CN101616395A - Fallback method, device and communication system based on circuit switching - Google Patents

Abstract

The invention discloses a fallback method, device and communication system based on circuit switching, relates to a communication network, can shorten the waiting time for initiating a call request after CS fallback, and enhance user experience. A fallback method based on circuit switching provided by an embodiment of the present invention includes: while entering the execution phase of CS fallback based on circuit switching, triggering the update of the LTE location area and its process through the execution command of CS fallback .

Description

Fallback method, device and communication system based on circuit switching

technical field

The present invention relates to a communication network, in particular to a fallback method, device and communication system based on circuit switching.

Background technique

In the existing Long Term Evolution UMTS Terrestrial Radio Access Network (LTE EUTRAN), GSM and EDGE radio access network (GERAN)/UTRAN and LTE EUTRAN are usually overlapping coverage, and there is no Support CS voice call or VoIP service. User equipment (UE) is attached to one of the core network nodes corresponding to GERAN and/or UTRAN, when the UE residing in the LTE cell initiates a circuit-switched (Circuit Switched, CS ) call fails, the call will fall back to the circuit domain, such as UTRAN or GERAN, this fallback is based on circuit switching fallback (CS fallback, CSFB).

Taking the call termination of a mobile terminal as an example, the call termination of the mobile terminal supports the CS fallback process of roaming retry. The prior art first performs the process of routing query and obtaining the roaming number (MSRN), and then uses the obtained MSRN Initiate paging. When the paging request fails or times out, the CS fallback process will be triggered. After the CS rollback is completed, update the location area in LTE.

In the process of realizing the present invention, the inventors found that there are at least the following problems in the prior art: when CS fallback supporting roaming retry is performed in the prior art, CS fallback and LAU are firstly processed separately, that is, CS fallback After the LAU is completed, the LAU is performed, and then the roaming retry is performed after the LAU is completed, and the call request is initiated again, resulting in a long waiting time for re-initiating the call request and poor user experience.

Contents of the invention

Embodiments of the present invention provide a fallback method, device and communication system based on circuit switching, which can shorten the waiting time for initiating a call request after CS fallback, and enhance user experience.

In order to achieve the above object, embodiments of the present invention adopt the following technical solutions:

A fallback method based on circuit switching, comprising:

The node function entity of the LTE access network issues an execution command of CS fallback based on circuit switching to the mobile terminal, and triggers the update of the location area in LTE.

A fallback device based on circuit switching, comprising:

The triggering unit is configured to send an execution command of CS fallback based on circuit switching to the mobile terminal, and trigger the update of the location area in LTE.

A communication system, comprising: an evolved base station and a mobile terminal,

The evolved base station is configured to issue an execution command of CS fallback based on circuit switching to the mobile terminal, and trigger the update of the location area in LTE;

The mobile terminal is configured to receive the trigger of the execution command, and obtain the location area identifier LAI of the location area, and when the mobile terminal finds that the LAI is different from the known current LAI, start the location area in LTE update.

In the technical solution provided by the embodiment of the present invention, while performing the execution phase of CS fallback, the update of the location area of the mobile terminal is triggered by executing a command, so as to start the update of the location area in LTE. The embodiment of the present invention uses a parallel method to perform CS rollback and LAU at the same time, so that the time for LAU completion is greatly advanced, and solves the problem of using a serial method in the prior art, that is, the CS rollback is performed only after the CS rollback is completed. The LAU causes a long waiting time for initiating a call request after the CS rollback and poor user experience, thereby shortening the waiting time for initiating a call request after the CS rollback and enhancing user experience.

Description of drawings

FIG. 1 is a flowchart of a CS fallback method provided in Embodiment 1 of the present invention;

FIG. 2 is a flowchart of a CS fallback method provided in Embodiment 2 of the present invention;

FIG. 3 is a flow chart of a CS fallback method provided in Embodiment 3 of the present invention;

FIG. 4 is a schematic diagram of a fallback device based on circuit switching provided by Embodiment 1 of the present invention;

FIG. 5 is a schematic diagram of a fallback device based on circuit switching provided in Embodiment 2 of the present invention;

FIG. 6 is a schematic diagram of a communication system provided by Embodiment 2 of the present invention.

