WO2009152757A1

WO2009152757A1 - Data message sending method, apparatus and communication system

Info

Publication number: WO2009152757A1
Application number: PCT/CN2009/072289
Authority: WO
Inventors: 周青; 银宇; 胡颖
Original assignee: 华为技术有限公司
Priority date: 2008-06-16
Filing date: 2009-06-16
Publication date: 2009-12-23
Also published as: CN101610462A; CN101610462B

Abstract

A data message sending method, apparatus and communication system used for a user terminal to shift between networks. The method comprises: sending a protocol context request to a data receiving node when a data tunnel is unused; receiving the protocol context response sent by the data receiving node that responding to the protocol context request, the protocol context response including usable data tunnel information; sending data messages to the data receiving node through the usable data tunnel.

Description

Data message sending method, device and communication system

This application claims priority to Chinese Patent Application No. 200810099683.5, entitled "A Data Packet Transmission Method, Apparatus, and Communication System", filed on June 16, 2008, the entire contents of which are incorporated by reference. Combined in this application.

Technical field

The present invention relates to the field of communications technologies, and in particular, to a data message sending method, apparatus, and communication system.

Background technique

With the development of telecommunication technology, the mobile packet network is developed from the 3rd generation (3G: the 3rd generation) network to the Evolved Packet System (EPS) network. The core network of the mobile packet network is also traditional wireless. The GPRS (General Packet Radio Service) network is developed to the Evolved Packet Core (EPC), which includes the Mobility Management Entity (MME) and the Serving Gateway (SGW: Serving GW) and Public Data Network Gateway (PGW: PDN GW). The MME and the SGW are located on the same Public Land Mobile Network (PLMN) network, and the interface between them is S11. The SGW and the PGW may be located on the same network or on different PLMN networks. If the SGW and the PGW are located in the same PLMN network, for example, the UE is located in the home network, the interface between them is the S5 interface; if the SGW and the PGW are located in different PLMN networks, for example, the user equipment (UE: User Equipment) is located in the visited network, through the attribution The Home Routed mode is routed to the home network, and the interface between them is the S8 interface. The protocol of the S5 interface and the S8 interface may be a general packet radio service channel protocol (GTP: GPRS Tunnel Protocol) or a proxy mobile IP (PMIP: Proxy Mobile IP) protocol.

The MME needs to save the GTP or PMIP protocol context between the SGW and the PGW, such as the tunnel endpoint identifier (TEID: Tunnel Endpoint Identifier), the channel endpoint identifier and the data allocated by the PGW under the GTP protocol for the SGW to send the uplink data. The channel is - correspondingly, when the endpoint identifier of the channel is known, the corresponding data channel for the SGW to send the uplink data packet can be uniquely determined, and the data channel can be an available data channel or an unavailable data channel; or The GRE Key: Generic Routing Encapsulation Key (GRE Key) for the SGW to send uplink data packets, which is allocated by the PGW under the PMIP protocol, and the general routing encapsulation keyword and The data channel is - correspondingly, when the general routing encapsulation keyword is known, the corresponding data channel for the SGW to send the uplink data packet can be uniquely determined, and the data channel can be an available data channel or unavailable data. aisle. Normally, after the GTP or PMIP protocol context is allocated by the PGW, the SGW is notified, and the SGW notifies the MME. In the case of implementing the PMIP and GTP protocol conversion by using the interworking node, the GTP or PMIP protocol context is allocated by the IWP, the IWP notifies the SGW, and the SGW notifies the MME again; when the user terminal is in a different visited public land mobile network (VPLMN) When moving between, the MME (source MME) in the source VPLMN network sends the protocol context assigned by the saved interworking proxy (IWP: Interworking Proxy) to the MME (target MME) in the target VPLMN network, and the target MME transmits the above information to the target VPLMN network. The medium SGW (target SGW), the target SGW will send the uplink data message using the protocol context information obtained from the MME.

In the process of implementing the present invention, the inventors have found that: when the interworking node implements the PMIP and GTP protocol conversion, when the user terminal moves from a GTP VPLMN network to another GTP VPLMN network, or from a PMIP VPLMN When the network moves to the VPLMN network of another PMIP, the IWP used by the user terminal may not be the same. If the SGW sends the uplink data, the new IWP does not recognize the GRE Key or TEID in the protocol context saved by the MME. The protocol context saved by the MME is unavailable, and the uplink data packet transmission fails.

Summary of the invention

The embodiment of the invention provides a data message sending method, a device and a communication system, which can correctly send an uplink data message when the saved protocol context is unavailable.

The embodiment of the invention provides a data packet sending method, which is applied to switch between network terminals of a user terminal, and includes:

Sending a protocol context request to the data receiving node when the data channel is unavailable;

Receiving a protocol context response sent by the data receiving node in response to the protocol context request, the protocol context response including information of available data channels;

Transmitting a data message to the data receiving node through the available data channel.

The embodiment of the invention further provides a data message sending device, which is applied to the switching of the user terminal between networks, and includes: a request sending unit, configured to send a protocol context request to the data receiving node when the data channel is unavailable;

a response receiving unit, configured to receive a protocol context response sent by the data receiving node in response to the protocol context request, where the protocol context response includes information of available data channels, and a message sending unit, configured to pass the available The data channel sends a data message to the data receiving node.

The embodiment of the invention further provides a data message sending system, including:

a first mobility management node, configured to send information that is unavailable to the data channel when determining that the data channel is unavailable;

a second mobility management node, configured to receive information that the data channel sent by the first mobility management node is unavailable, construct and send a data channel unavailable indication, where the data channel unavailable indication includes that the data channel is unavailable Information;

a data message sending device, configured to receive a data channel unavailability indication; after receiving the data channel unavailability indication, sending a protocol context request; receiving a protocol context response responsive to the protocol context request, where the protocol context response includes Information of available data channels; transmitting data messages through the available data channels;

And a data message receiving device, configured to receive the protocol context request, send the protocol context response, and receive the data message.

Serving a general wireless packet service support node, configured to send information that the data channel is unavailable when it is determined that the data channel is unavailable;

a mobility management node, configured to receive information that the data channel sent by the serving universal wireless packet service support node is unavailable, construct and send a data channel unavailable indication, where the data channel unavailable indication includes that the data channel is unavailable Information

a data message receiving device, configured to receive the protocol context request; send the protocol context Responding; receiving the data message.

a mobility management node, configured to construct and send a data channel unavailable indication when determining that the data channel is unavailable, where the data channel unavailable indication includes information that the data channel is unavailable;

It can be seen from the foregoing technical solutions provided by the embodiments of the present invention that, when the data channel is unavailable, that is, the saved protocol context is unavailable, the protocol context request may be sent to obtain information about the available data channel, and then the information may be available. The data channel sends a data packet, which prevents the uplink data from being sent incorrectly, and ensures that the uplink data packet is correctly sent when the saved protocol context is unavailable.

DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly described below. Obviously, the drawings in the following description For some embodiments of the present invention, other drawings may be obtained from those skilled in the art without departing from the drawings.

1 is a flowchart of Embodiment 1 of a method for sending a data packet according to an embodiment of the present invention;

2 is a signaling flowchart of Embodiment 2 of a data packet sending method according to an embodiment of the present invention; FIG. 3 is a signaling flowchart of Embodiment 3 of a data packet sending method according to an embodiment of the present invention;

6 is a signaling flowchart of Embodiment 6 of a data packet sending method according to an embodiment of the present invention; FIG. 7 is a structural diagram of Embodiment 1 of a data packet sending apparatus according to an embodiment of the present invention;

FIG. 8 is a structural diagram of Embodiment 2 of a data packet sending apparatus according to an embodiment of the present invention;

FIG. 9 is a structural diagram of Embodiment 1 of a data packet sending system according to an embodiment of the present invention; FIG. 10 is a structural diagram of Embodiment 2 of a data packet sending system according to an embodiment of the present invention; FIG. 11 is a structural diagram of Embodiment 3 of a data packet sending system according to an embodiment of the present invention.

detailed description

BRIEF DESCRIPTION OF THE DRAWINGS The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention.

