WO2012174900A1

WO2012174900A1 - Joint transmission method and system

Info

Publication number: WO2012174900A1
Application number: PCT/CN2012/072645
Authority: WO
Inventors: 于晓谦; 邓云
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-23
Filing date: 2012-03-20
Publication date: 2012-12-27
Also published as: CN102843665B; CN102843665A

Abstract

Disclosed is a joint transmission method, comprising: determining an anchor network element for joint transmission, and establishing a data interface between a radio link control (RLC) layer of the anchor network element and a media access control (MAC) layer of a first network element; the anchor network element and the first network element being located in different systems; the RLC layer of the anchor network element directly sending downlink data from an upper layer to an MAC layer of the present network element and then sending same to a user equipment (UE), and/or sending same to the MAC layer of the first network element through the data interface and then sending same to the UE. Further disclosed is a joint transmission system. By means of the present invention, the problems that the existing working frequency band of the communication system cannot satisfy the requirement of higher transmission rate and that a single communication has insufficient capacity under carrier aggregation are solved.

Description

Method and system for joint transmission

The present invention relates to the field of communication technologies, and in particular to a method and system for joint transmission. Background technique

For wireless communication technologies, each wireless communication system operates in a planned frequency band. With the development of wireless communication technologies, communication systems require increasingly large transmission rates to meet the higher demands of a variety of wireless transmission services. The existing operating band of the communication system may not be able to meet the higher transmission rate requirements and require a larger working bandwidth.

The Long Term Evolution (LTE) system and the Universal Mobile Telecommunications System (UMTS) have a layered protocol stack structure, from the lowest physical layer to the Medium Access Control (MAC) layer. Radio Link Control (RLC) layer, packet data convergence protocol (PDCP) layer to higher layer, each layer has relatively independent functions, and with the upper layer and next There is data interaction at the layer. For the LTE system, when transmitting data, the data packet at the transmitting end arrives at the PDCP layer from the upper layer, and is subjected to functions such as header compression and ciphering to generate a PDCP protocol data unit (PDU). The next layer, the RLC layer, is processed by the RLC layer and then sent to the MAC layer and the physical layer in turn, and finally sent to the receiving end through the air interface. At the receiving end, the reverse process is performed, and the data is processed through the physical layer, the MAC layer, the RLC layer, and the PDCP layer, and finally sent to a higher layer.

In order to achieve a higher transmission rate, 3GPP proposes a carrier aggregation (CA, Carrier Aggregation) technical solution, which utilizes multiple carriers (each carrier may be an independent cell or a resource carrier that only provides data transmission). User equipment service. Existing carrier The aggregation scheme mainly utilizes multiple carriers in a single system to simultaneously provide services for user equipment, such as

In UMTS, two or more carriers are used to simultaneously communicate with user equipment, or two or more carriers in LTE are used to simultaneously communicate with user equipment. However, in an actual network, due to the limitation of the number of carrier frequencies, some mobile operators do not have enough frequencies to simultaneously deploy to multiple UMTS and LTE systems, and the mobile operator adjusts the carrier frequency of UMTS and LTE according to the number of user equipments accessing the network. . In this kind of network deployment, there may be insufficient capacity of a single system, which limits the throughput of the user terminal, and load balancing between systems can only be achieved by switching and redirection. Summary of the invention

In view of this, the main objective of the embodiments of the present invention is to provide a joint transmission method and system, to solve the problem that the existing working frequency band of the communication system cannot meet the higher transmission rate, and the capacity of the single communication system under carrier aggregation is insufficient. problem.

To achieve the above objective, the technical solution of the embodiment of the present invention is implemented as follows:

An embodiment of the present invention provides a method for joint transmission, where the method includes:

Determining an anchor network element of the joint transmission, and establishing a data interface between a radio link control (RLC) layer of the anchor network element and a medium access control (MAC) layer of the first network element; the anchor network element And the first network element is located in a different system;

The RLC layer of the anchor network element directly sends downlink data from the upper layer to the local network element.

