WO2017193555A1 - Cell handover method and system - Google Patents

Abstract

The present disclosure relates to a cell handover method and system. The method comprises: a first target base station sends handover information and a record message to a handover recording node, so that the handover recording node records first-time handover information, the first target base station being a target base station determined by a source base station according a target physical cell identifier reported by user equipment (UE), and the target physical cell identifier being a physical cell identifier of a cell of a second target base station and determined by the UE; if the UE fails to access the second target base station, the second target base station obtains a first-time handover target base station through searching; the first target base station cooperates with the second target base station to perform second-time handover preparation, and the first target base station sends a first-time handover complete notification to the source base station; the second target base station sends RRC connection reestablishment and reconfiguration to the UE, and configures RRC by using a second handover resource, so that the UE successfully accesses the second target base station; the second target base station sends a path handover request, so that a data bearer channel is handed over to the second target base station, thereby improving the success rate of cell handover.

Description

Method and system for cell handover Technical field

The present application relates to the field of mobile communications, for example to a method and system for cell handover.

Background technique

In a Long Term Evolution (LTE) system, after a user equipment (UE) initiates a data service call, it is between different macro base stations (evolved Node Bs, eNBs) or home macro base stations (Home eNodeBs, HeNBs). When moving, you need to switch to ensure data service continuity.

In actual deployment, there is a case where the physical cell identifier (PCI) of the neighboring base station cell in the vicinity of the source base station is the same. The eNB cannot accurately identify the target base station expected by the UE when the handover decision is made, and may switch to the wrong target base station, causing the handover to fail. .

Summary of the invention

Based on this, a method and system for cell handover are provided to improve the cell handover success rate.

A method for cell handover, the method comprising:

The first target base station sends a handover information record message to the handover record node, so that the handover record node records the first handover information, where the first target base station is the target base station determined by the source base station according to the target physical cell identifier reported by the user equipment UE. The physical cell identifier is a physical cell identifier of a cell of a second target base station that meets a handover threshold determined by the UE;

If the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target base station queries the handover record node to obtain the first handover target base station as the first target base station;

The first target base station cooperates with the second target base station to perform secondary handover preparation, and the second target base station allocates a second handover resource;

Sending, by the first target base station, a first handover completion notification to the source base station;

The second target base station sends a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and uses the second handover resource to configure the RRC, so that the UE succeeds in accessing the second target base station according to the second handover resource. Sending a configuration success response to the second target base station;

The second target base station sends a path switch request to switch the data bearer channel to the second target base station.

A system for cell handover, the system comprising:

The secondary switching source base station processing module is configured to enable the first target base station to send a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the source base station according to the user equipment. a target base station determined by the target physical cell identifier reported by the UE, where the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE;

The secondary handover target base station processing module is configured to enable the second target base station to query the handover record node to obtain the first handover target if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station The base station is the first target base station;

The secondary handover source base station processing module is further configured to cooperate with the secondary handover target base station processing module to cooperate with the second target base station to perform secondary handover preparation, the second target base station Allocating a second switching resource;

The secondary handover source base station processing module is further configured to enable the first target base station to send a first handover completion notification to the source base station;

The secondary handover target base station processing module is further configured to enable the second target base station to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC by using the second handover resource, so that the UE according to the Transmitting the second handover resource to the second target base station successfully, and sending a configuration success response to the second target base station;

The secondary handover target base station processing module is further configured to cause the second target base station to send a path switch request to switch the data bearer channel to the second target base station.

The method and system for the cell handover described above, the first target base station sends a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the target physical cell identifier reported by the source base station according to the user equipment UE. Determined target base station, target physical cell identifier The physical cell identifier of the cell of the second target base station that meets the handover threshold determined by the UE, if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target base station queries the handover record node to obtain The first target base station is the first target base station, the first target base station cooperates with the second target base station to perform the second handover preparation, the second target base station allocates the second handover resource, and the first target base station sends the first handover completion notification to the source base station, The second target base station sends the RRC connection re-establishment and the RRC connection reconfiguration to the UE, and configures the RRC by using the second handover resource, so that the UE successfully sends the configuration to the second target base station according to the second handover resource successfully accessing the second target base station. In response, the second target base station sends a path switch request to switch the data bearer channel to the second target base station. Even if the physical cell identifier of the neighboring cell is the same, causing the first handover to fail, the first handover target may be obtained by first switching the information. , thereby performing resource reconfiguration between the wrong target base station and the correct target base station , So that again a successful handover, improve the success rate cell switching.

A system for cell handover, the system comprising: a first target base station, a second target base station, and a handover record node;

The first target base station is configured to send a handover information record message to the handover record node, so that the handover record node records the first handover information, where the first target base station is a target base station according to the target reported by the user equipment UE a target base station determined by the physical cell identifier, where the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE;

The second target base station is configured to: if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, querying the handover record node to obtain the first handover target base station as the first target base station ;

The first target base station is further configured to cooperate with the second target base station to perform secondary handover preparation;

The second target base station is further configured to allocate a second handover resource;

The first target base station is further configured to send a first handover completion notification to the source base station;

The second target base station is further configured to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC by using the second handover resource, so that the UE accesses the second according to the second handover resource. The target base station succeeds, and sends a configuration success response to the second target base station;

The second target base station is further configured to send a path switch request to switch the data bearer channel to the second target base station.

Embodiments of the present disclosure also provide a non-transitory computer readable storage medium storing a computer Execution of instructions, the computer executable instructions being arranged to perform the above method.

An embodiment of the present disclosure further provides an electronic device, including:

At least one processor;

a memory communicatively coupled to the at least one processor; wherein

The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to cause the at least one processor to perform the method described above.

In the system for cell handover, the first target base station sends a handover information record message to the handover record node by using the cooperation of the first target base station, the second target base station, and the handover record node, so that the handover record node records the first handover information, first. The target base station is a target base station determined by the source base station according to the target physical cell identifier reported by the user equipment UE, and the target physical cell identifier is a physical cell identifier of the second target base station that meets the handover threshold determined by the UE, if the UE uses the first target base station. The first target base station fails to access the second target base station, and the second target base station queries the handover record node to obtain the first handover target base station as the first target base station, and the first target base station cooperates with the second target base station to perform secondary handover preparation. The second target base station allocates a second handover resource, the first target base station sends a first handover completion notification to the source base station, and the second target base station sends a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and uses the second handover resource to configure the RRC. So that the UE accesses the second target according to the second handover resource The base station succeeds in transmitting a configuration success response to the second target base station, and the second target base station sends a path switch request to switch the data bearer channel to the second target base station, even if the physical cell identifier of the neighboring cell is the same, causing the first handover to fail. The first time the information is switched, the error target base station can be switched for the first time, so that the resource reconfiguration between the error target base station and the correct target base station is performed, so that the handover is successful again, and the success rate of the cell handover is improved.

BRIEF abstract

1 is an application environment diagram of a method for cell handover in an embodiment;

2 is a flow chart of a method for cell handover in an embodiment;

3 is a sequence diagram of an eNB performing an S1 handover to an eNB in an embodiment;

4 is a sequence diagram of an eNB performing an X2 handover to an eNB in an embodiment;

5 is a sequence diagram of an eNB performing an S1 handover to a HeNB in an embodiment;

6 is a sequence diagram of an eNB performing an X2 handover to an HeNB when there is an X2GW in an embodiment;

7 is a sequence diagram of an eNB performing an X2 handover to an HeNB without an X2GW in an embodiment;

8 is a structural block diagram of a system for cell handover in an embodiment;

9 is a structural block diagram of another system for cell handover in an embodiment;

FIG. 10 is a schematic structural diagram of an electronic device in an embodiment.

Embodiments of the invention

FIG. 1 is an application environment diagram of a method for cell handover in an embodiment. As shown in FIG. 1 , the application environment includes a macro base station eNB, a home macro base station HeNB, a home macro base station gateway HeNB GW, an X2 gateway X2GW path, and mobility. The management entity MME and the serving gateway S-GW, wherein the eNB and the HeNB are network devices that provide wireless access for users, and the MME and the S-GW belong to nodes of the core network. The eNB establishes an S1 connection with the MME separately, and an X2 connection can be established between the eNB and the neighboring eNB. The HeNB needs to establish an S1 connection with the MME after the S1 convergence of the HeNB GW. The H2 can directly establish an X2 connection between the HeNB and the eNB, that is, the X2 connection can be established directly or through the X2GW. The handover scenario of the source base station to the target base station may be divided into an S1 handover by the eNB to the eNB, an X2 handover of the eNB to the eNB, an S1 handover of the eNB to the HeNB, and an X2 handover of the eNB to the HeNB.

As shown in FIG. 2, in an embodiment, a method for cell handover is provided, which is applied to the foregoing application environment, and includes the following steps:

In step S610, the first target base station sends a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the target base station determined by the source base station according to the target physical cell identifier reported by the user equipment UE, and the target The physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE.

The method for the UE to determine the cell of the second target base station eNB2 that meets the handover threshold is self-definable. For example, the source base station eNB sends a configuration message to the UE, and carries the measurement policy, and the UE measures the neighboring cell according to the measurement policy to obtain the second threshold that meets the handover threshold. The cell of the target base station, or the UE determines the cell of the second target base station that meets the handover threshold according to the history information. Obtaining a physical cell identifier of a cell of the second target base station to obtain a target physical cell identifier. The UE reports the target physical cell identifier to the source eNB, and reports the target physical small The manner of the area identifier is not limited, for example, the target physical cell identifier may be carried in the measurement report. The source eNB searches for the maintained neighboring cell information by using the target physical cell identifier, and confirms that the handover target base station is the first target base station eNB1. Since the neighboring cells have the same PCI, the target base station determined by searching the neighboring cell information by the target physical cell identifier is not the eNB2, but the erroneous target base station, that is, the eNB1. In an embodiment, the source eNB determines a target base station according to the autonomous decision, and the determined target base station is the eNB1, which is different from the second target base station eNB2 determined by the UE. In this case, the handover may also be unsuccessful. The source eNB initiates a handover procedure to the eNB1. The handover procedure is different according to the type of the target base station and the handover type. The handover type includes but is not limited to the S1 handover and the X2 handover. The X2 handover is further divided into an X2 handover with X2GW and no X2GW. The X2 handover, the type of eNB1 includes but is not limited to a macro base station, a home macro base station. After the handover process is initiated, the eNB1 allocates a first handover resource to the UE, and the source eNB sends an RRC connection configuration message to the UE. The UE determines the handover threshold to be the cell of the eNB2, and the UE uses the first target base station according to the RRC connection configuration message. The allocated first handover resource is switched to the second target base station. Since the resource and the target base station do not match, the first handover is unsuccessful, and the UE cannot access the second target base station.

The first target base station sends a handover information record message to the handover record node, and the transmission time point can be adjusted according to requirements, such as sending in the previous step of the UE attempting to access the second target base station, so that the handover record node can be queried for the first time immediately after the handover failure. Switch information. The switching record node is a device that stores the switching information record. After receiving the switching information record message, the first switching information is acquired and recorded. The switch record node may be one or more according to the type of the target base station and the switch type, and may be one of the nodes involved in the handover process or other independent devices not related to the handover process. The switching information includes information such as the source base station identifier, the identifier assigned by the user at the source base station, and the target base station identifier. The format and transmission mode of the information are not limited. The storage form of the first switching information in the switching record node is not limited, and the conversion processing is performed in a form that is easy to find.

Step S620: If the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target base station queries the handover record node to obtain the first handover target base station as the first target base station.

After the handover fails, the UE may send a re-establishment request message to the eNB2, and the carrying cause value is a handover failure. The eNB2 may initiate a process of querying the handover target node for the first handover of the target base station, such as sending the source base station identifier to the handover record node, and the user is at the source. The identifier assigned by the base station is used to query that the first handover target base station is the first target base station, and the converted query keyword may also be sent to the handover record node for query.

Step S630, the first target base station cooperates with the second target base station to perform secondary handover preparation, and the second target base station allocates the second handover resource.

The secondary handover preparation needs to prepare a handover resource, and the eNB1 may send a secondary handover request message to the eNB2, and the eNB2 may allocate the second handover resource and respond to the secondary handover request response message.

Step S640, the first target base station sends a first handover completion notification to the source base station.

Depending on the type of the handover and the type of the target base station, the first handover completion notification may be directly sent to the source base station to release the UE context resource, or the first handover completion notification may be forwarded by other nodes, such as the MME, the HeNB GW, and the X2GW. The resources and other related information allocated by the user on the base station are UE context resources. And according to the handover type and the target base station type, the time point for transmitting the first handover completion notification may be different, for example, the release of the UE context resource may be performed after the step of the secondary handover completion notification.

In one embodiment, when switching to X2 handover, step S140 is performed after the step of the second target base station transmitting a path switch request to switch the data bearer channel to the second target base station.

After the data bearer channel is switched to the second target base station, the second target base may notify the first target base station that the secondary handover is complete, and the first target base station sends the UE context resource release request to the source base station, and may also pass other nodes, such as the HeNB GW. The X2GW transits the UE context resource release request to release the resource. Then, the release of the first handover completion notification and the secondary handover completion notification corresponding resources are combined, which reduces the unnecessary data interaction process and improves the efficiency.

Step S650: The second target base station sends a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and uses the second handover resource to configure the RRC, so that the UE successfully accesses the second target base station according to the second handover resource to the second The target base station sends a configuration success response.

The RRC connection re-establishment message may carry the newly allocated resource, that is, the second handover resource, and request the UE to re-establish the RRC according to the new resource. After receiving the RRC connection re-establishment message, the UE uses the second handover resource to establish the signaling bearer of the UE, and the RRC is successfully reconstructed. Then, an RRC Connection Reestablishment Complete message is sent to the eNB2. The second target base station sends an RRC connection reconfiguration to the UE, and the UE uses the second handover resource to configure the RRC, and the signaling bearer and the data bearer parameter are configured. If the configuration succeeds, the UE successfully accesses the second target base station according to the second handover resource, An RRC Connection Configuration Complete message is sent to eNB2.

Step S660, the second target base station sends a path switch request to switch the data bearer channel to the second target base station.

The second target base station may directly send a path switch request to the MME or the transit node, such as the HeNB GW and the X2GW, to switch the data bearer channel of the core network and the eNB1 to the data bearer channel of the core network and the eNB2, and the path switch succeeds. Path switch request confirmation message. The second target base station receives the path switch request acknowledgement message, and may also notify the first target base station that the secondary handover is completed, so that the first target base station performs corresponding processing.

In this embodiment, the first target base station sends a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the target determined by the source base station according to the target physical cell identifier reported by the user equipment UE. The base station, the target physical cell identifier is a physical cell identifier of the cell of the second target base station that meets the handover threshold determined by the UE, and if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target The base station queries the handover record node to obtain the first handover target base station as the first target base station, the first target base station cooperates with the second target base station to perform secondary handover preparation, the second target base station allocates the second handover resource, and the first target base station sends the second handover resource to the source base station. For the first handover completion notification, the second target base station sends an RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configures the RRC using the second handover resource, so that the UE succeeds in accessing the second target base station according to the second handover resource, to the first The second target base station sends a configuration success response, and the second target base station sends a path switch. Requesting, so that the data bearer channel is switched to the second target base station, even if the physical cell identifier of the neighboring cell is the same, resulting in the first handover failure, the first handover target information can be obtained by first switching the information, thereby performing the wrong target base station and the correct target. The resource reconfiguration between the base stations makes the handover successful again, and improves the success rate of the cell handover.

In one embodiment, the handover record node includes at least one of a server, a home macro base station gateway, and an X2 gateway according to the handover type and the type of the target base station.

The node involved in the handover process may be different according to the type of the target base station, and the node involved in the handover process may be different. For example, if the target base station is an eNB, an S1 connection may be established with the MME, or an X2 connection may be established with the neighboring eNB. If the home macro base station gateway and the X2 gateway are required, the switch record node can be an independent server and provide support for the handover process. If the target base station is the HeNB, the H1 GW needs to perform the S1 convergence and establish an S1 connection with the MME. The H2 can directly establish an X2 connection between the HeNB and the eNB, that is, the X2 connection can be directly established, or the X2GW can be forwarded through the X2GW. The switch record node can be directly set in the home macro base station gateway or the X2 gateway without setting up a separate server. It can be understood that the handover record node can include multiple, such as when switching to a macro base station. When switching to the macro base station, the switching record node is the server. When switching to the S1 handover of the macro base station to the home macro base station, the handover record node includes at least one of a server and a home macro base station gateway. When switching to the X2 handover of the macro base station to the home macro base station, the handover record node includes at least one of a server, a home macro base station gateway, and an X2 gateway. Deploying the switch record node according to the switch type and the type of the target base station saves resources and is flexible and convenient.

In one embodiment, the source base station is a macro base station, the first target base station is at least one of a macro base station and a home macro base station, and the second target base station is at least one of a macro base station and a home macro base station, where the first target The base station is of the same type as the base station of the second target base station, and is switched to S1 handover or X2 handover.

The handover scenario of the source base station to the target base station may be divided into an S1 handover by the eNB to the eNB, an X2 handover of the eNB to the eNB, an S1 handover of the eNB to the HeNB, and an X2 handover of the eNB to the HeNB. The X2 handover of the eNB to the HeNB is further divided into an X2 handover with an X2GW and an X2 handover with no X2GW. The improvement of the switching success rate can be ensured for different switching scenarios.

In an embodiment, after step S660, the method further includes: the second target base station sends a second handover completion notification to the first target base station, and the first target base station sends a data clear message to the handover record module to clear the first handover information.

Clearing the first switch information saves storage space, prevents invalid data from interfering with the next switch information query, and improves response speed.

The steps of the method for the cell handover are different. The implementation of the method for the cell handover is described in detail in the following, and the application of the cell handover method is not limited to the following application scenarios. .

Scenario 1: The eNB performs S1 handover to the neighboring eNB, and the handover record node can be deployed on an independent server. FIG. 3 is a schematic diagram of an implementation step of the eNB performing S1 handover to the neighboring eNB, where the source eNB is the first handover source base station; The error target base station, that is, the first target base station, is also the secondary handover source base station. The eNB2 is a desired target base station, that is, the second target base station, and the Server is an independent server, and the first target base station is responsible for notifying the server to record and clear the handover information. The steps of the cell handover method are as follows:

101 UE measurement determines that eNB2 meets a handover threshold;

102, the UE reports the measurement report to the source eNB, and carries the PCI of the eNB2;

103, the source eNB finds the maintained neighboring cell information through the PCI, and confirms that the target base station is the eNB1;

104. The source eNB initiates an S1 handover preparation message Handover Required to the MME, and the target handover The base station is eNB1;

105 MME initiates a handover request message Handover Request to eNB1;

106, eNB1 allocates a first handover resource to the UE, and returns a handover request acknowledgement message Handover RequestACK to the MME;

The MME sends a handover command Handover Command to the source eNB;

The source eNB sends an RRC connection configuration message to the UE, RRC Connection Reconfiguration;

109 eNB1 sends a handover information record notification to the server;

110 Server records the first switching information;

The UE sends an RRC connection configuration complete message RRC Connection Reconfiguration Complete to the eNB2, performs handover, and switches to the eNB2 using the first handover resource allocated by the eNB1;

After the handover fails, the UE sends a re-establishment request message to the eNB2, and the carrying cause value is a handover failure.

113 eNB2 initiates a query to the server for the first handover of the target base station, and the query result is eNB1;

114 that eNB1 and eNB2 cooperate to perform secondary handover preparation, and eNB2 allocates a second handover resource;

eNB1 sends a handover notification Handover Notify to the MME, notifying that the first handover is completed;

The MME sends a UE context release command UE Context Release Commnad to the source eNB, and releases the UE context resource.

117. The source eNB releases the resource, and responds to the MME with a UE context release complete message UE Context Release Complete;

eNB2 sends an RRC connection reestablishment message RRC Connection Reestablishment message to the UE, and establishes an RRC by using a new resource;

119. The UE sends an RRC connection reestablishment complete message to the eNB2, and the re-establishment is successful.

120 eNB2 sends an RRC connection reconfiguration message RRC Connection Reconfiguration message to the UE, and configures RRC using the new resource;

The UE sends an RRC Connection Reconfiguration Complete message to the eNB2, and the configuration is successful.

122: eNB2 sends a path switch request message Path Switch Request to the MME, requesting path switching;

The MME responds to the eNB2 with the path switch request acknowledgement message Path Switch Request ACK, and the path switch succeeds;

124 that eNB2 notifies eNB1 that the secondary handover is completed;

125 eNB1 sends a handover information clear message to the server;

126 Server clears the switch information record.

Scenario 2: The eNB performs X2 handover to the neighboring eNB, and the handover record node can be deployed on an independent server. FIG. 4 depicts an implementation step of the eNB performing X2 handover to the neighboring eNB, where the source eNB is the first handover source base station; The error target base station, that is, the first target base station, is also the secondary handover source base station. The eNB2 is a desired target base station, that is, the second target base station, and the Server is an independent server, and the first target base station is responsible for notifying the server to record and clear the handover information. The steps of the cell handover method are as follows:

201 UE measurement determines that eNB2 meets a handover threshold;

202, the UE reports the measurement report to the source eNB, and carries the PCI of the eNB2;

203, the source eNB searches for the maintained neighboring cell information through the PCI, and confirms that the target base station is the eNB1;

204. The source eNB initiates an X2 handover request message Handover Request to the eNB1.

205 eNB1 allocates a first handover resource to the UE, and returns a Handover Request ACK to the eNB1:

The source eNB sends an RRC Connection Reconfiguration message to the UE.

207 eNB1 sends a handover information record notification to the server;

208 Server records the first switching information;

209 UE sends an RRC Connection Reconfiguration Complete message to eNB2, performs handover, and switches to eNB2 using the first handover resource allocated by eNB1;

After the handover fails, the UE sends a re-establishment request message to the eNB2, and the carrying cause value is a handover failure.

211 eNB2 initiates a query to the server for the first handover of the target base station, and the result is eNB1;

212 that eNB1 and eNB2 cooperate to perform secondary handover preparation, and eNB2 allocates a second handover resource;

213 eNB2 sends an RRC Connection Reestablishment message to the UE, and establishes an RRC by using a new resource;

214. The UE sends an RRC Connection Reestablishment Complete message to the eNB2, and the re-establishment is successful.

215 eNB2 sends an RRC Connection Reconfiguration message to the UE, using the new resource. Configure RRC.

216. The UE sends an RRC Connection Reconfiguration Complete message to the eNB2, and the configuration is successful.

217 eNB2 sends a Path Switch Request message to the MME, requesting path switching;

218 that the MME responds to the eNB2 with a Path Switch RequestACK message, and the path switch succeeds.

219 eNB2 notifies eNB1 that the secondary handover is completed;

The eNB1 sends a UE Context Release message to the source eNB, and the source eNB releases and releases the UE context resource.

221 eNB1 sends a handover information clear message to the server;

222 Server clears the switch information record.

In scenario 3, the eNB performs an S1 handover to the neighboring HeNB. For the HeNB deployment, there is an S1 convergence logical network element HeNB GW. When the S1 handover is performed from the eNB to the HeNB, the handover record node may be deployed on the HeNB GW or on the independent server. FIG. 5 describes the eNB to the neighboring HeNB. The implementation step of the S1 handover, where the source eNB is the first handover source base station; the HeNB1 is the error target base station, that is, the first target base station, and is also the secondary handover source base station; the HeNB2 is the desired target base station, that is, the second target base station, and the handover is performed. The recording node is deployed on the HeNB GW, and the first target base station is responsible for notifying the HeNB GW to record and clear the handover information. The steps of the cell handover method are as follows:

301 UE measurement determines that HeNB2 meets a handover threshold;

The UE reports the measurement report to the source eNB, and carries the PCI of the HeNB2.

303, the source eNB searches for the maintained neighboring cell information through the PCI, and confirms that the target base station is the HeNB1;

The source eNB initiates an S1 handover preparation message Handover Required to the MME, and the target handover base station is HeNB1;

305 MME initiates a Handover Request message to the HeNB GW, and the target handover base station is HeNB1;

306 HeNB GW initiates a Handover Request message to HeNB1;

307 HeNB1 allocates a first handover resource to the UE, and returns a Handover Request ACK to the HeNB GW;

308 HeNB GW forwards Handover Request ACK to MME;

309. The MME sends a Handover Command message to the source eNB.

The source eNB sends an RRC Connection Reconfiguration message to the UE.

311 HeNB1 sends a handover information record notification to the HeNB GW;

312 HeNB GW records the first handover information;

313, the UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, performs handover, and switches to the eNB2 using the first handover resource allocated by the eNB1;

314. After the handover fails, the UE sends a re-establishment request message to the HeNB2, and the carrying cause value is a handover failure.

315 HeNB2 initiates a query to the HeNB GW for the first handover target base station, and the query result is HeNB1;

316 HeNB1 and HeNB2 cooperate to perform secondary handover preparation, and HeNB2 allocates second handover resources;

317 HeNB1 sends a Handover Notify to the HeNB GW, notifying that the first handover is completed;

318 HeNB forwards Handover Notify to the MME;

319. The MME sends a UE Context Release Commnad message to the source eNB, and releases the UE context resource.

320 the source eNB releases the resource, and responds to the MME with the UE Context Release Complete;

321 HeNB2 sends an RRC Connection Reestablishment message to the UE, and establishes an RRC by using a new resource;

322. The UE sends an RRC Connection Reestablishment Complete message to the HeNB2, and the re-establishment is successful.

