CN105873148A - Method and device for network switching - Google Patents

Abstract

The present invention provides a method and device for network handover, wherein the method includes: obtaining the attachment result issued by the first network after the joint attachment request sent by the terminal to the first network; When the upattach is successful, send a radio resource control connection request with a custom value to the first network. The resource control joint release command is used to switch from the first network to the second network. This solution avoids the situation that the CS service cannot be performed due to the inability to reflect the hidden failure of the joint attachment, and can directly switch from the first network (the current network) to the second network (another available network) when the hidden failure of the joint attachment occurs. network), which solves the problem that the CS service cannot be performed due to the hidden failure of the joint attachment of the UE in the LTE network, and improves user perception.

Description

Method and device for network switching

technical field

The present invention relates to the field of wireless technology, in particular to a method and device for network switching.

Background technique

3GPP TS24.301 specifies three different Evolved Packet System attach types (EPS attach type, Evolved Packet System attach type), as follows:

1: EPS attach (Evolved Packet System Attach);

2: combined EPS/IMSI attach (joint attachment - Joint Evolved Packet System and Global Mobile Subscriber Unique Identity attachment);

3: EPS emergency attach (Evolved Packet System emergency attach).

When a mobile phone that supports CSFB (Circuit Switched Fallback) initiates an attach, it will initiate a combined EPS/IMSI attach. After the MME (Mobility Management Entity) receives the joint attachment request, it will select a suitable MSC (Mobile Switching Center) for CS (Voice) registration, and the TMSI (Temporary Mobile Subscriber Identity) and LAI (Location Area Identity) assigned by the MSC Such information is included in the EPSAttach Accept (EPS Attach Accept) message and sent to the UE, which indicates that the joint attachment is successful. After that, the mobile phone can perform CSFB calls and send short messages and other circuit domain services on the long-term evolution network (LTE network, 4G network).

However, there is a relatively hidden fault in the prior art, which makes it impossible for CSFB terminals to initiate CSFB services, receive or send short messages in the 4G network. There are many reasons for this failure, such as defining the TA-LA (Tracking Area-Location Area) correspondence on the MME on the 4G side, pointing to the wrong MSC Server (MSC server), etc. Such faults are highly concealed, and such faults cannot be reflected in the statistical indicators of the eNodeB (Node B).

This kind of failure will cause 4G customers to only perform PS services in the 4G service signal coverage area, but cannot perform circuit domain services such as voice calls (ie, CSFB services), receiving or sending short messages, etc., seriously affecting customer perception.

Contents of the invention

The present invention provides a method and device for network switching to solve the problem in the prior art that the UE cannot perform CS services due to the hidden failure of joint attachment in the LTE network.

In order to solve the above technical problems, an embodiment of the present invention provides a method for network switching, including:

After obtaining the joint attach request sent by the terminal to the first network, the attach result issued by the first network;

When the attach result indicates that the attach is successful only on the Evolved Packet System EPS, send a radio resource control connection request with a cause value of a user-defined value to the first network, where the cause value is used to trigger the first network to disconnect Sending a radio resource control joint release command carrying the measurement frequency point of the second network;

Handover from the first network to the second network according to the radio resource control joint release instruction.

The present invention also provides a network switching device, including:

An acquisition module, configured to acquire an attachment result issued by the first network after the joint attachment request sent by the terminal to the first network;

A sending module, configured to send a radio resource control connection request with a cause value of a custom value to the first network when the attach result indicates that the attach is successful only on the Evolved Packet System EPS, and the cause value is used to trigger The first network issues a radio resource control joint release command carrying a measurement frequency point of the second network;

A switching module, configured to switch from the first network to the second network according to the radio resource control joint release instruction.

The beneficial effects of above-mentioned technical scheme of the present invention are as follows:

In the above solution, the network switching method obtains the attachment result issued by the first network after the joint attachment request sent by the terminal to the first network; and when the attachment result indicates that the attachment is only successful on the evolved packet system EPS, send The first network sends a radio resource control connection request with a custom value as the reason value. The cause value is used to trigger the first network to issue a radio resource control joint release command carrying the measurement frequency point of the second network; avoiding the failure to reflect joint attachment recessiveness failure; then, according to the radio resource control joint release command, switch from the first network to the second network; thereby avoiding the situation that the CS service cannot be performed due to the joint attachment recessive failure, and can be used when the joint attachment recessive failure occurs , directly switching from the first network (the current network) to the second network (another available network), which solves the problem that the UE cannot perform the CS service due to the hidden failure of joint attachment in the LTE network, and improves user perception.