Detailed ways

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. The following descriptions are only some embodiments of the present invention. For those of ordinary skill in the art, On the premise of not paying creative efforts, other implementation modes of the present invention can also be obtained according to these embodiments.

Embodiments of the present invention provide a fallback method, device and communication system based on circuit switching, which can shorten the waiting time for initiating a call request after CS fallback, and enhance user experience.

Embodiment 1 of the present invention provides a fallback method based on circuit switching, as shown in FIG. 1 , including:

Step 101 , the LTE access network node functional entity sends an execution command of CS fallback based on circuit switching to the mobile terminal, triggering the update of the location area in LTE.

In the technical solution provided by the embodiment of the present invention, while performing the execution phase of CS rollback, the update of the location area in LTE is triggered by executing a command, so as to start updating the location area in LTE. The embodiment of the present invention uses a parallel method to perform CS rollback and location area update LAU at the same time, so that the time for LAU completion is greatly advanced, and it solves the problem of using a serial method in the prior art, that is, the completion of CS rollback After the LAU is performed on the target network, the waiting time for initiating a call request after the CS rollback is longer and the user experience is poor. This can shorten the waiting time for initiating a call request after the CS rollback and enhance user experience.

The second embodiment of the present invention is described by taking the CSFB of terminating a call of a mobile terminal supporting roaming retry as an example. In the following description, words such as old and new are used to distinguish functional entities of the same type that implement different functions. For example, the old call processing and roaming location management functional entity represents the call processing and roaming location management functional entity allocated before the current move of the user equipment, and the new call processing and roaming location management functional entity represents the user equipment allocated again after the current move Call processing and roaming location management functional entities.

As shown in FIG. 2 , it is a flow chart of a CS fallback method supporting roaming retry provided by Embodiment 2 of the present invention, which specifically includes:

Step T1, the gateway call processing function sends a routing information (SRI) message to the home subscription database to perform routing query. The gateway call processing function supports the roaming retry (MTroaming retry) terminated by the mobile terminal. The SRI message includes: the called mobile Information elements such as terminal number, gateway call processing function address, call reference number (Call Reference Number) and roaming retry support for mobile terminal termination.

Step T2, the home subscription database sends a provision roaming number (PRN) message to the old call processing and roaming location management functional entity according to the above information element.

The old call processing and roaming location management functional entity is used to send paging messages to the mobile terminal; the call processing and roaming location management functional entity that receives the location area update message from the mobile terminal is the new call processing and roaming location management functional entity .

The old call processing and roaming location management functional entity where the called mobile terminal is located is registered in the home subscription database.

Step T3, the old call processing and roaming location management functional entity obtains the roaming number (MSRN) of the mobile terminal, and sends the MSRN to the gateway call processing function through confirmation messages (ACK) PRN ACK and SRI ACK.

Step T4, the gateway call processing function uses the MSRN to generate an initial address message (IAM), and sends the IAM to the home subscription database to initiate a call request. When the home subscription database transfers the call request to the old call processing and roaming location management functional entity, the old call processing and roaming location management functional entity initiates a paging request (Paging) according to the call request to obtain all information about the called mobile terminal. location area.

When the paging request fails or times out, the CSFB process will be triggered.

Step T5, when the step T4 ends, when the paging request fails or times out, the CS rollback process starts.

There are three methods of CS fallback, cell reselection, packet switched handover (Packet Switched Handover, PS handover) and network assisted cell change (Network Assisted Cell Change, NACC), among them, when the user equipment UE is in the idle state, usually adopt The first method; when the UE is in an active state, the latter two methods are usually used. For each method, CSFB includes three stages: decision-making stage, preparation stage and execution stage.

In the decision-making phase, the evolved base station (eNodeB) generates a measurement report through the measurement data from the called UE, and obtains the location area (LA) to which the target cell belongs; in the preparation phase, it mainly allocates resources, etc.; in the execution phase, the The called mobile terminal executes the CSFB according to the instruction from the eNodeB, and returns the current CS call to the circuit domain.

When the paging request fails or times out, a CS fallback decision-making process is triggered, and the decision-making process obtains the location area to which the target cell belongs. After the decision-making process is completed, the LTE access network node functional entity will be triggered to send a "relocation required" request (Relocationrequired) to the mobility management functional entity in LTE to enter the CS fallback preparation phase. When the CS fallback preparation phase After the end, it will enter the execution phase of CS fallback.

The LTE access network node functional entity sends a CS fallback execution command to the mobile terminal to enter the CS fallback execution phase.

Step T6, while entering the execution phase of CS fallback, the mobile terminal accepts the trigger of the execution command, and obtains the location area identifier LAI of the target cell, so as to be used for the location area update of LTE, specifically including:

The mobile terminal obtains the location area identifier LAI from the system information or redirection information from the target cell, and compares it with the currently known location area LAI of the source serving cell. If they are different, the mobile terminal will trigger the LTE The location area update process, that is, the mobile terminal sends a new LAI to the LTE access network node functional entity or mobility management functional entity, and the LTE access network node functional entity or mobility management functional entity uses the above LAI to perform LTE location district updates.

Step T7, when the embodiment of the present invention enters the CS fallback execution phase, the LTE access network node functional entity or the mobility management functional entity also triggers the roaming retry function, that is, triggers the old call processing and roaming location management functions The entity sends a re-initiation call processing RCH message to the gateway call processing function entity, and the RCH message notifies the gateway call processing function entity to release the last CS call.

When the above-mentioned mobile terminal performs CS fallback or after performing CS fallback, the LTE access network node or the mobility management functional entity returns the location area update result in LTE to the functional entity in the target network, triggering the Joint updating of location areas of mobile terminals.

The above functional entities in the target network, that is, the call processing and roaming location management functional entities include the Visited Mobile Switching Center Server VMSC and/or the Visitor Location Register VLR. The joint update of the location area of the mobile terminal in the target network is as follows:

The called mobile terminal uses the acquired new location area identifier (LAI) to initiate a location area update to the new call processing and roaming location management functional entity. The new call processing and roaming location management functional entity registers with the home subscription database, and informs the home subscription database of this update; the home subscription database updates its own data information, and at the same time, the home subscription database informs the old call processing and roaming location management functional entity Delete the relevant data including the context of the called mobile terminal; the old call processing and roaming location management functional entity stops the paging timer and notifies the gateway call processing function; the new call processing and roaming location management functional entity downloads from the updated The new relevant data including the context of the called mobile terminal in the home subscription database, and complete the update of the location area in the target network.

In the above description, since the update of the location area in LTE is carried out at the same time as the execution phase of PS handover, the update of the location area in LTE does not need to be executed after the CS fallback has been completed, so that it can shorten the CS fallback. Waiting time for call requests to enhance user experience. In addition, after the update of the location area in LTE is completed, the PS handover may be in the execution stage or has been executed, so the joint update of the location area of the mobile terminal in the target network is performed when the mobile terminal is performing PS handover or after the PS handover is completed. , compared with the prior art, it also advances the completion time of the joint update of the location area of the mobile terminal in the target network, thereby shortening the waiting time for initiating a call request after CS fallback and enhancing user experience.

Step T8, after the call is released, the GMSC will perform steps T1 to T4 again (at this time, it is a new VMSC/VLR in step S4), obtain a new MSRN, and initiate a call request again. However, if the LAU has not ended at this time, the HLR in step T2 will postpone sending the PRN message, thereby postponing the call request again until the LAU is completed.

Step T9, when the call request in step T8 arrives at new VMSC/VLR, new VMSC/VLR sends Paging again, paging called mobile terminal, after finding this called mobile terminal, start a normal mobile terminal termination call.

According to the above description, in the embodiment of the present invention, a parallel method is adopted to process the process of CS fallback, location area update (LAU), and last CS call release. When the CS call release process ends, the CS fallback is over, and the LAU is basically completed, and the call request can be made again (if the LAU still has some unfinished tasks, it needs to wait until the LAU is completed). In short, after the above-mentioned CS fallback is completed, the call request can be initiated again without waiting for the entire LAU processing process and the CS call release process, which greatly shortens the waiting time for initiating a call request after CS fallback, and enhances the user experience. experience.

As shown in Fig. 3, the third embodiment of the present invention describes the embodiment of the present invention in two CS fallback modes, PS handover and NACC, in which steps U1 to U4, U8 and U9 are the same as those described in the second embodiment of the present invention Steps T1 to T4, T8 and T9 are similar and will not be repeated, and mainly describe steps U5 to U7.

When the PS switching method is adopted for CS fallback, steps U5 to U7 are as follows:

Step U5, when step U4 ends, when the paging request fails or times out, a PS handover decision-making process is triggered, and the location area to which the target cell belongs is obtained in the decision-making process. After the decision-making process is completed, the eNodeB will be triggered to send a relocation request (Relocation required) to the MME to enter the PS handover preparation phase. When the PS handover preparation phase is over, it will enter the PS handover execution phase.

The eNodeB sends an execution command of PS handover to the mobile terminal, so as to enter the execution phase of PS handover.

Step U6, while entering the PS handover execution phase, the eNodeB sends the execution command to the called mobile terminal through the above-mentioned execution command to trigger the update of the location area in LTE, specifically including:

The called mobile terminal obtains the location area identifier LAI from the system information or redirection information from the target cell, and compares it with the currently known location area LAI of the source serving cell. If different, the mobile terminal will trigger the LTE location area update process, that is, the mobile terminal sends the acquired new location area identifier to the eNodeB or MME, and the eNodeB or MME uses the above-mentioned LAI to perform the LTE location area update.

Step U7, Embodiment 3 of the present invention When entering the PS handover execution stage, the eNodeB also triggers the roaming retry function, that is, triggers the old VMSC/VLR to send an RCH message to the gateway call processing function entity, and the RCH message notifies the The gateway call processing functional entity releases the last CS call.

When the above-mentioned mobile terminal performs PS handover or after performing PS handover, the LTE access network node or the mobility management functional entity returns the location area update result in LTE to the functional entity in the target network, triggering the location area of the mobile terminal in the target network joint update.

The above-mentioned functional entities in the target network include the new visited mobile switching center server VMSC and/or the visitor location register VLR.

In the above description, since the update of the location area in LTE is carried out at the same time as the execution phase of PS handover, the update of the location area in LTE does not need to be executed after the CS fallback has been completed, so that it can shorten the CS fallback. Waiting time for call requests to enhance user experience. In addition, after the update of the location area in LTE is completed, the PS handover may be in the execution stage or has been executed, so the joint update of the location area of the mobile terminal in the target network is performed when the mobile terminal is performing PS handover or after the PS handover is completed. , compared with the prior art, it also advances the completion time of the joint update of the location area of the mobile terminal in the target network, thereby shortening the waiting time for initiating a call request after CS fallback and enhancing user experience.

When the CS fallback adopts the NACC method, the steps U5 to U7 are as follows:

Step U5, when step U4 ends, when the paging request fails or times out, a decision-making process of the NACC is triggered, and the decision-making process obtains the location area to which the target cell belongs. After the decision-making process is completed, the eNodeB will be triggered to send a relocation request (Relocation required) to the MME to enter the NACC preparation phase. When the NACC preparation phase is over, it will enter the NACC execution phase.

The eNodeB issues a NACC execution command to the mobile terminal to enter the NACC execution phase.

Step U6, while entering the NACC execution phase, the eNodeB triggers the location area update in LTE through the above execution command, specifically including:

The called mobile terminal obtains the location area identifier LAI of the target cell from the system information or redirection information from the target cell, and compares it with the currently known location area LAI of the source serving cell. If different, the mobile terminal will trigger the LTE location area update process, that is, the mobile terminal will send the acquired new location area identifier to the eNodeB or MME, and the eNodeB or MME will perform the update of the LTE location area using the above-mentioned LAI.

Step U7. In the embodiment of the present invention, when entering the NACC execution phase, the eNodeB also triggers the roaming retry function, that is, triggers the old VMSC/VLR to send a re-initiation call processing RCH message to the gateway call processing function entity, and the RCH message notifies The gateway call processing functional entity releases the last CS call.

When the above-mentioned mobile terminal executes NACC or after executing NACC, the LTE access network node or the mobility management functional entity returns the location area update result in LTE to the functional entity in the target network, triggering the joint location area of the mobile terminal in the target network renew. The above-mentioned functional entities in the target network include the new visited mobile switching center server VMSC and/or the visitor location register VLR.

In the above description, since the update of the location area in LTE is performed simultaneously with the execution phase of NACC, after the update of the location area in LTE is completed, NACC may be in the execution phase or has been executed, so when the mobile terminal is executing NACC Update the location area of the mobile terminal in the target network when or after the execution of NACC. However, compared with the prior art, the completion time of the update of the location area of the mobile terminal in the target network is advanced, thereby shortening the time for initiating a call after CS rollback Request waiting time to enhance user experience.

After the above-mentioned PS handover or NACC is over, there is no need to wait for the entire process of the LAU in LTE and the mobile terminal LAU in the target network, and the release process of the CS call, and the call request can be initiated again, which greatly shortens the PS handover or NACC The waiting time for initiating a call request after completion enhances user experience.

As shown in FIG. 4 , Embodiment 1 of the present invention also provides a fallback device based on circuit switching, including:

The triggering unit 401 is configured to issue an execution command of CS fallback based on circuit switching to the mobile terminal, and trigger the update of the location area in LTE.

In the technical solution provided by the embodiment of the present invention, while performing the execution phase of CS fallback, the update of the location area of the mobile terminal is triggered by executing a command, so as to start the update of the location area in LTE. The embodiment of the present invention uses a parallel method to perform CS rollback and LAU at the same time, so that the time for LAU completion is greatly advanced, and solves the problem of using a serial method in the prior art, that is, the CS rollback is performed only after the CS rollback is completed. The LAU causes a long waiting time for initiating a call request after the CS rollback and poor user experience, thereby shortening the waiting time for initiating a call request after the CS rollback and enhancing user experience.

As shown in FIG. 5, the fallback device based on circuit switching provided by the embodiment of the present invention includes:

The triggering unit 501 is configured to send an execution command of CS fallback based on circuit switching to the mobile terminal, and trigger the update of the location area in LTE.

While entering the execution phase of CS fallback, the mobile terminal accepts the trigger of the trigger unit 501, acquires the location area identifier LAI, and compares it with the currently known location area LAI of the source serving cell. If different, the mobile terminal will trigger an LTE location area update process, send the new LAI to the LTE access network node functional entity or the mobility management functional entity, and execute the update of the LTE location area.

The above-mentioned triggering unit 501 is further configured to trigger the call processing and roaming location management functional entity to send an RCH message to the gateway call processing functional entity, and the RCH message notifies the gateway call processing functional entity to release the last CS call, and according to the new The update result of the location area information of the new mobile terminal roaming number MSRN is obtained for retrying the CS call.

Further, the above-mentioned circuit switching-based fallback device further includes: an update result returning unit 502, configured to return the location area update result in LTE to the functional entity in the target network for joint location area update of the target network.

When the above-mentioned mobile terminal executes CS fallback or after performing CS fallback, the update result return unit 502 returns the location area update result in LTE to the functional entity in the target network, triggering the location area of the mobile terminal in the target network Joint update.

Since the update of the location area in LTE is performed simultaneously with the execution phase of PS handover, after the update of the location area in LTE is completed, the PS handover may be in the execution phase or has already been executed. Therefore, when the mobile terminal is performing PS handover or After performing the PS handover, update the location area of the mobile terminal in the target network. However, compared with the prior art, the completion time of updating the location area of the mobile terminal in the target network is advanced, so that the call request initiated after CS fallback can be shortened. Waiting time, enhance user experience.

As shown in FIG. 6, the embodiment of the present invention also provides a communication system, including: an evolved base station 601 and a mobile terminal 602,

The evolved base station 601 is configured to issue an execution command of CS fallback based on circuit switching to the mobile terminal, and trigger the update of the location area in LTE;

The mobile terminal 602 is configured to receive the trigger of the execution command and obtain the location area identifier LAI of the location area, and when the mobile terminal finds that the LAI is different from the known current LAI, it starts to perform the location area identifier LAI in the LTE. district updates.

The evolved base station 601 is also used to return the location area update result in LTE to the functional entity in the target network when/after the mobile terminal performs CS fallback, for joint location area update of the target network.

In the technical solution provided by the embodiment of the present invention, while performing the execution phase of CS fallback, the update of the location area of the mobile terminal is triggered by executing a command, so as to start the update of the location area in LTE. The embodiment of the present invention uses a parallel method to perform CS rollback and LAU at the same time, so that the time for LAU completion is greatly advanced, and solves the problem of using a serial method in the prior art, that is, the CS rollback is performed only after the CS rollback is completed. The LAU causes a long waiting time for initiating a call request after the CS rollback and poor user experience, thereby shortening the waiting time for initiating a call request after the CS rollback and enhancing user experience.

Those of ordinary skill in the art can understand that all or part of the steps in the above embodiments can be implemented through program instructions and related hardware. The software corresponding to the embodiments may be stored in a computer-readable medium.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (12)

1, a kind ofly it is characterized in that, comprising based on Circuit-switched backing method:

LTE access network node functional entity issues fill order based on Circuit-switched CS rollback to portable terminal, triggers the renewal of lane place among the LTE.

2, according to claim 1ly it is characterized in that based on Circuit-switched backing method, the Target cell of described fill order indicating mobile terminal CS rollback,

Described portable terminal is accepted described exectorial triggering, obtains the lane place identifier LAI of described Target cell, and described portable terminal is found this LAI and known current LAI not simultaneously, begins to carry out the renewal of lane place among the LTE.

3, according to claim 2ly it is characterized in that the lane place identifier LAI that described portable terminal obtains described Target cell by system information or redirection information from described Target cell based on Circuit-switched backing method.

4, according to claim 3 based on Circuit-switched backing method, it is characterized in that, described LTE access network node functional entity or Mobility Management Entity function return to functional entity in the objective network with the location area updating result among the LTE, in order to the co-location district of objective network to upgrade.

5, according to claim 4ly it is characterized in that based on Circuit-switched backing method the functional entity in the described objective network comprises Visited Mobile Switching Center server VMSC and/or VLR Visitor Location Register VLR.

6, describedly it is characterized in that according to claim 1 to 5 is arbitrary, in the step of updating of described triggering mobile terminals lane place, also comprise based on Circuit-switched backing method:

Trigger call treatment and roaming position management function entity and send the processing RCH message that makes a call again to gateway call processing capacity entity, the described gateway call processing capacity of described RCH message informing entity discharges last CS and calls out.

7, describedly it is characterized in that based on Circuit-switched backing method described LTE access network node functional entity is the base station eNodeB of evolution according to claim 1 to 5 is arbitrary.

8, a kind ofly it is characterized in that, comprising based on Circuit-switched backspace mechanism:

Trigger element is used for issuing fill order based on Circuit-switched CS rollback to portable terminal, triggers the renewal of lane place among the LTE.

9, according to claim 8ly it is characterized in that based on Circuit-switched backspace mechanism,

Described trigger element, also be further used for triggering call treatment and roaming position management function entity and send RCH message to gateway call processing capacity entity, the described gateway call processing capacity of described RCH message informing entity discharges last CS to be called out, and upgrades the result according to new location area information and obtain new mobile terminal roaming number MSRN to be used for retry CS calling.

10, according to Claim 8 or 9 describedly it is characterized in that, also comprise based on Circuit-switched backspace mechanism:

Upgrade the result and return the unit, be used for location area updating result with LTE and return to functional entity in the objective network, in order to the co-location district of objective network to upgrade.

11, a kind of communication system is characterized in that, comprising: the base station of evolution and portable terminal,

The base station of described evolution is used for issuing fill order based on Circuit-switched CS rollback to portable terminal, triggers the renewal of lane place among the LTE;

Described portable terminal is used to accept described exectorial triggering, obtains the lane place identifier LAI of described lane place, and described portable terminal is found this LAI and known current LAI not simultaneously, begins to carry out the renewal of lane place among the LTE.

12, communication system according to claim 11, it is characterized in that, also comprise: the base station of described evolution also is used for when portable terminal is being carried out the CS rollback/after the location area updating result of LTE is returned to functional entity in the objective network, in order to the co-location district of objective network to upgrade.

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