedicated radio bearer is mapped to a Discovery-dedicated logical channel, and is identified by a Discovery-dedicated logical channel identifier, and the Discovery message identified by the Discovery-dedicated logical channel is transmitted through the D2D shared transport channel, The Discovery dedicated radio bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.

Optionally, the processor 1320 is specifically configured to establish a mapping relationship between the ProSe protocol layer and the D2D shared transport channel at the medium access control protocol layer.

Optionally, the processor 1320 is specifically configured to, when the number of bits of the first Discovery message is greater than a preset threshold, transfer the first Discovery message to the packet data convergence protocol layer, and transfer the first Discovery message to the packet data convergence protocol layer. Mapping to the Discovery dedicated radio bearer; or passing the first Discovery message to the medium access control protocol layer;

The processor 1320 is also specifically configured to map the first Discovery message to the D2D shared transport channel, and add a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify A Discovery message transmitted through the D2D shared transmission channel.

Optionally, the processor 1320 is further configured to transmit the first Discovery message to the physical layer through the D2D shared transport channel, and set a flag bit in the D2D link control information corresponding to the first Discovery message, by The transmission resource of the D2D communication data transmits the first Discovery message, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the first Discovery message is carried by the Discovery dedicated radio bearer A Discovery message or a Discovery message delivered from the ProSe protocol layer to the MAC protocol layer.

Optionally, the processor 1320 is further specifically configured to transmit the first Discovery message to the physical layer through the D2D shared transmission channel, and determine the D2D link corresponding to the first Discovery message according to scheduling information or available transmission resources. Control information, setting a flag bit in the D2D link control information corresponding to the first Discovery message, and transmitting the first Discovery message through the transmission resource indicated by the D2D link control information; wherein, the first Discovery message The corresponding D2D link control information is used to indicate the transmission resource information bearing the first Discovery message.

Optionally, the D2D link control information determined by the processor 1320 indicates the transmission resource information carrying the transmission resource information of the first Discovery message and the transmission resource information of D2D communication data common to the D2D communication data, and the transmission resources of the D2D communication data simultaneously carry The first Discovery message is distinguished from the D2D communication data by using a logical channel identifier.

Optionally, the D2D link control information determined by the processor 1320 indicates transmission resource information of the D2D communication data carrying the first Discovery message, and the transmission resource of the D2D communication data only carries the first Discovery message, wherein, The first Discovery message and D2D communication data are distinguished by different transmission resources.

Optionally, the processor 1320 is further configured to control the receiver 1310 to receive a second Discovery message sent by other terminal devices;

The processor 1320 is further configured to determine whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel;

The processor 1320 is further configured to, when the second Discovery message comes from a D2D shared transmission channel, the terminal device processes the second Discovery message according to the mechanism for transmitting the first Discovery.

In the above solution, the terminal device establishes a mapping relationship from the ProSe protocol layer to the D2D shared transmission channel, and when the terminal device determines that the number of bits of the first Discovery message generated by the ProSe protocol layer is greater than the preset threshold, the first Discovery message is mapped to the D2D shared transmission channel. Transmission channel, otherwise, map the first Discovery message to the D2D Discovery transmission channel; it can flexibly transmit Discovery messages with different numbers of bits, improve the effectiveness of data transmission, and prevent packet loss caused by the number of bits in the Discovery message being greater than the fixed number of bits .

In the above description, specific details, such as specific system architectures, interfaces and techniques, are set forth for purposes of illustration rather than limitation, in order to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that the present application may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

Claims (27)

1. A method of data transmission, the method comprising:

   the terminal equipment establishes a mapping relation from a device-to-device proximity service (D2D) ProSe protocol layer to a D2D shared transmission channel;

   the terminal equipment determines whether the bit number of a first Discovery message generated by the ProSe protocol layer is greater than a preset threshold value;

   when the bit number of the first Discovery message is greater than a preset threshold value, mapping the first Discovery message to the D2D shared transmission channel, and transmitting the first Discovery message through the D2D shared transmission channel; or

