CN112218285B

CN112218285B - Method, equipment and system for transmitting uplink user data

Info

Publication number: CN112218285B
Application number: CN201910626454.2A
Authority: CN
Inventors: 张成晨; 舒林
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-07-11
Filing date: 2019-07-11
Publication date: 2022-06-14
Anticipated expiration: 2039-07-11
Also published as: WO2021004534A1; CN112218285A

Abstract

The embodiment of the application provides a method, equipment and a system for transmitting uplink user data, which are used for solving the problems that in the prior art, forward incompatibility is caused when head overhead is reduced, and complexity of data transmission processing is increased. The method comprises the following steps: the terminal equipment determines that only uplink user data needs to be sent; the terminal equipment sends a first message to a mobile management network element, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises the uplink user data.

Description

Method, equipment and system for transmitting uplink user data

Technical Field

The present application relates to the field of communications technologies, and in particular, to a method, a device, and a system for transmitting uplink user data.

Background

In recent years, the application of the internet of things is more and more popular, and the idea of interconnecting everything is gradually realized. In application of the internet of things, energy saving is a very important subject, and many application scenarios of the internet of things require that terminal equipment with cellular internet of things (CIoT) characteristics (hereinafter referred to as internet of things terminal equipment for short) have a battery service life of ten years or more. For the purpose of energy saving, a number of techniques, such as energy saving mode, discontinuous reception or early data transmission, etc., are introduced in the 3rd generation partnership project (3 GPP) standard.

For example, in the 3GPP system, the conventional signaling and data transmission path can be divided into a user plane and a control plane, where the user plane is mainly used for transmitting data and the control plane is mainly used for transmitting signaling. At present, data transmission of terminal equipment of the internet of things is optimized. Particularly, for infrequent data transmission, data can be transmitted through the control plane, that is, the internet of things terminal device can transmit data in a manner of carrying data in signaling. Because the data can be transmitted under the condition of not establishing the user plane connection, the transmission mode can improve the transmission efficiency and reduce the consumption of signaling, resources and the like. Experiments prove that the lower the number of bytes sent by the terminal equipment of the internet of things each time is, the longer the service life of the battery of the terminal equipment of the internet of things is, the higher the utilization rate of wireless air interface resources is under the condition of covering the same sending times equally. Therefore, when determining what kind of signaling to transmit data, reducing the length of other information besides the data content is very important for energy saving and air interface resource utilization rate of the terminal device of the internet of things. The length of the other information outside the data content is also called header overhead, short header overhead, and the shorter the length of the other information outside the data content, the less header overhead, and vice versa. In order to reduce the overhead of transmitting data through the control plane, one processing method is to compress all optional information into one Information Element (IE) for transmission, including the data content itself, information required for transmitting the data content, and optional information unrelated to the transmitted data content, so as to reduce the length of other information besides the data content and reduce the overhead. However, with the evolution of the system and the upgrading of the technology, if some new optional information needs to be transmitted later because of the added extension characteristics, this IE must be modified, which causes the problems of forward incompatibility, etc., and reduces the scalability of the future function. Meanwhile, in order to ensure that the network side can correctly analyze the received IE, the terminal device must additionally add information carried by each optional message in the IE, and when the network side receives the IE, the network side must check information carried by each optional message to correctly analyze the IE, which increases the complexity of data transmission processing.

Disclosure of Invention

The embodiment of the application provides a method, equipment and a system for transmitting uplink user data, which are used for solving the problems that in the prior art, forward incompatibility is caused when head overhead is reduced, and complexity of data transmission processing is increased.

In order to achieve the above purpose, the embodiment of the present application adopts the following technical solutions:

in a first aspect, a method for uplink user data transmission is provided, where the method includes: the terminal equipment determines that only uplink user data needs to be sent; the terminal equipment sends a first message to a mobile management network element, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises the uplink user data. That is to say, the uplink user data transmission method provides a first message dedicated to uplink user data transmission via the control plane, that is, when the terminal device determines that only uplink user data needs to be sent, the terminal device sends the first message dedicated to uplink user data transmission to the mobility management element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data is not required to be sent, the terminal device may send other messages to the mobility management element, where the other messages may be, for example, service request (service request) messages, which are used to request to establish a signaling connection between the terminal device and the mobility management element and/or request to establish user plane resources of a PDU session of the terminal device, and this is not particularly limited herein. Based on the method for transmitting the uplink user data, not only can the expandability of future functions be realized, but also the complexity of data transmission processing is reduced because more optional information is not needed. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In one possible design, before the terminal device determines that only uplink user data needs to be transmitted, the method further includes: the terminal equipment sends a second message, wherein the second message is used for requesting to establish a PDU session; and the terminal equipment receives a third message from the session management network element, wherein the third message carries a first permission identifier, and the first permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission. Based on the scheme, the terminal equipment can know that the PDU session can be used for controlling the plane user data transmission.

In one possible design, the second message carries a control plane user data transmission identifier, where the control plane user data transmission identifier is used to instruct the terminal device to request control plane user data transmission using the PDU session. Based on the scheme, the mobility management network element may determine whether to allow the PDU session for control plane user data transmission according to the control plane user data transmission identifier.

In a second aspect, a method for uplink user data transmission is provided, where the method includes: the method comprises the steps that a mobile management network element receives a first message from a terminal device, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises uplink user data sent by the terminal device; the mobile management network element acquires the NAS data content from the NAS data information according to the information required for transmitting the NAS data content; and the mobile management network element sends the NAS data content. That is to say, the method for transmitting uplink user data provides a first message dedicated to transmitting uplink user data through the control plane, so that not only can expandability of future functions be achieved, but also the complexity of data transmission processing is reduced because more optional information is not required. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In one possible design, before the mobility management element receives the first message from the terminal device, the method further includes: the mobile management network element receives a second message from the terminal equipment, wherein the second message is used for requesting to establish a PDU session; the mobility management network element determines to allow the PDU session for control plane user data transmission; the mobility management network element stores the mapping relation between the PDU session identifier and a first permission identifier, wherein the first permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission; correspondingly, the sending, by the mobility management element, the NAS data content includes: and when the data type of the NAS data content is control plane user data, the mobility management network element sends the NAS data content to a session management network element according to the mapping relation between the PDU session identifier and the first permission identifier. That is to say, in the embodiment of the present application, a specific PDU session for transmitting control plane user data may be established, and then information required for transmitting the NAS data content may not include a PDU session identifier, so that overhead may be further reduced, and transmission overhead may be further reduced.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity is used to indicate that the terminal device requests control plane user data transmission using the PDU session; the mobility management network element determining to allow the PDU session for control plane user data transmission, comprising: and the mobility management network element determines to allow the PDU session for the control plane user data transmission according to the control plane user data transmission identification. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, the determining, by the mobility management network element, that the PDU session is allowed for control plane user data transmission includes: the mobile management network element sends a third message to the session management network element, wherein the third message is used for requesting to establish a session context of the PDU session; the mobility management network element receives the first permission identification from the session management network element; and the mobility management network element determines to allow the PDU session to carry out control plane user data transmission according to the first permission identification. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session; before the mobility management element sends the third message to the session management element, the method further includes: the mobility management network element determines to allow the PDU session to be used for the control plane user data transmission according to the control plane user data transmission identifier; correspondingly, the third message further comprises a second permission identifier, wherein the second permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission. That is to say, in the embodiment of the present application, the mobility management element may determine whether to allow the PDU session to be used for data transmission of the control plane user, and then the session management element performs secondary determination to determine whether to allow the PDU session to be used for data transmission of the control plane user.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of NAS data information, a length of the NAS data content, a PDU session identifier, a downlink data expected DDX, and a data type of the NAS data content; the information required for transmitting NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identification, the DDX and the data type of the NAS data content occupy 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of NAS data information, a length of the NAS data content, a PDU session identifier, DDX, and a data type of the NAS data content; the information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identification occupies 1 byte, and the data type of the DDX and the NAS data content is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of the NAS data information, a length of the NAS data content, a PDU session identifier, and a data type of the NAS data content; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identification and the data type of the NAS data content are in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of the NAS data information, a length of the NAS data content, a PDU session identifier, and a data type of the NAS data content; the information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identification occupies 1 byte, and the data type of the NAS data content is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the first message further includes a data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the DDX; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identification and DDX are in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the first message further includes a data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the DDX; the information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length of NAS data content occupies 2 bytes, the PDU session identification occupies 1 byte, and DDX is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the first message further includes a data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content and a PDU session identification; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length of NAS data content occupies 2 bytes, and the PDU session identification is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the first message further includes a data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content and the DDX; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the DDX is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the first message further includes a data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information and the length of the NAS data content; the information required for transmitting the NAS data content occupies 3 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, and the length of the NAS data content occupies 2 bytes. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of NAS data information, a length of the NAS data content, and a data type of the NAS data content; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the data type of the NAS data content is in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

With reference to the first aspect or the second aspect, in a possible design, the information required for transmitting the NAS data content includes an identifier of NAS data information, a length of the NAS data content, a DDX, and a data type of the NAS data content; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the data types of the DDX and the NAS data content are in the remaining 1 byte. Based on the coding mode, the overhead can be further reduced, and further the transmission overhead can be reduced.

In one possible design, the uplink user data is control plane user data or short message SMS.

In one possible design, the first message is a control plane service request message.

In a third aspect, a communications apparatus is provided for implementing the various methods described above. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the mobility management element in the second aspect, or a device including the mobility management element. The communication device comprises corresponding modules, units or means (means) for implementing the above method, and the modules, units or means can be implemented by hardware, software or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above functions.

In a fourth aspect, a communication apparatus is provided, including: a processor and a memory; the memory is configured to store computer instructions that, when executed by the processor, cause the communication device to perform the method of any of the above aspects. The communication device may be the terminal device of the first aspect, or a device including the terminal device; alternatively, the communication device may be the mobility management element in the second aspect, or a device including the mobility management element.

In a fifth aspect, a communication apparatus is provided, including: a processor; the processor is configured to be coupled to the memory, and to execute the method according to any one of the above aspects after reading the instruction in the memory. The communication device may be the terminal device in the first aspect, or a device including the terminal device; alternatively, the communication device may be the mobility management element in the second aspect, or a device including the mobility management element.

In a sixth aspect, there is provided a computer readable storage medium having stored therein instructions which, when run on a computer, cause the computer to perform the method of any of the above aspects.