The MAC layer is sent to the user equipment (UE), and/or sent to the MAC layer of the first network element through the data interface, and then sent to the UE.

The anchor network element that determines the joint transmission includes:

In the LTE system, the eNB is set as an anchor network element for joint transmission; or, in the UMTS system, the RNC is set as an anchor network element for joint transmission.

The protocol stack corresponding to the system where the anchor network element is located and the protocol stack corresponding to the system where the first network element is located; and the RLC layer of the protocol stack corresponding to the system where the anchor network element is located Establishing an internal data interface of the UE between the MAC layers of the protocol stack corresponding to the system where the first network element is located.

The UE receives the downlink data from the anchor network element network element, and sends the uplink data to the upper layer through the MAC layer and the RLC layer of the protocol stack corresponding to the system in the anchor network element of the UE; and/or,

The UE receives the downlink data from the first network element, and is sent by the MAC layer of the protocol stack corresponding to the system where the first network element is located in the UE to the system where the anchor network element of the UE is located. After the RLC layer of the protocol stack, it is sent to the upper layer.

The method also includes:

The RLC layer of the anchor network element receives the uplink data from the MAC layer of the local network element, and then sends the uplink data to the upper layer, and/or receives the uplink data from the MAC layer of the first network element through the data interface, and then sends the uplink data to the upper layer.

The uplink data from the upper layer is sent to the anchor network element through the RLC layer, the MAC layer, and the physical layer of the protocol stack corresponding to the system where the anchor network element in the UE is located; and/or,

The uplink data from the upper layer is sent by the RLC layer of the protocol stack corresponding to the system where the anchor network element is located in the UE to the MAC layer and the physical layer of the protocol stack corresponding to the system where the first network element of the UE is located. After being sent to the first network element.

The embodiment of the invention further provides a system for joint transmission, comprising: a setting module, and an anchor network element and a first network element located in different systems;

The setting module is configured to establish a data interface between an RLC layer of the anchor network element and a MAC layer of the first network element;

The RLC layer of the anchor network element directly sends downlink data from the upper layer to its own MAC layer, and then sends the data to the user equipment (UE), and/or sends the MAC layer to the first network element through the data interface. Then sent to the UE.

In the LTE system, the eNB is an anchor network element for joint transmission; or, in the UMTS system, the RNC is an anchor network element for joint transmission. The system further includes: a UE;

The UE internally has a protocol stack corresponding to the system in which the anchor network element is located and a protocol stack corresponding to the system in which the first network element is located;

Correspondingly, the setting module is further configured to establish internal UE data between the RLC layer of the protocol stack corresponding to the system where the anchor network element is located in the UE and the MAC layer of the protocol stack corresponding to the system where the first network element is located. interface.

The UE is configured to receive downlink data from the anchor network element, and send the data to the upper layer through the physical layer, the MAC layer, and the RLC layer of the protocol stack corresponding to the system where the internal anchor network element is located; and/or, from the The downlink data of the first network element is sent by the MAC layer of the protocol stack corresponding to the system in which the first network element is located to the RLC layer of the protocol stack corresponding to the system where the internal anchor network element of the UE is located. After that, send it to the upper layer.

The RLC layer of the anchor network element receives uplink data from its own MAC layer, sends it to the upper layer, and/or receives uplink data from the MAC layer of the first network element through the data interface, and then sends the uplink data to the upper layer.

The UE is further configured to send the uplink data to the anchor network element by using the RLC layer, the MAC layer, and the physical layer of the protocol stack corresponding to the system where the internal anchor network element is located; and/or, the uplink data is internally The RLC layer of the protocol stack corresponding to the system in which the anchor network element is located is sent to the first network element by the MAC layer and the physical layer of the protocol stack corresponding to the system in which the first network element is located.