Description of drawings

FIG. 1 is a schematic diagram of steps of a network handover method according to an embodiment of the present invention;

FIG. 2 is a schematic flowchart of a method for network switching according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a network switching device according to an embodiment of the present invention.

detailed description

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

The inventor noticed during the invention that:

In the process of network optimization, a fault was found that caused CSFB terminals to fail to initiate CSFB services, receive or send short messages in the 4G network. The inventor analyzes the cause of the fault by tracking the Attach signaling process on the UE (terminal) side. The specific process is: analyze the Attach Request signaling, and find that the EPS attach type is Combined handover EPS/IMSI attach (joint handover EPS/IMSI attach); Analyze the results in Attach Accept (attachment acceptance), and find that Attach Result (attachment result) is EPS only.

In other words, when the UE initiates a joint attach, only the EPS Attach succeeds, and the IMSI Attach fails. This kind of failure prevents UE from registering with the MSC of the 2/3G network, and causes the UE to be unable to perform circuit domain services such as voice calls (CS Fall Back services), receive or send short messages, etc. on the 4G network, but can perform PS (Packet Exchange) business, because EPS Attach is successful.

This kind of failure causes 4G customers to only perform PS services in the 4G service signal coverage area, but cannot perform CS domain services such as voice calls (CSFB services), receiving or sending short messages, etc., which seriously affects customer perception.

Therefore, the present invention provides a network switching method for the problem that the UE cannot perform CS services due to the joint attachment failure of the UE in the LTE network in the existing technology. As shown in FIG. 1 , the network switching method may include:

Step 11: After acquiring the combined EPS/IMSIattach sent by the terminal to the first network, the attach result (Attach Result) issued by the first network;

Step 12: When the attach result indicates that the attach is successful only on the Evolved Packet System EPS, send a radio resource control connection request (RRC ConnectionRequest) with a cause value of a custom value to the first network, and the cause value is used for triggering the first network to issue a radio resource control joint release instruction carrying a measurement frequency point of the second network;

Step 13: Handover from the first network to the second network according to the radio resource control joint release instruction.

Wherein, the first network may be a 4G network, and the second network may be a 2/3G network.

The method for network switching provided by the embodiment of the present invention obtains the attachment result sent by the first network after the joint attachment request sent by the terminal to the first network; and when the attachment result indicates that the attachment is only successful on the evolved packet system EPS , sending a radio resource control connection request with a reason value of a custom value to the first network, and the cause value is used to trigger the first network to issue a radio resource control joint release command carrying the measurement frequency point of the second network; avoiding failure to reflect the joint In the case of hidden attach failure; then, according to the radio resource control joint release command, switch from the first network to the second network; thereby avoiding the situation that the CS service cannot be performed due to the joint hidden failure of the joint attach, you can In the event of a permanent failure, directly switch from the first network (the current network) to the second network (another available network), which solves the problem that the UE cannot perform CS services due to the hidden failure of joint attachment in the LTE network, and improves user perception.

Wherein, the step of sending the radio resource control connection request whose cause value is a self-defined value to the first network includes: using the three establishment cause (Establishment Cause) reserved values left empty in the radio resource control connection request signaling of the protocol specification Any one of them defines the custom value, wherein the custom value is inter-system redirection (interRAT-Redirect); and the custom value is sent to the first network.

In this solution, choose to use any one of the three establishment reason reserved values left in the wireless resource control connection request signaling of the protocol specification to define a custom value, so that once the terminal finds that the joint attach request fails, only the PS domain succeeds. Switch to the 2/3G network as early as possible to prevent the terminal from staying in the 4G network and unable to perform CS services, thereby improving user experience.

Specifically, according to the radio resource control joint release instruction, the step of switching from the first network to the second network specifically includes: disconnecting the connection with the first network according to the radio resource control joint release instruction and establish a connection with the second network.

This step provides a solution to the situation where CS services such as calling and sending text messages cannot be performed on the 4G network, that is, let the terminal return to the 2/3G network. Although the rate is slower, at least it can make calls and send text messages. The short message avoids the situation that the joint attachment is unsuccessful and the CS service cannot be performed, and the priority of the CS service is still placed at the highest position.

In order to ensure the normal progress of the CS service of the terminal, after the method provided by the embodiment of the present invention successfully establishes the connection with the second network, it further includes: triggering a timer of the terminal; before the timer expires, prohibiting sending A redirection request for handover from the second network to the first network.

In this solution, by setting a timer and triggering the timer before sending a redirect request from the first network to the second network, it prevents the terminal from reselecting, redirecting or switching 4G networks too frequently, and guarantees to a certain extent CS service quality.

In addition, the method provided by the embodiment of the present invention further includes: when the attachment result includes the EPS and the UMSI, executing the voice service requested by the user. This step provides corresponding operations under normal attach results. That is to say, when the attach results include EPS and GSMUSI, the terminal will respond to the user's request and then perform corresponding operations, which satisfies the user's normal requirements. need.

The network switching method provided by the embodiment of the present invention will be specifically described below, as shown in FIG. 2 .

Step 21: After the UE initiates a joint attach request (combined EPS/IMSI attach) on the LTE network, it receives the Attach Accept issued by the MME, and judges the Attach Result in the Attach Accept.

Step 22: If the Attach Result is EPS only, go to Step 23;

If the Attach Result includes EPS and IMSI, that is, the combined EPS/IMSI attaches successfully, go to step 26.

Step 23: Trigger the UE to initiate an RRC ConnectionRequest whose cause value is interRAT-Redirect.

Define an IE (information element): newly define an Establishment Cause (establishment reason) named interRAT-Redirect in the RRC Connection Request.

According to the protocol 3GPP TS36.311, the cause value of RRC Connection Request occupies 3 bits in total, that is, there are 8 (2 to the 3rd power) different indication values, and only 5 of them are used in the protocol, namely: emergency (emergency call), highPriorityAccess (high priority access request), mt-Access (called access), mo-Signalling (calling signaling), mo-Data (calling data). The remaining 3 indication values are spare1 (spare 1)\spare2 (spare 2)\spare3 (spare 3), that is, the reservation is not used.

Use one of these three reserved bits to define an Establishment Cause named interRAT-Redirect.

The mechanism for triggering the UE to report the establishment of an RRC Connection Request whose cause value is interRAT-Redirect is: UE initiates a combined EPS/IMSI attach, and receives the Attach result carried in the Attach Accept issued by the MME as EPS only, then triggers the UE to initiate the cause value as InterRAT-Redirect RRC Connection Request.

Step 24: After the eNode B receives the RRC ConnectionRequest whose cause value is interRAT-Redirect, it triggers the eNode B to issue the RRC ConnectionRelease command carrying the 3G and 2G measurement frequency points, and initiates the process of 4G redirection to the 2/3G network.

The purpose of this step is to ensure that the UE can fall back to the 2/3G network in time after the joint attachment part of the 4G network fails (IMSI attach failure), so as to avoid the failure of the voice call connection or the failure to send and receive short messages.

Step 25: After the UE is successfully redirected to the 2/3G network, the timer T-Prohibit of the UE is triggered to take effect. During the T-Prohibit time, the UE does not initiate reselection, redirection or handover procedures to the 4G network.

A timer named T-Prohibit is defined on the UE side. The function of this timer is: within the T-Prohibit time range, the UE residing on the 2/3G network is prohibited from initiating reselection, redirection or handover procedures to the 4G network, that is, within the T-Prohibit time Stay in the 2/3G network to ensure the normal CS service of the terminal. The longer the timer is set, the longer the UE stays on the 2/3G network, and the more guaranteed its CS voice service is, but the rate perception will be affected; the shorter the timer is set, the UE will reselect frequently , Redirect or switch the 4G network, the speed perception will be better, but the probability of encountering a 4G cell with joint attachment failure will be higher, so the CS service will be affected. In a specific implementation, the time length of the timer can be set according to actual needs, which is not limited in the present invention.

The mechanism that triggers the timer T-Prohibit of the UE to take effect is: the UE initiates an RRC Connection Request whose reason value is interRAT-Redirect, and the UE successfully redirects to the 2/3G network.

Step 26: Execute the voice service requested by the user.

Based on the same inventive concept, the embodiment of the present invention also provides a network switching device, as shown in Figure 3, the device may include:

An acquisition module 31, configured to acquire an attachment result issued by the first network after the joint attachment request sent by the terminal to the first network;

The sending module 32 is configured to send a radio resource control connection request with a cause value of a user-defined value to the first network when the attach result indicates that the attach is successful only on the Evolved Packet System EPS, and the cause value is used to trigger The first network issues a radio resource control joint release command carrying a measurement frequency point of the second network;

The switching module 33 is configured to switch from the first network to the second network according to the radio resource control joint release instruction.

The apparatus for network switching provided by the embodiment of the present invention acquires the attachment result issued by the first network after the joint attachment request sent by the terminal to the first network; and when the attachment result indicates that the attachment is successful only on the evolved packet system EPS , sending a radio resource control connection request with a reason value of a custom value to the first network, and the cause value is used to trigger the first network to issue a radio resource control joint release command carrying the measurement frequency point of the second network; avoiding failure to reflect the joint In the case of hidden attach failure; then, according to the radio resource control joint release command, switch from the first network to the second network; thereby avoiding the situation that the CS service cannot be performed due to the joint hidden failure of the joint attach, you can In the event of a permanent failure, directly switch from the first network (the current network) to the second network (another available network), which solves the problem that the UE cannot perform CS services due to the hidden failure of joint attachment in the LTE network, and improves user perception.

Wherein, the sending module may include:

Define a submodule, used to define the custom value by using any one of the three established cause reserved values left in the radio resource control connection request signaling of the protocol specification, wherein the custom value is cross-system redirection ;

A sending submodule, configured to send the custom value to the first network.

Specifically, the switching module may be specifically configured to: according to the radio resource control joint release instruction, disconnect the connection with the first network and establish a connection with the second network.

In order to ensure the normal progress of the CS service of the terminal, the device provided in the embodiment of the present invention may further include:

The trigger module is used to trigger the timer of the terminal after the connection with the second network is successfully established; the prohibition module is used to prohibit sending the message of switching from the second network to the first network before the timer expires. Redirect request.

In addition, the device provided in the embodiment of the present invention may also include:

An executing module, configured to execute the voice service requested by the user when the attaching result includes the EPS and the UNIQIM.

It should be noted that, the implementation embodiments of the above network switching method are all applicable to the embodiment of the network switching device, and can also achieve the same technical effect.

In order to solve the above-mentioned technical problem, an embodiment of the present invention further provides a terminal, including: the above-mentioned apparatus for network switching.

Wherein, the implementation embodiments of the above-mentioned apparatus for network switching are all applicable to the embodiment of the terminal, and can also achieve the same technical effect.

What has been described above is a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications can also be made without departing from the principle of the present invention. These improvements and modifications should also be considered as Be the protection scope of the present invention.

Claims (10)

1. A method for network switching, characterized in that, comprising: After obtaining the joint attach request sent by the terminal to the first network, the attach result issued by the first network; When the attach result indicates that the attach is successful only on the Evolved Packet System EPS, send a radio resource control connection request with a cause value of a user-defined value to the first network, where the cause value is used to trigger the first network to disconnect Sending a radio resource control joint release command carrying the measurement frequency point of the second network; Handover from the first network to the second network according to the radio resource control joint release instruction. 2. The method according to claim 1, wherein the step of sending a radio resource control connection request whose cause value is a user-defined value to the first network comprises: Define the self-defined value by using any one of the three established cause reserved values left in the radio resource control connection request signaling of the protocol specification, where the self-defined value is cross-system redirection; sending the custom value to the first network. 3. The method according to claim 1, wherein, according to the radio resource control joint release instruction, the step of switching from the first network to the second network is specifically: Disconnect the connection with the first network and establish a connection with the second network according to the radio resource control joint release instruction. 4. The method according to claim 3, further comprising: after successfully establishing a connection with the second network: Trigger the timer of the terminal; Before the timer expires, it is prohibited to send a redirection request for switching from the second network to the first network. 5. The method of claim 1, further comprising: When the attachment result includes the EPS and the UMSID, the voice service requested by the user is executed. 6. A device for network switching, characterized in that it comprises: An acquisition module, configured to acquire an attachment result issued by the first network after the joint attachment request sent by the terminal to the first network; A sending module, configured to send a radio resource control connection request with a cause value of a user-defined value to the first network when the attach result indicates that the attach is successful only on the Evolved Packet System EPS, and the cause value is used to trigger the The first network issues a radio resource control joint release command carrying the measurement frequency point of the second network; A switching module, configured to switch from the first network to the second network according to the radio resource control joint release instruction. 7. The device according to claim 6, wherein the sending module comprises: Define a submodule, used to define the custom value by using any one of the three established cause reserved values left in the radio resource control connection request signaling of the protocol specification, wherein the custom value is cross-system redirection ; A sending submodule, configured to send the custom value to the first network. 8. The device according to claim 6, wherein the switching module is specifically used for: Disconnect the connection with the first network and establish a connection with the second network according to the radio resource control joint release instruction. 9. The apparatus of claim 8, further comprising: A triggering module, configured to trigger a timer of the terminal after the connection with the second network is successfully established; A prohibiting module, configured to prohibit sending a redirection request for switching from the second network to the first network before the timer expires. 10. The apparatus of claim 6, further comprising: An executing module, configured to execute the voice service requested by the user when the attaching result includes the EPS and the UNIQIM.