The data packet sending method provided by the embodiment of the present invention is applied to the user terminal to switch between networks. FIG. 1 is a flowchart of the first embodiment of the data packet sending method, including:

Step 101: Send a protocol context request when the data channel is unavailable;

The data sending node can learn that the data channel is unavailable through information sent by other nodes, for example, as sent by the MME; or it can detect whether the data channel is available by itself, and can send information requesting reply through the data channel, and if the reply is received, the data channel is available. Conversely, the data channel is not available;

In the embodiment of the present invention, the data sending node may receive the data channel unavailability indication that the acquiring data channel is unavailable, wherein the data channel unavailability indication that the data channel included in the data channel is unavailable, the data sending node may learn that the data channel is unavailable; the data channel is unavailable. The corresponding protocol context that is saved is not available; the indication may be specifically sent by the target MME, which is the MME in the network to which the user terminal switches. The target MME may send a data channel unavailability indication when it determines that the data channel is unavailable; or the target MME receives the data channel from the source MME or the source service general WLAN support node (SGSN: Serving GPRS Support Node) is unavailable. After the information, the sending data channel is unavailable. The source MME is the MME in the network before the user terminal switches, and the source SGSN is the SGSN in the network before the user terminal switches. In the embodiment of the present invention, the data sending node may be a target SGW. The data channel in the embodiment of the present invention may be an uplink data channel, and the corresponding data channel unavailable indication is an indication that the uplink data channel is unavailable.

Specifically, the source MME, or the source SGSN, or the target MME may deploy the IWP according to the source VPLMN network, and currently the inter-PLMN handover occurs, determining that the uplink data channel is unavailable, or the PMIP protocol and the GTP protocol are generated according to the mobile user. Switch between, determine the uplink data When the corresponding scene appears, it can be determined that the uplink data channel is unavailable.

The data channel unavailable indication may be an indication of display, for example, adding a new message as a data channel unavailable indication, or adding a parameter passing data channel unavailable indication in the existing information; the data channel unavailable indication may also It is an implicit indication. For example, the GRE Key or TEID can be set to an invalid value of 0, or all digits of the binary representation, indicating that the uplink data channel is unavailable, or not carrying the TEID or GRE Key, indicating that the uplink data channel is unavailable.

When the data sending node is unavailable, the protocol context request sent may be a newly added message or an existing message. In the embodiment of the present invention, the preferred protocol context request is an existing message; The protocol context request may be different, for example, it may be a bearer update request or a bearer creation request in the GTP protocol, or a PBU (Proxy Binding Update) request in the PMIP protocol.

Step 102: Receive a protocol context response that responds to a protocol context request, where the protocol context response includes information of available data channels;

The protocol context response received by the data sending node may be sent by the data receiving node. The information of the available data channel in the protocol context response may be a protocol context, such as a TEID under the GTP protocol or a GRE key under the PMIP protocol. The protocol context response corresponds to the protocol context request, and may be a bearer update response or a bearer creation response in the GTP protocol, or a proxy binding acknowledgement (PB A: Proxy Binding Acknowledge) message in the PMIP protocol, where the data receiving node It can be PGW, new IWP, etc.

Step 103: Send a data packet through an available data channel.

After receiving the protocol context response, the data sending node may determine the available data channel according to the information of the available data channel, and then send the data packet to the data receiving node through the available data channel, where the data packet is received by the data sending node. Data packets into the network.

As can be seen from the above, when the data channel is unavailable, that is, when the saved protocol context is unavailable, the protocol context can be sent to obtain the information of the available data channel, and then the data packet can be sent through the available data channel, thereby preventing the uplink. The data is sent incorrectly, ensuring that the upstream data message is sent correctly when the saved protocol context is not available.

Further, in order to enable the system resources to be effectively utilized, the data packet transmission may be closed before the protocol request is sent, thereby reducing the resources required for the data transmitting device to send the data packet. It is also possible to prevent data packets from being sent to the wrong data receiving node.

If the data packet transmission is disabled, the data packet transmission can be enabled after receiving the protocol context response, so that the data sending node can send data packets through the available data channel to ensure the correct operation of the system.

Further, in order to make the data packet received by the data receiving node as correct as possible, when the data packet is sent off, the received data packet can be buffered, so that after the data packet is sent, the available data channel can be used. The buffered data packet is sent to the data receiving node. When the user terminal switches between the GTP network and the GTP network, the processing flow when the protocol context of the MME is incorrect is changed due to the change of the IWP. The specific signaling process is as shown in Figure 2, including:

Step 201: The source evolved base station (eNodeB) determines that the UE needs to initiate a handover, and sends a Handover Required message to the source MME, requesting to switch from the GTP network to which the UE belongs to the target visited GTP network, where the handover may also be The access network switches to the home network, or switches from one visited network to another, and the subsequent embodiment is similar. Step 202: The source MME sends a Forward Relocation Request message to the target MME, where the forwarding location update request is sent. The message carries the protocol context information saved by the MME, including the user plane address of the PGW, the TEID of the PGW, and the SGW user plane address allocated by the source SGW for downlink data transmission, and the downlink TEID;

The source MME may determine whether the uplink data channel is available before sending the forwarding location update request message. If the source MME determines that the source VPLMN network deploys the IWP and the inter-PLMN handover occurs, the uplink data channel may be considered as unavailable; The uplink data channel may be unavailable according to other reasons. For example, if the source MME has a board switching, the TEID of the saved PGW fails after the board is switched, and the uplink data channel is also unavailable.

When the source MME determines that the uplink data channel is unavailable, the source MME may carry an uplink data channel unavailability indication in the forwarding location update request message, and the uplink data channel unavailability indication may be an explicit indication, and may be in the forwarding location update request message. The extension of a specific parameter, such as the uplink available (UL_Bearer_Valid) parameter, is used to pass the uplink data channel unavailability indication. The value of 1 indicates that the uplink data channel can be directly used, and the value of 0 indicates that the uplink data channel is unavailable; The uplink data channel unavailability indication may also be an implicit indication. For example, the TEID may be set to an invalid value of 0, or the binary representation of all 1s, indicating that the uplink data channel is unavailable, etc., and the embodiment of the present invention does not limit the uplink data channel. The specific form of indication of the unavailable indication;

Step 203: The target MME sends a Create Bearer Request message to the target SGW, where the Create Bearer Request message carries the protocol context information received from the source MME, including the user plane address of the PGW, the TEID of the PGW, and the source SGW. The allocated SGW user plane address for downlink data transmission, the downlink TEID, Handover indication;

If the source MME does not send the uplink data channel unavailability indication, the target MME may determine whether the uplink data channel is available before sending the foregoing create bearer request message. If the target VPLMN network deploys the IWP and the inter-PLMN handover occurs, the uplink may be considered as uplink. The data channel is unavailable, or the uplink data channel unavailability indication is included in the forwarding location update request message received from the source MME, and the uplink data channel is considered unavailable;

When the target MME determines that the uplink data channel is unavailable, the target MME may carry the uplink data channel unavailability indication in the foregoing create bearer request message, which may be an explicit indication, such as extending a specific parameter in the create bearer request message. The upper row carries the available parameters to transmit the uplink data channel unavailability indication. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. The indication may also be an implicit The indication, such as by setting TEID to an invalid value of 0, or all 1s in binary, indicates that the upstream data channel is unavailable;

Step 204: The target SGW closes the uplink data transmission. At this time, the target SGW does not receive the uplink data packet from the UE because the UE has not switched.

Step 205: The target SGW sends a create bearer request message to the PGW. In this embodiment, the create bearer request message from the MME carries the uplink data channel unavailability indication, indicating that the uplink data channel is not established. Upon completion, the target SGW sends a create bearer request message to the PGW;

The target SGW may include the following information in the create bearer request message:

The SGW user plane address and the downlink TEID for downlink data transmission, which are received by the source SGW, are used in the step 203, and are used for downlink data transmission;

The identification information of the user may be an international mobile subscriber identity (IMSI International Mobile) Subscriber Identifier), or IMSI and Network Service Access Point Identifier (NSAPI: Network Service Access Point Identifier. or IMSI and Access Point Name (APN): The above information can be created from the MME in step 203. The request to obtain the bearer request may further include the information for the uplink data transmission in the protocol context obtained in step 203, including the user plane address of the PGW, and the TEID of the PGW;

Since the IWP is introduced to implement interworking between the networks, the above-mentioned create bearer request is forwarded to the IWP by the IP network, and the IWP forwards the bearer request message to the PGW. If the protocol other than GTP is adopted between the IWP and the PGW, the IWP will perform corresponding Protocol conversion.