323 HeNB2 sends an RRC Connection Reconfiguration message to the UE, and configures RRC using the new resource;

324. The UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, and the configuration is successful.

325 HeNB2 sends a Path Switch Request message to the HeNB GW to request path switching.

326 HeNB GW forwards a Path Switch Request message to the MME;

327 MME replies to the Path Switch Request ACK message to the HeNB GW, and the path switch succeeds;

328 HeNB GW replies to HeNB2 with a Path Switch Request ACK message;

329 HeNB2 notifies HeNB1 that the secondary handover is completed;

330 HeNB1 sends a handover information clear message to the HeNB GW;

331 HeNB GW clears the handover information record.

In scenario 4, the eNB performs X2 handover to the neighboring HeNB (with X2GW). For HeNB deployment, the eNB and the HeNB can be routed through the X2GW, that is, the X2 message between the eNB and the HeNB is encapsulated in the X2AP MESSAGE TRANSFER message, and the X2GW performs bidirectional routing. In the X2GW routing and forwarding scenario, the switch record node can be deployed on the X2GW or the HeNB GW. Of course, it can also be deployed on a separate server. The HeNB GW and the X2GW are often deployed together in actual use, but the logical functions are separate. In the following description, the two logical network elements are still described. 6 is a diagram showing an implementation step of an X2 handover (with X2GW) of an eNB to a HeNB, where the source eNB is the first handover source base station, and HeNB1 is the error target base station, that is, the first target base station, and is also the secondary handover source base station; HeNB2 For the desired target base station, that is, the second target base station; the handover record node is deployed on the X2GW, and the first target base station is responsible for notifying the X2GW to record and clear the handover information. The steps of the method for cell handover are as follows:

401 UE measurement determines that HeNB2 meets a handover threshold;

402 UE reports a measurement report to the source eNB, and carries the PCI of the HeNB2;

403. The source eNB searches for the maintained neighboring cell information through the PCI, and confirms that the target base station is the HeNB1.

404. The source eNB initiates an X2 handover message Handover Request to the X2GW.

405 X2GW routes and forwards a message Handover Request to HeNB1;

406 HeNB1 allocates a first handover resource to the UE, and responds to the Handover Request ACK to the X2GW;

407 X2GW routing forwarding message Handover Request ACK to the source eNB;

408: The source eNB sends an RRC Connection Reconfiguration message to the UE.

409 HeNB1 sends a handover information record notification to the X2GW;

410 X2GW records the first handover information;

411, the UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, performs handover, and switches to the eNB2 using the first handover resource allocated by the eNB1;

412. After the handover fails, the UE sends a re-establishment request message to the HeNB2, and the carrying cause value is a handover failure.

413 HeNB2 initiates a query to the X2GW for the first handover of the target base station, and the query result is HeNB1;

414 HeNB1 and HeNB2 cooperate to perform secondary handover preparation, and HeNB2 allocates a second handover resource;

415 HeNB2 sends an RRC Connection Reestablishment message to the UE, and establishes RRC using the new resource.

416. The UE sends an RRC Connection Reestablishment Complete message to the HeNB2, and the re-establishment is successful.

417 HeNB2 sends an RRC Connection Reconfiguration message to the UE, and configures RRC with the new resource.

418. The UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, and the configuration is successful.

419 HeNB2 sends a Path Switch Request message to the HeNB GW to request path switching.

420 HeNB GW forwards a Path Switch Request message to the MME;

421 MME replies to the Path Switch Request ACK message to the HeNB GW, and the path switching succeeds;

422 HeNB GW replies to HeNB2 with a Path Switch Request ACK message;

423 HeNB2 notifies HeNB1 that the secondary handover is completed;

424 HeNB1 sends a UE Context Release message to the X2GW to notify the source eNB to release the UE context resource.

425 X2GW routing forwards the UE Context Release message to the source eNB;

426 eNB1 sends a handover information clear message to the X2GW;

427 X2GW clears the switch information record.

In scenario 5, the eNB performs X2 handover to the neighboring HeNB (without X2GW). The eNB and the HeNB can directly establish an X2 connection. In this scenario, the switch record module can be deployed on the HeNB GW or on a separate server. FIG. 7 is a diagram showing an implementation step of an X2 handover (without X2GW) of an eNB to a HeNB, where the source eNB is the first handover source base station, and HeNB1 is the error target base station, that is, the first target base station, and is also the secondary handover source base station; HeNB2 For the desired target base station, that is, the second target base station; the handover record node is deployed on the HeNB GW, and the first target base station is responsible for notifying the HeNB GW to record and clear the handover information. The steps of the method for cell handover are as follows:

501 UE measurement determines that HeNB2 meets a handover threshold;

502. The UE reports the measurement report to the source eNB, and carries the PCI of the HeNB2.

503, the source eNB searches for the maintained neighboring cell information through the PCI, and confirms that the target base station is the HeNB1;

504: The source eNB initiates an X2 handover message Handover Request to the HeNB1.

505 HeNB1 allocates a first handover resource to the UE, and responds to the Handover Request ACK to the source eNB;

506: The source eNB sends an RRC Connection Reconfiguration message to the UE.

507 HeNB1 sends a handover information record notification to the HeNB GW;

508 HeNB GW records the first handover information;

509, the UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, performs handover, and switches to the eNB2 using the first handover resource allocated by the eNB1;

After the handover fails, the 510 UE sends a re-establishment request message to the HeNB2, and the carrying cause value is a handover failure.

511 HeNB2 initiates a query to the HeNB GW for the first handover of the target base station, and the query result is HeNB1;

512 HeNB1 and HeNB2 cooperate to perform secondary handover preparation, and HeNB2 allocates second handover resources.

513 HeNB2 sends an RRC Connection Reestablishment message to the UE, and establishes an RRC using the new resource.

514: The UE sends an RRC Connection Reestablishment Complete message to the HeNB2, and the re-establishment is successful.

515 HeNB2 sends an RRC Connection Reconfiguration message to the UE, and configures the RRC with the new resource.

516. The UE sends an RRC Connection Reconfiguration Complete message to the HeNB2, and the configuration is successful.

517 HeNB2 sends a Path Switch Request message to the HeNB GW to request path switching.

518 HeNB GW forwards a Path Switch Request message to the MME;

519 MME replies to the Path Switch Request ACK message to the HeNB GW, and the path switch succeeds;

520 HeNB GW replies to HeNB2 with a Path Switch Request ACK message;

521 HeNB2 notifies HeNB1 that the secondary handover is completed;

522 HeNB1 sends a UE Context Release message to the source eNB, and notifies the source eNB to release the UE context resource.

523 eNB1 sends a handover information clear message to the HeNB GW;

524 HeNB GW clears the handover information record.

In an embodiment, as shown in FIG. 8, a system for cell handover is provided, including:

The secondary handover source base station processing module 710 is configured to enable the first target base station to send a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the source base station reported by the user equipment UE. The target base station identified by the target physical cell identifier, where the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE.

The second handover target base station processing module 720 is configured to: if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target base station queries the handover record node to obtain the first handover target base station. A target base station.

The secondary handover source base station processing module 710 is further configured to cooperate with the secondary handover target base station processing module 720 to cooperate with the second target base station to perform secondary handover preparation, and the second target base station allocates the second handover resource.

The secondary handover source base station processing module 710 is further configured to cause the first target base station to send a first handover complete notification to the source base station.

The secondary handover target base station processing module 720 is further configured to enable the second target base station to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC using the second handover resource, so that the UE accesses according to the second handover resource. After the second target base station succeeds, a configuration success response is sent to the second target base station.

The secondary handover target base station processing module 720 is further configured to cause the second target base station to transmit a path switch request to switch the data bearer channel to the second target base station.

In one embodiment, the handover record node includes at least one of a server, a home macro base station gateway, and an X2 gateway according to the handover type and the type of the target base station.

In one embodiment, the source base station is a macro base station, the first target base station is at least one of a macro base station, and a home macro base station, and the second target base station is at least one of a macro base station and a home macro base station, where the first target The base station is of the same type as the base station of the second target base station, and is switched to S1 handover or X2 handover.

In an embodiment, the secondary handover target base station processing module 720 is further configured to enable the second target base station to send a secondary handover completion notification to the first target base station, and the secondary handover source base station processing module 710 is further configured to enable the first The target base station sends a data clear message to the switch record module to clear the first switch information.

In an embodiment, as shown in FIG. 9, a system for cell handover is provided, including: The target base station 810, the second target base station 820, and the handover record node 830.

The first target base station 810 is configured to send a handover information record message to the handover record node 830, so that the handover record node 830 records the first handover information, and the first target base station is determined by the source base station according to the target physical cell identifier reported by the user equipment UE. The target base station, the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE.

The second target base station 820 is configured to query the handover record node 830 to obtain the first handover target base station as the first target base station if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station.

The first target base station 810 is also configured to cooperate with the second target base station 820 for secondary handover preparation.

The second target base station 820 is also configured to allocate a second handover resource.

The first target base station 810 is also configured to send a first handover complete notification to the source base station.

The second target base station 820 is further configured to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC by using the second handover resource, so that the UE succeeds in accessing the second target base station according to the second handover resource. The second target base station sends a configuration success response.

The second target base station 820 is further configured to transmit a path switch request to switch the data bearer channel to the second target base station.

In one embodiment, the source base station is a macro base station, the first target base station 810 is at least one of a macro base station and a home macro base station, and the second target base station 820 is at least one of a macro base station and a home macro base station, where A target base station 810 and the second target base station 820 have the same base station type, and switch to S1 handover or X2 handover.

In one embodiment, the handover record node 830 includes at least one of a server, a home macro base station gateway, and an X2 gateway, depending on the type of handover and the type of the target base station.

The embodiment of the present invention further provides a non-transitory computer readable storage medium storing computer executable instructions, the computer executable instructions being configured to perform the method in any of the above embodiments.

The embodiment of the invention further provides a schematic structural diagram of an electronic device. Referring to FIG. 10, the electronic device includes:

At least one processor 100, one processor 100 is taken as an example in FIG. 10; and a memory (memory) 101 may also include a communication interface 102 and a bus 103. The processor 100, the communication interface 102, and the memory 101 can complete communication with each other through the bus 103. Communication interface 102 can be used for information transmission. The processor 100 can call logic instructions in the memory 101 to perform the methods of the above-described embodiments.

In addition, the logic instructions in the memory 101 described above may be implemented in the form of a software functional unit and sold or used as a stand-alone product, and may be stored in a computer readable storage medium.

The memory 101 is a computer readable storage medium, and can be used to store a software program, a computer executable program, and a program instruction/module corresponding to the method in the embodiment of the present invention. The processor 100 performs the function application and the data processing by running the software program, the instruction and the module stored in the memory 101, that is, the cell switching method in the above method embodiment.

The memory 101 may include a storage program area and a storage data area, wherein the storage program area may store an operating system, an application required for at least one function; the storage data area may store data created according to usage of the terminal device, and the like. Further, the memory 101 may include a high speed random access memory, and may also include a nonvolatile memory.

The technical solution of the embodiment of the present invention may be embodied in the form of a software product stored in a storage medium, including one or more instructions for causing a computer device (which may be a personal computer, a server, or a network) The device or the like) performs all or part of the steps of the method described in the embodiments of the present invention. The foregoing storage medium may be a non-transitory storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like. A medium that can store program code, or a transitory storage medium.

The technical features of the above-described embodiments may be combined in any combination. For the sake of brevity of description, all possible combinations of the technical features in the above embodiments are not described. However, as long as these techniques are There is no contradiction in the combination of the technical features, and should be considered as the scope of the description.

The above-described embodiments are merely illustrative of several embodiments of the present disclosure, and are not to be construed as limiting the scope of the disclosure. It should be noted that a number of variations and modifications may be made to the embodiments of the present disclosure, which are within the scope of the present disclosure. Therefore, the scope of the disclosure should be determined by the appended claims.

Industrial applicability

The application improves the success rate of cell handover.

Claims (12)

A method for cell handover includes: The first target base station sends a handover information record message to the handover record node, so that the handover record node records the first handover information, where the first target base station is the target base station determined by the source base station according to the target physical cell identifier reported by the user equipment UE. The target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE; If the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, the second target base station queries the handover record node to obtain the first handover target base station as the first target base station; The first target base station cooperates with the second target base station to perform secondary handover preparation, and the second target base station allocates a second handover resource; Sending, by the first target base station, a first handover completion notification to the source base station; The second target base station sends a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and uses the second handover resource to configure the RRC, so that the UE succeeds in accessing the second target base station according to the second handover resource. Sending a configuration success response to the second target base station; The second target base station sends a path switch request to switch the data bearer channel to the second target base station. The method according to claim 1, wherein the handover recording node comprises at least one of a server, a home macro base station gateway, and an X2 gateway according to a handover type and a type of a target base station. The method according to claim 1, wherein the source base station is a macro base station, the first target base station is at least one of a macro base station and a home macro base station, and the second target base station is a macro base station, a home base station. At least one of the stations, wherein the first target base station and the second target base station have the same base station type, and the handover is an S1 handover or an X2 handover. The method of claim 1, wherein the step of the second target base station transmitting the path switch request to switch the data bearer channel to the second target base station further comprises: Sending, by the second target base station, a secondary handover completion notification to the first target base station; The first target base station sends a data clear message to the handover record module to clear the first handover information. The method according to claim 1, wherein, when the handover is an X2 handover, the step of the first target base station transmitting a first handover completion notification to the source base station transmits a path handover request at the second target base station, Performed after the step of switching the data bearer channel to the second target base station. A system for cell handover, comprising: The secondary switching source base station processing module is configured to enable the first target base station to send a handover information record message to the handover record node, so that the handover record node records the first handover information, and the first target base station is the source base station according to the user equipment. a target base station determined by the target physical cell identifier reported by the UE, where the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE; The secondary handover target base station processing module is configured to enable the second target base station to query the handover record node to obtain the first handover target if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station The base station is the first target base station; The secondary handover source base station processing module is further configured to cooperate with the secondary handover target base station processing module to cooperate with the second target base station to perform secondary handover preparation, the second target base station Allocating a second switching resource; The secondary handover source base station processing module is further configured to enable the first target base station to send a first handover completion notification to the source base station; The secondary handover target base station processing module is further configured to enable the second target base station to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC by using the second handover resource, so that the UE according to the Transmitting the second handover resource to the second target base station successfully, and sending a configuration success response to the second target base station; The secondary handover target base station processing module is further configured to cause the second target base station to send a path switch request to switch the data bearer channel to the second target base station. The system according to claim 6, wherein the handover record node comprises at least one of a server, a home macro base station gateway, and an X2 gateway according to a handover type and a type of a target base station. The system according to claim 6, wherein the source base station is a macro base station, the first target base station is at least one of a macro base station and a home macro base station, and the second target base station is a macro base station and a home macro base. At least one of the stations, wherein the base station type of the first target base station and the second target base station Similarly, the switch is an S1 switch or an X2 switch. A cell handover system includes: a first target base station, a second target base station, and a handover record node; The first target base station is configured to send a handover information record message to the handover record node, so that the handover record node records the first handover information, where the first target base station is a target base station according to the target reported by the user equipment UE a target base station determined by the physical cell identifier, where the target physical cell identifier is a physical cell identifier of a cell of the second target base station that meets the handover threshold determined by the UE; The second target base station is configured to: if the UE fails to access the second target base station by using the first handover resource allocated by the first target base station, querying the handover record node to obtain the first handover target base station as the first target base station ; The first target base station is further configured to cooperate with the second target base station to perform secondary handover preparation; The second target base station is further configured to allocate a second handover resource; The first target base station is further configured to send a first handover completion notification to the source base station; The second target base station is further configured to send a radio resource control RRC connection re-establishment and an RRC connection reconfiguration to the UE, and configure the RRC by using the second handover resource, so that the UE accesses the second according to the second handover resource. The target base station succeeds, and sends a configuration success response to the second target base station; The second target base station is further configured to send a path switch request to switch the data bearer channel to the second target base station. The system according to claim 9, wherein the source base station is a macro base station, the first target base station is at least one of a macro base station and a home macro base station, and the second target base station is a macro base station, a home base station. At least one of the stations, wherein the first target base station and the second target base station have the same base station type, and the handover is an S1 handover or an X2 handover. The system according to claim 9, wherein the handover record node comprises at least one of a server, a home macro base station gateway, and an X2 gateway according to a handover type and a type of a target base station. A non-transitory computer readable storage medium storing computer executable instructions arranged to perform the method of any of claims 1-5.

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