In a seventh aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any of the above aspects.

In an eighth aspect, a communication device (which may be a chip or a system of chips, for example) is provided, which comprises a processor for implementing the functionality referred to in any of the above aspects. In one possible design, the communication device further includes a memory for storing necessary program instructions and data. When the communication device is a chip system, the communication device may be constituted by a chip, or may include a chip and other discrete devices.

In a ninth aspect, a method for uplink user data transmission is provided, including: the method comprises the steps that a mobile management network element receives a first message from a terminal device, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises uplink user data sent by the terminal device; the mobile management network element acquires the NAS data content from the NAS data information according to the information required for transmitting the NAS data content; under the condition that the data type of the NAS data content is control plane user data, the mobile management network element sends the NAS data content to the session management network element; the session management network element receives the NAS data content from the mobility management network element. For the description of the information required for transmitting the NAS data content, reference may be made to the possible design of the first aspect or the second aspect, which is not described herein again. That is, the method for transmitting uplink user data provides a first message dedicated to transmitting uplink user data through the control plane, so that not only can the expandability of future functions be realized, but also the complexity of data transmission processing is reduced because more optional information is not required. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In one possible design, the method further includes: the terminal equipment determines that only uplink user data needs to be sent; the terminal equipment sends a first message to the mobile management network element. That is, when the terminal device determines that only the uplink user data needs to be sent, the terminal device sends a first message dedicated to transmitting the uplink user data to the mobility management element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data is not required to be sent, the terminal device may send other messages to the mobility management element, where the other messages may be, for example, service request (service request) messages, which are used to request to establish a signaling connection between the terminal device and the mobility management element and/or request to establish user plane resources of a PDU session of the terminal device, and this is not particularly limited herein.

In one possible design, before the mobility management element receives the first message from the terminal device, the method further includes: the mobile management network element receives a second message from the terminal equipment, wherein the second message is used for requesting to establish a PDU session; the mobility management network element determines to allow the PDU session for control plane user data transmission; the mobility management network element stores the mapping relation between the PDU session identifier and a first permission identifier, wherein the first permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission; correspondingly, the sending, by the mobility management element, the NAS data content to the session management element includes: and the mobile management network element sends the NAS data content to the session management network element according to the mapping relation between the PDU session identifier and the first permission identifier. That is to say, in the embodiment of the present application, a specific PDU session for transmitting control plane user data may be established, and then information required for transmitting the NAS data content may not include a PDU session identifier, so that overhead may be further reduced, and transmission overhead may be further reduced.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session; the mobility management network element determining to allow the PDU session for control plane user data transmission, comprising: and the mobility management network element determines to allow the PDU session for the control plane user data transmission according to the control plane user data transmission identification. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, the determining, by the mobility management network element, that the PDU session is allowed for control plane user data transmission includes: the mobile management network element sends a third message to the session management network element, wherein the third message is used for requesting to establish the session context of the PDU session; the mobility management network element receives the first permission identification from the session management network element; and the mobility management network element determines to allow the PDU session to carry out control plane user data transmission according to the first permission identification. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session; before the mobility management element sends the third message to the session management element, the method further includes: the mobility management network element determines to allow the PDU session to be used for the control plane user data transmission according to the control plane user data transmission identifier; correspondingly, the third message further includes a second permission flag indicating that the PDU session is permitted for control plane user data transmission. That is to say, in the embodiment of the present application, the mobility management element may determine whether to allow the PDU session to be used for data transmission of the control plane user, and then the session management element performs secondary determination to determine whether to allow the PDU session to be used for data transmission of the control plane user.

In a tenth aspect, a method for uplink user data transmission is provided, including: the method comprises the steps that a mobile management network element receives a first message from a terminal device, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises uplink user data sent by the terminal device; the mobile management network element acquires the NAS data content from the NAS data information according to the information required for transmitting the NAS data content; under the condition that the data type of the NAS data content is short message SMS, the mobile management network element sends the NAS data content to a short message function network element; the short message function network element receives the NAS data content from the mobility management network element. For the description of the information required for transmitting the NAS data content, reference may be made to the possible design of the first aspect or the second aspect, which is not described herein again. That is, the method for transmitting uplink user data provides a first message dedicated to transmitting uplink user data through the control plane, so that not only can the expandability of future functions be realized, but also the complexity of data transmission processing is reduced because more optional information is not required. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In an eleventh aspect, a communication system is provided, which includes a mobility management network element and a session management network element; the mobile management network element is configured to receive a first message from a terminal device, where the first message includes NAS data information of a non-access stratum, where the NAS data information includes NAS data content and information required for transmitting the NAS data content, and the NAS data content includes uplink user data sent by the terminal device; the mobility management network element is further configured to obtain the NAS data content from the NAS data information according to the information required for transmitting the NAS data content; the mobility management network element is further configured to send the NAS data content to the session management network element when the data type of the NAS data content is control plane user data; the session management network element is configured to receive the NAS data content from the mobility management network element. For the description of the information required for transmitting the NAS data content, reference may be made to the possible design of the first aspect or the second aspect, which is not described herein again. That is, the communication system provides a first message dedicated to the transmission of uplink user data through the control plane, thereby not only achieving scalability of future functions, but also reducing the complexity of data transmission processing since more optional information is not required. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In one possible design, the communication system further includes a terminal device; and the terminal equipment is used for sending a first message to the mobile management network element after determining that only the uplink user data needs to be sent. That is, when the terminal device determines that only the uplink user data needs to be sent, the terminal device sends a first message dedicated to transmitting the uplink user data to the mobility management element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data is not required to be sent, the terminal device may send other messages to the mobility management element, where the other messages may be, for example, service request (service request) messages, which are used to request to establish a signaling connection between the terminal device and the mobility management element and/or request to establish user plane resources of a PDU session of the terminal device, and this is not particularly limited herein.

In one possible design, the terminal device is further configured to send a second message, before determining that only uplink user data needs to be sent, the second message being used to request establishment of a PDU session; the terminal device is further configured to receive a third message from the session management network element, where the third message carries a first permission identifier, and the first permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission. Based on the scheme, the terminal equipment can know that the PDU session can be used for controlling the plane user data transmission.

In one possible design, the mobility management element is further configured to receive a second message from the terminal device before receiving the first message from the terminal device, where the second message is used to request that a PDU session be established; the mobile management network element is also used for determining that the PDU session is allowed to be used for the control plane user data transmission; the mobility management network element is further configured to store a mapping relationship between the PDU session identifier and a first permission identifier, where the first permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission; correspondingly, the mobile management network element is configured to send the NAS data content to the session management network element, and includes: the mobility management element is configured to send the NAS data content to the session management element according to a mapping relationship between the PDU session identifier and the first allowed identifier. That is to say, in the embodiment of the present application, a specific PDU session for transmitting control plane user data may be established, and then information required for transmitting the NAS data content may not include a PDU session identifier, so that overhead may be further reduced, and transmission overhead may be further reduced.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session; the mobility management network element, configured to determine that the PDU session is allowed for control plane user data transmission, includes: and the mobility management network element is used for determining to allow the PDU session to be used for the control plane user data transmission according to the control plane user data transmission identifier. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, a mobility management network element for determining that the PDU session is allowed for control plane user data transmission includes: the mobility management network element is configured to send a third message to the session management network element, where the third message is used to request to establish a session context of the PDU session; receiving the first allowed identifier from the session management network element; and determining to allow the PDU session to carry out control plane user data transmission according to the first allowed identification. Based on this scheme, the mobility management element may determine to allow the PDU session for control plane user data transmission.

In one possible design, the second message includes a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session; the mobility management network element is further configured to determine, according to the control plane user data transmission identifier, that the PDU session is allowed to be used for control plane user data transmission before sending the third message to the session management network element; correspondingly, the third message further includes a second permission flag indicating that the PDU session is permitted for control plane user data transmission. That is to say, in the embodiment of the present application, the mobility management element may determine whether to allow the PDU session to be used for data transmission of the control plane user, and then the session management element performs secondary determination to determine whether to allow the PDU session to be used for data transmission of the control plane user.

In a twelfth aspect, a communication system is provided, which includes a mobility management element and a short message function element; the mobile management network element is configured to receive a first message from a terminal device, where the first message includes NAS data information of a non-access stratum, where the NAS data information includes NAS data content and information required for transmitting the NAS data content, and the NAS data content includes uplink user data sent by the terminal device; the mobile management network element is further configured to acquire the NAS data content from the NAS data information according to the information required for transmitting the NAS data content; the mobile management network element is further configured to send the NAS data content to the short message function network element when the data type of the NAS data content is a short message SMS; the short message function network element is configured to receive the NAS data content from the mobility management network element. For the description of the information required for transmitting the NAS data content, reference may be made to the possible design of the first aspect or the second aspect, which is not described herein again. That is, the communication system provides a first message dedicated to the transmission of uplink user data through the control plane, thereby not only achieving scalability of future functions, but also reducing the complexity of data transmission processing since more optional information is not required. Meanwhile, the first message comprises the NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

In one possible design, the communication system further includes: a terminal device; the terminal device is configured to send a first message to a mobility management network element after determining that only uplink user data needs to be sent. That is, when the terminal device determines that only the uplink user data needs to be sent, the terminal device sends a first message dedicated to transmitting the uplink user data to the mobility management element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data needs to be sent, the terminal device may send another message to the mobility management element, where the other message may be, for example, a service request (service request) message for requesting to establish a signaling connection between the terminal device and the mobility management element and/or requesting to establish a user plane resource of a PDU session of the terminal device, which is not specifically limited herein.