The PGW responds to the created bearer request or other protocol-converted message forwarded by the IWP, and the IWP receives the response message from the PGW;

Step 206: The IWP allocates the PGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the uplink data transmission, and the IWT sends a Create Bearer Response message to the target SGW, where the created bearer response message carries the above The PGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the uplink data transmission;

Step 207: The target SGW obtains, from step 206, the PGW user plane address of the GTP bearer between the target SGW and the PGW allocated by the IWP, and the TEID of the uplink data transmission. At this time, the uplink message can be sent, so the target SGW opens the uplink 4艮. Send the text. Receiving the node; the following steps further ensure that the data message can be transmitted through the corresponding downlink data channel;

Step 208: The target SGW allocates an SGW user plane address and a TEID for the uplink data transmission between the evolved base station and the target SGW, and sends a create bearer response message to the target MME, where the created bearer response message carries the target SGW allocation evolution. S1 carries the SGW user plane address and TEID for uplink data transmission between the base station and the target SGW;

Step 209: The target MME sends a handover request (Handover Request) message to the target evolved base station, where the handover request message carries the S1 user that is used for uplink data transmission between the evolved base station and the target SGW received from the target SGW in step 208. Face address and TEID;

Step 210: The target evolved base station allocates an S1 bearer between the evolved base station and the target SGW for downlink data transmission TEID (SI downlink TEID), and the target evolved base station sends a handover request to the target MME. The Handover Request Ack message carries the S1 downlink TEID information in the handover request acknowledgement message.

Step 211: The target sends a create bearer request to the target SGW, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 212: The target SGW sends a create bearer response to the target MME, and is used to establish a GTP bearer for forwarding downlink data packets between the source SGW and the target SGW.

Step 213: The target ΜΜΕ sends a Forwarding Location Update Response (Forward Relocation Response) message to the source ΜΜΕ, where the forwarding location update response message carries the downlink data between the source SGW and the target SGW allocated by the target SGW in steps 211 and 212. 4艮GTP bearer information;

Step 214: The source MME sends a create bearer request message to the source SGW, where the source MME sends a GTP bearer that forwards the downlink data packet between the source SGW and the target SGW.

Step 215: The source SGW sends a create bearer response message to the source MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 216: The source MME sends a Handover Command message to the source evolved base station.

Step 217: The source evolved base station sends a handover command message to the user terminal UE.

Step 218: The UE initiates handover, is separated from the source eNodeB, and is attached to the target eNodeB.

Step 219: The UE sends a Handover Confirm message to the target evolved base station. At this time, the target evolved base station can forward the downlink packet to the UE.

The uplink data sent by the UE is sent to the target SGW through the target evolved base station; since the target SGW has obtained the correct protocol context from the IWP in step 206, the target SGW opens the uplink packet transmission in step 207. Therefore, the target SGW will forward the uplink packet to the IWP, and the IWP will forward the uplink data to the PGW;

Step 220: The target evolved base station sends a Handover Notify message to the target MME.

Step 221, the target MME sends a Forward Location Update (Forward Relocation Complete) message to the source MME; Step 222: The source MME sends a Forward Relocation Complete Ack message to the target MME.

Step 223: The target MME sends an update bearer request message (Update Bearer Request) to the target SGW, where the update bearer request message carries the S1 downlink TEID information allocated by the target evolved base station in step 210;

Step 224: The target SGW allocates the SGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the downlink data transmission, and the target SGW sends an update bearer request message to the PGW, where the update bearer request message carries the target SGW and the PGW. The SGW user plane address carried by the GTP, and the TEID of the downlink data transmission;

Since the IWP is introduced to implement interworking between the networks, the update bearer request is forwarded by the IP network to the IWP, and the IWP forwards the update bearer request message to the PGW. If an agreement other than GTP is adopted between the IWP and the PGW, the IWP will perform corresponding Protocol conversion.

The PGW responds to the update bearer request or other protocol-converted message forwarded by the IWP, and the IWP will receive the response message from the PGW; in step 225, the IWP sends an Update Bearer Response message to the target SGW;

Step 226: The target SGW sends an update bearer response message to the target MME.

As shown in the above, in the embodiment, when the MME determines that the uplink data channel is unavailable, the MME transmits the uplink data channel unavailability indication to the target SGW. After the target SGW obtains the foregoing indication, the MME sends the Create Bearer Request message after obtaining the true protocol context from the PGW. When the uplink data transmission is enabled, the uplink data can be prevented from being sent incorrectly, and the uplink data packet can be correctly sent when the saved protocol context is unavailable. When the user terminal switches between the GTP network and the GTP network, the processing flow of the protocol context is incorrect due to the change of the IWP. The specific signaling process is as shown in Figure 3, including:

Before the handover, both the downlink data packet and the downlink data packet are sent and received by the source evolved base station, the source SGW, and the PGW.

Step 301: The source evolved base station determines that the UE needs to initiate a handover, and sends a handover request request message to the source MME, requesting to switch from the GTP network to which the UE belongs to the target visited GTP network. Step 302: The source MME sends a forwarding location update request message to the target MME, where the forwarding location update request message carries the protocol context information saved by the MME, including the user plane address of the PGW, and the TEID of the PGW.

When the source MME determines that the uplink data channel is unavailable, the source MME may carry an uplink data channel unavailability indication in the forwarding location update request message, and the uplink data channel unavailability indication may be an explicit indication, and may be in the forwarding location update request message. The extension of a specific parameter, such as the uplink bearer available parameter, is used to pass the uplink data channel unavailability indication. The value of 1 indicates that the uplink data channel can be directly used, and the value of 0 indicates that the uplink data channel is unavailable; the uplink data channel The unavailability indication may also be an implicit indication. For example, the TEID may be set to an invalid value of 0, or the binary representation of all 1s, indicating that the uplink data channel is unavailable, etc., and the embodiment of the present invention does not limit the uplink data channel unavailability indication. Specific form of expression;

Step 303: The target MME sends a create bearer request message to the target SGW, where the create bearer request message carries the protocol context information received from the source MME, including the user plane address of the PGW, and the TEID of the PGW.

When the target MME determines that the uplink data channel is unavailable, the target MME may carry an uplink data channel unavailability indication in the foregoing create bearer request message, and the uplink data channel unavailability indication may be an explicit indication, such as expanding in creating a bearer request message. A specific parameter, such as an uplink bearer available parameter, is used to transmit an indication that the uplink data channel is unavailable. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. Can Either an implicit indication, such as by setting TEID to an invalid value of 0, or a binary representation of all 1s, indicating that the upstream data channel is not available;

Step 304: The target SGW allocates an SGW user plane address and a TEID for uplink data transmission between the evolved base station and the target SGW, and sends a create bearer response message to the target MME, where the created bearer response message carries the target SGW allocation evolution. S1 carries the SGW user plane address and TEID for uplink data transmission between the base station and the target SGW;

Step 305: The target MME sends a handover request message to the target evolved base station, where the handover request message carries the SGW user plane address used for uplink data transmission between the evolved base station and the target SGW received from the target SGW in the previous step. TEID;

Step 306: The target evolved base station allocates an S1 bearer between the evolved base station and the target SGW for the downlink data transmission TEID (SI downlink TEID), and the target evolved base station sends a handover request acknowledgement message to the target MME, where the handover request acknowledgement message carries the foregoing S1 Downstream TEID information.

Step 307: The target MME sends a create bearer request to the target SGW, and is used to establish a GTP bearer for forwarding downlink data packets between the source SGW and the target SGW.

Step 308: The target SGW sends a create bearer response to the target MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 309: The target MME sends a forwarding location update response message to the source MME, where the forwarding location update response message carries the GTP bearer that is used by the target SGW to forward the downlink data packet between the source SGW and the target SGW in steps 307 and 308. Information

Step 310: The source MME sends a create bearer request message to the source SGW, where the source MME sends a GTP bearer that forwards the downlink data packet between the source SGW and the target SGW.

Step 311: The source SGW sends a create bearer response message to the source MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 312: The source MME sends a handover command message to the source evolved base station.

Step 313: The source evolved base station sends a handover command message to the user terminal UE.

The uplink data packet sent by the UE is sent to the source PGW through the source evolved base station and the source SGW.

The PGW is sent to the source evolved base station, and the source evolved base station forwards to the target evolved base station, and the target evolved base station buffers the downlink data packet; Step 314: The UE initiates handover, is separated from the source eNodeB, and is attached to the target eNodeB.

Step 315: The UE sends a handover confirmation message to the target evolved base station.

At this time, the target evolved base station may forward the downlink message to the user terminal UE;

The uplink data sent by the UE is sent to the target SGW through the target evolved base station; Step 316: The target SGW closes the uplink data transmission, and buffers the received uplink data packet. Because the target SGW receives the target MME from the target MME in step 303. The uplink data channel unavailability indication, that is, the user plane address of the PGW and the TEID of the PGW included in the protocol context information received by the target SGW may be incorrect. Therefore, the target SGW does not send the uplink data packet to the PGW;

The target SGW may discard or buffer the received uplink data packet.

Step 317: The target evolved base station sends a handover notification message to the target MME.

Step 318: The target MME sends a forwarding location update complete message to the source MME.

Step 319: The source MME sends a forwarding location update completion confirmation message to the target MME.

Step 320: The target MME sends an update bearer request message to the target SGW, where the update bearer request message carries the S1 downlink TEID information allocated by the target evolved base station in step 306;

Step 321: The target SGW allocates an SGW user plane address of the GTP bearer between the target SGW and the PGW, and a TEID of the downlink data transmission, and the target SGW sends an update bearer request message to the PGW, where the update bearer request message carries the target SGW and the PGW. The SGW user plane address between the GTP bearers and the TEID of the downlink data transmission.

In step 303, the target SGW receives the uplink data channel unavailability indication from the target MME, that is, the protocol context information received by the target SGW includes the user plane address of the PGW and the TEID of the PGW, which may be incorrect, and therefore, the target SGW The format of the update bearer request message sent to the PGW can be as follows:

The destination address of the IP layer is the PGW address, and the address may be delivered by the MME to the target SGW in step 303;

The TEID in the GTP protocol header is filled in with 0, indicating that the destination TEID is undefined;

The update bearer request message includes an SGW user plane address of the GTP bearer between the target SGW and the target SGW, and a TEID of downlink data transmission; The further update bearer request further includes the identifier information of the user, such as the IMSI+NS API, the IMSI+APN, and the foregoing information may be obtained in the create bearer request message sent by the MME in step 303;

The update bearer request message may further include the protocol context information obtained in step 303, including the user plane address of the PGW and the TEID of the PGW.

The target SGW may also send a create bearer request message Create Bearer Reuqest to the PGW, and the following information is included in the create bearer request:

The target SGW allocates the SGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the downlink data transmission;

The identification information of the user, such as IMSI+NSAPI, IMSI+APN, may be obtained in the Create Bearer Request message sent by the MME in step 303.

The request to create the bearer may further include the protocol context information obtained in step 303, including the user plane address of the PGW and the TEID of the PGW.

The IWP is introduced to implement the interworking between the networks. The update bearer request or the create bearer request is forwarded by the IP network to the IWP. The IWP forwards the update bearer request or creates a bearer request message to the PGW. If the IWP and the PGW are other than the GTP. For other agreements, the IWP will perform the corresponding protocol conversion.

The PGW responds to the update bearer request forwarded by the IWP, or creates a bearer request, or other protocol-converted message, and the IWP receives the response message from the PGW. Step 322: The IWP allocates the PGW user plane address of the GTP bearer between the target SGW and the PGW. And the TEID of the uplink data transmission, the IWP sends an update bearer response message to the target SGW, where the update bearer response message carries the PGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the uplink data transmission.

If the target SGW sends a create bearer request to the IWP, the IWP sends a bearer response to the target SGW, and the created bearer response message carries the PGW user plane address of the GTP bearer between the target SGW and the PGW, and the TEID of the uplink data transmission.

Step 323: The target SGW sends an update bearer response message to the target MME.

Step 324: The target SGW obtains, from step 322, the PGW user plane address of the GTP bearer between the target SGW and the PGW allocated by the IWP, and the TEID of the uplink data transmission, which can be sent. The packet is sent, so the target SGW sends the uplink packet to the IGW, and forwards the uplink data packet received from the UE to the IWP according to the PGW user plane address of the GTP bearer between the target SGW and the PGW and the TEID of the uplink data transmission. And sending the buffered uplink data packet to the IWP, the IWP will forward the uplink data packet to the PGW;

Wherein, step 323 and step 324 have no sequential relationship;

As shown in the above, in the embodiment, when the MME determines that the uplink data channel is unavailable, the MME transmits an uplink data channel unavailability indication to the target SGW. After receiving the indication, the target SGW closes the uplink data transmission, buffers the received uplink data, and the target SGW obtains the uplink data from the PGW. After the real protocol context, the uplink data transmission is opened and the buffered uplink data is sent, so that the uplink data is prevented from being sent incorrectly, and the uplink data packet is correctly sent when the saved protocol context is unavailable. When the user terminal switches between the PMIP network and the PMIP network, the processing flow when the protocol context of the MME is incorrect is changed due to the change of the IWP. The specific signaling process is as shown in Figure 4, including:

Step 401: The source evolved base station determines that the UE needs to initiate the handover, and sends a handover request request message to the source MME, requesting to switch from the PMIP network to which the UE belongs to the target visited PMIP network. Step 402: The source MME sends a forwarding location update request message to the target MME. The forwarding location update request message carries the protocol context information saved by the MME, including an LMA address of the PGW for uplink data transmission, a GRE Key of the tunnel between the PGW and the source SGW allocated by the PGW, and a downlink data transmission. The MAG address of the source SGW, the GRE Key of the tunnel between the PGW and the source SGW allocated by the source SGW;

The source MME may determine whether the uplink data channel is available before sending the forwarding location update request message. If the IVP is deployed on the source VPLMN network, and the inter-PLMN handover occurs, the uplink data channel may be considered as unavailable, or the source MME may be over-sold. If the source MME determines that the uplink data channel is unavailable, the source MME can carry the information in the forwarding location update request message. The MME fails to perform the CRC check after the switchover of the saved PGW. The uplink data channel unavailability indication, the uplink data channel unavailability indication may be an explicit indication, such as extending a specific parameter in the forwarding location update request message, and carrying the available parameters as above, to deliver the uplink data channel unavailability indication, The value of 1 indicates the uplink data channel Can be used directly, the value of 0 means that the uplink data channel is not available; the upstream data channel unavailability indication can also be an implicit indication, such as by setting the GRE Key to an invalid value of 0, or the binary representation of all 1s, indicating uplink Data channel is not available;

Step 403: The target MME sends a create bearer request message to the target SGW, where the create bearer request message carries protocol context information received from the source MME, including an LMA address of the PGW for uplink data transmission, a PGW and a source SGW allocated by the PGW. The GRE Key of the tunnel between the GRE Key of the tunnel and the source SGW for downlink data transmission, and the GRE Key, Handover indication of the tunnel between the PGW and the source SGW allocated by the source SGW;

When the target MME determines that the uplink data channel is unavailable, the target MME may carry an uplink data channel unavailability indication in the foregoing create bearer request message, and the uplink data channel unavailability indication may be an explicit indication, such as expanding in creating a bearer request message. A specific parameter, such as an uplink bearer available parameter, is used to transmit an indication that the uplink data channel is unavailable. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. Can be an implicit indication, such as by setting the GRE Key to an invalid value of 0, or a binary representation of all 1s, indicating that the upstream data channel is not available;

Step 404: The target SGW closes the uplink data transmission. At this time, the target SGW does not receive the uplink data packet from the UE because the UE has not switched.

Step 405: The target SGW sends a Proxy Binding Update message to the PGW.

Since the create bearer request message from the MME carries the Handover indication, and carries the uplink data channel unavailability indication, indicating that the uplink data channel is not established, the target SGW sends a proxy binding update message to the PGW.

The target SGW can include the following information in the proxy binding update message:

The MAG of the SGW for downlink data transmission allocated from the source SGW received in step 403 Address, downlink GRE Key, used for downlink data transmission;

The information of the user, such as IMSI+NSAPI, IMSI+APN, may be obtained in the Create Bearer Request message sent by the MME in step 403.

Further, the proxy binding update may further include the GRE key of the tunnel between the PGW and the source SGW allocated by the PGW obtained in step 403.

Since the IWP is introduced to implement interworking between networks, the above proxy binding update message is forwarded to the IWP by the IP network, and the IWP forwarding proxy binds the update message to the PGW. If an agreement other than PMIP is adopted between the IWP and the PGW, the IWP will Perform the corresponding protocol conversion.

The PGW responds to the proxy binding update message forwarded by the IWP or other protocol-converted message, and the IWP receives the response message from the PGW;

Step 406: The IWP allocates a GRE key of the tunnel between the target SGW and the PGW, and the IWP sends a Proxy Binding Ack message to the target SGW, where the proxy binding acknowledgement message carries the tunnel between the target SGW and the PGW. GRE Key;

Step 407: The target SGW obtains the GRE key of the tunnel between the target SGW and the PGW that is allocated by the IWP, and the uplink STP is sent by the target SGW.

Step 408: The target SGW allocates an SGW user plane address and a TEID for the uplink data transmission between the evolved base station and the target SGW, and sends a create bearer response message to the target MME, where the created bearer response message carries the target SGW allocation evolution. S1 carries the SGW user plane address and TEID for uplink data transmission between the base station and the target SGW;

Step 409: The target MME sends a handover request message to the target evolved base station, where the handover request message carries the SGW user plane address used for uplink data transmission between the evolved base station and the target SGW received from the target SGW in the previous step. TEID;

Step 410: The target evolved base station allocates an S1 bearer between the evolved base station and the target SGW for the downlink data transmission TEID (SI downlink TEID), and the target evolved base station sends a handover request acknowledgement message to the target MME, where the handover request acknowledgement message carries the foregoing S1 Downstream TEID information.

Step 411: The target MME sends a create bearer request to the target SGW, and is used to establish a GTP bearer for forwarding downlink data packets between the source SGW and the target SGW.

Step 412: The target SGW sends a create bearer response to the target MME, where the source SGW is established. And forwarding the GTP bearer of the downlink data packet with the target SGW;

Step 413: The target MME sends a forwarding location update response message to the source MME, where the forwarding location update response message carries the GTP bearer that is used by the target SGW to forward the downlink data packet between the source SGW and the target SGW in steps 411 and 412. Information

Step 414: The source MME sends a create bearer request to the source SGW, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 415: The source SGW sends a create bearer response to the source MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 416: The source MME sends a handover command message to the source evolved base station.

Step 417: The source evolved base station sends a handover command message to the user terminal UE.

Step 418: The UE initiates a handover, is separated from the source eNodeB, and is attached to the target eNodeB.

Step 419: The UE sends a handover confirmation message to the target evolved base station.

At this time, the target evolved base station may forward the downlink packet to the UE;

The uplink data sent by the UE is sent to the target SGW through the target evolved base station; since the target SGW has obtained the correct protocol context from the IWP in step 406, the target SGW opens the uplink packet transmission in step 407. Therefore, the target SGW will forward the uplink packet to the IWP, and the IWP will forward the uplink data to the PGW;

Step 420: The target evolved base station sends a handover notification message to the target MME.

Step 421: The target MME sends a forwarding location update complete message to the source MME.

Step 422: The source MME sends a forwarding location update completion confirmation message to the target MME.

Step 423: The target MME sends an update bearer request to the target SGW, where the update bearer request message carries the S1 downlink TEID information allocated by the target evolved base station in step 410.

Step 424: The target SGW allocates a GRE key of the tunnel between the target SGW and the PGW, and the target SGW sends a proxy binding update message to the PGW. The proxy binding update message carries the GRE key of the tunnel between the target SGW and the PGW.

Since the IWP is introduced to implement interworking between networks, the above proxy binding update message is forwarded to the IWP by the IP network, and the IWP forwarding proxy binds the update message to the PGW. If an agreement other than PMIP is adopted between the IWP and the PGW, the IWP will Perform the corresponding protocol conversion. The PGW responds to the proxy binding update message forwarded by the IWP or other protocol-converted message, and the IWP receives the response message from the PGW;

Step 425: The IWP sends a proxy binding message confirmation message to the target SGW.

Step 426: The target SGW sends an update bearer response message to the target MME.

In this embodiment, the PBU message obtaining protocol context information may not be sent to the PGW in steps 405 and 406, but the PBU message protocol context information is sent to the PGW in steps 424 and 425. Therefore, the target SGW needs to open the uplink data transmission after receiving the PBA response in step 425. At this time, the target SGW needs to buffer the received uplink data packet.

As shown in the above, in the embodiment, when the MME determines that the uplink data channel is unavailable, the MME transmits an uplink data channel unavailability indication to the target SGW, and the target SGW closes the uplink data transmission after receiving the foregoing indication, and obtains the update message from the PGW by sending a proxy binding update message. After the real protocol context is opened, the uplink data transmission is opened, so that the uplink data is prevented from being sent incorrectly, and the uplink data packet is correctly sent when the saved protocol context is unavailable. When the user terminal switches from the GTP network to the PMIP network, the protocol used by the S8 interface changes, resulting in a process flow when the protocol context of the MME is incorrect. In this embodiment, the target SGW and the PGW can pass the IWP. The specific signaling process of this embodiment is as shown in FIG. 5, and includes:

Step 501: The source evolved base station determines that the UE needs to initiate a handover, and sends a handover request message to the source MME, requesting to switch from the GTP network to which the UE belongs to the target visited PMIP network.

Step 502: The source MME sends a forwarding location update request message to the target MME, where the forwarding location update request message carries the protocol context information saved by the MME, and the protocol context information saved by the MME includes the user plane address of the PGW, and the TEID of the PGW. ;

The source MME may determine whether the uplink data channel is available before transmitting the forwarding location update request message. If the terminal switches from the GTP network to the PMIP network, the uplink data channel may be considered as unavailable.

When the source MME determines that the uplink data channel is unavailable, the source MME may carry the uplink data channel unavailability indication in the forwarding location update request message, and the uplink data channel unavailability indication may be an explicit indication, such as in the forwarding location update request message. Extend a specific parameter, as above The bearer available parameter is used to transmit the uplink data channel unavailability indication. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel unavailable indication may also be an implicit indication. If the TEID is set to an invalid value of 0, or all digits of the binary representation, the uplink data channel is unavailable;

Step 503: The target MME sends a create bearer request message to the target SGW, where the create bearer request message carries protocol context information received from the source MME, including a PGW user plane address for uplink data transmission, a PGW and a source SGW allocated by the PGW. The TEID of the GTP tunnel between the GTP tunnel, and the user plane address of the source SGW for the downlink data transmission, the TEID of the GTP tunnel between the PGW and the source SGW allocated by the source SGW, and the Handover indication;

If the source MME does not send the uplink data channel unavailability indication, the target MME may determine whether the uplink data channel is available before sending the foregoing create bearer request message. If the terminal switches from the GTP network to the PMIP network, the uplink data channel may be considered as unavailable, or If the uplink data channel unavailability indication is included in the forwarding location update request message received from the source MME, the uplink data channel is considered to be unavailable;

When the target MME determines that the uplink data channel is unavailable, the target MME may carry an uplink data channel unavailability indication in the foregoing create bearer request message, and the uplink data channel unavailability indication may be an explicit indication, such as expanding in creating a bearer request message. A specific parameter, such as an uplink bearer available parameter, is used to transmit an indication that the uplink data channel is unavailable. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. Can be an implicit indication, such as by setting TEID to an invalid value, all 0s or all 1s represented by binary, indicating that the upstream data channel is unavailable;

Step 504: The target SGW closes the uplink data transmission. At this time, the target SGW does not receive the uplink data packet from the UE because the UE has not switched.

Step 505: The target SGW sends a proxy binding update message to the PGW.

Since the create bearer request message from the MME carries the uplink data channel unavailability indication in addition to the Handover indication, indicating that the uplink data channel is not established, the target SGW will send a proxy binding update message to the PGW; wherein, the target SGW The proxy binding update message may be sent directly to the PGW, or the proxy binding update message may be sent to the PGW through the target IWP; the target SGW may include the following information in the proxy binding update message: The SGW user plane address for downlink data transmission and the downlink TEID allocated by the target SGW, for downlink data transmission;

The information of the user, such as IMSI+NSAPI, IMSI+APN, may be obtained in the Create Bearer Request message sent by the MME in step 503.

In this case, the PGW and the source SGW have used the same user identification information to establish a GTP tunnel. The target SGW needs to carry an indication in the PBU message to indicate that the PGW downlink data does not switch. The above indication may be extended in the PMIP protocol by a Connection-Status option (Option). If the Option value is 0 (Inactive), it means that no handover is initiated; the PBU message can also reuse existing indications, such as Handover. It is indicated that when the Handover indication is included in the PBU message, the PGW does not switch to the downlink data.

Step 506: The PGW allocates a GRE key of the tunnel between the target SGW and the PGW, and the PGW sends a proxy binding acknowledgement message to the target SGW, where the proxy binding acknowledgement message carries the GRE Key of the tunnel between the target SGW and the PGW;

Since the target SGW carries the Handover indication in the PBU message, the PGW will preferentially send the GTP tunnel to the source SGW for the downlink data, and the GTP tunnel between the PGW and the source SGW is deleted before being sent to the target SGW. Wherein, the PGW can directly report to the target SGW;

Step 507: The target SGW obtains the GRE key of the tunnel between the target SGW and the PGW that is allocated by the PGW, and then sends an uplink packet, so the target SGW opens the uplink packet sending.

Step 508: The target SGW allocates an SGW user plane address and a TEID for the uplink data transmission between the evolved base station and the target SGW, and sends a create bearer response message to the target MME, where the created bearer response message carries the target SGW allocation evolution. S1 carries the SGW user plane address and TEID for uplink data transmission between the base station and the target SGW;

Step 509: The target MME sends a handover request message to the target evolved base station, where the handover request message carries the SGW user plane address used for uplink data transmission between the evolved base station and the target SGW received from the target SGW in the previous step. TEID;

Step 510: The target evolved base station allocates an S1 bearer between the evolved base station and the target SGW for downlink The data transmission TEID (SI downlink TEID), the target evolved base station sends a handover request acknowledgement message to the target MME, where the handover request acknowledgement message carries the S1 downlink TEID information;

Step 511: The target MME sends a create bearer request to the target SGW, and is used to establish a GTP bearer for forwarding downlink data packets between the source SGW and the target SGW.

Step 512: The target SGW sends a create bearer response to the target MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 513: The target MME sends a forwarding location update complete message to the source MME, where the forwarding location update complete message carries the GTP bearer that is used by the target SGW to forward the downlink data packet between the source SGW and the target SGW in steps 511 and 512. Information

Step 514: The source MME sends a create bearer request message to the source SGW, where the source MME sends a GTP bearer that forwards the downlink data packet between the source SGW and the target SGW.

Step 515: The source SGW sends a create bearer response message to the source MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 516: The source MME sends a handover command message to the source evolved base station.

Step 517: The source evolved base station sends a handover command message to the UE.

Step 518: The UE initiates handover, is separated from the source eNodeB, and is attached to the target eNodeB.

Step 519: The UE sends a handover confirmation message to the target evolved base station.

The uplink data sent by the UE is sent to the target SGW by the target evolved base station; since the target SGW has obtained the correct protocol context from the PGW in step 506, the target SGW opens the uplink packet transmission, so The target SGW forwards the foregoing uplink packet to the PGW.

Step 520: The target evolved base station sends a handover notification message to the target MME.

Step 521: The target MME sends a forwarding location update complete message to the source MME. The target network does not reuse the context sent by the source MME. Therefore, the message needs to carry the delete bearer indication. When the source MME receives the delete bearer indication, it needs to Initiate the operation of deleting the pre-switch. The target MME may also not include the delete bearer indication in the forwarding location update complete message, and the source MME determines whether the uplink data channel unavailability indication is sent to the target MME. To initiate the operation of deleting the pre-switching;

Step 522: The source MME sends a forwarding location update completion confirmation message to the target MME.

Step 523: The target MME sends an update bearer request message to the target SGW, where the update bearer request message carries the S1 downlink TEID information allocated by the target evolved base station in step 510.

Step 524: The target SGW sends a proxy binding update PBU message to the PGW, where the PBU message carries an indication, which is used to indicate that the PGW downlink data is switched. In order to carry the foregoing indication in the PBU message, the method may be similar to the method in step 505 in the PMIP. The extension of a Connection-Status Option is 1 (active), indicating that the switch is initiated. The PBU message can also carry the normal PBU message. After receiving the message, the PGW switches the downlink data. The PGW receives the above-mentioned proxy. After the update message is bound, the downlink data packet is sent to the target SGW.

The PGW may further initiate a GTP bearer between the delete and the source SGW.

Step 525: The PGW sends a proxy binding acknowledgement message to the target SGW.

Step 526: The target SGW sends an update bearer response message to the target MME.

The bearer between the PGW and the source SGW may be deleted in the following manner: The source MME sends a delete bearer request to the source SGW, and the source SGW sends a delete bearer request to the PGW, and the PGW deletes the bearer between the source SGW and the downlink. Data is switched to the target SGW;

As shown in the above, in the embodiment, when the MME determines that the uplink data channel is unavailable, the MME transmits an uplink data channel unavailability indication to the target SGW, and the target SGW closes the uplink data transmission after receiving the foregoing indication, and obtains the update message from the PGW by sending a proxy binding update message. After the real protocol context is opened, the uplink data transmission is opened, so that the uplink data is prevented from being sent incorrectly, and the uplink data packet is correctly sent when the saved protocol context is unavailable. When the user terminal switches from the PMIP network to the GTP network, the protocol used by the S8 interface changes, and the processing flow when the protocol context transmitted by the MME is incorrect is correct. In this embodiment, the target SGW and the PGW can pass the IWP. The specific signaling process of this embodiment is as shown in FIG. 6, and includes:

Step 601: The source evolved base station determines that the UE needs to initiate a handover, and sends a handover request request message to the source MME, requesting to switch from the PMIP network to which the UE belongs to the target visited GTP network.

Step 602: The source MME sends a forwarding location update request message to the target MME, where the forwarding is performed. The location update request message carries the protocol context information saved by the MME, and the protocol context information saved by the MME includes an LMA address of the PGW for uplink data transmission, a GRE Key of the tunnel between the PGW and the source SGW allocated by the PGW, and The MAG address of the source SGW for downlink data transmission, the GRE Key of the tunnel between the PGW and the source SGW allocated by the source SGW;

The source MME may determine whether the uplink data channel is available before transmitting the forwarding location update request message. If the terminal switches from the PMIP network to the GTP network, the uplink data channel may be considered as unavailable.

When the source MME determines that the uplink data channel is unavailable, the source MME may carry the uplink data channel unavailability indication in the forwarding location update request message, and the uplink data channel unavailability indication may be an explicit indication, such as in the forwarding location update request message. The extension of a specific parameter, the above line carries the available parameters, to pass the uplink data channel unavailability indication, the value of 1 indicates that the uplink data channel can be directly used, the value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. The indication may also be an implicit indication, such as by setting the GRE Key to an invalid value of 0, or a binary representation of all ones, indicating that the upstream data channel is unavailable;

Step 603: The target MME sends a create bearer request message to the target SGW, where the create bearer request message carries protocol context information received from the source MME, including an LMA address of the PGW for uplink data transmission, a PGW and a source SGW allocated by the PGW. The GRE Key of the tunnel between the GRE Key of the tunnel and the source SGW for downlink data transmission, and the GRE Key, Handover indication of the tunnel between the PGW and the source SGW allocated by the source SGW;

If the source MME does not send the uplink data channel unavailability indication, the target MME may determine whether the uplink data channel is available before sending the foregoing create bearer request message. If the terminal switches from the PMIP network to the GTP network, the uplink data channel may be considered as unavailable, or If the uplink data channel unavailability indication is included in the forwarding location update request message received from the source MME, the uplink data channel is considered to be unavailable;

When the target MME determines that the uplink data channel is unavailable, the target MME may carry an uplink data channel unavailability indication in the foregoing create bearer request message, and the uplink data channel unavailability indication may be an explicit indication, such as expanding in creating a bearer request message. A specific parameter, such as an uplink bearer available parameter, is used to transmit an indication that the uplink data channel is unavailable. The value of 1 indicates that the uplink data channel can be directly used. The value of 0 indicates that the uplink data channel is unavailable; the uplink data channel is unavailable. Can Either an implicit indication, such as by setting the GRE Key to an invalid value, all 0s or all 1s in binary representation, indicating that the upstream data channel is not available;

Step 604: The target SGW closes the uplink data transmission. At this time, the target SGW does not receive the uplink data packet from the UE because the UE has not switched.

Step 605: The target SGW sends a create bearer request message to the PGW.

The destination bearer request message is sent by the target SGW to the PGW. The target SGW can directly send the bearer request message to the PGW. The target SGW can directly send the bearer request message. The create bearer request message is sent to the PGW, and the create bearer request message may also be sent to the PGW through the target IWP. The target SGW may include the following information in the create bearer request message:

The SGW MAG address used for the downlink data transmission and the downlink GRE key allocated by the target SGW are used for downlink data transmission;

The identification information of the user, such as the IMSI+NSAPI, the IMSI+APN, may be obtained in the Create Bearer Request message sent by the MME in step 603.

Since the PGW and the source SGW have established the PMIP tunnel with the same user identification information, the target SGW needs to carry an indication in the PBU message to indicate that the PGW downlink data does not switch, such as a Handover indication.

Step 606: The PGW allocates a GTP user plane address and a TEID between the target SGW and the PGW, and the PGW sends a Create Bearer Response message to the target SGW, where the Create Bearer Response message carries the PGW user plane address of the GTP tunnel between the target SGW and the PGW. And TEID;

Since the target SGW carries the Handover indication in the create bearer request message, the PGW will preferentially send the PMIP tunnel to the source SGW for the downlink data, and the PMIP tunnel between the PGW and the source SGW is deleted after being sent to the PMIP tunnel. a target SGW; the PGW may send a create bearer response message directly to the target SGW, or may send a create bearer response message to the target SGW by using the target IWP;

Step 607: The target SGW obtains the PGW user plane address and the TEID between the target SGW and the PGW, which are allocated by the PGW, and sends an uplink packet, so the target SGW opens the uplink packet transmission.

Step 608: The target SGW allocates an S1 bearer between the evolved base station and the target SGW for the uplink number. And sending a create bearer response message to the target MME according to the sent SGW user plane address and the TEID, where the create bearer response message carries the target SGW to allocate the SGW user plane address for the uplink data transmission between the evolved base station and the target SGW. And TEID;

Step 609: The target MME sends a handover request message to the target evolved base station, where the handover request message carries the SGW user plane address used for uplink data transmission between the evolved base station and the target SGW received from the target SGW in the previous step. TEID;

Step 610: The target evolved base station allocates an S1 bearer between the evolved base station and the target SGW for the downlink data transmission TEID (SI downlink TEID), and the target evolved base station sends a handover request acknowledgement message to the target MME, where the handover request acknowledgement message carries the foregoing S1 Downstream TEID information;

Step 611: The target MME sends a create bearer request message to the target SGW, where the source is used to establish a source.

The GTP bearer that forwards the downlink data packet between the SGW and the target SGW;

Step 612: The target SGW sends a create bearer response message to the target MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 613: The target MME sends a forwarding location update response message to the source MME, where the forwarding location update response message carries the GTP bearer that is used by the target SGW to forward the downlink data packet between the source SGW and the target SGW in steps 611 and 612. Information

Step 614: The source MME sends a create bearer request message to the source SGW, where the source MME sends a GTP bearer that forwards the downlink data packet between the source SGW and the target SGW.

Step 615: The source SGW sends a create bearer response to the source MME, where the GTP bearer that forwards the downlink data packet between the source SGW and the target SGW is established.

Step 616: The source MME sends a handover command to the source evolved base station.

Step 617: The source evolved base station sends a handover command to the user terminal UE.

Step 618: The UE initiates handover, is separated from the source eNodeB, and is attached to the target eNodeB.

Step 619: The UE sends a handover confirmation message to the target evolved base station.

The uplink data sent by the UE is sent to the target SGW through the target evolved base station; in the target SGW, the uplink packet is sent, and therefore, the target SGW forwards the uplink packet. To PGW;

Step 620: The target evolved base station sends a handover notification to the target MME.

Step 621: The target MME sends a forwarding location update complete message to the source MME. The target network does not reuse the context sent by the source MME. Therefore, the message needs to carry the delete bearer indication. When the source MME receives the delete bearer indication, it needs to Initiate the operation of deleting the pre-switch. The target MME may also not include the deletion bearer indication in the forwarding location update completion message, and the source MME determines whether it is necessary to initiate the operation of deleting the pre-switch bearer according to whether the uplink data channel unavailable indication is sent to the target MME.

Step 622: The source MME sends a forwarding location update completion confirmation message to the target MME; there is no order relationship between the step and the subsequent steps 623-626.

Step 623: The source MME sends a Delete Bearer Request message to the source SGW, where the delete bearer request message carries the user identifier, APN information, and deletes the GTP bearer between the source MME and the source SGW.

Step 624: The source SGW sends a proxy binding update message to the PGW, where the proxy binding update message carries the user identifier, APN information, and deletes the PMIP tunnel between the source SGW and the PGW. The source SGW may directly send the proxy to the PGW. Binding the update message, and sending a proxy binding update message to the PGW through the target IWP;

Step 625: The PGW sends a proxy binding acknowledgement message to the source SGW. After the PMIP tunnel between the PGW and the source SGW is deleted, the PGW sends the downlink data to the target SGW.

The PGW may send a proxy binding acknowledgement message directly to the source SGW, or may send a proxy binding acknowledgement message to the source SGW through the target IWP.

Step 626: The source SGW sends a Delete Bearer Response message to the source MME.

The PGW may be configured to switch the downlink data to the target SGW by using the following method: the target MME sends an update bearer request request to the target SGW, the target SGW sends an update bearer request to the PGW, and the PGW switches the downlink data to the target SGW.

As shown in the above, in the embodiment, when the MME determines that the uplink data channel is unavailable, the MME transmits an uplink data channel unavailability indication to the target SGW, and the target SGW closes the uplink data transmission after receiving the foregoing indication, and obtains a real message from the PGW by sending a create bearer request message. Open the number of uplinks after the protocol context According to the transmission, it is possible to prevent the uplink data from being sent incorrectly, and to ensure that the uplink data message is correctly transmitted when the saved protocol context is not available.

The data packet sending apparatus provided by the embodiment of the present invention is applied to the switching of the user terminal between the networks. The structure of the first embodiment of the data packet generating apparatus is as follows:

The request sending unit 701 is configured to send a protocol context request triggered by the data channel unavailable indication received by the receiving unit 701.

The response receiving unit 702 is configured to receive a protocol context response in response to the protocol context request, where the protocol context response includes information of available data channels;

A message sending unit 703 is configured to send a data message through an available data channel.

As can be seen from the above, in the embodiment of the data message sending apparatus, when the data channel is unavailable, that is, when the saved protocol context is unavailable, the protocol context may be sent to obtain information of the available data channel, and then the datagram may be sent through the available data channel. Therefore, it is possible to prevent the uplink data from being sent incorrectly, and to ensure that the uplink data message is correctly transmitted when the saved protocol context is not available.

Further, in order to enable the system resources to be effectively utilized, the data packet generating apparatus provided by the embodiment of the present invention may further include a closing unit, configured to close the data packet transmission before the request sending unit 701 sends the protocol context request; thereby reducing data. The sending device needs to send the data packet, and can also prevent the data packet from being sent to the erroneous data receiving node; and can also include an opening unit, configured to enable the closing unit after the response receiving unit 702 receives the protocol context response. The closed data message is sent; thus ensuring that the message generation unit 703 can send data through the available data channels to ensure proper operation of the system.

When the data packet sending apparatus provided by the embodiment of the present invention is not available through the information acquisition data channel sent by the other device, the data packet sending apparatus provided by the embodiment of the present invention may further include:

An indication receiving unit, configured to receive an indication that the data channel is unavailable, and the data channel unavailable indication includes information that the data channel is unavailable;

At this time, the request sending unit 701 is configured to send a protocol context request when the receiving unit receives the data channel unavailability indication.

Further, the embodiment of the present invention further provides a second embodiment of the data packet sending apparatus, as shown in FIG. 8, which includes:

The indication receiving unit 801 is configured to receive an indication that the data channel is unavailable; The closing unit 802 is configured to: after the indication receiving unit 801 receives the data channel unavailable indication, turn off the data packet sending;

The buffer unit 803 is configured to buffer the received data message after the closing unit 802 closes the sending of the data packet;

The request sending unit 804 is configured to send a protocol context request triggered by the data channel unavailable indication received by the receiving unit 801;

The response receiving unit 805 is configured to receive a protocol context response that responds to the protocol context request, where the protocol context response includes information of available data channels;

The opening unit 806 is configured to: after the response receiving unit 805 receives the protocol context response, enable data packet transmission by the closing unit 802 to be turned off;

The message sending unit 807 is configured to send a data message through the available data channel after the data unit is opened by the opening unit 806, and send the data message buffered by the buffer unit 803 through the available data channel.

As can be seen from the above, the data packet sending apparatus can buffer the received data packet after the data packet is closed, and then send the buffered data packet to the data receiving node through the available data channel, thereby Ensure that the data packets received by the data receiving node are as correct as possible.

The data packet sending apparatus provided by the embodiment of the present invention can be used as the SGW, and can be used as the SGW in the network to which the user terminal is switched, that is, the target SGW.

The data packet sending system provided by the embodiment of the present invention is further described below. FIG. 9 is a diagram showing the structure of the first embodiment of the data packet sending system, including:

a first mobility management node 901, configured to send, when the data channel is unavailable, information that the data channel is unavailable;

The first mobility management node may specifically be a mobility management node of the network where the user terminal is located before the handover, that is, the source mobility management node;

The second mobility management node 902 is configured to receive information that the data channel sent by the first mobility management node is unavailable, construct and send a data channel unavailable indication, and the data channel unavailable indication includes information that the data channel is unavailable;

The second mobility management node may specifically be a mobility management node of the network where the user terminal is located after handover, that is, the target mobility management node; a data message sending device 903, configured to receive a data channel unavailable indication; send a protocol context request triggered by a data channel unavailable indication; receive a protocol context response that responds to the protocol context request, and the protocol context response includes information of available data channels ; send data messages through the available data channels;

The data message sending device may specifically be a target SGW or the like;

The data message receiving device 904 is configured to receive a protocol context request, send a protocol context response, and receive a data message.

The data message sending device may be specifically a PGW, an IWP in the network after the user terminal is switched, or the like; as can be seen from the above, in the embodiment, the data message sending device receives the data channel unavailability indication, that is, when the saved protocol context is unavailable, The protocol context request can be sent to obtain the information of the available data channel, and the data packet can be sent through the available data channel, so that the uplink data can be prevented from being sent incorrectly, and the uplink data packet can be correctly sent when the saved protocol context is unavailable.

Figure 10 illustrates the structure of the second embodiment of the data packet sending system, including:

The service general wireless packet service support node 1001 is configured to send information that the data channel is unavailable when the data channel is determined to be unavailable;

The mobility management node 1002 is configured to receive information that the data channel is unavailable, construct and send a data channel unavailable indication, and the data channel unavailable indication includes information that the data channel is unavailable; the data packet sending apparatus 1003 is configured to receive Data channel unavailability indication; sending protocol context request triggered by data channel unavailability indication; receiving protocol context response responding to protocol context request, protocol context response including available data channel information; transmitting data message through available data channel ;

The data message receiving device 1004 is configured to receive a protocol context request, send a protocol context response, and receive the data message.

As can be seen from the above, in the embodiment, the data packet sending apparatus receives the data channel unavailability indication, that is, when the saved protocol context is unavailable, the protocol context request may be sent to obtain the available data channel information, and then may be sent through the available data channel. The data packet can prevent the uplink data from being sent incorrectly, ensuring that the uplink data packet is correctly sent when the saved protocol context is unavailable.

Figure 11 is a diagram showing the structure of the third embodiment of the data packet sending system, including:

The mobility management node 1101 is configured to construct and send data when determining that the data channel is unavailable. The channel unavailable indication, the data channel unavailable indication includes information that the data channel is unavailable; the data message sending device 1102 is configured to receive the data channel unavailable indication; and send the protocol context triggered by the received data channel unavailable indication Request; receiving a protocol context response in response to a protocol context request, the protocol context response including information of available data channels; transmitting data messages over the available data channels;

The data message receiving device 1103 is configured to receive a protocol context request, send a protocol context response, and receive the data message.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium, the program When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The data packet sending method, device and communication system provided by the embodiments of the present invention are described in detail above. The description of the above embodiments is only used to help understand the method and the idea of the present invention; The present invention is not limited by the scope of the present invention, and the details of the present invention are not limited by the scope of the present invention.

Claims

Rights request

A data transmission method is applied to a user terminal to switch between networks, and is characterized in that:

2. The data packet sending method according to claim 1, wherein before the sending of the protocol context request, the method further comprises:

Close the data message transmission;

Before sending the data message through the available data channel, the method further includes:

Enable data packet transmission.

The data packet sending method according to claim 2, wherein after the sending of the data packet is closed, the method further comprises:

Cache the received data message;

After the data packet is sent, it further includes:

Transmitting the buffered data message to the data receiving node through the available data channel.

The data packet sending method according to any one of claims 1 to 3, wherein the available data channel is a general packet radio service channel protocol data channel;

The sent protocol context request is a bearer update request, and the received protocol context response is an update response; or

The protocol context request sent is a bearer creation request, and the received protocol context response is a response.

The data packet sending method according to claim 4, wherein the information of the available data channel included in the sent protocol context request is a channel endpoint identifier.

The data packet sending method according to any one of claims 1 to 3, wherein the available data channel is a general routing encapsulation protocol data channel;

The protocol context request sent is a proxy mobile internet protocol proxy binding update request; the received protocol context response is a proxy mobile internet protocol proxy binding acknowledgement.

The data packet sending method according to claim 6, wherein the universal routing encapsulation protocol data channel is a general routing encapsulation protocol uplink data channel;

The proxy mobile internet protocol proxy binding update request sent includes information indicating that downlink data is not to be handed over.

The data packet sending method according to claim 6, wherein the information of the available data channel included in the sent protocol request is a general routing encapsulation keyword.

The data packet sending method according to claim 1, wherein when the data channel is unavailable, the sending of the protocol context request includes:

Receiving a data channel unavailability indication, the data channel unavailability indication including information that the data channel is not available.

A data message sending device, which is applied to a user terminal to switch between networks, and is characterized in that:

a request sending unit, configured to send a protocol context request to the data receiving node when the data channel is unavailable;

The data message transmitting apparatus according to claim 10, further comprising: a closing unit, configured to close the data message transmission before the request sending unit sends the protocol context request;

An opening unit, configured to: after the response receiving unit receives the protocol context response, enable data packet sending;

The message sending unit is configured to send a data message through the available data channel after the opening unit starts to send the data message.

The data packet transmitting apparatus according to claim 11, further comprising: a buffering unit, configured to cache the received data message after the closing unit closes the data packet transmission;

The message sending unit is further configured to send to the data receiving node by using the available data channel Sending a data packet buffered by the cache unit.

The data message transmitting apparatus according to any one of claims 10 to 12, further comprising: an indication receiving unit, configured to receive a data channel unavailability indication, wherein the data channel unavailability indication includes that the data channel is not available Information used;

The request sending unit is configured to send the protocol context request when the receiving unit receives the data channel unavailable indication.

14. A data message sending system, comprising:

15. A data message sending system, comprising:

16. A data message sending system, comprising: