WO2009132550A1

WO2009132550A1 - Handover method, communication system and device thereof

Info

Publication number: WO2009132550A1
Application number: PCT/CN2009/071278
Authority: WO
Inventors: 胡伟华
Original assignee: 华为技术有限公司
Priority date: 2008-04-30
Filing date: 2009-04-15
Publication date: 2009-11-05
Also published as: CN101572928B; CN101572928A

Abstract

A handover method, communication system and device thereof are used for realizing the data lossless handover in the instance of that the serving gateway SGW changes. The handover method includes: an access network element of the target side receives an end mark packet after the access network handover is occurring and the SGW of the source side handovers to the SGW of the target side; the access network element of the target side sends the downlink data from the core network of the target side to the user equipment according to the indication of the end mark packet. A communication system, serving gateway and packet data network gateway are also provided.

Description

Switching method and communication system and related equipment

This application claims priority to Chinese Patent Application No. 200810094473.7, entitled "A Switching Method and Communication System and Related Equipment", filed on April 30, 2008, the entire contents of In this application.

Technical field

The present invention relates to the field of communications, and in particular, to a handover method, a communication system, and related devices.

Background technique

In the current access network element switching process of the Evolved Packet System (EPS), in order to ensure that user data is not lost during the handover process, it is lossless. The access network that needs the source-side network forwards the downlink data that has not been sent to the terminal, and forwards it to the target-side network, and sends it to the terminal through the access network of the target network. The access network of the target network needs to distinguish the downlink data forwarded by the source network and the downlink data sent by the core network of the target network, and try to ensure that the data forwarded by the source network is sent to the terminal first, and then the received data is sent. Downstream data of the user plane of the target network core network. To help the access network achieve the above-mentioned downlink data sorting, the access network proposes a requirement for the core network, that is, the access network needs to know when the downlink data forwarded by the source side network ends, and therefore requires the core network service gateway (SGW, Serving). The gateway sends the end tag packet to the target side access network, and the target side access network receives the end tag packet, and knows that the data forwarded by the source side network is sent, and the downlink data received from the target core network can be delivered. The terminal is gone.

The foregoing method requires the SGW to deliver an end tag packet to the target side access network, and if the core network service gateway remains unchanged, the core network service gateway may be changed or the mobility management network element may be implemented. There may be changes, switching in this case, and data lossless requirements. At the same time, due to the 3rd Generation Partnership Project (3GPP, 3rd Generation Partnership Project), there are GSM/EDGE Radio Access Network (GERAN, GSM/EDGE Radio Access Network), UMTS Terrestrial Radio Access Network (UTRAN, UMTS Territorial Radio Access Network). Evolved UMTS Territorial Radio Access Network (EUTRAN) Different access technologies, the handover can be divided into internal handover of the same access technology, and switching between different access technologies. The handover between the EUTRAN of the Evolved Access Network and the different access technologies of the second-generation/third-generation network inevitably leads to a change in the SGW of the control plane. Therefore, in the prior art, how to implement lossless transmission of data in the case of a changed handover of the SGW Program.

Summary of the invention

Embodiments of the present invention provide a handover method, a communication system, and a related device, which can implement lossless transmission of data when a change occurs in the SGW.

The handover method provided by the embodiment of the present invention includes: when an access network handover occurs and a source side service gateway

After the SGW is switched to the target side SGW, the target side access network element receives the end tag packet. The target side access network element sends downlink data from the target side core network to the user equipment according to the indication of the end tag packet.

The communication system provided by the embodiment of the present invention includes: a network side core network device, configured to send an end tag packet to the target side access network element after the access network handover occurs and the source side serving gateway SGW switches to the target side SGW; The target side access network element is configured to receive the end tag packet sent by the network side core network device, and send the downlink data from the target side core network network to the user equipment after receiving the end tag packet.

The service gateway provided by the embodiment of the present invention includes: a triggering unit, after the access network switching occurs, and the source side serving gateway SGW switches to the target side SGW, and is configured to trigger the sending unit when the preset sending condition is met; And sending, by the triggering unit, the end tag packet to the target side access network element, where the end tag packet is used to indicate that the target side access network element is in accordance with the indication of ending the tagged packet. The user equipment delivers downlink data from the target side core network.

The packet data network gateway provided by the embodiment of the present invention includes: an end tag packet triggering unit, configured to trigger an end tag packet sending unit when a preset sending condition is met; and an end tag packet sending unit, configured to use the end tag The triggering of the packet triggering unit sends an end tag packet to the source side access network element, where the end tagging packet is used to indicate that the target side access network element sends the target device to the user equipment according to the indication of the end tag packet. Downstream data of the side core network.

In this embodiment, after the source side serving gateway SGW switches to the target side SGW, the data transmission path of the data gateway PGW will be two, one is the old bearer path for sending data to the source side SGW, and one is its target to the target. After the SGW sends the data, the PGW sends the data to the source SGW. After the data from the source side is sent, the data from the target side is sent. In the embodiment of the present invention, the network side core network device sends an end tag to the target side access network element. a packet, the end marker packet is used to instruct the target side access network element to send downlink data from the target side core network to the user equipment, so even if the serving gateway changes, the target side access network element can still be from the network side core. The network device obtains the end tag packet to determine that the source side data has been transmitted, and can forward the data from the target side, so that the lossless transmission of the data can still be achieved if the SGW changes.

DRAWINGS

1 is a flowchart of an embodiment of a handover method according to an embodiment of the present invention;

2 is a flowchart of another embodiment of a handover method according to an embodiment of the present invention;

3 is a flowchart of another embodiment of a handover method according to an embodiment of the present invention;

4 is a flowchart of another embodiment of a handover method according to an embodiment of the present invention;

FIG. 5 is a flowchart of still another embodiment of a handover method according to an embodiment of the present invention;

6 is a flowchart of still another embodiment of a handover method according to an embodiment of the present invention;

7 is a schematic diagram of an embodiment of a communication system according to an embodiment of the present invention;

8 is a schematic diagram of an embodiment of a service gateway according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of an embodiment of a packet data network gateway according to an embodiment of the present invention.

detailed description

Embodiments of the present invention provide a handover method, a communication system, and related equipment, which are used to implement lossless handover of data in the case where a change occurs in the SGW.

The switching method embodiment in the embodiment of the present invention includes:

After the access network handover occurs and the source side serving gateway SGW switches to the target side SGW, the end marker packet is sent to the target side access network element, so that the target side access network element can end the indication of the marked packet according to the Downstream data from the target side core network is delivered to the user equipment.

It should be noted that after the location change of the user equipment, the user equipment may enter the coverage of another network from the coverage of one network. In this case, the access network switching needs to be performed, and the network that provides services for the user before the handover is called The source network, the network that provides services for users after the handover is called the target network. The SGW that serves the user equipment in the source network becomes the source SGW. The switched network is called the target side network, and the target side network provides the user equipment. The SGW of the service becomes the target side SGW.

In this embodiment, after the source side serving gateway SGW switches to the target side SGW, the data gateway There are two data transmission paths of the PGW, one is the old bearer path for sending data to the source side SGW, and the other is the new bearer path for sending data to the target side SGW. After updating the bearer, the PGW will no longer The source side SGW sends the data to the target side SGW. To ensure the order of the data, the target side access network element needs to send the data from the source side first and then the data from the target side, and the embodiment of the present invention. The medium network side core network device sends an end tag packet to the target side access network element, where the end tag packet is used to instruct the target side access network element to send downlink data from the target side core network to the user equipment, so even the service If the gateway changes, the target-side access NE can still obtain the end-tagged packet from the network-side core network device to determine that the source-side data has been sent, and the data from the target side can be forwarded, so that the SGW can be changed. Lossless transmission of data is still possible.

The network side core network device in the foregoing embodiment may be a source side SGW, or a target side SGW, or a packet data network gateway (PGW), and specifically sends an end tag packet to the target side access network element. The sending method is illustrated by the following examples:

1. The end tag packet is sent by the source side SGW:

In this embodiment, after determining that the source side data transmission is complete, the source side SGW sends an end tag packet to the target side access network element by using the source side access network element, and is used to indicate that the target side access network element is delivered to the user equipment. Downstream data from the target side core network.

In this embodiment, according to the EPS network (internal switching of the core network mobility management network element is not changed) and the 3GPP network (internal change of the core network mobility management network element switching), the following embodiments can be further divided into the following embodiments. :

A. EPS network (internal does not change the switching of the core network mobility management network element):

Referring to FIG. 1, an embodiment of a handover method in an embodiment of the present invention includes:

101. The user equipment transmits uplink and downlink data by using the source base station and the PGW.

In this embodiment, the EPS network is used, and the access network element is described by taking a base station as an example.

102. The source base station negotiates with the target base station to perform handover.

When the user equipment meets the handover condition (e.g., from the coverage of one network to the coverage of another network), a handover preparation procedure is performed between the source base station and the target base station, and the user equipment is instructed to switch to access the target base station. The specific process is not limited.

103. The source base station forwards downlink data that is not sent to the user equipment to the target base station. 104. The target base station sends the received forwarding data to the user equipment.

105. The user equipment sends uplink data to the PGW through the target base station.

106. The target base station sends a path switch request to a mobility management entity (MME, Mobile Management Entity).

In this embodiment, the target base station sends a path switching request to the MME, and notifies the MME that the user equipment changes the cell, and the path switching request includes the global cell identity information of the target cell, and the MME may determine, according to the global cell identity information, that the user equipment is served. The SGW, that is, the new SGW is selected to provide the service to the user equipment. In the embodiment of the present invention, the new SGW selected by the MME is referred to as the target side SGW.

107. The MME sends a create bearer request to the target side SGW.

The MME sends a bearer request to the target SGW (that is, the selected new SGW), where the request includes the bearer context information of the user, including the user plane resource information allocated by the core network user plane anchor PGW for receiving the uplink data.

After receiving the request to create a bearer, the target side SGW allocates user plane resources for receiving uplink data.

108. The target side SGW sends an update bearer request to the PGW.

The target side SGW allocates user plane resources for receiving downlink data, and sends an update bearer request message to the PGW, where the message includes user plane information for receiving downlink data.

After receiving the update bearer request message, the PGW updates the bearer context of the user, saves the user plane information, and starts to send the downlink user data that is subsequently received from the data source to the target side SGW, and then forwards the data to the target side base station through the target side SGW.

109. The PGW returns an update bearer response message to the SGW.

The update bearer response message may include a user plane message 110 allocated by the PGW to receive the uplink data, and the target side SGW sends a create message to the MME.

The target SGW sends a create bearer response message to the MME, where the message includes the user plane resource information allocated by the target SGW to receive the uplink data.

After the MME receives the Create Bearer Response message, the MME starts a timer, and the timer is used to determine whether the source side data sent by the PGW to the source side SGW is sent by the target side access NE. A person skilled in the art may have multiple implementation manners, which are not limited herein. For example, the timing experience value of a timer may be estimated according to the average transmission rate of the data, and the end of the experience value may determine that the source side data is transmitted. The technical judgment is not mentioned here.

111. The PGW sends downlink data to the user equipment by using the target side base station.

112. The MME sends a path switch confirmation message to the target side base station.

The MME sends a path switch request acknowledgement message to the target side base station to confirm that the handover path is successful. After receiving the path switch confirmation message, the target base station forwards the uplink data from the user equipment by using the user plane resource information in the message.

113. The user equipment sends uplink data to the PGW by using the target side base station.

114. The target-side base station notifies the source-side base station that the handover is successful, and requests the source-side base station to release the resource.

115. The MME sends a delete bearer request to the source SGW.

After the MME starts the timer in step 110, that is, after the MME confirms that the source side data is transmitted, the MME sends a delete bearer request message to the source side SGW, where the delete bearer request message carries the indication information, which is used to indicate the source side SGW. A path switchover occurs, and the source side data has been delivered, or directly indicates that the source side SGW needs to deliver the end tag packet, and may even specify a specific bearer list that the source side SGW needs to deliver the end tag.

In this embodiment, the timer that is started by the MME is set to have an overflow threshold, and the threshold may be an empirical value. When the timer overflows, the data on the source side may be considered to have been sent. In the application, the other method can also be used to determine whether the data on the source side has been sent. The specific manner is not limited herein.

It should be noted that, in this embodiment, the data on the source side refers to the data that is sent by the PGW through the source side SGW, and the data on the target side refers to the data that is sent by the PGW through the target side SGW, that is, after the SGW is switched. When the PGW sends data, there are two paths, one is the path where the source side SGW is located, which is called the source side path, and the other is the path where the target side SGW is located, which is called the target side path. When the PGW receives the update bearer indication. When the data is sent from the source-side path and the data is sent from the target-side path, the source-side data has been delivered for the PGW, but due to the PGW. The data sent by the source side path to the source side SGW may still be in the middle of the transmission before the update of the bearer indication is received. Therefore, the MME needs to start a timer. When a certain preset value is reached, the data on the source side path may be determined. All the source-side SGWs are redirected to the access network, and the source-side data is delivered to the source-side SGW. Therefore, the bearer deletion request carrying the indication information can be sent to the source-side SGW.

116. The source side SGW feeds back the bearer response message to the MME.

117. The source side SGW sends an end tag packet to the source side base station.

118. The source side base station forwards the end tag packet to the target side base station, and after receiving the end tag packet, the target side base station can learn that the downlink data from the target side core network can be sent to the user equipment.

It should be noted that there is no fixed execution order between step 116 and step 117. After the end of the label packet transmission is completed, the source side SGW releases its own user plane resource.

In the foregoing embodiment, the MME sends the indication information to the source-side SGW to carry the indication information. It can be understood that, in an actual application, the source-side SGW may not receive the indication of the MME, but always receives the MME. Sending the delete bearer command, directly releasing the end tag packet before releasing the user plane resource, or determining whether the end tag packet needs to be delivered according to the service quality requirement of the user bearer context, for example, according to the service quality requirement, the data required on a bearer is known. If it is not damaged, the source side SGW can send and end an end tag packet on the bearer path.

It should be noted that the process of sending the end tag packet before the source side SGW releases the user plane resource may also adopt the following manner:

After the MME does not need to wait for the timer to expire, the MME sends a delete bearer request to the source SGW. The delete bearer request does not carry the indication information, and the source side SGW starts a timer after receiving the delete bearer request, when the timer is started. After the preset time is reached, the SGW confirms that the source side data is transmitted, that is, sends the end tag packet, and releases the user plane resource.

B. 3GPP network (internal change of core network mobility management network element switching):

Referring to FIG. 2, another embodiment of the handover method in the embodiment of the present invention includes:

201. The source side access network element determines to initiate a handover.

202. The source side access network element sends a handover request message to the source side mobility management network element.

The source side access NE requests the source side mobility management network element to start the handover and indicates the bearer context that requires data forwarding.

203. The source-side mobility management network element sends a forward handover request to the target-side mobility management network element. The source-side mobility management network element selects the target-side mobility management network element, and sends a forward handover request message, where the message includes the user's mobility management context and user plane bearer context information.

204. Allocating resources to the target network;

The target side mobility management network element determines whether the current source side SGW can continue to serve the user equipment. If not, it reselects a new SGW, that is, the target side SGW.

The target-side mobility management network element controls the target network to allocate corresponding bearer resources and data forwarding resources to the handover users.

205: The target-side mobility management network element feeds back the forward handover response message to the source-side mobility management network element.

206. The source-side mobility management network element sends a create bearer request to the source side SGW.

If the data forwarding uses indirect data forwarding, the source-side mobility management network element interacts with the source-side SGW to construct an indirect data forwarding channel.

207. The source side SGW sends a bearer response to the source side mobility management network element to generate a bearer response.

208. The source-side mobility management network element sends a handover command to the source-side access NE to indicate that the source network starts to switch.

209. The source side access network element sends a handover command to the user equipment to notify the UE to start the handover.

210. The source side access network element starts to forward data to the target network.

212. The target side access network element sends a handover notification to the target side mobility management network element.

After the target side access network element confirms that the user equipment is accessed, the handover notification is sent to the target side mobility management network element.

213. The target side mobility management network element sends a forward handover completion message to notify the source side mobility management network element.

214. The source-side mobility management network element returns a forward handover completion confirmation message to the target-side mobility management network element.

215. The target side mobility management network element sends an update bearer request message to the target side SGW to update the user plane bearer information.

216. The target side SGW sends an update bearer request to the PGW.

The target SGW initiates an update bearer process, and updates bearer information on the PGW, including user plane bearer information and the type of access network of the user.

217. The PGW feeds back an update response to the target side SGW.

218. The target side SGW returns an update bearer response message to the target side mobility management network element. 219. The source-side mobility management network element sends a delete bearer request to the source side SGW.

The source-side mobility management network element sends a delete bearer request message to the source side SGW after receiving the forward handover complete message from the target network, if the SGW changes from the received forward handover complete message. The indication information is used to indicate that the source side SGW has a path switch, and the source side data has been delivered, or the display indicates that the end tag packet needs to be delivered, and even indicates that the source side SGW needs to deliver the end tag.

In this embodiment, the source-side mobility management network element may also set a timer, and send a delete bearer request message after the timer expires.

It should be noted that, in this embodiment, the data on the source side refers to the data that is sent by the PGW through the source side SGW, and the data on the target side refers to the data that is sent by the PGW through the target side SGW, that is, after the SGW is switched. When the PGW sends data, there are two paths, one is the path where the source side SGW is located, which is called the source side path, and the other is the path where the target side SGW is located, which is called the target side path. When the PGW receives the update bearer indication. When the data is sent from the source-side path and the data is sent from the target-side path, the source-side data has been delivered for the PGW, but the PGW passes the source before receiving the update bearer indication. The data sent by the side path to the source side SGW may still be in the middle. Therefore, the source side mobility management network element needs to start a timer. When a preset value is reached, it can be determined that the data on the source side path has all passed the source side SGW. After the access to the access network, the source side data has been delivered to the source side SGW. Therefore, the bearer deletion request carrying the indication information can be sent to the source side SGW.

220. The source side SGW sends a bearer deletion response to the source side mobility management network element.

221. The source SGW sends an end tag packet to the source side access NE.

222. The source side access network element forwards the end tag packet to the target side access network element, and after receiving the end tag packet, the target side access network element may start sending downlink data from the target side core network to the user equipment. .

It should be noted that there is no fixed execution order between step 220 and step 221. After the end of the transmission of the label packet, the source side SGW releases its own user plane resource.

In the above embodiment, the source-side mobility management network element does not need to obtain the source-side mobility management network element in the source-side SGW. The source-side SGW may not need to obtain the source-side mobility management network element. Indicates, and always receives the delete bearer command sent by the MME, releasing The user-side resource sends an end-marking packet before the user-side resource, or determines whether it needs to deliver the end-tagged packet according to the quality of service requirements of the user's bearer context. For example, according to the quality of service requirement, the source-side SGW may be The bearer path context ends the tag package.

It should be noted that, the process in which the source side SGW sends the end tag packet before releasing the user plane resource may also adopt the following manner: the source side mobility management network element does not need to wait for the timer to expire after step 213. The source side SGW sends a delete bearer request, and the delete bearer request does not carry the indication information. After receiving the delete bearer request, the source side SGW starts a timer. After the timer reaches the preset time, the SGW confirms that the source side data is sent. , that is, the end tag package is sent, and the user plane resource is released.

Second, the end tagged packet is sent by the PGW:

In this embodiment, the PGW sends an end marker packet to the target side access NE by the source side access NE to indicate that the target side access NE sends downlink data from the target side core network to the user equipment.

In this embodiment, according to the EPS network and the 3GPP network, the following two embodiments can be further divided into: A. EPS network (internal does not change the switching of the core network mobility management network element):

Referring to FIG. 3, another embodiment of the handover method in the embodiment of the present invention includes:

301. The user equipment transmits uplink and downlink data by using the source base station and the PGW.

302. The source base station negotiates with the target base station to perform handover.

When the user equipment meets the handover condition (for example, from the coverage of one network to the coverage of another network), the source base station and the target base station perform a handover preparation process, and instruct the user equipment to switch from the source base station to the target. Base station, the specific process is not limited.

303. The source base station forwards downlink data that is not sent to the user equipment to the target base station.

304. The target base station sends the received forwarding data to the user equipment.

305. The user equipment sends uplink data to the PGW by using the target base station.

306. The target base station sends a path switch request to the MME.

In this embodiment, the target base station sends a path switching request to the MME, and notifies the MME that the user equipment changes the cell, and the path switching request includes the global cell identity information of the target cell, and the MME may determine, according to the global cell identity information, that the user equipment is served. The SGW selects a new SGW to provide services for the user equipment, that is, the target side SGW. 307. The MME sends a create bearer request to the target side SGW.

In this embodiment, the MME sends a request to the target SGW to include the indication information, which is used to indicate that the SGW has a path switch, or directly indicates that the end tag packet needs to be delivered, and even indicates that the bearer list of the end tag packet needs to be delivered.

308. The target side SGW sends an update bearer request to the PGW.

In this embodiment, the update bearer request sent by the target side SGW includes the indication information, which is used to indicate that the SGW has a path switch, or directly indicates that the end tag packet needs to be delivered, and even indicates that the bearer list of the end tag packet needs to be delivered.

309. The PGW returns an update bearer response message to the SGW.

The update bearer response message may include a user face letter allocated by the PGW for receiving uplink data.

310. The target side SGW sends a create response message to the MME.

311. The PGW sends downlink data to the user equipment by using the target side base station.

312. The PGW sends an end tag packet to the source side base station.

In this embodiment, the update bearer request received by the PGW from the target side SGW includes the indication information, which is used to indicate that the SGW has a path switch, or directly indicates that the end tag packet needs to be delivered, and even indicates that the bearer of the end tag packet needs to be delivered. List. The PGW can learn that the SGW changes according to the indication information, and then the data is sent from the source side path, and the data is sent by the target side path. Therefore, the PGW can learn that the source side data has been delivered, so that the end marker packet can be delivered. .

It should be noted that, in this embodiment, the data on the source side refers to the data that is sent by the PGW through the source side SGW, and the data on the target side refers to the data that is sent by the PGW through the target side SGW, that is, after the SGW is switched. When the PGW sends data, there are two paths, one is the path where the source side SGW is located, which is called the source side path, and the other is the path where the target side SGW is located, which is called the target side path. When the PGW receives the update bearer indication. When the data is sent from the source side path and the data is sent from the target side path, the source side data has been delivered for the PGW.

313. The source side base station forwards the end tag packet to the target side base station, and the target side base station receives the foregoing end tag packet, so that the downlink data from the target side core network can be started to be sent to the user equipment.

314. The MME sends a path switch confirmation message to the target side base station.

315. The user equipment sends uplink data to the PGW by using the target side base station.

316. The target-side base station notifies the source-side base station that the handover is successful, and requests the source-side base station to release the resource.

317. The MME sends a delete bearer request to the source SGW.

318. The source side SGW feeds back the bearer response message to the MME.

It should be noted that, after the end of the marking packet transmission is completed, the source side SGW releases its own user plane resource.

In the above embodiment, the MME sends the indication to the PGW to create the bearer request, and the target SGW sends the indication to the PGW by updating the bearer request. It can be understood that, in actual applications, the PGW may not It is necessary to obtain the indication of the MME, and always send the end tag packet after receiving the update bearer request sent by the target side SGW, or determine whether it is necessary to deliver the end tag packet according to the service quality requirement of the user bearer context, for example, according to the service. The quality requirement indicates that the data on the bearer is not damaged, and the PGW can end the tagged packet in the context of the bearer path. When the PGW receives the update bearer indication, the data is sent from the source side path, and the data is sent by the target side path. Therefore, the PGW may directly send the end tag packet without obtaining an indication from the MME. That is, after receiving the update bearer request sent by the target side SGW, the path switch is directly performed, and the data is not sent from the source side path, but the data is sent by the target side path, and the end tag packet is sent directly to the old bearer path. .

Referring to FIG. 4, another embodiment of the handover method in the embodiment of the present invention includes:

401. The source side access network element determines to initiate a handover.

402. The source side access network element sends a handover request message to the source side mobility management network element.

403. The source-side mobility management network element sends a forward handover request to the target-side mobility management network element. The source-side mobility management network element selects the target-side mobility management network element, and sends a forward handover request message, where the message includes the mobility management context of the user. And the user plane carries context information.

404. The target network allocates resources;

405. The target side mobility management network element feeds back the forward handover response message to the source side mobility management network element.

406. The source-side mobility management network element sends a create bearer request to the source side SGW.

407. The source side SGW feeds back to the source side mobility management network element to create a bearer response.

408. The source-side mobility management network element sends a handover command to the source-side access NE to indicate that the source network starts to switch.

409. The source side access network element sends a handover command to the user equipment to notify the UE to start the handover.

410. The source side access network element starts to forward data to the target network.

412. The target side access network element sends a handover notification to the target side mobility management network element. After the target side access network element confirms that the user equipment is accessed, the handover notification is sent to the target side mobility management network element.

413. The target side mobility management network element sends a forward handover completion message to notify the source side mobility management network element.

414. The source side mobility management network element returns a forward handover completion confirmation message to the target side mobility management network element.

415. The target side mobility management network element sends an update bearer request message to the target side SGW to update the user plane bearer information.

In this embodiment, the update bearer request carries the indication information, where the indication information is used to indicate that the SGW has a path switch, or directly indicates that the end tag packet needs to be delivered, and even indicates that the bearer list of the end tagged packet needs to be delivered.

416. The target side SGW sends an update bearer request to the PGW.

417. The PGW feeds back an update response to the target side SGW.

418. The PGW sends an end tag packet to the source side access network element.

In this embodiment, the update bearer request received by the PGW from the target side SGW includes the indication information, which is used to indicate that the SGW has a path switch, or directly indicates that the end tag packet needs to be delivered, and even indicates that the bearer of the end tag packet needs to be delivered. List.

The PGW can learn that the SGW changes according to the indication information, and then the data is sent from the source side path, and the data is sent by the target side path. Therefore, the PGW can learn that the source side data has been delivered, so that the end marker packet can be delivered. .

419. The source side access network element forwards the end tag packet to the target side access network element, and the target side access network element receives the foregoing end tag packet, so that the downlink information from the target side core network can be started to be sent to the user equipment. Data

420. The target side SGW returns an update bearer response message to the target side mobility management network element.

It should be noted that, after the end of the marking packet transmission is completed, the source side SGW releases its own user. Resources.

In the foregoing embodiment shown in FIG. 3 and FIG. 4, the process of the PGW transmitting the end tag packet to the source side access network element may be: the PGW sends an end tag packet to the source side SGW, and the source side SGW connects to the source side. The inbound network element forwards the end tag packet. It can be understood that, in an actual application, the PGW may also send the end tag packet to the source side access network element by using other methods, which is not limited herein.

In the foregoing embodiment, the update bearer request sent by the target-side mobility management network element to the target-side SGW carries the indication information, and the target-side SGW sends the indication to the PGW by updating the bearer request, which is understandable, in actual application. The PGW may not need to obtain the indication of the target side mobility management network element, but always sends the end tag packet after receiving the update bearer request sent by the target side SGW, or judges whether it is based on the service quality requirement of the user bearer context. The end tag packet needs to be delivered. For example, according to the quality of service requirement, the data is required to be lossless on a bearer, and the PGW can end the tag packet in the bearer path context.

It should be noted that the process of sending the end tag packet by the PGW may also adopt the following manner: When the PGW receives the update bearer indication, the data is sent from the source side path, and the target side is transferred. The data is sent by the path. Therefore, the PGW can directly send the end tag packet without receiving an indication from the MME, that is, after receiving the update bearer request sent by the target side SGW, the PGW can directly perform path switching, and no longer send data from the source side path. The data is sent by the target side path, and the end tag packet is sent directly to the old bearer path.

3. The end tag packet is sent by the target side SGW:

In this embodiment, after the source side data transmission is completed, the target side SGW sends an end tag packet to the target side access network element, where the target side access network element sends the downlink data from the target side core network to the user equipment. .

Referring to FIG. 5, another embodiment of the handover method in the embodiment of the present invention includes:

501. The user equipment transmits uplink and downlink data through the source base station and the PGW.

502. The source base station negotiates with the target base station to perform handover.

When the user equipment meets the switching conditions (for example, moving from one network coverage to another) The coverage of the network, the source base station and the target base station perform a handover preparation process, and instruct the user equipment to switch from the source base station to the target base station, and the specific process is not limited.

503. The source base station forwards downlink data that is not sent to the user equipment to the target base station.

504. The target base station sends the received forwarding data to the user equipment.

505. The user equipment sends uplink data to the PGW by using the target base station.

506. The target base station sends a path switch request to the MME.

In this embodiment, the target base station sends a path switching request to the MME, and notifies the MME that the user equipment changes the cell, and the path switching request includes the global cell identity information of the target cell, and the MME may determine, according to the global cell identity information, that the user equipment is served. The SGW selects a new SGW to provide services for the user equipment, that is, the target side SGW.

507. The MME sends a create bearer request to the target side SGW.

In this embodiment, the MME sends a request to the target SGW to include the indication information, which is used to indicate that the SGW has performed the path switching, and the source side data has been delivered, or directly indicates that the end tag packet needs to be delivered, and even indicates that the The bearer list of the end tag package is delivered.

It should be noted that, in this embodiment, similar to the first embodiment, the MME also needs to start a timer, and sends a create bearer request after the timer expires.

In this embodiment, the data on the source side refers to the data sent by the PGW through the source side SGW, and the data on the target side refers to the data that is sent by the PGW through the target side SGW, that is, after the SGW is switched, the PGW sends the data. There are two paths, one is the path where the source side SGW is located, which is called the source side path, and the other is the path where the target side SGW is located, which is called the target side path. When the PGW receives the update bearer indication, The data is sent from the source side path, and the data is sent by the target side path.

508. The target side SGW sends an update bearer request to the PGW.

The target side SGW allocates a user plane resource that receives downlink data, and sends an update bearer request message. For the PGW, the message contains the user plane information for receiving the downlink data.

509. The PGW returns an update bearer response message to the SGW.

510. The target side SGW sends an end tag packet to the target side base station according to the indication of the ΜΜΕ; the target side SGW forwards the end tag packet to the target side base station, and is used to indicate that the target side base station can start to send the user equipment from the target side core network. Downstream data.

511. The target side SGW sends a create response message to the MME.

512. The PGW sends downlink data to the user equipment by using the target side base station.

513. The MME sends a path switch confirmation message to the target side base station.

514. The user equipment sends uplink data to the PGW by using the target side base station.

515. The target-side base station notifies the source-side base station that the handover is successful, and requests the source-side base station to release the resource.

516. The MME sends a delete bearer request to the source SGW.

517. The source side SGW feeds back the delete response message to the MME.

In the above embodiment, the MME sends the indication request to the target side SGW to carry the indication information. It can be understood that, in an actual application, the target side SGW may not need to obtain the indication of the MME, but according to the user bearer context. The service quality requirement is to determine whether the end tag package needs to be delivered. For example, according to the service quality requirement, the target side SGW can deliver the end tag packet.

It should also be noted that The way described:

After the MME does not need to wait for the timer to expire, the MME sends a request to create a bearer request to the source SGW. The target bearer does not carry the indication information, and the target SGW sends an update bearer request to the PGW after receiving the request to create the bearer. After the PGW feedback update bearer response, a timer is started. After the timer reaches the preset time, the target side SGW confirms that the source side data transmission is completed, that is, the end tag packet is sent, and the user plane resource is released.

B. 3GPP network (changing the switching of the core network mobility management network element):

Referring to FIG. 6, another embodiment of the handover method in the embodiment of the present invention includes:

601. The source side access network element determines to initiate a handover.

602. The source side access network element sends a handover request message to the source side mobility management network element.

603. The source-side mobility management network element sends a forward handover request to the target-side mobility management network element. The source-side mobility management network element selects the target-side mobility management network element, and sends a forward handover request message, where the message includes the mobility management context of the user. And the user plane carries context information.

604. The target network allocates resources;

605. The target-side mobility management network element feeds back the forward handover response message to the source-side mobility management network element.

606. The source-side mobility management network element sends a create bearer request to the source side SGW.

607. The source side SGW sends a bearer response to the source side mobility management network element to generate a bearer response.

608. The source-side mobility management network element sends a handover command to the source-side access NE to indicate that the source network starts to switch.

609. The source side access network element sends a handover command to the user equipment to notify the UE to start the handover.

610. The source side access network element starts to forward data to the target network. 612. The target side access network element sends a handover notification to the target side mobility management network element.

613. The target-side mobility management network element sends a forward handover completion message to notify the source-side mobility management network element. 614. The source-side mobility management network element returns a forward handover completion confirmation message to the target-side mobility management network element.

615. The target side mobility management network element sends an update bearer request message to the target side SGW to update the user plane bearer information.

In this embodiment, the update bearer request sent by the target side mobility management network element to the target side SGW includes indication information, which is used to indicate that the SGW has a path switch, and the source side data has been delivered, or directly indicates that the delivery needs to be completed. Mark the package, even indicating the list of bearers that need to deliver the end tag package.

It should be noted that, in this embodiment, similar to the first embodiment, the target-side mobility management network element also needs to start a timer, and sends an update bearer request after the timer expires.

616. The target side SGW sends an update bearer request to the PGW.

617. The PGW feeds back the updated load response to the target side SGW.

618. The target side SGW sends an end tag packet to the target side access network element, where the target side access network element can start to send downlink data from the target side core network to the user equipment.

619. The target side SGW returns an update bearer response message to the target side mobility management network element.

In the foregoing embodiment, the update bearer request sent by the target side mobility management network element to the target side SGW carries the indication information. It can be understood that, in the actual application, the target side SGW may not need to obtain the source side mobility management network element. The indication of the quality of service by itself based on the user's hosting context To determine whether the end tag packet needs to be delivered, for example, according to the quality of service requirement, the data on the bearer is required to be lossless, and the target side SGW may end the tag packet in the bearer path context. The way described:

After the MME does not need to wait for the timer to expire, the MME sends an update bearer request to the source SGW. The update bearer request does not carry the indication information, and the target side SGW sends the update bearer request to the PGW after receiving the create bearer request, and After the PGW feedback update bearer response, a timer is started. After the timer reaches the preset time, the target SGW confirms that the source side data transmission is completed, that is, the end tag packet is sent, and the user plane resource is released.

The above describes how to ensure non-destructive switching of data when the user equipment changes from the source network to the target network, specifically,

When the source network is GERAN, the source side access network element is a base station subsystem, and the source side mobility management network element is a Serving GPRS Supporting Node (SGSN);

When the source network is UTRAN, the source side access network element is a radio network controller, and the source side mobility management network element is an SGSN;

When the source network is EUTRAN, the source side access network element is an evolved base station, and the source side mobility management network element is an MME;

When the target network is GERAN, the target side access network element is a base station subsystem, and the target side mobile management network element is an SGSN;

When the target network is UTRAN, the target side access network element is a radio network controller, and the target side mobile management network element is an SGSN;

When the target network is EUTRAN, the target side access network element is an evolved base station, and the target side mobile management network element is an MME.

In the above embodiment, after the source side serving gateway SGW switches to the target side SGW, the network side core network device sends an end tag packet to the target side access network element, where the end tag packet is used to indicate the target side access network element. The downlink data from the target side core network is sent to the user equipment, so even if the service gateway changes, the target side access network element can still obtain the end tag packet from the network side core network device, so as to be used for data lossless handover, The lossless switching of data is achieved in the event of a change in the SGW. The following describes the embodiment of the communication system in the embodiment of the present invention. Referring to FIG. 7, the embodiment of the communication system in the embodiment of the present invention includes:

The network side core network device 702 is configured to send an end tag packet to the target side access network element 701 after the access network handover occurs and the source side serving gateway SGW switches to the target side SGW.

The target side access network element 701 is configured to receive the end tag packet sent by the network side core network device 702, and send the downlink data from the target side core network network to the user equipment after receiving the end tag packet. .

The network side core network device 702 includes:

Source side SGW, or target side SGW, or PGW.

For ease of understanding, the following is a detailed description of the embodiment of the communication system:

The source side access network element interacts with the target side access network element to determine that handover is required, and the source side access network element and the target side access network element perform handover preparation, and forward data to complete the handover;

The target side access network element sends a path switch request to the MME in the network side core device, and the MME completes the bearer creation and update process between the path switch request and the target side SGW and the PGW, and receives the response of the target side SGW feedback. Then, a timer is started, and a path switch confirmation message is sent to the target side access NE.

When the MME-initiated timer overflows, the source-side data is sent, and the MME sends a delete bearer request to the source SGW. The delete bearer request includes indication information, which is used to indicate that the SGW path changes. The source side SGW sends an end tag packet;

The source side SGW feeds back the bearer response to the MME, and sends an end marker packet to the source side access network element, and the source side access network element forwards the end marker packet to the target side access NE, and the source side SGW sends the end. After tagging the package, release its own user plane resources.

The following describes the SGW embodiment in the embodiment of the present invention. Referring to FIG. 8, the service gateway embodiment in the embodiment of the present invention includes:

Trigger unit 801, when an access network handover occurs and the source side serving gateway SGW switches to the target side

After the SGW, when the preset transmission condition is met, the sending unit 802 is triggered;

The sending unit 802 is configured to send, according to the triggering of the triggering unit 801, the end tag packet to the target side access network element, where the end tag packet is used to indicate that the target side access network element according to the end tag packet The indication sends downlink data from the target side core network to the user equipment. It should be noted that the trigger unit 801 may specifically include at least one of the following subunits:

The indication receiving subunit 8011 is configured to receive the indication information sent by the mobility management network element, and confirm that the preset transmission condition is met according to the indication information, where the indication information is used to indicate the sending end tag packet;

Or

The bearer processing request receiving sub-unit 8012 is configured to receive a bearer processing request sent by the mobility management network element, and confirm that the preset sending condition is met according to the bearer processing request, where the bearer processing request includes deleting a bearer request, or creating a bearer request, Or updating the bearer request, where the bearer processing request is sent by the mobility management network element after determining that the downlink data of the source side core network is sent; the determining unit sub-unit 8013 is configured to receive the delete bearer request, or After the bearer request is created, or the bearer request is updated, a timer is started, and when the timer expires, it is determined that the preset sending condition is met.

It should be noted that the bearer processing request received by the bearer processing request receiving unit 8012 may be to delete a bearer request, or create a bearer request, or update a bearer request.

The service gateway in this embodiment may further include:

The determining unit 803 is configured to further determine, according to the preset quality of service parameter, that the end tag packet needs to be delivered when the triggering unit triggers the sending unit, and if yes, instruct the sending unit to send the end tag packet;

The resource release unit 804 is configured to release the user plane resource after the sending unit 802 sends the end tag packet to the target side access network element.

When the SGW in the embodiment is used as the source SGW, the bearer processing request receiving unit 8012 in the triggering unit 801 receives the delete bearer request from the MME.

And the sending unit 802 sends the end tag packet to the target side access network element according to the deleting bearer request;

And the source side SGW needs to include a resource release unit 804;

When the SGW in the embodiment is used as the target SGW, the bearer processing request receiving unit 8012 in the triggering unit 801 receives the update bearer request from the MME.

Then, the sending unit 802 sends the end to the target side access NE according to the update bearer request. Tag package.

Referring to FIG. 9, the embodiment of the packet data network gateway in the embodiment of the present invention includes: an end tag packet triggering unit 901, configured to meet the pre-sale after the access network handover occurs and the source side serving gateway SGW switches to the target side SGW. When the transmission condition is set, the trigger end tag transmission unit 902 is triggered;

An end tag packet sending unit 902, configured to send an end tag packet to the source side access network element according to the trigger of the end tag packet triggering unit 901, where the end tag packet is used to indicate the target side access network element Downlink data from the target side core network is delivered to the user equipment according to the indication of the end tag packet.

In this embodiment, the end tagged packet triggering unit 901 may include at least one of the following subunits:

The sending indication receiving subunit 9011 is configured to receive the indication information sent by the target side serving gateway SGW, and confirm that the preset sending condition is met according to the indication information, where the indication information is used to indicate that the end tag packet is sent;

Or

The update bearer request receiving unit 9012 is configured to receive an update bearer request sent by the target side SGW, and confirm that the preset sending condition is met according to the update bearer request.

It should be noted that the update bearer request sent by the target SGW may include the indication information. The packet data network gateway in this embodiment may further include:

The sending determining unit 903 is configured to further determine, according to the preset quality of service parameter, whether to send the end tag packet when the end tag packet triggering unit triggers the end tag packet sending unit, and if yes, instruct the end tag packet sending The unit sends the end tag packet.

It will be understood by those skilled in the art that all or part of the steps of implementing the foregoing embodiments may be performed by a program to instruct related hardware, and the program may be stored in a computer readable storage medium. The method includes the following steps: the target side access network element receives the end tag packet;

The target side access network element sends downlink data from the target side core network to the user equipment according to the indication of the end marking packet. The above-mentioned storage medium may be a read only memory, a magnetic disk or an optical disk or the like.

The foregoing describes a handover method, a communication system, and related devices provided by the present invention. For those skilled in the art, the embodiments of the present invention may be changed in specific implementation manners and application scopes. In the above, the contents of this specification are not to be construed as limiting the invention.

Claims

Rights request

A handover method, comprising: receiving, by a target side access network element, an end tag packet;

The target side access network element sends downlink data from the target side core network to the user equipment according to the indication of the end marking packet.

The method according to claim 1, wherein the receiving, by the target side access network element, the end tag packet comprises:

The method according to claim 2, wherein the target side access network element receives the end tag packet sent by the source side SGW through the source side access network element, and includes:

After receiving the indication information of the mobility management network element, or receiving the deletion bearer request sent by the mobility management network element, the source side SGW sends the end tag packet to the target side access network element by using the source side access network element;

The indication information or the deletion bearer request is sent after the mobile management network element determines that the downlink data of the source side core network is sent, and the indication information is used to indicate that the source SGW sends an end tag packet;

Or,

The source side SGW receives the delete bearer request sent by the mobility management network element, and determines that the downlink data of the source side core network is sent, and then sends the end tag packet to the target side access network element by using the source side access network element. .

The method according to claim 3, wherein the indication information is included in the delete bearer request.

The method according to claim 3, wherein after the source side SGW receives the delete bearer request sent by the mobility management network element, the source side access network element sends an end tag to the target side access network element by using the source side access network element. The package also includes:

And determining, according to the QoS requirement of the user bearer context, whether the end tag packet needs to be delivered, and if so, triggering the step of sending the end tag packet to the target side access NE by the source side access NE.

6. The method according to claim 3, wherein the mobility management network element determines The downlink data transmission of the source side core network is completed:

When the access network is switched, if the core network mobility management network element does not change, the mobile management network element starts a timer after receiving the create bearer response sent by the target side SGW;

After the timer expires, the mobility management network element determines that the downlink data of the source side core network is sent.

Or,

When the access network is switched, if the core network mobility management network element changes, the source side mobility management network element starts a timer after receiving the forward handover completion message sent by the target side mobility management network element; After the timer expires, the source-side mobility management network element determines that the downlink data of the source-side core network is transmitted.

The method according to claim 3, wherein the determining, by the source side SGW, the downlink data transmission of the source side core network comprises:

After receiving the delete bearer request, the source SGW starts a timer;

After the timer expires, it is determined that the downlink data of the source side core network is sent.

The method according to claim 1, wherein the target side access network element receiving the end tag packet comprises: a bundle tag packet.

The method according to claim 8, wherein the target side access network element receives the end tag packet sent by the PGW through the source side access network element, including:

After receiving the indication information sent by the mobility management network element by the target side SGW, the PGW sends an end marker packet to the target side access network element by using the source side access network element, where the indication information is used to indicate that the PGW is sent. End tag package;

Or,

After receiving the update bearer request sent by the target side SGW, the PGW sends an end tag packet to the target side access NE through the source side access NE.

The target side access network element receives the end tag packet sent by the target side SGW.

The method according to claim 10, wherein the target side access network element receives the end tag packet sent by the target side SGW, including:

After receiving the indication information of the mobility management network element, or after receiving the creation of a bearer request or an update bearer request sent by the mobility management network element, the target side SGW sends an end tag packet to the target side access network element, where The indication information, the creation of the bearer request, or the update of the bearer request is sent by the mobile management network element after the downlink data of the source-side core network is sent, and the indication information is used to indicate that the source-side SGW delivers the end tag packet. ;

Or,

The target side SGW receives the create bearer request or the update bearer request sent by the mobility management network element, and determines that the downlink data of the source side core network is sent, and then sends an end tag packet to the target side access network element.

The method according to claim 11, wherein the indication information is included in the create bearer request or the update bearer request.

The method according to claim 11, wherein after the target side SGW receives the create bearer request or the update bearer request sent by the mobility management network element, the target side SGW sends the end tag packet to the target side access network element. Includes:

According to the quality of service requirement of the user bearer context, it is determined whether the end tag packet needs to be delivered, and if so, the step of sending an end tag packet to the target side access NE is triggered.

The method of claim 11, wherein the determining, by the mobility management network element, the downlink data transmission of the target side core network comprises:

Or

When the access network is switched, if the core network mobility management network element changes, the target side mobility management network element starts a timer after transmitting the forward handover completion message to the source side mobility management network element;

After the timer expires, the target side mobility management network element determines that the downlink data transmission of the source side core network is completed.

The method according to claim 11, wherein the determining, by the target side SGW, the downlink data transmission of the source side core network includes:

After receiving the request to create a bearer or update the bearer, the target SGW starts a timer. After the timer expires, it determines that the downlink data of the source core network is sent.

16. A method according to any one of claims 3, 4, 5, 6, 7, 9, 11, 12, 13, 14 or 15, characterized in that

The mobility management network element is a mobility management entity MME, or a serving general packet radio service node SGSN.

17. A communication system, comprising:

The network side core network device is configured to send an end tag packet to the target side access NE after the access network handover occurs and the source side serving gateway SGW switches to the target side SGW.

The target side access network element is configured to receive the end tag packet sent by the network side core network device, and send the downlink data from the target side core network network to the user equipment after receiving the end tag packet.

The communication system according to claim 17, wherein the network side core network device comprises:

Source side SGW, or target side SGW, or PGW.

19. A service gateway, comprising:

a triggering unit, when an access network handover occurs and the source side serving gateway SGW switches to the target side SGW, and is configured to trigger the sending unit when the preset sending condition is met;

a sending unit, configured to send the end tag packet to the target side access network element according to the trigger of the trigger unit, where the end tag packet is used to indicate that the target side access network element indicates according to the end tag packet Downstream data from the target side core network is delivered to the user equipment.

The service gateway according to claim 19, wherein the trigger unit comprises at least one of the following subunits:

And the indication receiving unit is configured to receive the indication information sent by the mobility management network element, and confirm that the preset transmission condition is met according to the indication information, where the indication information is used to indicate that the end tag packet is sent;

Or

a bearer processing request receiving subunit, configured to receive a bearer processing request sent by the mobility management network element, where Confirming that the preset transmission condition is met according to the bearer processing request, the bearer processing request includes deleting a bearer request, or creating a bearer request, or updating a bearer request, where the bearer processing request determines the mobility management network element The downlink data of the source side core network is sent after the transmission is completed;

Or

The self-determining sub-unit is configured to start a timer after receiving the delete bearer request, or create a bearer request, or update the bearer request, and when the timer expires, determine that the preset sending condition is met.

The service gateway according to claim 20, wherein the service gateway further comprises:

The determining unit is configured to further determine, according to the preset service quality parameter, whether to issue the end tag packet when the trigger unit triggers the sending unit, and if yes, instruct the sending unit to send the end tag packet.

The service gateway according to any one of claims 19 to 21, wherein the service gateway comprises: a source side serving gateway SGW or a target side serving gateway SGW.

The service gateway according to claim 22, wherein when the serving gateway is a source side SGW, the serving gateway further includes:

And a resource release unit, configured to release the user plane resource after the sending unit sends the end tag packet to the target side access network element.

24. A packet data network gateway, comprising:

End tag packet triggering unit, configured to trigger an end tag packet sending unit when the preset sending condition is met;

An end tag packet sending unit, configured to send an end tag packet to the source side access network element according to the trigger of the end tag packet triggering unit, where the end tag packet is used to indicate that the target side access network element is configured according to the The indication of the end tag packet delivers downlink data from the target side core network to the user equipment.

The packet data network gateway according to claim 24, wherein the end tag packet triggering unit comprises at least one of the following subunits:

The sending indication receiving unit is configured to receive the indication information sent by the target side serving gateway SGW, and confirm that the preset sending condition is met according to the indication information, where the indication information is used to indicate the sending end tag packet;

Or The update bearer request receiving subunit is configured to receive an update bearer request sent by the target side SGW, and confirm that the preset sending condition is met according to the update bearer request.

The packet data network gateway according to claim 24 or 25, wherein the sending determining unit is configured to further perform the preset service quality when the end tag packet triggering unit triggers the end tag packet sending unit The parameter determines whether it is necessary to deliver the end tag packet, and if so, instructs the end tag packet sending unit to send the end tag packet.