   And when the bit number of the first Discovery message is less than or equal to the preset threshold, mapping the first Discovery message to a D2DDiscovery transmission channel.
2. The method according to claim 1, wherein the step of the terminal device establishing the mapping relationship of the ProSe protocol layer to the D2D shared transport channel comprises:

   the terminal equipment adds a Discovery special radio bearer on a packet data convergence protocol layer, establishes a mapping relation from a ProSe protocol layer to the Discovery special radio bearer, wherein the Discovery special radio bearer is used for bearing Discovery messages, the Discovery messages borne by the Discovery special radio bearer are mapped to a Discovery special logic channel and are identified through a Discovery special logic channel identifier, the Discovery messages of the Discovery special logic channel identifier are transmitted through a D2D shared transmission channel, the Discovery special radio bearer corresponds to the Discovery special logic channel, and the Discovery special logic channel corresponds to the Discovery special logic channel identifier.
3. The method according to claim 1, wherein the step of the terminal device establishing the mapping relationship of the ProSe protocol layer to the D2D service logical channel comprises:

   the terminal device establishes a mapping relation from a ProSe protocol layer to a D2D shared transmission channel on a media access control protocol layer.
4. The method according to claim 2 or 3, wherein when the number of bits of the first Discovery message is greater than a preset threshold, mapping the first Discovery message to the D2D shared transmission channel, and the step of transmitting the first Discovery message through the D2D shared transmission channel comprises:

   when the bit number of the first Discovery message is greater than a preset threshold, the terminal device transmits the first Discovery message to the packet data convergence protocol layer, and maps the first Discovery message to the Discovery dedicated radio bearer; or passing the first Discovery message to a media access control protocol layer;

   the terminal device maps the first Discovery message to the D2D shared transmission channel, and adds a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel.
5. The method of claim 1 or 4, wherein after the step of mapping the first Discovery message to the D2D shared transport channel, the method further comprises:

   the terminal device transmits the first Discovery message to a physical layer through the D2D shared transmission channel, sets a flag bit in D2D link control information corresponding to the first Discovery message, and transmits the first Discovery message through a transmission resource of D2D communication data, where the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the Discovery message is a Discovery message carried by the first Discovery dedicated radio bearer or a Discovery message transmitted from the ProSe protocol layer to the mac protocol layer.
6. The method of claim 5, wherein a flag bit is set in the D2D link control information corresponding to the first Discovery message, and wherein transmitting the first Discovery message over the transmission resource of D2D communication data comprises:

   the terminal device determines, according to scheduling information or available transmission resources, D2D link control information corresponding to the first data packet, where the D2D link control information corresponding to the first Discovery message is used to indicate transmission resource information carrying the first Discovery message;

   and the terminal equipment sets a flag bit in the D2D link control information corresponding to the first Discovery message, and transmits the first Discovery message through the transmission resource indicated by the D2D link control information.
7. The method of claim 5, wherein the D2D link control information indicates transmission resource information for carrying the first Discovery message and transmission resource information for D2D communication data common to D2D communication data, wherein the transmission resource for the D2D communication data simultaneously carries the first Discovery message and the D2D communication data, and wherein the first Discovery message is distinguished from the D2D communication data by a logical channel identifier.
8. The method of claim 5, wherein the D2D link control information indicates transmission resource information of D2D communication data carrying the first Discovery message, wherein the transmission resource of the D2D communication data carries only the first Discovery message, and wherein the first Discovery message and the D2D communication data are distinguished by different transmission resources.
9. The method according to claim 4 or 5, characterized in that the method further comprises:

   the terminal equipment receives second Discovery messages sent by other terminal equipment;

   the terminal device determines whether the second Discovery message contains the Discovery dedicated logical channel identifier and/or whether the value of the flag bit is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel;

   and when the second Discovery message comes from a D2D shared transmission channel, the terminal device processes the second Discovery message according to a mechanism for transmitting the first Discovery.
10. A data transmission apparatus, characterized in that the apparatus comprises: the device comprises an establishing module, a determining module and a mapping module;

    the establishing module is used for establishing a mapping relation from a device-to-device proximity service (D2D) ProSe protocol layer to a D2D shared transmission channel;

    the determining module is configured to determine whether a bit number of a first Discovery message generated by the ProSe protocol layer is greater than a preset threshold after the establishing module establishes a mapping relationship from the D2 dpross protocol layer to the D2D shared transmission channel;

    the mapping module is configured to map the first Discovery message to the D2D shared transmission channel and transmit the first Discovery message through the D2D shared transmission channel when the determining module determines that the number of bits of the first Discovery message is greater than a preset threshold; or when the determining module determines that the bit number of the first Discovery message is less than or equal to the preset threshold, mapping the first Discovery message to a D2 ddidiscovery transmission channel.
11. The apparatus of claim 10, wherein the establishing module is specifically configured to add a Discovery dedicated radio bearer in a packet data convergence protocol layer, and establish a mapping relationship between a ProSe protocol layer and the Discovery dedicated radio bearer, where the Discovery dedicated radio bearer is used to carry a Discovery message, the Discovery message of the Discovery dedicated radio bearer is mapped to a Discovery dedicated logical channel and identified by a Discovery dedicated logical channel identifier, the Discovery message of the Discovery dedicated logical channel identifier is transmitted through the D2D shared transport channel, the Discovery dedicated radio bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.
12. The apparatus according to claim 10, wherein the establishing module is specifically configured to establish a mapping relationship from a ProSe protocol layer to a D2D shared transport channel at a medium access control protocol layer.
13. The apparatus according to claim 11 or 12, wherein the mapping module is specifically configured to, when the determining module determines that the number of bits of the first Discovery message is greater than a preset threshold, pass the first Discovery message to the packet data convergence protocol layer, map the first Discovery message to the Discovery dedicated radio bearer, and map the first Discovery message to the D2D shared transport channel, and add a Discovery dedicated logical channel identifier to the first Discovery message, wherein the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel; or

    The mapping module is specifically configured to, when the determining module determines that the number of bits of the first Discovery message is greater than a preset threshold, transfer the first Discovery message to a media access control protocol layer, map the first Discovery message to the D2D shared transmission channel, and add a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel.
14. The apparatus according to claim 10 or 13, wherein the apparatus further comprises a control module, the control module is configured to deliver the first Discovery message to a physical layer through the D2D shared transmission channel, set a flag bit in D2D link control information corresponding to the first Discovery message, and transmit the first Discovery message through a transmission resource of D2D communication data, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries a Discovery message, and the first Discovery message is a Discovery message carried by the Discovery dedicated radio bearer or a Discovery message delivered from the ProSe protocol layer to the media access control protocol layer.
15. The apparatus of claim 14, wherein the control module is specifically configured to deliver the first Discovery message to a physical layer through the D2D shared transmission channel, determine D2D link control information corresponding to the first Discovery message according to scheduling information or available transmission resources, set a flag bit in the D2D link control information corresponding to the first Discovery message, and transmit the first Discovery message through the transmission resources indicated by the D2D link control information; wherein the link control information of D2D corresponding to the first Discovery message is used to indicate transmission resource information carrying the first Discovery message.
16. The apparatus of claim 14, wherein the D2D link control information determined by the control module indicates transmission resource information carrying the first Discovery message and transmission resource information of D2D communication data common to D2D communication data, wherein the transmission resource of the D2D communication data simultaneously carries the first Discovery message and D2D communication data, and wherein the first Discovery message is distinguished from the D2D communication data by logical channel identification.
17. The apparatus of claim 14, wherein the D2D link control information determined by the control module indicates transmission resource information for D2D communication data carrying the first Discovery message, wherein the transmission resource for D2D communication data carries only the first Discovery message, and wherein the first Discovery message and D2D communication data are distinguished by different transmission resources.
18. The method of claim 13 or 14, wherein the apparatus further comprises a receiving module; the receiving module is used for receiving a second Discovery message sent by other terminal equipment;

    the determining module is further configured to determine whether the second Discovery message received by the receiving module includes the Discovery dedicated logical channel identifier and/or whether the value of the flag is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel;

    the mapping module is further configured to, when the determining module determines that the second Discovery message comes from a D2D shared transmission channel, process the second Discovery message according to a mechanism for transmitting the first Discovery.
19. A terminal device, characterized in that the terminal device comprises a memory and a processor; the memory is used for storing data;

    the processor is configured to establish a mapping relationship from a device-to-device proximity services D2D ProSe protocol layer to a D2D shared transport channel;

    the processor is configured to determine whether a bit number of a first Discovery message generated by the ProSe protocol layer is greater than a preset threshold; and when the bit number of the first Discovery message is greater than a preset threshold, mapping the first Discovery message to the D2D shared transmission channel, and transmitting the first Discovery message through the D2D shared transmission channel; or, when the bit number of the first Discovery message is less than or equal to the preset threshold, mapping the first Discovery message to a D2 ddidiscovery transmission channel.
20. The terminal device of claim 19, wherein the processor is specifically configured to add a Discovery dedicated radio bearer in a packet data convergence protocol layer, and establish a mapping relationship between a ProSe protocol layer and the Discovery dedicated radio bearer, where the Discovery dedicated radio bearer is used to carry a Discovery message, the Discovery message of the Discovery dedicated radio bearer is mapped to a Discovery dedicated logical channel and identified by a Discovery dedicated logical channel identifier, the Discovery message of the Discovery dedicated logical channel identifier is transmitted through the D2D shared transport channel, the Discovery dedicated radio bearer corresponds to the Discovery dedicated logical channel, and the Discovery dedicated logical channel corresponds to the Discovery dedicated logical channel identifier.
21. The terminal device according to claim 19, wherein the processor is specifically configured to establish a mapping relationship of a ProSe protocol layer to a D2D shared transport channel at a medium access control protocol layer.
22. The terminal device of claim 20 or 21, wherein the processor is configured to pass the first Discovery message to the packet data convergence protocol layer, map the first Discovery message to the Discovery dedicated radio bearer, and map the first Discovery message to the D2D shared transport channel when the number of bits of the first Discovery message is greater than a preset threshold, and add a Discovery dedicated logical channel identifier to the first Discovery message, wherein the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transport channel;

    or the processor is specifically configured to, when the number of bits of the first Discovery message is greater than a preset threshold, deliver the first Discovery message to a media access control protocol layer, map the first Discovery message to the D2D shared transmission channel, and add a Discovery dedicated logical channel identifier to the first Discovery message, where the Discovery dedicated logical channel identifier is used to identify the Discovery message transmitted through the D2D shared transmission channel.
23. The terminal device according to claim 19 or 22, wherein the processor is further configured to deliver the first Discovery message to a physical layer through the D2D shared transmission channel, set a flag bit in D2D link control information corresponding to the first Discovery message, and transmit the first Discovery message through a transmission resource of D2D communication data, wherein the flag bit is used to indicate whether the transmission resource of the D2D communication data carries the Discovery message, and the first Discovery message is a Discovery message carried by the Discovery dedicated radio bearer or a Discovery message delivered from the ProSe protocol layer to the media access control protocol layer.
24. The terminal device of claim 23, wherein the processor is further specifically configured to deliver the first Discovery message to a physical layer through the D2D shared transmission channel, determine D2D link control information corresponding to the first Discovery message according to scheduling information or available transmission resources, set a flag bit in the D2D link control information corresponding to the first Discovery message, and transmit the first Discovery message through the transmission resources indicated by the D2D link control information; wherein the link control information of D2D corresponding to the first Discovery message is used to indicate transmission resource information carrying the first Discovery message.
25. The terminal device of claim 23, wherein the processor-determined D2D link control information indicates transmission resource information carrying the first Discovery message and transmission resource information of D2D communication data common to D2D communication data, wherein the transmission resource of the D2D communication data simultaneously carries the first Discovery message and D2D communication data, and wherein the first Discovery message is distinguished from D2D communication data by logical channel identification.
26. The terminal device of claim 23, wherein the D2D link control information determined by the processor indicates transmission resource information for D2D communication data carrying the first Discovery message, wherein the transmission resource for D2D communication data carries only the first Discovery message, and wherein the first Discovery message and D2D communication data are distinguished by different transmission resources.
27. A terminal device according to claim 22 or 23, characterized in that the terminal device further comprises a receiver; the receiver is used for receiving a second Discovery message sent by other terminal equipment;

    the processor is configured to determine whether the second Discovery message includes the Discovery dedicated logical channel identifier and/or whether the value of the flag is a preset value, so as to determine whether the second Discovery message comes from a D2D shared transmission channel;

    the processor is configured to, when the second Discovery message comes from a D2D shared transmission channel, process, by the terminal device, the second Discovery message according to a mechanism for transmitting the first Discovery.