The method and system for joint transmission according to the embodiment of the present invention establish a data interface between the RLC layer and the MAC layer of the two systems, and establish a data interface between the RLC layer and the MAC layer of the two system sides of the UE. The joint transmission of data between the two systems, so that the UE can simultaneously use the carriers of the two systems to perform data transmission on the carriers of the two systems, expand the working bandwidth of the UE, and increase the data transmission rate, which satisfies Highly demanding wireless transmission services; can also improve UE throughput, improve data transmission performance, and enable network load balancing Effect. DRAWINGS

1 is a schematic flowchart of a method for joint transmission according to an embodiment of the present invention;

2 is a schematic structural diagram of a protocol stack inside a UE according to an embodiment of the present invention;

3 is a schematic structural diagram of a network according to an embodiment of the present invention;

4 is a schematic diagram of a flow of data in a row according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a line data transmission process according to an embodiment of the present invention; FIG.

6 is a protocol stack structure of a UE in Embodiment 2 of the present invention;

7 is a deployment structure of a network according to Embodiment 2 of the present invention;

8 is a schematic diagram of a downlink data flow direction according to Embodiment 2 of the present invention;

FIG. 9 is a schematic diagram of a downlink data transmission process according to Embodiment 2 of the present invention. detailed description

The method for joint transmission in the embodiment of the present invention is as shown in FIG. 1 and includes:

Step 101: Determine an anchor network element of the joint transmission, and establish a data interface between the RLC layer of the anchor network element and the MAC layer of the first network element, where the anchor network element and the first network element are located in different systems.

The application scenario of joint transmission in the embodiment of the present invention is mainly joint transmission between two different systems, where two different systems are two wireless network systems using different wireless access technologies. When deploying a joint transmission network, the operator generally selects one network element device from the two different systems as the anchor network element, for example:

In the LTE system, the eNB is set as an anchor network element for joint transmission; in the UMTS system, the RNC is set as an anchor network element for joint transmission.

The LTE system can also be divided into an LTE TDD system and an LTE FDD system. In these two systems, an eNB or a home eNB can be set as an anchor network element for joint transmission. Joint transmission can be performed between any two of the above mentioned systems.

After the anchor network element is determined, a data interface needs to be established between the RLC layer of the anchor network element and the MAC layer of the first network element, and the establishment of the data interface is performed by the anchor network element and the first network element.

It should be noted that the anchor network element may also adopt other names, such as an access network element (a radio network controller in UMTS or a base station in LTE) of the initial access system of the UE, a primary network element, Or the UE accesses the access network element of the system, and so on.

Step 102: The RLC layer of the anchor network element directly sends the downlink data from the upper layer to the MAC layer of the local network element, sends the data to the UE, and/or sends the data to the MAC layer of the first network element through the data interface, and then sends the data to the UE.

The essence of the step is that the RLC layer of the anchor network element distributes the downlink data from the upper layer (there are two paths to be selected, that is, directly sent to the MAC layer of the local network element, and sent to the first network element through the data interface. At the MAC layer), when distributing, the path is also selected as follows:

Manner 1: The RLC layer of the anchor network element sends the downlink data to the side with better quality of the wireless channel. Specifically, the radio channel quality of the cell controlled by each system can be obtained by the measurement report of the UE, and after the comparison, the downlink data is sent to the MAC layer of the network element in the system with the better quality of the radio channel.

Manner 2: The RLC layer of the anchor network element sends the downlink data to the lower side of the network load. Specifically, each system can obtain the load of the system through measurement, and the anchor network element can compare the loads of the two systems to obtain a network with a lower load. The RLC layer of the anchor network element sends the downlink data to the MAC layer of the network element in the lower load side system.

Manner 3: The RLC layer of the anchor network element does not distribute the downlink data based on the two-system wireless channel quality or load condition, but distributes the downlink data to the MAC layers of the two systems at a fixed ratio. For example, the downlink data can be simultaneously distributed to the MAC layer of the network element in the two systems in a ratio of 1:1. Of course, it can also be distributed in other proportions. The first mode and the second mode may be referred to as a dynamic mode, and the third mode may be referred to as a fixed mode. In order to implement the joint transmission, the dual-mode configuration is also required for the UE: the protocol stack corresponding to the system where the anchor network element is located and the protocol stack corresponding to the system where the first network element is located are established in the UE; and corresponding to the system where the anchor network element is located A data interface is established between the RLC layer of the protocol stack and the MAC layer of the protocol stack corresponding to the system where the first network element is located. This will be specifically explained by the following embodiments.

When performing joint transmission:

For the downlink data, the UE receives the downlink data from the MAC layer of the anchor network element, and sends the uplink layer to the upper layer through the MAC layer and the RLC layer of the protocol stack corresponding to the system where the internal anchor network element of the UE is located; and/or, the UE receives the The downlink data of the MAC layer of the first network element is sent by the MAC layer of the protocol stack corresponding to the system in which the first network element is located in the UE to the RLC of the protocol stack corresponding to the system where the internal anchor network element of the UE is located. After the layer, it is sent to the upper layer.

In addition, the method for joint transmission in the embodiment of the present invention may also be applied to the transmission of uplink data: the RLC layer of the anchor network element receives the uplink data from the MAC layer of the local network element, and then sends the uplink data to the upper layer, and/or receives through the data interface. The uplink data from the MAC layer of the first network element is sent to the upper layer.

Specifically, the uplink data from the upper layer is sent to the anchor network element through the RLC layer, the MAC layer, and the physical layer of the protocol stack corresponding to the system where the internal anchor network element of the UE is located; and/or the uplink data from the upper layer is used by the UE. The RLC layer of the protocol stack corresponding to the system in which the internal anchor network element is located is sent to the first network element through the internal data interface of the UE to the MAC layer and the physical layer of the protocol stack corresponding to the system in which the first network element is located.

For the joint transmission of the uplink data, the network sends a scheduling command to the UE, and performs uplink scheduling on one side and the other side of the system where the anchor network element of the UE is located, that is, the side of the system where the non-anchor network element is located. The UE performs uplink data transmission in the anchor point and the non-anchor point system according to the scheduling of the network.

It should be noted that the uplink joint transmission is an optional solution, that is, for uplink data transmission, the UE and the network side may optionally use the joint transmission of the uplink data as described above.

For data transmission, the network element and corresponding layer that the data passes through in a system. It is determined, therefore, the first network element (MAC layer) can be determined according to the difference of the system. The joint transmission scheme of the present invention will be described below by way of specific examples.

In the embodiment of the present invention, in a scenario where joint transmission is performed between two different systems, the UE has a dual mode configuration, that is, the UE can simultaneously use two wireless communication technologies, and can perform data transmission on the frequency bands of the two networks at the same time. . To this end, the data transmission function portion is divided within the UE according to the dual mode network.

The embodiments of the present invention are described by taking an LTE system and a UMTS system as an example.

The UE can simultaneously use the LTE and UMTS radio access technologies for data transmission. Then, the UE can aggregate the LTE and UMTS carriers in the area covered by the LTE and the UMTS, that is, obtain the data transmission services of the LTE cell and the UMTS cell at the same time.

To this end, the data transmission function is divided into the UMTS side and the LTE side within the UE. The LTE side has a protocol stack structure of LTE, which is a PDCP layer, an RLC layer, a MAC layer, and the like from top to bottom. The functions, working principles, and interactions between layers of the layers comply with the LTE standard. The UMTS side has UMTS. The protocol stack structure, from top to bottom, is the PDCP layer, the RLC layer, the MAC layer, etc. The functions, working principles, and interactions between layers of each layer follow the UMTS standard.

In addition, for data exchange between the UMTS side and the LTE side, a data interface may be set between the UMTS side and the LTE side inside the UE.

The eNB of the LTE system (referred to as the LTE eNB for short) is set as the anchor network element of the joint transmission, so that the first network element in the UMTS system can be determined as the RNC, that is, the UMTS RNC.

In this case, the protocol stack structure inside the UE is as shown in FIG. 2, and the LTE side has a PDCP layer.

RLC layer, MAC layer, etc.; UMTS side has MAC layer and the like. In order to implement data exchange between the UMTS side and the LTE side, a data interface can be established on the MAC layer on the UMTS side and the RLC layer on the LTE side.

In this embodiment, the network is deployed as shown in FIG. 3, where Cell 1 is a cell provided by an LTE eNB, Cell 2 is a cell provided by a UMTS NodeB, and the UE is in a cross coverage area of two cells. In the domain, in order to implement joint transmission, a data interface needs to be established between the anchor network element LTE eNB and the first network element UMTS RNC for data transmission.

Since the anchor network element is an LTE eNB, the downlink data of the UE that uses the scheme for data transmission is from the LTE core network, and the uplink data is sent to the LTE core network through the LTE eNB.

If the UE uses the LTE and UMTS carriers for data transmission, the downlink data from the LTE core network first reaches the LTE eNB when the LTE eNB is used as the anchor network element. The LTE eNB distributes the downlink data, assuming a fixed manner, and the result of the distribution is: a part of the downlink data is directly sent by the LTE eNB to the UE; and another part of the downlink data is first sent to the UMTS RNC through the data interface of the LTE eNB and the UMTS RNC, and then The UMTS NodeB is sent to the UE, and the flow direction of the downlink data (network side to UE) is shown in FIG. 4, and includes two paths: one is LTE eNB→UE; − is LTE eNB→UMTS RNC→UMTS NodeB→UE, uplink The data (UE to the network side) flows in the opposite direction.

Specifically, the transmission process of the downlink data in this embodiment is as shown in FIG. 5, and includes: Step 501: The downlink data first arrives at the RLC layer of the LTE eNB (the LTE eNB also has a standard LTE protocol stack structure), and the downlink data is The form of the RLC Service Data Unit (SDU);

Step 502: After the RLC SDU passes through the RLC process of the LTE eNB, the RLC SDU constitutes one or more RLC PDUs.

Step 503: The RLC layer of the LTE eNB distributes the RLC PDU by using a data distribution algorithm.

Step 504, the result of the distribution may be: the RLC layer of the LTE eNB directly sends a part of the RLC PDU to the MAC layer of the LTE eNB, and then sends the signal to the UE; through the data interface between the LTE eNB and the UMTS RNC, the RLC layer of the LTE eNB After another part of the RLC PDU is sent to the MAC layer of the UMTS RNC, it is sent to the UE through the UMTS NodeB. For uplink data transmission, the path is opposite to the transmission path of the downlink data described in FIG. After receiving the downlink data, the UE performs the transmission process of the downlink data in the UE according to the protocol stack structure in the UE shown in FIG. 2:

The MAC layer on the UMTS side receives part of the downlink data sent by the UMTS system, and the downlink data is sent to the RLC layer on the LTE side and then sent to the upper layer through the data interface on the UMTS side and the LTE side.

The LTE side MAC layer receives part of the downlink data sent by the LTE system, and then sends it to the upper layer through the RLC layer on the LTE side.

For uplink data transmission, its transmission path inside the UE is opposite to the transmission path of the above downlink data.

In the second embodiment, the UMTS RNC is used as the anchor network element, and the first network element can be determined as the LTE e phoenix.

In this case, the protocol stack structure of the UE is as shown in FIG. 6. The UMTS side has a protocol stack structure of UMTS, which is a PDCP layer, an RLC layer, a MAC layer, etc. from top to bottom, and a MAC layer on the LTE side. In order to implement data exchange between the UMTS side and the LTE side, a data interface may be set in the RLC layer on the UMTS side and the MAC layer on the UMTS side.

In this embodiment, the network is deployed as shown in FIG. 7. The cell 1 is a cell provided by the UMTS NodeB, and the cell 2 is a cell provided by the LTE eNB. The UE is in the cross coverage area of the two cells. A data interface is established between the first network element LTE eNB and the anchor network element UMTS RNC for data transmission.

Since the anchor network element is a UMTS RNC, the downlink data of the UE using the scheme for data transmission is from the UMTS core network, and the uplink data is sent to the UMTS core network through the UMTS RNC.

If the UE uses the LTE and UMTS carriers for data transmission, the downlink data from the UMTS core network first reaches the UMTS when the LTE eNB is used as the anchor network element. RNC. The UMTS RNC distributes the downlink data, assuming a fixed method, and the result of the distribution is:

The other part of the downlink data is sent by the UMTS RNC to the LTE eNB through the data interface of the LTE eNB and the UMTS RNC, and then sent by the LTE eNB to the UE. As shown in FIG. 8, the downlink data (the network side to the UE) flows. There are two paths: one is UMTS RNC→LTE eNB→UE; — is UMTS RNC→UMTS NodeB→UE, and the uplink data (UE to network side) flows in the opposite direction.

The downlink data transmission process is as shown in FIG. The form of the RLC SDU;

Step 902: After the RLC SDU passes through the RLC process of the UMTS RNC, the RLC SDU constitutes one or more RLC PDUs.

Step 903: The RLC layer of the UMTS RNC distributes the RLC PDU by using a data distribution algorithm.

Step 904, the result of the distribution is: The RLC layer of the UMTS RNC sends a part of the RLC PDU to the MAC layer of the UMTS RNC, and then sends it to the UE through the UMTS NodeB; through the data interface between the LTE eNB and the UMTS RNC, the RLC layer of the UMTS RNC After transmitting another part of the RLC PDU to the MAC layer of the LTE eNB, it is sent to the UE.

For uplink data transmission, the path is opposite to the transmission path of the downlink data described in FIG.

After the UE receives the downlink data, according to the protocol stack structure in the UE shown in FIG. 6, the transmission process of the downlink data in the UE is:

The MAC layer on the UMTS side receives part of the downlink data sent by the UMTS system, and then passes through the RLC layer on the UMTS side, and then sends it to the upper layer;

After the RLC layer on the LTE side, it is sent to the upper layer;

The MAC layer on the LTE side receives part of the downlink data sent by the LTE system, and the downlink data is sent to the RLC layer on the UMTS side through the data interface on the UMTS side and the LTE side. Send to the previous level.

It should be noted that, for the RLC PDU generated by the UMTS RNC, if it is sent to the MAC layer of the LTE eNB, the MAC layer of the LTE eNB will have the same ciphering, deciphering, and integrity protection as the PDCP layer ( Integrity protection ) and the function of integrity verification. For the downlink data, when the MAC layer of the LTE eNB receives the RLC PDU from the UMTS RNC, the RLC PDU may be first ciphered, and the integrity control operation may be performed on the data of the control plane. On the LTE side of the UE, the MAC layer receives the MAC PDU from the lower layer, performs the integrity verification and deciphering processing after the MAC layer process, and finally sends it to the RLC layer of the UMTS RNC.

In order to implement the foregoing joint transmission method, the embodiment of the present invention further provides a joint transmission system, including: a setting module, and an anchor network element and a first network element located in different systems;

a setting module, configured to establish a data interface between an RLC layer of the anchor network element and a MAC layer of the first network element;

The RLC layer of the anchor network element directly sends the downlink data from the upper layer to its own MAC layer, and then sends it to the user equipment (UE), and/or sends it to the MAC layer of the first network element through the data interface, and then sends the data to the UE.

In the LTE system, the eNB is an anchor network element for joint transmission; or

In the UMTS system, the RNC is an anchor network element for joint transmission.

The system further includes: a UE;

The UE has a protocol stack corresponding to the system where the anchor network element is located and a protocol stack corresponding to the system where the first network element is located;

Correspondingly, the setting module is further used for a protocol corresponding to the system where the anchor network element is located inside the UE. The internal data interface of the UE is established between the RLC layer of the stack and the MAC layer of the protocol stack corresponding to the system where the first network element is located.

The UE is configured to receive the downlink data from the anchor network element, and send the data to the upper layer through the physical layer, the MAC layer, and the RLC layer of the protocol stack corresponding to the system where the internal anchor network element is located; and/or, from the first network The downlink data of the element is sent to the upper layer by the MAC layer of the protocol stack corresponding to the system in which the first network element is located, and is sent to the upper layer through the internal data interface of the UE to the RLC layer of the protocol stack corresponding to the system where the internal anchor network element of the UE is located.

The RLC layer of the anchor network element receives the uplink data from its own MAC layer, sends it to the upper layer, and/or receives the uplink data from the MAC layer of the first network element through the data interface, and then sends the uplink data to the upper layer.

The UE is further configured to send the uplink data to the anchor network element after passing through the RLC layer, the MAC layer, and the physical layer of the protocol stack corresponding to the system where the internal anchor network element is located; and/or, the uplink data is used by the internal anchor. The RLC layer of the protocol stack corresponding to the system in which the network element is located is sent to the first network element by the MAC layer and the physical layer of the protocol stack corresponding to the system in which the first network element is located.

The above is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A method for joint transmission, the method comprising:

The RLC layer of the anchor network element directly sends the downlink data from the upper layer to the MAC layer of the local network element, and then sends the data to the user equipment (UE), and/or sends the MAC layer to the first network element through the data interface. Then sent to the UE.

2. The method of joint transmission according to claim 1, wherein determining the anchor network element of the joint transmission comprises:

In the LTE system, the eNB is set as an anchor network element for joint transmission; or

In the UMTS system, the RNC is set as the anchor network element for joint transmission.

3. A method of joint transmission according to claim 1 or 2, characterized in that

The protocol stack corresponding to the system where the anchor network element is located and the protocol stack corresponding to the system where the first network element is located; and the RLC layer and the first part of the protocol stack corresponding to the system where the anchor network element is located The internal data interface of the UE is established between the MAC layers of the protocol stack corresponding to the system in which the network element is located.

The method for joint transmission according to claim 3, wherein the UE receives the downlink data from the anchor network element, and passes through the MAC layer and the RLC layer of the protocol stack corresponding to the system where the anchor network element of the UE is located. Sent to the upper layer; and/or,

The method for joint transmission according to claim 3, further comprising: transmitting, by the RLC layer of the anchor network element, uplink data from a MAC layer of the local network element The upper layer is received, and/or the uplink data from the MAC layer of the first network element is received by the UE internal data interface, and then sent to the upper layer.

6. The method of joint transmission according to claim 5, characterized in that

A system for joint transmission, comprising: a setting module, and an anchor network element and a first network element located in different systems;

8. The system of joint transmission according to claim 7, wherein:

The system for joint transmission according to claim 6 or 7, wherein the system further comprises: a UE;

The joint transmission system according to claim 9, wherein the UE is configured to receive downlink data from an anchor network element, and pass the physical layer of the protocol stack corresponding to the system where the internal anchor network element is located. And the MAC layer and the RLC layer are sent to the upper layer; and/or the downlink data from the first network element, and the MAC layer of the protocol stack corresponding to the system where the first network element is located passes the internal data interface of the UE. It is sent to the RLC layer of the protocol stack corresponding to the system where the internal anchor network element of the UE is located, and then sent to the upper layer.

11. The system of joint transmission according to claim 9, wherein:

12. A system for joint transmission according to claim 11 wherein: