WO2012174798A1

WO2012174798A1 - Method and system for establishing data forwarding channel and allocating internet protocol

Info

Publication number: WO2012174798A1
Application number: PCT/CN2011/079742
Authority: WO
Inventors: 彭聪; 司伟
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-24
Filing date: 2011-09-16
Publication date: 2012-12-27
Also published as: CN102223669B; CN102223669A

Abstract

Provided are a method and system for establishing a data forwarding channel and allocating IP. The method comprises: in the process of executing an S1 handover, a target eNB receives a handover request message from a core network, the core network incorporating in said handover request message a first identifier identifying whether same is forwarded by a direct path (S102); the target eNB establishes the data forwarding channel according to the first identifier and allocates the IP (S104). The technical solution provided by the present invention can ensure that data forwarding is performed normally during S1 handover, thus avoiding the occurrence of data packet loss and service interruption during handover.

Description

TECHNICAL FIELD The present invention relates to the field of Long-Term Evolution (LTE) wireless communication, and in particular to a data creation in the field of LTE wireless communication. Method and system for transmitting channels and allocating IP. BACKGROUND OF THE INVENTION Mobility management is an important attribute of a mobile communication system, and handover is a key content of mobility management. A reasonable handover operation can reduce the possibility of dropped calls of user equipment (User Equipment, UE for short) and reduce service data interruption. Improve system stability and user experience. In the Long Term Evolution (LTE) system, the state of the user terminal (UE) is divided into two types: a connected state (RRC CO NECTED) and an idle state (RRC_IDLE). When the UE in the RRC_CONNECTED state moves from the serving cell to another cell, a handover is triggered to ensure uninterrupted service. When a UE switches from a cell of one base station (eNB) to a cell of another eNB, handover across the base station is triggered. If there is an X2 interface (X2 Interface) between the handover source base station and the handover target base station and is connected to the same MME, according to the prior art (3GPP protocol, 23.401), the source eNB will initiate an X2 interface handover (X2 Interface Handover). Otherwise, a switch through the S 1 interface (SI Interface Handover) will be initiated. In order to reduce the interruption of the service data during the S1 handover, the 3GPP introduces data forwarding, that is, the downlink data that the source eNB will deliver to the UE in the future when the handover is performed and the UE does not send the data. The AM mode uplink data delivered to the core network in sequence is back-transmitted to the target e B, and the PDCP sequence number information is transmitted to the target e B through signaling, and the target eNB delivers the reverse-transmitted uplink and downlink data packets. The source eNB decides whether to perform data back-transmission on the service data according to the service attribute of each service that the UE has established, and carries the information to the core network and the target e B through signaling. If there is an X2 coupling between the source eNB and the target eNB, direct path back propagation is performed, that is, the source eNB directly sends the backhaul data to the target e B, otherwise the indirect path is reversed, that is, the source eNB sends the backhaul data. To the core network, the core network forwards the backhaul data to the target e B. The backhaul path is determined by the source eNB and is carried to the core network by the direct path backhaul flag in the S1 port signaling. The core network determines whether the indirect path backhaul needs to be implemented according to the direct path backhaul flag. In order to receive the backhaul data, the target e B needs to allocate the backhaul path IP for each service (ERAB) that the UE needs to reverse the data, and transmit the IP to the core network through the SI port signaling. If the direct path is back-transmitted, the core network directly sends the IP of the target eNB to the source e B, and the source eNB directly sends the back-transmission data to the target eNB. If the non-direct path is back-transmitted, the core network saves the IP of the target eNB. On the core network side, the backhaul IP is allocated to the service that needs to be reversed, and the IP is sent to the source e B. The source eNB sends the backhaul data to the core network, and the core network forwards the backhaul data to the target eNB. Virtual Local Area Network (VLAN) technology refers to dividing a physical transmission network into multiple virtual local area networks in a transmission network. Each virtual local area network is isolated and cannot access each other. In this way, broadcast storms appearing in the network are avoided, and at the same time, data security and confidentiality between the virtual local area networks are played. After receiving the data packet with the VLAN tag, the eNodeB determines the packet belongs to the sub-interface according to the VLAN ID. When a packet is sent out of the NE, the interface ID of the NE is determined based on the route query. The VLAN ID corresponding to the sub-interface is encapsulated. By tagging the received and sent packets, the packets are distinguished according to the VLAN ID of the tag, and the packets are sent and received through a real interface. There is an S1/MP/X2 connection in the LTE eNodeB. Considering the Packet Switched Core (PS Core), the PS Core (referred to as EPC) and the Operation and Maintenance Center (OMC) network deployment are deployed in a computer room in most cases. Considering that S1/MP is divided into one VLAN separately, another VLAN is separately allocated to the X2 interface, so that packets that are communicated between the base stations of the same L2 transmission network are not forwarded by L3. When the S1 port and the X2 port are divided into different VLANs, the S1 port and the X2 port of the eNB cannot access each other, which is equivalent to two virtual different networks. Therefore, if the eNB allocates IP on the X2 port and establishes a channel on the X2 port to receive data, and the data is transmitted from the S1 interface to the eB, the eNB will not receive it. However, the related art does not relate to how the target eNB knows whether the path of the data back-transmission at the time of handover is directly reversed or not directly transmitted. Therefore, the target eNB cannot determine whether the data back-transmission channel is established through the S1 port or the X2 port, and cannot be determined. The IP of the backhaul channel is the IP in the VLAN assigned to the S1 port or the IP in the VLAN of the X2 port. This will result in the data back-transmission not being performed normally during the SI handover, causing data loss and service interruption during handover. SUMMARY OF THE INVENTION The present invention provides a method and system for creating a data backhaul channel and allocating IP, in order to solve the problem that data back propagation cannot be performed normally during S1 handover, causing data loss and traffic interruption. At least one of the above issues. According to one aspect of the invention, a method of creating a data backhaul channel and assigning an IP is provided. The method for creating a data backhaul channel and allocating an IP according to the present invention includes: in performing the S1 handover, the target base station receives a handover request message from the core network, where the core network will be the first identifier of the direct path backhaul. The packet is carried in the handover request message; the target base station creates a data backhaul channel according to the first identifier and allocates an IP. Before the target base station receives the handover request message from the core network, the method further includes: after the source base station determines to perform the S1 handover, the core network receives the handover requirement message from the source base station, where the handover requirement message carries a direct path reverse The second identifier is transmitted; the core network carries the first identifier in the handover request message according to the second identifier. The foregoing sending, by the core network, the first identifier, in the handover request message, according to the second identifier, includes: if the MME in the core network does not need to be changed, the MME adds a first identifier to the handover request message according to the second identifier, and adds The first identified handover request message is sent to the target base station; if the MME in the core network needs to be changed, the source MME adds, in the forward handover request message, whether it is the third identifier of the direct path back propagation according to the second identifier, and The forward handover request message after the third identifier is added is sent to the target MME, and the target MME adds the first identifier to the handover request message according to the third identifier, and sends the handover request message after adding the first identifier to the target base station. Adding a first identifier to the handover request message or adding a third identifier to the forward handover request message by using one of the following manners: adding a cell carrying the first identifier or the third identifier; using a reserved field in the current cell Carrying the first identifier or the third identifier. The foregoing target base station creates a data backhaul channel according to the first identifier and allocates the IP according to the first identifier: if the first identifier indicates that the direct path is backhauled, the data back channel is established through the X2 port, and the IP of the X2 port VLAN is allocated for the backhaul data; If the first identifier indicates that the direct path is not backhauled, the data backhaul channel is established through the S1 port, and the IP of the S1 port VLAN is allocated for the backhaul data. After the target base station creates the data backhaul channel according to the identifier and allocates the IP according to the identifier, the method further includes: the target base station sends a handover request acknowledgement message to the core network, where the handover request acknowledgement message carries the allocated IP. According to another aspect of the present invention, a system for creating a data backhaul channel and allocating an IP is provided. The system for creating a data backhaul channel and allocating an IP according to the present invention includes: a core network, comprising: an extension module, configured to carry, in the handover request message, a first identifier that is a direct path backhaul; a target base station; the target base station includes: The first receiving module is configured to receive a handover request from the core network during the performing S1 handover The switching request message carries a first identifier that is a direct path back-transmission; the processing module is configured to create a data back-transmission channel according to the first identifier and allocate an IP. The system further includes: a source base station, comprising: a determining module, configured to determine whether an S1 handover needs to be performed; and a first sending module, configured to send a handover request message, where the handover request message carries a direct path backhaul The second network includes: a second receiving module, configured to: after the source base station determines to perform the S1 handover, receive the handover request message from the source base station; and the second sending module is configured to carry the first identifier according to the second identifier Sent in the switch request message. The processing module includes: a determining unit, configured to determine whether the first identifier indicates direct path back-transmission; and the processing unit is configured to: when the output of the determining unit is YES, establish a data back-transmission channel through the X2 port, and allocate X2 for the back-transmission data IP of the port VLAN; when the output of the judgment unit is no, the data back channel is established through the S1 port, and the IP of the S1 port VLAN is allocated for the backhaul data. The target base station further includes: a third sending module, configured to send a handover request acknowledgement message to the core network, where the handover request acknowledgement message carries the allocated IP. With the present invention, the core network carries the identifier of the direct path back-transmission in the handover request message and sends it to the target base station, and the target base station creates a data back-transmission channel according to the identifier and allocates the IP. The problem that the data back-transmission cannot be performed normally during the S1 handover in the related art, causing data packet loss and service interruption during the handover, thereby ensuring normal data back-transmission during S1 handover, and avoiding data packet loss and service during handover. Interruption. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawings: FIG. 1 is a flowchart of a method for creating a data backhaul channel and assigning an IP according to an embodiment of the present invention; FIG. 2 is a diagram of a method for creating a data backhaul channel and assigning an IP according to a preferred embodiment of the present invention; FIG. 3 is a diagram showing an interface relationship between a UE that generates an S1 handover, a handover source e B, a target e B, an MME, and an S-GW according to a preferred embodiment of the present invention; FIG. 4 is a second preferred embodiment of the present invention. A flowchart of a method of creating a data backhaul channel and assigning an IP; 5 is an interface diagram of a UE, a handover source e B, a target e B, a handover source MME, a target MME, and an S-GW, where an S1 handover (S-GW does not change) occurs across an MME according to a preferred embodiment of the present invention. 6 is a structural block diagram of a system for creating a data backhaul channel and allocating an IP according to an embodiment of the present invention; FIG. 7 is a structural block diagram of a system for creating a data backhaul channel and allocating an IP according to a preferred embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. 1 is a flow chart of a method of creating a data backhaul channel and assigning an IP according to an embodiment of the present invention. As shown in FIG. 1, the method for creating a data backhaul channel and allocating an IP mainly includes the following processing: Step S102: In performing the S1 handover process, the target base station receives a handover request message from the core network, where, whether the core network The first identifier of the direct path backhaul is carried in the handover request message. Step S104: The target base station creates a data backhaul channel according to the first identifier and allocates an IP. The related art does not relate to how the target eNB knows whether the path of the data back-transmission at the time of handover is directly reversed or not directly transmitted. Therefore, the target eNB cannot determine whether to establish a data back-transmission channel through the S1 port or the X2 port, and cannot determine the back-propagation. Whether the IP of the channel is the IP in the VLAN assigned to the S1 port or the VLAN in the X2 port. This will result in data back-transmission not being performed normally during S1 handover, causing data loss and service interruption during handover. In the method shown in FIG. 1, the core network carries the identifier of the direct path back-transmission in the handover request message and sends the identifier to the target base station, and the target base station creates a data back-transmission channel according to the identifier and allocates the IP. The above technical problem is solved, and the data back-transmission is normally performed during the S1 handover, thereby avoiding data packet loss and service interruption during handover. Preferably, before performing step S102, the following processing may also be included:

(1) After the source base station determines to perform the S1 handover, the core network receives the handover request message from the source base station, where the handover requirement message carries a second identifier of whether the direct path is reversed.

(2) The core network carries the first identifier in the handover request message according to the second identifier. In a preferred implementation process, the source base station (source eNB) determines that an SI handover is required, and sends a Handover Required message to the core network through the S1 interface, where the handover request message includes but is not limited to a mobility touch. Switching. The Handover Required message includes, but is not limited to, the RRC context of the UE, the UE capability, and the Direct Forwarding Path Availability. Preferably, the foregoing sending, by the core network, the first identifier in the handover request message according to the second identifier, includes: processing, if the MME in the core network does not need to be changed, adding, by the MME, the first request in the handover request message according to the second identifier. Identifying, and sending a handover request message after adding the first identifier to the target base station; if the MME in the core network needs to be changed, the source MME adds, in the forward handover request message, whether the direct path is reversed according to the second identifier. The third identifier is sent to the target MME, and the target MME adds a first identifier to the handover request message according to the third identifier, and sends a handover request message after adding the first identifier to the third MME. Target base station. Preferably, the foregoing first identifier is added to the handover request message or the third identifier is added to the forward handover request message by using one of the following manners:

(1) adding a cell carrying the first identifier or the third identifier;

(2) Use the reserved field in the current cell to carry the first identity or the third identity. In the preferred implementation process, the core network may fill in the Handover Request message according to the cell in the Handover Required message, which may be divided into two cases: (1) If the MME does not need to change, the MME according to whether in the Handover Required message The identifier of the direct path back-transmission is filled in the Handover Request message, and is the identifier of the direct path back-transmission. The Handover Request message is sent to the target e B through the S1 port. (2) If the MME needs to change, the source MME fills in the forward relocation request message according to whether the direct path is backed up in the Handover Required message, and forwards the Forward Relocation Request message to the Forward Relocation Request message through S10. The target MME sends the Handover Request message to the target e B through the S1 interface according to the direct path back-propagation identifier in the Forward Relocation Request message. The direct path back propagation identifier cell may be added to the Handover Request message or the Forward Relocation Request message, or the reserved field in the existing cell (that is, the current cell) may be used to carry the identifier of the direct path backhaul. . Preferably, the foregoing step S104 may further include: (1) If the first identifier indicates that the direct path is backhauled, the data backhaul channel is established through the X2 port, and the IP of the X2 port VLAN is allocated for the backhaul data;

(2) If the first identifier indicates that the direct path is not backhauled, the data backhaul channel is established through the S1 port, and the IP of the S1 port VLAN is allocated for the backhaul data. Preferably, after the target base station creates a data backhaul channel according to the identifier and allocates the IP, the target base station needs to send a handover response message to the core network, where the handover response message carries the allocated IP. In a preferred implementation process, the target eNB allocates resources for the UE to be handed over according to the Handover Request message, prepares radio resource information, and waits for the UE to access. The target eNB creates a transmission channel according to whether the identifier of the direct path back-transmission and the service back-reverse identifier in the Handover Request message are the uplink and downlink back-transmission data, and allocates an IP. If the identifier indicates that the direct path is back-transmission, the data is reverse-transmitted. The IP address of the X2 port VLAN is allocated. Otherwise, the IP address of the S1 port VLAN is allocated for the backhaul data, and then a Handover Request Acknowledge message is sent to the core network, where the handover request acknowledgement message includes the reverse of the service that needs to be reversed. The channel destination IP and the reconfiguration message (ie, the handover command) containing the mobility information forwarded by the target eNB to the UE through the core network and the source eNB. After that, the core network forms a handover command according to the Handover Request Acknowledge message (Handover

Command) message, if it is a direct path backhaul, the core network fills the service backhaul destination IP address sent by the target eNB into the Handover Command message. If it is an indirect path backhaul, the core network saves the destination IP address from the target eNB, and Create an uplink and downlink data backhaul channel for the service that needs to be backhaul, assign the destination IP to the backhaul channel, fill the assigned IP into the Handover Command message, and send it to the source e B through the S1 port. The source eNB receives the Handover Command message, decodes the handover command, and sends the handover command to the UE, and sends the uplink and downlink reverse transmission data of each service to the corresponding IP carried in the Handover Command message. The data is directly sent to the target eNB through the X2 port. If the data is forwarded by the indirect path, the backhaul data is sent to the core network through the S1 interface, and then sent by the core network to the target eNB through the S1 interface.

The UE accesses the target e B, and sends a reconfiguration complete message to the target eNB. The target eNB sends a Handover Notify message to the core network to notify the core network that the handover is complete, and the core network sends a context release command to the source eNB to start sending downlink data to the target eNB. After receiving the uplink data, the target eNB sends the uplink back-transmission data to the core network, sends the downlink back-transmission data to the UE, and starts to process the uplink and downlink data normally, and the handover is completed. After the S1 interface is switched to the S1 interface and the X2 interface of the target eNB is divided into different VLANs, the target eNB can correctly create the backhaul channel and allocate the backhaul IP to enable the backhaul data to be received normally. The flowchart of the S1 handover when the MME in the core network does not need to be changed will be described below with reference to FIGS. 2 and 3. 2 is a flow chart of an IP allocation method in accordance with a preferred embodiment of the present invention. The connection relationship between the UE, the e B, the MME, and the S-GW that performs the S1 handover in the same MME is as shown in FIG. 3, and the two e Bs are coupled with the same MME, and the two eNBs are coupled. There is no X2 port, and the two eNBs are connected to the same S-GW. Before the handover, the UE and the eNB1 have a UU interface, that is, an air interface. After the handover, the UU interface of the UE and the eNB1 is disconnected, and the UU interface is established with the eNB2. It should be noted that the MME and S-GW of the core network are drawn in the same block diagram in FIG. As shown in FIG. 2, the IP allocation method mainly includes the following processing: Step S202: The triggering source eNB determines that the UE in the RRC connected state needs to perform inter-station handover, and is not available because the UE sends the measurement report or the load balancing. The X2 port, the decision needs to perform the S1 handover, the data back propagation type is the indirect path back propagation, all the services of the UE are in the AM mode, and the downlink backhaul is needed; Step S204: The source eNB sets the handover requirement (Handover Required) message through The S1 port is sent to the MME, and the Handover Required message includes, but is not limited to, the RRC context of the UE, the UE capability, and the direct path backhaul flag (whether the direct path backhaul identifier is FALSE); Step S206: The MME of the core network according to the Handover Required message The cell in the fill in the switch request

(Handover Request) message, the message includes, but is not limited to, the RRC context of the UE, the UE capability, and the service list that needs to be established by the target eNB; Step S208: The MME, according to the identifier of the direct path back-transmission in the Handover Required message, the Handover Whether the identifier field of the direct path back-propagation or the reserved field as the direct path back-propagation identifier specified by the protocol is set to FALSE in the request message; Step S210: Send the Handover Request message to the target eNB through the S1 port; Step S212: The target eNB allocates resources for the UE to be handed over according to the Handover Request message, prepares radio resource information, and waits for the UE to access. Step S214: The target eNB determines the backhaul path according to whether the identifier of the direct path back-transmission in the Handover Request message is FALSE. For the non-direct path back-transmission, the IP of the S1 port VLAN is allocated for the back-transmission data; Step S216: The target eNB establishes a Handover Request Acknowledge message to be sent to the MME, which includes but is not limited to the uplink and downlink of the service that needs to be reversed. The backhaul data channel destination IP and the packet forwarded by the target eNB to the UE through the core network and the source eNB Reconfiguration message mobility information (i.e., handover command); Step S218: The MME constructs a Handover Command message according to the Handover Request Acknowledge message. The MME notifies the S-GW to create an uplink and downlink reverse transmission channel for all services of the handover UE, and brings the destination IP allocated by the target eNB to the S-GW. The W-GS allocates the destination IP to the MME and sends it to the MME. The MME fills the destination IP address of the S-GW into the Handover Command message, and then sends the message to the source eNB through the S1 port. Step S220: The source eNB receives the Handover Command message and decodes it. The handover command is sent to the UE, and the uplink and downlink reverse transmission data of each service is sent to the destination IP address allocated by the S-GW carried in the Handover Command message, and the reverse transmission data is sent to the S-GW of the core network through the S1 interface. And the S-GW sends the re-transmitted data to the destination eNB through the S1 interface, and the target eNB receives the uplink and downlink reverse transmission data. Step S222: The UE accesses the target e B, and sends a reconfiguration complete message to the target eNB. S224: The target eNB sends a Handover Notify message to the MME to notify the MME that the handover is complete. Step S226: The MME sends a context release command to the source eNB, and notifies the S-GW of the handover path, and the S-GW stops sending downlink data to the source eNB to start to the target eNB. Sending the downlink data and receiving the uplink data of the target eNB, the target eNB delivers the uplink back-transmission data to the core network in sequence, sends the downlink back-transmission data to the UE, and starts to process the uplink and downlink data normally, and the handover is completed. . The flowchart of the S1 handover when the MME in the core network does not need to be changed will be described below with reference to FIGS. 4 and 5. 4 is a flow chart of a method of creating a data backhaul channel and allocating an IP according to a preferred embodiment 2 of the present invention. The connection relationship between the UE, the e B, the MME, and the S-GW that performs S1 handover in different MMEs is as shown in FIG. 5, and there is an S1 coupling between e Bl and MME1, and an S1 coupling exists between e B2 and MME2. The eB, e B2, MME1, and MME2 are both connected to the same S-GW. The X2 port is coupled between the two eNBs. Before the handover, the UE and the eNB1 have a UU port, that is, an air interface, and the UU port of the UE and the eNB1 after the handover. Broken, establish a UU port with e B2. As shown in FIG. 5, the IP allocation method mainly includes the following processing: Step S402: The triggering source eNB determines that the UE in the RRC connected state needs to perform inter-station handover, because the UE sends a measurement report or load balancing. Since the source eNB and the target eNB are connected to different MMEs, the source eNB decides that an S1 handover is required. Since there is an X2 port between the source eNB and the target eNB, the source eNB determines that the data back propagation type is a direct path backhaul. All services of the handover UE are in the AM mode, and downlink back-transmission is required. Step S404: The source eNB establishes a Handover Required message and sends the message to the source MME through the SI port. The Handover Required message includes, but is not limited to, the RRC context of the UE, the UE capability, and whether it is an identifier of the direct path backhaul (for example, the direct path backhaul flag is TRUE); Step S406: The source MME fills in a Forward Relocation Request according to the cell in the Handover Required message. Step S408: The source MME fills in the Forward Relocation Request message according to whether the backhaul identifier of the direct path in the Handover Required message is TRUE. Whether the identifier of the direct path backhaul is TRUE; Step S410: The source MME selects the target MME, and sends a Forward Relocation Request message that is filled with the identifier of the direct path backhaul to the target MME. Step S412: The target MME receives the Forward Relocation Request, the Handover Request message is filled in according to the cell in the message, where the message includes, but is not limited to, the RRC context of the UE, the UE capability, and the service list that needs to be established by the target eNB; Step S414: The target MME is in the Handover Required message. Is it the sign of the direct path back pass, fill in the Handover Whether the request message is a direct path backhauled identifier cell or a reserved field of the direct path backhaul identifier specified by the protocol is TRUE, and the Handover Request message is sent to the target eNB through the SI port; Step S416: The target eNB according to the Handover Request The message allocates resources for the UE to be switched in, prepares radio resource information, and waits for the UE to access. Step S418: The target eNB determines whether the backhaul path is a direct path back according to whether the identifier of the direct path back-transmission in the Handover Request message is TRUE. The IP address of the X2 port VLAN is allocated for the backhaul data. Step S420: The target eNB sets up a Handover Request Acknowledge message to be sent to the MME, where the Handover Request Acknowledge message includes but is not limited to the uplink and downlink backhaul data channel destination IP of the service that needs to be reversed. And the target eNB forwards the reconfiguration message (ie, the handover command) containing the mobility information to the UE through the core network and the source eNB; Step S422: The target MME sets up a Forward Relocation Response message according to the Handover Request Acknowledge message, and sends the message to the source MME. Because the direct path is backhauled, the target MME directly fills the backhaul path IP allocated by the target e B into the Forward Relocation Response message. Step S424: The source MME sets up a Handover Command message according to the Forward Relocation Response message, and fills the backhaul destination IP in the Forward Relocation Response message into the Handover Command message, and then sends the message to the source eNB through the S1 port. Step S426: The source eNB receives The Handover Command message is decoded to obtain the handover command, and is sent to the UE, and the uplink and downlink reverse transmission data of each service is sent to the backhaul destination IP carried in the Handover Command message, that is, the target eNB allocates the backhaul destination IP, and the target The eNB receives the uplink and downlink reverse transmission data; Step S428: The UE accesses the target e B, and sends a reconfiguration complete message to the target eNB. Step S430: The target eNB sends a Handover Notify message to the target MME to notify the handover completion. Step S432: Target MME Sending a Modify Bearer Request message to the S-GW; Step S434: The target MME sends a Forward Relocation Complete Notification message to the source MME. Step S436: The source MME sends a context release command to the source eNB, and the source eNB releases the local UE resource. . The S-GW switches the path to the target eNB, stops sending the downlink data to the source eNB after transmitting the End Marker packet to the source eNB, and starts processing the uplink and downlink data on the target eNB. The source eNB forwards the End Marker packet to the target e B. After receiving the End Marker packet, the target eNB delivers the uplink reverse transmission data to the core network in sequence, and sends the downlink back-transmission data to the UE, and starts to process the uplink and downlink data normally. The switch is complete. 6 is a structural block diagram of a system for creating a data backhaul channel and allocating an IP according to an embodiment of the present invention. As shown

As shown in FIG. 6, the system for creating a data backhaul channel and allocating IP mainly includes: a core network 10 and a target base station 20; and the core network 10 includes: an expansion module 100, configured to carry a first identifier that is a direct path backhaul In the handover request message, the target base station 20 may further include: a first receiving module 200, configured to receive a handover request message from the core network in the process of performing the S1 handover, where the handover request message carries a direct path reverse The first identifier is transmitted; the processing module 202 is configured to create a data backhaul channel according to the first identifier and allocate an IP. Preferably, as shown in FIG. 7, the system may further include: a source base station 30; wherein, the source base station 30 includes: a decision module 300, configured to determine whether an S1 switch needs to be performed; and the first sending module 302 is configured to And sending a handover request message, where the handover requirement message carries a second identifier that is a direct path back propagation; The core network 10 further includes: a second receiving module 102, configured to: after the source base station determines to perform the S1 handover, receive a handover requirement message from the source base station; and the second sending module 104 is configured to carry the first identifier according to the second identifier Sent in the switch request message. Preferably, as shown in FIG. 7, the processing module 202 may further include: a determining unit (not shown in FIG. 7) configured to determine whether the first identifier indicates direct path back-transmission; the processing unit (not shown in FIG. 7), setting In order to determine whether the output of the unit is YES, the data back channel is established through the X2 port, and the IP of the X2 port VLAN is allocated for the back data; when the output of the determining unit is no, the data back channel is established through the S1 port, and is reversed. The data is assigned to the IP of the S1 port VLAN. Preferably, as shown in FIG. 7, the target base station 20 further includes: a third sending module 204, configured to send a handover request acknowledgement message to the core network, where the handover request acknowledgement message carries the allocated IP. For the specific implementations of the above-mentioned target base station, the source base station, and the modules in the core network and the units in the core network, reference may be made to the descriptions of FIG. 1 to FIG. 5 , and details are not described herein again. From the above description, it can be seen that the present invention achieves the following technical effects: On the basis of the existing LTE technology, the target eNB that divides the VLAN when the S1 handover is effectively solved cannot be known because the backhaul path of the handover cannot be known. The problem of correctly transmitting the backhaul channel to receive the backhaul data and not correctly assigning the IP of the backhaul channel according to the VALN division ensures that the data backhaul of the S1 handover is successful, and the data loss and service interruption of the handover process are reduced. The earth improves the performance and user experience of the LTE system. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device so that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

1. A method of creating a data backhaul channel and assigning an internet protocol IP, including:

During the performing S1 handover, the target base station receives a handover request message from the core network, where the core network carries the first identifier of the direct path back-transmission in the handover request message; The first identifier creates a data backhaul channel and assigns an IP.

The method according to claim 1, wherein before the target base station receives the handover request message from the core network, the method further includes:

After the source base station determines that the S1 handover is performed, the core network receives a handover request message from the source base station, where the handover requirement message carries a second identifier that is a direct path back propagation; The second identifier carries the first identifier and is sent in the handover request message.

The method according to claim 2, wherein the sending, by the core network, the first identifier in the handover request message according to the second identifier, includes:

If the MME in the core network does not need to be changed, the MME adds the first identifier to the handover request message according to the second identifier, and adds the handover request message after the first identifier. Sent to the target base station;

If the MME in the core network needs to be changed, the source MME adds, according to the second identifier, a third identifier that is directly forwarded by the direct path in the forward handover request message, and adds the third identifier. Transmitting the forward handover request message to the target MME, the target MME adding the first identifier to the handover request message according to the third identifier, and adding the handover request message after the first identifier Send to the target base station.

The method according to claim 3, wherein the first identifier is added to the handover request message or the third identifier is added to the forward handover request message by using one of the following manners:

Adding a cell carrying the first identifier or the third identifier;

The first or third identity is carried using a reserved field in the current cell.

The method according to claim 1, wherein the creating, by the target base station, the data backhaul channel according to the first identifier and allocating the IP includes: If the first identifier indication is a direct path backhaul, the data back channel is established through the X2 port, and the IP of the X2 port VLAN is allocated for the back data;

If the first identifier indicates that the direct path is not backhauled, the data back channel is established through the S1 port, and the IP of the S1 port VLAN is allocated for the backhaul data.

The method according to any one of claims 1 to 5, wherein after the target base station creates a data backhaul channel according to the identifier and allocates an IP, the method further includes: sending, by the target base station, the core network to the core network The handover request acknowledgement message, where the handover request acknowledgement message carries the allocated IP.

7. A system for creating a data backhaul channel and assigning an internet protocol IP, comprising: a core network and a target base station; the core network comprising:

An extension module, configured to carry a first identifier that is a direct path backhaul in the handover request message;

The target base station includes:

a first receiving module, configured to receive the handover request message from the core network during an S1 handover process;

The processing module is configured to create a data backhaul channel according to the first identifier and allocate an IP.

The system according to claim 7, further comprising: a source base station, where the source base station includes:

a decision module, configured to determine whether an S1 switch needs to be performed;

The first sending module is configured to send a handover request message, where the handover requirement message carries a second identifier that is a direct path back propagation;

Then the core network further includes:

a second receiving module, configured to receive, after the source base station determines to perform the S1 handover, the handover request message from the source base station;

The second sending module is configured to carry the first identifier in the handover request message according to the second identifier.

The system according to claim 7, wherein the processing module comprises: a determining unit, configured to determine whether the first identifier indicates direct path back-transmission; and the processing unit is configured to output in the determining unit When the data is backed up through the X2 port Channel, and assign IP of the X2 port VLAN to the back-transmission data; when the output of the judging unit is no, the data back-channel is established through the S1 port, and the IP of the S1 port VLAN is allocated for the back-transmission data.

The system according to any one of claims 7 to 9, wherein the target base station further comprises: a third sending module, configured to send a handover request acknowledgement message to the core network, where the handover request The acknowledgement message carries the assigned IP.