WO2014022974A1

WO2014022974A1 - Method, device, and system for data transmission

Info

Publication number: WO2014022974A1
Application number: PCT/CN2012/079786
Authority: WO
Inventors: 黄英; 黄华; 黄敏
Original assignee: 华为技术有限公司
Priority date: 2012-08-07
Filing date: 2012-08-07
Publication date: 2014-02-13
Also published as: CN104521166A

Abstract

Embodiments of the present invention relate to the field of communications. Provided are a method, device, and system for data transmission, comprising: when a switchover of a UE from a source access network to a target access network occurs, a source access network control node transmits a first message to a target access network control node, where the first message comprises at least information used for indicating the sequence numbers of data packets that have not been successfully transmitted to the UE by the source access network control node; the source access network control node transmits to the target access network control node the data packets that have not been successfully transmitted to the UE, thus facilitating the target access network control node to transmit to the UE, when the UE switches over to the target access network, the data packets that have not been successfully transmitted to the UE. With the present invention, when the UE performs a network switchover, prevention of data loss caused when switching networks is implemented, thus facilitating users in accessing networks.

Description

Method, device and system for data transmission

The present invention relates to the field of communications, and in particular, to a method, device, and system for data transmission. Background technique

Wireless local area network (WLAN) uses wireless technology to send and receive data through free space, often as an extension or replacement for traditional wired LANs such as Ethernet. The wireless network access point (AP) of the WLAN network can be installed in public places such as airports, train stations, hotels and cafes to provide high-speed access to the public. In recent years, WLAN networks have developed rapidly and become a good complement to the 3rd generation partnership project (3GPP) network. The 3GPP network can be wideband code division multiple access (WCDMA). Network, time division-synchronous code division multiple access (TD-SCDMA) network, enhanced data rate global mobile communication system (GSM) evolution technology (enhanced data rate for GSM evolution, EDGE) networks, etc. However, the coverage of the WLAN network is small. Therefore, when the user moves, the UE (user equipment) switches between the WLAN network and the 3GPP network very frequently.

In the existing network handover, the UE can only support connection with only one of the WLAN network and the 3GPP network at the same time. When connecting to one of the networks, the other network can no longer be used. Therefore, when the UE performs network handover, in order to be able to switch to the target access network, the connection with the source access network is interrupted, so that some data from the network server may remain in the source access network control node. Send to the UE, at this time, it will cause the loss of this part of the data.

For example, the UE is currently connected in the 3GPP network. When the UE switches to the WLAN network, the connection between the UE and the 3GPP network is interrupted. At this time, if some data remaining in the base station from the network server has not been sent to the UE, The connection of the 3GPP network is interrupted, causing the base station to be unable to communicate with the UE, resulting in loss of data in the base station.

Therefore, the existing network switching method is likely to cause data loss, resulting in inconvenience for users to access the network. Summary of the invention The present invention provides a method, a device, and a system for transmitting data. The present invention can prevent data loss caused by network switching when the UE performs network switching, and facilitates user access to the network.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions:

In a first aspect, the present invention provides a data transmission method, including:

When the user equipment UE initiates a handover from the source access network to the target access network, the source access network control node sends a first message to the target access network control node, where the first message includes at least the source Information about the sequence number of the data packet that the access network control node did not successfully send to the UE;

And the source access network control node sends, to the target access network control node, a data packet that is not successfully sent to the UE, so that, after the UE switches to the target access network, the target access The network control node sends the data packet that was not successfully sent to the UE to the UE.

In a first possible implementation manner of the first aspect, the source access network control node sends the first message to the target access network control node when the UE initiates a handover from the source access network to the target access network. , including:

When the UE initiates a handover from the source access network to the target access network, the source access network control node sends the first message to the target access network control node through the core network node.

In conjunction with the first possible implementation manner of the first aspect, in a second possible implementation manner of the first aspect, the source access network control node sends the unsuccessfully sent to the target access network control node The data packet of the UE includes: the source access network control node sends a data packet that is not successfully sent to the UE to the target access network control node by using a pre-established data forwarding tunnel;

The data forwarding tunnel is a channel through which the source access network control node and the target access network control node send data through the core network node, and is initiated by the source access network control node.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation, before the source access network control node sends the first message to the target access network control node, the method further includes:

The source access network control node receives, by the core network node, a second message sent by the target access network control node, where the second message includes indication information that the UE wants to switch to the target access network. And/or an indication of the information that forwards the sequence number of the packet.

With reference to the second possible implementation and the third possible implementation of the first aspect, in a fourth possible implementation, when the source access network is a wireless local area network (WLAN), the target access network When planning a 3GPP network for a third generation partner;

When the UE initiates a handover from the source access network to the target access network, the source access network control node sends the first message to the target access network control node through the core network node, including: When the UE switches from the WLAN network to the 3GPP network, the WLAN network control node sends the first message to the base station through the core network node;

The source access network control node sends a data packet that is not successfully sent to the UE to the target access network control node by using a pre-established data forwarding tunnel, including:

Transmitting, by the WLAN network control node, a data packet that is not successfully sent to the UE to the base station by using a pre-established data forwarding tunnel; or

When the source access network is a 3rd Generation Partnership Project 3GPP network, and the target access network is a wireless local area network WLAN network;

When the UE initiates a handover from the source access network to the target access network, the source access network control node sends the first message to the target access network control node through the core network node, including:

When the UE switches from the 3GPP network to the WLAN network, the base station sends a first message to the WLAN network control node through the core network node;

The source access network control node sends the data packet that is not successfully sent to the UE to the target access network control node by using a pre-established data forwarding tunnel, including:

And transmitting, by the base station, the data packet that is not successfully sent to the UE to the WLAN network control node by using a pre-established data forwarding tunnel.

In combination with all possible implementation manners of the first aspect, the information about the sequence number of the data packet includes:

Data aggregation layer protocol serial number PDCP-SN corresponding information; or,

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN. In a second aspect, the present invention provides another method for data transmission, including:

When the user equipment UE is in a handover from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node, where the first message includes at least the indication Information that the source access network control node does not successfully send the sequence number of the data packet of the UE;

And determining, by the target access network control node, information of a sequence number of a data packet that is not successfully sent to the UE according to the first message;

Receiving, by the target access network control node, the data packet sent by the source access network control node that is not successfully sent to the UE according to the first message; After the UE is handed over to the target access network, the target access network control node sends the data packet that is not successfully sent to the UE to the UE according to the first message.

In a first possible implementation manner of the second aspect, when the UE initiates a handover from the source access network to the target access network, the target access network control node receives the first sent by the source access network control node. The message, including:

When the UE initiates a handover from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node through the core network node.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the target access network control node receives the unsuccessfully sent by the source access network control node The data packet of the UE includes:

The target access network control node receives, by using a pre-established data forwarding tunnel, a data packet sent by the source access network control node that is not successfully sent to the UE;

With the second possible implementation of the second aspect, in a third possible implementation, before the target access network control node receives the first message sent by the source access network control node, the method further includes:

The target access network control node sends a second message to the source access network control node by using the core network node, where the second message includes indication information that the UE wants to switch to the target access network and / or send an indication of the information forwarding the serial number of the packet.

With reference to the second possible implementation and the third possible implementation of the second aspect, in a fourth possible implementation, when the source access network is a wireless local area network (WLAN), the target access network When planning a 3GPP network for a third generation partner;

When the UE initiates a handover from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node through the core network node, including:

When the UE switches from the WLAN network to the 3GPP network, the base station receives the first message sent by the WLAN network control node through the core network node;

The target access network control node receives, according to the first message, a data packet that is sent by the source access network control node and is not successfully sent to the UE, by using a pre-established data forwarding tunnel, and includes:

Receiving, by the base station, the data packet sent by the WLAN network control node that is not successfully sent to the UE by using a pre-established data forwarding tunnel according to the first message; or

When the source access network is a 3rd Generation Partnership Project 3GPP network, and the target access network is a wireless local area network WLAN network; When the UE performs the handover from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node through the core network node, including:

When the UE switches from the 3GPP network to the WLAN network, the WLAN network control node receives the first message sent by the base station through the core network node;

And the WLAN network control node receives, according to the first message, a data packet sent by the base station that is not successfully sent to the UE by using a pre-established data forwarding tunnel.

With reference to all possible implementation manners of the second aspect, the information about the sequence number of the data packet includes: information corresponding to a data aggregation layer protocol sequence number PDCP-SN; or

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN. In a third aspect, the present invention provides a method for data transmission, including:

After the user equipment UE is handed over from the source access network to the target access network, the UE receives a data packet that is forwarded by the target access network control node and is not successfully sent to the UE;

The data packet that is not successfully sent to the UE is that when the UE initiates a handover from the source access network to the target access network, the source access network control node has not successfully sent to the a data packet of the UE, and sent by the source access network control node to the target access network control node. In a fourth aspect, the present invention provides an access network control node, including:

a first sending unit, configured to send a first message to the target access network control node when the user equipment UE initiates a handover from the source access network to the target access network, where the first message includes at least Information that the source access network control node does not successfully send the sequence number of the data packet of the UE;

a second sending unit, configured to send, to the target access network control node, a data packet that is not successfully sent to the UE, so that, after the UE switches to the target access network, the target access network The control node sends the data packet that was not successfully sent to the UE to the UE.

In a first possible implementation manner of the fourth aspect, the first sending unit is specifically configured to: when the UE transits from the source access network to the target access network, go to the target access network through the core network node. The control node sends the first message. With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, the second sending unit is specifically configured to access the target by using a pre-established data forwarding tunnel The network control node sends a data packet that is not successfully sent to the UE;

With reference to the second possible implementation of the fourth aspect, in a third possible implementation, the access network control node further includes:

a receiving unit, configured to receive, by the core network node, a second message sent by the target access network control node, before the first sending unit sends the first message to the target access network control node, The second message includes an indication of the indication information that the UE wants to switch to the target access network and/or information for transmitting a sequence number of the forwarded packet.

With reference to the second possible implementation and the third possible implementation manner of the fourth aspect, in a fourth possible implementation manner, when the source access network is a wireless local area network (WLAN), the target access network When planning a 3GPP network for a third generation partner;

The first sending unit is specifically configured to: when the UE wants to switch to the 3GPP network, send the first message to the base station by using the core network node;

The second sending unit is configured to send, by using a pre-established data forwarding tunnel, a data packet that is not successfully sent to the UE to the base station; or

The first sending unit is specifically configured to: when the UE wants to switch to the WLAN network, send the first message to the WLAN network control node by using the core network node;

The second sending unit is configured to send, by using a pre-established data forwarding tunnel, the data packet that is not successfully sent to the UE to the WLAN network control node.

In combination with all possible implementation manners of the fourth aspect, the information about the sequence number of the data packet includes:

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN. In a fifth aspect, the present invention provides another target access network control node, including: a receiving unit, configured to receive, by the user equipment UE, a first message sent by the source access network control node when the handover from the source access network to the target access network occurs, where the first message includes at least the source Information about the sequence number of the data packet that the access network control node did not successfully send to the UE;

a determining unit, configured to determine information about a sequence number of a data packet that is not successfully sent to the UE according to the first message, where the receiving unit is further configured to receive, according to the first message, the source access network control a data packet sent by the node that is not successfully sent to the UE;

And a sending unit, configured to send the data packet that is not successfully sent to the UE to the UE according to the first message, after the UE switches to the target access network.

In a first possible implementation manner of the fifth aspect, the receiving unit is specifically configured to: when a UE initiates a handover from a source access network to a target access network, receive a source access network control node by using a core network node. The first message sent.

With reference to the first possible implementation manner of the fifth aspect, in a second possible implementation manner of the fifth aspect, the receiving unit is further configured to receive the source access network by using a pre-established data forwarding tunnel. a data packet sent by the control node that is not successfully sent to the UE;

With the second possible implementation of the fifth aspect, in a third possible implementation, the sending unit is further configured to send, by using the core network node, the second message to the source access network control node. And the second message includes an indication that the UE wants to switch to the target access network and/or an information that sends a forwarding packet sequence number.

With reference to the second possible implementation and the third possible implementation manner of the fifth aspect, in a fourth possible implementation manner, when the source access network is a wireless local area network (WLAN), the target access network When planning a 3GPP network for a third generation partner;

The receiving unit is specifically configured to: when the UE switches from the WLAN network to the 3GPP network, receive, by the core network node, the first message sent by the WLAN network control node;

The receiving unit is further configured to receive, according to the first message, a data packet that is sent by the WLAN network control node and is not successfully sent to the UE by using a pre-established data forwarding tunnel; or

The receiving unit is specifically configured to: when the UE switches from the 3GPP network to the WLAN network, receive, by the core network node, the first message sent by the base station;

The receiving unit is further configured to receive, according to the first message, a data packet that is sent by the base station and is not successfully sent to the UE by using a pre-established data forwarding tunnel. In combination with all possible implementation manners of the fifth aspect, the information about the sequence number of the data packet includes:

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN. In a sixth aspect, the present invention provides a user equipment UE, including:

a receiving unit, configured to: after the user equipment UE switches from the source access network to the target access network, the UE receives a data packet that is not successfully sent by the target access network control node to the UE;

The data packet that is not successfully sent to the UE is that when the UE initiates a handover from the source access network to the target access network, the source access network control node has not successfully sent to the a data packet of the UE, and sent by the source access network control node to the target access network control node. In a seventh aspect, the present invention provides a system for data transmission, including a core network node, the one access network control node, the another access network control node, and the user equipment UE.

In a first possible implementation manner of the seventh aspect, when the source access network is a wireless local area network (WLAN), and the target access network is a third generation partner plan 3GPP network;

The system specifically includes: the core network node, the UE, the WLAN network control node, and the base station; wherein the source access network control node is a WLAN network control node, and the target access network control node is a base station. In a second possible implementation manner of the seventh aspect, when the source access network is a 3rd Generation Partnership Project 3GPP network, and the target access network is a wireless local area network (WLAN) WLAN network;

The system specifically includes: the core network node, the UE, the WLAN network control node, and the base station; wherein the source access network control node is a base station, and the target access network control node is a WLAN network control node. The present invention provides a method, device, and system for data transmission. According to the present invention, when a handover occurs from a source access network to a target access network, if the source access network control node does not send The data packet of the UE, the source access network control node may first send a first message including a sequence number indicating a data packet that is not successfully sent to the UE to the target access network control node, so that the target access The network control node learns the sequence number of the data packet that is not successfully sent to the UE; the source access network control node may send the data packet that is not successfully sent to the UE to the target access network control node; and when the UE switches to After the target accesses the network, the target access network control node will not successfully send the data packet to the UE. Send to the UE. It can be seen that, in the present invention, when the UE performs network switching, data loss caused by network switching is avoided, and the user is convenient to access the network. DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described. It is obvious that the drawings in the following description are only some embodiments of the present invention. Other drawings may also be obtained from those of ordinary skill in the art in view of the drawings.

FIG. 1 is a flowchart of a method for data transmission according to an embodiment of the present invention;

2 is a flowchart of another method for data transmission according to an embodiment of the present invention;

3 is a flowchart of a third method for data transmission according to an embodiment of the present invention;

4 is a flowchart of a fourth method for data transmission according to an embodiment of the present invention;

FIG. 5 is a flowchart of a fifth method for data transmission according to an embodiment of the present invention;

6 is a structural diagram of an access network control node according to an embodiment of the present invention;

FIG. 7 is a structural diagram of another access network control node according to an embodiment of the present invention;

FIG. 8 is a structural diagram of still another access network control node according to an embodiment of the present invention; FIG.

FIG. 9 is a structural diagram of a user equipment UE according to an embodiment of the present invention;

FIG. 10 is a structural diagram of a system for data transmission according to an embodiment of the present invention. detailed description

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Referring to FIG. 1, a flowchart of a method for sending data according to an embodiment of the present invention includes:

11: When the UE initiates a handover from the source access network to the target access network, the source access network control node sends a first message to the target access network control node, where the first message includes at least the source access network control Information about the serial number of the data packet that the node did not successfully send to the UE;

The source access network is the current network where the UE is located, the target access network is the network to be switched to; the source access network control node is the network element in the source access network, and the target access network node is the target access network. The network element in the middle.

Further, it should be noted that the scenario in which the UE performs the handover from the source access network to the target access network may include, but is not limited to, the following scenarios: The signal strength of the source access network cannot meet the Internet access requirements of the mobile terminal;

Or, due to policy control of the source access network, the source access network decides not to provide network services for the mobile terminal (for example, when the user owes a fee);

Or, the mobile terminal changes geographical location, and the source access network cannot cover the moved location of the mobile terminal; or, the mobile terminal actively sends an instruction to switch from the source access network to the target access network.

12: The source access network control node sends a data packet that is not successfully sent to the UE to the target access network control node, so that after the UE switches to the target access network, the target access network control node is not successfully sent to the UE. The data packet is sent to the UE.

FIG. 2 is a flowchart of another method for sending data according to an embodiment of the present invention;

21: When the UE initiates a handover from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node, where the first message includes at least the source access network. Information about the sequence number of the packet that the control node did not successfully send to the UE.

22: The target access network control node determines, according to the first message, information about a sequence number of a data packet that is not successfully sent to the UE. 23: The target access network control node receives, according to the first message, a data packet sent by the source access network control node that is not successfully sent to the UE.

24: After the UE switches to the target access network, the target access network control node sends, to the UE, a data packet that the source access network control node does not successfully send to the UE according to the first message.

Referring to FIG. 3, a flowchart of a third method for data transmission according to an embodiment of the present invention includes:

31: After the UE switches from the source access network to the target access network, the UE receives the data packet that is not successfully sent to the UE and is forwarded by the target access network control node.

The data packet that is not successfully sent to the UE is a data packet that the source access network control node has not successfully sent to the UE when the UE initiates a handover from the source access network to the target access network, and is controlled by the source access network. The node sends to the target access network control node.

This embodiment provides a method for data transmission. In this embodiment, when a handover occurs from a source access network to a target access network, if the source access network control node stores information that is not sent to the UE, The data packet, the source access network control node may first send a first message including a sequence number indicating a data packet that is not successfully sent to the UE to the target access network control node, so that the target access network controls The node learns the information of the sequence number of the data packet that is not successfully sent to the UE; the source access network control node may send the data packet that is not successfully sent to the UE to the target access network control node; and when the UE switches to After the target accesses the network, the target access network control node sends the data packet that is not successfully sent to the UE to the UE. It can be seen that, in the method provided by the embodiment, when the UE performs network switching, data loss caused by network switching is avoided, and the user is convenient to access the network. Referring to FIG. 4, a method for data transmission according to an embodiment of the present invention is provided. The method for data transmission provided by this embodiment can support handover between a 3GPP network and a WLAN network. For convenience of description, this embodiment is described by taking an example in which a UE is switched from a WLAN network to a 3GPP network.

Specifically, in this embodiment, the source access network is a WLAN network, and the target access network is a 3GPP network, and in the embodiment, the 3GPP network belongs to a long term evolution (LTE) network system as an example. The LTE network system is composed of the following nodes: an evolved network base station (E-UTRAN eNodeB, eNB), a mobility management entity (MME), a service gateway (SGW), a public data gateway (publ ic data network getaway, P), home subscriber server/authentication authorization^ accounting (HSS/AAA). The PDW is a core network node, and the eNB is a target access network control node.

A method for data transmission specifically includes:

201: The UE performs a selection of a 3GPP network, and initiates a handover process.

It should be noted that the UE performs the selection of the 3GPP network and initiates the handover process belongs to the prior art, and is not specifically described herein.

202: The UE initiates an attach procedure to the UE through the eNB.

In the attaching process, the UE sends a message carrying a "handover" indication to the UE, and the "handover" is used to indicate that the UE is ready to switch to the 3GPP network.

203: The HSS/AAA performs authentication and authentication on the UE, and determines whether the UE has the right to access the current 3GPP network. The HSS/AAA is used to authenticate the UE to determine whether the UE has the right to access the 3GPP network. For example, the operator can sign the HSS/AAA subscription information to determine whether the UE belongs to the subscriber of the 3GPP network. And performing identity authentication on the UE. When the UE passes the authentication of the HSS/AAA, the UE is allowed to access the 3GPP network. Otherwise, the network handover is not allowed, and the current process is terminated.

In the present embodiment, in order to explain the method of preventing data loss at the time of handover, the UE authentication is described as an example.

204: 匪 E initiates a location update process between the core network nodes, and obtains user subscription information from the HSS.

It should be noted that the execution process of this step 204 belongs to the prior art, and details are not described herein again.

205: The PDW receives the second message sent by the eNB, and sends a second message to the WLAN network control node.

The second message includes indication information that the UE wants to switch to the 3GPP network and/or a command or indication for instructing the WLAN network control node to send information of the forwarding packet sequence number to the eNB.

206: After receiving the second message sent by the PDW, the WLAN network control node sends the first message to the PDW. The first message and the second information are all signaling messages, and the first message includes information indicating a sequence number of the data packet that the WLAN network control node does not successfully send to the UE.

For example, the WLAN network control node may use the sequence number of the data packet that was not successfully transmitted to the UE as the first message, but is not limited to this form.

In this embodiment, the serial number of the foregoing data packet may specifically be a PDCP-SN (Packet Data Convergence).

Protocol serial number, data aggregation layer protocol sequence 歹lj); or GTP-N (packet bearer service of the packet domain number); or PMIP-SN (Proxy Mobi le IP Serial Number) IP sequence number); or PDCP-SN and PMIP-SN; or GTP-N and PMIP_SN.

The eNB may add a function to handle the PDCP_SN, GTP-N, and PMTP-SN capabilities; or the ability to convert the correspondence between the PDCP-SN and the PMTP-SN; or the ability to convert the correspondence between the GTP-N and the PMTP-SN .

It should be noted that the first message may further include information of a sequence number of a data packet that has been successfully sent to the UE. At this time, in this embodiment, the first message may be specifically in the following two forms, and the purpose is to let the eNB know the data packet successfully sent by the WLAN network control node to the UE and the data packet that is not successfully sent to the UE, and Packets that are not successfully sent to the UE are forwarded to the eNB, but are not limited to the following two forms:

The first type: the first message includes two parts, the first part is the serial number of the data packet that has been successfully sent to the UE, and the second part is the serial number of the data packet that is not successfully sent to the UE, and the two parts are respectively arranged in the a preset part of the first message;

Second: The first message includes the sequence number of the first forwarded packet and includes a list. The WLAN network control node sets a flag bit for the sequence number of each data packet, and indicates whether the data packet corresponding to the flag bit has been successfully sent to the UE by using the flag bit (for example, 0 can be used to indicate that the corresponding data packet is not successfully sent. For the UE, 1 indicates that its corresponding data packet has been successfully sent to the UE), and the sequence number and the identification bit of the data packet are arranged in a preset manner to obtain the list, for example, the first forwarding packet sequence number is 5 The list sent at the same time is 10011. After receiving the first message, the eNB learns that the data packet UE with the sequence number of 5, 8, 9 has been received, and the data packet with the sequence number of 6, 7 has not been received.

It should also be noted that, when the WLAN network control node sends the first message to the PDW, it also initiates establishment of a data forwarding tunnel between the WLAN network control node and the eNB.

207: The PDW receives the first message sent by the WLAN network control node, and forwards the first message to the eNB.

Specifically, the PDW receives the first message sent by the WLAN network control node, and forwards the first message to the eNB through 匪E.

208: The eNB receives the first message, and determines, according to the first message, information about a sequence number of a data packet that is not successfully sent to the UE. Specifically, the eNB may further learn, according to the first message, a sequence number of the data packet that the control node of the WLAN has successfully sent to the UE. The eNB may also number the sequence number of the data packet that the control node of the WLAN does not successfully send to the UE according to the first message.

After the above step 208, the following operations are performed:

The control node of the WLAN sends a data packet that is not successfully sent to the UE to the PDW through the pre-established data forwarding tunnel.

The PDW forwards the data packet that is not successfully sent to the UE to the eNB through the foregoing pre-established data forwarding tunnel. The eNB receives the data packet that is not successfully sent to the UE according to the first message, and saves the data packet.

The eNB may learn, according to the first message, whether all the data packets that are not successfully sent to the UE are received.

It should be noted that, because the UE does not complete the process of handover to the 3GPP network in the eNB process, the eNB cannot send the data packet that is not successfully sent to the UE to the UE through the 3GPP network, and is temporarily saved by the eNB. The data packet that has not been successfully sent to the UE can be sent to the UE after the handover is completed, thereby avoiding the loss of the data packet.

It should be noted that the above steps 205-208 may also be performed at any time between step 202 and step 204, and may also be performed between step 209 and step 210.

209: The PDW establishes a radio bearer between the 3GPP and the UE.

Further, after the PDW establishes the radio bearer of the 3GPP and the UE, the UE can exchange data with the 3GPP network through the bearer.

After the foregoing step 209, the eNB sends a data packet that is not successfully sent to the UE according to the first message to the UE. Optionally, the eNB may send the data packets sent by the WLAN network control node that are not successfully sent to the UE to the UE in the order of the data packet sequence number, so as to avoid the data packet loss when the UE performs network switching.

210: After receiving the command for releasing the WLAN radio resource sent by the PDW, the WLAN network control node releases the WLAN resource with the UE.

It should be noted that, in this embodiment, the 3GPP network belongs to the LTE network, and it can be understood that the method in this embodiment can be applied to other types of 3GPP networks, for example, when the 3GPP network belongs to the universal mobile communication system (universal mobi system). When the network system is used, the MME is replaced with a serving GPRS support node (SGSN), and the eNB is replaced by a radio network controller (RNC); when the 3GPP network is connected In the network system of the gsm edge radio access network (GERAN), the SGW is replaced by the SGSN, and the eNB is replaced by a base station controller (BSC).

This embodiment provides a method for data transmission. According to this embodiment, when the UE switches from the WLAN network to

In the case of the 3GPP network, the WLAN network control node can send the packet to the eNB first through the PDW according to the second information sent by the eNB. Including a first message indicating a sequence number of a data packet that is not successfully sent to the UE, so that the eNB knows the information of the sequence number of the data packet that was not successfully sent to the UE, and the WLAN network control node may not succeed again. The data packet sent to the UE is forwarded to the eNB through the PDW. After the UE switches to the 3GPP network, the eNB sends the data packet that is not successfully sent to the UE to the UE. It can be seen that, in the method provided by the embodiment, when the UE performs network switching, data loss caused by network switching is avoided, and the user is convenient to access the network. 5 is a flowchart of a method for data transmission according to an embodiment of the present invention. It should be noted that the method for data transmission provided by this embodiment can support a UE between a 3GPP network and a WLAN network. For the convenience of description, this embodiment is described by taking an example in which a UE is switched from a 3GPP network to a WLAN network.

Specifically, in this embodiment, the source access network is a 3GPP network, and the target access network is a WLAN network, and in the embodiment, the 3GPP network belongs to the LTE network system, and the LTE network system is represented by the following node. The components are: eNB, MME, SGW, PDW, HSS/AAA, where PDW is a core network node, and eNB is a source-standard access network control node.

A flow chart of a method for data transmission, specifically comprising:

301: The UE performs a selection of the WLAN network, and initiates a handover process.

The process of selecting a WLAN network by the UE and initiating the handover process belongs to the prior art, and is not specifically described herein.

302: The HSS/AAA performs authentication and authentication on the UE, and determines whether the UE has the right to access the current WLAN network. The HSS/AAA is used to authenticate the UE to determine whether the UE has the right to access the WLAN network. For example, the operator can determine whether the UE belongs to the subscription user of the WLAN network by using the HSS/AAA subscription information. The UE is authenticated. When the UE passes the authentication of the HSS/AAA, the UE is allowed to access the WLAN network. Otherwise, the network handover is not allowed, and the current process is terminated.

303: The PDW receives the second message sent by the WLAN network control node, and sends a second message to the eNB.

Specifically, when the UE has the right to access the current WLAN network, the PDW receives the second message sent by the WLAN network control node, and sends a second message to the eNB through the UE.

The second message includes indication information that the UE wants to switch to the WLAN network and/or a command or indication for instructing the eNB to send the information of the forwarding packet sequence number to the WLAN network control node.

304: After receiving the second message sent by the PDW, the eNB sends the first message to the PDW.

Specifically, after receiving the second message sent by the PDW, the eNB sends the first message to the PDW through the 匪E. The first message and the second information are all signaling messages, and the first message includes information indicating a sequence number of the data packet that the eNB does not successfully send to the UE.

For example, the eNB may use the sequence number of the data packet that was not successfully transmitted to the UE as the first message, but is not limited to this form.

In this embodiment, the sequence number of the foregoing data packet may be specifically a PDCP-SN; or a GTP-N; or

PMIP-SN; or PDCP-SN and PMIP-SN; or GTP-N and PMIP_SN.

The WLAN network control node may add a function to process the PDCP_SN, GTP-N, and PMTP-SN capabilities; or the ability to convert the correspondence between the PDCP-SN and the PMTP-SN; or convert the correspondence between the GTP-N and the PMTP-SN. The ability to relate.

It should be noted that the first message may further include information of a sequence number of a data packet that has been successfully sent to the UE. At this time, in this embodiment, the first message may be specifically in the following two forms, and the purpose is to let the WLAN network control node know the data packet successfully sent by the eNB to the UE and the data packet that is not successfully sent to the UE, and Packets that are not successfully sent to the UE are forwarded to the WLAN network control node, but are not limited to the following two forms:

Second: The first message includes the sequence number of the first forwarded packet and includes a list. The eNB sets a flag bit for the sequence number of each data packet, and indicates whether the data packet corresponding to the flag bit has been successfully sent to the UE by using the flag bit (for example, 0 can be used to indicate that the corresponding data packet is not successfully sent to the UE, It is indicated by 1 that its corresponding data packet has been successfully sent to the UE), and the serial number and the identification bit of the data packet are arranged in a preset manner to obtain the list. For example, the first forwarding packet sequence number is 5, and the list sent at the same time is 10011. After receiving the first message, the WLAN network control node learns that the data packet UE with the sequence number 5, 8, 9 has been received, and the sequence number is 6. , 7 packets were not received.

It should be noted that, when the eNB sends the first message to the PDW, the eNB also initiates establishment of a data forwarding tunnel between the WLAN network control node and the eNB.

305: The PDW receives the first message sent by the eNB, and forwards the first message to the WLAN network control node.

306: The WLAN network control node receives the first message, and determines, according to the first message, information about a sequence number of a data packet that is not successfully sent to the UE.

Specifically, the WLAN network control node may further learn, according to the first message, a sequence number of the data packet that the eNB has successfully sent to the UE. The WLAN network control node may further number the sequence numbers of the data packets that the eNB did not successfully send to the UE according to the first message.

After the above step 306, the following operations are performed: The eNB sends a data packet that is not successfully sent to the UE to the PDW through the foregoing pre-established data forwarding tunnel.

The PDW forwards the data packet that is not successfully sent to the UE to the WLAN network control node by using the foregoing pre-established data forwarding tunnel.

The WLAN network control node receives the data packet that is not successfully sent to the UE according to the first message, and saves the data packet. The WLAN network control node may learn, according to the first message, whether all the data packets that are not successfully sent to the UE are received.

It should be noted that, in the data processing of the WLAN, the UE does not complete the process of switching to the WLAN network. Therefore, the WLAN network control node cannot send the data packet that is not successfully sent to the UE to the UE through the WLAN network. The WLAN network control node temporarily saves the data packet that has not been successfully sent to the UE, and after the handover is completed, the UE can transmit to the UE, thereby avoiding the loss of the data packet.

307: The UE initiates an attach procedure to the WLAN network.

In the attaching process, the UE sends a message carrying a "handover" indication to the WLAN network, where the "handover" is used to indicate that the UE is ready to switch to the WLAN network.

308: The process of establishing a session on a WLAN network.

It should be noted that the execution process of this step 308 belongs to the prior art, and details are not described herein again.

309: The WLAN network control node establishes a communication tunnel between the UE and the WLAN network.

Further, after the communication tunnel of the UE and the WLAN network is successfully established, the UE can exchange data with the WLAN network through the communication tunnel.

After the above step 309, the WLAN network control node sends a data packet that is not successfully sent to the UE according to the first message to the UE.

Optionally, the WLAN network control node may send the data packets that are not successfully sent to the UE by the received eNB to the UE in the order of the data packet sequence number, so as to avoid the data packet loss when the UE performs network switching.

It should be noted that the foregoing steps 303-306 in this embodiment may also be performed at any time between step 307 and step 310.

310: After receiving the command for releasing the 3GPP radio resource sent by the PDW, the eNB releases the 3GPP radio resource with the UE.

It should be noted that, in this embodiment, the description is made that the 3GPP network belongs to the LTE network. It can be understood that the method in this embodiment can be applied to other types of 3GPP networks, for example, when the 3GPP network belongs to the UMTS network system,匪E is replaced with SGSN, eNB is replaced by RNC; when 3GPP network belongs to GERAN network system, then SGW is replaced by SGSN, and eNB is replaced by BSC. The embodiment provides a data transmission method. In this embodiment, when the UE is switched from the 3GPP network to the WLAN network, the eNB can control the node according to the WLAN network control node according to the second information sent by the WLAN network control node. Transmitting a first message including a sequence number indicating a data packet that was not successfully sent to the UE, so that the WLAN network control node knows the information of the sequence number of the data packet that was not successfully sent to the UE; the eNB may send the unsuccessfully to the eNB. The data packet of the UE is forwarded to the WLAN network control node by using the PDW; and after the UE switches to the WLAN network, the WLAN network control node sends the data packet that is not successfully sent to the UE to the UE. It can be seen that, in the method provided by the embodiment, when the UE performs network switching, data loss caused by network switching is avoided, and the user is convenient to access the network. FIG. 6 is a structural diagram of an access network control node according to an embodiment of the present invention. The access network control node 400 includes:

The first sending unit 401 is configured to: when the user equipment UE initiates a handover from the source access network to the target access network, send a first message to the target access network control node, where the first message includes at least Information about the serial number of the data packet that the network control node did not successfully send to the UE;

The second sending unit 402 is configured to send, to the target access network control node, a data packet that is not successfully sent to the UE, so that after the UE switches to the target access network, the target access network control node is not successfully sent to the UE. The data packet is sent to the UE.

further,

The first sending unit 401 is specifically configured to: when the UE initiates a handover from the source access network to the target access network, send the first message to the target access network control node by using the core network node.

further,

The second sending unit 402 is configured to send, by using a pre-established data forwarding tunnel, a data packet that is not successfully sent to the UE to the target access network control node;

The data forwarding tunnel is a channel for sending data between the source access network control node and the target access network control node through the core network node, and is initiated by the source access network control node.

Further, referring to FIG. 7, the foregoing access network further includes:

The receiving unit 403 is configured to receive, by the core network node, a second message sent by the target access network control node before the first sending unit 401 sends the first message to the target access network control node, where the second message includes the UE wanting to switch to An indication of the target access network and/or an indication of the information of the forwarded packet sequence number.

further,

When the source access network is a wireless local area network WLAN network, and the target access network is a third generation partner plan 3GPP network, the first sending unit 401 is specifically configured to: when the UE wants to switch to the 3GPP network, pass the core network node to the base station. Send the first message; The second sending unit 402 is configured to send, by using a pre-established data forwarding tunnel, a data packet that is not successfully sent to the UE to the base station; or

When the source access network is a third-generation partner project 3GPP network, and the target access network is a wireless local area network WLAN network, the first sending unit 401 is specifically configured to: when the UE wants to switch to the WLAN network, pass the core network node to the WLAN. The network control node sends the first message;

The second sending unit 402 is configured to send, by using a pre-established data forwarding tunnel, a data packet that is not successfully sent to the UE to the WLAN network control node.

Further, the information of the serial number of the data packet includes any one of the following forms:

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN.

The embodiment provides an access network control node, so that when the UE initiates a handover from the access network to the target access network, the access network control node can send the second information according to the target access network control node. Transmitting, by the core network node, a first message including a sequence number indicating a data packet that is not successfully sent to the UE, to the target access network control node, so that the target access network control node learns that the target access network control node is not successfully sent to the UE. The information of the serial number of the data packet; after that, the access network control node sends the data packet sent by the core network node to the target access network control node that is not successfully sent to the UE; finally, after the UE switches to the target access network Then, the target access network control node sends the data packet that is not successfully sent to the UE to the UE. It can be seen that the access network control node provided in this embodiment avoids data loss caused by network switching when the UE performs network switching, and is convenient for the user to access the network. FIG. 8 is a structural diagram of an access network control node according to an embodiment of the present invention. The access network control node 500 includes:

The receiving unit 501 is configured to: when the user equipment UE initiates a handover from the source access network to the target access network, receive a first message sent by the source access network control node, where the first message includes at least the source access network Information about the sequence number of the data packet that the control node did not successfully send to the UE;

a determining unit 502, configured to determine information about a sequence number of a data packet that is not successfully sent to the UE according to the first message, where the receiving unit 501 is further configured to send, according to the first message, the unsuccessfully sent to the UE by the source access network control node Data packet The sending unit 502 is configured to: after the UE switches to the target access network, send, to the UE, a data packet that is not successfully sent to the UE according to the first message.

further,

The receiving unit 501 is specifically configured to: when the UE initiates a handover from the source access network to the target access network, receive, by the core network node, the first message sent by the source access network control node.

further,

The receiving unit 501 is further configured to: receive, according to the first message, a data packet that is sent by the source access network control node and is not successfully sent to the UE by using a pre-established data forwarding tunnel;

further,

The sending unit 502 is further configured to send, by using the core network node, a second message to the source access network control node, where the second message includes indication information that the UE wants to switch to the target access network and/or information that sends the forwarding packet sequence number. Instructions.

further,

When the source access network is a wireless local area network WLAN network, and the target access network is a third generation partner plan 3GPP network, the receiving unit 501 is specifically configured to receive, when the UE changes from the WLAN network to the 3GPP network, receive the core network node The first message sent by the WLAN network control node;

The receiving unit 501 is further configured to receive, according to the first message, a data packet that is sent by the WLAN network control node and is not successfully sent to the UE by using a pre-established data forwarding tunnel; or

When the source access network is a 3GPP partner plan 3GPP network, and the target access network is a wireless local area network (WLAN) WLAN network, the receiving unit 501 is specifically configured to receive, when the UE is switched from the 3GPP network to the WLAN network, receive the core network node. The first message sent by the base station;

The receiving unit 501 is further configured to: receive, according to the first message, a data packet that is sent by the base station and is not successfully sent to the UE by using a pre-established data forwarding tunnel.

The information corresponding to the tunneling protocol serial number GTP-N; or

Proxy mobile IP serial number information corresponding to PMTP-SN; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN. The embodiment provides an access network control node, so that when the UE initiates a handover from the source access network to the access network, the access network control node can send the source network access node through the core network node. The first message including the sequence number of the data packet indicating the unsuccessfully transmitted to the UE is used to learn the serial number information of the data packet that is not successfully sent to the UE; after that, the receiving source access network control node passes through the core. The data packet sent by the network node that is not successfully sent to the UE; finally, after the UE switches to the access network, the access network control node sends the data packet that is not successfully sent to the UE to the UE. It can be seen that, when the UE performs network switching, the access control node of the embodiment avoids data loss caused by network switching, and facilitates user access to the network. FIG. 9 is a structural diagram of a user equipment UE according to an embodiment of the present invention. The user equipment UE700 includes: a receiving unit 701, configured to receive, after the user equipment UE switches from a source access network to a target access network, a data packet that is not successfully sent to the UE by the target access network control node;

The embodiment provides a user equipment UE, which can enable the UE to receive the handover from the source access network to the target access network, and after the UE switches to the target access network, can receive the target access network control node. A packet that was successfully sent to the UE. It can be seen that the UE provided in this embodiment avoids data loss caused by network switching when the UE performs network switching, and facilitates user access to the network. Referring to FIG. 10, a system structure diagram of data transmission according to an embodiment of the present invention includes a core network node 600, a user equipment UE700, the foregoing access network control node 400, and the access network control node 500.

Further, when the source access network is a WLAN network and the target access network is a 3GPP network;

The foregoing system specifically includes: a core network node, a UE, a WLAN network control node, and a base station;

The source access network control node is a WLAN network control node, and the target access network control node is a base station.

Further, when the source access network is a 3GPP network and the target access network is a WLAN network;

The source access network control node is a base station, and the target access network control node is a WLAN network control node.

A system for transmitting data according to this embodiment, by using the embodiment, when a handover occurs from a source access network to a target access network, if the source access network control node stores a signal that is not sent to the UE. a data packet, the source access network control node may first send, by the core network node, a first message including a sequence number indicating a data packet that is not successfully sent to the UE to the target access network control node, so that the target The access network control node learns that the UE is not successfully sent to the UE. The sequence number of the data packet; afterwards, the source access network control node may send the data packet that is not successfully sent to the UE to the target access network control node through the core network node; finally, after the UE switches to the target access network, The target access network control node then sends the data packet that was not successfully sent to the UE to the UE. It can be seen that, in the system provided by the embodiment, when the UE performs network switching, data loss caused by network switching is avoided, and the user is convenient to access the network.

Through the description of the above embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general hardware, and of course, by hardware, but in many cases, the former is a better implementation. . Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, may be embodied in the form of a software product stored in a readable storage medium, such as a floppy disk of a computer. A hard disk or optical disk or the like includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform the methods described in various embodiments of the present invention.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the appended claims.

Claims

claims

1. A method of data transmission, characterized by including:

When the user equipment UE is switched from the source access network to the target access network, the source access network control node sends a first message to the target access network control node, where the first message at least includes instructions for indicating the source access network. Information about the sequence number of the data packet that the access network control node failed to send to the UE;

The source access network control node sends the data packet unsuccessfully sent to the UE to the target access network control node, so that when the UE switches to the target access network, the target access network The network control node sends the data packet unsuccessfully sent to the UE to the UE.

2. The method according to claim 1, characterized in that,

When the UE switches from the source access network to the target access network, the source access network control node sends a first message to the target access network control node, including:

When the UE switches from the source access network to the target access network, the source access network control node sends the first message to the target access network control node through the core network node.

3. The method according to claim 2, characterized in that,

The source access network control node sends the data packet that was unsuccessfully sent to the UE to the target access network control node, including:

The source access network control node sends the data packet that was unsuccessfully sent to the UE to the target access network control node through the pre-established data forwarding tunnel;

Wherein, the data forwarding tunnel is a channel for sending data through the core network node between the source access network control node and the target access network control node, and is initiated and established by the source access network control node.

4. The method according to claim 3, characterized in that, before the source access network control node sends the first message to the target access network control node, it further includes:

The source access network control node receives a second message sent by the target access network control node through the core network node, where the second message includes indication information that the UE wants to switch to the target access network. and/or an indication to send information about the sequence number of the forwarded packet.

5. The method according to claim 3 or 4, characterized in that when the source access network is a wireless local area network (WLAN) network and the target access network is a 3rd Generation Partnership Project (3GPP) network;

When the UE switches from the source access network to the target access network, the source access network control node sends the first message to the target access network control node through the core network node, including:

When the UE switches from the WLAN network to the 3GPP network, the WLAN network control node sends the first message to the base station through the core network node;

The source access network control node sends the data packet that was unsuccessfully sent to the UE to the target access network control node through the pre-established data forwarding tunnel, including:

The WLAN network control node sends the data packet that was unsuccessfully sent to the UE to the base station through the pre-established data forwarding tunnel; or,

When the source access network is a 3GPP network and the target access network is a WLAN network;

When the UE switches from the 3GPP network to the WLAN network, the base station sends the first message to the WLAN network control node through the core network node;

The source access network control node sends the unsuccessful data packet sent to the UE to the target access network control node through the pre-established data forwarding tunnel, including:

The base station sends the data packet unsuccessfully sent to the UE to the WLAN network control node through a pre-established data forwarding tunnel.

6. The method according to any one of claims 1 to 5, characterized in that the sequence number information of the data packet includes any of the following forms:

Data convergence layer protocol sequence number PDCP-SN corresponding information; or,

Tunnel protocol sequence number The information corresponding to GTP-N; or,

Agent mobile IP serial number PMTP-SN corresponding information; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN.

7. A method of data transmission, characterized by including: When the user equipment UE is switched from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node, and the first message at least includes instructions for indicating the Information about the sequence number of the data packet that the source access network control node failed to send to the UE;

The target access network control node determines, based on the first message, information about the sequence number of the data packet that was not successfully sent to the UE;

The target access network control node receives the data packet sent by the source access network control node that was unsuccessfully sent to the UE according to the first message;

After the UE is switched to the target access network, the target access network control node sends the data packet unsuccessfully sent to the UE to the UE according to the first message.

8. The method according to claim 7, characterized in that,

When the UE switches from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node, including:

When the UE switches from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node through the core network node.

9. The method according to claim 8, characterized in that,

The target access network control node receives the data packet sent by the source access network control node that was unsuccessfully sent to the UE according to the first message, including:

The target access network control node receives the data packet sent by the source access network control node that was unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message;

10. The method according to claim 9, characterized in that, before the target access network control node receives the first message sent by the source access network control node, it further includes:

The target access network control node sends a second message to the source access network control node through the core network node, where the second message includes indication information that the UE wants to switch to the target access network and /or send an indication of the information to forward the packet sequence number.

11. The method according to claim 9 or 10, characterized in that when the source access network is a wireless local area network (WLAN) network and the target access network is a 3rd Generation Partnership Project (3GPP) network;

When the UE switches from the source access network to the target access network, the target access network control node receives the first message sent by the source access network control node through the core network node, including:

The target access network control node receives the data packet sent by the source access network control node and unsuccessfully sent to the UE through the pre-established data forwarding tunnel according to the first message, including:

The base station receives the data packet sent by the WLAN network control node and unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message; or,

The WLAN network control node receives the data packet sent by the base station and unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message.

12. The method according to claims 7-11, characterized in that the sequence number information of the data packet includes any of the following forms:

Tunnel protocol sequence number The information corresponding to GTP-N; or,

Agent mobile IP serial number PMTP-SN corresponding information; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN.

13. A method of data transmission, characterized by including: When the user equipment UE is switched from the source access network to the target access network, the UE receives the data packet forwarded by the control node of the target access network that was unsuccessfully sent to the UE;

Wherein, the data packet unsuccessfully sent to the UE is a data packet that the source access network control node has not successfully sent to the UE when the UE switches from the source access network to the target access network. The data packet of the UE is sent by the source access network control node to the target access network control node.

14. An access network control node, characterized by: including:

The first sending unit is configured to send a first message to the target access network control node when the user equipment UE is switched from the source access network to the target access network, where the first message at least includes instructions for indicating the Information about the sequence number of the data packet that the source access network control node failed to send to the UE;

The second sending unit is configured to send the data packet unsuccessfully sent to the UE to the target access network control node, so that when the UE is switched to the target access network, the target access network The control node sends the data packet unsuccessfully sent to the UE to the UE.

15. The access network control node according to claim 14, characterized in that,

The first sending unit is specifically configured to send the first message to the target access network control node through the core network node when the UE switches from the source access network to the target access network.

16. The access network control node according to claim 15, characterized in that,

The second sending unit is specifically configured to send the data packet unsuccessfully sent to the UE to the target access network control node through a pre-established data forwarding tunnel;

17. The access network control node according to claim 16, further comprising:

a receiving unit configured to receive the second message sent by the target access network control node through the core network node before the first sending unit sends the first message to the target access network control node, The second message includes indication information that the UE intends to switch to the target access network and/or an indication of sending a sequence number of a forwarded data packet.

18. The access network control node according to claim 16 or 17, characterized in that, When the source access network is a WLAN network and the target access network is a 3GPP network;

The first sending unit is specifically used to send the first message to the base station through the core network node when the UE wants to switch to the 3GPP network;

The second sending unit is specifically configured to send data packets that are unsuccessfully sent to the UE to the base station through a pre-established data forwarding tunnel; or,

The first sending unit is specifically configured to send the first message to the WLAN network control node through the core network node when the UE wants to switch to the WLAN network;

The second sending unit is specifically configured to send the data packet unsuccessfully sent to the UE to the WLAN network control node through a pre-established data forwarding tunnel.

19. The access network control node according to any one of claims 14 to 18, characterized in that the information on the sequence number of the data packet includes any of the following forms:

Tunnel protocol sequence number The information corresponding to GTP-N; or,

Agent mobile IP serial number PMTP-SN corresponding information; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN.

20. An access network control node, characterized by including:

A receiving unit, configured to receive a first message sent by the source access network control node when the user equipment UE is switched from the source access network to the target access network, where the first message at least includes instructions for indicating the source access network. Information about the sequence number of the data packet that the access network control node failed to send to the UE;

The determining unit is configured to determine, based on the first message, the information about the sequence number of the data packet that was not successfully sent to the UE; the receiving unit is further configured to receive the source access network control based on the first message. Data packets sent by the node that were unsuccessfully sent to the UE;

A sending unit, configured to send the data packet unsuccessfully sent to the UE according to the first message to the UE after the UE is switched to the target access network.

21. The access network control node according to claim 20, characterized in that,

The receiving unit is specifically configured to receive the first message sent by the source access network control node through the core network node when the UE switches from the source access network to the target access network.

22. The access network control node according to claim 21, characterized in that,

The receiving unit is further specifically configured to receive a data packet sent by the source access network control node and unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message;

23. The access network control node according to claim 22, characterized in that,

The sending unit is further configured to send a second message to the source access network control node through the core network node, where the second message includes indication information that the UE wants to switch to the target access network and /or send an indication of the sequence number of the forwarded packet.

24. The access network control node according to claim 22 or 23, characterized in that,

When the source access network is a wireless local area network (WLAN) network and the target access network is a 3GPP network;

The receiving unit is specifically configured to receive the first message sent by the WLAN network control node through the core network node when the UE switches from the WLAN network to the 3GPP network;

The receiving unit is further specifically configured to receive a data packet sent by the WLAN network control node that is unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message; or,

The receiving unit is specifically configured to receive the first message sent by the base station through the core network node when the UE switches from the 3GPP network to the WLAN network;

The receiving unit is further specifically configured to receive a data packet sent by the base station and unsuccessfully sent to the UE through a pre-established data forwarding tunnel according to the first message.

25. The access network control node according to any one of claims 20 to 24, characterized in that the information on the sequence number of the data packet includes any of the following forms:

Tunnel protocol sequence number The information corresponding to GTP-N; or,

Agent mobile IP serial number PMTP-SN corresponding information; or,

Information corresponding to GTP-N and PMTP-SN; or,

Information corresponding to PDCP-SN and PMTP-SN.

26. A user equipment UE, characterized by: including:

A receiving unit configured to, after the user equipment UE is switched from the source access network to the target access network, receive the data packet forwarded by the target access network control node and unsuccessfully sent to the UE;

27. A data transmission system, characterized in that it includes a core network node, an access network control node according to any one of claims 14-19, and an access network control node according to any one of claims 20-25. node and the user equipment UE according to claim 26.

28. The system according to claim 27, characterized in that when the source access network is a wireless local area network (WLAN) network and the target access network is a 3rd Generation Partnership Project (3GPP) network;

The system specifically includes: the core network node, the UE, a WLAN network control node and a base station;

Wherein, the source access network control node is a WLAN network control node, and the target access network control node is a base station.

29. The system according to claim 27, characterized in that when the source access network is the third generation partnership project

3GPP network, when the target access network is a wireless local area network WLAN network;

The system specifically includes: the core network node, the UE, a WLAN network control node and a base station; wherein the source access network control node is a base station, and the target access network control node is a WLAN network control node.