Drawings

Fig. 1a is a schematic structural diagram of a communication system according to an embodiment of the present application;

fig. 1b is a schematic structural diagram of another communication system provided in the embodiment of the present application;

fig. 2 is a schematic diagram of a 5G network architecture according to an embodiment of the present application;

fig. 3 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 4 is a flowchart illustrating a method for uplink user data transmission according to an embodiment of the present application;

fig. 5 is a schematic diagram of a first coding method of NAS data information according to an embodiment of the present application;

fig. 6 is a schematic diagram of a second encoding method of NAS data information according to an embodiment of the present application;

fig. 7 is a schematic diagram of a third encoding method of NAS data information according to an embodiment of the present application;

fig. 8 is a schematic diagram illustrating a fourth encoding manner of NAS data information according to an embodiment of the present application;

fig. 9 is a schematic diagram of a fifth encoding manner of NAS data information according to an embodiment of the present application;

fig. 10 is a schematic diagram of a sixth encoding manner of NAS data information according to an embodiment of the present application;

fig. 11 is a schematic diagram of a seventh encoding method of NAS data information according to an embodiment of the present application;

fig. 12 is a schematic diagram illustrating an eighth encoding manner of NAS data information according to an embodiment of the present application;

fig. 13 is a schematic diagram of a ninth encoding method for NAS data information according to an embodiment of the present application;

fig. 14 is a schematic diagram of a tenth encoding method of NAS data information according to an embodiment of the present application;

fig. 15 is a schematic diagram of an eleventh encoding manner of NAS data information according to an embodiment of the present application;

fig. 16 is a schematic encoding diagram of control plane service types according to an embodiment of the present application;

fig. 17 is a flowchart illustrating a method for establishing a specific PDU session for transmitting control plane user data according to an embodiment of the present application;

fig. 18 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 19 is a schematic structural diagram of a mobility management network element according to an embodiment of the present application.

Detailed Description

To facilitate understanding of the technical solutions of the embodiments of the present application, a brief description of the related art of the present application is first given as follows.

In the current 3GPP system, the traditional path for signaling and data transmission can be divided into a user plane and a control plane, where the user plane is mainly used for transmitting data and the control plane is mainly used for transmitting signaling. Generally, a terminal device transmits data through a user plane, that is, the terminal device enters a connection state after initiating an initial non-access-stratum (NAS) message, and then the terminal device can send the data to a Radio Access Network (RAN) device, and the RAN device forwards the data to a User Plane Function (UPF) network element. And for the terminal equipment of the Internet of things, data transmission is optimized. Particularly, for infrequent data transmission, data can be transmitted through the control plane, that is, the terminal device of the internet of things can transmit data in a manner of carrying data in signaling. There are two scenarios for transmitting data through the control plane, namely, idle (idle) state and connection (connection) state. In a connected state, the terminal device carries data through a NAS transport (NAS transport) message. In idle state, the terminal device has two options: 1) the terminal device initiates an initial NAS message, data is included in the initial NAS message, and the terminal device enters a connected state thereafter. 2) The terminal device sends a Radio Resource Control (RRC) early data request (early data request) message to the RAN device, and includes a NAS message in the RRC early data request, where the NAS message includes data, and the RAN device forwards the NAS message in the RRC early data request to an access and mobility management function (AMF) network element. The latter option in the idle state may also be referred to as an Early Data Transmission (EDT) scenario. In the EDT scene, the terminal equipment enters the idle state immediately after entering the connected state for a short time, and the RRC connection is not really established.

The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Where in the description of the present application, "/" indicates a relationship where the objects associated before and after are an "or", unless otherwise stated, for example, a/B may indicate a or B; in the present application, "and/or" is only an association relationship describing an associated object, and means that there may be three relationships, for example, a and/or B, and may mean: a exists singly, A and B exist simultaneously, and B exists singly, wherein A and B can be singular or plural. Also, in the description of the present application, "a plurality" means two or more than two unless otherwise specified. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. In addition, in order to facilitate clear description of technical solutions of the embodiments of the present application, in the embodiments of the present application, words such as "first" and "second" are used to distinguish identical items or similar items with substantially identical functions and actions. Those skilled in the art will appreciate that the terms "first," "second," etc. do not denote any order or quantity, nor do the terms "first," "second," etc. denote any order or importance. Also, in the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as examples, illustrations or illustrations. Any embodiment or design described herein as "exemplary" or "e.g.," is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion for ease of understanding.

In addition, the network architecture and the service scenario described in the embodiment of the present application are for more clearly illustrating the technical solution of the embodiment of the present application, and do not constitute a limitation to the technical solution provided in the embodiment of the present application, and it can be known by a person of ordinary skill in the art that, along with the evolution of the network architecture and the occurrence of a new service scenario, the technical solution provided in the embodiment of the present application is also applicable to similar technical problems.

As shown in fig. 1a, a communication system 10a provided for the embodiment of the present application includes a mobility management element 101 and a session management element 102 in the communication system 10 a. The mobile management network element 101 is configured to receive a first message from a terminal device, where the first message includes NAS data information, the NAS data information is composed of NAS data content and information required for transmitting the NAS data content, and the NAS data content includes uplink user data sent by the terminal device; the mobile management network element 101 is further configured to obtain NAS data content from the NAS data information according to information required for transmitting the NAS data content; the mobility management element 101 is further configured to send the NAS data content to the session management element 102 when the data type of the NAS data content is control plane user data. The session management network element 102 is configured to receive NAS data content from the mobility management network element 101.

Optionally, as shown in fig. 1a, the communication system 10a may further include a terminal device 103, where the terminal device 103 is configured to send a first message to the mobility management element 102 when it is determined that only uplink user data needs to be sent.

The specific implementation of the above scheme will be described in detail in the following method embodiments, which are not described herein again.

As shown in fig. 1b, another communication system 10b provided in the embodiment of the present application is a communication system 10b, where the communication system 10b includes a mobility management element 101 and a short message function element 104. The mobile management network element 101 is configured to receive a first message from a terminal device, where the first message includes NAS data information, the NAS data information is composed of NAS data content and information required for transmitting the NAS data content, and the NAS data content includes uplink user data sent by the terminal device; the mobile management network element 101 is further configured to obtain NAS data content from the NAS data information according to information required for transmitting the NAS data content; the mobility management element 101 is further configured to send the NAS data content to the short message function element 104 when the data type of the NAS data content is a Short Message Service (SMS). And the short message function network element 104 is configured to receive NAS data content from the mobility management network element 101.

Optionally, as shown in fig. 1b, the communication system 10b may further include a terminal device 103, where the terminal device 103 is configured to send the first message to the mobility management element 102 when it is determined that only uplink user data needs to be sent.

Both the communication system 10a shown in fig. 1a and the communication system 10b shown in fig. 1b provide a first message dedicated to the transmission of uplink user data via the control plane, that is, when the terminal device determines that only uplink user data needs to be sent, the terminal device sends the first message dedicated to the transmission of uplink user data to the mobility management network element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data is not needed to be sent, the terminal device may send other messages to the mobility management element, where the other messages may be, for example, service request (service request) messages, which are used to request to establish a signaling connection between the terminal device and the mobility management element and/or request to establish a user plane resource of a Protocol Data Unit (PDU) session of the terminal device, and is not limited in this respect. Based on the communication system, the expandability of future functions can be realized, and the complexity of data transmission processing is reduced because more optional information is not needed. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

Alternatively, the communication system 10a shown in fig. 1a and the communication system 10b shown in fig. 1b may be applied to the fifth generation (5rd generation, 5G) currently being discussed or other networks in the future, and the embodiment of the present application is not limited in this respect.

For example, assuming that the communication system 10a shown in fig. 1a and the communication system 10b shown in fig. 1b are applied to a current 5G network architecture, as shown in fig. 2, a network element or entity corresponding to the mobility management network element 101 may be an AMF network element in the 5G network architecture, a network element or entity corresponding to the session management network element 102 may be a Session Management Function (SMF) network element in the 5G network architecture, a network element or entity corresponding to the short message function network element 104 may be a short message function (SMSF) network element in the 5G network architecture, and the terminal device 103 may be a terminal device in the 5G network architecture. Furthermore, the terminal device 103 may also be a communication device, such as a chip.

In addition, as shown in fig. 2, the 5G network architecture may further include a RAN device, a UPF network element, a Unified Data Management (UDM) network element, an authentication server function (AUSF) network element, and the like, which is not specifically limited in this embodiment of the present application.

The terminal device communicates with the AMF network element through a next generation network (N) 1 interface (N1 for short), the RAN device communicates with the AMF network element through an N2 interface (N2 for short), the RAN device communicates with the UPF network element through an N3 interface (N3 for short), the SMF network element communicates with the UPF network element through an N4 interface (N4 for short), and the UPF network element communicates with a data network (data network, DN) through an N6 interface (N6 for short). In addition, the serving interface provided by the AMF network element to the outside may be Namf; the service interface externally provided by the SMF network element can be Nsmf; the service interface externally provided by the SMSF network element can be Nsmsf; a serving interface externally provided by the UDM network element can be Nudm; the service interface externally provided by the PCF network element may be Npcf, and the service interface externally provided by the AUSF network element may be Nausf. The related description may refer to 5G system architecture (5G system architecture) in 3GPP Technical Standard (TS) 23.501 standard, which is not repeated herein.

Optionally, the terminal device in this embodiment may be a device for implementing a wireless communication function, for example, a terminal or a chip that can be used in the terminal. The terminal may be a User Equipment (UE), an access terminal, a terminal unit, a terminal station, a mobile station, a distant station, a remote terminal, a mobile device, a wireless communication device, a terminal agent or a terminal device, etc. in a 5G network or a PLMN which is evolved in the future. An access terminal may be a cellular telephone, a cordless telephone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device having wireless communication capabilities, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, or a wearable device, a Virtual Reality (VR) terminal device, an Augmented Reality (AR) terminal device, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like. The terminal may be mobile or stationary.

Optionally, the RAN device in this embodiment refers to a device accessing a core network, and may be, for example, a base station, a broadband network service gateway (BNG), a convergence switch, a non-third generation partnership project (3rd generation partnership project, 3GPP) access device, and the like. The base stations may include various forms of base stations, such as: macro base stations, micro base stations (also referred to as small stations), relay stations, access points, etc.

Optionally, the relevant functions of the terminal device or the mobility management network element in the embodiment of the present application may be implemented by one device, or may be implemented by multiple devices together, or may be implemented by one or more functional modules in one device, which is not specifically limited in this embodiment of the present application. It is understood that the above functions may be network elements in a hardware device, or software functions running on dedicated hardware, or a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

For example, the functions related to the terminal device or the mobility management element in the embodiment of the present application may be implemented by the communication device 300 in fig. 3. Fig. 3 is a schematic structural diagram of a communication device 300 according to an embodiment of the present application. The communication device 300 includes one or more processors 301, a communication line 302, and at least one communication interface (illustrated in fig. 3 as including the communication interface 304 and one processor 301 for example only), and optionally may also include a memory 303.

The processor 301 may be a general-purpose Central Processing Unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more ics for controlling the execution of programs in accordance with the present disclosure.

The communication line 302 may include a path for connecting different components.

The communication interface 304, which may be a transceiver module, is used for communicating with other devices or communication networks, such as ethernet, RAN, Wireless Local Area Networks (WLAN), etc. For example, the transceiver module may be a transceiver, or the like. Optionally, the communication interface 304 may also be a transceiver circuit located in the processor 301, so as to implement signal input and signal output of the processor.

The memory 303 may be a device having a storage function. Such as, but not limited to, read-only memory (ROM) or other types of static storage devices that may store static information and instructions, Random Access Memory (RAM) or other types of dynamic storage devices that may store information and instructions, electrically erasable programmable read-only memory (EEPROM), compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be separate and coupled to the processor via a communication line 302. The memory may also be integrated with the processor.

The memory 303 is used for storing computer-executable instructions for executing the present invention, and is controlled by the processor 301. The processor 301 is configured to execute the computer-executable instructions stored in the memory 303, so as to implement the method for uplink user data transmission provided in the embodiment of the present application.

Alternatively, in this embodiment of the application, the processor 301 may also execute a function related to processing in the method for uplink user data transmission provided in the following embodiments of the application, and the communication interface 304 is responsible for communicating with other devices or a communication network, which is not specifically limited in this embodiment of the application.

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

In particular implementations, processor 301 may include one or more CPUs such as CPU0 and CPU1 in fig. 3, for example, as an example.

In particular implementations, communication device 300 may include multiple processors, such as processor 301 and processor 308 in fig. 3, for example, as an example. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions).

In particular implementations, communication device 300 may also include an output device 305 and an input device 306, as one embodiment. The output device 305 is in communication with the processor 301 and may display information in a variety of ways. For example, the output device 305 may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device 306 is in communication with the processor 301 and may receive user input in a variety of ways. For example, the input device 306 may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

The communication device 300 may also be referred to as a communication means at times, and may be a general purpose device or a special purpose device. For example, the communication device 300 may be a desktop computer, a portable computer, a network server, a Personal Digital Assistant (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, the terminal device, the network device, or a device with a similar structure as in fig. 3. The embodiment of the present application does not limit the type of the communication device 300.

The method for uplink user data transmission according to the embodiment of the present application will be specifically described below with reference to fig. 1a to 3.

It should be noted that, in the following embodiments of the present application, names of messages between network elements or names of parameters in messages are only an example, and other names may also be used in a specific implementation, which is not specifically limited in this embodiment of the present application.

Taking the application of the communication system shown in fig. 1a or fig. 1b to the 5G network shown in fig. 2 as an example, as shown in fig. 4, a method for transmitting uplink user data provided by the embodiment of the present application includes the following steps:

s401, the terminal equipment determines whether only the uplink user data needs to be sent.

The terminal device in this embodiment may be an internet of things terminal device in an idle state (i.e., idle state), where the idle state refers to a state of NAS signaling connection between the terminal device and the AMF network element that are registered in the network. When the terminal device is in the idle state, the NAS signaling connection based on the N1 interface between the terminal device and the AMF network element is not established, and neither AN Access Network (AN) signaling connection between the terminal device and the RAN device, AN N2 connection between the RAN device and the AMF network element, nor AN N3 connection between the RAN device and the UPF network element exists.

The uplink user data in the embodiment of the present application may include control plane user data (control plane user data) or SMS. The control plane user data refers to user data (user data that is to be sent via the control plane) transmitted via the control plane, and may also be referred to as control plane data (control plane data), CIoT control plane data, user data, CIoT user data (CIoT user data), 5G session management data (5G session management data, 5GSM data), or the like, and is not limited specifically herein.

S402, if the terminal equipment determines that only the uplink user data needs to be sent, the terminal equipment sends a first message to the AMF network element. Accordingly, the AMF network element receives the first message from the terminal equipment. The first message comprises NAS data (data over NAS) information, the NAS data information is composed of NAS data contents and information required for transmitting the NAS data contents, and the NAS data contents comprise uplink user data.

That is, the first message in the embodiment of the present application is dedicated to the transmission of uplink user data through the control plane. For example, as shown in fig. 4, the first message in the embodiment of the present application may be, for example, a control plane service request (control plane service request) message.

It should be noted that, in this embodiment of the present application, NAS data information may also be referred to as NAS data IE, information required to transmit NAS data content may also be referred to as IE required to transmit NAS data content, a value (value) required to transmit NAS data content, or a field (field) required to transmit NAS data content, and NAS data content may also be referred to as NAS data content IE, NAS data value (value), or NAS data field (field), which is described herein in a unified manner, and the names of the respective IEs in the first message are not specifically limited in this embodiment of the present application.

Optionally, the first message in this embodiment may be included in a message sent by the terminal device to the RAN device. The message sent by the terminal device to the RAN device may be a message for establishing AN RRC connection (i.e., AN signaling connection between the terminal device and the RAN device), AN RRC early data request message, or a new type of message that may be defined in the future, which is not specifically limited herein. After receiving the message, the RAN device forwards a first message in the message to the AMF network element.

Optionally, in this embodiment of the present application, the terminal device may actively initiate transmission of uplink user data through the control plane when determining that only uplink user data needs to be sent; the terminal device may also be triggered to initiate transmission of uplink user data through the control plane after receiving a paging request sent by the network side and determining that only uplink user data needs to be sent, which is not specifically limited in this embodiment of the present application.

Optionally, as shown in table one, the first message in this embodiment includes, in addition to the NAS data information, five optional IEs that must be carried by a control plane service type (control plane service type) and an initial NAS message defined by a current 3GPP protocol, which are described in a unified manner herein and are not described in detail below.

Watch 1

The NAS data information in table one is a mandatory IE in the first message, and is applicable to a scenario where the first message is dedicated to transmitting uplink user data through the control plane. Optionally, as shown in table two, the NAS data information in the embodiment of the present application may also be an optional IE in the first message. This scenario can be used for both uplink user data transmission via the control plane and paging response, and also for changing the terminal device from idle state to connected state for transmitting uplink signaling messages. That is, the terminal device determines that only uplink user data needs to be sent, and may send a first message to the AMF network element; or, the terminal device receives the page sent by the network side, and can send the first message to the AMF network element even if no uplink user data needs to be sent, where the first message does not include NAS data information; or, when the terminal device needs to transmit an uplink signaling message that can only be sent in a connected state, even if there is no uplink user data to be sent, the terminal device may send a first message to the AMF network element to change the terminal device from an idle state to a connected state, where the first message does not include NAS data information, which is not specifically limited in this embodiment of the present application. The following embodiments are all exemplarily described by taking NAS data information as an optional IE in the first message, and are herein described in a unified manner, which is not described in detail below.

Watch two

The extended protocol identifier, the security header type, the null nibble, the message type (in the present invention, the message type is a control plane service request message identifier), and the next-generation key set identifier in the first or second table are five optional IEs that must be carried by the initial NAS message defined by the 3GPP protocol, and the related description may refer to the existing 3GPP protocol, which is not described herein again.

The control plane service type in the first table or the second table is used to indicate whether the first message is a Mobile Originating (MO) request or a Mobile Terminating (MT) request, and occupies 4 bits. The MO request is a request initiated by the terminal equipment actively and is used for transmitting uplink user data through a control plane; the MT request is for a page response.

The NAS data information in the above-mentioned table one or table two includes NAS data contents and information necessary for transmitting the NAS data contents. The information required for transmitting the NAS data content specifically includes one or more of an identifier (IEI) of the NAS data content, a length of the NAS data content, a PDU session identifier, a downlink data expected or not (DDX), and a data type of the NAS data content.

The identifier of the NAS data information is used for identifying the IE as the NAS data information, and when the NAS data information is the optional IE in the first message, the identifier of the NAS data information does not need to be carried; when the NAS data information is the optional IE in the first message, the identifier of the NAS data information needs to be carried, which is described in a unified manner herein and is not described in detail below.

The length of the NAS data content is used for representing the length of the uplink user data.

The data type of the NAS data content is used to characterize the data type of the uplink user data, and the possible data type is control plane user data or SMS. If the data type of the NAS data content is control plane user data, the PDU session identifier is used to identify the PDU session for transmitting the uplink user data, and the terminal device must fill this field. If the data type of the NAS data content is SMS, the terminal device does not need to fill the PDU session identification field, and the AMF network element may ignore the PDU session identification field.

DDX is used to identify whether the terminal device expects downlink data after sending the uplink user data, and possible values are: there will be no uplink data transmission and no downlink data transmission after sending the uplink user data, there will be no uplink data transmission but only one downlink data transmission after sending the uplink user data, and not both.

It should be noted that the terminal device needs to perform encryption protection on the NAS data information, specifically, encrypt the NAS data content, the PDU session identifier, the DDX, and the data type of the NAS data content.

Several possible coding schemes for NAS data information are given below:

the information required for transmitting the NAS data content comprises the identification of NAS data information, the length of the NAS data content, PDU session identification, DDX and the data type of the NAS data content. The information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length of NAS data content occupies 2 bytes, and the PDU session identification, DDX and the data type of the NAS data content occupy 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 5, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; the PDU session identifier occupies 4 bits (bit), the DDX occupies 2 bits, and the data type of the NAS data content occupies 2 bits, namely the PDU session identifier, the DDX and the data type of the NAS data content occupy 1 byte. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, and the overhead is less, so that the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

And the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification, the DDX and the data type of the NAS data content. The information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length of NAS data content occupies 2 bytes, the PDU session identification occupies 1 byte, and the data type of DDX and NAS data content is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 6, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; PDU conversation identification occupies 1 byte; DDX occupies 2 bits, and the data type of the NAS data content occupies 2 bits, i.e. the data types of DDX and NAS data content occupy 4 bits in 1 byte together, and the byte still has free bits of 4 bits available for extension. Optionally, in the coding scheme, the data type of the NAS data content may occupy 3 bits or 4 bits, and the DDX may occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 5 bytes, that is, the overhead is 5 bytes, the overhead is less, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

And thirdly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the data type of the NAS data content. The information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identification and the data type of the NAS data content are in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 7, where the identifier of the NAS data information occupies 1 byte; the length occupies 2 bytes; the PDU session identifier occupies 4 bits, and the data type of the NAS data content occupies 2 bits, that is, the PDU session identifier and the data type occupy 6 bits in 1 byte together, and the byte still has 2 bits of idle bits available for extension. Optionally, in the encoding manner, the data type of the NAS data content may also occupy 3 bits, and the PDU session identifier may occupy 5 bits; or, the data type of the NAS data content occupies 2 bits, and the PDU session identification occupies 6 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, the overhead is small, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

And fourthly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the data type of the NAS data content. The information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identification occupies 1 byte, and the data type of the NAS data content is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 8, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; PDU conversation identification occupies 1 byte; the data type of the NAS data content occupies 2 bits, and the bytes occupied by the data type of the NAS data content still have free bits of 6 bits for expansion. Optionally, in the coding scheme, the data type of the NAS data content may occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 5 bytes, that is, the overhead is 5 bytes, the overhead is less, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

The coding mode is five, the first message also comprises the data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the DDX. The information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length of NAS data content occupies 2 bytes, and the PDU session identification and DDX are in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 9, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; the PDU session identifier occupies 4 bits and DDX occupies 2 bits, i.e. DDX and PDU session identifier occupy 6 bits of 1 byte together, and the byte still has 2 bits of spare bits available for extension. Optionally, in the encoding manner, the DDX may also occupy 3 bits, and the PDU session identifier may occupy 5 bits; alternatively, DDX takes 2 bits and PDU session identification takes 6 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, and the overhead is less, so that the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

The coding mode six, the first message also includes the data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the PDU session identification and the DDX; the information required for transmitting the NAS data content occupies 5 bytes, and specifically includes: the identification of NAS data information occupies 1 byte, the length occupies 2 bytes, the PDU session identification occupies 1 byte, and DDX is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 10, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; PDU conversation identification occupies 1 byte; DDX occupies 2 bits, and the byte occupied by DDX also has free bits of 6 bits available for extension. Optionally, in the coding scheme, the DDX may occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 5 bytes, that is, the overhead is 5 bytes, the overhead is less, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

The coding mode is seven, and the first message also comprises the data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content and the PDU session identification. The information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU conversation identification is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 11, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; the PDU session identification takes 1 byte. Optionally, in the encoding method, the PDU session identifier may occupy 4 bits, or 5 bits, or 6 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, the overhead is small, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

The coding mode is eight, and the first message also comprises the data type of the NAS data content; accordingly, the information required for transporting the NAS data content includes the identity of the NAS data information, the length of the NAS data content, and the DDX. The information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of NAS data information takes 1 byte, the length of NAS data content takes 2 bytes, and DDX is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 12, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; DDX occupies the byte occupied by 2 bits DDX and there remain free bits of 6 bits available for extension. Optionally, in the coding scheme, DDX may occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, and the overhead is less, so that the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

Ninth, the first message further includes the data type of the NAS data content; correspondingly, the information required for transmitting the NAS data content comprises the identification of the NAS data information and the length of the NAS data content; the information required for transmitting the NAS data content occupies 3 bytes, and specifically includes: the identification of the NAS data information occupies 1 byte, and the length of the NAS data content occupies 2 bytes.

For example, the coding mode of the NAS data information may be as shown in fig. 13, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content takes 2 bytes. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 3 bytes, that is, the overhead is 3 bytes, the overhead is less, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

And the coding mode ten, and the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content and the data type of the NAS data content. Wherein, the information required for transmitting the NAS data content occupies 4 bytes, specifically including: the identification of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the data type is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 14, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; the data type of the NAS data content occupies 2 bits, and the bytes occupied by the data type of the NAS data content still have free bits of 6 bits for expansion. Optionally, in the coding scheme, the data type of the NAS data content may also occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, and the overhead is less, so that the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

The coding mode eleven, the information required for transmitting the NAS data content comprises the identification of the NAS data information, the length of the NAS data content, the DDX and the data type of the NAS data content; the information required for transmitting the NAS data content occupies 4 bytes, and specifically includes: the identification of NAS data information takes 1 byte, the length of NAS data content takes 2 bytes, and the data type of DDX and NAS data content is in the remaining 1 byte.

For example, the coding mode of the NAS data information may be as shown in fig. 15, where the identifier of the NAS data information occupies 1 byte; the length of the NAS data content occupies 2 bytes; DDX occupies 2 bits, and the data type of the NAS data content occupies 2 bits, i.e. the data types of DDX and NAS data content occupy 4 bits in 1 byte together, and the byte still has free bits of 4 bits available for extension. Optionally, in the coding scheme, the data type of the NAS data content may occupy 3 bits or 4 bits, and the DDX may occupy 3 bits or 4 bits. That is to say, except for the NAS data content, the information required for transmitting the NAS data content occupies 4 bytes, that is, the overhead is 4 bytes, the overhead is small, the battery life of the terminal device is further prolonged, and the overhead of air interface resources is reduced.

It should be noted that the first to eleventh encoding manners are illustrated by taking NAS data information as an optional IE in the first message. If the NAS data information is the optional IE in the first message, the NAS data information may not need to carry the identifier of the NAS data information, so that the information required for transmitting the NAS data content may be further reduced by 1 byte, which is described in a unified manner herein and is not described in detail below.

In the fifth to ninth encoding methods, the information required for transmitting the NAS data content does not include the data type of the NAS data content, but carries the data type of the NAS data content in the first message. For example, the data type of the NAS data content may be included in the existing control plane service type IE, and a possible encoding manner of the control plane service type IE is shown in fig. 16, where 3 bits are used to fill the value of the control plane service type, and another free bit may be used to fill the value of the data type of the NAS data content. Of course, the control plane service type IE may further include an identifier of the control plane service type, which is used to identify that the IE is the control plane service type, and this embodiment of the present application is not specifically limited to this. For example, in this embodiment of the present application, a value of an existing control plane service type may also be extended in the existing control plane service type IE, and the extended control plane service type may indicate: (1) a control plane user data request initiated by the terminal equipment; (2) an SMS request initiated by the terminal equipment; (3) and the terminal equipment terminates the request. The encoding format of the existing control plane service type IE does not need to be changed, and is described in the unified manner herein, and will not be described further below.

In the coding methods eight to eleventh, the information required for transmitting the NAS data content does not include a PDU session identifier, and the coding methods are typically applicable to two scenarios: (a) the terminal device pre-establishes a session for a particular PDU for transmitting uplink user data. (b) And the terminal equipment does not need to send a PDU session identifier to the AMF network element, for example, the data type of the NAS data content is SMS, and the PDU session identifier is not needed. The description is unified here and will not be repeated below.

In the third encoding mode, the fourth encoding mode, the seventh encoding mode, the ninth encoding mode and the tenth encoding mode, information required for transmitting NAS data content does not include DDX, and the encoding modes are typically applicable to two scenarios: (a) and the terminal equipment sends the DDX to the RAN equipment through the AS layer, and the RAN equipment sends the DDX to the AMF network element. (b) The terminal device does not need to send DDX to the AMF network element, for example, the data transmission mode of the terminal device is solidified to be that only single uplink data needs to be sent or the data type of the NAS data content is SMS, and DDX is not needed. The description is unified here and will not be repeated below.

It should be noted that, in this embodiment of the application, when the terminal device determines that only uplink user data needs to be sent, if and only if the terminal device determines that the control plane is used to transmit data, the terminal device sends the first message to the AMF network element. If the terminal device determines that only uplink user data needs to be sent, but the terminal device determines to use conventional user plane transmission, or the terminal device receives a paging message sent by a network side but determines to use conventional user plane transmission, the terminal device may send a second message to the AMF network element, where the second message is used to request establishment of user plane resources of a PDU session of the terminal device, and/or request establishment of a signaling connection between the terminal device and the AMF network element. For example, the second message may be a service request message, and the subsequent processing is related to the prior art and is not described herein again.

Optionally, in this embodiment of the application, if the terminal device determines that only the uplink user data does not need to be sent, a second message may be sent to the AMF network element, where the second message is used to request to establish a user plane resource of a PDU session of the terminal device, and/or request to establish a signaling connection between the terminal device and the AMF network element. For example, if the terminal device does not have uplink user data to send, or the terminal device needs to send other optional information to the network side in addition to sending the uplink user data, the terminal device sends the second message to the AMF network element. For example, the second message may be a service request message, and the subsequent processing is related to the prior art and will not be described herein again.

Further, if the first message includes NAS data information, the method for uplink user data transmission provided in the embodiment of the present application further includes the following steps S403 to S405:

s403, the AMF network element acquires the NAS data content from the NAS data information according to the information required by the transmission of the NAS data content in the NAS data information.

It should be noted that, in this embodiment of the application, the AMF network element needs to decrypt the NAS data information first, specifically, decrypt the encrypted NAS data content, the PDU session identifier, the DDX, and the data type of the NAS data content.

S404, under the condition that the data type of the NAS data content is the control plane user data, the AMF network element sends the NAS data content to the SMF network element.

In this embodiment of the present application, the AMF network element may select the SMF network element according to a PDU session identifier included in information required for transmitting NAS data content, or may select the SMF network element according to a PDU session identifier locally stored by the AMF network element and used for controlling a plane user data transmission, which is not specifically limited in this embodiment of the present application. Of course, if the information required for transmitting the NAS data content does not include the PDU session identifier, and the AMF network element does not locally store the PDU session identifier used for the control plane user data transmission, the AMF network element does not perform data forwarding, but sends a service rejection message to the terminal device, optionally, the service rejection message carries a rejection reason value, where the rejection reason value indicates that there is no PDU session available for the control plane user data transmission, which is described in a unified manner herein and is not described in detail below. The method for establishing the specific PDU session for transmitting the control plane user data will be described in detail in the following embodiments, which are not repeated herein.

S405, when the data type of the NAS data content is the SMS, the AMF network element sends the NAS data content to the SMSF network element.

Optionally, the method for transmitting uplink user data provided in the embodiment of the present application further includes the following steps S406 to S407:

s406, the AMF network element sends an N2 message to the RAN device. Accordingly, the RAN device receives the N2 message from the AMF network element.

For non-EDT scenarios: 1) and if the DDX indicates that no uplink data transmission or downlink data transmission exists after the uplink user data is sent in the first message and the AMF network element does not sense that the downlink data needs to be transmitted, the AMF network element requests the RAN equipment to release the RRC connection through the N2 message. 2) If there is no uplink data transmission but there is only one downlink data transmission after the DDX indicates sending the uplink user data in the first message, after the AMF network element forwards the next downlink data to the terminal device, if the AMF network element does not sense that there is more downlink data to be transmitted, the AMF network element requests the RAN device to release the RRC connection through an N2 message.

For an EDT scenario: 1) and if in the first message, the DDX indicates that there is no uplink data transmission or downlink data transmission after sending the uplink user data, and the AMF element does not sense that there is downlink data to be transmitted, the AMF element sends an end indication (end indication) to the RAN device through an N2 message, so as to indicate that the terminal device has no subsequent uplink or downlink data or signaling. 2) If there is no uplink data transmission but there is only one downlink data transmission after the DDX indicates sending the uplink user data in the first message, after the AMF network element forwards the next downlink data to the terminal device, if the AMF network element does not sense that there is more downlink data to be transmitted, the AMF network element sends an end identifier to the RAN device through an N2 message to indicate that the terminal device has no subsequent uplink or downlink data or signaling. 3) And if the DDX does not indicate the two situations in the first message and the AMF network element senses that more data or signaling needs to be transmitted, the AMF network element indicates the RAN equipment to continue establishing the RRC connection through the N2 message and enters a connected state.

S407, performing RRC connection establishment, RRC connection release, or EDT end procedure between the terminal device and the RAN device.

For a non-EDT scenario, if the AMF network element requests the RAN device to release the RRC connection through an N2 message, the RAN device releases the RRC connection between the terminal device and the RAN device.

For the EDT scenario, if the AMF network element sends an end identifier to the RAN device through an N2 message, the RAN device sends an RRC early data complete (early data complete) message to the terminal device to end the EDT procedure; alternatively, if the AMF network element indicates to the RAN device to continue establishing the RRC connection through the N2 message, the RAN device continues to establish the RRC connection with the terminal device.

The embodiment of the present application provides a first message dedicated to transmitting uplink user data through a control plane, that is, when a terminal device determines that only uplink user data needs to be transmitted, the terminal device transmits the first message dedicated to transmitting the uplink user data to an AMF network element. Of course, if the terminal device desires to use other optional functions, that is, the terminal device determines that only uplink user data is not required to be sent, the terminal device may send other messages to the AMF network element, where the other messages may be, for example, service request messages for requesting to establish a signaling connection between the terminal device and the AMF network element and/or requesting to establish user plane resources of a PDU session of the terminal device, which is not specifically limited herein. Based on the method for transmitting the uplink user data, not only can the expandability of future functions be realized, but also the complexity of data transmission processing is reduced because more optional information is not needed. Meanwhile, the first message comprises NAS data information, and the NAS data information consists of NAS data content and information required for transmitting the NAS data content, namely the first message is only used for transmitting uplink user data through the control plane and does not need to transmit other information except the information required for transmitting the NAS data content, so that the overhead can be further reduced, and the transmission overhead is further reduced.

The actions of the terminal device or the AMF network element in steps S401 to S407 may be executed by the processor 301 in the communication device 300 shown in fig. 3 calling the application program code stored in the memory 303, which is not limited in this embodiment.

Taking the application of the communication system shown in fig. 1a to the 5G network shown in fig. 2 as an example, a method for establishing a specific PDU session for transmitting control plane user data is given below, as shown in fig. 17, the method includes the following steps:

s1701, the terminal equipment sends an uplink NAS transmission message to the AMF network element. Correspondingly, the AMF network element receives the uplink NAS transmission message from the terminal equipment. The upstream NAS transport message includes a PDU session setup request.

Optionally, the uplink NAS transport message may further include a control plane user data transport identifier, where the control plane user data transport identifier is used to instruct the terminal device to request to use the PDU session for control plane user data transport.

Optionally, the session establishment request may include the control plane user data transmission identifier.

S1702, the AMF network element sends a session context setup request message to the SMF network element. Accordingly, the SMF network element receives a create session context setup request message from the AMF network element. The create session context setup request message includes the PDU session setup request in step S1701.

Optionally, in this embodiment of the application, if the uplink NAS transport message includes a control plane user data transport identifier, the AMF network element may determine whether to allow the PDU session for control plane user data transport according to the control plane user data transport identifier. For example, the AMF element determines whether to allow the PDU session for the control plane user data transmission according to the control plane user data transmission identifier and by combining the local configuration information or the subscription information. One possible implementation is: if the PDU session is the first PDU session established by the terminal equipment, the AMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; if the PDU session is not the first PDU session established by the terminal equipment and all the existing PDU sessions can not be used for the data transmission of the control plane user, the AMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; and if the PDU session is not the first PDU session established by the terminal equipment and at least one existing PDU session is already used for the control plane user data transmission, the AMF network element determines that the current PDU session is not allowed to be used for the control plane user data transmission.

Of course, in this embodiment of the present application, if the uplink NAS transport message does not include the control plane user data transport identifier, the AMF network element may refer to the existing processing manner, which is not described herein again.

Optionally, in this embodiment of the present application, the AMF network element may further store information whether the PDU session is available for transmitting control plane user data. For example, if the AMF network element determines that the PDU session is allowed to be used for data transmission of the control plane user, the mapping relationship between the PDU session identifier and the allowed identifier 1 may be stored, where the allowed identifier 1 indicates that the PDU session is allowed to be used for data transmission of the control plane user; or, if the AMF network element determines that the PDU session is not allowed to be used for control plane user data transmission, the mapping relationship between the PDU session identifier and the disallowed identifier 1 may be stored, where the disallowed identifier 1 indicates that the PDU session is not allowed to be used for control plane user data transmission.

Optionally, in this embodiment of the application, the create session context setup request message may further include the permission identifier 1 or the non-permission identifier 1.

S1703, the SMF network element sends a create session context setup response message to the AMF network element. Correspondingly, the AMF network element receives the response message for establishing the session context from the SMF network element. The create session context setup response message includes a PDU session setup accept message.

Optionally, if the SMF network element receives the allowed identifier 1 or the disallowed identifier 1 sent by the AMF network element, but the PDU session establishment request does not include the control plane user data transmission identifier, then:

in one possible implementation manner, the SMF network element determines whether to allow the PDU session for control plane user data transmission according to the local configuration information or the subscription information. One possible implementation is: if the PDU session is the first PDU session established by the terminal equipment, the SMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; if the PDU session is not the first PDU session established by the terminal equipment and all the existing PDU sessions can not be used for the data transmission of the control plane user, the SMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; and if the PDU session is not the first PDU session established by the terminal equipment and at least one existing PDU session is used for the control plane user data transmission, the SMF network element determines that the current PDU session is not allowed to be used for the control plane user data transmission.

In another possible implementation manner, if the AMF network element determines that the PDU session is allowed to be used for control plane user data transmission, the SMF network element determines that the PDU session is allowed to be used for control plane user data transmission; otherwise, if the AMF network element determines that the PDU session is not allowed to be used for the control plane user data transmission, the SMF network element determines that the PDU session is not allowed to be used for the control plane user data transmission.

Optionally, if the PDU session establishment request includes the control plane user data transmission identifier, the SMF network element may determine whether to allow the PDU session for the control plane user data transmission according to the control plane user data transmission identifier. For example, the SMF element determines, according to the control plane user data transmission identifier, in combination with the local configuration information or subscription information, whether to allow the PDU session for control plane user data transmission. One possible implementation is: if the PDU session is the first PDU session established by the terminal equipment, the SMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; if the PDU session is not the first PDU session established by the terminal equipment and all the existing PDU sessions can not be used for the data transmission of the control plane user, the SMF network element determines to allow the current PDU session to be used for the data transmission of the control plane user; and if the PDU session is not the first PDU session established by the terminal equipment and at least one existing PDU session is used for the control plane user data transmission, the SMF network element determines that the current PDU session is not allowed to be used for the control plane user data transmission.

Of course, if the SMF network element does not receive the allowed identifier 1 or the disallowed identifier 1 sent by the AMF network element, and the PDU session establishment request does not include the control plane user data transmission identifier, the SMF network element may refer to the existing processing method, which is not described herein again.

Optionally, in this embodiment of the present application, the SMF network element may further store information whether the PDU session is available for transmitting control plane user data. For example, if the SMF network element determines that the PDU session is allowed to be used for control plane user data transmission, the mapping relationship between the PDU session identifier and the allowed identifier 2 may be stored, and the allowed identifier 2 indicates that the PDU session is allowed to be used for control plane user data transmission; or, if the SMF network element determines that the PDU session is not allowed to be used for control plane user data transmission, the mapping relationship between the PDU session identifier and the disallowed identifier 2 may be stored, where the disallowed identifier 2 indicates that the PDU session is not allowed to be used for control plane user data transmission.

Optionally, in this embodiment of the application, the create session context setup response message may further include permission identifier 2 or disallowance identifier 2.

Optionally, the PDU session establishment accept message may include the allowed identifier 2 or the disallowed identifier 2.

Optionally, in the embodiment of the present application, the permission identifier 2 may be the same as or different from the permission identifier 1, and this is not specifically limited in the embodiment of the present application.

Optionally, in this embodiment of the present application, the disallowed indication 2 and the disallowed indication 1 may be the same or different, and this is not specifically limited in this embodiment of the present application.

Of course, in this embodiment of the present application, if the SMF network element does not need to perform secondary determination, the creating session context setup response message does not include the allowed identifier 2 or the disallowed identifier 2, which is described in a unified manner herein and is not described in detail below.

S1704, the AMF network element sends a downlink NAS transmission message to the terminal equipment. Correspondingly, the terminal equipment receives the downlink NAS transmission message from the AMF network element. The downstream NAS transport message includes a PDU session setup accept message.

Optionally, in this embodiment of the application, if the AMF network element does not store the information of whether the PDU session is available for transmitting the control plane user data in step S1702, after receiving the session context setup response message sent by the SMF network element, the AMF network element may store the information of whether the PDU session is available for transmitting the control plane user data. If the AMF network element already stores the information whether the PDU session is available for transmitting the control plane user data, after receiving the create context setup response message sent by the SMF network element, the AMF network element may update the information whether the PDU session is available for transmitting the control plane user data.

Optionally, in this embodiment of the application, if the PDU session establishment accept message includes the allowed identifier 2 or the disallowed identifier 2, the terminal device may determine whether to allow the PDU session for data transmission of the control plane user according to the allowed identifier 2 or the disallowed identifier 2; otherwise, the terminal device may determine whether to allow the PDU session for control plane user data transmission based on whether user plane resources are established.

Based on the above scheme, a specific PDU session for transmitting control plane user data can be established, and then information required for transmitting NAS data content may not include a PDU session identifier, so that overhead can be further reduced, and transmission overhead can be further reduced.

The actions of the terminal device, the AMF network element, or the SMF network element in steps S1701 to S1704 may be executed by the processor 301 in the communication device 300 shown in fig. 3 calling the application program code stored in the memory 303, which is not limited in this embodiment.

It is to be understood that, in the above embodiments, the method and/or the steps implemented by the terminal device may also be implemented by a component available for the terminal device; the methods and/or steps implemented by the mobility management element may also be implemented by components available to the mobility management element; the methods and/or steps implemented by the session management network element may also be implemented by components available to the session management network element; the methods and/or steps implemented by the short message function network element may also be implemented by components available to the short message function network element.

The above-mentioned scheme provided by the embodiment of the present application is introduced mainly from the perspective of interaction between network elements. Correspondingly, the embodiment of the present application further provides a communication device, where the communication device may be the terminal device in the foregoing method embodiment, or a device including the foregoing terminal device, or a component (e.g., a chip) that can be used for the terminal device; alternatively, the communication device may be a mobility management network element in the foregoing method embodiment, or a device including the foregoing mobility management network element, or a component (e.g., a chip) that can be used for the mobility management network element; alternatively, the communication device may be a session management network element in the foregoing method embodiment, or a device including the session management network element, or a component (e.g., a chip) that can be used for the session management network element; alternatively, the communication device may be a short message function network element in the above method embodiment, or a device including the above short message function network element, or a component (e.g. a chip) that can be used in the short message function network element. It is to be understood that the communication device comprises corresponding hardware structures and/or software modules for performing the respective functions in order to realize the above-mentioned functions. Those of skill in the art would readily appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed in hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

Fig. 18 shows a schematic structural diagram of a communication device 180, where the communication device 180 may be a terminal device or a chip in the terminal device in the foregoing method embodiment, and may implement the method and the function related to the terminal device in the foregoing method embodiment. The communication device 180 includes a transceiver module 1801 and a processing module 1802. The transceiver module 1801, which may also be referred to as a transceiver unit, is used to implement a transceiving function, and may be, for example, a transceiving circuit, a transceiver, or a communication interface.

The processing module 1802 is configured to determine that only uplink user data needs to be sent; the transceiver module 1801 is configured to send a first message to the mobility management element, where the first message includes NAS data information, and the NAS data information includes NAS data content and information required for transmitting the NAS data content, where the NAS data content includes uplink user data.

Optionally, the transceiver module 1801 is further configured to send a second message, where the second message is used to request to establish a PDU session; the transceiving module 1801 is further configured to receive a third message from the session management network element, where the third message carries a first permission identifier, and the first permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission.

Optionally, the second message carries a control plane user data transmission identifier, where the control plane user data transmission identifier is used to indicate the terminal device to request to use a PDU session for control plane user data transmission.

All relevant contents of each step related to the above method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

In the present embodiment, the communication device 180 is presented in a form of dividing each functional module in an integrated manner. A "module" herein may refer to a particular ASIC, a circuit, a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other device that provides the described functionality. In a simple embodiment, one skilled in the art may appreciate that the communication device 180 may take the form of the communication device 300 shown in fig. 3.

For example, the processor 301 in the communication device 300 shown in fig. 3 may cause the communication device 300 to execute the method for uplink user data transmission in the foregoing method embodiment by calling a computer stored in the memory 303 to execute the instructions.

In particular, the functions/implementation procedures of the transceiving module 1801 and the processing module 1802 in fig. 18 may be implemented by the processor 301 in the communication device 300 shown in fig. 3 calling a computer executing instructions stored in the memory 303. Alternatively, the functions/implementation procedures of the processing module 1802 in fig. 18 may be implemented by the processor 301 in the communication device 300 shown in fig. 3 calling a computer executing instructions stored in the memory 303, and the functions/implementation procedures of the transceiving module 1801 in fig. 18 may be implemented by the communication interface 304 in the communication device 300 shown in fig. 3.

Since the communication device 180 provided in this embodiment can execute the method for transmitting uplink user data, the technical effects obtained by the method can be obtained by referring to the method embodiments, and are not described herein again.

Or, for example, taking the communication device as the mobility management element in the foregoing method embodiment as an example, fig. 19 shows a schematic structural diagram of a mobility management element 190. The mobility management element 190 includes a transceiver module 1901 and a processing module 1902. The transceiver module 1901, which may also be referred to as a transceiver unit, is used to implement a transceiving function, and may be, for example, a transceiving circuit, a transceiver, or a communication interface.

The receiving and sending module 1901 is configured to receive a first message from the terminal device, where the first message includes NAS data information, the NAS data information is composed of NAS data content and information required for transmitting the NAS data content, and the NAS data content includes uplink user data sent by the terminal device; a processing module 1902, configured to obtain NAS data content from NAS data information according to information required for transmitting the NAS data content; the transceiver module 1901 is further configured to transmit NAS data content.

Optionally, as shown in fig. 19, the mobility management element 190 further includes a storage module 1903; the transceiving module 1901 is further configured to receive a second message from the terminal device, where the second message is used to request to establish a PDU session; a processing module 1902, further configured to determine that a PDU session is allowed for control plane user data transmission; the storage module is used for storing the mapping relation between the PDU session identifier and a first permission identifier, wherein the first permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission; accordingly, the transceiver module 1901 is configured to transmit NAS data content, and includes: the transceiver module 1901 is configured to send the NAS data content to the session management network element according to a mapping relationship between the PDU session identifier and the first permission identifier when the data type of the NAS data content is control plane user data.

Optionally, the second message includes a control plane user data transmission identifier, where the control plane user data transmission identifier is used to instruct the terminal device to request to use a PDU session for control plane user data transmission; a processing module 1902 configured to determine that a PDU session is allowed for control plane user data transmission, comprising: a processing module 1902 configured to determine, based on the control plane user data transmission identity, that a PDU session is allowed for control plane user data transmission.

Optionally, the processing module 1902, configured to determine that the PDU session is allowed for control plane user data transmission, includes: a processing module 1902, configured to send a third message to the session management network element, where the third message is used to request to establish a session context of the PDU session; receiving a first allowed identification from the session management network element through the transceiving module 1901; and determining to allow the PDU session to carry out control plane user data transmission according to the first allowed identification.

Optionally, the second message includes a control plane user data transmission identifier, where the control plane user data transmission identifier is used to instruct the terminal device to request to use a PDU session for control plane user data transmission; a processing module 1902, further configured to determine, according to the control plane user data transmission identity, that the PDU session is allowed for control plane user data transmission; correspondingly, the third message further comprises a second permission identifier, and the second permission identifier is used for indicating that the PDU session is permitted to be used for data transmission of the control plane user.

All relevant contents of the steps related to the method embodiment may be referred to the functional description of the corresponding functional module, and are not described herein again.

In the present embodiment, the mobility management element 190 is presented in the form of dividing each functional module in an integrated manner. A "module" herein may refer to a particular ASIC, a circuit, a processor and memory that execute one or more software or firmware programs, an integrated logic circuit, and/or other device that provides the described functionality. In a simple embodiment, the mobility management element 190 may take the form of the communication device 300 shown in fig. 3, as will be appreciated by those skilled in the art.

For example, the processor 301 in the communication device 300 shown in fig. 3 may execute the instructions by invoking a computer stored in the memory 303, so that the communication device 300 performs the method for uplink user data transmission in the above method embodiment.

Specifically, the functions/implementation processes of the transceiver module 1901, the processing module 1902 and the storage module 1903 in fig. 19 can be implemented by the processor 301 in the communication device 300 shown in fig. 3 calling a computer stored in the memory 303 to execute instructions. Alternatively, the function/implementation procedure of the processing module 1902 in fig. 19 may be implemented by the processor 301 in the communication device 300 shown in fig. 3 calling a computer executing instruction stored in the memory 303, the function/implementation procedure of the transceiving module 1901 in fig. 19 may be implemented by the communication interface 304 in the communication device 300 shown in fig. 3, and the function/implementation procedure of the storage module 1903 in fig. 19 may be implemented by the memory 303 in the communication device 300 shown in fig. 3.

Since the mobility management element 190 provided in this embodiment may execute the method for transmitting uplink user data, reference may be made to the method embodiment for obtaining technical effects, and details are not described herein again.

It should be noted that one or more of the above modules or units may be implemented in software, hardware or a combination of both. When any of the above modules or units are implemented in software, which is present as computer program instructions and stored in a memory, a processor may be used to execute the program instructions and implement the above method flows. The processor may be built in a SoC (system on chip) or ASIC, or may be a separate semiconductor chip. The processor may further include a necessary hardware accelerator such as a Field Programmable Gate Array (FPGA), a PLD (programmable logic device), or a logic circuit for implementing a dedicated logic operation, in addition to a core for executing software instructions to perform an operation or a process.

When the above modules or units are implemented in hardware, the hardware may be any one or any combination of a CPU, a microprocessor, a Digital Signal Processing (DSP) chip, a Micro Controller Unit (MCU), an artificial intelligence processor, an ASIC, an SoC, an FPGA, a PLD, a dedicated digital circuit, a hardware accelerator, or a non-integrated discrete device, which may run necessary software or is independent of software to perform the above method flow.

Optionally, an embodiment of the present application further provides a communication device (for example, the communication device may be a chip or a chip system), where the communication device includes a processor and is configured to implement the method in any method embodiment described above. In one possible design, the communication device further includes a memory. The memory for storing the necessary program instructions and data, the processor may call the program code stored in the memory to instruct the communication device to perform the method of any of the above-described method embodiments. Of course, the memory may not be in the communication device. When the communication device is a chip system, the communication device may be composed of a chip, or may include a chip and other discrete devices, which is not specifically limited in this embodiment of the present application.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The procedures or functions described in accordance with the embodiments of the present application are all or partially generated upon loading and execution of computer program instructions on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or can comprise one or more data storage devices, such as a server, a data center, etc., that can be integrated with the medium. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

While the present application has been described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

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

Claims

1. A method for uplink user data transmission, the method comprising:

the terminal equipment determines that only uplink user data needs to be sent, wherein the uplink user data is control plane user data;

the terminal equipment sends a first message to a mobile management network element, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, and the NAS data content comprises the uplink user data.

2. The method of claim 1, wherein before the terminal device determines that only uplink user data needs to be transmitted, the method further comprises:

the terminal equipment sends a second message, wherein the second message is used for requesting to establish a Protocol Data Unit (PDU) session;

the terminal device receives a third message from a session management network element, where the third message carries a first permission identifier, and the first permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission.

3. The method of claim 2, wherein the second message carries a control plane user data transmission identity, and wherein the control plane user data transmission identity is used to instruct the terminal device to request control plane user data transmission using the PDU session.

4. A method for uplink user data transmission, the method comprising:

a mobile management network element receives a first message from a terminal device, wherein the first message comprises non-access stratum (NAS) data information, the NAS data information comprises NAS data content and information required for transmitting the NAS data content, the NAS data content comprises uplink user data sent by the terminal device, and the uplink user data is control plane user data;

the mobile management network element acquires the NAS data content from the NAS data information according to the information required for transmitting the NAS data content;

and the mobile management network element sends the NAS data content.

5. The method of claim 4, wherein before the mobility management element receives the first message from the terminal device, the method further comprises:

the mobility management network element receives a second message from the terminal equipment, wherein the second message is used for requesting to establish a Protocol Data Unit (PDU) session;

the mobility management network element determines to allow the PDU session for control plane user data transmission;

the mobility management network element stores a mapping relation between the PDU session identifier and a first permission identifier, wherein the first permission identifier is used for indicating that the PDU session is permitted to be used for control plane user data transmission;

correspondingly, the sending, by the mobility management network element, the NAS data content includes:

and under the condition that the data type of the NAS data content is control plane user data, the mobile management network element sends the NAS data content to a session management network element according to the mapping relation between the PDU session identifier and the first permission identifier.

6. The method of claim 5, wherein the second message comprises a control plane user data transmission identity, and wherein the control plane user data transmission identity is used for indicating that the terminal device requests control plane user data transmission using the PDU session; the determining, by the mobility management element, that the PDU session is allowed for control plane user data transmission includes:

and the mobility management network element determines to allow the PDU session to be used for the control plane user data transmission according to the control plane user data transmission identifier.

7. The method of claim 5, wherein the determining, by the mobility management element, that the PDU session is allowed for control plane user data transmission comprises:

the mobility management network element sends a third message to the session management network element, where the third message is used to request to establish a session context of the PDU session;

the mobility management network element receiving the first permission identification from the session management network element;

and the mobility management network element determines to allow the PDU session to carry out control plane user data transmission according to the first permission identification.

8. The method of claim 7, wherein the second message comprises a control plane user data transmission identity, and wherein the control plane user data transmission identity is used for indicating that the terminal device requests control plane user data transmission using the PDU session; before the mobility management element sends the third message to the session management element, the method further includes:

the mobility management network element determines to allow the PDU session to be used for control plane user data transmission according to the control plane user data transmission identifier;

correspondingly, the third message further includes a second permission identifier, where the second permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission.

9. A communication apparatus, characterized in that the communication apparatus comprises: the device comprises a processing module and a transceiving module;

the processing module is configured to determine that only uplink user data needs to be sent, where the uplink user data is control plane user data;

the transceiver module is configured to send a first message to a mobility management network element, where the first message includes NAS data information, the NAS data information includes NAS data content and information required to transmit the NAS data content, and the NAS data content includes the uplink user data.

10. The communication device of claim 9,

the transceiver module is further configured to send a second message, where the second message is used to request to establish a PDU session;

the transceiver module is further configured to receive a third message from a session management network element, where the third message carries a first permission identifier, and the first permission identifier is used to indicate that the PDU session is permitted to be used for data transmission of a control plane user.

11. The communications apparatus as claimed in claim 10, wherein the second message carries a control plane user data transmission identity, the control plane user data transmission identity is used to instruct the communications apparatus to request control plane user data transmission using the PDU session.

12. A mobility management element, wherein the mobility management element comprises: the device comprises a processing module and a transmitting-receiving module;

the receiving and sending module is configured to receive a first message from a terminal device, where the first message includes NAS data information of a non-access stratum, where the NAS data information includes NAS data content and information required to transmit the NAS data content, the NAS data content includes uplink user data sent by the terminal device, and the uplink user data is control plane user data;

the processing module is configured to acquire the NAS data content from the NAS data information according to the information required for transmitting the NAS data content;

the transceiver module is further configured to send the NAS data content.

13. The mobility management element according to claim 12, wherein the mobility management element further comprises a storage module;

the transceiver module is further configured to receive a second message from the terminal device, where the second message is used to request to establish a PDU session;

the processing module is further configured to determine that the PDU session is allowed for control plane user data transmission;

the storage module is configured to store a mapping relationship between the PDU session identifier and a first permission identifier, where the first permission identifier is used to indicate that the PDU session is permitted to be used for control plane user data transmission;

correspondingly, the transceiver module is configured to transmit the NAS data content, and includes: and the transceiver module is configured to send the NAS data content to a session management network element according to a mapping relationship between the PDU session identifier and the first permission identifier when the data type of the NAS data content is control plane user data.

14. The mobility management element according to claim 13, wherein the second message comprises a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session;

the processing module, configured to determine that the PDU session is allowed for control plane user data transmission, includes: and the processing module is used for determining to allow the PDU session to be used for the control plane user data transmission according to the control plane user data transmission identifier.

15. The mobility management element of claim 13, wherein the processing module, configured to determine that the PDU session is allowed for control plane user data transmission, comprises:

the processing module is configured to send a third message to the session management network element, where the third message is used to request to establish a session context of the PDU session; receiving, by the transceiver module, the first permission identifier from the session management network element; and determining to allow the PDU session to carry out control plane user data transmission according to the first permission identification.

16. The mobility management element according to claim 15, wherein the second message comprises a control plane user data transmission identity, the control plane user data transmission identity being used to instruct the terminal device to request control plane user data transmission using the PDU session;

the processing module is further configured to determine, according to the control plane user data transmission identifier, that the PDU session is allowed to be used for control plane user data transmission;

17. The method according to claim 1 or 4 or the communication device according to claim 9 or the mobility management element according to claim 12, wherein the information required for transmitting the NAS data content comprises an identification of the NAS data information, a length of the NAS data content, a packet data unit, PDU, session identification, a downstream data expected, DDX, and a data type of the NAS data content;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identifier, the DDX, and the data type occupy 1 byte altogether.

18. The method according to claim 1 or 4 or the communication device according to claim 9 or the mobility management network element according to claim 12, wherein the information required for transporting the NAS data content comprises an identification of the NAS data information, a length of the NAS data content, a PDU session identification, a DDX, and a data type of the NAS data content;

wherein the information required for transmitting the NAS data content occupies 5 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identifier occupies 1 byte, and the DDX and the data type are in the remaining 1 byte.

19. The method according to claim 1 or 4 or the communication device according to claim 9 or the mobility management network element according to claim 12, wherein the information required for transporting the NAS data content comprises an identification of the NAS data information, a length of the NAS data content, a PDU session identification and a data type of the NAS data content;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identifier and the data type are in the remaining 1 byte.

20. The method according to claim 1 or 4 or the communication device according to claim 9 or the mobility management network element according to claim 12, wherein the information required for transporting the NAS data content comprises an identification of the NAS data information, a length of the NAS data content, a PDU session identification and a data type of the NAS data content;

wherein, the information required for transmitting the NAS data content occupies 5 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identifier occupies 1 byte, and the data type is in the remaining 1 byte.

21. The method of claim 1 or 4, or the communication device of claim 9, or the mobility management network element of claim 12, wherein the first message further comprises a data type of the NAS data content;

correspondingly, the information required for transmitting the NAS data content includes an identifier of the NAS data information, a length of the NAS data content, a PDU session identifier, and a DDX;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identifier and the DDX are in the remaining 1 byte.

22. The method of claim 1 or 4, or the communication device of claim 9, or the mobility management element of claim 12, wherein the first message further comprises a data type of the NAS data content;

wherein, the information required for transmitting the NAS data content occupies 5 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, the PDU session identifier occupies 1 byte, and the DDX is in the remaining 1 byte.

23. The method of claim 1 or 4, or the communication device of claim 9, or the mobility management network element of claim 12, wherein the first message further comprises a data type of the NAS data content;

correspondingly, the information required for transmitting the NAS data content includes an identifier of the NAS data information, a length of the NAS data content, and a PDU session identifier;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the PDU session identifier is in the remaining 1 byte.

24. The method or the communication device or the mobility management element according to any of claims 1-16, wherein the first message further comprises a data type of the NAS data content;

correspondingly, the information required for transmitting the NAS data content includes an identifier of the NAS data information, a length of the NAS data content, and a DDX;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the DDX is in the remaining 1 byte.

25. The method or the communication device or the mobility management element according to any of claims 1-16, wherein the first message further comprises a data type of the NAS data content;

correspondingly, the information required for transmitting the NAS data content includes an identifier of the NAS data information and a length of the NAS data content;

wherein, the information required for transmitting the NAS data content occupies 3 bytes, the identification of the NAS data information occupies 1 byte, and the length of the NAS data content occupies 2 bytes.

26. The method or the communication apparatus or the mobility management element according to any one of claims 1 to 16, wherein the information required for transmitting the NAS data content includes an identification of the NAS data information, a length of the NAS data content, and a data type of the NAS data content;

the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the data type is in the remaining 1 byte.

27. The method or the communication device or the mobility management element according to any of claims 1-16, wherein the information required for transporting the NAS data content comprises an identification of the NAS data information, a length of the NAS data content, a DDX, and a data type of the NAS data content;

wherein the information required for transmitting the NAS data content occupies 4 bytes, the identifier of the NAS data information occupies 1 byte, the length of the NAS data content occupies 2 bytes, and the DDX and the data type are in the remaining 1 byte.

28. A method or terminal device or mobility management network element according to any of claims 1-27, wherein the first message is a control plane service request message.

29. A communication system, characterized in that the communication system comprises a mobility management element and a session management element;

the mobile management network element is configured to receive a first message from a terminal device, where the first message includes NAS data information of a non-access stratum, where the NAS data information includes NAS data content and information required to transmit the NAS data content, the NAS data content includes uplink user data sent by the terminal device, and the uplink user data is control plane user data;

the mobility management network element is further configured to acquire the NAS data content from the NAS data information according to the information required for transmitting the NAS data content;

the mobile management network element is further configured to send NAS data content to the session management network element when the data type of the NAS data content is control plane user data;

the session management network element is configured to receive the NAS data content from the mobility management network element.